乙型肝炎病毒突变与隐匿性感染的相关性

隐匿性HBV感染(OBI)指在机体肝组织中存在HBV DNA,血清HBsAg阴性,伴或不伴有血清HBV DNA阳性的感染状态.OBI与隐源性肝硬化和肝细胞癌有关,是输血、器官移植播散HBV的潜在危险因素,也是目前疫苗接种失败的主要原因之一.OBI的形成与多种机制有关,其中病毒突变是重要因素.此文就HBV基因不同区域突变与OBI感染的关系作一综述.     

隐匿性乙型肝炎病毒感染的流行病学研究进展

HBV感染是指血清中HBsAg和HBV DNA检测阳性.然而随着高灵敏分子生物学技术在HBV检测中的应用,发现部分HBV感染者血清HBsAg阴性,但血清或肝组织HBVDNA持续存在,从而提出隐匿性HBV感染(occult hepatitisB virus infection,OBI)的概念^[1].HBsAg阴性的HBV感染与许多临床情况有关,由于HBsAg阴性HBV感染难以用常规方法检出,成为较复杂的流行病学和临床问题^[2].目前OBI的流行病学研究主要集中于OBI在不同人群患病率的横断面调查,由于选取研究对象的方法不-,检测指标及方法各异,造成结果差别很大.本文就近年来OBI的流行病学调查方法、发病情况等研究进展进行综述.     

隐匿性乙型肝炎病毒感染的研究进展

隐匿性乙型肝炎病毒感染（occult HBV infection, OBI）是公共健康的一大难题,也是全球临床医学面临的挑战。由于目前检测方法以及临床实际问题的限制,不同研究中对于OBI的定义也不同。OBI的存在会影响临床诊断和输血安全,且OBI在临床高危人群中有再激活的风险,可能会导致肝硬化、肝癌和肝衰竭等终末期肝病。本文就近年OBI定义和不同人群流行率、OBI发生机制以及临床意义等研究进展进行综述。     

住院孕妇显性和隐匿性HBV感染及分子进化特征分析

目的了解住院孕妇显性和隐匿性乙型肝炎病毒感染(OBI)及其病毒株S基因分子进化特征。方法采用以医院为基础的住院孕妇队列研究,招募2012年6月1日—2013年3月15日医院产科孕妇1 130人,收集人口学资料和血清,并采用罗氏电化学发光法检测乙型肝炎病毒表面抗原(HBsA g)及巢式PCR进行HBV S片段的扩增并测序,分析并比较住院孕妇显性乙型肝炎病毒(HBV)感染与OBI的人口学分布特征及S区序列变异。结果在1 130名孕妇中,HBV感染比例为16.55%,其中显性HBV感染和OBI的比例分别为8.4%和8.1%。共获得136株HBV S基因序列,其中基因C型17株,基因B型119株。与基因B型显性HBV株相比,OBI株出现更高的核苷酸和氨基酸替换率,8个核苷酸位点出现统计学显著的次要等位基因频率,并导致HBV S基因和对应的HBV P基因出现非同义氨基酸替换,分别为5个(G44E、T126A、R129Q、W156L和Y200F)和4个(I438L、K478N/D、N481S/D和L511F)。此外,3例OBI出现W35终止码替换,1例OBI出现第123位和第124位点的插入替换。结论住院孕妇存在较高的HBV感染比例,OBI与显性HBV感染比例大致相当;B基因型OBI株出现统计显著的核苷酸和/或氨基酸位点替换,可能与OBI的发病机制有关。     

乙肝母婴传播类型与乙肝疫苗免疫效果的关系

持续性乙型肝炎病毒(hepatitis B virus,HBV)感染分为两类:乙型肝炎表面抗原(hepatitis B surface antigen,HBsAg)阳性(显性HBV感染)和阴性(隐匿性HBV感染,occult hepatitis B infection,OBI)。对显性感染的认识相对清楚,但对OBI的认识仍然有限。本文重点介绍OBI的危害及其流行情况,并分别阐述了母婴不同乙肝传播类型与乙肝疫苗免疫效果的关系。HBV以母婴传播为主,两类HBV感染在母婴传播上表现为四种类型:(Ⅰ)母亲HBV显性-子代HBV显性;(Ⅱ)母亲HBV显性-子代OBI;(Ⅲ)母亲OBI-子代OBI;(Ⅳ)母亲OBI-子代HBV显性。HBV疫苗免疫后时代可能以Ⅱ型传播为主。应加强对OBI的研究,重新评估现有HBV免疫策略对HBV母婴传播的影响。     

隐匿性乙型肝炎病毒感染研究进展

隐匿性HBV感染（OBI）已成为世界性公共卫生问题之一,严重影响乙型肝炎的临床诊断并威胁到输血安全。本文分析近年来关于OBI的概念、致病机制、在健康人群和不同患者中的流行率以及传播可能性方面的研究数据,结果显示OBI在健康人群及不同患者中均存在一定的流行率,并可能通过输血等途径传播,应引起重视。     

长沙地区无偿献血人群隐匿性乙型肝炎病毒感染情况分析

目的 了解长沙地区无偿献血人群隐匿性乙型肝炎病毒感染(occult hepatitis B virus infection,OBI)流行情况,探讨HBV基因型分布特征和S区氨基酸突变的情况。方法 对长沙地区检测结果为HBsAg-/HBV DNA+的无偿献血血液样本进行HBV血清标志物检测,对其中的OBI样本进行HBV病毒载量检测和S区基因扩增,分析血清学标志物抗HBs与病毒载量检出与否的关系,并对扩增产物进行HBV基因分型和突变位点分析。结果 2019年1月—2020年1月长沙地区173 893份无偿献血标本共确认58例OBI样本,OBI流行率为0.033%;共发现7种血清学模式,抗HBc单独阳性最多,占38.98%,所有样本中抗HBc阳性率为89.83%;16例样本能检测出病毒载量,其中14例样本浓度小于100 IU/ml;抗HBs阳性组和阴性组间的病毒载量检出率无统计学差异;75.0%(12/16)样本扩增出S区序列,基因型均为B型,均发生突变,其中11例的HBsAg抗原决定簇及周边主要亲水区域(major hydrophilic region, MHR)发生氨基酸突变。结论 长沙地区无偿献血者中的OBI感染率在全国属于偏低水平;HBV基因型主要是B型,MHR区的氨基酸突变可能是造成OBI的原因,突变有本地特点。     

四川地区自然人群中隐匿性乙型肝炎病毒感染状况及病毒学特征

目的 调查四川地区自然人群中隐匿性乙型肝炎病毒(OBI)感染状况及病毒学特征。方法 筛查四川地区自然人群OBI感染率,检测乙型肝炎病毒(HBV)标志物[乙肝e抗原(HBeAg)、乙型肝炎表面抗原(HBsAg)、乙肝核心抗原(HBcAg)],行HBsAg,抗-HBs定量和抗-HBe及抗-HBc的定性检测,实时定量荧光聚合酶链反应(RT-PCR)检测HBsAg(-)/HBcAb(+)患者血清样品,检测血液中谷草转氨酶(AST)、谷丙转氨酶(ALT)、总胆红素(TBil)水平。分析OBI患者病毒学特征和基因型。结果 116 668份血液标本,HBsAg(阴性)但HBV DNA(阳性)检出率为0.098%,0.085%为OBI。99例OBI感染人群血清学特征中占比最高为抗-HBc阳性(40.40%),其次为抗-HBc阳性/抗-HBs阳性(26.26%),抗-HBc阳性/抗-HBe阳性次之(24.24%),抗-HBc阳性/抗-HBs阳性/抗-HBe阳性(9.09%)最低。抗-HBc阳性/抗-HBe阳性OBI患者病毒载量最高,其次为抗-HBc阳性/抗-HBs阳性者、抗-HBc阳性者、抗-HBc阳性...     

多种肝脏疾病中隐匿性HBV感染检出率及其S基因MHR免疫逃逸相关突变特点分析

目的　分析多种肝脏疾病中隐匿性HBV感染（occult HBV infection, OBI）检出率,并探讨OBI患者HBV S基因主要亲水区（major hydrophilic region, MHR）免疫逃逸相关突变特点。方法　回顾性分析2005年1月—2017年12月就诊于中国人民解放军总医院第五医学中心的91 037例HBV感染住院患者临床资料,筛选出OBI患者并扩增其HBV S基因序列,分析其HBV S基因MHR免疫逃逸相关突变特点。结果　91 037例住院患者中OBI总检出率为0.53%（487/91 037）,急性乙型肝炎患者中OBI检出率最高（9.26%,130/1404）,肝硬化患者中OBI检出率最低（0.26%,78/29 921）。62例OBI患者组与124例非OBI患者组相比,OBI患者组MHR免疫逃逸相关突变总体检出率显著高于非OBI患者组（59.68% vs. 35.48%;P＜0.05）;OBI患者组MHR多个免疫逃逸相关突变的联合检出率显著高于非OBI患者组（43.55% vs. 22.58%;P＜0.05）;其中,sT118K、sK122R和sV168A 3种单点突变的检出率显著高于非OBI患者组。结论　本研究显示临床HBV感染患者中有较高的OBI检出率,而且不同肝脏疾病中OBI检出率不同。此外,HBV S基因MHR的免疫逃逸相关突变与临床实践中OBI的发生密切相关。     

孕妇显性或隐匿性乙型肝炎病毒感染肝功能指标比较研究

目的探讨妊娠合并显性乙型肝炎病毒(hepatitis B virus,HBV)或隐匿性乙型肝炎病毒感染(occult hepatitis B virus infection,OBI)对孕妇肝功能指标的影响。方法采用以医院为基础的住院孕妇队列研究。以活产分娩且肝功能检查资料完善的2 195例孕妇为研究对象,收集其临产前血清,检测乙型肝炎病毒表面抗原(hepatitis B virus surface antigens,HBs Ag)和HBV S/pre S/C片段,分析并比较显性HBV感染、OBI与非HBV感染孕妇的肝功能指标的差异。结果显性HBV感染孕妇的ALT、TBAS水平显著高于非HBV感染孕妇,而TP和ALB则明显降低,GLB在3组孕妇中总体差异有统计学意义(P0.05),AST、ALP、GGT、TBIL、DBIL在3组孕妇中总体差异无统计学意义(P0.05)。结论显性HBV感染的活产孕妇妊娠期间ALT、TBAS、TP、ALB指标值异于非HBV感染活产孕妇,未发现OBI活产孕妇肝功能指标与显性HBV、非HBV感染活产孕妇的差异。提示临床应加强对显性HBV感染孕妇的肝功能监测,减少不良妊娠结局发生,促进母婴健康。     

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.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.