Since the first human case of H5N1 avian influenza virus infection was reported in 1997, this highly pathogenic virus has infected hundreds of people around the world and resulted in many deaths. The ability of H5N1 t...Since the first human case of H5N1 avian influenza virus infection was reported in 1997, this highly pathogenic virus has infected hundreds of people around the world and resulted in many deaths. The ability of H5N1 to cross species boundaries, and the presence of polymorphisms that enhance virulence, present challenges to developing clear strategies to prevent the pandemic spread of this highly pathogenic avian influenza (HPAI) virus. This review summarizes the current understanding of, and recent research on, the avian influenza H5N1 virus, including transmission, virulence, pathogenesis, clinical characteristics, treatment and prevention.展开更多
Human bocavirus(HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool s...Human bocavirus(HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool samples, from patients with gastroenteritis. Since then, other viruses related to the first HBoV isolate(HBoV 1), namely HBoV 2, HBoV 3 and HBoV 4, have been detected principally in human faeces. HBo Vs are small nonenveloped single-stranded DNA viruses of about 5300 nucleotides, consisting of three open reading frames encoding the first two the non-structural protein 1(NS1) and nuclear phosphoprotein(NP1) and the third the viral capsid proteins 1 and 2(VP1 and VP2). HBoV pathogenicity remains to be fully clarified mainly due to the lack of animal models for the difficulties in replicating the virus in in vitro cell cultures, and the fact that HBo V infection is frequently accompanied by at least another viral and/or bacterial respiratory and/or gastroenteric pathogen infection. Current diagnostic methods to support HBoV detection include polymerase chain reaction, real-time PCR, enzymelinked immunosorbent assay and enzyme immunoassay using recombinant VP2 or virus-like particle capsid proteins, although sequence-independent amplification techniques combined with next-generation sequencing platforms promise rapid and simultaneous detection of the pathogens in the future. This review presents the current knowledge on HBoV genotypes with emphasis on taxonomy, phylogenetic relationship and genomic analysis, biology, epidemiology, pathogenesis and diagnostic methods. The emerging discussion on HBoV s as true pathogen or innocent bystander is also emphasized.展开更多
AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164...AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164 patients was investigated. Complete history, route of infection, assessment of alcohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene sequencing of 5＇ NTR type-specific PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows （version 10.0） was used for univariate regression analysis with further multivariate analysis. RESULTS： The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 （mainly the subtype 1b） was found to be independent of age in subjects older than 40 years, high viral load, more severe necro-inflammatory activity, advanced stage of fibrosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive predictive factors for the genotypes lb and 3a, respectively.CONCLUSION： In Serbia and Montenegro, the genotypes 1b and 3a predominate in patients with chronic HCV infection. The subtype lb is characteristic of older patients, while the genotype 3a is common in drug abusers. Association of the subtype lb with advanced liver disease, higher viral load and histological activity suggests earlier infection with this genotype and eventually its increased pathogenicity.展开更多
Objective To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV). Methods Human peripheral blood lymphocytes (PBLs) were isolated from healthy...Objective To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV). Methods Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient(SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supernatant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experime-ntal animals and induced neoplasms. Results In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors, tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence. Conclusions EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.展开更多
AIM： To investigate the genetic characteristics and pathogenicity of hepatitis E virus （HEV） and assess the potential risk factors for sporadic hepatitis E.
China is currently experiencing one of the most rapidly expanding HIV epidemics in the world. Although the overall prevalence rate is still low, with a population of 1.3 billion, high-risk factors which have contribut...China is currently experiencing one of the most rapidly expanding HIV epidemics in the world. Although the overall prevalence rate is still low, with a population of 1.3 billion, high-risk factors which have contributed to the HIV/AIDS epidemics worldwide continue to prevail in China, including a high rate of injecting drug use and needle sharing, commercial sex with low rates of condom use, and concurrent sex with both commercial sex workers and noncommercial casual or steady sex partners. In addition, there are increasing “double risk” populations overlapping drug users and sex workers, as well as increasing rates of STDs and HIV among high-risk populations. Sexual transmission, therefore, may serve as a bridge connecting high-risk populations with general populations. There is an urgent need to prevent the spread of HIV from these high-risk oooulations into the general oooulation of China.展开更多
Aristolochic acids （AAs）, a natural mixture of 8-methoxy-6-nitro-phenanthro-（3,4-d）-1,3-dioxolo-5-carboxylic acid （AAI）and 6-nitro-phenanthro-（3,4-d）-1,3-dioxolo-5-carboxylic acid （AAII）, derived from aristo...Aristolochic acids （AAs）, a natural mixture of 8-methoxy-6-nitro-phenanthro-（3,4-d）-1,3-dioxolo-5-carboxylic acid （AAI）and 6-nitro-phenanthro-（3,4-d）-1,3-dioxolo-5-carboxylic acid （AAII）, derived from aristolochiaceae species, has beenreported to cause AAS-induced nephropathy and upper urothelial cancer. In this review, we summarize the informationon the nephrotoxicity and carcinogenesis of AAs and their derivatives. AAs nephrotoxicity can lead to apoptosis andoxidative stress of renal tubular cells, and inhibition of the expression of aquaporins. AAs can also reduce the capabilityfor renal tubular epithelial cell repair after acute injury and further produce renal fibrosis by activating TGF-β-Smadsignaling and promoting the migration of macrophages. Moreover, AAs-induced carcinogenesis may be due to theformation of covalent adducts with DNA which can lead to the mutation in certain tumor suppressor genes orproto-oncogenes and the different catalyzing capacity of the microsomal cytochrome P450 of individuals in AAImetabolism.展开更多
基金National Natural Science Foundation of China (30979144 and 81271821)
文摘Since the first human case of H5N1 avian influenza virus infection was reported in 1997, this highly pathogenic virus has infected hundreds of people around the world and resulted in many deaths. The ability of H5N1 to cross species boundaries, and the presence of polymorphisms that enhance virulence, present challenges to developing clear strategies to prevent the pandemic spread of this highly pathogenic avian influenza (HPAI) virus. This review summarizes the current understanding of, and recent research on, the avian influenza H5N1 virus, including transmission, virulence, pathogenesis, clinical characteristics, treatment and prevention.
文摘Human bocavirus(HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool samples, from patients with gastroenteritis. Since then, other viruses related to the first HBoV isolate(HBoV 1), namely HBoV 2, HBoV 3 and HBoV 4, have been detected principally in human faeces. HBo Vs are small nonenveloped single-stranded DNA viruses of about 5300 nucleotides, consisting of three open reading frames encoding the first two the non-structural protein 1(NS1) and nuclear phosphoprotein(NP1) and the third the viral capsid proteins 1 and 2(VP1 and VP2). HBoV pathogenicity remains to be fully clarified mainly due to the lack of animal models for the difficulties in replicating the virus in in vitro cell cultures, and the fact that HBo V infection is frequently accompanied by at least another viral and/or bacterial respiratory and/or gastroenteric pathogen infection. Current diagnostic methods to support HBoV detection include polymerase chain reaction, real-time PCR, enzymelinked immunosorbent assay and enzyme immunoassay using recombinant VP2 or virus-like particle capsid proteins, although sequence-independent amplification techniques combined with next-generation sequencing platforms promise rapid and simultaneous detection of the pathogens in the future. This review presents the current knowledge on HBoV genotypes with emphasis on taxonomy, phylogenetic relationship and genomic analysis, biology, epidemiology, pathogenesis and diagnostic methods. The emerging discussion on HBoV s as true pathogen or innocent bystander is also emphasized.
文摘AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164 patients was investigated. Complete history, route of infection, assessment of alcohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene sequencing of 5＇ NTR type-specific PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows （version 10.0） was used for univariate regression analysis with further multivariate analysis. RESULTS： The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 （mainly the subtype 1b） was found to be independent of age in subjects older than 40 years, high viral load, more severe necro-inflammatory activity, advanced stage of fibrosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive predictive factors for the genotypes lb and 3a, respectively.CONCLUSION： In Serbia and Montenegro, the genotypes 1b and 3a predominate in patients with chronic HCV infection. The subtype lb is characteristic of older patients, while the genotype 3a is common in drug abusers. Association of the subtype lb with advanced liver disease, higher viral load and histological activity suggests earlier infection with this genotype and eventually its increased pathogenicity.
基金Supportedby the National Natural Science Foundation of China(39730200) and by a specialgrantfrom Departmentof Education,Hunan Province(02B040 ).
文摘Objective To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV). Methods Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient(SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supernatant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experime-ntal animals and induced neoplasms. Results In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors, tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence. Conclusions EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.
基金Supported by The 863 National High Technology Research and Development Program of China,No.2006A02Z453the National Natural Science Foundation of China,No.30570063
文摘AIM： To investigate the genetic characteristics and pathogenicity of hepatitis E virus （HEV） and assess the potential risk factors for sporadic hepatitis E.
文摘China is currently experiencing one of the most rapidly expanding HIV epidemics in the world. Although the overall prevalence rate is still low, with a population of 1.3 billion, high-risk factors which have contributed to the HIV/AIDS epidemics worldwide continue to prevail in China, including a high rate of injecting drug use and needle sharing, commercial sex with low rates of condom use, and concurrent sex with both commercial sex workers and noncommercial casual or steady sex partners. In addition, there are increasing “double risk” populations overlapping drug users and sex workers, as well as increasing rates of STDs and HIV among high-risk populations. Sexual transmission, therefore, may serve as a bridge connecting high-risk populations with general populations. There is an urgent need to prevent the spread of HIV from these high-risk oooulations into the general oooulation of China.
文摘Aristolochic acids （AAs）, a natural mixture of 8-methoxy-6-nitro-phenanthro-（3,4-d）-1,3-dioxolo-5-carboxylic acid （AAI）and 6-nitro-phenanthro-（3,4-d）-1,3-dioxolo-5-carboxylic acid （AAII）, derived from aristolochiaceae species, has beenreported to cause AAS-induced nephropathy and upper urothelial cancer. In this review, we summarize the informationon the nephrotoxicity and carcinogenesis of AAs and their derivatives. AAs nephrotoxicity can lead to apoptosis andoxidative stress of renal tubular cells, and inhibition of the expression of aquaporins. AAs can also reduce the capabilityfor renal tubular epithelial cell repair after acute injury and further produce renal fibrosis by activating TGF-β-Smadsignaling and promoting the migration of macrophages. Moreover, AAs-induced carcinogenesis may be due to theformation of covalent adducts with DNA which can lead to the mutation in certain tumor suppressor genes orproto-oncogenes and the different catalyzing capacity of the microsomal cytochrome P450 of individuals in AAImetabolism.
