应用RT—PCR方法检测鸭病毒性肝炎新型和I型病毒

鸭病毒性肝炎病毒是危害养鸭业的重要病毒性传染病,主要感染低日龄雏鸭,临床上分离到的病原主要为鸭病毒性肝炎I型病毒和鸭病毒性肝炎新型病毒,为了加快本病的检测速度,尽快确诊病原,根据GeneBank上两种毒株的基因组序列,选择两种毒株的差异基因序列分别设计了一对特异性的检测引物,将两对引物放在一个PCR反应体系中,两种毒株分别进行特异性扩增,根据扩增片段的大小进行鉴别,建立了可以同时检测鸭病毒性肝炎病毒I型和新型毒株的复合RT—PCR方法,该检测方法快速,特异性强,灵敏性高,可以用于鸭病毒性肝炎病毒的分型鉴别检测。     

Results of adrenalectomy in 36 dogs with hyperadrenocorticism caused by adrenocortical tumour

Summary

A total of 38 adrenocortical tumours were removed from 36 dogs with hyperadrenocorticism. The surgical approach was by way of a unilateral flank laparotomy (32 dogs; 14 left and 18 right), a bilateral flank laparotomy (3 dogs) or a midline celiotomy (1 dog).

Two dogs were euthanized during surgery because their tumours could not be resected. Eight dogs died from post‐operative complications. Pancreatic necrosis with peritonitis was the most common cause of death. Eight of the 26 dogs that survived had signs of recurrence of hyperadrenocorticism. Unsuppressible hyperadrenocorticism was found in four dogs; one dog had probably pre‐existent pituitary‐dependent hyperadrenocorticism, and adrenocortical function could not be re‐examined in the remaining three dogs.

Among the 37 tumours examined microscopically expansion of neoplastic tissue into blood vessels was found in 22 of them. Four adrenal glands with adrenocortical tumours also contained phaeochromocytomas. Necropsy was performed in eight dogs. Metastases were found in the lungs of two dogs and in the lungs and liver in one dog.

In combination with the data of previous reports, it is suggested that histological findings in surgery specimens are not good predictors for the clinical outcome.     

茵陈蒿汤加味配合西药治疗犬传染性肝炎的试验研究

为了观察3种治疗方法治疗犬传染性肝炎的疗效并进行对比，选出较好的治疗方案，以提高犬传染性肝炎的治愈率。本研究选宠物医院确诊为犬传染性肝炎的病犬60只，将患犬随机分4组，分别采用茵陈篙汤加味配合西药、单用茵陈篙汤加味、单用西药的治疗方法，并设对照组。结果显示，茵陈篙汤加味配合西药组的治愈率86.67%；茵陈篙汤加味组治愈率73.33%；西药组治愈率66.67%；对照组治愈率为0。试验表明，采用茵陈篙汤加味配合西药治疗犬传染性肝炎的疗效高于其他两种方法，为临床治疗该病提供了确实可行的治疗方法。     

Seroepidemiology and genotyping of hepatitis E virus in Singapore reveal rise in number of cases and similarity of human strains to those detected in pig livers

Hepatitis E virus (HEV) causes 20 million infections worldwide yearly, of which only about 3.3 million are symptomatic. In developed Asian countries, HEV strains detected in human sera and in food sources were genetically similar, suggesting that indigenous HEV infections may be largely food‐borne. To assess the burden of hepatitis E in Singapore, we performed a seroepidemiologic study of the infection. Additionally, we carried out HEV genotyping on archived, residual HEV IgM‐positive serum samples collected between 2014 and 2016 (n = 449), and on pig liver samples (n = 36) purchased from wet markets and supermarkets. Our study shows a rise in hepatitis E incidence (IgM) from 1.7 to 4.1 cases per 100,000 resident population from 2012 to 2016 and an increase in hepatitis E IgG positivity rate among residents from 14% in 2007 to 35% in 2016. Other findings also suggest the epidemiology of hepatitis E in Singapore has shifted, from it being mainly a disease imported from the Indian subcontinent, to one that is now increasingly prevalent in our resident population. Genotypes obtained from 143 human samples identified the majority to be genotype 3 (n = 121), 21 to be genotype 1 and one to be genotype 4. Further phylogenetic analyses suggest genotype 3a to be the cause of indigenous infections in residents, which showed genetic similarity to the genotype 3a strains detected in pig livers. This link between the strains in the majority of human samples and those in pig livers consumed by the public suggests a possible food‐borne route of HEV infection in Singapore.     

Ⅰ型鸭病毒性肝炎弱毒疫苗的研制

本试验从山东地区分离的多株Ⅰ型鸭病毒性肝炎毒株中筛选出免疫原性优良毒株CL,将其在SPF鸡胚中盲传致弱后制备鸭肝炎弱毒疫苗。安全检验、保存期和免疫效力试验结果表明。研制的鸭肝炎弱毒疫苗安全可靠,无毒副作用;-20℃条件下可保存6个月以上;接种后抗体产生快,3d便可产生较强的免疫力,7d时抗体中和效价为2^63,一次免疫抗体可维持6周以上。     

鸭病毒性肝炎的流行病学调查和发病原因分析

本文通过1996年1月～1998年9月郑州地区296例鸭病毒性肝炎病例的分析,结合种鸭场、养鸭户的调查,对鸭病毒性肝炎的发病规律和发病原因进行了综合的分析研究。结果发现,郑州地区鸭病毒性肝炎发病日龄以5～15日龄最多,发病日龄在逐年增大;发病月份以5～6和9～11月最高,而且混合感染病例增加。在病因的调查中发现,除了种鸭免疫和母源抗体影响外,相当多的发病属于养殖户对传染病的认识不足而造成的。     

新型鸭肝炎病毒FS株全基因组序列分析

本试验参考GenBank中已公布的新型鸭肝炎病毒全基因组序列,应用Primer Premier5．O软件,在序列保守区域分别设计了7对引物,通过RT-PCR方法对本实验室已鉴别纯化的新型鸭肝炎病毒Fs株进行了分段扩增,经过测序拼接整理,获得Fs株全基因组序列（GenBank中登录号为EU877916）。序列分析表明,Fs株全长7792个碱基,一个大的开放阅读框编码2251aa。将各基因与国内外已发表的新型鸭肝炎病毒参考毒株进行相似性分析,结果表明,与G株（GenBank登录号为EU755009）核苷酸相似性最高,为99．2％,而FS株与G株和C—GY株（GenBank登录号为EU352805）的氨基酸相似性最高,均为99．6％,与DHV—HS株和DHV-HSS株的相似性最低,均为83．6％。系统发育树分析发现,与G株亲缘关系最近。