热休克蛋白27在大鼠急性胰腺炎中的表达及其对细胞间连接的影响

目的探讨热休克蛋白27(HSP27)在轻型急性胰腺炎(MAP)及重症急性胰腺炎(SAP)大鼠模型中的表达及其对腺泡细胞间连接的影响。方法雄性Wistar大鼠90只,随机分3组:A组为SAP组,B组为MAP组,C组为对照组。3组动物于成模后1,3,8h分批处死。检测血清淀粉酶(SAM),计算胰腺系数;Western-blot半定量分析HSP27蛋白和磷酸化蛋白含量;RT-PCR半定量分析HSP27 mRNA表达;透射电镜观察细胞间连接的变化。结果A,B组SAM水平升高,但B组明显低于A组(P<0.05);A组胰腺系数迅速升高并持续增长,间质水肿严重(P<0.05),细胞间连接损伤;B组间质水肿比A组轻(P<0.05),细胞连接比较稳定;A,B两组HSP27蛋白及其mRNA表达均显著高于对照组(P<0.05),B组明显高于A组(P<0.05);B组HSP27磷酸化蛋白(Ser78)含量显著高于对照组和A组(P<0.05),A组与对照组比较无明显差异(P>0.05)。结论细胞间连接破坏是急性胰腺炎的共同特征,但SAP损伤更严重,可能与细胞间连接调控因子HSP27及其磷酸化表达相对下降。提示HSP在AP发生、发展中具有重要作用。     

重症急性胰腺炎iNOSmRNA对大鼠内分泌功能影响

目的探讨重症急性胰腺炎大鼠胰腺内分泌功能变化，研究iNOSmRNA在胰腺内分泌功能损伤中的作用。方法制作大鼠重症急性胰腺炎动物模型，对胰腺病理损伤评分；检测血清脂肪酶，血糖水平；分离胰岛，进行葡萄糖刺激胰岛素分泌试验；应用逆转录聚合酶链反应技术，检测胰岛iNOSmRNA的表达情况。结果重症急性胰腺炎大鼠病理学评分、血糖、血清脂肪酶升高，葡萄糖刺激胰岛素分泌量较对照组明显减少，差异有显著性；逆转录聚合酶链反应提示重症急性胰腺炎组胰岛的iNOSmRNA表达增强，差异有显著性。结论重症急性胰腺炎对胰腺内分泌有较大影响，重症急性胰腺炎iNOSmRNA对胰腺内分泌功能可能发挥作用。     

鱼油对急性坏死性胰腺炎大鼠胃肠功能的影响

目的 探讨鱼油对急性坏死性胰腺炎胃肠道功能的影响及可能机制.方法 SD大鼠被分为三组:急性坏死性胰腺炎组(A组,n=8)、急性坏死性胰腺炎鱼油干预组(F组,n=8)和对照组(C组,n=8).观察5 d后各组大鼠胰腺组织病理变化.同时检测各组大鼠胃肠道食物残渣量及血浆超氧化物歧化酶SOD、谷胱甘肽过氧化物酶(GSH-Px)活力、D乳酸浓度和淀粉酶浓度.结果 病理学检查提示A组和F组均表现为严重的胰腺坏死,但F组的炎细胞浸润程度显著低于A组(P<0.01).与C组比较,A组胃肠道食物残渣分布出现异常,其D乳酸水平显著升高(P<0.01);F组胃肠道食物残渣分布与C组比较无统计学意义,D乳酸水平显著低于A组(P<0.01).A组GSH-Px、SOD显著低于C组(P<0.01);F组GSH-Px、SOD显著高于A组(P(0.01).结论 ANP时除表现为胰腺局部严重的炎症外,同时还并发存在胃肠道功能障碍及全身抗氧化防御系统损坏(GSH-Px、SOD是体内最重要抗氧化酶);应用鱼油干预可使ANP大鼠胰腺局部炎症减轻、ANP胃肠道功能障碍得以纠正,可能与其影响抗氧化酶系统有关.     

大黄素对大鼠重症胰腺炎TNFα、IL-6及胰腺腺泡细胞凋亡的影响

目的 :探讨大黄素治疗重症急性胰腺炎 (SAP)的作用机理。 方法 :用胰胆管内逆行注射去氧胆酸钠法制作大鼠SAP模型 ,随机分为对照组、SAP组、大黄素治疗组 ,动态测定术后 0h、6h、12h各组血清TNFα及IL - 6浓度 ,并取胰组织作病理学检查 ,同时应用TUNEL技术分析大鼠胰腺腺泡细胞凋亡的变化。 结果 :发现大黄素给药后 6h及 12h时血清TNFα、IL - 6水平明显降低 ,腹水量减少 ,胰组织病变程度改善 ;术后 6hSAP组胰腺腺泡细胞凋亡指数为 (3 92± 0 94 ) ,大黄素治疗组为(2 6 5 0± 6 72 ) ,两组比较 ,P <0 0 5。 结论 :大黄素可明显抑制大鼠胰酶及TNFα、IL - 6的释放 ,并且诱导已受损的不可恢复的腺泡细胞凋亡 ,从而改善大鼠重症胰腺炎的病情发展。     

鱼油对大鼠急性坏死性胰腺炎抗氧化酶的影响

目的探讨大鼠抗氧化酶系统与急性坏死性胰腺炎(acute necrotizing pancreatitis,ANP)的关系以及鱼油对ANP大鼠抗氧化酶系统的影响。方法48只SD大鼠被分为急性坏死性胰腺炎组(A组,n=16)、急性坏死性胰腺炎鱼油干预组(F组,n=16)和对照组(C组,n=16);A组、F组应用3.5%牛磺胆酸钠逆行胰胆管注射法诱导ANP模型,F组尚通过皮下注射鱼油进行药物干预;在模型制备后30h、5d后分别处死各组的其中8只大鼠,观察各自胰腺病理变化并测定其血清SOD、GSH-Px活力和淀粉酶浓度。结果病理学检查提示鱼油组的胰腺炎症严重程度低于急性胰腺炎组;血清学检查提示急性坏死性胰腺炎组30h、5d后血清SOD、GSH-Px活力明显低于对照组(分别P<0.05及P<0.01),急性坏死性胰腺炎经鱼油治疗后血清中SOD、GSH-Px活力升高(P<0.05,P<0.01)。结论急性坏死性胰腺炎大鼠血清抗氧化酶含量明显降低;鱼油对急性坏死胰腺炎有治疗作用,其上调抗氧化物酶系统可能是其作用机制之一。     

急性胰腺炎大鼠胰腺细胞凋亡与胰腺炎症细胞的关系

目的: 探讨急性胰腺炎(AP)胰腺细胞凋亡的可能机制.方法: 胆胰管逆行加压注射4%的牛磺胆酸钠诱导大鼠AP,建立模型,应用末端脱氧核苷酸转换酶(TdT)介导的原位末端标记(TUNEL)法检测术后3h、6 h和12 h胰腺细胞凋亡情况,并对胰腺炎症细胞进行分类记教.结果: 胰腺炎组术后6 h胰腺凋亡细胞显著高于3 h和12 h(3 h P<0.05,12 h P<0.01);白细胞进行性增多,6 h巨噬细胞百分比明显高于3 h和12h(3 h P<0.05,12 h P<0.01),中性粒细胞百分比显著低于3 h和12 h(3 h P<0.05,12 h P<0.01).结论: AP胰腺细胞凋亡可能与炎症细胞的不同种类有关.     

N-乙酰半胱氨酸对大鼠急性坏死性胰腺炎胰腺损伤的影响

目的 探讨急性坏死性胰腺炎(ANP)胰腺损伤与核因子-κB(NF-κB)活化、胰腺细胞凋亡的关系及N-乙酰半胱氨酸(NAC)对胰腺损伤的影响.方法 33只Wistar大鼠分为正常对照、盐水对照和胰腺炎组.以3.5%牛磺胆酸钠逆行注入胰胆管制作ANP模型,于造模前、后1 h应用NAC,12 h后取材,采用凝胶电泳迁移率实验测定胰腺组织NF-κB活性、改良TUNEL法检测细胞凋亡.同时观察血淀粉酶、脂肪酶、胰腺组织湿/干重比率及病理改变. 结果盐水对照组NF-κB活性很低(2.00±0.33),胰腺炎组NF-κB明显活化(6.03±0.41),造模前使用NAC抑制NF-κB活性(3.28±0.42),降低淀粉酶及胰腺湿/干重比率,促进胰腺细胞凋亡(P<0.05).NF-κB活化与凋亡呈负相关(r=-0.96,P<0.01),与胰腺损伤病理呈正相关(r=0.63,P<0.01);胰腺损伤病理分级与凋亡呈负相关(r=-0.98,P<0.01).结论 NAC可能通过抑制胰腺NF-κB活化、促进胰腺细胞凋亡,减轻胰腺损伤.     

吡咯烷二硫氨基甲酸酯对大鼠重症急性胰腺炎的影响

目的　探讨核转录因子 (NF κB)抑制剂吡咯烷二硫氨基甲酸酯 (PDTC)对大鼠重症急性胰腺炎 (SAP)的影响。方法　将 3 6只Wistar大鼠随机分组 :假手术组 (n =6) ,假手术 静脉注射组 (n =6) ,SAP组 (n =12 )和试验组 (n =12 )。各组于造模 6h后 ,测定血清淀粉酶及脂肪酶含量 ,取胰腺组织进行病理学评分 ,采用免疫组织化学法检测NF κB激活水平及胰腺细胞凋亡情况。结果　SAP组和试验组的胰腺细胞内NF κB呈激活状态 ,存在胰腺细胞凋亡 ,与前两组差异有显著性 (P <0 .0 1) ,试验组大鼠的胰腺组织病理学评分、血清淀粉酶及脂肪酶含量、NF κB激活及细胞凋亡水平与SAP组差异存在显著性 (P <0 .0 5 )。结论　在SAP发病机制中 ,NF κB是多种炎症介质的始动因子 ,PDTC可以有效抑制胰腺细胞中NF κB的激活 ,促进胰腺细胞凋亡 ,减少胰酶释放 ,减轻胰腺组织的病理损害。     

牛磺胆酸钠诱导的急性坏死性胰腺炎大鼠脏器功能障碍观察

目的 探讨急性坏死性胰腺炎大鼠脏器功能障碍及病程演进规律.方法 大鼠分为两组,急性坏死性胰腺炎(acute necrosis pancreatitis,ANP)组64只,对照组48只.采用经胰管逆行注射5%牛磺胆酸钠诱导ANP,对照组予胰管内注射生理盐水.分别于模型诱导后3、6、9、12、18、24 h(每一时间点各8只大鼠)处死,测定大鼠呼吸、体温、心率、血白细胞、肝肾功能及血气分析,另有16只ANP大鼠观察其24 h生存率.结果 ANP组24 h生存率为75%.ANP组在模型制备后3 h体温、心率、血白细胞明显高于对照组(P<0.05),6 h血清乳酸脱氢酶水平显著升高(2 613 vs 1822 IU/L.P<0.05),9 h血清肌酐水平显著升高(27.5vs 18.7 μmol/L,P<0.05),12 h动脉血PaO2显著降低(7.8vs 12.5 kPa,P<0.05),18 h之后各脏器处于衰竭期.对照组无脏器功能障碍表现.ANP组各时间点胰腺病理学评分显著高于对照组.结论 在5%牛磺胆酸钠诱导的ANP病程中,3 h后出现全身炎症反应综合征,6 h出现肝功能障碍,9 h后进入多脏器功能障碍期,18 h后进入多脏器衰竭期.     

血管紧张素Ⅱ受体拮抗剂早期干预大鼠急性胰腺炎的疗效

目的观察急性胰腺炎大鼠血浆血管紧张素Ⅱ水平变化并探讨血管紧张素Ⅱ受体拮抗剂——缬沙坦(Valsartan)对其的早期干预作用。方法 54只雄性Wistar大鼠随机分为对照组、急性胰腺炎组、缬沙坦干预组。采用胆胰管逆行注射法制做大鼠急性胰腺炎模型。缬沙坦干预组在制模后10 min给予缬沙坦 40 mg/kg。在病程不同时间点测定大鼠血清淀粉酶、脂肪酶、血浆血管紧张素Ⅱ水平,并观察胰腺组织病理学改变。结果急性胰腺炎组随病变进展,胰腺炎病理由水肿向出血坏死发展,血管紧张素Ⅱ水平持续升高。缬沙坦干预组血浆血管紧张素Ⅱ水平较急性胰腺炎组明显升高(P<0．05),其血清淀粉酶、脂肪酶水平,胰腺组织病理学评分较急性胰腺炎组明显下降(P<0．05)。结论早期应用缬沙坦可使急性胰腺炎大鼠血浆血管紧张素Ⅱ水平明显升高,对大鼠急性胰腺炎有一定的治疗作用。     

Native pancreatic α-cell adaptation in streptozotocin-induced diabetic primates: importance for pig islet xenotransplantation

Abstract: Background: Metabolic compatibility between donor and recipient species is an important matter for pig islet xenotransplantation. Glucagon is a key hormone for the function of pig islets as well as control of hypoglycemia in the recipients of the islets. Because a discrepancy exists in the composition of glucagon cells of pig and human/primate islets, the present study was designed to determine the role of native recipient glucagon cells in the treatment of diabetes by islet transplantation in a “pig‐to‐primate” model. Methods: Streptozotocin‐treated (50 mg/kg) monkeys (n = 12, follow‐up of 6 to 231 days) were compared with non‐diabetic animals (n = 5; follow‐up, 180 days). Metabolic [fasting and intravenous glucose tolerance tests (IVGTTs) for serum levels of glucose, insulin, glucagon] and morphologic (endocrine volume density and cell mass for insulin and glucagon) were compared between non‐diabetic and diabetic animals. Six additional diabetic primates were given transplants of 15 000 adult pig islet equivalents without immunosuppression to monitor glucose, glucagon, insulin, and porcine C‐peptide levels until 48 h after transplantation. Results: Elevated fasting blood glucose, pathologic IVGTT, destruction of 95% of β‐cell mass, and glycosylated hemoglobin (>13%) were assessed in diabetic monkeys. The serum glucagon levels and glucagon cell mass correlated significantly with diabetes time course of diabetes (R = 0.940, p = 0.005; R = 0.663, p = 0.019, respectively). A mean increase of 89% in glucagon cell mass was observed for primates suffering from diabetes >53 days. No response of glucagon secretion was observed for diabetic animals during IVGTT, because no increase of serum insulin levels followed glucose loading. Blood glucose levels dropped after pig islet xenografts in diabetic primates. This reduction was maintained by an insulin level >20 μU/ml over the period of time of xenograft function (porcine C‐peptide >0.1 ng/ml). A total restoration of native primate glucagon sensitivity to insulin was found after pig islets xenotransplantation as revealed by a reduction of 80% of the glucagon level. When graft dysfunction (>24 h post‐transplantation), the insulin level dropped and glucagon levels rose again (>50 pg/ml). Conclusions: Native glucagon cells provide morphologic and functional plasticity to diabetes. Adult pig islet xenotransplantation can restore the sensitivity of primate glucagon to insulin but cannot protect the diabetic recipient against hypoglycemia.     

Function of pancreatic endocrine cells in experimental acute pancreatitis

This experimental study was carried out to clarify changes in pancreatic endocrine function in acute pancreatitis. Male Donryu rats were divided into 2 groups, consisting of a group with acute pancreatitis induced by Block's method, and another group with simple laparotomy as control. Histological examination in the former group revealed an interstitial edematous pancreatitis, but there was no marked alteration of endocrine cells in spite of inflammatory changes in the exocrine region. Insulin and glucagon levels in the pancreatic tissue of rats with acute pancreatitis were significantly lower than those of control rats. Autoradiographic studies using³H-leucine showed a significant decrease of grain counts for endocrine granules in rats with acute pancreatitis. The release of insulin from isolated islets of Langerhans was not reduced until 72 hours after the development of acute pancreatitis, while the release of glucagon from isolated islets was reduced 6 hours after the development of acute pancreatitis. These findings indicate that there is a reduction of synthesis and secretion function in endocrine cells of the pancreas in acute pancreatitis, and suggest that the damage to A cells occurs more rapidly than damage to B cells.

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Résumé Une étude expérimentale a été conduite pour étudier les modifications des fonctions endocriniennes du pancréas au cours de la pancréatite aigue. Pour ce faire des rats mâles (de race Donryu) ont été divisés en deux groupes: le premier constitué de rats chez qui fut provoquée une pancréatite aigue selon la méthode de Block, le second formé de rats chez qui fut pratiqué une simple laparotomie.L'examen histologique du pancréas des rats du premier groupe met en évidence une pancréatite aigue oedémateuse interstitielle, sans qu'il y ait d'altérations importantes des cellules endocrines en dépit des modifications inflammatoires des cellules exocrines.Le taux de l'insuline et du glucagon au niveau du tissu pancréatique des rats du premier groupe a été trouvé significativement abaissé par rapport aux rats du second groupe. Les études autoradiographiques employant un corps marqué (3H leucine) ont montré une baisse significative du nombre des granules endocriniens chez les rats atteints de pancréatite aigue oedémateuse.La libération de l'insuline à partir des ilôts de Langerhans isolés ne fut réduite que 72 heures après le développement de la pancréatite aigue cependant que ce phénomène de réduction s'observait dès la 6ème heure pour le glucagon. Ces faits indiquent que la pancréatite aigue s'accompagne d'une réduction de la synthèse et de la secrétion des hormones pancréatiques et suggèrent que l'atteinte des cellules A est plus précoce que celle des cellules B.

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Presented at the XVIth Congress of the Japanese Society of Gastroenterological Surgery, Kyoto, Japan, July 11, 1980.     

Total pancreatectomy and autologous islet cell transplantation as a means to treat severe chronic pancreatitis

Autologous islet cell transplantation after near-total or total pancreatic resection can alleviate pain in patients with severe chronic pancreatitis and preserve endocrine function. From February 2000 to February 2003, a total of 22 patients, whose median age was 38 years, underwent pancreatectomy and autologous islet cell transplantation. Postoperative complications, metabolic studies, insulin usage, pain scores, and quality of life were recorded for all of these patients. The average number of islet cells harvested was 245,457 (range 20,850 to 607,466). Operative data revealed a mean estimated blood loss of 635 ml, an average operative time of 9 hours, and a mean length of hospital stay of 15 days. Sixty-eight percent of the patients had either a minor or major complication. Major complications included acute respiratory distress syndrome (n = 2), intra-abdominal abscess (n = 1), and pulmonary embolism (n = 1). There were no deaths in our series. All patients demonstrated C-peptide and insulin production indicating graft function. Forty-one percent are insulin independent, and 27% required minimal amount of insulin or a sliding scale. All patients had preoperative pain and had been taking opioid analgesics; 82% no longer required analgesics postoperatively. Pancreatectomy with autologous islet cell transplantation can alleviate pain for patients with chronic pancreatitis and preserve endocrine function. Presented at the Presidential Plenary Session, at the Forty-Fourth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Florida, May 18–21, 2003 (oral presentation).     

Intramuscular Autotransplantation of Pancreatic Islets in a 7-Year-Old Child: A 2-Year Follow-Up

A 7-year-old girl with severe hereditary pancreatitis underwent total pancreatectomy. A total of 160 000 islet equivalents (6400 islet/kg) were transplanted to the brachioradialis muscle of the right forearm. Her plasma C-peptide level was undetectable after pancreatectomy but increased to 1.37 ng/mL after 17 days; at this time point, her insulin requirement was 0.75 units of insulin/kg/day. At 5- and 27-months, her hemoglobin A1c (HbA1c) and insulin requirements were 4.5 and 5.3% and 0.3 and 0.18 units/kg/day, respectively. Basal and stimulated C-peptide levels were 0.67 ± 0.07 and 3.36 ± 1.37 ng/mL, respectively. Stimulated insulin levels were 30% higher in the islet-bearing arm compared to the contralateral arm after glucagon stimulation. After surgery and islet transplantation, the quality of life improved dramatically and she gained 8 kg of weight. In summary, a normal HbA1c, a low insulin requirement and the absence of recurrent hypoglycemia and the gradient of insulin between the arms indicate that the intramuscularly transplanted islets contribute to a long-term clinically significant metabolic control.     

Human islet xenograft survival in diabetic rats. A functional and immunohistochemical study

Prolonged survival of human islet xenografts under the kidney capsule of diabetic rats was achieved. Human islet xenograft survival time for the nonimmunosuppressed and single-dose antithymocyte serum-treated rats were 3.7 +/- 0.33 days (mean +/- SE, n = 6) and 4.2 +/- 0.63 (n = 4), respectively. In the recipients given 5 doses of ATS after islet transplantation, the graft survival time was significantly prolonged to 18.2 +/- 1.9 days (n = 6). An intravenous glucose tolerance test was performed on 3 recipients with a functional graft 12 days after xenotransplantation. The mean K rate was 1.44 +/- 0.43 (n = 3) compared with that of 2.1 +/- 0.14 (n = 5) found in normal control rats. Human C-peptide was present in the rat recipients following islet transplantation. In addition all 3 recipients showed significant basal human C-peptide values posttransplant and achieved levels of above 2.4 ng/ml during IVGTT. Morphologic and immunohistochemical examination of the islet grafts show that in recipients without immunosuppression or with a single dose of ATS, there was marked degree of fibrosis with little endocrine tissue left in the graft area by day 5. In contrast, the xenograft from recipients treated with 5 doses of ATS still contained well-preserved islet tissue with many insulin and glucagon containing cells on the day of graft removal when blood glucose had returned to the hyperglycemic level. Infiltration of the graft area with lymphoid cells (OX1+, OX8+, and W3/25+) was prominent, but they were not detected within the islets. Staining with monoclonal antibody clone L243 did not detect any expression of human class II antigen on the human pancreatic endocrine cells undergoing rejection by the host. This study has shown that with adequate immunosuppression human islet xenograft can normalize the blood glucose with prolonged survival time in diabetic rat recipients. The discordant xenotransplantation model used in this study would be useful for future xenotransplantation studies.     

Rapid failure of pig islet transplantation in non human primates

Abstract: We have previously demonstrated that adult pig islets of Langerhans are not destroyed in vitro by primate sera. Whether these islets can function when placed into the liver of non-human primates is not known. We now report on the outcome of pig islet xenotransplantation into five non diabetic primates (four baboons and one macacus fascicularis) receiving intraportally purified adult pig islets. The average number of islet-equivalent per graft was 110000 (60–180000). All animals received associations of ATG, cyclosporine or LF 195 (a deoxyspergualin analog), mycophenolate mofetil and corticosteroids. A specific porcine C-peptide (C-pep) RIA test was used to monitor insulin secretion. Two hours after grafting, porcine C-peptide was positive (from 0.37 to 4.25 ng/ml) in all monkeys except one. Primate C-pep was normal in all cases. Only two monkeys had detectable levels of porcine C-pep on day 1 or 2 with undetectable levels thereafter, even after glucagon challenge between days 6 and 10. Several normal islets with moderate inflammatory infiltration were observed in one animal liver on day 2 (the time of necropsy) as well as islets with IgM and complement deposition. Among animals sacrificed on days 14, 16 and 38, some residual islet cells could be identified only in livers collected on day 14. Partial glycaemic control was achieved in some rats receiving islets from the same preparations. In conclusion, adult pig islets are not able to maintain insulin secretion for more than 24 h when injected intraportally into non diabetic immunosuppressed monkeys, suggesting immediate islet xenograft destruction.     

Xenin-25 amplifies GIP-mediated insulin secretion in humans with normal and impaired glucose tolerance but not type 2 diabetes

Glucose-dependent insulinotropic polypeptide (GIP) potentiates glucose-stimulated insulin secretion (GSIS). This response is blunted in type 2 diabetes (T2DM). Xenin-25 is a 25-amino acid neurotensin-related peptide that amplifies GIP-mediated GSIS in hyperglycemic mice. This study determines if xenin-25 amplifies GIP-mediated GSIS in humans with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or T2DM. Each fasting subject received graded glucose infusions to progressively raise plasma glucose concentrations, along with vehicle alone, GIP, xenin-25, or GIP plus xenin-25. Plasma glucose, insulin, C-peptide, and glucagon levels and insulin secretion rates (ISRs) were determined. GIP amplified GSIS in all groups. Initially, this response was rapid, profound, transient, and essentially glucose independent. Thereafter, ISRs increased as a function of plasma glucose. Although magnitudes of insulin secretory responses to GIP were similar in all groups, ISRs were not restored to normal in subjects with IGT and T2DM. Xenin-25 alone had no effect on ISRs or plasma glucagon levels, but the combination of GIP plus xenin-25 transiently increased ISR and plasma glucagon levels in subjects with NGT and IGT but not T2DM. Since xenin-25 signaling to islets is mediated by a cholinergic relay, impaired islet responses in T2DM may reflect defective neuronal, rather than GIP, signaling.     

Generation of functional islet-like clusters after monolayer culture and intracapsular aggregation of adult human pancreatic islet tissue

BACKGROUND: Cellular replacement therapy represents a promising strategy for treating type I diabetes; however, such an approach is limited due to the inadequate availability of human donor tissue. Here we investigated the extent to which human islet tissue can be expanded in monolayer culture and brought back to islet function. METHODS: Adult human pancreatic cells were proliferated with a serum-free media in monolayer cultures through multiple passages. Expanded cells were dispersed and encapsulated in alginate-poly-l-lysine microcapsules wherein the cells spontaneously coalesced into islet-like clusters. Encapsulated cell clusters were subsequently transplanted into the peritoneal cavity of streptozotocin-induced diabetic severe combined immunodeficiency mice. RESULTS: The cultured monolayer cells secreted insulin in response to glucose stimulation and maintained endocrine gene expression. Encapsulated islet-like clusters displayed cellular architecture similar to freshly isolated and encapsulated adult human islets maintained in culture, exhibiting an immunoreactive core of insulin, glucagon, and somatostatin, as well as peripheral cytokeratin-19 staining. Encapsulated aggregates significantly reduced hyperglycemia in transplanted mice within 1 week and normoglycemia was achieved after 5 weeks. Human C-peptide was detected in transplanted mice concomitant with the reduction in hyperglycemia. Capsules recovered 8 weeks posttransplantation exhibited insulin immunoreactivity. CONCLUSIONS: Collectively, these data indicate that adult human pancreatic islet cells can be expanded by three serial passages while maintaining their endocrine properties and can yield functional islet-like cell clusters through intracapsular aggregation that reverse hyperglycemia in diabetic mice. This culture and aggregation process could serve as a platform for proliferation and differentiation studies of endocrine lineage cells.     

逆行胃左动脉行腹腔干灌注治疗大鼠胰腺炎的模型制作

目的 建立用于治疗大鼠胰腺炎的区域动脉灌注动物新模型,并探讨此模型的技术要点,及其在胰腺炎治疗中的优势。方法 取雄性SD大鼠48只,随机分组为A、B组（各24只）。5%牛磺胆酸钠逆行胰胆管泵入建立重症急性胰腺炎（SAP）模型,A组通过逆行胃左动脉行腹腔干灌注,B组通过左股静脉穿刺输注。输注等量美兰染色液,确定插管部位并观察胰腺局部染色程度和持续时间。而后输注等量治疗药物5-Fu,分别于12 h、24 h处死后,检测血清中淀粉酶,并做胰腺病理检查。结果 通过区域动脉灌注等量美兰染液,发现胰腺局部染色程度明显提高,持续时间明显延长。A组24 h亚组有1只死亡,B组24 h亚组有7只死亡,死亡率有统计学差异（P＜0.05）。A组血清淀粉酶水平明显低于B组（P＜0.05）,A组胰腺病理检查评分分值明显低于B组（P＜0.05）。结论 逆行胃左动脉灌注模型是有效、稳定的大鼠区域动脉灌注模型,通过显著增加胰腺局部药物浓度,从而达到提高治疗SAP的治疗效果的目的。