中文摘要：

目的：聚合酶链反应方法检测后天感染鸭乙型肝炎病毒模型中共价闭环状DNA的表达。方法：实验于2006—06／2007—01在解放军总医院老年医学研究所完成。1日龄北京雏鸭6只经腿静脉注射上海麻鸭DHBV阳性血清（中国医学科学院提供）0.2mL/只，感染7d后处死动物取血分离血清并取肝组织，同时取同日龄正常鸭6只肝组织作为对照。聚合酶链反应技术检测肝脏、血清中鸭乙型肝炎病毒DNA及共价闭环状DNA的表达。结果：①血清斑点杂交显示模型制备成功，平均病毒吸光度值为0．62±0．12。②琼脂糖凝胶电泳显示，模型肝脏、血清中DHBVDNA均高表达，而共价闭环状DNA仅在模型肝脏表达，正常鸭DNA与共价闭环状DNA均不表达。结论：后天感染鸭乙型肝炎病毒模型中共价闭环状DNA高表达，可作为临床乙肝药物筛选模型。

英文摘要：

AIM： To study covalent closed circular DNA （cccDNA） expression in duck model with acquired duck hepatitis B virus （DHBV） detected by polymerase chain reaction （PCR）. METHODS： The experiment was carried out in Institution of Geriatrics and Gerontology, Chinese PLA General Hospital from June 2006 to January 2007. Six ducks of 1 day old were intravenously injected with DHBV-positive serum （offered by Chinese Academy of Medical Science, 0.2 mL for each duck）, seven days later, ducks were executed to separate the serum and take out liver tissues. Meanwhile six normal age-matched ducks were adopted as controls. The expressions of DHBV DNA and cccDNA in serum and liver were detected by PCR method. RESULTS： （1）The DHBV models were confirmed successfully by using serum dot blot hybridization, and serum DHBV absorbance value was 0.62±0.12. （2）Agarose gel electrophoresis showed that the DHBV DNA was highly detectable in the serum and liver of DHBV model, and cccDNA was detectable only in DHBV model liver. DHBV DNA and cccDNA were negative in control duck liver. CONCLUSION： The cccDNA is highly expressed in duck models with acquired DHBV, which is the ideal model for HBV drug screening.