内毒素对肠黏膜微血管内皮细胞内分泌一氧化氮和内皮素的影响

目的是研究内毒素（lipopolysaccharide; LPS）导致肠黏膜微血管内皮细胞损伤的作用机制。将所培养的肠黏膜微血管内皮细胞分为空白对照组和LPS组，每组按时间分为4个亚组：3h、6h、9h、12h。空白对照组加维持培养液，LPS组加1μg/ml LPS培养液，在CO2培养箱内静置培养。结果表明，一氧化氮（NO）分泌明显升高，3h后达到高峰，随后逐渐降低，而内皮素（endothelin; ET）分泌急剧升高，9h后达到高峰，随后又开始逐渐降低，但一直保持在较高的水平。所以引起了NO和ET的升高可能是LPS导致肠黏膜微血管内皮细胞的损伤机制。     

三种鳜对柱状嗜纤维菌脂多糖免疫应答的比较研究

从柱状嗜纤维菌提取菌体脂多糖作为免疫原,分别注射接种翘嘴鳜,斑鳜和大眼鳜后,检测了供试鱼血清中凝集抗体效价和血液中白细胞吞噬活性以及采用直接荧光抗体法测定了受免鳜血液中各种淋巴细胞数量的变化。结果表明,接种ＬＰＳ后,３种受免鳜血清中凝集抗体效价均在第３周达到峰值,血液中蚕噬细胞的吞活性和Ｔ,Ｂ淋巴细胞样细胞的比率均在第２周最高。     

丁酸钠对脂多糖诱导的奶牛乳腺上皮细胞系炎性损伤的修复作用

本研究拟通过分析丁酸钠对脂多糖(LPS)诱导的奶牛乳腺上皮细胞系(MAC-T细胞)炎性损伤的修复作用,进一步从体外角度阐述丁酸钠对奶牛乳腺健康的调控机制。在MAC-T细胞中添加不同浓度(0、1、10、100、1 000、10 000 ng/mL)的LPS,检测细胞活力,以确定LPS的适宜浓度,建立细胞氧化损伤模型;并进一步在MAC-T细胞中添加不同浓度(0、2、4、8、16、32μmol/L)的丁酸钠,检测细胞凋亡率,以确定丁酸钠的适宜浓度。最终选用1 000 ng/mL LPS和16μmol/L丁酸钠用于本试验。试验分为3组,分别为对照组、LPS处理组和LPS+丁酸钠处理组,分别对其细胞形态、氧化应激指标及凋亡蛋白mRNA表达水平进行检测。结果表明：1)对照组MAC-T细胞呈扁平的无规则形态,贴壁状态良好;而LPS处理组MAC-T细胞核固缩、破裂,并出现大面积死亡脱落现象;LPS+丁酸钠处理组MAC-T细胞边缘清楚,胞内颗粒较少,死亡脱落现象明显减少。2)与对照组相比,LPS处理组MAC-T细胞中超氧化物歧化酶(SOD)活性和总抗氧化力(T-AOC)显著降低(P<0.05),丙...     

Lactic Acid Inhibits NF-κB Activation by Lipopolysaccharide in Rat Intestinal Mucosa Microvascular Endothelial Cells

To investigate whether lactic acid could inhibit the LPS-activation of NF-κB p65 in rat intestinal mucosa microvascular endothelial cells (RIMMVECs), RIMMVECs, cultured in vitro, were pretreated with different concentrations of lactic acid and then exposed to lipopolysaccharide (LPS). Cells and cell culture media were then collected at different time intervals. Production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was examined at the protein level by enzyme-linked immunosorbent assay. The influence of lactic acid on the LPS-activation of NF-κB was examined at mRNA and protein levels by real-time quantitative PCR and Western blot analysis, respectively. TNF-α and IL-6 protein levels were significantly decreased after pretreatment with lactic acid compared with cells exposed to LPS only. After pretreatment with 7.5, 5.0, and 2.5 μL mL-1 lactic acid, NF-κB mRNA levels were increased by 1.51-, 2.62- and 3.00-fold, respectively, compared with levels in control cells without LPS treatment. Western blot analysis indicated that the level of NF-κB p65 in the lactic acidpretreated group was significantly lower than that in the group treated with LPS only (positive control) and was unchanged compared with the group without LPS treatment (blank control). These results suggest that lactic acid may inhibit LPSactivation of NF-κB, leading to the down-regulation of TNF-α and IL-6.     

包被LPS抗原检测鸡源鲍氏志贺氏菌抗体的间接ELISA方法的建立

以鸡源鲍氏志贺氏茵菌体提取的脂多糖(LPS)成分作为检测抗原,以辣根过氧化物酶标记的免抗鸡IgG抗体为第二抗体,以TMB为显色剂,成功建立了检测鸡源鲍氏志贺氏茵抗体的间接ELISA方法.通过对间接ELISA反应条件的一系列研究,确定了各种最适工作条件:鸡源鲍氏志贺氏茵LPS抗原最适包被质量浓度为5mg·L-1,最适包被...     

小鼠子宫内膜细胞炎症模型的建立

用0.25％胰酶-EDTA消化法分离培养小鼠子宫内膜细胞,用细菌脂多糖(LPS)诱导子宫内膜细胞炎症,以培养细胞的形态学和传统炎症指标作为炎症发生和发展的判断标准.以不同浓度的LPS作用于细胞,收集不同时段的细胞,用RT-PCR的方法测定细胞中IFN-γmRNA的表达丰度.结果表明,100 ng/mL LPS是体外培养...     

芹菜素对LPS诱导小鼠急性肺损伤的保护作用

[目的]揭示芹菜素的抗炎作用机制.[方法]通过建立小鼠模型,研究芹菜素对LPS诱导急性肺损伤的保护作用.[结果]芹菜素可以降低LPS诱导的肺组织损伤和肺组织MPO活性.与LPS组相比,芹菜素治疗组可以显著降低肺泡盥洗液中TNF-α、IL-1β、IL-6的表达水平,并抑制NF-κB信号通路的激活.[结论]芹菜素可以通过抑制NF-κB的激活并降低炎性细胞因子的水平,从而对小鼠急性肺损伤产生抗炎保护作用.     

微生物源性抗氧化剂对LPS诱导的大鼠肝脏损伤的保护作用

以脂多糖(LPS)致大鼠氧化损伤为模型研究微生物源性抗氧化剂(microbe-derived antioxidantm,MA)对大鼠抗氧化功能和肝脏损伤修复的作用。选用100只雄性SD大鼠(185.74±6.86)g,随机分成4组,分别为对照组、LPS组、LPS+0.5MA组和LPS+1.0MA组。各处理组试验鼠均饲喂基础日粮,LPS+0.5MA组和LPS+1.0MA组饮水中分别添加MA 0.5mL/只/d和1.0mL/只/d;试验第29天,LPS组、LPS+0.5MA组和LPS+1.0MA组分别腹腔注射LPS 3mg/kg,对照组注射等剂量的生理盐水。结果表明,MA可显著提高正常大鼠血清和肝脏中超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05);MA处理后,显著减缓LPS所致的血清和肝脏SOD和GSH-Px酶活性下降(P0.05),显著降低血清和肝脏丙二醛(MDA)和一氧化氮(NO)水平(P0.05),有降低血清谷草转氨酶(AST)和谷丙转氨酶(ALT)活性的趋势(P0.05)。结论,MA具有提高大鼠抗氧化能力,修复肝脏氧化损伤的作用,且呈一定的剂量效应。     

Relation of Japanese <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">vesicatoria</Emphasis> with worldwide strains revealed with three specific monoclonal antibodies

Strains of Xanthomonas campestris pv. vesicatoria Dye 1978 (Xcv), the causal agent of bacterial spot, have been classified into two groups based on their ability to hydrolyze starch. Three monoclonal antibodies (MAbs), 7AH10, 5HB3, and 4AD2, were produced immunized against the living bacteria and were specific to and could distinguish Xcv strains able or unable to hydrolyze starch (Amy⁺ or Amy^–). The MAb 7AH10, obtained against strain UPB141(Amy^–) reacted in an enzyme-linked immunosorbent assay with all the Amy^– strains (n = 19) and 1 of 11 Amy⁺ strains. Against Xcv 2625, an Amy^– unusual phenotype strain, MAb 5HB3, recognized 97% of our worldwide collection of Xcvs (n = 30). Also against that strain, the MAb 4AD2 reacted with none of the homologous Amy^– phenotypes and with 90% (n = 11) of the heterologous Amy⁺ phenotypes. For all the MAbs, cross reactions with other pathovars or species were less than 4% (n = 67). By assaying a Japanese collection of strains against the three MAbs, the Amy⁺ strains were distinguished from the Amy^– strains, and their relation with other world strains could be demonstrated. All the MAbs reacted with the lipopolysaccharide fraction of the bacterial cell wall during immunoblotting.     

Effects of deltamethrin on hematological parameters and enzymatic activity in Ancistrus multispinis (Pisces, Teleostei)

Deltamethrin (DM) is a pyrethroid insecticide widely used in Brazilian crops and in pest-control programs because of its low environmental persistence and toxicity. It has been shown to exert a wide range of effects on non-targeted organisms including fishes. The aim of this study to evaluate the effects of deltamethrin through the hematological and biochemical parameters using Ancistrus multispinis as animal model. First, blood of A. multispinis was collected by cardiac puncture in order to evaluate the basal values of the total cell counts, hemoglobin and hematocrit rates. A. multispinis showed low number leukocytes, red blood cells and hemoglobin compared to other species. The intoxication with DM (0.1 or 0.3 mg kg⁻¹) induced leukocytosis and increases the number of erythrocytes and hemoglobin levels 96 h after the injection when compared to vehicle-injected animals. The injection of lipopolysaccharide (LPS) also induced a significant leukocytosis and increased the erythrocytes number 4 h after the injection. The combination of the higher dose of DM with LPS showed an additional effect in the number of leukocytes and erythrocytes. The GST and EROD activities were also evaluated in the gills and liver, respectively, 96 h after intoxication with both doses of DM. The GST activity decreased after DM intoxication in both doses while EROD activity was not significantly different. These results suggest that A. multispinis is a valuable model for ecotoxicological studies. Also, DM can affect the metabolizing system (GST) and immunologic system of A. multispinis, a condition that can be worsened in the presence of inflammation or infection.