溴氰菊酯对DMPC和DPPC多层脂质体结构影响的~(31)PNMR研究

用~(31)P NMR(核磁共振)研究了溴氰菊酯对脂质体中磷脂头部运动的影响。实验发现含溴氰菊酯的DMPC(二棕榈酰磷脂酰胆碱)和DPPC(二豆蔻酰磷脂酰胆碱)多层脂质体的比纯DMPC和DPPC多层脂质体小。的减小是由磷酯基团运动自由度增大所引起的。可能是因为溴氰菊酯的加入,破坏了磷脂的双层有序排列,在多层脂质体层间形成非双层HI相,或者是由于溴氰菊酯的存在,在制备多层脂质体过程中单层脂质体增多。实验还发现溴氰菊酯使~(31)P各向同性峰增大。     

舒筋灵对家兔溴氰菊酯静脉染毒的拮抗作用

家兔静脉染毒溴氰菊酯所产生的急性毒性症状与大鼠相似,半数致死量为1.35mg/kg。家兔静脉染毒溴氰菊酯2.7mg/kg后立即静脉注射舒筋灵300mg/kg,可有效地拮抗溴氰菊酯的毒作用,缓解中毒症状,使家兔死亡率从100%降低至25%(P<0.05)。家兔溴氰菊酯2.15mg/kg静脉染毒后5分钟给予舒筋灵300mg/kg,可降低死亡率50%(P<0.05)。在染毒后10分钟给舒筋灵,舒筋灵已不能拮抗溴氰菊酯对家兔的毒作用。表明舒筋灵对以溴氰菊酯的拮抗作用只在溴氰菊酯的作用初期有效。     

Insecticides and Arable Weeds: Effects on Germination and Seedling Growth

The decline of many arable weed species in Northern Europe has been attributed to the intensification of modern agriculture and in particular, increasing pesticide use. In this study, we examined the effect of two insecticides, dimethoate and deltamethrin, on the germination and seedling growth of six arable weed species. Although germination was unaffected by insecticide application, seedling growth of four species was decreased by exposure to deltamethrin (Capsella bursa-pastoris and Poa annua), dimethoate (Agrostemma githago), or by both insecticides together (Urtica urens). While increased herbicide use, seed cleaning, and changing sowing times may be of primary importance in explaining the reduction of northern Europe’s arable weed flora, our results indicate that insecticide use may also be a contributory factor. Moreover, those species that exhibit apparent tolerance of the insecticides tested, particularly the grass Avena fatua, may benefit from continued insecticide use. The ability to tolerate these agrochemicals, in tandem with reduced herbivory and competition from plants, whose growth is reduced by insecticide application, is likely to confer a significant competitive advantage on insecticide-resistant weed species.     

Effects of deltamethrin on the activation or expression of Nrf2 and on the GCS-HS protein level in primary astrocytes with laser scanning confocal microscope

Objective： To examine the effects of deltamethrin（DM） and tBHQ on the activation of Nrt2 and expression of GCS-HS in primary astrocytes. Methods： Rat primary astrocytes were treated with DM （10μmol/L） and tBHQ （40μmol/L）, for 1 and 6 h respectively. Results： Analysis using immunofluorescent confocal microscopy revealed that tBHQ treatment led to a dramatic increase in the level of Nrt2. The ratio of cytoplasmic Nrt2 protein to nuclear Nrt2 protein was markedly reduced in astrocytes by either tBHQ or DM treatment. The level of Nrf2 was reduced by combined tBHQ with DM treatment for 1 h, but treatment the ratio of cytoplasmic Nrf2 protein to nuclear Nrf2 protein was increased compared with that of the tBHQ only. The expression of GCS-HS in astrocytes was not altered by DM or tBHQ or both in astrocytes. Conclusion： These findings demonstrated for the first time that Nrf2 was activated by pesticides and antioxidants in astrocytes, implicating a tote of Nrf2 in response to pesticide neurotoxicity ingla.     

溴氰菊酯染毒大鼠的脑组织中GCS亚单位和Nrf2表达的时间进程

目的研究溴氰菊酯(DM)对大鼠大脑皮层和海马组织γ-谷氨酰半胱氨酸合成酶(GCS)轻亚单位(GCSl)和重亚单位(GCSh)mRNA表达,以及GCSh和转录因子NF-E2相关因子2(Nrf2)基因蛋白表达时间进程的影响。方法DM染毒组(DM12·50mg/kg bw)和溶剂对照组大鼠染毒1次,分别于大鼠染毒后不同时间点处死大鼠,分离皮层和海马。用逆转录聚合酶链式反应(RT-PCR)方法测定mRNA表达的相对量。联合用免疫组织化学方法和图像分析系统检测海马和大脑皮层中GCS重亚单位蛋白(GCS-HS)和Nrf2蛋白的水平。结果(1)DM染毒后第5h和第48h大鼠大脑皮层中GCSh mRNA相对水平分别降低至对照组的83·9%、86·0%(P<0·05),第5h、24h和48h Nrf2mRNA分别增高至0h对照组的146·4%、145·2%和147·9%(P<0·05)。(2)DM染毒后第5h和24h海马中GCSh mRNA相对水平分别增高至0h对照组的118·4%、118·4%(P<0·05),第5h海马中GCSl mRNA比0h对照组、24h和48h组均高,增高至对照组的121·4%(P<0·05)。DM染毒后各时间点海马Nrf2mRNA水平未见明显的变化(P>0·05)。(3)DM染毒后海马不同分区(CA1、CA2、CA3和齿状回)和大脑皮层中的GCS催化亚单位(GCS-HS)和转录因子Nrf2蛋白水平均未见明显改变。结论本实验条件下DM染毒后,大鼠海马GCSh和GCSl mRNA基因表达出现上调,而脑皮层GCSh基因表达出现下调,Nrf2mRNA水平表达出现上调,但海马和皮层组织中的GCS-HS和Nrf2蛋白水平未见显著变化。     

固相萃取-高效液相色谱法测定桔梗中拟除虫菊酯的农药残留

目的:建立桔梗中甲氰菊酯、高效氯氟氰菊酯、溴氰菊酯、氰戊菊酯、氯菊酯、联苯菊酯共6个拟除虫菊酯类农药残留的提取、净化及其残留量测定的方法。方法:样品运用石油醚提取,商品CARB/NH2小柱净化,乙腈-二氯甲烷(5∶95)洗脱,HPLC-DAD检测。色谱条件:采用Hypersil BDS C18(250 mm×4.6 mm,5μm)色谱柱,流动相为乙腈-水(70∶30),流速1 mL.min-1,检测波长230 nm。结果:样品4水平添加时的6个拟除虫菊酯类化合物回收率在75.63%～107.5%范围内,RSD在2.3%～9.9%范围内,可以满足农药残留分析的要求。结论:该方法灵敏度高,选择性强,操作简单、快速,净化效果好。可应用于桔梗药材中痕量农药残留的检测。     

溴氰菊酯药浴阳性鼠阻断内脏利什曼病传播的实验研究

用中华白蛉分别饲吸两组染有杜氏利什曼原虫的背纹仓鼠（Ｃｒｉｃｅｔｕｌｕｓｂａｒａｂｅｎｓｉｓ），一组系经澳氰菊酯药浴后９－４５ｄ的仓鼠，另一组系未经药浴的仓鼠。实验结果表明饲吸药浴鼠的白岭在２４ｈ内全部中毒致死，饲吸未经药浴鼠的白蛉存活率很高。在剖检的吸血白蛉中，有６９．１％的白蛉，在其消化道内发现有前鞭毛体的感染，这些前鞭毛体不仅在白蛉消化道内发育良好，且随饲吸时间的推移，前鞭毛体侵入食道、咽和喙部。背纹仓鼠是杜氏利什曼原虫理想的保虫宿主，经药浴的仓鼠进行人工感染，已失去感染能力。     

糖原分支酶基因体外增强淡色库蚊抗药性的研究

目的构建淡色库蚊糖原分支酶基因(GBE)的昆虫表达载体,通过细胞转染法鉴定其与蚊虫抗药性相关的关系。方法用基因重组方法构建GBE的昆虫表达载体;通过脂质体转染法将昆虫表达载体转入伊蚊C6/36细胞,继而通过观察细胞形态及3H TdR掺入法检测稳定表达GBE基因的细胞对溴氰菊酯杀虫剂的敏感性。结果成功构建GBE基因的昆虫表达载体同时通过筛选获得稳定表达该基因的细胞株。3H TdR掺入法结果显示转染GBE基因能够提高细胞的存活率,并与对照组差异有显著性(P<0.05)。结论 GBE基因在与淡色库蚊溴氰菊酯抗性相关,且其在细胞对抗溴氰菊酯的毒性作用中有保护作用。     

溴氰菊酯和倍硫磷混用、轮用对淡色库蚊抗性发展的影响

目的　观察杀虫剂不同用药方式对淡色库蚊抗性发展的影响。方法　以淡色库蚊（Culex pipiens pallens）为试虫,用溴氰菊酯和倍硫磷混剂和单剂隔代轮用进行抗性选育,以溴氰菊酯和倍硫磷单剂作为对照。结果　淡色库蚊经16代处理,其抗性系数在溴氰菊酯和倍硫磷混用为14.65;两者轮用为17.74（溴氰菊酯）和2.77（倍硫磷）;单剂连用则分别为729.08和24.73。结论　两种作用机制不同的杀虫剂混用或轮用均能延缓害虫对杀虫剂抗性的发展。     

溴氰菊酯在家兔中死后弥散研究

目的 通过对溴氰菊酯死后弥散现象的研究,观察不受死后再分布现象影响的组织脏器,为溴氰菊酯的法医学检材采取提供实验依据. 方法 家兔处死半小时后分别经口给予4LD50溴氰菊酯,室温下分别放置24 h和48 h解剖,检测心血、股动脉血、尿液、胆汁、心、肝、脾、肺、肾、脑、左下肢肌肉中溴氰菊酯的浓度,比较其变化规律. 结果 家兔处死半小时后经口给予4LD50溴氰菊酯,灌胃24 h后溴氰菊酯就可以从胃弥散至其他组织器宫,心血、周围血、尿液和胆汁中的浓度均高于其他脏器.与24 h组相比,48 h家兔尿液、胆汁、心、脾、肾和左下肢肌肉中溴氰菊酯浓度的变化没有统计学意义. 结论 溴氰菊酯在尿液、胆汁、心、脾、肾和肌肉中的浓度比较稳定,不受死后弥散的影响,在对溴氰菊酯中毒的法医学鉴定可以采取上述检材进行毒物检验和浓度确定.