大气PM_(2.5)对大鼠心血管系统的急性毒性作用

目的观察大气PM2.5对机体心血管系统的影响,比较PM2.5对不同生理、病理状态下大鼠心血管系统毒性的差异。方法在上海市非工业区采集大气PM2.5,选取SH和WKY大鼠各24只,采用气管滴注染毒方法给大鼠肺灌注不同剂量PM2.5,观察PM2.5对不同机体心血管系统的急性毒作用,测量染毒后动物血清心肌酶学(乳酸脱氢酶LDH和肌酸激酶同工酶CK-MB)及血压、心率、心电图。结果大鼠PM2.5染毒后,测定大鼠血清心肌酶发现,WKY和SH大鼠血清LDH和CK-MB随染毒剂量增加而增加,且与对照组相比有统计学差异;同时SH大鼠各实验组心肌酶含量除CK-MB的低剂量组外均高于WKY大鼠的相应组含量,表明PM2.5对SHR的心血管毒性作用可能大于对WKY大鼠的作用。此外,两种大鼠肺灌注PM2.5后血压和心率与对照组相比有明显改变,且染毒后大鼠心电图ST段与T波发生改变。结论结果提示暴露于PM2.5对机体心血管系统有一定的损伤作用,心肌出现缺血缺氧反应。     

炎性因子在大气PM2.5心血管毒性中的作用研究

探讨炎性因子在PM2.5心血管毒性中的可能作用机制。PM2.5染毒心血管内皮细胞24h后，提取内皮细胞中的mRNA，通过逆转录多聚酶链式反应（RT-PCR）技术及电泳的方法确定PM2.5染毒前后心血管内皮细胞中IL-4、嗜酸性粒细胞活化趋化因子（extaxin）相对含量的变化。结果表明随着大气PM2.5染毒浓度的增加，0.05mg/ml，0.2mg／ml染毒组心血管内皮细胞中IL-4和extaxin mRNA表达产物的相对含量显著增高，说明IL-4、extaxin等Ⅰ型变态反应相关炎性因子在PM2.5的心血管毒性中可能起一定作用。     

气管滴注硫酸镍对大鼠炎症和肺损伤发生的影响

目的观察气管滴注硫酸镍对大鼠的急性毒性作用及其机制。方法将28只体重为280～310g的雄性Wistar大鼠随机分为对照组、硫酸镍低、中、高剂量组,根据镍在细颗粒物中的含量,设计镍的染毒剂量分别为7.5、75和750μg/kg。采用一次性气管滴注染毒,24h后处死动物,收集支气管肺泡灌洗液(BALF)进行细胞计数,总蛋白(TP)、乳酸脱氢酶(LDH)和炎性因子(IL-6、TNF-α)的测定;收集血液测定血清中炎性因子(IL-6、TNF-α)、C-反应蛋白(CRP)和镍的水平。结果不同剂量硫酸镍均可引起大鼠BALF中白细胞总数、中性粒细胞数、巨噬细胞显著升高(P<0.01),较高剂量Ni(75和750μg/kg)可引起BALF中TP水平、LDH活力和炎性因子IL-6、TNF-α水平显著增高(P<0.05或P<0.01);硫酸镍染毒24h后,大鼠血清TNF-α水平明显增高,与对照组相比差异有显著性(P<0.05);血清CRP水平随硫酸镍剂量升高而增高,但仅高剂量组差异有显著性(P<0.05)。此外,随着硫酸镍染毒剂量的增加,血清中镍水平也呈现明显的上升趋势。结论硫酸镍气管滴注可引起Wistar大鼠急性肺损伤和全身炎症反应,与含相同剂量镍的PM2.5相比,硫酸镍的作用较弱,提示镍在PM2.5的毒性作用中可能发挥重要作用,但PM2.5中其他成分的作用也不容忽视。     

气管滴注大气细颗粒物对大鼠的急性毒性

目的 探讨大气细颗粒物(PM2.5)对大鼠的急性毒性作用及其可能的作用机制.方法 将28只体重为280～310 g的雄性Wistar大鼠随机分为4组,即空白对照组、颗粒物低、中、高剂量组(7.5、15和30 mg/kg).采用一次性气管滴注染毒颗粒物,24h后处死动物,进行支气管肺泡灌洗液(BALF)细胞计数,并对BALF中总蛋白(TP)、乳酸脱氢酶(LDH)和炎性因子(IL-6、TNF-α)的水平进行测定.同时观察了不同染毒组大鼠血清中炎性因子(IL-6、TNF-α)和C-反应蛋白(CRP)的水平.结果 各染毒组大鼠BALF白细胞总数、中性粒细胞数、TP及TNF-α水平均较对照组高,差异均有统计学意义(P＜0.05或P＜0.001).与对照组比较,各染毒组大鼠血清IL-6和CRP水平升高,差异均有统计学意义(P＜0.05或P＜0.001);中、高剂量组TNF-α水平升高,差异均有统计学意义(均P＜0.05).结论 大气细颗粒物能引起染毒大鼠肺脏急性损伤和全身炎症,后者可能与其心血管系统损伤机制有关.     

沙尘暴PM25、PM10对大鼠肺泡巨噬细胞炎性因子分泌的影响

目的：探讨沙尘暴PM2.5、PM10对大鼠肺泡巨噬细胞分泌NO、白细胞介素8(IL-8)及肿瘤坏死因子-α(TNF-α)的影响。方法沙尘暴颗粒物样品采自北京市城区,实验细胞为原代培养的大鼠肺泡巨噬细胞。细胞毒性测定用四甲基偶氮唑盐微量酶反应比色(MTT)法,NO的测定用Griess重氮化反应法,细胞因子IL-8、TNF-α的测定采用放射免疫法。结果(1)沙尘暴PM2.5、PM10作用24h后对大鼠肺泡巨噬细胞产生一定的细胞毒性。随着染毒剂量的增加,巨噬细胞存活率逐渐减低,高剂量组约为对照的80％。(2)20～150μg／ml的沙尘暴PM2.5、pm10染毒24h后均能剂量依赖性地诱导巨噬细胞分泌炎性因子NO、IL-8及TNF-α。(3)沙尘暴PM2．5的细胞毒性比相同浓度的PM10大,而对巨噬细胞分泌炎性因子NO、TNF-α的作用却小于PM10,结论：沙尘暴PM2.5、PM10可刺激大鼠肺泡巨噬细胞分泌炎性因子NO、IL-8及TNF-α。     

不同地区大气PM2.5致大鼠肺损伤的比较实验研究

目的利用动物实验比较不同地区大气PM2.5对呼吸系统的毒性作用。方法采集广州、东莞、深圳和肇庆4个城市的大气PM2.5。将雄性SD大鼠分为3个染毒组(10、3和1 mg/kg)和1个对照组,每组7只。4个城市的PM2.5均按此分组并染毒。气管滴注PM2.5,对照组滴注等量生理盐水。分别于48 h和28 d后处死动物,收集左侧肺和一定量的肺泡灌洗液(BALF),观察肺部病理变化和测定灌洗液中总蛋白(TP)、超氧化物歧化酶(SOD)、乳酸脱氢酶(LDH)、白介素-6(IL-6)和肿瘤坏死因子(TNF-α)的变化。结果肇庆地区大鼠体重增长率较高,东莞地区最低。PM2.5主要导致间质炎性细胞浸润、支气管炎症等。与对照组比较,PM2.5导致肺泡灌洗液中TP、LDH、IL-6和TNF-α水平增高,SOD活力降低,差异有统计学意义(P<0.05)。广州PM2.5组LDH的漏出量最高,深圳PM2.5组肺泡灌洗液中SOD活力最低,东莞PM2.5组肺泡灌洗液中IL-6释放量最高,肇庆PM2.5染毒48 h组SOD活力均高,LDH、TNF-α、IL-6均较低。结论本次采集的四城市大气PM2.5可致大鼠肺组织发生氧化应激损伤和炎性反应。广州、东莞、深圳PM2.5对上述效应指标的影响强于肇庆。     

乙酸铅暴露对雄性大鼠心血管系统的炎性作用

目的探讨乙酸铅经口暴露对雄性大鼠心血管系统炎性指标的影响。方法将40只健康成年SPF级雄性Wistar大鼠随机分为4组,分别为对照(0 mg/kg)组和90、180、360 mg/kg乙酸铅染毒组,每组10只。采用经口灌胃方式进行染毒,染毒容量为10 ml/kg,每天1次,每周连续染毒5 d,持续染毒60 d。测定大鼠血铅、血浆内皮素1(ET-1)、血清细胞间黏附分子-1(ICAM-1)及血清和心脏组织匀浆中白介素-1β(IL-1β)、白介素-6(IL-6)、白介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)的表达水平;同时,观察大鼠心脏和胸主动脉组织病理学变化。结果与对照组相比,各剂量乙酸铅染毒组大鼠的血铅水平均升高,差异有统计学意义(P0.05);且随着乙酸铅染毒剂量的升高,大鼠的血铅水平呈上升趋势。与对照组相比,360 mg/kg乙酸铅染毒组大鼠血浆ET-1和血清ICAM-1水平均升高,差异有统计学意义(P0.05);且随着乙酸铅染毒剂量的升高,大鼠的血浆ET-1和血清ICAM-1水平均呈上升趋势。与对照组比较,360 mg/kg乙酸铅染毒组大鼠血清中IL-β、IL-8和TNF-α的水平及180 mg/kg乙酸铅染毒组大鼠血清中IL-8和TNF-α水平均升高,差异有统计学意义(P0.05);而各剂量乙酸铅染毒组大鼠血清中IL-6的水平均无明显改变。且随着乙酸铅染毒剂量的升高,大鼠血清中IL-β、IL-6、IL-8和TNF-α的水平均呈上升趋势。与对照组比较,仅360 mg/kg乙酸铅染毒组大鼠心脏组织匀浆中IL-8水平升高,差异有统计学意义(P0.05);而各剂量乙酸铅染毒组大鼠心脏组织匀浆中IL-1β、IL-6、TNF-α的水平均无明显改变。且随着乙酸铅染毒剂量的升高,大鼠血清中IL-8和TNF-α的水平均呈上升趋势,而IL-β、IL-6的水平均呈先上升后下降的趋势。大鼠血清和心脏组织匀浆中IL-8和TNF-α水平均呈正相关(均P0.05),而两者IL-1β和IL-6水平间无统计学相关性(P0.05)。病理学检查可见,180、360 mg/kg乙酸铅染毒组心脏组织出现炎性细胞浸润,360 mg/kg乙酸铅染毒组血管组织外膜出现炎性细胞浸润。结论乙酸铅对大鼠心血管系统具有一定的炎性损伤作用。     

清肺化痰中药对大气PM2.5致大鼠肺损伤的干预作用研究

目的探讨中药清肺化痰丸对大气PM2.5致大鼠肺损伤的干预作用。方法于某居住区采集大气PM2.5。健康成年SD雄性大鼠64只随机分为8组:每组8只,分别为空白对照组(不做任何处理)、生理盐水对照组(气管滴注1.5 ml/kg生理盐水)、溶剂对照组(每天灌胃给予10 ml/kg的0.2%羧甲基纤维素,共1周)、干预对照组(每天灌胃给予2.40 g/kg清肺化痰丸,共1周)、染毒对照组(气管滴注40 mg/kg的PM2.5生理盐水混悬液染毒,隔天1次,共3次)以及低、中、高剂量干预组(气管滴注40 mg/kg的PM2.5生理盐水混悬液染毒,隔天1次,共3次,再每天分别灌胃给予0.65、1.20和2.40 g/kg清肺化痰丸,共1周。收集肺泡灌洗液(BALF)进行细胞计数,并测定BALF中酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、乳酸脱氢酶(LDH)、总蛋白(TP)、白蛋白(ALB)、白介素-1β(IL-1β)、白介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平。结果与生理盐水对照组比较,染毒对照组大鼠BALF中ACP、AKP、LDH活力和TP、ALB、IL-6、IL-1β、TNF-α含量及中性粒细胞百分比均升高,差异均有统计学意义(P0.05)。与染毒对照组比较,各剂量干预组大鼠BALF中ACP、AKP、LDH活力和TP、ALB、IL-6、IL-1β、TNF-α含量及中性粒细胞百分比均降低,差异均有统计学意义(P0.05),且随干预剂量的升高其降低幅度增加。结论中药清肺化痰丸对气管滴注PM2.5导致的肺损伤有一定减轻作用。     

某部地下工程作业环境中空气颗粒物对肺脏的毒理学研究

目的研究地下工程作业环境空气中颗粒物对肺脏的毒理效应。方法将采集的PM10和PM2.5制成颗粒物悬液,采用气管滴注法对6组Wistar大鼠进行染毒,每天1次,连续染毒7d。最后一次染毒结束24h后,处死大鼠,取肺泡灌洗液进行分析,检测总蛋白(TP)、巨噬细胞炎性蛋白-2(MIP-2)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)的含量或活力。肺组织作病理切片。结果随染毒剂量的增大,各项指标均出现含量或活力增高,PM10高剂量组与对照组相比,差异均有统计学意义(P0.01),PM10中剂量组与对照组相比,差异均有统计学意义的指标有TP(P0.05)、LDH(P0.01)和AKP(P0.05)。PM2.5中剂量组与对照组相比,差异有统计学意义的指标有LDH(P0.05)和AKP(P0.01)。而PM10低剂量组和PM2.5低剂量组与对照组相比,差异无统计学意义。结论地下工程作业环境中空气PM10和PM2.5能够引起肺部血管通透性改变和肺组织损伤。     

大气PM2.5对自发性高血压大鼠心脏的急性毒作用

[目的]了解敏感个体急性暴露PM2.5可能出现的心脏损伤。[方法]12-13周龄的雄性自发性高血压 (spontaneous hypertension,SH)大鼠24只,随机分4组,其中3个实验组分别气管滴注不同浓度的PM2．5颗粒物悬浮液1．6、 8．0、40．0 mg/kg体重,对照组气管滴注生理盐水,连续染毒3 d。[结果]各组大鼠的心脏/体重比值相差不大。高浓度组与对照组相比,心脏生长转化园子β1(transforming growth factor-β1,TGF-β1)的mRNA表达明显升高(P<0．01)。心脏病理学改变随着染毒浓度的增加越加严重。[结论] PM2.5对SH大鼠心脏有一定的急性毒作用,并可引起心脏重构。     

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.