published_or_final_version / abstract / toc / Zoology / Master / Master of Philosophy

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No description available.

In a cross-sectional study we examined Iipoprotein composition and CETP mass in 15 sedentary and 12 exercising, healthy male volunteers, aged between 17-35 years. The exercising group were defined as individuals participating in at least five weekly 45 minute exercise sessions of an aerobic nature (60-85% estimated maximal oxygen uptake). The sedentary subjects were only irregularly engaged in bouts of physical activity, not more than 45 minutes per week. Seasonal data were collected: one data collection in the fall and one in the spring. A 20 day food and exercise journal was maintained during each season's data collection period. Blood lipids were measured on two and anthropometric and aerobic capacity testing were performed on 1 occasion during each season. Statistical analyses consisted of a two way ANOVA (exercise and season) to control for seasonal effects on blood lipids and Iipoprotein levels. Pearson product moment correlations were calculated between those variables that showed significant seasonal or level of activity changes. Exercising males consumed significantly greater amounts of energy (p<O.OOI), carbohydrates (p<O.OOOI), protein (p<O.OOOI), and dietary fibre (p<O.OOOI) than sedentary males; sedentary males however, consumed significantly greater amounts of alcohol than exercising males. Exercising males had significantly higher aerobic capacities and degrees of mesomorphy than sedentary subjects and exhibited significantly lower apo AI values. No differences were noted between the 2 groups in BMI, % body fat, other plasma lipids or CETP mass. In summary, regular physical activity in young, healthy male subjects was associated with increased energy and carbohydrate intake and improved aerobic capacity as compared to sedentary subjects. Moderate differences in physical activity were not however associated with alterations in plasma Iipoprotein composition or CETP concentration.

No description available.

The application of Molecular Biochemistry for transfection studies in eukaryotic systems is well documented. Of the numerous methods employed for the introduction of foreign DNA into eukaryotic cells, the use of low density lipoproteins (LDL) as carriers of DNA into cells has not been reported. LDL was isolated, characterized with respect to its protein and lipid components, and then variously modified in an attempt to enhance its affinity for DNA. It was found that both unmodified and modified LDL could interact with DNA, at physiological pH. The carbodiimide modified LDL (ECDI - LDL) showed the greatest affinity for DNA. LDL and ECDI - LDL were used to study LDL receptor binding in skin fibroblasts. This was followed by a study of receptor binding activities of both unmodified LDL and ECDI - LDL complexed to DNA (pBR322). Although the extent of binding of ECDI - LDL and ECDI - LDL - DNA complexes to plasma membranes was greater, the internalization and degradation of both modified and unmodified LDL complexes were equivalent. This additional binding was attributed to non - receptor - specific affinity of the carbodiimide modified complexes for the plasma membrane. The transfection of foreign DNA into eukaryotic cells in culture was monitored by assaying for the expression of the cloning vector, pSV2cat, complexed to LDL or ECDI - LDL and introduced into the cells by LDL receptor - mediated endocytosis. Of the cell lines in which the expression of the pSV2cat recombinant DNA was monitored, the human lung fibroblasts showed the greatest activity of the expressed chloramphenicol acetyl transferase enzyme. Although transfection efficiency was lower than that of the calcium phosphate - DNA coprecipitation procedure, the LDL receptor - mediated transfection of eukaryotic cells was carried out under physiological conditions and may be applicable in vivo. / Thesis (Ph.D)-University of Durban-Westville, 1987.

In a cross-sectional study we examined lipoprotein composition and CETP mass in 15 sedentary and 12 exercising, healthy male volunteers, aged between 17-35 years. The exercising group were defined as individuals participating in at least five weekly 45 minute exercise sessions of an aerobic nature (60-85% estimated maximal oxygen uptake). The sedentary subjects were only irregularly engaged in bouts of physical activity, not more than 45 minutes per week. Seasonal data were collected: one data collection in the fall and one in the spring. A 20 day food and exercise journal was maintained during each season's data collection period. Blood lipids were measured on two and anthropometric and aerobic capacity testing were performed on 1 occasion during each season. Statistical analyses consisted of a two way ANOVA (exercise and season) to control for seasonal effects on blood lipids and lipoprotein levels. Pearson product moment correlations were calculated between those variables that showed significant seasonal or level of activity changes. Exercising males consumed significantly greater amounts of energy (p $<$ 0.001), carbohydrates (p $<$ 0.0001), protein (p $<$ 0.0001), and dietary fibre (p $<$ 0.0001) than sedentary males; sedentary males however, consumed significantly greater amounts of alcohol than exercising males. Exercising males had significantly higher aerobic capacities and degrees of mesomorphy than sedentary subjects and exhibited significantly lower apo AI values. No differences were noted between the 2 groups in BMI, % body fat, other plasma lipids or CETP mass. In summary, regular physical activity in young, healthy male subjects was associated with increased energy and carbohydrate intake and improved aerobic capacity as compared to sedentary subjects. Moderate differences in physical activity were not however associated with alterations in plasma lipoprotein composition or CETP concentration.

Penicillium chrysogenum was investigated to determine whether there are lipoproteins specifically associated with fatty acid synthesis and in what fraction of P. chrysogenum they are located. Radio-activity labeled free fatty acids and CoA thioester substrates were added to cell-free extracts and incubated. Samples of these incubation mixtures were analyzed for lipoprotein content with electrophoresis and for the presence of radioactivity with a radiochromatogram scanner and scintillation spectrometer.Label from fatty acyl thioester substrates migrated with protein fractions having alpha-2 or beta mobility showing the existence of lipoproteins associated with fatty acid metabolism in cell-free extracts of P. chryogenum. The percent distribution of radioactivity from the thioester incubations supported previous work in this laboratory on the desaturase system and suggested the presence of a long chain fatty acyl-CoA-ACP synthetase enzyme in Penicillium chrysogeum.

Bibliography: leaves 105-151. / xi, 151, [47] leaves, [3] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis examines the effect of remodelling HDL on the metabolism of apo A-I. The major focus is on the effects of CETP and LCAT in the regulation of apo A-I concentration in DHL. The effects of incubation of HDL with CETP in the presence of VLDL and/or LDL on apo A-I concentration in HDL are examined. The characterization of the dissociated apo A-I from HDL is presented. The studies demonstrate that the dissociation of apo A-I from HDL mediated by CETP is preventable and reversible in a process dependent on LCAT activity. The mechanism by which HDL apo A-I content is increased is also explored. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 1997?

Includes bibliographical references (leaves 198-223) / xxiv, 223 leaves, [13] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the metabolism of plasma lipoprotein triacylglyceride in sheep (Ovis aries) under normal fed conditions, fasting and alloxan diabetes. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, Waite Agricultural Research Institute, 1987