In the first study, I aimed to compare the angiotensin II type 1 receptor (AT1R) expression levels of the isolated pancreatic islets from normal and mouse model of T2DM. In addition, 4-week-old diabetic mice were orally treated with AT1R antagonist losartan for 8 weeks. It is found that AT1R mRNA was upregulated markedly in diabetic islets and double-immunolabeling confirmed that AT1R was localized to beta-cells. Losartan selectively improved glucose-induced insulin release and (pro)insulin biosynthesis in diabetic islets. Oral losartan treatment delayed the onset of diabetes, and reduced hyperglycemia and glucose intolerance in diabetic mice. These data indicate that AT1R antagonism improves beta-cell function and glucose tolerance in young T2DM mice. / In the second study, I aimed to examine how the upregulated RAS could impair beta-cell function, where oxidative stress is the potential mediator. Meanwhile, T2DM results in oxidative stress-mediated activation of uncoupling protein 2 (UCP2), a negative regulator of islet function. Thus, it was postulated that some of the protective effects of AT1R antagonism might be mediated through interference with this pathway and tested this hypothesis in a mouse model of T2DM. In order to achieve this, losartan was given to 4-week-old diabetic mice for 8 weeks. UCP2-driven oxidative damage and apoptosis were analyzed in isolated islets. Results showed that losartan selectively inhibited oxidative stress via NADPH oxidase downregulation; this in turn suppressed UCP2 expression, thus improving beta-cell insulin secretion while decreasing apoptosis-induced beta-cell mass loss in diabetic mice islets. These data indicate that islet AT1R activation in young diabetic mice can lead to progressive islet beta-cell failure through UCP2-driven oxidative damage and apoptosis. / The mechanisms by which chronic hyperglycemia associated with glucotoxicity causes beta-cell dysfunction and apoptosis remain ambiguous. Voltage-gated outward potassium (Kv) current, which mediates beta-cell membrane potential and limits insulin secretion, could play a role in glucotoxicity. Meanwhile the RAS has been shown to be upregulated by prolonged exposure to high glucose. In the third part of my study, I therefore investigated the effects of prolonged exposure to high glucose and angiotensin II (Ang II) on the expression and activity of Kv channels in mouse pancreatic beta-cell. Dissociated mice beta-cells, incubated in 5.6 mM or 28 mM glucose for 3-5 days, were used for electrophysiological study; while isolated islets cultured for 1-7 days were proceeded for gene/protein expression analysis. Both Kv channel expression and current were markedly increased by prolonged glucose incubation. Simultaneously, Ang II reduced Kv current under normal glucose condition, while high glucose incubation abolished the effect of Ang II. Moreover, the ability of Ang II on Kv current reduction was eliminated by inhibiting AT2R but not AT1R. These data indicated that Ang II reduced Kv current via AT2R, which was abolished by prolonged high glucose incubation. On the other hand, high glucose increased Kv channel expression and current, which might alter the ability of insulin secretion in beta-cell. (Abstract shortened by UMI.) / Chu, Kwan Yi. / Adviser: P. S. Leung. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3246. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 163-188). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Conclusions. The growing epidemic of type 2 diabetes and its cardiorenal complications place a major burden on our health care system. Diabetic kidney disease is of particular importance in Asian populations including Chinese. In this series of studies, using a large prospective cohort established since 1995, I confirmed the powerful predictive value of albuminuria on cardio-renal complications. Inhibition of the RAAS interacted with both modifiable and genetic factors, notably the ACE I/D polymorphism, on the development of cardio-renal complications. In addition, it was found that CKD predicts CVD independent of albuminuria. Based on two prospective studies, I confirmed the effectiveness of global risk-factor control using structured care protocol to prevent these devastating complications. (Abstract shortened by UMI.) / I then examined the possible independent and interactive effects of CKD and albuminuria on cardio-renal outcomes in the original cohort of 5,004 patients. Glomerular filtration rate was estimated (eGFR) by the Modification of Diet in Renal Disease equation. The frequency of CKD as defined by eGFR <60ml/min/1.73m 2 was 15.8% in the cohort at baseline, when 6% of patients had serum creatinine ≥150mumol/L. / In collaboration with colleagues, I have conducted a series of studies to examine the prognostic factors for cardio-renal complications in Chinese type 2 diabetic patients. The modulating effects of RAAS inhibition and the effectiveness of rnuitidisciplinary care to prevent ESRD are also examined. / Research Hypotheses. (1) Albuminuria is a prognostic factor on cardio-renal outcomes in type 2 diabetes patients; (2) Chronic Kidney Disease is associated with other metabolic risk factors and phenotypes and is a prognostic factor on cardio-renal outcomes in type 2 diabetes patients; (3) Angiotensin-converting-enzyme insertion/deletion polymorphism is a prognostic factor on cardio-renal outcomes in type 2 diabetes patients, and has an effect on treatment responses with RAAS blockage with ACE inhibitors; (4) Structured care models by risk stratification using various prognostic factors and adherence to care protocol can improve cardio-renal outcome in type 2 diabetes patients. / Results. In a prospective cohort of 5,004 patients, I examined the effect of albuminuria and ACE inhibition on survival and cardio-renal outcomes in 3,773 patients who had been observed for at least 6 months with a mean follow up period of 35.8 months. / Taken together, measurement of serum creatinine alone without GFR estimation may underestimate the frequency of CKD in Chinese type 2 diabetic patients. Estimated GFR was inversely associated wit-29h an increasing frequency of micro- and macrovascular complications cross-sectionally and an increased risk of all-cause mortality prospectively, independent of albuminuria and metabolic control. / So Wing Yee. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3422. / Thesis (M.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 203-243). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.

Background. Diabetes mellitus is a complex metabolic disorder characterized by clustering of multiple cardiovascular risk factors. Diabetic albuminuria is associated with increased prevalence of both micro-vascular and macro-vascular complications. This thesis examined vascular function (Flow-mediated dilatation, FMD) in type 2 diabetic patients with particular emphasis on its relationships with nephropathy. Independent predictors for FMD in Chinese population using data from both diabetic and non-diabetic subjects as well as the predictive value of FMD on clinical endpoints and death in type 2 diabetic patients with nephropathy were examined. / Conclusions. In Chinese subjects with or without type 2 diabetes, hyperglycaemia, hypertriglyceridemia, smoking and albuminuria were independent predictors for FMD. Type 2 diabetic subjects with overt nephropathy had impaired endothelium-dependent and endothelium-independent dilatation, suggesting vascular dysfunction beyond the endothelium. In agreement with studies from Caucasians, smoking was the most important determinant for vascular dysfunction in Chinese type 2 diabetic patients with overt nephropathy. Furthermore, FMD was predictive of new onset of cardiovascular events and related death in Chinese type 2 diabetic patients with overt nephropathy. / In diabetic patients with overt nephropathy, smoking (current and ex-smokers), waist hip ratio (WHR) and serum creatinine were independent predictors for impaired FMD. The latter was predictive of advancement of IMT and was an independent predictor for new onset of combined cardiovascular diseases and related death after a follow up period of 42 months (log rank test=6.04, p=0.014 using Cox regression analysis) after controlling for all confounding factors. In addition, fasting total cholesterol and plasma glucose were predictive for all-cause mortality while serum creatinine predicted new onset of renal endpoint. In a subgroup analysis in diabetic patients with overt nephropathy, smokers who developed CVD or ESRD had greater diminution of FMD than those who did not develop clinical endpoints. / Methods and results. FMD was assessed using high-resolution ultrasound scan. In the cross-sectional study, the sample population was divided into four groups according to the presence or absence of type 2 diabetes and level of albuminuria. They included the non-diabetic group (N=52), diabetic group with normoalbuminuria (N=18), diabetic group with microalbuminuria (N=18) and diabetic group with overt nephropathy defined as macroalbuminuria and renal insufficiency (N=22). Compared to non-diabetic subjects, type 2 diabetic subjects with nephropathy had impaired FMD (4.54% +/- 2.25 vs. 2.50% +/- 2.31, p<0.05) and impaired GTN-dependent dilatation (GTND) (14.30% +/- 3.77 vs. 12.70% +/- 4.70, p<0.05). They also had reduced endothelium-dependent dilatation to endothelium-independent dilatation ratio when compared to non-diabetic subjects (0.19 +/- 0.17 vs. 0.32 +/- 0.15, p<0.05). These findings suggest that the impaired vascular dilatation was due to dysfunction of both endothelium and vascular smooth muscle cells. In the entire cohort, fasting plasma glucose, fasting triglyceride, smoking and albuminuria were independent predictors for FMD. / Lai Wai Keung Christopher. / "February 2006." / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6298. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 202-252). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Conclusion. The equations developed in this study provide a more accurate estimate of GFR, ranging from normal to renal impairment, in both Chinese diabetic and non-diabetic patients, compared to currently available GFR formulae. / Hypothesis/objectives. Type 2 diabetes mellitus is a major health burden associated with increased morbidity and mortality as well as socio-economic impact. A rapid increase in disease prevalence has been reported and predicted in China and other Asian countries. Patients with low and declining GFR and microalbuminuria are at high CVD risk. A simple and precise predictive equation of GFR for Chinese diabetic patients is essential in the light of the growing epidemic of diabetes and CKD in Chinese population both for monitoring and treatment purposes. In this pilot study, a set of accurate, simple and clinically practical equations to predict GFR in Chinese type 2 diabetic patients was established. Their performance was validated using separate samples of diabetic and non-diabetic subjects and compared with other widely used GFR formulae. / Methods. 202 type 2 diabetic patient and 46 non-diabetic patients were enrolled in the study. Of these 135 were randomly selected as the training sample; the remaining 67 diabetic patients and 46 non-diabetic patients constituted 2 validation groups. The prediction equation was developed by stepwise regression applied to the training sample. The equation was then tested and compared with other prediction equation including MDRD and CG equations in the validation samples. / Results. Independent factors associated with GFR included age, serum creatinine concentration, serum urea nitrogen level and serum albumin levels (P < 0.005 for all factors). Two predictive formulae, sRFCD and RFCD, were established. Simplified Renal formula in Chinese Diabetes (sRFCD) Study (ml/min/1.73 m2) is: GFR (for men) = 90400 x (Age)-0.495 (yr) x [ SCr]-1.097 (mumol/l) GFR (for women) = 58983 x (Age)-0.542 (yr) x [SCr]-1.012 (mumol/l) and Renal formula in Chinese Diabetes (RFCD) Study (ml/min/1.73 m2) is: GFR (for men) = 11825 x (Age)-0.494 x [SCr]-1.059 (mumol/l) x [Alb]+0.485 (g/l) GFR (for women) = 34166 x ( Age)-0.489 x [SCr] -0.877 (mumol/l) x [SUN] -0.150 (mmol/l) The multiple regression model explained 89.9% and 89.4% respectively of the variance in the logarithm of GFR. Compared to other GFR formulae, the sRFCD and RFCD formulae showed less bias and were more precise and accurate in estimating GFR in diabetic patients whereas the sRFCD and MDRD formulae showed better performance in non-diabetic patients. / Leung Tak Kei. / "July 2006." / Adviser: Juliana C. N. Chan. / Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5117. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 161-180). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Patients’ perceptions of health care and support is a key determinant in self-efficacy and active participation in the management of chronic conditions. Nurses play a significant role in Diabetes Self-Management Education by providing clients with tools, empowerment and knowledge to self-manage their condition. The purpose of this study was to examine and describe diabetes patients’ perceptions of nurses’ support for self-management in Botswana. The aim was to improve clients’ skills in self-management and to strengthen diabetes health care management. This study was carried out at the Diabetes Clinic of Excellence, in the city of Francistown, the second largest city in Botswana. The study population comprised of Type 2 Diabetes patients registered at the Diabetes Clinic for their follow-up. All were aged 18 years and above. Three hundred and fifty-four (354) patients participated in the study. The study used a non-experimental, descriptive, quantitative design. Probability sampling method was used to recruit diabetes patients from the selected clinic. Data were were collected using a structured, researcher developed, questionnaire mostly in face-to-face interviews, a few participants completed the questionnaire. The Quantitative data analysis included descriptive and inferential statistics using SPSS (Statistical Package for Social Science Software (version 25). Spearman rho was used to determine statistical correlation between patients’ perceptions and their self-management practices. The findings showed that generally, patients’ perceptions of professional support was positive regarding most of the constructs measured. However, there were areas that showed less satisfaction with the support such as foot-care, risk control, and ability to identify signs of low and high blood sugar level and carrying of Identification Band (ID). Perceptions of nurses’ motivational behaviour showed varied responses. Patients’ self-care activities were sub-optimal and showed some variations which tended to correspond with their perceptions of professionals support. The Spearman's correlation results ranged from strong, moderate, and weak positive correlation. A few demographic variables showed some impact on self-care activities. Based on the findings, the study concludes that professional support through DSME and DSMS, self-management and patients’ perceptions of care play a significant role in diabetes management. / Health Studies / M.A. (Nursing Science)

Zhang, Ji. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 100-104). / Abstracts in English and Chinese. / Chapter CHAPTER 1. --- Introduction / Chapter 1.1. --- Introduction of genetic association studies --- p.1 / Chapter 1.1.1. --- Application of genetic association studies in complex diseases --- p.3 / Chapter 1.1.2. --- Application of genetic association studies in type-2 diabetes --- p.4 / Chapter 1.2. --- Study design of genetic association studies --- p.7 / Chapter 1.3. --- Overview of statistical approaches in association studies --- p.10 / Chapter 1.3.1. --- Preliminary analyses --- p.10 / Chapter 1.3.1.1. --- HardýؤWeinberg equilibrium testing --- p.10 / Chapter 1.3.1.2. --- Inference of missing genotype data --- p.12 / Chapter 1.3.1.3. --- SNP tagging --- p.14 / Chapter 1.3.2. --- Single-point and multipoint tests for association --- p.15 / Chapter 1.4. --- Other relevant methods employed in this study --- p.20 / Chapter 1.4.1. --- Self-Organizing Maps (SOM) with further classification by K-means clustering --- p.20 / Chapter 1.4.2. --- Random forests --- p.27 / Chapter 1.5. --- Main objectives of this study --- p.31 / Chapter CHAPTER 2. --- Materials and methods / Chapter 2.1. --- Study cohort --- p.32 / Chapter 2.2. --- Study design --- p.34 / Chapter 2.2.1. --- Construction of sample sets for each stage using SOM and K-means clustering --- p.34 / Chapter 2.2.2. --- Stage 1 analysis by random forests --- p.37 / Chapter 2.2.3. --- Stage 2 analysis by chi-square test --- p.42 / Chapter 2.2.4. --- Two-stage genetic association study by chi-square test --- p.43 / Chapter 2.2.5. --- Comparison of results: random forests plus chi-square test versus chi-square test --- p.43 / Chapter 2.2.6. --- Validation of results in the whole sample set by allelic chi-square test --- p.44 / Chapter 2.2.7. --- Extensions of the study: cumulative effects of candidate SNPs on risk of type-2 diabetes --- p.45 / Chapter CHAPTER 3. --- Results / Chapter 3.1. --- Effects of sample classification by SOM and K-means clustering --- p.50 / Chapter 3.2. --- Genetic associations in stage 1 --- p.64 / Chapter 3.3. --- Genetic associations in stage 2 and validation of results --- p.69 / Chapter 3.4. --- Cumulative effects of candidate SNPs on risk of type-2 diabetes --- p.76 / Chapter CHAPTER 4. --- Discussion / Chapter 4.1. --- Overall strategy --- p.81 / Chapter 4.1.1. --- Effects of SOM and K-means clustering --- p.82 / Chapter 4.1.2. --- Effects of random forests in the first stage of association study --- p.83 / Chapter 4.1.3. --- Comparison of our method with traditional chi-square test --- p.84 / Chapter 4.1.4. --- Joint effects of candidate SNPs selected by the hybrid method --- p.86 / Chapter 4.2. --- Biological significance of candidate SNPs --- p.88 / Chapter 4.2.1. --- Gene CDKAL1 --- p.89 / Chapter 4.2.2. --- Gene KIAA1305 --- p.90 / Chapter 4.2.3. --- Gene DACH1 --- p.91 / Chapter 4.2.4. --- Gene FUCA1 --- p.92 / Chapter 4.2.5. --- Gene KCNQ1 --- p.93 / Chapter 4.2.6. --- Gene SLC27A1 --- p.94 / Chapter 4.3. --- Limits and improvement of this study --- p.96 / Chapter 4.4. --- Conclusion --- p.99 / REFERENCES --- p.100

Lui, Ming Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 117-129). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract --- p.III / Abstract in Chinese --- p.V / List of Abbreviations --- p.VII / List of Figures --- p.X / List of Tables --- p.XII / Table of Contents --- p.XIII / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Overview on type 2 diabetes --- p.1 / Chapter 1.1.1 --- Definition of diabetes --- p.1 / Chapter 1.1.2 --- Diagnostic criteria --- p.2 / Chapter 1.1.3 --- Prevalence and societal impact --- p.2 / Chapter 1.1.4 --- Risks factors for type 2 diabetes --- p.4 / Chapter 1.1.4.1 --- Metabolic syndrome --- p.4 / Chapter 1.1.4.2 --- Genetics of type 2 diabetes --- p.6 / Chapter 1.1.4.3 --- "Environmental risk factors, lifestyle and energy imbalance" --- p.8 / Chapter 1.1.5 --- Pathophysiology of type 2 diabetes --- p.9 / Chapter 1.1.5.1 --- Insulin secretion and signaling --- p.9 / Chapter 1.1.5.1.1 --- Insulin Secretion --- p.9 / Chapter 1.1.5.1.2 --- Insulin signaling --- p.11 / Chapter 1.1.5.2 --- Natural history of type 2 diabetes --- p.12 / Chapter 1.1.5.3 --- Insulin resistance --- p.13 / Chapter 1.1.5.4 --- Impairment in insulin secretion --- p.15 / Chapter 1.1.5.5 --- Endocannabinoid system: A new target for energy balance and metabolism --- p.16 / Chapter 1.1.5.6 --- Effects of diabetes mellitus and its complications --- p.16 / Chapter 1.2 --- Biology of prostacyclin synthase (PTGIS) --- p.18 / Chapter 1.2.1 --- Molecular information of PTGIS --- p.18 / Chapter 1.2.2 --- Transcriptional control of PTGIS --- p.19 / Chapter 1.2.3 --- Protein structure of PGIS --- p.21 / Chapter 1.2.4 --- Sub-cellular localization and tissue distribution --- p.22 / Chapter 1.2.5 --- Function of PGIS --- p.25 / Chapter 1.2.5.1 --- Function of PGI2 in blood vessels --- p.26 / Chapter 1.2.5.2 --- Role of PGh in embryo development --- p.26 / Chapter 1.2.5.3 --- Role of PGI2 in apoptosis --- p.27 / Chapter 1.2.5.4 --- Targeted knock-out mice phenotype --- p.27 / Chapter 1.2.6 --- Relationship between PTGIS and diseases --- p.28 / Chapter 1.2.6.1 --- Genetic association --- p.28 / Chapter 1.2.6.2 --- Inactivation and tyrosine nitration of PGIS by peroxynitrite --- p.29 / Chapter 1.3 --- Biology of peroxisome proliferator-activated receptor delta (PPARD) --- p.30 / Chapter 1.3.1 --- Molecular information of PPARD --- p.30 / Chapter 1.3.2 --- Transcriptional control of PPARD --- p.31 / Chapter 1.3.3 --- Translational control and protein structure --- p.32 / Chapter 1.3.4 --- Sub-cellular localization and tissue expression --- p.35 / Chapter 1.3.5 --- Function of PPARδ --- p.37 / Chapter 1.3.5.1 --- Mechanisms of action --- p.37 / Chapter 1.3.5.2 --- Ligands for PPARδ --- p.38 / Chapter 1.3.5.3 --- PPARδ in lipoprotein metabolism --- p.39 / Chapter 1.3.5.4 --- PPARδ action in adipose tissue --- p.39 / Chapter 1.3.5.5 --- PPARδ action in skeletal and cardiac muscle --- p.40 / Chapter 1.3.5.6 --- PPARδ action in liver --- p.42 / Chapter 1.3.5.7 --- PPARδ and endocannabinoid system --- p.42 / Chapter 1.3.5.8 --- PPARδ action in inflammation --- p.43 / Chapter 1.3.5.9 --- Targeted knock-out mice phenotype --- p.44 / Chapter 1.3.5.10 --- Disease association --- p.44 / Chapter 1.4 --- Functional relationship of PGIS and PPARδ: possible role in energy metabolism --- p.46 / Chapter 1.5 --- Methods for studying genetics of type 2 diabetes and linkage analysis results --- p.47 / Chapter 1.5.1 --- Genome-wide scan --- p.47 / Chapter 1.5.2 --- Candidate gene approach --- p.48 / Chapter 1.6 --- Hypothesis and objectives --- p.49 / Chapter 1.7 --- Long-term significance --- p.49 / Chapter Chapter 2: --- Association Study of Prostacyclin Synthase and Peroxisome Proliferator-Activated Receptor Delta Gene Polymorphisms with Type2 Diabetes and Related Metabolic Traits / Chapter 2.1 --- Introduction and research design --- p.50 / Chapter 2.2 --- Study population --- p.52 / Chapter 2.2.1 --- Ethics approval --- p.52 / Chapter 2.2.2 --- Subjects --- p.52 / Chapter 2.2.3 --- Clinical assessments --- p.52 / Chapter 2.3 --- Materials and methods --- p.55 / Chapter 2.3.1 --- DNA samples --- p.55 / Chapter 2.3.2 --- Marker selection --- p.55 / Chapter 2.3.3 --- Genotyping --- p.57 / Chapter 2.3.4 --- Statistical analysis --- p.59 / Chapter 2.4 --- Results and Discussion --- p.60 / Chapter 2.4.1 --- Clinical characteristics of the study population --- p.60 / Chapter 2.4.2 --- Genotyping and LD analysis --- p.60 / Chapter 2.4.3 --- Association with type 2 diabetes and related metabolic traits --- p.61 / Chapter 2.4.3.1 --- Single SNP association with type 2 diabetes --- p.61 / Chapter 2.4.3.2 --- Single SNP association with metabolic traits --- p.64 / Chapter 2.4.3.3 --- Gene-gene interaction on type 2 diabetes --- p.74 / Chapter 2.4.3.4 --- Gene-gene interaction on metabolic traits --- p.74 / Chapter 2.5 --- Limitation and improvement --- p.79 / Chapter 2.6 --- Conclusions --- p.79 / Chapter Chapter 3: --- Functional Studies of Prostacyclin Synthase rs508757-A/G Intronic Polymorphism / Chapter 3.1 --- Introduction and research design --- p.80 / Chapter 3.2 --- Materials and methods --- p.81 / Chapter 3.2.1 --- Bioinformatics --- p.81 / Chapter 3.2.1.1 --- Cross-species alignment --- p.81 / Chapter 3.2.1.2 --- BLAST search and open reading frame prediction --- p.81 / Chapter 3.2.1.3 --- Transcription factor binding sites prediction --- p.82 / Chapter 3.2.2 --- PCR amplification from cDNA --- p.82 / Chapter 3.2.3 --- Culture of mammalian cell --- p.83 / Chapter 3.2.3.1 --- Cell line --- p.83 / Chapter 3.2.3.2 --- Medium and supplement --- p.83 / Chapter 3.2.3.3 --- Cell culture wares --- p.83 / Chapter 3.2.3.4 --- Cell culture conditions --- p.84 / Chapter 3.2.4 --- Construction of reporter vectors with rs508757 flanking sequence --- p.84 / Chapter 3.2.4.1 --- Cloning and vector preparation --- p.84 / Chapter 3.2.4.2 --- Site-directed mutagenesis --- p.84 / Chapter 3.2.5 --- Dual-luciferase reporter assay --- p.85 / Chapter 3.2.5.1 --- Transfection of VSMC --- p.85 / Chapter 3.2.5.2 --- Cell lysis and luminescence measurement --- p.86 / Chapter 3.2.6 --- Circular Dichroism --- p.87 / Chapter 3.2.6.1 --- Introduction to DNA quardruplex structure and circular dichroism --- p.87 / Chapter 3.2.6.1.1 --- DNA quardruplex --- p.87 / Chapter 3.2.6.1.2 --- Circular dichroism --- p.88 / Chapter 3.2.6.2 --- Circular dichroism measurement --- p.89 / Chapter 3.2.6.2.1 --- DNA samples --- p.89 / Chapter 3.2.6.2.2 --- CD spectroscopy --- p.89 / Chapter 3.2.7 --- Statistical analysis --- p.90 / Chapter 3.3 --- Results and Discussion --- p.91 / Chapter 3.3.1 --- Cross-species alignment --- p.91 / Chapter 3.3.2 --- BLAST search and ORF prediction --- p.92 / Chapter 3.3.3 --- PCR results on testing the presence of a new transcript --- p.93 / Chapter 3.3.4 --- Effect of rs508757 flanking sequence on SV40 promoter activity --- p.94 / Chapter 3.3.5 --- Circular dichroism experiment on rs508757 flanking sequence --- p.96 / Chapter 3.3.6 --- DNA slipping model --- p.98 / Chapter 3.3.7 --- Transcription factor binding site prediction --- p.99 / Chapter 3.4 --- Limitation and improvement --- p.107 / Chapter 3.5 --- Conclusions --- p.107 / Chapter Chapter 4: --- "General Discussion, Conclusion and Future Perspectives" / Chapter 4.1 --- General discussion --- p.108 / Chapter 4.2 --- Future perspectives --- p.115 / Chapter 4.2.1 --- "Association on type 2 diabetes and molecular interaction between transcription factors, PTGIS and PPARD" --- p.115 / Chapter 4.2.2 --- Association with diabetic nephropathy --- p.115 / Chapter 4.2.3 --- Study tissue or cell type specific actions of PGIS and PPARδ --- p.116 / Chapter 4.3 --- Conclusions to my project --- p.116 / Chapter Chapter 5: --- Bibliography --- p.117 / Appendix --- p.130

It is currently accepted that the most appropriate diet in the treatment of non-insulin-dependent diabetes mellitus &quoteNIDDM&quote is high in carbohydrates, high in fibre and low in fat. Dietary fibre reduces the rate of carbohydrate absorption, which may have a beneficial effect on insulin action. Furthermore, high fibre diets also increase the amount of carbohydrates which are not absorbed from the small intestine. These malabsorbed carbohydrates are fermented by the bacterial population in the large intestine, producing short chain fatty acids &quoteSCFA&quote, including propionate, which has been shown to alter liver carbohydrate metabolism. This thesis investigated the actions of slowed carbohydrate absorption and carbohydrate malabsorption in streptozotocin-induced &quoteSTZ&quote diabetic rats. High carbohydrate diet supplemented with guar gum, a soluble dietary fibre, fed to STZ diabetic rats improved insulin sensitivity. investigation of the alterations in the stomach and small intestine demonstrated that guar increased the viscosity of the meal in the intestine. The action of increased fermentation, producing more propionate, was investigated by supplementing propionate into the diets of STZ diabetic rats or when perfused into isolated rat livers. No changes in insulin action or liver glucose metabolism were measured. in addition, it was shown that guar gum reduces food intake in STZ diabetic rats. Mild reductions in food intake in STZ diabetic rats were shown to increase insulin action. In summary, STZ diabetic rats fed high carbohydrate, high fibre diets reductions in food consumption and slowed carbohydrate absorption are important factors which may lower blood glucose concentrations and increase insulin action. increased SCFA production is unlikely to contribute significantly to the improvements in insulin action.

Thesis (Ph. D.)--University of Wisconsin--Madison, 2000. / Includes bibliographical references (leaves 125-131).

[Formulae and special characters can only be approximated here. Please see the pdf version of the Abtract for an accurate reproduction.] Type 2 diabetes at least doubles the risk of cardiovascular disease. This can partly be explained by the increased prevalence of risk factors such as hypertension, dyslipidaemia and obesity. However, the underlying abnormality of insulin resistance and the presence of more recently identified risk factors including endothelial dysfunction, increased inflammation, and increased oxidative stress might also contribute towards the heightened cardiovascular risk. Fish oil, which contains eicosapentaenoic acid (EPA, 20:5 n-3), has wide-ranging beneficial effects on these and other abnormalities, and has reduced cardiovascular mortality in secondary prevention studies. Animal and human studies have recently established that in addition to EPA, docosahexaenoic acid (DHA, 22:6 n-3) also has beneficial effects, and furthermore, may have less detrimental effects than EPA on glycaemic control which has worsened in some fish and fish oil studies involving Type 2 diabetic subjects. Study 1 : This intervention study aimed to determine the independent effects of EPA and DHA on cardiovascular risk factors and glycaemic control in individuals with Type 2 diabetes receiving treatment for hypertension. In a double-blind placebo-controlled trial of parallel design, 59 subjects in good to moderate glycaemic control (HbA1c < 9%) were recruited from media advertising and randomised to 4 g/day of EPA, DHA or olive oil (placebo) for 6 weeks. Thirty-nine men and 12 post-menopausal women aged 61.2±1.2 yrs completed the study. Relative to placebo, and with Bonferroni adjustments for multiple comparisons, serum triglycerides fell by 19% (p=0.022) and 15% (p=0.022) in the EPA and DHA groups respectively. There were no changes in serum total cholesterol, or LDL- and HDL-cholesterol, although HDL2-cholesterol increased 16% with EPA (p=0.026) and 12% with DHA (p=0.05). HDL3-cholesterol fell by 11% (p=0.026) with EPA supplementation and LDL particle size increased by 0.26±0.10 nm (p=0.02) with DHA. Urinary F2-isoprostanes, an in-vivo marker of oxidative stress was reduced by 19% following EPA (p=0.034) and by 20% following DHA. DHA but not EPA supplementation reduced collagen-stimulated platelet aggregation (16.9%, p=0.05) and thromboxane release (18.8%, p=0.03), but there were no significant changes in PAF-stimulated platelet aggregation. Fasting glucose rose by 1.40±0.29 mmol/l (p=0.002) following EPA and 0.98±0.29 mmol/l (p=0.002) following DHA. Neither EPA nor DHA had any significant effect on HbA1c, fasting serum insulin or C-peptide, insulin sensitivity, stimulated insulin secretion, 24-hr ambulatory blood pressure and heart rate, markers of inflammation, and fibrinolytic or vascular function. Study 2 : This study aimed to examine the influence and causes of increased inflammation on vascular function in subjects recruited for Study 1. Compared with healthy controls (n=17), the diabetic subjects (n=29) had impaired flow-mediated dilatation (FMD) (3.9±3.0% vs 5.5±2.4%, p=0.07) and glyceryl-trinitrate mediated dilatation (GTNMD) (11.4±4.8% vs 15.4±7.1%, p=0.04) of the brachial artery. They also had higher levels of the inflammatory markers C-reactive protein (2.7±2.6 mg/l vs 1.4±1.1 mg/l, p=0.03), fibrinogen (3.4±0.7 g/l vs 2.7±0.3 g/l, p<0.001) and tumor necrosis factor-alpha (20.9±13.4 pg/l vs 2.5±1.7 pg/l, p<0.001). In diabetic subjects, after adjustment for age and gender, leukocyte count was an independent predictor of FMD (p=0.02), accounting for 17% of total variance. Similarly, leukocyte count accounted for 23% (p<0.001) and IL-6 for 12% (p=0.03) of variance in GTNMD. Von Willebrand factor, a marker of endothelial cell activation was correlated with leukocyte count (r=0.38, p=0.04), FMD (r=-0.35, p=0.06) and GTNMD (r=-0.47, p=0.009), whilst P-selectin, a marker of platelet activation was correlated with fibrinogen (r=0.58, p=0.001). Conclusion : EPA and DHA have similar beneficial effects on triglycerides, HDL2 cholesterol and oxidative stress in individuals with Type 2 diabetes and hypertension. However, DHA also increases LDL particle size and reduces collagen-stimulated platelet aggregation and thromboxane release, thus offering more potential than EPA as an anti-thrombotic agent. The beneficial effects of both oils were potentially offset by deterioration in glycaemic control. Neither oil affected blood pressure or vascular function. Longer-term studies with major morbidity and mortality as the primary outcome measures are required to assess the overall benefits and risks of EPA and DHA. The cross-sectional observations from Study 2 are consistent with the hypothesis that impaired vascular function in individuals with Type 2 diabetes and hypertension is at least in part secondary to increased inflammation, with associated endothelial and platelet activation.