早期营养减轻湿热复合创伤后应激的研究

目的　高温高湿创伤复合应激条件下超氧化物歧化酶 (SOD)、丙二醛 (MDA)、一氧化氮 (NO)和醛固酮(ALD)的变化规律 ,为提高部队应对应激反应的能力提供实验依据。方法　 (1)湿热创伤对照组动物以去离子水灌胃1周 ,造成背部浅Ⅱ°烫伤 ,置于仿真模拟气候舱 [干球温度 (37± 0 5 )℃ ,相对湿度 (6 5± 5 ) % ]1～ 2h ,每组各分为热应激 1,2 ,4 ,10h 4个时相点 ;(2 )湿热创伤给药组 ,给予维生素C、L -精氨酸、维生素E组成的复合营养素灌胃 1周 ,创伤和湿热、时相点处理同 (1)。结果　对照组和给药组血浆SOD、MDA含量变化的有显著性差异 (P <0 0 5 ) ;对照组1h与对照组其余各时相点及给药组各时相点血浆NO、血清ALD含量比较均有显著性差异 (P <0 0 5 ,P <0 0 1)。结论　早期肠道营养对于减轻应激、保护器官及预防并发症的发生有重要意义     

高温对大鼠血管活性物质含量及脂质过氧化的影响

目的　探讨高温对大鼠内皮素 (ET)、心钠素 (ANP)、内源性洋地黄物质 (EDLS)释放及脂质过氧化的影响。方法　将 4 8只Wistar大鼠随机分为对照组、热习服组、热应激组。用放射免疫法测定ET、ANP、EDLS及超氧化物歧化酶 (SOD)含量 ,分光光度法测定丙二醛 (MDA)含量。结果　 3组间ET含量差异无显著性 (P >0 0 5 ) ;热习服组和热应激组大鼠血浆ANP含量明显低于对照组 ,差异有显著性(P <0 0 5 ) ;热习服组与热应激组的EDLS含量明显高于对照组 ,差异有显著性 (P <0 0 1)。热习服组和热应激组大鼠血清SOD含量明显低于对照组 (P <0 0 1)。MDA含量比较 ,热应激组高于对照组 ,差异有显著性 (P <0 0 1) ,热习服组与对照组比较 ,差异无显著性 (P >0 0 5 )。结论　高温环境对大鼠ANP、EDLS水平有影响 ,热习服与热应激后导致ANP明显下降 ,而EDLS含量明显升高。大鼠质脂过氧化作用增强 ,抗氧化酶作用减弱。     

叶酸对高同型半胱氨酸小鼠血脂、MDA及SOD活性的影响

目的　研究叶酸 (Folic Acid,FA)对高同型半胱氨酸 (HCY)小鼠血脂、心肝 MDA含量及心肌 SOD活性的影响 ,探讨防治心血管疾病的措施。　方法　昆明小鼠 2 4只 ,雄性 ,(2 0± 1) g,分 3组 :即正常对照组 (NS组 ) ,高同型半胱氨酸组 (HCY组 )与叶酸处理组 (FA组 )。 HCY动物造模给药途径为腹腔注射。 NS组给生理盐水 ,HCY组和 FA组给 HCY16μmol· kg- 1 d- 1 ;腹腔注射 2 h后 ,NS组和 HCY组经口灌胃给生理盐水 ,FA组给 FA 1.0μmol· kg- 1 d- 1 ,连续 5 d。末次给药后 4 h,腹腔静脉采血取血 ,分离脏器。测定血脂 ,心肝 MDA,心肌 SOD。　结果　HCY组与 NS组比 SOD活性有所升高 ,心肝 MDA、血浆 AL P含量增加 ,差异显著。FA组与 HCY组比心肝 MDA和血浆 AL P含量显著降低。与 NS组比 HCY组动物的 TG、TC、L DL、VL DL含量显著增高 ,HDL 显著下降 (P<0 .0 5 ) ;FA组与 HCY组比 TG、TC、L DL、VL DL含量显著下降 ,HDL显著增高 (P<0 .0 5 )。　结论　叶酸作为一种细胞的保护因子在临床应用可抵抗高同型半胱氨酸引起的高血脂和脂质氧化 ,预防心脏和肝脏损伤具有重要的实践意义     

L-精氨酸对热应激大鼠血清皮质醇变化的影响

目的 观察补充L-精氨酸对热应激大鼠血清皮质醇含量的变化，探讨L-精氨酸对热应激胸腺具有保护作用的可能机制。方法 青春期雄性SD大鼠，随机分为对照组、L-精氨酸灌胃组、维生素E饲料组，观察各组常温和41℃应激1，2h后及热应激后0，4，8h3个时间点的血清皮质醇的变化。结果 (1)高温应激后各组血清皮质醇含量均明显升高，其中热应激后4h升到最高，补充L-精氨酸组明显低于未补充组；(2)补充适量L-精氨酸可减轻热应激大鼠胸腺和脾脏的急性萎缩。结论 适量的L-精氨酸能够抑制热应激引起的血清皮质醇含量的显著升高及减小胸腺和脾脏指数，适量的L-精氨酸对热应激大鼠胸腺具有明显的保护作用，可以增强机体的免疫力。     

维生素A干预对大鼠抗氧化能力及细胞膜流动性影响的研究

目的　通过对大鼠补充不同剂量维生素A(VA)观察机体抗氧化能力及对红细胞膜流动性的影响 ,了解抗氧化活性的最佳剂量。方法　将Wistar大鼠随机分为 4组 ,分别为维生素A缺乏组 (VA1组 )补充1 1 4 3(VA2组 )、4 2 86 (VA3组 )和 1 4 2 86 μgRE·kg- 1 ·d- 1 (VA4组 )维生素A三个剂量组。测定各组大鼠血浆VA含量、SOD、MDA和GSH Px的含量和活性 ,用荧光偏振度P值和微粘度 η值评价红细胞膜的流动性。 结果　各组血浆中VA水平随补充剂量的增加而增加。血浆中SOD、GSH -Px和MDA的结果显示 ,补充剂量为VA2、VA3组SOD的水平较VA缺乏组和VA4组明显偏低 (P <0 0 1 )。VA3组的MDA较其它 3个剂量组明显下降 (P <0 0 1 )。VA4组的SOD、MDA含量明显高于其它三个剂量组 (P <0 0 1 )。VA3组血浆中GSH -Px的活性明显升高 ,P <0 0 1。细胞膜流动性的结果显示 :VA3组P值最小 (P <0 0 1 ) ;VA4组P值明显增高 (P<0 0 1 )。微粘度 η在VA3组与VA缺乏组和VA2组之间未见明显差异 ,与VA4组相比明显下降 (P <0 0 1 )。结论　维生素A补充剂量为 4 2 86 μgRE·kg- 1 ·d- 1 时 ,能够发挥较好抗氧化作用 ,红细胞膜的流动性明显增加 ,过量摄入维生素A可造成机体的中毒反应 ,增加机体的氧化损伤     

2,3,7,8-四氯二苯并二恶英对SD大鼠肝脏SOD、GST、MDA影响的实验研究

目的　研究 2 ,3 ,7,8 四氯二苯并二恶英 (TCDD)对SD大鼠肝脏SOD、GST、MDA的影响。方法　把 5 0只雌性SD大鼠随机分为 10组 :染毒 2 4h组 (染毒剂量为 :0 0 1、 0 1、 1、 10、 5 0 μg/kg)、染毒 2 4h对照组 ;染毒72h组 (染毒剂量为 :0 1、 1、 10 μg/kg)、染毒 72h对照组 ,每组 5只。采用一次性腹腔注射染毒 ,测定其肝脏中SOD、GST的活性和MDA的含量。结果　染毒 2 4h后 ,与对照组相比 ,各染毒组SOD活力有所下降 ,但差异无显著性 ;各染毒组GST活力都有所增加 ,但只有 5 0 μg/kg组差异有显著性 (P <0 0 5 ) ,且染毒剂量与GST活力之间有剂量 效应关系 ;各染毒组MDA含量都有所增加 ,其中 10、 5 0 μg/kg组差异有显著性 (P <0 0 5 ) ,且染毒剂量与MDA含量之间存在剂量 效应关系。染毒 72h后 ,与对照组相比 ,各染毒组SOD活力均显著下降 (P <0 0 5 ) ,且染毒剂量与SOD活力之间有剂量 效应关系 ;各染毒组GST活力都有所增加 ,但差异无显著性 ;各染毒组MDA含量都有所增加 ,其中 1、10 μg/kg组差异有显著性 (P <0 0 5 ) ,且染毒剂量与MDA含量之间存在剂量 效应关系。 结论　急性染毒后 ,TCDD对SD大鼠的肝脏具有脂质过氧化作用 ,引起MDA含量增加 ,SOD活力降低 ,TCDD能诱导GST的活力 ,但诱导作用     

高温下精氨酸对一氧化氮和细胞增殖的影响

目的　探讨精氨酸对高温下血清一氧化氮 (NO)含量和淋巴细胞增殖活性的影响。方法　BALB/C小鼠 ,随机分为对照组、精氨酸补充组 [0 5 ,1 5 ,2 5 ,3 5 g/ (kg .bw) ],每组 35只 ,其中 5只为常温对照。 14d后 ,除常温对照外均放入 (41± 0 5 )℃动物高温仓热应激 12 0min ,结束后 0 ,2 ,4 ,8,12 ,2 4h共 6个时相分别眼眶采血 ,常温组在灌胃第 3,7,11,14d时采尾血。观察指标测定血清NO浓度、淋巴细胞增殖活性。结果　 (1)在常温下补充精氨酸后第 3d各实验组血清NO含量最高 ,第 7d后基本稳定 ,补充组各个时间点都高于未补充组 ,其中补充精氨酸 0 5 g/(kg .bw)组各个时间点明显高于其他补充组。 (2 )热应激后补充 0 5和 1 5 g/ (kg .bw)及未补充组血清NO浓度有先下降 (0～ 2h最低 )而后上升 ,4～ 8h基本稳定。而补充高浓度精氨酸的两组〔2 5和 3 5 g/ (kg .bw)〕热应激后持续上升 ,而且在 12h内 ,血清NO含量明显高于低浓度的两组和对照组。 (3)在热应激下补充精氨酸的各组刀豆蛋白(ConA)刺激指数高于对照组 ,补充精氨酸的各组 ,以 1 5 g/ (kg .bw)时ConA刺激指数达到最大。热应激后 ,小鼠淋巴细胞增殖活性受到抑制 ,其中 4～ 8h最低。结论　高温环境应激下小鼠对精氨酸的需要量增加 ,而血清NO含量的变     

高温复合创伤对兔血一氧化氮及平均动脉压的影响

目的探讨急性热暴露复合创伤后血浆一氧化氮(NO)早期变化及其对血压的可能影响,为急性应激条件下NO的作用机制研究提供理论依据.方法建立兔急性热暴露复合创伤模型,实验动物分为常温无创组、常温创伤组、高温无创组、高温创伤组.于0、1、2 h不同时间点取血测定NO含量,全程监测血压变化.结果急性热暴露创伤后1 h左右,兔血浆NO浓度下降,然后升高,高温创伤组NO浓度在1、2 h时分别为(42.75±8.24)、(59.54±9.05)μmol/L,差异有显著性(P＜0.05),而正常对照组则为(56.63±3.79)、(55.22±7.15)μmol/L,两组于1 h时的差异有显著性(P＜0.05).在高温和创伤条件下,兔平均动脉压(MAP)于60～70 min降至最低点,继之有一个短暂的回升,然后则迅速下降.结论急性热暴露复合创伤兔早期血浆NO浓度先降低后升高,且与MAP的变化有一定关系.     

石雕作业环境暴露对小鼠血浆脂质过氧化的影响

目的探讨石雕作业环境暴露对小鼠血浆脂质过氧化的影响。方法 80只小鼠随机分为4组,分别为对照组和暴露于石雕作业现场的低(2 h/d)、中(4 h/d)、高(8 h/d)剂量组。暴露15 d后,每组先取10只摘眼球取血,枸橼酸钠抗凝,测定血浆中的丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力;其余小鼠脱离石雕作业环境继续饲养15 d后,重复前述操作。结果暴露结束0 d时,各组MDA、SOD和GSH-Px差异均有统计学意义(均P0.05)。暴露结束15 d后,各组MDA、SOD差异亦有统计学意义(均P0.05),而GSH-Px差异无统计学意义(P0.05)。同剂量组暴露结束15 d与0 d时相比,MDA的含量均有所下降,但仍高于正常水平(P0.05);而SOD和GSH-Px活力差异则无统计学意义(均P0.05)。结论石雕作业环境暴露可使小鼠血浆中MDA含量升高,SOD、GSH-Px活力下降,脱离该作业环境其MDA、SOD和GSH出现可逆性变化。     

冷库工人血浆中HSP70抗体及脂质过氧化水平的研究

目的　研究低温作业人群中HSP70抗体水平及血浆中SOD、GSH、MDA等脂质过氧化指标水平,探讨低温作业对人可能的危害与机制。方法　选冷库作业工人为研究对象,其中保鲜冷库(0℃组) 5 3人,水产冷库(-2 0℃组) 5 3人,另选不从事有毒有害职业的村民5 7人作为对照。用Westernblot ELISA法研究血浆中热应激蛋白抗体表达水平,用试剂盒检测血浆中SOD、GSH、MDA等生化指标。结果　对照组5 7人中有3人出现血浆HSP70抗体1∶10阳性,阳性率为5 %;而0℃组5 3人中有14人阳性,占2 6%;-2 0℃组5 3人有11人出现阳性(2 .1%)。对照组1人出现1∶2 0阳性(2 %) ,0℃组有8人阳性,占15 %;-2 0℃组也有8人出现阳性(15 %)。0℃组与-2 0℃组分别与对照组相比,其血浆HSP70抗体水平明显增高,差异有显著性(P <0 .0 5 )。此外,0℃组与-2 0℃组中还各有1人出现1∶40阳性,而对照组没有检出。0℃组与-2 0℃组相比,HSP70抗体水平差异没有显著性(P >0 .0 5 )。对于各生化指标,0℃组与-2 0℃组分别与对照组相比,其血浆中SOD活性、GSH含量均下降,差异有显著性(P <0 . 0 5 )。而MDA含量增高(P <0 . 0 5 )。0℃组与-2 0℃组相比,各指标差异均无显著性。结论　在冷作业工人中存在着血浆中HSP70抗体水平的升高及脂质过氧化程度加重。     

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.     

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.     

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.     

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.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.