多氯联苯、苯并(a)芘及其联合作用对人胚肺细胞热休克蛋白70表达的影响

目的 研究多氯联苯1254(Aroclor 1254)、苯并(a)芘(BaP)及其联合作用下人胚肺(HEL)二倍体细胞热休克蛋白70(HSP70)的表达规律及其可能的意义.方法 培养HEL细胞,作如下处理:Aroclor 1254处理组:细胞接受不同剂量Aroclor 1254(6.25、12.50、25.00、50.00 μmol/L)处理24 h;Aroclor 1254 BaP联合作用组:细胞先按Aroclor 1254处理组方案预处理,24 h后37℃恢复1 h,再以50 μmol/L BaP染毒2 h;同时设立苯并(a)芘(50 μmol/L,染毒2 h)和DMSO(10 mL/L)分别作为阳性对照组和溶剂对照组.利用免疫印迹方法(Western-blot)检测HEL细胞中HSP70、β-actin的表达水平,采用灰度比(HSP70/β-actin)定量分析.结果 Aroclor 1254处理组,不同浓度多氯联苯1254(6.25、12.50、25.00、50.00 μmol/L)处理后,灰度比分别为0.98±0.05、0.97±0.09、0.99±0.06、0.95±0.08,与溶剂对照组(0.99±0.05)及阳性对照组(1.01±0.06)相比无明显变化(P＞0.05);联合作用组,灰度比随多氯联苯1254浓度的增加而逐渐下调,分别为0.89±0.03、0.83±0.02、0.81±0.05、0.72±0.03,与溶剂对照组及阳性对照组相比均明显下调(P＜0.05).结论 HSP70表达下降可能与多氯联苯1254增强BaP代谢活化产物的遗传毒性作用有关.     

多氯联苯增强苯并(a)芘致HepG2细胞DNA的损伤作用

目的研究多氯联苯1254对苯并(a)芘致HepG2细胞DNA损伤的影响。方法设11.5、23.0和46.0μmol/L多氯联苯1254剂量组,苯并(a)芘50μmol/L剂量组,10 m l/L二甲基亚砜为溶剂对照。用不同浓度多氯联苯1254预处理HepG2细胞,24 h后染毒,通过单细胞凝胶电泳和高效液相-电化学技术,检测细胞中的DNA链断裂和8-羟基脱氧鸟嘌呤核苷酸(8-OHdG)。结果50μmol/L苯并(a)芘诱导HepG2细胞中DNA O liver尾矩(OTM)值为1.66±0.21,8-OHdG含量为(23.31±6.02)8-OHdG/106dG,溶剂对照组OTM值为0.79±0.15,8-OHdG含量为(12.31±3.24)8-OHdG/106dG,两组比较差异均有统计学意义;11.5、23.0和46.0μmol/L单独处理组OTM值分别为0.88±0.20、1.01±0.15和1.10±0.16,8-OHdG含量分别为(19.57±7.57)、(22.80±9.16)和(31.74±9.25)8-OHdG/106dG,46.0μmol/L组与溶剂对照组比较,8-OHdG含量显著增加,差异有统计学意义;经11.5、23.0和46.0μmol/L的多氯联苯1254预处理,苯并(a)芘诱导的OTM值分别为2.14±0.22、2.43±0.32和2.71±0.31,8-OHdG含量分别为(32.50±3.81)、(49.23±16.66)和(60.36±18.04)8-OHdG/106dG,与苯并(a)芘单独作用组比较均显著增加,差异有统计学意义。结论多氯联苯1254能使苯并(a)芘诱导的HepG2细胞DNA损伤作用显著增强,表明多氯联苯1254对苯并(a)芘的遗传毒性作用具有一定的协同效应。     

苯并(a)芘作用下人胚肺细胞JWA基因的表达及其与DNA损伤修复的关系

目的研究苯并(a)芘诱导人胚肺(ccc-HPF-1)细胞DNA损伤修复中基因JWA和热休克蛋白(hsp70)的表达规律,探讨JWA基因参与细胞DNA损伤修复的作用和可能机制。方法建立ccc-HPF-1细胞DNA损伤模型,在S9活化状态下分别以10～100μmol／L苯并(a)芘处理细胞3h收获细胞或再恢复24h,用碱性单细胞凝胶电泳鉴定DNA损伤和修复情况,免疫印迹方法检测JWA和hsp70的表达水平。结果在DNA损伤模型中,苯并(a)芘活跃地调节JWA的表达,50μmol／L和100μmol／L处理组JWA和hsp70明显上调,在恢复期内10～100μmol／L处理组两者都处于较高的表达水平并且JWA和hsp70的表达规律几乎完全一致。结论JWA是一个有效的环境应答基因,活跃地参与细胞应答与DNA切除修复有关的信号通路。     

雌马酚对血管内皮细胞凋亡和增殖影响

目的探讨大豆异黄酮(SI)代谢物雌马酚对血管内皮细胞凋亡和增殖的影响。方法体外培养血管内皮细胞(ECV-304),采用不同浓度雌马酚(0、6.25、12.50、25.00、50.00和100.00μmol/L)处理24 h,收集细胞,采用流式细胞术分析细胞内活性氧(ROS)、细胞凋亡和细胞周期;采用免疫组织化学技术分析凋亡相关蛋白Bax、Bcl-2和caspase-3表达;采用噻唑蓝(MTT)法分析雌马酚对ECV-304细胞增殖影响。结果与对照组比较,6.25μmol/L雌马酚组ECV-304细胞内ROS含量下降,100.00μmol/L雌马酚组ECV-304细胞内ROS含量升高;与对照组比较,25.00、50.00、100.00μmol/L雌马酚组ECV-304细胞早、晚期凋亡率明显升高,并可导致细胞G1期阻滞(P<0.05);MTT实验结果显示,0、6.25、12.50、25.00、50.00、100.00μmol/L雌马酚组ECV-304细胞增殖抑制率分别为-(8.23±2.21)%、-(3.29±1.07)%、(6.75±1.73)%、(25.46±4.82)%和(36.93±4.66)%,低剂量雌马酚对细胞生长具有促进作用,高剂量雌马酚对细胞生长具有抑制作用;与对照组比较,25.00μmol/L雌马酚组作用24 h后,细胞内Bax和caspase-3表达增加,而Bcl-2表达减少。结论低浓度雌马酚可降低细胞内ROS含量,促进ECV-304细胞增殖;高浓度雌马酚可导致细胞凋亡、细胞周期阻滞,抑制细胞增殖。     

有机污染物对人肝肿瘤细胞的遗传毒性

目的 用人肝肿瘤细胞HepG2／体外微核试验检测3种持久性有机污染物（POPs）Aroclor1254、毒杀芬和滴滴涕的遗传毒性。方法 人肝肿瘤细胞HepG2经Aroclor1254、毒杀芬和滴滴涕染毒24h，继续在补充细胞松弛素B（3μg/ml）的培养液中培养24h后，计数1000个双核细胞中的微核。结果 20，40μmol／L毒杀芬处理HepG2细胞的微核率与溶剂对照相比显著增加（P〈0.01，P〈0．01）；经Aroclor1254（23～184μmol／L）和滴滴涕（17．8～60μmol／L）处理的HepG2细胞的微核率与溶剂对照相比，差异无统计学意义。结论 Arodor1254和滴滴涕未显示对HepG2细胞明显的遗传毒性；毒杀芬可诱导HepG2细胞遗传损伤，有必要进一步评价其对人类健康的潜在危害。     

苯并[a]芘对人支气管上皮细胞H19与SAHH表达的影响

[目的]探讨苯并[a]芘(BaP)对人支气管上皮细胞(16HBE)长链非编码RNA(lncRNA)H19和S-腺苷高半胱氨酸水解酶(SAHH)表达的影响,并初步探究H19和SAHH的关系。[方法]用不同浓度(1、2、4、8、16、32μmol/L)BaP染毒16HBE细胞24 h,设置未处理组(仅加培养液)和溶剂对照组;以16μmol/L BaP染毒16HBE细胞不同时间(1、2、4、8、12、24 h),以0 h为对照组。用实时荧光定量逆转录-聚合酶链式反应(RT-PCR)检测H19的表达水平;通过免疫印迹试验(Western blot)检测SAHH的蛋白表达水平;采用lncRNA原位荧光杂交(FISH)技术结合激光共聚焦显微镜观察H19和SAHH的定位。[结果]RT-PCR结果显示,溶剂对照组与未处理组相比,H19表达差异无统计学意义。随着染毒浓度和时间的增加,16HBE细胞H19表达呈现逐渐升高的趋势。8、16、32μmol/L BaP染毒24 h及16μmol/L BaP染毒4、8、12、24 h时,H19表达量分别高于溶剂对照组和0 h组(均P0.05)。BaP染毒浓度为32μmol/L时,H19表达量达到峰值,较溶剂对照组增加了78.0%;16μmol/L BaP染毒24 h时,H19表达量达到峰值,较0 h组增加了48.3%。Western blot结果显示,溶剂对照组与未处理组的SAHH表达差异无统计学意义。随着染毒时间和浓度的增加,16HBE细胞SAHH表达逐渐降低(P0.05)。BaP浓度为32μmol/L时,SAHH表达降至最低,较溶剂对照组降低了37.2%;16μmol/L BaP染毒24 h时,SAHH表达降至最低,较0 h组降低了33.1%。免疫荧光结果显示,H19和SAHH均在细胞质及细胞核中表达,表达主要分布在核周质及核膜;与0 h组相比,16μmol/L BaP染毒细胞24 h后H19在核周质处的荧光加强,而SAHH的荧光明显减弱,两者在胞质、胞核中共定位的荧光强度增加。[结论]BaP染毒可引起16HBE细胞H19表达升高而SAHH表达降低;H19与SAHH在细胞内的共定位表达提示两者可能存在相互作用。     

B(a)P作用下的人支气管上皮细胞DNA损伤与XPA、XPC蛋白表达的关系

[目的]探讨苯并(a)芘[B(a)P]作用下人支气管上皮细胞16HBEDNA损伤与着色性干皮病A、C蛋白(XPA,XPC)表达的关系。[方法]用B(a)P(0、1、2、4、8、16、32、64μmol/L)浓度染毒细胞24h,用四甲基偶氮唑盐微量酶反应比色法(MTT)检测B(a)P对细胞活性的影响。用彗星试验检测细胞DNA损伤并以Olive尾矩值(OTM值)评价DNA损伤程度。并用Western-blot检测XPA和XPC蛋白的表达水平。[结果]B(a)P浓度>4μmol/L的各组细胞活性均显著降低(P<0.05)。各染毒组细胞DNA损伤程度则显著增高(P<0.05)。不同浓度B(a)P染毒细胞中XPA、XPC蛋白的表达量有差异。在1μmol/L B(a)P染毒组,可检出XPA蛋白表达水平增高,但随着染毒浓度增加其表达量逐渐降低(P<0.05)。与对照组相比各染毒组细胞XPC的表达均显著降低(P<0.05)。回归分析显示XPA与OTM值之间决定系数为0.572,XPC与OTM值之间为0.852。[结论]B(a)P引起的XPA和XPC蛋白表达水平的变化与DNA损伤之间存在高度相关。     

苯并(a)芘对肺癌细胞DNA损伤及修复基因表达水平的影响

目的 探讨苯并（a）芘（BaP)对肺癌细胞DNA损伤及核酸切除修复（NER）基因－着色性干皮病B、C、G基因（XPB、XPC、XPG）和切除修复交叉互补基因1（ERCC1）表达的影响。方法 以噻唑蓝（MIT）法检测BaP对细胞的毒作用，单细胞凝胶电泳检测DNA损伤情况，逆转录聚合酶链反应（RT－PCR）检测基因表达水平。结果 BaP(0.625－20.000μmol/L）处理肺癌A549细胞24h，细胞生存力从95.0%降至70.0%。10μmol/L BaP处理12、24h，细胞生存力分别降至87.0%、73.0%，DNA损伤逐渐加重；BaP染毒24h后孵育12h，细胞生存力降至59.0%，DNA损伤最严重；继续孵育至24h，细胞生存力恢复至71.0%，DNA损伤逐渐修复。BaP处理引起XPB和XPC基因表达升高，在染毒24h和染毒后12h达峰值，分别为基底水平的4.5和11.2倍，随后逐渐下降；XPG和ERCC1基因在染毒期间表达下降，染毒结束后逐渐恢复。结论 BaP导致肺癌A549细胞DNA损伤，细胞在修复受损DNA时伴随NER基因表达水平改变。     

苯并[a]芘与铅联合神经毒性的细胞学研究

目的苯并[a]芘(BaP)、铅及其联合作用对体外神经元的毒性及细胞凋亡率的影响.方法取8日龄SD大鼠小脑粒细胞培养,按以下分组进行处理空白对照组;溶剂对照组;低浓度铅染毒组;高浓度铅染毒组;低浓度BaP染毒组;高浓度BaP染毒组;低浓度铅+低浓度BaP染毒组;低浓度铅+高浓度BaP染毒组;高浓度铅+低浓度BaP染毒组;高浓度铅+高浓度BaP染毒组;高、低浓度的BaP染毒分别为BaP50μmol/L+S9-mix和BaP5μmol/L+S9-mix,高、低浓度的铅染毒分别为50和5μmol/L的PbAc,溶剂对照组用等量DMSO平行处理,空白对照组不作处理.染毒90min,胰酶消化法收集标本.台盼蓝染色法检测存活率;DNA断点末端核糖核酸转移酶地高辛标记(TUNEL)法检测大鼠小脑粒细胞凋亡率,并对细胞存活率与凋亡率进行相关分析.结果各染毒组细胞存活率均低于对照组,高剂量组降低程度高于低剂量组,联合染毒组降低程度高于单独染毒组(P<0.05～P＜10E-7).各染毒组细胞凋亡率显著升高,高剂量组升高程度高于低剂量组,联合染毒组升高程度高于单独染毒组(P＜0.001～P＜10E-9).细胞凋亡率与存活率间呈负相关(r=-0.76125,P＜0.05).结论 BaP、铅均有一定的体外神经毒性,二者联合作用可使毒性增强.细胞凋亡可能是BaP引起体外神经毒性的机制之一.     

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.