RNA interference unveils the importance of Pseudotrichonympha grassii cellobiohydrolase,a protozoan exoglucanase,in termite cellulose degradation

Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down‐regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β‐glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.     

稀碱法提取金线莲多糖的研究

目的：研究稀碱法提取金线莲多糖的最佳条件。方法采用DNS法测定多糖含量,以多糖含量为指标,对金线莲多糖的提取沉淀过程中的影响因素进行考察。结果稀碱法提取金线莲多糖的最佳条件是提取温度70℃、提取时间1.5h、料液比1∶35、提取次数2次,静置时间5h、离心转数7000r· min -1、离心时间5min。结论稀碱法提取金线莲多糖是一种效率高且稳定可行的提取方法。     

金线莲多糖的提取及清除氧自由基作用的研究

研究金线莲多糖的提取及其对氧自由基的清除作用,采用水提醇沉法提取金线莲粗多糖,用Sepha-dex G-100凝胶柱色谱纯化粗多糖;通过比色法测定金线莲多糖对.OH与O2-.清除率。结果显示金线莲多糖对.OH和O2-.有清除作用,对.OH达到50%清除率所需金线莲多糖粗品、纯品浓度分别为0.81 mg/ml、0.87 mg/ml,金线莲多糖粗品、纯品对O2-.的EC50分别为1.34 mg/ml、1.81 mg/ml,其清除能力为金线莲多糖粗品大于纯品。说明金线莲多糖对氧自由基有较强清除作用,其活性大小与剂量呈正相关。     

0.5%心居康杀白蚁饵剂防治台湾乳白蚁药效试验研究

目的研究0.5%心居康杀白蚁饵剂对台湾乳白蚁(Coptotermes formosanusShiraki)的防治效果。方法2001年在无锡和杭州进行了试验研究,试验分实验室和建筑物现场试验两个部分进行。结果无论是地上(AG)投药,还是地下(IG)投药,不论是室外投药还是室内投药,消灭一个族群需要35~69 d,平均(54.75±12.25)d。消灭一个族群只需要0.5%心居康杀白蚁饵剂48~150 g,平均(103.05±28.9)g,折合有效成分(0.52±0.146)g。结论0.5%心居康杀白蚁饵剂均可以达到消灭台湾乳白蚁的整个族群。     

台湾金线莲丛生芽诱导和组培研究

台湾金线莲（Anoectoehilus formosanus）为兰科开唇兰属植物，又称“宝石兰”，分布于中国、日本、斯里兰卡等国，是一种珍贵的药用植物。本文研究了濒危植物台湾金线莲（Anoeetoehilus formosanus）种子播种材料丛生芽诱导的途径，初步建立了台湾金线莲试管苗的组培快繁流程。研究结果表明，培养基最佳pH为5．1～5．4。丛生芽诱导的培养基为1／2MS＋6-BA5．0（mg／L）＋NAA1.0，继代培养采用液体培养基1／2MS附加6-BA2．0（mg／L），振荡培养2个月，可使其生长旺盛。添加0．2％活性碳和150g／L香蕉汁对其发根具有良好的效果。     

Hepatoprotective and antihyperliposis activities of in vitro cultured Anoectochilus formosanus

The pharmacological effects of an aqueous extract of the whole plants of in vitro cultured Anoectochilus formosanus were investigated experimentally for hepatoprotective and antihyperliposis activities. The extract showed significant antihepatotoxic activity against carbon tetrachloride induced cytotoxicity in primary cultured rat hepatocytes. In an assay for antihyperliposis using aurothioglucose-induced obese mice, the extract suppressed significantly the increase in the weights of body and liver, ameliorated triglyceride levels in the liver and serum, and also significantly reduced the deposition of adipose tissue.     

金线莲石油醚提取物的降血糖作用

目的研究金线莲石油醚提取物的降血糖作用及其机制。方法以正常小鼠作为正常对照组,将四氧嘧啶诱导成功的糖尿病小鼠随机分为模型对照组、二甲双胍组、金线莲石油醚提取物600mg／kg组和300mg／kg组。给药14d后,测定小鼠空腹血糖、肝糖原及血清丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。结果金线莲石油醚提取物能显著降低糖尿病小鼠空腹血糖,使小鼠血清中SOD活性升高,MDA含量显著下降,并能显著增加小鼠肝糖原含量。结论金线莲石油醚提取物降血糖作用显著,其降低血糖机制可能与其增加外周组织对葡萄糖的利用及提高糖尿病小鼠的抗氧化能力有关。     

白蚁菌圃抗炎机制的研究

目的 探讨白蚁菌圃抗炎的作用机制。方法 采用角叉菜胶致正常及切除双侧肾上腺小鼠足肿胀;角叉菜胶致大鼠胸膜炎;蛋清致小鼠足肿胀的炎症模型。分别用酶联免疫吸附法、紫外分光光度法和荧光分光光度法测炎性渗出液中白三烯(LTB4)、前列腺(PGE2)、5-羟色胺(5-HT)及组胺的水平。结果 角叉菜胶致正常组及去肾上腺组小鼠足肿胀炎症组织及血清中PGE2含量与阴性对照组比有显著性差异;在蛋清致足肿胀中的组胺和5-羟色胺的含量与阴性对照组比有显著性差异;在角叉菜胶致胸膜炎大鼠胸腔渗出液中白三烯含量与阴性对照组比有显著性差异。结论 白蚁菌圃的抗炎作用可能与其抑制炎症部位PGE2、LTB4、5-HT及组胺的水平有关,其抗炎作用不依赖下丘脑-垂体-肾上腺皮质系统的调节。     

氟虫胺对台湾乳白蚁的药效研究

目的：为了探讨氟虫胺对白蚁的防治效果；方法：试验采用击倒法、传毒法、群体法和模拟法；结果：0．05％以上浓度的氟虫胺对台湾乳白蚁的击倒速度、传毒能力强，处理的木材具有较强的抗蛀能力，0.05％，0．1％，0．5％氟虫胺施药15d后全部死亡；结论：氟虫胺对台湾乳白蚁有很好的杀灭效果，值得研究与推广应用。