Appendix A

Glossary 298 Appendix A

A Angstrom units (lO-IOm)_ and/or of short duration; or a disease that has a rapid onset. aa amino acid. severe symptoms and brief duration. See also chronic. Ab antibody. ADCC antibody-dependent cell-mediated cytotoxicity. ABC antigen binding protein. addiction See dependence. ABO A system of human blood groups. additive response Where administration of two drugs ABPI Association of the British Pharmaceutical Industry. produces a response that is the simple sum of their individ• absorption In pharmacology. the uptake of a drug from ual responses, i.e. there is not synergism or antagonism. its site of administration. adenyl cyclase See adenylyl cyclase. abundance The term used to describe the average adenyl ate cyclase See adenylyl cyclase. number of molecules of a particular mRNA per cell. adenylyl cyclase The enzyme that produces the second abuse liability of drugs The propensity of a drug to messenger cyclic-AMP from ATP. lead to drug-seeking behaviour. Certain drugs. especially ADH ANTIDIURETIC HORMONE (vasopressin). OPIOID ANALGESICS. such as heroin. have a strong progression adhesion The mechanism by which cells form contacts into drug dependence. with one another and/or an appropriate substratum, e.g. abuse of drugs The nonmedical use of drugs. i.e. integrins, selectins. 'recreational use' without the intention to treat a disease. It is adhesion molecules See cell adhesion molecules. usually a pejorative term, reflecting how drugs can seriously ADI acceptable daily intake (environmental chemistry). interfere with health. See also misuse of drugs. adjuvant A chemical agent that augments the activity of accessory cells Cells that. along with B- and/or another agent. such as an antigen. when used in conjunction. T-Iymphocytes, are involved in the expression of the ADP ADENOSINE DIPHOSPHATE (adenosine 5'-diphosphate). immune response. ADP.ribosylation The addition of a ribosyl group ACE angiotensin-converting enzyme. derived from the ADP moiety of nicotinamide adenine acetylation The addition of an acetyl group to a dinucleotide to a protein. (Certain toxins have their effects molecule. through this mechanism. e.g. cholera toxin ADP-ribosylates acetylcholinesterase See cholinesterases. and inactivates the GTPase activity of G•. ) ACh ACETYLCHOLINE (unofficial). adrenal Pertaining to the adrenal gland. AChE acetylcholinesterase. adrenolytic An agent that blocks the effects of AChR acetylcholine receptor. ADRENALINE and NORADRENALINE secreted by the adrenal acquired immune deficiency syndrome (AIDS) medulla, or released from adrenergiC nerve terminals. Caused by the human immunodeficiency virus (HIV). The ADROIT Adverse Drug Reaction On-line Information virus destroys a subgroup of lymphocytes resulting in Tracking. suppression of the body's immune response. adverse drug reaction A seriously unpleasant or acridine orange (basic orange) A chemical used in harmful effect of a drug administered at a dose normal for experimental biology as a fluorochrome to distinguish therapeutic use. They are divided into groups. such as type A. between double-stranded DNA (fluoresces green) and single• which are dose-related and expected (often inevitable), and stranded nucleic acids (fluoresces orange-red). type B. which are rare and often due to allergic reactions acromegaly A disease caused by excessive secretion of (sometimes called idiosyncratic reactions). growth hormone from the anterior pituitary gland as a result aequorin A CALCIUM-BINDING PROTEIN, which is used of a benign pituitary tumour. especially in experimental electrophysiology. that emits a actin A protein found in most cells, which can polymerize flash of light when it binds calcium ions. to form noncontractile filaments. aetiology The study of the cause of disease. action potential The transient localized reversal of the AFC antibody forming cell. electrical potential across a nerve or muscle cell membrane. affective disorder A mental illness characterized by and its restoration. In nerves it can be blocked with changes in mood (affects). TETRODOTOXIN. afferent Leading to; e.g. nerves that transmit information active immunity Immunity that results from from the periphery to the CNS. stimulation of the host's tissues by antigen leading to the affinity In pharmacology, is used as a chemical measure of formation of specific antibodies. the strength of a ligand's tendency to react with a receptor or active transport The mechanism by which substances other binding site. It may be estimated using either are moved across membranes which involves energy and functional or chemical (e.g. radioligand-binding) techniques. carrier proteins. Often against a concentration gradient. A number of forms of equation or treatments have been activity In pharmacology is a general term used to denote derived that describe the reversible binding of chemicals to the potency of a drug. saturable sites. The form of expression for binding of oxygen activity·ratio For series of drugs. is the inverse ratio of with haemoglobin was derived by Hill (see Hill equation) the concentrations reqUired to give a quantitatively and is similar to those later derived by LangmUir (see eqUivalent biological response. If the EC so values for three Langmuir equation) for gases. Analogous relationship agonists A, Band C are I. 10 and 100 nM, respectively. then results from application of the law of mass action. and are the activity ratios for Band C, relative to A = 1.00, are 0.10 used in enzymology as the Michaelis-Menton equation. and 0.01, respectively. Thus. the higher the index. the higher Special applications to the actions of antagonists are found the potency of that drug; which is the reCiprocal of the in the Clark equations and Gaddum-Schild equations for equipotent molar ratio. The term is used largely inter• occupancy of drugs at receptors. See also association changeably with relative potency. but may be preferable constant; dissociation constant; pAz. where evidence is lacking of similar slopes and maxima (as Ag antigen. reqUired for the latter). agar A galactan (agarose and agaropectin) used in gel form acute A pharmacological response that is qUick in onset in experimental techniques. such as gel diffUSion. gel

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 299 electrophoresis and gel filtration. different chemicals showing allosteric interaction is that of agenesis The absence of an organ or tissue. the benzodiazepines and GABA interacting at GABA A aggregation The clumping together of platelets. receptors. Positive and negative cooperativity in binding are agonist Any agent. whether an endogenous mediator or often detected by deviations of the Hill slope from unity. an exogenous chemical. that on combination with a receptor allotopic Interaction of two drugs acting at different sites induces a change in that receptor that leads to a biological on a receptor; as opposed to syntopic interaction where they response. A full agonist produces the maximum biological act at the same site on the receptor. Allosteric interactions response that is achievable in a particular system (though and uncompetitive antagonism are examples of allotopic probably at less than full receptor occupancy). and is an interactions. See also allosteric interaction; antagonism - agent with relatively high efficacy. A partial agonist. by pharmacodynamic. definition. gives a less than maximum biological response. alternative medicine See complementary medicine. and has a lower efficacy. such that. even when all receptors alternative splicing Where different proteins can be are occupied. it gives insufficient stimulus to achieve a produced at translation from a single gene. as a result of maximum response. It is important to appreciate that partial different splicing of the primary mRNA transcript. This is agonists can act as antagonists. since when given together often tissue-specific. with full agonists they occupy receptors unfruitfully. See also Alzheimer's disease A progressive disease where nerve intrinsic activity; intrinsic efficacy; stimulus. cells in the brain degenerate. A common cause of dementia. agranular leukocyte See agranulocyte. amenorrhoea Stopping or absence of menstrual periods. agranulocyte (agranular leukocyte) A white blood cell. aminopeptidases A group of enzymes that remove the such as a lymphocyte and a monocyte. that has non• amino-terminal amino acid residues from peptides or granular cytoplasm. proteins. often leading to inactivation. AIDS Acquired Immune Deficiency Syndrome. amino terminus (N-terminus) The end of a protein or akaryote A cell that lacks a nucleus. peptide chain that bears the free a-amino group. albumin A protein that is water-soluble and coagulated by AMP ADENOSINE MONOPHOSPHATE (adenosine 5'• heat. Serum albumin. found in blood plasma. is important monophosphate). for maintaining plasma volume. aminotransferase See transaminase. alcian blue (copper phthalocyanine) A basic dye used anabolism See metabolism. experimentally to stain polysaccharides and glycoproteins. anaemia A collection of conditions where there is a aldehyde dehydrogenase An enzyme involved in a reduced capacity of the blood to carry oxygen. stage in the catabolism of alcohols. In humans this enzyme amino acid Any of a class of compounds of general shows pharmacogenetic polymorphism. resulting in the formula RCH (NH2) COOH where R is a side-chain. They rate of alcohol metabolism differing in different genetic have many functions. as neurotransmitters. as building groups. blocks of peptides and biosynthetic precursors of many aldosteronism A disease caused by the excessive other molecules. production of ALDOSTERONE due to a tumour of the adrenal amino acid transmitter A neurotransmitter that gland (Conn's syndrome). liver damage or heart failure. chemically is an amino acid. EXCitatory amino acids. e.g. alkylating agent An agent that reacts with nucleophilic glutamate and aspartate. are the principal transmitters. groups. substituting them with alkyl groups. e.g. in proteins mediating fast excitatory synaptic responses in the CNS. and nucleic acids. others. e.g. GABA. are major inhibitory neurotransmitters in allele One of the alternative forms of a gene at a given the CNS. locus on a chromosome. amphipathic Molecules having both hydrophobic and allergen A substance. an antigen. to which the body has hydrophilic properties or regions. become hypersensitive and so causes an immune response anaesthesia A state of insensibility. which may be a termed an allergic reaction. general or local loss of sensation. allergic reaction An immune response caused by the analogue One of a group of chemicals that are closely reaction of allergens with antibodies as a result of prior related in terms of chemical structure. exposure to the antigen. These reactions may be local or analysis of variance (AN OVA) A statistical procedure generalized (e.g. anaphylactic shock). Also. there may be used in the analysis of groups of data. to partition total reactions (type B adverse drug reactions) to some drugs. variability into components according to the source of the allergy A type of immune response to otherwise variability. It is a principle used in experimental design to innocuous antigens (called allergens) exhibited by allow sometimes complex analysis of one-way. two-way sets hypersenitive individuals. e.g. hay fever. of data. all-or-none responses Are quantal responses; those anaphylatoxins The fragments C3a and C5a that are which are present or absent (e.g. death or survival). formed during complement fixation. allosteric interaction An interaction of two chemical anaphylaxis An extreme local reaction to a drug or substances. or two molecules of the same chemical substance. allergen in hypersensitive persons. causing an immediate• which act at different sites on the same macromolecule. In type immune response. Anaphylactic shock is an extreme enzymology it is common for an allosteric regulator to alter generalized reaction (e.g. to a bee sting). including hypoten• (positively or negatively) the enzymatic modification of sion and bronchoconstriction, and is a medical emergency. another molecule. In some cases. binding of one molecule angina pectoris A pain felt in the centre of the chest and enhances affinity for the binding of the other; an instance of sometimes spreading to the arm. shoulder or jaw. It is due to such positive cooperativity. with just one type of interactant the demand for oxygen by the heart muscle exceeding supply. involved. is the binding of oxygen molecules with the angio-oedema (angioneurotic oedema) A reaction to an haemoglobin molecule. (The opposite phenomenon is allergy resulting in the rapid development of swellings of the negative cooperativity.) An important instance of two skin and other sites, including the larynx. Common causes

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 300 Appendix A are food allergy, drug allergy, insect stings and infections. in response to an antigen. It binds specifically and reverSibly angiogenesis The development and formation of new with the antigen as a result of contact between specific blood vessels. antibody combining Sites, Fab portions (located at the angiotensin-converting enzyme A proteolytic variable (N-terminal) end of the heavy chain and light chain enzyme that converts angiotensin I to the vasoconstrictor in the molecule) and antigenic determinants (epitope). The angiotensin II. See ACE INHIBITORS. Fc portion of an antibody is responSible for determining anion A negatively charged ion. which component of the immune system the antibody will anion channel See ion channels. bind to. Antibodies are produced by plasma cells derived anorexia A loss of appetite that can be induced by from B-lymphocytes. The body can make a vast variety of APPETITE SUPPRESSANTS or anorectic agents. The psychological antibodies, each B-lymphocyte being genetically state anorexia nervosa is characterized by an unwillingness to programmed early in development to produce an antibody eat, extreme weight loss and fear of becoming fat. of single specificity. Involved in immunity and allergy. ANOVA analysis of variance. anticoding strand See antisense strand. anoxia A state where tissues receive inadequate oxygen. anticodon Three consecutive nucleotide sequences in antagonism - chemical (antagonism by tRNA complementary to the codon in mRNA. neutralization) When the responses to an agonist are antidote An agent that counteracts a poison. reduced by an antagonist through a mutual chemical antigen A protein that is treated by the body as foreign reaction, where the product is inactive and diminishes the and so triggers an immune response, resulting in the effective concentration of the agonist. There is no interaction production of antibodies in the blood at receptor level, but the kinetics of this interaction may be antigenic determinant See epitope. very similar to those for competitive receptor interaction. antigenicity The capacity to function as an antigen. This form of antagonism is of particular importance in antimetabolite An analogue of a normal metabolite that tOXicology, e.g. to reduce the toxic effects of heavy metals disrupts normal metabolic processes by acting as a (e.g. Cd'.. "Sr") by binding them to a chelating agent such counterfeit. See ANTICANCER AGENTS; DHYDROFOLATE as sodium calcium edetate (in therapeutics, to hasten their REDUCTASE INHIBITORS; SULPHONAMIDES. excretion as inactive complexes). See also antagonism - antimicrobial An agent that destroys or inhibits the pharmacodynamic, growth of microbes. antagonism - functional (physiological antagonism) anti-oncogene A gene that counteracts the effect of an Where antagonism between two drugs is due to their having oncogene. See tumour suppressor gene. opposite or opposing actions. In this case either drug can be antisense A strand of DNA having a sequence identical to regarded as the antagonist. See also antagonism• mRNA which codes for the protein. pharmacodynamic. antisense strand The strand of a double-stranded antagonism - pharmacodynamic Where drug DNA, from which RNA is transcribed. antagonism is the result of interaction at receptors or bind• antisense technology An experimental technique used ing sites. There are a number of subcategories. I. allotopic; to prevent expression of a gene through the use of synthetic The antagonist binds at a different site to the agonist, though nucleotide sequences, complementary to specific DNA or closely associated with the receptor. Also referred to as non• RNA sequences. competitive, allosteric. It may be reversible or irreversible. antiserum A serum containing antibodies for use against 2. syntopic; The antagonist and agonist bind in a mutually antigens of a particular kind. See also immunity. exclusive fashion to a common binding site. This AP-' A transcriptional regulatory protein. It is the product competition for the binding site may be reversible, slowly of C-jun, a proto-oncogene. reverSible, or irreversible over a meaningful time-span: (a) aplasia The failure of development of an organ or tissue. where equilibrium antagonism can be achieved, this apoptosis Programmed cell death. Encompassing the relationship is universally termed competitive antagonism, series of events which are in response to specific and classical treatment can be applied to derive parameters developmental or physiological signals, which leads to death such as the affinity of the antagonist. In operational terms and removal of the cell. this latter situation can be termed surmountable apparent pKB The prefix 'apparent' is sometimes antagonism; (b) non-equilibrium antagonism poses more introduced when there are assumptions in the methods used problems, does not so readily allow derivation of affinity to determine pKB' or where it is recognized that some parameters, and is sometimes referred to as (irreversible) composite 'macroscopic' affinity is estimated rather than the competitive binding, or (probably incorrectly) as true of 'microscopic' affinity for the reaction of interest. In noncompetitive antagonism. In operational terms this latter functional determina tions the use of the term is situation can be termed insurmountable antagonism. recommended when the affinity of an antagonist has been antagonism - pharmacokinetic Where one drug estimated from the dose-ratio at a single antagonist antagonizes the other by decreasing the concentration of the concentration from the Gaddum-Schild equation, or when latter at its site of action. See also antagonism• no Schild analysis has been carried out, and consequently pharmacodynamic. the interaction is presumed to be competitive. antagonism of responses Where administration of APUD amine-precursor-uptake-decarboxylation cells two drugs produces a response that is less than the sum of (peptide- and amine-storing cells) are a diverse group, their individual responses. Normally, one drug has no effect embryologically of neural crest origin that are characterized on its own, but attenuates the effects of the other, so is by these cytochemical characteristics: they secrete amine regarded as the antagoniSt. See also antagonism• and/or peptide mediators; at one extreme they may be pharmacodynamic; insurmountable antagonism. released into the bloodstream to act at a distance (Le. anterior Relating to the front of the body. endocrine action); and at the other to act locally at an antibody (immune body) An immunoglobulin produced adjacent cell (paracrine action). See local homones.

SMALL CAPS = cross-reference to an entry in the A~Z Section bold = cross-reference to an entry in the Glossary Glossary 301

A.R. analytical standard of reagent. neurotransmitter ACETYLCHOLINE) is more involved in arachidonic acid A fatty acid precursor of functions such as the digestive processes. prostaglandins. autoradiography A technique where a radio labelled Ari"ens equation See intrinsic activity. compound is used to locate and label large molecules (e.g. P-ARK An enzyme that phosphoylates the occupied form of receptor proteins. mRNA). cell components or body organs. a G-protein coupled receptor. e.g. the l3-adrenoceptor. Their image is then recorded on photographic film to leading to uncoupling of that receptor and desensitization. produce an autoradiograph or autoradiogram. ARMI age-related memory impairment. autoreceptor A receptor that is activated by the mediator arrhythmia (dysrhythmia) An abnormality of heart secreted by the cell on which it resides. rhythm or rate of heartbeat. usually caused by disturbance of autosome A non-sex chromosome. the electrical impulses and their conduction within the heart. auxotonic Contractions against an increasing resistance. They include ectopic beats (isolated irregular beats). e.g. in muscle. tachycardias (too fast a heartbeat). bradycardias (too slow a axon A nerve fibre. a Single elongated process that extends heartbeat) and atrial flutter and ventricular fibrillation. from the neuronal cell body and which carries nerve Arthus reaction A severe local inflammatory response. impulses away from it. a skin reaction characterized by erythema. oedema. necrosis. baccillus A term used to describe both rod-shaped local haemorrhage. A type III hypersensitivity reaction. bacterial cell and a large genus of Gram-positive. spore• Arunlakshana and Schild plot See Schild plot. bearing bacteria with this form (e.g. B. anthrax). ascites fluid The fluid that accumulates in the peritoneal background Spontaneous rate or level. cavity during certain pathological conditions. bacteriology The science of the study of bacteria. aspiration The withdrawal of fluid or tissue from the bacteriophage A virus whose host is a bacterium. body by suction. balanced salt solution (BSS) Any of a number of assay Means to measure. In pharmacology the term solutions used to provide correct pH. ionic and osmotic embraces biological. chemical and hybrid (e.g. conditions for the maintenance and growth of cells. immunoassay) methods. The term bioassay is generally used BALBlc mice An inbred strain of mice which is when some functional response is used. predisposed to myeloma formation following association constant Sometimes known as the affinity intraperitoneal injection of. e.g. mineral oil. constant or affinity (units. molar) for reaction at BAN British Approved Name (for a drug). equilibrium. It is the reciprocal of the dissociation constant. basal Pertaining to the base. asthma An obstructive airways disease characterized by base A proton acceptor. Often used to refer to the nitrog• acute attacks of shortness of breath (caused by difficulty in enous bases. the purine and pyrimidine bases of nucleotides. exhalation). often with increased secretions in the airways. base analogue An analogue similar enough to a purine asymptote/-otic Approaching closer and closer but or pyrimidine base to substitute for these bases. resulting in never meeting. abnormal base paIring. e.g. point mutations. ataxia Lack of coordination. clumsiness. unsteady gait. base pair A pair of bases. one purine. one pyrimidine. each impaired eye and limb movements and speech difficulties. in a separate nucleotide in which each base is hydrogen bonded atheroma A degeneration of the walls of blood vessels. to the other in opposite strands of double-stranded DNA. causing atherosclerosis. characterized by fatty deposits and base pairing The weak bonding between pyrimidine scar tissue. and purine bases within nucleic acids. See base paIr. atherOSClerosis An arterial wall disease where the inner base sequence The specific order of pyrimidine and layer is thickened and so results in impaired blood flow. See purine bases in a polynucleotide. atheroma. basic dye A dye having a coloured cation which combines atopy The tendency to develop hypersensitivity states due with anionic groups used to stain nucleic acids and so nuclei. to heredi ted factors. basic orange See acridine orange. ATPase ADENOSINE TRIPHOSPHATASE. basophil A polymorph neutrophil classed as a granulo• ATP-y-S - ADENOSINE-5'-(,\"THIO) TRIPHOSPHATE: a cyte involved in immediate-type hypersensitivity reactions. nonhydrolysable analogue of ATP. when it releases e.g. histamine. is stained by basic dyes. attention-deficit hyperactivity disorder A basophilia The affinity of a specimen to being stained by condition in children characterized by hyperkinesia. basic dyes. Auerbach's plexus See myenteric plexus. B-cells See B-Iymphoc:ytes. autacoid A mediator that acts close to its site of release. BChE butyrylchoUnesterase. See local hormone. becquerel (Bq) The SI unit used to describe activity of a autocrine A cell that release a mediator that acts on the radioactive source. One Bq being the decay of a cell type from which it was released. See local hormones. radionucleide at a rate of I spontaneous nuclear transition autoimmune disease Any of a number of diseases per second (replaces curie). where there is an immune response of a person's antibodies benign In general. means harmless. not threatening to life. with some of their own cells. which act as antigens. In relation to tumours it is used where the growth does not autonomic nervous system The system involved in invade and destroy other cells or tissue. i.e. it is not the control of involuntary bodily functions. such as blood maUgnant (cancerous). pressure. heart rate and the activity of muscles and internal bilateral Of or relating to both sides of the body. a tissue. organs. The sympathetic nervous system (utilizing the an organ or both of a pair of organs. neurotransmitter NORADRENALINE and the hormone bil harzia See schistosomiasis. ADRENALINE) is primarily involved in eliCiting these functions bilirubin The main pigment found in bile formed from involved in the ·fight. fright or flight' response. The the break down of the blood pigment haemoglobin. parasympathetic nervous system (utilizing the bimodal distribution A frequency distribution with

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross·reference to an entry in the Glossary 302 Appendix A two peaks instead of the usual one of unimodal distributions populations. (e.g. the Gaussian distribution). In pharmacology. bimodal biostatistics Statistics as applied to biology. and trimodal distributions are sometimes seen if large biophase A (largely hypothetical) area around the sample characteristics are displayed in a histogram when receptor that limits drug access. there are two or more populations with distinct (unimodal) biosynthesis The production of a chemical compound characteristics being sampled (e.g. rate of acetylation of by a living organism. drugs is commonly bimodal; dibucaine numbers as an biotechnology A term. which is used in a variety of indication of activity of cholinesterase in cleaving ways. that denotes application of biological techniques to suxamethonium is trimodal). chemical manufacture. e.g. genetic engineering. binding isotherm The (normally hyperbolic) biotype A group of organisms having the same genotype. relationship between the concentration of a ligand. and the biphasic In pharmacology. biphasic responses may proportion bound or adsorbed onto binding sites. The indicate contribution of two components to drug responses relationship is described by the Langmuir equation and through a displacement in time of two peaks of activity. or allows estimation of the equilibrium dissociation constant. by a dose-response curve that appears to be made up of the the Bm ... and after suitable analysis the Hill slope. superimposition of two separate curves displaced vertically Experimentally. the relationship is best estimated by the use or laterally. of radio-labelled ligands. bipolar A neuron having two processes extending in binding site That part of a molecule (e.g. of a receptor different directions from its cell body. protein) with which another molecule (e.g. an agonist bipolar disorder An illness characterized by swings in ligand) can form a complex. mood between opposite extremes. See manic-depressive binomial distribution Is a frequency distribution illness. shown by many all-or-none responses - qualitative Black & Leff model An operational model (1983) that responses - for example death or survival (in contrast to provides a mathematical framework for drug-receptor quantitative responses which are continuous variables). interactions. A key aspect of the model is that it seeks to bioassay To measure (assay). using some functional describe for agonists at receptors. the relationship between biological responses. The purpose of a bioassay may hyperbolic concentration-occupancy curves. and hyperbolic commonly be to estimate the potency of a drug or principle. concentration-effect curves. in terms of a further hyperbolic or to measure the amount or concentration of a pharmaco• coupling function. The usual parameters of affinity etc. are logically-active chemical. In a wider sense. any pharmaco• used in the descriptive equations. and a key descriptive logical measurement from a toxicity test to a clinical trial. is a parameter called the transducer function (1). the equivalent bioassay. The outcome of a bioassay may be absolute (e.g. of efficacy. which can be derived. The models are usually Ees.). but is more commonly comparative. with some actual represented by three-dimensional graphs plotting axes for or implied standard (e.g. in relative potency determinations). agonist concentration. receptor occupancy and effect. bioavailability In a pharmaceutical formulation. is the block/blocker The process where an antagonist prevents amount that. after administration and subsequent an agonist drug exerting its effect. usually by preventing the absorption and distribution. is then biologically available to action of the latter at a receptor (e.g. ~-blockers). act pharmacologically. blood-brain barrier The means by which the nerves biochemistry The study of chemical changes within and within the brain are normally kept separate from the blood produced by living organisms. cells and large molecules within the blood. bioequivalence If the bioequivalence between two drug blood clotting Where liquid blood is converted into a preparations is equal. it means that their bioavailability solid clot to plug a wound which is associated with bleeding. (rate and extent) is the same. It is important to establish that It involves activation of coagulation factors. proteins which equivalent preparations of a medicine have the same are responSible for the conversion of soluble fibrinogen to bioavailability. and thus therapeutic effect. particularly in insoluble fibrin which forms a meshwork with red blood generic forms of 'parent' proprietary medicines. cells. platelets and other plasma proteins to form the clot. biogenic amine Any of a group of organic compounds blood dyscrazias See dyscrazia. which includes the catecholamines. which contain one or blotting An experimental technique used to identify and more amine groups. They have a role in brain functioning. assay target molecules. e.g. RNA (Northern blot technique). biological half-life The time taken by the body to DNA (Southern blot technique). protein (Western blot eliminate 1/, of the amount of a substance. e.g. a drug. technique). through the normal routes of elimination. B-Iymphocyte (B-cell; bursa equivalent) A small biological standardization A form of bioassay used lymphocyte which originates in bone marrow (haemopoi• in standardizing the pharmacological activity of a etic stem cells). found in lymph nodes. spleen. other second• preparation of a biologically active substance. ary lymphoid tissue and blood. Whilst in bone marrow it Standardization normally entails comparison of the activity undergoes rearrangement of its immunoglobulin genes to of a laboratory sample with a national or international produce genes which encode antibody of a single specificity. standard. Biological or hybrid biological/chemical methods Following encounter with antigen. B-lymphocytes prolifer• (e.g. immunoassays) may be used. ate and differentiate into antibody-producing plasma cells. biology The study of living organisms. BMA British Medical Association. bioluminescence The emission by living organisms of Bm •• A direct measure of receptor concentration or density visible light. determined using radioligand-binding techniques. commonly biolysis Death and tissue disintegration. in units such as pmoles/mg membrane protein. It is the biometrics See biostatistics. asymptotic maximum of a binding isotherm. but is usually biometry The application of mathematical techniques to determined by calculation from the form of the isotherm (or the quantification of the characteristics of living organisms. less satisfactorily from the Scatchard plot). It is the measured

SMALL CAPS = crossRreference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 303 equivalent of receptor density (Rt) used in receptor modelling. cachectin See tumour necrosis factor. BNF British National Formulary. cadherin Any of a family of cell-surface proteins which body cavity The internal cavity surrounded by the body are involved in cells adhering to one another. Cadherin wall in which internal organs are suspended. molecules on different cells bind to each other in a Ca'-• bolus injection A single dose of a drug administered dependent manner. over a short period. calcium-binding protein An endogenous protein that, BP British Pharmacopoeia. when bound to calcium, results in a conformational change, BPC British Pharmaceutical Codex. so activating or inactivating it. Exogenous calcium-binding brachial Pertaining to the arm. proteins, e.g. aequorin, are used in experimental biology. brady- A prefix denoting slowness. calcium channel See ion channel. bradycardia A decrease in the rate of heartbeat. calcium pump See Ca'+-ATPase. bradykinesia Slow and poor movement. As seen in caldesmon An endogenous calcium-binding protein Parkinson's disease and extrapyramidal disorders it is which is abundant in smooth muscle and may be involved in caused by several groups of drugs as an adverse drug smooth muscle contraction. reaction, which is commonly a forseeable side-effect (e.g. calmodulin An endogenous calcium-binding protein ANTIPYSCHOTICS, such as phenothiazines). that once bound to Ca" modulates the activity of various bronchitis An obstructive airways disease caused by proteins and enzymes. inflammation of the bronchi and characterized by a chronic calsequestrin An endogenous calcium-binding protein shortness of breath (due to a difficulty in exhaling) and in the sarcoplasmic reticulum of muscle. coughing, with inflammation and increased secretions and CAM cell-adhesion molecules. blockage of the airways. cAMP cyclic-AMP (see cyclic adenosine 3',5'• bronchoconstriction (bronchospasm) A narrowing of monophosphate) . the bronchioles of the lungs, caused by a contraction of the cancer The symptoms of the disease due to unrestrained smooth muscle that surrounds the airways, often cell growth and tumours. They are described as malignant, exacerbated by excessive secretions within the airways. as such cells or growths invade and destroy other calls or bronchoconstrictor An agent that contracts bronchial tissues. There are various types of cancer, including smooth muscle, resulting in the constriction of the airways. carcinoma (arising in the epithelium, which lines the bronchodilator An agent that relaxes bronchial smooth internal organs and skin), sarcoma (arising in connective muscle, resulting in the widening of the airways. tissue of bone, cartilage, skin etc.), lymphoma (lymph BSA bovine serum albumin. nodes, including Hodgkin's disease) and leukaemia (arising BSE bovine spongiform encephalopathy. in blood-forming organs, including the bone marrow). BSF-1 B-cell stimulating factor. cannula A small, usually plastic tube inserted into e.g. a BSS balanced salt solution. vein or artery to allow administration of drugs or tracers, or buccal A term for the mouth or hollow part of the cheek, allow measurement of e.g. blood pressure. or a form of drug administration where the drug, in solid caudal Positioned towards the lower end of the spine. form, is placed between the cheek and jaw - the buccal cavity. caudal block Nerve block induced by injecting a local buffer A solution that compensates for changes in pH on anaesthetic into the lower part of the spine. addition of acid or alkali by absorbing protons from acids canonical sequence See consensus sequence. and releasing them on addition of alkali. cAPK See cyclic AMP-dependent protein kinase. butyrylcholinesterase See cholinesterases. capsule A gelatine or Similar container for liquid or solid C1 A component of the complement system which forms of drugs that are to be taken orally. comprises Clq, C Ir and Cis. It binds to antibody-antigen carbohydrate Any of a number of compounds of the complexes to initiate the classical pathway. general form C,(H,O)" which includes sugars and C3a (anaphylatoxin) A component of the complement polysaccharides. system which is cleaved from C3 by enzymatic action and carboxypeptides Proteolytic enzymes which remove the causes vasodilatation and polymorphonuclear leucocyte C-terminal amino acid from a peptide. They often function accumulation. to inactivate peptide mediators, though in some instances C3b (opsonin) A component of the complement system they change the peptide's spectrum of activity. See which can promote phagocytosis of the antigen-antibody CARBOXYPEPTIDASE INHIBITORS. complex to which it has adhered. C-terminus carboxy-terminus. CSa (chemotactic factor) A component of the complement carboxy-terminus (C-terminus) The end of a protein system which is cleaved from C5 by enzymatic action. It chain that bears the free carboxyl group. causes vasodilatation and polymorphonuclear leucocyte carcinogen Any agent capable of causing cancer. accumulation. carcinoid tumour A cancerous growth of C6 I C6b I C7 Components of the complement system neuroendocrine glandular tissue, leading to a large and often that attract polymorphorphonuclear leucocytes. dramatic release of potent autacoids. C9 A component of the complement system which causes carcinoma A malignant type of neoplasm that arises in lysis by forming pores in cell membranes. the epithelium. CAAT-box A conserved sequence in the promoter region cardiac muscle The type of (involuntary) striated of DNA involved in the initiation of transcription. It is muscle that makes up the contractile muscle of the heart. located 70-80 base pairs upstream from the start point of cardiogenic Arising in the heart. transcription. carditis Inflammation of the heart or its linings. Ca2+-ATPase (calcium pump) A protein found in the carrageenan (carrageenin; carragheen) A substance plasma membrane that uses a mechanism of active derived from algae and used in experimental biology to cause transport to move calcium ions across the membrane. inflammation.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the GLossary 304 Appendix A carrier An individual who is heterozygous for a recessive chemical antagonism See antagonims - chemical. gene, which codes for a genetic disease, and one normal chemical drug name This is not normally used outside allele. This usually implies a carrier of a recessive disease, technical circles because, though precise and unambiguous, such as cystic fibrosis, who will remain unaffected it can be very large and unWieldy. Instead, official 'trivial' or throughout their life. shortened names are used, such as a generic drug name carrier·mediated transport The transport of solutes (these, however, may vary from country to country). For across cell membranes with the aid of a carrier protein. example, N-(4-hydroxyphenyl)acetamide is the chemical carrier protein A membrane protein which transports name for the analgeSiC given the general name of molecules across a membrane by active transport or paracetamol in the UK and acetaminophen in the USA. facilitated diffusion. chemoattractant Any chemical that attracts cells or catabolism See metabolism. organisms to move towards it. catalase An enzyme that catalyses the decomposition of chemokine A cytokine that is chaemotactic for H20 2 to molecular oxygen and water. See free· radical. leucocytes. catecholamine Monoamine derivatives of amino acids chemotaxis The moving away or towards a chemical that have a catechol ring, e.g. NORADRENALINE, DOPAMINE. source by microorganisms or motile cells. cation A positively charged ion. chemotherapy The use of chemicals to treat disorders, CCK See CHOLECYCTOKININ. e.g. cytotoxic ANTICANCER AGENTS in the treatment of cancer CD I. controlled drug (UK). 2. See cluster of and ANTIBIOTICS for microbial infections. differentiation. Cheng·Prusoff equation A relationship originally CD antigens Cell surface antigens present on leucocytes derived for enzymology but commonly used in radioligand• that are detected by certain monoclonal antibodies (COl, binding studies, which allows calculation of the displacing C02, CD3 etc.) affinity of a ligand from its displacement curve. The equation cDNA See complementary DNA. is K;; IC so 1(1 + [AJ/KL), where K; is the equilibrium a·cell Glucagon-secreting cells in the islets of Langerhans dissociation constant of the competing (non-radioactive) in the pancrease. ligand, [AJ is the conc .1tration of free radioligand used in ~·cell Insulin-secreting cells in the islets of Langerhans in the assay and KL is the dissociation constant of the the pancrease. radioligand used. The concentration of free radioligand is cell·adhesion molecules (CAM) A large and varied over a range and so allows estimation of the IC so , the heterogenous group of cell-surface glycoproteins produced concentration of inhibiting ligand giving 50% displacement by cells which bind to each other and to other cell types, e.g. of the 'hot' radioligand (affinity Ko). If certain conditions are cadherin. integrin, selectin. met. K; should approximate to the IC so. cell fractionation A method of separating cell chimaeric receptor A receptor syntheSized by genetic components by breaking them up by centrifugation. engineering techniques and is composed of protein cell·free system A mixture of cell components sequences from twO or more types of receptor. It is used to reconstituted in vitro and used for various processes, such as identify the function of different parts of receptor molecules. to study genetic processes, e.g. DNA replication. chirality See isomer. cell hybrid A cell produced in vitro by the fusion of two chi.square test (X 2 test) A (nonparametric) statistical somatic cells, which may be from different species with test used to compare two or more groups, for instance different genetic constitutions. frequencies in a 2x2 contingency table where the two cell line A culture of cells that can be propagated columns must represent mutually exclusive categories. as indefinitely. must the two rows. The null hypothesis is that there is no cell·mediated hypersensitivity See type IV association between the variable defining the row and the hypersensitivity. variable defining the column. The test reports the value of cell·mediated immunity See immune response. the chi-square statistic, and the Pvalue. The test is of value in cellulitis Inflammation of the subcutaneous tissues. evaluating the presence, or absence, of association between centiMorgan (eM) A measure of distance between two qualitative characteristics. genes based on the frequency with which they are inherited chlamydial infection An infection caused by a group together. One cM is eqUivalent to I % of recombination and of microorganisms called clamydia (Chlamydiaceae), which approximately to I megabase. are larger than viruses but smaller than bacteria. central dogma The dogma that genetic information can chole· Relating to the biliary system. only be transferred in the direction DNA -+ protein. cholestasis The failure of the normal bile flow to the central nervous system (CNS) In vertebrates this intestine, causing cholestatic jaundice. comprises the brain and the spinal cord. cholinergic Nerve fibres that release ACETYLCHOLINE. centrifugation See ultracentrifugation. cholinesterases Enzymes that hydrolyse choline esters, centrifuge See ultracentrifuge. especially ACETYLCHOLINE; of which there are two main cephalic Pertaining to the head. forms: acetylcholinesterase ('true cholinesterase) is specific cerebrospinal fluid (CSF) The fluid filling the cavity in for acetylcholine, rapid in this action, and has a discrete the brain and spinal cord. distribution being especially located near cholinergic nerve cervical Pertaining to structures connected with the neck. terminals (and in erythrocytes); butyrylcholinesterase CF complement fixation. ('pseudo' cholinesterase) is less selective and is able to CFT complement fIXation test. hydrolyse some drugs (e.g. SUCCINYLCHOLINE CHLORIDE). cGMP cyclic-GMP; cyclic guanosine 5'-monophosphate. Many drugs are known that inhibit the action of these chelating agent Any of a number of agents that enzymes. See ANTICHOLINESTERASES. combine with metal ions and form a stable compound. They chromatin A protein found in the nucleus which stains can be used to render toxic metals less poisonous. with basic dyes. It is used in the study of the behaviour of

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 305 chromosomes. them into a bacterium or other microorganism, which is chromatography A technique used to separate then selected and propagated. compounds from a mixture on the basis of their affinity for cloning vector See vector. and migration with a nonpolar solvent {e.g. water}. on a clotting factor See coagUlation factor. polar support {e.g. paper}. In gel filtration chromatography. cluster of differentiation A set of monoclonal molecules are separated on the basis of size through a antibodies that distinguish between cell surface antigens column of beads, in affinity chromatography, separation and {CD antigen} on leucocytes, e.g. CD25 is the receptor for purification of a sample is achieved by the differing affinities interleukin-2. of molecules for particular chemical groups through a CMV cytomegalovirus. column onto which the mol~cules bind. cNOS constitutive nitric oxide synthase. chromosome A structuf@ in the nucleus containing DNA CNS See central nervous system. which carries the genetic information essential to that cell. coagulation factor Any of a group of blood proteins See gene. which are involved in blood clotting, e.g. Factor XII, chromosome abberation An abnormality in the fibrinogen, kallikrein. number or structure of chromosomes in a cell. coaxial bioassay A bioassay in which one type of tissue chromosome mapping The assigning of a gene or is set up within the lumen of another type, and is used to other DNA sequence to a particular position on a specific detect the release of mediators from one tissue to another chromosome. See also linkage map; physical mapping. tissue. chronic A term used to describe a disease of long duration, coccus (p1. cocci) Any spherical bacterium, e.g. which is usually of slow onset and slowly reversing {if at all}. Staphylococcus, Streptococcus. It does not mean severe. See acute. coding sequence The nucleotide sequence in DNA or chronotropic Affecting rate of action. RNA that specifies a polypeptide. CIE counter-current immunoelectrophoresis: see coding strand The strand of the DNA molecule that acts electrophoresis. as the template for mRNA syntheSiS. (Cin,)max The peak plasma concentration reached duringr codominant gene One or more genes that, when constant infusion of a drug. present together, specify a phenotype unlike that specified circadian rhythm (diurnal rhythm) The intrinsic by any of the individual genes. rhythmic changes with a periodicity of approXimately 24 codon A sequence of three consecutive nucleotide bases hours in an organism. that specifies for a particular amino acid. cirrhosis A progressive disease of the liver caused by coefficient of linear correlation See correlation damage to the cells. coefficient. cistron (structural gene) The DNA sequence coding for a coefficient of linear regression See regression single polypeptide. analysis. CL clearance rate: the rate at which a substance is removed coefficient of variation (variation coefficient) A from the blood as it passes through an organ. device to allow ready comparisons of variability between Clark plot A graphical method of estimation of the affinity populations of very different means. It is the {standard of a competitive antagonist from a linear plot of the deviation/mean}, often expressed as a percentage. Gaddum-Schild equation. In practice, any advantages of this coenzyme See cofactor. plot have been overlooked, and the logarithmic form of this cofactor Any non-peptide organic molecule necessary for equation is almost universally used in the Schild plot. the activity of a given enzyme. class The taxonomic group immediately ranking above the cohort A group of individuals of the same age in a order and below the phylum. population. cleari ng The use of a clearing agent, a solvent, to increase colitis Inflammation of the colon or gut, pOSSibly due to the transparency of a specimen for microscopy. infection or Crohn's disease. clinical pharmacology The scientific study of drugs in collagen A major structural fibrous protein of connective humans. tissue. clinical trials These are systematic studies of medically colony-stimulating factor Any of a group of factors active agents in humans. Such trials advance through early involved in the maturation of leucocytes. It includes phases in normal volunteers (to determine duration of action GM-C SF, which is involved with the maturation of and metabolism), to eventual studies in patients with disease. macrophages and neutrophils. Commonly new active agents are compared to existing combination drug A formulation that contains more standard treatments, and to dummy treatments (placebos). than one active agent. To avoid bias, assessment of the efficacy of treatment may be commensal A microbe that colonizes its host without single-blind {where either the patient or the doctor does not causing it harm. know the identity of treatments} or double-blind {where Committee on Safety of Medicines (CSM) An neither knows until the trial is finished}. independent body set up to give advice via the Medicines clone A collective term for all individual organisms or cells Control Agency {MCA} , which administers the Medicines produced asexually or by parthenogenesis from a single Act, to the licensing authorities under the Ministry of Health. individual; or a copy of genetically engineered DNA competitive anatgonism See antagonism• sequences. pharmacodynamic. cloned line A term used in tissue culture to describe a complement The group of globulin blood proteins population of cells descended directly from a single clone. involved in inflammatory and immune responses. They are cloning The isolation of a particular gene or DNA involved in the lysis of foreign cells following antibody sequence, e.g. from a DNA library. In recombinant coating and promote foreign cell removal by phagocytic cells. technology genes or DNA sequences are cloned by inserting Activation of complement results from a cascade reaction

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 306 Appendix A triggered by antigen-antibody complexes ('classical pathway') congenital Present at birth. or by certain initiating surfaces ('alternative pathway'), e.g. conserved sequence A nucleotide sequence in genetic microorganism-derived substances. material or of amino acids in a polypeptide chain that has complementary DNA (eDNA; copy DNA) Single• remained virtually unchanged throughout evolution; usually stranded DNA syntheSized by reverse transcriptase from an taken to imply that the sequence has an important function, RNA template. e.g. promotor regions. complementary medicine A general term that is constitutive Of an enzyme or receptor syntheSized by the sometimes applied to alternative, non-orthodox systems of cell in the absence of any stimulus. See inducible. medicine and healing, including herbal remedies, constriction A narrowing or obstruction of a hollow homoeopathy, faith healing, hypnosis, acupuncture and organ, commonly applied to blood vessels aromatherapy. (vasoconstriction). See VASOCONSTRICTORS. complement cascade See complement. contact sensitivity (contact dermititis) A type of complement fixation The activation of the delayed hypersensitivity in the skin. complement system, and binding of complement to an contact dermititis See contact sensitivity. antibody-antigen complex. continuous response (variable response) A variable complement fixation test A diagnostic test (e.g. for that changes smoothly. syphilis) where complement is added to a test system in contralateral Pertaining to the opposite side. order to determine the presence of antibody or antigen in controlled drugs Drugs that are deSignated as the blood. controlled drugs (under the UK Misuse of Drugs complement-fixing antibody Antibodies that fix or Regulations, 1985) because they are subject to social misuse, activate complement when they combine with their e.g. cocaine, barbituates. homologous antigens. cooperativity See allosteric interaction; Hill equation. compliance The extent to which patient behaviour correlation coefficient A (nonparametric) statistical accords with medical advice, and in relation to drugs relates to method to quantify the degree of linear association between the accuracy and frequency of taking prescribed medicines. two variables (also referred to as Spearman correlation or COMT catechol-O-methyl transferase. coefficient of linear correlation). If two variables x and y ConA concanavalin A. (normally plotted in the form of a scatter diagram), are c-onc (proto-one) A general term for the viral counterpart perfectly related in such a way that yalways increases when x of a viral oncogene (e.g. c-myc for v-myc). increases, then the correlation coefficient (r) equals 1.0. If y concentration ratio See dose-ratio. perfectly decreases as x increases, then r = -1.0. The concentration-response curve The relationship correlation coefficient has no units, and always is between -1 between concentration (or dose) and biological response. It and + 1. If there is a weak or no relationship between x and y, is normally plotted with the y-axis scaled in terms of the then r tends to zero, and a Pvalue may be calculated in maximum response seen with higher concentrations. With a testing the null hypothesis that the population correlation linear concentration scale, it commonly takes a hyperbolic coefficient equals zero (along with the confidence interval for curve. With a logarithmic concentration scale the curve the correlation coeffiCient). A high correlation coeffiCient commonly takes the form of a symmetric sigmoid curve. The does not necessarily imply a causal relationship between x lateral pOSition of the curve (location parameter) is an and y, or yand x. indication of absolute potency of the drug, usually quoted as cosmid A type of cloning vector. the Ee so . The significance of the form of the curve in terms co-transmitter A neurotransmitter that is stored in, of receptor theory is noted elsewhere: see Black & leO' and released from, the same neuron as another model; Langmuir equation; logistic equation; semilog plot. neurotransmitter. e.g. NORADRENALINE and NEUROPEPTIDE Y in conditioning Associative learning. sympathetic neurons. (C,)max The peak plasma concentration reached after a counter stain A second contrasting stain used to stain single dose of a drug. features that have not taken up the first stain. confidence interval A statistic of precision, also useful covariance A parameter used to measure the extent to for denoting on graphs the likely errors in estimates of which two variables are related. When the variables are not at sample means; see standard error ofthe mean. The 95% all correlated, then the covariance is zero. See correlation confidence interval is the most used, and indicates a proba• coefficient. bility of P = 0.05 that the true mean lies within that interval. COX cyclooxygenase (enzyme). confluence The point at which cells in culture have COX-' Constitutive form of cyclooxygenase enzyme. formed a continuous sheet over the dish and have usually COX-2 Inducible form of cyclooxygenase enzyme. stopped dividing. cranial nerve Any of 12 pairs of nerves that arise directly confocal scanning light microscope A special type from the brain: I (olfactory); II (optic); III (oculomotor); IV of light microscope in which the linear resolution is superior (trochlear); V (trigeminal); VI (abducens); VII (facial); VlII to that obtained in conventional light microscopes. (vestibulocochlear); IX (glossopharyngeal); X (vagus); XI conformational isomers See isomer. (accessory); XII (hypoglossal). They comprise part of the confounding In statistics, the relationship between two peripheral nervous system. or more variables may be obscured by a relationship with CRF I CRH CORTICOTROPIN-RELEASING FACTOR. further unrecognized or uncontrolled variables. Such Crohn's disease A chronic inflammatory disease of the difficulties may often be avoided by careful experimental gastrointestinal tract. which leads to colitis. design and attention to sampling, sometimes at the price of cryostat An instrument used to cut very thin slices of loss of higher order information. Recognition of specimens, e.g. tissues. confounding is important in the interpretation of possible CSF See cerebrospinal fuid. causal relationships in surveys and trials. CSF colony-stimulating factor.

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CSF·1 MACROPHAGE-COLONY-STIMULATING FACTOR. from mast cells and certain basophilleucocytes during CSM Committee of Safety of Medicines. inflammation. C-terminus See carboxy terminus. degrees of freedom The number of independent culture A nutrient-rich medium on which has grown a comparisons that can be made from samples (often n-l, population of a particular type of cell or microorganism. where n is the number of observations). curie (ei) A unit of radiation corresponding to an amount delay·accelerating factor (DAF) A membrane-bound of radioactive material producing 3.7 x 1010 disintegrations glycoprotein that binds activated complement components per second (the activity of radium). Replaced by the SI unit C3b and C4b and thereby inhibits further action of the becquerel (lBq = one disintegration per second). complement. Cushing's syndrome A disorder caused by raised levels delayed hypersensitivity See type IV of CORTICOSTEROID hormones in the bloodstream. hypersensitivity. cutaneous Pertaining to the skin. deletion mutation A type of mutation in which one or CVS cardiovascular system. more nucleotides are lost from the genome. cyclic 3',S'·adenosine monophosphate (cAMP A dementia A progreSSive decline in all areas of mental second messenger molecule, a nucleotide produced from processes which is usually the result of organic brain ATP by the action of the enzyme adenylyl cyclase, and disorder, the most common being Alzheimer's disease. inactivated by phosphodiesterase enzymes to 5' -AMP. Many demyelination The breakdown of myelin, the fatty mediators and drugs cause their effects by increasing or sheath that surrounds and electrically insulates nerve fibres. decreasing the activity of adenylyl cyclase, and thus A characteristic of multiple sclerosis. concentration of cAMP in the cell. cAMP has its effects by denaturation The structural and functional Changes to activating protein kinase enzymes. globular protein or nucleic acid in solution, brought about cyclic AMP (cAMP) See cyclic 3'.5'-adenosine by extremes of heat, pH, some chemicals or X-rays. monophosphate. dendrite A short branching process of the neuronal cell cycl ic AMP·dependent kinase See cAMP kinase, body which synapses with other neurons. cyclic guanosine monophosphate A second dendrite cells Mobile, non-phagocytic cells derived from messenger molecule formed from guanosine bone marrow and which come specialized for particular monophosphate by the enzyme guanylyl cyclase on functions. G-protein receptor activation. denervation Where a nerve supply to a particular cyclic nucleotide See cAMP; cGMP. structure or structures has been interrupted. cycloplegia ParalysiS of the ciliary muscles of the eye. density gradient centrifugation See cystitis Inflammation of the inner lining of the bladder. ultracentrifugation. cytochrome Any of the group of respiratory protein deoxyribonuclease (Dnase; DNAse) An enzyme that pigments that function as electron carriers in biological depolymerizes DNA. oxidation. Usually found in the mitochondria. deoxyribonucleic acid (DNA) A nucleic acid, a large cytokine Any of a group of peptides that are soluble linear molecule, made of two complementary chains of mediators involved in regulatory inflammatory and deoxyribonucleotides. Each nucleotide consists of one of the immune responses. Includes interleukins 1-10, interferons, bases adenine, guanine, cytOSine and thymine. It is the colony-stimulating factors and various growth factors. physical carrier of genetic information. cytotoxic 1-ce1l (cytolytic T-cell; Tcyt) AT-lymphocyte deoxyribophage A bacteriophage with a DNA genome. that lyse cells that bear antigens for which the T-cell is deoxyribovirus A virus with a DNA genome. specific for. dependence A state (addiction) where regular, repeated Da dalton. and probably excessive taking of a drug causes the individual DAF See delay-accelerating factor. to become accustomed to it, resulting in detrimental effects. Dale-Schultz reaction See Schultz-Dale reaction. Stopping dosing precipitates a withdrawal syndrome, which dalton (dal; Da atomic mass unit) The unit of atomic mass may have marked psychological andlor physical symptoms. used as a unit to express molecular mass. Equal to I on the See also habituation. atomic mass scale. dephosphorylation The removal of a phosphate group, dansyl chloride A reagent that reacts with amino acids e.g. of a protein by a phosphatase enzyme. and proteins to form derivatives that show intense yellow depolarization The reduction in electrical potential fluorescence under UV irradiation. difference across a membrane. dark field microscopy A type of microscopy used for depot formulation Usually intramuscular injection of a studying living cells which produces an illuminated object on specially formulated drug which is released slowly and steadily a dark background. into the blood. See routes of administration of drugs. deamidase An enzyme that catalyses the removal of an depression A mental state characterized by extreme amido group from a compound. sadness, hopelessness and pessimism. See ANTIDEPRESSANTS. deaminase An enzyme that catalyses the hydrolysis of depressor To lower blood pressure. See also amino compounds. ANTIHYPERTENSIVES; HYPOTENSIVES. deamination Removal of an amino group (-NHz). dermal Relating to the skin. decarboxylase An enzyme that hydrolyzes the carboxyl dermatitis Inflammation of the skin. radical, -COOH. descending Extending or directed downward or caudally. deficiency (deletion) The absence, or inactivation of a desensitization In pharmacology, is a decreased gene or segment of chromosome. responsiveness to a drug on repeated administration. The degenerative disease Where a disease is caused by term is used for short time-scale changes (seconds to tissue deterioration. minutes). and the term tolerance is reserved for longer time• degranulation The release of granules and mediators scales (hours to days). Homologous desensitization refers to

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 308 Appendix A desensitization confined to one receptor or effector system, diphtheria A bacterial infection caused by whereas heterologous desensitization is a more generalized Corynebacterium diphtheriae which typically affects the phenomenon, throat and can cause fever and fatal complications. Mass designer drugs Drugs of abuse made specifically for the immunization has made this serious disease rare. illegal drug market. diploid Where each chromosome except the Y sex determinant (antigenic determinant; determinant chromosome is represented twice, i.e. organisms whose cells group) See epitope. have two copies of the genetic complement of that species. dextral On or pertaining to the right. See also haploid. dextro- A prefix denoting the right side. displacement analysis A form of radioligand• dextro-isomer See isomer. receptor binding where the characteristics of an unlabelled diabetes insipidus A rare metabolic disorder drug can be determined by analysis of its ability to compete characterized by excessive production of dilute uric acid with the binding of a drug of known properties which is caused by a deficiency of the hormone VASOPRESSIN. radio labelled. See Cheng-Prusoff analysis. diabetes mellitus A metabolic disorder of carbohydrate dissociation constant The equilibrium dissociation metabolism in which sugars are not oxidized to produce constant for a reversible reaction can be used as a measure of energy due to a lack of the hormone INSULIN, leading to affinity of a ligand for a receptor. The term affinity is usually hyperglycaemia. See ANTIGLYCAEMIC AGENTS. quoted with the dissociation constant arranged so diacylglycerol (DAG) A second messenger cleavage pro• Kd = koIT Ikon (units, M·l). By convention, KA often denotes duct of phospholipase C activity following receptor activa• the constant for an agonist, whereas KB is that for an tion on phosphatidyl inositol bisphosphate (PIP,). It acti• antagonist. However, sometimes in pharmacology, vates protein kinase C when bound to Ca" and phosphatidyl particularly in older papers, affinity denoted KA is taken to serine, and is readily converted to arachidonic acid. mean the equilibrium association constant (l/Kd ; units M). dialysis Separation of substances in liquid by virtue of distribution (of a drug) How a drug is distributed in the differences in their capacities to pass through membranes. body following absorption. Haemodialysis is used in medicine to separate low molecular distribution-free tests See nonparametric tests. weight compounds (e.g. toxins, or drugs and their diuresis The increased secretion of urine by the kidneys. metabolites in overdose) from blood. Peritoneal dialysis is a See DIURETICS. procedure used in drug overdose, in which saline solution is diurnal Occuring every day. perfused continuously through the peritoneal cavity. diurnal rhythm See circadian rhythm. diapedesis Migration of cells, e.g. leucocytes, through the diverticular disease A disorder characterized by the walls of blood vessels into the surrounding tissue during presence of small pouches or sacs protruding into the inflammation. intestine, commonly the colon. Diverticulosis is when diastole (ventricular diastole) The period between two inflammation is present, and when severe can then perforate contractions of the heart when both atria and ventricles are the wall of the bowel. Treatment is surgical, and with drugs. relaxed and the heart refills with blood from the veins; see division The taxonomic group immediately above that of also systole. class (and more inclusive) and below kingdom in botany. It diesterase An enzyme that splits esters, including the corresponds to the category phylum in zoology. linkages between the nucleotides of a nucleic acid e.g. a dl racemic mixture (isomers). nuclease. DMSO dimethylsulphoxide; a non-ionized polar solvent differential centrifugation See ultracentrifugation. used as a cryoprotectant in freezing and as a solvent for both differential leucocyte count (differential blood hydrophilic and lipophilic substances. count) The determination of the proportions of the different DNA deoxyribonucleic acid. types of leucocytes in a sample of blood used in the DNA cloning The isolation and multiplication of a diagnosis of disease. particular gene. See PCR. differentiation A term used in embryology to describe DNA fingerprinting (genetic fingerprinting) The use the process in cell development where cells become of a pattern of DNA fragments obtained on restriction specialized for particular functions. In oncology, the term analysis of certain highly variable repeated DNA sequences, describes the degree of similarity of tumour cells to the e.g. tandem repeat sequences which are virtually unique to structure of the organ from which the tumour arose. an indiVidual. This DNA 'profile', which can be detected in diffusion The movement of molecules of a substance minute amounts of cells (e.g. in blood or semen), can be from an area of high to low concentration. used in criminal cases and paternity suits. dilatation (dilation) A widening of a hollow organ, DNA homology The degree of 'relatedness' between base commonly applied to blood vessels (vasodilation). See sequences in different DNA molecules or different parts of VASODILATORS. the same molecule. dilator A drug or mediator that causes dilatation of a DNA hybridization A technique involving reassociation hollow organ. of complementary DNA or RNA in order to identify and dimorphism Where two clearly separable forms exist. isolate chosen DNA or RNA molecules from a mixture. See dinoflagellates A group of mainly single-celled algae or in situ hybridization. protozoa that are equipped with flagella. A number that are DNA library See library. found in seawater produce powerful toxins (e.g. SAXITOXIN). DNA ligase An enzyme that acts on double-stranded dioestrus (diestrus) The quiescent period following DNA to join DNAs end to end and to repair 'nicks' in the ovulation in the mammalian oestrous cycle. DNA backbone. Used experimentally in genetic engineering. dipeptide The compound formed when two amino acids DNA polymerase Any of several enzymes which poly• are joined together by a peptide bond. merize deoxyribo nucleotides, i.e. catalyses DNA synthesis. diphasic See biphasic. DNA probe A known, short, labelled DNA sequence

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introduced to DNA in order to detect complementary DNA ds double stranded. sequences through DNA hybridization techniques. ductless gland See endocrine gland. DNA profiling See DNA fingerprinting. Dunn's post test A statistical multiple comparison test DNA replication The mechanism by which a new copy used post hoc after certain other multiple group tests (e.g. of DNA is made. . Kruskal-Wallis) to narrow down which groups are DNAse deoxyribonuclease. significantly different from which other groups. DNA sequencing The determination of the sequence of duodenal ulcer See peptic ulcer. nucleotides in a length of DNA. duplicate genes Two identical genes that display the DNA splicing The rearrangement of DNA sequences into same phenotypic action, but occur on different different combinations which can occur naturally, or chromosomes. experimentally in genetic engineeing procedures. dura The thickest and outermost of the three meninges DNA synthesis See DNA replication. surrounding the brain and spinal cord. do/ar Pain; one of the classic signs of inflammation. -dynia A suffix denoting pain. dolorimetry The measurement of pain. dys- A prefix meaning abnormal, disturbed or impaired. domain A structurally defined compact globular section of dyscrazia A term that formerly referred to any disease a protein molecule. state, but now is used only in relation to blood diseases for dominant allele The member of a pair of alleles which adnormalities of blood cells or their numbers (e.g. is phenotypically indistinguishable in both homozygous and agranulucytosis, thrombocytopenia). A number of drugs heterozygous condition. cause blood dyscrazias as adverse drug effects. dorsal Relating to the back of the body. dyskinesia Abnormal muscle movements, such as jerking dorsilateral Pertaining to back and sides. and twitching; e.g. tardive dyskinesia. dorsispinal Pertaining to back and spine. dysmenorrhoea The term used for pain or discomfort dorsoventral Extending from the back (dorsal) surface just before or during menstrual periods. See also dose The amount of a drug administered which is a critical amenorrhoea. amount in order to achieve the desired therapeutic effect dysphoria A feeling of discomfort or lack of well-being. without unnecessary adverse effects or side-effects. An initial See euphoria. (loading) dose may be administered, followed by a smaller dysrhythmia See arrhythmia. maintenance dose given at regular intervals appropriate to dystonia A disorder of skeletal muscle tone (either the particular drug and for the individual and metabolism increased or decreased) causing abnormal positions and and excretion (pharmacokinetics) in a particular patient movements. It is sometimes caused by disorders of the basal dose-ratio (concentration-ratio) Is defined as the factor ganglia of the brain due to adverse drug reaction (e.g. (x) by which the dose of an agonist must be increased in the ANTIPSYCHOTICS). See also extrapyramidal disorders; presence of an antagonist, so as to obtain the same tardive dyskinesia. magnitude of response as in the absence of the antagonist. Eagle's medium Any of a number of media used in With a competitive antagonist at equilibrium, the null tissue culture. method supposes that receptor occupancy by the agonist is Earle's BSS Earle's balanced salt solution. equal in the two states. See Gaddum-Schild equation; pAx; early gene A gene that is expressed early in development Schild-plot. EBV Epstein-Barr virus. dose-response curve See concentration-response ECso The concentration of a drug causing 50% of the curve. maximum biological effect It is commonly used dosimetry Calculation of appropriate doses for given interchangeably with EDso; but where the concentration is conditions. known, it is best to use EC so , (preferably as molar dot-blot A variation on Southern hybridization used to concentration) and reserve EDso, for where a dose has been quantify a given nucleic acid sequence. See Southern blot given (as in vivo systems). Also, for EC so the response will technique. generally be graded, whereas for the EDso; the response may double-blind See clinical trials. well be quanta!. double-reciprocal plot See reciprocal plot. ECso effective concentration/dose in 50% of subjects down-regulation A decrease in rate of production, or of ECE endothelin-converting enzyme. number, e.g. following receptor desensitization. eclampsia A condition of late pregnancy, or during or drachm A unit of weight used in pharmacy, I drachm = directly after delivery, characterized by convulsions (and 3.883g (60 grains) or volume, 1 fluid drachm = 3.696ml (1/8 preceded in pre-eclampsia by hypertension, oedema and floz). proteinurea. dragee A pill that has been coated with sugar. ectopic Not in its correct or normal position. Draize test A test for topical mucosal toxicity. eczema An inflammatory condition of the skin, usually DRG dorsal root ganglion. due to an allergic reaction. drip See routes of administration of drugs. ED effective dose. drug Any substance that affects the structure or EDso effective dose in 50% of subjects. functioning of a living organiSm. edema See oedema. drug dependence See dependence. EDRF endothelium-derived relaxing factor. drug interactions Said to occur when one drug changes EDTA ethylenediaminetetraacetic acid; used as a chelating the magnitude of effect or duration of action of another. agent. See also ANTICOAGULANTS. drug resistance Decreased reactivity to a certain drug effective concentration See ECse. type. effector A cell or organ by which an animal responds to drug screening Assessing chemical agents for a given internal or external stimuli. type of pharmacological activity in a suitable test system. efferent Leading away from; e.g. nerves that take

SMAll CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 310 Appendix A information from the eNS to the periphery. ELISA enzyme-linked immunosorbent assay; an assay efferent function of primary afferents A term where antibodies are used to measure a particular substance used to describe a newly identified function of primary following its labelling by an enzyme. See immunoassay. afferent sensory nerves, where release of transmitters from elixir A medicated liquid preparation for taking by mouth, the peripheral ('wrong') end of the nerve has a function, e.g. which is intended to disguise a potentially unpleasant taste neurogenic inflammation. by including a sweetening substance like glycerol or alcohol, efficacy In relation to drug effects, is a term used to and often with aromatic agents. describe the strength of a drug's action. In therapeutics it is elongation factor Proteins required for polypeptide taken to be the capacity of a drug to produce the desired chain elongation during protein synthesis. effect or result (e.g. the extent to which pain is relieved). In elution The washing out of a substance by a solvent, e.g. in receptor pharmacology, it is the mathematical term that chromatography. Stephenson (1956) introduced for a parameter, efficacy (e), Em molar extinction coefficient (concentration in g-moles/e). which is proportionality constant relating the stimulus, EM electron microscope. produced by an agonist on occupying the receptor, to the EMBA European Medicines Evaluation Agency. subsequent biological responses. In the equations: R = f(5) embedding A process by which permanent microscope and 5 = e.p, R is the biological response, S is stimulus, e is slides or specimens for electron microscopy are prepared. efficacy, p is the proportion of receptors occupied, and [ embolism A condition where a blood clot (thrombus) or denotes some simple function. According to this other tissue lodges in an artery to obstruct blood flow. There formulation, the ability of an agonist to produce a response are various types according to the area obstructed (e.g. at a given level of receptor occupancy depends both on e and pulmonary embolism in the case of the lung). Treatment is on the receptor density. The concept is an advance on that of by surgery, or with drugs that can dissolve blood clots intrinsic activity, and it may take values varying between (FIBRINOLYTICS or thrombolytics) , or prevent formation of zero for an antagonist, through small positive values for further clots (ANTICOAGULANTS). partial agonist, to larger positive values for a full agonist. Its embolus A blood clot, particle of tissue or pus which use in modelling has been extended in intrinsic efficacy. when carried in the bloodstream can effect a distant site. See efflux The movement of an entity across a defined barrier embolism. or out of a specialised compartment. embryotoxicology The property of causing damage to EGF epidermal growth factor. the embryo in the period of development of the foetus EIA enzyme immunoassay. See ELISA. (organogenesis) up to about 12 weeks of gestation. eicosanoids A family of fatty acid mediators derived emesis Vomiting; see ANTIEMETICS. from arachidonic acid, and which includes prostaglandins, emphysema A lung disease where there is damage to the thromboxanes and leukotrienes. alveoli of the lungs (which are tiny air sacs in which oxygen ejp excitatory junction potential. exchange with the blood takes place), resulting in shortness elastin A major connective tissues protein in blood vessels. of breath. It is often accompanied by chronic bronchitis, and electro blotting A form of blotting where transfer of the can in turn lead to heart failure and respiratory failure. It is nucleic acid or protein of interest from the gel is effected by generally due to smoking, but exacerbated by air pollution electrophoresis. (and a genetic predisposition in some individuals). The electrochemical gradient The gradient across a cell damage to the alveoli cannot be repaired, but symptomatic membrane with respect to an ion or other solute. It relief maybe given by BRONCHODILATORS, CORTICOSTEROIDS comprises both the electrical and concentration gradients. and DIURETICS. electrogenic Generating an electrical potential across a empirical Based on or acting on observation or membrane. experiment and not on theory. In chemistry, it means the electrogenic transport The transport of molecules formula shOWing the constituents of the compound in across an energy-transducing membrane leading to a change proportions but not configuration. in the potential difference across the membrane. enantomers See isomers. electroinjection The introduction of substances, encephalopathy Any of a group of disorders that affect including DNA into intact cells by means of electric field the functioning of the brain. impulses. encode The assigning of DNA bases such that they electrolyte A solution that produces ions. represent the sequence of a given protein. electron microscopy A form of microscopy where an endemic Disease present in a population at low levels all electron beam interacts with a specimen and thereby the time. contributes to the formation of an image. endo- A prefix meaning within. electrophoresis Methods of separating molecules, on endocarditis Inflammation of the endocardium (the the basis of their electrical charge and size, and hence lining of the heart). It occurs usually where there has been different migration characteristics in an electriC field. There damage due to congenital heart disease or rheumatic fever, are several types, e.g. free electrophoresis where the and where the immune system is damaged (as in AIDS). molecules are present in a liqUid medium, surface EndocarditiS may be caused by a number of microorganisms, electrophoresis when the molecules move through a thin film including bacteria and fungi, particularly after dental of buffer on a strip of e.g. cellulose acetate or paper, and gel extractions and heart surgery. Antibiotics may be used both electrophoresis where the molecules in the sample move prophylactically and in treatment. through a gel, often composed of agarose or polyacryemide. endocrine gland A ductless gland secreting hormones electrophysiology The stUdy of physiological processes directly into the blood. in relation to electrical phenomena. endocrine system Endocrine glands and the blood• elimination The removal of the active form of a drug borne hormones they secrete. from the body. See excretion. endoenzyme An enzyme that cleaves bonds within a

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 311 polymer chain. eosi n A red/brown acid dye used experimentally to stain endogenous Produced within the body; in contrast to eosinophils. exogenous agents which are administered to the body. Some eosinophil A PMN that contains basic polypeptides in agents (e.g. hormones, local hormones, neurotransmitters), the cytoplasm and so stains red with the acidic dye eosin. though formed endogenously, may be administered Eosinophils are involved in the immune response, e.g. to exogenously as drugs. parasitic infection. endometriosis The abnormal presence of tissue similar eosinophil chemotactic factor A peptide released to the endometrial lining of the uterus in various sites within from mast cell granules that stimulates chemotaxis of the pelvis. The abnormal tissue may undergo similar eosinophils. responses to hormones as the endometrium, causing pain eosinophilia An increase in the number of eosinophils in and dysmenorrhoea. Treatment is with hormone the blood. antagonists and/or surgery. epi- A prefix meaning above or upon. endometritis Inflammation of the endometrium of the epidemic disease Those diseases occuring or tending to uterus. occur in extensive outbreaks, or in unusually high incidence endometrium The mucous membrane layer lining the in certain times or places. uterus within the muscle layer (myometrium). epidemiology A term originally used to denote the study endoneurium Connective tissue surrounding bundles of and control of epidemic disease, but is now often broadened nerve fibres together in a nerve. to mean the study of the occurrence and distribution of all endonuclease See restriction endonuclease. diseases in a population. endopeptidase An enzyme that hydrolyses peptide epidural The space between the dura mater and wall of bonds and thereby splits a peptide into smaller fragments. the vertebral canal around the spinal cord. See ENDOPEPTIDASE INHIBITORS. epi lepsy A group of CNS diseases characterized by a endothelium The tissue that lines the blood vessels, tendency to recurrent seizures ('fits'), usually of sudden heart and lymphatic ducts. See epithelium. onset. There are various schemes of classification: grand mal endotoxic shock A serious life-threatening fall in blood - a generalized seizure in which the patient falls down pressure with cardiovascular collapse due to the release of unconscious; petit mal (absence seizures) - generalized endotoxin from the cell wall of dead microbes. seizure characterized by momentary loss of consciousness endotoxin A toxic component of a living microbe's without abnormal movements; simple partial seizures - structure that is generally released on the death or disruption where consciousness is maintained during a partial physical of the microbe. Although generally less toxic than exotoxins, seizure, including Jacksonian epilepsy, where twitching they account for a number of adverse effects of bacteria, occurs and spreads across the body in a pattern; complex including pyrogenesis and increased capillary permeability partial seizures (temporal lobe epilepsy) - where conscious (e.g. in endotoxic shock). contact with surroundings is lost and there may be end-plate Where a nerve fibre terminates with a muscle stereotyped abnormal behaviour. Status epilepticus is an fibre. extension of one of these conditions to prolonged or enema An infusion of liquid into the rectum, via the anus, repeated epileptic seizures without periods for recovery, and as a method of administering laxatives, diagnostic agents is a medical emergency. Treatment of some of these is with (e.g. radio-opaque agents) or therapeutic drugs to act locally appropriate ANTIEPILEPTICS; see also ANTICONVULSANTS. (e.g. steroids in colitis), or sometimes agents for absorption epineurium The fibrous connective tissue sheath around for systemic effects (paraldehyde as an antiepileptic). a nerve. enhancer gene A modifier gene that enhances the epithelium (pI. epithelia) The tissue that covers the entire action of a non-allelic gene. external surface of the body and lines the hollow organs of enteral Pertaining to the intestinal tract. the body (except blood vessels). See endothelium. enteral drug administration Administration of a epitope Any region on an antigenic macromolecule with drug by the alimentary tract, mouth or rectum. the ability to elicit and combine with specific antibody. enteric-coated tablets These are tablets covered with a epp end-plate potential layer (originally shellac varnish) that dissolves slowly. They equilibrium dissociation constant See are intended to prevent release until the tablet has left the dissociation constant. stomach, where the active drug is gastro-irritant (e.g. equilibrium potential The potential at which a aspirin) or is broken down by gastric juices. particular ion type passes equally in both directions across a enteric nervous system The intrinsic nervous system cell membrane. in the hollow organs (see intrinsic nerves) , especially the equipotent molar ratio (EPMR) For series of drugs, is gut, which includes all neurons with cell bodies within the the ratio of the molar concentrations required to give the various neuronal plexi. It forms a division within the same effect. If the EC so values for three agonists A, Band C autonomic nervous system. In the gut there are neurons are I, 10 and 100 nM, respectively, then the EPMRs for Band with motor, sensory and associative function, so it has simple C, relative to A=l.OO, are 10.0 and 100, respectively. Thus, the attributes of the CNS, and can be used as an experimental higher the index, the lower the potency of that drug. It is the paradigm of it. reciprocal of the relative activity or relative potency. The enterotoxins These cause gastroenteritis and related measure is useful in denoting the concentration required to toxic effects in the alimentary tract. They are usually achieve a given response, occupancy etc. See activity ratio. exotoxins elaborated by microbes contaminating ingested ER endoplasmic reticulum. food or living within the gut. error In statistics there are different types of error and enucleate Lacking a nucleus. consequences. Type I error is a false positive result, where a enzyme A biologically active protein catalyst, many of difference is treated as significant when in fact there is no which are important drug targets e.g. ACE INHIBITORS. real difference. Type II error is a false negative result, where a

SMALL CAPS = cross-reference to an entry in the A~Z Section bold = cross-reference to an entry in the Glossary 312 Appendix A difference is treated as insignificant when in fact there is a causing gastroenteritis are termed enterotoxins. Examples of real difference. exotoxins include: clostridium toxin (Clostridium tetani) in erythema Redness of the skin. bolulism food poisoning; pertussis toxin (BordetelJa erythr- A prefix meaning redness. pertussis) causing some Side-effects in whooping cough; erythroblast Nucleated cell of bone marrow which gives cholera toxin (Vibrio cho/erae) in cholera; and diphtheria rise to erythrocytes. toxin (Corynebacterium diphtheriae) in diphtheria. erythrocyte A red blood cell. exponential curve/relationship Curves of this form erythrogenic Producing reddening. are of a class where a variable approaches an asymptote at a erythropoiesis The production of erythrocytes. continuously declining rate. The rate of exponential decline erythropoietin A hormone that stimulates the final is proportional to the size of the variable at any time. From differentiation of erythrocytes from precursor cells. this it follows that there is a fractional decrease per unit time, esoteric Arising with the organism. and this can be expressed in terms of a time-constant (k), essential Substances that cannot be synthesized by the commonly quoted as a half-life (t l!1l (where 11/1; 0.G993/k). body (e.g. certain amino acids, fatty acids). An example of exponential decline is the decay of radioactive essential drugs Medicines 'listed' by the WHO as a species, and of exponential growth, that of microorganisms common core of basic drugs (currently about 300). at low concentrations in culture. established cell line (continuous cell line) A expression In molecular biology, is the production of a population of cells capable of unlimited in vitro propagation. protein from a particular gene. estrogen See oestrogen. expression vector A cloning vector in which DNA is ethics committees Independent bodies concerned with cloned and expressed. advising over ethical considerations arising in medicine, and extra- A prefix meaning located outside. which also play an essential part at the planning stage of extraction ratio The rate, between 0 and I, of extraction clinical trials. of a drug by an organ relative to its rate of entry. ethnopharmacology (or pharmacoanthropology) The extrapyramidal disorders (of movement) These are identification and investigation of traditional medicines. caused by several pharmacological groups as an adverse eUkaryte An organism whose cells possess a membrane• drug reaction; commonly a foreseeable side-effect, which bound nuclei in which the DNA is organized into may be difficult to avoid with higher dose-schedules. The chromosomes. See prokaryote. syndrome is due to effects of drugs on the basal ganglia and euphoria A feeling of confident well-being, the opposite associated structures within the brain (corpus striatum and of dysphoria. It can be induced by some opioids, such as substantia nigra), and is most commonly incurred with morphine, and prolonged use of glucorticosteroids. ANTIPSYCHOTIC drugs, such as phenothiazines working as European Pharmacopoeia (Eur. P.) This lists official dopamine-receptor antagonists. See also tardive dyskinesia. preparation of drugs, like the British Pharmacopoeia (BP). extravasate The forcing of fluid, e.g. blood plasma, from The BP and EP are likely to converge in their coverage. its proper channels, e.g. venules, into the surrounding tissue. exipient A normally inert substance added to a medicine extravasation See plasma extravasation. to make it of a more suitable form for administration (e.g. extrinsic Lying outside, for example, an organ. See Soya flour in tablets, wax in pills). extrinsic nerves. excitory amino acids See amino acids. extrinsic Of an organ, those nerves with their cell bodies excretion (of a drug) The way in which a drug is removed outside an organ, i.e. nerves that completely degenerate after from the body; usually by the kidneys, hepato-biliary system de nervation of the organ. or the lungs. exudation The slow escape of liquid exudate containing exo- A prefix meaning from. proteins and PMNs through intact blood vessels. exoc~ ine gland A gland that secretes substances through Fab portion (Fab fragment) That part of the antibody a duct (e.g. the salivary glands), usually under the control of molecule containing the antigen binding site. hormones or neurotransmitters. See also endocrine gland. facilitated diffusion Carrier-mediated transport of exocytosis The process by which secretory granules or molecules along a concentration gradient across the cell vesicles fuse with the cell membrane and release their membrane with no expenditure of energy. con tents from the cell. facilitation Increase in responsiveness of a post-synaptic exogenous Originating outside an organism. See also membrane to successive stimuli. endogenous. FACS fluorescence-activated cell sorter. exon The codon, the sequence of bases in DNA, that factorial design A method for studying effects and inter• encodes for a particular amino acid. See also intron. actions between treatments and subjects. HaVing its origins in exoreceptor The postulated binding site adjacent to a agricultural field trial, all combinations of treatment, subjects receptor to which a drug molecule can bind and influence etc. under investigation are allocated into blocks. Factorial the interaction between the drug molecule and the receptor analysis shows whether factors are independent or not, and (e.g. binding of the long-acting ~-adrenoceptor agonist yields unbiased estimates of effects of treatments. SALMETEROL to the ~-adrenoceptor). false transmitter A chemical that replaces a normal exorphin An opioid formed outside the body, e.g. the substrate or metabolite in the synthesis of a neurotransmit• opiate MORPHINE. ter, e.g. METHYLDOPA which produces methylnoradrenaline. exotoxin A poison actively elaborated by a living microbe familial diseases Any of many diseases found in some and secreted into its environment, and therefore is the families, but not others, which are largely genetically caused. counterpart of endotoxin. They are generally very potent family The taxonomic group immediately above that of heat-sensitive proteins comprised of an active toxic A moiety genus and below order. and a B inactive binding moiety. Some that are active on favism An inherited defect in the enzyme glucose-G• neural processes are termed neurotoxins, whereas those phosphate dehydrogenase.

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Fc receptor Present on some cells including macrophages (microseconds), examples include reactive oxygen and and is the receptor to which the constant region of antibody nitrogen species, superoxide radicals (02~)' Reactive oxygen heavy chains (the Fc region) attaches. radicals can attack key molecules, e.g. enzymes, DNA and FDA Food and Drug Administration. membrane lipids, and contribute to some diseases. fever See pyrexia. free·radical scavenger A chemical that reacts with FGF fibroblast growth factor. free-radicals. Examples include vitamins E and C, fibrin Insoluble protein which forms the clot produced by superoxide dismutase and catalase. the action of thrombin on fibrinogen during blood clotting. freeze drying (Iypholization) Removal of volatile fibrinogen The soluble blood plasma protein of fibrin. substances, e.g. water from deep frozen material by fibrinolysis Dissolving of blood clots. See blood clotting. sublimation under high vacuum to preserve that material, fibroblast Connective tissue cell involved in the synthesis e.g. peptides. and secretion of components of the extracellular matrix, e.g. freeze· fracture A specimen-preparation method used to of collagen. enable the interior of a cell to be visualized in electron fibronectin A cell-adhesion molecule, a glycoprotein microscopy. located on the external surface of the plasma membrane of frequency distribution A graph or table showing the most animal cells. Involved in cell-substratum interactions. frequency with which a characteristic occurs in a sample or Fisher's exact test A method of analysing frequency population. The shape of the resultant curve is bell-shaped in data, for instance in a 2x2 contingency table where the two Normal (Gaussian) distributions, and peaks in a less columns must represent mutually exclusive categories, as symmetrical way (skewed-to-the-right) with binomial and must the two rows. The null hypothesis is that there is no Poisson distributions. The peak represents some central association between the variable defining the row and the tendency and can be represented in the form of some average variable defining the column. The test is of value in (mean, median). See also probability distribution. evaluating the presence, or absence, of association between Freund's complete adjuvant A complete water-oil qualitative characteristics. emulsion containing a killed microorganism which enhances FITC fluorescein isothiocyanate; a fluorochrome that antigenicity. It is used experimentally to induce an immune fluoresces greenish yellow. response. Freund's incomplete adjuvant does not contain the FITC·dextran FITC complexed to dextran used for microorganisfil. observation and quantification, e.g. plasma extravasation. Friedman test A (non parametric) significance test fixation A method using a fixative to kill cells but to that compares the medians of three or more paired samples. preserve their structure and organization. A stage in The null hypothesis is that all column medians are equal. It microscope slide preparation. yields a Pvalue in testing this null hypothesis, which if low, fixative A chemical used to preserve cells and cellular leads to the conclusion that the samples are unlikely to come structures, e.g. formaldehyde. from populations with equal medians. The test assumes that FLAP 5-lipoxygenase activating protein. the data are sampled from populations with similar flora The entire plant or bacterial life particular to a given distribution characteristics (which may not be Gaussian). part of the body or geological region. FSH FOLLICLE-STIMULATING HORMONE. fluorescein A fluorochrome. full agonist See agonist. fluorescent dye A dye that can fluoresce. See functional antagonism See antagonism - functional. fluorochrome. Freund's incomplete adjuvant See Freund's fluorimetry (fluorescence spectrophotometry) The complete adjuvant. measurement of the intensity of emitted light of a light• GABA Y-AMINOBUTYRIC ACID. activated fluorophore to determine concentration of a Gaddum-Schild equation Gaddum (1937) solved the fluorescent-labelled compound. equations quantifying the actions of competitive antagonists fluorochrome A fluorescent dye, e.g. acridine orange, acting at receptors using the null method, where the dose• FITC, used in experimental biology to label biologically ratio, x, can be defined as the ratio of concentrations of active molecules, e.g. as a probe or tracer. agonist giving equal occupancy of receptors - and hence Food and Drug Administration (FDA) The USA equal responses - in the absence and presence of competitive authority concerned in evaluating evidence of drugs safety antagonist. It could then be shown that (x-I) = [A]lKd where and efficacy, clinical trials and the general process of drug Kd is the equilibrium dissociation constant and [AJ the registration. Its regulations have an international impact. concentration of the antagonist. formulary A book (or increasingly a computer database) Galenical medicines These are medicines that contain that details formulations or doses of drugs, e.g. the British natural, normally herbal, constituents follOWing the methods Pharmacopoeia. of Galen, the 2nd-century AD Greek physician. formulation The pharmaceutical term for the mode of gamete See germ cell. presentation of a medicine, e.g. capsule, tablet, pill, cream, gamma globulin Any of a group of blood serum. lotion, emulSion, solution, pessary, suppository. form for proteins, including immunoglobulins, defined as being injection and so on. Modern medicines are often quite within a particular range of electrophoretic mobility. complex and sophisticated products that are stable, have gamma spectrometry A technique that uses gamma reliable bioavailability and acceptability (taste etc.). electromagnetic radiation in experimental biology. FPLC fast protein liqUid chromatography. ganglion A group of nerve cell bodies. FRAME Fund for the Replacement of Animals in Medical GAP·protein See GTPase-activating proteins. Experiments. gastric ulcer See peptic ulcer. free·radical An atom or molecule that has an gastro·oesophageal reflux (acid reflux) independent existence with an unpaired electron. They are Regurgitation of acid and enzymes into the oesophagus from highly reactive and usually have a brief lifetime the stomach due to, for example, hiatus hernia or weakness

SMALL CAPS = cross-reference to an entry in the A~Z Section bold = cross-reference to an entry in the Glossary 314 Appendix A of the oesphageal sphincter; common in pregnancy. equivalent generic drug. However, during the period of the Gaussian distribution See Normal distribution; patent that is granted to the inventor (commonly 16-20 years probability distribution. for a new chemical entity or formulation, but depending on GOP guanosine diphosphate. the country concerned), only a proprietary form of the drug gel A colloidal formulation, e.g. of a medicine as ajelly-like may be available: in this case a generic prescription will be mass, which is convenient for topical application. filled with a proprietary drug (complete with packaging etc., gel electrophoresis See electrophoresis. in the latter name). Although the generic form has the same gene The genetic makeup of living organisms is molecular structure as the proprietary form of the drug, determined by genes (contained in 23 pairs of chromosomes concern has been expressed about the bioequivalence of in humans). The gene is the basic unit of inheritance and is preparations, and regulatory authorities normally reqUire the sequence of DNA bases that codes for a complete proof that, at a given dose, the generic drugs substituted for functional polypeptide chain or RNA molecule. their parent proprietary drug have a bioavailability that gene action The functioning of a gene in determining ensures equivalent pharmacological effect. See also chemical the phenotype of an individual. drug name; names of drugs. gene amplification An increase in the number of gene targeting Any of several techniques enabling copies of a particular DNA sequence in a sample when the mutation or replacement of a given gene using recombinant rest of the genome remains unchanged. Experimentally or DNA technology. gene knock-out A technique by which diagnostically used to increase the amount of a DNA sample specific genes can be disrupted and rendered non-functional to facilitate its analysis. See also polymerase chain reaction. (usually through the use of antisense technology). When gene assignment Localization of genes to individual applied to embryonic stem cells, it can be used to generate chromosomes. animals (mice) mutant for a specific gene. See transgenic gene bank See gene library. technology. gene cluster A group of two or more closely linked genes gene therapy The use of genetic intervention to treat that encode for the same or similar products. See linkage. disease caused by genetic defects. Techniques (still mostly gene disruption See gene knock-out. experimental) include treatment of a genetic defect by gene duplication The generation of additional copies of insertion of a normal gene (e.g. cystic fibrosis), blockade of a gene during normal cellular processes. Thought to be the expression of an abnormal gene (e.g. the BCL2 leukaemia origin of families of related genes. gene) with antisense technology and the introduction of a gene expression The process by which the information gene for an enzyme that converts a prodrug into a cytotoxic encoded by a gene is converted into a protein. In clinical metabolite (e.g. thymidine kinase to convert 5-fluorocytosine genetics it refers to the way in which a gene is expressed in a to 5-fluorouracil). given individual. genetic code The sequence of DNA nucleotides that gene fusion The process of altering the coding sequence determines the amino acid sequence of the translated protein of a gene to produce a novel hybrid gene by joining it to the 'read' in triplets of bases called codons. coding sequence of a different gene. genetic engineering A gene therapy term meaning gene library All the genetic information of the species. the use of techniques (mainly recombinant DNA See library. technology) to modify the structure of genes, or to create or gene locus The site on a chromosome occupied by a gene. delete genes. Potentially, these techniques may be used to gene overlap Where one sequence of DNA codes for correct diseases in humans due to genetic defects (e.g. cystic more than one protein. This is achieved because of the use of fibroSiS). Used in animal husbandry (e.g. to introduce different reading frames. human genes manufacturing human peptide gene pool The total number of genes in a given pharmaceuticals, such as insulin, growth hormone) is now population at a given time. quite advanced and used in transgenic technology. gene product The protein. rRNA, tRNA or other genetic induction Gene activation as a result of structural RNA encoded by a gene. inactivation of a repressor protein by an agent, which gene regulatory proteins This includes proteins that consequently activates transcription of a structural protein, regulate gene expression by interfering with a control site in or activation by a chemical inducer. DNA. See transciptional regulators; transcription factors. genetic map (chromosome map) A map of the positions gene rendundancy Where there are several copies of of gene loci on a chromosome. the same gene in a given cell. genetiC polymorphism The existence of multiple generations of drugs A 'new' generation occurs when alleles at a gene locus. there is a significant advance in the development of a class of genetics The science of the study of genes and biological drugs. whether in potency. duration of action, absorption. inheritance. spectrum of action and so on. For example, in a number of gene transfer The transfer of genes from one species ANTIBIOTIC families there are first, second, third generations. into another, used in gene therapy. e.g. cephalosporins. genitourinary tract (urogenital tract) The sexual generic drug name The official or standard name for organs and bladder, and related structures. the active chemical(s} in a medicine, in contrast'to a genome The total genetic material of an organism, the medicine's proprietary drug name (trade or brand name). genes and the intervening DNA sequences. See Genome In the UK, doctors in general and hospital practice are Project. encouraged to refer to, and prescribe. drugs by the generic Genome Project An international research programme name (written correctly they have no initial capital letters). aimed at mapping all the genes in a genome, e.g. of yeast or Under NHS recommendations for generic substitution, a of man (Human Genome Project). prescription written for a proprietary drug (with initial genotype The total genetic complement of a set of genes capital letters) ,can be supplied in the form of a (cheaper) that the individual possesses, containing contributions from

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 315 both parents. Not all this information is expressed. See messenger pathway by stimulating adenylyl cyclase. phenotype. G6PD deficiency (glucose 6-phosphate dehydrogenase genus The taxonomic group immediately above (more enzyme deficiency) A genetically inherited condition, inclusive) that of species and constituting the principal relatively common in Indian. African and some subdivision of a family. Meditteranean races. In affected people serious adverse geometric mean See mean. reactions occur when they take certain drugs, e.g. the germ cell (gamete; sex cell) A cell that participates in antimalarial drug primaquine. which causes red blood cell fertilization and development. haemolysis leading to severe anaemia. GI gastrointestinal. GT See transducin. Gj G-protein that couples receptors to the cAMP second GYPase-activating proteins Proteins that interact messenger pathway, inhibiting adenylyl cyclase. with the GTP-bound forms of guanine-nucleotide binding glaucoma An eye condition characterized by a raised proteins to stimulate intrinsic GTPase activity. e.g. RAS intraocular pressure in the eye, which if left untreated can protein related GTPases. damage the optic nerve. There are various forms, including GYP-binding protein See guanine-nucleotide binding simple (open-angle) glaucoma, which is chronic and seen protein. more commonly in middle-age and is often familial, and GYP-guanosine 5'-triphosphate An important acute (closed-angle) glaucoma. The former is either treated molecule in signal transduction as it forms cGMP, an with beta-blockers and some other drugs, or surgery. See important second messenger. ANTIGLAUCOMA TREATMENTS. guanine-nucleotide binding protein Anyone of a glycoprotein A protein covalently attached to one or family of diverse proteins which includes G-proteins. more sugar molecules. transducin and the RAS proteins. They are involved in GM-CSF granulocyte-macrophage-colony-stimulating transducing signals from cell-surface receptors to effector factor. mechanisms, e.g. enzymes. GMP I. guanosine monophosphate (GUANOSINE 5'• Gy gray; SI unit for the amount of ionizing radiation MONOPHOSPHATE). 2. Good Manufacturing Practice; a code of absorbed by tissue. practice covering the manufacture of pharmaceuticals. gynaecomastia Enlargement of breasts in the male. It GNR Gram-negative, rod-shaped bacteria. can be caused by elevated levels of female sex hormones GnRF gonadotropin-releasing factor. (oestrogen) in the blood. Some drugs may cause it as a side• Go G-protein involved in coupling receptors to the cAMP effect (e.g. CIMETIDINE, DIGOXIN, SPIRONOLACTONE). second messenger pathway, inhibiting adenylyl cyclase. habituation A state where regular (possibly excessive) Overlaps with Gj class. taking of a drug causes an individual to become accustomed goitre A collection of disease states characterized by an to it, but not to the extreme psychological or physical stage of enlarged thyroid gland. Goitre has a number of causes: (a) a dependence. shortage of iodine in the diet (endemic goitre); (b) a haematinic A general term for any substance that is hyperplasia (tumour) of the gland (sporadic goitre); (c) required for production of haemoglobin and related blood swelling due to overactivity in Grave's disease (exothalmic elements, or agents used to improve the condition of the goitre); or (d) autoimmune thyroiditis (Hashimoto's blood, particularly to treat deficiencies in anaemia. Agents disease). Additionally, some chemicals and drugs may cause include iron salts, cobalt salts, vitamin B12 and the goitre as an adverse drug reaction. erythropoietins. G-protein See guanine nucleotide binding protein. haematology The study of blood. Gq G-protein involved in coupling receptors to haemodialysis See dialysis. phosphatidyinositol second messenger pathway. haemoglobin The oxygen-carrying pigment of the red graded response A response that is a continuous blood cells (erythrocytes) of the blood. Some familial variable (e.g. contraction of smooth muscle; change in blood abnormal forms cause anaemia (e.g. sickle-cell disease). pressure; change in cAMP level), in contrast to a discontinu• Other abnormal forms that carry oxygen poorly and cause ous variable (e.g. numbers of patients in a group responding). anoxia, are caused by acute reaction with chemicals, for Gram-negative Oecolourizing and staining of bacteria instance, methaemoglobin by nitrates, and a number of to counterstain when treated to Gram's stain. other drugs and chemicals, carboxyhaemoglobin by carbon Gram-positive Bacteria that hold the colour of the monoxide. primary stain when treated to Gram's stain. haemolysis (hemolysis. USA) The destruction of red Gram's stain A differential bacterial stain used as a blood cells (erythrocyctes). It may occur within the body primary means of identification. through infection, poisoning, or as an adverse drug reaction. grandfather drug The original or archetype in a series, haemorrhoids (piles) An enlargement of the wall of the from which generations of successor drugs have been anus, sometimes caused as a consequence of prolonged developed. See generations of drugs. constipation and often following childbirth. There may be grand mal See epilepsy. pain and bleeding. Treatment of first-degree haemorrhoids is granulocyte See leucocyte. normally through adjustment of diet, but second- and third• granulocytopenia See neutropenia. degree severity may require surgical intervention. growth factor A general term to describe cell-specific half-life (t'I,) The time taken for a measured variable to proteins or peptides responsible for cell division or differen• fall to half. When the rate of decline is in the form of a single tiation, e.g. epidermal growth factor, nerve growth factor. exponential curve (with a time-constant, k), this value is a growth hormone A polypeptide hormone secreted by constant and independent of the starting value; i.e. a the anterior pituitary gland that promotes an increase in constant fraction is lost per unit time; also t'/, = 0.6993/ k. body size. See HUMAN PITUITARY GROWTH HORMONE. Commonly used to describe the rate of decline of blood G. G-protein that couples receptors to the cAMP second concentrations of drugs, and of decay of radioactive species.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 316 Appendix A half-time See half-life. contact); type II is associated with genital herpes (which is hallucinogen An agent that induces hallucinations or sexually transmitted). Herpes zoster (shingles). caused by the illusions. varicella-zoster virus. remains in a dormant form in sensory haploid Where each chromosome is represented once, i.e. nerves following chickenpox, and can later be activated to cells have one set of chromosomes which represent the affect the eye (ophthalmic zoster) or skin (dermosomes). The genetic complement of that species. See diploid. pain of shingles can be severe, especially in the elderly. hapten A small non-antigenic molecule which when Treatment of all forms of herpes is mainly with ACICLOVIR. combined with a larger carrier molecule becomes an antigen. hetero- A prefix denoting different hard drugs Drugs used for nonmedical or social purposes heterodimer A protein composed of two different which seriously affect the individual from functioning in subunits. SOCiety and which induce dependence. e.g. heroin. See also heterolateral Pertaining to the opposite side. soft drugs. heteromeric receptor A receptor composed of two or harmonic mean See mean. more different subunits. HCG human chorionic gonadotropic hormone: see heteroscedastic See homoscedastic. GONADOTROPHIN. heterozygote An individual who has two different HD50 haemolytic dose 50; the quantity of complement alleles at the same chromosonallocus. A heterozygote who needed to lyse 50% of a standardized suspension of has one dominant disease gene and one normal gene will be sensitized erythrocytes. affected by the disease (as in Huntington's disease); one who HDL high density lipoprotein. has a recessive disease gene and a normal gene will be a hDNA hybrid DNA. carrier (as in cystic fibrosis). heat shock proteins A group of proteins whose HGG human gamma globulin. synthesiS is transiently increased in response to a sudden rise high performance liquid chromatography See in temperature or other stress in order for the organism to chromatography. survive, e.g. by protecting chromosomes. Hill equation/slope/plot An equation (A.v. Hill. 1909) heat shock response A cellular response to stress. e.g. relating the proportion of total receptor sites binding a increased temperature. resulting in slowing down of synthe• ligand according to affinity and concentration. The Hill sis of normal proteins and activation of previously inactive equation can be written in a form such that occupancy (or genes resulting in the synthesis of heat shock proteins. response) can be plotted against concentration of ligand, and heavy chain (A chain; H chain) The heavier of the two when the Hill plot is in its double logarithmic form. it will types of polypeptide chain in immunoglobulin. show a straight line with a slope (nH) referred to as the Hill HeLa cells A tissue culture of an aneuploid line of human slope. If there is positive cooperativity in binding. the Hill epithelial cells propagated since 1952. derived from cervical slope will be greater than unity, whereas if there is negative carcinoma. cooperativity or heterologous binding then the Hill slope will helminth Originally denoted any paraSitic worm. but now be less than unity. Unity slope indicates a simple I: I relation• usually includes free-living or parasitic worms, including the ship of ligand and binding at the receptor, and in this case flatworms (Platyhelminthes). roundworms (Nematoda) and the Hill equation is eqUivalent of the Langmuir equation. Annelida. Infection may be treated with ANTHELMINTIC drugs. histochemistry The study of the distribution of hemo- US spelling of the prefix haemo-. chemical components in cells. helper 1-cell (T H. Th. T helper cell) A T-Iymphocyte that histogram In statistics. is a graphical method used to helps B-lymphocytes during antibody formation. They are display and analyse an observed sample of data. commonly involved in delayed hypersensitivity. as an aid in judging the population frequency distribution hemolysis The term for haemolysis in the USA. underlying that of the sample. The frequency of the number Henderson-Hasslebach equation At equilibrium. of observations (j) is plotted against intervals in the sample relates to the proportions of dissociated and undissociated or population variable (x). such that the area of the weak acids/bases to the pH of the solution. rectangles is proportional to the number of obsr lations that heparin A sulphonated proteoglycan present in mast cells it contains, and the total area is 100%. The term . ,ometimes and also used as an ANTICOAGULANT. (incorrectly) applied to graphs that are (discon' 1 bar hepatic Pertaining to the liver. diagrams or columns of data not related to di os. hepatitis Inflammation of the liver. with accompanying histology The study of the chemical comI dOll and damage or death of liver cells. It may be due to infection (e.g. structure of tissues in relation to their functiu". viral hepatitis), toxic substances or immunological histones One of a group of major basic pr. ein \. hich are abnormalities. There are several types of infectious hepatitis: components of chromatin. hepatitis A (infectious hepatitis) is mainly transmitted by HIV human immunodeficiency virus. faecal-contaminated food; hepatitis B (serum hepatitis) is HLA human leucocyte antigens. transmitted by infected blood, needles and sexually; further hnRNA heterogenous nuclear RNA. forms are hepatitis C (non-A. non-B hepatitis), hepatitis D Hodgkin's disease A lymphoma, a can, ,rising in and hepatitis E. Prevention by immunization is lymphoid tissue including lymph nodes and \ spleen. recommended for those at risk, and treatments include Hofstee plot A plot formerly used in analysis of the avoidance of alcohol and occasionally the use of INTERFERONS. activity of an enzyme in catalysing a reaction. It plots the rate HEPES A zwitterionic pH buffer used especially for tissue of reaction (v) on the y-axiS against the relative rate of culture. reaction (v/ s. where s is substrate concentration) on the x• herpes An inflammation with blistering of the skin or axis. The intercept on the x-axis is an estimate of the mucous membranes. caused by the herpes virus. Herpes maximum reaction rate (\I). simplex virus (HSV) is of two sorts: type I causes the homeostasis The physiological mechanisms that common cold sore around the lips (which is contagious by maintain the internal state of the body.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 317 homo- A prefix denoting same. to allergens, e.g. where a primed individual on exposure to homogenate A finely divided and mixed tissue the antigen gives an exaggerated immune response. See Type preparation. I-]V hypersensitivity. homologous A fundamental similarity. hypersensitivity reactions Inappropriate immune homologous desensitization See desensitization. reactions. Inappropriately deployed T-cell activity underlies homologous series In chemical terms, a series of hypersensitivity reactions. See type I; type II; type II]; type analogues that are closely related in chemical structure, and ]V hypersensitivity. are often explored in discovering optimal properties for hypertension Higher than normal blood pressure for a development into drugs. person of that age. WHO defines hypertension as a blood homology Resemblance by virtue of common descent. pressure consistently exceeding 160/95 mm Hg homomeric receptor Receptors composed of two or (systolic/diastolic). However, since there is a considerable more identical subunits. range of blood pressures for a population group, high blood homoscedastic In statistics, where the variance of one pressure in itself may not denote hypertension. but a rising variable is constant. Conversely, heteroscedastic is where the pressure with secondary pathology usually is an indication variance changes with the magnitude of the other variable. for treatment. Clinically, hypertension is divided into a The former situation allows for easier analysis. number of disease states each with different aetiology. homozygote An individual who has two identical alleles Essential hypertension is the most common, and here the at a locus. A person who is homozygous for a recessive dis• determinants of the disease are not well understood. Renal ease gene (e.g. cystic fibrosis) will be affected by that disease. hypertension has its origins in kidney disease (e.g. narrowing hormone A mediator released into the blood from a of the renal arteries). Phaeochromocytoma is characterized ductless gland of the endocrine system to mediate its effect by episodes of extreme hypertension due to release of at highly specific receptors distant from its site of release. adrenaline and noradrenaline from a tumour of adrenal Also, mediators released by exocrine glands from ducts and gland tissue. Other specific causes of hypertension include canals are termed exocrine hormones. See also local Cushing's disease and pre-eclampsia. Treatment depends on hormones. cause. See ANTIHYPERTENSIVES. host In parasitology, the larger partner in a host-parasite hyperthermia Elevated body temperature. relationship: in medical usage normally humans. hyperthyroidism Overactivity of the thyroid gland, with HPLC high pressure/performance liquid chromatography. elevated levels of thyroid hormones (THYROXINE) in the HRT hormone replacement therapy. bloodstream. See goitre. Human Genome Project An international project hypertrophy An increase in·the size of an organ or tissue concerned with mapping and sequencing the complete brought about by an increase in the size of its cells, as with human genome. See Genome Project. muscles after exercise (rather than of number, as in tumours humoral mediated immunity See immune response. or hyperplasia). See also neoplasm. hybrid Offspring of genetically dissimilar parents. In hypo- A prefix in medical terms denoting below normal. recombinant technology, the method used to produce DNA hypoglycaemia Abnormally low levels of blood glucose. molecules composed of segments of different origin. hyposensitization See desensitization. hybridization The joining of two complementary hypotension A lower than normal blood pressure. sequences of DNA (or DNA and RNA) by base pairing However, since there is a considerable range of blood single-stranded nucleic acids, e.g. from different sources. See pressures for a population group, low blood pressure in itself in situ hybridization. may not denote any pathology. It is more normally seen as an hydrophilic Having affinity for water. acute medical condition due to excess loss of body fiuids (e.g. hydrophobic Having repulsion for water. in burns, vomiting and diarrhoea) or blood (e.g. hyper- A prefix in medical terms denoting above normal. haemorrhage). There are a number of other causes, including hyperalgesia Increased sensitivity to pain. myocardial infarction, Addison's disease, pulmonary hyperbolic curve I relationship An important curve embolism. Postural hypotension (othostatic hypotension) is in pharmacology because it commonly describes the a temporary fall in blow pressure when the subject rises from relationship between the concentration of a drug and the a supine position, and is due to impaired physiological biological response. In receptor pharmacology, this compensa tory reflexes. Many drugs can cause hypotension as relationship is predicted for the simple binding of agonists at part of a serious adverse drug reaction, or as a minor side• receptors. The logistic equation can be used to fit effect. Many antihypertensives cause postural hypotension or hyperbolic curves to concentration-occupancy and periods of hypotenSion. concentration-response data, allowing estimation of hypothermia Reduced body temperature. parameters equivalent to the location, slope and maximum hypotoniC 1. Abnormally low muscle tension or strength. response of the logistic relationshi p. See also Black & Leff 2. Lower osmotic strength than physiological salt solution. model; Langmuir equation; logistic equation; semilog plot. i.a. intraarterial drug administration. hyperkinesis A state of overactive restlessness in children. lAP islet-activating protein (Pertussis toxin). hyperplasia An increase in the production and growth of iatrogeniC disease is produced as a result of medical or normal cells in a tissue, where the organ becomes bigger but drug treatment (e.g. as a result of an adverse drug reaction). retains its form. See also hypertrophy; neoplasm. IBD inflammatory bowel disease. hyperpolarization Where the cell membrane potential IBS irritable bowel syndrome. is increased, i.e. made more negative. ICE I. interleukin-l ~ converting-enzyme. 2. 'street' name hyperreactivity See hypersensitivity. for methamphetamine. hypersensitivity In pharmaCOlogy, when a response ICH International Conference on Harmonization (drug occurs at lower than normal dose. In immunology, the term regulatory requirement). often is used to denote a state of being abnormally sensitive ICso A potency measure of the inhibitory action of drug or

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 318 Appendix A ligand, in terms of the concentration of ligand to produce immunity: active immunity can be stimulated by vaccination, inhibition of control response to 50%. Inhibition may be of a and passive immunity by injection of antibodies in antiserum functional response, or of radioligand-binding. Under most or transfer of maternal antibodies across the placenta. conditions it is an essentially empirical measure since the immunization The means by which an organism is control level is arbitrary: also an IC so estimate is a function rendered immune to a specific communicable disease, either of the slope of the inhibition curve. However, in radioligand• by active immunity or passive immunity. binding, the displacement IC so may, via the Cheng-Prusoff immunoassay A method of quantifying amounts of a equation, be used to calculate the K; which under defined substance, e.g. protein or other antigen. conditions is equal to the Kd of the ligand. immunocompetent Where the immune system of an ICso inhibitory concentration 50%. individual is fully operative. ICV intracerebroventricular drug administration. immunocompromised A term that refers to a person IDDM insulin-dependent diabetes mellitus. whose immune defences are much lower than normal due to idiosyncratic response See adverse drug reaction. either a congenital (present at birth) or acquired condition. idiotype The segment of an antibody molecule that is The commonest deficiencies are: of certain of the white cells responsible for its antigenic specificity. (neutrophils) which are the first line of defence in acute lED individual effective dose. infections: of the white cells, macro phages and IEP isoelectric point. T-lymphocytes, which are involved in cell-mediated killing of Ig immunoglobulin. foreign, or 'parasitized' host cells: and of the antibodies. IgA - immunoglobulin A A type of immunoglobulin immunodeficient (immunodepression) The state where that is produced by certain lymphoid tissues secreted in the immune system of the individual is to some extent saliva, tears, milk. There are two subclasses: IgA\ and IgA2. depressed or deficient. IgD - immunoglubulin D An immunoglobulin that immunodepression See immunodeficient. appears as a surface-bound immunoglobulin on B cells immunoelectrophoresis See electrophoresis. before and in conjunction with IgM. immunofluorescence A technique where fluorescent IgE - immunoglobulin E An antibody i!1volved in dyes. used as markers. are attached to antibodies in order to local inflammatory reactions. Binding of antigen to IgE detect antigens. bound to receptors on mast cells and basophilleucocytes immunogen A substance that can stilTllllate an immune leads to release of all contents, including heparin, histamine response. and leukotrienes. immunoglobulins (Igs) A class of proteins syntheSized IGF insulin-like growth factor. by B-Iymphocytes of the immune system which includes all IgG - immunoglobulin G The main immunoglobulin the antibodies. They exist both membrane-bound on the type to be produced at the end of a primary immune surface of the B cells. where they act as receptors for response and in a secondary response. antigens. and as antibodies secreted during an immune IgM - immunoglobulin M (macroglobulin) The first response. They consist of two identical light chains and two class of immunoglobulin produced in a primary immune identical heavy chains. The class includes IgA. IgD. IgE. IgC. response. IgM is a complement-fiXing antibody. and IgM. immediate early genes A group of genes including immunology The study of the immune system. c-myc, c-fos and c-jun that are rapidly and tranSiently immunostimulant An agent that enhances induced in a response to agents that induce cell division. immunological processes. They all code for proteins that are involved in regulation of immunosuppression The production of immuno• transcription. defiCiency by artificial means (e.g. radiation or drugs). immediate hypersensitivity See type I immunosuppressive An influence (e.g. an hypersensitivity. IMMUNOSUPRESSANT) that depresses the function of the immortalized cell line Cells in vitro that continue cell immune system. Some such drugs may be used in division indefinitely. therapeutics to maintain survival of transplanted organs (e.g. immune complex A complex of antigen-antibody and methotrexate: cyclophosphamide: cyclosporin: complement. If the complex is deposited in blood vessels, mycophenolate mofetil) or to treat some autoimmune activation of the complement pathway results in diseases such as rheumatoid arthritis (e.g. corticosteroids. hypersensitivity reactions. such as prednisolone: azathioprine). immune response The selective response of an implant A form of drug depot administration where a organism which is a consequence of activation of the solid formulation of the drug is given at intramuscular or immune system by antigens. Specific antibodies (humoral subcutaneous sites. The commonest example is mediated) or cytotoxic cells (cell mediated) are produced in contraceptive hormone drugs. response to foreign substances, e.g. parasites, or transplanted inactivated vaccine A suspension of killed organs perceived by the body as foreign. microorganisms used as antigens to produce immunity. immune response genes (lr genes) A group of genes incapacitating concentration 50 (le,o) The of the major histocompatibility complex that are involved concentration of smoke or gas that incapacitates 50% of test in determining the degree of immune response. animals in a set time. immune system The cells, tissues and mediators that inducer T·cell A T-Iymphocyte that is involved in the enable an organism to initiate and maintain an immune activation of regulatory cells. such as initial stage suppressor response, to protect the body from infection. T-cells. The term is sometimes applied to those T-cells which immunity A state of protection against infection and activate other effector cells and B-cells. disease through the activity of the immune system, composed inducible A protein or gene whose synthesis is stimulated of circulating antibodies and white blood cells. by a specific inducing agent. Therapeutically, immunization can be used to boost the infarction Death of part or all of an organ.

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infection The outcome of the interaction of host and International Pharmacopoeia (Int. P) The microbe that results in some observable, normally pharmacopoeia of the World Health Organization, a detrimental, change, formulary intended to meet international needs. inferior Lower in the body in relation to another structure. interneuron A neuron in the eNS synapsing between inflammation An acute or chronic bodily reaction to sensory neurons and motor neurons in a typical spinal chemical, physical injury or infection. It is characterized by reflex arc. the 'cardinal signs': calor (heat); rubor (redness); dolor (pain); inti ma The inner layer of an artery or vein or organ. and tumor (swelling). Inflammation is initially protective, intolerance When there is a greater than expected but chronic inflammatory diseases can be incapacitating. See reaction to a drug. The term hypersensitivity is preferred. ANTIINFLAMMATORY AGENTS; CORTICOSTEROIDS. intradermal Injections made into the skin. See routes of infusion The continuous administration (by injection) of administration of drugs. a drug or fluid, over a period of minutes, hours or days. intracellular Within a cell. inhibitor An agent that prevents or reduces a given intradermal Within the dermis of the skin. process or reaction. intraluminal Within the lumen of a structure. inhibitory amino acids See amino add transmitter. intramolecular Occuring within a molecule. iniation codon (start codon) A codon (usually AUG, or intramural Within the substance of the walls of an organ. GUG) that signals the first amino acid in a protein sequence. intramuscular Lying within or going into muscle. initiation factors Proteins that initiate transcription or intraocular Within the eyeball. translation of RNA during protein synthesis. intraocular pressure The hydrostatic pressure within INN International Nonproprietary Name. the eyeball. innate Pertaining to an inborn character, i.e. that intraparietal Within the wall of an organ, the parietal determined by genetic makeup. region of the cerebellum or the body wall. innate immunity Protection against infection because intraperitoneal (i.p.) Within the peritoneal cavity or of a pre-existing mechanism. See acquired immunity, peritoneum. innervation The nerve supply to an organ or tissue. intrathecal Injections made into the subarachnoid space inoculation A method used to confer active immunity of the spinal cord. This route is used to localize the actions of by injecting a living or mildly infective pathogen. WCAL ANAESTHETICS and ANALGESICS to certain segments of the inos inducible nitric oxide synthase. body supplied by sensory nerves originating from the area of inositol 1,4,5 triphosphate (IP,; insP,) A second injection. See also routes of administration of drugs. messenger produced by the action of phosphoUpase C on intravenous Going into or located in veins. See also the membrane phospholipid phosphatidylinositol which acts routes of administration of drugs. to liberate calcium ions from intracellular stores, following intravesical Within the urinary bladder. activation by a G-protein-activatated receptor. intravital Occuring while the organism or cell is alive. insertion mutagenesis Where a gene is altered by intravital stain A non-toxic dye that can be injected to insertion of an unusual nucleotide sequence. selectively mark cells or tissue. insertion vector A cloning vector having a single site at intrinsic activity A treatment by Ariens (1954) that which a sequence of exogenous DNA can be inserted, attempts to relate receptor occupancy and biological insomnia Inability to fall asleep or remain asleep for an response in a way that allows for the behaviour of partial adequate length of time. agonists, using the proportionality parameter intrinsic in situ In its original place. activity (a), such that R = u.p; where R is the biological in situ hybridization A technique where a labelled response, and p is proportion of receptors occupied. Full probe is used to detect and locate any specific agonists are assumed all to produce a maximum with full complementary DNA or RNA sequence in a tissue section, receptor occupancy, so they have a = 1.0. Antagonists have cultured cell or cloned bacterial cell using radioactive nucleic no intrinsic activity, so a = O. Partial agonist have a values acid. Its position can be determined by autoradiography. between 0 and 1.0: for instance a partial agonist producing insufflation The administration of a drug by blowing 50% of maximum response has a = 0.5. This concept has into a cavity. been refined in the definitions of efficacy and intrinsic insurmountable antagonism A term applied by efficacy; however, it remains a useful shorthand for denoting Gaddum to the behaviour of agonist concentration-response the maximum response to a partial agonist. See also agonists. curves in the presence of an antagonist; where suffiCient intrinsic efficacy An extension of the concept of efficacy increase in an agonist concentration can not fully surmount (e) by Furchgott (1965 onward) to separate drug-dependent the effect of the antagonist, and the maximum response is parameters and tissue-dependent parameters inherent in the depressed: the opposite of surmountable antagonism. Such previous formulation of efficacy. Intrinsic efficacy (e) is an operational description of behaviour is preferable in defined in the equation e = E. (RJ where R, is receptor density. pharmacology to the use of terms such as non-competitive in See also agonist; B_; efficacy; intrinsic activity. instances when, in reality, nothing is known of the intrinsic nerves Of an organ, those nerves with their cell mechanism of action of the antagonist. See also antagonism bodies within the organ, i.e. nerves that do not completely - pharmacodynamic. degenerate after denervation of the organ. integrins A family of cell-surface transmembrane intron Noncoding segment of a DNA which separates two receptor proteins which have functions in regulation of cell of the coding sequences. See exon. adhesion and migration. inverse agonist A term used particularly to describe the interferons A group of inducible cytokines synthesized effects of certain benzodiazepines, to indicate the behaviour in response to viral and other stimuli. of analogues that though activating receptors, have the interleukins A group of mediators within the cytokine opposite action to normal benzodiazepine agonists (e.g. are group. anxiogenic rather than anxiolytic).

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in vitro A term used to describe biological actions more easily prepared are often used in medicine even when observed under artificial conditions of tissues or cells in the main pharmacological activity resides only in one isomer laboratory glassware (e.g. organ-bath or culture-medium). (though sometimes toxicity may reside in the other). involuntary muscle A muscle not under voluntary isometric contraction Where muscle tension is control. See cardiac muscle; smooth muscle. increased, but the muscle is not shortened. ion channels Highly organized protein structures that isotonic contraction Where the muscle shortens span the cell membrane, providing a pore through which without generating any extra force. certain ions may pass. Voltage-gated ion channels may pass isotonic solutions Having equal solute concentrations, sodium, potassium, calcium or chloride ions depending on thus osmotic pressure. Often implicitly isotonic with human transmembrane potential. Ligand-gated ion channels form plasma extracellular fluid. See physiological salt solution. part of a neurotransmitter receptor and open or close on isotopes Atoms of the same element differing in the receptor occupancy, and pass certain ions depending on the number of neutrons in the nucleus. They differ very little in type of receptor. The effect of channels opening depends on chemical properties, but some unstable isotopes, the cell type and the intracellular and extracellular radioisotopes, emit radiation, and can be used in medicine concentrations of ions, but allowing sodium or calcium to for a variety of purposes. enter the cell normally causes depolarization and activation, -itis A suffix meaning inflammation, e.g. tonsilitis. but the opposite may hold for potassium and chloride. IUPHAR International Union of Pharmacology. ion exchange Adsorption of ions onto a resin in i.v. intravenous. exchange for others. JAN Japanese Accepted Name (for a drug). ion eXChange Chromatography A method used to joule The SI unit of energy. separate molecules using their different net charges to K+- channel See ion channel. differentially bind them to a column of, e.g. carboxylated kary- A prefix denoting a cell nucleus. polymer anions binding to the column. See Kb See kilobase. chromatography. Kbp See kilobase. ionic bond Electrostatic bond. KD See dissociation constant. ionophore A compound that can carry ions 'across a lipid Kelvin The SI unit of temperature. barrier, e.g. plasma membrane. K; The measure of displacing potency of a Iigand in ionotropic receptor A cell-surface receptor which has radioligand-binding assay: under appropriate conditions. an associated ion channel. equals KD.1t is commonly estimated from the ICso, using the ion pump A protein that transports an Ion across a Cheng-Prusoff equation. biological membrane against a concentration gradient by killer cell (k cell) A non-phagocytic cell related to active transport. macrophages and leucocytes that can lyse foreign cells in the iontophoresis A method of delivering drugs across the presence of antibody. skin using an electric current to drive electrically charged kilobase (Kb; Kbp) A unit of length of DNA equivalent to drug molecules. 1000 base pairs in DNA or 1000 nitrogenous bases in RNA. IP3 inositol 1.4,5 trisphosphate. kilodalton (K; kD; kdal) Unit of mass equal to 1000 IPSP inhibitory postsynaphic potential; post-synaptic daltons, or 1000 units of molecular mass. AbbreViated to K. membrane hyperpolarization. kinase An enzyme that catalyses the transfer of a Ir genes immune response genes. phosphate group. iridal Pertaining to the iris. kinesis Movement. ISA intrinsic sympathomimetic activity. kingdom A taxonomic group corresponding to division ischaemia Reduced blood supply. in botany. isoelectric point (IEP) The pH at which an amphoteric Km Michaelis constant. molecule, e.g. a protein, carries no net charge. knock-out See gene knock-out. isomers These forms of a chemical can be cig trans• Kruskal-Wallis test A (nonparametric) significance isomers or optical isomers. Cig trans-isomers differ in their test to compare the medians of three or more unpaired arrangement about rigid bonds (trans- is where identical sample groups. The null hypothesis is that all group medians groups are on opposite sides of the bond, and cis- when on are equal. the same side). They have different chemical properties as Kupffer cell A phagocytic cell lining the hepatic well as different biological properties. Optical Isomers sinusoids. (enantiomers) are stereoisomers that are mirror images of kymograph An instrument that records physical one another, and rotate polarized light in opposite directions variables, e.g. blood pressure. muscle tension. (Jaevoand dextra-isomers; 1- and d- or (+)- and (-)-isomers). labelled A molecule that can be detected and traced by In general, isomers are possible when molecules show virtue of it having a radioactive element or other detectable chirality, that is, 'handedness' such that the molecule cannot chemical attached to it. be superimposed on its mirror image, e.g. due to four labelling Techniques for detecting the presence and different groups being attached to one carbon atom. Two movement of molecules. e.g. by using radioactive isotopes such isomers can be described by an unambiguous notation for autoradiography or in situ hybridization. system as either' /? or'S (for rectus or sinister). They have laevo- (Ievo-, USA) A prefix denoting left. identical chemical properties except when they interact with laevo-isomer See Isomers. other molecules that are themselves chiral, e.g. in biological Langendorff preparation An isolated heart systems. Not all molecules show chirality, e.g. glucose is preparation used to test drug effects on heart rate and chiral but ethanol is not. Only one chiral form of glucose contractile force. occurs naturally. Racemic mixtures are a mix of equal Langmuir equation (Langmuir adsorption isotherm) amounts of optical isomers (denoted ± or d/ ~ and being An equation (Langmuir, 1918), originally formulated for

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 321 adsorption of gases, describing the hyperbolic relationship inhibition of the cell. See ion channels. between the proportion (p) of binding sites (receptors) that ligases (synthetases) Enzymes that catalyse covalent bond are occupied at equilibrium by a ligand (drug) according to formation using energy obtained from cleavage of a the affinity (Kd; the equilibrium dissociation constant) and pyrophosphate bond, such as in ATP. concentration (x) of that ligand: viz. p ~ x(x+KJ. For a light chain The smaller of the two polypeptide chain simple \:\ relationship of ligand and binding at the receptor, types that are present in an immunoglobulin monomer. the Langmuir equation is the same as the Hill equation. linctus A medicated syrup that is thick and soothing late gene A gene expressed late in the life-cycle. enough to relieve sore throats or loosen a cough. Latin square design A systematic method of allocating linear regression See regression analysis. treatments in a block design, with the object of minimizing Lineweaver-Burk plot A form of double-reciprocal confounding. For instance, ih a 4x4 Latin square to study the plot used in analysis of the activity of an enzyme in effects of low and high doses of two drugs, all four catalysing a reaction. The reCiprocal of the reaction velOCity combinations are given in each row of a block design, but is plotted against the reciprocal of the substrate each row contains a different order. concentration. The intercept of the fitted line gives the law of mass action States that a chemical reaction reCiprocal of the Michaelis-Menten constant. A similar proceeds at a rate that is proportional to the active mass treatment can be applied to drug dose-response (molar concentration) of the reactant substance (or the relationships, but is less satisfactory than some other product of the active masses of reactants when there is more methods because of statistical uncertainties in the weighting than one). The law applies to the reaction of drugs with of experimental points. proteins, including receptors or enzymes. liniment A medicated lotion for rubbing into the skin. LO lethal dose. Many of them contain ethyl alcohol and/or camphor, and are LOs. Denotes the lethal dose that kills 50% of a sample of intended to relieve minor muscle aches and pains. experimental animals, and as such is a statistically acceptable linkage The tendency or degree to which alleles of two or measure of acute toxicity, though not necessarily a very more given genes are inherited together. Linked genes occur meaningful pharmacological or clinical measure. on the same chromosome and are said to constitute a LOL low-denSity lipoprotein. linkage group. least-squares methods Techniques for minimizing linkage group See linkage. errors in obtaining best estimates of parameters. These linkage map A map of the relative positions of the gene methods minimize the sums of the squares of the deviations loci on a chromosome which is deduced from the frequency of the imperfect data points from the fitted line or model with which they are inherited together: distances of which relationship. are measured in centiMorgans. leishmaniasis A protozoan disease (genus Leishmania) linkage mapping Chromosome mapping determining common in the tropics and transmitted by sandfiies. the relative pOSitions of known genes in a linkage group. lethal dose (LD) A dose of a chemical that kills all test lipophilic Having affinity for lipids. samples/animals in a given time. See also LDso. lipopolysaccharide (LPS) A molecule that consists of a lethal gene A gene that, under certain conditions, causes lipid linked to a polysaccharide. death of the individual carrying it. lipoprotein A micellar complex of protein and lipid, e.g. leucopenia A condition when there is a low level of cholesterol. leucocytes (white blood cells) in the bloodstream. It may be liposomes A drug-delivery system comprised of small caused by an adverse drug reaction. vesicles of phopholipid-protein membrane with an aqueous leucocyte (leukocycte; white blood cell) A nucleated drug-containing interior. They may allow absorption from blood corpuscle that lacks haemoglobin; includes the intestine, and thus administration of substances such as monocytes, granulocytes (neutrophils, eosinophils, the peptide insulin, that would otherwise be digested. Also basophils) and lymphocytes (T- and B-cells). liposomes may reduce the toxicity of substances leukaemia A malignant growth, a cancer where abnormal administered intravenously. white blood cells proliferate in the bone marrow. lipoxygenase Soluble enzymes located in the cytosol leukocyte See leucocyte. that catalyse addition of an oxygen molecule to the double leukotriene Mediators formed from arachidonic acid as bonds of some unsaturated fatty acids, or their derivatives; a result of the action of 5-lipoxygenase on arachidonate, and e.g. 5' -lipoxygenase which is the first enzyme in the synthesis released during innammation. of leukotrienes. leva- A prefix denoting left. live vaccine A vaccine made from active but non• LH LUTEINIZING HORMONE. pathogenic viruses. library A collection of cloned DNA fragments representing In natural logarithm. either all expressed genes, a cDNA library, or a whole local (action of drugs) Where application or injection is genome, a genomic library. such that drug action is limited to a certain area of the body, ligand This term has various uses, particularly for in contrast to systemic action, where the drug passes into the molecules that bind to receptors, and radioactive atoms or blood circulation and thus has a general action. See also molecules that bind to sites (radioligand binding). routes of administration of drugs. ligand binding assay A technique used to assess the local hormones Mediators released and acting locally, characteristics of receptors using radioactively labelled drug rather than blood-borne as with endocrine hormones. Most molecules. See displacement (competition) analysis; are paracrine agents (released from one cell to act at a second saturation analysis. cell), rather than autocrine agents (released by a cell to act ligand-gated ion channel Receptor - ion channel on the same cell). The term is used largely synonymously complex that opens or closes in response to binding of with autacoid. Examples include HISTAMINE, NITRIC OXIDE specific ligand molecules, thereby causing excitation or and the prostaglandins.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 322 Appendix A location parameter A term referring to left-right MAC minimum alveolar concentration (for drug vapour). position of curve on the x-axis. For functional responses, it macerate To wear down or soften, e.g. by digestion. will be the position on concentration-response curve macro· A prefix meaning large. estimated in terms of EC so or log EC so. For receptor• macroglobulin See IgM. occupancy relationships, it can be the KD or log KD. macromolecule A molecule of very high molecular log See logarithm. weight, e.g. protein. logarithm A power to which a fixed number (base) must macrophage A large phagocytic mononuclear leucocyte be raised to produce a given number. scavenger cell present in connective tissue and many organs. logarithmic transformation A transformation can major gene A gene that is individually associated with be used for a number of purposes, including to linearize or pronounced phenotypic effects. simplify a relationship, or to normalize variances. For dose• major histocompatibility complex A multigene response lines, if the logarithm of the dose is used, then a cluster that encodes for cell surface glycoproteins. the hyperbolic curve is transformed to a symmetrical sigmoid glycoproteins are involved in the cellular immune response curve which is easier for display and analysis. The Hill plot to distinguish self from non-self. is a double-logarithmic form to linearize the curve and allow malaria An infectiOUS parasitic disease caused by parameter estimation. Where a frequency distribution is Plasmodium spp. prevalent in tropical and subtropical skewed-to-the-right (as when the true distribution is log• regions, spread by mosquitos. normal, which is common in pharmacology)' then working malignant In general, a term that describes any condition with the logarithms of the data values will tend to normalize in the body which if untreated may be a threat to health (e.g. variances. malignant hypertension). Specifically, it is used to describe logistic equation An equation that can be used to fit any condition that tends to become progressively worse and hyperbolic curves; in pharmacology, particularly to results in death, and is mainly used for cancerous tumours. concentration-response and concentration-occupancy manic·depressive illness A disorder characterized by curves. Parameters equivalent to the location, slope and disturbance of mood, most commonly bipolar (depression maximum response of the logistic relationship can be alternating with mania). estimated. The ability of microcomputer programs to Mann-Whitney test This is a (nonparametric) iteratively fit these three parameters simultaneously, has significance test to compare the median of two unpaired resulted in a reduced use of graphical devices such as sample groups. The null hypothesis is that the two population transformations. medians are equal. A Pvalue for this hypothesis is calculated logistic regression analysis Using the logistic from the sample size and the sum of ranks in each group. This equation to fit binding data or dose-response curves directly test assumes that the data are representative or randomly without using a transformation to a linear form. sampled from two populations having identically shaped logit See regression analysis. distributions (which do not need to be Gaussian). log·normal distribution See normal distribution; MAO monoamine oxidase (enzyme). transformations. MAO! MONOAMINE-OXIDASE INHIBITORS. lotion A medicated liquid used to bathe or wash skin, the MAP microtubule-associated protein, or mitogen• hair or eyes. associated protein. lozenge A hard, often sweet and flavoured, base map distance The relative distance apart of two gene containing a medicament. They are intended to be slowly loci on the same chromosome. dissolved in the mouth to treat local irritation or infection. MAP kinase serine-threonine protein kinase: an enzyme LPS lipopolysaccharide. whose activity is stimulated by the action of mitogens and LTP long-term potentiation. growth factors. Involved in phosphorylation of lupus erythematosus An autoimmune disease; a transcription factors and consequent stimulation of gene chronic inflammatory condition of the connective tissue. expression. Treatment is with NSAID ANALGESICS or IMMUNOSUPRESSANTS. mast cell A granular leucocyte derived from myelOid Lyme disease A disease caused by a bacterium tissue, having granules containing mediators including (spirochaeta, Borrelia burgdorferi) transmitted by the bite of HISTAMINE, 5-HYDROXYTRYPTAMINE, HEPARIN and TNF«. tick that lives on deer and can also infest dogs. It causes acute Degranulation occurs when an allergen cross-links IgE. inflammation at the site of the bite, followed by headache, matched·pairs t·test In comparing two treatments, the lethargy, fever and muscle pain. There can be serious chronic confounding effects of between-subject variability can be symptoms. Treatment is with ANTIBIOTICS. minimized by matching subjects as closely as possible, or lymphocyte A type of agranulocyte leucocyte. An ideally by using subjects as their own controls. In a matched• immunologically competent cell which recognizes antigens, pairs t-test, matched data are arranged in rows: and comprises B-lymphocytes and T-lymphocytes and occurs treatments in two columns. In analysing the two related in the spleen, blood and lymphatic tissue. samples, the null hypothesis is that the two population Iymphokine A non-immunoglobulin oligopeptide, a means are equal. The paired t-test first computes the cytokine synthesized by T-lymphocytes. It acts to modulate difference between columns for each subject (row), and for an immune response. this single sample the null hypothesis is that the mean of lymphoma A malignant disease, a cancer arising in these differences equals zero. A Pvalue for this is calculated, lymphoid tissue (mainly of the nodes and spleen), including together with the 95% confidence interval for the mean Hodgkin's disease. difference. With this treatment, the analysis is exactly lysis Dissolution or break down of a cell through damage equivalent to the one-sample t-test. The paired t-test to its cell membrane allowing escape of the cell contents. assumes that the data on each row are repeated lysosome A cytoplasmic particle that contains enzymes. measurements on the same subject or measurements on It has a role in intracellular digestive processes. matched subjects (e.g. matched for age and gender). The test

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 323

also assumes that the differences in the overall population of the membrane's selective permeability to ions. and the follow a Normal distribution. different concentrations of ions determined by the activity of matched-pair study See case-control study. ion pumps. maximum response The maximum responses to memory cells Lymphocytes that respond quickly to agonists at a given receptor to give a graded response. antigen because of being primed through a previous contact. depends on efficacy: full agonists give the same maximum meninges The membranes that cover the brain and spinal and partial agonists. by definition. give a smaller maximum. cord. The maxima of concentration-response curves is thus a meningitis Inflammation of the membranes covering variable that must be estimated experimentally to allow the brain and spinal cord (meninges). commonly through calibration of the y-axis in terms of per cent of maximum. or infection by bacteria or viruses. before some linearizing transforms (e.g. the Hill plot) can be mepp miniature end-plate potential. used. The maximum can best be mathematically estimated. messenger ribonucleic acid (mRNA) The linear along with the location parameter and slope. using the sequence of nucleotides that is transcribed from a single logistic equation. strand of DNA. to which it is complementary. It carries the MCA Medicines Control Agency (UK). information for protein synthesis to the ribosomes. M-CSF macrophage-colony-stimulating factor: a protein messenger RNA (mRNA) See messenger ribonucleic growth factor that stimulates the growth of monocytes and acid. macrophages. meta-analysis An analytical technique for collecting and MCV hepatitis C virus. grouping results and conclusions from a number of clinical MOP (muramyl dipeptide) A component of a modified trials. form of Freund's complete adjuvant. metabolism The sum of the chemical activities in a cell mean (arithmetic. geometric. harmonic) The term is used that are involved in function. construction (anabolism). loosely to imply arithmetic mean (the sum of all the repair. breakdown (catabolism) and energy supply. observations divided by the number of observations). i.e. the metabolism of drugs The process whereby the body average. In statistics. if the values are sampled randomly detoxifies chemicals and excretes them as metabolites. from a Normal population. then the sample mean gives an metabotropic receptor A receptor that is G-protein unbiased estimate of the population mean. However. if the linked. often exclusively used to describe the non-ion underlying population is not Normally distributed. then the channel receptor for glutamate. arithmetic mean gives a biased estimate. and it is best instead methaemoglobin (metHG; methemoglobin. USA) An to estimate the median or the mode. If the underlying oxidized form of haemoglobin that is not able to carry frequency distribution is known to be log-normal (e.g. EC 50 oxygen. so production of It can lead to toxic anoxia. Blood and Kd values). then the geometric mean will give a better can be converted (normally reversible) into this form by estimate. The geometric mean is obtained by averaging the drugs and chemicals (e.g. nitrates. nitrofurantoin). logarithms of the values. then taking the antilogarithm of the methylene blue A dye used in experimental biology as a result. Similarly. the harmonic mean is used in averaging vital stain. reciprocals of values. methyl green A basic dye used to differentially stain mechanoreceptor (mechanoceptor) A speCialized RNA (red) and DNA (green). sensory structure that responds to mechanical changes in the me-too drug A slang term for a medicine developed by a environment. e.g. tenSion. movement. pressure. manufacturer to obtain a share of a (lucrative) market. but MEO minimum effective dose (of a drug). which does not represent any advance in its actions over medial Situated towards the midline of the body. earlier drugs. median The median of a sample is the middle or central MHC major histocompatibility complex. value when all values in a sample are arranged in order of MIC minimum inhibitory concentration. magnitude. It provides a less biased estimate of the popula• micelle A structered aggregation of molecules that occurs tion mean than the arithmetic mean when the underlying at high concentrations of certain surface-active agents (e.g. distribution is not known. or is known not to be Normal. bile salts). Medians (sample and popUlation) are used in the calcula• Michaelis-Menton equation/kinetics This tions of many nonparametric variants of significance tests. equation. which is central to enzymology. describes the mediator A chemical released or formed by cells in relationship between the initial rate of reaction (v) and the response to a stimulus that exerts an effect on another. or the substrate concentration (C). It gives the initial rate of same cell type. e.g. autacoid. hormone. neurotransmitter. reaction as v = Vmax C/(Km+C); where Vmax is the maximum Medicines Control Agency (MeA) Part of the UK velocity of reaction. C is the concentration of substrate and drugs regulatory system that administers the Medicines Act. Km is the Michaelis-Menton constant. C is equal to the acting on evidence received advice from the Committee on Michaelis-Menton constant when vis 50% of Vmax . Safety of Medicines (CSM). micro- A prefix meaning small. mediodorsal In the dorsal midline. microbe A microorganism that is too small to see with the megabase (Mb) A unit of length of DNA equivalent to naked eye (e.g. bacterium. virus. protozoan. some fungi). 1 million nucleotides. The shortest human chromosome microbiology The study of microorganisms. (number 21) is about 50Mb long. the longest (number 1) microcirculatory system The vessels of the blood and about 250Mb. lymphatic system which are visible only with a microscope. megakaryocyte A cell in the bone marrow that micrograph (photomicrograph) A photograph of an produces platelets. image viewed through a microscope. -megaly A suffix denoting enlargement. microinjection Injection of cells using a micropipette. membrane potential The electrical potential micrometer In light microscopy. a device to measure a difference that exists across an excitable membrane because specimen. e.g. ocular micrometer. slide micrometer.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 324 Appendix A micrometre (micron) ~m 1O·'m monocyte A type of phagocytic agranulocyte leucocyte. microtome An instrument used to cut extremely thin Its function is the ingestion of foreign particles. slices of a material (e.g. tissue) which is usually embedded in monomer A molecule composed of a single unit, such as a a medium such as wax. protein composed of a single polypeptide chain. See MID minimum infectious dose. oligomer. MIF macrophage migration inhibition factor: a protein Monthly Index of Medical Specialities (MIMS) produced by activated T-Iymphocytes which prevents the A comprehensive compendium of drugs that is available to movement of macrophages. CPs, pharmacists and other health professionals. migratory cells These are cells, such as leucocytes and morbidity Diseased state, normally expressed as a macrophages, that enter tissues from the bloodstream. morbidity rate. See mortality. -mimetic A suffix meaning to imitate or mimic, e.g. morphology The structure and form of an organism or SYMPATHOMIMETICS are agents that mimic the actions of the structure. sympathetic nervous system. mortality The incidence of death in a population per MIMS See Monthly Index of Medical Specialities. year, usually expressed as mortality rate (per 10.000). minim A unit of volume used in pharmacy equivalent to motoneuron See motor neuron. '/" part of a fluid drachm. motor When applied to nerves, refers to those that carry miosis Constriction of the pupil of the eye. impulses from the CNS (efferent) to bring about an effect. misuse of drugs A term referring to inappropriate use e.g. in a gland or muscle. of drugs, e.g. unethical uses. See abuse of drugs. motor end-plate (neuromuscular junction) Where the mitogen A compound that stimulates cells to undergo motor neuron terminates in close contact with a skeletal mitosis non-specifically. muscle fibre. mixed nerve A nerve containing both sensory (afferent) motor neuron A neuron carrying impulses away from and motor (efferent) components. the CNS to an effector. mixed spinal nerves Spinal nerves after union of the motor unit A motor neuron and associated muscle fibres. ventral (efferent) and dorsal (afferent) roots. MR modified-release (formulation of drug). MLD (minimal lethal dose) The smallest quantity of a toxic Mr relative molecular mass. compound that has been recorded to cause death. MRC Medical Research Council. modality Relating to statistical mode. MRI magnetic resonance imaging (or scanning). mode Most commonly the occurring value in a sample. MRL maximum residue limit. modified-release preparation (sustained-release mRNA messenger RNA. preparation) Usually a tablet or capsule designed to release MRT mean residence time (drug turnover time). its active constituents over a period of time. See also routes mucosa The lining of the gut. consisting of three layers: of administration of drugs. the inner epithelium; lamina propria: muscularis mucosae. modifier gene A gene that alters the phenotypic mucous membrane (mucosa) The moist membrane expression of a non -allelic gene. lining internal structures, e.g. respiratory tract. mol mole. mucus The fluid secreted by mucous membranes. mole (mol) The 51 unit of the amount of a substance which multi determinant Antigen carrying more than one contains as many elementary units as there are atoms in antigenic determinant. 0.012 kg of 12c. One mole of a substance has a mass equal to multidrug resistance Where a number of organisms its molecular weight in grams. have acquired resistance to antibiotic or other antibacterial molarity (M) The concentration (strength) of a solution. It agents. each with a different mechanism of action. and thus is expressed as the weight of dissolved substance in grams per are multi drug resistant. litre divided by its molecular weight to give moles per litre. multi gene family Similar but not identical genes. Le. molar solution A solution where the number of grams haVing a higher level of base sequences in common that of dissolved substance per litre equals its molecular weight, encode for different but related proteins; thought to have so the concentration is 1M (one molar), Le. I mole of solute arisen from duplication and divergence of an ancestral gene. per litre of solution. multipolar A nerve cell having more than two main molecular biology The study of biological phenomena cellular processes. at the molecular level. Recently, it has taken on special multispecificity Refers to the ability of a single type of meanings and is used particularly to denote the study of antibody molecule to combine with different antigens. genes, gene products and sometimes pharmaceuticals multivalent An antibody with more than one antigen• manufactured by processes using genetic materials. binding site. molecular mass The sum of the atomic masses of all the murine Pertaining to or derived from any member of the atoms in a molecule. See relative molecular mass. family Muridae. which includes mice and rats. Often applied molecular weight See relative molecular mass. to mice exclUSively. molecule The smallest unit of a substance that can exist muscle spindle A stretch receptor (proprioceptor) of independently and still have the properties characterisitic of muscle. that substance. muscularis mucosa The outer, smooth muscle layer of monoamine oxidase An enzyme that OXidatively the gut mucosa. deaminates intra neuronal biogenic amines. including the mutagen Anything (e.g. chemical) that increases the rate neurotransmitter catecholamines. of mutation in living cells. monoclonal antibody Antibody that has been mutagenesis The production of mutations, e.g. by produced by a single clone of B cells and which therefore X-rays or chemicals. consists of antibody molecules that are identical and specific mutant A cell or organism with altered genetic material for a single antigenic determinant. such that it differs from its precursor cell or parent. See

SMA.LL C,\PS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 325 mutation. marketing purposes and commonly in packaging. mutation A change in DNA sequence, ranging from an NANC non-adrenergic non-cholinergic (neuro• alteration in a single base (e.g. sickle-cell haemoglobin) to transmission): that component of response not mediated by loss or gain of chromosomal material (e.g. the Philadelphia noradrenaline or acetylcholine. POSSible mediators include chromosome in chronic myeloid leukaemia). The change in purines, e.g. ATP, and peptides, e.g. substance P. the chemical structure or amount of DNA results in a change nano 10- 9 in the characteristics of an individual cell or organism. The narcolepsy An extreme tendency to fall asleep in a quiet mutation results from alteration in the protein {or RNAs} environment, although such individuals can be easily roused. specified bt the DNA that has mutated. Treatment may be with CENTRAL STIMULANTS, e.g. mutualism An intimate but not necessarily obligatory dexamphetamine. association between two different species in which there is nascent Newly formed, e.g. of DNA or RNA material, or mutual aid and benefit (c.f. commensual, parasite, that part of a neurotransmitter pool. symbiosis). natriuresis Excretion of sodium in the urine. myalgia Muscle pain. natriuretic Causing a sodium loss into the urine (a myasthenia gravis An autoimmune disease where property of DIURETICS). antibodies against skeletal muscle nicotinic receptors are natural killer cell (NK cell) A large granular produced. lymphocyte which, when activated by INTERFERON, binds to mycology The study of fungi. and kills certain virally-infected cancerous cells. mycotoxins Toxins derived from fungi. nebulizer See aerosols. mydriasis Dilation of the pupil of the eye. NC cells Natural cytotoxic lymphocytes. myel· A prefix denoting the spinal cord, bone or myelin. NCE New chemical entity. myelin The material consisting of lipid and protein that necrosis The relatively uncontrolled process of cell death. forms the protective sheath around some nerve endings. Contrast with apoptosis. myelin sheath An insulating sheath wrapped in a tight NED normal equivalent deviate. spiral around a nerve axon formed of the membrane of negative staining A technique used in electron Schwann cell in peripheral nerves, or of oligodendrocyte in microscopy in which a specimen is surrounded by a heavy the CNS. metal stain. The result is to outline the shape of the specimen myelitis Inflammation of the spinal cord. and penetrate its surface clefts to produce a 'negative myelocyte A bone marrow cell. impression'. myeloma A malignant cancer of myelOid tissue. NEL no-adverse-effect level (chemical hazard). myenteric plexus (Auerbach's plexus) The nerve plexus neoplasm Any abnormal or new growth. Correctly, the that lies between the circular and longitudinal smooth term can be applied to relatively harmless swellings (benign) muscle layers of the small instestine. or cancerous (malignant) growths. Nevertheless, the term myo· Pertaining to muscle. neoplastic disease is often loosely taken as synonymous with myoblast A precursor cell of skeletal muscle fibres. cancerous growth. See hyperplasia; hypertrophy. myocardial infarction (heart attack) The sudden nerve block The interruption of the transmission of an death of part of the heart muscle, characterized by severe impulse through a nerve, e.g. with a local anaesthetic unremitting pain. It is usually caused by coronary injection. thrombosis, obstruction of the coronary arteries. nerve ending The structure on the distal end of a myocarditis An acute or chronic inflammation of the peripheral nerve. It may comprise a free nerve ending or a muscle of the heart (cardiac muscle). receptor organ. myocardium The muscular wall of the heart. nerve fibre The axon of a neuron and its myelin sheath if myocyte A muscle cell. present. myogenic Originating within muscle cells. nerve impulse The all-or-none response, comprising an myometrium The muscular uterine wall. action potential which is propagated along the length of an myosin An ubiquitous protein, especially in muscle fibrils, excitable cell, such as a nerve axon. having ATPase activity and which interacts with actin in, for nerve plexus A diffuse network of neurons and ganglia. example, muscle to form a contractile complex. nervous system The network of cells specialized to NAD+ (NADH) nicotinamide adenine dinucleotide (reduced carry information in the form of nerve impulses to and from form). all parts of the body. It comprises the eNS and peripheral NADP+ (NADPH) nicotinamide adenine dinucleotide nervous system. phosphate (reduced form). neural tube The embryonic tube that differentiates into Na+,K+·ATPase (Na'·K'pump) A plasma membrane protein the brain and spinal cord. with ATPase activity which by active transport moves Na+ neurobiology The study of the physiology, biochemistry, ions out of the cell, and K+ ions into the cell using energy morphology and development of the brain and nervous derived from ATP hydrolysiS. It sets up the ionic gradients system - the cellular and biochemical basis of brain function. across the membrane and maintains membrane potential. neuroblastoma A tumour of the adrenal glands or the names of drugs There are three main types. The sympathetic nervous system. Cultured cells derived from chemical drug name is the full name of the chemical that is neuroblastoma are used extensively in experimental biology, the active component, but has the disadvantage in medical e.g. electrophysiology. use that it is often very long and complex. The generic drug neuroendocrine Pertaining to both the nervous {neuro} name is the official 'trivial' official name (e.g. paracetamoI), and endocrine systems. and is used in normal medical prescribing and neuroendocrine cells See neurosecretory cells. administration. The proprietary drug name, the trade neurogenic Innervated by nerves or originating in name, is normally capitalized (e.g. Panadol), and is used for nervous tissue.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 326 Appendix A neurogenic inflammation Inflammation that is a NO NITRIC OXIDE (nitrogen monoxide) (mediator). consequence of released mediators from nerves. The term is nociception The reception. conduction and processing of often used to refer to the efferent function of primary noxious stimuli. Usually results in the sensation of pain. afferent nerves. nociceptive reflex A reflex that protects tissue from neuromodulator An endogenously released mediator injury. that modifies the effect of a neurotransmitter. nociceptive system See nocifensive system. neuromuscular junction The site at which a nerve nociceptors Sensory receptors located on afferent axon terminal contacts a muscle cell. neurons that detect noxious stimuli resulting from. for neuron (neurone; nerve cell) The major cell type that example. chemical or physical tissue damage. makes up nervous tissue. It is specialized for transmission of nocifensive system (nociceptive system) The neurons information in the form of nerve impluses. that are involved in nociception. neuropeptide Any of many small peptides that function non-equilibrium antagonist A term that has been as neurotransmitters. e.g. SUBSTANCE P. applied to antagonism where the antagonist binds essentially neurophysins Proteins that function to transport irreversibly to the receptor. e.g. phenoxybenzamine with hormones from nerve axons to the blood of neuroendocrine u-adrenoceptors. The affinity of such antagonists for the (neurosecretory) cells. receptor cannot be estimated. but they can be used in neuroplasm The protoplasm of nerve cells. receptor occlusion studies to estimate affinities of agonists. neurosecretion Release of mediators from neurons. See non-granular leucocyte A leucocyte with a clear neurosecretory cells. homogenous cytoplasm. neurosecretory cells (neuroendocrine cells) Nerve nonparametric A type of statistical test (a distribution• cells that release mediators that travel in the blood to their free test) that does not assume that the sampled data has a target cells. e.g. cells in the hypothalamus that act on the particular probability distribution (many assume. for pituitary gland. instance. approximation to a Normal distribution). However. neurotoxin(s) A loose group of toxins that act there will still generally be assumptions about random and predominantly to disrupt neurotransmission and other independent sampling. with the data being reasonably neural processes. Some original examples were exotoxins representative and with samples drawn from populations produced by microbes (e.g. tetanus toxin). but the term is with the same distribution (unknown). It may be noted that often extended to include natural toxins or venoms of diverse with sampling distributions that are noticeably skewed-to• structure from many animal and plant phyla (e.g. the-right (as is often the case in pharmacology where the log• tetrodotoxin. conotoxins. bungarotoxins). normal distribution is common), then application of the neurotransmitter A mediator released from the logarithmic transformation may be used to normalize terminal of a neuron which transmits the neuronal signal variances and allow parametric tests. across a synapse to act locally at another neuron or other cell nonsense codon See termination codon. type. e.g. muscle. Selectivity of signalling is achieved by the Normal distribution (Gaussian distribution) relatively close apposition of release site and effector cell. A particular probability distribution believed to underlie neurotrophic Influences that nourish nervous tissue. much quantitative physical data. and so is the basis of many neurotrophic factors Peptides that support survival standard parametric significance tests and other analyses. and growth of neurons. However. in pharmacology. and much of biology in general. neurotropic Having an affinity for nervous tissue. it is the logarithm of the variable. not the variable itself. that including viruses or bacteria that infect nervous tissue or is Normally distributed; in other words. there is a log-normal toxins that act on nerve cells. distribution. This is especially true of the distribution of neurovascular Pertaining to both nervous and vascular sensitivities of individuals in a population to chemical tissue. substances (e.g. Eeso and LDso values). See also frequency neutropenia (granulocytopenia) A decrease in the distribution; probability distribution. number of neutrophils in the blood. It may be caused by a normal equivalent deviate (NED) In statistics. NED number of diseases and as an adverse drug reaction. and is used to obtain a generalized form of the relationship increases susceptibility to infection. between population standard deviation for a Normal neutrophil A large granular leucocyte. a phagocytic PMN. distribution and the resultant cumulative frequency. In It responds to chemotactic stimuli and is important in the graphical form. the x-axis is a standardized Gaussian curve early stages of acute inflammation. containing a wide range with mean zero and a standard deviation of unity. and the of enzymes. y-axis is the cumulative frequency from 0 to 100%. This neutrophilia Having affinity for neutral dyes. curve takes a symmetrical sigmoid form (whereas the non• NGF nerve growth factor. cumulative version is a bell-shaped curve). Points on this NHS National Health Service (UK). curve are given in standard NED statistical tables. Thus 0 SO NIDDM non-insulin dependent diabetes mellitus. corresponds to 50%; -1 and + 1 SO corresponds to 15.97 and NIH National Institutes of Health (USA) 84.13 %. respectively; -2 and +2 SO correspond to 2.27% and nitrergic nerve A nerve that uses NITRIC OXIDE as the 97.73%. respectively; etc. This information can be used in a neurotransmitter. number of ways. In pharmacology. is has been used as the nitric oxide synthase The enzyme that produces the basis of a theoretically justified linearizing transformation. neurotransmitter and smooth muscle relaxant nitric oxide The probit is defined as NED + 5 (so as to eliminate most (NO) following deamination of arginine. It exists in negative NED values). For quantal dose-response lines (e.g. constitutive and inducible forms. mortality data). if the data are plotted with probits on the NK natural killer cell. y-axis versus the logarithm of dose on the x-axis. then in a NMDA N-methyl-D-aspartate. generalized case. the data will fit a straight line. This NMR nuclear magnetic resonance. linearizing transformation allows weighting of experimental

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 327 points in fitting the best linear relationship by least-squares by the agonist species. The variable, x, was termed the dose• methods: but values much smaller than ca. 5% and much ratio or concentration ratio (see Gaddum-Schild equation). greater that ca. 95%, have near negligible weight. Estimates Its use in receptor studies was extended by Stephenson of interest include EDso or LDso (the x-intercept (1956), who assumed that equal responses to two agonists corresponding to the line intercept at the level of probit 5.0) results from equal stimulus, which then allows meaningful and the slope (which is inversely related to the variance of comparisons of the agonists' efficacy and relative potency. sensitivities to the drugs within the samples). See also occupancy Receptor occupancy is normally quoted as a quantal responses. proportion of the total receptor population occupied by the normal flora The collection of (non-pathological) ligand, so takes values between zero and unity. microbes usually present as colonists in an environment such OD optical density. as the gut. oedema An abnormal accumulation of fluid in the body normal saline solution See physiological salt tissues, which may be localized (e.g. is a swelling) or solution. generalized (e.g. after heart failure). It can be caused by normal salt solution See physiological salt solution. i'\iury as a component of inflammation, or as a symptom of Northern blot technique A technique that is used to various diseases (heart failure, cirrhosis of the liver). It may identify RNA. RNA is separated according to size by use of a also be caused by a number of drugs (e.g. CONTRACEPTIVES, denaturing gel and electrophoresis prior to being blotted CORTICOSTEROIDS). Treatment of oedema depends on the onto a solid support. The mRNA transcripts are then cause, but DIURETICS are commonly used. detected by hybridization with a radioactive labelled probe. oesophageal ulcer See peptic ulcer. The abundance of the mRNA is indicated by the intensity of ointment A general term that is used to describe a group the radioactive signal. See also Southern blot technique. of essentially greasy preparations which are insoluble in NOS nitric oxide synthase. water and so do not wash off. They are used as bases for nosocomial synonomous with HAl. many therapeutic preparations for topical application NO synthase See nitric oxide synthase. (particularly in the treatment of dry lesions or ophthalmic NSAID NON-STEROIDAL ANTIINFLAMMATORY DRUGS. complaints). Most ointments have a form of PARAFFIN as nucleic acid hybridization See DNA hybridization. their base, but a few contain LANOLIN. nucleic acids Chains of RNA or DNA, two organic acids Oligomer A molecule composed of only a few monomer present in the nucleus (and sometimes the cytoplasm) of all units. living cells. They are the basic units of protein synthesis and of oligonucleotide A laboratory prepared short chain of heredity. Nucleic acids are long chains of linked nucleotides nucleotides. which in DNA contain the purine bases adenine and guanine, oligopeptide A short polypeptide (comprising less than plus the pyrimidine bases thymine and cytosine; whereas in 10 amino acids. RNA the place of thymine is taken by uracil. oncogene A gene that under certain conditions can cause nucleoside The glycoside resulting from removal of the cancer by stimulating abnormal uncontrolled cell growth and phosphate group from a nucleotide, i.e. the base-ribose excessive proliferation in the cell in which it occurs, or is moiety of a nucleotide introduced to. A mutant form of proto-oncogene. nucleotide The structural unit of a nucleic acid, oncology The study and practice of treating tumours. consisting of a nitrogen-containing base (a purine or a one-sample t-test (Student's one-sample t-test) pyrimidine), linked to a sugar molecule, i.e. a nucleoside, A (parametric) significance test that compares the mean of and a phosphate group. Nucleic acids are long chains of one sample group with a theoretical value. The null linked nucleotides. See also gene. hypothesis is that the population mean equals the theoretical nucleotide sequence The order of nucleotide residues value (e.g. zero, unity, or some determined population value). in a nucleic acid. Both a P value and the 95% confidence interval for the null allele A mutant aIlele that results in an absence of a difference between the population mean and the hypothetical functional gene product. value in testing this null hypothesis can be calculated. The test null hypothesis In statistical significance tests this is a assumes that the data are representative and randomly statement of the model tested. Generally, null hypotheses are sampled from a larger popUlation, each observation is for there being no real difference between two or more independent and the population has a Normal distribution. samples, or difference of the samples from some theoretical open reading frame A sequence of DNA that contains value (e.g. one or zero), or from a known population value. a signal for the start of translation, a length of amino acid A difference is said to be significant when the observed encoding triplets to form a protein and then a signal for difference, as compared to that stated in the null hypothesis, termination of translation. It may therefore indicate the is so great at a given probability value (P

SMALL CAPS ~ cross-reference to an entry in the A-Z Section bold ~ cross-reference to an entry in the Glossary 328 Appendix A unknown. parameter A term sometimes used to denote a variable, osteoarthritis A type of arthritis (joint inflammation) such as heights or weights of individuals, and sometimes a in which there is degeneration of the cartilage that lines the statistical measurement, such as an average, standard joints. It is exacerbated by stress, and characterized by deviation or regreSSion coefficient. creaking joints. Treatment of symptoms is by NSAIDS, parametric A type of statistical test that assumes an CORl'ICOSTEROIDS or surgery. underlying probability distribution, in contrast to osteoporosis A loss of the bone tissue, leading to a distribution-free or non-parametric tests. Student's t-test in tendency to become brittle and fracture. The cause can be its various forms is a commonly used parametric test. infection, injury, as part of Cushing's syndrome, especially in parasite A microbe or other small creature that lives on long-term CORl'ICOSTEROIO therapy, or in the elderly and in (ectoparasite) or in (endoparasite) a host, and which women following the menopause. normally derives benefit from the association but contributes OTC over-the-counter, i.e. non-prescriptionmedicine. nothing to its host's welfare (c.f. commensual, mutualism, ototoxicity ToxiC damage to the inner ear, including symbiosis). Examples in medicine include many viruses, drug-induced damage to the nerve serving the inner ear bacteria, fungi, protozoa and worms. (eighth cranial nerve) the cochlea and semicircular canals, so parasiticide An agent that detroys parasites (excluding causing deafness or loss of the sense of balance. This is a fungi and bacteria). See also ACARICIDE; ANTHELMINTIC; common adverse effect seen with the use of the antibiotic TRYPANOCIDE. NEOMYCIN and related aminoglycosides. parasympathetic nervous system See autonomic oxytocic An agent that stimulates the rate of childbirth, nervous system. especially through stimulation of uterine smooth muscle. parental Administration by any route other than by P450 cytochrome P450 mixed-function drug metaboling mouth. See also routes of administration of drugs. enzyme. parietal Of or situated on the wall of an organ or other pAz Index of potency of antagonists deVised by Schild (see body structure. pAJ. It is the negative 10gIO of antagonist concentration that pars A part of an organ. gives an agonist concentration-ratio (dose-ratio) x = 2. The partial agonist See agonist; efficacy; intrinsic activity; index may have different uses, (i) Where there is simple stimulus. equilibrium competition between agonist and antagonist for pascal (Pa) The SI unit of pressure, equal to one newton a single site, pA2 '" pKB (-loglO K5 of the antagonist), and the per square metre. affinity constant can be calculated from the Gaddum-Schild passive immunity Immunity acquired by injection of equation or from a Schild plot. (ii) Where the antagonism is antibodies, or in the foetus by transfer of maternal not competitive, or there is not equilibrium (or it is not antibodies through the placenta. known), the index can be used as a simple empirical measure pastille A soft lozenge. of antagonist potency (With no inference of affinity). patch clamp A technique used in experimental electro• pAx Logarithmic index of potency of antagonists devised by physiology where a hollow glass patch pipette forms a tight Schild (1941, 1949). Defined as the negative logarithm of the seal with a cell membrane following suction being applied, It molar concentration of an antagonist such that the dose of can be used to record activity of single ion channels. an agonist needs to be increased by a factor of x so as to patch test A type of skin test where the antigen is applied obtain the same size of response as in the absence of to the surface of the skin. Used, for example, to detect allergy antagonist. In general terms, x is referred to as the dose-ratio and assist in medical diagnosis. or concentration-ratio. The indexes pA2 and pAlO are where patents for drugs See generic drug name. the ratio, x, is 2 and 10, respectively; and theoretically (pA2. pathogen A disease-causing microorganism. pAlO) = 0.95 for competitive antagonism. The index may be pathogenesis The mechanism or process of interpreted in two main ways; see pAz, development of a disease. pacemaker A cell or region of an organ that determines pathogenic Capable of causing a disease, the rate of activity in other cells or organs. pathology The science of disease or dysfunction, or the Pacinian body A sensory receptor sensitive to pressure. characteristic symptoms and signs of a disease. packed cell volume (haematocrit) The volume of ·pathy A suffix denoting disease (e.g. neuropathy). erythrocytes in blood expressed as a fraction of the total patient information leaflet (Pll or Product blood volume. Information leaflet) The technical literature placed by the PAF platelet-activating factor. drug manufacturer in the packaging of medicines, which is PAGB Proprietary Association of Great Britain. intended to be read by the patient or carer. In the case of PAGE polyacrylamide gel electrophoresis; an experimental ore drugs these safety warnings are particularly important. technique used to separate large molecules such as proteins PC Pharmaceutical Codex. or nucleic acid. PCD programmed cell death; see apoptosis. paracrine See local homones. PCR polymerase chain reaction, paraesthesia (pins and needles) Spontaneously occuring POE phosphodiesterase (enzyme), tingling sensations, especially in the extremities. Can be PDEI PHOSPHODIESTERASE INHIBITOR. caused by damage to peripheral nerves. PDGF platelet-derived growth factor. paralytic ileus A condition of the gastrointestinal tract, PEM prescription event monitoring; see epidemiology. characterized by a failure of the normal peristaltic peptic ulcer A disease state characterized by ulceration, contractions and resultant obstruction of the intestine, e.g. initially of the mucosa of the alimentary tract, caused by the following abdominal surgery. action of pepsin and hydrochloric acid. It may be in the body parallel imports Refers to the system whereby drugs are of the stomach (gastric ulcer), the duodenum (duodenal reimported for sale from a country where the drugs are sold ulcer),jejunum (jejunal ulcer; especially in Zollinger-Ellison at a cheaper price. syndrome) or of the oesophagus (oesophageal ulcer;

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 329 associated with reflux oesophagitis). pharmacognosy The study of the pharmacological peptidase An enzyme that catalyses the hydrolysis of a agents derived from plants. See pytopharmacolology. peptide to smaller fragments, often resulting in inactivation pharmacokinetics The study of the handling of a drug of biological activity. within a body, including study of absorption, distribution, peptide A chain of a small number of amino acids linked metabolism and excretion of a drug and its metabolites. by peptide bonds. Many act as biologically active mediators, pharmacology The science of drugs. The effect of e.g. neurotransmitters or hormones. chemical substances on living processes. It can be divided peptide bond The covalent bond that joins the alpha• into pharmacodynamics (what the drug does to the body) amino group of one amino acid to the carboxyl grou p of and pharmacokinetics (what the body does to the drug). It another. is much concerned with the development of novel drugs. peptidyl transferase The enzyme that catalyses the pharmacopoeia A book listing drugs used in medicine. formation of peptide bonds during ribosomal protein It includes details of their chemical formulae, preparation, synthesis. dosages and other properties. peptone A soluble product of protein hydrolysis. pharmacy The preparation (formulation), supply and percutaneous Through the skin, such as the route of dispensing of medicines (and the place where this is done). administration of ointments which are absorbed through the phase contrast microscopy An optical microscopic skin. See also routes of administration. method which enables unstained, living cells to be observed perfusion The passing of fluid through channels such as by use of the way different cell components diffract light blood vessels. resulting in a high-contrast image. peri. A prefix denoting situated around, near or enclosing. phases of clinical trials There are four phases to the pericyte A type of cell that surrounds very small blood clinical study of new drugs: phase I, clinical pharmaCOlogy; vessels, such as capillaries arterioles and venules. phase II. clinical investigation; phase III, formal therapeutic peripheral nervous system The autonomic nervous trials; phase IV. post-marketing/licensing studies. system, the cranial nerves and the spinal nerves. phenotype The expression of observable characteristics peripheral neuropathy Numbness, tingling, pain and (Visual, biochemical or otherwise measurable) determined by muscle weakness. particularly of the extremi ties, resulting an indiVidual's genes (genotype) and their interaction with from disease or peripheral nerve damage. the environment. Two individuals with idel]\ic~1 genotypes peripheral vascular disease Pain and coldness of the (e.g. identical twins) may express differel]l j!llllflotypes. extremities, resulting from narrowing of the blood vessels, phenotypic See phenotype. e.g. in Raynaud's disease, diabetes or varicose veins. phenylketonuria A deficiency of the enzyme that peritoneum The membrane lining the abdominal cavity. metabolizes phenylalanine. It is an inherited condition. permissive cell A cell that supports virus replication. pheromone A substance secreted by an animal that pessaries Formulations of drugs inserted in the vagina. influences the behaviour of other individuals ,f that species. pH acid-base scale; the log of reciprocal of hydrogen ion PHI PEPTIDE HISTIDINE ISOLEUCINE. concentration, a measure of the acidity of a solution. PHM PEPTIDE HISTIDINE METHIONINE. phaeochromocytoma A type of tumour of phosphatase An enzyme that catalyses removal of a neuroendocrine glandular tissue of the type normally found phosphate group. in the adrenal medulla, leading to large and often dramatic phosphodiesterase An enzyme that hydrolyses release of adrenaline and noradrenaline. phosphodiester bonds For example, cyclic AMP to adenosine phage Bacteriophage. monophosphate to terminate the activity of this second phagocytic The ability of a cell to carry out phagocytosis. messenger. phagocytosis Uptake by endocytosis of large solid phosphoinositide system An important intracellular particles. or other cells into the cell often following second messenger system where G-protein coupled receptor opsonization. stimulation leads to phospholipase C activation, which Pharmaceutical Price Regulation Scheme (PPRS) breaks down the phospholipid phosphatidyl inositol A voluntarily adhered to scheme in the UK by manufacturers (4,5)bisphosphate into diacylglycerol (DAG) and inositol as a means of limiting profit margins for drugs sold under (1,4,5) - trisphosphate (InsP,) , both of which function as the National Health Service. second messengers, DAG to activate protein kinase C, InsP, pharmacist A practitioner of pharmacy, whether in the to release Caz+ from intracellular stores. pharmaceutical industry. universities, hospital pharmacies or phospholipase An enzyme that catalyses phospholipid shops and high-street pharmacies. hydrolysis, resulting in diacylglycerol and a phosphate of the pharmacoanthropology The study of difference in the phosphOlipid headgroup. properties of drugs (pharmacodynamics and phospholipase C The phospholipase enzyme that pharmacokinetics) between different genetic groups. breaks down phosphatidylinositol (4,5)bisphosphate into pharmacodynamics The study of the effects of drugs diacylglycerol and inositol (1,4,5) - trisphosphate both of on the body, including mechanisms and the interaction of which function as second messengers. Activation of drugs with cells. See pharmacokinetics. phospholipase C is via stimulation of G-protein coupled pharmacogenetic polymorphism The existence receptors. within a population of more than one phenotype with phospholipid (phosphatide) Ester of phosphoric acid, respect to the effects, or more usually metabolism, of a drug containing one or two fatty acid molecules, a nitrogenous (e.g. hydrolYSis of SUXAMETHONIUM, acetylation of drugs such base and an alcohol. The major component of the lipid as ISONIAZID, and of phenylthiourea taste-thresholds). bilayer in all biological membranes. pharmacogenetics The study of the modification of photophobia An intolerance to light, such that normal pharmacological effects resulting from hereditary differences. levels are uncomfortable. It occurs in some eye disorders (e.g. See pharmacogenetic polymorphism. iriditis, corneal damage and chronic glaucoma), in some

SMALL CAPS = cross~reference to an entry in the A-Z Section bold:::: cross-reference to an entry in the Glossary 330 Appendix A systemic infections (e.g. meningitis) or can be induced by plasmid cloning vector A plasmid that is used in drugs that dilate the pupil (MYDRIATICS). recombinant DNA studies because it accepts foreign DNA. photoreceptor A sense organ that responds to light. plasmin The enzyme present in blood plasma that photosensitivity An abnormal reaction to sunlight (e.g. degrades fibrin and therefore is involved in fibrinolysis. a rash). Phototoxicity is where drug treatment lowers plasminogen The inactive precursor of the enzyme sensitivity of the skin to ultraviolet light, so that there is plasmin. burning. One form is photoallergy, where the drug combines platelet (thrombocyte) A component of blood I-211m in with skin proteins to form an allergen, to which the body diameter and disc-shaped. They contain biologically active reacts with an allergic reaction. Undesirable mediators, e.g. histamine. Their functions are many, includ• photosensitization is caused by a wide variety of drugs in ing those involved in blood coagulation and aggregation. standard usage (e.g. phenothiazines, SULPHONAMIDES, pleio- (pleo-) A prefix denoting multiple. sulphonylurea HYPOGLYCAEMICS, TETRACYCLINES, CONTRA· pleiotrophy When a gene has more than one phenotypic CEPTIVES). SUNSCREENS applied to the skin help in treatment. effect. phylum The taxonomic group immediately above (more pleiotropic May refer to a gene or mutation that has inclusive) that of class and below kingdom in zoology. It multiple effects; e.g. a pleiotropic gene may affect more than corresponds to the category division in botany. one phenotypic characteristic. See pleiotropic response. physical mapping A linear map of the locations of pleiotropic response Where the response to a drug is genes on a chromosome as determined by physical mediated through more than a single mechanism. The term detection of overlaps between cloned DNA fragments. is used particularly in relation to a receptor coupling through physiological salt solution (normal saline) A sterile more than one G-protein pathway (sometimes called solution of sodium chloride in purified water: O.9g sodium promiscuous coupling). chloride in 100ml. It is isotonic with body fluids. pleomorphism The inherent varibility among e.g. cells physiology The study of functions and activities of living in a pure culture or clone of a given organism, in terms of organs. shape or size. physo- A prefix denoting air or gas. pleura The covering of the lungs (viscera pleura) and phyt- (phyto-) A prefix denoting of plant origin. inner surface of the chest wall (parietal pleura). phytopharmacology The study of the interaction of pleural cavity The space between the parietal and plants and drugs, both the derivation of botanical sources of visceral pleura. drugs and the effect of drugs on plants. See pharmacognosy. plexus A network of interlacing nerves or vessels. phytotoxin A poisonous substance produced by a plant. PMN polymorphonuclear granulocyte; any of several types pia mater The vascular membrane covering the surface of of leucocyte characterized as having granular cytoplasms the brain and spinal cord. and lobed nuclei, including eosinophils, basophils, mast pico 10'''. cells and neutrophils. pigment A substance that gives colour. PMS post-marketing surveillance. PIL patient information leaflet. PNS peripheral nervous system. pills Solid spherical or ovoid drug, dose forms (originally p.o. per as; by mouth (drug administration). often made by a rolling process), which are now largely -poiesis A suffix denoting production or formation. superseded by tablets. 'The Pill' is slang for oral point mutation A mutation where a single nucleotide contraceptives, which actually are in tablet form. is replaced by another. pilo- A prefix denoting hair. poisons 'All things are poisonous and there is nothing that PIP. phosphatidylinositol 4,5, bisphosphate. is harmless, the dose alone decides that something is no pKA A logarithm of acid ionization constant (K,J poison' (Paracelsus, 1493-1541). This statement still holds, pK B Equivalent to -logIOKB' where by convention KB is the and many compounds previously regarded as poisons are equilibrium dissociation constant of an antagonist. today used as medicines, e.g. curare, belladona, alkaloids, Numerically, identical to pAz for simple equilibrium vinca alkaloids. competition at a single site. The term apparent pKB may be Poisson distribution In statistics, the frequency used when there is no evidence whether or not there is distribution characteristic of events that are randomly competition, but there is assumed to be (e.g. when distributed in a period of time (e.g. radioactive calculating pKB from a single concentration of antagonist). disintegrations) or space (e.g. haeocytometer squares). PKC protein kinase C. polar A molecular structure that has two oppositely PL product licence. charged regions that are spatially separated. placebos Dummy treatments, having only psychological polyclonal Pertaining to cells or molecules that have effects. arisen from more than one clone. -pi asia A suffix denoting formation. polyclonal antibody Specific antibodies obtained plasma The fluid component of blood or lymph. from immunization of an animal. The antibodies are plasma extravasation The movement of plasma from therefore the products of different clones of antibody• blood vessels, e.g. post-capillary venules into surrounding producing cells: see monoclonal antibody. tissues. During inflammation this gives rise to oedema. It polymer A large molecule that is composed of repeating results from the formation of gaps between endothelial cells identical or similar subunits. due to endothelial cell contraction caused by release of polymerase An enzyme that joins nucleotides together. inflammatory mediators. It may be neutrophil-dependent. polymerase chain reaction (peR) An enzyme-based plasmid An autonomously replicating DNA element, experimental technique used for copying and amplifying a separate from the chromosome. These units, which occur specific DNA sequence. only in bacteria, can be used as vectors of small (up to about polymodal See bimodal. lOkb) fragments of foreign DNA. polymorphism The ability of an organism in a

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 331 population to occur in two or more morphologically distinct primary transcript The original RNA product that has forms, as a result of two or more relatively common alleles not been modified. The initial transcription of a ribonucleic at a given genetic locus. acid molecule in DNA. polynucleotide A linear sequence of nucleotides. primase The RNA polymerase which synthesizes the polypeptide A chain of amino acids linked by peptide RNA primer for DNA synthesis during replication. bonds, but of lower molecular weight than a protein. primer (oliogonucleotide primer) A short DNA sequence POM prescription-only medicine used to initiate the synthesis of DNA. as in a polymerase porphyria One of a group of six uncommon disease states chain reaction. characterized by disturbed metabolism of the pigment haem priming The initiation of synthesis of a DNA strand. (which occurs in the blood pigment haemoglobin), leading prion A modified, disease-causing form of a protein, e.g. to the accumulation in the body of porphyrins, causing red, that apparently causing Creutzfeldt-Jakob disease. brown or bluish urine. There are a number of diseases. Aside probabilit:;' distribution In statistics. is a function that from a number of porphyric disease states, some drug• gives the probability of observing each value that the variable induced porphyrias are known (e.g. that caused by may have. Graphically, the probability (probability density TAMOXIFEN), and many drugs should not be used in for continuous variables) is plotted against the value of a individuals who suffer from porphyria. variable. and has a characteristiC shape for a number of positional cloning Isolation of a gene based on the common distributions (e.g. Normal or Gaussian; log• knowledge of the gene's position on the chromosone. normal; binomial; Poisson). Experimentally. data are positive cooperativity See allosteric interaction; Hill generally plotted as a histogram which shows the frequency equation. of a particular value, or range of values. See also frequency positive gene control Enhancement of gene distribution. expression which occurs as a result of the binding of specific probability value In statistics, is the probability of expressor molecules to promoter sites. obtaining a result at least as unlikely as the observed one, if posology The science of dosage. See dose. the null hypothesis of no effect is true. Probability levels of post-synaptic potential The membrane potential of 5% (P<0.05); 1% (P

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 332 Appendix A protein kinase An enzyme that phosphorylates certain curve reflects the variance in sensitivity to the drug of the amino acid residues in a protein. Some forms of this enzyme experimental units under study. are regulated by second messengers. See PROTEIN KINASE quantile In statistics, one fourth of the data in a sample INHIBITORS. when these are ordered and divided into four equal numbers protein kinase A cAMP activated serine-threonine of observations. It is a useful method for displaying data, protein kinase. and, graphically, they can be incorporated into a Tukey ('box protein kinase C A ubiquitous serine-threonine protein and whisker') plot. kinase. quantitative Relating to size or amount. protein tyrosine kinase See tyrosine protein kinase. quantitative variation Continuous variation. proteolysis The breakdown of a protein molecule by quaternary structure The relationship of the various hydrolysis of peptide bonds. subunits in a protein to each other. prothrombin A precursor of thrombin. quench-freezing A process used to rapidly freeze a proto-oncogene A gene that normally regulates cell specimen by plunging it into liqUid nitrogen. growth and proliferation but which when mutated can cause racemic mixture See isomers. cancer. See also mutation; oncogene. radioimmunoassay (RIA) A very sensitive experimental pruritus Itching: as well as occuring in several disease technique by which substances are detected and quantified states, it is a very common side-effect of certain drugs, using radioactive labelled specific antibodies. especially those that release HISTAMINE in the body. radioisotopes Unstable isotopes that spontaneously psoriasis A chronic skin complaint characterized by disintegrate (With a characteristic half-life), losing mass and thickened patches of itchy scaling skin. Treatment is emitting particles (e.g. neutron, positron, electron, a-particle problematical, but includes phototherapy and drugs, etc.) or photons (y-ray, X-ray). Radioisotopes can be used for including CORTICOSTEROIDS and METHOTREXATES. diagnosis (e.g. rate of clearance of a labelled compound) or PSS physiological salt solution. treatment (131 I for goitre), or as probes or tracers in pulmonary hypertension Raised blood pressure experimental work. within the blood vessels supplying the lungs. radioligand Radioacitivity labelled ligand used, for pulsed-field gel electrophoresis An example, in radio ligand receptor binding experiments. electrophoresis technique for separating large DNA radioligand-receptor binding A technique fragments by applying an electric field first in one direction developed for assessing the characteristics of receptors or of and then at an angle to the first direction. drugs through the use of radioactively labelled ligand purine A heterocyclic compound containing fused molecules. See displacement analysis; saturation analysis. pyrimidine and imidazole rings. They are biologically active radiopharmaceutical See radioisotopes. mediators and are components of nucleic acids and radionuclide An unstable atomic nucleus which emits coenzymes. radiation and changes from one element to another, or to a purinoceptor A cell surface receptor that recognizes different isotope, as a result of spontaneous radioactive decay PURINES. See ADENOSINE RECEPTOR AGONISTS; PURINE p2 randomized block design An experimental design for RECEPTOR AGONISTS. distributing treatments or doses between subjects. Having its purinergic Nerves that secrete PURINES acting as origins in agricultural field trial, all combinations of neurotransmitters. treatment, subjects etc. under investigation are allocated into py- (pyo-) A prefix denoting pus. blocks. It allows analysis of effects and interactions between pyelonephritis Inflammation of the kidney, usually due treatments and subjects. Factorial analysis shows whether to bacterial infection. factors are independent or not, and yields unbiased estimates pyrexia (fever) A body temperature raised above normal, of effects of treatments. See factorial design. and is usually taken as indicating an infection. It is treated random sample A subgroup of a large population with ANTIPYRETICS, e.g. PARACETAMOL, NSAID ANALGESICS. selected by a random process. pyrimidine Heterocyclic organic compounds which exist range The lowest and highest value in a set 0 lata. as components of nucleic acids and coenzymes. ranked response Ranked or ordered data ' .. ~t1- pyrogen A substance that produces fever (e.g. PGE,). parametric measures that may be used to est' Normally they are produced via cytokine action as a result of responses, espeCially in behavioural pharma< microbial or other infection, with the result that the body's rbc red blood cell. 'thermostat' in the brain is set to high. Prostaglandins are RC-IUPHAR Receptor Committee of the L mal nal pyrogens, and NSAID ANALGESICS, such as ASPIRIN, which Union of Pharmacology. prevent their production are commonly used ANTIPYRETICS. RCT randomized controlled trial. pyrogenesis Increasing body temperature caused by a reading frame A nucleotide sequence t. legins with pyrogen. an initiation codon, ends with a terminatit ~don and pyschoactive drug A drug that has mood and/or partitions the nucleotides into a series of at acid- behavioural modifying properties. encoding triplets in between. Q10 (temperature coefficient) The increase in the rate of a receptive field (of a neuron) The restri j area on a chemical process due to raising the temperature by lO·C. sensory organ which when stimulated influences the activity quantal responses Are 'all-or-none' responses, or of that neuron. qualitative responses, e.g. death or survival (in contrast to receptor The receptor protein is a macromolecule at quantitative responses which are continuous variables). The which drugs bind in order to produce their responses. underlying distribution is the binomial distribution. Log Agonists mediate their responses through activating the dose-response lines for quantal responses are frequently receptor, whereas syntopic antagonists bind at the same sites sigmOidal in shape, and since this is the same form as the without activating responses. The receptor was originally integrated frequency distribution curve, the slope of the visualized in empirical terms. Ehlich {late 19th/early 20th

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 333 century) postulated a specific binding site with which receptor nomendature. They have sometimes been referred biological stains, drugs and antibodies fit an anchor as pieces to as SUbtypes, but often merely represent a close variant in in ajigsaw. Langley theorized a 'receptive substance' in one species of a recognized receptor in another species. relation to the interactions of pilocarpine and atropine at However, in some instances a single alteration in the amino muscarinic receptors (1878), and nicotine and curare at acid sequence of the species homologue produces dramatic nicotinic receptors (1905); a formulation that for the first changes in recognition properties, and in other instances a time specifically identified the affinity and active mass of the given subtype may not be represented in all mammalian drug as determinants of reaction with the receptor. The species. In these circumstances it has become usual practice reaction of agonists and antagonists in terms of biological to regard the human isoform as the 'standard' receptor, and response has been extensively modelled in the absence of a to denote the species within in the name of the isoform. detailed knowledge of the nature of the receptor (see receptor occlusion These are studies using non• agonist; antagonism - pharmacodynamic; efficacy; equilibrium antagonists that bind essentially irreversibly to Gaddum-Schild equation; Hill equation; Langmuir the receptor, e.g. phenoxybenzamine with a-adrenoceptors. equation; stimulus). However, it is now recognized that in Such antagonists can be used to estimate receptor reserve, structural and coupling terms, receptors fall into and to estimate the affinity of agonists. superfamilies with common characteristics, including: (a) receptor organ See sense organ. direct ligand-gated ion channel receptors; (b) G-protein• receptor potential The local graded depolarization of a coupled receptors; (c) tyrosine-kinase-linked or guanylyl• sensory neuron terminal membrane following stimulation. cyclase-linked receptors; (d) intracellular receptors (normally receptor reserve A term in receptor pharmacolOgy intranuclear receptors). Other types of binding sites with denoting the same concept as spare receptors, but in a more which drugs interact indude, enzymes, ion channels, carrier exact sense. A strong full agonist can produce a maximum molecules, nucleic acids; plasma albumin; but unless the response without occupying all receptors; demonstrated, for drug produces a specific activation (that can, in principle, be instance, by receptor occlusion studies. Thus at any point in antagonized by an allotopic interaction) such sites are not time, there are spare receptors not contributing to the normally considered as being drug receptors. These agonist response: however, there Is a dynamiC relationship so structural and mechanistic considerations are now no specific population of receptors is 'spare'. conSidered as important criteria in receptor classification, receptor-tyrosine kinase Integral tyrosine kinase taken as complementary to properties defined in terms of activity of a receptor, e.g. for growth factors. recognition characteristics (see receptor classification). recessive gene A gene whose effects are only shown in receptor classification Receptors can be classified into an indiVidual if its allele is the same. families on the basis of a number of criteria, Operational reciprocal plot A graphical method used as a classification based on the recognition characteristics is linearizing transformation. Single reciprocal plots are evidently the most relevant to the use of drugs in analytical where only one axis is transformed, and double-reciprocal pharmacology and in therapeutics. The property of plots are where both are transformed. The Scatchard plot is selectivity (or specificity where this is achievable) is a vital an example of a single or semireciprocal plot. The drug attribute, and through the use of selective agonists and Lineweaver Burk plot an example of a double-reciprocal antagonists, receptors can fairly readily be divided into major plot. See also transformation. families: for example, muscarinic cholinoceptors, nicotinic recombinant Any new individual cell or molecule that cholinoceptors, a-adrenoceptors, 13-adrenoceptors etc. It arises as a result of recombination either naturally or in the might be noted that the examples chosen are sometimes laboratory by recombinant DNA technology. referred to as subtypes of receptor, but additional recombinant DNA technology Procedures used to classificational criteria (especially receptor structure and join DNA sequences from different sources. The coupling mechanism; see receptor) suggest that it is more introduction of new genetic material (e.g. that of another helpful to distinguish by separate families of receptors of species) or reorganized genetic material into host cells. When very different characteristics (viz. nicotinic receptors are of done by artificial techniques, it is a form of genetic the intrinsic-ion-channel superfamily and are involved in engineering. It is used particularly in biotechnology to 'fast' signalling: whereas muscarinic receptors are of the produce biopharmaceuticals, normally proteins, e.g. G-protein-coupled superfamily and are involved in 'slow' insertion of human genes for INSULIN or GROWTH HORMONE, signalling). On the other hand, most families of receptors into bacterial cells, which multiply rapidly in culture and with quite closely similar recognition characteristics and syntheSize large amounts of the human protein in question. receptor structure homologies, can meaningfully be recombinant protein A protein produced from a subdivided into yet further subsets. For instance; e.g. recombinant DNA template. 13-adrenoceptors all couple positively to adenylyl cyclase and redox potential (oxidation-reduction potential) A share >60% sequence homology; nevertheless they can be measure of the tendency of a system to donate electrons or divided into 131, 132 and 133 receptor variants, each with a accept electrons. distinct distribution and pharmacology. IncreaSingly it is referred pain Pain felt in a part of the body at some these latter subsets or variants that are most commonly distance from its cause. termed receptor SUbtypes (rather than the 0.- and 13-families refractory period The time of recovery needed for a themselves). However, a further complication arises when neuron that has just transmitted an impulse, or a muscle there are yet further, very similar, variants (sometimes the fibre that has just contracted. product of the same gene, representing alternative regression analysis A statistical method of analysing transcripts): these are usually labelled with additions to the and describing the dependence of one variable on one or subscripts (e.g. alA-' alB-, alc-adrenoceptors). The more other variables. A linear relationship is most readily recognition of the existence of species homologues or analysed, so non-linear data are normally subjected to a isoforms of receptors has produced some confusion in linearizing transformation (e.g,logarithms,logits, probits,

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 334 Appendix A reciprocals) before analysis (though modern computer at different sites. programs now more readily allow nonlinear curve fitting, for reticulocyte A large, immature erythrocyte or cell of the example, to the logistic equation in pharmacology). In reticular system. regression analysis the data are normally displayed in the reverse transcription See reverse transcriptase. form of a scatter diagram plotting the dependent variable reverse transcriptase RNA-dependent (and mainly in (y), e.g. drug response against the independent variable (x), retroviruses) DNA polymerase. It is the enzyme that e.g. logarithm of drug concentration. Analysis yields a synthesizes DNA on an RNA template. Enables viral RNA to straight line fitted through the data, summarized in the be integrated into host DNA. The opposite of transcription, parameters of regression coefficient (slope, b) and reverse transcription is used to synthesize DNA for probes. y-intercept, and their 95% confidence intervals. In pharma• Reye's syndrome A disorder in children which may be cology, the EC so and its confidence interval. may often be caused by ingestion of aspirin (though it may certainly have estimated. The Pvalue testing the null hypothesis that the other causes). It is rare but serious, and since 1986 in the UK slope equals zero can be calculated. Linear regression aspirin bottles and packets have been labelled as calculation assumes that any relationship between x and y is contrindicated in children under 12 years old, unless linear, and that the y values (at all values of x) follow a specifically indicated (as in juvenille arthritis). Normal distribution with a standard deviation that does rheumatoid arthritis A type of arthritis Goint not vary with x. inflammation) in which the joints of the body, particularly relative activity See relative potency. of the fingers, wrists and toes, become stiff, swollen, painful relative molecular mass (Mr) The ratio of the mass of and eventually deformed. It is progressive but periodic. one molecule of a substance to 'I" the mass of an atom of Treatment is by NSAID ANALGESICS, CORTICOSTEROIDS, 12C. Formerly known as molecular weight. IMMUNOSUPPRESEANTS and a number of other drugs. relative potency In determination of potency of drugs, rhodamine A group of fluorochrome dyes, used to there is a contribution to responses that is a function of visualize cell structures by immunofluorescent techniques. tissue or subject sensitivity, and a contribution that is drug• RIA radioimmunassay. dependent (see receptor, efficacy). Potency can be expressed ribosomal ribonucleic acid A major component of in absolute terms (EC so etc.) or relative terms. The relative ribosomes, and is the most abundant RNA in cells. Involved approach compares one drug with another, often a reference in protein synthesis. . or standard drug. The comparative method that yields a ribosomal RNA See ribosomal ribonucleic acid. relative potency is satisfactory in terms of experimental risk-to-benefit ratio In any treatment or medical design, because biases due to between-subject or between• intervention, there is an inherent risk in the intervention that tissue variability can be eliminated through the use of needs to be assessed in terms of the benefits that accrue from suitable experimental designs. the treatment (if successful). replication The process by which DNA makes copies of RNA ligase An enzyme that catalyses exon rejoining in itself during cell division. the splicing of certain mRNAs. repolarization When a neuronal membrane returns to RNA (ribonucleic acid) A large linear molecule made up of its normal electrically charged state after a nerve impulse. nucleotides, ribonucleotides which contain the bases uracil, reporter gene A gene whose product, an enzymatic guanine, cytosine and adenine. RNA occurs in several forms, marker or protein, can be used as a genetic label. For transfer RNA (tRNA), ribosomal RNA (rRNA) and example, a gene for neomycin resistance incorporated into a messenger RNA (mRNA). All are concerned with protein plasmid before transfection allows the subsequent detection synthesis. All cellular RNAs are synthesized by transcription of successfully transfected cells. of chromosomal DNA which acts as the template. repressor protein A protein that inhibits mRNA RNase (RNAse: ribonuclease) An enzyme that cleaves RNA. translation by binding to mRNA. routes of administration of drugs There are many respiratory burst (metabolic burst) Where cell-surface different routes but common ones include: intravascular stimulation of neutrophils, e.g. by opsonized bacteria, injection or infusion (into the blood vessels, e.g. by drip, results in a markedly increased oxygen consumption. Much mainly intravenous (into veins) but sometimes intra-arterial of the oxygen may be used to form superoxide radicals. (into arteries): intramuscular (injection into muscles): resting potential The potential difference across a subcutaneous (injection beneath the dermis of the skin): nerve or muscle cell membrane when not being stimulated. intradermal (injection into the skin): transdermal (across the restriction analysis A technique that uses restriction skin, e.g. from skin patches): topical (application to the skin enzymes to cut DNA into identifiable sections, and thereby or mucous membranes); per rectum (by an ointment or determine the identity of DNA. suppository into the rectum); intravaginally (by an ointment restriction endonuclease (restriction enzyme) Any of or pessary into the vagina); intrathecal (by injection into the a group of endonucleases produced by microorganisms. subarachnoid space of the spinal cord); intranasally (often as They recognize short palindromic base sequences in DNA a spray); orally (by mouth); inhalation. and cut the double helix at a particular point. Each rRNA ribosomal RNA. endonuclease recognizes a different specific DNA sequence. rutherium red A dye used experimentally for staining They are used in genetic engineering. mucopolysaccharides and as a specific ATPase inhibitor. restriction enzyme See restriction endonuclease. SAD seasonal affective disorder. restriction fragment length polymorphism sagittal In the median longitudinal plane of the body, or (RFLP) Variations between individuals in DNA fragments parallel to it. that are recognized as cutting sites by specific restriction SAR structure-activity relationship. enzymes. Used as markers in chromosome mapping. sarcoma A malignant type of neoplasm, a cancerous restriction mapping A procedure used to characterize growth, which arises in the connective tissue of skin etc. a region of DNA by using restriction enzymes to cut DNA saturation analysis Where the amount of radioactivity

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 335 in a radioligand-receptor binding assay, in the presence of a inflammation. known concentration of labelled drug, is measured for a selectivity In drug action, selectivity is the capacity of range of non-saturating concentrations of drug, under equi• agents to effect one system without effecting others. To be librium conditions. It allows determination of B.... and K•. useful in therapeutics or analytical pharmacology, drugs are scanning electron microscope (SEM) An electron selected for having reasonable selectivity. Nevertheless, no microscope that can produce an image in 3-D from electrons drugs even approach complete specificity of drug action. reflected from the specimen's surface. Quantitatively, the margin of selectivity can be expressed in S.c_ subcutaneously (drug administration). See also routes terms of ratios of doses to achieve effects on different of administration of drugs. systems, receptors etc. Scatchard plot A form of analysis that has been used for SEM standard error of the mean. the display of radioligand-binding data. It is a form of single• semilog plot A graph where one axis only is logarithmic. reciprocal plot. where the bound/free ratio of radio ligand is This device is usually used as a simplifying or linearizing plotted on the y-axis, and bound concentration on the x-axis. transformation. Examples include a logarithmic y-axiS to The fitted straight line intercepts the receptor concentration linearize an exponential curve. Also, a logarithmic x-axis (Bm.J on the x-axis. The slope is the reciprocal of the used nearly universally to convert hyperbolic dose-response equilibrium dissociation constant (K d). The plot is used relationships to a SigmOidal relationship. especially to check for one-site binding. but because of sense strand (coding strand) The strand of a double• statistical difficulties in weighing of points, it is now used stranded DNA molecule that is complementary to the RNA only for the display of data, rather than for analysis and formed by transcription. parameter derivation. sensitivity A characteristic of tissues, test systems or scatter diagram A plot of observations against another subjects to recognize or react to a chemical at high dilutions. observation or an independent variable. Used particularly in It is a system-related variable, but clearly also contributes to displaying data together with determination of correlation the measured potency of a drug when this is expressed in coefficient and in progression analysis. absolute units (e.g. EC 50). See potency. Schild plot (Arunlakshana & Schild plot) A graphic sensitization The condition where an animal responds method described by Arunlakshana & Schild (1959) used to with an enhanced allergic or immune response on second display data and to estimate the pA, value of an antagonist, encounter with an allergen (see hypersensitivity). an index of potency (see pAz; pA,J. Observed values of the sensory neuron A nerve that conducts afferent impulses variable (x-I) (where x is the dose-ratio or concentration from the periphery to the CNS. ratio) are plotted against the -loglo of antagonist concen• sensory receptors Any cell; or cell part, that is trations. The intercept of a fitted linear relationship on the specialized to respond to stimuli such as light, heat, concentration axis is the estimated pA, value. In the special mechanical pressure, and then conveys that information via case where the Schild slope (b) is unity, and there is simple sensory nerves to the CNS. equilibrium competition between agonist and antagonist for serine kinase See protein kinase. a single site, pA, " pKB (-loglo Kd of the antagonist). serOlogy The study of blood serum and its constituents. Schild slope See Schild plot. serotoninergic Neurons secreting SEROTONIN (5-HT). schistosomiasis (bilharziasis) A tropical disease caused serum The liquid portion of blood that remains following by blood flukes of the genus Schistosoma. ANTISCHISTOSOMES centrifugation of spontaneously clotted blood. It differs from are the drugs used in its treatment. plasma by the absence of fibrinogen, and is used to provide Schultz-Dale reaction The contractile reaction of an passive immunization. isolated tissue preparation from a sensitized animal, often sex cell See germ cell. uterus or intestine, to allergen to demonstrate anaphylactic sickle·cell disease (sickle-cell anaemia) A hereditary hypersensitivi ty. blood disease that occurs mostly in black people and some scintillator A substance that produces a fluorescent flash people of Mediterranean and Indian origin. It is caused in when struck by high energy radiation. See also fluorescence. the child when both parents carry the defective gene. In this SD standard deviation. disease the red blood cells (erthyrocytes) are abnormal, SDS (sodium dodecyl sulphate) A detergent widely used to containing an abnormal form of haemoglobin. and cause a solubilize membrane protein assemblies because of its ability serious form of anaemia. where sickle-shaped erthyrocytes to disrupt protein-lipid and protein-protein interactions. are formed (sickling) when the blood is deprived of oxygen, seasonal affective disorder (SAD) A mental and these cells are removed from circulation causing depression related to low light levels. as in winter. jaundice and anaemia. Treatment is supportive, with secondary cell culture A cell culture originating from supplements of folic acid, antibiotics and oxygen therapy. cells taken from a primary culture. side·effect An unwanted effect of a drug which is dose• second messenger Intracellular compounds, such as related and commonly predictable (sometimes unavoidable). cAMP. IP3, formed as a result of stimulation of receptors on The term normally is used for relatively trivial unwanted the cell which then activate the cell's specific response. A actions of a drug (e.g. dry mouth) rather than potentially given second messenger pathway is generally shared by a serious adverse drug elTects. number of different receptors (~-adrenoceptors and SIF small intensely fluorescent cells (APUD cells). histamine-H, receptors; both couple to G, to stimulate sigmoid curve/relationship A form of curve that is adenylyl cyclase and so raise cAMP). In molecular terms, S-shaped. normally inflecting at, and symmetrical about, the each stage represents an amplification of the original signal. 50% response value. This form is common for log dose• section A thin slice of tissue prepared for microscopy. response lines with either graded or quantal responses. For selectins A family of cell adhesion molecules that are graded receptor-mediated responses this curve reflects, produced by leucocytes and epithelial cells and are involved amongst other things, the coupling-function between in leucocyte binding to vascular endothelium at sites of receptor occupancy and biological response (see Black &

SMALL CAPS = cross~reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 336 Appendix A

LetT model). For quantal responses it reflects the cumulative origin (e.g. certain cramps) or from within the CNS (e.g. probability distribution. hiccups. tics). In smooth muscle. the cause may be an im• signal transduction The process by which a cell balance within the autonomic nervous system or the release responds to an external signal. It may involve activation of of local hormones (e.g. colic. asthma. Raynaud's disease). second messengers. such as enzymes. or opening/closing of Spearman correlation See correlation coefficient. ion channels. species The basic unit in taxonomy. Individuals are sign test A (non parametric) significance test allowing assigned to a species on the basiS of similarities in asexual quick comparison of two samples. Taking the data as organisms. and also on the basis of ability to interbreed in arranged in a matched-pairs statistical test the signs of the sexually reproducing organisms. In taxonomic hierarchy. the column differences are noted and the total of + signs next (more inclusive) level is genus. compared with the total of - signs (ignoring zeros). and a P species homologues (of receptors and enzymes) The value is obtained by consulting tables. The null hypothesis is advent of application of molecular biological techniques to that the two population medians are equal. This test is rather the elucidation of the structure of receptors and enzymes has insensitive to real differences. and other non parametric tests shown that these macromolecules may vary to the extent of may be preferred for more exact purposes (e.g. the Wilcoxon being different in every species studied. These differences in matched-pairs test). structure may be accompanied by differences in function single-blind study See clinical trials. that vary from trivial to dramatic. Such variation may sinistral On or pertaining to the left. present difficulties in drug development. to the extent that site-directed mutagenesis Refers to in vitro much testing is now done on cloned human protein material. techniques where mutations are made at specific It should be noted that variants also occur within species predetermined sites in DNA. (genetic polymorphism). See also receptor classification. SI Units System International d'unites (International specificity In pharmacology. this term would infer a System of Units). special. exclusive and sole action of a drug at only one site skeletal muscle The type of striated muscle that makes (e.g. a receptor). This has not yet been achieved; at the best up the majority of the musculature of the body. It is attached only high selectivity can be achieved. In prinCiple. antisense to the skeleton and is responsible for the movement of limbs. oligonucleotide reactions can come close to specificity. for breathing etc. Nerve supply is by cholinergic fibres of the spinal nerves The 31 pairs of nerves that connect to the somatic (VOluntary) nervous system. so the muscle is caused human spinal cord. They are part of the peripheral nervous to contract by ACETYLCHOLINE and blocked by system. NEUROMUSCULAR BWCKING AGENTS. splicing The removal of introns from messenger RNA SLE systemic lupus erythrematosus. and the joining together of adjacent exons. smooth muscle (involuntary muscle; plain muscle) SR sustained release (drug preparation). Unlike striated muscle. smooth muscle has no cross• SRS-A slow-reacting substance of anaphylaxis (a mix of striations under the microscope. indicating an organization three leukotrienes). characteristic of muscle controlled by the autonomic ss Single-stranded. nervous system. and reacts more slowly to SSRI selective SEROTONIN re-uptake inhibitor neurotransmitters than striated muscle (skeletal muscle) of (ANTIDEPRESSANTS) . the voluntary nervous system. standard deviation (SO) In statistics. the standard SOD superoxide dismutase. deviation of a sample. is a measure of scatter or dispersion of sodium pump See Na+,K+-ATPase. values in that sample. and provides an unbiased estimate of soft drugs Drugs used for nonmedical social purposes the true population value of the standard deviation. It is which are less socially disabling and less likely to cause useful as a descriptive statistic in its own right; for instance. dependence than hard drugs. it is valuable to know the standard deviation of the heights or somatic Body celis as opposed to cells of the germ line. weights of individuals in a population. It is also used in See germ cell. deriving measures of precision of an estimate of the mean: somatic nervous system Refers to that part of the see coefficient of variations; standard error of the mean. peripheral nervous system that conveys sensory information standard error of the mean (SEM) In statistics is a to the CNS and motor commands to the skeletal muscles. measure of precision of an estimate of the mean obtained by somatosensory Sensation arising from muscle. skin or repeated sampling. Means of repeated samples from a internal organs. Normal distribution are themselves distributed about a sonicator (sonifer) An instrument that produces sound population mean. but with a smaller standard deviation energy for the disintegration of cells in a liquid medium that depends on the size of the sample (n). As a statistic of (sonication) . precision in experimental work it must be quoted together SOP standard operating procedure. with n; alternatively. it may be converted to a confidence Southern blot technique A very sensitive experimen• interval (SEM x t. where t is Student's t for appropriate tal technique used to detect the presence of DNA sequences. degrees of freedom). amongst restriction fragments. that are complementary to a starch blocker A trivial name for the class of drugs radiolabelled DNA or RNA probe. DNA is separated by (mainly intestinal a-amylase inhibitors) that block dietary electrophoresis on a gel. transferred to membrane filters conversion of polysaccharides and sucrose to mono• and then labelled probes are applied to locate comple• saccharides. Such drugs are used in diabetes management. mentary DNA sequences. See Northern blot technique. status epilepticus See epilepsy. spacer DNA DNA that separates one gene from another. steady-state In relation to drug metabolism. when the spare receptors See receptorreserve. • rate of drug intake equals the rate of drug elimination. a spasm An involuntary strong contraction of a muscle. In steady-state concentration is achieved. the skeletal muscle of the body the cause may be of local stenosis Narrowing or contraction of a duct.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 337 stimulus In receptor pharmacology. stimulus denotes the the drug is released gradually over time. Also known as ability of an agonist. on binding to the receptor. to induce controlled- or modified-release formulation. activation of that receptor. Stephenson (1956) introduced a symbionts See symbiosis. parameter. efficacy. which is a proportionality constant symbiosis An intimate. obligatory and mutually relating the stimulus produced by an agonist on occupying beneficial association between two different species the receptor. to the subsequent biological responses. Thus (symbionts). See commensual; mutualism; parasite. stimulus is an essentially hypothetical entity. but is essential sympathetic nervous system See autonomic to mathematical modelling of these events. See also intrinsic nervous system. activity; intrinsic efficacy; null method. sympathin The name given by early physiologists stochastic process Ratltlom processes including those Cannon and Rosenblueth (1933) to the neurotransmitter varying randomly in time; e.g. binding and dissociation of substance released from sympathetic neurons that did not drug molecules at the receptor. opening and closing of ion exactly match the physiological effects of ADRENALINE. and channels. Their analysis involves probability theory. which is now known to be NORADRENALINE. stoichiometry The relative proportions of molecules in a syndrome A collection of signs and symptoms that. in reaction. e.g. of drug molecules binding to a receptor or a occurring together. constitute a given disease. binding protein. synergism Where the combined effects of responses to stop codon See termination codon. two drugs is more than simply arithmetically additive. stretch receptor A sensory receptor that monitors the synomyn Any of two or more codons that specify the degree of stretch. e.g. muscle spindle. same amino acid. striated muscle Any muscle type showing cross• synovial fluid The fluid in the joint cavities that striations under the miscroscope. including skeletal muscle lubricates the joint. and cardiac muscle but not smooth muscle. syntopic Interaction of two drugs acting at the same sites stringency A term used in DNA hybridization which on a receptor; as opposed to allotopic. where they act at refers to the degree to which different DNA sequences will different site on the receptor. Competitive antagonism is an form duplexes. High stringency conditions (e.g. high example of syntopic interaction. See also antagonism• temperature) result in duplex formation only between pharmacodynamic. identical DNAs. low stringency (e.g. low temperature) allows syrup A concentrated aqueous solution sweetened with duplex formation between non-identical. but related. DNAs. sugar or some other substance. It may be used for localized structure-activity-relati'onship The relationship soothing on the throat. or to disguise the taste of drugs. between chemical structure and biological activity. systemic Affecting the whole body. The systemic admini• Student's t-test See matched-pairs statistical test; stration of a drug. the opposite of local administration. can one-sample t-test; unpaired t-test. be by injection or orally. See also routes of administration sub- A prefix denoting below. of drugs. subtype (of receptor) See receptor classification. systemic circulation Blood course from ventricle via superinfection A second infection during infection by the body to atria. As opposed to the pulmonary circulation. one organism by a microorganism resistant to the treatment systOle The period of the cardiac cycle when the heart is for the first infection. contracting. See diastole. superior Situated uppermost in the body in relation to systOlic See systole. another structure or surface. t,/. half-life. superoxide See superoxide radical. TEA tetraethylammonium ion. superoxide dismutase (SOD; superoxide tablet A solid drug form made by compaction and usually oxidoreductase) A term used to describe a range of of a rounded disk form. They have now largely superseded metalloenzymes which catalyse the dismutation of pills. Tablets may be soluble. effervescent. dispersible. coated superoxide. thereby protecting cells from the toxic effects of or uncoated. enteric coated. modified-release or superoxide radicals with the formation of hydrogen peroxide sustained-release. See also capsule. and molecular oxygen. tachy- A prefix denoting fast. superoxide radical Refers either to 0," (superoxide tachykinin Any of a family of peptide neurotransmitter anion) or peroxide anion. Superoxide is generated during the mediators characterized by C-terminal sequence homology respiratory burst in activated neutrophils. The potentially -Phe-X-Gly-Leu-Met-NH,. harmful effects of endogenously formed superoxide are tachyphylaxis Progressive diminution of a response with prevented through degredation by superoxide dismutase. repeated doses suppository A drug preparation formulated for insertion taenia A ribbon-shaped band of nerve or muscle. into any orifice of the body. normally the rectum. The term tandem repeat sequence Multiple copies of a short used for the vagina is pessary. The active drugs may have a DNA sequence lying in series along a chromosome. It is used local action (e.g. local anaesthetics). or be designed for in physical mapping and linkage mapping and also DNA systemiC action (e.g. antiasthma tics) . fingerprinting because each person's pattern of tandem suppressor gene A gene that reverses the effect of a repeats is likely to be unique. mutation in another gene. tardive dyskinesia A syndrome with abnormality of suppressor T-cell A T-Iymphocyte whose main function movement (particularly of the face. tongue. jaws and limbs). is to suppress the activity of other cells which playa role in characteristic of long-term use of ANTIPSYCHOTIC drugs. such cell-mediated immunity or humoral immunity. as phenothiazines. working as DOPAMINE RECEPTOR supra- A prefix denoting above. ANATAGONISTS. See also extrapyrimidal syndrome. surmountable antagonism See antagonism• TATA box The short nucleotide (7 -base) consensus pharmocodynamic. sequence in the promoter sequence preceding the start point sustained-release formulation A preparation where of transcription. involved in binding of the complex of

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 338 Appendix A transcription factors and RNA polymerase. become lodged elsewhere. ANTICOAGULANT drugs are used to taxonomy The science of biological classification. prevent clot formation in those at risk. See embolism. T-cell thymus derived cell: see T-Iymphocyte. thyrotoxicosis See goitre. T-cell receptor A protein on the surface of T• tincture An alcoholic drug solution. lymphocytes that recognizes molecules of MHC. tissue culture The in vitro culture and maintenance of TD50 Toxic dose 50% of sample. isolated tissues, cells or organs. TDIC50 (TCDso) Tissue culture infective dose (50%). The tissue fluid (interstitial fluid) The watery liquid present dose of a viral suspension that when used to inoculate tissue in the gaps between cells. cultures causes observable effects in 50% of those cultures. tight junction Refers to the area of closely opposed teratogen An agent that causes developmental plasma membrane of two adjacent cells. abnormalities in a foetus. tissue plasminogen activator A serine protease that teratogenesis Denotes production, usually by chemical converts plasminogen to plasmin. action, of physical or anatomical abnormality in the foetus. titre The concentration of specific antigens, antibodies or termination codon (stop codon) Any of three codons other particles in a sample. signalling the end of a protein coding region. TLC thin-layer chromatography. tertiary structure When referring to a polypeptide T-Iymphocyte (thymus dependent; T-cell) A type of chain, the overall conformation, i.e. the three-dimensional lymphocyte involved in cellular immune reactions and conformation of the polypeptide chain after folding. aiding in the production of antibodies. They originate in thalassaemia A group of inherited disorders that occur haemopoietic stem cells, but undergo essential maturation in mostly in people of Mediterranean, Middle Eastern and the thymus gland. They interact with other cells (e.g. B• Southeast Asian origin caused (in two different forms) in the lymphocytes) and e.g. antigens, lymphokines via receptor child when one or both parents carry the defective gene. In sites on their membranes. There are several subsets of T• thalassaemia, many of the erythrocytes are fragile and easily lymphocytes: see cytotoxic T-cells; helper T-cells; inducer broken up resulting in haemolytic anaemia and iron T-cells; suppressor T-cells. overload in internal organs (haemosiderosis). Treatment is TNF tumour necrosis factor. by whole blood transfusion and bone-marrow transplant. tolerance A diminished response to a drug due to prior The iron overload can be helped with iron-chelating (normally chronic) exposure. compounds which promote its excretion. tonicity The effective osmotic pressure of a solution; or T-helper cell See T-Iymphocyte. the normal state of contraction of a muscle. therapeutics The branch of medicine that is concerned topical Application of a drug to surface areas, e.g. skin, with the methods of treatment of disease, especially through eye. See also routes of administration of drugs. the use of drugs. Intervention may be curative (e.g. use of toxicity In general, a poisonous or toxic property in a antibiotics against infections), suppresive (e.g. use of insulin chemical. In relation to drugs, the term applies particularly to maintain diabetics) or prophylactic (e.g. chloroquine in to adverse drug reactions. prevention of malaria). toxin A poisonous protein or polypeptide produced by therapeutic ratio/index A concept introduced by pathogenic microorganisms: also extended to toxic peptide Ehrlich to express the ratio of the toxic dose of a drug to the and other natural products produced by higher organisms. effective dose, as a measure of therapeutic safety. The ratio toxoid A toxin that has been modified to destroy its determined in animal studies has been expressed in various toxicity but retain its ability to stimulate antibody ways, such as LDsoiEDso, LD1/ED gg etc. But these measures production (immunogenicity). (often of acute effects) are rarely directly applicable to toxicology The study of poisons. human therapeutics. However, some drugs clearly have a low TPA (t-PA) tissue-type plasmogen activator. therapeutic ratio, e.g. cardiac glycosides, whereas other have tracer A substance that once introduced into the body can a very large ratio, e.g. most antibiotics. be followed, e.g. due to radio or fluorescent labelling. therapeutic trial See cHnical trials. transaminase (aminotransferase) An enzyme that threshold The point when a stimulus evokes a response. catalyses the transfer of an amino group for an amino acid to thrombin An enzyme formed from the precursor a keto acid to form another amino acid. prothrombin which induces blood clotting by converting transcript The RNA that is synthesized by RNA fibrinogen to fibrin in shed blood. polymerase on a DNA or RNA template. thrombocytopenia A reduction in the number of blood transcriptase An enzyme that catalyses transcription. platelets. Because of the importance of these cells in the transcription The mechanism by which information formation of blood clots, there may be abnormal bleeding contained in the genetic code is transferred from DNA to associated with this condition. There are a number of causes, RNA, i.e. is transcribed. including as an adverse drug reaction to certain drugs, such transcriptional control The control of gene expression as OESTROGENS, PHENYLBUTAZONE, SULPHONAMIDES and when exerted at the level of initiation of transcription. (thiazide) DIURETICS. transcriptional regulators A group of proteins that thrombosis Formation of a blood thrombus (clot). A initiate or prevent transcription and hence gene number of factors can increase clot formation, including expression, by binding to DNA at specific control sites. obstruction or damage to blood vessels and contact of blood transcriptional terminator A sequence in a gene that with certain surfaces. Thrombosis in blood vessels results in signals the end of transcription. impaired blood supply and resultant anoxia, causing in transcription factor Any protein that binds to a arteries of the heart, coronary thombosis (See myocardial specific DNA sequence and is involved directly in regulating infarction), or in the brain, stroke. Thrombosis in veins is the initiation of transcription. associated with the inflammation of phlebitis and phlebo• transducin (G T) A G-protein that is involved in thrombosis. When the thrombus becomes dislodged it may transducing the signal from activated rhodopsin in the rod

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary Glossary 339 and cone cells of the sye. hours. Underlies, e.g., hay fever and anaphylactic shock. transduction The transfer of genetic material by a viral type II hypersensitivity reaction (cytotoxic vector from one cell to another. antibody-dependent) When the immune responses are transfect The genetic modification of cells in culture by directed against cells within the host which appear to be adding, e.g. viral DNA to the culture medium which enters foreign, e.g. when the host cells are altered by drugs. The the cells and is stably incorporated into the genome. antigen forms part of the cell surface and this evokes transfection The transfer of new genetic material into antibody production and activation of complement. cells. type III hypersensitivity reaction (immune transfer RNA (tRNA) The RNA that acts as an adapter complex-mediated) When antibody reacts with soluble molecule during protein synthesis to match amino acids to antigen which then activates complement, or attaches to their codons in mRNA. mast cells with subsequent release of mediators. Underlies transgenic Containing artificially introduced DNA from Arthus reaction. one genome into the germ line of another by genetic type IV hypersensitivity reaction (delayed• engineering. type/cell-mediated) In a primed individual, is the transgenic technology See transgenic. hypersensitivity reaction which occurs maximally within tRNA See transfer RNA. 24-48 hours after antigen contact, and which is mediated by transformations (transforms) A mathematical device a subset of T-Iymphocytes. It forms the basis of certain used to change the characteristics of a variable. Some trans• diagnostic skin tests. formations are linear (e.g. most metric to Imperial measure• tyrosine kinase See tyrosine protein kinase. ments), whilst others are non-linear (e.g. square root, tyrosine protein kinase (tyrosine kinase; protein logarithmic transformation, probits, reciprocal trans• tyrosine kinase) An enzyme that phosphorylates tyrosine formation). In statistics and pharmacology, log transforms residues on target proteins. Some receptors have intrinsic in particular are used to normalize variance, and to produce tyrosine kinase activity, e.g. growth factors. It is also symmetrical sigmoid curves for quantal dose-response involved in signal transduction, transmitting signals from curves and quantitative concentration-response curves. cell-surface receptors. Several potential oncogenes specify transformed cell Cultured cells that can divide proteins with tyrosine kinase activity. indefinitely as a result of e.g. viral infection or treatment ulcer See peptic ulcer. with carcinogens. ulcerative colitis See colitis. translated See translation. ultracentrifugation The use of a centrifugal field for translation The process by which information in the the sedimentation of macromolecules, determination of RNA genetic code is used to direct protein synthesis. molecular weights, separate organelles from broken cells. The translational control Control of gene expression at ultracentrifuge can achieve fields of the order of 5000 OOOg. the level of translation. ultracentrifuge A machine used to separate cell compo• transmembrane Across the membrane. nents by weight by spinning broken cells at various speeds. trimodal distribution See bimodal distribution. ultrafiltration Filtration under pressure. triplet A 3-base unit in DNA or RNA that codes for a ultrasonication The use of very high frequency (16kHz particular amino acid. or higher) by a sonicator. TRIS A buffer used in experimental biology. ultrastructure The fine structure of a cell, e.g. as seen tritium A radioisotope of hydrogen,3H; widely used as a with an electron microscope. tracer, e.g. radioligand-receptor binding. uni- A prefix denoting one or one of. trophic Pertaining to nutrition. unipolar Refers to a neuron that has one main process try pan blue A blue diazo dye used for vital staining. extending from the cell body. TTX tetrodotoxin. unpaired t-test (Student's two-sample t-test) This is a tumor Swelling; one of the classical signs of inflammation (parametric) significance test that compares the means of in a tissue. The other signs are calor (heat), rubor (redness) two independent samples. The n"ll hypothesis is that the two and dolor (pain). The swelling is due not to a growth of cell population means are equal. Both a Pvalue and the 95% size (as in hypertrophy) but by the collection of fluid confidence interval for the difference between the two between the cells (oedema). population means can be calculated. The test assumes that tumour Any abnormal swelling in any part of the body. the data are representative and randomly sampled from a Correctly, the term can be applied both to relatively harmless larger population, that the SO of the two populations are swelling (benign) or to cancerous (malignant) growths. equal, that each observation is independent, and that the tumour promotor An agent that hastens the effects of populations have a Normal distribution. The assumption of carcinogens, but are not carcinogenic in their own right. equal SOs (equivalent to equal variances) is often tumour suppressor gene (anti-oncogene) A gene problematic. Note that the assumption does not refer to the that normally slows cell growth and proliferation. Mutations data in the samples, but rather to the populations from in tumour suppressor genes can allow uncontrolled cell which the data were sampled. A commonly used test of the division and so can lead to malignancies. assumption of equal variances is the F test, which reports a P Tween A buffer used in experimental biology. value testing the null hypothesis that the two populations two-sample test See unpaired t-test. have equal SOs (equal variances). type I hypersensitivity reaction upmutation A mutation, usually in the promotor (anaphylactic/immediate) An unwanted immune response controlling the gene in question, in which transcription is which occurs when antigen evokes IgE production, which much enhanced. then fix to mast cells. Subsequent exposure with antigen upregulation When referring to receptors, where there is results in release of mediators, e.g. histamine, PAF, an increase in receptor number, Bm~' eicosanoids, from the mast cells. It occurs within minutes or urinogenital tract See genitourinary tract.

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary 340 Appendix A urticaria A common skin condition (also called nettle active constituent in 100ml of solution. rash or hives) characterized by raised itchy weals. It usually Western blot The separation of proteins by occurs only for a few hours, but may reoccur. It is seen in electrophoresis. some disease states, including angio-oedema. Commonly, it WHO World Health Organization. is caused by an allergic reaction to foodstuffs (e.g. shellfish, wild type Laboratory stock (normals) from which eggs, nuts), food additives (e.g. tartrazine) or drugs (e.g. mutants are derived. penicillin, aspirin). Treatment is with antihistamines, or if Wilcoxon matched-pairs test A (nonparametric) severe, corticosteroids. A similar condition in neonates, significance test that compares the median of two related erythaema neonatorum, is of unknown cause. samples. The null hypotheSiS is that the two population USAN United States approved name (for a drug). medians are equal. It is the nonparametric eqUivalent of the USP Unites States Pharmacopoeia. matched-pairs t-test. uter- (utero-) A prefix denoting the uterus. Wilcoxon rank sum test A (nonparametric) uV; UV ultraviolet (light). significance test that compares population values in a single u.v. radiation Electromagnetic radiation with sample with a theoretical value. The null hypothesis is that wavelengths in the band between visible light and X-rays the population median equals the theoretical value. (10-400 nm). withdrawal syndrome An abrupt withdrawal of a vaccination (active immunization) A form of drug causing a characteristic syndrome, often with both immunization where killed or weakened microorganisms physical and psychological discomfort or illness. Often the are introduced into the body. This induces protective withdrawal effects are the opposite of those of initial use of immunity against the appropriate pathogen, but itself does the drug, and may be incurred both by medical and not cause disease. nonmedical use of drugs. Drugs espeCially noted for serious vaccine The preparation of microorganisms or their withdrawal syndromes include amphetamines, barbiturates, antigenic components for vaccination. benzodiazepines, COCAINE, NICOTINE and OPIOID ANALGESICS. vagotomy The cutting of the vagus nerve. Treatment may consist of adoption of a gradual withdrawal, van der Waals bond (electron correlation attraction) or substitution of a weaker drug (e.g. METHADONE for The weak electrostatic bond between molecules. MORPHINE). vasoactive Causing dilation and/or constriction of a w/v per cent 'weight in volume'; the number of grams of blood vessel. an active constituent in 100ml of solution. vasoconstriction A narrowing of blood vessels. xenobiotic A chemical that is present in a natural vasodilalation A widening of blood vessels, e.g. in environment but which does not usually occur in nature, and response to a vasodila tor drug. therefore is foreign to a living cell. vasomotor nerve Any nerve that is involved in the yeast artificial chromosome (YAG) A vector control of the circulation of blood. constructed from the various DNA sequences needed for vector In genetic engineering, is a phage, virus, DNA or replication in yeast cells. It can be used to clone large (up to plasmid that another DNA is inserted into in order to 400kb) fragments of foreign DNA and is especially useful for introduce the DNA into other cells for DNA cloning or to chromosome mapping. study, e.g. gene expression. Zollinger-Ellison syndrome A rare disorder where vehicle A substance used to dissolve a drug or otherwise there is excessive gastric acid secretion due to high GASTRIN facilitate delivery (e.g. emulsifying agents). levels in the blood produced by an enlarged pancreas or ventral Pertaining to the underside of the body. pancreatic tumour. ventral root Of spinal nerves, a nerve root with some zymogen An inactive enzyme precursor. motor fibres; of cranial nerves, a nerve root with some zwitterion A molecule with positively and negatively sensory fibres. charged groups, e.g. an amino acid. V gene Any of the gene segments coding for part of the variable regions of immunoglobulin molecules. VH variable region of antibody heavy chain. virology The study of viruses. viscera The collective term for the internal organs. visceral afferent fibres Nerve fibres that convey sensory information to the spinal cord. visceral efferent fibres Nerve fibres of the sympathetic and parasympathetic nervous systems which convery information from the CNS to the periphery, e.g. to glands, smooth muscle. vital staining Staining of living cells with non-toxic dyes. VL variable region of antibody light chain. VLDL very low density lipoprotein. voltage clamp A device that clamps the membrane potential at a set level and therefore allows study of how membrane conductance changes in response to changes in the membrane potential. voltage-gated Ion channels in the cell membrane whose opening or closing depends on membrane potential. v-onc A general designation for viral oncogene, e.g. v-src. v/v per cent 'volume in volume'; the number of ml of an

SMALL CAPS = cross-reference to an entry in the A-Z Section bold = cross-reference to an entry in the Glossary .. I

Amino acid abbreviations (common natural)

alanine Ala A arginine Arg R asparagine Asn N (E) aspartic acid Asp D (E) cysteine Cys C glutamic acid Glu E (Z) glutamine Gin Q (Z) glycine Gly G histidine His H isoleucine Ile I leucine Leu L lysine Lys K methionine Met M phenylalanine Phe F proline Pro P serine Ser S threonine Thr T tryptophan Trp W tyrosine Tyr Y valine Val V (unspecified) X 342 Appendix B

Amino acid abbreviations (found in literature; related and unnatural)

2-aminobutanoic Abu ~-alanine ~Ala alloisoleucine alIe; allolIe asparagine Asp (NH,) asparagine or aspartic acid Asx citrulline Cit cysteic acid Cys pyroglutamic acid (5-oxoproline) Glp; pGlu;

Greek and Latin multiplicative prefixes

Greek Latin Greek Latin '/, hemi semi 32 dotrionca 1'/, sesqui 40 tetraconta 1 mono uni 50 pentaconta 2 di bi 60 hexaconta 3 tri trio ter 70 heptaconta 4 tetra (tetr) quadri 80 octaconta 5 penta (pent) quinque (quinqu) 90 nonaconta 6 hexa (hex) sexi (sex) 100 hecta (hect) 7 hepta (hept) septi (sept) 101 henhecta 8 ocata. octo (oct) 102 dohecta 9 ennea (enne) nona (non) 110 decahecta 10 deca. deci (dec) 120 eicosahecta 11 hendeca (hendec) undeca (undec) 132 doctriacontahecta 12 dodeca (dodec) 200 dicta (diet) 13 trideca (tridec) 300 trica 14 tetradeca (tetradec) 400 tetracta 15 pentadeca 1000 kilia 16 hexadeca 17 heptadeca 18 octadeca two-times bis 19 nonadeca three-times tris 20 eicosa. eicos (icosa. icos) four-times tetrakis 21 henicosa 22 docosa 23 tricosa 30 triconta 31 hentriconta