桦木酸对酒精性肝损伤小鼠线粒体凋亡通路的影响

目的研究桦木酸(betulinic acid,BA)对酒精性肝损伤小鼠线粒体信号通路的影响。方法 56只健康雄性小鼠随机分为8组,即正常对照组(NC),酒精模型组(MC),BA低、中、高剂量组(L-BA,M-BA, H-BA,按0.25、0.5、1 mg/kg bw给与),BA低、中、高剂量与酒精联合组(L-BAA, M-BAA, H-BAA)。NC、MC组灌胃1%的可溶性淀粉,其余各组灌胃混悬于可溶性淀粉中不同剂量的BA,1/d,连续14d后,除NC组,L-BA,M-BA,H-BA组灌胃生理盐水外,其余4组均按10 ml/kg灌胃50%酒精诱发酒精性肝损伤模型。检测血清细胞色素P450 2E1(CYP2E1)水平,采用Western blot检测肝脏线粒体信号通路中Bcl-2、Bax、Caspase-9和Caspase-3蛋白表达的变化。结果 BA预处理后,抑制由酒精引起的CYP2E1水平升高,显著降低酒精致肝损伤小鼠Bax/Bcl-2比值,明显减少Caspase-9和Caspase-3蛋白表达量,且呈量效关系。结论说明BA对酒精诱导肝损伤有预防性的保护作用,这种保护作用可能与调控线粒体凋亡通路有关。     

银杏黄酮对雄性小鼠酒精性氧化损伤的保护

目的　研究银杏黄酮对小鼠肝脏慢性酒精性氧化损伤的保护效应。方法　雄性小鼠给予银杏黄酮 96mg/ (kg·bw) ,再给予乙醇 3 2g/ (kg·bw) ,同时设正常对照组和酒精对照组〔乙醇 3 2 g/ (kg·bw)〕 ,连续灌胃 75d后测定血清谷丙转氨酶 (ALT)、谷草转氨酶 (AST)活性及血清与肝脏谷胱甘肽 (GSH)、谷胱甘肽过氧化物酶 (GSH -Px)、超氧化物岐化酶 (SOD)、过氧化氢酶 (CAT)的活性及丙二醛 (MDA)的含量。结果　小鼠摄入酒精 75d后 ,血清ALT、AST水平与正常对照组相比 ,有显著性差异 (P <0 0 1) ,肝脏及血清GSH -Px、SOD、CAT活性与GSH水平明显下降 ,MDA水平明显上升 (P <0 0 1) ;经银杏黄酮干预后 ,与酒精对照组相比 ,血清ALT、AST水平下降 ,肝脏与血清GSH-Px、SOD、CAT活性与GSH水平升高 ,MDA水平下降。结论　银杏黄酮对小鼠肝脏慢性酒精性氧化损伤具有一定的保护作用。     

紫苏提取物对化学性肝损伤保护作用的研究

目的研究紫苏提取物(Perilla frutescens extract,PE)对急性化学性肝损伤的保护作用。方法80只雄性KM小鼠(体重20±2g)随机分为8组:正常对照组(NC),模型对照组(MC),阳性药联苯双酯(DDB)组(200mg/kg),迷迭香酸(rosmarinic acid,RAD)低、高剂量预防组(11、44mg/kg),PE低、中、高剂量预防组(30、60、120mg/kg)。NC、MC组灌胃生理盐水,其它各组灌胃同等容量的相应药物,每天给药1次。实验20d后,用四氯化碳(CCl4 0.05ml/kg)和乙酰氨基酸(APAP 250mg/kg)腹腔注射分别制作急性化学性肝损伤模型。测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性、甘油三酯(TG)含量,肝组织匀浆超氧化物岐化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性、丙二醛(MDA)含量,并观察肝脏病理改变。结果PE(120mg/kg)能显著降低CCl4与APAP诱导的肝损伤小鼠血清ALT、AST活性、TG含量,升高肝脏SOD、GSH-Px活性,降低MDA含量能明显减轻肝组织损伤程度;PE对正常小鼠血清ALT、AST、TG无影响。结论PE对CCl4或APAP诱导的小鼠急性化学性肝脏氧化损伤具有显著保护作用。     

白桦脂醇对酒精性肝损伤的治疗作用

[目的]观察白桦脂醇对酒精性肝损伤的治疗作用。[方法]将大鼠随机分为6组,正常组、低剂量组、中剂量组、高剂量组、阳性对照组和模型组。采用白酒灌胃的方法建立大鼠酒精性肝病模型,给予白桦脂醇保护。检测血清中丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、碱性磷酸酶（ALP）。高密度脂蛋白（HDL）、低密度脂蛋白（LDL）以及肝匀浆中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—PX）、还原性谷胱甘肽酶（GSH）、谷胱甘肽-S-转移酶（GST）、丙二醛（MDA）水平,同时做肝脏的病理切片观察。[结果]酒精性肝损伤的大鼠血清ALT、AST、ALP活性和LDL含量明显升高。肝匀浆中SOD、GSH-PX、GST活力明显降低;MDA含量明显升高;GSH含量明显降低。白桦脂醇能明显降低模型组大鼠血清中ALT、AST、ALP活性（与模型组比较：P〈0．05）;可明显提高酒精性肝损伤大鼠肝组织中SOD、GSH-PX、GST活性（P〈0．01）和GSH含量（P〈0．05）;同时显著性降低肝组织中MDA含量（P〈0．05）。阳性对照组（益肝灵组）大鼠血清中ALT、AST、ALP活性明显降低和CHO含量明显降低（与模型组比较：P〈0．05）;可明显提高酒精性肝损伤大鼠肝组织中SOD、GSH—PX、GST活性（P〈0．01）和GSH含量（P〈0．05）;同时显著性降低肝组织中MDA含量（P〈0．05）。白桦脂醇还能明显改善由酒精引起的肝组织脂肪样变和坏死。[结论]白桦脂醇能抑制酒精诱导脂质过氧化反应对肝组织的损伤,对酒精性肝损伤有较好的治疗作用。     

银杏叶提取物预防大鼠酒精性肝损伤的机制研究

目的:观察银杏叶提取物(EGB)对大鼠酒精性肝损伤的预防作用,并研究其可能的分子机制。方法:无水乙醇灌胃13w,EGB采用预防性给药的方法,检测大鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性;肝组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和谷胱甘肽(GSH)、丙二醛(MDA)的含量;采用RT-PCR检测肝组织中血红素氧化酶-1(HO-1)mRNA表达水平。结果:与酒精组相比,EGB组ALT、AST活性均显著降低(P<0.05),MDA含量非常显著降低(P<0.01);SOD、GSH-Px活性和GSH含量较酒精组均显著升高(P<0.05);此外,EGB可以诱导HO-1mRNA高表达。结论:EGB通过减少酒精所致GSH的耗竭,增加抗氧化物质活性或含量,抑制脂质过氧化反应从而预防酒精性肝损伤,其机制可能与诱导HO-1表达有关。     

白桦脂醇对大鼠酒精性肝损伤保护作用

目的 观察白桦脂醇对大鼠酒精性肝损伤的抗氧化作用.方法 将大鼠随机分为6组,正常组、低剂量组、中剂量组、高剂组量、阳性对照组(益肝灵组)和模型组.采用白酒灌胃的方法建立大鼠酒精性肝病模式,给予白桦脂醇保护.测定肝匀浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、谷胱甘肽-S-转移酶(GST)活性和还原性谷胱甘肽(GSH)、丙二醛(MDA)含量,同时进行肝脏的病理切片观察.结果 高剂量白桦脂醇组中SOD、GSH-Px和GST活性和GSH含量明显升高,MDA含量明显降低,和模型组比较,差异均有统计学意义(P<0.01或P<0.05).阳性对照组可明显提高酒精性肝损伤大鼠肝组织中SOD、GSH-Px、GST活性和GSH含量,明显降低MDA含量,与模型组比较,差异均有统计学意义(P<0.01或P<0.05).高剂量白桦脂醇还能明显改善由酒精引起的肝组织脂肪样变和坏死.结论 白桦脂醇能抑制酒精诱导脂质过氧化反应对肝组织的损伤,对酒精性肝损伤有明显的保护作用.     

银杏黄酮对雌性小鼠酒精性氧化损伤的保护作用

目的:研究酒精对雌性小鼠肝脏的慢性氧化损伤及银杏黄酮的干预效果。方法:昆明种雌性小鼠每天给予96mg/kgbw的银杏黄酮后,再给予乙醇3.2g/kgbw,同时设正常对照组和酒精对照组(乙醇3.2g/kgbw),连续灌胃75d后测定血清谷丙转氨酶(GPT)、谷草转氨酶(GOT)活性及血清与肝脏谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物岐化酶(SOD)、过氧化氢酶(CAT)的活性及丙二醛(MDA)的含量。结果:小鼠摄入酒精75d后,所检测的各项指标与正常对照组相比,均有非常显著性(P<0.01)差异;经银杏黄酮干预后,与酒精对照组相比,血清ALT、AST水平显著下降,肝脏与血清GSH-Px、SOD、CAT活性与GSH水平明显提高,MDA水平明显下降。结论:银杏黄酮对雌性小鼠肝脏慢性酒精性氧化损伤具有一定的保护作用。     

果蔬发酵液对小鼠酒精性肝损伤的保护作用及氧化应激机制

目的研究果蔬发酵液(vegetables and fruits ferment liquid,VFFL)对小鼠酒精性肝损伤的保护作用及其氧化应激机制。方法 50只雄性ICR小鼠随机分为正常对照组、乙醇模型组、果蔬发酵液组[10、30、60ml/(kg·d)],正常对照组和乙醇模型组蒸馏水灌胃,其余组用不同剂量果蔬发酵液灌胃,连续30d,最后一次灌胃16h后,乙醇模型组和各果蔬发酵液组均1次性50%乙醇12ml/kg·bw灌胃,6h后处死、取血和肝组织。分别采用HE染色观察肝组织,试剂盒测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(AKP)含量及肝组织超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)、蛋白质羰基、活性氧(ROS)含量,TUNEL法测定肝细胞凋亡,蛋白免疫印迹法检测凋亡相关蛋白表达。结果与乙醇模型组比较,果蔬发酵液组的肝组织水肿和坏死明显减轻;血清中的ALT、AST、AKP水平和肝细胞凋亡明显低于乙醇模型组(P0.05);肝组织中SOD、GSH、GSH-Px水平明显高于乙醇模型组(P0.05),而ROS、MDA、蛋白质羰基含量明显低于乙醇模型组(P0.05);果蔬发酵液组的VDAC(电压依赖性阴离子通道蛋白)、Bcl-2蛋白表达增高(P0.05),细胞色素C、caspase-9、caspase-3、Bax蛋白表达下降(P0.05)。结论果蔬发酵液具有较好的抗氧化作用,它可通过阻止ROS介导的线粒体信号通路,抑制肝细胞凋亡,从而保护小鼠酒精性肝损伤。     

核桃低聚肽对急性酒精性肝损伤大鼠保护作用

目的探讨核桃低聚肽(WOPs)对急性酒精性肝损伤大鼠的保护作用及其机制。方法雄性SD大鼠72只,随机分为6组:空白对照组、模型组、乳清蛋白组(220 mg/kg)和低、中、高剂量WOPs组(220、440、880 mg/kg)。灌胃给予WOPs,连续30 d,用体积分数为50%乙醇以7 g/kg剂量灌胃染毒,制备大鼠急性酒精性肝损伤模型。分离大鼠血清及肝组织,分别检测血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)和肝组织氧化应激相关指标还原型谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)和丙二醛(MDA)含量。结果与模型组比较,WOPs各剂量组大鼠精神状态及行为异常情况均有好转;与模型组比较,低、中、高剂量WOPs组大鼠血清转氨酶ALT活力[分别为(62.38±9.36)、(52.57±9.11)、(64.17±10.40)U/L]、AST活力[分别为(200.40±50.87)、(191.80±76.12)、(173.63±41.35)U/L]明显降低(P 0.05),中、高剂量WOPs组大鼠肝组织SOD活力[分别为(149.21±20.28)、(153.45±19.37)ng/L]、GSH-Px活力[分别为(138.82±9.93)、(146.99±15.05)IU/L]和GSH含量[分别为(568.15±67.31)、(571.61±74.98)ng/L]明显升高(P 0.05);与模型组比较,低、中、高剂量WOPs组大鼠肝脏脂质过氧化代谢产物MDA水平[分别为(3.83±0.56)、(3.62±0.47)、(3.94±0.24)nmol/L]明显下降(P 0.05)。结论 WOPs对酒精引起的大鼠急性肝损伤具有保护作用,其机制可能与抑制酒精引起的机体过度氧化应激反应和脂质过氧化水平,提高机体抗氧化能力有关。     

海洋深层水保护小鼠亚急性酒精性肝损伤

目的研究两种不同离子浓度的海洋深层水(DSW)对亚急性酒精性肝损伤的保护作用。方法 18~22 g雄性昆明小鼠72只,随机分为空白对照组、亚急性酒精性肝损伤模型组、DSW-A(1倍、5倍和10倍浓度)组及DSW-B 5倍浓度组。各DSW试验组自由饮用相应的水溶液,两个对照组自由饮用去离子水,连续30 d,并于第15天起除空白对照组外每日灌胃给予50%乙醇溶液造模。实验结束时检测血清天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、总胆红素(T-BIL)、低密度脂蛋白(LDL)、总胆固醇(TC)、总甘油三酯(TG)水平,肝脏TC、TG、丙二醛(MDA)、还原型谷胱甘肽(GSH)水平、还原型谷胱甘肽/氧化型谷胱甘肽(GSH/GSSG)比值和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、黄嘌呤氧化酶(XOD)活性。取肝脏做HE染色,显微镜下观察并进行病理评分。结果与空白对照组相比,模型组出现严重的肝脂肪变性,病理评分和血清T-BIL显著升高(P0.01),血清TC、LDL、AST以及肝脏MDA均显著升高(P0.05),肝脏GSH-Px活性显著下降(P0.01)。与模型组相比,DSW-A1组血清T-BIL(P0.05)浓度显著降低,肝脏GSH-Px(P0.01)和XOD(P0.05)活性显著提高;DSW-A5组肝脏病理改变减轻,病理评分、血清T-BIL和肝脏MDA显著降低(P0.01),血清TG、TC显著降低(P0.05),肝脏GSH/GSSG比值(P0.05)、GSH浓度(P0.01)、GSH-Px(P0.01)和XOD(P0.01)活性显著提高;DSW-A10组肝脏病理改变减轻,血清LDL、AST显著降低(P0.05),病理评分、血清TG、TC、T-BIL和肝脏MDA显著降低(P0.01),肝脏GSH/GSSG比值(P0.05)和GSH-Px活性(P0.01)显著提高;DSW-B5组肝脏病理改变减轻,肝脏MDA、血清TC显著降低(P0.05),病理评分、血清TG、T-BIL和AST显著降低(P0.01),肝脏GSH-Px(P0.01)和XOD(P0.05)活性显著提高。结论连续30天饮用DSW-A和DSW-B可降低血清脂质浓度,提高机体抗氧化能力,保护亚急性酒精性肝损伤。     

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.