水源水雄激素受体干扰效应及在水处理工艺中的变化

我国很多饮用水源水已检测出雌激素受体干扰效应,但是其他效应如雄激素受体干扰效应却罕见报道。为了弥补这方面资料的缺乏,应用雄激素受体双杂交酵母结合S9代谢方法评价了我国6大流域23个水源地水源水以及3个供水厂不同工艺出水样品的雄激素受体干扰效应。结果显示,所有水源水样品浓缩液均没有检测出雄激素受体直接或间接诱导效应,但都观察到了抑制效应,抑制效应以抑制剂氟他胺当量浓度进行表征:直接抑制效应在0.67~3.68μg·L-1之间,间接抑制效应在0.52~3.02μg·L-1之间;长江三角洲和淮河流域水源地的水源水雄激素抑制效应明显高于其他流域;经S9代谢后,有16个水源地的氟他胺当量比代谢前降低。3个饮用水厂处理工艺能够使源水的雄激素受体抑制效应降低19.1%~70.5%。研究表明,我国水源水中普遍含有雄激素受体干扰效应物质,目前水厂常规处理工艺对雄激素受体干扰效应有一定的去除效果,但不能完全去除。雄激素受体双杂交酵母测试能够快速、综合地对水体中的雄激素受体干扰效应进行评价,是饮用水安全评价的重要补充手段。     

Evaluation of environmental stress by comet assay on freshwater snail Lymnea luteola L. exposed to titanium dioxide nanoparticles

The use of aquatic organisms to monitor for contamination is well-established. Therefore, this study was designed to assess the adverse effects of titanium dioxide nanoparticles (TiO₂NP) in freshwater snail Lymnea luteola L. (L. luteola). For TiO₂NPs ecotoxicity tests, snails were exposed for seven days. A dose and time-response relationship was observed for TiO₂NP-induced genotoxicity. Induction of oxidative stress in digestive gland was observed by a decrease in glutathione and gluthathions-S-transferase levels accompanied by elevated malondialdehyde levels at TiO₂NP (9 and 28 µg/mL). Superoxide dismutase activities were markedly reduced at TiO₂NP (9 and 28 µg/mL) at days 1 and 3, but not at day 7. Catalase activities were decreased at days 1 and 3 but increased at higher concentration of TiO₂NP at day 7. DNA fragmentation occurring in L. luteola due to ecotoxic impact TiO₂NP was further substantiated by alkaline single-cell gel electrophoresis assay and expressed in terms of percent tail DNA and olive tail moment. The results indicate that the interaction of these TiO₂NP with snail influences the toxicity, which is mediated by oxidative stress in a dose- and time-dependent manner. The measurement of DNA integrity in L. luteola thus provides an early warning signal of contamination of the aquatic ecosystem by TiO₂NP. Data suggest the freshwater snail L. luteola is a potential biomonitor organism.     

盐酸小檗碱对小鼠脾细胞的DNA损伤和氧化性损伤研究

为了探讨盐酸小檗碱对小鼠的DNA损伤和氧化性损伤。随机选取30只小鼠分成对照组以及7.5,15,30,60与120 mg?kg^-1实验组,处理后,应用小鼠脾细胞进行彗星实验与抗氧化酶实验。测定DNA损伤情况以及超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）活性以及丙二醛（MDA）含量变化。对盐酸小檗碱的DNA损伤与氧化性损伤作用进行比较研究。研究结果表明：彗星实验中,随着盐酸小檗碱浓度的增加,尾部DNA含量、尾长与尾矩均增加,与阴性对照组相比差异有统计学意义（p<0.05或p<0.01）,且呈剂量-效应关系;超氧化物歧化酶(SOD)与过氧化氢酶(CAT)活性随盐酸小檗碱剂量增加逐渐降低,丙二醛(MDA)含量明显下降,过氧化物酶(POD)活性在7.5 mg?kg^-1时上升,而后逐渐下降。在60 mg?kg^-1和120 mg?kg^-1时,有极显著性差异（p<0.01）产生。由此可见,盐酸小檗碱对小鼠脾细胞有一定的损伤作用,能够引起小鼠脾细胞的DNA损伤和氧化性损伤。     

硝基甲苯对小鼠睾丸生殖细胞DNA的损伤作用

为提供硝基甲苯的环境遗传毒理学依据和建立鱼类生殖细胞的培养方法,采用昆明小鼠睾丸支持细胞/生殖细胞共培养法以及彗星实验,研究了2,4-二硝基甲苯(2,4-DNT)、2,6-二硝基甲苯(2,6-DNT)、对硝基甲苯(4-NT)对小鼠睾丸生殖细胞DNA的损伤作用.结果表明,3种受试硝基甲苯化合物均能够诱导小鼠睾丸生殖细胞DNA单链断裂,而且其受损率与剂量对数具有明显的剂量-效应关系.2,4-DNT、2,6-DNT以及4-NT的各个剂量浓度引起细胞DNA损伤的程度,与对照组相比,均具有显着性差异(p<0.01,p<0.05).受试化合物的毒性顺序为2,6-DNT>2,4-DNT>4-NT,DNA的损伤作用二硝基甲苯大于单硝基甲苯.提示在体外条件下,2,4-DNT、2,6-DNT和4-NT具有生殖毒性,可以引起小鼠睾丸生殖细胞DNA损伤.     

TBT染毒导致的大鼠脂质过氧化与DNA损伤

采用连续灌胃的方式对SD大鼠进行三丁基锡(TBT)染毒,剂量为0、0.1、1.0、和10.0 mg·kg-1,分别在暴露的第4d、8d处死动物,取肝脏检测丙二醛(MDA)含量,取外周血检测淋巴细胞DNA损伤.结果表明,TBT暴露第4d时,淋巴细胞尾长和尾相显著升高(p＜0.001),而各浓度组的MDA含量与对照组相比都没有显著性差异;第8d时MDA含量随TBT暴露浓度的升高呈上升的趋势,高浓度组(10.0 mg·kg-1)和对照组相比有显著性差异(p＜0.05),淋巴细胞尾长和尾相在各浓度组与对照组相比都有显著性升高,但高浓度组升高的趋势稍下降.研究结果提示TBT染毒对大鼠有脂质过氧化和DNA损伤作用.     

甲醛致中华卵索线虫DNA损伤作用的研究

为了探讨甲醛致线虫DNA-蛋白质交联(DNA-protein crosslinks,DPC)和DNA断裂(DNA strand breakage,DSB)的作用,以中华卵索线虫(Ovomermis sinensis)为材料,经活体染毒后,采用KCl-SDS沉淀法和单细胞凝胶电泳法来检测液态甲醛染毒后线虫提取细胞中DNA-蛋白质交联物的含量及DNA的断裂效应.KCl-SDS沉淀法的结果表明,低浓度(5、25、125μmol·L-1)的液态甲醛不能引起DNA-蛋白质的交联(p＞0.05),较高浓度(625μmol·L-1)的甲醛可以引起明显的DNA-蛋白质的交联作用(p＜0.05)而单细胞凝胶电泳的结果则显示甲醛在低浓度(5、25μmol·L-1)时可以引起DNA链的断裂(p＜0.01),在较高浓度(125、625μmol·L-1)时可以引起交联作用(p＜0.05).研究结果表明,甲醛在较高浓度时可以导致明显的DNA-蛋白质交联作用,而在小于25μmol·L-1时以DNA断裂作用为主.     

纳米SiO2与常规SiO2颗粒对Hela细胞的细胞毒性作用

为了探讨纳米SiO2和常规SiO2颗粒对Hela细胞的细胞毒性作用,采用不同浓度的纳米SiO2和常规SiO2颗粒(0.05、0.1、0.2、0.4、0.8、1.6μg·μL-1)对Hela细胞进行12h染毒,应用MTT法检测细胞毒性效应.研究发现,较低浓度(≤0.2μg·μL-1)的纳米SiO2和常规SiO2对Hela细胞无明显细胞毒性(p>0.05);较高浓度时,纳米SiO2(≥0.4μg·μL-1)和常规SiO2(≥0.8μg·μL-1)对Hela细胞具有明显细胞毒性作用(p<0.01),并且随浓度增大细胞毒性增强;当浓度≥0.4μg·μL-1时,纳米SiO2的细胞毒性明显高于相同浓度的常规SiO2(p<0.05).以上结果表明,纳米SiO2和常规SiO2颗粒均能对Hela细胞产生细胞毒性,且纳米SiO2的细胞毒性强于常规SiO2;低浓度(≤0.2μg·μL-1)的纳米SiO2和常规SiO2具有很好的生物相容性.     

不同粒径大气颗粒物几种重金属成分分析及其致突变性研究

采集冬季太原市一采样点不同粒径大气颗粒物,经分析,总悬浮颗粒物日均浓度为1.04mg/m~3,严重超标。其中粒径小于7.0μm的占49.6％,小于3.3μm的占33.5％。颗粒物无机提取液中5种金属元素的浓度由高到低依次为Pb、Mn、Cr、Ni和Cd。每一种元素均呈随颗粒物粒径减小浓度增高的趋势。以SOS显色法和小鼠体内骨髓细胞染色体畸变试验检测颗粒物的无机提取液和模拟肺泡液溶出液的遗传毒性,表明小粒径颗粒物遗传毒性较强;小于1.1μm的颗粒物,仅用相当于5m~3或10m~3空气量的样品液,即可诱发SOS反应或致染色体损伤。     

Colloidal gold probe-based immunochromatographic assay for the rapid detection of lead ions in water samples

One-step immunochromatographic assay (ICA) has been developed using colloidal gold-labeled monoclonal antibody probe for the rapid detection of lead ions in water samples. The ICA was based on the theory of competitive reactivity, and the results can be easily judged based on the presence or absence of a red colored test line with visual detection. Under optimal conditions, this method shows high detecting sensitivity with a LOD (limit of detection) of 50 ng/ml. Stability test indicates that the immunochromatographic strips are stable for 8 weeks at room temperature. During practical application, nanometer TiO₂ is used to enrich the lead ions in water samples. The ICA is successfully applied in the measurement of lead ion concentrations in local water samples, and the results are highly consistent with that of ICP-MS. Detecting lead ions with ICA can be done within 4 min and is very useful for the rapid onsite testing.     

A protocol for the evaluation of genotoxicity in bile of carp (Cyprinus carpio) exposed to lake water treated with different disinfectants

A sensitive and rapid method to evaluate toxic and genotoxic properties of drinking water supplied from Lake Trasimeno (Umbria, Central Italy) was worked out analysing bile in Cyprinus carpio exposed for 20 d to lake water treated with 3 different disinfectants, sodium hypochlorite (NaClO), chlorine dioxide (ClO₂) and peracetic acid (PAA). Fish were sacrificed at 0, 10 and 20 d in order to investigate the time course of these endpoints. An aliquot of bile samples was fractionated by adsorption on C₁₈ silica cartridges and the genotoxic potential of whole bile and of bile fractions was evaluated by the single-cell microgel-electrophoresis (comet) assay on human colonic adenocarcinoma cells (Caco-2). Bile (both whole and fractionated) from specimens exposed to the three disinfectants always showed a genotoxic activity as compared to the control group. The results of this study provide evidence that all three disinfectants cause an increase in bile genotoxicity of chronically exposed fish.