双酚A等化学物对耗尽内源性雌激素诱导T47D细胞凋亡的影响

目的　在乳腺癌细胞株T4 7D细胞内采用雌激素耗尽的方法诱导其发生凋亡 ,然后观察对 壬基酚 (n 4 noniphenol,NP)、双酚A (bisphenolA ,BisA )和邻苯二甲酸酯二丁酯(dibutylphthalate ,DBP)对这种凋亡的影响 ,探讨环境雌激素是否能够抑制雌激素耗尽所诱导的细胞凋亡作用。方法　T4 7D细胞在达克尔培养液 (DMEM ,含 10 %小牛血清 )中进行常规传代培养 ,于实验前 4d将细胞用磷酸盐缓冲盐水洗涤后改为在无酚红DMEM培养 ,目的是耗尽细胞内源性雌激素。实验设溶剂对照、雌激素对照 (E2 )、抗雌激素他莫昔芬 (TAM)对照及 3个试验组 ,采用流式细胞术 ,琼脂糖凝胶电泳和HE染色镜检观察环境雌激素对雌激素耗尽所诱导的细胞凋亡的影响。结果　流式细胞仪分析结果表明 ,雌激素耗尽能够诱导T4 7D细胞发生凋亡 ,凋亡率为 34 5 % ,此时往培养液中分别加入 32× 10 -7mol/LNP和 32× 10 -7mol/LBisA ,对细胞处理 72h ,可显著抑制细胞凋亡作用 (凋亡率分别变为 2 0 1%和 16 5 % ) ;琼脂糖凝胶电泳显示 ,细胞凋亡特有的DNA ladder消逝 ;HE染色镜检表明 ,细胞出现活跃核分裂相。加入 5× 10 -7mol/LTAM可加重细胞的凋亡现象 (细胞凋亡率为 5 5 6 % )。结论　NP和BisA均可抑制雌激素耗尽所诱导的T4 7D细胞的凋亡作用 ;     

三种增塑剂对乳腺癌细胞株MCF-7增殖的影响

目的　观察对 壬基酚 (NP)、双酚A(BisA)和邻苯二甲酸酯二丁酯 (DBP)对乳腺癌细胞株MCF 7增殖的影响。方法　将MCF 7细胞在达尔克 (DMEM)培养液 (含 10 %小牛血清 )中采用开放式单层贴壁培养 ,开始实验前将培养细胞用磷酸盐缓冲液 (PBS)洗涤后改在无酚红DMEM (含 5 %胎牛血清 )中培养继续 4d以耗尽其内源性雌激素。实验设溶剂对照、雌激素对照、抗雌激素对照及 3种受试物各 4个剂量组 ,采用噻唑蓝 (MTT)法、3 H TdR掺入法及流式细胞术对MCF 7细胞的增殖情况进行分析。结果　与对照组相比 ,NP、BisA和DBP对细胞处理 2 4h ,分别在 96× 10 -7mol/L、96× 10 -7mol/L、96× 10 -6mol/L可促进MCF 7细胞增殖和细胞DNA合成 ,并推进G0 /G1期细胞进入S期 ,提高细胞增殖指数 ;随着培养时间延长至 96h ,3种化合物在较低浓度条件下也表现促进细胞增殖的效果。结论　对 壬基酚、双酚A和邻苯二甲酸酯二丁酯可促进雌激素依赖性乳腺癌细胞MCF 7的增殖 ,可能具有雌激素样作用。     

三种环境雌激素对乳腺癌细胞增殖及凋亡的影响

[目的 ]探讨环境中常见的三种类雌激素壬基酚 (NP)、双酚A(BisA)和邻苯二甲酸二丁酯 (DBP)影响人乳腺癌细胞T47D增殖和凋亡的分子生物学作用机制。 [方法 ]T47D细胞在含 10 %胎牛血清的DMEM培养液中进行常规传代培养 ,实验前将细胞转移至无酚红DMEM(含 5 %活性碳葡聚糖苷处理过的FBS)中继续培养 5d ,收集细胞 ,PBS洗涤后接种于内置盖玻片的 6孔板或 75ml培养瓶中 ,用 3 2× 10 -7mol/LNP、3 2× 10 -7mol/LBisA及 3 2× 10 -6mol/LDBP对细胞分别处理 72h ,用半定量RT PCR技术观察这 3种化合物对核增殖抗原PCNA、bcl 2及baxmRNA表达的影响 ,并用免疫组化方法对结果进行验证。 [结果 ]与溶剂对照组相比 ,NP和BisA对T47D细胞处理 72h可显著抑制baxmRNA表达而促进bcl 2和PCNAmRNA的表达 ,随后的免疫组化实验也证实了这一结果 ;DBP可促进PCNAmRNA及蛋白的表达 ,但对bcl 2及bax的表达未见统计学意义。 [结论 ]环境雌激素NP和BisA可通过调节PCNA、bcl 2及bax的表达而调节乳腺癌T47D细胞的增殖和凋亡作用。DBP通过促进核增殖抗原PCNA的表达而促进T47D的增殖作用     

三种环境雌激素对卵巢癌PEO4细胞增殖及凋亡相关基因表达的影响

目的　探讨几种常见的环境类雌激素壬基酚 (NP)、双酚A(BisA)和邻苯二甲酸二丁酯 (DBP)对人雌激素受体阳性卵巢癌细胞PEO4增殖和凋亡相关基因PCNA ,bcl 2和baxmRNA及相应蛋白质表达的影响。方法　PEO4细胞在DMEM培养液 (含 1 0 %小牛血清 )中进行常规传代培养 ,实验前将细胞转移至无酚红DMEM(含 5 %活性碳葡聚糖苷处理过的FBS)中继续培养 5d ,收集细胞 ,PBS洗涤后接种于内置血盖片的六孔板或 75ml培养瓶 ,32× 1 0 - 7mol LBisA和NP及 32× 1 0 - 6 mol LDBP对PEO4细胞分别处理 72h ,用半定量RT PCR技术观察其对核增殖抗原PCNA、bcl- 2及baxmRNA表达的影响 ,并用免疫组化方法对结果进行验证。结果　与溶剂对照组相比 ,32× 1 0 - 7mol LNP和BisA对PEO4处理 72h可促进核增殖抗原PCNA和抗凋亡基因bcl 2mRNA表达 ,但对baxmRNA的表达没有影响 ;DBP可促进PCNA的表达 ,但对bcl 2和bax的表达均没有明显的影响。随后进行的免疫组化实验结果显示 ,NP和BisA可促进Bcl 2蛋白的表达 ,并抑制Bax蛋白的表达。结论　对PCNA和bcl 2表达的影响可能是环境类雌激素调节卵巢癌细胞PEO4增殖和凋亡的重要机制之一。     

环境雌激素对卵巢癌细胞PE04凋亡的影响

目的探讨膳食中的环境雌激素大豆异黄酮(genistein,GS)及玉米赤霉烯酮(zearalenone,ZEA)对卵巢癌细胞PEO4凋亡的影响.方法将PEO4细胞在DMEM培养液(含10%小牛血清)中采用开放式单层贴壁培养,开始试验前将培养细胞用磷酸盐缓冲溶液洗涤后改为在无酚红DMEM培养液(含5%CDT-FBS)中继续培养5 d,其目的是耗尽细胞内储存的雌激素.实验设溶剂对照、雌激素对照、抗雌激素对照及2个试验组.观察指标包括亚二倍体细胞的峰高及位置,DNA断裂片段及凋亡小体的形成情况.结果雌激素耗尽能够明显诱导PEO4细胞发生凋亡,在这时候往培养液中分别加入32×10-9mol/L及96×10-9 mol/L的ZEA可抑制细胞的凋亡作用;而分别加入32×10-6mol/L及96×10-6 mol/L GS对细胞处理72 h可加重细胞的凋亡现象.结论 ZEA具有雌激素效应,可模拟雌二醇抑制细胞的凋亡作用;GS具有抗雌激素效应,在较大剂量范围内可促进细胞的凋亡.     

一些化工原料的雌激素样效应

采用雌激素受体阳性乳腺癌细胞株T47D在DMEM培养基 (含 1 0 %小牛血清 )中开放式单层贴壁培养的方法 ,探讨几种常见化工原料壬基酚 (NP)、双酚A(BisA)、邻苯二甲酸酯二丁酯 (DBP)的雌激素效应。于开始实验前将培养细胞用PBS洗涤后改为在无酚红DMEM(含 5 %CDT -FBS)中培养持续 5d ,其目的是耗尽内源性雌激素 ,实验设溶剂对照、雌激素阳性对照及 3种受试物各 4个剂量组 ,采用MTT法、3 H TdR掺入法及流式细胞术对T47D细胞增殖情况进行分析。结果显示NP、BisA和DBP对T47D细胞增殖的影响同雌激素类似 ,可促进T47D细胞增殖和细胞DNA合成 ,并推进G0 G1 期细胞进入S期 ,提高细胞增殖指数 ,随着培养时间 ,延长至 96h ,0 8μmol LNP、32 μmol LBisA和 32 0 μmol LDBP均对T47D细胞有明显促进增殖效果。结果提示这几种化合物具有雌激素效应 ,且其作用效果存在时间 -效应和剂量 -效应关系。由于T47D细胞增殖为雌激素依赖性 ,由此可推测它们有可能通过雌激素受体而发挥其作用的     

五溴联苯醚对MCF-7细胞c-myc和p53 mRNA及蛋白表达的影响

[目的]观察五溴联苯醚(5-BDEs)对乳腺癌细胞MCF-7c-myc和p53 mRNA及蛋白表达的影响,以探讨5-BDEs雌激素活性的分子生物学作用机制.[方法]将MCF-7细胞在DMEM培养液中进行常规传代培养.采用MTT比色法观察5-BDEs对MCF-7细胞增殖的影响,用逆转录聚合酶链反应(RT-PCR)技术和免疫组化方法检测5-BDEs对c-myc原癌基因和p53抑癌基因表达的影响.[结果]与溶剂对照组相比,在1×(10-4～10-8)mol/L浓度范围内,5-BDEs与1×10-8mol/L雌二醇作用类似可显著促进MCF-7细胞增殖(P<0.05),并表现出良好的剂量-效应和时间-效应关系.RT-PCR及免疫组化结果显示,1×(10-4～10-8)mol/L的5-BDEs可促进MCF-7 c-myc和抑制p53 mRNA及蛋白表达.[结论]5-BDEs具有雌激素样生物活性,可促进雌激素反应性肿瘤细胞MCF-7增殖,这一效应主要是通过影响c-myc mRNA和蛋白质的表达而实现的.     

膳食雌激素影响乳腺癌MCF-7细胞增殖和凋亡的机制探讨

目的:探讨膳食中常见的两种环境类雌激素大豆异黄酮(genistein,GS)、玉米赤霉烯酮(zearalenone,ZEA)影响人乳腺癌细胞MCF-7增殖和凋亡的分子生物学作用机制。方法:MCF-7细胞在DMEM培养液(含10%胎牛血清)中进行常规传代培养,实验前将细胞转移至无酚红DMEM(含5%活性碳葡聚糖苷处理过的FBS)中继续培养5d,收集细胞,PBS洗涤后接种于内置血盖片的六孔板或75ml培养瓶,32×10-9mol/LZEA和75×10-6mol/LGS对细胞分别处理72h,用半定量RT-PCR技术观察GS对核增殖抗原PCNA、bcl-2及baxmRNA表达的影响,并用免疫组化方法对结果进行验证。结果:与溶剂对照组相比,75×10-6mol/LGS对MCF-7细胞处理72h可显著提高baxmRNA表达而抑制bcl-2和PCNAmRNA的表达,随后的免疫组化实验也证实了这一结果;ZEA的作用效应则与GS相反。结论:膳食雌激素GS和ZEA可通过影响细胞增殖和凋亡相关调节基因PCNA、bcl-2和bax表达而调节人乳腺癌细胞MCF-7的增殖和凋亡作用。     

环境干扰物对卵巢癌细胞株PEO4增殖的影响

目的：观察环境干扰物壬基酚（4-n-nonyphenol,NP）、双酚A(bisphenolA,BisA）、邻苯二甲酸酯二丁酯（Dibutylphthalate DBP）对卵巢癌细胞株PEO4增殖的影响。方法PEO4细胞在DMEM培养基（含10％小牛血清）中采用开放式单层贴壁培养。试验前5d将细胞用PBS洗涤，改为在无酚红DMEM培养基（含5％活性碳－葡聚糖处理过的胎牛血清）中继续培养，以耗尽细胞内储存的柴激素，实验设溶剂对照、雌激素对照及3种受试物各4个剂量组，采用MTT法、^3H-TdR掺入法及流式细胞术对PEO4细胞的增殖情况进行分析。结果：3．2μmol/L NP、32μmol/L BisA和960μmol/L DBP对PEO4细胞处理72h可产生与雌激素类似的效果，即促进PEO4细胞增殖和细胞DNA合成，并推进G0／G1期细胞进入S期，提高细胞增殖指数，且其促进增殖作用存在时间－依赖和剂量－依赖关系。结论：对－壬基酚、双酚A和邻苯二甲酸酯二丁酯均能促进雌激素受体阳性卵巢癌细胞株PEO4增殖，提示近几年环境污染加剧可能与女性生殖肿瘤发病率增高有关。     

氯氰菊酯对人乳腺癌细胞MCF-7增殖的影响

目的通过观察氯氰菊酯(cypermethrin,CYP)对人乳腺癌细胞株MCF-7细胞增值的影响,探讨氯氰菊酯促进细胞增殖的生物学机制。方法 MCF-7细胞在加受试物前7 d改为无酚红完全培养基,以耗尽细胞内储存的雌激素。实验设为6组:无水乙醇(EtOH)溶剂对照组、雌二醇(E2)雌激素对照组、他莫西芬(TAM)抗雌激素对照组及氯氰菊酯3个浓度梯度(1.0×10-7mol/L、1.0×10-8mol/L、1.0×10-9mol/L)实验组。采用CCK8法检测各组细胞的增值情况,采用Hoechst 33342和Propidium Iodide双染荧光显微镜观察氯氰菊酯对雌激素耗尽诱导细胞凋亡作用影响。结果第4、5天细胞增殖实验,与EtOH溶剂对照组相比,除TAM抗雌激素组与EtOH溶剂对照组细胞增殖活力低外,其他4组细胞增殖活力低,依次为E2雌激素对照组、氯氰菊酯1.0×10-7mol/L组、氯氰菊酯1.0×10-8mol/L组、氯氰菊酯1.0×10-9mol/L组,P均<0.05;第3天与EtOH溶剂对照组比,E2雌激素对照组MCF-7细胞增殖活力高,P<0.05,第2天差异无统计学意义。荧光显微镜下见,EtOH溶剂对照组相比和TAM抗雌激素组细胞的凋亡作用明显,后者强于前者,而E2雌激素对照组、氯氰菊酯1.0×10-7mol/L组、氯氰菊酯1.0×10-8mol/L组、氯氰菊酯1.0×10-9mol/L组对细胞凋亡作用不明显。结论氯氰菊酯有可能是通过抑制乳腺癌细胞凋亡而发挥其促进细胞增殖作用的。     

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.