尾悬吊模拟失重对大鼠肺组织细胞凋亡的影响及其干预

[目的]研究尾悬吊模拟失重大鼠肺组织细胞凋亡情况的变化及其防护方法。[方法]采用尾悬吊模拟失重,分为悬吊7d、21d组和相应对照组以及悬吊7d地塞米松干预组,每组10只健康雄性SD大鼠,共50只。采用原位细胞凋亡检测技术检测肺组织的细胞凋亡情况,采用原位杂交技术检测肺组织BCL-2和BAX的表达情况。[结果]大鼠肺组织普遍存在凋亡细胞,7d尾悬吊模拟失重大鼠肺组织细胞凋亡水平明显高于对照组,差异具有统计学意义(P<0.05);21d组的差异无显著性(P>0.05)。7d尾悬吊模拟失重大鼠肺组织BCL-2 mRNA水平明显低于对照组,BAX mRNA水平明显高于对照组,差异均具有统计学意义(P<0.05);21d组的差异均无显著性(P>0.05)。地塞米松干预后细胞凋亡水平明显低于尾悬吊组,差异有统计学意义(P<0.05)。[结论]尾悬吊7d模拟失重大鼠肺组织存在细胞凋亡过度,凋亡调控基因也有相应变化;地塞米松可用于抑制模拟失重时肺组织的细胞过度凋亡。     

叶黄素对D-半乳糖致氧化损伤小鼠HO-1、TLR4表达的影响

目的研究叶黄素缓解D-半乳糖诱导小鼠氧化应激损伤的作用机制。方法 48只昆明种小鼠随机分为D-半乳糖模型对照组、叶黄素低剂量组(10mg/kg·d)、叶黄素高剂量组(40mg/kg·d)和正常对照组。6周后观察小鼠肝组织活性氧(ROS)、一氧化氮(NO)含量,总一氧化氮合酶(TNOS)、诱导型一氧化氮合酶(iNOS)和线粒体ATP酶(ATPase)活性,RT-PCR法检测血红素氧合酶(HO-1)和toll样受体4(TLR4)mRNA表达水平。结果叶黄素低、高剂量组小鼠肝组织ROS含量低于模型对照组(P0.01);低、高剂量组线粒体Na+-K+-ATP酶及高剂量组线粒体Ca2+-ATP酶活性高于模型对照组(P0.05);高剂量组TNOS、iNOS活性及NO含量低于模型对照组(P0.05);高剂量组小鼠肝HO-1mRNA表达高于模型对照组(P0.05),叶黄素低、高剂量组TLR4mRNA表达均低于模型对照组(P0.01)。结论叶黄素降低D-半乳糖小鼠氧化应激效应可能与其提高HO-1表达和下调TLR4mRNA表达有关。     

百草枯对大鼠肾损伤作用

目的 探讨百草枯(PQ)对肾损伤中诱导型一氧化氮合酶(iNOS)和血红素氧合酶-1(HO-1)作用机制.方法 84只SD大鼠随机分为对照组和染毒组,每组42只.染毒组腹腔注射百草枯25 mg/kg,对照组给予等量生理盐水.分别于给药后3,6,12 h,1,2,3,5 d观察肾组织病理学变化及HO-1、HO-1 mRNA、iNOS表达变化.结果 与对照组比较,染毒组于染毒3 h肾组织见充血、水肿及空泡变性等变化;染毒3 h后iNOS与HO-1呈阳性表达,染毒1d后达高峰,平均分分别为(8±2.23)和(7±2),明显高于对照组(P＜0.05),染毒3 h后HO-1mRNA表达水平为(0.53±0.21),明显高于对照组的(0.3±0.12)(P＜0.05),之后表达逐渐减弱,至染毒后5 d差异无统计学意义.结论 iNOS与HO-1与PQ染毒肾损伤过程有关.     

沙漠干热环境中暑大鼠肺损伤与NO、iNOS mRNA的变化研究

目的研究沙漠干热环境中暑大鼠肺损伤性变化与肺组织一氧化氮(NO)浓度、诱导型一氧化氮合酶(iNOS)mRNA表达量之间的关系。方法将48只雄性SD大鼠以随机数字表按简单随机分组法分为6组:沙漠干热环境轻度、中度、重度中暑组及各组相应的常温(室温25℃,湿度35%)对照组,然后将6组大鼠分别进行麻醉、固定、置管、接多导生理信号记录仪,3个中暑组放置在人工实验舱模拟的沙漠干热环境中,3个对照组放置在常温环境中,干热环境组分别在轻度、中度、重度中暑3个阶段的3个时间点麻醉处死大鼠,并留取血液标本和肺组织,相应对照组取材和时间点同实验组,依据分组相应时间点,打开胸腔,留取肺灌洗液、肺组织。应用HE染色观察肺组织病理学改变,应用一步法检测肺组织NO浓度,荧光定量PCR检测iNOS mRNA表达量的变化。结果沙漠干热环境各中暑组大鼠肺组织NO浓度和iNOS mRNA表达量与肺病理学评分和肺湿干重比的变化趋势一致,各个指标除了肺湿干重比(W/D)与中度中暑组和重度中暑组之间比较,差异无统计学意义外(P0.05),在其他各个中暑组之间差异均有统计学意义(P0.01),各项指标中暑组与其对应的对照组之间差异均有统计学意义(P0.01)。相关性分析提示,沙漠干热环境各中暑组肺损伤病理学评分与NO浓度、iNOS mRNA表达量之间显著相关,NO浓度、iNOS mRNA(P0.01)。结论沙漠干热环境下中暑可造成继发性急性肺损伤,随着中暑的发生发展而肺损伤逐渐加重,NO和iNOS可能在沙漠干热环境急性肺损伤过程中起重要作用,提示抑制iNOS的药物可能在减轻急性肺损伤过程中具有潜在的应用价值。     

脑白质损伤新生大鼠VEGF及iNOS表达变化研究

目的 研究缺氧缺血(HI)对新生大鼠脑白质细胞血管内皮生长因子(VEGF)及诱导型一氧化氮合酶(iNOS)表达的影响,探讨VEGF及iNOS在新生大鼠脑白质损伤(WMD)发病机制中的作用。方法 将3日龄大鼠随机分为实验组及假手术组,建立新生大鼠WMD模型,分别予HI后12、24、48、72 h及7 d处死,对其脑组织取材后行HE染色观察其病理改变,并应用免疫组织化学法检测其VEGF及iNOS的表达水平。结果 在新生大鼠脑白质中,1)VEGF表达水平予HI后12 h开始明显上升,24 h后达高峰,至7 d恢复正常,与对照组比较,实验组脑室周围白质VEGF的表达在12、24、48、72 h有统计学意义。2)实验组iNOS于HI后12 h表达开始增加,72 h达高峰,7 d仍有表达,与对照组比较,差异有统计学意义。 结论 HI可导致新生大鼠脑白质VEGF及iNOS的表达水平显著增高,参与新生大鼠WMD的病理生理过程。     

髓系抑制性细胞与诱导型一氧化氮合成酶在哮喘小鼠肺组织中的表达及意义

目的:探讨髓系抑制性细胞(MDSCs)及诱导型一氧化氮合酶(iNOS)在哮喘小鼠肺组织中的表达及意义。方法:将BALB/C小鼠随机分成哮喘组及对照组,每组10只。用卵清蛋白(OVA)致敏、激发建立小鼠哮喘模型,用HE染色观察两组小鼠肺组织病理改变;用免疫组织化学(免疫组化)方法检测小鼠肺组织中MDSCs积分光密度值平均值;用RT-PCR检测小鼠肺组织中iNOS mRNA的表达。结果:哮喘组可见气道壁增厚,炎性细胞浸润,对照组则无明显变化。哮喘组小鼠肺组织MDSCs、iNOS mRNA的表达水平显著高于对照组,差异有统计学意义(P<0.05)。结论:哮喘小鼠肺组织中MDSCs的聚集增加,iNOS的表达增多,MDSCs通过表达iNOS来实现其在哮喘小鼠气道炎症、气道高反应及免疫抑制等方面的重要作用。     

休克大鼠血管外膜阳离子氨基酸运体表达

目的观察败血症休克大鼠主动脉外膜阳离子氨基酸转运体(CAT-1、CAT-2B)和诱导型一氧化氮合酶(iNOS)基因表达。方法雄性Wistar大鼠盲肠结扎并穿孔复制败血症休克模型。逆转录-聚合酶链(RT-PCR)方法测定诱导型一氧化氮合酶(iNOS)、CAT-1、CAT-2B mRNA表达水平。结果败血症休克大鼠表现为严重的心功能降低、低血糖和高乳酸血症。血管外膜CAT-1、CAT2B、和iNOS的mRNA水平均比假手术组明显上调(均P<0.01)。结论败血症休克时血管外膜阳离子氨基酸转运体和诱导型一氧化氮合酶基因表达上调。     

模拟失重对大鼠心肌氧化应激水平的影响

目的 观察模拟失重大鼠心肌组织氧化应激水平变化,探讨模拟失重状态下心肌收缩功能下降的可能原因.方法 将20只SD大鼠随机分为对照组、模拟失重组,采用尾部悬吊法制作模拟失重模型.3周后所有大鼠断颈处死,取心肌组织测量一氧化氮(NO)、硝基酪氨酸、总抗氧化能力(T-AOC)、诱导型一氧化氮合酶(iNOS)含量;取血清测量iNOS活力.结果 模拟失重可显著增加心肌组织NO、硝基酪氨酸含量及iNOS活力,分别为6.23±0.17 U/mg prot、0.021±O.007 nmol/L和0.150±0.020 U/mg prot,而T-AOC则明显下降,为9.161±4.876 U/mg prot;对照组分别为4.25±0.21 U/mg prot、0.015±0.004 nmol/L、0.073±0.020 U/mg prot、19.112±12.816 U/mg prot.差异有统计学意义(P＜0.01,P＜0.05).血清iNOS活力呈增加趋势(P＞0.05).结论 3周模拟失重可增加大鼠的氧化应激水平,使抗氧化能力下降,可能是模拟失重状态下影响心肌收缩功能机制的重要环节之一.     

大鼠经脑内注射染锰后iNOS表达的变化

目的观察大鼠经脑内注射染锰后诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)表达的变化。方法健康雄性SD大鼠随机分为实验组和对照组,采用脑内注射方法染锰,于损伤后不同时间点取材,用免疫组织化学染色方法检测酪氨酸羟化酶(tyrosine hydroxylase,TH)表达的变化;用免疫组织化学染色和Western blot检测诱导型一氧化氮合酶表达的变化。结果①实验组大鼠染锰后1d,iNOS无明显表达;注射侧黑质与对侧相比,TH免疫反应阳性细胞无明显变化。②实验组大鼠染锰后7d,iNOS免疫反应阳性细胞明显增加;注射侧黑质与对侧相比,TH免疫反应阳性细胞明显减少。③对照组大鼠脑内注射后7d和1d,iNOS均无表达;注射侧黑质与对侧相比,TH免疫反应阳性细胞无明显变化。结论锰中毒可导致多巴胺能神经元的损伤,诱导型一氧化氮合酶可能在其中发挥重要的作用。     

博莱霉素致大鼠肺纤维化及与肺血管内皮细胞损伤的关系

目的 探讨血管内皮损伤与博莱霉素(BLM)致大鼠肺纤维化发生间的关系。方法 实验组大鼠经气管灌注BLM制作肺纤维化模型,采用免疫组化及图像分析系统对其肺组织中血管内皮细胞生长因子(VEGF)进行定性、定量分析。结果 (1)组织学观察:染BLM后3、7 d,大鼠肺泡腔及间隔水肿,炎细胞渗出,肺泡Ⅰ型及Ⅱ型上皮细胞变性、坏死,肺泡上皮细胞基底膜断裂,血管内皮细胞肿胀,核浓缩;7、14 d,大鼠肺泡Ⅱ型上皮细胞增生,肺泡间隔有较多成纤维细胞及新生毛细血管形成;28 d,大鼠肺泡间隔增厚,肺泡结构破坏,肺组织明显纤维化样改变。(2)VEGF免疫组化染色:对照组大鼠肺组织呈弱表达,主要分布于肺泡Ⅱ型上皮细胞、支气管黏膜上皮细胞、肺泡巨噬细胞及肺间质细胞。染BLM组大鼠VEGF呈明显高表达,其中,3 d至28 d,大鼠肺泡Ⅱ型上皮细胞VEGF持续高表达,表达量明显高于对照组,差异有统计学意义(P<0.05,P<0.01);7、14、28 d,大鼠肺间质细胞VEGF呈高表达;3 d至28 d,大鼠肺泡巨噬细胞VEGF表达均升高,与对照组的差异均有统计学意义(P<0.05,P<0.01)。结论 VEGF持续高表达与大鼠血管内皮细胞损伤有关,而血管内皮细胞的损伤可能是BLM诱发大鼠肺纤维化的重要启动因素之一。     

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.     

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.     

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.     

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.