除草剂乙草胺、异丙甲草胺的光降解及其致突变性

对两种常见的酰胺类除草剂乙草胺、异丙甲草胺的光降解进行了研究,采用Ames试验方法对母体及其光降解产物的致突变性进行了检验．结果表明,初始ｐＨ值的变化对这两种除草剂的光降解速率无明显影响,异丙甲草胺比乙草胺更易于发生光降解．乙草胺在光降解前后均表现出无致突变性;异丙甲草胺本身具有致突变性,在光降解过程中未表现出有其它致突变性物质产生．     

应用四膜虫刺泡发射评价加氯水体中有机浓集物的致突变性

应用致突变阴性、阳性对照（Cu^2＋,丝裂霉素MMC和环磷酰胺CP）评价四膜虫刺泡发射试验方法的可行性,并应用该方法检测养殖水体加氯消毒后的有机浓集物对四膜虫刺泡发射的影响效应．结果表明,水体加氯后的有机浓集物可引起四膜虫刺泡发射,且各处理浓度与刺池发射率呈良好的相关性,表明这些有机物中含有致突变性物质．     

广州市不同粒径大气颗粒物有机提取物的致突变性研究

为了了解广州市大气气溶胶中不同粒径颗粒物中有机物的污染水平以及其对人体健康的影响 ,用 6段分级采样器分段采集 相似文献   

18种国产香烟致突变性比较检测研究

使用蚕豆根尖细胞微核试验技术研究了18种国产香烟烟雾水溶物的致突变性,结果表明上述每种香烟均有明显的致突变性,其中淮海牌香烟致突变性最强,茶花牌香烟致突变性最弱。提示蚕豆根尖细胞微核技术可以用于香烟致突变性检测。同种香烟有滤嘴组和去除滤嘴组对比检测结果表明,过滤嘴可以减轻香烟的致突变性。     

电厂燃煤锅炉排放烟尘粒径和多环芳烃的分布及致突变特性

本文研究电厂UG-35/39-M型工业锅炉分别燃烧原煤和型煤时排放烟尘的径和多环芳烃的分布及其直接致突变特性.按粒径的大小将烟尘分成降尘、飘尘和烟气三部分收集,结果表明,多环芳烃主要分布在飘尘和烟气中,其中飘尘内集中了大部分高环的多环芳烃,烟气内集中了大部分低环的多环芳烃;飘尘和烟气的Ames试验致突变性之和比降尘高5—6倍,锅炉燃烧型煤排放烟尘的总量比烧原煤低50—60％,而且直接致突变性也比较低,由此看来,型煤燃烧技术是目前防治煤烟型大气污染的一种重要方法。     

An overview of short‐term tests for the mutagenic and carcinogenic potential of pesticides

Abstract

In the last few years, marked progress has been made in the development of methods for evaluating the mutagenic and carcinogenic potential of pesticide chemicals. The correlation of genetic and related biological activity in short‐term tests with carcinogenic activity in whole animals allows the utilization of short‐term mutagenicity bioassays to prescreen chemicals for effects related to mutation induction and presumptive carcinogenicity. In addition, bioassays now available can measure directly the chemical transformation of normal cells in culture into cells capable of producing tumors when injected into animals.

This paper will review briefly the major types of relevant short‐term tests and will develop a rationale for a phased approach to the evaluation of the mutagenic and carcinogenic potential of environmental chemicals. This approach involves the sequential application of bioassays which are organized into a three‐level matrix emphasizing first detection, then confirmation, and finally hazard assessment. Chemicals demonstrating positive results in the short‐term detection systems and confirmatory bioassays are pursued in higher level whole animal tests. A core battery of tests is proposed to operationally define a negative result. The phased approach should facilitate a cost effective utilization of limited testing resources and provide protection for human health in proportion to the anticipated hazard.

Results obtained in evaluating a series of thirty‐eight pesticide chemicals according to the phased approach are discussed in detail.     

Genotoxic fungicide methyl thiophanate as an oxidative stressor inducing 8-oxo-7,8-dihydro-2′ -deoxyguanosine adducts in DNA and mutagenesis

Dimethyl 4,4′ -(O-phenylene)bis(3-thioallophanate), commonly known as methyl thiophanate (MT), is a systemic fungicide and suspected carcinogen to humans. In this study, the oxidative potential of this category-III acute toxicant has been ascertained based on its capacity of inducing reactive oxygen species (ROS) and promutagenic 8-oxo-7,8-dihydro-2′ -deoxyguanosine (8-oxodG) adducts in DNA. The discernible MT dose-dependent reduction in fluorescence intensity of a cationic dye rhodamine (Rh-123) in human lymphocytes and increased fluorescence intensity of 2′,7′-Dichlorodihydro fluorescein diacetate (DCFH-DA) treated cells signifies decreased mitochondrial membrane potential (Δ Ψ m) due to intracellular ROS generation. The ³²P-post-labeling assay demonstrated the MT-induced 8-oxodG adduct formation in calf thymus DNA. Thus, it is concluded that MT, as a potent oxidative stressor, produces ROS leading to mitochondrial dysfunction, oxidative DNA damage and mutagenesis.     

鲁奇低温煤焦油的致突变性及致突变性组分的鉴定

煤焦油样品经提取分离为酸性、碱性和中性组分,后两组分再经硅胶柱制备色谱分作B_1—B_33个级分和N_1—N_66个级分.Ames试验表明,B_2级分致突变活性最高.该级分经HPLC进一步分级表明,其中d、f级分具较高的致突变性经HRGC、HRGC-MS分析,分别从d级分鉴定出苯并喹啉等60多种氮杂多环芳烃,f级分鉴定出氮杂苯并芴等40多种氮杂多环芳烃.     

二氧化氯和液氯消毒饮用水致突变性的比较

本文运用国内外广泛应用的Ａｍｅｓ试验,对二氧化氯与液氯消毒水样进行了致突变性的比较,结果表明,ＣｌＯ２消毒的水样未显示出致突变性,而液氯消毒的水样显示致突变性的研究结果为ＣｌＯ２在饮用水消毒中的应用提供了科学的依据。     

Evaluation of the antimutagenic and antiradical potentials of extracts from the tubers of (Tunisian) Cyperus rotundus

The mutagenic potential of aqueous, total oligomers flavonoids (TOF), ethyl acetate and methanol extracts from tubers of Cyperus rotundus L. was assessed using Ames Salmonella tester strains TA98 and TA100, and SOS chromotest strain Escherichia coli PQ37 with and without metabolic activation (S9). None of the different extracts produced a mutagenic effect. Likewise, the antimutagenicity of the same extracts was tested using the “Ames test” and the “SOS chromotest”. Our results showed that C. rotundus extracts possess antimutagenic effects against S. typhimurium TA98 and TA100 strains towards the mutagen aflatoxin B1 (AFB1), similar to E. coli PQ37 strain against AFB1 and Nifuroxazide mutagens using the SOS chromotest assay. A free radical scavenging test was used in order to explore the antioxidant capacity of the extracts obtained from the tubers of C. rotundus. TOF, ethyl acetate and methanol extracts showed an important free radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazine (DPPH) free radical. These extracts showed an IC50 value of respectively 5, 20 and 65?µg?mL^?1. The beneficial effects of TOF, ethyl acetate and methanol extracts of C. rotundus were assessed by antioxidant and antimutagenic activities.