茶多酚对大鼠长期毒性实验

以茶多酚 35 0、70 0、140 0mg/ (kg·d) ,给大鼠连续口服 180d。观察用药期间毒性反应及停药 14d期间恢复情况。茶多酚高剂量可轻度抑制大鼠体重的增长 ,引起部分大鼠肝和肾的损害 ,甚至个别动物出现死亡 ;中剂量组大鼠体重增长减慢 ,且表现有毛色灰暗 ,精神萎糜 ,停药后均可减轻或消失 ;低剂量组动物未见毒性反应。结果提示茶多酚对大鼠是无毒的 ,剂量为 35 0mg/ (kg·d)。     

Children's Health and the Environment—The First Herbert L. Needleman Award Lecture

Children today are exposed extensively to toxins in the environment. Prominent among these are exposures to over 70,000 synthetic chemicals, all newly developed in the past 50 years and largely untested for their hazards to children's health. Children are uniquely vulnerable to toxins, and with increasing incidence they are developing chronic, disabling, life-threatening diseases known or suspected to be of environmental origin–asthma, endocrine disruption, cancer, and the diseases caused by tobacco. Pediatricians need to consider toxic etiologies in the differential diagnosis of childhood illness.     

慢性苯中毒患者34例骨髓象的临床观察

目的　通过对慢性苯中毒患者骨髓象分析,了解其临床类型特点。方法　按诊断标准对患者进行分组诊断,３４ 例患者均进行骨髓穿刺,选取材、涂片、染色好的骨髓片计数有核细胞２００ 个,进行分类并观察细胞形态。结果　除２ 例再生障碍性贫血（ 简称再障） 患者外,其他患者均表现骨髓增生活跃或明显活跃,但各组患者粒红比值均数低于正常值均数。骨髓增生异常综合征（ Ｍ Ｄ Ｓ） 患者骨髓中原粒和早幼粒细胞百分率高于正常,分别为５ ．０８ 和７ ．８５（ 正常参考值分别为０ ．６４ 和１ ．５９） ,粒细胞和红细胞有细胞形态异常和核畸形。结论　慢性苯中毒可以导致 Ｍ Ｄ Ｓ,慢性重度苯中毒患者 Ｍ Ｄ Ｓ 发病率高于再障,应考虑将骨髓象检查列为苯中毒诊断的必要项目。     

ROC曲线在评价铅中毒指标中的应用

目的评价几种铅中毒指标筛选不同水平职业性铅接触的准确性。方法连续性收集１５７名铅接触工人的血标本,同时测定血铅、红细胞游离原卟啉（ＦＥＰ）、锌原卟啉（ＺＰＰ）、尿铅、尿δ氨基酮戊酸（δＡＬＡ）,以血铅≥４０、≥６０μｇ／ｄｌ的铅接触水平为金标准,用ＲｅｃｅｉｖｅｒＯｐｅｒａｔｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃ（ＲＯＣ受试者工作特征）曲线分析软件评价所测定指标筛选血铅≥４０、≥６０μｇ／ｄｌ职业性铅接触的价值,在ＲＯＣ曲线上制定各测定指标筛选上述２个铅接触水平的最佳临界点,用ＥＰＩＮＦＯＲ统计软件比较筛选血铅≥４０、≥６０μｇ／ｄｌ的平行试验的敏感度。结果筛选血铅≥４０、≥６０μｇ／ｄｌ的铅接触水平,ＲＯＣ曲线下的面积（ＡＵＣＲＯＣ）最大的是ＺＰＰ,其他依次为ＦＥＰ、尿铅、尿δＡＬＡ;联合ＺＰＰ与ＦＥＰ的平行试验的敏感度高于联合尿铅与尿δＡＬＡ的平行试验。结论筛选血铅≥４０、≥６０μｇ／ｄｌ水平的职业性铅接触,ＺＰＰ的准确性最高,并且联合ＺＰＰ与ＦＥＰ的平行试验的敏感度高于联合尿铅与尿δＡＬＡ的平行试验。     

铅中毒对小鼠颌下腺神经生长因子基因表达的影响

目的探讨铅中毒对小鼠颌下腺的毒性作用及对神经生长因子基因（NGFmRNA）表达的影响。方法采用小鼠实验性铅中毒模型,通过光镜与电镜观察颌下腺的病理组织学变化。应用地高辛标记的人NGFDNA探针,采用原位杂交的方法,定量分析铅对小鼠颌下腺NGFmRNA表达的影响。结果实验性铅中毒小鼠体重下降,血铅浓度升高,颌下腺铅含量增加。光镜和电镜结果呈现铅中毒小鼠颌下腺腺叶萎缩,纤维增生,腺间质血管扩张,腺间隙增加。粗面内质网扩张,线粒体肿胀。图像分析结果表明,铅中毒小鼠颌下腺纹状管和颗粒曲管直径减小。原位杂交的结果显示,铅中毒小鼠颌下腺颗粒曲管和纹状管的杂交信号显著减弱,颌下腺组织中NGFmRNA表达减少。结论铅对小鼠颌下腺具有毒性作用,影响颌下腺NGF的基因表达。     

上海市婴幼儿血铅水平与体格发育的关系

目的探讨低水平铅暴露对儿童体格发育的影响。方法在上海市5个区县30所托幼机构,对1969名儿童进行了血铅水平的流行病学调查和体格发育等指标测量,并根据儿童身高、体重、头围和胸围计算其Z标准分,然后与血铅水平进行相关分析和逐步回归分析。结果上海市儿童血铅水平几何均数为0．400μmol／L,≥0．483μmol／L的比例为37．8％,血铅水平的几何均数与儿童身高、体重及头围的Z标准分呈显著的负相关。结论低水平铅暴露对上海市婴幼儿的体格发育可能具有不利影响。     

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。     

Determination of N-nitrosodiethanolamine in urine by gas chromatography thermal energy analysis: application in workers exposed to aqueous metalworking fluids

 Objective: The aim of this study was to describe a detailed and validated methodology designed for the analysis of carcinogenic N-nitrosodiethanolamine (NDELA) down to sub-μg/l levels in urine and its application to a number of workers exposed to NDELA-contaminated aqueous metalworking fluids (MWF). Methods: Following a work-up procedure based on solid-phase extraction of NDELA, the urinary extracts were analysed without derivatization by gas chromatography on a polar wide-bore column with chemiluminescent detection using a thermal energy analyser (TEA). N-Nitroso-(2-hydroxypropyl)amine was used as an internal standard. The method was applied to 12 workers using “nitrite-free” or “nitrite-formulated” MWF and to 15 unexposed subjects. The NDELA content of the MWF was also determined using a similar, but simpler method able to easily quantify NDELA down to at least 0.1 mg/l. Results: Contamination by NDELA traces of some chemicals used for the sample preparation, particularly ethyl formate, must be carefully checked since it can give rise to false-positive results of up to 1 or 2 μg/l. The response was linear in the range of 0–500 μg/l. Between 0.5 and 10 μg/l, the recovery rate was close to 95%, while repeatability ranged from 12.5 to 6.4% (n = 5). The detection limit was 0.3 μg/l (Signal/noise = 3). No detectable NDELA could be observed in the control workers. There was no significant increase in NDELA levels at the end of shift spot samples from an exposed worker over 1 week. Higher NDELA concentrations were found in two workers (4.3 and 10.7 μg/l) exposed to “nitrite-formulated” fluids (contaminated with 65 and 18 mg NDELA per l, respectively) than in nine workers (range, 0.4–1.3 μg/l exposed to “nitrite-free” fluids with lower levels of NDELA (range, 0.5–6.6 mg/l). Conclusion: The detailed methodology described in this work and applied to a limited industrial situation was found to be suitable for monitoring NDELA in the urine of workers exposed to aqueous MWF. A much larger screening has been undertaken with the aim of obtaining better information on the real exposure of workers sometimes exposed to “nitrite-formulated” fluids that are still used. Received: 8 December 1998 / Accepted: 3 April 1999     

中毒剂量锌对大鼠小肠粘膜超微结构的影响

目的：阐明中毒剂量锌对肠粘膜免疫屏障结构的影响及其机理。方法：通过建立常锌（ＺＮ）、中毒剂量锌（ＺＰ）大鼠模型,应用病理形态学手段（电镜）对大鼠肠道粘膜的超微结构进行研究。结果：第４周末和第７周末血浆、红细胞膜和肠组织的锌含量ＺＰ组明显高于ＺＮ组（Ｐ＜０．０５）。第四周末和第七周末ＺＰ组光镜下肠粘膜未见异常改变;但是电镜下见肠道粘膜超微结构的严重损害。结论：中毒剂量锌可以引起肠道粘膜超微结构的严重损害;屏障功能削弱,大鼠小肠粘膜的免疫防御能力降低。     

刺梨利康饮对慢性汞中毒脂质过氧化损害的拮抗作用

用８３７－４９μｍｏｌ／Ｌ 含汞水饲养大鼠８ 周,复制出慢性汞中毒模型,然后分别自由饮用含维生素Ｃ６８１２－７６μｍｏｌ／Ｌ 的利康饮和ｉｐ １２５ｍｇ／ｋｇ 二巯基丙磺酸钠（ＤＭＰＳ）３ 周,探讨利康饮和ＤＭＰＳ 对慢性汞中毒大鼠尿汞排泄和脂质过氧化损害的影响。结果发现,慢性汞中毒引起血清、肝、脑和肾还原型谷胱甘肽（ＧＳＨ） 含量显著降低,血清、肝、脑和肾丙二醛（ ＭＤＡ） 含量、尿蛋白含量及尿碱性磷酸酶（ＡＫＰ） 活性显著升高;利康饮可显著增加尿汞排泄和血清维生素Ｃ 含量,并使慢性汞中毒引起的血清、肝、脑和肾ＧＳＨ 含量显著回升,血清、脑和肾ＭＤＡ 含量、尿蛋白含量及尿ＡＫＰ 活性显著回降;ＤＭＰＳ 虽有明显促进尿汞排泄效果和使血清ＭＤＡ 含量显著回降的作用,但对慢性汞中毒引起的其它脂质过氧化损害指标影响不明显。结果表明,刺梨利康饮具有一定排汞效果,并对慢性汞中毒引起的机体抗氧化功能降低和脂质过氧化损害具有明显拮抗作用。