大气污染物所致大鼠深部呼吸道损伤的研究

目的 探讨大气污染物引起机体呼吸道炎症的机制，为控制大气污染、制定防治对策提供依据。方法 将体重在180—220g的80只大鼠随机分为4组，即对照组、低剂量组、中剂量组、高剂量组，分别进行颗粒物和SO2、NO2染毒，颗粒物染毒采用气管注入法，各注入颗粒物7．5，15，30mg，灌注体积为lm1，对照组注入同体积的生理签水。染尘后的第2d，再进行SO2和NO2混合气体染毒，低、中、高剂量组的SO2和NO2的浓度分别为8，5；16，10；32，20mg／m^3，对照组为空气。连续染毒7d后，于染毒后的第ld处死一半大鼠，第8d处死其余大鼠。分别进行血清中酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、唾液酸(SA)、乳酸脱氢酶(LDH)、铜蓝蛋白(CP)、总蛋白、白蛋白和肺泡灌洗液(BALF)中ACP、AKP、SA、LDH、总蛋白的测定。结果 染毒后第ld，高剂量组大鼠血清中AKP、SA、CP白蛋白水平高于对照组，有显性差异(P＜0．05)，第8d高剂量组大鼠血清中SA、CP、白蛋白水平高于对照组(P＜0．05)。高剂量组大鼠染毒后第ld BALF中SA、LDH、和总蛋白水平高于对照组(P＜0．05)；第8d LDH和总蛋白仍呈高水平(P＜0．05，P＜0．01)。结论 大气污染物可致大鼠肺泡膜破坏，可能是呼吸道和肺部损伤的机制之一。     

大气污染对大鼠细胞因子的影响

目的　分析大气污染对大鼠细胞因子的影响 ,以揭示大气污染对呼吸系统损害及机体影响的机制 ,为预防和治疗大气污染对健康的损害提供依据。方法　将体重在 1 80～ 2 2 0g的大鼠随机分为 4组 ,即对照组、低剂量组、中剂量组、高剂量组 ,分别进行颗粒物和SO2 、NO2 染毒 ,颗粒物染毒采用气管注入法 ,各注入颗粒物 7 5 ,1 5 ,30mg ,灌注体积为 1ml,对照组注入同体积的生理盐水。染尘后的第 2d ,再进行SO2 和NO2 混合气体染毒 ,低、中、高剂量组的SO2 和NO2 的浓度分别为 8,5mg/m3;1 6 ,1 0mg/m3;32 ,2 0mg/m3,对照组为空气。连续染毒 7d后 ,于染毒后的第 1d和第 8d取腹主动脉血 ,采用ELISA法测定血清中IL - 4和IFN -r。结果　染毒后第 1d ,中、高剂量组大鼠血清中IL -4显著高于对照组 (P <0 0 5) ,到染毒后第 8d ,中剂量组IL - 4水平与对照组无差异 ,但高剂量组仍显著高于对照组。而大鼠血清IFN -r呈下降趋势 ,中、高剂量组大鼠血清IFN -r显著低于对照组 ,到染毒后第 8d ,仍未恢复正常。升高的IL - 4促进IgE分泌 ,IFN -r的减少使对IL - 4的抑制作用减弱 ,也间接使IgE升高。结论　大气污染物可诱导大鼠IL - 4的增高和IFN -r的下降 ,从而导致TH1与TH2之间失衡 ,使呼吸系统疾病和变态反应性疾病发生     

大气污染物对大鼠肺细胞毒性及病理学研究

目的探讨大气污染物对大鼠肺细胞毒性及病理学改变.方法 80只Wistar大鼠(体重180～220g)随机分为4组,即对照组和实验组(低、中、高剂量组),分别进行总悬浮颗粒物(TSP)和SO2、NO2染毒.TSP染尘采用气管注入法,实验组分别注入TSP(7.5,15,30mg)生理盐水混悬液1ml,对照组注入1ml生理盐水.染尘后第2d,实验组静式吸入含SO2和NO2的空气混合气,SO2的浓度分别为8,16,32mg/m^3;NO2浓度分别为5,10,20mg/m^3,对照组吸入一般空气.连续染毒7d后,计数支气管肺泡灌洗液(BALF)中WBC总数、嗜酸细胞(Eos)数及细胞分类,电镜下观察肺组织超微结构变化.结果高剂量组WBC总数显著高于对照组(P＜0.05);随着剂量的增加,肺泡壁增厚明显,高剂量组出现肺间质结缔组织增生、泡壁不光滑及肺泡融合.结论大气污染物可导致肺组织发生急性炎症,呼吸面积极度变小,并有早期硬化改变.     

大气混合污染物对大鼠肺组织CC16及细胞因子的影响

目的测定大气污染物对大鼠肺组织CC16、TNF-α和IL-6的mRNA表达影响。方法用日本产低流量PM10空气采样器采集PM10颗粒物,采样滤膜用生理盐水超声震荡洗脱,混悬液定容为15mg/ml。48只体重为200~240g Wistar大鼠随机分为3个实验组和1个对照组。实验组大鼠分别气管注入15mg/ml PM10的生理盐水混悬液1ml,对照组大鼠注入1ml生理盐水。次日,实验组大鼠静态吸入浓度分别为15、12、400mg/m3的SO2、NO2、CO空气混合气,每天吸入2h,对照组吸入正常空气。于吸入气体污染物1天、7天和30天后次日分别处死实验组和对照组大鼠,取肺组织,采用RT-PCR方法测定TNF-α、IL-6和CC16的mRNA表达水平;采用免疫组化和Western blotting测定肺和BALF中CC16的水平。结果吸入大气污染物组在吸入后1天和7天其肺组织CC16 mRNA的表达量明显低于对照组;细胞因子TNF-α和IL-6 mRNA表达增强,高于对照组,并于染毒初期即染毒第1天和第7天增高明显,染毒第30天,又呈下降趋势。免疫组化检测显示,实验组大鼠肺组织CC16表达水平在染毒后1天,7天时显著高于对照组,而在30天时低于对照组。BALF中CC16表现为1天和7天时显著低于对照和30天组。结论大气污染物作用于大鼠呼吸系统后,大鼠肺组织和BALFCC16表达量下降,TNF-α和IL-6 mRNA表达增强,并且在污染物作用早期变化明显。     

SO2和NO2混合气对大鼠呼吸系统的影响

目的探讨二氧化硫(SO2)和二氧化氮(NO2)混合气对大鼠呼吸系统的影响及损伤机制。方法40只成年大鼠随机分为4组，即1个对照组和3个染毒组，静式吸入染毒。3个染毒组sch和N02浓度分别为：低浓度组8，5mg／m^3：中浓度组16，10mg/m^3；高浓度组32，20mg／m^3，对照组吸入正常清洁空气。每天染毒2h，连续21d。乙醚麻醉下腹主动脉取血，做肺泡灌洗(BAL)，测定血清及肺泡灌洗液(BALF)中酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、谷胱甘肽-S转移酶(GST)的活性及白蛋白、丙二醛(MDA)含量。结果染毒后大鼠血清和BALF中ACP、AKP活性增强；白蛋白、MDA含量增加；高浓度组BALF中SOD活性明显下降，与对照组比较有显著性差异。结论SO2和NO2混合气可引起肺上皮细胞通透性增加及肺组织氧化损伤。     

大气混合污染物致大鼠肺氧化损伤作用

目的 探讨大气混合污染物对大鼠肺损伤的作用.方法 48只Wistar大鼠随机分为4组,即对照组和实验组(实际、中、高剂量组),进行可吸入颗粒物(PM10)及混合气体(SO2、NO2、CO)染毒.染尘采用一次性气管注入法,混合气体染毒采用静式吸入法,每天2 h,连续30 d.测定血清及支气管肺泡灌洗液(BALF)中相关生化酶的活性和脂质过氧化指标水平.结果 实验组BALF中的乳酸脱氢酶(LDH)活性(4.03,2.98,3.63 U/ml)及总蛋白水平(1.14,0.71,0.98 g/L)均显著高于对照组(1.91 U/ml,0.37 g/L),差异有统计学意义.高剂量丙二醛(MDA)平均水平(2.10 mmol/ml)明显高于对照组(0.95 mmol/ml,P＜0.05);实验组超氧化物歧化酶(SOD)活性(18.32,25.72,16.82 U/ml)均明显低于对照组(40.88 U/ml,P＜0.01);血清中各指标水平变化不明显.结论 大气混合污染物可引起肺的氧化损伤,并导致大鼠肺细胞膜的通透性增强.     

大气混合污染物对大鼠肺炎性损伤作用的研究

[目的]探讨大气混合污染物对大鼠肺炎性损伤的作用.[方法]48只Wistar大鼠随机分为l个对照组和3个实验组(高、中、实际剂量).实验组大鼠PM10的染尘剂量分别为16、8、13.8mg;SO2、NO2、CO混合气的染毒浓度分别为16、12、400mg/m3,8、6、200mg/m3,4.6、3.2、164mg/m3,每天吸入2h,连续吸入30d;对照组大鼠气管注入1ml生理盐水并吸入正常空气.测定染毒大鼠支气管肺泡灌洗液(BALF)中白细胞数及其分类,ACP、AKP、LDH活性、总蛋白和白蛋白含量以及FN-γ、TNF-α、IL-6水平.[结果]实验组大鼠BALF中巨噬细胞(AM)、中性粒细胞(Neu)百分比及LDH活性增高,与对照组比较差异均有统计学意义,并呈现出剂量-效应关系;各剂量组总蛋白、高剂量组自蛋白含量增加.[结论]大气混合污染物可导致大鼠肺的炎性损伤,其损伤机制可能为细胞膜通透性增加.     

染苯大鼠脂质过氧化和抗氧化能力的观察

目的 探讨苯对大鼠脂质过氧化及酶促体系和非酶促体系的抗氧化反应的影响。方法 健康SD大鼠48只,分成4组,设一对照组,其余3组按126mg/kg(低剂量组）,190mg/kg（中剂量组）、380mg/kg(高剂量组）量作灌胃染毒,于第1次染毒后第10天、第45天、第90天采血,取血清分别检测TAC、MDA含量及SOD活性。结果 低、中剂量组,在染毒第45天时,SOD活性下降,在染毒第90天时,SOD活性回升;高剂量组,随着染毒时间的延长,SOD活性及TAC含量均逐渐降低;低、中、高剂量组,MDA含量均随染毒时间的延长而升高,TAC与MDA含量均值间的相关系数r=0.7514,TAC含量与SOD活性均值间的相关系数r=0.8207。结论 苯能诱导大鼠产生脂质过氧化反应,使其抗氧化能力降低。     

大气污染物对大鼠肺特异性蛋白的影响

目的 探讨大气污染物对大鼠肺特异性蛋白的影响.方法 96只Wistar大鼠,随机分为3个实验组(低、中、高剂量)和1个对照组,分别观察1、15、30d,每组8只,乙醚麻醉下进行气管注入染尘,低、中、高剂量组大鼠分别气管注入1 ml含7.5、15、22.5 mg PM10的生理盐水混悬液,对照组大鼠注入1 ml生理盐水;低、中、高剂量组大鼠分别静态吸人SO2、NO2、CO的浓度分别为7.5、6、200mg/m3,15、12、400mg/m3,22.5、18、600mg/m3的空气混合气,每天吸入2 h,各组分别吸入1、15、30 d;对照组吸入正常空气.应用酶联免疫吸附试验检测支气管肺泡灌洗液(BALF)及血清中CC16、肺表面活性蛋白(SP)A及SP-B的水平.结果 高剂量染毒30 d大鼠BALF中CC16及SP.A水平分别为(4.60±1.10)和(31.3±2.05),明显低于对照组;高剂量染毒30 d大鼠血清CC16水平明显高于对照组及中、低剂量及1、15 d组;高剂量染毒1 d,低剂量组15及30 d大鼠血清中SP-A水平明显增高,差异均有统计学意义(P<0.05);SP-B水平变化不明显.结论 大气污染物可致Clara细胞及肺泡Ⅱ型细胞损害,BALF中CC16及SP-A水平下降;血清中CC16及SP-A升高,血清中SP-A和CC16分别可作为反映血气屏障早期和后期损伤的指标.     

2,3,7,8-四氯二苯并二恶英对SD大鼠肝脏SOD、GST、MDA影响的实验研究

目的　研究 2 ,3 ,7,8 四氯二苯并二恶英 (TCDD)对SD大鼠肝脏SOD、GST、MDA的影响。方法　把 5 0只雌性SD大鼠随机分为 10组 :染毒 2 4h组 (染毒剂量为 :0 0 1、 0 1、 1、 10、 5 0 μg/kg)、染毒 2 4h对照组 ;染毒72h组 (染毒剂量为 :0 1、 1、 10 μg/kg)、染毒 72h对照组 ,每组 5只。采用一次性腹腔注射染毒 ,测定其肝脏中SOD、GST的活性和MDA的含量。结果　染毒 2 4h后 ,与对照组相比 ,各染毒组SOD活力有所下降 ,但差异无显著性 ;各染毒组GST活力都有所增加 ,但只有 5 0 μg/kg组差异有显著性 (P <0 0 5 ) ,且染毒剂量与GST活力之间有剂量 效应关系 ;各染毒组MDA含量都有所增加 ,其中 10、 5 0 μg/kg组差异有显著性 (P <0 0 5 ) ,且染毒剂量与MDA含量之间存在剂量 效应关系。染毒 72h后 ,与对照组相比 ,各染毒组SOD活力均显著下降 (P <0 0 5 ) ,且染毒剂量与SOD活力之间有剂量 效应关系 ;各染毒组GST活力都有所增加 ,但差异无显著性 ;各染毒组MDA含量都有所增加 ,其中 1、10 μg/kg组差异有显著性 (P <0 0 5 ) ,且染毒剂量与MDA含量之间存在剂量 效应关系。 结论　急性染毒后 ,TCDD对SD大鼠的肝脏具有脂质过氧化作用 ,引起MDA含量增加 ,SOD活力降低 ,TCDD能诱导GST的活力 ,但诱导作用     

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.     

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.