乙肝疫苗免疫失败者中乙型肝炎病毒感染及S基因变异研究

目的研究乙肝疫苗免疫失败者中乙型肝炎病毒(HBV)隐匿性感染及编码S基因(surface)变异状况。方法选择乙肝疫苗免疫后抗-HBs阴性的儿童血清标本167份,利用聚合酶链反应(PCR)扩增HBVS基因片段,对PCR阳性产物进行脱氧核糖核酸(DNA)序列测定和基因片段分析。结果在167份标本中,HBV核酸阳性63份,在测序42份标本中11份标本S基因片段出现氨基酸变异,共有5个氨基酸位点发生变异,其中一个在"a"决定簇片段内。结论免疫失败儿童HBV隐匿性感染率较高,HBVS基因存在不同位点的变异。     

无偿献血者隐匿性乙肝感染病毒变异检测分析

目的通过对隐匿性乙肝感染者S区基因变异位点的分析及相关蛋白空间结构的预测,探讨无偿献血者隐匿性乙肝感染的分子生物学机制。方法对80例HBs Ag-/HBV DNA+无偿献血者进行血清学补充试验,并对追踪确认的隐匿性乙肝感染者,应用巢氏PCR技术对S区基因进行扩增和序列测定,并将测得基因片段与NCBI Gen Bank数据库做序列比对分析,明确突变位点,同时进行蛋白模型构建,进行空间结构的分析。结果 HBs Ag-/HBV DNA+无偿献血者血清学检测模式多样,以抗-HBc阳性为主,追踪试验确认4例隐匿性乙肝感染者,有3例巢氏PCR扩增出S区基因序列,2例发生突变,蛋白预测提示氨基酸改变可能影响抗原决定簇空间构象,造成抗体结合位点改变或识别能力减弱。结论隐匿性乙肝感染者S区容易发生变异,尤其是a抗原决定簇氨基酸的改变导致蛋白质空间构象的变化,可能是造成隐匿性乙肝发生的原因之一。     

乙型肝炎病毒X基因变异与隐匿性感染的关系

隐匿性HBV感染指患者血清HBsAg阴性,而血清和(或)肝组织HBV DNA阳性,其发生机制仍未明了.目前,对HBV基因变异的研究大多集中在S基因,而X基因是病毒复制的重要调节区,是转录、反转录和正链合成的起点,此处变异可能会影响到病毒的转录和复制,但由于X基因结构和功能的复杂性,目前对其变异与隐匿性HBV感染的关系研究相对较少.此文就HBV X基因变异对隐匿性HBV感染的发生和影响进行综述.     

应用慢性HBV感染者家系探索HBV基因变异率差异的影响因素

目的 探讨不同患者乙型肝炎病毒(hepatitis B virus,HBV)基因变异率情况及影响因素.方法 选取4组慢性HBV感染者家系共6对母子为研究对象,PCR扩增HBV全长序列,分析其基因变异率并探讨其与疾病进程的相关性.结果 6对母子均为B基因型HBV感染,不同患者间HBV核苷酸变异率分别为6.67×10-5、2.83×10-5、2.33×10-5、1.48×10-4、1.83×10-4、1.24×10-4个变异/位点/年,差异可高达7.85倍,其中家系内HBV变异率差异分别为2.36和6.35倍.免疫耐受期HBV基因变异率2.83×10-5和1.24×10-4个变异/位点/年,非免疫耐受期HBV基因变异率2.33×10-5～ 1.83×10-4个变异/位点/年.各编码区变异率亦有所差异,但差异均无统计学意义(x核苷酸2=2.812,P=0.422;x氨基酸2=2.344,P=0.504).结论 不同患者HBV基因变异率有较大差异,且可能与患者所处HBV感染自然病程有关.     

乙型肝炎病毒血清标志物单独核心抗体阳性者中乙型肝炎病毒隐匿性感染的分子特性

目的 探讨乙肝血清标志物单独抗核心抗体(HBc Ab)阳性者中乙肝病毒(hepatitis B virus,HBV)隐匿性感染(occult HBV infection,OBI)流行状况和病毒分子特性。方法 应用ELISA方法对本院乙肝标志物检测单独HBc Ab阳性者进行复检,采用荧光定量聚合酶链反应(real-time PCR)方法对复检单独HBc Ab阳性者的HBV-DNA进行荧光定量,对病毒核酸检测阳性者扩增Pre S/S基因区并进行直接测序分析。结果 在总共复检的343列单独HBc Ab阳性者中,有338例样本复测HBc Ab单独阳性。定量PCR检测发现OBI者6例(1. 8%),其中成功测序4例。序列结果分析发现2例B2基因型,2例C1基因型。4例样本均在Pre S/S基因区发生了变异,S基因区变异多在B细胞表位和T细胞表位区,其中有3例样本存在a决定簇变异。结论 单独HBc Ab阳性者确实存在OBI,HBV基因组S区a决定簇内存在变异,可能与OBI的发生相关。临床上要注意单独HBc Ab阳性者HBV隐匿性感染的漏诊。     

母儿传播的HBV初步基因分型及变异株检出

以4名HBsAg、HBeAg 均阳性的女性携带者及其子宫内感染HBV 的4 例胎儿为对象,研究母儿间病毒的基因分型与S区变异株。以双脱氧链末端终止法检测母儿所携HBVS区451～660 位核苷酸序列。母儿间同源性98% ～100% ,检出530、546、581位点变异致使126 位、131 位、143 位氨基酸替代。根据当前的基因分型方法, 2对母儿均为B型, 2对母儿母亲为B型, 胎儿为A、B混合型。HBV 子宫内传播存在S基因变异株。母儿间基因型别基本一致     

乙型肝炎肝硬化患者与乙型肝炎病毒携带者乙型肝炎病毒X基因序列比较研究

目的研究乙型肝炎肝硬化患者与乙型肝炎病毒（HBV）携带者HBV X基因序列的差异。方法对20例标本的PCR产物进行直接测序;并对3例乙型肝炎肝硬化患者和3例无症状HBV携带者HBV DNA的扩增片段进行克隆测序,并分析比较。结果肝硬化患者中X基因核心启动子双突变T1762/A1764、G1719T、T1727G/A、G1730C、T1753C等变异高于HBV携带者;前者X启动子区变异率明显高于后者;乙型肝炎肝硬化同一患者X区不同克隆之间的碱基序列同源性为91.3%-99.7%,而HBV携带者为96.0%-100.0%。结论乙型肝炎肝硬化患者,HBV DNA X区的CP启动子区以及X启动子区变异程度明显高于HBV携带者,同时乙型肝炎肝硬化患者体内存在变异程度更大的HBV准种群。     

乙型肝炎病毒基因变异与干扰素的疗效

HBV的基因变异与IFN治疗慢性乙型肝炎的疗效有关.此文就HBV基因前C/C区变异、X基因BCP变异和P基因区末端蛋白变异对IFN疗效的影响作了综述.     

太原地区孕妇HBV感染者a决定簇的变异

目的 了解太原地区孕妇乙型肝炎病毒（HBV）感染者HBVS基因a决定簇变异情况。方法 2001年11月～2004年7月，采集太原市传染病医院妇产科住院的HBsAg阳性孕妇外周血，采用ELISA法检测血清HBsAg、HBeAg，巢式PCR法检测血清HBVDNA，对41例孕妇标本进行了PCR产物直接测序，与Genebank中HBV中国大陆流行株进行多重序列比对，分析HBVS基因a决定簇变异情况。结果 14．63％（6／41）孕妇携带HBVS基因a决定簇变异株。检出的突变位点中，aa126，aa127，aa131，aa143为较常见的氨基酸变异位点，aa125，aa135，aa137及aa140变异报道较少，大多数位点的变异导致了氨基酸替换。结论 太原地区孕妇HBV感染者携带a决定簇突变株。     

乙肝感染患者HBV RT区耐药基因突变特点分析

目的探讨乙肝感染患者HBV RT区耐药基因突变的临床特征及耐药位点的分布情况。方法回顾性分析2020年1月至2021年12月在解放军总医院第五医学中心检验科进行NAs耐药基因突变检测且既往有明确应用NAs史的1 948例HBV感染患者, 记录其基本临床信息及耐药相关突变信息, 同时收集其乙肝血清学指标数据。根据HBV RT区耐药基因是否变异分为耐药基因变异组和未变异组, 并对两组结果的临床特征和基因型分布进行统计分析。同时, 将917例HBV RT区耐药基因变异患者的耐药基因变异模式、突变位点数、耐药类型以及NAs耐药相关各位点突变情况进行统计分析。计数资料采用χ2检验, 计量资料采用两独立样本t检验和Wilcoxon秩和检验。结果 1 948例HBV感染患者中有917例(47.07%)发生RT区耐药基因变异。HBV RT区耐药基因变异组急性乙型肝炎和慢性乙型肝炎患者比例均低于未变异组, 而HBV相关性肝硬化患者比例高于未变异组, 差异具有统计学意义。同时, HBV RT区耐药基因变异组患者的年龄、HBeAg阳性率、HBV DNA阳性率以及载量均高于未变异组, 差异具有统计学意义。两组...     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

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.     

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.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.