拟除虫菊酯杀虫剂的毒性和健康危害研究进展

在现今世界范围内，拟除虫菊酯杀虫剂已被广泛应用于防治农业病虫害以及用作室内杀虫剂，因此对人类日常生活产生重要影响。拟除虫菊酯杀虫剂的急性毒性研究已经有较多成果和进展，但对其长期慢性影响至今仍缺乏明确论证。此综述从PubMed、EBSCO和中国知网等数据库收集了国内外已发表的、有关拟除虫菊酯杀虫剂的动物实验、人群调查和实验室检验的长期、慢性影响的典型研究论文，并从中筛选出拟除虫菊酯杀虫剂的神经毒性、生殖发育毒性、免疫毒性与肿瘤研究等方面的研究进展，综述长期接触拟除虫菊酯杀虫剂可能对人体产生的神经、生殖及免疫系统方面的危害，为进一步研究和开发无害化农药杀虫剂提供参考思路。  

纳米与微米尺度氧化锌体外遗传毒作用特征的比较研究

为揭示纳米氧化锌(ZnO)遗传毒作用特征,以便为纳米材料的安全性评价提供科学依据,利用胞质分裂阻滞微核细胞组学实验和碱性彗星实验比较了纳米和微米尺度ZnO的遗传毒性。结果显示:①微米尺度ZnO在0.02～2.5μg·mL-1剂量下对微核、核质桥、核芽和核分裂指数(nucleus divided index,NDI)均无显著诱导作用(P>0.05);而纳米尺度ZnO在>0.5μg·mL-1剂量时可显著诱导细胞产生总微核、Ⅰ型微核和核芽(P<0.05),且均存在一定的剂量-效应关系,剂量为2.5μg·mL-1时,细胞的Ⅱ型微核数、核质桥数和NDI与对照组相比,也呈现出显著差异(P<0.05)。②剂量为2.5μg·mL-1时,处理9、18和24h后,与对照组相比,微米ZnO处理组中细胞各项指标的差异均无统计学意义(P>0.05),而纳米ZnO处理组中总微核数、Ⅰ型微核数和核质桥数具有时间-效应关系。③纳米ZnO在0.5μg·mL-1剂量时可诱导DNA损伤,而微米ZnO在2.5μg·mL-1剂量时才产生损伤效应。研究表明,纳米和微米尺度ZnO在遗传毒作用性质和毒性强弱方面均存在明显差异,纳米ZnO会诱导Ⅰ型、Ⅱ型微核、核芽和核质桥的产生以及DNA损伤,而微米ZnO仅在高剂量时会诱导DNA损伤。  

镧、铈、钕对小鼠肝细胞核的氧化损伤作用

轻稀土元素进入生物体后主要累积于肝脏,进入肝细胞,分布于细胞核上。为探讨轻稀土元素对小鼠肝细胞核的氧化损伤作用,选用5周龄雄性封闭群(ICR)小鼠灌喂10、20和40 mg.kg-1的稀土元素镧(La)、铈(Ce)和钕(Nd),6周后测定小鼠肝细胞核中超氧化物岐化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPx)的活性,并测定谷胱甘肽(GSH)和丙二醛(MDA)的含量。将实验数据进行ANOVA分析,结果显示,与对照组相比,各染毒组GPx活性和MDA含量显著升高(p<0.05);除Ce低剂量组外,各染毒组SOD和CAT活性显著降低(p<0.05),且其活性的降低与各稀土元素的暴露剂量有剂量-效应关系;除La低剂量组和Ce低、中剂量组外,各染毒组GSH含量显著升高(p<0.05)。结果表明,稀土元素La、Ce和Nd会造成小鼠肝细胞核的氧化损伤。  

Toxicity of the nerve agent tabun to Daphnia magna, a new experimental species in military toxicology

Daphnia magna, a freshwater microcrustacean, is currently tested as an alternative experimental species in research dealing with nerve agents poisonings treatment. Because of this, the toxicity of the nerve agent tabun (a cyanide-group containing organophosphate) to Daphnia had to be examined by estimating the EC₅₀ values. The immobilization of daphnids was chosen as the end-point. It was found that D. magna is sensitive to small amounts of tabun, even after 15 min exposure, and tabun toxicity increases with time. The estimated EC₅₀ values for 15, 30, 45, and 60 min exposure were as follows: 67.39, 38.10, 26.95, and 21.9 μg l^-1. In addition, the toxicity of media to which tabun was added 24 h before the start of experiments was examined. The results obtained indicate that daphnids can be used in experiments with nerve-agent intoxication treatment.  

Temporal changes in the fluoride levels of jaws of European deer in industrial regions of Western Pomerania,Poland

The factories processing natural phosphates and apatites in Poland release into the atmosphere considerable amounts of fluorine compounds. Fluoride is known to accumulate in the hard tissues of animals and humans. This paper describes the determination of fluoride in mandibles of deer in the years 1982 and 1990. In recent years, the establishments have restricted their output and modernized the technology of phosphate fertilizer production. The fluoride content in jaws has decreased, particularly in those animals having their habitat in the vicinity of the two factories.  

Biochemical evaluation of multiple herbal treatments in alloxan-induced diabetes in Wistar rats

Alloxan-induced diabetic rats were treated with multiple herbal preparation besides a control group receiving distilled water. The levels of glucose and alkaline phosphatase (ALP) increased abnormally in the alloxan treated group and the same were normalized upon treatment with the herbal preparation. The levels of blood urea nitrogen (BUN), alanine aminotransferase (ALT), protein and albumin in all groups remained unaltered. However, weekly body weight gain which got significantly altered in the alloxan-treated group was normalized by treatment with the herbal preparation. On the whole, a profound hypoglycemic effect was observed by the multiple herbal treatment in the diabetic rats.  

Retarding fluoride accumulation in Amaranthes viridis through liming and implications of phosphorous treatment

With an objective to retard fluoride being taken up by the plants from soil, a study was carried out on Amaranthes viridis. Four groups of treatment were carried out vis-à-vis fluoride alone, fluoride and calcium, fluoride and phosphorous and fluoride, calcium and phosphorous together at three different concentration levels vis-à-vis 1, 10 and 25 mg/kg soil of each. Sampling was carried out first on day 45 and at the end of reproductive phase on leaf and seed for accumulation of fluoride in the plants. It was observed that fluoride accumulation in plants could be averted through soil amendment by calcium treatment in the form of calcium carbonate thereby reducing the risk of human and livestock exposure to abnormal levels of fluoride through food chain other than protecting plants from getting affected. At the same time, fertilizing the soil contaminated with fluoride by superphosphate would aggravate fluoride accumulation and exacerbate fluorosis problem in human and livestock through food chain. Therefore it is recommended to use acid water-soluble orthophosphate or anhydrous dicalcium phosphate or soluble pyrophosphate fertilizers as an alternative.  

理论毒理学研究进展

毒理学是近代发展起来的科学,由于工农业生产的迅速发展,化学物质剧增,迄今登记在册的化学物质已超过2 600万种,每年还新增2 000多种,因此传统的毒性鉴定已远远不能满足时代的要求,针对各种化学物质的细致的毒理学研究更是难以实现.因此毒理学必须在理论层面实现突破,缩短研究时间,减少研究经费及人力、物力的消耗,同时可使化学物质得到更安全的应用.另外,动物保护已列入议事日程,不再允许大量使用动物做毒理方面的实验,这些促进了理论毒理学的发展.  

镧、铈、钕对小鼠肝细胞线粒体的氧化损伤作用

轻稀土元素进入生物体后主要累积于肝脏,进入肝细胞,除蓄积在细胞核中,还存在于线粒体中。为探讨轻稀土元素对小鼠肝细胞线粒体的氧化损伤作用,选用5周龄雄性ICR小鼠分别以10、20和40mg·kg~(-1)的镧(La)、铈(Ce)和钕(Nd)灌胃,6周后测定小鼠肝细胞线粒体中超氧化物岐化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)的活性,以及谷胱甘肽(GSH)和丙二醛(MDA)的含量。结果显示,与对照组相比,La中剂量组和Ce低剂量组SOD活性显著升高,La高剂量组和Nd中、高剂量组中SOD活性显著降低(P<0.05,P<0.01);除个别剂量组外,各染毒组CAT和GPx活性与GSH含量显著降低(P<0.05,P<0.01);Nd各剂量组、La高剂量组和Ce高剂量组的MDA含量显著升高(P<0.05,P<0.01)。研究表明,La、Ce和Nd所导致的CAT和GPx活性以及GSH含量降低可能是造成肝细胞线粒体氧化损伤的主要原因。