枸杞多糖对人白血病细胞株凋亡的影响

目的 :　探讨枸杞多糖 ( LBP- X)对人白血病 HL- 60细胞凋亡的影响。方法 :　 LBP-X与 HL- 60细胞共培养 ,MTT法检测 LBP- X对 HL- 60细胞增殖的抑制作用 ;以 DPH为荧光探针检测细胞膜流动性的变化 ;用 Hoechst332 5 8染色在荧光显微镜下观察细胞核形态学变化 ;琼脂糖凝胶电泳法和流式细胞仪检测法定性定量检测细胞凋亡。结果 :　LBP- X2 0～ 1 0 0 0 mg/L呈剂量依赖性抑制 HL- 60细胞增殖 ,且可降低 HL- 60细胞膜的流动性 ;LBP- X作用 48h后 ,荧光显微镜下细胞核固缩、凝聚和断裂 ,出现浓染致密的颗粒块状荧光 ;DNA琼脂糖凝胶电泳可见明显的“DNA条带”;流式细胞仪分析图上出现凋亡峰。结论 :　 LBP- X对诱导人白血病 HL- 60细胞凋亡有一定作用。     

褐藻糖胶对人白血病细胞株K562凋亡的影响

目的探讨海带提取物褐藻糖胶对体外培养的人髓系白血病细胞株K562生长的影响．从细胞凋亡角度研究其抗肿瘤机制。方法采用肿瘤细胞体外培养、单细胞凝胶电泳、凋亡细胞DNA琼脂糖凝胶电泳和流式细胞技术．观察不同剂量褐藻糖胶对体外培养的白血病细胞株K562细胞的影响。结果噻唑蓝（MTT）实验结果显示，褐藻糖胶对K562细胞均具有较强的杀伤作用，尤其以1g／L剂量组为明显。单细胞凝胶电泳实验结果表明，褐藻糖胶对肿瘤细胞DNA有明显损伤作用．尤其以1g／L剂量组的影响最为明显。DNA琼脂糖凝胶电泳和流式细胞仪检测结果显示．经褐藻糖胶处理后，肿瘤细胞洲亡率上升，其中1g／L剂量组较为明显。提示褐藻糖胶可能通过诱导肿瘤细胞凋亡而发挥抗肿瘤作用。结论褐藻糖胶可通过诱导肿瘤细胞凋亡，从而达到抗肿瘤的目的。     

9-羧酸蒽对人白血病细胞株HL-60增殖的影响

9-羧酸蒽anthracene-9-carboxylic acid，(9-AC)属于芳香族单羧酸类物质。以往9-AC研究往往局限在电生理和免疫组化方面。本实验采用体外细胞培养法，结合DNA凝胶电泳法观察9-AC对人髓性白血病细胞株HL-60细胞增殖作用的影响。     

枸杞多糖抑制人白血病细胞生长的研究

用体外培养法研究枸杞多糖 (LBP X)对人白血病HL 6 0细胞生长的抑制作用并探讨其作用机制。结果表明 :LBP X(2 0、10 0、5 0 0和 10 0 0mg L)与HL 6 0细胞共培养 48h后 ,LBP X抑制HL 6 0细胞增殖呈剂量依赖性关系 ,且可降低HL 6 0细胞的膜流动性 ,HL 6 0细胞的DNA琼脂糖凝胶电泳可见明显的“DNAladder” ,TUNEL方法检测呈阳性。这提示诱导HL 6 0细胞凋亡是LBP X抗肿瘤的重要机制     

马鞭草诱导人绒毛膜癌JAR细胞凋亡作用观察

[目的]探讨马鞭草C部位对人绒癌JAR细胞抑制作用机理. [方法]通过相差显微镜观察活细胞贴壁程度、细胞形态改变;荧光显微镜观察细胞形态学变化;透射电镜观察细胞超微结构变化;琼脂糖凝胶电泳观察用药后细胞DNA断裂情况;流式细胞仪检测细胞凋亡情况. [结果]马鞭草C部位可引起细胞数目减少并萎缩;荧光显微镜下观察到典型凋亡细胞的形态学特征;电镜下见到明显的凋亡小体;琼脂糖凝胶电泳出现"阶梯状条带";流式细胞仪检测发现用药后出现明显的凋亡峰. [结论]马鞭草C部位对人绒癌JAR细胞抑制作用机理是诱导其凋亡.     

硫芥诱导淋巴细胞凋亡与细胞周期的关系

目的 探讨硫芥诱导体外培养大鼠脾脏淋巴细胞凋亡及与细胞周期的关系。方法 体外分离培养大鼠脾脏淋巴细胞。以流式细胞仪、琼脂糖凝胶电泳分别检测细胞凋亡，细胞周期，和DNA片段改变。结果 硫芥可诱导淋巴细胞凋亡(P＜0．05)，对细胞周期有明显影响，主要是S期和G2／M期明显降低，引起淋巴细胞生长阻滞在Gl期；流式细胞仪PI染色出现亚二倍体峰(凋亡峰)，其Gl期DNA含量明显增加，S期含量减少；琼脂糖凝胶电泳呈典型的“梯状”带(DNA ladder)。结论 硫芥可抑制体外培养的淋巴细胞由Gl期进入S期，抑制体外培养的淋巴细胞增殖，通过诱导淋巴细胞凋亡实现作用机制。     

浓缩铀诱发细胞凋亡的形态及基因调控

目的　研究浓缩铀诱发人白血病HL 6 0细胞凋亡的电镜形态特征 ,以及对相关基因bcl 2和bax的调控作用。方法　探讨受浓缩铀内照射不同时间 ,诱发HL 6 0细胞凋亡的电镜形态 ;运用免疫组织化学技术探讨浓缩铀对HL 6 0细胞bcl 2和bax蛋白的表达 ,运用RNA分子杂交技术探讨浓缩铀对HL 6 0细胞bcl 2mRNA的转录水平表达的影响。结果　人白血病HL 6 0细胞在浓缩铀辐照作用下 ,可呈现核断裂和核染质边聚。对照的HL 6 0细胞中bcl 2蛋白呈高度表达 ,为 (88± 7) % ,而受浓缩铀辐照下 ,可下调至(6 1± 5 ) %。bax在对照细胞中表达很低 ,在浓缩铀作用下 ,未见明显改变。经浓缩铀辐照后 ,可使HL 6 0细胞中的bcl 2mRNA表达呈明显下调。结论　浓缩铀内照射可诱发人白血病HL 6 0细胞凋亡发生 ,且其诱发HL 6 0细胞的凋亡作用与其下调凋亡相关基因bcl 2的表达相关联     

大豆苷原对体外培养人胃癌细胞增殖和细胞周期的影响

目的:了解二羟异黄酮对胃癌细胞有无促增殖与诱导凋亡作用。方法:以不同浓度的二羟异黄酮处理人胃癌细胞系MGC-803细胞。然后分别用MTT法测定细胞增殖情况、流式细胞仪和琼脂糖凝胶电泳测定细胞周期和细胞凋亡等。结果:MTT 结果显示:二羟异黄酮对胃癌细胞具有促进和抑制增殖的双相作用-在低浓度(0.1-1 μmol/L)时促进细胞生长,在较高浓度(10-100 μmol/L)时对细胞生长则有抑制作用。流式细胞术结果显示:癌细胞群阻滞在G1期,没有明显凋亡峰的出现;凝胶电泳也末检测到明显的DNA阶梯状条带。结论:二羟异黄酮对体外培养的胃癌细胞的生长有双相作用,较高浓度可抑制胃癌细胞的生长并使细胞阻滞在G1期,而无诱导细胞凋亡的作用。     

巨噬细胞RAW264.7诱导共培养HL60细胞凋亡的实验研究

目的研究巨噬细胞RAW264.7诱导共培养HL60细胞凋亡的作用机理。方法用佛波脂(phorbol-1,2-myristate-1,3-acetate,PMA)、脂多糖(LPS)和γ-干扰素(IFN-γ)诱导培养的巨噬细胞RAW264.7,并与HL60细胞共培养12 h。采用MTT法、流式细胞计量术、DNA琼脂糖凝胶电泳及蛋白印迹技术,观察巨噬细胞与肿瘤细胞共培养体系中,RAW264.7细胞对HL60细胞的作用。结果与巨噬细胞RAW264.7共培养的HL60细胞存活率减少,表现出凋亡细胞特有的标志,即"G1亚峰"和DNA梯状电泳条带,在这一过程中还伴随有促凋亡基因P53和P21表达。结论诱导刺激巨噬细胞RAW264.7导致了共培养HL60细胞的凋亡。     

表没食子儿茶素没食子酸酯体外诱导HL-60细胞凋亡

目的 为研发天然抗白血病新药，研究茶多酚主要活性成分表没食子儿茶素没食子酸酯(EGCG)体外诱导细胞凋亡的作用。方法 采用体视显微镜、DNA凝胶电泳及透射电镜技术，观察EGCG对体外诱导人急性早幼粒白血病细胞(HL-60)凋亡的影响及其诱导凋亡的最佳作用时间和最佳作用浓度。结果 发现EGCG实验组中，HL—60细胞生长被显著抑制，DNA凝胶电泳中可见DNA条带，其细胞超微结构明显改变。当250ug／m1 EGCG作用细胞6h时，其诱导细胞凋亡的作用最明显。结论 EGCG可体外诱导HL-60细胞凋亡．可能是抗白血病的侯选药。     

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.