抽提条件对酶制剂中果胶酶活力测定的影响

用0．1mol/L氯化钠、0．02mol/L,pH7．4的磷酸缓冲液和蒸馏水,于40℃和4℃对浙江酶、华芬酶和Avizyme－1500酶制剂分别抽提1．5小时和12小时,对3种酶制剂中的果胶酶活力进行测定。结果表明：用0．1mol／L氯化钠于4℃抽提12小时,对浙江酶制剂中的果胶欧抽提效果最好;用蒸馏水于4℃抽提12小时,对华芬酶和Avizyme－1500酶制剂中的果胶酶抽提效果最好。     

家蚕血液、消化液中酸性核糖核酸酶和天冬酰胺酶活性的初步研究

测定了家蚕夏芳、长灰A和大造各品种血液、消化液中酸性核糖核酸酶及家蚕秋白、夏芳、长灰A和大造各品种天冬酰胺酶性变化。结果表明：各品种血液、消化液中酸性核糖核酸酶、天冬酰胺酶活性变化随发育呈现较强的规律性，血液中，4龄第3d、5龄第3d这两种酶均出现峰值，4龄眠前活性较低，消化液中，5龄第3d这两种酶活性均较高，不同品种这两种酶活性峰值出现时间有差异；各品种血液中酸性核糖核酸酶、天冬酰胺酶性均明显高于相应品种消化液中这两种酶活性；各品种之间血液、消化液中这两种酶活性有明显差异。     

苏云金芽孢杆菌YJ-2000菌株对家蚕安全性和杀虫活性的评价

应用时间-剂量-死亡率模型就苏云金芽孢杆菌(Bacillus thuringiensis)YJ-2000菌株对6种鳞翅目昆虫的杀虫活性作了初步评价。该菌株对家蚕基本无毒性,而对蔬菜害虫小菜蛾、菜粉蝶,水稻害虫三化螟、二化螟,桑树害虫桑螟幼虫均有不同程度的毒性,其中对小菜蛾和菜粉蝶的毒性最强;幼虫死亡率可高达100％。该菌株是对家蚕安全而对其它鳞翅目害虫具杀虫活性的特异性菌株,有望用于养蚕地区桑园及其邻近作物的鳞翅目害虫防治。     

假蒟提取物的体外抗氧化和抗炎效果研究

本研究旨在分析假蒟提取物的活性成分并评价其体外抗氧化和抗炎活性。试验通过ABTS法检测3种假蒟提取物(石油醚、正丁醇及乙酸乙酯提取物)的抗氧化能力;采用LPS法建立猪小肠上皮细胞(IPEC-J2)体外炎症模型,用假蒟提取物预处理后,以ELISA法检测细胞上清液中肿瘤坏死因子(TNF-α)、白细胞介素-1(IL-1)和白细胞介素-6(IL-6)的含量。结果表明,3种假蒟提取物总抗氧化活性由大到小依次是假蒟正丁醇提取物、乙酸乙酯提取物、石油醚提取物(P<0.05),其中假蒟正丁醇提取物总生物碱、总酚含量最高,分别为2.81 mEq/100 g、161.82 mg/g。与空白组相比,LPS组IPEC-J2细胞的TNF-α(P<0.05)、IL-1(P>0.05)及IL-6(P<0.05)含量均升高;与LPS组相比,假蒟预处理组的这几种细胞因子含量均显著降低(P<0.05),由高到低依次为乙酸乙酯提取物>石油醚提取物>正丁醇提取物。综合试验结果,假蒟提取物具有一定的抗氧化作用,能影响IPEC-J2细胞炎性因子的分泌,抑制炎症反应。     

微粒蒙脱石对猪组织铅水平、红细胞生成和肝脏ALA-D酶活性及铅诱导的脂质过氧化的影响

选60头体质量约33kg的“杜长大”杂交猪，随机分成2组，每组3个重复，一组饲以基础日粮＋10mg/kg铅＋0.5％微粒蒙脱石，另一组饲以基础日粮＋10mg／kg铅作为对照。研究结果表明：添加微粒蒙脱石组与对照组相比，明显降低了猪全血、脑、肝、肾、骨和毛等组织中铅含量：通过血细胞计数、血红素和血球容积测定表明，添加微粒蒙脱石组的红细胞生成显著增高，且肝脏中ALA—D酶活性显著提高。铅对肝脏的损伤作用明显。表现为丙二醛（MDA）含量显著升高（17．08％），过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）含量分别降低85．73％、52．17％、47．56％，而在日粮中添加微粒蒙脱石可以显著改善铅诱导的上述损伤。结果提示，微粒蒙脱石对铅中毒有潜在的治疗作用。     

Trans-10, cis-12 conjugated linoleic acid modulates phagocytic responses of canine peripheral blood polymorphonuclear neutrophilic leukocytes exposed to Clostridium difficile toxin B

Trans-10, cis-12 conjugated linoleic acid (t10c12-CLA) has been reported to enhance phagocyte function. Clostridium difficile toxin B (TcdB) has been known to inhibit Ras-homologous (Rho) guanosine triphosphatases (GTPases) which play essential roles in neutrophil immune functions. Here, we examined whether in vitro treatment with t10c12-CLA modulates the filamentous actin (F-actin) polymerization, phagocytic capacity, and oxidative burst activity (OBA) of canine peripheral blood polymorphonuclear neutrophilic leukocytes (PMNs) exposed to TcdB. Treatment with t10c12-CLA, but not linoleic acid, enhanced PMN F-actin polymerization, phagocytic capacity, and OBA, while TcdB suppressed these functions. t10c12-CLA reversed the suppressive effects of TcdB on these PMN functions. t10c12-CLA stimulated F-actin polymerization regardless of whether phagocytosis was stimulated by microspheres but only elevated OBA when microspheres were added. We asked whether the effects of t10c12-CLA were associated with changes in the activation of the Rho GTPase Cdc42. Treatment with t10c12-CLA augmented Cdc42 activity in both TcdB-treated and TcdB-naive PMNs during phagocytosis. Thus, t10c12-CLA up-regulates PMN phagocytic responses attenuated by TcdB. This effect is associated with an increase in actin polymerization and may involve the activation of Cdc42.