酚类化合物对小白鼠脾脏细胞DNA毒性的构效相关研究

应用彗星实验技术,测定了12种酚类化合物对小白鼠脾脏细胞DNA的损伤水平.应用Hansch法和量子化学MOPAC-PM3方法计算了12种酚类化合物的辛醇-水分配系数、分子折射率、分子最高占据轨道能和分子中最正原子电荷.运用SPSS统计软件进行回归分析,对小白鼠脾脏细胞DNA的损伤率进行了定量结构-活性相关研究(QSAR).结果表明,酚类化合物的亲脂性参数和分子折射率能有效地表征它们所引起的DNA的损伤程度.由化合物的电性效应引起的细胞毒性可忽略.     

可吸入颗粒物生物活性及其微观特征分析

采用质粒DNA评价法研究了2004年春季北京市区和郊区上甸子(本底区)PM₁₀的生物活性.结果表明,郊区上甸子2个PM₁₀的TD20值(引起20%质粒DNA损伤所需要的颗粒物剂量)分别为53μg·mL^-1和<50μg·mL^-1,市区2个PM₁₀的TD20值分别为125μg·mL^-1和100μg·mL^-1,说明郊区PM₁₀的生物活性明显高于市区.同时利用高分辨率场发射扫描电镜(FESEM)和图像分析技术,从PM₁₀微观特征上进行了生物活性差异的原因分析,认为其原因有:①上甸子PM₁₀中以细颗粒物为主,在0～0.7μm粒度范围内的细颗粒物的数量百分含量明显高于市区PM₁₀,而表面积则在0～1.0μm的范围内高于市区;②市区PM₁₀中以粒度较大的矿物颗粒物为主,而上甸子PM10则以生物活性较大的烟尘为主,数量百分含量高达58.8%.因此PM₁₀质量浓度并非评价可吸入颗粒物健康效应的唯一指标,颗粒物的粒度分布和类型可能在其生物活性中起重要作用.     

Genotoxicity evaluation and a primary risk assessment of organic pollutants in the drinking water sources of Nanjing, China

An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In this study, the comet assay was conducted to investigate the genotoxicity to human body caused by organic concentrates in the drinking water sources of Nanjing City from Yangtze River of China, and health and ecology risk due to expose to these organic pollutants were evaluated with the multimedia environmental assessment system （MEAS）. For all the water samples, they were collected from four different locations in the drinking water sourcr samples, es of Nanjing City. The results of the comet assay showed that all the organic concentrates from the water samples could induce different levels DNA damages on human peripheral blood lymphocytes, and a statistically significant difference （p〈0.01） was observed compared with the solvent control, which demonstrated the genotoxicity was in existence. According to the ambient severity （AS） of individual compound, we had sorted out the main organic pollutants in the drinking water source of the four waterworks, and the results showed that there was some potential hazard to human body for all the source water, namely the total ambient severity （TAS） of health for each water source was more than 1. However, the TAS of ecology for each water source was less than 1, which indicated that it was safe to ecology. The results of this investigation demonstrate the application of the comet assay and the MEAS in aquatic environmental monitoring studies, and the comet assay found to be fast, sensitive, and suitable for genotoxicity monitoring programs of drinking water source.     

Ecotoxicological Assessment of Sediment, Suspended Matter and Water Samples in the Upper Danube River. A pilot study in search for the causes for the decline of fish catches (12 pp)

Goals, Scope and Background Fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River between Sigmaringen and Ulm, despite intensive and continuous stocking and improvement of water quality since the 1970s. Similar problems have been reported for other rivers, e.g. in Switzerland, Great Britain, the United States and Canada. In order to assess if ecotoxicological effects might be related to the decline in fish catch at the upper Danube River, sediment, suspended matter and waste water samples from sewage treatment plants were collected at selected locations and analyzed in a bioanalytical approach using a battery of bioassays. The results of this pilot study will be used to decide if a comprehensive weight-of-evidence study is needed. Methods Freeze-dried sediments and suspended particulate matters were extracted with acetone in a Soxhlet apparatus. Organic pollutants from sewage water were concentrated using XAD-resins. In order to investigate the ecotoxicological burden, the following bioassays were used: (1) neutral red assay with RTL-W1 cells (cytotoxicity), (2) comet assay with RTLW1 cells (genotoxicity), (3) Arthrobacter globiformis dehydrogenase assay (toxicity to bacteria), (4) yeast estrogen screen assay (endocrine disruption), (5) fish egg assay with the zebrafish (Danio rerio; embryo toxicity) and (6) Ames test with TA98 (mutagenicity). Results and Discussion The results of the in vitro tests elucidated a considerable genotoxic, cytotoxic, mutagenic, bacteriotoxic, embryotoxic and estrogenic burden in the upper Danube River, although with a very inhomogeneous distribution of effects. The samples taken from Riedlingen, for example, induced low embryo toxicity, but the second highest 17β-estradiol equivalent concentration (1.8 ng/L). Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, with clear-cut dose-response relationships for the embryotoxic effects of contaminated sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that – at least for fish eggs – the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The effect observed most frequently in the fish egg assay was a developmental delay. A comparison of our own results with locations along the rivers Rhine and Neckar demonstrated similar or even higher ranges of ecotoxicological burdens in the Danube River. Conclusions The complex pattern of ecotoxicological effects caused by environmental samples from the Danube River, when assessed in an in vitro biotest battery using both acute and more specific endpoints, showed that integration of different endpoints is essential for appropriate hazard assessment. Overall, the ecotoxicological hazard potential shown has indeed to be considered as one potential reason for the decline in fish catches at the upper Danube River. However, based on the results of this pilot study, it is not possible to elucidate that chemically induced alterations are responsible for the fish decline. Recommendations and Perspective . In order to confirm the ecological relevance of the in vitro results for the situation in the field and especially for the decline of the grayling and other fishes, further integrated investigations are required. For linking the weight of evidence obtained by in vitro assays and fish population investigations, the application of additional, more specific biomarkers (e.g. vitellogenin induction, EROD and micronucleus assay) has been initiated in fish taken from the field as well as in situ investigations.     

应用电致化学发光分子探针技术对微小原甲藻的检测

以双特异分子探针技术(NPA-SH)为基础,运用电致化学发光技术(ECL)和磁性微球分选技术对其进行改进,成功建立了用于赤潮藻类定性定量分析的电致化学发光分子探针(ECL-MP)检测新技术.设计微小原甲藻特异性NPA探针并对其进行联吡啶钌和生物素标记,优化磁性微球使用量,在ECL检测装置中启动电化学反应,建立光信号与微小原甲藻细胞数目间的ECL-MP分析曲线并对其进行验证.结果表明,标记后的NPA探针具有一定的特异性和实用性;4μg是检测20μL目标藻杂交混合液的最适磁性微球使用量;在最适条件下,微小原甲藻细胞数的线性分析范围6.25×102～4×104个;比较ECL-MP和显微计数方法的样品检测结果,在95%置信区间内二者无显著差异(t-检验).ECL-MP方法为实现微小原甲藻现场样品的快速准确检测提供了一种新方法.     

人体颊黏膜细胞彗星实验方法学研究

为探索一种简便、直接检测环境诱变物对人体靶细胞遗传毒性的方法,笔者以甲醛作为染毒剂,对人体口腔颊黏膜细胞彗星实验的染毒时间、染毒温度和2种用于检测交联作用的方案进行了研究。结果显示:经7 5μmol L甲醛37℃染毒30和60min后,DNA的断裂程度较染毒15min更大;而经该浓度甲醛在4,23和37℃下染毒30min后均可引起DNA的断裂,但37℃下染毒对DNA的断裂作用更大。在2种应用于检测交联作用的方案中,加大电泳条件的交联检测方案还可检测兼具交联和断裂效应的诱变物。      

单克隆抗体酶免疫分析法测定大米中杀虫脒残留量

用抗杀虫脒单克隆抗体为试剂,建立了间接竞争法,直接竞争法和标记抗原的竞争法等３种测定大米中杀生脒残留量的ＥＬＩＳＡ法,标准曲线上抑制率为５０％时对应的杀虫脒浓度分别为１．３、１．７和５．３ｎｇ／ｍｌ,大米样品用甲醇提到,提取液经吸附剂柱简单净化后即可用上述ＥＬＩＳＡ对痕量杀虫脒进行定量,使用直接竞争法时,样品加标回收率为９０％－１１６％,平行测定的相对标准偏差为５．１％－１６％,方法检出限为０．５     

纳米MnO2与常规MnO2粉末对Hela细胞DNA损伤的对比研究

为探讨纳米MnO2与常规MnO2粉末对细胞DNA损伤作用的差别,采用不同浓度的纳米MnO2与常规MnO2粉末(0、100、200、400μg·mL-1)对Hela细胞进行染毒,应用单细胞凝胶电泳(彗星实验)检测Hela细胞的损伤效应.结果表明,与对照组相比,纳米MnO2和常规MnO2各染毒组细胞尾部DNA百分率(TailDNA%)和尾矩(TailMoment)均显著增加(p<0.01);同一浓度下,纳米MnO2组细胞尾部DNA百分率和尾矩显著高于常规MnO2组(p<0.01).以上结果表明,纳米MnO2和常规MnO2粉末均能导致Hela细胞DNA损伤,且纳米MnO2的损伤作用强于常规MnO2.