Actions of BW540C in an equine model of acute inflammation: A preliminary study

Summary

An equine model of acute non‐immune inflammation has been developed to facilitate studies of the inflammatory process and the actions of novel anti‐inflammatory drugs. Five polyester sponge strips soaked in sterile 2% carrageenin solution were placed in subcutaneous pouches prepared under local anaesthesia in the necks of conscious ponies. Serial removal of the strips and harvesting of the exudate enabled studies to be made of the cellular, biochemical and mediator aspects of the localised, acute inflammation, and the heat generated by the lesion was monitored by infra‐red thermometry. Maximal concentrations of the eicosanoids 6‐keto‐prostaglandin F_1α, thromboxane B₂ and leukotriene B, occurred at 9 h, whereas leukocyte numbers, lactate dehydrogenase (LDH) and total protein concentrations were greatest at 24 h. Lesional skin temperature was increased by approximately 4°C throughout the 24 h period. The novel anti‐inflammatory agent BW540C, administered orally at a dose‐rate of 20 mg/kg, did not affect leukocyte infiltration or the concentrations of protein, LDH and eicosanoids in exudate but serum thromboxane B₂ levels were reduced. Skin temperature rises were greater in drug‐treated animals.

It is concluded that higher doses of BW540C will be required for a clinically useful anti‐inflammatory action in horses.     

鸡传染性贫血病毒VP1、VP2基因的表达及免疫原性研究

为探索鸡传染性贫血重组蛋白亚单位疫苗的可行性,将鸡传染性贫血病毒基因分别克隆到转移载体p Fast Bac HTA中,再将其分别转化DH10Bac感受态细胞得到相应的重组表达载体,转染昆虫细胞Sf21获得含有VP1、VP2基因的重组杆状病毒v Bac-VP1、v Bac-VP2,应用悬浮培养的Sf21细胞表达重组蛋白。SDS-PAGE及Western blotting结果证明,VP1、VP2基因在昆虫细胞中得到了表达,动物试验进一步证实,重组蛋白免疫SPF鸡可产生ELISA抗体,提示杆状病毒表达的VP1、VP2具有良好的免疫原性。     

Serological evidence of USUTU virus occurrence in north-eastern Italy

In the recent years, USUTU virus (USUV), a flavivirus of the Japanese encephalitis virus complex, has been reported in Central Europe. As part of a systematic surveillance programme to monitor possible entrance and/or circulation of vector-borne viruses, since 2001, sentinel-chicken flocks were placed throughout the Italian territory nearby areas considered at risk of virus introduction. They have been periodically checked for the presence of antibodies against flaviviruses by indirect ELISA, plaque reduction neutralization test for USUTU, West Nile and tick-borne encephalitis viruses. In July 2007, a sentinel chicken in a flock of 20 animals located within the Ravenna province seroconverted to USUV reaching neutralizing titres up to 1:5120. A second chicken seroconverted to the same virus 2 months later. Although no virus was rescued from these animals and from wild or farm birds sampled in the area, these results still provided evidence of the circulation of USUV in north-eastern Italy.     

新城疫病毒山东分离株ShD-5-06 F和HN基因序列分析

从山东济南某非典型新城疫发病鸡群中分离到一株新城疫病毒株（ShD-5—06）,研究其生物学特性表明,该病毒具有新城疫强毒株的一些特征。从该分离株扩增出其F和HN基因,并与标准株进行同源性比较,为探讨NDV是否发生变异提供理论依据。本试验通过RT—PCR法特异性地扩增出F和HN基因全基因序列,并对其与已经发表的序列进行核苷酸序列测定和分析。结果表明,ShD-5—06株的F和HN基因开放性阅读框架（ORF）为1662bp和1716bp,分别编码489个和571个氨基酸。与国外发表的部分新城疫病毒强毒株和弱毒株之间相应序列进行比较,F基因核苷酸序列的同源性在84．1％～88．7％之间,氨基酸同源性在88．1％～93．3％之间;HN基因核苷酸序列的同源性在82．19,5～87．4％之间,氨基酸同源性在88．6％～90．9%之间;F蛋白裂解位点区（112～117）氨基酸组成与强毒株一致,说明NDV山东分离株（ShD-5—06）为新城疫强毒株。     

猪繁殖与呼吸综合征病毒致病机理的研究进展

猪繁殖与呼吸综合征(PRRS)是由猪繁殖与呼吸综合征病毒(PRRSV)引起的一种以妊娠母猪严重繁殖障碍及仔猪的呼吸道症状和高死亡率为特征的传染病。现已遍及世界各主要养猪国家和地区,成为危害养猪业最严重的传染病之一。作者就猪繁殖与呼吸综合征病毒致病机理方面的研究情况作一综述,为诊断技术、免疫机理研究、疫苗设计和疫病防制提供借鉴。     

Anticipating the species jump: surveillance for emerging viral threats

Zoonotic disease surveillance is typically triggered after animal pathogens have already infected humans. Are there ways to identify high‐risk viruses before they emerge in humans? If so, then how and where can identifications be made and by what methods? These were the fundamental questions driving a workshop to examine the future of predictive surveillance for viruses that might jump from animals to infect humans. Virologists, ecologists and computational biologists from academia, federal government and non‐governmental organizations discussed opportunities as well as obstacles to the prediction of species jumps using genetic and ecological data from viruses and their hosts, vectors and reservoirs. This workshop marked an important first step towards envisioning both scientific and organizational frameworks for this future capability. Canine parvoviruses as well as seasonal H3N2 and pandemic H1N1 influenza viruses are discussed as exemplars that suggest what to look for in anticipating species jumps. To answer the question of where to look, prospects for discovering emerging viruses among wildlife, bats, rodents, arthropod vectors and occupationally exposed humans are discussed. Finally, opportunities and obstacles are identified and accompanied by suggestions for how to look for species jumps. Taken together, these findings constitute the beginnings of a conceptual framework for achieving a virus surveillance capability that could predict future species jumps.     

牛血清中口蹄疫病毒非结构蛋白抗体时间分辨荧光免疫分析检测方法的建立

为研究快速定量检测牛血清中口蹄疫病毒非结构蛋白抗体的方法,试验通过优化抗原表达条件等步骤,在大肠杆菌原核表达系统中表达可溶性的3A-3B融合蛋白,并基于纯化的可溶性融合蛋白建立口蹄疫病毒非结构蛋白抗体时间分辨荧光免疫分析检测试剂盒。结果表明:建立的方法能够检测牛血清中的口蹄疫病毒非结构蛋白抗体,敏感性高,特异性强,对其他相关的牛类病原无交叉反应,其组内与组间变异系数分别低于10%和15%,具有良好的重复性。对300份临床牛血清样品进行检测,同Procheck公司的口蹄疫非结构蛋白抗体试剂盒进行比较,阳性样品符合率96%,阴性样品符合率93.3%,总的符合率95.7%。重复性试验组内与组间变异系数均小于10%。文章首次建立了口蹄疫病毒非结构蛋白抗体时间分辨荧光免疫分析检测方法,同传统的ELISA方法相比,该检测方法特异性相当、敏感性更高,操作更简单、快速,具有较高的应用推广价值。     

Experimental studies of the role of the little raven (Corvus mellori) in surveillance for West Nile virus in Australia

Objective To study the potential role of an Australian corvid, the little raven (Corvus mellori), in the surveillance for exotic West Nile virus (WNV) in Australia. Method In a series of trials, little ravens were infected with WNV (strain 4132 New York 1999) and Kunjin virus (strain K42886) by the intramuscular route. They were observed for 20 days during which blood and swab samples were taken for virus isolation. Tissue samples were taken from ravens humanely killed during the acute infection period, and at the termination of the trials, for virus isolation, histopathology and immunohistochemistry. Results Ravens infected with WNV became mildly ill, but all recovered and seroconverted. Blood virus titres peaked around 3 to 4 days after inoculation at levels between 10^3.0 to 10^7.5 plaque forming units/mL. Virus or viral antigen was detected in spleen, liver, lung, kidney, intestine, testis and ovary by virus isolation and/or immunohistochemistry. WNV was detected in oral and cloacal swabs from 2 to 7 days post inoculation. The molecular and pathogenic characteristics of the inocula were consistent with them being of high virulence, as expected for this isolate. Ravens infected with Kunjin virus developed viraemia and seroconverted, although they did not develop disease. Conclusions Little ravens do not develop severe disease in response to virulent WNV infection and for this reason may not be important sentinel hosts in the event of an outbreak of WNV, as in North America. However, as they have relatively high viraemias, they may be able to support virus cycles.