Rapid colorimetric field test to determine levels of deltamethrin on PermaNet® surfaces: association with mosquito bioactivity

Objective  To evaluate a simple and inexpensive colorimetric test to measure the amount of cyanopyrethroid insecticide residue from filter paper exposed to mosquito net surfaces.
Method  The net sampling protocol and colorimetric test (NetTest) were evaluated for deltamethrin-impregnated PermaNet^® 2.0 by comparison with high-performance liquid chromatographic assays and mosquito mortality (WHO Cone Test).
Conclusion  The observed correlation between the amount of deltamethrin adsorbed onto the filter paper and the entire amount of deltamethrin per unit area of net material was good: 0.967, five assays. The relationship between the surface levels of deltamethrin determined by the colorimetric test and the 'gold standard' mosquito bioassay reveals a relatively accurate field test with a sensitivity of 91.4% and specificity if 85.4% (76 samplings from 19 nets).     

溴氰菊酯对大鼠脑组织G蛋白转换的影响

目的 研究溴氰菊酯对大鼠脑组织中G蛋白在活性状态和非活性状态之间转换的影响。方法 雄性SD大鼠经溴氰菊酯腹腔注射处理，用Westernblot方法检测大鼠脑中GAP的含量，用酶学方法检测大鼠脑NDK的活性。结果 溴氰菊酯可以增加大鼠脑组织中GAP的含量，升高NDK活性。结论 溴氰菊酯具有加速G蛋白转换过程的作用。     

用荧光半定量RT-PCR检测蚊溴氰菊酯抗性

目的:建立蚊对菊酯类杀虫剂抗性的PCR检测方法。方法:应用荧光半定量RT鄄PCR,检测经SSH结合cDNA芯片分离鉴定的淡色库蚊对溴氰菊酯抗性相关基因NYD鄄Tr在抗性品系与敏感品系中的表达水平。结果:经荧光半定量RT鄄PCR检测,NYD鄄Tr进入指数期的循环数抗性品系早于敏感品系,抗性品系组比敏感品系组先进入指数增长期。结论:以NYD鄄Tr作为靶基因,荧光半定量RT鄄PCR可区分淡色库蚊对溴氰菊酯抗性品系与敏感品系,亦即可检测淡色库蚊溴氰菊酯抗性。     

Pyrethroid insecticides indirectly inhibit GABA-dependent Cl influx in synaptoneurosomes from the trout brain

Rainbow trout (Oncorhynchus mykiss) are extremely sensitive to the neurotoxic activity of pyrethroid insecticides. One possible target for pyrethroids is the GABA_A receptor of brain of the trout, the function of which can be tested by measurement of influx of ³⁶Cl ⁻ into synaptoneurosomes, in response to the application of agonists. γ-Aminobutyric acid produced a time- and concentration-dependent increase in influx of ³⁶Cl⁻ in synaptoneurosomes from the brain of the trout, which exhibited the pharmacology characteristic of a response mediated by activation of a GABA_A receptor. Deltamethrin, (1RS)-cia-cypermethrin and permethrin produced a dose-dependent increase in the basal uptake and a corresponding decrease in GABA-dependent influx, with a maximum inhibition of 70–82%. This effect of pyrethroid was stereospecific, of high potency and inhibited by tetrodotoxin (TTX) and t-butylbicy-clophosphorothionate (TBPS). The sensitivity of the effect of the pyrethroid to TTX suggested an activation by pyrethroid of the voltage-dependent sodium channel. Veratridine, a sodium channel activator, elicited similar changes in the basal uptake of chloride, which were TTX-sensitive. Neither deltamethrin nor veratridine had a measurable effect on the efflux of ³⁶Cl⁻ from synaptoneurosomes. Thus, pyrethroid insecticides may interfere with the function of GABA_A receptors indirectly through an interaction with the voltage-dependent sodium channel in the brain of the trout and consequently perturb chloride influx, possibly through a voltage-dependent chloride channel.     

拟除虫菊酯浸泡居民蚊帐防治疟疾效果的观察

1986年江苏盱眙县的两个乡,分别采用溴氰菊酯(15mg ai/m~2)和二氯苯醚菊酯(200mg ai/m~2)浸泡居民蚊帐作为抗疟措施之一.结果表明,这样处理与对照乡相比,可以大大减少蚊帐上的栖留蚊虫,并且基本控制了恶性疟的发生.两种拟除虫菊酯处理的效果无大差别,防疟效果与该县同时进行的DDT室内滞留喷洒相比,毫无逊色.蚊帐浸药,尤其是使用溴氰菊酯,更具有简便和经济的优点.我们认为,至少在江苏省盱眙县,采用溴氰菊酯浸泡蚊帐来代替常规DDT滞留喷洒,可以省时、省工和省钱,并且受到广大群众的欢迎.     

溴氰菊酯选育淡色库蚊和中华按蚊的研究

淡色库蚊经溴氰菊酯选育１０代，Ｌｅ５０由０．０４０２ｐｐｍ上升至２１．２７３８ｐｐｍ，抗性高达５２９．２０倍，抗性呈指数曲线上升；中华按蚊被处理８代，Ｌｅ５０由０．０２５６ｐｐｍ至第４代（Ｆ３）时的０．０４８ｐｐｍ，抗性指数为１．８８，其后逐比下降至处理起点水平上波动。溴氰菊酯与增效醚混用后，毒效明显增加，表明多功能氧化酶活力增强是拟除虫菊酯类抗性机理之一。     

溴氰菊酯卫生标准的研究

分装工人和喷药员接触0.022～24.070μg/m~3的溴氰菊酯,除了面部皮肤出现异常感觉之外,没有观察到任何急性中毒的表现和观察指标的变化。大鼠亚急性吸入染毒的无作用浓度为9.6mg/m~3。根据现场调查和动物吸入试验结果,建议车间空气中溴氰菊酯的最高容许浓度为0.03mg/m~3。     

溴氰菊酯对家兔心血管机能的影响

观察溴氰菊酯对家兔心血管机能的影响。溴氰菊酯2.5mg/kg 静脉注射能引起麻醉家兔血压升高、心率减慢、心电图异常。这些变化在30分钟时表现最明显,以后逐渐恢复,提示溴氰菊酯对麻醉兔心血管系统的作用为短暂性的,能为机体内环境的调节机制所补偿。     

门帘浸泡溴氰菊酯防治侵入室内蚊虫的研究

白色棉纱编织的门帘,孔径6×3mm,椭园形,254孔/100cm~2,浸泡溴氰菊酯40mga.i./m~2,具有较满意的毒杀侵入室内蚊虫的作用。当年室内蚊虫死亡率高达90％以上,第二年还有85％以上的毒杀效果,但不经门帘外逃的蚊虫的死亡率却很低。此种门帘不能减少侵入室内蚊虫的数量,也不能明显地干扰蚊虫的吸血活动。