山东省部分养殖场点马属动物主要病毒疫病调查

为了解山东省马属动物主要病毒疫病流行现状,采集青岛市2个马场以及济南、聊城和德州等驴养殖密集地市4个驴场的血清和全血样品各694份,分别进行马传染性贫血、H3N8亚型马流感血清抗体检测和非洲马瘟病原检测。结果显示:马传染性贫血、非洲马瘟检测全部为阴性,H3N8亚型马流感群体阳性率和样品阳性率分别为100%(6/6)和81.38%(520/639)。结果表明:马传染性贫血和非洲马瘟在这些养殖场点已得到很好的预防,但鉴于国外严峻的疫情形势,需要继续加强监测,防止病原传入;H3N8亚型马流感流行较为普遍,感染率较高,需要重点加强防控。本调查为山东省马属动物疫病防控提供了数据参考。

规模化养羊主要病毒性疫病的诊断与防治

羊病防控的问题备受世人关注,其中病毒性疾病危害巨大,发病原因也十分复杂,不仅威胁羊只的健康程度,同时关系到地区的公共卫生安全。如何强化病毒性疫病的诊断与防治工作,提高养羊的经济效益,对于规模化养羊来说至关重要。文章针对规模化养羊主要病毒性疫病的诊断与防治进行探讨。

用于诊断4种猪病毒病的寡核苷酸芯片的研制

制备可同时检测引起集约化养猪业常见4种传染病,病毒(猪流感病毒、口蹄疫病毒、猪伪狂犬病毒、猪蓝耳)的寡核苷酸芯片。根据4种猪疫病病毒特异性基因的保守区域设计合成了60 mer寡核苷酸探针,制备寡核苷酸芯片。采用不对称PCR和间接荧光标记技术进行单链DNA扩增和荧光标记,标记样品与寡核苷酸芯片杂交后,进行芯片清洗、扫描及结果分析。杂交结果显示,4种病毒的寡核苷酸检测探针均特异地与相应的标记样品杂交,芯片上呈现较强的阳性杂交信号,而除阳性质控探针外,阴性对照和空白对照均检测不到荧光信号。证明寡核苷酸芯片适用于快速、准确、高通量地诊断影响集约化养猪业的多种猪疫病病毒。

猪3种重要病毒寡核苷酸芯片诊断方法的建立

将猪细小病毒(PPV)、猪圆环病毒-Ⅱ(PCV-2)、猪瘟病毒(CSFV)分别应用生物信息学方法,针对病毒基因组保守序列设计特异性强的60-mer寡核苷酸探针,并将其按所设计阵列固定于表面经氨基化修饰的玻片上,制备出寡核苷酸芯片。分别设计出相应的引物,对待测样本进行不对称PCR扩增,从而产生大量可与寡核苷酸探针特异性互补的单链DNA片段,并通过间接荧光标记技术使扩增产物标记上荧光染料。将标有荧光染料的扩增产物与芯片上寡核苷酸探针杂交,扫描、分析芯片上荧光信号。试验结果表明,芯片上各样本对应探针位点呈现阳性荧光信号,而阴性对照和空白对照则基本不能检测到荧光信号。不对称PCR技术制备的单链DNA片段与寡核苷酸芯片进行杂交反应可同时、快速、特异性地检测多种猪疫病病毒。

新冠肺炎疫情对世界经济政治格局的影响

新冠肺炎疫情作为全球范围的“灰犀牛”和“黑天鹅事件”,不仅对人类健康构成影响,也对世界经济、政治造成冲击和影响,其程度取决于疫情蔓延的时间和各国防控措施的强度。本文试图根据新冠肺炎疫情的特征和蔓延程度,分析其对世界经济与政治格局的影响,并对各种观点进行评析,最后从加强国际协调行动、利用中国率先走出疫情的先机和庞大的国内市场资源重振产业链、构建内外协调的开放型经济新体制、对外着力营造周边环境四个方面提出我国应对疫情后世界格局演变的思路与措施,以供参考。

Construction and Immunogenicity of Associated DNA Vaccine of PRRS and PCV-2 Disease

[ Objective ] The aim of the study was to construct associated DNA vaccine of PRRS （Porcine reproductive and respiratory syndrome） and PCV-2 （Porcine circovirus type 2） disease and study its immunogenicity. [ Method] In_ this study, the ORF5 gene of PRRSV isolated in Liaoning was cloned into plRES-neo expression vector, and the neo gene of plRES-neo expression vector was substituted by the ORF2 gene of the PCV-2 Mongolia strain to construct the recombinant expression vector. The expression in BHK cells was detected through Western blot and IFA. Then the ELISA antibody level and the number of spleen T lymphocytes were detected after Balb/c mice were immunized with this DNA vaccine. E Result] The recombinant plasmid plRES-ORF2-ORF5 was constructed successfully and could express the target proteins in BHK cells, as indicated by Western blot and IFA. There was no significant difference in ELISA antibody between plRES-ORF2-ORF5 immunized group and inactived vaccine immunized groups, while the number of spleen T lymphocytes induced by DNA vaccine was higher than that induced by inactived vaccine. [ Conclusion] The recombinant plasmid plRES-ORF2-ORF5 should induce good humoral immune response and cellular immune response in mice, providing the conditions for better prevention and control of PRRS and PCV-2 disease.

Construction and Identification of a Goat Pox Virus Transfer Vector to Express Peste des Petits Ruminants H gene

[Objective] This study was to develop a live vector vaccine of goat pox virus of Peste des petits ruminants(PPR). [Method] Using PCR amplification technique, PPR H gene was obtained, then ligated into pGEM-T easy vector; the recombinants were digested by Nhe Ⅰ and Hind Ⅲ, and ligated into pEGFP-N1-P7.5, yielding the recombinant vector pEGFP-N1-P7.5-H; next the expression cassette EGFP-N1-P7.5-H was first released from recombinant vector pEGFP-N1-P7.5-H by double digestion of Hind Ⅲ and Nhe Ⅰ and ligated into pUC119-TK that was digested by Kpn Ⅰ, yielding the transfer vector pUC119-TK-EGFP-P7.5-H. [Result] Identification and double enzyme digestion showed that the transfer vector pUC119-TK-EGFP-P7.5-H was correctly constructed. From the transfer vector transfected BHK-21 cells which infected GTPV AV41, specific fluorescence was observed at 48th h of transfection. [Conclusion] The construction of goat poxvirus live vector laid a foundation for the live vector vaccine of PPR vaccine.

Cloning and Sequence Analysis of HN and F Protein Genes from a Strain of Goose Paramyxovirus

[ Objective] The study was to clone HN and F genes from GX1 strain of goose paramyxovirus and analyze their sequences. [ Method] According to the full nucleotide sequence of GPV-SF02 strain of goose paramyxovirus, two pairs of pdmers were designed to amplify the HN and F genes from GX1 strain of goose paramyxovirus isolated from diseased goose in Guangxi Zhuang Autonomous Region; the amplified products were ligated into pMD18-T vector and sequenced. [ Result ] HN and F genes of this strain tested were 1 716 and 1 662 bp in full nucleotide length, respectively; both showed the homologues of about 97.3% with GPV- SF02 strain, of 80.3% -97.5% with strains LaSota, F48E9 and JS, of just 84.8% with Miyadera strain. [ Conclusion] The results show that isolated strain BX1 matches to virulent APMV-1 strain, belonging to genotype Ⅶ of APMV-1 strain.

Significant increase in HBV, HCV, HIV and syphilis infections among blood donors in West Bengal, Eastern India 2004-2005: Exploratory screening reveals high frequency of occult HBV infection

AIM: To evaluate the prevalence of markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) and human immunodeficiency virus (HIV) among blood donors in Kolkata, Eastern India for two consecutive years and to conduct a pilot study to explore the presence of HBV DNA among hepatitis B surface antigen (HBsAg) negative but anti-HBc positive blood donors. METHODS: Seroprevalence of HBsAg, anti-HCV and anti-HIV was studied among 113 051 and 106 695 voluntary blood donors screened in 2004 and 2005, respectively. Moreover, a pilot study on 1027 HBsAg negative donors was carried out for evaluating the presence of HBV DNA by PCR on HBsAg negative/anti- HBc positive donors. RESULTS: A statistically significant increase in the prevalence of HBV (1448 vs 1768, P < 0.001), HIV (262 vs 374, P < 0.001), HCV (314 vs 372, P = 0.003) and syphilis (772 vs 853, P = 0.001) infections was noted among blood donors of Kolkata West Bengal in 2005 as compared to 2004. Moreover, the exploratory study on 1027 HBsAg negative donors revealed that 188 (18.3%)of them were anti-HBc positive out of which 21% were positive for HBV DNA. CONCLUSION: The findings of this study underscore the significantly increasing endemicity of hepatitis viruses, syphilis and HIV among the voluntary blood donors of our community. The pilot study indicates a high rate of prevalence of HBV DNA among HBsAg negative/anti-HBc positive donors and thus emphasizes the need for a more sensitive and stringent screening algorithm for blood donations.

T cell immunopathogenesis and immunotherapeutic strategies for chronic hepatitis B virus infection

Hepatitis B is caused by the host immune response and T cells play a major role in the immunopathogenesis. More importantly,T cells not only destroy hepatocytes infected by hepatitis B virus(HBV),but also control HBV replication or eradicate HBV in a noncytolytic manner.Therefore,analysis of T cell immune response during acute and chronic HBV infection is important to develop a strategy for successful viral control,which could lead to immunotherapy for terminating persistent HBV infection.There have been many attempts at immunotherapy for chronic HBV infection,and some have shown promising results.High viral load has been shown to suppress antiviral immune responses and immunoinhibitory signals have been recently elucidated, therefore,viral suppression by nucleos(t)ide analogs, stimulation of antiviral immune response,and suppression of the immunoinhibitory signals must be combined to achieve desirable antiviral effects.

Impact of human immunodeficiency virus infection on the course of hepatitis C virus infection: A meta-analysis

AIM: To analyze the influence of human immunodeficiency virus (HIV) infection on the course of hepatitis C virus (HCV) infection. METHODS: We performed a meta-analysis to quantify the effect of HIV co-infection on progressive liver disease in patients with HCV infection. Published studies in the English or Chinese-language medical literature involving cohorts of HIV-negative and -positive patients coinfected with HCV were obtained by searching the PUBMED, EMBASE and CBM. Data were extracted independently from relevant studies by 2 investigators and used in a fixed-effect meta analysis to determine the difference in the course of HCV infection in the 2 groups. RESULTS: Twenty-nine trails involving 16 750 patients were identified including the outcome of histological fibrosis or cirrhosis or de-compensated liver disease or hepatocellular carcinoma or death. These studies yielded a combined adjusted odds ratio (OR) of 3.40 [95% confidence interval (CI) = 2.45 and 4.73]. Of note, studies that examined histological fibrosis/ cirrhosis, decompensated liver disease, hepatocellular carcinoma or death had a pooled OR of 1.47 (95% CI = 1.27 and 1.70), 5.45 (95% CI = 2.54 and 11.71), 0.76 (95% CI = 0.50 and 1.14), and 3.60 (95% CI = 3.12 and 4.15), respectively. CONCLUSION: Without highly active antiretroviral therapies (HAART), HIV accelerates HCV diseaseprogression, including death, histological fibrosis/ cirrhosis and decompensated liver disease. However, the rate of hepatocellular carcinoma is similar in persons who had HCV infection and were positive for HIV or negative for HIV.

Immunogenicity of DNA and Recombinant Sendai Virus Vaccines Expressing the HIV-1 gag Gene

Combinations of DNA and recombinant-viral-vector based vaccines are promising AIDS vaccine methods because of their potential for inducing cellular immune responses. It was found that Gag-specific cytotoxic lymphocyte (CTL) responses were associated with lowering viremia in an untreated HIV-1 infected cohort. The main objectives of our studies were the construction of DNA and recombinant Sendai virus vector (rSeV) vaccines containing a gag gene from the prevalent Thailand subtype B strain in China and trying to use these vaccines for therapeutic and prophylactic vaccines. The candidate plasmid DNA vaccine pcDNA3.1(+)-gag and recombinant Sendai virus vaccine (rSeV-gag) were constructed separately. It was verified by Western blotting analysis that both DNA and rSeV-gag vaccines expressed the HIV-1 Gag protein correctly and efficiently. Balb/c mice were immunized with these two vaccines in different administration schemes. HIV-1 Gag-specific CTL responses and antibody levels were detected by intracellular cytokine staining assay and enzyme-linked immunosorbant assay (ELISA) respectively. Combined vaccines in a DNA prime/rSeV-gag boost vaccination regimen induced the strongest and most long-lasting Gag-specific CTL and antibody responses. It maintained relatively high levels even 9 weeks post immunization. This data indicated that the prime-boost regimen with DNA and rSeV-gag vaccines may offer promising HIV vaccine regimens.

Sequence Variation in the Gp120 region of SHIV-CN97001 during in vivo Passage

SHIV-CN97001 played an important role in assessing the immune effect and strategy of the AIDS vaccine which included genes of the predominant prevalent HIV-1 strain in China. In this study, SHIV-CN97001 was in vivo passaged serially to construct pathogenic SHIV-CN97001/rhesus macaques model. To identify variation in the gp120 region of SHIV-CN97001 during passage, the fragments of gp120 gene were amplified by RT-PCR from the plasma of SHIV-CN97001 infected animals at the peak viral load time point and the gene distances (divergence, diversity) were calculated using DISTANCE. The analysis revealed that the genetic distances of SHIV-CN97001 in the third passage animals were the highest during in vivo passage. It had a relationship between viral divergence from the founder strain and viral replication ability. The nucleic acid sequence of the V3 region was highly conservative. All of the SHIV-CN97001 strains had V3 loop central motif (GPGQ) and were predicted to be using CCR5 co-receptor on the basis of the critical amino acids within V3 loop. These results show that there was no significant increase in the genetic distance during serial passage, and SHIV-CN97001 gp120 gene evolved toward ancestral states upon transmission to a new host. This could partly explain why there was no pathogenic viral strain obtained during in vivo passage.

Characterization of a Putative Filovirus Vaccine:Virus-Like Particles

Filoviruses are hemorrhagic fever viruses endemic to parts of Africa and the Philippines. Infection carries with it a mortality rate of up to 90% and currently there are no effective vaccines or therapeutics available to combat infection. However, the filovirus virus-like particles (VLP), which are currently under development, have been shown to be a promising vaccine candidate. They provide protection from infection in the mouse, guinea pig, and nonhuman primate models of infection, eliciting high anti-glycoprotein antibody titers and T cell responses to viral proteins. In this review, we will highlight the development of the filovirus VLP and describe the current understanding of VLP immunogenicity and correlates of protection.

Hepatocellular carcinoma in patients with autoimmune hepatitis

AIM: To evaluate and confirm the low incidence of hepatocellular carcinoma (HCC) in patients with autoimmune hepatitis (AIH). At present only very few cases of HCC in patients with AIH and definite exclusion of chronic viral hepatitis have been published, suggesting that HCC due to AIH is rare. METHODS: In order to further investigate the incidence of HCC in patients with AIH, we reviewed our large cohort of 278 patients with AIH. RESULTS: Eighty-nine patients (32%) were diagnosed with liver cirrhosis, a preneoplastic condition for HCC. We studied a total of 431 patient years of cirrhosis in these patients, an average 4.8 years per patient. During this period none of the patients of our own study cohort developed HCC. However, three patients with HCC due to AIH associated liver cirrhosis were referred to our department for further treatment of HCC. In all three patients chronic viral hepatitis was excluded. CONCLUSION: We conclude that HCC may under rare circumstances develop due to chronic AIH dependent liver cirrhosis. Compared to other causes of liver cirrhosis such as chronic viral hepatitis, alcohol, or hemochromatosis, the incidence of HCC is significantly lower. Pathophysiological differences between AIH and chronic viral hepatitis responsible for differences in the incidence of HCC are yet to be further characterized and may lead to new therapeutic concepts in prevention and treatment of liver cancer.

Effect of liniment levamisole on cellular immune functions of patients with chronic hepatitis B

AIM: To explore the effects of liniment levamisole on cellular immune functions of patients with chronic hepatitis B. METHODS: The levels of T lymphocyte subsets and mlL-2R in peripheral blood mononuclear cells (PBMCs) were measured by biotin-streptavidin (BSA) technique in patients with chronic hepatitis B before and after the treatment with liniment levamisole. RESULTS: After one course of treatment with liniment levamisole, the levels of CD3+, CD4+, and the ratio of CD4+/CD8+ increased as compared to those before the treatment but the level of CD8+ decreased. The total expression level of mIL-2R in PBMCs increased before and after the treatment with liniment levamisole. CONCLUSION: Liniment levamisole may reinforce cellular immune functions of patients with chronic hepatitis B.

Circulating adhesion molecules in patients with virus-related chronic diseases of the liver

AIM: In the inflammatory state, intercellular adhesion molecule-1 (ICAM-1) and vascular cellular adhesion molecule-1 (VCAM-1) play a key role in promoting migration of immunological cells from the circulation to target site.Aim of our study was to investigate soluble forms of these molecules in patients with virus-related chronic liver diseases, to assess their behavior in different pathologies and correlation with severity of liver damage.METHODS: Circulating ICAM-1 and VCAM-1 were assayed by EIA commercial kits (R&D System Co.,Abington, UK) in 23 patients with chronic active hepatitis (CH), 50 subjects affected by liver cirrhosis (LC) and 15 healthy controls comparable for sex and age. In patients, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were also detected by autoanalyzer.RESULTS: LC patients had significantly higher ICAM-1 values than CH patients (38.56±7.4 ng/mL vs 20.89±6.42 ng/mL; P＜0.001) and these ones had significantly higher values than controls (12.92±1.08 ng/mL; P＜0.001). In CH group, ICAM-1 levels were significantly related to inflammatory activity (P= 0.041) and ALT values (r= 0.77;P＜0.05). VCAM-1 values were significantly increased only in LC patients (P＜0.001) and related to severity of liver impairment.CONCLUSION: These findings suggest that the determination of serum ICAM-1 can be considered as an additional useful marker of hepatocellular necrosis and inflammatory activity in chronic hepatitis, while serum VCAM-1 is an indicator of liver fibrogenesis and severity of disease in cirrhosis.

Hepatocellular carcinoma,human immunodeficiency virus and viral hepatitis in the HAART era

The incidence of hepatocellular carcinoma(HCC)in patients with human immunodeficiency virus(HIV) is rising.HCC in HIV almost invariably occurs in the context of hepatitis C virus(HCV)or hepatitis B virus (HBV)co-infection and,on account of shared modes of transmission,this occurs in more than 33% and 10% of patients with HIV worldwide respectively.It has yet to be clearly established whether HIV directly accelerates HCC pathogenesis or whether the rising incidence is an epiphenomenon of the highly active antiretroviral therapy(HAART)era,wherein the increased longevity of patients with HIV allows long-term complications of viral hepatitis and cirrhosis to develop.Answering this question will have implications for HCC surveillance and the timing of HCV/HBV therapy,which in HIV co-infection presents unique challenges.Once HCC develops,there is growing evidence that HIV co-infection should not preclude conventional therapeutic strategies,including liver transplantation.

Hepatitis B virus prevalence and transmission risk factors in inflammatory bowel disease patients at Clementino Fraga Filho university hospital

AIM: To evaluate the prevalence of hepatitis B virus (HBV) infection in inflammatory bowel disease (IBD) patients that followed up in our hospital and try to identify the possible risk factors involved in this infection transmission. METHODS: This was a cross-sectional study for which 176 patients were selected according to their arrival for the medical interview. All these patients had already IBD diagnosis. The patient was interviewed and a questionnaire was filled out. RESULTS: In the group of 176 patients whom we examined, we found that 17% (30) were anti-HBc positive. Out of 30 patients with positive anti-HBc, 2.3% (4) had positive HBsAg and negative HBV-DNA. In an attempt to identify the possible HBV infection transmission risk factors in IBD patients, it was observed that 117 patients had been submitted to some kind of surgical procedure, but only 24 patients had positive anti-HBc (P = 0.085). It was also observed that surgery to treat IBD complications was not a risk factor for HBV infection transmission, since we did not get a statically significant P value. However, IBDpatients that have been submitted to surgery to treat IBD complications received more blood transfusions then patients submitted to other surgical interventions (P = 0.015). CONCLUSION: There was a high incidence of positive anti-HBc (17%) and positive HBsAg (2.3%) in IBD patient when compared with the overall population (7.9%).

Hepatitis B and C virus co-infections in human immunodeficiency virus positive North Indian patients

AIM： To determine the prevalence of hepatitis B and C virus infections in human immunodeficiency virus （HIV） -positive patients at a tertiary care hospital in New Delhi, India. METHODS： Serum samples from 451 HIV positive patients were analyzed for HBsAg and HCV antibodies during three years （Jan 2003-Dec 2005）. The control group comprised of apparently healthy bone-marrow and renal donors. RESULTS： The study population comprised essentially of heterosexually transmitted HIV infection. The prevalence Fate of HBsAg in this population was 5.3% as compared to 1.4% in apparently healthy donors （P 〈 0.001）. Though prevalence of HCV co-infection （2.43%） was lower than HBV in this group of HIV positive patients, the prevalence was significantly higher （P 〈 0.05） than controls （0.7%）. Triple infection of HIV, HBV and HCV was not detected in any patient. CONCLUSION： Our study shows a significantly high prevalence of hepatitis virus infections in HIV infected patients. Hepatitis viruses in HIV may lead to faster progression to liver cirrhosis and a higher risk of antiretroviral therapy induced hepatotoxicity. Therefore, it would be advisable to detect hepatitis virus coinfections in these patients at the earliest.