重组委内瑞拉马脑炎病毒疫苗的研制现状

委内瑞拉马脑炎病毒引起的委内瑞拉马脑炎是一种自然疫原性疾病。该病毒可诱导感染的宿主产生细胞、体液和粘膜免疫应答,可通过分子生物学技术改造为理想的疫苗载体,从而表达病毒和细菌的多种蛋白。这些病原体包括Ⅰ型人类免疫缺陷病毒、流行性感冒病毒、人乳头瘤病毒16型、Norwalk样病毒、埃博拉病毒、苏丹病毒、马尔堡病毒、拉沙病毒、麻疹病毒、炭疽杆菌和金黄色葡萄球菌等,本文综述委内瑞拉马脑炎病毒介导的病原体疫苗的研制现状。     

微生物介导的麻疹病毒疫苗的研制现状

麻疹病毒引起的麻疹是一种严重危害儿童健康的病毒性疾病,采用疫苗防治该病是当前研究的热点领域之一。麻疹病毒的核壳蛋白、血凝素或融合蛋白是三种有效的疫苗候选分子,本文综述了鼠伤寒沙门氏菌、卡介苗、格式链球菌、根癌农杆菌、牛痘病毒、腺病毒血清型5、委内瑞拉马脑炎病毒、辛德巴斯病毒和人副流感病毒3型等微生物介导的麻疹病毒疫苗的研制现状。     

委内瑞拉马脑炎

委内瑞拉马脑炎(Venezuelan equine encephalitis,VEE)是由VEE病毒复合物引起的自然疫源性疾病.1938年-1972年间,VEE在西半球周期性的暴发.此后相当长的一段时间没有该病病例的报道.近10年在墨西哥和南美洲再次出现委内瑞拉马脑炎,证明它是一种新发传染病.另外,VEE病毒复合物也是一种潜在的、可以用于战争和恐怖活动的生物武器.目前,世界对生物防御的重视,重新引起人们对VEE的关注.本文就委内瑞拉马脑炎的病原学、流行病学、病理和临床表现、以及治疗和预防等方面予以综述.     

实时RT-PCR法检测感染小鼠不同组织标本中的委内瑞拉马脑炎病毒

目的为委内瑞拉马脑炎病毒所致疾病的早期诊断和流行病学研究提供技术支持。方法建立了委内瑞拉马脑炎病毒特异、敏感和快速的实时RT-PCR法,并对委内瑞拉马脑炎病毒感染昆明小鼠的不同组织标本中的病毒载量进行了定量检测。结果本研究建立的实时RT-PCR法敏感(10TCID50/ml)、特异(对其它甲病毒成员,如东部马脑炎病毒和西部马脑炎病毒检测为阴性)。该方法可从委内瑞拉马脑炎病毒感染小鼠后第1d的血液、脾脏、脑组织中检测到不同含量的病毒核酸,而在感染后第3d仅从脾脏和脑组织中检测到病毒核酸。结论实时RT-PCR法不仅是一种敏感、准确的检测方法,可用来了解病毒感染量与疾病严重程度的关系和评价病毒病疫苗的免疫效果,而且也为VEEV疾病的临床诊断和流行病学监测提供工具。     

委内瑞拉马脑炎疫苗研究进展

委内瑞拉马脑炎是一种由蚊虫传播的人兽共患病毒性传染病. 我国虽然尚未发现委内瑞拉马脑炎病例,但随着国际交流的日益频繁,该病传入我国的风险大大增加. 该病目前尚无特效药及疗法,预防接种安全高效的疫苗对减少疾病暴发起着非常关键的作用. 本文对委内瑞拉马脑炎疫苗的最新研究进展进行综述,旨在为该病的新型疫苗研究及防控策略的制定提供参考.     

多重PCR结合核酸侵入反应及纳米金显色技术检测病毒性脑炎脑膜炎病原体

目的建立一种病毒性脑炎脑膜炎病原体多重PCR结合核酸侵入反应及纳米金显色的检测方法。方法针对几种重要的脑炎脑膜炎病毒(东方马脑炎病毒、西方马脑炎病毒、流行性乙型脑炎病毒、西尼罗病毒和尼帕病毒)保守区基因设计引物,进行多重PCR反应、核酸侵入反应及纳米金显色反应,对多种脑炎脑膜炎病毒同时进行检测,以森林脑炎病毒、圣路易脑炎病毒、基孔肯雅病毒和登革病毒4种病原核酸评价其检测特异性,以体外转录的病毒RNA或扩增的PCR片段评价其检测敏感性,并对流行性乙型脑炎患者临床标本进行检测。结果成功建立了一种脑炎脑膜炎病毒多重PCR结合核酸侵入反应及纳米金显色的检测技术。建立的检测方法可特异的检测目的病原体,且与森林脑炎病毒、圣路易脑炎病毒、基孔肯雅病毒和登革病毒无交叉反应。该方法对不同靶标的检测灵敏度均为103拷贝/μL,临床标本检测结果均为阳性。结论建立的脑炎脑膜炎病毒多重PCR结合核酸侵入反应及纳米金显色技术的检测方法,具有较高的检测特异性及灵敏度,检测通量高,肉眼即可观察结果,在传染病病原体检测方面具有广阔的应用前景。     

美国《Emerging Infectious Diseases》2009年第15卷第4期有关人兽共患病论文摘译

P519 墨西哥委内瑞拉马脑炎病毒人工感染潜在储存宿主的实验／／Eleanor R．Deardorff，Naomi L．Forrester,Amelia P．Travassos da Rosa等 1993年墨西哥的恰帕斯州沿海地区爆发了马脑炎疫情，125匹马受到感染，病死率达50％。此次疫情的病原体是委内瑞拉马脑炎病毒（VEEV）IE亚型，与此前的马类疾病和死亡无关。为了进一步了解该病毒株在恰帕斯州的生态学，我们人工感染了5种野生啮齿动物，     

两种甲病毒基因组序列的一步RT-PCR检测

目的　通过对不同扩增条件的优化 ,建立两种马脑炎病毒的快速RT -PCR检测方法。方法　根据东部马脑炎病毒和西部马脑炎病毒基因组相应序列设计引物 ,然后采用两步法及两种一步法分别对其基因组序列进行RT -PCR扩增 ,并用琼脂糖凝胶电泳进行观察。结果与结论　三种方法均可从两种马脑炎病毒感染的乳鼠脑和细胞上清中扩增出单一的DNA片段 ,其大小与预期的相一致。与其他两种方法相比 ,本研究所建立的一步法更为简便快速、价格低廉 ,为进一步组装这些病毒的检测试剂盒奠定了基础。     

严重急性呼吸综合征疫苗研究进展

现在科学家已经确定一种变异的冠状病毒(SARS-CoV)就是引起严重急性呼吸综合征(SARS)的病原体。为了防止SARS再次蔓延，有效的疫苗研发已经成为当务之急。现对与SARS疫苗密切相关的病毒概况、病毒免疫机制、疫苗研究现状、疫苗接种途径等问题的研究新进展进行综合论述。     

病毒性肝炎遗传修饰动物模型研究进展

病毒性肝炎在全球的广泛分布和传播是一个严重的公共卫生问题,探索治疗病毒性肝炎的方法及预防用疫苗的研发都离不开合适的动物模型。本文对相关受体的发现和遗传修饰动物模型的发展、用途及优缺点进行综述,并对未来动物模型的研究发展方向进行了展望。     

Control of intraabdominal hemorrhage and shock: a comparison of fluid resuscitation, MAST, and balloon occlusion

Our study examined the efficacy of four treatment modalities in controlling hemorrhage and achieving hemodynamic stabilization in hemorrhagic shock: intravenous fluid replacement (IV); military antishock trousers used concomitantly with fluids (MAST); balloon occlusion at the level of the diaphragm with concomitant fluid replacement (balloon); and a combination of MAST inflation, balloon occlusion, and fluid resuscitation (MAST and balloon). Twenty-eight mongrel dogs were anesthetized, and the spleen was exposed and completely crushed. The abdomen was closed, and treatment was initiated and continued for four hours or until the dog died. For all conditions the hematocrit dropped during the course of the experiment; balloon occlusion was effective at slowing this drop (P less than .0001), but MAST had no statistically significant effect. Animals with balloons bled more slowly into the abdominal cavity than did animals in the other two groups (P less than .0001). MAST also were effective at slowing the bleeding (P less than .05). Of the balloon and the MAST and balloon dogs, all except one survived the entire four hours; this difference between balloon and nonballoon dogs is significant (P = .002). MAST did not have a statistically significant effect on survival. Perfusion pressure (PP) declined during the course of the experiment, and the balloon was effective at slowing this decline (P less than .0001); none of the other comparisons was statistically significant.     

A Call to Action to Enhance Filovirus Disease Outbreak Preparedness and Response

The frequency and magnitude of recognized and declared filovirus-disease outbreaks have increased in recent years, while pathogenic filoviruses are potentially ubiquitous throughout sub-Saharan Africa. Meanwhile, the efficiency and effectiveness of filovirus-disease outbreak preparedness and response efforts are currently limited by inherent challenges and persistent shortcomings. This paper delineates some of these challenges and shortcomings and provides a proposal for enhancing future filovirus-disease outbreak preparedness and response. The proposal serves as a call for prompt action by the organizations that comprise filovirus-disease outbreak response teams, namely, Ministries of Health of outbreak-prone countries, the World Health Organization, Médecins Sans Frontières, the Centers for Disease Control and Prevention—Atlanta, and others.     

Interplay between interferon-mediated innate immunity and porcine reproductive and respiratory syndrome virus

Innate immunity is the first line of defense against viral infection, and in turn, viruses have evolved to evade host immune surveillance. As a result, viruses may persist in host and develop chronic infections. Type I interferons (IFN-α/β) are among the most potent antiviral cytokines triggered by viral infections. Porcine reproductive and respiratory syndrome (PRRS) is a disease of pigs that is characterized by negligible induction of type I IFNs and viral persistence for an extended period. For IFN production, RIG-I/MDA5 and JAK-STAT pathways are two major signaling pathways, and recent studies indicate that PRRS virus is armed to modulate type I IFN responses during infection. This review describes the viral strategies for modulation of type I IFN responses. At least three non-structural proteins (Nsp1, Nsp2, and Nsp11) and a structural protein (N nucleocapsid protein) have been identified and characterized to play roles in the IFN suppression and NF-κB pathways. Nsp's are early proteins while N is a late protein, suggesting that additional signaling pathways may be involved in addition to the IFN pathway. The understanding of molecular bases for virus-mediated modulation of host innate immune signaling will help us design new generation vaccines and control PRRS.     

Disease Pandemics and Major Epidemics Arising From New Encounters between Indigenous Viruses and Introduced Crops

Virus disease pandemics and epidemics that occur in the world’s staple food crops pose a major threat to global food security, especially in developing countries with tropical or subtropical climates. Moreover, this threat is escalating rapidly due to increasing difficulties in controlling virus diseases as climate change accelerates and the need to feed the burgeoning global population escalates. One of the main causes of these pandemics and epidemics is the introduction to a new continent of food crops domesticated elsewhere, and their subsequent invasion by damaging virus diseases they never encountered before. This review focusses on providing historical and up-to-date information about pandemics and major epidemics initiated by spillover of indigenous viruses from infected alternative hosts into introduced crops. This spillover requires new encounters at the managed and natural vegetation interface. The principal virus disease pandemic examples described are two (cassava mosaic, cassava brown streak) that threaten food security in sub-Saharan Africa (SSA), and one (tomato yellow leaf curl) doing so globally. A further example describes a virus disease pandemic threatening a major plantation crop producing a vital food export for West Africa (cacao swollen shoot). Also described are two examples of major virus disease epidemics that threaten SSA’s food security (rice yellow mottle, groundnut rosette). In addition, brief accounts are provided of two major maize virus disease epidemics (maize streak in SSA, maize rough dwarf in Mediterranean and Middle Eastern regions), a major rice disease epidemic (rice hoja blanca in the Americas), and damaging tomato tospovirus and begomovirus disease epidemics of tomato that impair food security in different world regions. For each pandemic or major epidemic, the factors involved in driving its initial emergence, and its subsequent increase in importance and geographical distribution, are explained. Finally, clarification is provided over what needs to be done globally to achieve effective management of severe virus disease pandemics and epidemics initiated by spillover events.     

Barrett's Esophagus: Where Do We Stand?

Barrett''s esophagus (BE) is a precursor for esophageal adenocarcinoma, which has an increased incidence rate over the last few decades. Its importance stems from the poor five-year survival of esophageal adenocarcinoma and current data that suggest a survival benefit when surveillance programs are implemented. In this review, we will cover the pathophysiology and natural history of BE and the different endoscopic findings. The prevalence of BE in different geographic areas and the incidence of high-grade dysplasia and adenocarcinoma in this patient population is reviewed. Recent recommendation for screening and surveillance of BE has been covered in this review as well as the efficacy of nonconventional imaging modalities and endoscopic ablation therapies.     

The Technology Transfer from Europe to China in the 17th–18th Centuries: Non-Invasive On-Site XRF and Raman Analyses of Chinese Qing Dynasty Enameled Masterpieces Made Using European Ingredients/Recipes

Two masterpieces of the Qing Dynasty (1644–1912 CE), one in gilded brass (incense burner) decorated with cloisonné enamels stylistically attributed to the end of the Kangxi Emperor’s reign, the other in gold (ewer offered by Napoleon III to the Empress as a birthday present), decorated with both cloisonné and painted enamels bearing the mark of the Qianlong Emperor, were non-invasively studied by optical microscopy, Raman microspectroscopy and X-ray microfluorescence spectroscopy (point measurements and mapping) implemented on-site with mobile instruments. The elemental compositions of the metal substrates and enamels are compared. XRF point measurements and mappings support the identification of the coloring phases and elements obtained by Raman microspectroscopy. Attention was paid to the white (opacifier), blue, yellow, green, and red areas. The demonstration of arsenic-based phases (e.g., lead arsenate apatite) in the blue areas of the ewer, free of manganese, proves the use of cobalt imported from Europe. The high level of potassium confirms the use of smalt as the cobalt source. On the other hand, the significant manganese level indicates the use of Asian cobalt ores for the enamels of the incense burner. The very limited use of the lead pyrochlore pigment (European Naples yellow recipes) in the yellow and soft green cloisonné enamels of the Kangxi incense burner, as well as the use of traditional Chinese recipes for other colors (white, turquoise, dark green, red), reinforces the pioneering character of this object in technical terms at the 17th–18th century turn. The low level of lead in the cloisonné enamels of the incense burner may also be related to the use of European recipes. On the contrary, the Qianlong ewer displays all the enameling techniques imported from Europe to obtain a painted decoration of exceptional quality with the use of complex lead pyrochlore pigments, with or without addition of zinc, as well as cassiterite opacifier.