不同价态锰对神经母细胞瘤细胞的氧化损伤作用

目的　探讨不同价态、不同浓度锰引起神经细胞的脂质过氧化对细胞的损伤作用。方法　分别用 0 ,0 2 5 ,0 5 0 ,0 75mmol/L二价锰、三价锰对神经母细胞瘤细胞 (SH SY5Y)染毒 2 4h ,观察测定细胞超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH Px)、丙二醛 (MDA)、GSH Px/MDA及细胞膜脂荧光各向异性的变化。结果　二价锰、三价锰染毒各低、中、高剂量组细胞SOD活力 [(5 2 2 1 2± 5 7 74 ) ,(4 98 38± 37 2 9) ,(4 6 4 86± 2 4 0 9)和 (4 99 79± 30 86 ) ,(4 77 2 3± 6 1 6 6 ) ,(4 35 95± 74 0 4 )NU/mg蛋白 ]与对照组[(86 1 2 4± 35 74 )NU/mg蛋白 ]比较明显降低 ,差异有显著性 (P <0 0 5 ) ;GSH Px活力 [(1 9 0 4± 5 1 6 ) ,(1 7 74± 5 91 ) ,(1 5 99± 5 6 2 )和 (1 6 5 8± 6 1 9) ,(1 5 79± 7 2 9) ,(1 4 2 3± 5 2 0 )活力单位 ]均较对照组[(2 9 2 3± 7 83)活力单位 ]降低 ,差异有非常显著性 (P <0 0 1 ) ;GSH Px/MDA较对照组降低 ,差异有显著性 (P <0 0 5 ) ,而MDA和细胞膜脂荧光各向异性有所升高 (P <0 0 5 ) ;相同染毒剂量情况下 ,三价锰组上述指标的变化比二价锰组明显。结论　锰通过抑制SOD、GSH Px活力 ,降低细胞抗氧化能力 ,造成细胞膜功能的损伤。三     

牛黄及胆红素对三氯乙烯染毒小鼠脂质过氧化的拮抗作用

目的研究牛黄、胆红素对三氯乙烯(TCE)染毒ICR小鼠所致的脂质过氧化的拮抗作用。方法用TCE灌胃染毒ICR小鼠制造脂质过氧化模型,然后分别以牛黄、胆红素灌胃,测定ICR小鼠肝、肾组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH Px)、过氧化氢酶(CAT)。结果与阴性对照组比,TCE处理组肝、肾组织GSH Px、SOD、CAT活力降低,MDA含量增加,差异均有显著性(P<0.05);牛黄、胆红素染毒与TCE处理组比较,肝、肾组织GSH Px、SOD、CAT活力显著增强(P<0.05),脂质过氧化产物MDA含量减少。结论牛黄和胆红素均能较好地拮抗TCE所引起的ICR小鼠脂质过氧化。     

丙溴磷对家兔SOD、CAT、GSH-Px影响的实验研究

为探讨丙溴磷对SOD、CAT、GSH Px的影响及其意义 ,将家兔随机分为A组 (高剂量组 )、B组 (低剂量组 )、C组 (对照组 ) ,分别于染毒不同时间测定血浆超氧化物歧化酶 (SOD)、过氧化物酶 (CAT)、谷胱甘肽过氧化物酶 (GSH Px)等指标 ,同时测定全血胆碱酯酶 (ChE)活力。结果显示 ,A组、B组SOD、CAT、GSH Px与同组染毒前及对照组相比显著升高 (P <0 0 5和P <0 0 1) ,ChE与同组染毒前及对照组相比降低或显著降低(P <0 0 1) ,且ChE的显著降低发生于抗氧化酶指标显著升高之后。结果提示 ,丙溴磷可致SOD、CAT、GSH Px等抗氧化酶活性增高 ,可能造成脂质过氧化的增强 ,并可能是丙溴磷早期中毒的表现之一。     

锰的神经毒性机制探讨

目的通过染毒人神经母细胞瘤细胞(SH—SY5Y)探讨锰致细胞的氧化损伤，为进一步研究锰的神经毒性机制提供科学依据。方法分别用0．00，0．25，0．50，0．75mmol／L的锰化合物染毒细胞24h，检测锰染毒的细胞中的抗氧化酶活力，包括超氧化物岐化酶(SOD)、谷胱苷肽过氧化物酶(GSH—Px)、过氧化氢酶(CAT)活力和抗氧化剂谷胱苷肽(GSH)；用荧光分光光度计检测染锰细胞膜微粘度；用单细胞电泳检测细胞DNA链断裂情况；用0．50mmol／L锰染毒细胞24，48h，采用流式细胞仪检测细胞凋亡和细胞周期。结果锰染毒各组细胞抗氧化酶活力和抗氧化剂含量均有不同程度的降低，脂质过氧化产物丙二醛(MDA)有所升高；染锰细胞膜微粘度升高；锰染毒细胞各级彗星细胞数不同损伤程度增多，并与染锰浓度呈正相关；锰染毒24，48h的细胞，均出现明显的凋亡峰，细胞周期的分布也发生改变，S期细胞增多。结论锰可导致细胞处于氧化应激态和细胞损伤，这可能是锰的神经毒作用机制之一。     

丙溴磷对家兔大脑脂质过氧化和一氧化氮浓度的影响

为探讨丙溴磷对家兔脑组织脂质过氧化和一氧化氮浓度的影响 ,将家兔分为 2个剂量组经皮肤染毒丙溴磷 ,于染毒前和染毒后 5d、 10d ,分别测定各组大脑组织中谷胱甘肽过氧化物酶 (GSH Px)、超氧化物歧化酶 (SOD)活性和维生素E (VitE)、一氧化氮 (NO)浓度。结果染毒后家兔脑组织GSH Px、SOD活性明显增高 (P <0 0 5 ,P <0 0 1) ,VitE、NO浓度显著降低 (P <0 0 5 ,P <0 0 1) ,并呈一定的剂量 效应关系。提示丙溴磷所致的家兔脑组织脂质过氧化增强与NO浓度降低相互促进 ,并可能是脑功能受损的原因之一。     

装潢用聚氨酯漆挥发物对小鼠脂质过氧化反应的影响

目的 探讨装潢聚氨酯漆挥发物对小鼠脂质过氧化反应的影响。方法 将某聚氨酯漆分别以96cm^2（低剂量组）和160cm^2（高剂量组）均匀涂抹于普通木板供染毒用,静式吸入染毒,每日涂1次,每日吸入染毒2h,连续4周后,测定雌性昆明小鼠外周血中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH－Px）活性及谷胱甘肽（GSH）和丙二醛（MDA）含量。结果 低剂量组GSH－Px活性、高剂量组GSH含量和GSH－Px活性均显著高于对照组,SOD活性MDA含量无显著变化。结论 聚氨酯漆挥发物能使小鼠抗氧化反应增强。     

职业性锰暴露对电焊工脂质过氧化的影响研究

[目的]探讨锰暴露对机体脂质过氧化的影响。[方法]2004年,在淮安市选择84名锰焊作业人员,测定作业场所空气锰浓度,检测血清丙二醛(MDA)含量及超氧化物岐化酶(SOD)、谷胱甘肽过氧化物酶(GSHPx)活性,并以84名服务行业人员为对照。[结果]锰暴露组MDA含量高于对照组,血清SOD、GSHPx活性低于对照组(P<0.01);MDA、SOD与作业场所空气锰浓度呈现一定的剂量反应关系。[结论]锰能使机体脂质过氧化增加,抗氧化氧能力下降,MDA、SOD可以作为锰中毒的早期敏感指标。     

电刺激对大鼠大脑、肝等组织脂质过氧化水平的影响

[目的 ]探讨电刺激应激对实验动物体内脂质过氧化水平以及抗氧化能力的影响。 [方法 ]采用 5 0Hz的强脉冲、电压为 10 0V交流电对实验大鼠连续 10d进行电刺激 ,观察受刺激后大鼠肝、大脑组织中抗氧化酶GSH Px、GST和抗氧化物质GSH以及反映脂质过氧化水平的脂质过氧化代谢产物MDA的含量。 [结果 ]受试大鼠肝和大脑组织中抗氧化物质GSH含量明显下降和MDA含量明显升高 ,抗氧化酶GSH Px、GST的活性明显下降 ,与对照组相比P <0 0 5和P <0 0 1。 [结论 ]电刺激应激能增强大鼠脑和肝组织脂质过氧化水平     

混配农药对家兔组织脂质过氧化的影响

[目的 ]探讨混配农药染毒对家兔大脑、肝及肾组织脂质过氧化的影响及意义。 [方法 ]将家兔随机分为不同剂量的 6个混配农药染毒组 ,1个单剂农药 (丙溴磷 )染毒组和 1个对照组。混配农药组均经皮肤给予不同剂量和种类混配农药染毒 ,于染毒 15d后测定各组大脑、肝及肾组织中谷胱甘肽过氧化物酶 (GSH Px)活力与丙二醛 (MDA)的浓度 ,以及染毒前后血清胆碱脂酶 (ChE)活力。 [结果 ]除高剂量混配农药染毒组外 ,其余各组染毒后ChE活性均在正常范围内 ,但各混配农药染毒组家兔GSH Px活力和MDA浓度大脑分别为 (6 48～ 8 0 1)U/ml、(2 88～ 4 5 2 )nmol/L ,肝分别为(5 46～ 6 91)U/ml、(3 42～ 5 3 7)nmol/L ,肾分别为 (4 2 7～ 5 71)U/ml、(2 2 7～ 4 71)nmol/L ,均较对照组和丙溴磷组增高或显著增高 (P <0 0 5 ,P <0 0 1)。 [结论 ]混配农药可导致家兔大脑、肝及肾组织脂质过氧化增强 ,这对混配农药中毒所致组织功能受损的早期评价和防治可能有一定意义     

番茄红素对铅染毒小鼠脂质过氧化的保护作用

目的:观察染铅小鼠抗氧化系统的改变及番茄红素对抗氧化酶系统的影响。方法:小鼠经饮水铅染毒(醋酸铅)造成铅中毒模型后给予番茄红素,4周后处死,测定血清和肝匀浆的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH—Px)活力、丙二醛(MDA)含量。结果:给予番茄红素的小鼠血清和肝组织的SOD活性、GSH—Px活力上升,MDA含量降低,与中毒模型组相比,差异显著(P<0.05)。结论:铅中毒可引起小鼠过氧化损伤,番茄红素可以提高小鼠机体的抗氧化能力,减轻铅中毒引起的脂质过氧化。     

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.     

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.