蜂胶对辐射损伤大鼠外周血细胞及血清SOD的影响

[目的]观察黑蜂蜂胶对3．0Gy 60Co γ-射线照射大鼠外周血白细胞(WBC)及血清超氧化物歧化酶 (superoxide dismutase,SOD)活性的影响。[方法]将36只Wistar大鼠随机分成3组;单独照射组,蜂胶预防组,蜂胶治疗组。各组同时接受一次性全身γ射线照射。蜂胶预防组于照射前3 d起以0．2 g/kg灌服蜂胶,蜂胶治疗组于照射当天开始以同样剂量灌服蜂胶1次/d,连续7 d。各组于照前1 d,照后1、4、7 d采血。动态观察外周血白细胞数和SOD活性变化。 [结果]照射前、后给予蜂胶,在照后7d均显示出明显促进辐射大鼠白细胞数量的恢复。照射后4d,预防组和治疗组血清SOD活性与照射前相比差异无显著性。结果提示蜂胶可减轻辐射所致的大鼠血清SOD活性的下降。[结论]蜂胶具有一定的抗辐射损伤作用。     

豆豉中大豆异黄酮及苷元对四氧嘧啶糖尿病模型小鼠血糖及组织的活性作用

[目的]研究豆豉中大豆异黄酮及苷元(SI)对四氧嘧啶糖尿病模型小鼠血糖、血脂及肾、肝组织的影响.[方法]利用超声提取豆豉中的大豆异黄酮,经硅胶分离出大豆黄素和染料木素.给四氧嘧啶糖尿病小鼠按一定剂量给予所提取的大豆异黄酮及苷元灌胃10 d,检测血糖(GLU)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)4项指标,观察小鼠肝脏和肾脏的病理切片.[结果]与四氧嘧啶糖尿病模型组比较,SI中、高剂量组血糖显著降低(P<0.05);SI的3个剂量组比较,SI中、高剂量组降低血糖的效果显著高于低剂量组(P<0.05),中、高剂量组降低率分别达到18.996%和28.447%;SI高剂量组能显著降低TC、TG和升高HDL-C含量(P<0.05),SI中剂量组只能显著降低TG的含量;SI高剂量组的肝、肾组织较模型组有明显改善.[结论]豆豉中的大豆异黄酮及苷元可明显降低四氧嘧啶糖尿病模型小鼠的血糖水平,改善由糖尿病引起的高血脂症,并对小鼠的肝脏和肾脏具有一定的修复作用.     

大豆异黄酮对去卵巢大鼠肝线粒体的抗氧化作用

目的:探讨大豆异黄酮(soybean isoflavones,SI)对去卵巢大鼠肝线粒体抗氧化能力的影响。方法:3月龄SD雌性大鼠随机分为3组,每组10只,假手术对照组和模型组给予去离子水,干预组给予SI提取物,灌胃。于第13w末处死大鼠,电镜观察肝线粒体形态结构变化,氧电极法测定肝线粒体呼吸功能,并测定肝线粒体、胞浆及肝组织匀浆MDA的含量,肝组织匀浆GSH-Px活性。结果:与对照组比较,模型组和干预组大鼠肝线粒体结构和抗氧化功能均有显著下降,与模型组比较,干预组肝线粒体结构较完整,肝线粒体琥珀酸和NADH氧化呼吸链Ⅳ态呼吸速度(R4)显著下降,呼吸控制率(RCR)、磷氧比(P/O)和氧化磷酸化效率(OPR)有明显增加;干预组肝脏线粒体、胞浆及肝组织匀浆MDA含量明显下降或有下降趋势;干预组肝组织匀浆GSH-Px活性明显增强。结论:大豆异黄酮能够提高去卵巢大鼠肝组织的抗氧化能力。     

大豆异黄酮与大豆皂甙抗辐射作用的实验研究

目的 探讨大豆异黄酮和大豆皂甙对γ射线辐射损伤的防护作用。方法 实验分三批,清洁级雄性昆明小鼠,每批按体重随机分为假照射组、照射模型组、大豆异黄酮组和大豆皂甙组。各受试物组小鼠经口灌胃各组受试物,连续30d后三批小鼠除假照射组外其余剂量组用⁶⁰Co-γ射线照射剂量分别为3.0Gy、5.0Gy、7.0Gy进行一次全身照射,照射后仍然给予受试物。分别检测外周血白细胞数、骨髓有核细胞数和骨髓细胞微核率以及红细胞与肝脏超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。结果 给予大豆异黄酮和大豆皂甙的小鼠在照射后第3天和第14天外周血白细胞数、骨髓有核细胞数、红细胞和肝脏SOD活力均高于照射模型组(P<0.05),骨髓微核率和血浆MDA水平低于照射模型组(P<0.05)。结论 大豆异黄酮和大豆皂甙均能提高受照射小鼠的抗氧化能力,在一定程度上减缓由辐射引起的外周血白细胞和骨髓有核细胞数下降,减少微核的产生,对γ射线损伤具有良好的防护作用。     

大豆异黄酮对小鼠辐射损伤的防护效果

目的:探讨大豆异黄酮对60Coγ射线损伤小鼠的防护效果。方法:体重23～29g的80只雌性昆明小鼠随机均分为5组,即正常对照、阳性对照组(即单纯辐照组)及低、中、高剂量大豆异黄酮实验组。照前正常对照、阳性对照组及实验组每天分别以溶剂0.5%羧甲基纤维素钠(CMC-Na)和不同剂量大豆异黄酮(50、100及400mg/kgbw)连续灌胃14d,灌胃至D7,除正常对照组外,其余各组小鼠均接受5Gy60Coγ全身性照射1次,照射后继续灌胃2d及7d后宰杀,取血和肝、脾组织标本。结果:(1)与阳性对照组相比,不同浓度大豆异黄酮可显著提高肝组织抗氧化酶CAT和GSH-Px活性;(2)实验组辐照后短期内肝组织MDA含量一过性升高,但很快即显著降低至正常水平,降低幅度和速度均优于单纯辐照组;(3)照射后期实验组小鼠白细胞上升幅度均高于单纯辐照组,且不同浓度大豆异黄酮能升高受照小鼠脾淋巴细胞转化的刺激指数。结论:大豆异黄酮具有提高受辐照小鼠抗氧化能力和增强免疫功能,有利于受辐照后机体的恢复,能显著减轻辐射对机体的损伤。     

刺五加多糖对60Co γ射线辐照大鼠胃肠道及生殖系统的保护作用

目的 探讨刺五加多糖对⁶⁰Co γ射线辐照大鼠的胃肠道及生殖系统的影响。方法 68只雄性Wistar大鼠随机分成正常对照组、模型对照组、WR-2721组、523片组和刺五加多糖高(200 mg/kg·d)、中(100 mg/kg·d)、低(50 mg/kg·d)剂量组。5 Gy ⁶⁰Co γ射线(吸收剂量率为0.388 Gy/h)全身照射一次。分别于照前5d、照后第3、10、14天测定大鼠体重及外周血白细胞数;照后第14天断颈处死大鼠,测定大鼠肝、脾、胸腺指数、肠道长度,睾丸、附睾指数及精子相对计数。结果 照后模型对照组较正常对照组体重、脾脏、胸腺指数及肠道长度、睾丸、附睾指数及精子相对计数均明显下降,刺五加多糖各给药组各项指数相对模型对照组均升高;照前刺五加多糖各给药组WBC明显或非常明显高于正常对照组,且随给药剂量的增大,WBC值增高,提示刺五加多糖在动物正常情况下可以升高白细胞,照后模型对照组WBC明显低于正常对照组,而刺五加多糖给药组相对于模型对照组升高,刺五加多糖可以促进辐射大鼠外周血WBC的升高;照后模型对照组肝指数较正常对照组升高,辐射造成大鼠肝损伤,引起肝肿大,此时刺五加多糖中、低剂量组较模型对照组降低,提示药物对辐射大鼠肝脏有保护作用。结论 刺五加多糖对辐射大鼠的胃肠道及生殖系统有保护作用。     

大豆异黄酮对电离辐射小鼠抗氧化功能的影响

目的研究大豆异黄酮对电离辐射后抗氧化能力的影响 ,为研制防治辐射的功能食品提供理论依据。方法 30只雄性昆明小鼠 ,随机分为正常对照组、辐射对照组和补充 0 .5 %的大豆异黄酮组 ,喂养 2周后 ,后 2组以 4 .0Gyγ射线照射 ;于照射后 1周和 2周取血 ,2周杀死小鼠取脾脏、胸腺和肝脏 ,观察血和组织的抗氧化指标变化。结果辐射使小鼠血清和胸腺、肝脏的MDA水平明显升高 ,SOD和GSH -Px活力明显下降 (P <0 .0 5 )。补充大豆异黄酮 2周后 ,使血清、肝脏和胸腺MDA水平较辐射对照组分别降低 2 0 .7%、2 3.5 %和 2 4 .9% ,使血清、肝脏和胸腺SOD活性较辐射对照组分别提高 18.4 %、13.3%和 8.2 % ,使血清、肝脏和胸腺GSH -Px活力较辐射对照组分别提高 12 .6 %、13.6 %和 2 0 .5 % ,变化均具有统计学意义。结论膳食中补充 0 .5 %大豆异黄酮可明显提高电离辐射机体的抗氧化能力 ,进而提高机体抗辐射能力。     

大豆异黄酮对~(60)Co γ射线所致氧化损伤的保护作用研究

目的:研究大豆异黄酮(SI)对60Coγ射线照射小鼠氧化损伤及组织细胞DNA损伤的保护作用。方法:将小鼠随机分为SI高、中、低剂量组(333、167、83mg/kgbw)、模型组和对照组。辐射前,各剂量组每日给予不同剂量SI;模型组和对照组给予等体积0.5%羧甲基纤维素钠(CMC-Na)溶液。30d后,除对照组外,各组给予15Gy60Coγ射线全身一次性照射。照后D4处死动物,测定肝匀浆MDA含量,SOD和GSH-Px活性。同时各组分别取3只小鼠的肝、脾、肾、血进行彗星实验以观察细胞DNA损伤情况。结果:与对照组比,模型组MDA含量显著增高(P<0.01),SOD和GSH-Px活性显著降低(P<0.05);与模型组比,SI剂量组MDA含量显著降低(P<0.05)、SOD和GSH-Px活性显著增高(P<0.05)。模型组4种组织细胞之间DNA损伤程度不同,均显著高于各自的对照组(P<0.05),且SI剂量组的DNA损伤程度显著低于模型组(P<0.05),并随着SI剂量的增加,DNA损伤程度相应减轻。结论:SI对辐射所造成的氧化及DNA损伤具有保护作用。     

大豆异黄酮抗辐射效果的观察

目的观察大豆异黄酮对60Co-γ射线照射后小鼠生长和外周血象的影响.方法按体重将80只雌性昆明小鼠随机均分为5组,即正常对照、阳性对照及低、中、高剂量大豆异黄酮实验组.辐照前正常对照、阳性对照组及实验组每天分别以溶剂0.5%羧甲基纤维素钠(CMC-Na)和不同剂量大豆异黄酮连续灌胃14 d,灌胃至第7天,除正常对照组外,其余各组小鼠均接受4.56Gy60Co-γ全身性照射1次,照射后继续灌胃2 d及7天后将动物处死,迅速取血,EDTA抗凝进行检测.结果实验结束时,中、高剂量大豆异黄酮组小鼠体重增重与正常对照无显著差别,但与单纯辐照组相比差别显著(P＜0.05);辐照后第7天,大豆异黄酮各实验组白细胞上升均高于单纯辐照组,中剂量实验组显著高于单纯辐照组(P＜0.05);仅中剂量大豆异黄酮组网织红细胞照后第7天明显上升,与第2天有明显差异(P＜0.01);血红蛋白、血小板及红细胞虽各组间无明显差异,但低、中剂量大豆异黄酮组血红蛋白与正常对照组相近;中剂量组血小板下降幅度在各受辐照组中最小;单纯辐照组红细胞低于各大豆异黄酮干预组,中剂量干预组最接近正常对照组.结论大豆异黄酮对受辐照小鼠的血液系统有一定的保护效果,以中剂量组效果较好,且可预防辐射对生长发育的不良影响.     

大豆异黄酮对糖耐量异常大鼠肾损伤保护作用

目的 研究大豆异黄酮对D-半乳糖诱导的糖耐量异常大鼠早期肾损伤的保护作用.方法 采用剂量递增法持续腹腔注射D-半乳糖,诱导糖耐量异常大鼠模型;以大豆异黄酮作为拮抗糖耐量异常早期肾损伤的受试物,二甲双胍为阳性对照,观察正常大鼠、糖耐量异常模型大鼠及各受试物组大鼠的血糖,血浆尿素氮和尿微量白蛋白含量、肾脏超氧化物歧化酶(SOD)和谷胱甘肽过氧化酶(GSH-Px)活性、丙二醛(MDA)、晚期糖基化终产物(AGEs)含量变化以及肾细胞DNA氧化损伤程度.结果 模型组大鼠餐后2 h血糖,尿微量白蛋白、肾MDA和AGEs含量较正常对照组均明显增高(P＜0.05),SOD活性明显降低(P＜0.05),肾细胞DNA拖尾率明显升高.大豆异黄酮干预6周后,大鼠餐后2h血糖、尿微量白蛋白、肾MDA和AGEs含量较模型组明显降低(P＜0.05),肾脏SOD活性明显增高(P＜0.05),肾细胞DNA拖尾率明显降低.与二甲双胍组比较,大豆异黄酮高低剂量组AGEs含量显著降低(P＜0.05),其他指标间比较,差异均无统计学意义.结论 D-半乳糖诱导的糖耐量异常大鼠存在早期肾脏损伤;大豆异黄酮对糖耐量异常大鼠早期肾损伤有保护作用,其机制与其改善糖耐量,提高机体抗氧化能力和抑制非酶糖基化反应有关;大豆异黄酮抑制非酶糖基化作用明显强于二甲双胍.     

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.     

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.     

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.     

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.     

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.