Transplantation of Pancreatic Islet in an Immunoisolation Device

Background: Type-1 diabetes is caused by autoimmune destruction of insulin-producing B-cells in the pancreas. Today, transplantation of whole pancreas or islets is the only treatment that can restore endogenous insulin production. Within the past 20 years, pancreatic islet transplantation has become a clinical reality and an option in diabetes treatment. However, large use of this therapy is limited by shortage in organ donations and use of immunosuppressive drugs. Immunoisolation potentially allows elimination of immunosuppressive drugs and use of xenogenic tissue solving the problem of a shortage in organ donation. Aims: The present work was designed to ameliorate isolation of islets from different species and encapsulation of islets in immunoisolation devices (hollow fibres and microcapsules). Moreover, a mathematical model for immunoisolation membrane selection was developed. Results and Conclusions: The application of the automated method allows significant increase in the number of islets obtained. These islets were then used for in vitro or in vivo studies of immunoisolation devices, tested in different protocols. Experimental results indicate that islet transplantation using alginate gel microcapsule in the peritoneal cavity successfully control glycaemia in diabetic animals. However, it is not possible to translate in human application for the implantation site. An alternative strategy was developed based on membrane device to be used in the subcutaneous space. Despite permeability properties have been proved to be adequate, the in vivo functional response of transplanted islet in hollow fibre device was only temporary, probably for development of fibrotic tissue around the device. Future work: The use of theoretical model allows evaluation and selection of new membrane materials for islet immunoisolation. Efficacy of new devices would be determined by performing allo- or xeno- transplantations into diabetic recipients, exploring new sites of implantation that minimize surgical procedures and reduce implant failure

Apoptosis and Medicine

This book looks at the latest research studies on apoptosis in medicine. It is divided into three sections for convenient and easy reading. The first section which comprises two chapters is an introduction of the subject of apoptosis to the uninitiated. The second section which comprises a single solitary chapter looks at apoptosis in normal physiology during bone resorption under mechanical stress. The third and the final section reviews apoptosis in a number of pathological conditions with an emphasis on cancer

Treatment of Later Humoral Rejection with Anti-CD20 Monoclonal Antibody Rituximab: A Single Centre Experience

Humoral or vascular rejection is a B cell-mediated production of immunoglobulin (Ig) G antibody against a transplanted organ that results in immune complex deposition on the vascular endothelium, activation of the complement cascade, production of endothelial dysfunction and regional ischaemic injury

Histopathological changes in male wistar rats maintained on a water-based sutherlandia frutescens extract

In this study a standardized 46 week chronic drinking water toxicity protocol was used to elucidate the toxic potential of Sutherlandia frutescens (S. frutescens) using histopathologic, morphometric and transmission electron microscopic analysis. The histopathologic changes in the duodenum, heart, kidney, liver, lung, pancreas and spleen of male Wistar rats were evaluated. Fifty-four rats were randomly divided into four groups: Group 1 – Normal diet control (ND control), n=7, Group 2 – Normal diet + plant extract (ND + p), n=9, Group 3 – High fat diet control (HFD control), n=19Group 4 – High fat diet + p (HFD + p), n=19In the high fat group male Wistar rats were fed ±55 g/day of a specialised high fat diet over a 46 week period to induce obesity and an insulin resistant state. The treatment groups (groups 2 and 4) received a dose concentration of a tea extract of the S. frutescens plant in their drinking water daily. This study showed that the consumption of S. frutescens significantly reduces weight gain in male Wistar rats on a chronic high fat diet (p≤0.001 vs. HFD control group). S. frutescens appears to propagate periportal and centrilobular glycogen storage in rat hepatocytes in the experimental groups as exemplified by a significantly (p≤0.0001 vs. control groups) increased incidences of Periodic Acid Schiff (PAS) positive staining S. frutescens also reduced intracellular lipid accumulation as made evident by the significantly lower incidence of epicardial adipose tissue (EAT), hepatic steatosis and pancreatic interstitial fat. Obesity was associated with increased fibrotic lesions such as myocardial perivascular fibrosis, centrilobular hepatic fibrosis and pancreatic periductal fibrosis. Obesity associated hypertension contributed to the widespread and significant increase in the average lesion severity of arterial congestion in all organs in the HFD control group. Pulmonary infection was equally prevalent in all rats. Despite the complex histopathology in all groups, differences in the control groups, such as, the presence of a conservative polymorphonuclear leukocyte (PMNL) infiltration, substantial intra-alveolar oedema and focal arterial wall hypertrophy in the control groups was highly suggestive of Sendai viral infection. However histopathologic evidence, in the treatment groups, suggested chronic recurrent viral infection with superimposed Mycoplasma pulmonis (M. pulmonis) bacterial infection. The impact of advanced suppurative pulmonary infection was widespread and exemplified by increased lesion incidences of spontaneous murine progressive cardiomyopathy (MCP) and spontaneous chronic progressive nephropathy (CPN) among others. In conclusion S. frutescens administered for 46 weeks to male Wistar rats significantly lowered intracellular lipid accumulation and obesity associated myocardial, renal, hepatobiliary, pulmonary and pancreatic histopathology. Moreover, duodenal, cardiovascular, hepatobiliary, pulmonary, renal, pancreatic and splenic tissue did not show histopathologic evidence of direct plant extract associated toxicity or carcinogenicity

Studies in design and development of stomach specific drug delivery system using various approaches

Not availabl