[Clinical analysis of autoimmune pancreatitis: a single center study of 14 consecutive cases].

OBJECTIVE: To investigate the characteristic findings of autoimmune pancreatitis (AIP) to increase the recognition of AIP. METHODS: From February 2002 to April 2008, a total of 14 cases of AIP were reviewed by clinical, imaging, serologic, histopathologic features and treatment response. There were 13 male and 1 female, with a mean age of 53 years. The main clinical manifestations included progressive obstructive jaundice in 11 cases, upper abdomen pain in 3 cases. RESULTS: Diffuse enlargement of pancreas and diffuse narrowing of the main pancreatic duct (MPD) were observed in 11 cases, while 3 patients showed localized pancreatic head enlargement and focal narrowing of the MPD. Distal common bile duct stenosis was found in all cases. Increased expression of serum immunoglobulin G was found in 7 patients. Autoantibody test was positive in 5 of 12 patients. Nine of 14 patients with AIP had extrapancreatic organ involvement. Massive lymphocytes and plasma cells infiltration in pancreatic tissues were showed on pathology, as well as parenchymal fibrosis. Seven earlier patients were treated initially with surgical laparotomy or resection for suspected malignancy. Steroid therapy was given to the other patients and was responsive. There were 4 recurrences after initial treatment. CONCLUSION: AIP should be a differential diagnosis in pancreatic head mass in order to avoid unnecessary resection.

[Effect of inducible nitric oxide synthase on pancreas islet apoptosis in rats].

AIM: To investigate the effect and mechanism of cytokine and inducible nitric oxide synthase on apoptosis and function of rat pancreas islets cultured in vitro. METHODS: Islets from Wistar rats were cultured in vitro and divided randomly into four groups: blank control group, cytokine group of islets cultured with TNF-alpha+IL-1beta, aminoguanidine (AG) group of islets cultured with aminoguanidine, and AG + cytokine group of islets cultured with TNF-alpha+IL-1beta and aminoguanidine. The nutrient fluid nitric oxide level and islets cNOS/iNOS activity were detected by test kit and the expressions of iNOS mRNA and apoptosis related gene (Bax, Bcl-2) were evaluated by RT-PCR. The viability of the islets was examined by AO/EB staining and the function of the islets was detected by insulin secretion index assay. RESULTS: After co-cultured with cytokines IL-1beta and TNF-alpha, the expression and activity of iNOS in islet tissues enhanced (38.93+/-4.72) U/mL and the concentration of NO in medium increased remarkably(313.0+/-35.4) mol/L.The survival rate of cells and the insulin secretion index decreased with the up-regulation of proapoptosis gene and down-regulation of anti-apoptosis gene. But the activity of cNOS remained unchanged. Aminoguanidine reduced the cell apoptosis and increased the survival rate and insulin secretion index, and the activity of iNOS was inhibited. CONCLUSION: iNOS plays an important role in the apoptosis of islets cultured by cytokines TNF-alpha and IL1-beta. Aminoguanidine prevents the islets from the damage of iNOS, alleviates the impairment of cytokines to islets, lessens the cell apoptosis and ameliorates the survival and function of islets.

[The effect of iNOS gene expression inhibited by RNA inference on the pancreas islet apoptosis and function in rats].

OBJECTIVE: To investigate the effect of iNOS gene on cell apoptosis and insulin secretion of pancreas islet in rats by RNA inference (RNAi). METHODS: Islets obtained from thirty Wistar rats were randomly divided into five groups, and siRNA oligo was purchased from Genepharma in Shanghai. The cultured islets were transfected with iNOS siRNA, and then were divided into five groups. Islet cultured only was taken as blank control group, and cultured with TNF-alpha + IL-1 beta as cytokine group. Islet transfected with negative or iNOS siRNA were taken as negative transfection control group or RNAi group, while that transfected with iNOS siRNA and cultured with TNF-alpha + IL-1 beta as RNAi + cytokine group. Expression of iNOS mRNA was evaluated by RT-PCR and iNOS protein was evaluated by Western blot to detect the effect of RNAi. The expression of apoptosis correlated gene, Bax, Fas were analyzed, and the apoptotic cells were identified by TUNEL method meanwhile. Insulin secretion index assay the function of the islets. RESULTS: 500 - 600 IEQ islets could be extracted from every rat. RNAi attenuated the expression of iNOS and restrained the synthesis of iNOS protein.With treatment of cytokines IL-1 beta and TNF-alpha, the level of iNOS increased remarkably, the expression of Bax and Fas ascended distinctly, and insulin secretion index decreased strikingly. While, the expression of apoptosis gene and amount of apoptotic cells descended in group of RNAi + cytokine, and insulin secretion index were satisfying. CONCLUSION: The apoptosis from cytokines to islets mediated by iNOS could be suppressed by RNAi, which leaded to favorable function and survival of islets.

Protective effect of inducible nitric oxide synthase inhibitor on pancreas transplantation in rats.

AIM: To investigate the effect of inducible nitric oxide synthase inhibitor, aminoguanidine, on pancreas transplantation in rats. METHODS: A model of pancreas transplantation was established in rats. Streptozotocin-induced diabetic male Wistar rats were randomly assigned to sham-operation control group (n = 6), transplant control group (n = 6), and aminoguanidine (AG) treatment group (n = 18). In the AG group, aminoguanidine was added to intravascular infusion as the onset of reperfusion at the dose of 60 mg/kg, 80 mg/kg, 100 mg/kg body weight, respectively. Serum nitric oxide (NO) level, blood sugar and amylase activity were detected. Nitric oxide synthase (NOS) test kit was used to detect the pancreas cNOS and inducible NOS (iNOS) activity. Pancreas sections stained with HE and immunohistochemistry were evaluated under a light microscope. RESULTS: As compared with the transplant control group, the serum NO level and amylase activity decreased obviously and the evidence for pancreas injury was much less in the AG group. The AG (80 mg/kg body weight) group showed the most significant difference in NO and amylase (NO: 66.0 +/- 16.6 vs 192.3 +/- 60.0, P < 0.01 and amylase: 1426 +/- 177 vs 4477 +/- 630, P < 0.01). The expression and activity of tissue iNOS, and blood sugar in the AG (80 mg/kg body weight) group were much lower than those in the transplant control group (iNOS: 2.01 +/- 0.23 vs 26.59 +/- 5.78, P < 0.01 and blood sugar: 14.2 +/- 0.9 vs 16.8 +/- 1.1, P < 0.01). CONCLUSION: Selective iNOS inhibitor, aminoguanidine as a free radical, has a protective effect on pancreas transplantation in rats by inhibiting NO and reducing its toxicity.

Evaluation of CMU-1 preservation solutions using an isolated perfused rat liver model.

AIM: CMU-1 is a new preservation solution with a low potassium concentration as well as low viscosity that is highly effective in reducing preservation injury. The purpose of this experiment is to compare the protective effect of CMU-1 solution with that of UW during cold preservation and normothermic reperfusion. METHODS: Wistar rats were divided into two groups according to different preservation solution: CMU-1 group and UW group. After 6, 12 and 24 h cold storage of rat liver in different preservation solutions, the isolated perfused rat liver model was applied to reperfuse the liver for 120 min normothermically (37 degrees C) with Krebs-Henseleit solution, meanwhile the pH value of the preservation solution was measured. The perfusate was sampled for the evaluation of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH). At the end of the reperfusion, all of the bile product was collected, energy metabolic substrate and histological examination were performed. RESULTS: After preserving for 6 h, pH value of both groups did not change; after 12 h, both decreased but with no significant difference. After 24 h, pH value in UW solution group significantly decreased. The total adenine nucleotides level and AEC in liver tissue decreased with preservation time, but they were higher in CMU-1 group. And the amount of bile product after perfusion for 120 min in CMU-1 group was much more than that in UW group. However, there were no significant differences in ALT and LDH levels between two groups. Histology showed no difference. CONCLUSION: The preservation effect of CMU-1 solution is similar with that of UW solution. However, CMU-1 solution shows some advantages over UW solution in energy metabolism, preventing intracellular acidosis and bile product.