神经突起因子酵母双杂交诱饵质粒构建和转化

目的构建和转化神经突起因子（Neuritin）的酵母诱饵重组质粒，为通过酵母双杂交研究Neuritin的功能及作用机制奠定基础。方法用PCR扩增neuritin全长eDNA中编码开放读框的基因片段；将该基因片段与pLexA载体定向重组；用酶切和测序鉴定重组质粒；将核苷酸序列正确的重组质粒转化入EGY48[p8op—LaeZ]酵母菌株。结果成功构建pLexA-neufitin重组质粒。转化有重组质粒和pLexA空载体的2种EGY48[p8op—LaeZ]酵母都能在SD／Gal／Raf／-His／-Ura培养基中长成白色菌落，同时，转化pLexA-pos阳性对照质粒的酵母菌在相同条件下长成蓝色菌落，但都不能在SD／-His／-Leu／-Ura培养基中生长，在SD／-His／-Ura液中培养16h后，A600均值均为0．9。表明重组质粒表达的融合蛋白没有激活LEU2和laeZ酵母报告基因表达的活性，也没有酵母毒性作用。结论构建的诱饵重组质粒可以用于下一阶段的人胎脑cDNA文库筛选。     

结核杆菌ESAT-6蛋白酵母双杂交诱饵载体的构建及自激活检测

目的构建结核杆菌ESAT-6蛋白酵母双杂交诱饵载体,并检测其自激活作用。方法用PCR技术特异性扩增结核分枝杆菌H37Rv株的ESAT-6基因,将其克隆入酵母双杂交诱饵质粒pGBKT7中,用PCR、限制性酶切鉴定及序列测定,获得质粒pGBKT7-ESAT-6。用PEG/LiAc法将其转入酵母AH109b中,经表型筛选检测其自激活作用。结果获得了无自激活作用的诱饵载体pGBKT7-ESAT-6。结论ESAT-6无自激活作用,可用酵母双杂交方法钓取与之相互作用的分子。     

维甲酸受体变异蛋白酵母双杂交诱饵载体构建

目的 构建维甲酸受体变异蛋白(RARα-V)的诱饵表达载体.为应用酵母双杂交系统筛选与RARα-V相互作用的蛋白建立实验基础.方法 PCR扩增RARα-V,克隆入诱饵载体pGBKT7中,将构建好的诱饵载体pG-BKT7一RARα-v转化到酵母细胞AH109中,并利用蛋白印迹法(Western Blotting)分析诱饵蛋白的表达情况.同时检测诱饵蛋白有无毒性、渗漏和自激活作用.结果 成功扩增了RARα-V基因片断,并克隆入pGBKT7中,测序结果正确.诱饵载体成功转化到酵母细胞AH109中,诱饵蛋白无毒性,无自激活和渗漏,Western Blotting分析证实酵母细胞表达诱饵蛋白.结论 成功构建了RARα-V结合域的酵母诱饵表达载体,为进一步筛选与之相互作用的蛋白提供基础依据.     

酵母双杂交筛选胎肾上腺cDNA文库中HNP-1结合蛋白

[目的]筛选胎肾上腺cDNA文库中与α防御素HNP-1成熟肽具有相互作用的蛋白分子。[方法]通过聚合酶链反应(PCR)成功获得HNP-1成熟肽基因插入酵母表达载体pGBK-T7中构建诱饵质粒,同时提取胎肾上腺RNA,SMART技术制备人胎肾上腺cDNA文库,并采用Matchmaker LexA酵母双杂交系统从胎肾上腺cDNA文库中筛选与HNP-1成熟肽相互作用的蛋白。最后通过PCR筛选获得阳性克隆并测序,而后经回转实验,GST pull down以及免疫共沉淀再次验证两者的相互作用关系。[结果]成功构建诱饵质粒pGBKT7-HNP-1以及胎肾上腺cDNA文库并在酵母细胞中正确表达,筛选获得HNP-1成熟肽相互作用的蛋白-melanocortin 2 receptor (ACTH-R),CCAAT-enhancer-bind-ing proteins(C/EBP),Tramembrane trafficking protein(TMP21),low density lipoprotein receptor-related protein 6(LRP6)。最终选定促肾上腺皮质激素受体(ACTH-R)作为主要研究对象,且经GST pull down以及免疫共沉淀实验获得了证实两者间具有相互作用的相应的条带。[结论]从胎肾上腺cDNA文库中成功筛选得到α防御素HNP-1成熟肽相互作用蛋白——促肾上腺皮质激素受体。     

人防御素5基因毕赤酵母重组表达系统的构建

[目的]构建人防御素5(HD5)基因毕赤酵母表达系统,为进一步表达HD5基因提供理论依据和实验基础. [方法]构建好的毕赤酵母重组表达质粒pGAPZaA/HD5经Sac I线性化后应用LiCl法转化毕赤酵母菌株GS115感受态,Zeocin平板筛选,PCR鉴定转化子. [结果]线性化的重组质粒pGAPZαA/HD5成功转化进入毕赤酵母感受态,PCR鉴定结果与预期相符. [结论]成功构建HD5基因毕赤酵母表达系统.     

人肝再生增强子原核表达系统的构建与筛选

目的构建多个人肝再生增强子(hALR)的原核表达系统进行原核表达、鉴定及筛选,得出理想的系统用于进一步的研究。方法构建4个重组表达质粒pET28a( )/hALR、pET23a/hALR、pGEX-5x-1/hALR、pGEX-5x-2/hALR,分别转化3种宿主菌,诱导表达重组hALR蛋白,用SDS-聚丙烯酰胺凝胶电泳和Westem blotting鉴定重组蛋白。结果双酶切和DNA测序证实hALR cDNA正确插入4种表达载体并成功转化宿主菌,仅pET28a( )/hALR的BL21(DE3)菌株成功表达相对分子质量为23kDa的重组蛋白。结论筛选得出人肝再生增强子的原核表达系统,成功表达并鉴定重组hALR蛋白。     

人轮状病毒外衣壳糖蛋白VP7基因毕赤酵母重组表达系统的构建

[目的]构建人轮状病毒糖蛋白VP7基因毕赤酵母表达系统.[方法]构建好的毕赤酵母重组表达质粒VP7-pPICZαA经Sac Ⅰ线性化后应用电转化法转化毕赤酵母菌株GS115感受态中,Zeocin平板筛选,PCR鉴定转化子,MDH和MMH平板鉴定Mut表型.[结果]线性化的重组质粒VP7-pPICZα成功转化进入毕赤酵母感受态中,PCR鉴定结果与预期相符,表型确定为Mut+.[结论]成功构建人轮状病毒耱蛋白VP7基因的毕赤酵母表达系统     

球形幽门螺杆菌vacA基因表达质粒构建及表达

目的构建球形幽门螺杆菌vacA基因的重组表达质粒,初步观察其在E.coli中的表达。方法采用亚克隆技术,用BamHⅠ和SacⅠ从重组质粒pMD-18T-vacA上切下vacA基因,插入表达载体pET32a（＋）质粒,转化大肠埃希菌BL21,在氨苄青霉素阳性的LB平板上筛选阳性重组子,并经双酶切及PCR扩增鉴定。重组质粒pET32a（＋）-vacA转化大肠埃希菌,（IPTG）诱导表达后进行（SDS-PAGE）电泳和凝胶扫描定量分析。结果重组质粒酶切和PCR鉴定与预期结果相符,成功构建携带vacA基因的重组原核表达质粒pET32a（＋）-vacA。核酸序列测定及同源性分析证实,表达质粒pET32a（＋）-cagA中所含vacA基因与GenBank中的vacA序列同源性达到99.2%。vacA基因在大肠埃希菌中诱导表达后获得约156 kD蛋白,蛋白含量占全菌体蛋白含量15.5%。结论成功构建球形H.pylori vacA基因重组表达质粒,并获得高效表达,为研究该基因蛋白的生物学特性及DNA疫苗研制奠定了基础。     

L-精氨酸转运体-2的siRNA表达载体的构建及鉴定

目的:构建氨基酸转运体-2(CAT-2)的靶向小分子干扰RNA(siRNA)表达载体质粒,并测序鉴定,为下一步研究靶向siRNA对CAT-2蛋白表达和L-argine/iNOS/NO通路的影响建立基础。方法:根据L-精氨酸转运体CAT-2的mRNA序列及siRNA设计原则,并经BLAST比对,设计合成4对siRNA寡聚单链DNA,退火成双链dsDNA,用载体构建试剂盒BLOCK-iTTMPol II miR RNAi Expression Vector Kit with EmGFP进行重组质粒构建,将4对dsDNA分别插入到siRNA表达载体pcDNATM6.2-GW/EmGFPmiR中,构建4个siRNA表达质粒,并转化至感受态细菌DH5。筛选阳性克隆并提取重组质粒后测序分析。结果:CAT-2的siRNA重组载体质粒测序结果证实表达载体构建成功。结论:L-精氨酸转运体CAT-2 siRNA表达载体质粒成功构建,为下一步研究靶向siRNA对CAT-2蛋白表达和L-arg/iNOS/NO通路的影响建立基础。     

HBsAg结合胰腺细胞蛋白基因的酵母双杂交技术筛选

目的 应用酵母双杂交技术筛选胰腺细胞cDNA文库中与HBsAg相互作用的结合蛋白的基因.方法扩增人胰腺cDNA文库并纯化鉴定,将其转人酵母菌Y187;诱饵质粒PGBKT7-HBSAg转入酵母菌AH109.将以上二者进行配合,在SD/-Trp/-Leu/-His/-Ade和X-a-Gal培养基上进行双重菌落筛选;提取阳性质粒转化大肠埃希菌DH5a并测序,在GenBank中进行生物信息学分析.结果 获得了6个与HBsAg相结合的蛋白,包括顺乌头酸酶、CDK5RAP3、羧肽酶B1、胰脂肪酶、辅脂肪酶、弹性蛋白酶.结论 筛选出的胰腺细胞蛋白与2型糖尿病等代谢性疾病有较密切关系,为进一步研究并阐明乙肝病毒(HBV)感染引发糖脂代谢紊乱机制提供了新的思路.     

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.