麦胚黄酮类提取物对DMBA诱导的大鼠乳腺肿瘤的抑制作用

目的：本文旨在研究麦胚黄酮类提取物对 7，12－二甲基苯蒽（DMBA）诱发的大鼠乳腺肿瘤的影响作用。方法：出生50天的健康雌性SD大鼠82只，鉴于室温21度左右，相对湿度30％－70％，自然光照，基础饲料喂养一周后，按体重随机分为四组：阴性对照组、阳性对照组、低剂量组、高剂量组。除阴性对照组外其余每只大鼠经两次灌胃给致癌剂DMBA，每只15mg溶于1．5ml的植物油中，给予致癌剂的同时给低剂量组和高剂量组大鼠含麦胚黄酮类提取物 的饲料，对照组大鼠喂基础饲料，持续喂养24周。结果：阳性对照组、低剂量组、高剂量组大鼠乳腺肿瘤的发生率差异有显著性。结论：麦胚黄酮类提取物对DMBA诱导的大鼠乳腺肿瘤可能具有抑制作用。     

麦胚黄酮类提取物对荷瘤大鼠的抗氧化作用

为研究由麦胚提取的黄酮类化合物对 7,12 二甲基苯蒽 (DMBA)诱发大鼠乳腺肿瘤的抑制作用 ,将出生 5 0天的雌性SD大鼠随机分为阴性对照组、阳性对照组、低剂量实验组和高剂量实验组。阳性及阴性对照组大鼠喂基础饲料 ,除阴性对照组外的 3组大鼠经灌胃给致癌剂DMBA(每只 15mg溶于 1 5ml的植物油中 ) ,低 高剂量实验组大鼠同时给含麦胚黄酮类提取物的饲料 (分别为 2和 10g kg) ,持续喂养 2 4周。结果表明 ,高剂量组大鼠乳腺肿瘤的发生率较阳性对照组显著降低 ,实验组大鼠血液及肝脏中谷胱甘肽过氧化物酶活性和超氧化物歧化酶活性较阳性对照组大鼠有明显增加 ,丙二醛含量下降。提示麦胚提取的黄酮类化合物对抗过氧化物酶的诱导作用可能是其对乳腺癌具有化学预防作用的机制之一。     

大鼠慢性乙醇中毒血清中抗氧化指标的研究

目的：为研究大鼠慢性乙醇中毒血清抗氧化指标的改变和机体损伤。方法：采用复制大鼠慢性乙醇中毒模型，观测血清肝功能指标和抗氧化指标方法。结果：随着乙醇灌胃时间的增加，转氨酶出现上升灌胃4周后，SDO活力下降，GSH和GSH－Px增加（P＜0．01），灌胃8周后，SOD活性GSH－Px含量上升，GSH和GST下降（P＜0．01）；灌胃12周后，GSH、GSH－Px和GST减少，MDA较前明显增加，结论大鼠慢性乙醇中毒模型存在肝损害，可能通过自由基损伤。     

DEHP对大鼠脂质过氧化反应的影响

目的：探讨DEHP对大鼠脂质过氧化反应的影响。方法：通过对不同剂量DEHP染毒大鼠的血液,肝组织匀浆,线粒体匀浆中GSH－Px,GST,SOD,MDA指标的测定,结果：随着DEHP染毒剂量的增加,大鼠血中,组织中的GSH－Px,GST,SOD活性降低,MAD含量增加,尤其是大剂量组,差异均有显著性（P＜0．05,P＜0．01）,结论：DEHP可明显增加大鼠体内的脂质过氧化反应。     

氟对大鼠脾脏抗氧化酶活性的影响

目的：探讨氟对大鼠脾脏的影响。方法：选择健康雄性Wistar大鼠24只。随机分为实验组和对照组,每组12只。2个月后处死。测试骨氟、牙氟含量,脾脏组织液SOD、GSH－Px活性和MDA含量,脾脏脏器系数。结果：实验组骨氟、牙氟及MDA含量明显高于对照组（P＜0．01）,实验组SOD、GSH－Px活性和脾脏脏器系数显著低于对照组（P＜0．01）。结论：氟对大鼠脾脏有毒性作用。     

泛酸钙对全饥饿大鼠脑组织脂质过氧化的影响

目的：探讨泛酸钙对全饥饿大鼠脑脂质过氧化产物（MDA），还原型谷胱甘肽（GSH），谷胱甘肽过氧化物酶（GSH－Px)，超氧化歧化酶（SOD）的影响及可能的脑保护机制，方法：以饥饿SD大鼠为模型，灌胃补充泛酸钙，观察大鼠饥饿后不同时期脑MDA，GSH，GSH－Px及SOD的变化。结果：饥饿后大鼠脑MDA含量明显升高，泛酸钙补充后大鼠脑MDA量在禁食4与7天较饥饿前无明显升,高，与全饥饿对照组比较差异显，泛酸钙对饥饿大鼠脑SOD，GSH－Px活力无影响，但显提高GSH水平。结论：泛酸钙能抑制饥饿大鼠脑的脂质过氧化损伤，其部分作用可能是通过提高GSH水平来实现的。     

南瓜提取物对慢性苯染毒小鼠抗氧化酶的影响

目的：探讨南瓜提取物对慢性苯中毒所造成的机体抗氧化系统损伤的拮抗作用。方法：将小白鼠分为正常组、苯染毒组、苯＋南瓜提取物组，静式吸入染毒，60d后，取其肝、脾、脑检测组织匀浆中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）的活性及丙二醛（MDA）的含量。结果：苯染毒组小鼠机体内SOD、GSH—Px活性均降低，MDA含量升高，南瓜提取物组小鼠机体内SOD、GSH—Px活性均升高，MDA含量降低，结论：慢性苯染毒能够对机体的抗氧化酶系统产生损伤，导致机体组织内SOD、GSH—Px活性降低，MDA含量升高。而南瓜提取物能够减轻机体的氧化损伤，增强抗氧化系统的功能。     

呋喃丹对雄性大鼠急性生殖损伤的研究

目的：探讨农药呋喃丹对雄性大鼠生殖系统急性损害作用。方法：以0．3，1．5，3．0mg/kg剂量经口染毒7d，检测大鼠血清及睾丸组织匀浆中脂质过氧化指标超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px)、丙二醛（MDA）、活性氧，睾丸组织标志酶β－葡萄糖醛酸苷酶（β-G）、葡萄糖－6磷酸脱氢酶（G－6－PD）、乳酸脱氢酶同工酶X（LDHx）及一氧化氮（NO）、一氧化氮合酶（NOS）的含量或活力。结果：染毒7d大鼠血清GSH－Px、β-G、NOS活力下降，睾丸组织匀浆中MDA、活氧含量及β－G、NOS活力升高（P＜0．05），GSH－Px、SOD活力下降（P＜0．05）。结论：短时间接触呋喃丹可对大鼠睾丸组织产生脂质过氧化作用，对睾丸组织有损害。     

大气混合污染物对大鼠呼吸系统氧化损伤作用

目的 探讨大气混合污染物所致大鼠呼吸系统的氧化损伤。方法 48只Wistar大鼠随机分为3个实验组（1，7，30d组）和1个对照组。气管注入可吸入颗粒物（PM10）后，静态吸入sch、N02、CO的空气混合气，分别吸入1，7及30d。检测血清和支气管肺泡灌洗液（BALF）中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）的活力及谷胱甘肽（GSH）、丙二醛（MDA）的含量。结果 1d组对与对照组比较，血清SOD活力显著降低（P〈0．05），GSH和MDA含量显著增高（P〈0．01）；30d组与对照组比较，BALF中SOD、GSH—Px活力及GSH含量显著降低（P〈0．05或P〈0．01）。结论 大气混合污染物对大鼠呼吸系统产生氧化损伤作用。     

丙氨酰-谷氨酰胺二肽对烧伤大鼠血清谷胱甘肽浓度及抗氧化作用的影响

目的：研究丙氨酰－谷氨酰胺二肽（Ala-Gln)对烧伤大鼠血清谷胱甘肽（GSH）浓度及抗氧化作用的影响。方法：SD雄性大鼠30只，行烧伤和中心静脉插管后，随机分为三组，每组10只，A组为对照组，B组为常规TPN组，C组为含Ala-Gln的肠外营养组（Ala-Gln-PN)。7天后测定血清内谷胱甘肽、超氧化物歧化酶（SOD）及血清黄嘌呤氧化酶（XOD）浓度。结果：Ala-Gln组血清中GSH和SOD浓度明显升高，XOD明显减少，与对照组和TPN组比均有显著差异（P＜0．05）。结论：Ala-Gln能降低死亡率，明显升高血液中GSH浓度并能增强抗氧化作用。     

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.