克百威预处理对毒死蜱神经细胞毒性的影响

研究了氨基甲酸酯农药克百威预处理对有机磷农药毒死蜱神经细胞毒性的影响. 采用噻唑蓝(MTT)法测定克百威对原代培养皮层神经细胞存活率的影响,找出无细胞毒性浓度;采用无细胞毒性浓度的克百威对培养细胞进行不同时间的预处理后,加入毒死蜱(克百威仍存在)染毒48 h测定细胞毒性的变化;采用Western blot方法测定克百威不同时间预处理对毒死蜱激活ERK1/2作用的影响. 结果表明:10 μmol/L的克百威处理72 h显示无细胞毒性,10 μmol/L的克百威预处理(2～24 h)可减轻毒死蜱的毒性,其中预处理8 h时作用最强;克百威预处理降低了毒死蜱对ERK1/2的激活作用,抑制ERK1/2激活作用与细胞毒性减轻相关. 克百威预处理时间过短(0～2 h),对毒死蜱的细胞毒性及ERK1/2激活影响很小. 克百威预处理一段时间后可拮抗毒死蜱的细胞毒性,该作用机制与抑制ERK1/2激活有关;但克百威预处理时间过短,则不产生拮抗作用. 提示氨基甲酸酯农药与有机磷农药之间的联合作用模式受二者染毒时间间隔的影响.      

饮用水处理流程中有机提取物的毒性变化规律

利用Q67淡水发光菌发光抑制试验和Ames试验(2.5L/P为水样最高浓度 ) ,对北京第九自来水厂不同原水及不同水处理工艺流程出水有机浓集物进行了急性毒性和致突变性检验 .用GC/MS技术对优先污染物进行化学分析 .Ames试验结果表明 ,九厂水源水无致突变性 ,加氯主要导致生成直接和间接移码型致突变性物质及间接碱基置换型致突变性物质 .絮凝剂的加入会导致碱基置换型致突变性明显增强 .煤砂池和炭滤池能有效去除致突变性物质 .二次加氯并未引起明显致突变性改变 .管网水中未检出致突变性 .各处理工段中水样的急性毒性变化趋势和致突变性的变化趋势基本一致 ,毒性最强点出现在机械搅拌澄清池 .对水中优先污染物的测定表明 ,不存在多氯联苯污染 .机械搅拌澄清池和管网水中二甲苯、萘和酚类化合物浓度升高 ,但浓度均在亚 μg/L水平 ,不足以引起致突变性 .     

涕灭威、灭多威的遗传毒性研究

研究了涕灭威与灭多威的遗传毒性.在去离子水中分别加入涕灭威与灭多威标准品,涕灭威设计0.002、0.02、0.2、2、20μg/L共5个剂量组,灭多威设计0.02、0.2、2、20、200μg/L共5个剂量组.用微核试验检测其对鲤鱼血红细胞微核的诱发效应,采用Ames试验检测2种农药的致突变性,采用彗星试验检测其对人外周血淋巴细胞DNA的损伤效应,根据3种毒理学试验结果综合分析涕灭威与灭多威的遗传毒性.结果表明,所有剂量组这2种农药未诱导鲤鱼血红细胞微核率的明显上升(p0.05);2种农药各剂量组回变菌落数均未超过自发回变组的2倍,但在非代谢活化条件下,涕灭威2～20μg/L与灭多威20～200μg/L剂量组的TA97菌株回变菌落数分别达到(129.17±17.00)、(129.50±18.28)、(109.83±10.80)和(114.17±9.37)个/皿,明显高于自发回变组(p0.05,p0.01).在代谢活化条件下,灭多威200μg/L组的TA100与TA102菌株的回变菌落数为(147.83±23.29)、(275.83±20.63)个/皿,均高于自发回变组(p0.05);在彗星试验中发现,高浓度的涕灭威与灭多威均可导致人外周血淋巴细胞的DNA损伤,涕灭威20μg/L组,灭多威200μg/L组的尾部DNA(%)、尾长、Olive尾距3个指标经统计学分析,高于去离子水对照组(p0.01).研究未见涕灭威与灭多威对鲤鱼血红细胞产生明显的染色体损伤效应,虽未见其明显的致突变性,但在高浓度下存在一定的致突变的风险,并且这2种农药可能导致人外周血淋巴细胞的DNA损伤,因此涕灭威与灭多威污染对水环境和人体健康可能存在一定的远期危害.     

我国典型地区饮水中致突变性表征

报道上海,昆明,哈尔滨、沈阳、广州、武汉和深圳等城市自来水的致突变性特征,以及上述城市自来水厂源水及其氯化源水致突变性的比较研究。发现７城市自来水中均含有移码型直接致突变物。ＴＡ９８菌株是最敏感的监测菌株。另外,按水样比活性和沈集物比活性和沈集物比活性为指标,则上海,昆明,哈尔滨、沈阳、广州和武汉等６城市自来水厂氯化源水对ＴＡ９８和ＴＡ１００２菌株的致突变性均明显地高于源水,上海市尤为突出。该结果     

1-硝基芘和多环芳烃联合致突变性的研究

测定了１－硝基芘（１－ＮＰ）和其它（硝基一）多环芳烃对Ａ试验的６个菌株（ＴＡ９８，ＴＡ１００，ＹＧ１０２１，ＹＧ１０２４，ＹＧ１０２６，ＹＧ１０２９）的单一和联合致突变性，１，６－二硝基芘（１．６ＤＮＰ）、１－硝基芘（１－ＮＰ）和２－硝基坊（２－ＮＦ）所单一致突变性都为ＹＧ１０２４，ＹＧ１０２１，ＴＡ９８，ＹＧ１０２６，ＹＧ１０２９，ＴＡ１００，地２－ＮＦ的敏感性稍有差别，联合致突变性实验结果表明     

柴油机排出颗粒物致突变性研究

采用Ａｍｅｓ试验，检测６种国产和进口牌号柴油机排出颗粒物的诱变性，研究发现，６种柴油机排出颗粒物均呈阳性，其颗粒提取物和诱变性之间，存在剂量一反应关系。Ａｍｅｓ试验结果，主要引起ＴＡ９８－Ｓ９的回变菌落落数加，显示受试物中含有移码型直接致突物，试验还发现，国产和进口柴油机排出颗粒物的致突突变性，在怠速和加速工况下，其诱变活性有一定差异。     

Tactics for resistance management using multiple pesticides

One option for controlling the spread of pesticide resistance is the coordinated use of two or more pesticides. However, strategies using two pesticides are necessarily more diverse than those using a single pesticide, and inept application may result in resistance to both pesticides in the time when a single resistance would have arisen if a single pesticide had been used.This paper uses simple genetic models to assess the relative effectiveness of different multiple-pesticide application strategies. It is concluded that there are two basic advantages of multiple-pesticide attack: increased back selection and “redundant killing”. Back selection may be enhanced by any of the basic multiple attack strategies. Redundant killing is more effective if the dosages of the two pesticides are highly positively correlated (such that if a pest individual receives a higher dose of one pesticide than the population average, then it is likely to have received a higher than average dose of the second pesticide as well). Some limitations on redundant killing are discussed; these result from the selection of doubly-resistant genotypes (accompanied by extreme linkage disequilibrium between resistance genes).     

The photo-oxidation of automobile emissions: measurements of the transformation products and their mutagenic activity

Dilute mixtures of automobile emissions (comprising 50% exhaust and 50% surrogate evaporative emissions) were irradiated in a 22.7 m³ smog chamber and tested for mutagenic activity by using a variant of the Ames test. The exhaust was taken from a single vehicle, a 1977 Ford Mustang equipped with a catalytic converter. Irradiated and nonirradiated gas-phase emissions were used in exposures of the bacteria, Salmonella typhimurium, strains TA100 and TA98. A single set of vehicular operating conditions was used to perform multiple exposures. The mutagenic activities of extracts from the particulate phase were also measured with the standard plate incorporation assay. (In most experiments only direct-acting mutagenic compounds were measured.) The gas-phase data for TA100 and TA98 showed increased activity for the irradiated emissions when compared to the nonirradiated mixture, which exhibited negligible activity with respect to the control values. The particulate phase for both the irradiated and nonirradiated mixtures showed negligible activity when results were compared to the control values for both strains. However, the experimental conditions limited the amount of extractable mass which could be collected in the particulate phase. The measured activities from the gas phase and particulate phase were converted to the number of revertants per cubic meter of effluent (i.e. the mutagenic density) to compare the contributions of each of these phases to the total mutagenic activity for each strain. Under the experimental conditions of this study, the mutagenic density of the gas-phase component of the irradiated mixture contributed approximately two orders of magnitude more of the total TA100 activity than did the particulate phase. For TA98 the gas-phase component contributed approximately one order of magnitude more. However, caution must be exercised in extrapolating these results to urban atmospheres heavily impacted by automotive emissions, because the bacterial mutagenicity assay was used as a screening method, and additional assays using mammalian systems have not yet been conducted. In addition, only limited number of conditions were able to be tested. The significance and limitations of the results are discussed.     

In vitro toxicity of particulate matter emissions from residential pellet combustion

Particulate matter emissions (PM₁₀) from the combustion, in a residential stove, of two commercial brands of certified (ENplus A1) pellets, a non-certified brand and laboratory made pellets of acacia were tested for their ability to induce ecotoxic, cytotoxic, and mutagenic responses in unicellular organisms and a human cell line. Ecotoxicity was evaluated through the Vibrio fischeri bioluminescence inhibition assay. Moreover, cytotoxicity was assessed at two time points (24- and 48-hr) through two complementary techniques in order to evaluate the cellular metabolic activity and membrane integrity of human lung epithelial cells A549. The Ames test using two Salmonella typhimurium strains (TA100 and TA98) was employed to assess the mutagenic potential of the polycyclic aromatic hydrocarbon fraction extracted from the PM₁₀ samples. Results obtained with the bioluminescent bacteria indicated that only particles from the combustion of acacia pellets were toxic. All samples induced impairment on the A549 cells metabolic activity, while no significant release of lactate dehydrogenase was recorded. PM₁₀ emissions from acacia pellets were the most cytotoxic, while samples from both certified pellets evoked significant cytotoxicity at lower doses. Cytotoxicity time-dependency was only observed for PM₁₀ from the combustion of acacia pellets and one of the brands of certified pellets. Mutagenic activity was not detected in both S. typhimurium strains. This study emphasises the role of the raw material for pellet manufacturing on the toxicological profile of PM emissions. Alternative raw materials should be deeply investigated before their use in pelletisation and combustion in residential appliances.     

黄浦江上游水源保护区工业废水的致突变性

对黄浦江上游水源保护区9家工厂工业废水应用Ames试验进行致突变性研究,结果表明,这些废水对TA_(98)菌株均有明显的致突变作用,其中有2家厂的废水未经活化对TA_(100)有致突变作用。通过计算最低致突变剂量和致突变指数,确认了排放大户,为有效地控制排放提供依据。     

Enantioselective induction of oxidative stress by acetofenate in rat PC12 cells

In a non-chiral environment,the enantiomers of a racemate possessed the identical physico-chemical properties,but in the biological systems they possessed different activities.Considering that the involvement of oxidative damage has been implicated in the toxicities of various pesticides,this study investigated the possibility of enantioselective oxidative stress and cytotoxicity induction by acetofenate (AF) which contains an asymmetrical center on PC12 cells.The results of the cytotoxicity assay indicated that S-(+)-AF presented more toxic effects than R-(-)-AF and (±)-AF.It also demonstrated that S-(+)-AF possessed the strongest effects in induction of reactive oxygen species (ROS) production,decrease in superoxide dismutase (SOD) and catalase (CAT) activities,and increase in malondialdehyde (MDA) level.These results suggested that AF and its enantiomers could induce enantioselective cytotoxicity in PC12 cells mediated by oxidative stress.Therefore,the assessment in environmental safety and new chiral pesticide development should consider enantioselectivity.     

香港某地饮用水中非挥发性有机物致突变性的研究

应用大孔树脂吸附浓集水中有机物的技术,结合Ames致突变试验,研究了香港某地饮用水中非挥发性有机物（NOcs）的致突变性．结果表明,在加与不加代谢活化系统（±S9）条件下,1～2 L水中的非挥发性有机物即可诱发鼠伤寒沙门氏菌（TA98）的回复突变;此外,活性炭可部分吸附水中具致突变作用的有机物     

几种消毒剂对饮水致突变活性的影响

本研究应用Ａｍｅｓ致突变试验对武汉东湖水分别经氯、二氧化氯和臭氧消毒处理后的致突变活性进行了检测与比较。结果表明：东湖水以及臭氧消毒处理水样未呈现致突变性,氯与二氧化氯处理的水样致突变性检测结果为阳性,这３种消毒剂处理的各水样致突变比活性强度顺序由强至弱依次为氯〉二氧化氯〉臭氧;同时对东湖水用高锰酸钾预处理,以降低氯化消毒饮水致突变活性的效果也进行了比较,结果发现用高锰酸钾预处理东湖水,可降低氯化     

二苯甲酮对斑点叉尾鮰鱼卵巢细胞生长的影响

试验通过直接、间接两种染毒手段来探讨二苯甲酮(benzophenone)对斑点叉尾鮰鱼卵巢细胞(CCO)生长的影响,以MTT法为手段测定染毒前后CCO细胞的存活数量和各阶段的生长状态,结果发现:当二苯甲酮以1～10μg/mL的浓度直接作用于CCO细胞时,CCO细胞生长在不同阶段均受到抑制作用:在指数增长期细胞生长速率减小,稳定期的存活量约为正常条件下的72%～91%,并且随着二苯甲酮浓度的增大,对CCO生长的抑制效应也相应的加剧;但是1μg/mL浓度的二苯甲酮在经过斑点叉尾鮰鱼原代肝细胞代谢后间接作用时,其代谢产物对CCO的生长在各阶段又呈现明显的促进作用,稳定期细胞数量约为正常条件下的109%。     

改良MTT法在鱼类细胞毒性实验中的使用条件

文章利用斑点叉尾鮰鱼卵巢细胞(CCO)、鲤鱼上皮癌细胞(EPC)、草鱼肾细胞(CIK)探讨改良四噻唑蓝(MTT)比色法在测定污染物对鱼类细胞急性毒性实验中的最佳条件。通过实验发现其最佳实验条件为570nm波长下,MTT作用4h,MTT终浓度1mg/mL,最佳接种量的确定因每种细胞的特性而不同,生长速度快的细胞接种量较少。     

兰州市大气飘尘中致突变物变化规律的研究

本研究对兰州市不同污染区(石油化工为主、燃煤、商业及农村)在不同季节时的大气飘尘,作了对比采样.飘尘样品用溶剂抽提法提取后,用化学萃取法分离为五个有机物馏分.用毛细色谱-质谱-计算机联用系统进行了定性分析,并用毛细管色谱法进行了部分定量分析.用Ames试验(用TA1537、TA98和TA100三株菌.加与不加S-1)对其致突变活性进行了研究.并对有机致突变物在不同污染区、不同季节的变化规律及其来源进行了初步探讨.     

甲胺磷、乙草胺和铜单一与复合污染对黑土环境安全的胁迫研究

以黑土为环境介质,通过急性毒性试验法研究了东北黑土区普遍存在的2种农用化学品甲胺磷和乙草胺与重金属Cu对赤子爱胜蚓(Eiseniafoetida)的单一与复合毒性效应.单一毒性试验结果表明,3者对蚯蚓均有毒性,顺序为甲胺磷>乙草胺>Cu.复合毒性实验结果表明,2种有机农药与重金属Cu复合毒性效应十分复杂,与不同的浓度组合及染毒历时有关,一般随时间的延长,毒性加剧.2种有机农药通过不同途径毒害蚯蚓,复合毒性效应表现为协同作用.可见,3者对土壤生态系统环境安全性和土壤健康质量存在潜在危害,同时这几种污染物的共存进一步加大了潜在危害性,且复合毒性效应与各组浓度组合及污染暴露时间密切相关.     

Reduction of recruitment of Acartia pacifica nauplii from benthic resting eggs due to organochlorine pesticides

Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment ofnauplii to the water column population. The potential effects of two organochlorine pesticides, hexchloriobinzene （HCH） and dichlorodiphenyltrichloroethane （DDT）, on the recruitment of A ccu＇tla pacifica nauplii from benthic resting eggs in the seabed of Xiamen Bay were experimentally investigated. The abundance of A. pacifica nauplii hatched from the sediment significantly decreased with the increase of pesticide concentration. Trimmed Spearman-Karber analysis gave sediment 96-h LC50 values were 84.81 ng/g for HCH, and 157.94 ng/g for DDT. The median AI （Al50） was -0.77, which suggested that the combined effect of riCH and DDT showed a weak effect than individual effects. There was a positive relationship between mortality and exposure time in DDT treatment, while the relationship was not significant in HCH treatment. The results suggest that organochlorine pesticides can reduce recruitment of A. pacifica nauplii from benthic resting eggs to planktonic population.     

适合大棚蔬菜的农药评价筛选

通过对农药使用的危险性评价方法，共筛选出７７种适合于大棚生产的化学农药和生物农药，其中杀虫剂３５种，杀菌剂２５种，除草剂１７种。为使大棚蔬菜的农药残留量低于国家食品卫生标准，应优先使用高效农药，最理想级的农药用量为〈４９．５ｇ／ｈｍ＾２，理想级为〈１６３．５ｇ／ｈｍ＾２，被评为危险级和较危险级的２３种农药，不应在大棚蔬菜生产和绿色食品生产中使用。     

室内常见气传真菌孢子的细胞毒性研究

分别以MTT比色法和细胞克隆形成率实验，观察了室内常见气传真菌孢子对中国仓鼠（CHL）肺上皮细胞的存活和增殖能力的影响，并通过检测细胞培养液中乳酸脱氢酶（LDH）活力，胞内Ca^2 ,K^ 含量，观察真菌孢子对细胞膜通透性的影响，结果表明，室内常见气传真菌孢子能显影响CHL细胞的活性，并可使细胞膜通透性发生改变，引起胞内LDH外渗，细胞内外离子发生交换，细胞内K^ 浓度降低，而细胞外的Ca^2 有内流的趋势。