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Amphibian metamorphosis provides a wonderful model to study the thyroid hormone (TH) signaling disrupting activity of environmental chemicals, with Xenopus laevis as the most commonly used species. This study aimed to establish a rapid and sensitive screening assay based on TH-response gene expression analysis using Pelophylax nigromaculatus, a native frog species distributed widely in East Asia, especially in China. To achieve this, five candidate TH-response genes that were sensitive to T3 induction were chosen as molecular markers, and T3 induction was determined as 0.2 nmol/L T3 exposure for 48 hr. The developed assay can detect the agonistic activity of T3 with a lowest observed effective concentration of 0.001 nmol/L and EC50 at around 0.118–1.229 nmol/L, exhibiting comparable or higher sensitivity than previously reported assays. We further validated the efficiency of the developed assay by detecting the TH signaling disrupting activity of tetrabromobisphenol A (TBBPA), a known TH signaling disruptor. In accordance with previous reports, we found a weak TH agonistic activity for TBBPA in the absence of T3, whereas a TH antagonistic activity was found for TBBPA at higher concentrations in the presence of T3, showing that the P. nigromaculatus assay is effective for detecting TH signaling disrupting activity. Importantly, we observed non-monotonic dose-dependent disrupting activity of TBBPA in the presence of T3, which is difficult to detect with in vitro reporter gene assays. Overall, the developed P. nigromaculatus assay can be used to screen TH signaling disrupting activity of environmental chemicals with high sensitivity. 相似文献
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目的 调查热电厂作业场所危害因素分布特点及浓度,结合作业人员职业健康检查结果,探究各类职业病危害因素对作业人员健康的影响.方法 采用现场职业卫生学调查对热电厂各车间职业病危害因素进行识别,依据作业场所各类职业病危害因素健康效应、现场检测浓度和强度,结合作业人员近2年职业健康检查结果进行对照分析.结果 作业场所各类化学物质检测浓度均符合国家卫生限值要求,粉尘个别检测值超过卫生限值要求;个体噪声检测强度超出卫生限值要求;近2年职业健康检查结果显示,每年均筛检出噪声岗位职业禁忌证患者,且血压升高和肺功能异常人数有所增加.结论 热电厂作业工人听力异常受作业场所高噪声影响较明显,肺功能异常可能受粉尘、氢氧化钠、盐酸、氨等职业病危害因素影响. 相似文献
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脲酶抑制法检测环境样品中重金属离子研究 总被引：10，自引：0，他引：10
为探索利用脲酶快速检测环境样品中重金属离子的最佳条件，系统研究了重金属和缓冲液类型及其浓度对脲酶抑制率的影响。结果表明，不同浓度缓冲液中重金属离子浓度与脲酶抑制率呈显著的相关性，表现为随着重金属离子浓度的增加，脲酶抑制率也提高。缓冲液类型和浓度均能影响重金属对脲酶的抑制作用，其中磷酸缓冲液中，无论是Hg^2 还是Cu^2 对脲酶活性均有较强的抑制作用：在柠檬酸缓冲液中2种离子对脲酶的抑制作用存在显著差异。建立脲酶抑制检测技术的关键是选择合适的缓冲系统。此结果为脲酶抑制法在快速检测重金属离子中最佳检测条件的选择提供了理论依据。 相似文献
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Qinqin Lou Yinfeng Zhang Dongkai Ren Haiming Xu Yaxian Zhao Zhanfen Qin Wuji Wei 《环境科学学报(英文版)》2014,26(10):2084-2094
Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility. 相似文献
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采用现场职业卫生学调查方法了解炼化企业分析化验岗位接触各类危害因素情况,对正常情况下分析化验工作场所进行各类职业病危害因素检测,同时测量各通风橱控制点风速、排风罩罩口风速;通风橱(风机通风量增加、管道改造)以及排风罩改造后,再次进行控制点风速测量、工作场所危害因素采样检测,对比改造前后测量数据,探讨分析化验岗位职业病危害防治措施。结果显示,工作场所通风设施的风机选型、管道合理化布置、排风罩围挡的设置、补风等因素均对通风橱、排风罩控制点风速产生影响;通风设施改造后工作场所职业病危害因素浓度有所降低。由此可见,炼化企业分析化验工作场所通风设施是职业病危害防治的重要措施。 相似文献
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砷作为全球水生生态系统的重要污染物,普遍存在于淡水和海洋环境中,具有一定的生物累积性与生物毒性.水生生物作为生态系统的重要组成部分,砷在全球生物化学循环的过程中通过迁移、累积、转化、富集在水生生物体内,产生毒性作用,而砷对水生生物的毒性与其在水生生物中的赋存形态有关.目前关于砷在水生生物中的生物累积、生物转化及其代谢毒理的基础科学研究受到国内外研究者的广泛关注,而少有对该领域内的研究进展、研究热点、趋势方向的系统整合,本文针对这一领域文献进行梳理,系统阐述了砷在水生生物中的生物累积和生物转化情况;概述了砷在水生生物、小鼠/大鼠、人体、微生物等生物中的毒性作用及代谢机制;并提出了未来有关砷研究可关注的重点及方向.本文可为进一步阐明砷在水生生物中的生物累积转化规律及砷的代谢毒性作用,为研究者进一步深入探索该领域内科学问题提供参考资料,同时对水产品安全、环境生态、医学等相关领域的研究具有一定的借鉴意义. 相似文献
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羟基多氯联苯(hydroxylated polychlorinated biphenyls, OH-PCBs)作为多氯联苯(polychlorinated biphenyls, PCBs)在生物体内的主要代谢产物之一,能够通过食物链传递在高等动物体内产生蓄积并对其生命健康造成危害。本研究旨在探索OH-PCBs通过水产品摄食途径暴露后,在模式生物体内的蓄积和迁移规律。以鲫鱼为水产品代表,以小鼠为研究对象,向鲫鱼可食性组织添加3-OH-PCB101和4-OH-PCB101的混合标准溶液(1 000 ng·mL-1)制作加标饲料,并以小鼠每日摄食总量的10%对其进行投喂。分别在暴露实验的第12、24、72和168小时解剖取样,并收集粪便。检测结果显示,2种OH-PCB101在胃、肠等消化组织器官的浓度高于其他组织并能随着粪便排出,且倾向于在含血量较高的组织(如心、肺和脾)中蓄积。OH-PCB101在各组织中的蓄积量由高到低依次为大肠>胃>小肠>脾≈肺>心>肝>肾>血液≈脑>肌肉≈睾丸。同时发现在脑、心、肺、肝、肾、性腺、肌肉等组织样品中,4-OH-PCB101的蓄积浓度始终高于3-OH-PCB101。这表明,虽然通过水产品摄入的OH-PCB101主要通过粪便排出体外,然而在脑、心、肺、肝、胃和脾等11个组织及血液中均产生蓄积,并且2种OH-PCB101可能由于结构不同导致其在各组织中的蓄积量存在差异。本研究有助于揭示OH-PCBs通过摄食暴露后在生物体内的蓄积分布及排泄等归趋问题,同时表明在环境及生物体中蓄积的OH-PCBs等二代持久性污染物对人体健康仍存在潜在威胁。 相似文献
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通过职业病危害现场调查,分析了某MTBE装置的生产工艺、装置存在的主要职业病危害因素、检测结果、职业病危害防护措施,找出了职业病危害的关键控制点,并提出了防护对策. 相似文献