大黄和早期肠内营养对肠缺血-再灌注损伤大鼠肠屏障功能的影响

目的:观察大黄和早期肠内营养(EEN)对大鼠肠缺血-再灌注损伤(IRI)后肠黏膜屏障的影响.方法:将32只大鼠随机分为对照组、EN组、大黄组、大黄+EN组.在大鼠肠IRI模型上观察再灌注24h后肠黏膜形态学的变化、血清内毒素和细菌易位指标. 结果:肠IRI可导致肠黏膜发生严重损伤.肠IRI后24h,大黄组大鼠内毒素水平...     

生长激素对脓毒症大鼠肠黏膜屏障功能的影响

目的:研究生长激素(GH)对脓毒症大鼠肠黏膜屏障功能的影响。方法:将72只大鼠随机分对照组、脓毒症组、脓毒症加GH组,再将各组随机分为空肠组、回肠组和结肠组。空肠组大鼠取Treitz韧带处行空肠置管,距离Treitz韧带25 cm处造口;回肠组自回盲部向上25 cm处置管,末端回肠造口;结肠组行盲肠置管。各组分别于肠道置管造口灌入甘露醇/乳果糖(L/M),收集6 h全部尿液,采用高效液相色谱分析法(HPLC)测定尿L/M值。24 h后处死大鼠,分别取部分空肠、回肠、结肠肠管行体外肠黏膜通透性检测,于透射电镜观察肠上皮细胞间紧密连接(TJ)的超微结构改变。结果:脓毒症组大鼠肠黏膜TJ间隙增宽,肠道通透性增加,且回肠组更加明显;脓毒症加GH组肠黏膜TJ损伤和肠黏膜通透性的增加有所减轻。结论:GH能减轻脓毒症大鼠肠黏膜TJ损伤,改善肠黏膜屏障功能。     

预防性应用类高血糖素多肽-Ⅱ对缺血-再灌注肠黏膜屏障的影响

目的:观察类高血糖素多肽-Ⅱ(GLP-Ⅱ)对缺血-再灌注所致的肠黏膜屏障损害的预防保护作用.方法:采用夹闭肠系膜上动脉20 min所致肠道缺血-再灌注损伤小鼠模型,将30只小鼠随机分为正常(N)组、对照(C)组和GLP-Ⅱ预处理(P)组.观察缺血-再灌注后1天,肠黏膜形态、肠道细菌移位率、血浆内毒素水平和肠道IgA浓度的变化,并进行相关分析.结果:缺血-再灌注后,C组肠黏膜受到明显损伤,P组肠黏膜增生明显,C组和P组小鼠的肠道细菌移位率和血浆内毒素水平均明显高于N组(P＜0.01),肠道IgA浓度则明显降低(P＜0.01).与C组相比,P组的细菌移位率和内毒素水平要低于C组(P=0.005),IgA浓度要高于C组(P＜0.01).结论:缺血-再灌注严重损害了肠黏膜屏障,经GLP-Ⅱ预处理可以有效地减轻肠黏膜屏障的损伤.     

脓毒症时肠道细菌易位发生部位的研究

目的:研究脓毒症时肠道细菌易位发生的部位。方法:将36只大鼠随机分对照组和脓毒症组,各组内随机分为空肠组、回肠组和结肠组。空肠组大鼠于Treitz韧带处空肠置管,距离Treitz韧带20cm处造口;回肠组于回盲部上20cm处肠道置管,末端回肠造口;结肠组行盲肠置管。各组分别于肠道置管口灌入绿色荧光标记的大肠杆菌和乳果糖/甘露醇,于术后行肠道通透性检测,24h后荧光显微镜下观察大鼠肠系膜淋巴结、肝、脾组织中标记细菌的数量,肠系膜淋巴结细菌培养,并在荧光显微镜下观察。结果:空肠组、回肠组和结肠组大鼠肠黏膜的通透性和肠系膜淋巴结荧光细菌计数存在差异,回肠组明显高于空肠组和结肠组。结论:脓毒症时,各肠段细菌易位程度不同,回肠内易位细菌数量最多。     

大鼠肠缺血-再灌注后营养对肠黏膜屏障功能的影响

目的:研究不同营养物质及营养支持途径对大鼠肠道缺血-再灌注时肠黏膜屏障功能的影响. 方法:将大鼠随机分为缺血-再灌注组、对照组及缺血-再灌注后各营养支持组.实验结束行肠黏膜屏障功能指标的检测. 结果:缺血-再灌注后肠黏膜发生明显损伤,普通肠外营养(PN)组D-乳酸、血浆内毒素水平、细菌移位率均显著高于其他各组(P<0.05);普通肠内营养(EN)组血浆内毒素水平明显低于谷氨酰胺肠外营养(G-PN)组(P<0.05),EN和免疫肠内营养(IEN)组细菌移位率无显著差异(P>0.05). 结论:①肠内营养在维护肠黏膜屏障功能方面优于肠外营养.②谷氨酰胺对改善肠黏膜屏障功能有显著作用,但无法取代肠内营养的作用.③免疫增强型营养与普通肠内营养相比,对细菌移位的防治效果并不大.     

利用生物发光活体成像技术观察肠黏膜损伤状态下细菌易位的初步研究

[目的]临床上各种疾病会导致肠黏膜屏障损伤并伴随大量的细菌易位发生。本实验拟使用发光细菌的小鼠活体成像技术,观察肠黏膜损伤状态下易位细菌的动态移位过程。[方法]构建重组荧光脂酶基因(Lux)的质粒pXen-1、pXen-18,转化大肠杆菌DH5a,筛选阳性细菌克隆,扩增培养后,定量(107)注射到肠黏膜屏障损伤模型小鼠肠腔不同部位内,利用生物发光活体成像技术进行细菌易位的病理生理观察研究。实验分为四组:小肠注射菌实验组和对照组、盲肠注射菌实验组和对照组。其中实验组为肠道缺血再灌注损伤,对照组无任何干预措施。[结果]发光细菌小鼠活体成像观察到,存在肠黏膜损伤的小鼠肠腔内的细菌数量及分布发生明显的改变,提示细菌易位在肠黏膜损伤时起着重要的病理生理作用。注入小肠内的发光细菌数量在试验过程中明显下降,提示小肠肠腔环境可以杀灭一定的细菌。[结论]生物发光活体成像技术,可以直观、可靠、敏感地观察肠道内细菌的存活状态,并可观察肠黏膜损伤状态下细菌易位的动态过程。该技术为肠黏膜屏障损伤细菌易位机制的研究提供了一个有力的工具。     

不同腹腔减压方式对腹腔间室综合征大鼠肠道功能的影响

目的:观察腹腔开放减压和腹腔梯度减压两种方式对腹腔间室综合征(ACS)大鼠肠黏膜屏障的影响. 方法:将18只大鼠模型随机分为对照组、开放减压组和梯度减压组.其中开放减压组大鼠ACS持续4h后,经腹正中切口迅速使腹腔压力(IAP)降至0mmHg;梯度减压组大鼠ACS持续4h后,通过减慢气腹充气速度,以ΔIAP=-0.5 mmHg/min的速度减压,直至IAP恢复至0 mmHg(减压时间为50 min).在IAP降至0 mmHg后4h处死动物,取末端回肠行组织病理学检查、肠系膜淋巴结细菌易位测定、肠黏膜组织肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)和肠型脂肪酸结合蛋白(i-FABP)测定. 结果:梯度减压组与开放减压组比较,肠道病理损伤更小,细菌易位率更低,炎性因子水平更低.其中肠道通透性、细菌易位菌落数、IL-6水平在不同减压方式组之间差异有统计学意义(P＜0.05). 结论:不同的腹腔减压方式对ACS大鼠的肠道功能影响不同.梯度腹腔减压比开放减压对ACS大鼠肠道功能的损伤更小.     

腹腔感染病人肠黏膜通透性的变化

目的:观察腹腔感染病人肠黏膜通透性的变化,了解腹腔感染对肠黏膜屏障功能的影响. 方法:将20例病人在确诊腹腔感染24 h内测定肠道乳果糖与甘露醇吸收比值(L/M)、血清内毒素和肿瘤坏死因子α(TNF-α)水平,并同期采集病情严重度(APACHEⅡ评分和SOFA评分)、ICU滞留时间、住院时间和病情转归等. 结果:腹腔感染组LMR水平较正常组明显升高(P<0.01);血清内毒素和TNF-α水平与LMR间呈显著正相关(P<0.01,P<0.05);肠黏膜通透性与病人病情严重程度有显著相关性(P<0.01);腹腔感染病人肠黏膜通透性变化程度与病死率也有明显相关性(P<0.05). 结论:腹腔感染病人的肠黏膜通透性显著增加,腹腔感染可导致肠黏膜屏障功能损害.     

微生物酵素预防治疗肠道细菌易位的实验研究

目的探讨微生物酵素对他克莫司(FK506)作用下肠道细菌易位情况的影响。方法健康雄性Wistar大鼠84只,体重180～220g,随机分为对照组、免疫抑制组和预防治疗组;比较3组间肝和肠系膜淋巴结细菌培养阳性率、肠黏膜病理分析。结果免疫抑制组第5、7天脏器细菌培养阳性率分别为28.57%、42.86%,显著高于对照组的0、0(P<0.05);各时间点肠黏膜损伤评分均显著高于对照组(P<0.05);预防治疗组第7天脏器细菌培养阳性率为7.14%,显著低于免疫抑制组的0(P<0.05);第3、5、7天肠黏膜损伤评分均显著低于免疫抑制组(P<0.05)。结论 FK506可以引起肠黏膜上皮损伤,肠道机械屏障功能破坏,肠黏膜通透性增高,发生肠道细菌易位;应用微生物酵素在一定程度上能够减轻FK506引起的肠黏膜上皮损害,保护肠黏膜机械屏障功能,降低肠黏膜通透性,减少肠道细菌易位的发生。     

大鼠肠缺血-再灌注损伤后细菌易位发生部位的实验研究

目的:探讨肠道缺血-再灌注损伤对不同肠段细菌易位的影响。方法:将大鼠随机分为对照组(行假手术)和肠道缺血-再灌注组(分别于再灌注后1、6和24 h取材)。检测空肠、回肠和结肠的细菌、内毒素易位情况,各段肠系膜静脉中的肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)水平。结果:对照组和肠道缺血-再灌注1 h组各肠段系膜淋巴结细菌培养均阴性,再灌注后24 h组空肠、回肠系膜淋巴结细菌易位率明显高于对照组和结肠系膜淋巴结(P0.05);两组大鼠各段肠系膜静脉血培养、内毒素测定均为阴性;肠道缺血-再灌注后1 h和6 h组大鼠TNF-α浓度明显高于对照组(P0.05);各段肠系膜静脉血IL-6浓度均明显高于对照组(P0.05),再灌注后6 h组,空肠、回肠的肠系膜静脉血IL-6浓度明显高于结肠(P0.05)。结论:肠道缺血-再灌注损伤可造成肠道细菌易位,空、回肠更易遭受肠缺血-再灌注损伤的打击,从而发生细菌易位。     

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 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.     

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.     

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.     

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.     

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 risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.