3,4-双(4’-氨基呋咱基-3’)氧化呋咱对小鼠骨髓细胞微核和染色体的影响

为探讨3,4-双(4’-氨基呋咱基-3’)氧化呋咱(DATF)对小鼠骨髓细胞的遗传毒性,将健康SPF级昆明小鼠按体重随机分为5组,分别为0(阴性对照)、67.5、135、270 mg/kg DATF染毒组和阳性对照[40 mg/kg环磷酰胺(CP)]组,每组10只,雌雄各半。采用小鼠骨髓嗜多染细胞微核试验检测微核率和嗜多染红细胞与正染红细胞(PCE/NCE)的比值,采用骨髓细胞染色体畸变试验检测染色体畸变率。结果显示,各剂量DATF染毒组与阴性对照组小鼠体重和骨髓PCE微核率、PCE/NCE值和染色体畸变率间比较,差异均无统计学意义。提示在本实验剂量范围内,DATF对小鼠骨髓细胞无致突变和致畸变效应。     

长期低剂量接触2,3,7,8-四氯二苯并-p-二噁英对大鼠骨髓细胞微核和精子形态的影响

目的了解长期低剂量接触2,3,7,8-四氯二苯并-p-二噁英(TCDD)对雄性SD大鼠骨髓细胞微核和精子形态的影响。方法将1月龄SD大鼠随机分为4组,分别为阴性对照组(给予玉米油)和3个TCDD染毒组(日染毒剂量为2、10、50ng/kg)。13周后,另设微核阳性对照组(环磷酰胺,日染毒剂量为60mg/kg,连续3d)观察骨髓嗜多染红细胞微核率和精子畸形率。结果长期低剂量接触TCDD导致大鼠骨髓细胞微核率增加,精子畸形率增高。阴性对照组、2、10、50ng/kg染毒组、阳性对照组微核率分别为9.0‰,13.0‰,21.2‰,24.4‰和87.4‰,10、50ng/kg组微核率均高于阴性对照组(均P0.01);对照组、2、10、50ng/kg组精子畸形率分别为10.4‰,35.0‰,49.8‰,47.0‰,各染毒组畸形率均高于对照组(均P0.01),畸形以颈折叠为主。结论长期低剂量接触TCDD对哺乳动物体细胞和雄性生殖细胞具有致突变性,且生殖细胞对TCDD的毒性更敏感。     

牛磺酸对镉染毒小鼠的保护作用

[目的]初步探讨牛磺酸对镉所诱导的遗传毒性的拮抗作用。[方法]①小鼠骨髓嗜多染红细胞微核检测：受试动物按单纯氯化镉剂量分为：O．70mg、1．35mg、2．70mg三级及相应的加牛磺酸(1000mg／l(g)三组，另设阴性对照组和环磷酰胺组，共八组，分别计算其微核率。②小鼠精子畸形检测：按单纯氯化镉剂量为：0．50、1．00mg／kg二级及相应的加牛磺酸(1000mg／kg)二组，另设阴性对照组和环磷酰胺组，共六组，计算其精子畸形率。③受试动物分单纯氯化镉组(1．35mg／kg)、牛磺酸组(1000mg／kg)及相应的牛磺酸加氯化镉组，再设阴性对照组，共四组，用原子吸收分光光度法测其肝脏、睾丸中的镉(Cd)、铜(Cu)、锌(Zn)元素含量的变化。[结果]氯化镉各组脏器中CA含量均高于阴性对照组；牛磺酸加氮化镉各组肝脏Cd、Cu、Zn含量均为明显高于氯化镉各组，睾丸中Cd含量(0．539μg／g)则明显低于氯化镉各组(O．683μg／g。氯化镉各组小鼠骨髓嗜多染红细胞微核率分别为6．75‰、10．88‰、11.13‰和精子畸形率分别为40．88‰、59．00‰，明显高于阴性对照组(微核率1．88‰、精子畸形率33．38‰)，牛磺酸加氯化镉各组，微核率分别为4．75‰、5．13‰、5．63‰和精子畸形率分别为27，13‰、30．57‰，明显低于相应的氯化镉组。[结论]牛磺酸使急性镉中毒小鼠体内元素分布发生一定变化，且对镉的遗传毒性有一定的拮抗作用。     

四乙酰基六氮杂异伍兹烷致小鼠骨髓细胞突变性的实验研究

目的通过小鼠骨髓嗜多染红细胞微核试验及小鼠骨髓细胞染色体畸变试验研究四乙酰基六氮杂异伍兹烷(TAIW)的致突变性。方法两个试验各取50只SPF级小鼠随机分为5组,分别为阴性对照组,阳性对照组(环磷酰胺30mg/kg)和3个TAIW染毒组(剂量分别为500、1 000、2 000mg/kg),每组10只,雌雄各半。采用小鼠骨髓嗜多染红细胞微核试验检测微核率,小鼠骨髓细胞染色体畸变试验检测染色体畸变率。结果 TAIW 3个剂量组微核率(3.95‰、3.4‰、3.75‰)和嗜多染红细胞与正常红细胞的比值(1.06、1.05、1.03)与阴性对照组(3.85‰、0.95)比较,差异均无统计学意义(P0.05),TAIW 3个剂量组染色体细胞畸变率(0.5%、1.1%、1.5%)与阴性对照组(0.4%)比较,差异无统计学意义(P0.05)。结论当前试验条件下,TAIW无诱发骨髓细胞微核和染色体畸变的作用。     

香烟烟雾水溶物对小鼠的急性毒性和骨髓嗜多染红细胞微核率的影响

[目的]探讨香烟烟雾水溶物对雄性健康小鼠的急性毒性作用及其对骨髓嗜多染红细胞微核率的影响。[方法]以香烟烟雾水溶物为试验材料,用Horn's法测其LD50,进行小鼠骨髓嗜多染红细胞微核试验。[结果]该香烟烟雾水溶物的LD50为56.2 mg/kg,95%可信区间为33.8~82.5 mg/kg,按毒性分级标准,该水溶性提取物的毒性为中等毒;其低、中、高(1/8 LD50、1/4 LD50、1/2 LD50)剂量组的微核率分别为4.0‰、6.2‰、10.2‰,明显高于阴性对照组的1.8‰,并在一定范围内呈现明显的剂量-反应关系。[结论]香烟烟雾水溶物对小鼠有较强的急性毒性,属于中等毒,可引起小鼠骨髓嗜多染红细胞微核率增高,有一定的致突变作用。     

DBP、DOP对小鼠的联合遗传毒性

目的：采用微核试验和精子头部畸形试验研究邻苯二甲酸二丁酯（DBP）、邻苯二甲酸二辛酯（DOP）对小鼠的联合遗传毒性。方法：（1）微核试验：试验用昆明种小鼠50只，雌雄各半，体重18－22g，随机分为5组，每组10只。各组每天灌胃一次，连续5d，最后一次染毒后6h处死动物，取胸骨骨髓按常规方法制片。观察嗜多染红细胞的微核细胞率（‰）。（2）精子头部畸形试验：48只雄性小鼠，体重25－30g，分组及染毒剂量（以单次染毒剂量计）同微核试验。连续灌胃5d，第一次染毒后35d处死动物。分离两侧附睾置1ml生理盐水中，剪碎，吸管吹吸5－6次，使精子充分游离，滤去组织碎片，用1％Eosin Y染色30min，涂片高倍镜检。每只小鼠观察1000个完整无重叠精子，计数不同类型的畸形精子数目，计算精子畸形率（‰）及畸形精子类型构成比。结果：低剂量组（0．033g/kg)、中剂量组（0．33g/kg)和高剂量组（3．3g/kg)的微核率分别为1．74‰、5．42‰、4．88‰，其中高剂量组和中剂量组的微核率均显著高于对照组；低剂量组、中剂量组和高剂量组精子畸形率分别为3．74％、5．69％、6．32％，与对照组相比均有显著性差异。结论：微核试验结果显示，DBP、DOP能引起染色体丢失或断裂等染色体畸变。精子头部畸形试验结果表明，DBP、DOP可穿透血睾屏障作用于生殖细胞，干扰正常的生精过程。由于精子头部畸形基本不影响受孕能力，因而其对后代的潜在危害性可能更为严重。     

氯乙烯诱变性研究

目的近一步研究不同剂量下氯乙烯对哺乳动物的致突变作用及生殖毒性.方法通过小鼠静式吸入染毒法进行精子畸变试验和微核试验的方法,观察氯乙烯的致微核率和精子畸变率.结果试验动物经氯乙烯染毒后,精子畸变试验中高、中、低染毒组畸变率分别为4.12%、2.88%、2.32%,与阴性对照组畸变率1.46%相比差异均有非常显著性(P＜0.01);微核试验高、中、低剂量组微核率分别为13.1‰、9.5‰、8.4‰,与阴性对照组微核率3.3‰相比差异亦均有非常显著性.结论氯乙烯可能具有诱变作用.     

甲醛与苯对小鼠遗传毒性联合作用的研究

目的探讨甲醛和苯对小鼠遗传毒性的联合作用。方法将健康昆明种小鼠随机分为阴性对照组、甲醛组、苯组、联合组、阳性对照组,进行小鼠骨髓细胞微核试验及精子畸形试验。结果苯组、甲醛组和甲醛、苯联合组小鼠骨髓细胞微核率分别为（13．5±1．27）‰、（11．9±0．99）‰、（25．5±1．58）‰及精子畸形率分别为（101．2±4．22）‰、（94．8±3．71）‰、（167．2±3．78）‰,均明显高于各自的阴性对照组（P〈0．01）。析因分析表明,甲醛和苯联合染毒致小鼠骨髓细胞微核率及精子畸形率交互作用显著（P〈0．01）。结论析因分析量效曲线随染毒剂量增大而远离,甲醛及苯联合染毒对小鼠遗传毒性有协同作用。     

苯和二硫化碳诱导小鼠骨髓嗜多染红细胞微核的研究

目的探讨苯和二硫化碳对雌性小鼠体细胞遗传物质的影响.方法采用静式吸入法分别用苯和二硫化碳染毒NIH成年雌性小鼠15 d(2 h/d),分析受试小鼠骨髓嗜多染红细胞微核细胞率.结果苯染毒低、中、高剂量组浓度分别为706、1 922、4 864 mg/m^3,三剂量组的微核细胞率依次为7.2‰、7.3‰、8.3‰,与阴性对照组(2.1‰)比较有显著性差异(P＜0.05),二硫化碳染毒低、中、高剂量组浓度分别为199、651、1 209 mg/m^3,三剂量组的微核细胞率依次为3.0‰、4.2‰、5.1‰,中剂量组和高剂量组与阴性对照组比较有显著性差异(P＜0.05),具有较好的剂量-效应关系.结论苯和二硫化碳均能诱导雌性小鼠体细胞微核增加.     

吸入甲醛对小鼠精子畸形率和骨髓细胞微核率的影响

[目的]探讨吸入甲醛对小鼠生殖细胞和体细胞的遗传毒性作用。[方法]用不同剂量（5．18g／m^3、2．59g／m^3、1．29g／m^3）的甲醛静式吸入染毒小鼠5d和4d，均于末次染毒24h后颈椎脱臼处死小鼠，观察甲醛对小鼠精子畸形率和骨髓细胞微核率的影响。[结果]高剂量组的精子畸形率为3．88％，微核率为8．63‰，均超过正常值，且与阴性对照组比较差异均有统计学意义（P〈0．05）。[结论]吸入一定浓度的甲醛对小鼠生殖细胞和体细胞具有致遗传毒性作用。     

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.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

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.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.