铅暴露对机体免疫功能的影响

近几年来 ,人们进一步认识到铅不仅具有神经毒性 ,而且还具有免疫毒性。许多动物实验及临床报告均已证实 ,铅暴露能削弱机体的抵抗力 ,使机体对细菌、病毒感染的易感性增加。同时临床上也发现 ,铅暴露可使自身免疫功能紊乱而导致某些自身免疫性疾病。最近研究表明 ,0 483μｍｏｌ/Ｌ的血铅浓度虽然不足以引起临床症状 ,但已能损害免疫系统[1] 。本文就近几年来关于铅暴露对机体免疫功能的影响作一综述。铅暴露对Ｔ淋巴细胞的影响Ｔ淋巴细胞 (ＴＬ)依其膜表面ＣＤ分子的差异而分为ＣＤ 4的Ｔｈ细胞和ＣＤ8 的Ｔｓ及Ｔｃ细胞 (ＣＴＬ )。Ｕ…     

苯作业工人胸腺近期输出功能评价

目的　了解苯作业工人外周血单个核细胞 (peripheralbloodmononuclearcells ,PBMCs)中信号结合T细胞受体删除DNA环 (signaljointT cellreceptorexcisionDNAcircles,sjTRECs)的含量 ,推测苯作业工人幼稚T细胞含量和胸腺近期输出功能情况。方法　利用实时定量PCR和TaqMan方法检测 11例健康人和 6 2例苯作业工人每 10 0 0个PBMCs中sjTRECs的含量。结果　未经校正苯接触组sjTRECs含量 (中位数为 2 .5 6 )明显低于正常人 (中位数为 7.81) ,差异有显著性 (P <0 .0 1)。苯接触组年龄≤ 30岁者sjTRECs含量 (3.19 10 0 0PBMCs)明显高于年龄 >30岁者 (1.76 10 0 0PBMCs ,n =2 3) ,差异有显著性 (P <0 .0 5 )。结论　苯或苯化合物接触影响胸腺近期输出功能 ;sjTRECs含量与苯作业工人年龄有关。     

接触马拉硫磷对免疫功能的影响

随着环境污染与人群健康关系的研究工作不断深入,人们对农药的免疫毒性极为重视。为了探讨马拉硫磷对人体的免疫毒性,我们对某农药厂63例马拉硫磷作业工人的血清T淋巴细胞亚群CD3^ 、CD^ 、CD3^ 。免疫球蛋白IgG、IgA、IgM含量进行检测。结果报告如下。     

铅接触者的心缩功能改变的探讨

铅对人体心血管系统的影响已引起人们的关注,其对心电图的影响国内有很多报道,但是,铅对心功能的影响方面,目前尚未见有资料报道。本文为了探讨铅对人体心功能的影响,对47名铅接触者进行     

苯中毒患者胸腺近期输出功能和T细胞亚群变化

目的　分析职业性慢性轻度苯中毒工人外周血单个核细胞中信号结合T细胞受体删除DNA环 (sjTRECs)的含量和CD4+/CD8+比值 ,从而了解其初始 (naive)T细胞含量和胸腺近期输功能 ,以及外周T细胞亚群分布情况。方法　利用间接免疫荧光法检测 11例健康人和 5例轻度苯中毒患者外周血单个核细胞中CD4+/CD8+比值 ;采用实时荧光定量聚合酶链反应 (real timePCR)和TaqMan方法检测两组外周血单个核细胞中sjTRECs的含量。结果　每 10 0 0个外周血单个核细胞中sjTRECs含量在正常人中为 9 10± 4 5 5 ,轻度苯中毒为 2 80± 3 79,P <0 0 5 ;轻度苯中毒者CD4+/CD8+的比值 (0 92± 0 3 5 )明显低于正常人 (1 49± 0 2 1) ,P <0 0 1。结论　轻度苯中毒患者胸腺近期输出功能低下 ,长期低剂量接触苯可能引起一些工人的细胞免疫功能障碍     

铅接触者行为功能在铅中毒诊断中的价值

目的 研究铅接触者神经行为功能在铅中毒诊断中的价值。方法 对115名铅作业工人神经行为功能进行测试,<50分为不良,≥50分者为正常;同时对铅的接触指标及效应指标进行了测定。结果 神经行为功能分值最低分值为35.7分,最高为68.2分,并随血铅、尿铅、尿ALA(δ-氨基酮戊酸)的含量发生变化。结论 神经行为功能与铅接触的早期神经系统的影响存在着内在联系。     

铅对接触者神经行为功能影响的调查

按WHO行为测试方式,对50名铅作业者进行了神经行为功能调查测试,并与对照组进行比较分析,结果显示铅对运动协调、心理运动和反应速度功能影响、神经行为改变与铅作业工龄和铅接触浓度有一定关系。有统计意义P＜0．01或P＜0．05,铅作业对行为功能可能有一定影响。     

接苯工人胸腺近期输出功能和外周血T细胞亚群变化

目的分析接苯工人外周血单个核细胞中T细胞受体删除DNA环(TRECs)和T淋巴细胞亚群的含量,了解接苯后工人胸腺近期输出功能和外周T淋巴细胞亚群变化,为接苯后机体细胞免疫改变提供资料。方法利用间接免疫荧光法检测健康人和接苯工人外周血单个核细胞中CD3 ,CD4 ,CD8 的含量;采用实时荧光定量聚合酶链反应(real time PCR)和TaqMan方法检测标本外周血单个核细胞中TRECs的含量。结果在接苯工人外周血白细胞总数正常情况下,接苯组CD8 含量显著增加,CD4 /CD8 比值为(1.13±0.78),低于健康人(1.43±0.25)(P<0.05)。每1000个外周血单个核细胞中接苯组与对照组TRECs含量分别为(3.90±3.58)和(7.39±6.83),两者相比,差异有统计学意义(P<0.05)。结论长期低剂量接苯可能引起一些工人的胸腺近期输出功能低下,导致机体细胞免疫功能障碍。     

铅接触对神经行为功能影响的研究

运用世界卫生组织推荐的神经行为核心测试组合的６项分测验并采用因子分析法研究铅接触对神经行为功能的影响。铅接触工人共７８名，平均血铅浓度为２．１４μｍｏｌ／Ｌ；对照工人共７６名，平均血铅浓度为０．２０μｍｏｌ／Ｌ。两组除工龄、人均月收入外，其他因素均差异无显著性。对铅接触工人研究发现，在血铅≥２．７２μｍｏｌ／Ｌ时，运动协调功能和记忆力发生改变。分组研究发现，血铅水平与５种因子得分存在剂量－反应关系     

职业性铅接触对行为功能的影响

对35名铅作业工人进行成套的行为功能测验,接触组与对照组比较,16项行为功能测验中有14项得分有统计学意义(P<0.01或P<0.05)。半数项目行为功能测验得分有随着铅作业工龄增长而呈该增或该减的趋势。作者认为铅对作业工人行为功能的影响是肯定的,用行为功能测验的方法来研究铅的神经毒性是可取的简便的方法。     

The effect of long-term low-dose lead exposure on thyroid function in adolescents

This study investigated blood lead (Pb-B) levels and Pb-B effects on thyroid functions in long-term low-level-lead-exposed male adolescents who work as auto repairers. Pb-B and ALAD index (logarithm of activated delta-aminolaevulinic acid dehydratase/nonactivated delta-aminolaevulinic acid dehydratase) were measured as indicators of exposure to lead. Thyroid function tests including free thyroxine (FT4), free triiodothyronine (FT3), and thyrotrophin (TSH) were conducted and thyroid ultrasounds were performed in 42 lead-exposed adolescents and 55 healthy control subjects. Mean Pb-B levels and ALAD index were found significantly higher in the study group than in the normal control group (7.3+/-2.92 microg/dl vs. 2.08+/-1.24 microg/dl, P < 0.001 and 0.44+/-0.26 vs. 0.29+/-0.23, P < 0.05, respectively). FT4 levels were found significantly lower in the study group (1.02+/-0.18 mI/mL and 1.12+/-0.14 mIU/mL, P < 0.05). No subject in the control group had an abnormal FT4 level, but FT4 levels were found under normal limits in 11 subjects (26%) in the study group. FT3 and TSH levels in the study and control groups did not differ (P > 0.05). Thyroid volumes in the study and control groups did not exhibit any significant differences (P > 0.05). Pb-B was found to be negatively correlated to FT4 levels (r = -0.20, P = 0.044). This study revealed that long-term low-level lead exposure may lead to reduced FT4 level without significant changes in TSH and T3 levels in adolescents even at low Pb-B levels.     

阿特拉津对BALB／c小鼠T淋巴细胞功能的影响

目的探讨阿特拉津对小鼠T淋巴细胞功能的影响。方法健康BALB／c小鼠按体重随机分为阿特拉津高剂量组（400mg／kg）、中剂量组（200mg／kg）、低剂量组（100mg／kg）和阴性对照组（蒸馏水）,经口灌胃,每天1次,连续21d。试验结束后,眼球取血,处死小鼠,观察胸腺组织病理学变化,采用MTY还原法和流式细胞仪分别检测脾脏T淋巴细胞增殖情况和胸腺T淋巴细胞亚群分布,酶联免疫吸附法检测血清中白细胞介素-2（interleu—kin-2,IL-2）和白细胞介素．4（interleukin-4,IL-4）含量。结果阿特拉津暴露使小鼠胸腺皮质细胞减少,各剂量组脾脏T淋巴细胞转化率低于阴性对照组（均有P〈0．05）。阿特拉津中、高剂量组胸腺CD3＋T淋巴细胞亚群比例以及CD4＋T／CD8＋T比值均低于阴性对照组（均有P〈0．05）,各剂量组CD4＋T淋巴细胞亚群比例均明显低于阴性对照组（均有P〈0．05）,CD8＋T淋巴亚群比例随染毒剂量增高有降低趋势,但差异无统计学意义（均有P〉0．05）。阿特拉津高剂量组血清IL-2和IL4含量明显降低（均有P〈0．05）。结论阿特拉津能抑制小鼠T淋巴细胞功能,因而有免疫毒性作用。     

Occupational lead exposure and pituitary function

Summary Twenty-five moderately exposed lead workers (mean blood-lead level 1.9 mol/l) had lower plasma levels of follicle stimulating hormone than 25 individually matched controls without occupational lead exposure (blood-lead level 0.2 mol/l). In addition, the ten most heavily exposed individuals had higher levels of thyroid stimulating hormone, and the 14 workers under the age of 40 had decreased plasma levels of luteinizing hormone and serum levels of cortisol, as compared to the controls. All values were within normal reference limits. There was no significant change of the plasma testosterone level. These data indicate a complex effect on the endocrine system by moderate lead exposure, possibly mediated by changes at the hypothalamic-pituitary level. Besides the effect on hormone levels, there was also a decrease in plasma selenium level for the lead exposed workers.     

幼儿园环境中铅含量对儿童血铅值的影响

目的探讨幼儿园环境是否对儿童铅暴露产生影响。方法采集、测定幼儿园环境样品中铅含量,同时采集、测定儿童的手尘铅和血铅浓度,分析环境铅和血铅的相关关系。铅测定方法为原子吸收法。结果19所幼儿园室内地面尘、脱落漆皮。室内降尘、室外地面尘、土壤和自来水铅含量的几何均数分别为86．5μg/m2、235.5μg/g、445．9μg/g、172．4μg/m2、70．1μg/g及12.5μg／L。儿童双手尘铅的平均值为3．4μg。相关分析结果提示血铅与室外地面尘铅、儿童手尘铅呈正相关。多因素分析显示手尘铅被引入血铅的回归方程,而且其标准化回归系数最大,达0.3842,其偏回归系数为0．2018。结论幼儿园的环境卫生状况直接影响着儿童铅的摄入水平。因此有必要对儿童进行健康教育,使其养成勤洗手的卫生习惯,克服吮吸手指的不良行为。     

Influence of chronic low-level exposure to lead on plasma immunoglobulin concentration and cellular immune function in man

Summary The immunological status of individuals occupationally exposed to low levels of inorganic lead has been examined and compared with that of non-exposed, age and sex-matched controls. At the time of testing the exposed population had a mean (± SD) blood lead concentration of 38.4 ±5.6 g · 100 ml^–1 (n = 39) compared witha mean value of 11.8 ±g · 100 ml^–1 (n = 21) for the control group. No differences in the serum concentrations of IgG, IgA and IgM between the populations were observed and there existed no correlation between blood lead concentration and serum immunoglobulin levels. In addition assessment was made of the capacity of peripheral blood mononuclear cells to respond to the mitogen phytohaemagglutinin (PHA), a correlate of T cell function, and to spontaneously lyse cells of the erythroleukaemic cell line K562, a measure of NK cell function. In neither case was there a difference between exposed and control populations and no correlation between reactivity and blood lead concentration. Although previous studies in rodents have indicated that exposure to inorganic lead resulting in similar blood lead concentrations may compromise immune competence our data suggest that no similar effect occurs in man.     

铅对作业工人甲状腺功能的影响

目的　了解铅对作业工人甲状腺功能的影响。方法　选择暴露于铅作业环境下的人群 ,了解工人作业工龄 ,采用火焰原子吸收光谱法测定其作业环境中铅浓度 ,用原子吸收光谱法测定作业工人血铅 (PbB)浓度 ,用血液锌原卟啉测定仪测定血锌原卟啉 (ZPP)浓度 ,用放射免疫分析法检测血清中促甲状腺素 (TSH)、三碘甲状腺原氨酸 (T3)、甲状腺素 (T4 )、游离T3(FT3)、游离T4 (FT4 ) 5项甲状腺功能指标。结果　血铅 >2 .88μmol/L时 ,T3[(1 .54± 0 .39)nmol/L]、FT3[(5 .50± 1 .2 6)pmol/L]含量明显低于血铅 (1 .92～ 2 .88) μmol/L组 [T3(1 .71± 0 .45)nmol/L、FT3(6 .1 2± 1 .64)pmol/L] ,差异有显著性(P <0 .0 5)。铅作业工龄长短对甲状腺激素 (TH)含量未见明显影响。结论　高浓度血铅可能抑制了T4 的脱碘 ;铅作业工龄对甲状腺功能未见明显影响     

孕期低水平铅暴露与婴儿的行为发育

目的 观察孕期低水平铅暴露对婴儿行为发育的影响。方法 检测孕中期、产母及脐血铅水平并与3月龄的Bayley婴儿行为记录量表得分进行相关分析,以产母血铅及脐血铅水平的第70百分位(0.254μml/L)为分界点、分为相对高铅组及低铅组、进行t检验。结果 3月龄的Bayley婴儿行为记录的30项行为评分中有6项与孕期的铅暴露水平呈负相关关系;产母血铅高、低血铅组间婴儿的社交能力、持久和协调性差异有显著性。结论 孕期铅暴露即使在较低的水平也可能对婴儿的行为发育产生不良影响。     

职业铅接触对男性工人腰椎骨折的影响

目的探讨职业铅接触对男性工人腰椎骨折的影响。方法以上海某蓄电池厂152名男性铅作业工人为研究人群。采用石墨炉原子吸收分光光度法测定血铅（aPb）、尿铅（UPb），应用单光子骨密度仪（SPA-4）测定工人骨蛮度，并做Z评分。拍摄腰椎侧位x线平片，并诊断有无腰椎骨折。结果铅作业工人血铅浓度0．85（0．33-1．90）μmol／L，尿铅浓度4．84（0．46-21．31）μg／g Cr，腰椎骨折发病率为19．7％。工人腰椎骨折发病率随年龄和工龄增长而升高，但差异无统计学意义（P〉0．05）。工人骨密度随血铅、尿铅水平升高而明显下降，差异有统计学意义（P〈0．05）。工人随着体内铅接触水平的升高，腰椎骨折发病率随之明显升高，差异有统计学意义（P〈05）并呈线性相关（r血铅=-0．977，P〈0．05；r尿铅=0．994，P〈0．01）。随着骨量减少，工人腰椎骨折发病率明显升高，差异有统计学意义（P〈0．01）并呈线性相关（r=-0．980，P〈0．01）。结论职业铅接触可能引起职业人群骨密度下降，腰椎骨折发病率增高，腰椎骨折的发生可能与骨量减少有关。     

Occupational lead exposure

Summary Quantitative measures of saccadic eye movements were examined in 52 lead exposed autobody shop workers and 52 age matched controls with no history of occupational lead exposure. Three characteristics of saccadic eye movements were studied: 1) saccade accuracy; 2) number of overshoots; and 3) maximum velocity. The results indicated that workers exposed to inorganic lead showed a decrease in saccade accuracy and an increase in overshoots compared with controls. Saccade maximum velocity was lower in lead exposed workers than in controls but the difference was just short of statistical significance. Correlations between measures of saccadic eye movements and indicators of lead absorption—blood lead (Pb-B) and zinc protoporphyrin (ZPP) levels-were analyzed in the lead exposed workers. Saccade accuracy was negatively correlated with both Pb-B and ZPP levels. The number of overshoots was not correlated with either Pb-B or ZPP levels. Saccade maximum velocity was not correlated with Pb-B, however, there was a significant negative correlation with ZPP. Age effects observed in the control group were disrupted in lead exposed workers. In addition, saccadic eye movements in younger workers (below 30 years old) were more affected by exposure to inorganic lead than were saccadic eye movements in older workers (50 years and older). It is proposed that these findings are consistent with a relatively rapid buildup of metabolically active lead burden observed in the study group. The data suggest that quantitative assessment of eye movements may be an important tool for studying subclinical central nervous system (CNS) dysfunction due to inorganic lead exposure.Part of this study was presented at the XX International Congress on Occupational Medicine, Cairo, Egypt, Sept. 26–29 (1981)This study was supported in part by NIEHS grant ES00928 of the National Institute of Health, US Department of Health and Human Services