缺血预适应对大鼠肠系膜缺血再灌注损伤的保护作用研究

目的观察缺血预适应(IPC)对小肠缺血再灌注(I/R)的影响,探讨IPC对I/R的保护作用。方法 90只雄性SD大鼠随机分为3组:假手术组(n=30),I/R损伤组(n=30)和重组人IPC+l/R损伤组(n=30)。构建大鼠肠系膜I/R损伤模型和肠系膜IPC模型。采用硫代巴比妥酸反应方法来测定大鼠血清丙二醛(MDA)含量,采用比色法测定大鼠肠组织匀浆髓过氧化物酶(MPO)活性。采用Park/Chiu对肠组织损伤程度进行组织病理学评分。结果 IPC+l/R损伤组大鼠肠黏膜损伤较轻,显微镜下没有观察到绒毛剥脱,固有层崩解,溃疡,出血,大片上皮下间隙等表现。IR损伤组大鼠血清MDA、MPO水平及Chiu评分显著高于假手术组,相比较差异有统计学意义(t=6.912,24.376,19.553,P﹤0.05);经IPC处理后,IPC+l/R损伤组大鼠血清MDA、MPO水平及Chiu评分显著降低,与IR损伤组比较差异有统计学意义(t=3.293,6.010,4.302,P﹤0.05)。结论缺血预适应可以减轻大鼠肠系膜缺血再灌注诱导的氧化应激损伤,减轻肠组织中性粒细胞积聚,对小肠缺血再灌注损伤有一定的保护作用。     

血必净注射液对大鼠急性肺损伤的作用

[目的]探讨血必净注射液对大鼠急性肺损伤的干预作用及其机制。[方法]成年雄性Wistar大鼠36只随机分为3组:假手术组(C)、缺血再灌注组(I/R)、血必净组(XBJ),每组12只。通过阻断肠系膜上动脉的方法造成肠缺血再灌注模型。分别观察各组动物肺组织病理变化;测定肺组织丙二醛(MDA)、髓过氧化物酶(MPO)活性;以及肺组织TNF-α、IL-1β、IL-6的mRNA水平。[结果]缺血再灌注组肺泡壁明显增厚、间质内有大量多型核细胞浸润,肺组织MDA含量、MPO活性显著升高,TNF-α、IL-1β、IL-6mRNA水平明显高于假手术组。血必净组上述指标则低于缺血再灌注组。[结论]血必净注射液能有效的降低小肠缺血-再灌注致大鼠急性肺损伤,其作用机制可能和下调TNF-α、IL-1β、IL-6等表达有关。     

双歧杆菌黏附素对大鼠肠缺血-再灌注损伤的防护作用

目的:研究双歧杆菌分泌型黏附素对大鼠缺血-再灌注(I/R)后肠黏膜屏障的防护作用。方法:将54只大鼠随机分为假手术组(对照组)、模型组(I/R组)和黏附素预处理组(实验组),每组各24只。于造模成功后6 h、第1、第4和第7天,分别取6只大鼠的血和小肠标本,观察小肠组织病理改变,检测各时间点血中肿瘤坏死因子-α(TNF-α)I、L-6I、L-10、二胺氧化酶(DAO)和D-乳酸(D-LAC)的活性和含量。结果:与对照组比较I,/R组血中TNF-αI、L-6I、L-10、DAO和D-乳酸水平在各时相点均升高(P<0.05);与I/R组比较,实验组各时间点IL-6和DAO水平明显降低(P<0.05),TNF-α浓度术后第1天低于I/R组(P<0.05),术后第4和第7天实验组大鼠血浆D-LAC浓度明显低于I/R组(P<0.05),小肠病理改变较I/R组减轻(P<0.05)。结论:双歧杆菌黏附素对大鼠I/R后肠黏膜屏障具有防护作用,能减轻肠黏膜的I/R损伤。     

远程预处理对肺缺血再灌注氧化损伤的影响

目的研究远程预处理对兔肺缺血再灌注损伤的氧化应激反应。方法随机将18只日本大耳白兔分为3组(每组6只):假手术组(S组)、远程预处理组(R组)、缺血再灌注组(I/R组)。制备兔肺缺血再灌注损伤模型,实验结束将动物处死,观察肺组织形态学变化,检测肺湿/干重比值(W/D)值、丙二醛(MDA)含量、肺组织髓过氧化物酶(MPO)活性及超氧化物歧化酶(SOD)活性。结果与S组相比,I/R组肺组织W/D值、MPO和MDA表达均明显升高(p<0.05),而R组上述指标高于S组但低于I/R组(p<0.05);与S组相比,I/R组肺组织SOD活性明显降低,R组上述指标低于S组但高于I/R组(p<0.05)。结论远程预处理在肺缺血再灌注时的抗氧化性,可能与其清除氧自由基及增加内源性抗氧化酶活性有关。     

大鼠小肠缺血-再灌注损伤后隐窝细胞增殖在肠黏膜屏障损伤修复中的作用

目的:探讨大鼠肠道缺血-再灌注(I-R)损伤后肠道隐窝细胞的增殖特征及其在肠黏膜屏障损伤修复中的作用。方法:选50只大鼠,随机分为对照组(n=5)和I-R组(缺血30 min),其中I-R组根据再灌注(R)0、0.5、1、2、4、6、12、24和48 h再分为9组,每组5只。观察各组大鼠小肠组织的病理学改变。用免疫组化法检测小肠隐窝细胞的增殖程度(Ki67,Musashi-1)。用蛋白质印迹法检测小肠黏膜组织中紧密连接蛋白ZO-1和Oc-cludin的表达。用ELISA法检测血清中D-乳酸和IL-6浓度。从回肠灌注FITC-Dextran-4溶液后,用荧光分光光度法测算其在血清中的浓度。结果:与对照组比,I/R组在R 0～1 h时出现明显的肠黏膜结构损害,渗透性增高,炎性反应增强,黏膜屏障损伤。R 1～2 h时隐窝细胞增殖明显,肠黏膜屏障功能开始修复。R 2 h时肠道渗透性显著降低,紧密连接蛋白表达开始恢复。至R 12～24 h时肠黏膜损伤基本恢复。结论:肠道I-R损伤后,隐窝细胞的增殖在肠黏膜屏障修复中起着重要作用。     

卡巴胆碱对缺血再灌流大鼠肠黏膜组织炎症反应和血流量的影响

目的 研究缺血再灌流时卡巴胆碱对缺血再灌流大鼠肠组织炎症反应和血流量的影响.方法 Wistar大鼠开腹制做空肠袋,夹闭肠系膜上动脉(SMA)阻断血流45 min后恢复血流,制成肠缺血-再灌流模型.动物随机分为假手术组、缺血-再灌流+生理盐水组(I/R+NS)和缺血-再灌流+卡巴胆碱组(I/R+Ca).I/R+Ca组在SMA阻断血流同时向肠袋内注射卡巴胆碱(0.1mg/kg),I/R+NS组给予相同剂量的生理盐水.观察肠黏膜损伤情况;检测肠组织中DAO含量;ELLSA法测定肠组织中TNF-α含量;应用多普勒血流仪测定肠黏膜血流量.结果 I/R+Ca组与I/R+NS组相比,肠黏膜病理变化较轻.I/R+Ca组肠袋黏膜组织DAO活性较L/R+NS组显著增加(P<0.01);同时L/R+Ca组与I/R+NS组相比,肠黏膜血流量明显增加(P<0.01),而肠I/R+Ca组黏膜组织中TNF-α含量较I/R+Ns明显减少(P<0.01).结论 卡巴胆碱能促进缺血再灌流时肠黏膜血流恢复,增加肠黏膜血流量;抑制肠组织中TNF-α的生成,减轻肠黏膜病理损害,时肠黏膜具有保护作用.     

乌拉地尔对大鼠心肌缺血再灌注损伤保护作用的实验研究

目的利用SD大鼠心肌缺血再灌注(I/R)模型,观察α1受体阻滞剂乌拉地尔对大鼠心肌缺血再灌注心律失常和心肌梗死面积的影响,并初步探讨其量效关系。方法取SD大鼠100只,随机分成5组:假手术组,I/R损伤模型组,乌拉地尔治疗组(3 mg/kg,6 mg/kg,12 mg/kg),每组20只。观察各组缺血再灌注心律失常;血清心肌酶学、心肌梗死面积。结果⑴与I/R损伤模型组相比,乌拉地尔可以减少缺血再灌注损伤引起的心律失常发生率,显著缩短心律失常持续时间,降低室颤发生率和死亡率,并呈剂量依赖性。⑵明显减少缺血再灌注血清心肌酶学释放,各剂量组间比较差异无统计学意义(P>0.05)。⑶明显减少缺血再灌注心肌梗死面积,各剂量组间比较差异无统计学意义(P>0.05)。结论3、6和12 mg/kg乌拉地尔对大鼠缺血再灌注损伤心肌均有保护作用。     

乌司他丁对大鼠脑缺血再灌注后大脑皮质内质网应激相关分子表达的影响

目的观察乌司他丁对大鼠脑缺血再灌注后大脑皮质内质网应激(endoplasmic reticulum stress,ERS)相关分子表达的影响。方法健康SD大鼠90只,随机分为3组,假手术组(S组,n=30),脑缺血再灌注组(I/R组,n=30),乌司他丁处理组(U组,n=30)。采用线栓法制备大脑中动脉缺血再灌注模型,缺血2 h,再灌注24 h。HE染色观察大鼠脑组织病理改变,神经功能缺陷评分评价脑损伤程度,2,3,5-氯化三苯基四氮唑(TTC)染色法检测脑梗死体积,末端标记法(TUNEL)法检测细胞凋亡;采用western blot法检测缺血侧大脑皮层GRP78、CHOP、caspase-12蛋白表达情况。结果与S组比较,I/R组和U组大鼠脑缺血再灌注后的神经功能学评分(NDS)升高(P<0.05),脑梗死体积增大(P<0.05),细胞凋亡数明显增加(P<0.05),I/R组和U组再灌注24h缺血侧大脑皮质GRP78、CHOP和caspase-12蛋白均表达上调(P<0.05);与I/R组比较,U组大鼠脑缺血再灌注后的神经功能缺损明显改善(P<0.05),脑梗死体积减少(P<0.05),细胞凋亡数明显减少(P<0.05);U组缺血侧大脑皮质GRP78表达上调幅度明显大于I/R组、CHOP和caspase-12蛋白表达上调幅度明显小于I/R组(P<0.05)。结论乌司他丁可明显减轻大鼠脑缺血再灌注损伤,其机制可能与增加GRP78蛋白表达、拮抗CHOP和caspase-12蛋白表达,阻断内质网应激(ERS)启动的凋亡通路有关。     

瑞芬太尼预处理对大鼠肢体缺血再灌注肾损伤的影响

目的探讨瑞芬太尼预处理对大鼠肢体缺血再灌注肾损伤的影响。方法 108只健康雄性SD大鼠,体重210~230 g,随机分为假手术组(Sham组)、缺血再灌注组(IR组)和瑞芬太尼预处理组(RPC组),每组36只。Sham组仅暴露股动脉,不阻断血管;IR组双侧后肢缺血2 h,再恢复灌注;RPC组缺血前经尾静脉注射瑞芬太尼1.0μg·kg-1·min-1,持续30 min,余同IR组。再灌注后1、3、6、12、24、48 h,于大鼠尾静脉取血1 m L,采用全自动生化分析仪测定尿素氮(BUN)和肌酐(Cr)的含量,酶联免疫吸附法测定肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的水平。结果再灌注6、12、24、48 h血清BUN和Cr含量的比较,IR组和RPC组高于Sham组(P<0.05),RPC组低于IR组(P<0.05);再灌注1、3、6、12、24、48 h血清TNF-α和IL-6水平的比较,IR组和RPC组高于Sham组(P<0.05),RPC组低于IR组(P<0.05)。结论瑞芬太尼预处理能减轻大鼠肢体缺血再灌注肾损伤,其机制可能和降低血清TNF-α和IL-6水平、抑制机体炎性反应有关。     

异氟烷预处理对大鼠肝部分缺血再灌注时脑的保护作用

目的 通过观察在体大鼠肝部分缺血再灌注损伤下外周血中S-100β蛋白含量的变化,结合脑组织线粒体形态学的改变明确异氟烷预处理对大鼠肝部分缺血再灌注时对脑损伤是否具有保护作用.方法 SD大鼠简单随机法分成假手术组(S组),肝缺血再灌注组(I/R组),异氟烷预处理组(ISO组).S组:入腹后只分离肝十二指肠韧带,但不阻断肝门血供;I/R组:肝缺血60 min,再灌注120 min; ISO组:肝I/R前60 min ISO预处理30 min,后在空气中洗脱30 min,再灌注24 h迅速断头取前脑,透射电镜下观察脑线粒体超微结构;各组分别于缺血前及再灌注120 min后抽取静脉血采用双抗体夹心-ELAISA法测定S-100β蛋白含量.结果 I/R组超微结构脑线粒体肿胀,嵴断裂、溶解,内呈空泡状,线粒体形态及膜完整性发生了重大变化,外周血液S-100β蛋白I/R组[(1.52±0.26) μg/ml]显著高于对照组[(0.31 ±0.05)μg/ml](P＜0.05);ISO组线粒体仅有轻度肿胀,嵴及内膜间隙仍可见,S-100β蛋白ISO组[(0.79 ±0.21) μg/ml]明显低于I/R组(P＜0.05).结论 大鼠肝部分缺血再灌注后对脑组织造成了一定程度损伤,而异氟烷预处理对此具有一定保护作用.     

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.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

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.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.     

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.     

The rise and fall in incidence of malignant mesothelioma from a British Naval Dockyard, 1979-1999

BACKGROUND: The incidence of malignant mesothelioma in Britain is predicted to rise over the next 15-25 years because of past failure to protect the workforce against inhalation of asbestos. In British Naval dockyards, alternative insulation materials and respiratory protection were introduced from the mid-1960s. Aims This study was carried out to investigate the effects of these control measures on mesothelioma deaths in dockyard workers. METHODS: Cases of mesothelioma of the pleura and peritoneum between 1979 and 1999 in workers from the Devonport Naval Dockyard, south-west England, were sought from coroners' and medico-legal records. RESULTS: Three hundred and one cases were identified, 7% peritoneal. The peak incidence occurred in 1991 with 25 cases per annum (quadratic model fit R(2) = 74.2%, P < 0.001) and we predict that by 2003 the incidence will fall to fewer than five cases per annum. The mean time between first exposure and presentation was 48.5 years [95% confidence interval (CI) = 47.3-49.8], but this was significantly shorter in the more heavily exposed trades, when compared with the less heavily exposed (42 years, 95% CI = 39.0-45.0, versus 49.5 years, 95% CI = 48.2-50.9). Those with higher exposure were also at significantly greater risk of peritoneal disease (P < 0.023, Fisher's exact test). CONCLUSION: The reduction in incidence of mesothelioma is greater than can be accounted for by reduction in numbers of dockyard workers over the last 50 years. Changes in insulation materials and improved industrial hygiene measures introduced into the Devonport Dockyard from the mid-1960s have resulted in an earlier decline in the incidence of malignant mesothelioma than that predicted for the British workforce as a whole.