铅的生物标志物研究

生物标志物可以反映机体对毒物的接触程度,早期毒效应,以及不同个体对毒物的敏感性.对于毒物对机体健康损害的早期发现,早期阻断起着重要的作用.本文就铅的生物标志物研究作一综述.     

铅的生物标志物研究进展

生物标志物通常分为反映接触水平的接触标志物 ,反映化学物或其他代谢物早期生物学效应、机体结构或者功能改变和疾病的效应标志物和反映个体易感性的易感标志物 3大类。对于毒物对机体健康损害的早期发现、早期阻断起着重要的作用。现就铅的生物标志物研究进展综述如下。1　接触标志物1 1　血铅 (Pb -B)　血铅 ,主要是红细胞铅 ,是软组织铅的代表 ,是反映近期铅接触的敏感指标 ,与其他指标相关性较好 ,所以被较广泛地用作为铅吸收或铅负荷的指标 ,在评价其他指标时也常以血铅为准。但由于各国工业化程度不同经济状况、种族、生活习惯等不…     

成人铅接触的生物标志物研究进展

通过复习国内外文献,按照铅的接触性生物标志物——血铅、骨铅、尿铅、发铅、乳铅等进行汇总分析,探讨成人铅接触的生物标志物及与健康关系的评价。结果:(1)血铅包含血液铅、血浆铅。入血液循环的铅99%以上存于红细胞中,不到1%存在于血浆中;血浆铅是反映机体近期铅暴露水平的较好指标,亦代表能进入胎盘的那部分铅,比全血铅更说明铅对胎儿的危害。此外,血铅与骨铅呈正相关。(2)尿铅浓度升高提示近期有铅接触,但尿铅波动较大,有去离子化干扰的问题,影响因素较多。血铅与尿铅的相关系数在0.284~0.850之间。(3)骨铅可以作为累积性铅接触的生物标志物,用于研究慢性铅接触与健康的关系。其监测方法为X线荧光仪(XRF)。影响骨铅转运与年龄、妊娠及哺乳、钙离子的代谢密切相关。(4)发铅是检验环境铅暴露的理想指示器,既可反映人体铅负荷状态,亦可反映环境污染状况。但发铅的正常值范围较大,目前没有统一。(5)监测母血铅和乳铅水平对预防儿童铅中毒有重要意义。乳铅的波动范围也较大。总之,较可靠铅接触的生物标志物对评价人体接触剂量、筛选高危和易感人群、铅中毒的诊断、制定治疗方案以及评估疗效有重要意义;但在评价结果时应考虑个体因素、样本类型、检...     

应用生化标志物评价神经毒物的效应

预防中毒性疾病,首先要求减少与毒物的接触,识别机体的遗传易感性,　并尽早发现不可逆性损害前的有关生理生化改变。尽管在环境医学领域应用神　经毒性生物标志物意义重大,但应用标志物评价接触、效应及易感性研究却比　其他领域进展缓慢,其中主要影响因素为神经系统功能的复杂性、神经毒作用　的多重性、靶细胞分子的多样性及取材困难。此外,也可能与长期慢性接触所　致神经毒作用的迟发性,抑或在停止接触很长时间后才发生神经毒效应有关。　　　　最近,有关易感性、神经内分泌和脑损害的神经毒性标志物已见于其他综　述,故本文仅…     

国内职业医学生物监测现况

职业医学领域的监测包括环境监测(Ambient Monitoring, AM)、生物监测(Biological Monitoring, BM)和健康监护(Surveillance Health ,SH).随着生物监测技术的不断完善,其在职业有害因素评价体系中的地位日益加强,改变了长期以来均认为"环境监测为主、生物监测为辅"的观念,它与环境监测"相辅相成、互为补充"的观点正成为学术界共识.生物标志物是生物监测的重要研究对象,近几年伴随着分子生物标志物的发展,生物监测技术提高到了分子水平.生物标志物一般分为3类:①接触生物标志物:是指测定机体器官或组织内的外源性化学物及其代谢产物或外源性化学物与靶分子、靶细胞相互作用的产物,以反映内剂量和生物效应剂量;②效应生物标志物,指机体中可测出的生化、生理、行为或其他改变的指标,以及早期生物效应、结构和/或功能改变、疾病等;判断机体是否受到明确的或潜在的危害;③易感性生物标志物,指能反映机体先天遗传性或后天获得性的对外源性化合物接触产生反应能力大小的指标.     

职业性铅接触的生物标志物研究进展

随着现代工业生产的迅速发展,铅中毒多以低浓度铅接触导致的亚临床无症状中毒为主,给职业性铅中毒的早期发现、早期诊断、早期治疗带来了一定的困难。铅接触的生物标志物的日渐发展对现代职业卫生生物监测、铅损害效应的早期预警和早期干预具有重要作用。作者就职业性铅接触常用的生物标志物的研究进展做一归纳。     

接苯人群生物标志物研究进展

生物标志物可以分为四大类：内剂量、生物有效量（ＤＮＡ、ＲＮＡ和蛋白质加合物）、早期生物效应和个体易感性标志物。其中内剂量及生物有效量标志物都可作为接触标志物。一、内剂量标志物所谓内剂量系指职业接触、环境接触化学物进入机体内的量。内剂量与外剂量、生物有效量及生物效应有直接关联。苯只有经代谢活化后才能行使其致毒、致癌作用,因此人体接触苯后,通过机体代谢作用生成苯的各种活性代谢产物便成为接触苯后不同的内剂量标志物,样品多来源于血液和尿液。最有希望的代谢产物是反式,反式粘糠酸（ｔｒａｎｓｔｒａｎｓｍ…     

神经毒性的生物标志物—机制研究及其应用

神经毒性的生物标志物——机制研究及其应用ＭａｎｚｏＬｅｔａｌ．为预防中毒性疾病，应在有害化学物质对靶器官系统造成不可逆的损害之前识别，并减少毒物的接触。为此，开展有关生物监测及接触标志物与早期健康效应标志物的研究非常重要。对大多数神经毒物来说，最好的...     

接触生物标志物及其在危险度评价中的应用

生物标志物(biological marker,biomarker)是指能反映生物体与环境因子(化学的、物理的或生物的)相互作用引起的生理、生化、免疫和遗传等多方面的分子水平改变的物质。生物标志物可分为接触生物标志物(biomarkerofexposure)、效应生物标志物(biomarkerofeffect)和易感性标志物     

接触氯乙烯的生物标志物

氯乙烯是一种可损害多器官的毒物 ,也是已知人类致癌物。其活性代谢中间产物具有强烈烷化作用 ,可在体内形成多种加合物。以氯乙烯的代谢和毒性机制为基础 ,研究了一系列其致机体损伤的指标 ,并试图寻找氯乙烯的生物标志物。本文就氯乙烯在体内的代谢转归及其活性中间产物、接触生物标志物、遗传学改变、血清癌蛋白和肝损伤指标等效应标志物以及基于其代谢酶基因多态性的易感生物标志物进行综述     

Biomarkers for assessing reproductive development and health: Part 1--Pubertal development

The proposed National Children's Study has helped raise awareness of the issues related to children's health and the importance of monitoring the growth and development of children from preconception through adulthood. Many genetic predispositions can adversely impact the normal development process, and various environmental exposures have been linked to adverse reproductive health in rodent models and a small number of accidental human exposures. To monitor reproductive health and identify adverse effects at the earliest possible juncture, investigators must develop a network of biomarkers covering all stages and aspects of reproductive development and function. Biomarkers are biological indicators that can be measured repeatedly and are informative on one or more aspects of biological development or function. They can range from the anatomical level down to the molecular level and may provide information on the nature of an exposure, the effect of an exposure, or the susceptibility of individuals or populations to the toxic effects of an exposure. In theory, biomarkers can be used to monitor a wide variety of conditions and responses ranging from abnormal development to early indicators of late-onset disease. The main stumbling block with this theory has been finding appropriate biomarkers for particular conditions and exposures. Such biomarkers must be easily accessible, robust, and sensitive. Ideally, they will be expressed across a large section of the population, and can be monitored quickly, easily, conveniently, and with minimal cost. In this review, we discuss some of the current and emerging biomarkers of human pubertal development.     

From industrial hygiene and toxicology to environmental hygiene and toxicology: problems and prospects

BACKGROUND: Low-dose exposures to mixtures of substances have received increasing interest and they involve many different occupational and environmental situations. The presence in the population (working and general) of groups of susceptible individuals is an important public health issue that poses new challenges to science and society. OBJECTIVES: To discuss the evolution from traditional occupational hygiene and toxicology to the new environmental (general and occupational) hygiene and toxicology. RESULTS: Environmental hygiene and toxicology have remarkably improved analytical tools available to solve most of the analytical issues posed by the present exposure scenario. Biomarkers of low-dose exposure, early effects and individual susceptibility are being intensively investigated. CONCLUSIONS: The challenge in this field for the coming years appears to be not the analytical but the medical and ethical implications.     

Molecular epidemiology studies on occupational and environmental exposure to mutagens and carcinogens, 1997-1999

Molecular epidemiology is a new and evolving area of research, combining laboratory measurement of internal dose, biologically effective dose, biologic effects, and influence of individual susceptibility with epidemiologic methodologies. Biomarkers evaluated were selected according to basic scheme: biomarkers of exposure--metabolites in urine, DNA adducts, protein adducts, and Comet assay parameters; biomarkers of effect--chromosomal aberrations, sister chromatid exchanges, micronuclei, mutations in the hypoxanthine-guanine phosphoribosyltransferase gene, and the activation of oncogenes coding for p53 or p21 proteins as measured on protein levels; biomarkers of susceptibility--genetic polymorphisms of genes CYP1A1, GSTM1, GSTT1, NAT2. DNA adducts measured by 32P-postlabeling are the biomarker of choice for the evaluation of exposure to polycyclic aromatic hydrocarbons. Protein adducts are useful as a biomarker for exposure to tobacco smoke (4-aminobiphenyl) or to smaller molecules such as acrylonitrile or 1,3-butadiene. Of the biomarkers of effect, the most common are cytogenetic end points. Epidemiologic studies support the use of chromosomal breakage as a relevant biomarker of cancer risk. The use of the Comet assay and methods analyzing oxidative DNA damage needs reliable validation for human biomonitoring. Until now there have not been sufficient data to interpret the relationship between genotypes, biomarkers of exposure, and biomarkers of effect for assessing the risk of human exposure to mutagens and carcinogens.     

The role of biological monitoring in the evaluation of the risk of from chemical compounds

Over the years, the assessment of the risk to human health from occupational and environmental exposure to chemicals has become increasingly important. Exposure to chemicals, their biochemical effects and individual susceptibility can be estimated by biological monitoring carried out on potentially exposed subjects. Valid markers are needed to be effectively used within the framework of biological monitoring programs. Quality assurance, which includes all those activities necessary to provide adequate confidence that the results of laboratory test are reliable, is of the utmost importance. Among these activities the participation in external quality assessment schemes is strongly recommended. Biological monitoring has a key role also in the field of human reproduction since the level of exposure to many chemicals which are known or suspected to be reproductive toxicants can be assessed by specialized laboratories.     

砷致健康危害生物标志物研究进展

尿、发、指(趾)甲中砷水平可以反应短期砷接触内剂量,可作为人体内灵敏有效的砷暴露标志物.长期慢性砷接触可以诱发皮肤色素代谢异常和掌跖角化等典型的皮肤病变,尿中MMA(V)可认为是暴露的生物有效剂量.活性氧和抗氧化能力、炎性分子基因表达、外周血淋巴细胞微核和姊妹染色单体互换和染色体畸变是无机砷摄入的早期生物效应标志物.砷易感性标志物包括DNA修复酶、氧化和抗氧化酶、氧化应激相关酶以及异物代谢酶基因组多态性.砷对健康的危害是由于基因组不稳定性和氧化应激等毒理机制而导致的基因-基因、基因-环境交互作用的慢性复杂的渐进性损害.     

Biomarkers and their use in occupational medicine

Biomarkers of exposure, parent chemicals, metabolites, and also hemoglobin and DNA (deoxyribonucleic acid) adducts, even urinary mutagenicity, have been used successfully to identify exposed persons, follow-up exposure, and quantitatively assess exposure. Some have been validated as indicators of health risk. The avenues for future biomarkers of exposure are in the development of robust, simple, and inexpensive semiquantitative methods for daily use on every worker for assuring that no (excessive) exposure takes place. Some biomarkers of effect have also been well validated and are widely used in routine monitoring activities. However, with the exception of cholinesterase inhibitors, biomarkers of effect offer little advantage over the analysis of the chemical itself. Their use will be limited to carefully planned ad hoc studies. Biomarkers of susceptibility currently have no practical application in worker health protection. Biomarker research should concentrate on validating methods, in terms of the prediction of health effects, and on elucidating exposure-biomarker concentration relationships.     

Endocrine disrupting chemicals: harmful substances and how to test them

This paper presents an analysis of the opinions of different groups from: scientists, international regulatory bodies, non-governmental organizations and industry; with an interest in the problem of identifying chemical substances with endocrine disrupting activity. There is also discussion of the consequences that exposure to endocrine disruptors may have for human health, considering concrete issues related to: the estimation of risk; the tests that must be used to detect endocrine disruption; the difficulties to establish an association between dose, time of exposure, individual susceptibility, and effect; and the attempts to create a census of endocrine disruptors. Finally, it is proposed that not all hormonal mimics should be included under the single generic denomination of endocrine disruptors.     

Biological monitoring in waste landfills studies

The assessment of exposure to chemicals from waste landfills and their health impact is a crucial, yet extremely difficult task in waste landfill studies. Use of biological markers, both of exposure and of health effects, may be very helpful if adequately chosen and precisely applied. They must be validated before application in risk assessment studies by establishing the relationship between the biomarker, exposure and the health outcome. Biomarkers suitable for the application in the waste landfill studies are reviewed in this paper.     

多环芳烃的环境效应及其生物标志物在环境风险评价中的应用

多环芳烃是一种常见的有机污染物,也是目前国际上关注的一类持久性有机污染物。其致毒机理研究是环境科学研究领域的热点问题之一,而反映暴露剂量与生物效应的生物标记物的研究是环境致癌物风险评价的核心内容。本文综述多环芳烃的暴露途径、环境行为、毒理效应、致癌机理及其生物标志物在环境风险评价中的应用,并对今后的研究内容进行讨论.