长期接触低浓度二硫化碳对暴露人群DNA损伤的影响

目的 应用彗星试验方法检测长期接触低浓度二硫化碳(CS2)职业人群的口腔黏膜细胞DNA损伤以及损伤程度。方法 在湖北省某大型化纤厂随机抽取90例CS2接触工人作为暴露组,同时选择81例非接触工人作为对照组,进行彗星试验。结果 暴露组和对照组的彗星细胞拖尾率分别为0．51％和0．23％,经X^2检验,差异有非常显著性。另外,低作业年限暴露组(0．50％)和男性暴露组(0．56％)的彗星细胞拖尾率均非常显著高于对照组,分别为0．08％和0．25％。多因素非条件logistic回归分析结果表明,CS2暴露组DNA损伤的可能性明显高于对照组。结论 长期接触低浓度CS2,对工人口腔黏膜细胞的DNA有一定损伤。     

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。     

香烟烟气溶液和砷致淋巴细胞DNA损伤的协同作用

目的研究香烟烟气溶液和亚砷酸钠联合作用对大鼠淋巴细胞DNA的损伤,并探讨两者对DNA的损伤是否存在交互作用。方法大鼠淋巴细胞分为4组:亚砷酸钠单独作用组、香烟烟气溶液单独作用组、两者联合作用组和对照组,染毒后用单细胞凝胶电泳试验(彗星试验)检测淋巴细胞DNA的损伤,并检测细胞内丙二醛含量,同时采用2×2析因设计研究两者的交互作用。结果亚砷酸钠单独作用组、香烟烟气溶液单独作用组和两者联合作用组的彗星尾长和细胞拖尾率分别为[(11.68±3.79)μm,36%;(17.26±5.57)μm,75%;(32.10±6.18)μm,96%]均大于对照组[(6.74±1.09)μm,10%],差异均有统计学意义性(P<0.01)。而各染毒组细胞内丙二醛含量也高于对照组,差异有统计学意义(P<0.01)。析因设计分析结果表明,香烟烟气溶液和亚砷酸钠对彗星尾长的影响存在交互作用(P<0.01),对细胞内丙二醛含量的影响也存在交互作用(P<0.01),交互作用方式均为协同作用。结论香烟烟气溶液和亚砷酸钠对大鼠淋巴细胞DNA损伤存在交互作用,交互作用方式为协同作用。     

肝细胞癌与DNA修复能力关系

目的 探讨DNA修复能力(DRC)与肝细胞癌(HCC)的关联性。方法 运用彗星试验,检测150例新发HCC患者(病例组)和150例非肿瘤患者(对照组)的DNA修复能力。结果 博莱霉素(BLM)暴露前,病例组彗星尾长和尾矩分别为(3.98±2.35)和(1.41±0.85),对照组尾长和尾矩分别为(3.60±2.04)和(1.24±0.66),2组尾长和尾矩差异均无统计学意义(P>0.05);BLM暴露后经15min修复,病例组尾长和尾矩分别为(6.60±3.11)和(2.59±1.56),对照组尾长和尾矩分别为(4.69±2.44)和(1.58±0.96),2组尾长和尾矩差异均有统计学意义(P<0.01);用尾长作为检测指标计算DRC时,2组DRC中位数分别为78.65%和93.81%,差异有统计学意义(P<0.01);用尾矩作为检测指标计算DRC时,2组DRC中位数分别为77.78%和93.11%,差异有统计学意义(P<0.01)。结论 DNA修复能力低下可能是HCC发生的高危因素之一,可作为预警人群中HCC发病的生物标志物。     

镉对小鼠睾丸生殖细胞DNA损伤作用研究

目的 研究氯化镉对小鼠睾丸生殖细胞DNA的损伤作用.方法 用不同浓度氯化镉分别对小鼠睾丸细胞进行处理,分为阴性对照组(生理盐水)、微剂量组(0.04mmol\LCdCI2)、低剂量组(0.2mmol\L CdCI2)、中剂量组(1mmol\LCdCI2)、高剂量组(5mmol\L CdCI2),用单细胞凝胶电泳法分别计数各组400个细胞,按照不同的损伤程度进行分类;并分别测量各组50个彗星细胞尾长并计算均方值.结果 各组小鼠睾丸生殖细胞损伤率和尾长均方分别为阴性对照组8.0%、8.543±2.131,微剂量组48.5%、24.761±3.595,低剂量组65.0%、39.246±5.894,中剂量组71.5%、42.745±5.231,高剂量组87.5%、49.374±4.543;4个剂量组小鼠睾丸细胞DNA损伤率显著高于阴性对照组(P＜0.001),四个剂量组小鼠睾丸细胞DNA损伤的彗星细胞尾长均方值显著高于阴性对照组(P＜0.001),并且DNA损伤率和彗星细胞尾长均方值随着剂量增加而增加.结论 微量氯化镉对小鼠睾丸生殖细胞DNA即已存在明确损伤作用,且损伤程度与氯化镉剂量成正比.     

焦化作业工人淋巴细胞HSP70表达及作用

目的探讨热应激蛋白70（HSP70）在焦炉工人外周血淋巴细胞的表达水平及其意义。方法用微核试验和碱性单细胞凝胶电泳技术（彗星试验）检测淋巴细胞的染色体畸变和DNA损伤情况，用蛋白印迹（westem blot）法检测淋巴细胞HSP70表达水平。结果外周血淋巴细胞微核率和彗星尾长在高暴露组显著高于对照组，差异有统计学意义（P〈0．05）；HSP70的表达水平在高暴露组、低暴露组和对照组分别为1．12±0．36。1．34±0．83。0．89±0．40，低暴露组明显高于对照组（P〈0．05）；高暴露组工人的外周血淋巴细胞HSP70的表达水平与彗星尾长呈负相关（r=-0．416，P=0．03）。结论焦炉作业环境可诱发外周血淋巴细胞HSP70蛋白表达，较高水平HSP70的表达对细胞DNA损伤具有保护作用。     

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。     

抗肿瘤药接触对护士的遗传损伤

目的观察无特殊防护措施的职业性接触抗肿瘤药物所产生的遗传损伤。方法用胞质阻断微核试验(CBMN)和彗星试验(SCGE)检测某医院肿瘤科接触抗肿瘤药物的24名护士和非接触抗肿瘤药物的24名女医生(对照)外周血淋巴细胞的DNA和染色体损伤。结果暴露组微核细胞率为13.25‰±5.17‰,显著高于对照组3.79‰±2.19‰,P<0.01,暴露组彗星全长为(43.13±17.82)μm,也明显高于对照组(27.52±5.69)μm,P<0.01。结论肿瘤科护士外周血淋巴细胞的染色体和DNA已受到不同程度的损伤。     

饮水型砷暴露人群淋巴细胞DNA损伤影响因素分析

目的探讨饮水型砷暴露地区人体外周血淋巴细胞DNA的损伤。方法应用彗星试验,检测54例地砷病区有皮损患者(病例组)和51名无皮损者(对照组)外周血淋巴细胞DNA损伤水平。采集研究对象的尿液检测尿砷水平。调查研究对象年龄、性别、吸烟、饮酒、农药接触史等。结果病例组和对照组彗星尾长分别为(12.34±5.22),(7.35±3.67)μm,差异有统计学意义(P0.05);2组尿砷分别为(1.61±0.41),(1.52±0.55)ng/1 000 g肌酐,差异无统计学意义(P0.05);Logistic回归分析结果显示,吸烟和饮水年限为DNA损伤的危险因素。未发现饮酒对淋巴细胞DNA的损伤有影响。结论吸烟和饮水年限是DNA损伤的危险因素,彗星试验可作为砷污染地区人群健康监测的早期指标。     

锰致神经元细胞DNA损伤作用

目的 建立体外染锰细胞模型,探讨锰神经毒性作用机制。方法 成熟原代皮层与低、中、高不同浓度的锰液,(分别为0.2,0.6,1.0 mmol/L,共孵育24 h。观察各组神经细胞形态学的变化,单细胞凝胶电泳试验(SCGE)检测神经细胞的DNA损伤,以彗星细胞尾长及彗星样细胞百分率为评价损伤指标。结果 光镜下可见不同浓度锰孵育后神经细胞形态学发生改变,SCGE显示神经细胞DNA出现不同程度的损伤,彗星尾长分别为(117.3±30.8),(136.6±29.0),(218.7±22.6)μm;彗星样细胞百分率分别为40%,43%,96%,2指标均较对照组((84.1±11.8)μm,15%)显著增加(P<0.01)。尤以高浓度锰损伤组严重,显著高于中、低浓度组(P<0.01)。结论 锰不但能引起体外培养的神经细胞外在的形态学损伤,还可导致神经细胞DNA损伤。     

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.