Herbicide safety relative to common targets in plants and mammals

Most modern herbicides have low mammalian toxicity. One of the reasons for this safety is that the target site for the herbicides is not often present in mammals. There are approximately 20 mechanisms of action that have been elucidated for herbicides. Of these, some do share common target sites with mammals. The mechanisms include formation of free radicals, protoporphyrinogen oxidase (PROTOX), glutamine synthetase (GS) and 4-hydroxyphenylpyruvate dioxygenase (HPPD). PROTOX, HPPD and GS inhibitors have been shown to inhibit these enzymes in both plants and mammals and there are measurable effects in mammalian systems. However, the consequences of inhibiting a common target site in plants can be quite different than in animals. What may be a lethal event in plants, eg inhibition of HPPD, can have a beneficial effect in mammals, eg treatment for tyrosinemia type I. These chemicals also have low mammalian toxicity due to rapid metabolism and/or excretion of the herbicide from mammalian systems.     

二氟沙星的研究概况

从结构、制剂、毒理学、药代动力学、药效学、残留与耐药性等方面综述了二氟沙星的研究概况.二氟沙星是畜禽专用的氟喹诺酮类药物,具有良好的理化性能,已开发出注射液和口服液,具有氟喹诺酮类药物类似的毒理学结果,对幼年动物的骨骼有严重影响;口服吸收迅速,组织分布广;对畜禽细菌性疾病和支原体病均有良好的疗效.     

Creatinine concentration in plasma from dog, rat, and mouse: a comparison of 3 different methods

BACKGROUND: There are numerous methods for analyzing creatinine concentration in plasma, including the Jaffé alkaline picrate method in various modifications, enzymatic tests, and chromatographic methods. OBJECTIVE: The purpose of this study was to evaluate whether an enzymatic method could replace a Jaffé method for routine creatinine measurements in plasma from dogs, rats, and mice. The enzymatic method and a compensated Jaffé method were tested against a high-pressure liquid chromatography (HPLC) method, regarded as the gold standard for creatinine measurement. METHODS: Heparinized plasma samples were obtained from 20 beagle dogs, 20 Wistar rats, and 20 CD1-strain mice. The 2 test kits (Roche Diagnostics), Creatinine Jaffé Compensated and the enzymatic Creatinine Plus Version 2 reagent, were used on a Cobas Integra 400. The Jaffé compensated method used a calibration adjustment of 18 micromol/L to correct for the protein matrix in serum and plasma. The HPLC method was an isocratic method using a weak cation-exchange column following protein precipitation. RESULTS: Creatinine concentrations obtained using the enzymatic and the Jaffé methods differed significantly from the results obtained by the HPLC method. For dog plasma, mean values of 61.2, 61.8, and 67.8 micromol/L were obtained by the compensated Jaffé, enzymatic and HPLC methods, respectively. In the rat, respective mean values were 26.7, 21.9, and 23.0 micromol/L, and in the mouse, respective mean values were 14.2, 5.4, and 9.2 micromol/L. CONCLUSION: The enzymatic method can replace the Jaffé method for plasma creatinine determination in dogs, rats, and mice because results from the enzymatic method were closer to HPLC values than were those of the Jaffé method.     

三聚氰胺毒理学及检测方法的研究

三聚氰胺是一种重要的有机化工原料,由于其含氮量高达60%以上,近年来不法商人将其加入饲料和食品中。为了提高人们对三聚氰胺危害的认识,本文综述了三聚氰胺的理化性质、代谢、毒性;同时对饲料中三聚氰胺含量的检测方法进行了综述。     

生物芯片技术在药理学和毒理学研究中的应用

生物芯片技术是随着人类基因组计划的进展而发展起来的,具有广泛应用前景的先进技术。生物芯片包括基因芯片、蛋白质芯片、细胞芯片等等。它可以大规模、高通量地对成千上万基因进行同时研究,具有高通量、快速、简便、自动化等优点。生物芯片技术克服了传统生物学技术操作繁杂、自动化程度低,检测效率低等不足。尤其对大规模药物筛选、药物毒性的评价、指导临床用药等提供前所未有的好处。笔者主要讨论生物芯片技术、类型特点及其在药理学和毒理学研究中的应用。     

氟苯尼考对杂色鲍的急性毒性及组织毒理学

研究了氟苯尼考(florfen icol)对杂色鲍Haliotis diversicolorReeve稚鲍96 h的急性毒性,其LC50为(162.67±17.41)mg/L(95%置信限)。稚鲍中毒后的临床症状为:分泌大量黏液,附着力明显减弱,内脏团膨大,对外界刺激反应迟钝,呈麻痹状。组织切片观察结果表明:鲍消化腺和肾脏损伤严重,其它器官未见明显病变;随着浸浴时间和药物浓度的增加,消化腺中消化细胞空泡化,并与嗜碱性细胞逐渐从基膜脱落解体,管间结缔组织胶原纤维断裂,呈弥散状广泛坏死;肾腔上皮细胞萎缩,与基膜分离,腔体变小,微绒毛脱落,中毒严重时,肾上皮细胞融合,核解体消失。     

杀虫剂fluralaner及其衍生物的生物效应和毒理学研究进展

新型异唑啉类杀虫剂fluralaner通过干扰γ-氨基丁酸(GABA)门控氯离子通道发挥作用。作为新型高效GABA门控氯离子通道干扰剂,与环戊二烯类、苯基吡唑类和大环内酯类杀虫剂相比,fluralaner在分子结构、作用位点、选择性以及交互抗性等方面均有显著差异。本文综述了fluralaner及其衍生物的研发、毒性、防治范围以及作用机理等,并预测了其应用前景。     

A screening of multiple classes of pharmaceutical compounds for effect on preadult salmon lice Lepeophtheirus salmonis

The salmon louse, Lepeophtheirus salmonis Krøyer, is the major obstacle facing a sustainable future for farmers of salmonids in the North Atlantic Ocean. Medicinal compounds have been the most utilized tool to prevent salmon lice infestation; however, the active compounds have become less effective or considered environmentally unfriendly in the past years. Novel medicinal compounds are thus highly desired. In two experiment series, 26 medicinal compounds were screened for their efficacy against salmon lice, in a 30‐min exposure and 24‐h exposure, respectively. Pyriprole, imidacloprid, cartap and spinetoram were effective at 50 mg L^?1 in the short‐time exposure. In the 24‐h exposure, pyriprole, propoxur, cartap, imidacloprid, fenoxycarb, pyriproxyfen, nitenpyram, spinetoram, spiromesifen and diflubenzuron induced a high level of immobilization at 5 mg L^?1. The EC₅₀ values of the effective compounds were calculated in further titration studies for both exposure periods. Several physiological and biochemical pathways were discovered as possible targets for medicinal intervention against the salmon louse.     

中国大螟研究历史、现状与展望

为了深入研究大螟发生特点、探索其危害规律,提出合理有效的防治手段,有效防控大螟危害,笔者以近50年来中国的大螟研究为基础,综述了大螟生物学、生态学、为害特点、防治技术、人工饲养技术、抗药性和毒理以及预测预报等方面取得的进展,并提出了未来大螟研究的方向。