PINOCYTOSIS in FIBROBLASTS Quantitative Studies in Vitro
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Membrane Transport, Absorption and Distribution of Drugs
Chapter 2 1 Pharmacokinetics: Membrane Transport, Absorption and Distribution of Drugs Pharmacokinetics is the quantitative study of drug movement in, through and out of the body. The overall scheme of pharmacokinetic processes is depicted in Fig. 2.1. The intensity of response is related to concentration of the drug at the site of action, which in turn is dependent on its pharmacokinetic properties. Pharmacokinetic considerations, therefore, determine the route(s) of administration, dose, and latency of onset, time of peak action, duration of action and frequency of administration of a drug. Fig. 2.1: Schematic depiction of pharmacokinetic processes All pharmacokinetic processes involve transport of the drug across biological membranes. Biological membrane This is a bilayer (about 100 Å thick) of phospholipid and cholesterol molecules, the polar groups (glyceryl phosphate attached to ethanolamine/choline or hydroxyl group of cholesterol) of these are oriented at the two surfaces and the nonpolar hydrocarbon chains are embedded in the matrix to form a continuous sheet. This imparts high electrical resistance and relative impermeability to the membrane. Extrinsic and intrinsic protein molecules are adsorbed on the lipid bilayer (Fig. 2.2). Glyco- proteins or glycolipids are formed on the surface by attachment to polymeric sugars, 2 aminosugars or sialic acids. The specific lipid and protein composition of different membranes differs according to the cell or the organelle type. The proteins are able to freely float through the membrane: associate and organize or vice versa. Some of the intrinsic ones, which extend through the full thickness of the membrane, surround fine aqueous pores. CHAPTER2 Fig. -
Cellular Transport Notes About Cell Membranes
Cellular Transport Notes @ 2011 Center for Pre-College Programs, New Jersey Institute of Technology, Newark, New Jersey About Cell Membranes • All cells have a cell membrane • Functions: – Controls what enters and exits the cell to maintain an internal balance called homeostasis TEM picture of a – Provides protection and real cell membrane. support for the cell @ 2011 Center for Pre-College Programs, New Jersey Institute of Technology, Newark, New Jersey 1 About Cell Membranes (continued) 1.Structure of cell membrane Lipid Bilayer -2 layers of phospholipids • Phosphate head is polar (water loving) Phospholipid • Fatty acid tails non-polar (water fearing) • Proteins embedded in membrane Lipid Bilayer @ 2011 Center for Pre-College Programs, New Jersey Institute of Technology, Newark, New Jersey Polar heads Fluid Mosaic love water Model of the & dissolve. cell membrane Non-polar tails hide from water. Carbohydrate cell markers Proteins @ 2011 Center for Pre-College Programs, New Jersey Institute of Technology, Newark, New Jersey 2 About Cell Membranes (continued) • 4. Cell membranes have pores (holes) in it • Selectively permeable: Allows some molecules in and keeps other molecules out • The structure helps it be selective! Pores @ 2011 Center for Pre-College Programs, New Jersey Institute of Technology, Newark, New Jersey Structure of the Cell Membrane Outside of cell Carbohydrate Proteins chains Lipid Bilayer Transport Protein Phospholipids Inside of cell (cytoplasm) @ 2011 Center for Pre-College Programs, New Jersey Institute of Technology, Newark, New Jersey 3 Types of Cellular Transport • Passive Transport celldoesn’tuseenergy 1. Diffusion 2. Facilitated Diffusion 3. Osmosis • Active Transport cell does use energy 1. -
An Introduction to the Viruses
Chapter 1 An introduction to the viruses Viruses are obligate intracellular parasites of man, other animals, plants and bacteria. They can only multiply within cells, and thus differ from bacteria, which can multiply in tissues in an extracellular position, and also in artificial culture media in the laboratory. It has always been recognized that viruses are distinct from the bacteria, but originally other groups of infective agents were included among the viruses which are now known to be organisms of a different and more complex nature. These included the Chlamydiae, organisms causing diseases such as lymphogranuloma venereum and trachoma, and the Rickettsiae, the causative agents of typhus and related infections. The specific treatment of infections caused by these two groups of agents will not be considered in this work, which is restricted to the chemotherapy of infections caused by the true viruses. The Chlamydiae and Rickettsiae are complete organisms, with cell walls, which possess both types of nucleic acid, enzyme systems which function within their cytoplasm, and a number of cell organelles. The viruses, on the other hand, possess either DNA or RNA as their genetic material, but not both. In some cases they contain enzymes, but these exert their functions within the host cell after the virus particle has under gone a process of dissolution during the early stage of infection. Except in the case of the arenaviruses, a group which contains the virus of Lassa fever, the virus particles do not contain organelles. A virus is thus much more rudimentary in structure, and relies upon the host cell to provide the systems for synthesizing its components which it does not possess itself. -
Hollow Fiber Membrane Contactors for Post-Combustion Carbon Capture: a Review of Modeling Approaches
membranes Review Hollow Fiber Membrane Contactors for Post-Combustion Carbon Capture: A Review of Modeling Approaches Joanna R. Rivero 1 , Grigorios Panagakos 2,∗ , Austin Lieber 1 and Katherine Hornbostel 1 1 Department of Mechanical Engineering and Material Science, University of Pittsburgh, 3700 O’Hara St, Pittsburgh, PA 15213, USA; [email protected] (J.R.R.); [email protected] (A.L.); [email protected] (K.H.) 2 Department of Chemical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213, USA * Correspondence: [email protected] Received: 30 October 2020; Accepted: 25 November 2020; Published: 30 November 2020 Abstract: Hollow fiber membrane contactors (HFMCs) can effectively separate CO2 from post-combustion flue gas by providing a high contact surface area between the flue gas and a liquid solvent. Accurate models of carbon capture HFMCs are necessary to understand the underlying transport processes and optimize HFMC designs. There are various methods for modeling HFMCs in 1D, 2D, or 3D. These methods include (but are not limited to): resistance-in-series, solution-diffusion, pore flow, Happel’s free surface model, and porous media modeling. This review paper discusses the state-of-the-art methods for modeling carbon capture HFMCs in 1D, 2D, and 3D. State-of-the-art 1D, 2D, and 3D carbon capture HFMC models are then compared in depth, based on their underlying assumptions. Numerical methods are also discussed, along with modeling to scale up HFMCs from the lab scale to the commercial scale. Keywords: hollow fiber membrane contactor modeling; post-combustion carbon capture; carbon capture membrane modeling 1. Introduction In 2018, the Intergovernmental Panel on Climate Change issued a report detailing the irreversible impact of a global temperature rise of 1.5 ◦C[1]. -
Polymers and Solvents Used in Membrane Fabrication: a Review Focusing on Sustainable Membrane Development
University of Kentucky UKnowledge Chemical and Materials Engineering Faculty Publications Chemical and Materials Engineering 4-23-2021 Polymers and Solvents Used in Membrane Fabrication: A Review Focusing on Sustainable Membrane Development Xiaobo Dong University of Kentucky, [email protected] David Lu University of Kentucky, [email protected] Tequila A. L. Harris Georgia Institute of Technology Isabel C. Escobar University of Kentucky, [email protected] Follow this and additional works at: https://uknowledge.uky.edu/cme_facpub Part of the Chemical Engineering Commons, and the Materials Science and Engineering Commons Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Repository Citation Dong, Xiaobo; Lu, David; Harris, Tequila A. L.; and Escobar, Isabel C., "Polymers and Solvents Used in Membrane Fabrication: A Review Focusing on Sustainable Membrane Development" (2021). Chemical and Materials Engineering Faculty Publications. 80. https://uknowledge.uky.edu/cme_facpub/80 This Review is brought to you for free and open access by the Chemical and Materials Engineering at UKnowledge. It has been accepted for inclusion in Chemical and Materials Engineering Faculty Publications by an authorized administrator of UKnowledge. For more information, please contact [email protected]. Polymers and Solvents Used in Membrane Fabrication: A Review Focusing on Sustainable Membrane Development Digital Object Identifier (DOI) https://doi.org/10.3390/membranes11050309 Notes/Citation Information Published in Membranes, v. 11, issue 5, 309. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). -
Atypical Solute Carriers
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1346 Atypical Solute Carriers Identification, evolutionary conservation, structure and histology of novel membrane-bound transporters EMELIE PERLAND ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6206 ISBN 978-91-513-0015-3 UPPSALA urn:nbn:se:uu:diva-324206 2017 Dissertation presented at Uppsala University to be publicly examined in B22, BMC, Husargatan 3, Uppsala, Friday, 22 September 2017 at 10:15 for the degree of Doctor of Philosophy (Faculty of Medicine). The examination will be conducted in English. Faculty examiner: Professor Carsten Uhd Nielsen (Syddanskt universitet, Department of Physics, Chemistry and Pharmacy). Abstract Perland, E. 2017. Atypical Solute Carriers. Identification, evolutionary conservation, structure and histology of novel membrane-bound transporters. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1346. 49 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0015-3. Solute carriers (SLCs) constitute the largest family of membrane-bound transporter proteins in humans, and they convey transport of nutrients, ions, drugs and waste over cellular membranes via facilitative diffusion, co-transport or exchange. Several SLCs are associated with diseases and their location in membranes and specific substrate transport makes them excellent as drug targets. However, as 30 % of the 430 identified SLCs are still orphans, there are yet numerous opportunities to explain diseases and discover potential drug targets. Among the novel proteins are 29 atypical SLCs of major facilitator superfamily (MFS) type. These share evolutionary history with the remaining SLCs, but are orphans regarding expression, structure and/or function. They are not classified into any of the existing 52 SLC families. -
Comparison of Human Solute Carriers
Comparison of human solute carriers Avner Schlessinger,1,2,3* Pa¨ r Matsson,1,2,3 James E. Shima,1,2,3,4 Ursula Pieper,1,2,3 Sook Wah Yee,1,2,3 Libusha Kelly,1,2,3,5 Leonard Apeltsin,1,2,3,5 Robert M. Stroud,6 Thomas E. Ferrin,1,2,3 Kathleen M. Giacomini,1,2,3 and Andrej Sali1,2,3* 1Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 2Department of Pharmaceutical Chemistry, University of California, San Francisco, California 3California Institute for Quantitative Biosciences, University of California, San Francisco, California 4Graduate Program in Pharmaceutical Sciences and Pharmacogenomics, University of California, San Francisco, California 5Graduate Program in Biological and Medical Informatics, University of California, San Francisco, California 6Department of Biochemistry and Biophysics, University of California, San Francisco, California Received 14 August 2009; Revised 10 December 2009; Accepted 14 December 2009 DOI: 10.1002/pro.320 Published online 5 January 2010 proteinscience.org Abstract: Solute carriers are eukaryotic membrane proteins that control the uptake and efflux of solutes, including essential cellular compounds, environmental toxins, and therapeutic drugs. Solute carriers can share similar structural features despite weak sequence similarities. Identification of sequence relationships among solute carriers is needed to enhance our ability to model individual carriers and to elucidate the molecular mechanisms of their substrate specificity and transport. Here, we describe a comprehensive comparison of solute carriers. We link the proteins using sensitive profile–profile alignments and two classification approaches, including similarity networks. The clusters are analyzed in view of substrate type, transport mode, organism conservation, and tissue specificity. -
And Space-Saving Hollow Fiber Membrane Module Unit for Water Treatment
FEATURED TOPIC Energy- and Space-Saving Hollow Fiber Membrane Module Unit for Water Treatment Keiichi IKEDA*, Tomoyuki YONEDA, Shinsuke KAWABE, Hiroko MIKI, and Toru MORITA ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- We have developed and marketed a new POREFLON membrane module unit for water treatment. It has a smaller footprint and is more energy saving than conventional products. In addition to the features of the conventional POREFLON hollow fiber membrane such as fouling resistance, high strength, and bending resistance, the module unit features the cassette type module structure, increased effective membrane length, enhanced packing density, and newly developed air diffusers that generate large air bubbles to prevent fouling. In a pilot test for municipal wastewater treatment jointly conducted with Japan Sewage Works Agency and others, we achieved a power consumption per unit of 0.4 kWh/m3 or lower, which was the target point for the popularization of membrane treatment. The module unit passed another several field trials and was currently commercialized. This report introduces the development process, product specifications, and case studies regarding the new membrane module unit. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
Chapter 7: Membranes
BIOL 1020 – CHAPTER 7 LECTURE NOTES Chapter 7: Membranes 1. What are the major roles of biological membranes? 2. What about phospholipids makes a bilayer when mixed with water? Use the term amphipathic, and contrast with what detergents do. 3. Describe the fluid mosaic model: what does it mean to have a 2-dimensional fluid and not a 3-dimensional one, and what does the “mosaic” term mean here? 4. Discuss membrane fluidity: why it is important and the ways it can be adjusted. 5. Contrast integral and peripheral membrane proteins. 6. Define and discuss these terms related to transport/transfer across cell membranes: selectively permeable diffusion concentration gradient osmosis tonics isotonic hypertonic hypotonic turgor pressure 7. What is carrier-mediated transport? Differentiate between facilitated diffusion and active transport. 8. Describe how the sodium-potassium pump works. 9. Explain linked cotransport. 10. Define the processes of exocytosis and endocytosis (include different forms of endocytosis). 11. Summarize processes for transport of materials across membranes; include information about which ones are active (energy-requiring). 12. Discuss information transfer across a membrane (signal transduction); why is it needed, what are some concepts that you should associate with it? 13. Differentiate between the following in terms of structure and function: anchoring junctions (such as desmosomes) tight junctions gap juntions plasmodesmata 1 of 7 BIOL 1020 – CHAPTER 7 LECTURE NOTES Chapter 7: Membranes I. Roles of biological membranes A. membranes separate aqueous environments, so that differences can be maintained 1. the plasma membrane surrounds the cell and separates the interior of the cell from the external environment 2. -
V.ANIMAL VIRUSES Great Emphasis Is Placed on Animal Viruses Because They Are the Causative Agents of Most Dangerous Diseases of Human and Animals
V.ANIMAL VIRUSES Great emphasis is placed on animal viruses because they are the causative agents of most dangerous diseases of human and animals. Due to these diseases human has to face different problems like loss of economy, loss of valuable time and energy and even death. To avoid these problems government and scientists create interest among peoples to study various features of animal viruses than other viruses. If we understand the basic concepts effectively, may help us to develop new diagnostic techniques, treatment procedures and control measures. In this chapter we discussed about viral morphology, multiplication, pathogenesis, diagnosis and treatment procedures of various diseases. 1.CLASSIFICATION OF ANIMAL VIRUSES Many viruses in the environment are shown to be infectious to animals and humans. To distinguish these agents a specific system is adapted, classification system. Morphology is probably the most important characteristic feature of virus classification. Modern classifications are primarily based on virus morphology, the physical and chemical nature of virions, constituents and genetic relatedness. Nucleic acid properties such as general type, strandedness, size and segmentations are also included in the classification system. Recent ICTV (International committee on Taxonomy of Viruses) system of virus classification classifies 28 families of animal viruses and is summarized here along with diagramatic representation. THE SINGLE STRANDED DNA VIRUSES Circoviridae Circovirus Chicken anemia virus Parvoviridae Parvovirinae -
Expression and Function of Organic Anion Transporting Polypeptides in the Human Brain: Physiological and Pharmacological Implications
pharmaceutics Review Expression and Function of Organic Anion Transporting Polypeptides in the Human Brain: Physiological and Pharmacological Implications Anima M. Schäfer 1, Henriette E. Meyer zu Schwabedissen 1 and Markus Grube 2,* 1 Biopharmacy, Department Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland; [email protected] (A.M.S.); [email protected] (H.E.M.z.S.) 2 Center of Drug Absorption and Transport (C_DAT), Department of Pharmacology, University Medicine of Greifswald, 17489 Greifswald, Germany * Correspondence: [email protected]; Tel./Fax: +49-3834-865636 Abstract: The central nervous system (CNS) is an important pharmacological target, but it is very effectively protected by the blood–brain barrier (BBB), thereby impairing the efficacy of many potential active compounds as they are unable to cross this barrier. Among others, membranous efflux transporters like P-Glycoprotein are involved in the integrity of this barrier. In addition to these, however, uptake transporters have also been found to selectively uptake certain compounds into the CNS. These transporters are localized in the BBB as well as in neurons or in the choroid plexus. Among them, from a pharmacological point of view, representatives of the organic anion transporting polypeptides (OATPs) are of particular interest, as they mediate the cellular entry of Citation: Schäfer, A.M.; Meyer zu a variety of different pharmaceutical compounds. Thus, OATPs in the BBB potentially offer the Schwabedissen, H.E.; Grube, M. possibility of CNS targeting approaches. For these purposes, a profound understanding of the Expression and Function of Organic expression and localization of these transporters is crucial. -
Mechanism of Phagocytosis in Phagocytosis Is Mediated by Different Recognition Sites As Disclosed by Mutants with Altered Phagoc
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by PubMed Central Mechanism of Phagocytosis in Dictyostelium discoideum : Phagocytosis is Mediated by Different Recognition Sites as Disclosed by Mutants with Altered Phagocytotic Properties GÜNTER VOGEL, LUTZ THILO, HEINZ SCHWARZ, and ROSWITHE STEINHART Max-Planck-Institut für Biologie, D74 Tübingen, Federal Republic of Germany ABSTRACT The recognition step in the phagocytotic process of the unicellular amoeba Dicty- ostelium discoideum was examined by analysis of mutants defective in phagocytosis . Reliable and simple assays were developed to measure endocytotic uptake. For pinocytosis, FITC- dextran was found to be a suitable fluid-phase marker; FITC-bacteria, latex beads, and erythrocytes were used as phagocytotic substrates . Ingested material was isolated in one step by centrifuging through highly viscous poly (ethyleneglycol) solutions and was analyzed opti- cally. A selection procedure for isolating mutants defective in phagocytosis was devised using tungsten beads as particulate prey. Nonphagocytosing cells were isolated on the basis of their lower density . Three mutant strains were found exhibiting a clear-cut phenotype directly related to the phagocytotic event. In contrast to the situation in wild-type cells, uptake of E. coli B/r by mutant cells is specifically and competitively inhibited by glucose. Mutant amoeba phagocytose latex beads normally but not protein-coated latex, nonglucosylated bacteria, or erythrocytes. Cohesive properties of mutant cells are altered: they do not form EDTA-sensitive aggregates, and adhesiveness to glass or plastic surfaces is greatly reduced . Based upon these findings, a model for recognition in phagocytosis is proposed : (a) A lectin- type receptor specifically mediates binding of particles containing terminal glucose (E.