2,3,7,8-四氯二苯并-p-二恶英诱导肺癌SPC-A1细胞凋亡的研究

目的研究2，3，7，8-四氯二苯并-p-二恶英（TCDD）在体外诱导肺癌细胞系SPC-A1细胞凋亡的作用。方法用MTT法测定TCDD对SPC-Al细胞的毒性，采用流式细胞仪对细胞凋亡进行分析，通过HE染色观察细胞形态变化。结果SPC—A1细胞生长曲线表明，随着TCDD浓度增高，SPDAl细胞生长率明显下降；细胞凋亡可在TCDD浓度为10nmol／L，0．1μmol／L，1μmol／L处理24h后出现；TCDD诱导SPC-A1细胞的凋亡具有时间和浓度依赖性；凋亡细胞主要表现为细胞体积缩小，核染色质固缩，亚二倍体峰出现。结论TCDD在体外能有效诱导SPC—A1细胞发生凋亡。     

镉对正常大鼠肾成纤维细胞凋亡形态学的影响

[目的]观察氯化镉对正常大鼠肾成纤维（NRK）细胞凋亡的形态学及细胞凋亡率的影响。[方法]用20μmol／L氯化镉染毒NRK细胞24h,通过透射电镜观察细胞凋亡形态变化。分别用0、5、10、20、40、60μmol／L的氯化镉培养NRK细胞24h,用20μmol／L的氯化镉分别体外培养NRK细胞0．5、2、6、12、24h,通过流式细胞仪检测各组NRK细胞的凋亡率。[结果]氯化镉可以使NRK细胞出现凋亡征象即凋亡小体的形成,且凋亡率呈时间-效应、剂量-效应关系,剂量为0、5、10、20、40、60／amol／L的氯化镉染毒24h,凋亡率分别为3．01％、6．14％、10．0％、12．6％、23．5％和34．7％;20μmol／1氯化镉染毒NRK细胞0、0．5、2、6、12、24h,凋亡率分别为3．31％、5．96％、8．38％、8．59％、13．97％和16．16％。[结论]氯化镉可以诱导NRK细胞发生特征性的凋亡形态的变化,且氯化镉诱导NRK细胞发生凋亡存在时间-效应、剂量-效应关系。     

青蒿琥酯联合热疗诱导肺腺癌A549细胞凋亡作用

目的 探讨青蒿琥酯联合热疗诱导肺腺癌A549细胞凋亡的线粒体途径作用机制.方法 150μmol/L青蒿琥酯、青蒿琥酯联合热疗(43℃,1 h)作用A549细胞24 h,流式细胞技术检测细胞周期和凋亡率情况.荧光显微镜观察线粒体膜电位变化.免疫组化、western blot检测细胞色素c、Bcl-2和caspase-3表达,CaspACE<'TM>检测试剂盒检测活性caspase-3表达.结果 青蒿琥酯、青蒿琥酯联合热疗作用A549细胞24 h后,G0/G1期细胞数增多,S期和G2/M期细胞数减少(P<0.01);凋亡率分别是16.77%和28.90%(P<0.01).线粒体膜电位下降率分别为18.05%,50.98%(P<0.01).细胞色素c蛋白、caspase-3表达增加而Bcl-2蛋白表达减少(P<0.01).活性caspase-3蛋白水平增加A值分别为0.2641±0.0027,0.3613±0.0019,与对照组相比,差异有统计学意义(P<0.01).结论 青蒿琥酯、青蒿琥酯联合热疗可诱导肺腺癌A549细胞凋亡,激活线粒体途径可能是诱导凋亡重要作用机制.     

2,3,7,8-四氯二苯并二噁英对体外表皮细胞增殖的影响

目的 研究2,3,7,8-四氯二苯并二噁英(TCDD)对人角质形成细胞(HACAT)增殖的影响.方法 选用5个不同染毒浓度(7x10-12～7x10-8 mol/L),对生长至60%～70%汇合的HACAT细胞进行体外染毒,并在培养的不同时间点(6、12、24、48 h)进行检测,分别通过形态学、克隆形成实验和噻唑蓝(MTT)比色法观察TCDD对细胞增殖的影响.结果 TCDD对细胞形态的影响并不明显;对克隆形成率有明显的促进作用,但剂量-效应关系不明显;MTT检测结果显示,TCDD对HACAT细胞的生长增殖有促进作用,且与时间、浓度存在一定的依赖关系,染毒6、12、24 h,细胞增殖率随浓度的增加而增加,相关系数分别为0.561,0.687,0.720,差异有统计学意义(P＜0.01);但48 h组,细胞的增殖率不再增加,相反对细胞的生长表现为抑制作用.结论 TCDD对细胞形态无明显影响,但在一定染毒时间范围内(6～24 h),对体外HACAT细胞的生长增殖有促进作用,且与时间、浓度存在正相关.     

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。     

鱼藤酮对大鼠中脑原代培养细胞的毒性

目的 研究植物杀虫剂鱼藤酮(Rotenone)对大鼠中脑原代培养细胞的毒性作用.方法 采用大鼠胚胎中脑原代细胞培养法,用0.01、0.10、1.00μmol/L鱼藤酮对体外培养中脑原代培养细胞染毒24h,通过免疫细胞化学的方法观察神经细胞的存活数及形态学改变.结果 与对照(0μmol/L)组比较,0.10和1.00μmol/L鱼藤酮染毒组多巴胺神经元数目明显降低,差异有统计学意义(P<0.05,P<0.01);1.00μmol/L鱼藤酮染毒组星型胶质细胞数目明显下降,差异有统计学意义(P<0.05).随着鱼藤酮染毒浓度的升高,存活的多巴胺(DA)能神经元体积变小,突起减少、变短或断裂.结论 多巴胺神经元对鱼藤酮的毒性作用更敏感.     

Orai1和STIM1在姜黄素诱导人肺腺癌A549细胞凋亡中的作用

目的探讨不同浓度姜黄素诱导人肺腺癌A549细胞凋亡中Orai1和STIM1mRNA水平的改变。方法 A549细胞分别暴露于5、10、15、20、25和30μmol/L姜黄素12、24和48 h后,应用四甲基偶氮唑蓝(MTT)比色法测定细胞增殖活力;将不同浓度姜黄素孵育A549细胞24 h后,流式细胞仪检测细胞凋亡率;real-time PCR确定25μmol/L姜黄素处理24 h后,Orai1和STIM1mRNA表达水平。结果姜黄素对A549细胞的抑制作用呈剂量依赖性和时间依赖性,不同浓度姜黄素处理A549细胞24 h细胞存活率分别为96.5%、95.0%、77.4%、63.9%、57%、39.6%,与对照组相比,差异有统计学意义(P0.05或P0.01)。姜黄素处理后,流式细胞仪分析结果显示,细胞凋亡率呈明显剂量依赖关系(P0.05或P0.01)。经姜黄素处理后A549细胞Orai1和STIM1mRNA表达量均明显低于对照组(P0.01)。结论姜黄素可能引起A549细胞Orai1和STIM1 mRNA表达水平发生改变,通过下调Orai1和STIM1mRNA表达量引起细胞凋亡。     

液态甲醛对HepG_2细胞增殖影响及DNA损伤效应

为探讨液态甲醛致HepG2细胞增殖的抑制情况和DNA损伤效应,以HepG2细胞作为试验材料,甲醛染毒浓度分别为0(对照)、200、400、800、1600μmol/L。采用MTT试验检测甲醛暴露24h对HepG2细胞的抑制率,并计算半数致死浓度(IC50)。采用彗星试验检测甲醛暴露12h对HepG2细胞的DNA损伤效应。结果显示,200、400、800、1600μmol/L甲醛染毒组细胞抑制率分别为38.03%,46.01%,50.28%,73.65%,具剂量依赖性,IC50为484.59μmol/L。彗星试验结果显示,与对照组比较,200、400、800μmol/L甲醛染毒组彗星细胞率和彗星细胞尾长均较高,差异有统计学意义(P0.05或P0.01)。随着甲醛染毒剂量的增高,彗星细胞率及彗星细胞尾长均先升高后降低,且在400μmol/L甲醛染毒组达到峰值。此外,1600μmol/L甲醛染毒组彗星细胞率和尾长与对照组比较,差异无统计学意义(P0.05)。表明甲醛暴露对HepG2细胞的抑制具浓度依赖性。低浓度甲醛主要引起细胞DNA分子断裂,高浓度甲醛主要引起细胞DNA发生交联。     

溶酶体在2,2’,4,4’-四溴联苯醚诱导HepG2细胞凋亡中的作用

[目的]探讨2,2’,4,4’-四溴联苯醚(BDE 47)致人肝癌HepG2细胞凋亡机制. [方法]不同浓度BDE 47(0.00、6.25、12.50、25.00、50.00、100.00 μmol/L)染毒HepG2细胞24h,采用四氮唑盐比色法(MTT法)检测细胞存活率;用2’,7’-二氢二氯荧光素(DCFH-DA)探针检测活性氧水平;用吖啶橙(AO)探针及罗丹明(Rh123)荧光探针分别检测溶酶体膜通透性和线粒体膜电势,并通过溶酶体组织蛋白酶B特异性抑制剂环氧酶琥珀酰肽甲基酯(CA-074)验证溶酶体在BDE 47细胞毒性的作用. [结果]与对照组比较,50.00、100.00 μmol/L BDE 47染毒组HepG2细胞存活率明显降低(P＜0.01);各BDE47染毒组HepG2细胞凋亡率明显升高(P＜0.01),呈现剂量-效应关系(R2=0.981);各BDE47染毒组HepG2细胞活性氧含量明显升高(P＜0.01),≥12.50μmol/L BDE 47染毒组HepG2细胞内溶酶体膜通透性明显升高(P＜0.05; P＜0.01),各BDE47染毒组HepG2细胞内线粒体膜电势明显降低(P＜0.01),上述3项指标与染毒浓度均呈剂量-效应关系(R2=0.918,R2=0.636,R2=0.678).25 μmol/L CA-074能够明显干预50 μmol/L BDE 47对细胞的毒性作用使细胞存活率升高,细胞调亡减少(均P＜0.05). [结论]BDE47可能通过溶酶体介导线粒体途径诱导HepG2细胞凋亡.     

阿特拉津对大鼠支持细胞凋亡的影响

目的探讨阿特拉津对雄性SD大鼠睾丸支持细胞凋亡的影响及其作用机制。方法选用18~21日龄雄性SD大鼠,建立支持细胞原代培养模型。设溶剂对照组和阿特拉津10、50、100和200μmol/L 4个染毒剂量组,对支持细胞染毒24 h后,采用MTT法检测细胞活性,免疫荧光法观察波形蛋白的表达,流式细胞术测定细胞凋亡率,Real time-PCR与ELISA分别检测Fas L、caspase-3与caspase-8的mRNA表达及蛋白含量。结果阿特拉津50、100和200μmol/L染毒组细胞活力分别为82.47%、75.23%和53.76%,与溶剂对照组比较分别降低17.53%(P<0.05)、24.77%(P<0.05)、46.24%(P<0.01)。波形蛋白表达受抑制。阿特拉津50、100和200μmol/L染毒组细胞凋亡率分别为8.53%、13.07%和14.45%,与溶剂对照组比较分别升高86.86%(P<0.01)、186.13%(P<0.01)、216.06%(P<0.01)。Fas L、caspase-3、caspase-8的mRNA表达及蛋白含量上调(P<0.05或P<0.01)。结论阿特拉津可影响大鼠支持细胞活性,可通过Fas L途径诱导支持细胞凋亡。     

Dengue Virus Transmission by Blood Stem Cell Donor after Travel to Sri Lanka; Germany, 2013

Three days after donation of peripheral blood stem cells to a recipient with acute myeloblastic leukemia, dengue virus was detected in the donor, who had recently traveled to Sri Lanka. Transmission to the recipient, who died 9 days after transplant, was confirmed.     

Investigation and Control of Anthrax Outbreak at the Human–Animal Interface,Bhutan, 2010

In 2010, we investigated anthrax outbreak in Bhutan. A total of 43 domestic animals died, and cutaneous anthrax developed in 9 persons, and 1 died. All affected persons had contact with the carcasses of infected animals. Comprehensive preparedness and response guidelines are needed to increase public awareness of anthrax in Bhutan.     

Raccoons and skunks as sentinels for enzootic tularemia

We analyzed sera from diverse mammals of Martha's Vineyard, Massachusetts, for evidence of Francisella tularensis exposure. Skunks and raccoons were frequently seroreactive, whereas white-footed mice, cottontail rabbits, deer, rats, and dogs were not. Tularemia surveillance may be facilitated by focusing on skunks and raccoons.     

Risk for Travel-associated Legionnaires’ Disease,Europe, 2009

Legionnaires’ disease is underreported in Europe; notification rates differ substantially among countries. Approximately 20% of reported cases are travel-associated. To assess the risk for travel-associated Legionnaires’ disease (TALD) associated with travel patterns in European countries, we retrieved TALD surveillance data for 2009 from the European Surveillance System, and tourism denominator data from the Statistical Office of the European Union. Risk (number cases reported/number nights spent) was calculated by travel country. In 2009, the network reported 607 cases among European travelers, possibly associated with 825 accommodation sites in European Union countries. The overall risk associated with travel abroad was 0.3 cases/million nights. We observed an increasing trend in risk from northwestern to southeastern Europe; Greece had the highest risk (1.7). Our findings underscore the need for countries with high TALD risks to improve prevention and control of legionellosis; and for countries with high TALD risks, but low notification rates of Legionnaires’ disease to improve diagnostics and reporting.     

Travel-associated Diseases,Indian Ocean Islands, 1997–2010

Data collected by the GeoSentinel Surveillance Network for 1,415 ill travelers returning from Indian Ocean islands during 1997–2010 were analyzed. Malaria (from Comoros and Madagascar), acute nonparasitic diarrhea, and parasitoses were the most frequently diagnosed infectious diseases. An increase in arboviral diseases reflected the 2005 outbreak of chikungunya fever.     

Widening Rural–Urban Disparities in All-Cause Mortality and Mortality from Major Causes of Death in the USA, 1969–2009

This study examined trends in rural–urban disparities in all-cause and cause-specific mortality in the USA between 1969 and 2009. A rural–urban continuum measure was linked to county-level mortality data. Age-adjusted death rates were calculated by sex, race, cause-of-death, area-poverty, and urbanization level for 13 time periods between 1969 and 2009. Cause-of-death decomposition and log-linear and Poisson regression were used to analyze rural–urban differentials. Mortality rates increased with increasing levels of rurality overall and for non-Hispanic whites, blacks, and American Indians/Alaska Natives. Despite the declining mortality trends, mortality risks for both males and females and for blacks and whites have been increasingly higher in non-metropolitan than metropolitan areas, particularly since 1990. In 2005–2009, mortality rates varied from 391.9 per 100,000 population for Asians/Pacific Islanders in rural areas to 1,063.2 for blacks in small-urban towns. Poverty gradients were steeper in rural areas, which maintained higher mortality than urban areas after adjustment for poverty level. Poor blacks in non-metropolitan areas experienced two to three times higher all-cause and premature mortality risks than affluent blacks and whites in metropolitan areas. Disparities widened over time; excess mortality from all causes combined and from several major causes of death in non-metropolitan areas was greater in 2005–2009 than in 1990–1992. Causes of death contributing most to the increasing rural–urban disparity and higher rural mortality include heart disease, unintentional injuries, COPD, lung cancer, stroke, suicide, diabetes, nephritis, pneumonia/influenza, cirrhosis, and Alzheimer’s disease. Residents in metropolitan areas experienced larger mortality reductions during the past four decades than non-metropolitan residents, contributing to the widening gap.     

Outbreak of Panton-Valentine Leukocidin–Associated Methicillin-Susceptible Staphylococcus aureus Infection in a Rugby Team,France, 2010–2011

Staphylococcus aureus strains that produce Panton-Valentine leukocidin are known to cause community infections. We describe an outbreak of skin abscesses caused by Panton-Valentine leukocidin–producing methicillin-susceptible S. aureus (clonal complex 121) in a professional rugby team in France during July 2010–February 2011. Eight team members were carriers; 7 had skin abscesses.     

大龄单身女性寻求生育力保存的伦理问题探析

近年来,在肿瘤和卵巢相关疾病发生率逐年增加、不少大龄单身女性渴望为自己购买一份“生殖保险”等社会及个人因素催化下,人类对于生育力保存的需求急剧增加,满足这一需求正在或将成为重大挑战。对于寻求进行生育力保存的大龄单身女性来说,在合适的年龄应用玻璃化冷冻技术将其卵母细胞冻存是目前可采用的最佳生育力保存手段。而单身女性卵子冷冻将面临来自伦理道德、社会乃至法律的巨大挑战。本文概述国内外大龄单身女性卵子冷冻的现状,并对其可能涉及的相关伦理问题及解决途径进行综述,以促进理性正视单身女性卵子冷冻问题。     

Haemophilus ducreyi Associated with Skin Ulcers among Children,Solomon Islands

During a survey of yaws prevalence in the Solomon Islands, we collected samples from skin ulcers of 41 children. Using PCR, we identified Haemophilus ducreyi infection in 13 (32%) children. PCR-positive and PCR-negative ulcers were phenotypically indistinguishable. Emergence of H. ducreyi as a cause of nongenital ulcers may affect the World Health Organization’s yaws eradication program.