高功率微波单次辐照对眼视网膜组织结构的影响

目的研究高功率微波(high power microwave,HPM)单次辐照对动物视网膜病理结构的影响,为HPM安全防护提供实验依据。方法采用自行研制的HPM效应模拟源以远场平面波(平均功率100mW/cm2)进行单次照射,通过病理染色和超微结构观察研究HPM单次照射对大鼠视网膜结构的效应。结果 HPM单次照射后视网膜可出现不同程度的损伤,并伴有部位特异性,视网膜各层生物膜结构亦存在破坏。结论所用剂量范围内的HPM单次照射可导致动物视网膜损伤,生物膜结构是HPM损伤的重要靶点。     

微波长时间辐照对视网膜结构和功能的影响

目的 研究高功率微波(HPM)在不同条件下长期多次辐照对视网膜结构和功能的影响,为HPM安全防护提供依据.方法 大鼠随机分成辐照组(G1、G2、G3组)和对照组(G0组),HPM效应模拟源以远场平面波方式在3个不同平均功率(25、50和100 W/m2)条件下每天辐照6 win,持续辐照1个月,并在照后不同时间点通过组织病理切片和视网膜电流图(ERG)的方法检测HPM对视网膜结构和视功能的生物效应.结果 病理染色显示各辐照组在HPM照后1个月视网膜损伤较重,照后6个月依辐照剂量不同可出现视网膜局部的修复或反应性增生;ERG显示各组照后的b波幅值与照前相比有所降低,但G1组在照后2个月后可恢复,而G2和G3组直至照后6个月才恢复至照前水平.结论 实验所用剂量范围内的HPM重复辐照可以对动物视网膜造成一定程度的损伤生物效应,并呈现出一定的量效和时效关系.     

高功率微波辐射后大鼠心脏β1肾上腺素能受体和M2胆碱能受体表达的变化

目的探讨高功率微波(HPM)辐射后心脏β1肾上腺素能受体(β1-AR)和M2胆碱能受体(M2-AchR)表达的变化及其意义.方法采用平均功率密度为2～90mW/cm2的S波段HPM模拟源辐照150只Wistar雄性大鼠,应用光镜、免疫组织化学和图像分析技术,定量研究HPM辐照后大鼠心脏组织结构的改变及β1-AR和M2-AchR的表达变化规律.结果10 mW/cm2以上的HPM辐射后大鼠心肌纤维排列紊乱,出现颗粒变性甚至肌质凝聚,窦房结P细胞坏死,Purkinje纤维溶解等,且呈一定的剂量-效应关系(r=0.968,P＜0.05);于照后1 d大鼠左心室心内膜下及肌层心肌细胞膜和胞浆β1-AR表达增强,3 d达高峰,与假照射组相比,差异有统计学意义(P＜0.05),14 d逐渐恢复至正常水平;于照后1 d大鼠左心室心内膜下及肌层心肌细胞膜和胞浆M2-AchR表达明显增强并达高峰,与假照射组相比,差异有统计学意义(P＜0.01),14 d逐渐恢复至正常水平.结论一定功率密度的HPM辐射可造成大鼠心脏组织结构的损伤、左心室心内膜下及肌层心肌细胞β1-AR和M2-AchR表达增强,β1-AR和M2-AchR参与了HPM辐射所致心脏损伤的病理生理过程.     

高功率微波辐射致大鼠心和肝损伤形态学观察

目的 探讨高功率微波(HPM)辐射对大鼠心肌和肝实质细胞超微结构的影响.方法 成年Wistar大鼠36只,雌雄各半,随机分为空白对照组和微波辐射组,每组18只;辐照后1,7和14 d处死大鼠,冰浴下立即取心肌心尖部、肝右叶组织,制作常规透射电镜标本并观察.结果 高功率微波辐射后1,7 d时大鼠心肌细胞线粒体溶解空化,肌丝溶解、断裂;高功率微波辐射后最初大鼠肝细胞核内异染色质增多,部分线粒体嵴模糊,辐射后7 d部分线粒体肿胀;高功率微波辐射后14 d大鼠心肌细胞和肝细胞线粒体无明显肿胀,部分心肌肌丝仍有溶解、断裂,少数肝细胞胞质内有脂滴等.结论 高功率微波辐射对大鼠心肌和肝实质细胞有明确的损伤效应,高功率微波辐射致大鼠心肌细胞损伤较重,并且损伤的心肌恢复较慢.     

高功率微波对家兔视网膜睫状神经营养因子蛋白表达的影响

目的探讨高功率微波（HPM）急性辐照后,家兔视网膜组织睫状神经营养因子（CNTF）的蛋白表达量在不同时间的变化以及CNTF的分布,寻找HPM急性辐照后CNTF蛋白的变化规律。方法采用免疫组化以及半定量检测的方法检测90 W／cm^2、15 min辐照后0、3、6、12、24、72 h各个不同时相点家兔视网膜组织CNTF的蛋白表达变化及分布。结果CNTF在视网膜全层均有表达,主要分布于视网膜组织的细胞膜和胞浆中,而胞核染色不明显。CNTF蛋白表达在HPM辐照后有不同程度的变化,辐照后即刻下降约14％,而在6 h表达上调22％,并达到峰值水平,随后维持在对照水平。结论HPM急性辐照能即刻影响家兔视网膜CNTF蛋白的表达,其表达量与损伤时间之间存在时效关系。HPM辐照引起的CNTF表达变化可能参与了微波辐照所致的家兔视网膜组织损伤,为利用外源型CNTF治疗微波辐照所致的家兔视网膜组织损伤提供理论依据。     

非电离辐射对大鼠心肌细胞的损伤及其机制

目的探讨非电离辐射对大鼠心肌细胞损伤效应及机制。方法采用9GHz950mW/cm2微波脉冲和0～100MHz6×104V/m电磁脉冲分别辐照原代培养心肌细胞72h,用原子力显微镜、激光扫描共聚焦显微镜、流式细胞仪和全自动生化检测仪等多种实验手段检测受辐照细胞的细胞膜形态、结构和功能的变化。结果微波脉冲和电磁脉冲辐照后,心肌细胞搏动减慢,形态异常,活力下降,凋亡和坏死率明显增加。细胞膜出现数量不等、大小不一的电穿孔。细胞培养液中Na+、K+、Ca2+、Cl-、Mg2+和无机磷离子浓度显著升高(P<0.01)。结论心肌细胞是电磁辐射损伤的敏感细胞,脉冲电磁场可致心肌细胞膜电穿孔,细胞形态、结构和功能均受到严重损伤。电穿孔效应是解释电磁辐射非热效应的关键机制之一。电穿孔导致的细胞膜通透性和膜结构改变存在一定发展规律。     

微波辐照致大鼠心肌细胞凋亡机制的研究

目的探讨微波辐照诱导心肌细胞凋亡的分子病理机制。方法本实验以峰值功率密度950mW/cm2(9500W/m2)的脉冲微波辐照大鼠心肌细胞0、30、60、120s后,观察心肌细胞形态变化,检测心肌细胞凋亡率和多种凋亡相关基因的表达,以及心肌细胞内外Ca2 、钙调蛋白、钙通道蛋白的变化。结果辐照后心肌细胞呈现出典型的细胞凋亡形态。辐照60s后6、24h,心肌细胞凋亡率分别为(36.76±5.31)%和(26.44±3.94)%,与对照组(2.36±0.87)%相比较差异有显著性(P<0.01),心肌细胞凋亡率与辐照剂量呈正相关。Bax、p53、c-myc表达显著增强(P<0.01),Bcl-2表达一过性增强,随后明显降低(P<0.01)。细胞内Ca2 明显降低,同时细胞外Ca2 显著升高。与对照组相比,钙调蛋白、钙通道蛋白的表达呈有规律下降性变化(P<0.01),并与辐照时间呈正相关。结论心肌细胞是微波辐照损伤的敏感细胞,微波辐照可诱导心肌细胞凋亡,并存在剂量-效应关系。钙离子、钙调蛋白、钙通道蛋白以及多种基因参与微波辐照引起的心肌细胞凋亡,并发挥重要调控作用。     

微波辐照对心肌细胞凋亡促进基因影响

目的探讨微波辐照诱导心肌细胞凋亡的分子病理机制。方法以功率密度峰值为950mW/cm2的脉冲微波辐照心肌细胞0,30,60,120s后,采用倒置显微镜观察心肌细胞形态,流式细胞仪及原位末端标记方法检测心肌细胞凋亡率,免疫组织化学方法检测多种凋亡相关基因表达的变化。结果辐照后心肌细胞呈现出典型的细胞凋亡形态。辐照60s后6,24h,心肌细胞凋亡率分别为（36.76±5.31）和（26.44±3.94）,与对照组（2.36±0.87）比较,差异有统计学意义（P〈0.01）。原位末端标记结果表明,心肌细胞凋亡率与辐照剂量呈正相关。凋亡促进基因Bax、P53、双向调控基因c-myc表达显著增强（P〈0.01）,凋亡抑制基因Bcl-2表达一过性增强,随后明显降低（P〈0.01）。结论心肌细胞是微波辐照损伤的敏感细胞,微波辐照可诱导心肌细胞凋亡,并存在剂量效应关系。Bcl-2/Bax、P53、c-myc参与微波辐照诱导的心肌细胞凋亡并发挥重要调控作用。     

氟乙酰胺对大鼠心肌细胞的影响及乙酰胺解毒效果观察

目的　观察氟乙酰胺对大鼠心肌细胞的影响及乙酰胺解毒效果。方法　将 4组SD大鼠分别给予不同剂量的氟乙酰胺 (经口灌胃 ) ,其中 2组给予治疗剂量的乙酰胺 (腹腔注射 )。观察各组中毒后不同阶段心肌细胞和心肌酶 [天冬氨酸转氨酶 (AST)、乳酸脱氢酶 (LDH)、磷酸肌酸激酶(CK)、磷酸肌酸激酶同功酶 (CK MB)、α 羟丁酸脱氢酶 (HBDH) ]的变化。结果　氟乙酰胺高剂量组 (8mg/kg)染毒后 2 4h ,AST、CK、HBDH升高 ,分别为 (5 89.5 8± 82 1.72 )、(916 .78± 343.5 5 )、(5 0 4 .4 7±14 8.88)U/L ,与对照组 [分别为 (187.70± 4 6 .87)、(75 5 .6 5± 4 98.90 )、(347.2 5± 2 2 8.4 0 )U/L]比较 ,差异有显著性 (P <0 .0 1) ;心肌细胞变性、溶解坏死和炎症细胞浸润 ,雄性大鼠 3d内全部死亡。染毒后 5d ,氟乙酰胺低剂量组 (4mg/kg)的LDH[(14 86 .5 8± 6 2 9.80 )U/L]、HBDH[(5 14 .83± 2 0 1.78)U/L]明显升高 ,与对照组 [分别为 (84 1.17± 2 18.86 )、(337.2 5± 6 2 .0 7)U/L]比较 ,差异有显著性 (P <0 .0 1)。染毒后 10d各实验组心肌酶的差异无显著性 (P >0 .0 5 ) ;病理检查仍可见一定程度的间质纤维细胞增生。给予乙酰胺 (10 0mg/kg)后可减轻病理改变的程度。结论　急性氟乙酰胺中毒可引起心肌细胞可逆     

南北方武警战士外周血淋巴细胞热、冷损伤时热应激蛋白70表达的差异

[目的 ]分析祖籍在宁夏、江苏、广东三个地区的武警士兵外周血淋巴细胞热、冷损伤时热应激蛋白 70(HSP70 )表达水平的差异性及其可能的意义。 [方法 ]用流式细胞仪检测淋巴细胞中HSP70表达水平。 [结果 ]不同地区比较发现 ,宁夏籍士兵基础和热损伤时 ( 4 5℃ ,0 .5h)HSP70表达水平分别为 ( 80 9.93± 5 8.3 7)、( 95 9.2 3± 90 .2 8)荧光道数 ,均比广东籍士兵分别为 ( 75 4.3 4± 60 .82 )、( 887.2 9± 72 .85 )荧光道数显著升高 (P <0 .0 5 ) ;冷损伤条件下 ( 10℃ ,1h) ,三地区士兵HSP70表达水平差异未见显著性。 [结论 ]南北方武警战士淋巴细胞基础和热损伤条件下HSP70表达水平存在差异性 ;冷损伤条件下 ,三地区士兵HSP70表达水平差异无显著性。     

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.