Edo University Iyamho Department of Medical Laboratory Science Lecture Notes on Basic Clinical Chemistry Course Title: Basic Clinical Chemistry Course code : MLS 309(3Units) Course Lecturer: Professor Mathew Folaranmi OLANIYAN (Ph.D., PGDE. FMLSCN). [Search on SCOPUS Using ORCID Number: 0000-0003-1119-3461] Department of Medical Laboratory Science Faculty of Basic Medical Sciences College of Medical Sciences Edo University, Iyamho - Nigeria Mobile phone : +2348052248019 ; +2347033670802 e-mail: [email protected] ; [email protected] Scopus Author ID: 55245953400 websites: https://www.labroots.com/profile/179361 https://scholar.google.com/citations?user=MMTX_YgAAAAJ&hl=en https://independent.academia.edu/MATHEWOLANIYAN http://orcid.org/0000-0003-1119-3461 http://www.scopus.com/inward/authorDetails.url?authorID=55245953400&partnerID=MN8TO ARS Mathew Folaranmi OLANIYAN (Ph.D., PGDE. FMLSCN) is a Professor of Medical Laboratory Science Interested in Chemical and Microbial pathology, Toxicology, Immunology/Immunochemistry, Phytotherapy, Medical Laboratory Education and Management. 1 in the Department of Medical Laboratory Science, Faculty of Basic Medical Sciences, College of Medical Sciences, Edo University, Iyamho – Nigeria. Prof. MF Olaniyan teaches Basic Clinical Chemistry to 300 Level students on Bachelors of Medical Laboratory Science programme at every First semester. The course code is MLS 309 which is a 3unit course. The course provides basic knowledge in Clinical Chemistry required for an advance training and acquisition of specialized skills later in the programme. Clinical Chemistry/Clinical Biochemistry/Chemical Pathology is a medical science that involves the analysis of biochemical parameters in body fluids, tissues, excretions and other body wastes for the purpose of laboratory diagnosis of disease, treatment, research, crime detection and therapeutic drug monitoring. 2 Course outline 1. Traditional and S. 1 units in clinical chemistry; 2. Reference values 3. Gastric function test 4. Agents for Gastric stimulation. 5. Ward procedures and laboratory investigation of Gastric secretion: 6. Intestinal function tests 7. Digestion and absorption; 8. Causes of Malabsorption. 9. Laboratory investigation of malabsorption. 10. Renal functions of the kidney 11. Measurement of Renal plasma flow 12. Glomerular filtration rate 13. Creatinine clearance, insulin clearance, concentration and dilution tests; 14. Urinary, acidification tests 15. Urine specific gravity/Osmolarity. 16. Dye Excretion test. 17. Water and Electrolyte status. 18. Blood buffers. 19. Transport of blood gases; assessment of acid/base status 20. Lipids; definition and types of lipids; formation of free fatty acids, 21. Ketone bodies and lactate; measurement of plasma lipids and lipoprotein 22. Plasma proteins and physiology functions 23. Factors affecting synthesis and catabolism. 24. Methods for the determining of total protein in serum 25. Carbohydrate metabolism; 26. Blood glucose homeostasis, 27. Hyperglycemia diabetes mellitus-its cause and investigation: 28. Hypoglycemia—types causes and investigation Aim and Objective To provide adequate background knowledge for students in Clinical Chemistry which should be adequate enough for students to be able to pass the first professional examination and as a prerequisite learning experience required for those who may be interested in Chemical pathology/Immunology specialty. Expectations 3 At the end of the teaching, students must have acquired learning experiences in the under-listed areas that will be applicable in examinations and in professional practice 1. Basic concepts in Clinical Chemistry 2. Unit of measurements 3. Metabolism of carbohydrate, Fat/Lipids and proteins 4. Abnormalities and laboratory diagnosis of metabolic disorders 5. Gastrointestinal tract functions and the associated laboratory assessment 6. Renal/Kidney functions and the associated laboratory assessment 7. Liver functions and the associated laboratory assessment 8. Laboratory methods and techniques 4 LECTURE SERIES 3- 9 DIGESTION AND ABSORPTION OF FOODS Carbohydrates - Broken down to monossacharides: Sucrose to glucose + fructose, Lactose to Galactose, starch finally to Glucose. - Absorbed as monossacharrides in small intestine through Na+ dependent co-transport facilitated by diffusion Proteins - Broken down to amino acids and peptides - Absorbed in small intestine through Na+ dependent co-transport for amino acids and H+ dependent co-transport for di and tripeptides Lipids - Broken down to fatty acids, monoglycerides and cholesterol - Absorbed in small intestine through micelles formed with bisalts in the intestinal lumen facilitated by diffusion of fatty acids, monoglycerides and cholesterol into the cells Water Soluble vitamins - Absorbed in small intestine through Na+ dependent co-transport Vitamin B12 Absobed in ileum utilizing intrinsic Vitamin - B12 complex Bile acids Absobed in ileum through Na+ dependent co-transport Ca2+ Absorbed in the small intestine it is vitamin D dependent () Fe2+ On digestion Fe3+ is reduced to Fe2+ 5 Absorbed in small intestine by binding to apoferitin in cells and circulates in blood by binding to transferrin In the Stomach - Pesinogen to Pepsin in the presence of HCL - Protein converted to Peptones + Proteoses Small intestine - Trypsinogen is digested to trypsin in the presence of enterokinase - Trypsin influences conversion of chymotrypsinogen to chymotrypsin and procarboxypeptidase to carboxypeptidase - Proteins, Peptones, Proteoses are converted to dipeptides in the presence of trypsin/chymotrypsin and carboxypeptidase - Dipeptides are digested to amino acids in the presence of dipeptidase - PEPTONES means larger peptides - PROTEOSES means smaller peptides 6 GASTRIC FUNCTION TESTS What ever food or drink we consume is sent to stomach where it is stored for further degradation. The stomach is a major organ of digestion and performs the following functions: 1. Stomach is a reservoir of ingested food. 2. It has a great churning ability which promotes digestion. 3. Stomach elaborates HCl and proteases which are responsible for the initiation of digestive process. 4. The products obtained in the stomach stimulate the release of pancreatic juice and bile. Significance of Gastrointestinal Function Tests They are useful in the diagnosis of the following a. Gastric-ulcer/ Peptic-ulcer b. Pernicious anaemia c. Zollinger Ellison Syndrome d. Completion of surgical vagotomy Secretion of gastric HCl The parietal cells of gastric glands produce HCl. The pH in the gastric lumen is as low as 0.8 (against the blood pH 7.4). Therefore, the protons are transported against the concentration gradient by an active process. A unique enzyme called K+ activated ATPase present in the parietal cells is connected with the mechanism of HCl secretion. The process involves an exchange of H+ ions (of the parietal cells) for K+ ions (of the lumen). This is coupled with the consumption of energy, supplied by ATP. The H+ are continuously generated in the parietal cells by the dissociation of carbonic acid, - which in turn, is produced from CO2. The bicarbonate ions (HCO3 ), liberated from the carbonic - acid (H2CO3) dissociation, enter the blood in exchange for Cl ions. The latter diffuse into the gastric lumen to form HCl. Gastrin,a peptide hormone of gastrointestinal tract, stimulates HCl secretion. 7 Following a meal, there is a slight elevation in the plasma bicarbonate concentration which is linked to the gastric HCl secretion. This is referred to as alkaline tide The 4 main tests for assessment of gastric function are: 1. Examination of Resting Contents 2. Fractional Gastric Analysis using Test Meals 3. Examination of Contents after Stimulation 4. Tubeless Gastric Analysis. Examination of Resting Contents After an overnight fasting the stomach contents are completely collected using Ryle tube i. Volume: Normal volume: 20 to 50 ml of resting contents. Increase in volume can be caused hypersecretion of gastric juice, retention of gastric contents owing to delayed emptying of the stomach, and regurgitation of the duodenal contents. ii. Consistency: Normal gastric juice is fluid and does not contain food residue and may contain small amounts of mucus. Food residues are present in case of carcinoma of the stomach. iii. Colour: Normally it could be colourless, or slightly yellow or green due to regurgitation of bile from duodenum. A dark red or brown colour indicates altered blood or fresh-blood. iv. Bile: Increased quantities of bile can be as a result of intestinal obstruction or stasis. 8 v. Blood: Normally no blood Presence of small amount of fresh blood may be traumatic. Brown or reddish-brown blood may occur in gastric ulcer and sometimes in gastric carcinoma due to the formation of dark brown acid hematin as a result of the hemolysis of red blood cells by HCl. (d) Bleeding may also occur from gastritis. vi. Mucus: (a) A small amount of mucus may be present in normal cases. (b) Increased amount of mucus is present in gastritis and in gastric carcinoma. Pres•ence of mucus is inversely proportional to the amount of HCl present. (c) Swallowed saliva may contain excess of mucus. vii. Free and Total Oddity: (a) The acidity is determined by titration with a standard solution of NaOH using methyl orange or Topfer’s reagent which indicates end point by the change of red to yellow colour or using phenolphthalein indica•tor which shows end point by the change of yellow to red colour. (b) The presence of the amount of