过氧化苯甲酰对小鼠肝脏组织损伤作用

目的 探讨面粉增白剂过氧化苯甲酰(benzoyl peroxide,BPO)对小鼠肝脏组织的损伤作用.方法 64只昆明种小鼠随机分为对照组和低、中、高剂量BPO组,分别灌胃给予BPO50,100和200 mg/kg,每组16只,雌雄各半;灌胃6周后,测定各组肝脏组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量及三磷酸腺苷(ATP)酶活力.结果 高、中剂量BPO组SOD活力分别为(40.15±7.13),(46.01±6.69)U/(mg·prot),与对照组(53.15±6.55)U/(mg·prot)比较,差异有统计学意义(P<0.05);高剂量BPO组与对照组MDA含量分别为(1.93±0.37)和(1.57±0.33)nmol/(mg·prot),差异有统计学意义(P<0.05);高剂量BPO组Mg2+-ATP、Ca2+-ATP酶活力分别为(1.58±0.11)和(1.48±0.09)μmol Pi/(mg·prot),与对照组比较明显降低,差异有统计学意义(P<0.05);各剂量BPO组GSH-Px活力与对照组比较差异无统计学意义(P>0.05).结论 BPO在一定程度上可降低小鼠肝脏抗氧化及Ca2+、Mg2+-ATP酶活力.     

山茱萸多糖对高温暴露大鼠睾丸组织损伤影响

目的 观察山茱萸多糖(FCP)对高温暴露大鼠睾丸组织损伤的影响.方法 用FCP(0,10,50,100,150mg/kg)灌胃雄性SD大鼠14 d后温水浴造模,观察睾丸组织形态改变,测定睾丸及附睾系数、精子计数与活力、超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量及生殖细胞凋亡情况.结果 FCP可改善损伤睾丸组织形态,随浓度增加作用越明显;与损伤组SOD活力(195.05±25.62)NU/mg prot及MDA含量(3.02±1.18)nmol/mg prot比较,FCP150 mg组SOD活力(285.34±24.37)NU/mg prot明显升高,MDA含量(1.48±0.63)nmol/mg prot明显降低;与损伤组(64.05±1.35)%比较,FCP150mg组生殖细胞凋亡率(15.50±1.06)%明显下降,差异有统计学意义(P<0.01).结论 FCP对高温暴露大鼠睾丸组织的损伤具有保护作用.     

维生素C对甲醛胚胎发育毒性抑制作用

目的 探讨维生素C(VC)对甲醛诱导胎鼠发育毒性的影响.方法 应用体外全胚胎培养模型,观察100μg/mL VC对终浓度为9,27,81 μmol/L甲醛诱导昆明种小鼠胚胎发育毒性的影响.结果 与对照组比较,9μmol/L甲醛可使胚胎头长、颅臀长、谷胱甘肽(GSH)、丙二醛(MDA)含量分别升高到(1.66±0.21),(3.48±0.40)mm,(47.70±2.12)me,/(g·prot),(4.27±0.62)nmol/(mg·prot),差异有统计学意义(P<0.05);27 μmol/L甲醛使胚胎脏层卵黄囊(VYS)直径、头长、颅臀长、体节数、GSH含量分别下降到(4.35±0.65),(1.48±0.30),(3.19±0.43)mm,(25.2±1.2)对,(40.25±4.38)mg/(g·prot),MDA含量升高到(6.29±0.47)nmol/(mg·prot),与对照组比较,差异有统计学意义(P<0.05);VC能明显改善上述指标,但与对照组比较差异无统计学意义(P<0.01);VC不能明显改善81 μmol/L甲醛诱导的毒性损伤.结论 VC对一定剂量范围内的甲醛胚胎毒性具有明显抑制作用.     

枳实对糖尿病小鼠肾脏抗氧化能力及胰岛影响

目的 研究枳实提取物对实验性糖尿病小鼠肾脏抗氧化能力及胰岛形态的影响.方法 将枳实提取物分成高、中、低剂量[5.1,3.4,1.7 g/(kg·bw)]治疗糖尿病小鼠4周后,观察其一般状况、肾脏的抗氧化能力及胰岛形态变化.结果 枳实高剂量组小鼠末期血糖为(20.37±5.25)mmol/L,明显低于糖尿病组的(25.74±2.99)mmol/L(P<0.05);枳实高剂量组谷胱甘肽(GSH)含量为[(34.40±8.54)mg/(g·prot)],明显高于糖尿病组的[(21.38±3.91)mg/(g·prot)](P<0.01);枳实高剂量组丙二醛(MDA)和NO含量分别为[(0.89±0.37)nmol/(mg·prot)],[(1.27±0.56)μmol/(g·prot)],明显低于糖尿病组的[(1.46±0.39)nmol/(mg·prot)],[(2.15±0.85)μmol/(g·prot)](P<0.01或P<0.05),光镜下枳实提取物治疗组胰岛细胞损伤程度较糖尿病组轻.结论 枳实提取物能增强肾脏的抗氧化能力;保护胰岛组织细胞并降低胰岛细胞损伤.     

不同剂量葡萄籽原花青素对砷致雄性小鼠肝脏毒性拮抗作用研究

目的观察不同剂量葡萄籽提取物原花青素对三氧化二砷(As2O3)所致雄性小鼠肝脏毒性干预效果,研究其抗氧化损伤作用机制及其干预效果的差异。方法按体重分层将50只雄性昆明种小鼠随机分为5组:对照组(生理盐水0.9%)、As2O3组(4 mg/kg·bw)、和As2O3(4 mg/kg·bw)+GSPE低(100 mg/kg·bw)、中(200 mg/kg·bw)、高(400 mg/kg·bw)剂量组,每组10只,连续灌胃5周;称量小鼠体重、肝重,并计算其肝脏系数;测定肝脏组织的天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、T-AOC等指标,采用单因素方差分析对比组间差异。结果 As2O3组体重、GSH含量、T-AOC水平均低于对照组,肝重、肝脏系数、ALT、AST活力、MDA含量均高于对照组(P均<0.05);As2O3+GSPE(200、400)mg/(kg·bw)剂量组体重均高于As2O3组(P均<0.05);As2O3+GSPE(100、200、400)mg/(kg·bw)剂量组肝重、肝脏系数、ALT、AST活力、MDA含量均低于As2O3组(P均<0.05);GSH含量、T-AOC水平均高于As2O3组(P均<0.05)。As2O3+GSPE低剂量组小鼠体重比As2O3+GSPE中剂量组低(P<0.05);As2O3+GSPE低、中、高剂量组GSH含量(137.17±34.70)μmol/g prot、(198.02±41.28)μmol/g prot、(272.06±35.85)μmol/g prot、T-AOC水平(5.33±0.76)U/mL、(7.07±0.83)U/mL、(11.54±1.86)U/mL依次增高(P<0.05)。结论 GSPE可能通过抗氧化损伤作用拮抗As2O3致雄性小鼠的肝脏毒性,高剂量GSPE干预效果较好。     

硫酸镁对小鼠肾缺血再灌注损伤保护作用

目的 观察硫酸镁对小鼠肾缺血再灌注损伤的抗氧化保护作用.方法 雄性小鼠随机分为假手术组、模型组和硫酸镁高、低剂量(120、60 mg/kg)组,无创动脉夹夹闭左肾蒂45 min和再灌注3h制备急性肾缺血再灌注损伤模型,检测肾脏指数、血清尿素氮(BUN)和肌酐含量、肾组织丙二醛(MDA)含量以及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力,HE染色观察肾组织学变化.结果 硫酸镁高、低剂量组小鼠肾指数分别为(0.72±0.05)和(0.74±0.07)、血清BUN含量为(12.36±2.24)和(15.58±1.92) mmol/L、血清肌酐水平为(98.23±4.37)和(114.63±6.24) μmol/L、肾组织MDA含量为(2.11±0.24)和(2.27±0.21) nmol/(mg·prot),肾组织SOD活力为(4.03±0.68)和(3.51±0.58) U/(mg·prot),硫酸镁高剂量组肾组织GSH-Px活力为(323.90±23.50)U/( mg· prot),与模型组比较,差异均有统计学意义(P＜0.05),且肾组织病理变化较轻.结论 硫酸镁对小鼠急性肾缺血再灌注损伤具有保护作用,其机制可能与抑制脂质过氧化反应有关.     

三氧化二砷染毒小鼠肝脏中砷甲基化水平与肝脏氧化应激的关系

目的探讨三氧化二砷(As2O3)染毒小鼠肝脏组织中砷甲基化水平的变化及其与肝脏氧化应激关系,为揭示砷甲基化水平在砷毒性机制中的作用提供依据。方法将40只昆明种小鼠随机分为对照组(0.9%生理盐水)、As2O3低中高剂量组(1.0、2.0和4.0 mg/kg)组,连续灌胃5周;采用高效液相色谱与原子荧光联用技术(HPLC-HGAFS)测定肝脏组织中三价无机砷(As3+)、五价无机砷(As5+)、一甲基胂(MMA)、二甲基胂(DMA)含量及构成比(%),计算砷一甲基化指数(PMI)、二甲基化指数(SMI);利用试剂盒测定丙二醛(MDA)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)。结果随着As2O3剂量增加,小鼠肝脏组织中各形态砷代谢产物含量增加(P0.001),砷甲基化水平(i As%、MMA%、DMA%、PMI、SMI)提高(P0.001);小鼠肝脏MDA显著高于对照组(P0.001),GSH、SOD、T-AOC显著低于对照组(P0.001);1 mg/kg染毒剂量时,PMI与T-AOC呈负相关(P0.05),SMI与GSH、SOD呈负相关(P0.05);在2 mg/kg染毒剂量时,PMI、SMI与MDA呈正相关(P0.05)而与GSH、SOD呈负相关(P0.05);在4 mg/kg染毒剂量时,PMI与MDA呈正相关(P0.05),PMI、SMI与GSH、SOD呈负相关(P0.05)。结论随着砷染毒剂量的增加,小鼠肝脏组织中各种形态砷含量增多,砷甲基化水平提高,进而导致小鼠肝脏氧化损伤严重。     

叶黄素对砷致小鼠肝脏毒性的预防保护作用

目的观察提前给予小鼠叶黄素干预对砷肝脏毒性的预防效果。方法将84只SPF级昆明种小鼠,雌雄各半,随机分为35 d空白组、70 d空白组、35 d单纯叶黄素组、70 d单纯叶黄素组、砷染毒组、35 d叶黄素拮抗组和70 d叶黄素预防组,按叶黄素40 mg/kg,As2O35 mg/kg剂量灌胃给药。测定血清中谷氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)活性,肝脏匀浆丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、还原型谷胱甘肽(GSH)含量、总抗氧化能力(T-AOC)及一氧化氮(NO)含量,采用单因素方差分析对比组间差异。结果砷染毒组AST和ALT活性、MDA含量显著高于70 d空白组,SOD活性、GSH及NO含量、T-AOC水平显著低于70 d空白组(P<0.05);70 d叶黄素预防组AST及ALT活性、MDA含量低于35 d叶黄素拮抗组(P<0.05),SOD活性、NO及GSH含量、T-AOC水平均高于35 d叶黄素拮抗组(P<0.05)。结论提前给予叶黄素干预可以提高小鼠肝脏组织抗氧化损伤能力,从而拮抗砷的肝脏毒性作用。     

海藻萜类化合物联合VE对酒精性肝损伤大鼠影响

目的 研究凹顶藻萜类化合物(Laurencia extract,LET)与维生素E(VE)合用对乙醇诱导肝损伤大鼠的影响及其作用机制.方法 70只雄性Wistar大鼠随机分为7组.除空白组每天给予蒸馏水灌胃外,其余各组均每天乙醇12 mL/(kg·bw)灌胃,各干预组分别给予不同剂量LET加VE、VE、甘利欣灌胃,6周后测定血清肝功、血脂及肝匀浆中抗氧化指标.结果 不同剂量LET合用干预组血清肝功、血脂水平与乙醇模型组比较,差异有统计学意义(P<0.05);LET中、高剂量合用干预组谷胱甘肽过氧化物酶(GSH-Px)活力分别为(59.523±11.015),(59.541±13.724)U/(mg·prot);丙二醛含量(MDA)分别为(5.018±1.239),(4.799±1.628)nmol/(mg·prot);高剂量合用干预组超氧化物歧化酶活力(SOD)为(147.690±9.989)U/(mg·prot),与乙醇模型组GSH-Px(45.624±10.589)U/(mg·prot)、MDA含量(10.593±1.716)nmol/(mg·prot)、SOD活力(100.153±13.632)12/(mg·prot)比较,差异有统计学意义(P<0.05).结论 LET与VE合用能调整酒精性肝损伤大鼠体内脂质代谢,改善肝功能,减少脂质过氧化产物,对酒精造成的机体损伤表现出相应的保护效应.     

姜黄素干预对无机砷暴露小鼠急性肝脏损伤的拮抗作用

目的观察姜黄素干预对无机砷暴露所致急性肝脏损伤的拮抗作用。方法实验小鼠自由饮用不同浓度(10 mg/L、50 mg/L和100 mg/L)亚砷酸钠(NaAsO2)6周,再分别给予姜黄素灌胃干预(200 mg/kg和600 mg/kg,每周2次),分别测定小鼠血清ALT和AST活力,全血和肝脏GSH含量以及肝脏MDA含量。结果与单纯染毒组小鼠相比,姜黄素干预组血清ALT和AST活力显著下降,全血和肝脏GSH含量显著升高,且肝脏MDA含量显著降低,差异具有统计学意义(P<0.01)。结论姜黄素干预对无机砷暴露小鼠的急性肝脏毒性和氧化损伤具有一定的拮抗作用。 更多还原     

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.     

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.     

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.     

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.