Controlling the frontier: Regulatory T-cells and intestinal homeostasis

The intestine represents one of the most challenging sites for the immune system as immune cells must be able to mount an efficient response to invading pathogens while tolerating the large number and diverse array of resident commensal bacteria. Foxp3⁺ regulatory T-cells (Tregs) play a non-redundant role at maintaining this balance. At the same time Treg cell differentiation and function can be modulated by the intestinal microbiota. In this review, we will discuss effector mechanisms of Treg cells in the intestine and how these cells can be influenced by the intestinal microbiota.     

乌拉地尔在大鼠小肠的在体灌流吸收研究

目的:研究乌拉地尔在大鼠小肠上、下部的吸收情况,为开发其缓释制剂提供依据。方法:采用大鼠在体小肠回流实验装置,利用高效液相色谱法分别测定酚红和乌拉地尔的含量。结果:乌拉地尔在大鼠小肠上、下段的吸收速度常数Ka分别为0.269、0.271,t1/2分别为2.6、2.58h,吸收率分别为27.29%、28.26%(P>0.05)。结论:乌拉地尔在大鼠小肠上、下段的吸收率无显著性差异,适合制备缓释制剂。     

肠道微生态制剂在结直肠术后病人中的应用

目的:对结直肠手术后病人应用肠道微生态制剂治疗的效果进行评价. 方法:前瞻性、单盲、随机、对照临床试验.将32例结直肠中等以上手术的病人,随机分为试验组和对照组,每组各16例.试验组病人于术后第3天给予肠内营养 双歧杆菌/嗜酸性乳杆菌/粪链球菌(菌品名:金双歧),每天2次,每次4片,直至出院.对照组只给予肠内营养支持.观察病人术前及术后4～8 d的胃肠道症状、生命体征、粪便性状及量和菌群比例等. 结果:①胃肠道症状:两组病人术后恶心、呕吐、肠鸣音恢复等差异均无显著性意义(P＞0.05),总腹胀天数、总腹痛天数在两组间差异有显著性意义(P＜0.05).②腹泻及腹泻评分:两组病人在术后第6天腹泻例数差异有显著性意义(P＜0.05),总腹泻天数、总腹泻人数两组间差异有显著性意义(P＜0.05).两组病人腹泻评分在术后第6天有显著性意义.③菌群比例:试验组病人菌群比例(杆菌/球菌)术后3次均比对照组高,术后第2次监测,两组间差异有显著性意义(P＜0.05). 结论:在结直肠术后病人中,应用肠道微生态制剂可改善病人胃肠道症状、减轻腹泻严重程度和纠正肠道菌群失调.     

Drug specificity and intestinal membrane localization of human organic cation transporters (OCT)

This study was performed to investigate which human organic cation transporter, hOCT1, hOCT2 or hOCT3, participates with regard to cation specificity and membrane localization in the intestinal absorption of orally available cationic drugs. Inhibition of N-[methyl-³H]4-phenylpyridinium ([³H]MPP⁺) uptake by various compounds into Caco-2 cells and into cells (HEK-293 or CHO) that were stably transfected with hOCT1, hOCT2 or hOCT3 was compared. The uptake of [³H]MPP⁺ into Caco-2 cells was inhibited by atropine, butylscopolamine, clonidine, diphenhydramine, etilefrine, quinine and ranitidine with IC₅₀ values between 6 μM and 4 mM. Transepithelial, apical to basal flux of [³H]MPP⁺ across Caco-2 cell monolayers was also strongly inhibited by these compounds. The inhibitory potency of the cationic drugs and prototypical organic cations at Caco-2 cells correlated well with the inhibitory potency measured at CHO-hOCT3 cells but much less with that at HEK-hOCT1 and -hOCT2 cells. This is functional evidence for the predominant role of hOCT3. Etilefrine and atropine were specifically transported into CHO cells by hOCT3. In Caco-2 cells, the mRNA of all three hOCT and the proteins hOCT2 and hOCT3 were detected. More importantly, immunocytochemical analyses of human jejunum revealed for the first time that hOCT3 is localized to the brush border membrane whereas hOCT1 immunolabeling was mainly observed at the lateral membranes of the enterocytes.     

Incidental paraduodenal hernia found during laparoscopic colectomy

This paper describes a rare right paraduodenal hernia discovered during an elective laparoscopic colon resection. Our patient was a 60-year-old Asian man with a history of multiple bouts of diverticulitis and a lifelong history of mild constipation and postprandial abdominal pain. Prior CT scans and preoperative barium enema confirmed the diagnosis of diverticular disease, and no other abnormalities were appreciated. At laparoscopic exploration, a right paraduodenal hernia was found with complete herniation of the small intestine under the ascending colon and hepatic flexure. The unclear anatomy prompted conversion to an open laparotomy. This allowed safe reduction of the hernia and sac excision. Adhesions were lysed to relieve a partial duodenal obstruction, and a Ladds procedure was performed to correct the incomplete rotation. Additionally, a sigmoid colectomy was performed. After prolonged ileus, the patient was discharged on postoperative day 14. At 6-month follow-up, the patient was asymptomatic and doing well.     

Characterization of receptors for two<Emphasis Type="Italic"> Xenopus</Emphasis> gastrointestinal tachykinin peptides in their species of origin

Two tachykinin peptides, bufokinin and Xenopus neurokinin A (X-NKA) were recently isolated from Xenopus laevis. In this study we investigated the tachykinin receptors in the Xenopus gastrointestinal tract. In functional studies using stomach circular muscle strips, all peptides had similar potencies (EC₅₀ values 1–7 nM). The rank order of potency to contract the intestine was physalaemin (EC₅₀ 1 nM)bufokinin (EC₅₀ 3 nM)>substance P (SP)cod SP>NKA>>X-NKA (EC₅₀ 1,900 nM). No maximum response could be obtained for [Sar⁹,Met(O₂)¹¹]SP, eledoisin and kassinin. In stomach strips, the mammalian tachykinin receptor antagonists RP 67580 (NK1) and MEN 10376 (NK2) had agonistic effects but did not antagonize bufokinin or X-NKA. In intestinal strips, RP 67580 (1 M) reduced the maximal response to X-NKA but not bufokinin, while MEN 10376 was ineffective. [¹²⁵I]BH-bufokinin bound with high affinity to a single class of sites, of K_D 213±35 (stomach) and 172±9.3 pM (intestine). Specific binding of [¹²⁵I]BH-bufokinin was displaced by bufokininSP>NKAeledoisinkassinin>X-NKA, indicating binding to a tachykinin NK1-like receptor. Selective tachykinin receptor antagonists were weak or ineffective. Other iodinated tachykinins ([¹²⁵I]NKA and [¹²⁵I]BH-eledoisin) displayed biphasic competition profiles, with the majority of sites preferring bufokinin rather than X-NKA. In conclusion, there is evidence for two different tachykinin receptors in Xenopus gastrointestinal tract. Both receptors may exist in stomach, whereas the bufokinin-preferring NK1-like receptor predominates in longitudinal muscle of the small intestine. Antagonists appear to interact differently with amphibian receptors, compared with mammalian receptors.Abbreviations Buf Bufokinin - cSP Cod SP - Ele Eledoisin - Kass Kassinin - NKA Neurokinin A - Phys Physalaemin - Sar⁹ [Sar⁹,Met(O₂)¹¹]SP - SP Substance P     

结核性广泛粘连性小肠梗阻的手术处理

目的:探讨结核性广泛粘连性小肠梗阻(TBEAIO)的手术时机、方法及再梗阻的预防。方法:对8例TBEA IO的临床资料进行回顾性分析,并对其手术操作的可行性进行研究。结果:8例中男2例,女6例,平均年龄31.6岁,皆有典型小肠梗阻表现,经手术与术后病理证实为本病。7例行肠粘连松解、肠排列术,术中予以抗粘连预防,均获得满意疗效,1例就诊过晚,仅行破裂肠袢外引流,抢救无效死亡。结论:对TBEAIO应遵循手术指征,正确施行肠粘连松解术,做好肠袢再粘连、再梗阻的预防。     

北京市城市社区大肠癌筛查效果及问题分析

目的了解北京市试点社区大肠癌筛查的效果,对整个大肠癌筛查过程中所存在的问题进行分析,并提出改进的建议。方法选取北京市4个试点社区,按照不同的社区类型分为功能性社区和生活性社区,采取不同的模式开展大肠癌筛查,并对筛查中存在的问题进行分析。结果4个社区符合筛查条件的总人数为32010人,参与筛查的总人数为14978人,筛查率为46.79%;筛查缺失率为15.37%。结论北京市试点社区的大肠癌筛查效果基本令人满意,但筛查工作面临着组织困难,群众筛查依从性低的问题,需要我们在以后的工作中继续改进。     

Oral arginine improves intestinal recovery following ischemia-reperfusion injury in rat

Arginine and nitric oxide are critical to the normal physiology of the gastrointestinal tract and maintain the mucosal integrity of the intestine in various intestinal disorders. In the present study, we evaluate the effects of oral arginine (ARG) supplementation on intestinal structural changes, enterocyte proliferation, and apoptosis following intestinal ischemia–reperfusion (IR) in the rat. Male Sprague–Dawley rats were divided into three experimental groups: sham rats underwent laparotomy and superior mesenteric artery mobilization, IR rats underwent superior mesenteric artery occlusion for 30 min following by 24 h of reperfusion, and IR-ARG rats were treated with enteral arginine given in drinking water (2%) 48 h before and following IR. Intestinal structural changes, enterocyte proliferation, and enterocyte apoptosis were determined 24 h following IR. A nonparametric Kruskal–Wallis ANOVA test was used for statistical analysis with p <0.05 considered statistically significant. IR rats demonstrated a significant decrease in bowel weight in duodenum and jejunum, mucosal weight in jejunum and ileum, and villus height in jejunum and ileum compared with control animals. IR rats also had a significantly lower cell proliferation index in jejunum and ileum and a higher apoptotic index in ileum compared with control rats. IR-ARG animals demonstrated greater duodenal and jejunal bowel weight; duodenal, jejunal, and ileal mucosal weight; and jejunal and ileal cell proliferation index compared with IR animals. In conclusion, oral ARG administration improves mucosal recovery following IR injury in the rat.     

大鼠烫伤后小肠氨基酸吸收的变化

烫伤体表面积37％Ⅲ°的大鼠组,于伤后第三天断头致死,其小肠外翻囊3~H-脯氨酸吸收比值(1.87±0.27),较对照组的吸收比值(2.35±0.49)显著降低(P<0.05),同时烫伤组小肠粘膜ATP酶活性5.61±2.27nmole/min/mg蛋白质,Na~+,K~+-ATP酶活性2.86±0.83nmole/min/mg蛋白质,对照组小肠粘膜ATP酶活性9.63±1.04nmole/min/mg蛋白质,Na~+,K~+-ATP酶活性5.36±0.95nmole/min/mg蛋白质,两组比较不论是ATP酶或Na~+,K~+-ATP酶活性降低都非常显著(P<0.001)。对照组氨基酸吸收比值与小肠粘膜Na~+,K~+-ATP酶活性呈正相关,相关系数r=0.744,P(1)<0.025,烫伤组氨基酸吸收比值与小肠粘膜Na~+,K~+-ATP酶活性也呈正相关关系,相关系数r=0.776,P(1)<0.025,表明烫伤组氨基酸吸收比值下降,可能由于Na~+,K~+-ATP酶活性降低所致。