右旋甲硫氨酸与紫杉醇联合应用治疗胃癌

目的:研究右旋甲硫氨酸(D-Met)与紫杉醇联用治疗胃癌的效果. 方法:选用D-Met培养液培养7株胃癌细胞5 d,用流式细胞仪检测细胞周期;然后再用D-Met培养液培养7株胃癌细胞达96 h后,添加紫杉醇继续培养24 h,用氮四唑(MTT)法检测其吸光度(A490).另设L-Met培养液组为阴性对照组,Met-培养液组为阳性对照组,不添加紫杉醇组为平行对照组. 结果:与L-Met组相比,D-Met培养液组中除NCI-N87细胞的S期比例显著增高(P＜0.01)外,其余6株胃癌细胞的G2/M期比例均显著增高(P＜0.05或P＜0.01);Met-培养液组的7株胃癌细胞的G2/M期比例均显著增高(P＜0.05或P＜0.01).添加紫杉醇的D-Met和Met-培养液中,各株胃癌细胞抑制率均显著高于同种培养液不加药组(P＜0.05)和添加紫杉醇的L-Met培养液组(P＜0.01);D-Met培养液加紫杉醇组对MKN45细胞的抑制率显著高于Met-培养液加紫杉醇组(P＜0.05). 结论:D-Met环境作用于胃癌细胞5 d,可将大多数胃癌细胞阻滞于G2/M期,其效果与Met-环境相似;D-Met与紫杉醇联用可起到协同作用,对于MKN45细胞D-Met与紫杉醇联用的效果大于Met-与紫杉醇联用.     

胃癌细胞在右旋甲硫氨酸中氨基酸代谢的研究

目的:研究胃癌细胞在右旋甲硫氨酸(D-Met)环境中氨基酸的代谢. 方法: 将6株胃癌细胞分别接种于D-Met、Met-和左旋甲硫氨酸(L-Met)培养液中,培养5 d后,用高效液相色谱法检测培养液中20种氨基酸的浓度. 结果: Met-组6株胃癌细胞的Met含量显著低于L-Met组和D-Met组(P<0.05);D-Met组和Met-组SUN-1、KATO-Ⅲ和MKN45细胞的同型半胱氨酸(Hcy)含量显著高于L-Met组(P<0.05);除SUN-1和MKN45外,D-Met组和Met-组各株细胞Gln含量显著高于L-Met组(P<0.05);D-Met组和Met-组KATO-Ⅲ、NCI-N87和AGS的丙氨酸(Ala)含量显著低于L-Met组(P<0.05);D-Met组和Met-组SUN-16、KATO-Ⅲ和AGS的半胱氨酸(Cys)含量显著低于L-Met组(P<0.05). 结论:D-Met环境可影响胃癌细胞代谢,其效果与Met-环境相似.     

五种甲硫氨酸相关培养液对胃癌细胞增殖活性的影响

目的:比较五种甲硫氨酸(Met)相关培养液对胃癌细胞增殖活性的影响.方法:以左旋Met(L-Met)培养液组为对照组,用去除Met和同型半胱氨酸(Hcy)(Met-Hcy-)、去除Met并添加Hcy(Met-Hcy )、以右旋Met(D-Met)替代L-Met、左旋和右旋Met(DL-Met)培养液培养胃癌SUN-16细胞,采用MTT法检测其24、48、72、96和120 h的吸光度(A490)值.结果:Met-Hcy-、Met-Hcy 、D-Met和DL-Met组中胃癌细胞的A490均显著低于对照组(P＜0.01),且前三组间的A490接近,DL-Met组的A490界于其余三组和对照组之间;各实验组与对照组间的差异随时间延长而加大.结论:Met-Hcy-、Met-Hcy 和D-Met培养环境抑制胃癌细胞增殖的作用相似,DL-Met环境可造成Met半饥饿状态而抑制胃癌细胞,但效果较差;D-Met环境是目前造成肿瘤细胞Met饥饿的理想方法.     

阻断泛素-蛋白酶体通路对胃癌细胞株SGC-7901 DNA合成及细胞周期的影响

目的 研究阻断泛素-蛋白酶体通路对胃癌细胞株SGC-7901 DNA合成及细胞周期的影响。方法 将泛素-蛋白酶体通路特异性阻断剂MG-132加入胃癌细胞株SCC-7901，^3H-TdR掺入试验测定对胃癌细胞DNA合成的影响。流式细胞仪(FCM)检测细胞周期。结果 MG-132作用于胃癌细胞株SGC-7901后，细胞DNA合成显著受抑制，G0／G1期细胞比例增加，S、G2／M期细胞比例减少。结论 MG-132能显著抑制胃癌细胞株SGC-7901的DNA合成，使细胞产生G1期阻滞，表明阻断泛素-蛋白酶体通路可能是治疗胃癌的新思路。     

不同构型甲硫氨酸与化疗药物对胃癌细胞增殖与凋亡效应的影响

目的通过体外实验了解甲硫氨酸(Met)及其联合化疗药物对胃癌细胞增殖与凋亡的效应。方法选用人胃癌细胞株SGC-7901为培养对象，以RPMI-1640培养基为基础分为三组：L—Met组，含0．15％L—Met；D-Met组。含0．15％D-Met；Met—Hcy 组，不含Met而替以0．27％同型半胱氨酸(Hcy)；三组培养基中分别加人不同浓度的5-氟脲嘧啶(5-FU)，5-FU与细胞接触的终浓度分别为0、1、10mg／L。分别培养24和48小时用MTT法和流式细胞仪检测细胞增殖和凋亡状况。结果(1)细胞增殖状况：D—Met组存活的胃癌细胞最少，L—Met组存活的胃癌细胞明显多于另两组；各组中存活的肿瘤细胞随5-FU浓度的增高而显著减少；培养48小时存活的细胞明显多于培养24小时。（2)细胞凋亡状况：D—Met组早期凋亡率、晚期凋亡率和总细胞凋亡率最高；各组细胞凋亡率随5-FU浓度的提高和培养时间的延长相应增高。结论D—Met和5-FU均可诱导胃癌细胞凋亡、抑制肿瘤细胞增殖，D—Met较Met—Hcy更具优势。     

生长激素联合氟尿嘧啶对生长激素受体不同表达胃癌细胞株的影响

目的: 研究重组人生长激素(rhGH)联合氟尿嘧啶(5-FU)在体外对生长激素受体(GHR) 不同表达状态人胃癌细胞株的影响. 方法: 选用GHR高表达的SGC-7901和GHR低表达的MKN-45胃癌细胞株.每种细胞株分为空白对照组、5-FU处理组、rhGH处理组和联合处理组.采用四基偶氮唑蓝(MTT)比色法和流式细胞术,分析不同浓度rhGH及其与5-FU合用,对人胃癌细胞株的生长抑制、凋亡、细胞周期和增殖指数(PI)等的影响. 结果: SGC-7901细胞株:与空白对照组比,各浓度rhGH组的生长率、G2/M期比例和PI显著升高,细胞凋亡率显著降低(P<0.05);与5-FU处理组比, 各浓度rhGH+5-FU组的G2/M期比例和PI显著升高,抑制率和细胞凋亡率显著降低(P<0.05).MKN-45细胞株:不同浓度rhGH对该细胞株的分裂增殖无明显影响(P>0.05).联合处理组与5-FU处理组间的细胞抑制率、凋亡率和PI也无显著性差异(P>0.05). 结论: rhGH在体外能促进高表达GHR的胃癌细胞增殖,减弱5-FU的抗癌作用,但对低表达GHR的胃癌细胞无明显影响,也不能明显干扰5-FU的抗癌作用.     

刚地弓形虫培养上清抑制胃癌细胞株SGC-7901增殖

目的 观察弓形虫培养上清对胃癌细胞株SGC-7901增殖的影响. 方法 取对数期生长的SGC-7901细胞接种于细胞培养板中,实验组加入相同体积不同数量（1×106、1×107、1×108/ml）弓形虫速殖子培养上清,对照组加入等体积的RPMI-1640培养液,通过显微镜观察培养24 h后细胞形态;计数细胞,绘制生长曲线;MTT法测定培养24、48、72 h后细胞增殖情况;Western blotting检测弓形虫培养上清作用24 h凋亡相关蛋白Bax和Bcl-2的表达. 结果 经弓形虫速殖子培养上清作用24 h后,胞质中颗粒明显增多,细胞密度有所降低;细胞生长受到抑制,且呈浓度依赖性;经1×106、1×107、1×108/ml弓形虫培养上清作用24、48、72 h均能显著抑制SGC-7901细胞的增殖;作用24 h后,抗凋亡蛋白Bcl-2的表达降低,促凋亡蛋白Bax表达增强. 结论 弓形虫培养上清能抑制胃癌细胞株SGC-7901的增殖.     

DON对体外培养胃癌细胞SGC-7901、BGC-823凋亡的影响

目的探讨脱氧雪腐镰刀菌烯醇(DON)对胃癌细胞SGC-7901、BGC-823凋亡的影响及其可能机制。方法体外培养的胃癌细胞株SGC-7901、BGC-823细胞经100、500、1000μg/LDON处理72h,以流式细胞术(FCM)检测细胞凋亡情况及其量效关系,流式细胞术、免疫细胞化学和Westernblot检测凋亡相关蛋白Bax、Bcl-2蛋白的表达情况。结果FCM定量检测结果表明,DON各处理组细胞凋亡率均高于对照组,且均随DON浓度升高凋亡率相应增加,具有明显量效关系(SGC-7901:r=0.660,P<0.05,n=4;BGC-823:r=0.750,P<0.01,n=4)。FCM、免疫细胞化学和Westernblot结果显示,DON处理后SGC-7901、BGC-823细胞Bax蛋白表达上调,Bcl-2蛋白表达下降。结论DON可剂量依赖地诱导体外培养的胃癌细胞SGC-7901、BGC-823凋亡,其机制可能与上调Bax蛋白的表达,下调Bcl-2蛋白的表达有关。     

姜黄素诱导胃癌细胞SGC-7901凋亡机制

目的 探讨姜黄素诱导人胃癌细胞SGC-7901凋亡的可能机制。方法 体外培养人胃癌细胞SGC-7901,细胞计数盒8（CCK8）法观察不同浓度姜黄素对胃癌细胞SGC-7901的增殖抑制作用;流式细胞仪检测SGC-7901细胞周期;Western blot检测SGC-7901细胞核转录因子κB（NF-κB）、livin、caspase-3蛋白表达情况。结果 与对照组比较,各剂量姜黄素组SGC-7901细胞增殖活力均受到抑制,呈剂量效应关系（r=0.901,P<0.01）与时间效应关系（r=0.389,P<0.01）;与对照组（2.8%）比较,20、40、60 μmol/L姜黄素组SGC-7901细胞凋亡率[分别为7.7%、13.4%、20.7%]明显升高（P<0.05）;与对照组（58.59%）比较,20、40、60 μmol/L姜黄素组SGC-7901细胞周期G1期比例[分别为60.24%、65.13%、68.35%]明显升高（P<0.05）;与对照组比较,姜黄素组SGC-7901细胞内NF-κB、livin蛋白表达降低,caspase-3蛋白表达升高（P<0.05）,呈剂量效应关系。结论 姜黄素可抑制人胃癌细胞SGC-7901的活性,其机制可能与姜黄素下调NF-κB信号通路,促进livin解除对caspase的抑制效应而激活caspase-3,发挥其诱导细胞凋亡作用有关。     

组织蛋白酶B在紫杉醇诱导胃癌SGC-7901细胞凋亡中的作用

[目的]研究组织蛋白酶B(Cathepsin B)在紫杉醇诱导胃癌SGC-7901细胞凋亡中的作用.[方法]用0.1～0.5 μmol/L紫杉醇作用于SGC-7901细胞.另一组再加入Cathepsin B特异性抑制剂CA-074(Me)对照;再用0.3μmol/L紫杉醇对SGC-7901细胞分别作用0 h、6 h、12 h、24 h、36 h、48 h,另一组再加入CA-074(Me),通过形态学观察及流式细胞术检测细胞凋亡率的变化.[结果]①随着紫杉醇浓度的增高和作用时间的延长,SGC-7901细胞的凋亡率明显增高;②加入CA-074(Me)后,细胞凋亡率明显下降.[结论]Cathepsin B在紫杉醇诱导的细胞凋亡中有着相对重要的作用.     

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.     

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.