硒对体外心肌细胞过氧化损伤保护和骨架蛋白actin表达的影响

目的探讨硒对H2O2损伤心肌细胞的保护作用以及α-actin和β-actin表达的影响。方法培养乳鼠心肌细胞随机分为对照组,H2O2组,Se 0.05、0.5、1.0和5.0μmol/L组,采用透射电镜观察实验心肌细胞的超微结构,比色法检测心肌细胞培养介质中LDH和MDA含量,Western Blot检测α-actin和β-actin蛋白的表达。结果 Se 0.5μmol/L可减轻心肌细胞超微结构损伤;各加硒组LDH和MDA水平较H2O2组显著降低(P<0.05),较对照组显著升高(P<0.05),其中Se 0.5μmol/L组LDH和MDA含量在各加硒组中最低;Se 0.5μmol/L组α-actin表达水平较H2O2组升高并高于正常对照组;Se 0.5μmol/L组β-actin表达水平较损伤组升高,低于正常对照组。结论 0.5μmol/L硒对H2O2损伤心肌细胞具有较好的保护作用,可维持和保护α-actin和β-actin的表达,参与细胞骨架蛋白重构。     

原花青素对过氧化氢损伤血管内皮细胞的保护作用

目的：探讨原花青素对氧化损伤的人脐静脉内皮细胞（HUVEC）的保护作用。方法：体外培养内皮细胞,将细胞分为6组,即空白对照组（Control组）、氧化损伤组（H2O2组）、氧化损伤加入VitC对照组（VC＋H2O2组）、氧化损伤加入原花青素5μmol/L、25μmol/L、50μmol/L浓度组（procyanidin-L＋H2O2组、procyanidin-M＋H2O2组、procyanidin-H＋H2O2组）。将750μmol/LH2O2作用于加入VitC及不同浓度原花青素预培养24h的内皮细胞,继续培养18h,以细胞毒四唑盐（MTT）比色试验、乳酸脱氢酶（LDH）、一氧化氮（NO）、丙二醛（MDA）作为检测指标。结果：原花青素呈剂量依赖性降低H2O2对内皮细胞的生长抑制率,降低MDA、LDH量,增加培养液中NO2-/NO3-含量,各指标比较差异有统计学意义（P〈0.01）。结论：原花青素可保护和修复过氧化氢诱导的血管内皮细胞的损伤,其作用可能与抗氧化、促进NO释放有关。     

硫辛酸对大鼠脑氧化损伤保护作用

目的 探讨硫辛酸(LA)在体外对过氧化氢(H2O2)引起大鼠脑氧化损伤的保护作用.方法 新鲜的大鼠脑匀浆分为LA组和LA+H2O2组;LA组在脑匀浆中分别给予不同浓度的LA;LA+H2O2组在脑匀浆中给予上述各浓度的LA同时加人终浓度100 μmol/H2O2,上述反应作用1 h后测定大鼠脑匀浆中脂质过氧化产物丙二醛(MDA)和谷胱甘肽(GSH)的含量.结果 与对照组(LA和H2O2浓度均为0)比较,100 μmoVL H2O2能使脑匀浆MDA含量增加到(11.85±0.83)μmol/(g·pro),GSH含量下降到(21.21±4.91)μmol/(g·pro),差异均有统计学意义(P<0.05);与模型组(单独给予100 μmoVLH2O2)比较,同时加入100～300 μmol/L LA可使MDA含量平均下降20.2%～28.1%,GSH含量平均升高50.1%～63.3%,差异均有统计学意义(P<0.05).结论 一定浓度LA对H2O2引起的大鼠脑组织氧化损伤有明显的保护作用,可能与提高其GSH含量,降低MDA含量有关.     

氯化汞致大鼠肾损伤及原花青素的保护作用

[目的]观察氯化汞对大鼠肾脏的损伤作用及原花青素的保护作用。[方法]30只Wistar大鼠按体重随机分成5组,第1～4组以大豆油灌胃,第5组以原花青素450mg／kg灌胃;2h后,第1组皮下注射生理盐水,第2～5组分别皮下注射2．2、4．4、8．8、8．8μmol／kg氯化汞。第2天重复上述步骤后,收集24h尿液测定尿汞（Hg）和蛋白含量,以及碱性磷酸酶（ALP）、β-N-乙酰氨基葡萄糖苷酶（NAG）和乳酸脱氢酶（LDH）活力;腹主动脉采血测定血清尿素氮（BUN）;切取肾皮质测定Hg含量和还原型谷胱甘肽（GSH）、丙二醛（MDA）水平及超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活力。[结果]与对照组比较,各染毒组的尿蛋白含量、尿LDH活力、肾皮质Hg含量、GSH、MDA含量及S01）、GSH—PX活力差异均具有统计学意义（P〈0．05或P〈0．01）;4．4、8．8μmol／kg染毒组的尿汞含量、ALP、NAG活力、血清BUN含量的差异均具有统计学意义（P〈0．01）。原花青素干预组与8．8μmol／kg染毒组比较,尿LDH、AIP、NAG活力降低,尿蛋白含量下降,肾皮质GSH、MDA含量下降,SOD、GSH—Px活力升高,血清BUN含量下降,差异均具有统计学意义（P〈0．05或P〈0．01）。[结论]氯化汞可蓄积于大鼠肾脏并产生损伤,原花青素对大鼠氯化汞所致肾损伤具有一定程度的保护作用。     

锌硒锰镁联合拮抗二氧化硅致肺泡巨噬细胞毒性的作用

[目的]观察葡萄糖酸锌（ZnG）、亚硒酸钠（Na2SeO3）、氯化锰（MnCl2）和硫酸镁（MgSO4）联合作用对二氧化硅（SiO2）致肺泡巨噬细胞（AM）中过氧化氢（H2O2）、丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH—Px）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）水平变化的影响，寻找4者的最佳剂量组合。[方法]采用大鼠肺灌洗法纯化获得AM（1×10^9个／mL），同时加入SiO2及不同浓度的ZnG＋Na2SeO3＋MnCl2＋MgSO4溶液组合，另设不加组合溶液的SiO2对照组和阴性对照组。37℃，5％CO2培养箱培养18h后，检测上述5种指标。[结果]与SiO2对照组比较，ZnG、Na2SeP3、MnCl2与MgSO4联合使用均可明显降低AM中H2O2、MDA含量，升高GSH—Px、SOD和CAT的活性（P〈0．01），且以1．5mg／L的ZnG、1．0μmol／L的Na2SeO3、1．0mg／L的MnCl2、和0．5μmol／L的MgSO4联合作用效果最好。极差分析结果表明，对GSH—Px、SOD的影响，Na2SeO3的作用强于ZnG、MnCl2和MgSO4；对H2O2、MDA的影响，ZnG的作用强干Na2SeO3、MnCl2与MgSO4；对CAT的影响，MnCl2、ZnG的作用则要强于Na2SeO3与MgSO4。[结论]ZnG、Na2SeO3、MnCl2与MgSO4联合应用可明显拮抗SiO2粉尘所致AM的氧化损伤。     

番茄红素对人胚肺二倍体细胞抗氧化酶的影响

目的 观察不同浓度的番茄红素独用和与维生素E联用时对人胚肺二倍体细胞中抗氧化酶的影响.方法 处于对数生长期的人胚肺二倍体细胞(SL-7细胞),加入不同浓度的番茄红素和维生素E,作用24 h后再加入H2O2作用1 h,测定细胞内超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性.结果 0.5、1、5 μmol/L番茄红素与H2O2组比较,SOD、GSH-Px的活力增强(P＜0.05),10 μmol/L番茄红素组作用不明显;维生素E可使番茄红素的作用加强.结论 0.5、1、5 μmol/L番茄红素提高抗氧化酶的活性;10 μmol/L番茄红素作用丧失;番茄红素和维生素E联用后可增加抗氧化酶的活性.     

介孔纳米SiO2致小鼠巨噬细胞株RAW264.7细胞毒性与氧化损伤

[目的]探讨介孔纳米SiO2对小鼠巨噬细胞株RAW264.7细胞的毒性和氧化损伤作用。[方法]设4个浓度组（2.5、10、50、100I.tg／mL）和生理盐水对照组,染毒24h后,用四甲基偶氮唑盐（MTT）方法观察细胞毒性,并根据染毒后细胞的总蛋白（TP）、乳酸脱氢酶（LDH）、一氧化氮（NO）、谷胱甘肽（GSH）、超氧化物歧化酶（SOD）和丙二醛（MDA）的变化情况分析介孔纳米SiO2的细胞毒性和氧化损伤作用。[结果]10、50和100μg／mL浓度组细胞存活率随着染毒浓度的升高而降低,差异有统计学意义;50、100μg／mL浓度组细胞及其上清液中TP、LDH、NO和MDA含量随染毒浓度增加而升高,而GSH和SOD含量降低;而且与细胞发生融解破碎、间隙加大等形态学改变情况相符。[结论]介孔纳米SiO2对体外培养巨噬细胞株RAW264.7具有细胞毒性和氧化损伤作用,且随剂量的加大而增强。     

饮水消毒副产物DCN对HepG2细胞的脂质过氧化作用

目的研究饮水含氮消毒副产物二氯乙腈对体外培养的人肝肿瘤Hep G2细胞的脂质过氧化作用。方法二甲基亚砜(DMSO)溶解DCN,以DMSO处理组为溶剂对照组,设0.8、4、20、100μmol/L 4个暴露浓度,将Hep G2细胞分别染毒4和24 h后,检测Hep G2细胞内还原型谷胱甘肽(GSH)、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量。结果在细胞染毒4 h的条件下,与溶剂对照组相比,DCN浓度达到100μmol/L时,Hep G2细胞内SOD含量明显下降(P0.01),但GSH和MDA含量没有明显的变化;在染毒24 h条件下,与溶剂对照组相比,各染毒组的DCN使Hep G2细胞内GSH含量明显下降(P0.05),100μmol/L的DCN可引起Hep G2细胞内MDA含量上升(P0.05)和SOD含量下降(P0.01)。相关分析表明,当染毒时间延长至24 h,MDA含量的变化与SOD含量的变化呈负相关(r=-0.64,P0.05)。结论 DCN可导致Hep G2细胞氧化损伤,使其脂质过氧化反应增强、抗氧化作用降低。     

牛黄抗间二硝基苯所致氧化作用的研究

[目的]研究牛黄的抗氧化作用。[方法]分离培养原代大鼠肝细胞,采用正交试验设计,在0、0.1和0.5mmol/L间二硝基苯(m-DNB)诱导大鼠肝细胞氧化损伤的基础上,观察不同时间(0.5、2和5h)、不同剂量(0、5和10μmol/L)牛黄的抗氧化作用,测定大鼠肝细胞孵育系统丙二醛(MDA)、还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)含量和谷胱甘肽过氧化物酶(GSH-Px)活力。同时,观察10μmol/L牛黄预处理对m-DNB0、0.01、0.10、0.25、0.50、1.00和2.00mmol/L不同剂量组肝细胞悬液水平和m-DNB0、0.01、0.05、1.00mmol/L组肝细胞悬液OH·水平的影响。[结果]经牛黄处理后,大鼠肝细胞孵育系统MDA含量明显下降,GSH含量下降,GSH-Px活力升高。10μmol/L牛黄预处理可以显著降低含m-DNB的肝细胞孵育系统中和OH·水平,水平分别由2.38、3.49、5.08、6.35、9.20、10.95μmol/L降为1.74、2.38、3.17、3.65、5.08和6.19μmol/L(P<0.05),而OH·水平由31.27、45.50和52.87mm降为20.60、26.30和30.6mm峰高(P<0.05)。[结论]牛黄可能通过抑制脂质过氧化,清除自由基和GSH发生联合抗氧化作用。     

茶多酚对甲醛染毒大鼠肺损伤的保护作用

[目的]探讨茶多酚对甲醛染毒大鼠肺损伤的保护作用。[方法]30只3月龄,体重(200±20)g的SPF级SD大鼠,随机分为空白对照组、模型组、茶多酚组。将除正常对照组外的其余两组动物暴露于气态甲醛(10mg/m3)中3个月,每天4h,茶多酚组给予茶多酚水溶液200mg/kg.d-1灌胃。检测肺组织超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽(GSH)及肺组织形态学变化。[结果]模型组大鼠肺组织SOD活性及GSH含量明显低于正常对照组(P﹤0.01),MDA含量明显高于正常对照组(P﹤0.01);茶多酚组大鼠肺组织SOD活性及GSH含量高于模型组(P﹤0.05),MDA含量低于模型组(P﹤0.05)。肺组织形态学改变:模型组大鼠肺组织呈现间质性肺炎和肺泡性肺炎的病理学特点,茶多酚组肺炎状况明显改善。[结论]茶多酚水溶液能提高甲醛染毒大鼠肺组织SOD活性及GSH含量,降低MDA含量,使受损肺组织形态部分改善,表明茶多酚水溶液对甲醛染毒大鼠肺损伤具有一定的保护作用。     

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.     

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.     

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.     

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.     

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.     

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.