早期肠内营养对急性重症胰腺炎大鼠肠道粘膜屏障的保护作用

目的 探讨早期肠内营养对急性重症胰腺炎大鼠肠道粘膜屏障的保护作用。方法 SD大鼠48只，随机分成6组（n=8)；急性重症胰腺炎全肠外营养1天组（A组），模拟手术全肠外营养1天组（B组），急性重症胰腺炎全肠外营养5天组（C组）和肠内营养5天组（E组），模拟手术全肠外营养5天组（D组）和肠内营养5天组（F组）。采用逆行胰胆管注射3%牛磺胆酸钠溶液制成重症胰腺炎大鼠模型。E组和F组术后先予肠外营养，48h后开始肠内营养，观察大鼠的空肠组织形态学变化及空肠粘膜固有层CD4^ /CD8^ 比值。结果 急性重症胰腺炎大鼠均无死亡，E组和F组大鼠对肠内营养耐受良好，C组的CD4^ /CD8^ 比值明显低于D组。E组的空肠绒毛高度和CD4^ /CD8^ 比值明显高于C组。结论 重症胰腺炎大鼠肠道粘膜屏障功能受损。早期肠内营养可改善重症胰腺炎大鼠的肠道粘膜屏障功能。     

氧化苦参碱诱导跨膜蛋白Claudin-1表达在重症急性胰腺炎大鼠肠黏膜损害中的作用

目的:探讨氧化苦参碱(OM)在重症急性胰腺炎(SAP)肠黏膜屏障损害中的作用及其机制.方法:采用L-精氨酸(1 750 mg/kg)腹腔注射制备SAP大鼠模型.将80只Wistar大鼠随机分为Control组、OM对照组、SAP对照组、OM治疗组1、12、24、36、48 h 5个亚组,每组10只.分时取材,测定血浆内...     

Enteric immunologic abnormalities in human immunodeficiency virus infection.

The intestinal mucosa is an important portal of entry of HIV, and HIV-infected mononuclear cells are found in the intestinal lamina propria of 30 to 50% of HIV-infected patients even at early stages of the disease. HIV infection of epithelial cells has not consistently been detected and is still controversial. Intestinal T cells are phenotypically and functionally distinct from circulating T cells, especially in their state of activation and differentiation, which both affect the replication and cytopathicity of HIV. An increase in CD8+ cells and variable decreases in CD4+ cells have been found in the intestinal lamina propria by immunohistologic studies, resulting in a decreased CD4 to CD8 ratio; in addition, CD25 expression is reduced. Changes in intraepithelial lymphocytes are unclear. B-cell differentiation seems to be disturbed because IgA plasma cells and IgA2 secretion are reduced. Depletion or functional impairment of activated mucosal lamina propria lymphocytes by HIV infection could explain the breakdown of the mucosal immune barrier leading to opportunistic diseases; in addition, due to the interrelationship between mucosal immune system and epithelium, these changes might be responsible for the partial bowel atrophy and maturational defects in enterocytes of HIV-infected patients.     

An experimental study of emodin assisted early enteral nutrition for the treatment of severe acute pancreatitis

BACKGROUND/AIMS: Both emodin and early enteral nutrition (EEN) have been affirmed as effective means to restore the intestinal mucosal function and abate the severity of severe acute pancreatitis (SAP). However, whether a combined strategy applying both is more effective than either one alone is still undetermined. In this study, we investigated the feasibility and efficacy of emodin assisted early enteral nutrition (EAEEN) for the treatment of SAP. METHODOLOGY: Sixty male Wistar rats were randomly divided into four groups (n=15). SAP was induced in all the rats by a retrograde infusion of 5.0% sodium taurocholate into the pancreatic main duct. Rats in group A received no further intervention, group B with emodin alone, group C with early enteral nutrition (EEN) alone, and group D with emodin assisted early enteral nutrition (EAEEN), respectively, all through an enteral nutrition tube incubated after the induction of SAP. 72 hours after SAP induction, all surviving animals were sacrificed to collect blood and tissue samples for the following measurements: serum amylase, tumor necrosis factor-alpha (TNF-alpha), angiotensin II (AngII) and maleic dialdehyde (MDA), intestinal mucosal secretory IgA (SIgA), pancreatic myeloper oxidase (MPO) activity, and the wet-dry weight ratio of pancreatic tissue (pww/dw). The severity of pancreatic destruction was analyzed by pathological grading and scoring. The severity of intestinal mucosal damage was assessed by the wet-dry weight ratio of ileum (iww/dw), plasma D-lactate and plasma endotoxin. RESULTS: The results of every index in group B, C and D were significantly better than those in group A (P<0.05). Compared with group B and C, group D had significantly reduced levels of serum amylase, TNF-alpha, Ang-II and MDA (P<0.05). Group D also had significantly lowered plasma D-lactate and endotoxin, and decreased pancreatic MPO activity (P<0.05). The pww/dw and iww/dw ratios were decreased, while the SIgA level increased in this group, both with statistical significance (P<0.05). Furthermore, group D had significantly better pancreatic pathologic scores over group B and group C (P<0.05). CONCLUSIONS: Our results suggested that EAEEN could obviously abate the severity of experimental SAP in rats. This combined strategy was rational, safe and more effective than either EEN or emodin used alone, and has a broad potential for future clinical application.     

Abdominal paracentesis drainage attenuates intestinal inflammation in rats with severe acute pancreatitis by inhibiting the HMGB1-mediated TLR4 signaling pathway

BACKGROUND Our previous studies confirmed that abdominal paracentesis drainage(APD)attenuates intestinal mucosal injury in rats with severe acute pancreatitis(SAP),and improves administration of enteral nutrition in patients with acute pancreatitis(AP).However,the underlying mechanisms of the beneficial effects of APD remain poorly understood.AIM To evaluate the effect of APD on intestinal inflammation and accompanying apoptosis induced by SAP in rats,and its potential mechanisms.METHODS SAP was induced in male adult Sprague-Dawley rats by 5%sodium taurocholate.Mild AP was induced by intraperitoneal injections of cerulein(20μg/kg body weight,six consecutive injections).Following SAP induction,a drainage tube connected to a vacuum ball was placed into the lower right abdomen of the rats to build APD.Morphological changes,serum inflammatory mediators,serum and ascites high mobility group box protein 1(HMGB1),intestinal barrier function indices,apoptosis and associated proteins,and toll-like receptor 4(TLR4)signaling molecules in intestinal tissue were assessed.RESULTS APD significantly alleviated intestinal mucosal injury induced by SAP,as demonstrated by decreased pathological scores,serum levels of D-lactate,diamine oxidase and endotoxin.APD reduced intestinal inflammation and accompanying apoptosis of mucosal cells,and normalized the expression of apoptosis-associated proteins in intestinal tissues.APD significantly suppressed activation of the intestinal TLR4 signaling pathway mediated by HMGB1,thus exerting protective effects against SAP-associated intestinal injury.CONCLUSION APD improved intestinal barrier function,intestinal inflammatory response and accompanying mucosal cell apoptosis in SAP rats.The beneficial effects are potentially due to inhibition of HMGB1-mediated TLR4 signaling.     

Coexpression of CD4 and CD8 on peripheral blood T cells and lamina propria T cells in inflammatory bowel disease by two colour immunofluorescence and flow cytometric analysis.

Using two colour immunofluorescence with fluorescein isothiocyanate and phycoerythrin labelled monoclonal antibodies and multiparameter flow cytometry, we investigated the coexpression of CD4 and CD8 antigens on peripheral blood lymphocytes and lamina propria lymphocytes of patients with ulcerative colitis and Crohn's disease and normal control subjects. Both the absolute number and the proportion of peripheral blood CD4+, CD8+ cells in inflammatory bowel disease were small but significantly increased compared with those in normal control subjects. Peripheral blood lymphocytes activated with phytohaemagglutinin showed appreciably increased coexpression of CD4+, CD8+. These CD4, CD8 positive cells were large and granular. Thus the increased number of peripheral blood CD4+, CD8+ cells in inflammatory bowel disease suggests that chronic immune activation occurs not only in the active state of the disease but also in remission. The proportion of CD4+, CD8+ cells in the lamina propria was greater than in peripheral blood in normal subjects, suggesting chronic immune stimulation of the local immune system. This was also seen in patients with Crohn's disease or inactive ulcerative colitis. The proportion of CD4+, CD8+ cells was, however, significantly less in the lamina propria of patients with active ulcerative colitis. Whether this implies a possible defect in mucosal immunoregulation in active ulcerative colitis cannot be determined from these results.     

RNA干扰抑制IL-23表达对感染后内脏高敏感小鼠肠黏膜固有层DC活化Th17细胞功能的影响

背景：前期研究发现感染后内脏高敏感小鼠肠黏膜固有层树突细胞（DC）诱导活化Th17细胞与肠道感染消退后肠黏膜免疫系统的持续激活有关。推测DC可能系通过分泌白细胞介素-23（IL-23）活化Th17细胞。目的：应用RNA干扰技术抑制DC分泌IL-23,探讨感染后内脏高敏感小鼠肠黏膜固有层DC活化Th17细胞的机制。方法：建立旋毛虫感染后内脏高敏感小鼠模型,以免疫磁珠分选肠黏膜固有层DC和脾脏CD4＋T细胞。构建、鉴定小鼠IL-23小发夹RNA（shRNA）干扰质粒,以脂质体法转染DC（A组）以抑制IL-23表达,同时设置转染空脂质体的DC（B组）和转染无关序列shRNA干扰质粒的DC（C组）作为对照。各组DC与CD4＋T细胞共培养120 h,以单独培养的CD4＋T细胞（D组）作为对照。以ELISA方法检测DC转染前后培养上清液中的IL-23水平,以及DC与CD4＋T细胞共培养上清液和CD4＋T细胞单独培养上清液中的IL-17水平。结果：A组DC培养上清液中的IL-23水平较转染前显著降低（P〈0.05）,B、C两组转染前后IL-23水平无明显变化。A、B、C组DC与CD4＋T细胞共培养上清液中的IL-17水平均较D组显著增高（P〈0.05）,其中A组显著低于B、C两组（P〈0.05）,B、C组间差异无统计学意义。结论：感染后内脏高敏感小鼠肠黏膜固有层DC可能通过分泌IL-23活化Th17细胞,参与维持肠道感染消退后肠黏膜免疫系统的持续激活。     

Early prediction of intestinal mucosal barrier function impairment by elevated serum procalcitonin in rats with severe acute pancreatitis

ObjectivesThe aim of this study was to evaluate serum procalcitonin (PCT) levels as a prognostic indicator of intestinal barrier function impairment in rats with severe acute pancreatitis (SAP).MethodsThirty-six male Sprague Dawley rats were randomly grouped into SAP group (injected sodium taurocholate via biliopancreatic duct), Gln group (gavaged with glutamine after modeling), and control group. Blood, pancreatic, and terminal ileum tissues were obtained from the rats after 6 h of modeling. Serum amylase (Amy) levels were determined using an automatic biochemical detector, while endotoxin (ET), diamine oxidase (DAO), and PCT levels were measured by ELISA test. The pathology of pancreatic and small intestine tissues were observed. PCT protein expression in intestinal tissues were detected by immunohistochemistry and western blot.ResultPancreatic and intestinal injuries in Gln group were significantly lower than SAP group. Serum amylase, DAO, and PCT levels in SAP and Gln groups differed greatly and were significantly higher than control group. Immuno-histochemistry and western blot results showed that PCT protein expression levels in small intestine tissues of SAP group were higher than Gln group and control group. Serum PCT levels had a significant correlation with serum endotoxin, DAO levels and intestinal mucosal injury scores.ConclusionPCT expression in serum and intestinal tissues in SAP rats increased significantly in the early stages of SAP, and was closely related to the onset and degree of intestinal barrier function impairment. Thus, our results showed that measuring serum PCT can be used to predict intestinal mucosal barrier function impairment in SAP rats.     

感染后内脏高敏感小鼠肠道黏膜固有层树突细胞对CD4~+T 细胞的作用

背景: 多项证据提示感染后肠易激综合征(PI-IBS)患者的肠道黏膜中存在T细胞介导的低度炎症。树突细胞(DC)是肠道黏膜免疫系统中最重要的抗原呈递细胞,目前关于DC在PI-IBS中作用的报道尚少。目的: 研究肠道黏膜固有层DC在急性肠道感染的不同阶段对CD4~+ T细胞的影响,探讨DC在肠道感染消退后维持肠道黏膜免疫系统持续激活中的作用。方法: 建立旋毛虫感染后内脏高敏感小鼠模型以模拟人类PI-IBS。肠道黏膜固有层DC与脾脏CD4~+T细胞于体外共培养120h,ELISA法检测细胞培养上清液中Th17、Th2、Th1相关细胞因子IL-17、IL-4、IFN-γ水平。结果: 与单独培养相比,CD4~+T细胞与DC共培养后,感染后8周组IL-17水平增加值明显高于对照组(P=0.001)和感染后2周组(P=0.279):感染后2周组IL-4水平增加值明显高于对照组(P=0.041)和感染后8周组(P=0.204);三组间IFN-γ水平增加值差异均无统计学意义。结论: 感染后内脏高敏感小鼠肠道黏膜固有层DC诱导CD4~+T细胞分化为Th17细胞并使之活化可能是肠道感染消退后维持肠道黏膜免疫系统持续激活的主要机制。     

Small-bowel involvement in systemic lupus erythematosus: a morphometric and immunohistochemical study.

BACKGROUND: We have investigated the intestinal mononuclear cell subpopulations in patients with systemic lupus erythematosus (SLE) and correlated these with the disease activity. METHODS: Eighteen female outpatients were studied; in 10 of them lupus activity was measured with the Lupus Activity Criteria Count and the SLE Disease Activity Index. Eight patients were in lupus remission. The control group consisted of 10 healthy volunteers. Peroral jejunal biopsy was performed in all individuals, at the angle of Treitz, using a Watson capsule, under X-ray control. Histologic studies analysed the villous to crypt ratio, lamina propria cells, and intraepithelial lymphocyte count. Immunohistochemical evaluation was carried out with the indirect immunoperoxidase technique, using monoclonal antibodies against CD3, CD4, CD8, D1, D7, D9, and M1. RESULTS: Lamina propria CD3+, CD8+, D7+, and M1+ cells from patients with SLE did not differ significantly from those of controls. CD4+ cells were decreased in all patients with SLE, especially in the clinically inactive patients. D1+ and D9+ cells were also decreased in all patients. CONCLUSION: The finding of quantitative abnormalities in the cell-mediated immunity of the intestinal mucosa may reflect systemic defects of the immune system in SLE.     

Small-Bowel Involvement in Systemic Lupus Erythematosus: A Morphometric and Immunohistochemical Study

Background: We have investigated the intestinal mononuclear cell subpopulations in patients with systemic lupus erythematosus (SLE) and correlated these with the disease activity. Methods: Eighteen female outpatients were studied; in 10 of them lupus activity was measured with the Lupus Activity Criteria Count and the SLE Disease Activity Index. Eight patients were in lupus remission. The control group consisted of 10 healthy volunteers. Peroral jejunal biopsy was performed in all individuals, at the angle of Treitz, using a Watson capsule, under X-ray control. Histologic studies analysed the villous to crypt ratio, lamina propria cells, and intraepithelial lymphocyte count. Immunohistochemical evaluation was carried out with the indirect immunoperoxidase technique, using monoclonal antibodies against CD3, CD4, CD8, D1, D7, D9, and M1. Results: Lamina propria CD3+, CD8+, D7+, and M1+ cells from patients with SLE did not differ significantly from those of controls. CD4+ cells were decreased in all patients with SLE, especially in the clinically inactive patients. D1+ and D9+ cells were also decreased in all patients. Conclusion: The finding of quantitative abnormalities in the cell-mediated immunity of the intestinal mucosa may reflect systemic defects of the immune system in SLE.     

重症急性胰腺炎大鼠并发肠黏膜屏障功能障碍

目的探讨重症急性胰腺炎(SAP)大鼠肠黏膜屏障功能的状况。方法 48只SD大鼠,随机分两组:假手术组(A组,n=24)、SAP模型组(B组,n=24)。用3%牛磺胆酸钠制备SAP大鼠模型。麻醉苏醒,即开始灌胃,6h/次,A、B组用灌胃器按1 mL/100 g/次生理盐水灌胃。制模后各组在6、12、24 h 3个时间点取材;开腹后观察腹水量及其颜色,观察胃肠道大体情况;取血用酶联免疫吸附双抗夹心法检测血清二胺氧化酶(DAO)及D-乳酸浓度;取胰腺及回肠末段组织做病理检查,并进行胰腺病理组织评分;取回肠末段部分组织做扫描电镜检查。结果A组无腹水;B组腹水多,肠道明显扩张,积液积气,部分肠管发黑。B组血清DAO、D-乳酸的浓度较A组升高(P<0.01)。B组胰腺及回肠病理损害重,胰腺病理组织评分较A组高(P<0.05);扫描电镜检查A组基本正常,B组损伤重。结论 SAP大鼠并发肠黏膜屏障功能障碍。     

谷氨酰胺对急性坏死型胰腺炎大鼠肠道衰竭的治疗作用

目的观察谷氨酰胺(Gln)对急性坏死型胰腺炎(ANP)大鼠肠道衰竭的治疗作用,并探讨其作用机制.方法 Spraque-Dawley 大鼠54只,随机分为假手术组(SO)、ANP组、Gln治疗组(ANP+Gln),每组18只.采用5%牛磺胆酸钠溶液经胆胰管内逆行注射诱导大鼠ANP模型.大鼠中心静脉置管,用微量输液泵输注含等氮、等热卡的氨基酸溶液,ANP+Gln组加入3%丙氨酸-Gln双肽(相当于2%Gln溶液,剂量0.5g·kg-1·d-1).术后24、48、72 h分批处死大鼠并留取标本,分别做肠黏膜组织病理检查,肝、胰、脾、肠系膜淋巴结(MLN)和腹水等组织细菌培养,门静脉血内毒素测定,TUNEL法检测肠黏膜上皮细胞凋亡;逆转录-聚合酶链反应研究肠黏膜组织胰岛素样生长因子1(IGF-1)、Gln酶和Gln合成酶mRNA表达.结果 SO组大鼠各组织培养均无阳性细菌,ANP组细菌培养阳性率明显高于SO组,P＜0.05,以MLN阳性率最高;ANP+Gln组细菌培养阳性率则显著低于ANP组,P＜0.05.血浆内毒素在ANP组明显高于SO组(P＜0.05),且随着时间延长而递升;ANP+Gln组血浆内毒素较ANP组显著下降(P＜0.05).ANP组肠黏膜绒毛高度显著低于SO组 (P＜0.05),提示ANP时肠黏膜处于萎缩状态,而ANP+Gln组较SO组则差异无显著性 (P＞0.05).ANP组肠黏膜上皮细胞凋亡指数明显高于SO组(P＜0.05),而ANP+Gln组较SO组差异无显著性(P＞0.05).SO组肠黏膜IGF-1、Gln酶和Gln合成酶 mRNA表达恒定,ANP组三者表达均明显下调,而Gln则能显著上调IGF-1、Gln酶和Gln合成酶 mRNA表达.结论 ANP大鼠肠黏膜屏障处于衰竭状态,并由此导致肠道细菌和内毒素移居.Gln可能通过刺激肠黏膜IGF-1、Gln酶和Gln合成酶 mRNA表达,下调肠黏膜细胞凋亡,从而促进肠黏膜修复,有效地控制ANP并发肠道衰竭.     

骨桥蛋白在炎症性肠病患者结肠组织中的表达

背景：骨桥蛋白（OPN）是一种分泌型磷酸化糖蛋白,参与细胞信号转导,促进细胞黏附和迁移。近年研究发现炎症性肠病（IBD）患者血浆OPN水平升高,患者结肠黏膜中可检出OPN表达。目的：了解OPN在IBD患者结肠黏膜组织中的表达情况,探讨其在IBD发病机制中的作用。方法：以免疫组化半定量方法检测53例溃疡性结肠炎（UC）、62例克罗恩病（CD）和15例源自结肠腺瘤患者的正常结肠组织标本中OPN的表达。结果：OPN广泛表达于结肠黏膜上皮细胞和固有层渗出细胞。UC组和CD组结肠上皮细胞的OPN平均光密度值显著低于对照组（11．84±0．98和10．04±1．37对12．64±1．45,P〈0．05）,结肠黏膜固有层渗出细胞的OPN阳性细胞百分率则显著高于对照组（20．31％±4．50％和12．69％±3．06％对3．85％±0．66％,P〈0．001）。UC和CD患者的病情严重程度与结肠上皮细胞和固有层渗出细胞中的OPN表达量均无相关性。结论：OPN在IBD患者结肠黏膜上皮和同有层中的表达不一致,结肠上皮细胞中OPN表达下调可能与肠黏膜屏障功能受损有关,而黏膜固有层渗出细胞中OPN表达上调可能与免疫反应有关。     

八面蒙脱石灌肠对重症急性胰腺炎大鼠结肠屏障的保护作用

目的 探讨八面蒙脱石是否在急性胰腺炎有保护结肠屏障的作用及可能的机制.方法 72只雄性SD大鼠按完全随机法分为假手术组(SO组)、重症急性胰腺炎模型组(SAP组)、八面蒙脱石灌肠干预组(干预组),每组24只.采用胰胆管内逆行注射法诱导大鼠急性胰腺炎模型;SO组开腹往射生理盐水后关腹;干预组于造模前0.5 h行八面蒙脱石液灌肠(1 ml/100 g).术后分别于3、6、12 h取胰腺组织行病理学评分,并测定血清TNFα、血浆二胺氧化酶和内毒素水平,取结肠组织以RT-PCR法及Western blot法检测结肠黏膜细胞间紧密连接蛋白Occludin及其mRNA的表达.结果 (1)光镜下SAP组可见胰腺组织炎性细胞浸润、出血和腺泡坏死,干预组病变相对较轻,SO组为正常胰腺表现.(2)血清TNFα水平在SAP组最高,与其他两组的差别有统计学意义(P<0.05),干预组较SAP组降低(P<0.05).(3)SAP组各时间点的血内毒素和二胺氧化酶水平明显较SO组升高(P值均<0.01),而干预组则较SAP组降低(P<0.01);Occludin的蛋白及mRNA表达水平在SAP组明显减少(P<0.01),而下预组较之有所改善(P<0.01).结论 八面蒙脱石有助于维持SAP大鼠结肠屏障结构和功能,从而降低内毒素血症,改善炎症造成的组织损伤,对大鼠急性胰腺炎有保护作用.     

持续低效血液透析滤过对重症急性胰腺炎患者肠黏膜屏障功能及免疫功能的影响

目的 评价持续低效血液透析滤过（SLEDF）对重症急性胰腺炎（SAP）患者肠黏膜屏障功能及免疫功能的影响。方法 将51例SAP患者随机分为持续静脉静脉血液滤过（CVVH）组25例和SLEDF组26例,在常规治疗基础上分别接受CVVH和SLEDF治疗。比较两组患者预后、血、尿淀粉酶恢复正常时间、治疗前和治疗第2、4、8、14d血D-乳酸、内毒素（ET）、二胺氧化酶(DAO)、CD3⁺、CD4⁺、CD8⁺T淋巴细胞水平、CD4⁺/CD8⁺T淋巴细胞比值及血液净化相关并发症发生情况。结果 两组患者死亡率、血、尿淀粉酶恢复正常时间比较差异均无统计学意义,血D-乳酸、ET、DAO、CD3⁺、CD4⁺、CD8⁺T淋巴细胞水平和CD4⁺/CD8⁺T淋巴细胞比值在治疗前和治疗第2、4、8、14d比较差异均无统计学意义（P>0.05）。两组患者治疗第4、8、14d D 乳酸、ET和DAO水平均较同组治疗前降低,第8、14d均较同组治疗第4d降低（P＜0.05）。两组患者治疗第4、8、14d的CD3⁺、CD4⁺、CD8⁺T淋巴细胞水平和CD4⁺/CD8⁺T淋巴细胞比值均较同组治疗前升高,第8、14d均较同组治疗第4d升高（P＜0.05）;两组患者治疗第4、8d的CD8⁺T淋巴细胞水平较同组治疗前降低,第8、14d较第4d降低（P＜0.05）。结论 SLEDF和CVVH改善SAP患者肠道屏障功能障碍和免疫功能异常的作用相似,其中SLEDF操作方便,医疗费用低,值得临床推广。     

Experimental research on production and uptake sites of TNFalpha in rats with acute hemorrhagic necrotic pancreatitis

AIM:To determine the site of production and uptake of tumor necrotic factor alpha (TNFalpha),and evaluate the relationship between serum TNFalphaand pla-sma endotoxin (ET) in rats with acute hemorrhagic necrotic pancreatitis (AHNP).METHODS:Sprague Dawley rats were divided into AHNP group and control group (n = 12). AHNP model was induced by retrograde injection of 5% sodium taurocholate via pancreatic bile duct. The blood samples were obtained through portal vein 2 and 6 hours after the operation.RESULTS:The contents of TNFalphain portal vein were increased rapidly in the development of AHNP. They were lower in hepatic vein (280.59 plus minus 20.02) and femoral artery (310.82 plus minus 7.97) than in portal vein (354.91 plus minus 25.50) (P < 0.05), and higher in femoral artery than in hepatic vein 6 hours after the operation (P <0.05). TNFalphalevel in plasma was increased significantly when ET level in portal vein showed no increase. CONCLUSION: Pancreas, spleen, liver, intestinal tract and lung are the main organs to produce TNFalpha, and liver is also an important site for TNFalphauptake in the development of AHNP. Plasma endotoxin is not a trigger for TNFalpharelease in rats with AHNP.     

Hyperexpression of inducible costimulator on lamina propria mononuclear cells in rat dextran sulfate sodium colitis

BACKGROUND AND AIMS: The authors have previously shown that a third member of the CD28 family, inducible costimulator (ICOS), was increased in the inflamed intestinal mucosa of murine experimental colitis, and that the blockade of ICOS ameliorated the development of colitis. However, the role of ICOS in rat intestinal inflammation and its expression profile remains unclear. In the present study, the authors investigated the involvement of ICOS in the development of rat dextran sulfate sodium (DSS)-induced colitis, and the therapeutic potential of anti-ICOS monoclonal antibody (mAb) in colitis. METHODS: The authors first examined expression of ICOS protein in normal rat by immunohistochemistry and flow cytometry. Sprague-Dawley rats were fed 3.0% DSS. The expression of ICOS on infiltrating lamina propria mononuclear cells and splenocytes were examined. The DSS-fed rats were then administered anti-ICOS mAb to test its effect on the development of colitis. RESULTS: Unlike mice and human, ICOS was expressed on a part of CD4+ T-cells from the thymus, spleen, mesenteric lymph nodes and lamina propria. Levels of ICOS on CD4+ T-cells from the spleen and colonic lamina propria were significantly upregulated after Concanavalin A (Con A) stimulation. In addition, ICOS was also upregulated on CD4+ T-cells from DSS-fed rats compared with those from non DSS-fed rats. However, anti-ICOS mAb did not ameliorate the development of both acute and chronic DSS colitis. CONCLUSION: These results suggest that the different expression of ICOS in rats plays a distinct role in rat intestinal inflammation.     

Intestinal colonization with Candida albicans and mucosal immunity

AIM: To observe the relationship between intestinal lumen colonization with Candida albicans and mucosal secretory IgA (sIgA).METHODS: A total of 82 specific-pathogen-free mice were divided randomly into control and colonization groups. After Candida albicans were inoculated into specific-pathogen-free mice, the number of Candida albicans adhering to cecum and mucosal membrane was counted. The lymphocyte proliferation in Peyer‘s patch and in lamina propria was shown by BrdU incorporation, while mucosal sIgA (surface membrane) isotype switch in Peyer‘s patch was investigated. IgA plasma cells in lamina propria were observed by immunohistochemical staining. Specific IgA antibodies to Candida albicans were measured with ELISA.RESULTS: From d 3 to d 14 after Candida albicansgavaging to mice, the number of Candida albicans colonizing in lumen and adhering to mucosal membrane was sharply reduced.Candida albicans translocation to mesenteric lymph nodes occurred at early time points following gavage administration and disappeared at later time points. Meanwhile, the content of specific IgA was increased obviously. Proliferation and differentiation of lymphocytes in lamina propria were also increased.CONCLUSION: Lymphocytes in lamina propria play an important role in intestinal mucosal immunity of specific-pathogen-free mice when they are first inoculated with Candida albicans. The decreasing number of Candida albicans in intestine is related to the increased level of specific IgA antibodies in the intestinal mucus.