Effect of Dietary Administration of Lathyrus sativus Pulse on Intestinal Biochemical Parameters in Normal and Scorbutic Guinea Pigs

Objective In order to investigate that ascorbic acid deficiency is responcible for lathyrus toxicity, the effect of dietary feeding of lathyrus pulse in normal and scorbutic guinea pigs for 3 months, on intestinal biochemical parameters was undertaken. Methods The intestinal brush border membrane (BBM) marker and xenobiotic metabolising enzymes (XME) were assayed. Results Exposure to 80% lathyrus alone and in scorbutic conditions showed significant inhibition of alkaline phosphatase (28%-30%), sucrase (19%) and γ-glutamyl transpeptidase (GGT) (15%-27%) enzymes, while Ca2 -Mg2 -ATPase was significantly inhibited (38%) in scorbutic plus lathyrus treated group. The phase I XME (AHH) remained unchanged while the phase II enzyme glutathione-S-tranferase (GST) was significantly decreased (20%-22%) in lathyrus and scorbutic plus lathyrus treated groups. Quinone reductase (QR) activity was found to be significantly decreased in lathyrus exposed group (20%). The intestinal biomarker contents including hexose (2     

Structural Modulation of Gut Microbiota in Rats with Allergic Bronchial Asthma Treated with Recuperating Lung Decoction

ObjectiveTo investigate whether recuperating lung decoction (RLD) can modulate the composition of gut microbiota in rats during asthma treatment. MethodsFifteen Sprague-Dawley rats were divided randomly and equally into control group, model group, dexamethasone (DEX) group, RLD medium-dose group, and RLD high-dose group. The asthma model was established in all groups, except for the control group. The rats in the DEX and RLD groups were treated orally with DEX and RLD, respectively. The rats in the control and model groups were treated orally with 0.9% saline. The intestinal bacterial communities were compared among groups using 16S rRNA gene amplification and 454 pyrosequencing. ResultsThe microbial flora differed between the control and model groups, but the flora in the RLD groups was similar to that in the control group. No significant differences were observed between the RLD high-dose and medium-dose groups. RLD treatment resulted in an increase in the level beneficial bacteria in the gut, such asLactobacillusandBifidobacteriumspp. ConclusionOral administration of RLD increased the number of intestinal lactic acid-producing bacteria, such as Lactobacillus andBifidobacterium, in asthma model rats.     

Effect of Dachengqi Tang(大承气汤)Granule on Proliferation ofIntestinal Epithelial Cells in Rats with ExperimentalIntestinal Obstruction

Objective: To study the effects of Dachengqi Tang (DCQT) granule on the proliferation of the intestinal epithelial cells in rats with experimental intestinal obstruction. Methods: Experimental intestinal obstruction models were established in rats and autoradiography with 3 H-TdR was used to determine 3H-TdR labeling counts of intestinal epithelial cells in rats. Results: DCQT granule had no effects on 3H-TdR labeling counts of intestinal epithelial cells in normal rats. DCQT granule obviously increases the rate of renovation in intestinal epithelial cells of the intestinal obstruction rats. Conclusion: DCQT granule could reinforce the intestinal mucosa's defensive function by means of increasing the proliferation of intestinal epithelial cells.     

Isolation and characterization of a new heterotrophic nitrifying Bacillus sp. strain

Objective To characterize the heterotrophic nitrifying bacteria. Methods The bacteria were isolated from membrane bioreactor for treating synthetic wastewater using the method newly introduced in this study. Fluorescence in situ hybridization （FISH） was used to validate the nonexistence of autotrophic ammonia oxidizers and nitrite oxidizers. Batch tests were carried out to investigate the capability of heterotrophic nitrification by the pure culture. Phylogenetic analysis of the pure culture was performed. Results A heterotrophic nitrifier, named Bacillus sp. LY, was newly isolated from the membrane bioreactor system in which the efficiency of TN removal was up to 80%. After 24-day, incubation, the removal efficiency of COD by Bacillus sp. LY was 71.7 %. The ammonium nitrogen removal rate after assimilation nearly ceased by Bacillus sp. LY was 74.7% The phylogenetic tree of Bacillus sp. LY and the neighbouring nitrifiers were given. Conclusions The batch test results indicate that Bacillus sp. LY can utilize the organic carbon as the source of assimilation when it grows on glucose and ammonium chloride medium accompanying the formation of oxidized-nitrogen. It also can denitrify nitrate while nitrifying. Bacillus sp. LY may become a new bacterial resource for heterotrophic nitrification and play a bioremediation role in nutrient removal.     

Bacterial translocation and multiple system organ failure in bowel ischemia and reperfusion.

Portal circulation was reduced to 50-60% for one hour by partial occlusion of the superior mesenteric artery for the purpose of studying the relationship between reperfusion injury, bacterial translocation and multiple system organ failure. Forty dogs were divided randomly into four groups, and 1 x 10(10)/kg E. coli O111B4 were fed to each animal 12 hours before operation. Group I constituted the controls, in which sham operations were performed. The experimental procedure was completed in all the animals of the other three groups. Rubia yunnanensis, an anti-oxidant, was given to group III. Amikacin was given to group IV. The results showed that group II was characterized by bacteremia, hypoxemia, and hypotension as compared with group I. The levels of superoxide dismutase (SOD) in the whole blood were markedly lowered and malondialdehyde (MDA) values significantly elevated in group II after reperfusion compared with group I. Plasma levels of anaphylatoxin C5a and B2 (TXB2) were significantly raised in group II beginning with the reperfusion when compared with groups I, III and IV. Pathological changes in the intestine, liver and lung were remarkable only in group II, including acute necrosis of the intestinal mucosa, granulocyte infiltration, hemorrhage and edema of the lung, degenerative changes of myocardial and hepatic cells, and bacterial invasion of the blood, liver and lung. These results suggested that bowel ischemia and reperfusion may promote gut barrier failure and bacterial translocation, then contribute to the development to multiple system organ failure (MSOF) by allowing bacteria or endotoxin normally contained within the gut to reach the portal and systemic circulations where it fuels the septic process. Oxygen free radicals, anaphylatoxin and thromboxane may be potential factors in the development of gut barrier failure and MSOF.

     

Genotoxic and nongenotoxic effects of glycidyl methacrylate on human lung fibroblast cells

Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carded out to detect apoptic responses of cells to GMA exposure.The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS ceils in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.     

Effect of dietary administration of Lathyrus sativus pulse on intestinal biochemical parameters in normal and scorbutic guinea pigs

Objective In order to investigate that ascorbic acid deficiency is responcible for lathyrus toxicity, the effect of dietary feeding of lathyrus pulse in normal and scorbutic guinea pigs for 3 months, on intestinal biochemical parameters was undertaken. Methods The intestinal brush border membrane (BBM) marker and xenobiotic metabolising enzymes (XME) were assayed. Results Exposure to 80% lathyrus alone and in scorbutic conditions showed significant inhibition of alkaline phosphatase (28%-30%), sucrase (19%) and γ-glutamyl transpeptidasc (GGT) (15%-27%)enzymes, while Ca2+-Mg2+-ATPase was significantly inhibited (38%) in scorbutic plus lathyrus treated group. The phase Ⅰ XME (AHH) remained unchanged while the phase Ⅱ enzyme glutathioneS-tranferase (GST) was significantly decreased (20%-22%) in lathyrus and scorbutic plus lathyrus treated groups. Quinone reductase (QR) activity was found to be significantly decreased in lathyrus exposed group (20%). The intestinal biomarker contents including hexose (25%-34%) and phospholipids (20%-40%) were significantly reduced in lathyrus and scorbutic plus lathyrus exposed animals, while sialic acid showed a significant decrease (28%) in scorbutic plus lathyrus treated group. However, cholesterol levels were signifcantly enhanced (15%-28%) in lathyrus and scorbutic plus lathyrus treated animals. Conclusion The results indicate that oral feeding of lathyrus pulse to guinea pigs can alter BBM parameters as well as XME, which may result in the intestinal toxicity.Further, ascorbic acid deficiency could be one of the pre-disposing factors of lathyrus toxicity.     

Effect of Short—Term Exposure to Mercuric Chloride on the Air—Breathing Catfish,Heteropneustes fossilis

Alterations in the respiratory epithelium of gills of a catfish,Heteropneustes fossilis by the sublethal and lethal concentrations of HgCl2 have been observed using scanning electron microscope,Fish exposed to 0.1ppm shows a thin coat of mucus,but the continuous layer of mucus is not retained in 0.3ppm after 24 h of exposure.Epithelial cells of the gill filament are hyperplastic.Other changes in the respiratory epithelium are contraction of epithelium,formation of interlamellar bridge and diminishing number of microridges.Massive destruction of the respiratory epithelium by deep lesions and sloughing of epithelial layer in 0.5 and 1.0ppm solutions after 6-12 h of exposure apparently causes death to the fish.SEM observations are well in conformity wit the findings made at light microscopic level.     

Sensitivity of Different Cytotoxic Responses of Vero Cells Exposed to Organic Chemical Pollutants and their Reliability in the Bio-toxicity Test of Trace Chemical Pollutants

Objective To find a sensitive cytotoxic response to reflect the bio-toxicity of trace organic pollutants, the sensitivity and reliability of morphological change and proliferation inhibition of Vero cells exposed to 2, 4, 6-trichlorophenol （TCP） and the leachate from products related to drinking water （PRDW） were compared, and the mechanism of the morphological change in Vero cells exposed to chemical pollutants was studied. Methods Vero cells were treated by different concentration of TCP and the leachate from PRDW. Methylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide （MTT） assay was carried out for proliferation inhibition. Bioluminescence method was carried out as another method to test the toxicity of TCP. Flow Cytometry assay was used to test cell Apoptosis and damage of cell-membrane. Results 0.25 mg/L TCP had an effect on cell morphology, and the proportion of morphologically changed cells increased with increasing TCP concentration. At low TCP concentrations, inhibition of cell proliferation did not seem to correlate to TCP concentration, and was negative when TCP concentration was 〈1.0 mg/L. After exposure to leachate from PRDW extracted at different temperatures, the percentage of morphologically changed cells increased with extracting temperature, but the inhibition of cell proliferation failed to reflect the correlation between extracting temperature and proliferation inhibition of Vero cells. Although the Sensitivity of bioluminescence method seems to be similar to morphological change in Veto cells, the bacterial in this method is not homologous enough with human body cells to reflect the toxicity to human body. These imply cell morphological change is a more sensitive and reliable method to reflect bio-toxicity of organic pollutants than proliferation inhibition. Flow cytometry analysis and cell rejuvenation experiments indicated cell membrane damage, which results in cell morphological change, was an early and sensitive cytotoxic response comparing with necrosis. Conelusion These results indicated that the cell membrane toxicity represented by morphological changes is a more sensitive and reliable method to indicate the composite bio-toxicity of trace chemicals than proliferation inhibition, inhibition on bioluminescence and necrosis. Nevertheless, the quantification of morphological change should be studied further.     

固有淋巴细胞3群与肠道菌群的相互作用研究进展

近年来,肠道菌群的宏基因组、代谢组学的研究进展迅速,但与肠道免疫细胞的相互作用尚不十分清楚.固有淋巴细胞3群(ILC3)是一类富集于肠黏膜的固有免疫细胞,是抵御肠道微生物感染的重要防线.一方面,肠道菌群及其代谢产物直接或间接地影响ILC3的发育、增殖及功能,在不同的微生物信号的作用下,ILC3表型可以发生转变,其作用亦具有两面性;另一方面,ILC3维护了肠道菌群的共生平衡,并调节了其他免疫细胞对共生菌的反应.本文就ILC3与肠道菌群相互作用的研究进展进行综述.     

中药与肠道菌群相互作用的研究进展

健康人肠内菌群的平衡是相当稳定的。肠内菌群平衡对人的健康至关重要,菌群失调往往导致各种胃肠道等消化道疾病的发生。肠内菌微生物种类繁多,含酶丰富,对中药成分的转化有着相当重要的作用;同时,许多中药对肠道菌群的平衡也有着重要的影响。中药和肠道菌群的相互作用对于中药现代化研究具有重要意义。     

体外循环早期小肠粘膜细胞凋亡的实验研究

目的探讨体外循环(cardiopulmonarybypass,CPB)早期大鼠小肠粘膜上皮细胞凋亡规律及其意义。方法建立大鼠CPB模型。分别对CPB组、假手术组(shamoperation,SH)和正常组(normal,N)大鼠于术后3h、6h、12h和24h取回肠末端粘膜进行光镜、电镜观察,并用TUNEL方法研究肠上皮细胞凋亡。结果HE染色CPB组见较多的凋亡细胞分布于小肠黏膜上皮层;CPB后24h有少数的肠粘膜断裂;所有切片未见明显的炎症及坏死现象。电镜显示凋亡小体形成。TUNEL法见大量呈棕褐色的阳性细胞核,分布位置同HE染色。CPB后3h粘膜上皮细胞凋亡数较对照组明显增高(P<0.01),CPB后6h达到峰值。结论CPB早期大鼠肠粘膜上皮细胞出现大量凋亡,这些变化可能是CPB后肠道细菌及内毒素易位的细胞学基础。     

胰高血糖素样肽-2对肠道黏膜的保护作用

胰高血糖素样肽-2(GLP-2)是由一种肠内分泌L细胞分泌,特异性促进肠黏膜生长与损伤后修复的多肽类激素。GLP-2通过G蛋白耦联受体的转导实现其生物学作用,通过刺激隐窝细胞增生及抑制细胞凋亡显著地增加了肠黏膜上皮的表面积,促进肠道营养吸收,增强肠屏障功能,维护肠黏膜的连续性和完整性。GLP-2的上述特性,提示其对人类疾病尤其是肠道疾病具有治疗潜能。本文综述了GLP-2的生物学特性及其对肠道黏膜的保护作用。     

直肠镜下取肠液隐血检测和常规粪便隐血检测的差异分析

目的对比评价直肠镜下取肠液检测隐血和粪便隐血检测,揭示直肠镜下取肠液检测隐血和粪便隐血检测的差异所在。方法对本院1380例健康体检人群行粪便血红蛋白测定以及直肠镜检查和肠液血红蛋白测定,并对结果进行分析。结果体检人群中粪便血红蛋白的阳性率为13.77%,肠液血红蛋白的阳性率为3.12%,查出直肠息肉的有41例。结论粪便隐血检测是消化道出血筛查的重要方法,但是容易受到肛周出血性疾病如痔疮、肛裂的影响出现假阳性。同时因为粪便隐血检查的标本依靠受检者自主排便获得,标本在肠道中存留时间过长,容易受消化酶和肠道细菌作用,或者少量消化道出血与粪便混合不匀,取样不足的情况下容易检测出现假阴性。肠液血红蛋白的检测能避免这些因素的影响,得出不一样的结论。     

危重症肠黏膜屏障功能障碍的机制研究

肠黏膜具有选择性渗透吸收营养物质和防御肠道内微生物及致炎因子入侵等屏障功能。在正常情况下肠道屏障功能使细菌和内毒素局限在肠道内,防止机体受内源性微生物及其毒素的侵害。在严重感染、创伤、手术、休克、重症胰腺炎等应激状态或长期进行肠外营养的情况下,肠黏膜发生缺血缺氧损伤,其结构和功能可能受到严重损害,导致肠黏膜屏障功能障碍,发生肠道细菌易位,引起全身炎性反应综合征甚至诱发多脏器功能衰竭而危及生命。因此,肠屏障功能已成为判断危重患者预后的重要指标之一,了解肠屏障功能损伤的机制对于防治多脏器功能衰竭有重要的临床意义。     

胰高血糖素样肽-2与脓毒症肠道的保护

脓毒症是指明确或可疑的感染引起的全身炎症反应综合征,肠道在脓毒症的发生发展中地位非常重要。胰高血糖素样肽-2是一种特异性胃肠道生长因子,通过降低肠道通透性、减少细菌移位来提高肠道的屏障功能,刺激肠黏膜隐窝细胞的增殖及抑制肠上皮凋亡来促进损伤肠上皮的恢复。GLP-2的上述特性,提示其对脓毒症肠道具有一定的保护作用。     

宏基因组学和代谢组学在人类肠道微生态研究中的应用

人类胃肠道中寄居着庞大复杂的微生物,它们与人类健康和疾病有着密切的关系.采用宏基因组学研究技术分析肠道微生物,能在更高层次上揭示肠道菌群与宿主的关系,代谢组学相关技术能测量人体肠道生态系统某个时间点或整个时程的代谢动力学或代谢流.本文综述了宏基因组学和代谢组学相关技术在肠道菌群引起的人类疾病的可能应用.     

大成汤对大鼠缺血再灌注损伤影响的超微结构观察

目的观察大成汤对大鼠全身缺血再灌注损伤后肠道屏障功能破坏以及细菌移位状况、肠黏膜超微结构改变的影响。方法将大鼠分为正常对照组、实验对照组、大成汤组,取回肠近端肠壁组织约1mm^3清洗、固定、切片后透射电子显微镜下观察。结果缺血再灌注损伤后的小肠黏膜上皮吸收细胞局部微绒毛、黏膜下组织、细胞膜、细胞连接均有不同程度破坏,基底膜附近见细菌,固有层见较多淋巴细胞及中性粒细胞浸润。大成汤治疗较单纯缺血再灌注损伤电镜下改变程度轻,微绒毛有的变长、变密、增生,不典型的高尔基复合体增多,细胞连接基本正常。结论全身缺血再灌注损伤后,肠黏膜屏障功能不全,肠道细菌移位,大成汤有防治作用。     

槲皮素对小肠吸收阿昔洛韦的促进作用

目的: 研究槲皮素抑制P-糖蛋白(P-Glycoprotein P-gp)对小肠吸收阿昔洛韦的影响.方法: 采用小肠翻转实验和离体小肠吸收实验考察槲皮素促进阿昔洛韦的吸收.结果:小肠翻转实验结果表明,经不同浓度的槲皮素溶液孵育后,阿昔洛韦由小肠黏膜侧到浆膜侧的转运量随槲皮素浓度的增加而增加,经拟合符合Boltzmann 方程;离体小肠吸收实验结果表明,经不同浓度的槲皮素溶液孵育后,阿昔洛韦由小肠浆膜侧到黏膜侧的转运量随槲皮素浓度的增加而减少.结论:槲皮素为P-gp抑制剂,其多药耐药逆转作用有利于促进阿昔洛韦的吸收.