分子模拟在农药半抗原设计及其免疫识别机制中的应用

免疫半抗原的分子设计与合成是建立小分子免疫化学分析方法的关键步骤。在介绍农药半抗原设计一般策略的基础上,指出分子模拟技术在农药半抗原合理设计中的适用性在于其能通过对分子结构和动力学行为的模拟,获得能表示和解释农药分子免疫原性和生物活性的参数。重点阐述了分子模拟在免疫原和竞争原设计中的应用,揭示了采用分子模拟技术进行半抗原设计的优势在于其能够克服目前半抗原设计方法的经验性和主观随意性。运用分子模拟技术能够更好地研究抗原抗体反应中的分子间作用力,因此该技术有利于促进抗原抗体反应识别机制研究的深入进行。分子模拟技术还能够应用于解释抗体的交叉反应率,从而能应用于提高抗体宽谱性研究。     

菊酯类农药在稻田使用初探(二)——拟除虫菊酯类农药在稻田使用的环境安全性研究

本文研究拟除虫菊酯类农药在稻田使用对水生生物、天敌、稻飞虱再猖獗以及对施药人员健康的影响 ,并研究菊酯类农药在作物和土壤中的残留 ,从而评价拟除虫菊酯类农药在稻田使用对环境的安全性     

菊酯类农药在稻田使用初探（二）——拟除虫菊酯类农药在稻田？…

本文研究拟除虫菊酯类农药在稻田使用对水生生物、天敌、稻飞虱再猖獗以及对施药人员健康的影响,并研究菊酯类农药在作物和土壤中的残留,从而评价拟除虫菊酯类农药在稻田使用对环境的安全性。     

GC/MS技术检测鲜桃中14种菊酯类农药残留

本文建立了气质联用技术检测鲜桃中菊酯类农药残留的方法。用乙腈提取,C-NH_2小柱净化,气质联用仪分析菊酯类农药。该方法回收率在71.2%~102.1%之间,线性相关系数0.99,14种菊酯类农药检出限范围在0.006~0.037mg/kg。本方法准确可靠,可应用于桃果中等多种拟除虫菊酯类农药的测定。     

拟除虫菊酯类农药的免疫毒性研究进展

拟除虫菊酯类杀虫剂因其高效、对哺乳动物低毒和易降解等特性已被广泛使用,目前对其生态毒理学的研究主要集中在神经及内分泌干扰、发育和生殖毒性方面,而关于其免疫毒性的研究也越来越受到了关注。文章对拟除虫菊酯类农药的免疫毒性及其分子机制研究进展进行了总结,主要从免疫器官、免疫细胞、免疫分子和免疫功能等方面综述了此类杀虫剂对不同生物的免疫毒性及其可能的分子机制,同时总结了拟除虫菊酯类杀虫剂暴露与免疫相关疾病发生的关联,以期为拟除虫菊酯类农药免疫毒性的进一步探究提供参考。     

除草剂酶联免疫吸附测定研究进展

酶联免疫分析技术具有方便快速、特异性强、灵敏度高等优点,近年来广泛应用于农药残留检测.本文介绍了酶联免疫分析技术在除草剂残留检测中的应用研究进展,分别介绍了各类除草剂的半抗原合成方法以及抗体的灵敏度,探讨了酶联免疫吸附分析法存在的问题和应用前景.     

菊酯类农药对水田生物影响研究进展

拟除虫菊酯类农药是一个重要的杀虫剂类别,对有害昆虫具有良好的触杀作用.但是,在中国一直被禁止应用于水田害虫防治.本文综述了菊酯类农药对各种水田生物的急性和慢性作用机制、影响因子,提出拟除虫菊酯类农药能否在水田应用需要进行深入系统的研究论证.     

试论拟除虫菊酯类农药在水稻田中的应用

拟除虫菊酯类农药具有高效、广谱、残留较低等特点,但由于其对鱼类等水生生物毒性高,以及可能导致稻飞虱再猖獗等原因,我国禁止其在水稻田使用。本文论述了拟除虫菊酯类农药在稻田使用时对水生生物的毒性、稻飞虱再猖獗、害虫抗药性和天敌的影响,并对拟除虫菊酯类农药在水稻田中使用的可行性提出了建议。     

蔬菜和水果中菊酯类农药残留量的检测

用Agilent6890N气相色谱仪摸索建立了蔬菜和水果中的溴氰菊酯、甲氰菊酯、三氟氯氰菊酯、氰戊菊酯等拟除虫菊酯类农药残留量的检测方法。确定了12℃/min为最佳程序升温速率。当样品中的添加浓度为0.05～0.10mg/kg时,添加回收率为85.4%～110.4%。4种菊酯类农药的最低检测浓度为3×10-4～6×10-4mg/kg。     

拟除虫菊酯类农药对哺乳动物神经毒理的研究进展

对拟除虫菊酯类(SPs)农药对哺乳动物的神经毒理学研究过程及其最新进展进行了综述。拟除虫菊酯类农药是目前使用广泛的一类神经毒性杀虫剂,主要用于农业和卫生害虫的防治。已有研究结果显示拟除虫菊酯类农药对非靶标野生动物和人类的神经系统有一定的毒性作用,其对哺乳动物的神经毒性主要表现为急性和慢性神经毒性,而且其毒性作用与拟除虫菊酯类农药的立体结构相关,有一定的对映体选择性差异。     

毒死蜱多克隆抗体的制备

以三氯硫磷为起始原料,经三步反应合成得到毒死蜱半抗原O-乙基O-(3,5,6-三氯-2-吡啶基)N-(3-羧丙基)硫逐磷酸胺 (简称CHBu),此半抗原分别与牛血清蛋白(BSA)和卵清蛋白 (OVA)用碳二亚胺法和混合酸酐法通过偶联反应得到免疫抗原和包被抗原,其结合比分别为 14.6 ∶ 1 和6.2 ∶ 1。用所得的免疫原免疫兔子获得了高效价(抗血清: 2.56×104; 冻干粉: 2.56×106)、高亲和性、特异性好的多克隆抗体。交叉反应试验表明,该抗体与毒死蜱各结构类似物交叉反应率均小于4%;亲和性试验表明,在1~500 ng/mL浓度范围内,抑制率与浓度呈线性关系,线性回归方程为 y=23.503 lg(x)+28.556,r=0.991 9,抑制中浓度I50=8.2 ng/mL,最低检测限为1.0 ng/mL。     

Evaluation of chlorfenapyr for control of the bed bug,Cimex lectularius L.

BACKGROUND: The presence of bed bug populations resistant to pyrethroids demands the development of new control tactics, including the use of insecticides with new modes of action. Insecticides that disrupt oxidative phosphorylation in insect mitochondria can be an option. Laboratory assays were used to measure the toxicity of chlorfenapyr to susceptible strains and two strains highly resistant to pyrethroids. The effectiveness of two chlorfenapyr‐based formulations was compared, and behavioral responses of bed bugs to dry residues of aerosol sprays were evaluated. RESULTS: Chlorfenapyr was effective against all bed bug strains, killing them at a similar rate, regardless of their susceptibility status to pyrethroids. Dry residues aged for 4 months were as toxic as fresh dry residues. The aerosol formulation had contact activity and caused faster mortality than a water‐based formulation. Bed bugs did not avoid resting on surfaces treated with aerosol. CONCLUSION: Chlorfenapyr is an option for controlling pyrethroid‐resistant bed bugs. While it does not cause quick knockdown, its long residual activity and no avoidance behavior of bed bugs to dry residues appear to make this insecticide suitable for bed bug control. A faster insecticidal effect is obtained with the aerosol formulation, suggesting greater bioavailablity of the toxicant. Copyright © 2010 Society of Chemical Industry     

氯噻啉酶联免疫分析方法研究

建立了基于多克隆抗体的氯噻啉间接竞争酶联免疫分析(ic-ELISA)方法。设计合成了氯噻啉半抗原,将其分别与牛血清蛋白(BSA)和卵清蛋白(OVA)偶联制备免疫原和包被原。用免疫原免疫新西兰大白兔,制备多克隆抗体,抗体效价为2.56×106。通过对有机溶剂含量、离子强度和pH等影响因素的优化,确定了氯噻啉ic-ELISA的最佳检测条件(含体积分数10%甲醇的磷酸盐缓冲液、Na+浓度为0.14 mol/L、 pH 7.4),并建立了氯噻啉标准竞争曲线,该方法的抑制中浓度(IC50)为0.18 mg/L,最低检测限(IC10)为0.001 8 mg/L。所得多克隆抗体除与吡虫啉有较大的交叉反应外,与其他结构相似的化合物无明显交叉反应。在水、土壤和甘蓝中分别添加0.05~1 mg/kg的氯噻啉标准溶液,平均回收率为91.42% ~113.82%,相对标准偏差(RSD)为0.72% ~8.68%,符合农药残留检测要求。该ELISA方法可用于环境及农产品中氯噻啉残留检测。     

磁性分散固相萃取-QuEChERS结合气相色谱-串联质谱法检测不同柑橘基质中多种农药残留

基于磁性分散固相萃取 (MDSPE)-QuEChERS前处理技术，采用气相色谱-串联质谱法 (GC-MS/MS) 进行定性定量分析，建立了快速检测宽皮柑橘、甜橙、柠檬、柚子和金桔5种柑橘基质中75种农药残留的方法，优化了石墨化碳黑 (GCB)、N-丙基乙二胺 (PSA) 和磁性纳米粒子 (MNPS) 用量对不同柑橘中目标分析物回收率的影响。在优化条件下，目标分析物的线性范围在0.01~0.5 mg/kg之间，平均回收率为63%~118%，相对标准偏差为0.30%~16%。方法的检出限 (LOD) 为1~7 μg/kg，定量限 (LOQ) 为10~20 μg/kg。该方法简便、快速、安全、价格低廉，重现性良好，可用于不同柑橘中多种农药残留的快速确证检测。     

Pyrethroids and terrestrial non-target organisms

The discovery and development of the pyrethroid insecticides represents a major advance in the techniques of crop protection and disease vector control. These compounds combine outstanding efficacy against a broad spectrum of noxious insects with low toxicity to birds and mammals. This paper considers the effects of pyrethroids on other components of the terrestrial non-target fauna, with particular reference to effects on ‘beneficial’ organisms, including natural pest-control agents, pollinators, and organisms responsible for the maintenance of soil structure and fertility. This paper uses laboratory and field data to identify which groups of organisms may be potentially at risk from the use of pyrethroids, and draws on extensive field data to consider the significance of such hazards under conditions of normal use. Emphasis will be placed throughout on the evaluation of these compounds under practical conditions, including both crop and non-crop usages. Limitations to, and opportunities for, the use of pyrethroids are discussed, and the potential for further development is considered.     

Insecticide screening with isolated nerve preparations for structure-activity relationships

The sciatic nerve-sartorius muscle preparation from the frog, the nerve-muscle preparation from the crayfish, and the abdominal nerve cord preparation from the crayfish have been compared for their sensitivity to various insecticides. The crayfish nerve cord was the most sensitive to insecticides and had a broad spectrum of sensitivity. A method was developed with this preparation to compare a large number of synthetic pyrethroids for their potencies to stimulate and block the nerve which is the primary target site. Both stimulating and blocking actions on the nerve can be assessed with this preparation. Certain pyrethroids are active insecticidally despite their weak nerve action, whereas some other pyrethroids are relatively moderate in killing insects despite their potent nerve action. Thus the new method can be effectively used to establish the true structure-activity relationship of synthetic pyrethroids or any other insecticides acting directly on the nerve.     

A study of the disappearance of pesticides during composting using a gas chromatography-tandem mass spectrometry technique

A simple method for multi-residue analysis of pesticides by low-pressure gas chromatography-tandem mass spectrometry (LP-GC-MS-MS) has been validated in compost samples. The pesticide residues were extracted from the lyophilised samples with organic solvent by stirring. No sample clean-up was required prior to the analysis. The method was applied to determine the fate of two organochlorine pesticides (lindane and endosulfan) and two organophosphates (malathion and chlorpyrifos-methyl) during the composting process in the reactor of a pilot plant. Malathion, chlorpyrifos-methyl and lindane residues almost fully disappeared after 8 days of maturation in the reactor, while endosulfan residues were only partially degraded. Alongside this, a study of natural disappearance of the pesticides was carried out in the laboratory and a characteristic time profile was traced for each pesticide class.     

乙草胺人工抗原的合成及其单克隆抗体的制备

通过乙草胺与3-巯基丙酸在碱性条件下反应合成了半抗原——乙草胺-巯基丙酸(AMPA)。采用活性酯法将半抗原AMPA分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)偶联制备了人工抗原。通过紫外光谱测定了AMPA与BSA及OVA间的分子结合比分别为41和26。用AMPA-BSA免疫小鼠,制备得到的单克隆抗体的效价为1∶ 16×104。以AMPA-OVA作包被抗原,用乙草胺单克隆抗体建立了ELISA检测方法,IC50值为0.55 μg/L,方法的检测范围为0.04~5 μg/L,检测限为0.04 μg/L。     

半抗原的间隔臂长度对免疫识别的影响

分别以2甲4氯和二氯喹啉酸的3种不同间隔臂长度(0、4、6个碳)的包被抗原及相应的3种抗体为研究对象,通过抗体效价的测定及包被抗原与抗体的亲和性正交试验,讨论了半抗原的间隔臂长度对免疫识别的影响。结果表明,两种化合物均以接有4个碳链长度间隔臂的半抗原诱导产生的抗体效价最高;同一抗体更易识别间隔臂较长(6个碳)的抗原;对于同一包被抗原,抗2甲4氯抗体中均以不接臂的半抗原诱导产生的抗体的识别能力最强,而抗二氯喹啉酸中则以接有4个碳长间隔臂的半抗原诱导产生的抗体的识别能力最强,表明抗体的识别能力可能与IgG蛋白的空间构型有关。