锌对全身照射小鼠骨髓造血细胞辐射损伤的影响

[目的]探讨锌对γ射线诱发小鼠骨髓细胞辐射损伤的影响。[方法]小鼠按随机区组法分为空白对照组、辐射对照组以及3个加锌实验组。加锌组分别按每kg普通饲料加入30mg、60mg、120mgZn^2＋后喂饲两周，两对照组喂饲普通饲料。之后除空白对照组外，其余各组均以6Gy^60Coγ射线进行全身照射，2d后处死动物。分别测定外周血白细胞数、骨髓有核细胞数和DNA含量、骨髓细胞超氧化物歧化酶（SOD）活力和丙二醛（MDA）含量以及微核率。[结果]^60C0γ射线照射小鼠后2d，外周血白细胞数、骨髓有核细胞数和DNA含量均显著下降，细胞SOD活力下降而MDA含量升高，微核率升高；饲料中加入30～120mg／kg的锌，能使以上辐射损伤得到明显缓解。[结论]饲料中加锌对小鼠骨髓细胞具有辐射损伤防护作用。     

大蒜素对小鼠辐射损伤的辅助保护作用

目的 研究大蒜素对小鼠辐射损伤的辅助保护作用.方法 将60只昆明雄性小鼠随机分为辐射模型对照组、溶剂对照组、大蒜素低(0.17 g/kg)、中(0.33 g/kg)、高(1.00 g/kg)剂量组,用大蒜素灌胃20 d后,小鼠接受60Co-γ射线一次性全身辐照,观察对小鼠外周血白细胞总数、骨髓细胞微核率、骨髓细胞DNA含量、红细胞超氧化物歧化酶(SOD)活力等损伤指标的影响.结果 大蒜素高剂量组能明显增加经一次60Co-γ射线全身照射后小鼠的外周血白细胞总数,降低骨髓细胞微核发生率,提高骨髓细胞DNA含量,增加红细胞超氧化物歧化酶(SOD)的活力.结论 大蒜素对小鼠辐射损伤有辅助保护作用.     

方格星虫多糖对5.0Gy ^60Coγ辐射损伤小鼠的保护作用

目的观察方格星虫多糖对亚致死剂量60Coγ射线照射小鼠的保护作用。方法将60只雄性C57BL/6J小鼠随机分为正常对照组、模型组、尼尔雌醇组及低（100 mg/kg·d）、中（200 mg/kg·d）、高（400 mg/kg·d）三个剂量方格星虫多糖组,每天一次灌胃给药,尼尔雌醇组照射前一天给予尼尔雌醇3.3 mg/kg灌胃,照射后0.5 h再次给予1.67 mg/kg尼尔雌醇灌胃。灌胃2 w后,除正常对照组外,各组均以剂量率为0.8 Gy/min的60Coγ射线全身照射一次,照射剂量为5.0 Gy。于辐照后3 d、14 d测定小鼠体重、外周血WBC,辐照后14 d测定小鼠胸腺指数,脾指数,骨髓细胞和脾细胞DNA含量,血清SOD和MDA含量。结果γ射线全身照射后第3天,方格星虫多糖低、中剂量组小鼠外周血WBC数明显升高（P〈0.05）。照后第14天,低剂量组小鼠外周血WBC数显著增高（P〈0.01）,中、高剂量组脾脏重量指数明显升高（P〈0.01和P〈0.05）,中剂量组脾脏DNA含量明显增高（P〈0.01）;低、中剂量组骨髓细胞DNA含量明显增高（P〈0.05）;低、中、高三个剂量组小鼠血清SOD活力明显增强,血清MDA含量明显下降（P〈0.05）。结论方格星虫多糖对亚致死剂量γ辐射损伤小鼠具有一定保护作用。     

牦牛活性蛋白对X射线损伤小鼠的防护作用

目的探讨牦牛活性蛋白对辐射损伤小鼠的防护作用。方法健康昆明小鼠60只,随机分为正常对照组、模型组、阳性组(氨磷汀,150 mg/kg)、牦牛活性蛋白高、中、低剂量(10、5、2.5 mg/kg)6组。辐射前牦牛活性蛋白给药组连续灌胃14 d,正常组和模型组灌胃给予等容生理盐水,阳性组于照射前30min腹腔注射给药。除正常组外,其它实验组用X射线全身一次性照射,照射剂量5Gy,照射后第7 d观察牦牛活性蛋白对小鼠外周血象、抗氧化酶活力、脏器指数、骨髓DNA、白介素2(IL-2)、白介素6(IL-6)含量及B细胞淋巴瘤因子2(Bcl-2)、Bcl-2相关X蛋白(Bax)表达情况。结果牦牛活性蛋白对辐射后小鼠脏器指数有明显升高作用,血象有明显上升现象,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化力(T-AOC)活力明显增强,丙二醛(MDA)含量显著降低,骨髓DNA、IL-2含量显著升高,Bcl-2表达升高,Bax表达下降。结论研究结果表明,牦牛活性蛋白对X射线所致小鼠辐射损伤有一定的改善和保护作用。     

螺旋藻抗电离辐射损伤作用的探讨

目的 探讨螺旋藻（SP）抗电离辐射损伤作用。方法 按体重将162只昆明种小鼠随机分为9个组，每组18只，即阴性对照组和4Gy与7Gy照射组，每一照射组又各设阳性对照组和400，800，1200mg/kg3个给药物组。给药组灌胃SP，对照组则灌胃蒸馏水，灌胃后第8天照射。灌胃后第7天，照射后4h，照射后第7天各杀一批小鼠，测定血象，红细胞SOD活力等指标。结果 照射后白细胞，血小板呈下降趋势，给药组WBC均高于阳性对照组，对Hb影响不大；红细胞SOD活力照射后4h升高，照射后第7天降低。照射后血象与红细胞SOD活力呈正相关。结论 SP对辐射所致血象改变有保护作用，其作用可能是通过提高内源性SOD的活力来对抗辐射所致的氧化损伤，从而保护造血组织而实现的。     

人乳铁蛋白对小鼠辐射损伤保护作用

目的 研究人乳铁蛋白(HLF)对小鼠辐射损伤的保护作用.方法 无特定病原体级balb/c雄性小鼠随机分为正常对照组、照射对照组和HLF防护组.HLF防护组每天1次给小鼠灌胃质量浓度为1.0 g/L HLF溶液,连续7d.正常对照组和照射对照组用同样的方法灌胃给予等体积的生理氯化钠.最后1次灌胃后2h除正常对照组外,其余2组小鼠全身均匀接受2.0 GyX射线照射,24 h后颈椎脱臼法处死小鼠.观察HLF对小鼠周围血白细胞(WBC)和脏器指数、血清超氧化物歧化酶(SOD)活力、丙二醛(MDA)水平、骨髓嗜多染红细胞微核的影响.结果 HLF防护组SOD活力、周围血WBC、脾脏和胸腺指数均升高,而MDA水平降低,与照射对照组比较,差异有统计学意义(P＜0.05);HLF防护组的骨髓嗜多染红细胞微核率低于照射对照组(P＜0.05).结论 HLF对小鼠辐射损伤有一定的保护作用.     

五味子粗多糖对受照射小鼠肝脏脂质过氧化及抗氧化酶的影响

目的观察五味子粗多糖对受X射线照射小鼠肝脏脂质过氧化及抗氧化酶的影响。方法小鼠照射前胃肠道给予五味子粗多糖,照射后第3天将小鼠处死,测定肝脏中超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量。结果400mg/kg五味子粗多糖可明显提高受照小鼠肝组织SOD活性(P<0.05),降低肝组织MDA含量(P<0.05)。结论五味子粗多糖可减轻受照小鼠肝组织脂质过氧化,并提高抗氧化酶活性,对辐射损伤小鼠具有保护作用。     

人乳铁蛋白对小鼠急性辐射损伤影响

目的 研究人乳铁蛋白对X射线照射所致小鼠急性辐射损伤的影响.方法 无特定病原体级Balb/c雄性小鼠51只,随机分成3组,即对照组、辐射组和乳铁蛋白组.辐射组和乳铁蛋白组小鼠给予2.0 Gy X射线全身均匀照射,对照组不予照射.照射后2h,乳铁蛋白组每只腹腔注射人乳铁蛋白4.0 mg;对照组和辐射组小鼠腹腔注射生理氯化钠溶液各1.0 ml.观察人乳铁蛋白对腹腔巨噬细胞吞噬指数和吞噬百分率、周围血象、血清超氧化物歧化酶(SOD)活力、丙二醛(MDA)水平和脏器指数的影响.结果 与辐射组比较,乳铁蛋白组小鼠腹腔巨噬细胞吞噬指数和吞噬百分率、血清SOD活力和脾脏指数均显著升高(P ＜0.05,P＜0.01),血清MDA水平显著降低(P＜0.01);周围血白细胞计数、红细胞计数、血小板和胸腺、肝脏指数比较,差异无统计学意义(P＞0.05).结论 人乳铁蛋白对小鼠急性辐射损伤具有一定的保护作用.     

乳铁蛋白对辐射小鼠抗氧化作用的影响

目的探讨人乳铁蛋白对电离辐射后小鼠生存率以及对抗氧化的影响,研究人乳铁蛋白防治辐射损伤的作用及其机制。方法小鼠随机分成三组,即正常对照组、照射对照组和乳铁蛋白防护组。乳铁蛋白防护组的小鼠给予乳铁蛋白溶液3 ml灌胃,(1.0 g/l hLF,灌胃前30 min生理盐水配制,室温放置),正常对照组和照射对照组给与等量生理盐水灌胃,每组每天一次,连续7 d或30 d,末次给药2h后照射对照组和乳铁蛋白防护组的小鼠接受一次性X射线2 Gy或6.8 Gy全身均匀照射。7 d/2 Gy研究比较人乳铁蛋白对血清SOD活性、MDA含量的影响,以及肝脏组织形态学的变化,30 d/6.8 Gy研究观察小鼠生存质量、生存率。结果给予乳铁蛋白后可显著抑制受照射小鼠血清SOD活性的降低以及MDA含量的升高,同时也可减轻肝脏细胞的凋亡,并可提高小鼠辐射后30d的生存率。结论人乳铁蛋白可提高受到辐射后小鼠机体的抗氧化能力,提高小鼠的生存率,提示其具有一定辐射防护作用。     

急性致衰老动物模型的探讨

为探讨一种快速简便的衰老动物模型 ,采用γ射线辐射SD大鼠后 ,测定其超氧化物歧化酶 (SOD)与丙二醛 (MDA)的变化及给小鼠颈背部皮下连续注射D 半乳糖后 ,测定其SOD与MDA的变化。结果表明(1)γ 射线辐照法 :SOD活力 (nU ml)实验组为 15 3± 46 ,对照组为 2 0 2± 6 0 ;MDA的含量 (nmol ml)实验组为 2 70± 75 ,对照组为 2 5 3 2± 2 0 8。辐照后两组的SOD活力和MDA含量有显著性差异 ,且SOD活力显著下降 ,MDA含量显著升高。 (2 )D 半乳糖法 :其结果与辐照法相同。提示在短期内用γ射线辐照的SD大鼠 ,能做为衰老动物模型     

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.