Thesis (Ph.D.)--Flinders University, School of Medicine, Dept. of Clinical Pharmacology. / Typescript bound. Includes bibliographical references: (leaves 334-391) Also available electronically.

No description available.

Li Ka Shing Prizes for best PhD theses in the Faculties of Dentistry, Engineering, Medicine and Science, 2006-2007 / published_or_final_version / abstract / Pathology / Doctoral / Doctor of Philosophy

published_or_final_version / Physiology / Master / Master of Philosophy

published_or_final_version / Surgery / Master / Master of Medical Sciences

The metabolism and distribution of three commonly occurring PCB congeners, 4,4'-dichlorobiphenyl (4-DCB), 2,2',3,3',6,6'-hexachlorobiphenyl (236-HCB) and 2,2',4,4',5,5'-hexachlorobiphenyl (245-HCB), each displaying different structural features, were investigated at their principal metabolic site, the hepatocyte. Hepatocytes, isolated from male Sprague-Dawley rats (200-250 g) by collagenase perfusion, were suspended in medium 199 and maintained at 37°C in a gyratory shaker. The radiolabeled ¹⁴C-PCB congeners were added to the hepatocyte suspensions as a DMSO-albumin mixture. Each congener was rapidly taken up by the cells with less than 10% of the congener remaining in the medium. The congeners accumulated within the hepatocytes without being fully metabolized. Metabolism followed first order Michaelis-Menten kinetics for 20 min and plateaued by 90 min at which point only 32% of 4-DCB (0.01-100 uM) and 60% of 236-HCB (0.01-100 uM) was metabolized, while 245-HCB (0.1-200 uM) was not metabolized. Readdition of congener once metabolism had plateaued resulted in a reinitiation of metabolism with the same proportion of metabolites produced indicating that product inhibition was not the cause for the plateau. A partitioning of the PCB congeners within subcellular compartments and binding to cytosolic proteins influenced the extent of metabolism by decreasing the availability of congener for the drug metabolizing enzymes, cytochrome P-450. Spectral binding studies further revealed that the ability of a PCB congener to bind to the cytochrome P-450 system correlated with the extent of metabolism observed, with 236-HCB 4-DCB 245-HCB. The metabolic potential of the PCB congeners was influenced by both the affinity of the congener for cytochrome P-450 and the partitioning of congener within the hepatocyte, and not by product inhibition.

This study was designed to examine the influence of Cu deficiency on the binding, uptake, and degradation of apolipoprotein E-free high density lipoproteins (apo E-free HDL) in cultured rat hepatic parenchymal cells. The binding of apo E-free HDL during time course studies was slightly but significantly increased in cells derived from Cu-deficient rats. In saturation studies, the amount of surface-bound apo E-free HDL appeared to be saturable, although no difference was observed between Cu-deficient and adequate animals. The amount of total and specific cell-associated uptake of apo E-free HDL was significantly increased in hepatic parenchymal cells of Cu-deficient animals. The present data suggest that hepatic uptake of the HDL protein moiety may be increased in rats fed a diet deficient in copper.

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Lee, Ngan Hon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 120-133). / Abstracts in English and Chinese. / Acknowledgements --- p.IV / Abstract --- p.V / 論文摘要 --- p.VII / Table of Contents --- p.IX / List of Figures --- p.XI / List of Abbreviations --- p.XIII / Chapter 1 Introduction --- p.1 / Chapter 1.1 --- Hepatocellular carcinoma (HCC) --- p.1 / Chapter 1.1.1 --- Risk factors --- p.1 / Chapter 1.1.2 --- Molecular mechanism of HCC --- p.4 / Chapter 1.1.3 --- Treatment of HCC --- p.7 / Chapter 1.2 --- Gambogic acid (GA) - a compound derived from Tradition Chinese Medicine (TCM) --- p.9 / Chapter 1.2.1 --- Traditional Chinese Medicine (TCM) --- p.9 / Chapter 1.2.2 --- Gambogic acid --- p.13 / Chapter 1.3 --- Molecular mechanism of apoptosis --- p.18 / Chapter 1.3.1 --- Overview of apoptosis --- p.18 / Chapter 1.3.2 --- Caspases cascade --- p.18 / Chapter 1.3.3 --- Bcl-2 family --- p.20 / Chapter 1.3.4 --- Mitochondria in apoptosis --- p.23 / Chapter 1.4 --- Apoptosis as a strategy for cancer therapies --- p.26 / Chapter 1.5 --- Aims of study --- p.29 / Chapter Chapter 2 --- Materials and Methods --- p.30 / Chapter 2.1 --- Cell culture and treatment --- p.30 / Chapter 2.1.1 --- Cell lines used --- p.30 / Chapter 2.1.2 --- Gambogic acid (GA) --- p.31 / Chapter 2.1.3 --- Chemicals and reagents --- p.31 / Chapter 2.1.4 --- Preparation of solutions --- p.32 / Chapter 2.1.5 --- Procedures --- p.33 / Chapter 2.2 --- Apoptotic detection --- p.35 / Chapter 2.2.1 --- Chemicals and reagents --- p.35 / Chapter 2.2.2 --- Preparation of solutions --- p.35 / Chapter 2.2.3 --- Procedures --- p.37 / Chapter 2.3 --- Effects of GA on gene expression in HepG2 --- p.41 / Chapter 2.3.1 --- Chemicals and Reagents --- p.41 / Chapter 2.3.2 --- Preparation of solutions --- p.41 / Chapter 2.3.3 --- Procedures --- p.43 / Chapter 2.4 --- Protein expression in GA-induced apoptotic cells --- p.51 / Chapter 2.4.1 --- Chemicals and Reagents --- p.51 / Chapter 2.4.2 --- Preparation of solution --- p.51 / Chapter 2.4.3 --- Procedures --- p.54 / Chapter 2.5 --- Caspase cascade study in GA-induced apoptosis --- p.60 / Chapter 2.5.1 --- Chemicals and reagents --- p.60 / Chapter 2.5.2 --- Procedures --- p.60 / Chapter 2.6 --- Downregulation of mRNA using siRNA vector --- p.62 / Chapter 2.6.1 --- siRNA expression vector --- p.62 / Chapter 2.6.2 --- Chemicals and Reagents --- p.63 / Chapter 2.6.3 --- Preparation of solution --- p.63 / Chapter 2.6.4 --- Procedures --- p.64 / Chapter Chapter 3 --- Results --- p.71 / Chapter 3.1 --- GA induces apoptosis in hepatocellular cells --- p.71 / Chapter 3.2 --- Effects of gene expression in HCC --- p.80 / Chapter 3.3 --- Caspase cascade studies in GA-induced apoptosis --- p.83 / Chapter 3.4 --- Caspase 8 activation in GA-treated cells lead to Bid cleavage --- p.89 / Chapter 3.5 --- GA induces Bax conformational changes and cytochrome c release --- p.95 / Chapter 3.6 --- Levels of protein players involved in apoptosis and cell cycle --- p.101 / Chapter Chapter 4 --- Discussion --- p.106 / References --- p.120

Bibliography: leaves 116-138.