自噬基因Beclin1过表达诱导人卵巢癌细胞SKOV3自噬和凋亡的研究

目的:探讨自噬基因Beclin 1在人卵巢癌SKOV3细胞中过表达对其体外生长活性的影响。方法:构建自噬基因Beclin 1的真核表达载体pcDNA3.1/Beclin1,将其稳定转染SKOV3细胞,实现Beclin 1在SKOV3中的过表达;用MTT法分析Beclin1过表达对SKOV3增殖的影响,用流式细胞仪检测凋亡和自噬情况,电镜和荧光显微镜下观察自噬现象。结果:pcD-NA3.1/Beclin1转染SKOV3细胞后Beclin 1在mRNA和蛋白水平均高于空质粒pcDNA3.1转染组和未转染组。Beclin 1在SKOV3中的稳定过表达后G1期细胞明显增多,S期细胞比例明显减少,细胞增殖受到抑制,凋亡率为(21.26±3.89)%,高于空质粒pcDNA3.1转染组和未转染组,差异有统计学意义(P<0.05);流式细胞仪检测pcDNA3.1/Beclin1转染SKOV3细胞后MDC标记的自噬囊泡平均荧光强度高于pcDNA3.1转染组和未转染组。pcDNA3.1/Beclin1转染SKOV3细胞后在电镜下可见大量自噬囊泡形成。在荧光显微镜下见pcDNA3.1/Beclin1转染后SKOV3细胞中MDC标记的自噬囊泡明显增加。结论:自噬基因Beclin1过表达可诱导人卵巢癌细胞SKOV3自噬和凋亡,针对自噬基因Beclin1的卵巢癌基因治疗可能具有可行性。     

shSASH1基因对卵巢癌细胞SKOV3生物学功能的影响

目的 探讨SASH1对卵巢癌细胞SKOV3的增殖、凋亡与侵袭方面的影响.方法 标本组织来源于妇产科手术收集的50例卵巢癌组织.通过建立重组质粒pcDNA3.1-SASH1,并借助于脂质体2000转染到SKOV3,采用流式细胞计(FCM)分析实验和细胞侵袭实验,来探索SASH1对卵巢癌细胞SKOV3在细胞扩散、凋亡和侵袭中的影响.结果 pcDNA3.1-SASH1转染组中的s期细胞分值(％)低于正常(未转染的)对照组(x2=26.78,P＜0.01)或空载组(pcDNA3.1) (x2=25.12,P＜0.01).与空载组和正常(未转染的)对照组相比,pcDNA3.1-SASH1转染组中的SKOV3明显降低了癌细胞的生长、增殖和侵袭的能力(x2=31.25,P＜0.01),然而在空载组和正常(未转染的)对照组中没有明显的差异;pcDNA3.1-SASH1细胞组显示更多的凋亡细胞(x2=36.58,P＜0.01).结论 SASH1可抑制卵巢癌细胞SKOV3的生长、增殖和侵袭能力,并促进其凋亡.     

Notch1基因沉默对滋养细胞增殖与凋亡的影响

目的:探讨Notch1基因沉默后对滋养细胞增殖与凋亡生物学功能的影响。方法:构建Notch1蛋白基因干扰质粒,体外培养人早孕期胎盘绒毛膜外滋养细胞系HTR-8/SVneo细胞进行转染。应用实时荧光PCR计数检测转染后Notch1 mRNA相对表达水平,CCK-8检测细胞转染后活性情况,Western blotting检测Bcl-2凋亡蛋白家族表达情况。结果:同未转染组相比,空白质粒转染组与基因沉默组mRNA相对表达水平分别为0.97±0.03、0.31±0.10,基因沉默组mRNA表达与其它两组差异有统计学意义(P<0.05)。Notch1基因沉默组同空白质粒转染组相比细胞活性明显下降(P<0.05),同时Notch1基因沉默组抗凋亡蛋白Bcl-2表达较空白质粒转染组明显降低(P<0.05),而促凋亡蛋白Bax表达明显增加(P<0.05)。结论:Notch1基因可通过调节Bcl-2凋亡蛋白家族参与滋养细胞增殖与凋亡过程,是胎盘形成发展过程中的正向调节因子。     

丙型肝炎病毒基因1b型F蛋白对人肝细胞癌细胞株凋亡的影响

目的 研究丙型肝炎病毒(HCV)基因1b型F蛋白对人肝细胞癌细胞株HepG2凋亡的影响.方法 构建真核表达重组质粒pcDNA3.0-F-EGFP,并利用Lipofectamine 2000转染人肝细胞癌细胞系HepG2,同时设pcDNA3.0-C-EGFP-HepG2阳性对照、pcDNA3.0-HcpG2为阴性对照及未转染HepG2为空白对照,以Act-D、TNFα诱导四组细胞系发生凋亡,Annexin V-FITC/PI双染检测肿瘤细胞凋亡率,并使用细胞凋亡DNALadder检测,进一步验证HCV 1b型F蛋白在肝细胞凋亡的生物学功能效应.结果 pcDNA3.0-F-EGFP-HepG2细胞系在发生凋亡的时间上比peDNA3.0-C-EGFP-HepG2快,但相对空白质粒转染组及未转染HepG2细胞系有明显延迟,凋亡的发生率也明显低于阴性对照及空白对照细胞系(P<0.001).结论 外源性基因HCV 1b型F的引入及表达,对HepG2细胞的凋亡有抑制作用.     

全长型人Smac基因真核表达载体构建及表达

目的 构建全长型(full length,FL)人Smac基因(hSmac)真核表达载体pcDNA3.1 -FL hSmac,并在肝癌细胞中表达.方法 应用逆转录聚合酶链式反应(RT-PCR)技术从人宫颈癌细胞株Hela中扩增到Smac CDs基因片段,构建重组真核表达载体peDNA3.1 -FL hSmae.PCR、酶切鉴定重组质粒正确后,通过脂质体介导将其和作为阴性对照的空载体pcDNA3.1 分别转染人肝癌细胞株(SMMC-7721).同时转染含EGFP的质粒pcDNA3.1 -EGFP.利用荧光显微镜和流式细胞术检测转染效率.采用RT-PCR、western blot法检测外源基因Smac的表达.结果 PCR扩增片段与预期片段大小相符,插入片段测序结果与GenBank公布的一致,表明人Smac基因克隆成功.且鉴定证实真核表达载体pcDNA3.1 -FL hSmac构建成功.流式细胞术检测到转染效率高达48%,荧光显微镜下也可见非常明亮的绿色荧光.无论是在mRNA水平还是蛋白水平上,转染后的细胞中外源基因Smac表达均明显增加.结论 成功构建重组真核表达载体pcDNA3.1 -FL hSmac,并在肝癌细胞中明显表达,为研究Smac基因在细胞凋亡过程中的调控作用.以及探讨以Smac基因为基础的肿瘤基因治疗策略提代基础依据.     

ShRNA靶向干扰BHRF1基因抑制鼻咽癌细胞增殖的实验研究

目的观察BHRF1 shRNA质粒载体转染对人鼻咽癌CNE2细胞中的BHRF1基因沉默及细胞增殖和凋亡的影响,以及肿瘤细胞对放射敏感性的变化。方法利用RNAi技术将负载BHRF1 shRNA的质粒载体转染至人鼻咽癌CNE2细胞,一组为BHRF1 shRNA质粒载体转染过的CNE2细胞（观察组）,未进行转染的CNE2细胞确定为对照组,经RT-PCR扩增人鼻咽癌组织中BHRF1 cDNA片段,RT-PCR和Western blot检测BHRF1基因的蛋白水平的表达。并且利用顺铂进行实验,观察使用顺铂后,BHRF1 shRNA转染后的肿瘤细胞是否对放射敏感性有变化。结果 BHRF1 shRNA转染鼻咽癌CNE2细胞后,细胞内BHRF1 mRNA表达量（2.02±0.53）,对照转染前明显下调,明显下调,与对照组的（29.82±0.64）比较,差异有显著性意义（P〈0.01）;DDP和8G放疗作用24 h以后,被转染的细胞的中的蛋白表达大大降低（P〈0.05）,癌细胞凋亡率上升,明显比对照组癌细胞的凋亡率高（P〈0.05）。结论利用RNA干扰技术对人鼻咽癌治疗具有潜在应用价值,BHRF1 shRNA质粒载体不仅仅能调控细胞基因的表达,而且还能够提高癌细胞对顺铂的敏感性。     

特异性沉默hTERT基因表达对卵巢癌细胞增殖、凋亡及p53、p21的表达的影响

目的探索特异性沉默hTERT基因表达对卵巢癌细胞增殖凋亡及p53和p21表达的影响,为临床诊治提供参考依据。方法采用分子克隆技术构建表达hTERTshRNA的载体,特异性沉默hTERT基因表达;WestenBlot法、MTT比色法、流式细胞仪检测抑制hTERT基因表达对卵巢癌细胞p53表达及其增殖和凋亡的影响。结果pSIREN-hTERTshRNA转染有效阻抑A2780细胞中hTERT蛋白表达,抑制率为77%;随着A2780细胞中hTERT蛋白表达降低,p53和p21表达均明显增加;与空白对照及转染pSIREN-Con对照质粒相比,pSIREN-hTERT转染的A2780细胞生长速度明显降低;pSIREN-hTERT转染48hA2780细胞凋亡率为(26.76±7.42)%,明显高于对照质粒pSIREN-Con转染组(3.73±0.78)%及空白对照组(1.33±0.15)%。结论hTERTshRNA重组质粒可特异性抑制卵巢癌细胞hTERT的表达,诱导细胞增殖抑制和凋亡,且可能与上调p53和p21的表达有关。     

HO-1真核表达质粒的构建及在肾小管上皮细胞中的表达

[目的]构建HO-1基因真核表达质粒,转染大鼠肾小管上皮细胞,检测其在细胞中的表达效果.[方法]从大鼠肾组织中提取总RNA,通过逆转录PCR(RT-PCR)扩增大鼠HO-1基因片段,将其克隆入真核表达载体pcDNA3.1( )中,运用脂质体将重组质粒pcDNA 3.1( )-HO-1转染大鼠肾小管上皮细胞,通过RT-PCR和Western blot分析HO-1基因细胞转染及表达的效果. [结果]成功构建了HO-1基因真核表达重组质粒pcDNA 3.1( )-HO-1.RT-PCR及Western blot分析显示,HO-1基因能转染大鼠肾小管上度细胞并在细胞内有效表达. [结论]HO-1基因真核表达重组质粒pcDNA 3.1( )-HO-1的成功构建及其在肾小管上皮细胞中的有效表达为深入研究其生物学作用奠定了基础.     

过表达GCNF对HeLa细胞生物学行为的影响

目的:将成功构建的人pcDNA3.1-GCNF真核表达载体瞬时转染宫颈癌HeLa细胞,观察GCNF基因对HeLa细胞生物学功能的影响。方法:将重组质粒pcDNA3.1-GCNF转染HeLa细胞,通过MTT比色法、基质胶黏附实验和Transwell侵袭试验对转染后HeLa细胞增殖、黏附和侵袭力进行分析。结果:成功获得瞬时转染的pcDNA3.1-GCNF HeLa细胞,转染目的基因组(0.239±0.014)与转染空质粒组(0.198±0.020)及未转染组(0.204±0.012)相比,细胞增殖最快(P<0.05)。转染目的基因后细胞粘附、侵袭力未见明显改变。结论:GCNF基因促进了体外培养的宫颈癌HeLa细胞增殖,但对HeLa细胞粘附、侵袭力没有明显的影响。     

RNA干扰hTERT基因对人乳腺癌细胞株MCF-7周期及凋亡影响的研究

目的 观察载体介导的RNA干扰技术能否有效抑制人乳腺癌细胞株MCF-7的hTERT的表达及其对细胞周期及凋亡的影响.方法 构建2个针对hTERT基因表达短发夹状siRNA的真核表达载体（pshRNA-hTERT）并转染人乳腺癌细胞株MCF-7,通过RT-PCR检测该基因mRNA,Western blot蛋白质检测,端粒酶活性检测,流式细胞仪检测细胞周期及凋亡等方法检测RNAi效果,从中筛选出基因沉默效果好的靶位点.结果 转染乳腺癌细胞后,pshRNA - hTERT1,2质粒均能抑制hTERT基因表达,mRNA表达分别下调了54.6%,55.2% 蛋白表达分别下调46.6%,47.8%.端粒酶活性均明显下降.对乳腺癌细胞周期中S期细胞明显减少,G1/G0期细胞显著增加.结论 RNAi在体外明显抑制乳腺癌细胞中hTERT基因的表达和瘤细胞增殖.     

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.     

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.