牛磺酸对糖尿病大鼠视网膜谷氨酸及γ-氨基丁酸的影响

目的探讨牛磺酸对糖尿病大鼠视网膜谷氨酸（Glu）及γ-氨基丁酸（GABA）的影响,旨在评价牛磺酸对糖尿病视网膜病变的保护作用。方法将SD大鼠随机分成3组,即正常对照组、糖尿病组、牛磺酸干预糖尿病组。一次性腹腔内注射链脲佐菌素（STZ）,建立糖尿病大鼠模型,在普通饲料中加入1．2％牛磺酸营养干预3个月后,用免疫组化及氨基酸分析法观察视网膜中Glu及GABA的浓度与表达。结果与正常对照组比较,糖尿病大鼠视网膜中牛磺酸浓度下降了6．8％,G1u和GABA的浓度分别增加了19．9％、81．6％（P〈0．01）,且免疫反应性增强。膳食补充牛磺酸后,与糖尿病组比较,大鼠视网膜中牛磺酸浓度增加了9．5％,而Glu和GABA的浓度分别降低了9．9％、29．2％（P〈0．01）,同时Glu及GABA的强阳性染色明显减弱。结论糖尿病大鼠,视网膜中Glu和GABA浓度增加,牛磺酸浓度下降。体外补充牛磺酸可能通过降低Glu和GABA浓度保护Mtiller细胞,从而减轻视网膜损伤.     

不同病程糖尿病大鼠视网膜神经细胞凋亡及其GFAP和VEGF的动态表达

目的探讨糖尿病早期大鼠视网膜神经细胞凋亡情况与GFAP和VEGF的mRNA水平。方法将24只健康雄性8周龄SD大鼠随机平均分为正常对照组及糖尿病实验组,实验组大鼠给予一次性腹腔注射链脲佐菌素(STZ)60mg/kg以诱导糖尿病大鼠模型,按建模成功时间点再把对照组和实验组分别分为4、12周2组,每组各6只大鼠。监测糖尿病大鼠视网膜的TUNEL检测以及GFAP和VEGF的mRNA水平。结果糖尿病早期大鼠的视网膜GFAP和VEGF的mRNA表达增多,神经细胞凋亡数也明显增加,而且建模12周的大鼠随着病程增长增加比4周的大鼠情况更明显。结论视网膜神经细胞凋亡与GFAP和VEGF的mRNA表达增加可能是疾病进程的重要环节。     

牛磺酸对大鼠视网膜光化学损伤c-fos表达影响

目的观察饲料中添加牛磺酸对光化学损伤后大鼠光感受器细胞凋亡的影响，并进一步从氧化应激基因c-fos表达变化角度探讨其防护机制。方法70只SD大鼠随机分为对照组、牛磺酸组。分别喂饲标准饲料或添加4％牛磺酸饲料喂饲15d后接受（3000±200）lx持续0，1，3，6，9，12，24h光照，凋亡细胞原位末端标记法（TUNEL）检测光感受器细胞凋亡情况并计算凋亡指数（AI）；RT．PCR法及免疫印迹法检测视网膜内c-fos mRNA以及蛋白表达水平。结果感光细胞凋亡指数随光照时间延长逐渐增加，牛磺酸组AI显著低于对照组（P〈0．05）。其中光照12h牛磺酸组与对照组AI分别为（12．3±4．7）％和（32．4±6．2）％；视网膜c-fos mRNA光照1h后一过性表达增高，牛磺酸组较对照组低（P〈0．05）；光照后视网膜c-fos蛋白表达逐渐升高。于3h达峰值。牛磺酸组显著低于对照组（P〈0．05）。结论在视网膜光化学损伤条件下，牛磺酸可能通过抑制视网膜c-fos的转录及表达。阻断光感受器细胞凋亡转导从而保护视网膜。     

牛磺酸与大鼠视网膜代谢型谷氨酸受体基因表达

目的探讨膳食添加牛磺酸大鼠在光照和暗环境中视网膜代谢型谷氨酸受体6亚型(mGluR6)的mRNA表达的相互关系。方法36只断乳大鼠随机分为3组：对照组、牛磺酸低剂量组及牛磺酸高剂量组(分别在饲料中添加0．3％和0．6％的牛磺酸)．营养干预4周后，再随机分为光照组和暗环境组，继续喂养3d。用RT—PCR技术检测光照和暗环境下大鼠视网膜mGluR6的mRNA表达。结果暗环境下mGluR6的mRNA表达显著高于光照环境。在光照及暗环境中牛磺酸高、低剂量组mGluR6的mRNA表达均较对照组增加，以光照状态下的增加更为明显；光照时。高剂量组的mRNA表达明显高于低剂量组；暗环境下，高、低剂量组之间差异无统计学意义。结论在光照及暗环境中，牛磺酸可明显增加大鼠mGluR6的mRNA表达，有助于其参与调节视网膜的视杆信号传递。     

营养

n-6／n-3多不饱和脂肪酸对乳腺癌大鼠乳腺癌组织CYP17和CYP19表达的影响,不同脂肪酸构成比对大鼠血脂影响的研究，牛磺酸和锌对氟致神经系统损伤的拮抗作用,牛磺酸对模拟急性高原低氧大鼠小肠组织HIF-1α及HIF-1β表达的影响,牛磺酸对糖尿病大鼠视网膜Müller细胞凋亡的防护研究。     

依达拉奉对糖尿病早期大鼠视网膜的保护作用

目的探讨依达拉奉对糖尿病大鼠视网膜氧化应激的影响及意义。方法选择2014年6—9月30只雄性SD大鼠作为研究对象,适应环境后,将研究对象随机分为正常对照组、糖尿病组和依达拉奉干预组各10只。用细胞裂解液提取各组大鼠视网膜的总蛋白,分别用超氧化物歧化酶(superoxide dismutase,SOD)活性试剂盒、谷胱甘肽(glutathione,GSH)活性试剂盒、丙二醛(malondialdehyde,MDA)含量试剂盒检测视网膜中SOD活性、GSH活性以及MDA含量。应用Western-blot技术检测标本中神经胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达差异,以β-actin蛋白的表达作为内参对照。计量资料采用单因素方差分析,P0.05为差异有统计学意义。结果正常对照组、糖尿病组、依达拉奉干预组的SOD含量分别为(300.11±4.52)、(105.49±5.82)、(254.38±10.09)U/mg,GSH含量分别为(48.56±2.17)、(15.26±3.52)、(30.24±1.91)mg/g,MDA含量分别为(6.56±0.43)、(19.05±1.43)、(9.56±1.25)mmol/mg,3组SOD活性、GSH活性、MDA值比较,差异均有统计学意义(均P0.05)。Western条带结果显示正常对照组大鼠视网膜中GFAP表达量较低,而糖尿病模型大鼠的GFAP表达量较正常对照组明显升高,差异有统计学意义(P0.05),通过依达拉奉干预的糖尿病大鼠视网膜中GFAP表达量较糖尿病模型组显著降低,差异有统计学意义(P0.05)。结论依达拉奉可以抑制SOD活性、GSH活性的下降,减少MDA的生成,从而起到减轻氧化应激损伤、保护视网膜的作用,使得糖尿病大鼠视网膜中的GFAP表达量下调。依达拉奉的抗氧化保护作用提示依达拉奉可以作为早期糖尿病性视网膜病变(diabetic retinopathy,DR)干预的一个药物选择,但是其具体有效性还有待进一步研究。     

牛磺酸对糖尿病大鼠视网膜超微结构的影响

目的 观察糖尿病大鼠视网膜早期病变，探讨牛磺酸对糖尿病大鼠视网膜超微结构的影响。方法 选择健康成年SD大鼠50只，随机分成正常对照组(CON)、糖尿病1月组(DM1)、牛磺酸干预的糖尿病1月组(DM1 T)、糖尿病3月组(DM3)、牛磺酸干预的糖尿病3月组(DM3 T)。一次性腹腔内注射链尿佐菌素(STZ)，建立糖尿病大鼠模型。在普通饲料中加入1.2％牛磺酸进行营养干预，对各组视网膜进行光镜HE染色及透射电镜观察。结果 视网膜HE染色显示，糖尿病组视网膜较正常对照组明显变薄，神经节细胞数明显减少。牛磺酸干预后视网膜厚度较糖尿病组增加，神经节细胞数相对增多。观察超微结构发现糖尿病大鼠感光细胞外段膜盘排列紊乱，膜盘间隙增大，严重者出现膜盘断裂、溶解；视杆内段线粒体等细胞器肿胀变性，内网状层轴突肿胀、空泡样变。牛磺酸干预后感光细胞外段膜盘排列明显变整齐，线粒体肿胀较轻，内网状层轴突肿胀较糖尿病组轻。结论 牛磺酸可明显改善糖尿病视网膜的超微结构改变。     

牛磺酸对甲基汞染毒大鼠脑皮质Nrf2及HO-1、γ-GCS、Gpx-1表达的影响

目的研究甲基汞对大鼠脑皮质Nrf2及HO-1、γ-GCS、Gpx-1表达的影响及牛磺酸的干预作用。方法Wistar大鼠40只按体重随机分为4组,每组10只,分别为(1)对照组、(2)低剂量染甲基汞组、(3)高剂量染甲基汞组、(4)牛磺酸干预组,染毒前,1～3组大鼠只给予皮下注射生理盐水,第4组大鼠给予皮下注射1 mmol/kg牛磺酸;2 h后,第1组仍腹腔注射生理盐水,第2组大鼠腹腔注射4μmol/kg氯化甲基汞,3、4组大鼠则腹腔注射12μmol/kg氯化甲基汞溶液,每周染毒5次,隔日干预1次,连续4周。最后一次染毒24 h后,处死大鼠,分离大脑皮质,用冷原子吸收法检测汞含量,Real-time PCR和Western blotting法测定Nrf2、HO-1、γ-GCS、GPx-1的mRNA和蛋白的表达。结果与对照组比较,低、高甲基汞组中汞含量、HO-1和γ-GCS的mRNA和蛋白表达均显著升高;高甲基汞组Nrf2的mRNA和蛋白表达显著升高,Gpx-1的表达显著降低。与高甲基汞组比较,牛磺酸干预组大鼠大脑皮质中汞含量无明显差异;Nrf2、HO-1和γ-GCS的mRNA和蛋白表达明... 更多还原     

中磺酸抑制人单核细胞系THP-1细胞ACAT-1表达

目的观察牛磺酸对人单核细胞系THP-1细胞酰基辅酶A、胆固醇酰基转移酶-1（ACAT-1）表达的影响，以期为牛磺酸用于临床治疗动脉粥样硬化提供实验依据。方法在有或无干扰素-γ（IFN—γ）的条件下，用不同浓度的牛磺酸与THP-1持续孵育不同的时间，RT-PCR检测ACAT—1mRNA水平，Western Blot检测其蛋白表达。结果牛磺酸显著下调THP-1的ACAT-1mRNA和蛋白表达水平（P〈0．05～0．0l，n=3），并呈时间和剂量依赖性效应。IFN-γ促进ACAT-1mRNA和蛋白表达（P〈0．05），该作用被牛磺酸部分抑制（P〈0．01）。结论牛磺酸抑制ACAT-1的基础表达和由IFN-γ诱导的表达，这可能是其抗动脉粥样硬化的机制之一。     

牛磺酸对糖尿病大鼠视网膜NO及其合酶影响

目的 探讨牛磺酸对糖尿病大鼠视网膜一氧化氮(NO)及其合酶(NOS)表达的影响.方法 链脲佐菌素制备大鼠糖尿病模型,24只成年雄性SD大鼠随机分成对照组、糖尿病组、牛磺酸干预组,每组8只.牛磺酸干预组饲料添加1.2%牛磺酸.12周处死,取视网膜标本进行实验.硝酸还原酶测定NO含量,免疫组化法测定神经型一氧化氮合酶(nNOS)及诱导型一氧化氮合酶(iNOS)的表达.结果 糖尿病组与牛磺酸干预组NO含量表达为(2.138±0.260)和(1.053±0.159)μmol/L,差异有统计学意义(P＜0.01);糖尿病组与牛磺酸干预组iNOS吸光度分别为(0.390±0.022)和(1.101±0.006),后者明显低于前者(P＜0.01);牛磺酸干预组nNOS吸光度为(0.429±0.035),明显高于糖尿病组的(0.125±0.024)(P＜0.01).结论 牛磺酸通过减少视网膜NO含量和影响iNOS、nNOS表达,改变糖尿病性视网膜病变(DR).     

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.