【Abstract】Objective To explore Toll-like receptor 4 (TLR4) expression and distribution in rat pancreas.Methods Reverse transcriptase-polymerase chain reaction (RTPCR) and immunohistochemistry (IHC) were applied to detect expression of TLR4-mRNA and TLR4 protein respectively. Results RT-PCR of RNA isolated from rat pancreatic tissue yielded the predicted amplicon for the TLR4. IHC/immunofluorescence revealed TLR4 protein mainly distributed in the epithelium of the pancreatic duct, vascular endothelium of the exocrine section, endocrine islet also had some signs of distribution. No TLR4 protein signal could be detected in the acinar cells. Conclusion TLR4 could be detected in rat pancreas. Its distribution is consistent with its roles in immune surveillance, mainly in tissues exposed to the external environment such as pancreatic duct as well as in immunologically important settings such as pancreatic vascular endothelium. Islet also has some signs of distribution. No TLR4 expression in acinar cells, suggesting TLR4 immunological involvement in the pathophysiology of pancreas.
ObjectiveTo explore apoptosis of acinar cells during pancreatic allograft rejection in rats.MethodsGroups of Wistar rats underwent heterotopic pancreaticoduodenal transplantation from syngenic Wistar of allogenic SD rats. The grafts were harvested on postoperative day 3, 5 and 7. All graft samples were subjected to histological examination and apoptotic cells of graft acinar cells using in situ terminal deoxynucleotidy1 transferasemediated dUTP nickend labeling (TUNEL). Histopathological rejection score and apoptotic index (AI) were analyzed. ResultsThe incidence of apoptotic cells was increased steadily over time in allografts, in contrast with syngenic grafts. The apoptotic cells in allografts were mainly acinar cells and few infiltrating lymphocytes. A significant correlation between apoptotic index and histopathological rejection score was noted.ConclusionTUNEL can display apoptosis of single cell in situ. Apoptosis is an important mechanism of tissue injury in acute pancreatic allograft rejection in rats. Acinar cell apoptosis can be used as a valuble index to estimate the injury of grafts and to monitor the acute rejection.
【Abstract】 Objective To investigate the effect of verapamil on apoptosis, calcium and expressions of bcl-2 and c-myc of pancreatic cells in ischemia-reperfusion rat model. Methods Wistar rats were randomly divided into three groups: control group （n=10）; ischemia-reperfusion group （n=10）; verapamil treatment group （n=10）. The anterior mesenteric artery and the celiac artery of rats in both ischemia-reperfusion group and verapamil treatment group were occluded for 15 min followed by 12-hour reperfusion. Verapamil （1 mg／kg） was injected via caudal vein to the rats in verapamil treatment group 15 min before occlusion and 1 hour after the initiation of reperfusion, respectively; and ischemia-reperfusion group was given the same volume of salient twice intravenously. Pancreatic tissues were collected from the dead rats after twelve hours since the reperfusion. The pathologic characters of pancreatic tissue were observed under light microscope; The level of calcium in the tissue was measured by atomic absorption spectrometer; TUNEL was used to detect apoptosis of pancreatic cells; and the expressions of c-myc and bcl-2 in the cells were also analyzed by immunohistochemistry technique and flow cytometry. Results The pathologic change in verapamil treatment group was less conspicuous than that of ischemia-reperfusion group. Both the calcium level and the number of apoptotic cells in verapamil treatment group were less than those of ischemia-reperfusion group 〔（411.1±55.8） μg/g dry weight vs （470.9±31.9） μg/g dry weight, P＜0.05 and （9.5±2.9）% vs （18.4±3.1）% 〕, P＜0.05. After taking verapamil, the number of apoptotic cells decreased, whereas the expressions of bcl-2 and c-myc increased. The fluorescent indexes of bcl-2 and c-myc in verapamil treatment group were significantly higher than those of ischemia-reperfusion group (1.72±0.11 vs 1.41±0.07, P＜0.05; 1.76±0.19 vs 1.55±0.13, P＜0.05. Conclusion Ischemia-reperfusion injury can induce apoptosis of pancreatic cells. Verapamil could protect the injured pancreatic tissue by reducing the level of calcium, stimulating the expressions of bcl-2 and c-myc and inhibiting apoptosis of pancreatic cells.
In order to avoid lesion of adjacent organs which were often occurred after routine cryotherapy of pancreanoduodinal area, a new cryosurgical method of isolated pancreano-duodinal area was designed for treatment of neoplasm in this area, the feasibility of this method was tried in four pigs.After bile common duct, tail of pancreas, stomach, and jejunum were divided and protected by dry cotton pad, the isolated pancreano-duodinal area was twice fozen to -170℃, maintaining ten minutes with LCS 2000 cryogenic surgical system, then alimentary tract was reconstructed with cholecystojejunostomy and gastroenterostomy. Animals were observed for 1-4 weeks. There was only transient elevation of amylase postoperation and the liver function and blood sugar remained normal. No any complication was seen except a small pseudocyst in lesser omentum. Thorough destruction of pancreatic tissue by enough deep and time course of cryotherapy was emphasized and some technic problem also were discussed. Based on our experiment, cryosurgery of isolated pancreano-duodenum will be considered as a safe and effect therapy of pancreano-duodinal neoplasm.
Objective To approach the recent advances in diagnosis and surgical treatment of pancreatic endocrine tumors （PETs）. Methods Articles relevant to diagnosis and treatment of PETs were collected and reviewed. Results PETs are characterized by their ability to over-produce peptides and hormones， which cause specific clinical syndromes. Because of rare incidence and complex clinical syndromes， there are still impediments to early diagnosis of these tumors. Monitoring of serum hormones and imaging method allow early tumor detection. PETs have been investigated for the past several decades. With the great knowledge of these tumors in molecular genetic level， clinical managements have been greatly changed. Conclusions Avoiding misdiagnosis is important for treatment of PETs. Surgical approach is still considered as the preferred option for curtailing the malignant progression of PETs and controlling the associated biochemical syndromes.
【Abstract】 Objective To investigate the origin, prevention and treatment of postoperative complications and death rate after pancreaticoduodenectomy （PD）. Methods Retrospective study on the clinical materials of complications and death rate was done on 106 cases of PD performed in our hospital during July 1985 to December 2002. Results In this group, 37 cases (34.91%) had postoperative complications, and the incidence rate of severe complications was 19.81% (21/106), the death rate was 10.38% (11/106). Compared between the two groups with preoperative bilirubin gt;342 μmol/L and ≤342 μmol/L, the incidence of total complications increased evidently (P＜0.05), and the bleeding amount，infusion amount and operation time in those with complications or dead ones were evidently higher than those without complications (P＜0.05). Conclusion The safty and resectability of PD has improved evidently in recent years but good skills, careful operation, the experience of the operatior and careful perioperative treatment and nursing are of crucial importance to reduce the complications and death rate.
Due to its irregular shape and varying contour, pancreas segmentation is a recognized challenge in medical image segmentation. Convolutional neural network (CNN) and Transformer-based networks perform well but have limitations: CNN have constrained receptive fields, and Transformer underutilize image features. This work proposes an improved pancreas segmentation method by combining CNN and Transformer. Point-wise separable convolution was introduced in a stage-wise encoder to extract more features with fewer parameters. A densely connected ensemble decoder enabled multi-scale feature fusion, addressing the structural constraints of skip connections. Consistency terms and contrastive loss were integrated into deep supervision to ensure model accuracy. Extensive experiments on the Changhai and National Institute of Health (NIH) pancreas datasets achieved the highest Dice similarity coefficient (DSC) values of 76.32% and 86.78%, with superiority in other metrics. Ablation studies validated each component’s contributions to performance and parameter reduction. Results demonstrate that the proposed loss function smooths training and optimizes performance. Overall, the method outperforms other advanced methods, enhances pancreas segmentation performance, supports physician diagnosis, and provides a reliable reference for future research.
【Abstract】Objective To investigate the effect of donor blood transfusion on inducing pancreatic allograft tolerance in outbred rat model. Methods Wistar male rats were used as blood and pancreas donor, and diabetic recipients. One ml of donor blood injected into abdomen of diabetic recipients on the day of transplantation and azathioprine given 2 days pretransplant and continued for three days. Results Pancreas allograft survival was significantly prolonged (28 to 112 days, media survival time 64.2 days). One ml of donor blood alone injected into the abdomen and azathioprine given alone 2 days pretransplant did not improve allograft survival (media survival time 9.8 vs 10.2 days). Conclusion Donor blood injected on the day of transplantation and a 3 days course of azathioprine started 2 days pretransplant have b synergism in inducing long term graft survival in this rat model.
Objective To investigate the roles of cell apoptosis and the gene expressions of Fas, FasL, bcl-2 and bax in acute rejection of pancreaticoduodenal transplantation and to evaluate the function of duodenum biopsy for early detection of rejection in rats. Methods Wistar and SD rats were divided into two groups: ①Wistar rats that underwent allogenic pancreaticoduodenal transplantation from the organs of SD rats; ②Wistar rats that received homogenic transplantation. The grafts were then harvested on day 3, 5 and 7 after the transplantation, and all graft samples were observed with HE staining and TUNEL was also used to detect apoptotic cells. The expressions of Fas, FasL, bcl-2 and bax were measured by immunochemical method. According to Nakhleh’s score, pathologic features of transplanted pancreas and duodenum were ranged from one to three scores in order. Results The percentage of same or different scores between the pathological scores of pancreas and duodenum in allogenic pancreaticoduodenal transplantation group were 61.1% (11/18) and 38.9% (7/18) respectively, and there were 6 specimens of pancreatic tissue got higher scores with only one higher score for duodenum. There were significant differences of histopathologic rejection scores and apoptotic indices between the two groups, respectively (P＜0.05， P＜0.01). Apoptotic indices of pancreas and duodenum both showed positive correlations with histopathologic rejection scores (r=0.965， P＜0.01; r=0.942, P＜0.01). The rejection score and apoptotic index elevated, the expression of FasL increased, bcl-2 decreased, and Fas and bax changed over time after operation. Conclusion Apoptosis maybe significantly positive correlated with the degrees of damage of the acute pancreaticoduodenal allograft rejection, and the apoptotic index maybe valuable to estimate the damage. FasL and bcl-2 were significantly related to the impairment of acute pancreatic allograft rejection as well. Duodenum biopsy may contribute to the early diagnosis of the rejecting transplanted tissues.
Objective To evaluate the imaging features of pancreatic neuroendocrine carcinoma （PNEC）. Methods The imaging data of 7 patients with PNECs proved by surgery and pathology in West China Hospital of Sichuan University from Jul. 2007 to Dec. 2012 were retrospectively analyzed. The boundary， density， and strengthening features of tumor were observed. Results Seven tumors were found in all patients with 2 in pancreatic head， body， and tail， respectively. There was 1 tumor in pancreatic body and tail too. Five tumors were with unclear boundary. Five tumors had hypodense enhancement and 2 had isodense enhancement. Two cases had distal pancreatic duct dilation. None of them had liver metastases or lymph node involvement. Conclusion PNEC has certain characteristics on imaging. It is difficult to distinguish diagnosis from pancreatic cancer.