利用胶体金免疫层析技术快速定量检测单增李斯特菌方法的建立

〔目的〕建立胶体金免疫层析技术快速定量检测单增李斯特菌方法。〔方法〕利用胶体金标记和双抗体夹心免疫层析技术,建立单增李斯特菌的快速检测方法,评价其特异性和敏感性,并拟合标准曲线进行定量检测;在牛奶、橙汁、果冻等即食食品样品中添加单增李斯特菌模拟污染样品,评价该方法对半固体、液体等即食食品、可疑生物恐怖样品的检测能力。〔结果〕该法可在10min内完成定性和半定量检测,定量检测灵敏度为3.5×103cfu/ml,线性范围3.5×105～3.5×108cfu/ml,回收率在99%～101.7%之间。〔结论〕建立的检测单增李斯特菌的胶体金免疫层析方法,能快速、灵敏、特异、准确地对样品中的单增李斯特菌进行定性、定量检测。     

Taq Man-MGB探针Real-timePCR快速检测单增李斯特菌的研究

目的：建立TaqMan—MGB探针Real—time荧光PCR快速检测单增李斯特菌技术。方法：在对单增李斯特菌invA序列进行分析、比较基础上，设计一对特异性TaqMan—MGB探针法引物及探针，通过Real—timePCR反应条件和反应体系的优化，实现对单增李斯特菌的快速检测；用克隆到pMD18-T载体上的李斯特菌invA基因阳参片段及不同菌株、食品标本验证方法的特异性和敏感性。结果：方法的灵敏性高，其循环阈值与模板浓度的对数值具有很好的对应关系，最低可检测57个拷贝数，经18h增菌，可检测低至4．5cfu／ml的细菌；特异性强，检测6株单增李斯特菌标准株和100株单增李斯特菌样品分离株的PCR循环域值（cT值）均小于25，而90株威氏李斯特菌、英诺克李斯特菌、绵羊李斯特菌以及非李斯特菌PCR循环域值（CT值）大于35；快速，最快1h可出结果，实际样品20h可出结果，而常规细菌培养法需要一周以上；对103份速冻米面食品进行检测，13份阳性，与常规方法无显著性差异（P〉0．05）。结论：TaqMan—MGB探针的单增李斯特菌Real—time荧光PCR检测方法具有特异性强，敏感性高，易操作等优点，可推广应用。     

单增李斯特菌不同PCR快速检测方法比较

目的 比较3种PCR快速检测方法在检测单核细胞增生李斯特菌时的特异性和灵敏度方面的差异.方法 针对单核细胞增生李斯特菌的毒力基因iap和prfA基因,分别设计引物,进行单个PCR、多重PCR、套式PCR等3种方法检测.结果 3种PCR方法均具有较强的特异性;套式PCR的灵敏度为102 cfu/ml,高于单个PCR(103cfu/ml)和多重PCR(104cfu/ml).结论 多重PCR在特异性检测方面具有优势,而在灵敏度方面,套式PCR要明显优于单个及多重PCR方法.     

基于DPO引物构建的六重PCR检测食品中常见致病菌的方法研究

目的基于DPO引物在多重PCR检测中的优点,构建一种六重DPO-PCR方法用于检测食品及食源性疾病样本中常见的6种致病菌。方法以霍乱弧菌的vcc、志贺菌的ipa H、单增李斯特菌的iap、副溶血性弧菌的gyr B、金黄色葡萄球菌的nuc以及沙门菌的omp C为靶基因,设计6对DPO引物,经过反应体系优化,建立了六重DPO-PCR方法。结果六重PCR反应体系内部DPO引物之间干扰小;扩增后除靶基因外的其他15种细菌DNA无扩增条带出现;对6种致病菌的最低检出限分别为:霍乱弧菌,220 cfu/ml;志贺菌,150 cfu/ml;单增李斯特菌,190 cfu/ml;副溶血性弧菌,190 cfu/ml;金黄色葡萄球菌,700 cfu/ml;沙门菌,960 cfu/ml。结论用DPO引物构建的六重PCR方法具有特异性强,退火温度范围宽,引物之间干扰小,电泳图谱背景清晰,可以达到一管6检的目的,为食品及食源性疾病样本快速准确检测提供了一种新的高通量的快速检测方法。     

奶液模拟标本中单增李斯特菌real-time PCR检测方法的建立

目的建立了基于TaqMan探针的real-time PCR技术针对奶液模拟标本中单增李斯特菌的快速检测方法。方法用单增李斯特菌hlyO基因的部分片段作为靶基因,制作标准曲线,定量检测奶液中的单增李斯特菌。结果通过对不同李斯特菌及一些较为常见的致病菌的DNA进行扩增,只有单增李斯特菌能够产生扩增曲线,其余菌株均不产生扩增曲线。单增李斯特菌的检测灵敏度可以达到9copies/反应体系。结论该方法特异性好,灵敏度高,整个实验可在1.5h内完成,可用于食品中单增李斯特菌的快速检测和疫情暴发时的相关病原调查。     

套式PCR快速检测单增李斯特氏菌

根据GenBank数据库的单增李斯特氏菌iap基因设计两对引物,建立了套式PCR快速检测单增李斯特氏菌的方法。两对引物分别扩增出约1500bp和500bp片段,与预期大小一致。对菌液、模拟样品的检测表明,本方法能有效地克服食品基质、培养基成分和杂菌对PCR检验的干扰作用。套式PCR方法具有很好的特异性;灵敏性实验检测极限为101CFU／ml;人工污染猪肉检测极限为103CFU／ml;可在7h内完成检测,很适宜于进出口食品中单增李斯特氏菌的快速检测。     

发酵乳酸杆菌PCR快速检测方法研究

〔目的〕建立一种特异、灵敏的发酵乳酸杆菌快速检测方法。〔方法〕根据发酵乳酸杆菌纤维二糖tuf基因延伸因子基因tu设计一对PCR引物,进行引物的特异性和灵敏度试验。〔结果〕PCR得到了较好的特异性扩增,其他干扰菌都无扩增,灵敏度达1.3×104cfu/ml。〔结论〕该方法能够实现发酵乳酸杆菌的快速检测,具有灵敏度高、特异性好的特点。     

食品中单核细胞增生李斯特菌PCR快速检测方法

[目的]建立食品中单核细胞增生李斯特菌的快速、敏感、特异的PCR检测方法。[方法]选择Hly基因作为靶序列设计一对引物，用该引物对单增李斯特菌和10株非单增李斯特菌进行PCR扩增，并且用此方法对30份食品进行检测。[结果]扩增片断表现出极好的单增李斯特菌特异性，最低检出限为190cfu/ml。[结论]本实验建立的PCR检测方法为一种简便、快速、敏感、特异的单增李斯特菌检测方法。     

基于Taqman探针双重实时荧光PCR检测单增李斯特菌

目的:建立双重荧光PCR对单增李斯特菌(LMO)特异性检测同时检测其毒力基因的方法。方法:根据LMO溶血素基因hlyA和內华素基因InlA的保守序列分别设计特异性引物和Taqman探针,优化多重荧光PCR反应体系,进行特异性、敏感性试验。结果:用建立的方法检测LMO标准菌株和24株分离株均出现hlyA和InlA扩增曲线,而沙门菌等其他菌株未见扩增曲线;敏感性试验结果方法的敏感性达到2.5×102 cfu/ml。结论:本研究建立的LMO实时荧光PCR检测方法特异性好、灵敏度高,是快速检测LMO及其毒力基因的有效手段,可用于食品中LMO检测。     

荧光实时定量PCR检测单核李斯特菌方法学建立及应用

目的 建立检测单核细胞增多性李斯特菌的荧光定量PCR方法，并利用此方法检测人工污染的牛奶中单增李斯特菌菌量。方法 选择单增李斯特菌特异性的基因Listeriolysin O基因为靶目标设计引物，采用煮沸法抽提纯单增李斯特菌株（1／2a）DNA，建立SYBRGREEN实时定量PCR检测体系：结果 定量PCR对李斯特菌可产生特异扩增信号，对其他菌（大肠杆菌）无响应。标准曲线的相关系数为0．9521。最小检菌量约为100个菌落形成单位／反应体系。在人为污染牛奶检测中，与传统细菌计数方法结果相比，相关系数为0．839。结论 实时定量PCR是一种快速、灵敏的定量检测单增李斯特菌的方法，可用于牛奶样品的检测。     

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.