海洋低温碱性蛋白酶的遗传毒理学研究

应用NIH纯系小鼠骨髓细胞微核试验和染色体畸变试验,探究海洋低温碱性蛋白酶的遗传毒性作用及对人类的潜在危害。观察并计数嗜多染红细胞（PCE)与正红细胞（NRBC）的比值、微核率;染色体的畸变类型和畸变率,检测海洋低温碱性蛋白酶的诱变作用。结果表明,皮下注射环磷酰胺的小鼠,P／N比值＜1,微核率为22.97‰,染色体畸变率为18.32,与生理盐水（NS）对照组比较差异极显著（P＜0.01),而海洋低温碱性蛋白酶各组小鼠微核率均＜4‰,染色体畸变率为0.19%-0.25%,与NS组比较无显著性差异（P＞0.05）。未见海洋低温碱性蛋白酶各组对小鼠骨髓细胞的遗传毒性。     

Toxic effects of ammonia on the embryonic development of the cuttlefish Sepia pharaonis

The objective of this study was to investigate the effects of ammonia nitrogen on the embryonic development of the cuttlefish Sepia pharaonis . Embryos were exposed to different concentrations (0, 1, 3, and 5 mg/L) of total ammonia–nitrogen (TAN) during incubation. The developmental rate, malformations, mortality, hatching rate, incubation period, yolk utilization efficiency ratio, and weight of the newly hatched cuttlefish were determined. The results showed that ammonia nitrogen significantly inhibited the development of S. pharaonis embryos and induced malformations and even death. Hatching was delayed, the hatching rate was reduced, mortality and the incubation period increased, and the yolk utilization efficiency ratio and weight of the newly hatched cuttlefish significantly decreased in a dose‐dependent manner after the embryos were exposed to more than 1 mg/L TAN for prolonged period. These variables could be used as an integrative biomarker or indicator of aquatic environmental ammonia contamination. In summary, our results indicated that ammonia caused toxicity in the embryos. When the concentration of TAN is greater than 1 mg/L, ammonia levels should be reduced to prevent toxic effects on embryonic development.     

Influence of chlorine substituents on biological activity of chemicals: a review

A number of well known polychlorinated chemicals are toxicologically and environmentally unsafe. Because of their persistence they are in the focus of public discussions against chlorine chemistry. However, chlorinated organic chemicals in the molecular weight range between 200 and 600 constitute an important and indispensable segment in the arsenal of existing biologically active chemicals used as pharmaceuticals or crop‐protection agents. Over the course of time it has been found empirically that the introduction of a chlorine atom into one or more specific positions of a biologically active molecule may substantially improve the intrinsic biological activity. In some cases the presence of a chlorine atom is crucial for significant activity in compounds derived both from nature and chemical synthesis. But in other cases chlorination diminishes or abolishes biological activity, as shown for chlordane homologues. Thus a chlorine atom, like any other substituent, is a modulator of activity. Almost all non‐reactive chlorinated chemicals and chlorine‐free chemicals are devoid of any biological activity at the highest concentration typically used in primary screening tests for discovery of useful biological properties. The influence of a substituent such as chlorine on the biological activity of a potential drug or crop protection agent still has to be established empirically in biological experiments designed to detect desired activity or toxicological properties. Sometimes chlorine does prove to be the optimum for improvement of activity. Long‐term rigorous investigations of several hundred chlorinated compounds, registered by the authorities as pharmaceutical drugs or crop‐protection agents, show that the generalisation ‘all chlorinated chemicals are dangerous’, deduced from the negative toxicological properties of a hundred chlorinated and reactive compounds of low molecular weight that are relevant in terms of safe working conditions in the chemical industry and for ecological safety, is not justified. Chlorinated compounds are not necessarily toxic or dangerous. Highly reactive chemicals or polychlorinated compounds cannot be compared with regard to toxicological properties with unreactive compounds having a low degree of chlorination. The chlorine atom, as one of many possible substituents used in synthetic organic chemistry, will remain in the future one of the important tools for probing structure–activity relationships in life science research and as a molecular component in commercialised compounds, in order to provide safer, more selective and more environmentally compatible products with higher activity for medicine and agriculture. © 1999 WILEY‐VCH Verlag GmbH     

吡唑醚菌酯的降解代谢及毒理研究进展

吡唑醚菌酯是甲氧基丙烯酸酯类新型广谱杀菌剂，主要用于防控农作物上由真菌引起的病害，兼具保护、治疗和叶片渗透传导作用，具有高效、低毒、广谱等特点。吡唑醚菌酯上市至今已有近20年，在全球多种作物上登记使用，使用总量大、应用范围广，在土壤和水生态系统中蓄积污染，对环境和动植物存在较高的潜在风险。本文总结了吡唑醚菌酯的理化性质、作用特点及应用概况，对其在环境中的降解及在动植物体内的代谢、毒理、检测方法、残留限量等进行综述，以期为吡唑醚菌酯的生态环境与健康风险评价、降解代谢机理研究、环境污染修复、残留限量标准制定和科学施用提供参考。     

3种藻类膳食纤维的功能及毒理评价

对马尾藻、江蓠和麒麟菜３种膳食纤维的常规成分和功能性进行分析,并采用小鼠及人体试验,对这３种藻类膳食纤维的某些毒理和生理功能进行了初步研究。结果表明,这３种膳食纤维均属于无毒级,未发现致突变作用,食用安全,对便秘患者具有良好疗效,但效果不同,以麒麟菜膳食纤维的效果最好。     

新型吡唑酰胺类农药吡噻菌胺的研究进展

为阐明新型吡唑酰胺类杀菌剂吡噻菌胺的生态暴露风险与环境行为归趋,本文从合成路径、生物活性、生态毒理、分析方法和环境行为五方面进行分析总结,并对其应用前景进行展望。指出吡噻菌胺对真菌孢子萌发抑制作用显著,防治效果优于治疗效果;吡噻菌胺对水生生物具有较高的生态毒性,且对细胞活力及氧化应激具有显著的对映体选择性差异。建议后续深入开展不同环境下吡噻菌胺的行为特征及其水生生态毒理学研究,特别是对映体选择性的分子机制,探索高效低风险的手性对映体,建立科学精准的风险评估体系,降低其对水生生物安全和人类生殖健康的高潜在暴露风险。     

计算毒理学在农药毒性预测、活性筛查及风险评估中的应用

农药在农业病虫草害的防控中起着重要作用, 但农药应用后其母体和转化产物在农产品和水体、土壤、空气等环境中的残留存在一定的生物活性或毒性风险。传统的农药活性和毒性的评估手段不仅耗时、耗力、耗成本, 且违背实验动物“3R”原则, 也难以快速准确预测种类繁多且不断增加的农药化学品对人体和生态健康的风险。计算毒理学为农药化合物的毒性预测、活性筛查及风险评估提供了新的研究手段。本文主要介绍计算毒理学的发展及其在农药毒性预测、活性筛查及风险评估中的应用现状, 以期为新时代背景下农药对人类健康及环境安全的风险评估提供新思路。该领域的研究对指导农药的安全生产、科学使用管理具有重要意义, 对生态系统的保护具有重要参考价值。