二硫化碳慢性接触对儿苯酚胺类代谢的影响

采用综合累积暴露指数，将工人接触ＣＳ２浓度和接触期限结构起来定量评价暴露强度，并检测尿中２－硫代噻唑烷－４－羧酸和儿茶酚胺类神经递质代谢产物的含量。结果显示：接触组尿中ＴＴＣＡ增高，存在剂量－效应关系；高接触组高香草酸和香草扁桃酸排泄减少。     

二硫化碳对大鼠神经递质及其代谢产物的影响

目的探讨二硫化碳ＣＳ２的神经毒作用机理。方法应用高效液相色谱法，观察大鼠染毒ＣＳ２（０、１２００、２４００ｍｇ／ｍ３）２个月后，脑组织单胺类递质、氨基酸类神经递质及其代谢产物的改变。结果ＣＳ２染毒可使大鼠纹状体中３－甲氧－４－羟基扁桃酸含量下降，多巴胺代谢产物３，４－二羟基苯甲酸和高香草酸含量升高，兴奋性氨基酸及其代谢产物（谷氨酰胺、门冬氨酸和门冬酰胺）含量下降，且３－甲氧－４－羟基扁桃酸、门冬氨酸及门冬酰胺含量与动物行为改变之间具有一定的相关性。结论神经递质代谢紊乱在ＣＳ２的神经毒作用机理中起了重要作用。     

接触二硫化碳对子代神经行为及尿5-HIAA水平的影响

目的研究怀孕前父、母亲有不同浓度二硫化碳(CS2)接触史的儿童神经行为功能和尿中5-羟吲哚乙酸(5-HIAA)改变。方法选择怀孕前父亲或母亲有CS2接触史者所生育的子女61名为接触组,按父母接触水平分为高浓度组和低浓度组。同时选取同一地区父母无任何毒物接触史的39名儿童为对照组,进行神经行为功能和尿中5-HIAA水平测试。结果父亲或母亲接触高浓度组儿童注意力、反应速度、心理运动能力、运动协调能力都受到影响,低浓度组仅在视感知和运动协调能力方面有所影响。分成母亲接触组、父亲接触组与对照组比较,除心理运动能力外未见到其他指标测试结果的差异有显著性。尿中5-HIAA水平,接触组与对照组儿童间差异未见有显著性。结论接触CS2对子代可产生一定的神经行为改变,且有一定的剂量-反应关系。     

接触二硫化碳对女工生育和月经的影响

生产场所中ＣＳ２对神经、心血管、内分泌系统毒性作用已引起人们的关注。动物实验表明,ＣＳ２具有生殖毒性和胚胎毒性,人群流行病学调查亦有报道接触女工的自然流产率、子代先天缺陷发生率、低体重儿出生率、早产率均显著高于对照组,月经失调发生率亦增高,似与生产环...     

二硫化碳职业接触对心血管系统的影响

二硫化碳(CS2)对神经系统的损害已确认,但对心血管系统的影响虽广泛认同,但尚未确认。本次通过82例职业性慢性轻度CS2中毒病人及66例对照组的血压、血脂及脂蛋白、心电图、眼底检查结果的分析,观察了CS2对心血管系统的影响,进一步了解CS2的中毒表现,并为今后研究提供了方向。     

职业性接触二硫化碳对神经行为功能影响研究

本文运用世界卫生组织推荐的神经行为核心测试组合对２３名接触二硫化碳的男性作业工人及年龄、文化程度和生活习惯与接触组相近的２９名对照工人的神经行为功能进行测试。结果表明：作业工人在接触平均ＣＳ２浓度为１２～５５ｍｇ／ｍ３、尿ＴＴＣＡ水平在０．９５３ｍｇ／ｇ·肌酐的情况下，４项神经行为测试（数据广度、视觉保留、数字译码和目标追踪）的得分显著低于对照组。进一步采用多元回归分析的方法调整年龄、文化程度对神经行为功能的影响，结果发现，数字译码测试项与接触工作环境ＣＳ２浓度呈负相关，而目标追踪测试项与工人尿ＴＴＣＡ水平呈负相关，提示长期高浓度接触ＣＳ２可影响作业工人的感知速度功能，而短期高浓度接触ＣＳ２影响精细操作控制和感知速度功能。     

二硫化碳对实验大鼠神经系统线粒体影响的实验研究

目的 探讨二硫化碳(CS2)染毒对大鼠线粒体复合酶以及ATP酶活力的影响.方法 健康雄性Wistar大鼠20只随机分成对照组和CS2组,每组10只,CS2组大鼠腹腔注射CS2玉米油溶液,开始4周染毒剂量为150 mg/Kg、1次/d、6次/周,后4周染毒剂量为300 mg/Kg、1次/d、6次/周.对照组腹腔注射等量的玉米油溶液.染毒结束后进行神经(感觉和运动)功能测试.提取脑组织、脊髓、坐骨神经的线粒体进行线粒体复合酶Ⅰ、Ⅱ、Ⅲ、Ⅳ和ATP酶的活力检测.结果 神经功能的测试结果表明CS2组染毒4周后在热板仪上停留的时问由对照组的12.48s延长到了22.35 s,到染毒8周时,其在热板仪上停留的时间比对照延长了182%;但在后肢撑力实验中,只有8周后肢撑力指数增加明显,是对照组的125%.另外坐骨神经中线粒体复合酶Ⅲ和Ⅳ的活力明显低于对照组,差异具有统计学意义(P＜0.05).染毒大鼠脑组织和脊髓中Na+-K+ATPase、Ca2+-Mg2+-ATPase的活力均呈下降的趋势,尤其是在脊髓中下降尤为严重;但在坐骨神经中只有Ca2+-Mg2+-ATPase的活力下降,差异有统计学意义(P＜0.05).结论 线粒体酶损伤可能参与CS2导致的神经系统毒作用.     

铅接触对神经行为功能和单胺类神经递质代谢的影响

对接铅工人的血铅、锌卟啉水平，行为功能和尿液中单胺类神经递质及其代谢产物的含量进行了研究。结果显示：血铅、锌卟啉的平均含量分别为３．４０μｍｏｌ／Ｌ和４．７μｍｏｌ／Ｌ，比对照组明显增高；尿液中高香草酸（ＨＶＡ）和肾上腺素（Ｅ）的含量显著高于对照组；工人的行为功能受到一定影响，表现为简单反应时、利手提转捷度、数字译码、视觉保留时间、目标追踪和情感状态的改变。结果提示：运用神经行为核心测试组合以及检测尿中肾上腺素、多巴胺及其代谢产物高香草酸和３，４－双羟苯乙酸的变化，有助于及早发现铅对神经系统的损害，以及探索铅致行为功能改变的生物学基础。     

职业接触二硫化碳生物接触限值的探讨

目的 探讨我国职业接触二硫化碳(CS2)的生物接触限值.方法 用高效液相色谱法测定工人班末尿中2-硫代噻唑烷-4-羧酸(TTCA)含量,用气相色谱法测定接触CS2工人作业场所空气中CS2浓度,探讨二者的相关关系,比较生物接触限值和PC-TWA判定结果.结果 CS2作业工人班末尿中TTCA含量与其接触的工作场所空气中CS2浓度呈正相关,回归方程式Y=0.265X-0.165 (r=0.91,P＜0.01).基于本次研究的回归方程,根据GBZ 2.1-2007《工作场所有害因素职业接触限值第1部分:化学有害因素》规定的CS2的PC-TWA 5 mg/m3推算,CS2接触工人班末尿中TTCA浓度生物限值为1.2 mgTTCA/g Cr.结论 建议我国CS2生物接触限值修订为1.2 mg TTCA/g Cr.     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.