苯并(a)芘和铅对小鼠大脑神经元损伤的研究

[目的]研究苯并(a)芘(BaP)、铅单独及其联合作用对小鼠大脑神经元DNA的损伤。[方法]将80只昆明种小鼠随机分为10组(每组8只) ,即空白对照组、溶剂对照组、低浓度铅染毒组、高浓度铅染毒组、低剂量BaP染毒组、高剂量BaP染毒组、低浓度铅+低剂量BaP联合染毒组、低浓度铅+高剂量BaP联合染毒组、高浓度铅+低剂量BaP联合染毒组及高浓度铅+高剂量BaP联合染毒组。空白对照组不作处理,溶剂对照组用等容量植物油平行处理;低、高浓度的铅染毒分别为5 .4、5 4mg/L的醋酸铅饮水染毒;低、高剂量BaP染毒分别为0 .5、5mg/kg的BaP植物油溶液,每周4次腹腔注射,联合染毒组接受两种处理。染毒8周后取各组小鼠脑组织制作细胞悬液,单细胞凝胶电泳法检测小鼠大脑神经元DNA的损伤。[结果]①单独染毒:BaP 5mg/kg染毒组小鼠大脑神经元DNA的损伤程度高于对照组(P <0 .0 5 )。②联合染毒:5 .4mg/L的醋酸铅+ 0 .5mg/kg的BaP染毒组(P <0 .0 5 ) ;5 .4mg/L的醋酸铅+ 5mg/kg的BaP染毒组(P <0 0 1) ;5 4mg/L的醋酸铅+ 0 .5mg/kg的BaP染毒组(P <0 .0 1) ;5 4mg/L的醋酸铅+ 5mg/kg的BaP染毒组(P <0 .0 1)小鼠大脑神经元DNA的损伤程度显著高于对照组。[结论]高剂量BaP连续8周暴露可损伤小鼠大脑神经元;BaP与铅对小鼠大脑的神经毒性有协同作     

正己烷对实验大鼠肝细胞凋亡的影响

[目的]研究正己烷（n-Hexane）对染毒大鼠肝细胞凋亡的影响。[方法]将40只雄性SD大鼠随机分成5组，即阴性对照组、75、150、300mg／kg染毒组和阳性对照组（环磷酰胺），每组8只。经腹腔注射染毒4周旨，观察大鼠的一般状况和体重变化，用流式细胞仪检测肝细胞凋亡情况。[结果]大鼠体重随染毒时间而增加，阴性对照组增加最快；流武细胞仪检测结果显示，肝细胞凋亡率（AV^＋／PI^-）组间比较差异有统计学意义（P〈0．01），与染毒剂量作相关分析，相关系数为0．913，无明显的相关性（P〉0．05）。[结论]正己烷可引起肝细胞凋亡和坏死比例的增加。     

谷胱甘肽对汞致肾细胞凋亡影响的实验研究

目的 探讨谷胱甘肽（GSH）对汞致肾细胞凋亡的影响，进一步阐明无机汞肾损伤的分子机制。方法 昆明种小鼠24只随机分成3组，即对照组、单纯汞染毒组和GSH干预组。单纯汞染毒组小鼠腹腔注射3．0mg／kg氯化汞（HgCl2）溶液，对照组腹腔注射0．9％的氯化钠溶液，注射量为每10g体重注射0．2ml。GSH干预组于注射3．0mg／kg，HgCl2溶液前2h腹腔注射3mmol／kg谷胱甘肽溶液。24h后将小鼠颈椎错位处死，制备透射电镜标本，观察凋亡细胞形态；免疫组化法检测凋亡相关基因bcl-2和bax蛋白表达。制备单细胞悬液，用流式细胞仪进行凋亡细胞百分数分析。结果 对照组小鼠肾近曲小管细胞形态规则；单纯汞染毒组表现微绒毛排列紊乱，染色质聚集成块，核破碎释放出凋亡小体，凋亡小体被邻近细胞吞噬等典型细胞凋亡形态；GSH干预组显示接近正常的肾小管上皮细胞的形态。凋亡细胞百分数汞染毒组明显高于对照组（P〈0．01），GSH干预组明显低于汞染毒组（P〈0．01）。免疫组化检测GSH干预组bcl-2蛋白的表达明显高于汞染毒组（P〈0．01）；bax蛋白的表达显著低于汞染毒组（P〈0．01）。结论 GSH可以抵抗汞所致的肾细胞凋亡，使凋亡相关基因bcl-2蛋白的表达上调，bax蛋白的表达下调。     

谷胱甘肽和牛磺酸对大鼠汞急性氧化损伤的影响

目的探讨谷胱甘肽(GSH)和牛磺酸对汞急性氧化损伤的影响。方法将32只Wistar大鼠随机分为对照、HgC12、GSH HgC12和牛磺酸 HgC124组。对照组皮下注射0．9％的生理盐水,HgC12组皮下注射2．5mg／kg体重的HgC12溶液。GSH HgC12和牛磺酸 HgC12组于注射相同剂量HgC12前2h分别腹腔注射3mmoL／kg体重的GSH溶液和4mmoL／kg体重的牛磺酸溶液。测定尿肌酐、尿汞含量和肝与肾GSH、丙二醛(MDA)、汞含量及谷胱甘肽过氧化物酶(GSH-Px)活力。结果与对照组比较,HgCl2组尿汞、肝汞、肾汞、肾MDA的含量和肾GSH-Px活力明显增加。预先给予GSH和牛磺酸,可使汞染毒大鼠。肾MDA含量均较HgCl2染毒组显著减低;肾GSH-Px活力既显著高于对照组,也显著高于HgCl2组。GSH组尿汞、肝汞显著低于HgCl2组。结论GSH和牛磺酸对汞致急性。肾氧化损伤有一定的保护作用。     

硫酸镍对雌性大鼠性腺机能的影响

目的 观察硫酸镍(NiSO4)腹腔注射染毒对雌性大鼠下丘脑-垂体-性腺轴的毒作用及其机制。方法 对健康性成熟Wistar雌性大鼠腹腔注射NiSO4 5．00，2．50，1．25mg/kg染毒，0．2ml／100g体重，1次／d，连续21d。阴道脱落上皮细胞涂片10d观察动情周期，第22d皮下注射人工合成促性腺激素九肽类似物(GnRH)前放免法测血清卵泡刺激素(FSH)、黄体生成素(LH)、孕酮(P)、雌二醇(E2)，注射GnRH后放免法测血清FSH、LH。第24d腹腔注射孕马血清促性腺激素(PMSO)，48h后腹腔注射人绒毛膜促性腺激素(HCG)后体视显微镜下挤出卵丘团，计数每只动物的超排卵数。同时取阴道、子宫、卵巢、垂体测镍含量。结果 5．00，2．50mg／kg组动物阴道、子宫、卵巢与NS组比较镍含量有显性差异；1．25mg,／kg组动物子宫、卵巢镍含量与NS组比较有显性差异；染毒组的动物出现动情周期延长；注射GnRH前，5．00mg／kg组血清FSH、LH与NS组比较有显性差异，注射GnRH后各染毒组血清FSH、LH与NS组比较均无显性差异；染毒5．00，2．50mg／kg组血清E2、P含量与NS组比较有显性差异；5．00mg／kg组动物超排卵数与NS组比较有显性差异。结论 腹腔注射硫酸镍染毒可引起雌性大鼠卵巢损伤，其机制可能与镍的直接作用和间接作用有关。     

构树叶总黄酮对表皮细胞防护作用研究

目的 研究构树叶提取物构树总黄酮(total flzvonoids of broussonetia papyrifera,TFBP)对铅、砷染毒的人永生化表皮细胞氧化损伤的防护效果。方法 在人永生化表皮细胞培养的基础上,在0．1mmol／L的醋酸铅、5．0μmol／L的亚砷酸钠的染毒体系中,分别加入0～200mg／L TFBP,测定细胞裂解液中丙二醛(MDA)含量和超氧化物歧化酶(SOD)和谷胱甘肽过氧化酶(GSH-Px)的活力,评价TFBP的抗氧化效果。结果 0．1mmol／L的醋酸铅对细胞染毒产生氧化损伤,而添加高于100mg／L TFBP后,MDA含量由4．23nmol／mg Pro降低到1．87nmol／mg Pro,SOD活力由25．90 U／mg Pro增加到37．12U／mg Pro,但GSH-Px的活力变化不大。砷 TFBP 150mg／L、200mg／L组与砷染毒组相比,GSH-Px和SOD活力差异有显著性。结论 该试验条件下,TFBP对铅、砷染毒的人永生化表皮细胞氧化损伤有防护效果。     

谷胱甘肽和牛磺酸对汞急性肾毒性影响的实验研究

目的 探讨预先投予GSH和牛磺酸对汞急性肾毒性的影响。方法 将32只Wistar大鼠随机分为对照、HgCl2染毒、GSH HgCl2和牛磺酸 HgCl2 4组。对照组皮下注射0．9％的生理盐水,汞染毒组皮下注射2．5mg／kg的HgCl2溶液,注射容量为5ml／kg。GSH和牛磺酸组于注射相同剂量Hg口2前2h分别腹腔注射3mmoL/kg的GSH溶液和4mmol／kg的牛磺酸溶液。测定尿N-Z乙酰-β-D氨基葡萄糖苷酶(NAG)、碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)活性,尿蛋白和尿肌酐含量,血清尿素氮(BUN)以及尿汞和肾汞含量。结果 与对照组比较,HgCl2染毒组尿NAG、ALP、LDH活性显著升高,尿蛋白、BUN、尿汞、肾汞含量明显增加。预先投予GSH和牛磺酸后,可使汞染毒大鼠尿NAG和ALP活性、尿蛋白和BUN含量均较HgCl2染毒组显著减低;GSH组尿汞显著低于单纯染汞组,而牛磺酸组尿汞、肾汞与汞染毒组比较差异则无显著性。结论 GSH和牛磺酸对汞致急性肾损伤有一定的保护作用。     

用彗星试验检测苯并(a)芘致小鼠体细胞DNA的损伤

[目的]建立彗星试验检测苯并（a）芘腹腔染毒小鼠体细胞DNA损伤的方法。[方法]雄性昆明种小鼠随机分为空白对照组、溶剂对照组和高、中、低剂量3个染毒组，每组4只。3个染毒组和溶剂对照组分别腹腔注射二甲基亚砜（0．01ml／g体重）和苯并（a）芘（250、125、62．50mg／g体重）。染毒3h后，处死小鼠，取出肝、肾和小肠组织制备单细胞悬液用于彗星试验。IMI彗星分析软件分析彗星尾距（oliver tail moment，TM）评价细胞DNA损伤的程度。[结果]高剂量组小鼠肝、肾和小肠细胞的彗星尾距值均增加，中、高剂量组小肠细胞的彗星尾距值均是溶剂对照组的5．22倍（P〈0．05）；中、高剂量组小鼠肾细胞的尾距值分别是溶剂对照组的8．27和7．16倍（P〈0．05）。高剂量组肝细胞的彗星尾距值是溶剂对照组的3．99倍。低剂量组仅小肠细胞的彗星尾距均值（1．285μm）增加（P〈0．05）。[结论]彗星试验可检测苯并（a）芘腹腔染毒小鼠肝、肾和小肠细胞的DNA损伤。     

定量脑电图变化与对硫磷中毒救治中阿托品使用剂量的关系

[目的]探索定量脑电图（quantitative electroencephalography,QEEG）变化与有机磷中毒过程中阿托品使用剂量的关系。[方法]90只健康Sprague-Dawley90天龄大鼠随机分为空白对照组（10只）、阳性对照组（10只）、染毒组（固定剂量对硫磷＋不同剂量阿托品）（7组,70只）。染毒组腹腔注射固定剂量对硫磷（5mg／kg）＋递增剂量阿托品（阿托品剂量分别为：10、20、50、100、200、500、750mg／kg）;空白对照组给予腹腔注射玉米油5mg／kg;阳性对照组腹腔注射对硫磷5mg／kg。给药后第0、5、10、20、30、60、120min测大鼠QEEG（每次测定5min）并采用癫痫分级评价阿托品中毒状态下行为学得分。[结果]随着阿托品剂量递增,6频段功率相应增大：阳性对照组和10、20、50、100、200、500、750mg／kg剂量染毒组脑电图6功率分别为：7．52±0．33、7．14±0．37、7．38±1．36、7．80±0．68、16．26±1.77、29．24±2．74、31．41±2．94、36．17±2．37;其6功率与阿托品剂量呈剂量依赖关系（r=0．946,P=0．000）。癫痫分级评价结果显示随阿托品剂量增加,癫痫得分相应增加。[结论]QEEG中6频段功率能够反映有机磷中毒过程中阿托品剂量改变,癫痫分级能够反映大鼠中毒状态下行为学改变。     

环磷酰胺对小鼠免疫抑制的动物模型建立

[目的]建立肿瘤化疗免疫抑制动物模型，为建立保健食品减轻化疗毒副作用功能的评价方法提供科学依：活。[方法]给予C57BL／6J正常小鼠和荷瘤小鼠腹腔内注射不同剂量的环磷酰胺(CP)，隔日连续腹腔注射4—5次，观察：对小鼠免疫学指标及肝肾功能的影响。[结果]正常小鼠和荷瘤小鼠腹腔注射20、50、100me／kg体重的CP后，各剂量组均出现不同程度的免疫抑制和肝肾功能损伤。①正常小鼠20mg／kg体重以上剂量组，白细胞计数、抗体生成细胞以及巨噬细胞功能显著下降，谷草转氨酶(AST)升高；50mg／kg体重剂量组的脾脏指数下降；50mg／kg体重以上剂量组天然杀伤细胞(NK)细胞活性均出现显著下降，以及谷丙转氨酶、尿素的升高。②荷瘤小鼠20mg／kg体重以上剂量组白细胞计数、巨噬细胞功能显著下降，50mg／kg体重以上剂量组脾脏指数、NK细胞活性、抗体生成细胞功能均出现显著下降，以及谷草转氨酶、各丙转氨酶、尿素的升高。③正常小鼠注射60mg／kg体重的CP后，血清白细胞介素-2及肿瘤坏死因子均出现显著下降；荷瘤小鼠注射60mg／kg体重的CP后，血清白细胞介素．2出现显著下降。[结论]给予C47BL／6J正常小鼠和荷瘤小鼠腹腔注射20-50mg／kg体重的CP，隔日连续45次，即可建立免疫抑制动物模型。建议采用正常小鼠免疫抑制模型。     

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.     

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.     

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.     

The risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.