Acute toxicity of chlorpyrifos to the non-target organism Cnesterodon decemmaculatus

Chlorpyrifos is the most used insecticide in Argentina. Cnesterodon decemmaculatus is a widely distributed, endemic fish from Neotropical America. It attains high densities in the shallow water assemblages of Argentina and Brazil. The aim of this study was to assess the acute toxicity of chlorpyrifos to C. decemmaculatus. The mean 96-h LC₅₀ of three independent determinations was 105.3 (±?3.1) μg/L. Sublethal effects were observed. Swimming behavioral changes at each chlorpyrifos exposure concentration were reported. C. decemmaculatus represents a good model for ecotoxicological risk assessment.     

12种中草药的乙醇提取液对印鼠客蚤的毒效研究

目的:探讨中草药灭蚤的可行性。方法:用乙醇提出12种中草药的可溶成分,以瓶膜法测定其对印鼠客蚤的毒力。结果:在0.5g/ml(生药)的浓度下,10种中草药对印鼠客蚤有速效击倒作用,其中鸡血藤、巴豆仁、除虫菊花的10min击倒率大于50％;5种中草药的KD_(50)小于15min,比2％DDVP为优;巴豆仁接触30min恢复24h死亡率为70％。结论:除虫菊花、黎芦、鸡血藤、巴豆仁、贯众用于杀蚤有一定价值。     

济南市德国小蠊对常用化学杀虫剂的敏感性测定

目的 :了解济南市德国小蠊 (BlattellaGermanica)对常用化学杀虫剂的抗药性 ,指导科学、合理使用杀虫剂。方法 :药膜接触法。结果 :野外品系德国小蠊与敏感品系比较 ,对氯氰菊酯、溴氰菊酯、残杀威、DDVP的抗性系数分别为 10 .2 2、3 .2 1、1.18、1.19。结论 :济南市德国小蠊对 4种杀虫剂的敏感性不一 ,在害虫防制时须选择使用适当的杀虫剂     

致倦库蚊有机磷抗性相关扩增酯酶B基因的多样性

本实验从佛山和成都两地的致倦库蚊群体中筛选出３个酯酶类型不同的有机磷（ＯＰ）抗性品系，ＦＳ－１、ＦＳ－２和ＣＤ－１品系。各品系的酯酶基因Ｂ扩增水平、酯酶活性和ＯＰ抗性水平三者一致。各品系酯酶Ｂ基因限制性酶切片段比较分析表明，我国的ＯＰ抗生库蚊群体中不仅有世界性分布的酯酶Ｂ１和Ｂ２，而且在佛山和成都地区各有一个新的独立扩增的酯酶Ｂ，分别命名为Ｂ６和Ｂ７。     

复配杀虫母液灭蚊效果评价

目的 :评价复配杀虫母液灭蚊虫效果。方法 :设试验区和对照区 ,试验区用有效成分含量 2 0 %的复配杀虫母液按 5 m l/ m3超低容量喷雾 ;对照区用 2 0 % DDVP同浓度超低容量喷雾。结果 :复配杀虫母液超低容量喷雾 2 h后 ,蚊密度下降率为 93.3% ,RPI为 2 6 .7;4h后下降率为 98.3% ,RPI为 12 .4。结论 :复配杀虫母液用超低容量喷雾能迅速杀灭成蚊 ,是特殊情况下短时间内降低室内成蚊密度较为理想的杀虫药剂。     

酸血症对有机磷农药中毒家兔模型阿托品化量影响的实验研究

目的：探讨酸中毒对有机磷农药中毒病人阿托品化量的影响。方法：采用家兔80只,随机分为两组,一组制造酸血症模型,另一组对照,两组均注射公斤体重相同剂量的有机磷农药,制造有机磷农药中毒模型,而后用阿托品解救,并达到阿托品化状态,比较两组阿托品的用量。结果：酸血症组阿托品用量明显高于对照组。结论：有机磷中毒病人合并酸中毒时,阿托品化量,高于正常。及时纠正酸中毒, 有利于有机磷中毒患者的治疗。     

德国小蠊抗药性检测方法比较研究

目的　对德国小蠊两种常用抗性检测方法进行比较 ,以了解不同方法在抗性系数 (RR)上的差异 ,为根据需要选择适宜的抗性检测方法提供帮助。方法　分别参照WHO和Atkinson等 (1991)及Zhai等 (1992 )的方法。结果　用药膜法测定KT50 ,德国小蠊对二氯苯醚菊酯、溴氰菊酯和氯氰菊酯的抗性倍数分别是 6.93、13 .85和 5 .60倍 ;而用点滴法测定LD50 ,德国小蠊对上述 3种药剂的抗性倍数分别为 2 2 .17、64 .3 2和 2 7.0 3倍。可见 ,用点滴法比用药膜法测定德国小蠊对二氯苯醚菊酯、溴氰菊酯和氯氰菊酯的抗性系数分别要高出 3 .2 0倍、4.64倍和 4.83倍。结论　点滴法较药膜法更为灵敏 ,能较为准确地反映出德国小蠊的实际抗性水平 ,而药膜法相对简单易行 ,适于现场抗性检测。     

德国小蠊抗性及敏感品系羧酸酯酶生化特征比较研究

目的 研究德国小蠊敏感品系和抗性品系羧酸酯酶(CarE)生化性质上的差异，旨在从生化水平上确定CarE在德国小蠊抗性中的作用，初步揭示德国小蠊抗性机制。方法 参照Asperen(1962)和高希武(1991)方法测定CarE活性。结果 德国小蠊抗性品系中的CarE活性要高于敏感品系中的CarE活性。抗性品系与敏感品系对α-乙酸萘酯(α-NA)的亲和力要大于对β-乙酸萘酯(β—NA)的亲和力，而敏感品系CarE对α—NA的亲和力要大于抗性品系CarE。时间进程曲线显示，在以α-NA为底物时，抗性品系与敏感品系CarE时间进程曲线趋势不一致。对9种德国小蠊野外品系CarE活性的测定结果表明，除1种品系外，其余品系均使CarE活性提高，幅度在1．23～2．83倍之间。结论 德国小蠊抗性品系和敏感品系在CarE生化特征上的差异，显示出德国小蠊抗性品系对几种拟除虫菊酯类杀虫剂产生的高度抗性，与其体内CarE活性的提高有密切关系，表明CarE活性的提高是北京地区野外德国小蠊品系普遍存在的一种抗性机制。     

新型吡啶类鬼臼毒素衍生物对淡色库蚊的生物活性研究

目的研究新型吡啶类鬼臼毒素衍生物对3龄淡色库蚊幼虫的的毒杀活性。方法采用WHO生物测试法测定吡啶类鬼臼毒素衍生物对3龄淡色库蚊幼虫的毒杀活性。结果12种新型吡啶类鬼臼毒素衍生物对3龄淡色库蚊幼虫的毒杀作用有明显的差异,化合物4.4、4.5和4.6的毒杀作用明显高于其它化合物。结论12种新型吡啶类鬼臼毒素衍生物对3龄初淡色库蚊幼虫毒杀作用的差异可能与结构上的差异有关。     

Neurochemical effects of repeated gestational exposure to chlorpyrifos in developing rats.

The neurochemical effects in developing rats exposed during gestation to the anticholinesterase organophosphorus insecticide chlorpyrifos (CPS) were determined. Pregnant rats were dosed daily with CPS (0, 3, or 7 mg/kg) in corn oil from gestation days (GD) 6-20. Pups were euthanized on postnatal days (PND) 1, 3, 6, 9, 12, and 30 for the determination of brain cholinesterase (ChE) and choline acetyltransferase (ChAT) activities, along with muscarinic receptor (mAChR) densities, the levels of the high-affinity choline uptake (HACU) system, and the vesicular acetylcholine transporter (VAChT). ChE activities were inhibited about 15 and 30% on PND 1, in the low- and high-dosage groups, respectively, and were not different from control values by PND 6. mAChR densities on PND 1 were reduced in the high-dosage group by about 18, 21, and 17%, using 3H-N-methylscopolamine, 3H-quinuclidinyl benzilate, and 3H-4-DAMP, respectively, as ligands, and were not different from control levels by PND 6. ChAT activity was decreased by approximately 12% in the high-dosage group on PND 9, 12, and 30. HACU levels, using 3H-hemicholinium-3 as the ligand, were reduced by approximately 25% on PND 6 in the low- and high-dosage groups, and by approximately 14 and 21% on PND 12 and 30, only in the high-dosage group. Levels of the VAChT were reduced by a range of 13-31% on PND 3 through 30 in the high-dosage group, using 3H-AH5183 (vesamicol) as the ligand. These data suggest that gestational exposure to 7 mg/kg/day CPS results in long-term alterations of presynaptic cholinergic neurochemistry.