连续肌注恩诺沙星对中华草龟的急性和慢性毒理研究

为研究恩诺沙星对人工养殖中华草龟Chinemys reevesiis的药物毒性影响,在急性毒性试验中,将60只体质量约20 g的中华草龟随机分为6组,分别注射剂量为649.9、484.1、360.5、268.5、200.0、0(对照)mg/kg(体质量)的恩诺沙星,在慢性毒性试验中,将16只体质量约为100 g的中华草龟随机分为4组,分别注射剂量为0(对照)、10、30、50 mg/kg(体质量)的恩诺沙星,连续注射30 d,停药30 d,并在第0、2、13、28、40、50、60 d各抽取0.4 m L血液进行生化检测。结果表明:急性毒性试验中,观察两周后用Bliss法计算出半数致死浓度(LD50)为434.45 mg/kg,对死亡龟进行组织学检查显示,龟肝组织的肝细胞索结构混乱,有较严重淤血,大量嗜酸性粒细胞浸润,胃肠壁有水肿;慢性毒性试验中,注射过程中高剂量组(50 mg/kg)3只龟死亡,中剂量组(30 mg/kg)1只龟死亡,龟血清谷草转氨酶(AST)活性随时间呈先上升后下降的趋势,中剂量组显著高于低剂量组(10 mg/kg)和对照组(P0.05),在停止注射后,中、高剂量组总胆红素(T-bil)含量均迅速上升,剖检和组织学检查可见高剂量组肝脏密度减小,肝组织出现大小不一的空泡变性,肝小叶和肝细胞索无法辨识,肺组织结构混乱,胃肠道内有黄色黏稠液体,胃肠壁变薄、水肿,而肾组织无严重病变,注射部位肌肉出现较严重的水肿和炎症。研究表明,连续肌注恩诺沙星对中华草龟具有明显的肝毒性,且对肺、胃、肠道和肌肉组织也有一定的毒性,无肾毒性。     

噻嗪酮对稻纵卷叶螟F1代生存的影响

噻嗪酮对稻纵卷叶螟Ｆ_１代生存的影响陈忠孝，胡国文，凌逸军（中国水稻研究所，杭州３１０００６；江苏农学院，扬州２２５００１）ＥｆｆｅｃｔｏｆＢｕｐｒｏｆｅｚｉｎｏｎＦ_１ＧｅｎｅｒａｔｉｏｎＳｕｒｖｉｖａｌｏｆＲｉｃｅＬｅａｆ－ｆｏｌｄｅｒ￥ＣＨＥＮＺ...     

Incidence of prolonged prothrombin time in dogs following gastrointestinal decontamination for acute anticoagulant rodenticide ingestion

Objective: To determine the effect of gastrointestinal (GI) decontamination on the incidence of prolonged prothrombin time (PT) in dogs after anticoagulant rodenticide ingestion. Design: Retrospective study. Setting: Urban emergency room. Animals: One hundred and fifty‐one client‐owned dogs. Measurements: Dogs presented to the emergency room within 6 hours of ingestion of an anticoagulant rodenticide and had a PT measured within 2–6 days of toxicant ingestion before initiating vitamin K therapy were included. Dogs were categorized as treated or untreated based on the institution of vitamin K therapy following PT testing. The signalment, body weight, type of rodenticide ingested, time elapsed between ingestion and initial presentation, method(s) of GI decontamination, and the times elapsed between both toxicant ingestion and initial hospital presentation until determination of PT were recorded. The PT results were recorded as well as any treatment received following the recheck examination. Any reported incidents of bleeding or untoward effects between exposure and reexamination were recorded. Main results: Of 151 dogs, only 11 dogs (8.3%) developed prolonged PT requiring vitamin K supplementation. None of the 11 dogs with prolonged PTs exhibited signs of bleeding or required transfusion therapy. No differences in age, weight, or time elapsed between treated and untreated patients were found. Conclusions: The incidence of prolonged PT is low in dogs receiving GI decontamination within 6 hours of anticoagulant rodenticide ingestion. Delaying vitamin K therapy until a PT has been assessed 48–72 hours after initial exposure appears to be safe and sensitive in dogs following anticoagulant rodenticide ingestion.     

Prospective determination of the specificity of a commercial snake venom detection kit in urine samples from dogs and cats

Objective To determine the specificity of a snake venom detection kit in urine samples from dogs and cats presenting to a referral centre for diseases unrelated to snake envenomation. Design Urine was collected from 50 dog and 25 cats presented for investigation and treatment of diseases unrelated to snake envenomation. Urine was collected as a voided sample, by cystocentesis or by catheterisation, and routine urinanalysis was performed. Snake venom testing was performed within 2 h of collection using a commercially available snake venom detection kit, which was observed continuously during the 10-min colour reaction phase for evidence of a visible colour indicating a positive test. Results No false-positive reactions occurred in any sample analysed. Conclusion The snake venom detection kit appears to have 100% specificity for using urine as a test sample.     

氯胺磷对油茶尺蠖AChE活力的影响及对桃蚜的毒力

于广东省中山市南葫镇翠亨村木荷上采集油茶尺蠖5龄幼虫,参照Ellman et al.(1961)的方法测定高浓度(20倍液)氯胺磷处理后油荼尺蠖乙酰胆碱酯酶的活性,结果显示,20倍稀释液氯胺磷对油荼尺蠖乙酰胆碱酯酶活性的抑制率为9.09％.于鸡屎藤叶背面和藤上采集桃蚜,配制80倍、160倍、240倍、320倍、400倍氯胺磷稀释液,在实验室用喷雾法测定氯胺磷对桃蚜的毒力,结果表明:随着氯胺磷浓度的增加,其防治效果越好,稀释80倍的氯胺磷溶液在24h内桃蚜死亡率达90％.