超营养剂量酵母硒对荷瘤小鼠抗氧化和免疫机能的影响

目的:研究超营养剂量酵母硒对荷瘤小鼠抗氧化状态和免疫功能的影响。方法:60只昆明小鼠随机分为三组:对照组、酵母硒Ⅰ组和Ⅱ组,小鼠饲喂低硒日粮,对照组灌服0.5 ml生理盐水,酵母硒Ⅰ组和Ⅱ组灌胃酵母硒,剂量分别为3.2μg/d和6.4μg/d,D13小鼠接种艾氏腹水癌(EAC),试验结束测定血液抗氧化指标和免疫指标。结果:酵母硒Ⅰ组和Ⅱ组均能提高肿瘤移植小鼠血液谷胱甘肽过氧化物酶活性(P<0.05)和超氧化物歧化酶活性(P<0.01),但仅酵母硒Ⅱ组显著降低脂质过氧化值(P<0.05);酵母硒Ⅱ组显著提高NK细胞活性、巨噬细胞吞噬功能和迟发变态反应程度、血清抗绵羊红细胞抗体水平,酵母硒Ⅰ组与对照组差异不显著。结论:超营养剂量酵母硒的抑瘤机制可能主要是抗氧化作用和免疫调节作用,且作用与剂量有关。     

富硒酵母对铜负荷导致小鼠肝损伤的保护作用

目的探讨富硒酵母对小鼠铜负荷致肝损伤的保护作用。方法采用过量(512mg/kgbw·d)硫酸铜灌胃致小鼠肝损伤后,给予低、中、高(20、40、60mg/kgbw·d)的富硒酵母4w,观察补硒对肝脏丙二醛(MDA)含量、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性以及血清和肝组织中铜含量的影响,并进行肝脏病理组织学检查和肝细胞凋亡检测,同时测定血清中谷丙转氨酶(ALT)和谷草转氨酶(AST)活性。结果过量硫酸铜能导致小鼠肝脏损伤,与低、高剂量富硒酵母添加组相比,补充中剂量富硒酵母能显著缓解这种损伤,表现为血清和肝组织的铜含量显著降低,肝组织中SOD、GSH-Px活性增强,MDA含量减少,肝细胞凋亡显著减少。结论适量的富硒酵母能降低铜负荷导致的小鼠肝功能损伤,其机制可能与减轻铜离子介导的脂质过氧化有关。     

维生素E对双酚A暴露的发育期雄性小鼠生殖系统及抗氧化能力的影响

目的研究双酚A(BPA)暴露对雄性小鼠生殖系统及抗氧化能力的影响,以及大剂量补充维生素E对BPA作用的影响。方法 32只4～5周龄雄性昆明小鼠随机分为3组,分别为空白对照组(玉米油灌胃0.2ml/d,n=10),BPA组(每天给予BPA 0.5mg/kg BW灌胃,n=11)和维生素E干预组(每天给予BPA 0.5mg/kg BW和维生素E 150mg/kg BW灌胃,n=11)。干预3周后处死动物,测量血和各组织抗氧化活性,并检测生殖功能指标。结果 BPA组的睾丸湿重,BPA组和维生素E干预组的精囊湿重、精囊脏器系数和精子计数显著低于空白对照组(P<0.05或P<0.01);而维生素E干预组精囊脏器系数显著高于BPA组(P<0.05);BPA组和维生素E干预组的精子畸形率显著高于空白对照组(P<0.01);BPA组精子活动度显著低于空白对照组与维生素E干预组(P<0.05)。BPA组和维生素E干预组肝脏SOD活力显著高于空白对照组(P<0.05)。BPA组血清睾酮水平低于维生素E干预组和空白对照组,但差异无显著性。结论双酚A的短期暴露对雄性小鼠的生殖系统可能产生一定抑制作用,并显示出对实验动物抗氧化能力增强;短期补充维生素E对双酚A暴露所引起的生殖系统抑制可产生一定保护作用。     

枸杞对老龄小鼠抗氧化功能影响的实验研究

目的探讨枸杞对老龄小鼠抗氧化功能的影响。方法按照《保健食品检验与评价技术规范》GB/T15193-2003中抗氧化功能检验方法 ,采用2.50、5.00、10.00g/kg.bw剂量的枸杞给小鼠经口灌胃30d,按试剂盒说明分别测定丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)。结果与老龄对照组比较,高剂量组能显著降低血中MDA含量和显著提高血清SOD活力(P0.05),各剂量组对血清GSH-Px活力无明显影响(P0.05)。结论枸杞对老年小鼠具有抗氧化功能。     

马桑果致小鼠肝脏损伤初步研究

目的研究马桑果对健康昆明小鼠肝脏的损伤作用,为探讨马桑果的毒性以及对机体的损伤机制提供依据。方法选取健康昆明种小鼠80只,随机分为空白对照组、5、10、20 g/kg BW染毒组,每组20只,雌雄各半。建立小鼠急性染毒模型,空白对照组用蒸馏水灌胃,记录灌胃后临床表现,在试验后24 h处死小鼠,采集血清,检测天门冬氨基转移酶(aspartate aminotransferase,AST)、丙氨酶氨基转移酶(alanine aminotransferase,ALT)、碱性磷酸酶(alkaline phosphatase,ALP);解剖小鼠取肝脏,计算肝脏的脏器系数,HE染色观察各组小鼠的脏器组织病理学改变。结果24 h处死的小鼠中,20 g/kg BW染毒组肝脏脏器系数明显高于空白对照组及5、10 g/kg BW染毒组,差异均有统计学意义(均P<0.05);20 g/kg BW剂量组雄性小鼠的ALT、AST、ALP 3个值与空白对照组及5、10 g/kg BW剂量组相比较有明显升高趋势,差异均有统计学意义(均P<0.05)。20 g/kg BW剂量组的雌性小鼠ALT、ALP的值显著高于空白对照组、5 g/kg BW剂量组,差异均有统计学意义(均P<0.05)。20 g/kg BW剂量组的AST值显著高于空白对照组及5、10 g/kg BW,差异有统计学意义(P<0.05)。10和20 g/kg BW染毒组中多数小鼠肝脏出现明显损伤,呈现病变程度随着剂量增加而加重的趋势,肝脏损伤表现为肝脏充血,细胞水肿,脂肪病变,炎症细胞浸润。在空白对照组未发现异常病变。结论马桑果对小鼠肝脏有明显的损害作用,提示除了神经系统,肝脏也是马桑果中毒的靶器官之一。     

番茄红素对自然衰老大鼠抗氧化功能的研究

目的:探讨番茄红素对自然衰老大鼠的抗氧化作用。方法:选用15月龄SD雄性大鼠48只按其血清丙二醛(MDA)含量分层随机分成4个组,根据样品的人体推荐量设166.6 mg/kg BW、83.3 mg/kg BW、41.7 mg/kg BW三个剂量实验组和一个阴性对照组。阴性对照组给予等体积的玉米胚芽油,每天灌胃一次,连续灌胃60 d。60 d后处死,测定超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和过氧化脂质(LPO)含量(以MDA计)以及脂褐质(LIP)含量。结果:实验组的血清过氧化脂质(LPO)含量和组织匀浆液中的脂褐质(LIP)含量低于阴性对照组(P<0.05),组织匀浆液中SOD及GSH-Px活力高于于阴性对照组(P>0.05)。结论:番茄红素对自然衰老大鼠具有抗氧化的功能。     

慈菇多糖对S180荷瘤小鼠的抑瘤作用

目的观察慈菇多糖干预S180肿瘤模型的小鼠实验,研究其抗肿瘤的功效。方法将ICR雄性小鼠48只按体重随机分为6组:模型组、慈菇多糖低、中、慈菇多糖高剂量组(100、200、300 mg/kg·d)、香菇多糖组(0.577 mg/kg,2次/周)和环磷酰胺组(20 mg/kg·d)。前11 d慈菇多糖组按各自剂量灌胃,其余组以等量蒸馏水灌胃,第11 d建立S180荷瘤小鼠动物模型。造模次日开始,各剂量组小鼠给予相应药物,连续11 d。第23 d测定小鼠抑瘤率、瘤重、脏器指数、血清细胞因子、丙二醛(MDA)及超氧化物歧化酶(SOD)。结果与模型组比较,环磷酰胺组的抑瘤率最高(72.4%),慈菇多糖高剂量组次之(68.4%),两组瘤重均降低;慈菇多糖中、高剂量组和香菇多糖组的脾脏指数升高;慈菇多糖各剂量组的TNF-α、IL-2水平均有所提高;慈菇多糖各剂量组、香菇多糖组MDA值下降,慈菇多糖高剂量组、香菇多糖组SOD值升高。结论慈菇多糖可抑制荷瘤小鼠肿瘤的生长,可能与提升小鼠免疫功能和增强抗氧化作用有关。     

番茄红素对溴代苯诱导小鼠脂质过氧化损伤的拮抗作用

目的探讨番茄红素对溴代苯诱导小鼠脂质过氧化损伤的拮抗作用。方法将50只健康成年SPF级昆明雄性小鼠随机分为5组,即对照组、溴代苯模型组和低、中、高剂量番茄红素+溴代苯组,每组10只。低、中、高剂量番茄红素+溴代苯组小鼠经口灌胃浓度分别为0.33、0.67和2.00 g/L的番茄红素溶液,对照组和溴代苯模型组灌胃等体积的溶剂(含98%水、0.8%甘油、0.7%无水乙醇、0.5%玉米油),染毒容量为0.02 ml/g,每天1次,连续染毒30 d;番茄红素暴露结束0.5 h后,测定红细胞超氧化物歧化酶(SOD)活力、全血谷胱甘肽过氧化物酶(GSH-Px)活力及总抗氧化能力(T-AOC)。番茄红素暴露结束3 h后,除对照(橄榄油)组外,其余4组立即一次性灌胃染毒0.4 mg/kg的溴代苯溶液,染毒容量为0.01 ml/g,22 h后,测定肝脏中丙二醛(MDA)含量和SOD、GSH-Px活力及T-AOC。结果番茄红素暴露后,与溴代苯模型组相比,中、高剂量番茄红素+溴代苯组小鼠红细胞SOD活力、全血GSH-Px活力及全血T-AOC显著升高(P<0.05,P<0.01);溴代苯染毒后,与溴代苯模型组相比,中、高剂量番茄红素+溴代苯组小鼠肝脏中SOD活力、GSH-Px活力及T-AOC明显增强(P<0.05,P<0.01),MDA含量显著下降(P<0.05,P<0.01)。随着番茄红素暴露剂量的升高,小鼠肝脏中MDA含量呈下降趋势,而血液及肝脏中SOD、GSH-Px活力及T-AOC呈上升趋势。结论番茄红素对溴代苯引起的小鼠脂质过氧化损伤具有一定的拮抗作用。     

北京蜂胶对老龄小鼠抗氧化功能影响的实验研究

目的探讨北京蜂胶对老龄小鼠抗氧化功能的影响。方法按照《保健食品检验与评价技术规范》(2003年版)中抗氧化功能检验方法,采用0.183、0.367、1.101g/kg.bw剂量的北京蜂胶给小鼠经口灌胃30d,按试剂盒说明分别测定丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)。结果与阴性对照组比较,0.183、0.367、1.101g/kg.bw剂量组能显著提高血清GSH-Px活力,1.101g/kg.bw剂量能显著降低血中MDA含量,对血清SOD活力无明显影响。结论北京蜂胶具有抗氧化功能。     

小麦低聚肽对老龄小鼠抗氧化功能的影响

目的评价小麦低聚肽的体内和体外抗氧化能力。方法 12月龄清洁级雄性KM种小鼠48只,按血清MDA水平随机分为4组,即阴性对照、低、中、高剂量组(小麦低聚肽0、500、1000、2000mg/kg BW),灌胃30d。处死后测定血清中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化能力(T-AOC)。体外抗氧化功能评价采用体外还原能力、清除DPPH自由基、清除羟自由基3方面的指标。结果小麦低聚肽具有较强的体外还原能力(R=0.97),DPPH自由基和羟自由基清除能力(RDPPH.=0.90,R.OH=0.91),并能够增强小鼠血清SOD和GSH-Px活性(P<0.05),提高血清总抗氧化能力(P<0.05)。结论小麦低聚肽具有较好的抗氧化功能。     

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.