麦根腐长蠕孢毒素对小麦超氧物歧化酶的影响

感病品种沈免85-14黄化苗用根腐毒素处理6,12,24h 后,相对酶活随毒素浓度升高而明显下降;抗病品种Jup73Atd“S”用中等浓度毒素处理的,除处理3h 之外,其余的相对酶活性均升高.以处理12h 达高峰,处理24h 后高浓度有抑制作用而低浓度有激活作用。旗叶圆片、无细胞提取液和线粒体试验呈现了类似的规律.电泳结果表明,根腐毒素对感病品种黄化苗的3条酶带(a,b,c)均有抑制作用,而对抗病品种Jup73Atd“S”这3条酶带均有激活作用,a,c 带的变化大于b 带.旗叶接菌后3d,Jup73Atd“S”5条带均激活,其中a,b_2,b_3,c 带更明显;中间型品种龙辐3号各带均受抑制,而以b_3带受抑最重.     

Avermectin exposure induces apoptosis in King pigeon brain neurons

The effect of avermectin was studied on King pigeon brain nerve cells by cytotoxicity [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, MTT] and apoptosis [acridine orange/ethidium bromide (AO/EB) assay, transmission electron microscope (TEM) evaluation, measurement of mitochondrial membrane potential (Δψm), phosphatidylserine (PS) exposure, caspases activities, DNA fragmentation, reactive oxygen species (ROS) and caspase-3 mRNA expression] within the 2.5–10 μg L⁻¹ concentration-range. The results revealed that within the concentrations of 2.5–10 μg L⁻¹, avermectin showed obvious cytotoxicity and induced apoptosis in a dose-dependent manner to neurons of King pigeon in vitro. Cell viability were 99.93 ± 8.52%, 82.02 ± 4.99% and 78.23 ± 5.67% after 24 h of treatment with avermectin at the concentrations of 0, 2.5 and 5 μg L⁻¹, which decreased to 56.36 ± 2.17% of 10 μg L⁻¹. Treated cells showed typical apoptosis morphological changes including cytoplasmic vacuolation, chromatin condensation, unclear nuclear membrane and decreased/swollen mitochondria. Typical biochemical hallmarks of apoptosis including Δψm loss, PS exposure, activations of caspase-3, caspase-8 and caspase-9, DNA fragmentation were observed too. Moreover, the levels of ROS in the avermectin treatment groups increased significantly compared to control group. Furthermore, the caspase-3 mRNA levels increased significantly following AVM treatment. In conclusion, our experimental results show that avermectin has cytotoxicity to brain neurons of King pigeon in vitro and the mechanism of neurotoxicity induced by avermectin is closely related to apoptosis.     

表面活性剂SDS对草鱼急性毒性效应的研究

为了研究阴离子表面活性剂对鱼类的急性毒性效应,设计了不同浓度的十二烷基硫酸钠(SDS)溶液对草鱼进行暴露实验并测定其体内各组织SOD活性。急性毒性测试表明,SDS对草鱼的48h、96hLC50分别为11．8mg／L和5．2mg／L。低浓度的SDS(小于0．2mg/L)暴露对草鱼的超氧化物歧化酶(SOD)活性有极显著诱导作用,但随着SDS浓度升高和暴露时间延长,草鱼各组织SOD活性均呈明显的下降趋势,提示SDS暴露所引起的酶活性变化与暴露浓度和暴露时间有一定的相关性。这些结果显示,阴离子表面活性剂SDS对草鱼抗氧化酶有毒性效应,SOD活性变化可以作为评价环境中有毒污染物的生物敏感性指标。     

Evaluation In Vitro of Canine Neutrophil Function

Polymorphonuclear granulocyte (PMN) phagocytosis may be affected by many pathological changes. A panel of tests requiring relatively small volumes of blood was applied to 16 healthy dogs in order to obtain normal values and to standardize techniques. PMNs were isolated by discontinuous Percoll gradients; chemotaxis was tested in a modified Boyden chamber using the leading front method; fluorescinated yeast uptake was evaluated on a slide and superoxide (SO) production and adherence was carried out on a microtitre plate. The different aspects of phagocytosis showed no correlation with one another. Better results were obtained using a 60 min incubation period using interleukin-8 (25 ng/mL) as an activator for chemotaxis, and incubating plates for 30 min with phorbol myristate acetate (10(-6)mol/L) to assess SO production.     

光合细菌在水稻上的施用方法及作用机理研究

采用盆栽试验研究了光合细菌在水稻上的应用,结果表明,不同的处理对水稻的生理活性、生长性状及产量的影响不同。对过氧化氢酶(CAT)及色素无显著影响,但可提高水稻超氧化物歧化酶(SOD)酶活,提高土壤中细菌、放线菌及固氮菌数量,增加水稻分蘖,提高产量。水稻超氧化物歧化酶、分蘖和产量提高分别为对照的68.29%,30.88%和36.75%。光合细菌在水稻上的施用方法以菌液沾根增产效果最好。     

Cu/Zn SOD蛋白在布鲁菌S19疫苗株中的过表达及鉴定

以Cu/Zn SOD为目的基因,通过基因工程技术分别构建了组成型过表达系统pBBR-trc-sod和诱导型过表达系统pBBR-lacPtrc-sod,在布鲁菌S19疫苗株中进行了Cu/Zn SOD的过表达。同时,以大肠杆菌为宿主表达纯化的重组Cu/Zn SOD蛋白免疫家兔制备多克隆抗体,对2种过表达系统中Cu/Zn SOD蛋白的表达量进行分析。结果显示,诱导型Cu/Zn SOD过表达系统的表达量更高,且能与所制备的多抗发生特异性反应。结果表明,构建的过表达系统能够实现Cu/Zn SOD蛋白在布鲁菌S19疫苗株中过表达;同时,该试验也提示我们这种表达系统可应用于布鲁菌S19疫苗的抗原改造。     

桑树黄酮类化合物清除超氧离子自由基O_2~·的研究

用氮蓝四唑（ＮＢＴ）光化还原法，对从桑叶、桑嫩芽、桑枝、桑皮、蚕沙中提取的黄酮类化合物清除超氧离子自由基Ｏ·２的效果进行了测定．结果表明，这类化合物有较强的清除作用，在浓度为５μｇ·ｍＬ－１时，从桑嫩叶、桑枝、桑皮中提取的这类化合物其清除率分别为６８．５％、８３．１％、５６．８％，其清除作用比芸香甙（芦丁）、抗坏血酸强．桑叶黄酮类化合物的清除率为４７．２％，比抗坏血酸强．蚕沙中提取的黄酮类化合物在浓度为６μｇ·ｍＬ－１时也有很强的清除作用．作者在文末讨论了桑树黄酮类化合物清除Ｏ·２的机理．     

硝酸银对黄瓜植株茎尖保护酶类活性的影响

为探讨硝酸银在黄瓜中的诱雄机理，以2片真叶期的雌性系和雌雄同株系为试材，测定了硝酸银处理后不同时间茎尖过氧化物酶、超氧化物歧化酶和过氧化氢酶的活性．结果发现：硝酸银处理后，黄瓜植株茎尖过氧化物酶和过氧化氢酶活性升高，超氧化物岐化酶的活性则先受到硝酸银的抑制，然后升高．     

杉木种子劣变与质膜伤害

本文对杉木种子劣变与质膜伤害的关系进行了研究。研究表明,自然老化和人工老化的种子随着处理时间的延长,脱氢酶活性急剧下降;种子浸泡液的相对电导度、可溶性糖含量和可溶性蛋白含量显著增加,超氧物歧化酶(SOD)活性下降。显然,质膜伤害是杉木种子劣变的重要原因之一,杉木种子活力的保持与其体内能否维持较高水平的SOD活性有关。     

离体条件下盐胁迫对马铃薯试管苗叶绿素含量,脯氨酸累积和抗氧化酶活性的影响

离体条件下,研究了2个马铃薯品种在0～80 mmol NaCl胁迫下的试管苗生长、叶绿素含量、脯氨酸和丙二醛含量及氧化酶活性的反应.2品种苗高随盐浓度增加及培养时间的延长而显著降低.与品种紫花白相比,同一盐浓度下静石2号在苗鲜重、根长和根数等方面受抑制程度更强.盐胁迫培养3周后,试管苗叶片中叶绿素a,b与总量及类胡萝卜素含量在40～80 mmol高盐浓度下显著降低.两个品种试管苗中脯氨酸和丙二醛含量随盐浓度的增加而增加,而静石2号中脯氨酸和丙二醛的累积量和累积率都高于紫花白,表明在盐胁迫下静石2号膜脂过氧化程度相对较高.2品种SOD和POD活性均在低盐浓度(20 mmol)下显著增加而高盐浓度下降低.离体条件下,紫花白试管苗呈现出比静石2号高的SOD、POD活性以及较强的耐盐能力,表明其具有进一步在田间进行耐盐基因型筛选的必要性.