Xenotransplantation of neonatal porcine islets have been demonstrated to be a viable alternative to exogenous insulin therapy for diabetes mellitus. The use of liberase has gained much success in islet isolation but factors such as batch-to-batch variation and deterioration of a batch with storage time have hampered the quality and reproducibility of tissue dissociation. Islet culture aims to optimise islet survival and insulin release in response to glucose challenge. However, it is difficult to recover and preserve islets in vitro. Mitochondria play a key role in the secretion of insulin from pancreatic islet cells in response to glucose stimulation. Mitochondrial dysfunction results in the induction (at mRNA and protein levels) of a molecular stress protein/heat chock protein called Cpn60. Since mitochondrial impairment will have a significant effect on the ability of in vitro cultured islet cells to function properly (i.e. release insulin in response to glucose stimulation), the expression of Cpn60 was investigated as a function of exposing neonatal porcine islet cells to various growth conditions. The best choice of media to culture neonatal porcine islet cells was found to be not heated activated serum which showed the least levels of Cpn60 expression at mRNA levels suggesting that the cells had low levels of mitochondrial stress. Neonatal porcine islet cells would be best digested in cells digested with new liberase (QC 1050) while in 2% not heat inactivated porcine serum (NPS) as this gave the lowest levels of Cpn60 expression suggesting low levels of mitochondrial stress. Although expression of Cpn60 at mRNA levels seems to be modulated during the growth of the porcine islet cells in media supplemented with different serum, heat treatment of serum and liberase content, no firm conclusion can be made with regard to the effect of the different treatments on mitochondrial health status until the porcine Cpn60 protein can be unequivocally identified.

Abstract inserted as part of Final MPH Thesis: Non-Communicable Diseases like diabetes, cardiovascular diseases, cancers and others, have become the major cause of premature death, morbidity and disability in many Pacific countries including Samoa. These are linked by common preventable risk factors like obesity, hypertension, smoking, unhealthy diets and physical inactivity. OBJECTIVES: To determine the trends and development of Non-Communicable diseases and its risk factors in Samoa over the last 24 years using the recently developed diagnostic criteria. RESEARCH DESIGN AND METHODS: This research thesis combines 3 large surveys that were done in 1978, 1991, and 2002, looking at the trends in the prevalence of diabetes, and the prevalence of the NCD risk factors such as blood pressure, obesity, cholesterol and smoking. The 3 survey samples were selected randomly from around similar regions (Urban Upolu, Rural Upolu, and Rural Savaii) of Samoa in 1978, 1991 and 2002, with a total of 5973 individuals (1978 survey = 1467; 1991 survey = 1778; 2002 survey = 2728) available for the thesis analysis. The 1978 and 1991 data sets were secured from Professor P Zimmet, and the 2002 STEPs survey data set was secured from the Samoa Ministry of Health. The 3 surveys methodologies, survey procedures, questionnaires and anthropometric measurements were similar though the diagnostic criteria used to measure obesity slightly differ between the surveys. The blood pressure measurements were similar though the diastolic blood pressure measure in 1978 was higher. The 1978 and 1991 surveys used fasting venous blood sampling to measure fasting plasma glucose, and cholesterol levels at the laboratory. OGTT was also used in 1978 and 1991, but not 2002. The 2002 survey used capillary sampling to measure fasting glucose using a glucometer, and cholesterol level using a cholesterol meter. The combined data was then cleaned, standardized and matched with each survey, to make analysis easier. The recent diagnostic criteria were then applied to all the surveys to diagnose diabetes (1999 WHO Diabetes Criteria), hypertension (WHO 1999, JNC-VII 2003, NHF 1999 Hypertension Criteria), obesity (BMI ≥30 kg/m??), and hypercholesterolaemia. The prevalences using the recent diagnostic criteria were then mapped out. RESULTS: The overall age-standardized prevalence of type 2 diabetes (known or previously unknown) utilizing the current 1999 WHO diagnostic criteria for men and women ≥20 years of age has increased from 5.4% (males 4.8%, females 5.9%) in 1978, to 12.0% (males 10.9%, females 13.5%) in 1991, and to 20.1% (males 17.2%, females 22.2%) in 2002. Among the individuals with diabetes in the 3 surveys, more than 60% had previously undiagnosed diabetes. Compared with the 1978 survey, the diabetes prevalence in 2002 represents a 4-fold increase over the 24 year period. This has occurred along with increasing obesity, urbanization and modernization, aging, cultural changes, and changes in physical activity. There is a high prevalence of non-communicable disease risk factors. The age-standardized prevalence of hypertension defined by the WHO 1999 and JNC-VII 2003 criteria was 47.2% in 1978, 22.5% in 1991, and 24.0% in 2002. The high prevalence of hypertension in 1978 was due to the method used for recording diastolic blood pressure. Hypertension was more common in the urban regions than rural regions in 1978 and 1991 while in 2002, there was no statistical difference between the rates of hypertension between the different regions due to the rise in the prevalence rate of hypertension in rural regions. There is a high prevalence of overweight and obesity in Samoa. Using the WHO classification for BMI, there was an increase in obesity (BMI ≥ 30kg/m??) prevalence in Samoa in the last decade, increasing steeply from 34.9% in 1978 to 51.3% in 1991, and slowing down to an increase to 57.4% in 2002. The prevalence of obesity is significantly higher in females compared with their male counterparts. The overweight prevalence (BMI 25-29.9kg/m??) was 34% in 1978, 31% in 1991 and 29% in 2002. The prevalence of obesity has increased by 65% from 1978 to 2002 with an increase of 47% from 1978 to 1991, and 12% from 1991 to 2002. Prevalence of obesity is increasing with age and is more of a problem in women than men. It is higher in the urban regions but there has been a faster rise in obesity prevalence in rural regions from 1978 to 2002 as the rural regions become urbanized. The prevalence of hypercholesterolaemia (total cholesterol ≥ 5.2 mmol/l) was 30.5% in 1978, and this increased to 51.1% in 1991. There was a marked decline of hypercholesterolaemia in 2002 (14.4%), which may be due to differences in the method of measurement. Although smoking prevalence remains high in Samoa it declined significantly from 42.4% 1978 to 35.3% 1991 but remained essentially steady at 38% in 2002. There was a significant gender difference in smoking with about 60% of men and 20% of women smoking regularly. CONCLUSION: Samoa is experiencing an increasing problem with Non-Communicable diseases like diabetes and some of its risk factors. Diabetes prevalence has dramatically increased by 4-fold in the last 24 years. The prevalence of hypertension has stabilized around 23% though there was a decrease from 1978. The prevalence of obesity has also increased. Smoking prevalence has slightly increased from 1991 to 2002 with a significant number of the population smoking. Hypercholesterolaemia is more common in 1991 with an apparent decrease in 2002. These findings have important implications for public health efforts and policy developments to contain the epidemic of Non-Communicable diseases in Samoa.

The focus of this thesis was leptin and its role in the development of obesity and non-insulin-dependent diabetes mellitus (NIDDM). Studies in Psammomys obesus, a polygenic animal model of obesity and NIDDM, showed that ob gene expression and plasma leptin concentration correlated significantly with body weight, percentage body fat and plasma insulin concentration. In addition, plasma leptin concentrations were significantly elevated in insulin resistant Psammomys obesus independent of body weight. Dietary energy restriction from weaning in Psammomys obesus prevented excessive body weight gain, hyperleptinemia and hyperglycemia compared with ad libitum fed animals. Interestingly, 19% of the energy-restricted animals still developed hyperinsulinemia and tended to have increased plasma leplin compared with normoinsulinemic energy-restricted Psammomys obesus. Fasting for 24 hours significantly reduced plasma leptin concentration in lean, insulin-sensitive but not obese, insulin-resistant P. obesus, suggesting a dysregulation in the response of leptin to acute caloric deprivation in these animals. The effects of leptin administration to P. obesus were also investigated. Single daily intraperitoneal injection of 5 mg leptin/kg body weight for 14 days had no significant effect in lean or obese P. obesus. This dose had previously been shown to rapidly and significantly reduce food intake and body weight in ob/ob and wild-type mice, suggesting relative leptin resistance in P. obesus. Acute (8 hour) effects of administration of 5 mg leptin/kg body weight were also investigated. No significant effects on food intake or plasma insulin were detected, however blood glucose concentrations were significantly elevated in obese, glucose intolerant P. obexus, suggesting an exacerbation of insulin resistance in susceptible animals. Treatment of lean, healthy P. obesus with 45 mg leptin/kg body weight/day for 7 days resulted in significant decreases in food intake and percentage body fat, showing that the leptin resistance observed in this species could be overcome by the administration of very large doses of leptin. In another study, leplin was shown to significantly inhibit maximal insulin binding to isolated adipocytes, suggesting that leptin may respresent an important link between obesity and NIDDM. Links between aspects of obesity and NIDDM and polymorphisms in the ob and p3-adrencrgic receptor genes were also investigated in two human populations.

Factors which may account for the high frequency of macrovascular disease in diabetics are age, sex, cigarette smoking, hypertension, obesity, lack of exercise, diet, hyperglycaemia, hyperinsulinaeroia, hypercholesterolaemia, hypertriglyceridaemia, low HDL-cholesterol concentration, elevated free fatty acid concentration and enhanced platelet aggregation. Twenty seven (13 men and 14 women) non-insulin-dependent diabetics and thirty eight age, height and weight matched healthy subjects (10 men and 28 women) were studied. None of the subjects were smokers, or hypertensive. No subject had any clinical evidence of peripheral arterial disease, coronary heart disease or cerebrovascular disease. All had apparently normal peripheral pulses and normal ankle/arm blood pressure indices. Methods for determining arterial compliance in the segment between the left subclavian artery and each common femoral artery, and proximal resistance at the common femoral artery and posterior tibial artery, have been reviewed and developed. An appropriate food intake methodology for deriving food indices from food records was developed. Biochemical determinants have been made of glucose tolerance, glycosylated haemoglobin, serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, plasma free fatty acid and insulin. A significant decrease in the arterial compliance, and a significant increase in the arterial proximal resistance at the common femoral artery and posterior tibial artery in non-insulin-dependent diabetics, compared with their healthy controls, have been found. Significant negative correlation between arterial compliance and proximal resistance and, a significant positive correlation between the arterial proximal resistance of common femoral artery and posterior tibial artery were found. Differences between control (healthy subjects) and non-insulin-dependent diabetic groups indicate that preclinical peripheral arterial disease can be recognised even in mild diabetics by non-invasive measurement of arterial compliance or proximal resistance. There were significant and negative correlations between arterial compliance and each of blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid and plasma insulin concentration. There were significant and positive correlations between arterial proximal resistance of common femoral artery and posterior tibial artery and each of blood glucose, glycosylated haemoglobin and plasma free fatty acid concentration. Multivariate analysis to examine each of the biochemical factors Including blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid, plasma Insulin and lipids, showed that the factor which most influenced the arterial compliance and the proximal resistance of posterior tibial artery was the glucose level in the fasting state or the glucose response after a glucose load. In addition, the factors which most influenced proximal resistance of the common femoral artery were free fatty acid -level in the fasting state or glucose response after a glucose load. The factors which most influenced arterial compliance were glucose level in men, and the insulin level in the fasting state or the plasma free fatty acid response after a glucose load in women. These findings indicate that blood glucose, plasma free fatty acid and plasma insulin are risk factors for changes in arterial wall characteristic at a stage when no clinical evidence of macrovascular disease is apparent. Arterial compliance was decreased and the proximal resistance of posterior tibial artery was increased in those with a low intake of protective foods compared with those with a high intake whether healthy subjects or non-insulin-dependent diabetics. Arterial compliance was decreased in non-fish eaters compared with the fish eaters whether healthy subjects or non-insulin-dependent diabetics. Proximal resistance of the posterior tibia! artery in non-fish eaters was increased compared with fish eaters in healthy subjects. Overall, food variety, a protective food score consumption and fish consumption emerge as importance determinants of arterial wall characteristics at a stage when no clinical evidence of macrovascular disease is apparent.

Gastric emptying, and small intestinal glucose exposure and absorption, are potentially important determinants of postprandial blood glucose homeostasis and energy intake. The studies presented in this thesis were designed to provide novel insights into the interrelationships of upper gastrointestinal function with glycaemia and appetite in both health and type 2 diabetes. The issues which were addressed relate in particular to : ( i ) the physiology, regulation and measurement of gastric and small intestinal motility, ( ii ) the relationships between small intestinal glucose exposure, incretin hormone release, antropyloroduodenal motility and appetite, and ( iii ) the impact of gastric and small intestinal motility on glycaemia. The study reported in chapter 4 evaluated the effect of variations in small intestinal glucose delivery on blood glucose, plasma insulin, and incretin hormone ( GLP - 1 and GIP ) concentrations in healthy subjects. While initially rapid, and subsequently slower, duodenal glucose delivery potentiated incretin and insulin responses when compared to constant delivery of an identical glucose load, the overall glycaemic excursion was not improved. These observations add to the rationale for the use of dietary and pharmacological strategies designed to reduce postprandial glycaemic excursions in health and type 2 diabetes by slowing gastric emptying, rather than initially accelerating it. Fat is a potent inhibitor of gastric emptying. In chapter 5, the acute effect of slowing gastric emptying by fat, on postprandial glycaemia in type 2 diabetes, has been evaluated. Ingestion of a small amount of olive oil, as a 'preload' 30 min before a carbohydrate meal, was shown to markedly slow gastric emptying, affect intragastric meal distribution, delay the postprandial rises in blood glucose, plasma insulin, and GIP, and stimulate GLP - 1. In contrast, the effects of including the same amount of oil within the meal, on gastric emptying, as well as glycaemic and incretin responses, were relatively modest. As blood glucose levels had not returned to baseline by 210 min ( the end of each experiment ), effects on the overall glycaemic ( or insulinaemic ) response could not be determined ; this represents a priority for future studies. The energy content of a meal is a major determinant of its rate of gastric emptying. The study reported in chapter 6 demonstrated that the substitution of an artificial sweetener ( "diet" mixer ) for sucrose ( "regular" mixer ) in a mixed alcoholic beverage has a major impact on the rate of gastric emptying and alcohol absorption in healthy adults. A low calorie alcohol - containing drink ( made with "diet" mixer ) emptied from the stomach much more rapidly and resulted in higher blood alcohol concentrations when compared with a relatively high calorie alcoholic drink ( made with "regular" mixer ). These observations highlight the need for community awareness of factors, other than the alcohol content of a beverage, which should be taken into account in considering safe levels of consumption and the potential for inebriation. Upper gastrointestinal motor function and incretin hormone ( GLP - 1 and GIP ) secretion are known to be major determinants of postprandial glycaemia and insulinaemia, however, the impact of small intestinal flow events on glucose absorption and incretin release has not been evaluated. In the study reported in chapter 7, intraduodenal pressures and impedance signals were recorded simultaneously in healthy humans, while glucose was infused into the duodenum in the presence and absence of the anticholinergic drug, hyoscine butylbromide. The frequency of duodenal flow events ( evaluated by impedance ) was suppressed by hyoscine much more than that of duodenal pressure waves, or propagated pressure wave sequences ( evaluated by manometry ). Blood glucose and plasma 3 - OMG concentrations ( the latter provide an index of glucose absorption ) were lower during hyoscine than saline. Plasma insulin, GLP - 1, and GIP concentrations were initially lower during hyoscine. The disparity between impedance measurements and manometry in detecting alterations in flow during hyoscine infusion was marked and, accordingly, supports the potential utility of small intestinal impedance monitoring to evaluate alterations in gastrointestinal transit in various disease states. The observations also indicate that the frequency of small intestinal flow events is a determinant of both glucose absorption and incretin release. Intraduodenal administration of the local anaesthetic, benzocaine, has been shown to attenuate the release of cholecystokinin ( CCK ) by small intestinal lipid, and the perceptions of fullness, discomfort, and nausea induced by gastric distension during small intestinal lipid infusion, implying that local neural mechanisms may regulate CCK release in response to intraduodenal nutrients. In chapter 8, the effects of intraduodenal administration of benzocaine on : ( i ) blood glucose, incretin hormone and insulin concentrations ( ii ) antropyloroduodenal motility, and ( iii ) gut sensations and appetite, in response to an intraduodenal glucose infusion, were evaluated in healthy subjects. Benzocaine attenuated the perceptions of abdominal bloating and nausea, but had no effect on antro - pyloro duodenal motility, blood glucose concentrations, or incretin responses. These observations indicate that the induction of sensations by small intestinal glucose is mediated by local neural pathways. GLP - 1 is released from L - cells whose density is greatest in the distal jejunum and ileum, GIP predominantly from duodenal K cells, and cholecystokinin ( CCK ) from I cells, which appear confined to the duodenum and jejunum. The study reported in chapter 9 evaluated the effects of infusion of glucose into different gut regions ( mid - jejunal vs duodenal ) on incretin hormones, CCK, appetite and energy intake in healthy subjects. There was no difference in the incretin responses between infusion at the two sites ( 85 cm apart ), however the stimulation of CCK and suppression of hunger and energy intake, were greater with the duodenal compared to the jejunal infusion. These observations indicate that the site of small intestinal glucose exposure is a determinant of CCK release and appetite. Both glucose and fat are known to be potent stimuli for incretin secretion, but the effect of protein is uncertain. Protein may also stimulate insulin secretion directly via absorption of amino acids. In the study reported in chapter 10, gastric emptying, and the blood glucose, insulin and incretin responses, alter a 300 mL drink containing 50 g glucose, 25 g protein, or both 50 g glucose and 25 g protein, were evaluated in healthy subjects. This study established that the addition of protein to an oral glucose load improved the glycaemic response, predominantly by slowing gastric emptying. However, protein also stimulated incretin and insulin secretion. These observations have implications for the use of protein in the dietary management of type 2 diabetes. The relationship between glycaemia, incretin hormones, appetite suppression and modulation of antropyloroduodenal motility with duodenal glucose delivery is poorly defined. In chapter 11, the effects of intraduodenal glucose infusions at different caloric rates ( of 1 kcal / min, 2 kcal / min and 4 kcal / min, or control ( saline ) ) on antropyloroduodenal motility, plasma GLP - 1, GIP and CCK, appetite and energy intake have been evaluated in healthy subjects. While there was a rise in blood glucose in response to all the intraduodenal glucose loads, there was no significant difference in the response to infusions at 2 kcal / min and 4 kcal / min. An initial, transient, small rise in GLP - 1 was evident, in response to all glucose loads, but a sustained and progressive rise only occurred with the 4 kcal / min infusion. In contrast, a load - dependent stimulation of GIP occurred in response to all glucose infusions. The stimulation of CCK was much greater in response to the 4 kcal / min infusion. While antral pressures were suppressed by all rates of glucose infusion, the stimulation of basal pyloric pressure was load - dependent. Energy intake was suppressed only by the 4 kcal / min infusion. This may potentially reflect the substantially greater stimulation of CCK, consistent with the observations reported in chapter 9. This study establishes that there is a substantial discordance in the acute effects of small intestinal glucose on glycaemia, incretin hormones, CCK, motility and appetite. It is planned to perform measurements of plasma insulin on the stored samples - these results were, unfortunately, not available at the time of the submission of this thesis and are critical to the overall interpretation of the data. / Thesis (Ph.D.)--University of Adelaide, School of Medicine, Discipline of Medicine, 2007.

230 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--University of Adelaide, Dept. of Psychiatry, 1976

A five stage selection protocol originally applied to mouse embryonic stem cells (mESCs) was examined for the derivation of insulin producing cells from human embryonic stem cells (hESCs). Insulin gene expression was observed and insulin protein was measured by radioimmunoassay. However, the radioimmunoassay results were shown to be susceptible to false positive findings due to the presence of exogenous insulin within differentiation media and it was concluded that this particular strategy was not ideal for the derivation of insulin producing cells from hESCs. An investigation was then undertaken regarding the in vivo differentiation of cells derived from hESCs seeded within 3D scaffolds to determine if this would result in the derivation of insulin producing cells. Within scaffolds there were abundant cells which stained positively for ectoderm lineage markers including nestin. Cells which stained positively for markers of endothelial progenitors representing the mesoderm lineage were also observed and rare cells stained for endoderm markers including insulin. These investigations also demonstrated that transplanting scaffolds seeded with cells derived from hESCs between the liver lobules of immunodeficient mice could lead to the formation of teratomas. Factors that may have influence the formation of teratomas were further investigated and it was demonstrated that teratoma formation was inhibited by altering in vitro treatment of cells. An in vitro investigation was then performed to determine the extracellular matrix (ECM) producing capacity of hESCs and differentiated cells derived from hESCs because ECM proteins are required for the formation of 3D structures similar to pancreatic islets. The results from this investigation indicated that differentiated cells produced multiple ECM proteins at substantially higher levels than hESCs. The ECM producing differentiated cells could be useful in the development of surrogate islet like tissue by supplying a suitable ECM structure within a 3D scaffold environment to aid the function of ??-cell surrogates. Furthermore, these differentiated cells derived from hESCs were shown to produce an adhesive basement membrane in vitro, which is derived from human sources, and could be utilized in the derivation, propagation and differentiation of hESCs.

Thesis (M.D.S.)--University of Hong Kong, 1989. / Includes bibliographical references (p. 116-125) Also available in print.

No description available.

<p>Syftet med studien var att beskriva på vilket sätt barn med diabetes och deras föräldrar blir informerade om kostens betydelse och vilken information som ges vid sjukdomen diabetes. Studien har en deskriptiv design och bygger på fem intervjuer av sjuksköterskor som arbetar med barn med diabetes på två olika sjukhus i Mellansverige. Intervjuerna har gjorts av båda författarna tillsammans. Den analysmetod som används var kvalitativinnehållsanalys. De kategorier som framkom var: Tidig information om kostens betydelse, Informationen anpassas efter individ och familj,<strong> </strong>Informationshjälpmedel, Motiverande samtal och Samarbete mellan hem och skola. Barnen och deras föräldrar informeras av både läkare, sjuksköterska och dietist. Diabeteskosten är till största del dietistens område, men även sjuksköterskan informerar om diabeteskosten då patienterna ofta har många frågor som gäller just kosten.    Sjuksköterskorna använder sig av många olika hjälpmedel när de ska undervisa patienterna då alla lär sig på olika sätt. Med hjälp av de olika hjälpmedlen kan undervisningen anpassas till barnets ålder. Patientundervisningen sker till största del på sjukhuset, men även i den skola där barnet går eftersom det är viktigt att alla personer som finns runt barnet får lära sig om diabetes och diabeteskosten.</p>