To study the expression of CTLA4Ig gene in diabetic rat and the effect of CTLA4Ig on longterm survival of the pancreatic islet. The rat pancreatic islet cell and muscle cell transfected with the cDNA for CTLA4Ig packaged with lipofectin vector. We examined the expression level of CTLA4Ig gene, T lymphocyte reaction and observed the expression of CTLA4Ig cDNA in diabetic rat and the action of CTLA4Ig in longterm survival of pancreatic islet transplanted and the transplanted rats. Results: The T lymphocyte reaction from peripheral intravenous blood at seventh day after surgery, the difference between two group was significant (Ｐ＜0.05). Only 2 out of 10 recipients of the experiment group (A) at the seventh day after pancreatic islet allograft had any detectable levels of CTLA4Ig, their concentration was 14 ng/ml, and 31 ng/ml. The average time of maintaining blood glycose in normal levels of the group A after pancreatic islets graft, 14.8±12.3 days, was significantly longer than 3.6±5.1 days of the control group (B) (Ｐ＜0.05). The average survival time of the group A, 24.0±10.8 days (the longest time was 45 days), was significantly longer than 11.8±4.8 days (the longest time was 21 days) of the group B (Ｐ＜0.01). Conclusions: The muclse cells and pancreatic islets of the recipient rat was transfected with CTLA4IgcDNA packaged with lipofectin, and CTLA4IgcDNA was expressed in recipient tissue, its expressed product CTLA4Ig make pancreatic islets transplanted and recipient rat survive longer significantly.
Objective To review the general approaches in isolation and purification of pancreatic islets and progress in several aspects. Methods The latest l iterature concerning acquisition of pancreatic islets was reviewed and analyzed interms of the choice of pancreatic islet donors, the digestion and isolation of pancreas, the purification of islet and the assay of outcome. Results The profile of the isolation and purification depends on the selection of reagents and methods of operation in every step and l inkup between every step. Conclusion Pancreatic islet transplantation is the most effective method to treat type 1 diabetes, the problem of inadequate sources of pancreatic islets could be resolved by the optimal process and the establ ishment of standardized operation.
Objective To study the effect of anti-CD40L monoclonal antibody on the rejection of rat pancreatic islet xenografts and its mechanism. Methods The animal models of human-rat pancreatic islet xenografts were established and were treated with anti-CD40L monoclonal antibody. The levels of blood glucose of transplantation rats were measured and the survival of grafts and transplantation rats were observed after transplantation. The morphological changes of grafts were observed and the levels of cytokines (IL-2 and TNF-α) were quantified by ELISA. Results ①Level of blood glucose in all the rats with diabetes decreased to normal on day (2.3±0.2) after transplantation. The average level blood glucose of control group began to increase on day (8.1±0.6), while the treatment group began to increase on day (18.5±1.2) after transplantation, which was significantly postponed compared with control respectively (P＜0.01). ②Grafts of treatment group and control group survived for (22±8.2) and (10±2.1) days respectively. Survival of grafts in treatment group was significant longer than that in control group (P＜0.01). ③Survival of transplantation rats were (35±6.5) and (21±5.7) days in treatment group and control group respectively. The survival of transplantation rats in treatment group was significant longer than that in control group (P＜0.05). ④Levels of serum IL-2 and TNF-α in control group increased dramatically within (3.2±0.3) days and reached peak within (7.3±0.5) days after transplantation, which were significantly higher than those measured before transplantation (P＜0.01); While in treatment group, the levels of serum IL-2 and TNF-α began to increase on day (22.6±1.7) after transplantation, and reached peak on day (28.5±2.2), which was significantly postponed than those in control group (P＜0.01). Conclusion Anti-CD40L monoclonal antibody can inhibit the rejection of rat pancreatic islet xenografts and prolong the survival time of transplantation rats and grafts.
Objective To investigate the effect of nidus vespae on lymphocyte blastisation in mixed culture system of lymphocyte and pancreatic islet. Methods Solution of nidus vespae was extracted with ethanol from its herb. Rat lymphocyte and pig pancreatic islet were isolated and then were mixed together and cultured in incubators of 37 ℃ (concentration in volume: 5%CO2). Three different concentrations of extracted solution of nidus vespae （experimental group Ⅰ: 4.0 g/ml, group Ⅱ: 0.4 g/ml, group Ⅲ: 0.2 g/ml） were added to the mixed culture system of lymphocyte, respectively. Radioactive nuclide counts per minute were measured by 3H-thymdine test in order to examine the role of nidus vespae in inhibiting blatisation of lymphocyte, and the results were also compared with control group and CsA group, respectively. Results The counts were all reduced significantly (P＜0.001) in 3 experimental groups compared with control group (group Ⅰ 45.3%, group Ⅱ 29.6%and group Ⅲ 9.2%). It also showed that the inhibitory effect became ber in higher concentration but still weaker than that in CsA group (80.7%). Conclusion Nidus vespae could inhibit the blastisation of lymphocyte in mixed culture system of lymphocyte and pancreatic islet, and the effect increased as the the concentration increased, which may suggest that nidus vespae could suppress the rejection induced by T cells.
【Abstract】ObjectiveTo investigate the value of volumetric interpolated breathhold examination (3DVIBE) MRI sequence in the diagnosis of functional islet cell tumors of the pancreas. MethodsDedicated MRI scan was performed for 3 patients suspected to have functional islet cell tumors of the pancreas on clinical and laboratory basis. The MRI scan protocol included routine axial T1W and T2W, coronal true fast imaging with steady state procession (TrueFISP) and MRCP, gadoliniumenhanced 3DVIBE dynamic triphasic acquisitions and enhanced 2D GRE T1W scan. The three phases images of 3DVIBE sequence were acquired at 15 s, 40 s and 65 s after injection of contrast agent, corresponding to the early arterial, late arterial and portal venous phase respectively. The imaging features were compared with surgical and pathological findings. ResultsThe triphasic images of 3DVIBE sequence depicted clearly the morphology of small functional islet cell tumors of the pancreas and reflected accurately the characteristics of tumor blood supply, while other MRI sequences might miss these small lesions. ConclusionThinslice and fast dynamic MRI sequence, as exemplified by 3DVIBE sequence, is very useful in the detection and characterization of pancreatic functional islet cell tumors.