双酚A雄性生殖毒性研究进展

目前,对环境雌激素双酚A(BPA)是否诱发雄性生殖毒性仍有争议.笔者就国内外关于BPA雄性生殖毒性的研究进行了综述.文献报道表明,BPA虽然胚胎毒性不明显,但对雄性动物具有生殖毒性,而且睾丸和前列腺为主要靶器官,即使低剂量暴露BPA亦可出现毒性效应.     

双酚A雄性生殖系统毒性的研究进展

双酚A(4,4’-二羟基二苯丙烷,BPA)是人类环境中广泛存在的具有雌激素样效应的内分泌干扰物,其对男性生殖的损害日益引起人们的关注。研究表明BPA对睾丸组织中不同类型的细胞均能产生毒性效应。本文就近年来BPA暴露对雄性生殖系统的研究成果进行综述。建议今后的研究工作中应加强对男性生殖流行病学方面的调查研究,深入探讨BPA的睾丸毒性机制,为暴露人群制定有效的干预策略。     

双酚A对生殖健康影响的研究进展

双酚A(Bisphenol A,BPA)是一种目前普遍存在的环境化学污染物,具有内分泌干扰特性及潜在的生殖毒性,可能影响人类生殖健康。正常人群中BPA检出率高,但其对生殖健康的潜在影响是不明确的。本文主要着眼于正常人群暴露BPA对生殖健康影响的相关研究,以期为BPA暴露与生殖健康关系的研究提供参考与建议。     

抗生素的雄性生殖毒性作用研究进展

近年来,随着不孕不育人数的快速攀升,外源性化学物的生殖毒理学研究已成为目前毒理学研究的热点.动物实验和流行病学调查结果表明,多种抗生素对精子有明显的损伤作用.在我国,抗生素在临床和养殖业中滥用现象非常普遍.而在使用抗生素时却忽视了抗生素对雄性生殖功能的影响.该文对抗生素的雄性生殖毒性作用进行了综述,以引起人们重视抗生素的生殖毒性作用,并为育龄男性临床合理用药提供参考依据.     

锰对雄性生殖功能的影响

近年来化学物的生殖毒性日益为人们重视。WHO第79届执委会第8个五年工作计划(1990～1995)已将人类生殖毒性研究列为重点研究项目之一。锰为古老而又接触面相当广泛的一种职业毒害,随着对其生殖毒性研究的深入,锰对雄性生殖系统毒性越来越受到重视。锰对雄性生殖功能的影响主要表现于性功能与性器官两个方面,分述如下。     

双酚A与不良妊娠结局的流行病学研究进展

双酚A(BPA)可通过饮水、食物、空气等途径进入人体,普通人群血清、尿液或妊娠妇女的羊水、绒毛膜、胎盘中可普遍检出ng级的BPA。BPA作为一种环境雌激素干扰物,有强烈的抗雄激素作用、弱雌激素样作用和胚胎毒性,可影响生殖健康。该文就母亲BPA暴露水平对人类不良妊娠结局(包括流产、早产和低出生体重)影响的相关流行病学研究进行综述,以期为后续BPA对人类生殖健康影响的研究方向和方法提供参考。     

汞及其化合物对雄性生殖毒性研究进展

近年来,环境对生殖的影响日益受到重视。国内、外许多学者已对汞对雌性生殖毒性及对子代健康发育的影响进行了广泛的研究,但有关汞及其化合物对雄性生殖毒性的研究则相对较少。本文就汞及其化合物对雄性生殖毒性研究做一综述,供开展深入研究参考。     

农药污染的雄性生殖毒性

在职业生产和日常生活中,农药污染物可通过皮肤、呼吸、消化道等多种途径进入体内,损伤生殖器官和生精细胞功能,影响内分泌功能,引起生殖相关基因的异常表达,从而影响男(雄)性精子发生的正常进行,导致男性少精、弱精、精子畸形或无精子症。为探讨农药污染对生精细胞毒性的一般规律与内在机制,该文对农药污染与雄性生殖毒性之间的关系进行综述,为预防并干预有机农药的雄性生殖毒性,保障生殖健康等提供基础资料。     

双酚A对断乳期SD大鼠F1子代雄性生殖发育影响

[目的]探索双酚A(BisphenolA,BPA)对断乳期F1雄性子代SD大鼠生殖和发育的影响. [方法]从孕0 d对母鼠染毒50 mg/kg、100 mg/kg、200 mg/kgBPA至断乳期停止染毒,对睾丸的Bax、Bcl-2、PCNA、ER的表达进行免疫组织化学分析. [结果]图象分析结果表明,随着BPA染毒剂量的增高,Bax表达的细胞灰度值有降低的趋势,50 mg/kg、100 mg/kg和200 mg/kg BPA组的Bax与对照组相比,差异均有统计学意义(P<0.05);而Bcl-2表达的细胞灰度值有增高的趋势;100 mg/kg、200 mg/kg BPA组的Bcl-2与对照组相比,差异有统计学意义(P(0.05);PCNA表达的细胞灰度值50 mg/kg,100 mg/kg,200 mg/kg BPA组与对照组相比.差异均有统计学意义(P<0.05);生精细胞ER表达的灰度值有增高的趋势,50 mg/kg,100 mg/kg,200 mg/kg BPA组与对照组相比,差异均有统计学意义(P<0.05).[结论]BPA导致F1雄性子代生殖发育毒性的机制,可能是导致生精细胞凋亡增强,增殖减慢,细胞内转录、表达受阻.     

维生素E对双酚A暴露的发育期雄性小鼠生殖系统及抗氧化能力的影响

目的研究双酚A(BPA)暴露对雄性小鼠生殖系统及抗氧化能力的影响,以及大剂量补充维生素E对BPA作用的影响。方法 32只4～5周龄雄性昆明小鼠随机分为3组,分别为空白对照组(玉米油灌胃0.2ml/d,n=10),BPA组(每天给予BPA 0.5mg/kg BW灌胃,n=11)和维生素E干预组(每天给予BPA 0.5mg/kg BW和维生素E 150mg/kg BW灌胃,n=11)。干预3周后处死动物,测量血和各组织抗氧化活性,并检测生殖功能指标。结果 BPA组的睾丸湿重,BPA组和维生素E干预组的精囊湿重、精囊脏器系数和精子计数显著低于空白对照组(P<0.05或P<0.01);而维生素E干预组精囊脏器系数显著高于BPA组(P<0.05);BPA组和维生素E干预组的精子畸形率显著高于空白对照组(P<0.01);BPA组精子活动度显著低于空白对照组与维生素E干预组(P<0.05)。BPA组和维生素E干预组肝脏SOD活力显著高于空白对照组(P<0.05)。BPA组血清睾酮水平低于维生素E干预组和空白对照组,但差异无显著性。结论双酚A的短期暴露对雄性小鼠的生殖系统可能产生一定抑制作用,并显示出对实验动物抗氧化能力增强;短期补充维生素E对双酚A暴露所引起的生殖系统抑制可产生一定保护作用。     

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.     

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.     

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.     

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.     

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.