五种杀虫剂对桃小食心虫和梨小食心虫的防治效果研究

【目的】明确3种新型非乳油制剂4%高氯·甲维盐微乳剂、20%高氯·毒死蜱微胶囊剂、20%氯虫苯甲酰胺悬浮剂和两种常规乳油制剂4.5%高效氯氰菊酯乳油、1.8%阿维菌素乳油对桃小食心虫Carposina niponensis Walsingham和梨小食心虫Grapholitha molesta Busck的防治效果,为化学农药的合理使用提供参考。【方法】3种新型农药制剂按照推荐用量分别分成高、中、低3种不同浓度处理,两种乳油制剂采用常规推荐用量处理进行果园桃小食心虫和梨小食心虫防治效果试验。【结果】4%高氯·甲维盐微乳剂26.67 mg·kg-1在药后5、10、15 d对桃小食心虫的防治效果分别为100%、95.22%和95.11%,4.5%高效氯氰菊酯乳油的防治效果与其相当,防效都在90%以上;而4%高氯·甲维盐微乳剂40 mg·kg-1药后5、10、15 d对梨小食心虫的防治效果分别为83.33%、88.89%和93.70%,显著好于4.5%高效氯氰菊酯乳油,后者15 d后最高防效仅为78.99%;以上两种药剂的防效显著高于其它3种药剂20%高氯·毒死蜱微胶囊剂、20%氯虫苯甲酰胺悬浮剂和1.8%阿维菌素乳油。【结论】桃小食心虫第一代发生前期和梨小食心虫第3代发生前期,推荐使用对环境友好的4%高氯·甲维盐微乳剂26.67~40 mg·kg-1(1 000~1 500倍液)进行防治。     

几种常见杀虫剂对玉米草地贪夜蛾的控制作用

草地贪夜蛾是一种刚入侵我国的世界性迁飞害虫,严重威胁玉米生产安全。本试验选择200 g/L氯虫苯甲酰胺悬浮剂、200 g/L氯虫苯甲酰胺悬浮剂+激健、200 g/L氯虫苯甲酰胺悬浮剂+5%甲维盐微乳剂、150 g/L茚虫威悬浮剂、25%甲维·茚虫威水分散粒剂、60 g/L乙基多杀菌素悬浮剂6个处理开展了田间防控草地贪夜蛾的试验。结果发现,施药后1 d,60 g/L乙基多杀菌素悬浮剂速效性最好,校正防效高达89.24%;药后3 d,60 g/L乙基多杀菌素悬浮剂校正防效最高为94.35%,200 g/L氯虫苯甲酰胺悬浮剂及其与激健、甲维盐复配处理校正防效均在85.00%以上;药后7 d,仍以60 g/L乙基多杀菌素悬浮剂校正防效最高达96.38%,200 g/L氯虫苯甲酰胺悬浮剂及其与激健、甲维盐复配处理校正防效均在90.00%以上,150 g/L茚虫威悬浮剂、25%甲维·茚虫威水分散粒剂校正防效相对略低。本试验首次采取药剂复配和加入激健助剂防控草地贪夜蛾,对延缓害虫抗性、减少农药使用、降低农药残留、科学防控草地贪夜蛾具有积极的指导作用。     

云南弥渡县番茄潜叶蛾的发生情况及田间防治效果

外来入侵性害虫番茄潜叶蛾Tuta absoluta(Meyrick)于2018年3月26日在云南弥渡县被发现,为明确其发生为害情况,筛选出有效的防治药剂,阻止该虫的发生和蔓延,本研究采用性诱剂进行田间调查分析了番茄潜叶蛾的发生情况,通过田间药效试验比较噻虫嗪、噻虫胺、虫螨腈、苏云菌杆菌、乙基多杀菌素、阿维·氯虫苯甲酰胺、噻虫·高氯氟和阿维·灭蝇胺对番茄潜叶蛾的防治效果.调查结果表明该虫在番茄种植区域均有发生,大棚番茄地发生尤其严重,为害株达100％,百叶幼虫量55.00～101.67头/百叶,周诱蛾量4.70～61.20头/板,果子的为害率达19.33％,最高达40％.田间药效的结果表明:33％阿维·灭蝇胺SC防效较好,药后3 d防效达74.30％,其次30％虫螨腈SC、6％阿维·氯虫苯甲酰胺SC和6％乙基多杀菌素SC药后3 d防效64.25％、67.98％、54.85％,药后5 d防效79.08％、79.00％、73.45％,药后7 d防效81.60％、80.45％、65.70％.结果表明番茄潜叶蛾在弥渡县大棚发生为害较为严重,性诱剂对成虫有良好的诱集效果,虫螨腈、阿维·氯虫苯甲酰胺、乙基多杀菌素和阿维·灭蝇胺可作为幼虫的防治药剂.     

三种酰胺类新农药对水稻孕穗期稻纵卷叶螟的防效试验

单季杂交晚稻孕穗期稻纵卷叶螟Cnaphalocrocis medinalis Guenée发生不整齐,为害重,在主治药剂氟虫腈即将禁用之际,急需防治高龄幼虫的长效药剂,酰胺类农药是满足这一条件的新一代农药。3种酰胺类农药试验结果,在单季稻孕穗期防治稻纵卷叶螟,20%氟虫双酰胺(WDG)150g/hm2处理速效性与持效性表现最好,药后3d防效达90.3%,药后15d防效高达96.2%;20%氯虫苯甲酰胺(SC)150mL/hm2处理速效性略低于氟虫双酰胺,持效接近,药后3d、15d防效分别达75.2%、91.2%;40%氯虫·噻虫嗪(WDG)120mL/hm2处理速效介于氟虫双酰胺和氯虫苯甲酰胺之间,持效略低于前二者,药后3d、15d防效分别为83.2%、88.3%。对照药剂5%氟虫腈(SC)750mL/hm2和90%杀虫单3000g/hm2处理药后3d、15d的防效均低于上述3种酰胺类新药剂。保叶效果以氯虫苯甲酰胺、氟虫双酰胺处理最高,药后15d保叶率分别为83.6%和85.0%,二者无显著差异,其次为氯虫·噻虫嗪处理为59.6%,3种酰胺类新药剂保叶效果均显著高于对照药剂氟虫腈和杀虫单。结果表明,3种酰胺类农药孕穗期防治稻纵卷叶螟的药效、持效性和保叶效果均高于当前主治药剂氟虫腈、杀虫单,可在生产上推广应用。     

氯虫苯甲酰胺对草地贪夜蛾的毒力及田间防效

草地贪夜蛾Spodoptera frugiperda(Smith)是威胁粮食安全的重要害虫,本文测定了氯虫苯甲酰胺对草地贪夜蛾的室内毒力及田间防效,从中筛选出高效的施药方法和施药剂量,为当前草地贪夜蛾防治提供合理用药的参考。结果表明,在室内条件下,使用氯虫苯甲酰胺直接喷雾处理对草地贪夜蛾3龄和4龄幼虫毒力最高,LC_(50)值分别为0.42 mg/L和0.57 mg/L,使用0.5 mg/L 20%氯虫苯甲酰胺悬浮剂对草地贪夜蛾幼虫毒力较高,在处理后第5天均有超过90%的死亡率。在田间条件下使用氯虫苯甲酰胺对草地贪夜蛾幼虫有较好的防效,使用60.0 g.a.i./ha 0.4%氯虫苯甲酰胺颗粒剂喇叭口点施防治低龄幼虫防效较好,药后第1天、第3天和第7天低龄幼虫(1～3龄)的防效分别为90.3%、100%和100%,使用22.5 g.a.i./ha 20%氯虫苯甲酰胺悬浮剂喇叭口喷雾防治高龄幼虫(4～6龄)的防效较好,药后第1天、第3天和第7天高龄幼虫的防效分别为71.7%、84.5%和95.3%。     

2.5%高效氟氯氰菊酯微乳剂对苹果桃小食心虫的田间应用技术研究

田间应用及安全性评价结果表明,2.5%高效氟氯氰菊酯微乳剂稀释2000～4000倍防治苹果树桃小食心虫Carposina niponensis Walsingham,药后5d各地防效分别为78.14%～99.57%、87.50%～96.58%、80.73%～96.20%,药后10d各地防效分别为84.49%～98.60%、77.78%～94.44%、80.66%～99.29%,药后15d各地防效分别为83.35%～100%、77.55%～98.90%、88.89%～96.58%。2.5%高效氟氯氰菊酯微乳剂稀释2000～3000倍处理与对照药剂2.5%高效氟氯氰菊酯乳油3000倍处理防效相当。最佳用药量以2000～3000倍为宜,施药适期为苹果果实膨大期,且桃小食心虫卵孵化盛末期,虫果率达1%时,用药后5～10d可有效控制虫害,持效期较长。药后苹果树未见异常。     

三种生物源农药对桃树蚜虫的防治效果研究

为筛选生产上防治桃树蚜虫的生物源农药,开展了1.5%除虫菊素水剂、0.3%苦参碱水剂和5%桉油精可溶液剂对桃树蚜虫的田间防效试验。结果表明,3种生物源农药中以0.3%苦参碱水剂防治效果最好,药后1 d防效为70.12%,药后7 d防效为91.96%,与对照药剂70% 吡虫啉水分散粒剂防效相当,具有较好的速效性和持效性。苦参碱对桃树安全,是防治桃蚜的理想药剂,生产上推荐使用浓度为1 000倍液。     

3种药剂对广东地区草地贪夜蛾3龄幼虫室内毒力测定及其田间药效评价

为明确几种药剂对广东地区草地贪夜蛾Spodoptera frugiperda幼虫的室内毒杀作用及田间防治效果,合理使用化学农药对草地贪夜蛾进行科学防治提供理论依据.本研究采用浸叶法测定了氯虫苯甲酰胺、高效氯氟氰菊酯和甲氨基阿维菌素苯甲酸盐对草地贪夜蛾3龄幼虫的室内毒杀作用;采用茎叶喷雾法,测定了 200克/升氯虫苯甲酰胺悬浮剂、150克/升氯虫苯甲酰胺?高效氯氟氰菊酯微囊悬浮-悬浮剂、25克/升高效氯氟氰菊酯乳油和5％甲氨基阿维菌素苯甲酸盐水分散粒对田间玉米上草地贪夜蛾幼虫的防治效果.室内毒力测定试验结果表明:甲氨基阿维菌素苯甲酸和氯虫苯甲酰胺对草地贪夜蛾3龄幼虫都有较好的毒杀作用,LC50分别为0.037 mg/L和0.094 mg/L;而高效氯氟氰菊酯对草地贪夜蛾的毒杀作用较一般,LC50为5.336 mg/L.田间试验结果表明,供试的3种药剂对草地贪夜蛾幼虫速效性一般,药后1 d的防治效果为40.79％～59.67％;药后3 d的防治效果为67.27％～88.55％;药后7 d其防治效果为55.75％～90.97％.氯虫苯甲酰胺和甲氨基阿维菌素苯甲酸盐对草地贪夜蛾具有较好室内的毒杀作用和田间防治效果,是目前防治草地贪夜蛾的理想药剂;高效氯氟氰菊酯对草地贪夜蛾室内的毒杀作用和田间防治效果较差,不推荐用来防治草地贪夜蛾.     

玉米种子丸粒化包衣处理对草地贪夜蛾的防治效果

本研究明确了乙基多杀菌素和氯虫苯甲酰胺丸粒化包衣后对玉米种子的安全性和玉米幼苗对草地贪夜蛾的防治效果,为玉米苗期草地贪夜蛾防治提供新技术。首先在室内验证了乙基多杀菌素和氯虫苯甲酰胺拌土后对草地贪夜蛾的防治效果,又进行了种子丸粒化包衣处理,测定了丸粒化包衣方式下药剂对种子萌发的影响和对草地贪夜蛾的防治效果。结果表明,250 mg/kg的乙基多杀菌素和氯虫苯甲酰胺拌土处理后,草地贪夜蛾对14天的玉米苗的取食率分别为1.67%、5.01%,与对照组取食率27.02%差异显著。药种比为1:100和1:200的乙基多杀菌素和氯虫苯甲酰胺丸粒化包衣处理组与对照组的发芽率之间无显著差异。乙基多杀菌素和氯虫苯甲酰胺丸粒化包衣处理组在播种后第7天对草地贪夜蛾广州种群防治效果显著,其中药种比为1:100的乙基多杀菌素丸粒化包衣处理组致死率最高为89%;两药剂丸粒化包衣处理组在播种后第21天对草地贪夜蛾云南种群仍有较好防治效果,两个浓度的乙基多杀菌素丸粒化包衣处理对草地贪夜蛾的致死率均达100%。本研究表明玉米种子丸粒化包衣技术可有效防控玉米苗期草地贪夜蛾的危害。     

三种药剂对早稻二化螟的防效及施药适期探讨

试验结果表明,氯虫苯甲酰胺、氯虫·噻虫嗪有对二化螟Chilo suppressalis(Walker)有较好的防效和较长的持效,一次施药可兼治多个峰次。20%氯虫苯甲酰胺150mL/hm2、40%氯虫·噻虫嗪120g/hm2和2.15%甲氨基阿维菌素苯甲酸盐750mL/hm2在二化螟2龄幼虫高峰期施药,药后8d对幼虫防效分别达94.7%、91.2%和91.0%;药后18d的防效依次为99.0%、98.0%、73.2%,氯虫苯甲酰胺、氯虫·噻虫嗪处理防效仍高于药后8d,但甲氨基阿维菌素苯甲酸盐处理防效明显下降;药后18d对主峰保苗效果(枯心)氯虫苯甲酰胺和氯虫·噻虫嗪分别为99.0%、98.0%,甲氨基阿维菌素苯甲酸盐处理偏低,为73.2%。对后峰保苗效果(枯鞘)氯虫苯甲酰胺为84.9%好于氯虫·噻虫嗪处理的69.3%,甲氨基阿维菌素苯甲酸盐的防效仅为7.1%。氯虫·噻虫嗪不同时期施药处理后,主峰卵孵高峰后14d考查,防治效果和保苗效果以卵孵高峰施药最好,其次为2龄幼虫高峰期施药;主峰卵孵高峰后24d考查,主峰卵孵高峰至3龄幼虫高峰施药对主峰均有较好的防效,但对后峰的防效,随着施药时间推迟而提高,但在螟虫重发地区施药过迟,前期的大量枯鞘会影响稻苗生长与分蘖。因此作者建议在二化螟发生量大、后峰数量多地区,采用主峰卵孵高峰和后峰卵孵高峰2次防治对策,在螟虫发生较轻、后峰数量较少或全代发生较为集中地区,可根据当地虫情发生情况,适当推迟施药,达到一次用药,解决全代螟害。甲氨基阿维菌素苯甲酸盐持效期较短,可根据螟虫发生峰次施用。     

金纹细蛾飞行能力测定

【目的】明确金纹细蛾Lithocolletis ringoniella自身生理状态下的飞行能力,了解其飞行生物学的基础参数。【方法】利用昆虫飞行磨系统,室内测定了金纹细蛾雌雄成虫不同日龄和性别以及5日龄雌雄成虫补充营养(5%蜂蜜水)与交配状态下的飞行距离、飞行时间、飞行速度等参数。【结果】连续吊飞12 h的结果显示,金纹细蛾3-6日龄成虫飞行能力较强,5日龄成虫飞行能力最强; 5日龄雌成虫的平均 飞行距离、飞行时间和飞行速度分别为2.293±0.254 km, 5.341±0.617 h和0.711±0.126 km/h, 5日龄雄成虫的平均飞行距离、飞行时间和飞行速度分别为2.142±0.276 km, 5.132±0.628 h和0.620±0.132 km/h, 说明雌雄成虫间飞行能力差异不显著。金纹细蛾5日龄雌雄成虫取食5%蜂蜜水后其飞行能力较对照显著提高,取食5%蜂蜜水后5日龄雌成虫的飞行距离、飞行时间和飞行速度较对照(取食清水)的分别提高46.945%, 15.430%和15.978%;5日龄雄成虫的飞行距离、飞行时间和飞行速度较对照分别提高42.610%, 13.590%和6.529%。交配后5日龄雌成虫的飞行距离、飞行时间和飞行速度较未交配雌成虫的分别提高41.628%, 7.152%和39.925%,而5日龄雄成虫交配后飞行能力则较未交配雄成虫的分别降低35.823%, 17.888%和46.129%。【结论】金纹细蛾成虫具有一定的飞行能力,补充营养和雌雄交配状态对飞行能力有重要影响。     

Anthelmintic effects of bithionol, paromomycin sulphate, flubendazole and mebendazole on mature and immature Hymenolepis nana in mice

The anthelmintic effects of anti-tapeworm drugs, bithionol, paromomycin sulphate, flubendazole and mebendazole on immature and mature Hymenolepis nana in mice were compared. Immature worms were not affected by paromomycin sulphate or flubendazole administered for 12 consecutive days (days one to 12 after infection) at 100 mg/kg/day but 48% and 100% of H. nana were eliminated from mice by bithionol and mebendazole respectively, at the same dosage regimen. Bithionol, paromomycin sulphate, flubendazole and mebendazole given at 100 mg/kg/day for five consecutive days (days 12 to 16 after infection) eliminated 32%, 29%, 36% and 100% of mature worms respectively. 10 and 20 mg of mebendazole/kg/day for five consecutive days (days 12 to 16 after infection) had little effect on mature worms whereas 50 and 100 mg/kg/day for the same period eliminated 99% and 100% of mature worms, respectively. ED50 of mebendazole in the elimination of mature H. nana was 14 or 15 mg/kg/day for five days from the reduction in dry weight or in number of worms recovered respectively. The effects of mebendazole given 2 to 4 days, 8 to 10 days or 13 to 15 days after infection at 100 mg/kg/day were compared. Very low, if any, activity of the drug given 2 to 4 days after infection was seen, whereas the drug given 8 to 10 days or 13 to 15 days after infection eliminated 84% and 86% of H. nana respectively.     

Residues of profenofos in spring onion

Profenofos is one of the commonly used insecticides in the control of Trips tabaci on spring onion in Iran. Residues of profenofos in spring onion were determined in two different fields under the same conditions. In the first field, onion plants were sprayed with profenofos (40EC) at the rate of 1000 g/ha. Spraying was repeated 2 weeks later. In the second field one spraying was preformed at the same rate. Spring onionwere sampled at different time intervals and analyzed for profenofos residues using a GC equipped with NPD detector. In the first field's samples, the residues were 0.097 and 0.025 mg/kg at 2 and 6 days after spraying, respectively. The residues declined to 0.002 mg/kg on the day twelve. Two days after the second spraying the residues was 0.27 mg/kg, which reduced to 0.032 on the day sixth. However the residues were not detectable 32 days after the second spraying. In the second field, residue levels were 0.193 and 0.043 mg/kg at 2 and 6 days after spraying. Residues, which found after 32 days, were less than 0.001 mg/kg. The rate of residue decay in the first field was higher than the second field.     

应用氯氰菊酯和B.t.i H-14混配杀虫剂现场防治城市蚊幼虫的效果评价

采用常量喷雾或注射器滴注方法观察氯氰菊酯、B .t.iH 1 4混配杀虫剂对城市中小型蚊幼虫孳生地现场防治蚊幼虫的效果。结果表明用 2 5mg L、5 0mg L混配杀虫剂分别处理蚊幼虫孳生地 ,1天后蚊幼虫下降率均为 1 0 0 %。容器指数由处理前的 5 3 5和 5 1 6下降至零的持效期分别为 1 4和 2 1天。2 5mg L混配杀虫剂在 2 1天内的毒杀持效与单独使用 5 0mg LB t iH 1 4、1 0mg L氯氰菊酯相当 ,而5 0mg L混配杀虫剂持效比单独使用 5 0mg LB .t.iH 1 4,1 0mg L氯氰菊酯延长 7天 ,表明混配杀虫剂在现场能有效防治蚊幼虫 ,减少化学杀虫剂的用量。     

Dacarbazine induces genotoxic and cytotoxic germ cell damage with concomitant decrease in testosterone and increase in lactate dehydrogenase concentration in the testis

Treatment of cancers with cytotoxic agents such as alkylating drugs often, but not always results in transient to permanent testicular dysfunction. The present study was planned to investigate the effects of dacarbazine [5-(3,3-dimethyltriazeno) imidazole-4-carboxamide] on testicular function in mice. Swiss albino mice (9-12 weeks old) were treated with 0, 5, 25, 50, or 100mg/kg body weight/day dacarbazine (i.p.) for 5 days at intervals of 24h between treatments. Mice were sacrificed on days 7, 14, 21, 28, 35, 49, and 70 after the last treatment (6 mice/dose/sample time), and the epididymal sperm count, sperm motility, sperm morphology, testicular histopathology (qualitative histopathology, seminiferous tubular diameter and epithelial height), and intra-testicular levels of testosterone and lactate dehydrogenase were assessed. Dacarbazine decreased the body weight only on day 28 at 25mg/kg dose-level, but increased the paired testes weights at 50mg/kg on day 7, at 25-100mg/kg on day 14, and at 25 and 50mg/kg on day 21 (P<0.05-0.01; one-way ANOVA and Bonferroni's post hoc test). The sperm count was decreased on all sampling days except at 5 and 25mg/kg dose-levels on day 70, but with severe oligospermia on days 28 and 35 (P<0.05-0.001). The sperm motility was decreased at 100mg/kg on days 14 and 21, at 5, 25, and 100mg/kg on day 28, and at all dose-levels on day 35 (P<0.05-0.001). Dacarbazine induced both head and tail abnormalities and some sperms with cytoplasmic droplets, but significant increase was seen in all dose groups on days 14 and 21, and at 100mg/kg dose-level on day 35. Drug-induced epithelial sloughing was seen on days 14-35 and other histopathological changes observed were vacuoles and abnormal cells. The STD was increased at 25-100mg/kg on day 7, at all dose-levels on day 14, at 50-100mg/kg on days 21 and 28, but without any effects on days 35-70 (P<0.05-0.001), and the tubular lumen was found dilated. The SE was increased on days 7, 21 and 28 at 100mg/kg and on day 14 at 50-100mg/kg. Dacarbazine reduced the intra-testicular testosterone level at 100mg/kg on day 7, at 5, 50 and 100mg/kg on day 14, at all dose-levels on days 21, 28, and 35, and at 50mg/kg on day 49 (P<0.05-0.001). The intra-testicular lactate dehydrogenase concentration increased at all dose-levels up to day 35, but without any effect on days 49 and 70 (P<0.05-0.001). There was no particular dose-response of dacarbazine on any parameters tested. The sperm count (except on day 7-positive correlation; Pearson product moment correlation) or sperm motility did not have any relation but increase in abnormal sperms showed negative correlation with decrease in testosterone level on days 7, 21 and 28. Decrease in sperm count was in negative correlation on days 14 and 35, and increase in abnormal sperms showed positive correlation on day 35 with increase in LDH level. Finally, the decrease in sperm motility had no correlation with increase in abnormal sperm shapes. We conclude that dacarbazine is genotoxic and cytotoxic to the mouse testis in a transient fashion, and these effects are exerted along with decrease in testosterone and increase in lactate dehydrogenase levels in the testis.     

氯胺酮对小鼠Ⅲ度烧伤死亡率和瘢痕形成的作用

目的观察氯胺酮对小鼠Ⅲ度烧伤死亡率和疤痕形成的作用,为临床应用提供实验依据。方法小鼠背部用95%酒精造成Ⅲ度火焰烧伤,烧伤面积7cm2,烧伤时间30s;氯胺酮用量10～20mg/kg,分别于烧伤后或烧伤前后腹腔注射,对照组注射等量生理盐水,通过烧伤小鼠早期死亡率和烧伤后期瘢痕面积观察其作用。结果 BALB/c和C57BL/6小鼠烧伤后立即、4h、24h腹腔注射氯胺酮20mg/kg,小鼠死亡率分别为42.8%和100%,与对照组无明显差别（P〉0.05）;C57BL/6小鼠烧伤前10min和烧伤后4h、24h注射氯胺酮10mg/kg,小鼠死亡率为100%,与对照组也无差别。烧伤时间减为20s,于烧伤烧伤后立即和24h注射氯胺酮20mg/kg,35d后测定瘢痕面积,治疗组明显小于对照组（P〈0.05）。结论氯胺酮无明显降低小鼠烧伤早期死亡率的效果,但有减少烧伤瘢痕面积的作用,可能与氯胺酮抗炎作用有关。     

Effect of supplementary feeding of vitamin K1 on difethialone treated Indian gerbil, Tatera indica Hardwicke in laboratory

Two dosages (1 and 2 mg/kg) of vitamin K1 supplementation for 5 and 15 days were given to Indian gerbil T. indica fed on difethialone bait (0.0025%) for one day. The results indicated that the lower dosage could not reverse the anticoagulation process, however the period of mortality was considerably increased from 3-9 days (in control) to 5-14 days (5 days supplementation regime). Subsequently when the vitamin K1 dosage was doubled and given for 15 days, there was 100% reversal of anticoagulation process and all the test gerbils became normal within a month of poisoning with difethialone bait.     

Regulation of inflammatory responses to Bordetella pertussis by N(G)-monomethyl-L-arginine in mice intranasally infected

To investigate effect of MMLA, an inhibitor of nitric oxide (NO) production, on regulation of inflammatory responses to Bordetella pertussis infection, mice were infected intranasally, and treated with various concentrations of MMLA. Ten days after infection, mice treated with MMLA at dosage of 100 mg/kg, given intraperitoneally in a single dose or for 5 consecutive days, showed at histopathologic examination, a significant decrease of intensity of inflammation (scores, 0.6 +/- 0.2 and 0.9 +/- 0.5 respectively). A decrease of cellular accumulation of neutrophils and lymphocytes in the bronchoalveolar lavage (BAL) fluid was observed in infected mice treated with MMLA, especially at dosage of 10 mg/kg, given in a single dose intraperitoneally. In addition, BP-infected mice treated with MMLA (100 mg/kg, intraperitoneally) for 5 consecutive days showed higher mortality rate than untreated mice infected with B. pertussis, and the number of B. pertussis in lungs of mice treated with MMLA was significantly increased. However, MMLA treatment of infected mice had some effect on levels of IFN-gamma and nitrite/nitrate (end-stable products of NO) in the BAL fluid. This study indicates that NO may play a role either as microbiocidal agent or as a modulator of immune regulation, inasmuch as it may upregulate tissue inflammatory response to B. pertussis.     

2''-Deoxycoformycin Inhibition of Adenosine Deaminase in Rat Brain: In Vivo and In Vitro Analysis of Specificity, Potency, and Enzyme Recovery

2'-Deoxycoformycin (DCF), a potent inhibitor of adenosine deaminase (ADA), is increasingly used as a tool to investigate adenosine metabolism and neuromodulation. To advance further the usefulness of DCF for studies of purines in the CNS, we determined the inhibitory potency of this compound against ADA and adenylate deaminase (AMPDA) in brain, the rate of ADA recovery in various brain regions after single or repeated intraperitoneal DCF administrations, and the effect of DCF on several neurotransmitter synthetic enzymes. In vitro, the Ki values for inhibition of ADA and AMPDA were found to be 23 pM and 233 microM, respectively. In vivo, DCF inhibited ADA with ED50 values ranging from 155 to 280 micrograms/kg at 2 h posttreatment, and 98% inhibition was achieved with 1 mg/kg. AMPDA activity was not affected by doses up to 5.0 mg/kg. In contrast to the greater than 95% inhibition of ADA seen 1 day after DCF at 5 mg/kg, the effectiveness of a second similar DCF treatment on the activity that had recovered by 14 days was dramatically reduced. Eight days after DCF treatment with doses of 5-50 mg/kg, the degree of ADA activity recovery in 10 brain regions examined was similar; it averaged 35% of control values at the low dose but showed some heterogeneity, ranging from 15 to 54% of control values, at the higher doses. Forty days after treatment with a single dose of 5 mg/kg, ADA activity recovered by 68-78% of control values in brain regions with normally high levels of activity and by 44-59% of control values in other regions. The activities of choline acetyltransferase, glutamic acid decarboxylase, and histidine decarboxylase (an enzyme colocalized with ADA in hypothalamic neurons) were unaffected by DCF treatment, a result suggesting the lack of a generalized neurotoxic effect. The very low doses of DCF required for ADA inhibition in vivo are consistent with the high potency of this drug against ADA in vitro, and any physiological effects observed at low doses might therefore be ascribed to inhibition of ADA.     

Effect of parenterally injected benzimidazole compounds on Echinococcus multilocularis and Taenia crassiceps metacestodes in laboratory animals.

In mice infected with metacestodes of Taenia crassiceps, the following compounds were at least partially effective when injected intraperitoneally at the dosage indicated: cambendazole (500 mg/kg), mebendazole (6.25 mg/kg), oxibendazole (500 mg/kg), 5-benzamido-2(4-thiazolyl)benzimidazole (500 mg/kg), 2-carboethoxyamino benzimidazole (125 mg/kg), and 2-carbomethoxyamino benzimidazole (500 mg/kg). The following were inactive at the dosage indicated: parbendazole (500 mg/kg), thiabendazole (1,000 mg/kg), and fenbendazole (1,000 mg/kg). Mebendazole, which showed some activity at 6.25 mg/kg, was highly active as a single intraperitoneal dose at 25 mg/kg. When injected subcutaneously, mebendazole was much less active than when given intraperitoneally. In mice infected with metacestodes of Echinococcus multilocularis, intraperitoneal injection of mebendazole at 75 to 150 mg/kg, daily for 3 days, was highly effective (95 to 100% reduction in cyst mass). In contrast, oral administration at 1,000 mg/kg, daily for 3 days, was only partially effective. The drug was also effective when given intraperitoneally to infected cotton rats. A water-soluble benzimidazole, carboxymethyleneamino cambendazole, was approximately 50% effective in mice when injected daily for 3 days at a dosage of 75 or 150 mg/kg. The results suggest that, in metacestode infections of medical importance, it may be possible to kill the parasite by delivering a drug to its immediate vicinity, and so to reduce the required dosage with respect to the host.