雌激素对去卵巢大鼠生长发育及骨代谢影响

目的 探讨雌激素对去卵巢大鼠生长发育、血液生化指标、骨营养状况及子宫增生的影响及作用机制.方法 4月龄雌性SD大鼠腹腔假手术或切除双侧卵巢,分为假手术组(Sham)、去卵巢对照组(0vx)和雌激素组(EC).用自行配制的含有β-雌二醇的饲料喂养7周,实验期间记录各组大鼠体重和摄食量,并计算食物利用率.实验结束后测定大鼠血清生化指标、股骨密度、骨钙含量,同时对子宫进行病理组织学观察.结果 实验结束时雌激素组体重、食物利用率明显低于去卵巢对照组(P<0.01);雌激素组大鼠骨密度均明显高于去卵巢对照组(P<0.05);雌激素组大鼠子宫未见明显萎缩.结论 雌激素可显著抑制大鼠去卵巢后体重增加,并有效减少骨量丢失,增强骨密度,对骨钙含量有增加趋势;同时对子宫的增生作用非常明显.     

大豆异黄酮对去卵巢大鼠骨力学性能的影响

目的　探讨植物雌激素大豆异黄酮对大鼠去侧巢后骨密度和骨力学指标变化的影响。方法　腹腔手术切除大鼠双侧卵巢 ,分为去卵巢对照组、大豆异黄酮剂量组和雌激素对照组 ,并设假手术对照组。喂养 16周后 ,分离股骨 ,双能量X射线骨密度仪测定骨密度 (BMD) ,三点弯曲实验法测定骨力学指标弯曲强度 (Flexuralstrengh)和弯曲弹性模量 (Flexuralelasticmodule) ,分析天平称量骨的重量。结果　大鼠去卵巢后骨密度显著下降 ,股骨的力学性能指标有较大变化。给予大豆异黄酮和雌激素后 ,可使骨密度显著提高 (P <0 0 1) ,存在一定的剂量 -效应关系 ,弯曲强度和弯曲弹性模量明显增加。雌激素组 (EC)大鼠的股骨长度和不同状态下的骨重量显著降低 ,其它各组之间经统计学分析无显著性变化。结论　大豆异黄酮和雌激素可增加去卵巢大鼠股骨骨密度、改善骨的生物力学性能     

大豆异黄酮类对去卵巢大鼠骨丢失的影响

目的　研究大豆中植物雌激素——异黄酮类对去卵巢大鼠骨丢失的预防作用。方法　将 3月龄 SD雌性大鼠按体重分为 5组 ,每组 1 1只 :假手术对照组 (假手术 +饲含酪蛋白饲料 ,Sham) ;去异黄酮组 (去卵巢 +饲含去异黄酮类大豆分离蛋白饲料 ,Soy- ) ;异黄酮组 (去卵巢 +饲含异黄酮类大豆分离蛋白饲料 ,Soy+) ;酪蛋白组 (去卵巢 +饲含酪蛋白饲料 ,即去卵巢对照组 ,Ovx) ;雌激素对照组 (去卵巢 +饲含酪蛋白饲料 +注射雌二醇 ,E2 )。在实验期第 3周、第 6期和第 9周各进行为期三天的钙代谢试验。第 1 0周末处死大鼠 ,测定骨钙、骨密度 ,并对股骨远端松质骨进行骨组织形态学测量。结果　异黄酮组和雌激素对照组粪钙、尿钙排出量显著低于酪蛋白组和去异黄酮组 (P<0 .0 5) ,钙表观吸收率和钙贮留量显著高于酪蛋白组和去黄酮组 (P<0 .0 5) ,钙代谢呈正平衡。异黄酮组和雌激素对照组骨钙、骨密度高于酪蛋白组和去异黄酮组 (P<0 .0 5)。与雌激素对照组比较 ,异黄酮组骨小梁面积百分率和骨小梁数目明显减少 ,骨小梁间隙明显增宽 (P<0 .0 5) ;但与酪蛋白组和去异黄酮组比较 ,异黄酮组骨小梁面积百分率和骨小梁数目明显增多 ,骨小梁间隙明显减少 (P<0 .0 5)。结论　含有异黄酮类的大豆分离蛋白具有预防骨丢失的作用 ,而?     

淫羊藿、杜仲对卵巢切除大鼠骨密度和骨钙含量的影响

目的探讨淫羊藿、杜仲对卵巢切除大鼠骨密度和骨钙含量的影响。方法取SPF级雌性SD大鼠60只,切除卵巢建立大鼠骨密度低下模型后随机分成6组:淫羊藿和杜仲低、中、高剂量组(g/kg·bw)0.15、0.30、0.90,碳酸钙和溶剂对照组,假手术组。统一用低钙饲料和相应受试物灌胃3个月后,处死大鼠,测定其体重、股骨中心和远心端骨密度和骨钙等含量。结果假手术组大鼠末期体重及增重低于溶剂对照组,股骨中心、远心端骨密度和重量、骨钙含量高于溶剂对照组;高剂量组(0.90g/kg·bw)大鼠骨钙含量、股骨中心和远心端骨密度高于溶剂对照组,中、高剂量组大鼠股骨中心、远心端骨密度和重量、骨钙含量比碳酸钙对照组高,但未达显著性水平。结论淫羊藿和杜仲能增加卵巢切除大鼠骨密度和骨钙含量,对雌激素缺乏诱发的骨钙丢失有抑制作用。     

大豆异黄酮联合碳酸钙调节去势大鼠骨代谢的研究

[目的]观察大豆异黄酮联合碳酸钙对去势大鼠骨代谢的调节作用。[方法]将60只雌性SD大鼠随机分为6组,分别为假手术组、3个剂量组、碳酸钙组和去卵巢对照组,每组10只。假手术组单纯开腹,其余5组切除双侧卵巢。低、中、高剂量组分别灌胃给予受试物(大豆异黄酮4.8、9.7、29.0 mg/kg BW,碳酸钙25.5、50.9、152.8mg/kg BW),碳酸钙组灌胃给予碳酸钙152.8 mg/kg BW,实验共3个月。每周记录一次体重。实验结束后测定大鼠血清碱性磷酸酶(AKP)和血清钙,取股骨检测股骨中点和远心端骨密度和骨钙含量。[结果]低、中剂量组大鼠股骨远心点骨密度与去卵巢对照组比较显著增加(P﹤0.05),低、高剂量组大鼠股骨骨钙含量与去卵巢对照组比较显著增加(P﹤0.05)。[结论大豆异黄酮联合碳酸钙具有增加去势大鼠骨密度和骨钙含量的作用。     

大豆异黄酮对去势大鼠骨量丢失的抑制作用研究

目的:研究大豆异黄酮(Soybeanisoflavone,SI)对去势后大鼠由于体内雌激素水平下降引起的骨量丢失的抑制作用。方法:腹腔手术切除大鼠双侧卵巢,分为对照组、SI组和雌激素对照组,并设假手术对照组,喂养16w后,测定雌二醇、骨生化指标、骨密度、骨钙、骨磷等指标,扫描电镜和组化分析观察骨小梁微观结构的变化。结果:SI显著降低血清中骨吸收指标TRAP活性,同时明显提高骨形成指标BGP含量;SI具有弱雌激素作用,可抑制去卵巢大鼠体内雌激素水平的下降,骨密度和骨钙、骨磷含量增加,松质骨的骨丢失得到抑制。结论:SI可降低骨吸收、促进骨形成,对去卵巢引起的骨量丢失有明显的抑制作用。     

大豆异黄酮对去势大鼠骨代谢的影响

[目的]探讨大豆异黄酮改善激素缺乏大鼠骨营养状况及作用机制。[方法]选用卵巢切除大鼠所诱发的骨质疏松模型,给予大豆异黄酮治疗,同时设假手术组及模型对照组。3个月后测定大鼠骨密度、骨钙含量及骨代谢酶学指标。[结果]大豆异黄酮可提高去势大鼠的骨密度、骨钙含量;降低血清碱性磷酸酶(AKP)及抗酒石酸酸性磷酸酶(TRACP)的活性(P<0.05),其作用与剂量有关。[结论]大豆异黄酮能够增加去势大鼠的骨密度,有类似雌激素样作用,可有效防治卵巢切除大鼠的骨量丢失,其作用机制可能是通过降低骨转换率来实现。     

硫酸软骨素加钙对卵巢切除大鼠骨密度和骨钙含量的影响

目的探讨硫酸软骨素加钙对卵巢切除大鼠模型骨密度和骨钙含量的影响。方法选用卵巢切除大鼠所诱发的骨质疏松模型，给予硫酸软骨素加钙治疗，同时设假手术组及模型对照组。3个月后测定大鼠骨密度、骨钙含量。结果发现假手术组和高剂量组大鼠股骨骨密度和股骨钙含量显著高于阴性对照组（P〈0．05）。结论表明硫酸软骨素加钙能增加卵巢切除大鼠的骨密度，对雌激素缺乏所诱发的骨钙丢失具有抑制作用。     

大豆异黄酮对去卵巢大鼠血脂及骨生化指标的影响研究

探讨大豆异黄酮对去卵巢大鼠血清中血脂指标、骨代谢生化指标及激素水平的影响。选择 4月龄的Wistar大鼠 ,根据体重随机分为 6组。除 1组行单纯开腹手术外 ,其它 5组均切除双侧卵巢 ,分别为 :去卵巢对照组 ;高剂量大豆异黄酮组 ;中剂量大豆异黄酮组和低剂量大豆异黄酮组 ;雌激素组。喂养 16周后 ,处死大鼠 ,分离血清进行分析指标的测定。结果发现 :给予去卵巢大鼠大豆异黄酮后 ,血清中高密度脂蛋白(HDL)含量与去卵巢对照组相比有所增高 (P <0 0 5 ) ;总胆固醇 (TC)、甘油三酯 (TG)指标下降 ;骨吸收指标显著降低 ,骨形成指标骨钙素水平与去卵巢组比有所提高 ;同时 ,大鼠切除卵巢后 ,体内雌激素水平显著下降。结果显示 :大豆异黄酮对去卵巢大鼠的血脂有一定的调节作用 ,对骨吸收有显著的抑制作用     

大豆异黄酮对大鼠骨代谢生化指标的影响

目的：探讨植物雌激素－－大豆异黄酮对大鼠骨代谢生化指标的影响。方法：Wistar大鼠随机分组后，给予不同剂量的大豆异黄酮，喂养3个月后，对血清中骨形成生化指标碱性酸酶（AKP），骨钙素（BGP）和骨吸收生化指标抗酒石酸酸性磷酸酶（STrACD)及雌二醇进行检测，结果：具有弱雌激素样作用的大豆异黄酮对实验大鼠的子宫、卵巢无刺激作用。与对照组相比，大豆异黄酮可影响骨代谢生化指标，高剂量的大豆异黄酮（41．6mg/k.bw)具有同时抑骨形成和骨吸收的作用，使骨转化率降低，但对骨吸收的作用大于骨形成。结论：大豆异黄酮对骨代谢生化指标有一定的调节作用，能够抑制骨吸收，预防骨质疏松的发生。     

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.