甲基叔丁基醚职业暴露人群淋巴细胞遗传损伤研究

目的研究甲基叔丁基醚(MTBE)暴露对淋巴细胞遗传毒性损伤,为建立MTBE职业人群暴露限值体系提供参考。方法人B淋巴母细胞分别用不同浓度MTBE溶液染毒24 h,彗星实验检测细胞尾部DNA百分比及Olive尾矩,Annexin V-FITC/PI双染流式细胞术检测细胞凋亡百分比。选择某炼化厂60名MTBE职业暴露工人为暴露组,55名未接触MTBE工人为对照组,微核实验检测外周血淋巴细胞微核率,彗星实验检测外周血淋巴细胞尾部DNA百分比及Olive尾矩,酶联免疫吸附试验检测外周血血浆丙二醛(MDA)、8-羟基脱氧鸟苷(8-OHd G)及谷胱甘肽-过氧化物酶(GSH-Px)水平。结果人B淋巴母细胞经10、12.5μmol/L的MTBE染毒24 h后,尾部DNA百分比、Olive尾矩和细胞凋亡百分比均高于对照组(P0.05)。暴露组工人外周血微核阳性率为8.93%,高于对照组的3.92%,但差异无统计学意义(P0.05);暴露组尾部DNA百分比为(15.70±7.67)%,高于对照组的(14.65±6.20)%,差异无统计学意义(P0.05);暴露组Olive尾矩为7.00±4.94,高于对照组的3.84±1.97(P0.01);暴露组与对照组工人血浆MDA、8-OHd G及GSH-Px水平差异均无统计学意义(P0.05)。结论MTBE暴露可诱导人B淋巴母细胞和人外周血淋巴细胞发生遗传损伤。     

彗星分析用于放射工作者DNA损伤评价研究

目的 探讨不同放射工种、工龄的放射工作人员DNA损伤水平。方法 采用碱性彗星分析方法检测放射组和对照组外周血淋巴细胞的DNA单链断裂水平。CASP软件分析彗星图像,主要观察彗星尾部DNA百分含量(TDNA%)、彗星尾长(TL)、尾矩(TM)和Olive尾矩(OTM)等指标,用SPSS 13.0软件进行统计学分析。结果 放射组的TDNA%,TL,TM,OTM明显高于对照组(F=5.26,P < 0.01),不同工种,工龄间差异均有统计学意义(F=2.67,P <0.01)。结论 放射性工作人员DNA损伤程度与放射工龄和工种有一定的相关性。     

镉致人肝癌细胞DNA损伤不同检测方法比较

目的观察镉对人肝癌细胞SMMC-7721DNA的损伤作用,探讨CASP软件在单细胞凝胶电泳（SCGE）结果分析中的应用。方法用SCGE检测不同浓度CdCl2作用SMMC-7721细胞24h后对DNA的损伤。用传统计数分级的方法分析SCGE结果,计算DNA脱尾率;用CASP软件分析,得出彗星头部（HDNA%）和尾部DNA百分含量（TDNA%）、彗星尾长（TL）、彗星全长（CL）、尾矩（TM）Olive尾矩（OTM）6个指标。结果CdCl2作用于SMMC-7721细胞24h后,肿瘤细胞DNA的彗尾逐渐变长。除40μmol/L剂量组处。传统方法分析得5,10,20μmol/L剂量组肿瘤细胞脱尾率逐渐加大,与对照组比较差异有统计学意义（P〈0.05）;CASP分析得10,20μmol/L剂量组细胞彗星头部DNA百分含量逐渐降低,尾部DNA百分含量增加,彗星尾长和全长及尾矩和Olive尾矩值均增大,细胞DNA损伤逐渐加重,各项指标与对照组比较差异有统计学意义（P〈0.05）。结论镉可以导致人肝癌细胞SMMC-7721DNA的损伤。CASP软件分析结果与传统方法一致,并可以提供多个指标,具有简便客观的优点。     

甲醛暴露工人外周血淋巴细胞遗传物质损伤水平的研究

目的评价甲醛暴露工人外周血淋巴细胞DNA和染色体损伤水平。方法选择2家密度板厂151名甲醛暴露工人(暴露组)和某推土机厂112名非甲醛暴露工人(对照组)为研究对象,用气相色谱法检测作业环境的甲醛浓度,采用彗星试验和胞质分裂阻滞微核试验,评价其外周血淋巴细胞DNA和染色体损伤水平。结果暴露组工人作业环境中的甲醛8h时间加权平均浓度(0.10～7.88mg/m3)高于对照组(<0.01mg/m3)。高暴露组Olive尾矩为3.95,95%CI为3.53～4.43;低暴露组Olive尾矩为3.03,95%CI为2.49～3.67;对照组Olive尾矩为0.93,95%CI为0.78～1.10,各组间差异均有统计学意义。暴露组彗星尾长为6.78,95%CI为6.05～7.60,均高于对照组,差异有统计学意义。高暴露组彗星尾长为12.59,95%CI为11.80～13.43;低暴露组彗星尾长为11.25,95%CI为10.12～12.50,差异无统计学意义。高暴露组的微核率为(0.65±0.36)%,低暴露组的微核率为(0.41±0.25)%,对照组的微核率为(0.27±0.13)%,各组间的差异均有统计学意义。各指标均有随暴露水平增加而增高的趋势,按吸烟情况分层后仍有增高的趋势。结论甲醛暴露可导致工人外周血淋巴细胞的DNA和染色体损伤水平增高,并且有随暴露水平增加而增高的趋势。     

甲醛暴露工人XRCC1基因多态性与DNA损伤的关系研究

目的探讨甲醛暴露工人DNA修复基因XRCC1多态性与外周血淋巴细胞DNA损伤的关系。方法选择某密度板厂的151名甲醛暴露工人(暴露组)和某推土机厂的112名非甲醛暴露工人(对照组)为研究对象。用气相色谱法检测作业环境的甲醛浓度,应用彗星实验测定研究对象外周血淋巴细胞DNA损伤,以Olive尾距和彗星尾长反映DNA损伤水平,用PCR-RFLP方法分析XRCC1基因的多态性;用多元协方差分析调整工人的年龄、工龄、职业甲醛暴露及吸烟与饮烟情况,比较XRCC1基因不同基因型个体的Olive尾距和彗星尾长。结果使用多元协方差分析校正甲醛暴露工人的年龄、工龄、甲醛暴露水平和吸烟与饮酒情况后,携带Arg280His位点变异基因型个体的Olive尾距和彗星尾长(几何均值分别为4.30和13.42)均显著高于野生型基因型的个体(几何均值分别为3.38和11.71),差异均有显著性(Olive尾距:P<0.05,彗星尾长:P<0.01);未发现XRCC1基因其他3个位点的多态性与甲醛暴露工人Olive尾距和彗星尾长有显著关联。结论XRCC1基因Arg280His位点的多态性影响甲醛暴露工人的DNA损伤水平。     

氧化乐果对小鼠睾丸Sertoli细胞DNA的损伤作用

目的 研究有机磷农药氧化乐果对小鼠睾丸Sertoli细胞DNA的损伤作用.方法 将40只清洁级昆明雄性小鼠随机分为对照(蒸馏水)组和1.0、2.0、4.0 mg/kg氧化乐果染毒组,每组10只.采用灌胃方式进行染毒,染毒容量为20 ml/kg,每天1次,连续染毒14d.采用单细胞凝胶电泳技术检测小鼠睾丸Sertoli细胞的DNA损伤情况.结果 与对照组比较,2.0、4.0 mg/kg氧化乐果染毒组彗星长度均明显增加,各剂量氧化乐果染毒组彗星尾长、Olive尾矩、尾长/头长、尾部DNA含量也均升高,差异有统计学意义(P＜0.05).且随着氧化乐果染毒剂量的升高,各指标均呈上升趋势.结论 氧化乐果对小鼠睾丸Sertoli细胞DNA有明显的损伤作用.     

电子垃圾处理区域人群遗传损伤的研究

目的 探讨长期居住在电子垃圾处理环境中居民遗传损伤.方法 于2005年11月在天津市郊县电子垃圾处理较集中的3个村采集居民1 256份血液标本进行染色体核型分析,从中随机抽取171份血液标本进行微核实验,随机抽取12份标本进行彗星试验.对照组为远离电器拆废地区的60位村民(男女各半).结果 暴露组染色体结构畸变率为6.23%,染色体数目畸变率为0.29%.随体相连、四射体等均超出了正常范围,与对照组比较有统计学意义(P＜0.05);暴露组微核出现率为16.99‰,对照组为3.47‰,差异有统计学意义(P＜0.01).彗星试验结果显示,暴露组头、尾部DNA百分含量、尾长、彗星全长、尾矩、Olive尾矩高于对照组,差异均有统计学意义(P＜0.001).结论 居住在该电子垃圾处理区域人群的染色体畸变率、微核发生率及彗星电泳检测的DNA损伤率均高于对照组.提示不科学的电子垃圾处理产生的污染物是该地区人群潜在的遗传诱变剂.     

电子废物回收处理污染对人类的遗传毒性

目的 对长期居住在天津市近郊某镇电子垃圾处理较集中的3个村庄的居民进行细胞遗传学研究,分析电子垃圾污染物对人体的损伤效应.方法 在当地居民中随机选择171位村民进行染色体畸变(CA)和胞浆阻滞微核(CBMN)分析,并进行彗星分析检测DNA损伤.选取与该镇毗邻区域且从未接触电子垃圾处理的30位村民(男女各半)作为对照组.结果 暴露组染色体总畸变率5.50%,与对照组差别有统计学意义(P<0.01);微核率暴露组16.99‰,对照组3.47‰,差异有统计学意义(P<0.01);彗星分析检测彗星尾部DNA百分含量(TDNA%)、尾矩(TM)、Olive尾矩(OTM)差异均有统计学意义(P<0.01).女性的染色体畸变率、微核率和DNA损伤水平均明显高于男性.结论 电子垃圾污染物是潜在的遗传诱变剂,能够造成污染人群的细胞遗传学损伤.     

低浓度苯系物暴露与加油站工人淋巴细胞遗传损伤的关系研究

目的探讨低剂量接触苯系物对加油站工人外周血淋巴细胞的DNA损伤作用。方法采用彗星试验检测加油站暴露组与对照组工人外周静脉血淋巴细胞DNA损伤,采用气相色谱-质谱法检测相应工作区空气中苯系物的浓度。结果暴露区苯、甲苯、乙苯、二甲苯浓度均高于对照区(P0.001);暴露组彗星尾矩和Olive尾矩均高于对照组,差异均有统计学意义(P0.05)。结论长期低浓度苯系物暴露可能导致加油站工人淋巴细胞DNA遗传损伤。     

三种方式染毒丙烯酰胺对雄性小鼠睾丸细胞DNA损伤的影响

目的 研究腹腔注射、灌胃、皮肤染毒丙烯酰胺(AA)对小鼠睾丸细胞DNA损伤的影响.方法 将24只清洁级健康雄性昆明小鼠随机分为4组,分别为空白对照组、腹腔染毒组、灌胃染毒组和皮肤染毒组,每组6只.染毒剂量为25mg/kg,每天1次,连续染毒5 d.首次染毒后第6天称体重和睾丸重,计算睾丸系数.采用单细胞凝胶电泳实验对彗星细胞的尾长、尾部DNA%、尾矩(tail moment,TM)、Olive尾矩(olive tail moment,OTM)进行检测.结果 染毒后腹腔染毒组和灌胃染毒组小鼠体重均低于空白对照组,差异有统计学意义(P＜0.01).与空白对照组比较,腹腔染毒组、灌胃染毒组和皮肤染毒组小鼠的睾丸重量及其脏器系数均较低,差异均有统计学意义(P＜0.05或P＜0.01).与空白对照组比较,腹腔染毒组、灌胃染毒组和皮肤染毒组小鼠睾丸细胞DNA的尾长、尾部DNA%、尾矩、Olive尾矩均较高,差别有统计学意义(P＜0.05或P＜0.01).各染毒组两两比较发现,睾丸细胞DNA的尾长、尾部DNA%、尾矩、Olive尾矩间差异均有统计学意义(P＜0.05),均以灌胃染毒组最高,腹腔染毒组次之,皮肤染毒组最低.结论 丙烯酰胺可致雄性小鼠睾丸细胞产生DNA损伤,且以灌胃染毒方式产生的毒性作用最为敏感.     

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.     

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.     

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.     

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.     

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.