冷应激对心肌细胞损伤的影响

目的 :探讨冷应激对心肌细胞损伤 ,特别是对心肌细胞凋亡的影响 ,为寻求保护或减轻冷应激心肌损伤研究提供可能途径。方法 :将体外培养的Wistar大鼠乳鼠心肌细胞分别置于 - 10℃、- 2 0℃进行冷应激 ,然后取培养液测定乳酸脱氢酶 (LDH)的活性 ,同时用流式细胞仪 (FCM )测定心肌细胞的凋亡率 ,用荧光分光光度法测定细胞内活性氧 (ROS)含量的变化。结果 :心肌细胞经 - 10℃、 - 2 0℃冷应激后 ,细胞凋亡率由 ( 3.73± 1.0 3) % ,分别增加到 ( 19.58±6.17) % (P <0 .0 1)和 ( 34 .54± 6.0 3) % (P <0 .0 1) ;ROS含量由 ( 18.8± 2 .1)荧光强度·mgpr- 1分别增加到 ( 34 .8± 2 .0 )和 ( 4 0 .8± 1.3)荧光强度·mgpr- 1(P <0 .0 1,P <0 .0 1) ;冷应激后 ,细胞培养液中LDH的活性也显著增高。结论 :冷应激后心肌细胞凋亡是心肌细胞死亡的重要途径 ,其机制可能是ROS升高造成心肌细胞的氧化应激所致     

应激心肌细胞中NGFI-B转位至线粒体的氨基酸序列研究

目的探讨应激心肌细胞中NGFI-B发生线粒体转位的必需氨基酸序列,为揭示应激机体心肌损伤的病理学机理提供科学依据。方法建立心肌细胞应激损伤的离体细胞模型;构建NGFI-B缺失突变体与GFP的融合表达载体,分别命名为Δ1-pEGFP-N1(仅有N端152个AA的NGFI-B)和Δ2-pEGFP-N1(缺失N端152个AA的NGFI-B),并导入心肌细胞,采用细胞免疫荧光法观察其在应激心肌细胞中的亚细胞定位,采用流式细胞术观察离体心肌细胞的凋亡率。结果应激条件下,Δ1-pEGFP-N1转染心肌细胞后,发生向线粒体的转位,Δ2-pEGFP-N1转染心肌细胞后,仍滞留于核。Δ1-pEGFP-N1转染心肌细胞后,能显著降低应激引起的心肌细胞凋亡,Δ2-pEGFP-N1转染心肌细胞后,对应激引起的心肌细胞凋亡没有显著的保护作用。结论 NGFI-BN端的152个氨基酸对应激心肌细胞中NGFI-B发生线粒体转位进而导致细胞凋亡发挥重要作用。     

白藜芦醇对心肌缺血再灌注损伤的保护作用及机制研究

目的 研究白藜芦醇对大鼠心肌缺血再灌注损伤的保护作用,并进一步阐明其机制.方法 建立心肌缺血再灌注损伤模型,持续观察标准Ⅱ导联心电图变化,测定乳酸脱氢酶(LDH),丙二醛(MDA)及超氧化物歧化酶(SOD)含量,确定心肌损伤程度.心肌细胞凋亡的检测采用逆转录聚合酶链反应检测bcl-2和bax mRNA的表达;Western blot检测bcl-2和bax蛋白表达.结果 白藜芦醇能降低大鼠心肌冠脉结扎后ST段抬高,降低LDH和 MDA水平,升高SOD水平,抑制bax而增强bcl-2的表达,减少心肌细胞凋亡.结论 白藜芦醇对冠脉结扎诱发的大鼠心肌缺血再灌注损伤有保护作用,其机制可能与上调bcl-2蛋白表达,下调bax蛋白表达抑制心肌细胞凋亡有关.     

白藜芦醇对心肌缺血再灌注损伤的保护作用及机制研究

目的研究白藜芦醇对大鼠心肌缺血再灌注损伤的保护作用,并进一步阐明其机制。方法建立心肌缺血再灌注损伤模型,持续观察标准Ⅱ导联心电图变化,测定乳酸脱氢酶(LDH),丙二醛(MDA)及超氧化物歧化酶(SOD)含量,确定心肌损伤程度。心肌细胞凋亡的检测采用逆转录聚合酶链反应检测bcl-2和bax mRNA的表达;Western blot检测bcl-2和bax蛋白表达。结果白藜芦醇能降低大鼠心肌冠脉结扎后ST段抬高,降低LDH和MDA水平,升高SOD水平,抑制bax而增强bcl-2的表达,减少心肌细胞凋亡。结论白藜芦醇对冠脉结扎诱发的大鼠心肌缺血再灌注损伤有保护作用,其机制可能与上调bcl-2蛋白表达,下调bax蛋白表达抑制心肌细胞凋亡有关。     

X射线对体外培养乳鼠心肌细胞损伤的实验研究

目的 研究X射线对体外培养的心肌细胞活性及凋亡的影响。方法 体外培养新生大鼠心肌细胞,分为对照组和放射组,放射组分别用X射线10Gy、20Gy、30Gy、40Gy单剂量照射心肌细胞,采用MTT法观察X射线对乳鼠心肌细胞活性的影响;血生化自动分析仪定量测定X射线作用后心肌细胞乳酸脱氢酶(LDH)的改变;吖啶橙/碘化丙啶(AO/PI)双染色法在激光扫描共聚焦显微镜下观察心肌细胞凋亡的形态学改变;流式细胞仪定量检测心肌细胞的凋亡率。结果 ①X射线剂量在10~40Gy均能抑制心肌细胞活性并成剂量依赖性;②细胞心肌酶谱检测到LDH释放量与X射线剂量相关;③流式细胞仪发现心肌细胞凋亡率与X射线照射剂量有相关性。结论 本研究结果显示X射线对心肌细胞有毒性作用,可致心肌细胞损伤,表现为心肌细胞坏死和凋亡发生率增加。     

枸杞多糖对慢性辐射小鼠细胞凋亡及bcl-2基因表达的影响

目的：探讨枸杞多糖(LBP)对辐射小鼠细胞凋亡及凋亡相关基因bcl-2表达的影响。方法：以水提取-乙醇沉淀法制备枸杞多糖，并制成0．8％的饲料，给予受试小鼠(枸杞多糖组)。正常对照组、辐射对照组给予普通饲料。除正常对照组外，另两组均用^60Coγ射线对动物进行全身性照射，每天照射1次，每天照射剂量为0.084Gy，每周照射5d，连续照射6w，照射总剂量为2.52Gy。检测骨髓微核率、睾丸精母细胞染色体畸变、精子畸形率、肝细胞caspase-3 mRNA表达水平、细胞凋亡及凋亡相关基因bcl-2表达等指标。结果：LBP可使辐射引起的微核率、染色体畸变、及精子畸形率显降低，骨髓细胞增殖活性提高，凋亡率降低，使辐射小鼠bcl-2基因表达提高、caspase-3 mRNA表达水平降低。结论：枸杞多糖的抗辐射作用与其调控细胞bcl-2基因表达，影响细胞凋亡有关。     

热应激大白鼠心肌钙调素含量与钙代谢的研究

观察了热应激大鼠心肌钙调素（ＣａＭ）及钙代谢的变化。结果表明，当热应激大鼠肛温达３９℃时，心肌ＣａＭ含量升高，之后则随肛温升高而下降，呈抛物线型，至肛温４２℃以上时，较对照下降３７．５％。热应激大鼠心肌和细胞内质网、线粒体Ｃａ２＋－ＡＴＰ酶活力随肛温升高逐步下降，至肛温４２℃以上时，分别下降３６．５％，３５．５％和３８．４％。心肌细胞内质网Ｃａ２＋主动转运速率和Ｃａ２＋－ＡＴＰ酶活力变化密切相关。热应激大鼠心肌组织及细胞内质网、线粒体钙含量随肛温升高呈二次函数曲线型下降。提示，过热机体心肌ＣａＭ含量下降，心肌细胞内钙代谢紊乱是导致心功能紊乱甚至心力衰竭的重要原因。     

不同温度热疗对肝癌HepG2细胞增殖与凋亡的影响

目的 探讨不同温度热疗对体外培养肝癌HepG2细胞增殖与凋亡的影响. 方法 采用水浴对肝癌HepG2细胞行43℃、46℃、48℃、50℃实验组和37℃对照组热疗,用倒置显微镜观察热疗后24 h的细胞形态变化,四甲基偶氮唑蓝(methyl thiazolyl tetrazolium,MTT)法检测细胞增殖水平,流式细胞仪测定细胞凋亡和坏死率. 结果 46℃、48℃、50℃与43℃、37℃比较,细胞增殖明显受抑制,24、48、72、96 h分别为54.9%、78.0%、82.0%、65.2%、80.3%、87.7%、72.3%、87.5%、91.0%、82.7%、91.3%、92.8%(P<0.05).而43℃细胞增殖抑制不明显(P>0.05).46℃组的细胞凋亡率最高为34.17%±1.75%,与其它各组之间差异有统计学意义(P<0.01),50℃组的细胞坏死率最高为57.36%±4.07%,各组之间差异均有统计学意义(P<0.05). 结论 46℃及以上的热疗能够明显抑制HepG2细胞的增殖,引起明显的细胞凋亡与坏死.     

原发性肝细胞肝癌细胞凋亡与bcl—2基因的关系

目的：研究细胞凋亡相关基因bcl-2与原发性肝细胞肝癌（HCC）细胞凋亡的关系。方法：采用TdT酶介导的生物素化dutp缺口末端标记技术(Tunel)和名疫组化SP法，检测肝癌组织的细胸凋亡的指数和bcl-2基因的表达并以慢性肝炎肝组织作为对照。结果：慢性肝炎肝组织细胞凋亡指数显高于癌组织细胞（P＜0．01）,bcl-2在癌组织中的表达为51．3％，在对照组织中的表达为25％，肝癌组织中bcl-2表达与癌组织凋亡指数呈负相关，结论：在HCC中，癌细胞凋亡明显受到抑制，其发生可能与bcl-1基因调节障碍有关。     

miRNA-374对缺血再灌注损伤的保护作用

目的探讨miRNA-374对心肌缺血再灌注损伤是否存在保护作用。方法取SD新生大鼠,分离心肌组织细胞培养,随机分为空白组(Blank)、阴性对照组(NC)(转染miRNA-374阴性对照序列),miRNA-374模拟组(转染miRNA-374模拟基因),miRNA-374抑制剂组(转染miRNA-374抑制剂)、siRNA-DTNA组(转染siRNA-DTNA)和miRNA-374抑制剂siRNA-DTNA组(转染miRNA-374抑制剂和siRNA-DTNA)。分别观察各组心肌细胞超氧化物歧化酶(SOD)、丙二醛(MDA)和乳酸脱氢酶(LDH)的水平,并检测各组心肌细胞增殖及凋亡情况。结果①过表达miRNA-374和DTNA会使AKT、Hes1、bcl2表达上升,使Notch1、DTNA、BAX、HIF-1α表达下降;②上调miRNA-374、下调DTNA能保护心肌细胞、促进心肌细胞增殖、改变心肌细胞的细胞周期、抑制心肌细胞凋亡。结论 miRNA-374通过介导DTNA下调,并阻断Notch1通路,从而保护心肌细胞免受缺血再灌注的损伤。     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

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.     

Fatigue and health in a seafaring population

Background Occupational fatigue is relatively common withinthe general population and has been linked to reduced performance,injury and longer term ill-health. Despite growing acknowledgementof this problem in the maritime sector, little research hasbeen conducted into the risk factors, prevalence and consequencesof seafarers' fatigue. Aims To examine the prevalence of fatigue among seafarers, identifypotential risk factors and assess possible links with poor performanceand ill-health. Methods Cross-sectional questionnaire survey of seafarers workingin the offshore oil support, short-sea and deep-sea shippingindustries. A number of tools were used including the fatiguesubscale of the profile of fatigue-related symptoms, the CognitiveFailures Questionnaire, the General Health Questionnaire andthe SF36 General Health scale. Results In all, 1855 questionnaires were completed giving anoverall response rate of 20%. Fatigue symptoms were associatedwith a range of occupational and environmental factors, manyunique to seafaring. Reporting a greater number of risk factorswas associated with greater fatigue [e.g. OR = 2.53 (1.90–3.35)for those with three or four risk factors and OR = 9.54 (6.95–13.09)for those with five or more risk factors]. There was also astrong link between fatigue and poorer cognitive and healthoutcomes, with fatigue the most important of a number of riskfactors, accounting for 10–14% of the variance. Conclusions Seafarers' fatigue could impact on safety withinthe industry and may be linked to longer term individual ill-health.It can only be addressed by considering how multiple factorscombine to contribute to fatigue.     

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.     

Hydrazine inhalation hepatotoxicity

Abstract Hydrazine is a hazardous chemical commonly used as a reactant in rocket and jet fuel cells. Animal studies have demonstrated hepatic changes after hydrazine inhalation. Human case reports of hydrazine inhalation hepatotoxicity are rare. We report a case of mild hepatotoxicity following brief hydrazine vapour inhalation in a healthy young man, which resolved completely on expectant management.     

Fitness standards in airline staff

Employers have a legal duty to manage safety and to meet this duty it is necessary to control risks arising from pre-existing medical conditions. Such conditions can be identified at the time of job placement, but there is little published information about the approach to fitness standards by most airlines. This review is therefore limited to the practice of one major airline. It is illustrated by reference to various occupations within the airline, with the associated rationale.