人小肠三叶因子的克隆及酶联免疫吸附检测

人小肠三叶因子的cDNA,克隆到原核表达载体pGEX-4T-1中,经IPTG诱导后,hITF以GST-hITF融合蛋白的形式表达,融合蛋白占细菌总蛋白的15%左右。经过Glutathione-Sepharose 4B亲和柱和Sephacry1 S 100分子筛层析纯化了hITF。SDS-PAGE和氨基酸分析证明得到了hITF纯品。以天然hITF为抗原免疫青紫蓝兔制备了抗血清,用纯化的IgG建立了hITF的酶联免疫吸附检测(ELISA)方法,给出了标准工作曲线。应用于纯化过程中样品峰的确立。     

从大口黑鲈胃、肠道中分离的部分好氧菌的研究

从大口黑鲈（Microptens salmoides)胃、肠道中分离到24个好氧菌株。经过自动微生物鉴定系统（VITEK－AMS－60和VITEK－AMS－CC2）鉴定结果是：真菌只有1个菌株（茁芽毛孢酵母Tri-chosporon pullulans)；细菌有23个菌株，其中革兰氏阳性菌只有1个菌株（干燥棒状杆菌Corynebacterium xerosis)，1个非发酵性菌株（食酸假单胞菌Pseudomonas acidovorans)，其余21个菌株均是革兰氏阴性菌；革兰氏阴性菌中，支气管败血性鲍特氏菌（Bordetella bronchiseptica)5个，尿放线杆菌（Actinobacillus ureae)4个，粘黄杆菌（Flavobacterium gleum)4个，产吲哚黄杆菌（F.indologenes)3个，恶臭假单胞菌（P.putida)3个，泡囊假单胞菌（P.vesicularis)2个。24个菌株中5个水解淀粉，5个水解牛奶；在22种药物敏感试验中，恶臭假单胞菌肠14菌株和支气管败血性鲍特氏菌肠17菌株分别对17种药物有耐药性；24个菌株中，对氨苄青霉素、先锋V（头孢唑啉）、青霉素G不敏感的菌分别有23株、23株、22株。     

肠道菌群调控脂质代谢的分子机制

人类肠道菌群基因组又被称为“人类第二基因组” ,其在人体脂肪的分解合成过程中起到了重要的调控作用。 体内肠道菌群的失调,会引起肥胖、糖尿病等在内的代谢综合症的发生。 本文从肠道菌群通过调控在脂质代谢中 起重要作用的酶类和调控因子从而为机体提供能量、减脂和改善健康状况的研究进展方面进行了综述。     

超氧化物歧化酶在模拟人体胃肠环境中稳定性的研究

本文以中国药典中的人工胃液和人工肠液作为模拟人体胃肠环境，对超氧化物歧化酶的稳定性进行了一系列单独及综合的研究。研究结果发现，超氧化物歧化酶在人工胃液中会受到较强的破坏，而在人工液中则颇为稳定。同时还发现，尽管是天然结构的超氧化物歧化酶对胃蛋白酶和胰酶具有较强的耐受力，但被胃酸处理后结构松散的超氧化物歧化酶却可被胃蛋白酶和胰酶较有效地水解。     

Effect of epidermal growth factor on growth and maturation of fetal and neonatal rat small intestine in organ culture

Summary Small intestinal explants from pre- and post-natal rats were incubated in an organ culture system in the absence and presence of epidermal growth factor (EGF). The rate of synthesis of small intestinal DNA and protein as well as the activity of lactase and alkaline phosphatase increased rapidly between 17 and 20-day gestational age, whereafter they declined. The maximal incorporation of³H-thymidine and¹⁴C-alanine into DNA and protein, respectively, was significantly stimulated by EGF (100 ng/ml). EGF had no effect on the activity of either lactase or alkaline phosphatase in the small intestinal explants.Acknowledgment. The project was supported by grants from the Veterans Administration Research Service. The authors wish to thank Dr. M. C. Geokas, Chief, Department of Medicine, Veterans Administration Medical Center, Martinez, CA, for providing us with excellent laboratory facilities and for his encouragement in this study.     

Calcium ionophore plus excision induce a large conductance chloride channel in membrane patches of human colon carcinoma cells HT-29cl.19A

In excised inside-out membrane patches of the human colon carcinoma HT-29cl.19A cells a large conductance (373±10 pS) chloride channel was found. Channel activity could only be observed after excision of patches from cells incubated with calcium ionophore. The channel was never observed in cell-attached patches. The channel was strongly voltage dependent, being open only between +30 and –30 mV clamp potentials. The selectivity sequence among anions, deduced from reversal potentials, was I>Br>Cl>F>gluconate. The P_Na/P_Cl was 0.09. Although a similar type of channel, has been described earlier, this is the first report stating its appearance in patches of intestinal epithelial cells requiring the combined action of Ca²⁺ ionophore and excision, suggesting its control by an intracellular compound.     

Microcalorimetric investigation of effect of berberine alkaloids from Coptis chinensis Franch on intestinal diagnostic flora growth

The inhibitory effect of three berberine alkaloids (BAs) from Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Bifidobacterium adolescentis growth was investigated by micro- calorimetry. The power-time curves of B. adolescentis with and without BAs were acquired, meanwhile the extent and duration of inhibitory effect on the metabolism were evaluated by the growth rate con- stant (k), half inhibitory ratio (IC50), maximum heat-output power (Pmax), peak time of maximum heat-output power...     

双歧杆菌BB-12的功能特性及研究进展

双歧杆菌BB-12是肠道益生菌——双歧杆菌的一个亚种,对维持肠道菌群平衡有着重要影响.综述了双歧杆菌BB-12的来源及研究进展,对其调节肠道菌群、通肠润便、提高免疫以及护肝方面的功能特性研究进行阐述,并对其前景进行展望.     

肠癌患者与健康人群肠道菌群基因组DNA鉴定与特征

目的探讨肠道肿瘤患者与健康人群肠道菌群构成及基因组DNA的变化特征.方法分别采集肠癌患者与健康人晨起粪便,进行需氧和厌氧培养,鉴定菌株并进行菌落计数.采用试剂盒法提取粪便中肠道细菌总基因组DNA,进行琼脂糖凝胶电泳.结果肠癌组与健康对照组比较,肠杆菌数量增多,以大肠埃希菌数量显著,乳酸杆菌和双歧杆菌明显减少,厌氧菌和需氧菌的数量比例颠倒,两组数据比较差异均具有统计学意义(P0.05).粪便总基因组DNA经琼脂糖凝胶电泳在23 130 bp处有清晰、明亮的单一条带,且肠癌组与健康对照组均有相同大小的条带.结论肠癌组与健康对照组肠道菌群组成存在差异,肠道菌群总基因组DNA没有变化.     

幼鼠小肠缺血-再灌注肠组织的形态学观察

目的:观察幼鼠小肠缺血-再灌注(ischemia/reperfusion,I/R)肠组织形态学变化。方法:将32只4周龄(Sprague Dawley,SD)大鼠随机分成2组即假手术组(Sham组)和缺血-再灌注组(I/R组),每组各16只。Sham组仅暴露腹腔脏器,不作任何干预;I/R组经阻断肠系膜上动脉60 min后恢复血供,于再灌注30、60、90、120 min每组动物各处死4只取小肠组织进行组织学Chiu’s评分,结果进行单因素方差分析和组间t检验。结果:Sham组肠组织形态正常;I/R组小肠组织发生了明显的缺血和炎症反应并随再灌注时间延长而加重,各观察时间点组织学评分在组间比较差异均有统计学意义,各值在I/R组高于Sham组(P<0.05)。结论:幼鼠肠I/R导致肠组织病理损伤并随再灌注时间延长而加重。