染料木素对前列腺癌细胞恶性增殖的抑制作用

目的研究染料木素（Gen）对人前列腺癌细胞（PC-3）的影响。方法将PC-3细胞在DMEF-12培养液（含10％胎牛血清）中采用开放式单层贴壁培养，采用四甲基偶氮噻唑蓝（MTT）比色法、细胞核分裂指数、集落形成和^3H-TdR掺入试验方法进行检测。染料木素剂量设为10，20，40，80μmol／L。以二甲基亚砜（DMSO）为溶剂对照。结果不同剂量的染料木素对PC-3细胞的生长增殖有不同的抑制作用。在MTT试验中，不同浓度染料木素对PC-3细胞的7d抑制率分别为27．7％，58．8％，72．3％，84．4％。在核分裂指数试验中，随着染料木素剂量的增高，其核分裂指数明显降低；遮集落形成试验中，随着染料木素剂量的增加，集落形成抑制作用增加；在^3H-TdR掺入试验中，可见随着染料木素剂量的增高，^3H-TdR掺入到PC-3细胞中明显的减少，与阴性对照组比较差异有统计学意义。结论染料木素对PC-3细胞的生长增殖有明显抑制作用，可能是染料木素抑制前列腺癌的机制之一。     

鞘氨醇对人结肠癌细胞的抑制作用

目的 研究鞘氨醇对人结肠癌细胞的影响。方法 采用四甲基偶氮唑盐法(MTT)、细胞核分裂指数和3H-TdR掺入试验方法，所设剂量鞘氨醇分别为0，0．82，1．63，3．125，6．25，12．5μmol／L，以二甲基亚砜(DMSO)为溶剂对照。结果 鞘氨醇对HT-29细胞的生长有明显抑制作用。在MTT试验中，不同浓度鞘氨醇对HT-29细胞的7d抑制率分别为18％，45％，72％，87％和89％；在核分裂指数试验中，随着鞘氨醇剂量的增高，其核分裂指数明显降低；在^3H-TdR掺入试验中。可见随着鞘氨醇剂量的增高，^3H-TdR掺入到HT-29细胞中明显的减少，与阴性对照组相比有显著性差异。结论 鞘氨醇对HT-29细胞的生长增殖有明显抑制作用，这可能是鞘磷脂抑制结肠癌的机制之一。     

共轭亚油酸诱导人胃腺癌细胞(SGC-7901)凋亡的作用

目的 研究共轭亚油酸单体（c9,t11-CLA)诱导人体胃腺癌细胞（SGC－7901）凋亡作用。方法 采用细胞生长曲线,凋亡细胞的荧光显微镜、电镜观察,流式细胞光度术的检测以及P53蛋白表达方法。结果 显示出c9,t11-CLA对SGC－7901细胞有明显的抑制作用,并可诱导SGC－7901细胞产生凋亡,并随着c9,t11-CLA浓度的增加,细胞凋亡率逐渐增加;而P53蛋白表达则随着c9,t11-CLA浓度的增加呈逐渐降低的趋势。结论 这可能是c9,t11-CLA抑制肿瘤细胞机制之一。     

β-紫罗兰酮对人乳腺癌细胞抑制作用

目的　研究 β 紫罗兰酮对人乳腺癌细胞 (MCF 7)生长的影响。 方法　采用细胞核分裂 ,生长曲线 ,集落形成和DNA合成实验 ,观察了用不同浓度 β 紫罗兰酮 (2 5、5 0、10 0和2 0 0 μmol L)对MCF 7细胞生长作用。 结果　β 紫罗兰酮可明显抑制MCF 7细胞增殖、细胞核分裂、集落形成和细胞DNA的合成 ,随着剂量的增加 ,抑制作用增强 ,IC50 值为 10 4 μmol L。细胞核分裂的抑制率分别为 2 4h 12 88%～ 6 8 6 7%。 4 8h 2 0 79%～ 87 79% ;集落形成抑制率分别为 2 4h 14 11%～ 6 5 18% ,4 8h 6 5 8%～ 72 4 8% ;DNA合成实验抑制率为 2 4h 16 75 %～6 5 33% ,4 8h 35 10 %～ 81 89%。结论　β 紫罗兰酮可抑制MCF 7细胞的生长 ,其机制需要进一步探讨。     

环氧合酶-2在c9,t11-共轭亚油酸抑制肿瘤细胞转移中的作用

目的 研究c9,t11-共轭亚油酸（c9,t11-CLA）抑制人胃腺癌细胞（SGC-7901）转移作用与亚油酸代谢途径中限速酶环氧合酶-2（COX-2）的关系。方法采用体外细胞培养方法,用COX-2的选择性抑制剂NS．398抑制SGC-7901细胞中COX-2的活性,再加入200、100、50和25μmol／L浓度的c9,t11-CLA,利用重组基底膜侵袭实验、黏附实验、趋向运动实验检测c9,t11-CLA抑制肿瘤细胞转移的作用与COX-2的关系。结果与NS-398组比较,NS-398＋100Ixmol／Lc9,t11-CLA和NS-398＋200μmol／L c9,t11-CLA对SGC-7901细胞的侵袭有明显的抑制作用,穿过膜的细胞数分别为48．7±1．5（F=14．309,P=0．000）和43．7±4．0（F=19．005,P=0．000）;NS-398＋200μmol／L c9,t11-CLA组能显著降低SGC-7901细胞对基质成分层粘连蛋白、纤维粘连蛋白和基质胶的黏附作用,所测吸光度值（A值）分别为0．052±0．011,0．058±0．008（F=3．063,P=0．021）和0．042±0．004（F=6．692,P=0．001;F=11．999,P=0．000）;NS-398＋200ixmol／L c9,t11-CLA对SGC-7901细胞的趋向运动能力无明显的抑制作用（F=1．380,P=0．276）,其中NS-398＋2001xmol／L c9,t11-CLA组细胞数为26．6±3．4。结论 c9,t11-CLA具有抑制SGC-7901细胞体外侵袭能力、黏附能力和趋向运动能力,这种抑制作用可能与COX-2途径有关。     

共轭亚油酸诱导人乳腺癌细胞(MCF-7)凋亡的作用

目的　为了研究共轭亚油酸单体 (c9,t11 CLA)对人乳腺癌细胞 (MCF 7)凋亡的影响。方法　采用细胞生长曲线 ,凋亡细胞的荧光显微镜和电镜观察、流式细胞光度术的检测以及p5 3蛋白表达的方法 ,观察了用不同浓度c9,t11 CLA(2 5、5 0、10 0和 2 0 0 μmol L)诱导MCF 7细胞凋亡作用。结果　c9,t11 CLA可明显抑制MCF 7细胞生长 ,8天的抑制率分别为 -6 0 %、4 5 2 %、99 0 %和 99 4 %。通过荧光显微镜和电镜技术观察到了发生凋亡的MCF 7细胞 ;用流式细胞光度术也检测到c9,t11 CLA可诱导MCF 7细胞产生凋亡 ,并随着c9,t11 CLA浓度的增加 ,细胞凋亡率逐渐增加 ;而p5 3蛋白表达则随着c9,t11 CLA浓度的增加呈现逐渐降低的趋势。结论　c9,t11 CLA可诱导MCF 7细胞产生凋亡 ,这可能是c9,t11 CLA抑制肿瘤细胞生长的机制之一。     

共轭亚油酸对人胃腺癌细胞侵袭及转移相关基因表达的影响

目的 研究c9,t11－共轭亚油酸（CLA）对人胃腺癌细胞（SGC－7901）侵袭能力的影响,探讨其抑制肿瘤转移的可能机制。方法 用重组基底膜侵袭实验评价癌细胞侵袭能力;用逆转录聚合酶链反应（RT－PCR）检测SGC－7901细胞中组织基质金属蛋白酶抑制剂（TIMP）－1、TIMP－2和nm23-H1mRNA的表达。结果 在200、100和50μmol/L浓度时,c9,t11-CLA对SGC－7901细胞侵袭重组基底膜的抑制率分别为53.7%、40.9%和29.3%。c9,t11-CLA可诱导SGC－7901细胞中TIMP－1、TIMP－2和nm23-H1mRNA的表达。结论 c9,t11-CLA抑制SGC-7901细胞侵袭重组基底膜。c9,t11-CLA的抗侵袭活性与诱导肿瘤细胞中TIMP－1、TIMP－2和nm23-H1mRNA的表达等有关。     

共轭亚油酸对肿瘤细胞亚油酸代谢途径中限速酶的影响

目的采用体外细胞培养方法,研究不同浓度c9,t11-共轭亚油酸(c9,t11-CLA)对人胃腺癌细胞(SGC-7901)中亚油酸代谢途径的限速酶的影响。方法用200、100、50和25μmol／L浓度的c9,t11-CLA处理SGC-7901细胞24h,四甲基偶氮唑盐实验检测c9,t11-CLA对SGC-7901细胞增殖的抑制作用,采用逆转录聚合酶链反应检测c9,t11-CLA对SGC-7901细胞中亚油酸代谢途径的Δ6-脱氢酶、△5-脱氢酶、环氧合酶(COX)-1、COX-2和5-脂氧合酶(5-LOX)mRNA表达的影响。结果在200、100、50和25μmol／L浓度时,c9,t11-CLA对SGC-7901增殖的抑制率分别为54．3％、20．5％、10．5％、2．93％;均可下调COX-2mRNA的表达,上调Δ6-脱氢酶、COX-1mRNA的表达,但对Δ5-脱氢酶和5-LOXmRNA表达的影响不显著。结论c9,t11-CLA可通过调节Δ6-脱氢酶和COX的表达抑制肿瘤细胞的增殖,说明c9,t11-CLA通过影响亚油酸代谢途径中限速酶的基因表达而改变类二十碳烷酸的形成,推测c9,t11-CLA影响肿瘤细胞中亚油酸代谢途径的限速酶是其发挥抗癌活性的另一作用机制。     

c9,t11-共轭亚油酸氧化稳定性的研究

目的：研究75％c9，t11-共轭亚油酸（c9，t11-CLA）在不同条件下的氧化稳定性，并在同等条件下与亚油酸（LA）进行比较，探讨影响75％c9，t11-CLA氧化稳定性的因素。方法：测定75％c9，t11-CLA和LA在暴露于空气、充氮保护、加入0．02％没食子酸丙酯、色拉油中及0．02％Ca^2＋存在条件下的过氧化值，同时进行气相色谱分析，观察5个不同时间75％c9，t11-CLA和IA含量的变化。结果：当75％c9，t11-CLA和LA在暴露于空气、充氮保护、加入0．02％没食子酸丙酯、色拉油中及0．02％Ca^2＋存在的条件下，75％c9，t11-CLA在不同处理条件下的氧化稳定性顺序为：0．02％没食子酸丙酯组〉充氮保护组〉色拉油组〉暴露于空气组〉0．02％Ca^2＋组（P〈0．05）。75％c9，t11-CLA的氧化速度快于亚油酸（IJA）的氧化速度（P〈0．05）。结论：0．02％没食子酸丙酯可明显提高c9，t11-CLA的氧化稳定性。增强c9，t11-CLA的稳定性已成为保护c9，t11-CLA有效生物活性的至关重要的因素。     

共轭亚油酸对正常动物细胞和人体肿瘤细胞间通讯功能的影响

为探讨c9,t11-共轭亚油酸 (CLA)的抑癌作用可能机制 ,在促癌物 (TPA)存在下 ,对正常细胞(CHL)以及人体肿瘤细胞 (SGC 790 1细胞和MCF 7细胞 )的细胞间隙连接通讯功能 (GJIC)的影响 ,采用划痕标记染料示踪技术 (SLDT) ;c9,t11 CLA剂量为 2 5 (mol L ,5 0 (mol L ,10 0 (mol L和 2 0 0 (mol L ,阴性对照为乙醇。结果显示 ,c9,t11 CLA可明显地提高TPA对CHL细胞的GJIC的抑制效应 ,当c9,t11 CLA浓度为 2 0 0 (mol L作用 48h时 ,细胞间隙通讯功能基本上与阴性对照组相近 ;当用c9,t11 CLA作用SGC 790 1细胞和MCF 7细胞2 4h和 48h时 ,可见 (2 4h 10 0 μmol L的MCF 7细胞 ) 2 4h 2 0 0 μmol L和 48h 10 0、2 0 0 μmol L剂量组的肿瘤细胞有一定的细胞间隙通讯功能。提示c9,t11 CLA可提高SGC 790 1细胞和MCF 7细胞的GJIC的功能 ,并且不同程度的拮抗TPA对CHL细胞GJIC的抑制效应     

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.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.     

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.     

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.     

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.