Mechanism of micronuclei formation in polyploidizated cells of Allium cepa exposed to trifluralin herbicide

The trifluralin is an agent that promotes a cellular damage due to its direct action on the microtubules. This action leads to a decontrol in the cellular division, bringing about polyploid cells. In this work, we show the evidences that the exceeding genetical material of theses polyploidizated cells tends to be eliminated from the nucleus in the form of micronucleus. Our analyses prove this fact, both by the presence of a number of cells carrying micronucleus, and by the evidences of the elimination of the exceeding material itself, after exposition of the Allium cepa root tips tested with several concentration of trifluralin herbicide. It was noticed that the residual concentration induced a number of polyploid cells, micronuclei and mini cells. Inferences about the implications of the elimination of genetic material from micronuclei, such as cell viability and apoptosis, are also presented.     

Evaluation of new metallized direct dyes for mutagenicity using the Salmonella mammalian mutagenicity assay

A series of new metallized direct dyes based on benzidine congeners, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine, were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA100. All of the dyes examined were judged to be non-mutagenic with and without metabolic activation while toxicity was seen in some dyes at high doses. The study also suggested that the standard Salmonella mutagenicity plate-incorporated assay was an excellent method for evaluation of dyes for mutagenicity.     

复方硝基酚钠的小鼠显性致死试验

本文选用Ｂａｌｂ／Ｃ雄性小鼠和昆明系雌性小鼠进行显性致死试验研究鱼虾促生长药物添加剂复方硝基酚钠对雄性生殖细胞的致突变性。设３个复方硝基酚钠剂量组，即以１６０、５３．３和１６ｍｇ／ｋｇ本品给雄性小鼠经口染毒，每日１次，连续５日，同时设空白对照和阳性对照。各组雄鼠与未染毒雌鼠连续交配８周。试验结果为阴性，可初步认为复方硝基酚钠对雄性生殖细胞无致突变性。本文空白对照组的试验结果符合显性致死试验的要求，但母鼠的受孕率在３４．８％～６０．０％之间。选用Ｂａｌｂ／Ｃ雄性小鼠和昆明系雌性小鼠进行显性致死试验尚属首次。     

马波沙星的致突变性和致畸性研究

选用Wistar大鼠和昆明系小鼠对马波沙星的遗传毒性进行研究。试验结果显示，马波沙星在抑菌剂量之下对鼠伤寒沙门氏菌不产生致突变作用；马波沙星不引起小鼠骨髓有微核多染红细胞率增加；马波沙星不引起雄性小鼠生殖细胞染色体畸变而造成的早期胚胎死亡；20mg／kg b．w．和100mg／kg b．w．剂量马波沙星对母鼠的生殖机能和胎鼠的生长发育无明显影响，对胎鼠不产生致畸作用，500mg／kg b．w．剂量马波沙星对胎鼠体长和骨骼发育有一定影响，但不存在剂量反应关系。上述结果表明，马波沙星无明显的致突变性和致畸性。     

Studies on Mutagenicity and Teratogenicity of Sarafloxacin

Wistar rats and closed Kunming strain mice were selected to study the genetic toxicity of sarafloxacin. The results indicated that sarafloxacin had no significant toxic effect of an excreted mutagen in S. typhimurium strains, and did not induce significantly higher percentages of polyehromatic erythrocytes with micronuclei (MNPCE) in mice. No significant mutagenic activity was observed in dominant lethal assay.At 5 and 50mg/kg b.w. , sarafloxacin did not produce significant effects on the reproductive parameters of litters and fetal growth, and did not induce the teratogenic effects on fetuses. Sarafloxacin induced some toxic effects on body length and skeletal growth in fetuses of 500mg/kg b.w., but had no significant dose - response relationship among the administered dosages of sarafloxacin. The results of the genetic toxicology above indicated that no evidence showing sarafloxacin was mutagenic and potentially teratogenic for animals.     

林蛙卵油多不饱和脂肪酸的急性毒性及致突变性研究

[目的]研究林蛙卵油多不饱和脂肪酸的安全性.[方法]通过经口急性毒性试验、骨髓微核试验和精子畸形试验,研究林蛙卵油多不饱和脂肪酸的急性毒性及致突变性.[结果]林蛙卵油多不饱和脂肪酸对小鼠一般状态没有影响,试验过程中未见小鼠死亡及其他毒性表现.林蛙卵油多不饱和脂肪酸的最大耐受剂量大于60 g/kg体重(小鼠,经口).根据急性毒性的分级标准,林蛙卵油PUFAs属于无毒级物质,安全性较高.[结论]该林蛙卵油多不饱和脂肪酸为无毒级物质、无急性毒性和致突变性,且安全性好.     

黑松花粉致突变效应的评价

本文报道了黑松花粉对动物体细胞和生殖细胞致畸变作用，并测定其畸变率．结果表明：黑松花粉无明显致突变效应。     

腐霉素的致突变性研究及其潜在致癌性预测

腐霉素是一种具有抗球虫性能的聚醚类抗生素。本文选择Ａｍｅｓ试验，微核试验和精子畸形试验等三种试验组合来检测腐霉素的致突变性，并在此基础上，用致癌性预测和选择试验组合的方法（ＣＰＢＳ法）预测其潜在致癌性。试验结果表明，腐霉素Ａｍｅｓ试验，微核试验和精子畸形成试验均为阴性；ＣＰＢＳ法预测霉素可能是潜在致癌物的概率为８．５２％，因而被评为非致癌物。     

Copper salts in the post-metallization of non-genotoxic direct dyes

Copper (II) salts are used as metallizing agents in the synthesis of new non-genotoxic direct dyes for cotton. Specifically, cotton fabric is dyed with non-genotoxic disazo direct dyes and then treated with copper salts. The complexes are characterized by neutron activation analysis, absorption spectrometry and standard Salmonella mammalian mutagenicity assay, and the after-treated fabrics are evaluated for lightfastness and washfastness. Direct dyes possessingortho-propoxy andortho’-hydroxy substituted systems formed the corresponding nonmutagenic 1:2 dye:metal complex and undergo significant improvement in lightfastness following metallization.     

Evaluation of new direct dyes for mutagenicity using the salmonella mammalian mutagenicity assay

A series of new direct dyes based on benzidine congeners, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine, were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA100. All of the dyes examined were judged to be non-mutagenic with and without metabolic activation while toxicity was seen in some dyes at high doses. The study also suggested that the standard Salmonella mutagenicity plate-incorporated assay was an excellent method for evaluation of direct dyes for mutagenicity.