基准剂量在镉接触环境流行病学研究中的应用

[目的]通过环境流行病学研究，估测环境镉接触引起肾功能不全的基准剂量。[方法]镉污染区居住的居民为接触组，非污染区居民为对照组。尿镉(UCd)为接触生物标记物；β微球蛋白(UBM)、尿N-乙酰-β-D-氨基葡萄糖苷酶(UNAG)、尿视黄醇结合蛋白(URBP)和尿白蛋白(UALB)为效应生物标记物，并均用尿肌酐校正。[结果]长期接触镉可引起肾脏的损害。本次调查β2微球蛋白、视黄醇结合蛋白、尿NAG酶和尿白蛋白重污染区显著高于对照区，与尿镉的增长呈明显的剂量效应关系。计算得基准剂量(BMD)，推出基准剂量的95％低限水平(LBMD)。镉所引起的各肾脏损伤指标的LBMD值是不同的，大小依次为尿NAG同功酶B(NAG-B)、NAG、UBM和UALB。[结论]镉引起的肾小球损害晚于肾小管损害；而NAGB的基准剂量值最低，证明NAGB是监测肾小管损害的相对敏感的指标。     

基准剂量在镉性肾损伤健康风险评价中的应用研究

[目的]通过环境流行病学调查,研究镉性肾损伤健康风险评价中尿镉与尿β-微球蛋白、尿NAG酶间的剂量-反应关系及其相应的基准剂量,并通过基准剂量的比较确定敏感指标. [方法]选择黄石市某有色冶炼厂周边镉污染区居民为接触组,非污染区居民为对照组.尿镉为镉性肾损伤的内暴露指标,尿β-微球蛋白、尿NAG酶为效应指标,均用尿肌酐校正. [结果]尿镉与尿β-微球蛋白、尿NAG酶间存在明显的剂量-反应关系,尿NAG酶对应尿镉BMDL值(1.117 μg/g.cr)大于尿β-微球蛋白对应尿镉BMDL值(0.623 μg/g.cr). [结论]镉性肾损伤主要表现为肾小管损害,尿β-微球蛋白是该污染区镉性肾损伤健康风险评价的相对敏感的指标.     

镉经饮水染毒对去卵巢大鼠维生素D3代谢的影响

[目的 ]探讨镉经饮水染毒对去卵巢大鼠维生素D3 代谢的影响。 [方法 ]将雌性 6月龄SD大鼠行人工去卵巢术 ,分别经饮水给不同剂量的镉 ,2 4周后处死。用放射免疫法测定 2 5 羟维生素D3 和 1,2 5 双羟维生素D3 ,石墨炉原子吸收法测定血、尿镉 ,放射免疫法测定血清雌二醇、甲状旁腺激素 ,同时测定肾功能指标尿 β2 微球蛋白、尿N 乙酰 β D 氨基葡萄糖苷酶和尿钙。 [结果 ]去卵巢大鼠体内雌二醇下降 ,甲状旁腺激素显著升高。经镉染毒的去卵巢大鼠体内 1,2 5 双羟维生素D3 的水平降低 ,且有剂量 效应关系。而各组血清 2 5 羟维生素D3 水平无明显差异。与对照组相比 ,各镉染毒组的尿钙、β2 微球蛋白及NAG水平均升高 ,高剂量组 (2 0 0mg/L)有显著性差异。血液 1,2 5 (OH) 2 D3 水平与肾小管损伤指标尿 β2 微球蛋白及尿钙呈显著性负相关。 [结论 ]结果提示镉接触能造成去卵巢大鼠维生素D3 代谢损害 ,主要使活性维生素D3 水平下降 ,且与镉导致的肾功能损害相关     

低浓度环境镉暴露对全年龄段人群肾功能的影响

目的旨在确定镉暴露是否与儿童、青少年和成人的早期肾损害生物标志物相关联。方法按分层抽样方法,抽取1 235名调查对象,采集血、尿等生物样本进行检测,并对结果进行流行病学分析。结果男性尿镉的中位数为0.38μg/g肌酐,女性为0.42μg/g肌酐。多元线性回归表明,校正了性别、BMI、血铅和尿肌酐之后,在包含儿童的所有年龄组中,尿镉与肾小管生物标志物(NAG酶和β2微球蛋白)呈正相关,且儿童血镉和肾小管生物标志物呈正相关。结论在包含儿童在内的一般人群中,暴露于低浓度的镉依然会影响肾小管功能。     

镉砷接触工人肾功能损伤研究

目的　探讨镉、砷对作业工人肾功能的联合作用。方法　以我国中南某厂镉、砷作业工人 114名为本研究的职业接触对象。以尿镉 (UCd)、尿砷 (UAs)作为接触标志物 ,尿 β2 微球蛋白(Uβ2 MG)、尿白蛋白 (UALB)、尿N 乙酰 β D 氨基葡萄糖苷酶 (UNAG)作为镉、砷致肾小管和肾小球损害的效应标志物。结果　UCd、UAs水平与Uβ2 MG、UALB、UNAG水平间均为正相关 ,具有明显的剂量-效应关系 (P <0 .0 5 ,P <0 .0 1)。结论　镉、砷对作业工人肾脏功能的联合作用主要表现为相加作用。     

基准剂量法在职业性铅暴露评价中的应用

目的应用职业流行病学资料估算铅接触引起肾功能损害的基准剂量.方法 2002年4月至2003年5月,以血铅作为接触标志物,尿蛋白、尿N-乙酰-β-D-氨基葡萄糖苷酶（NAG）、尿β2-微球蛋白（β2-MG）作为效应标志物,将数据进行二分变量处理作为效应终点,采用基准剂量计算软件（BMDS 1.3.1）计算基准剂量反应为10%时,各效应标志物的血铅基准剂量和基准剂量的95%可信区间下限（BMDL）.结果肾功能3项指标异常率随血铅水平增高而增高,存在剂量-反应关系,其血铅的基准剂量为323.6～754.3 μg/L,BMDL值为274.2～541.5 μg/L,BMDL值大小依次为尿NAG、尿蛋白和尿β2-MG,尿NAG是监测肾功能损害的最敏感指标.结论基准剂量法应用到各种毒物参考剂量和参考浓度的制定中具有可行性.     

镉致作业工人肾功能损害可逆性研究初探

[目的 ]观察接受依地酸二钠 (EDTA)治疗慢性镉接触工人尿镉和肾功能改变 ,以探讨镉接触致肾损害的可逆性。 [方法 ]收集 1986年以来某冶炼厂接受EDTA治疗的 17名镉接触工人 (其中男 14名 ,女 3名 )每年治疗前后尿镉和尿 β2 微球蛋白 (β2 MG)的记录 ,分析其变化的情况。 [结果 ]尿 β2 MG一直异常 (≥ 0 8mg/g·Cr)或由正常转为异常的工人 ,尿镉平均水平基本高于 10 μg/g·Cr ,治疗期间尿 β2 MG一直正常或出现异常又转为正常的工人 ,尿镉平均水平在 10μg/g·Cr以下 ;整个治疗过程中 ,不论尿镉升高或降低 ,尿 β2 MG异常率均有所上升 ;随着镉接触终止时间的延长 ,尿 β2 MG没有下降 ;尿镉水平低于 10 μg/gCr ,肾损害可以恢复 ,反之 ,则不可逆。[结论 ]尿镉的水平是影响镉接触工人肾功能变化的主要因素 ,EDTA对镉接触工人肾功能损害没有明显疗效。     

慢性铅接触者肾损害早期监测指标的研究

[目的]估算引起肾功能损害的血铅的基准剂量(BMD)和基准剂量可信区间下限(LBMD)，探索铅接触引起肾损害的生物接触限值。[方法]选择某蓄电池厂的工人135名为铅接触组，以机械工人和学生为对照。观察了血铅含量与尿总蛋白(TP)、尿β2-微球蛋白(β2-MG)和尿N-乙酰-β-D-氨基葡萄糖苷酶(NAG)的关系。用BMDS Version1．3．1软件的logistic模型进行基准剂量估算。[结果]引起肾损害的血铅BMD和LBMD分别为299．4～588．7μg／L和253．4～402．3μg／L，引起肾损害血铅LBMD大小依次为TP、β2-MG和NAG。[结论]尿NAG是监测肾功能损害最敏感的指标，进行铅接触人群肾功能评价时血铅水平达到250～400／μg/L要引起重视。     

应用基准剂量法探讨砷、镉接触人群肾功能损害危险性评价

目的研究砷接触人群肾功能损害情况,探讨镉在砷接触人群肾功能损害方面与砷的联合作用。方法以贵州省地方病办公室1991年3月确诊并经1997年3月和2001年3月临床复查的122例砷中毒患者为本次调查对象,无砷污染区居民123名作为对照。以尿砷、尿镉作为接触标志物,尿β2微球蛋白(Uβ2MG)、尿白蛋白、尿N乙酰βD氨基葡萄糖苷酶(UNAG)作为砷、镉致肾小管和肾小球损害的效应标志物。同时分别计算尿砷、尿镉的基准剂量(BMD)及其下限值(BMDL)。结果接触组的接触指标和效应指标均高于对照组,尿砷、尿镉水平与Uβ2MG、尿白蛋白、UNAG水平间均为正相关,具有明显的剂量效应关系;砷、镉联合毒性比单独砷或镉同等剂量下的毒性更大。尿砷的BMD和BMDL值(以肌酐含量计)分别为12191～17188μg/g和10211～14444μg/g;尿镉的BMD和BMDL值(以肌酐含量计)分别为105～148μg/g和088～124μg/g。结论砷、镉联合毒性剂量明显低于单一毒性剂量,镉可能增强了砷在长期砷接触人群中对肾脏的损伤作用;运用BMD方法计算砷接触人群肾功能损伤尿砷、尿镉的BMD和BMDL值,尿砷、尿镉的BMDL值分别为以肌酐含量计10211μg/g、088μg/g。     

白银市某镉污染区人群尿镉基准剂量研究

目的估测环境镉接触致人群肾损伤的基准剂量(BMD),推出基准剂量的95%下限(BMDL),探讨镉的生物接触限值。方法选择甘肃省白银市某镉污染区居民为调查对象。以尿镉为人体镉负荷指标,以尿β2-微球蛋白和尿NAG酶为肾功能指标,应用BMD法对资料进行拟合与分析。结果随着体内镉接触水平的升高,Uβ2-MG和UNAG的异常发生率均明显升高,经趋势卡方检验,差异有统计学意义(P<0.01);选择Log-Logistic为最优模型计算尿镉BMD和BMDL,当以尿NAG为效应指标时,BMD/BMDL值为(6.46/5.21)μg/g·cr,以尿β2-MG为效应指标时,BMD/BMDL值为(3.16/2.26)μg/g·cr。结论在运用BMD法时应注意效应指标临界值的选取、剂量的设置以及最优模型的选择;建议以更为敏感的尿β2-MG为效应指标所计算的BMDL值为依据,适当降低尿镉的生物接触限值。     

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.     

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.     

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.     

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.