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B Viruses (b + viruse)
Kinds of B Viruses Selected AbstractsA new look at viruses in type 1 diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 1 2003Hee-Sook Jun Abstract Type 1 diabetes (T1D) results from the destruction of pancreatic beta cells. Genetic factors are believed to be a major component for the development of T1D, but the concordance rate for the development of diabetes in identical twins is only about 40%, suggesting that nongenetic factors play an important role in the expression of the disease. Viruses are one environmental factor that is implicated in the pathogenesis of T1D. To date, 14 different viruses have been reported to be associated with the development of T1D in humans and animal models. Viruses may be involved in the pathogenesis of T1D in at least two distinct ways: by inducing beta cell-specific autoimmunity, with or without infection of the beta cells, [e.g. Kilham rat virus (KRV)] and by cytolytic infection and destruction of the beta cells (e.g. encephalomyocarditis virus in mice). With respect to virus-mediated autoimmunity, retrovirus, reovirus, KRV, bovine viral diarrhoea-mucosal disease virus, mumps virus, rubella virus, cytomegalovirus and Epstein-Barr virus (EBV) are discussed. With respect to the destruction of beta cells by cytolytic infection, encephalomyocarditis virus, mengovirus and Coxsackie B viruses are discussed. In addition, a review of transgenic animal models for virus-induced autoimmune diabetes is included, particularly with regard to lymphocytic choriomeningitis virus, influenza viral proteins and the Epstein-Barr viral receptor. Finally, the prevention of autoimmune diabetes by infection of viruses such as lymphocytic choriomeningitis virus is discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source] Influenza virus assays based on virus-inducible reporter cell linesINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 5 2009Yunsheng Li Background, Virus-inducible reporter genes have been used as the basis of virus detection and quantitation assays for a number of viruses. A strategy for influenza A virus-induction of a reporter gene was recently described. In this report, we describe the extension of this strategy to influenza B virus, the generation of stable cell lines with influenza A and B virus-inducible reporter genes, and the use of these cells in various clinically relevant viral assays. Each of the cell lines described herein constitutively express an RNA transcript that contains a reporter gene coding region flanked by viral 5,- and 3,-untranslated regions (UTR) and therefore mimics an influenza virus genomic segment. Upon infection of the cells with influenza virus the virus-inducible reporter gene segment (VIRGS) is replicated and transcribed by the viral polymerase complex resulting in reporter gene expression. Findings, Reporter gene induction occurs after infection with a number of laboratory strains and clinical isolates of influenza virus including several H5N1 strains. The induction is dose-dependent and highly specific for influenza A or influenza B viruses. Conclusions, These cell lines provide the basis of simple, rapid, and objective assays that involve virus quantitation such as determination of viral titer, assessment of antiviral susceptibility, and determination of antibody neutralization titer. These cell lines could be very useful for influenza virus researchers and vaccine manufacturers. [source] Pathogen-reduction methods: advantages and limitsISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2009H. G. Klein Pathogen-reduction (inactivation) provides a proactive approach to reducing transfusion-transmitted infection. Pathogen-reduction technologies have been successfully implemented by plasma fractionators resulting in no transmission of human immunodeficiency, hepatitis C, or hepatitis B viruses by US-licensed plasma derivatives since 1987. Fractionation technologies cannot be used to treat cellular blood components. Although blood donor screening, deferral and disease testing have drastically reduced the incidence of transfusion-transmitted diseases, the threat of new or re-emerging pathogens remains. Of particular concern is the silent emergence of a new agent with a prolonged latent period in which asymptomatic infected carriers would donate and spread infection. The ultimate goal of pathogen-inactivation is to reduce transmission of potential pathogens without significantly compromising the therapeutic efficacy of the cellular and protein constituents of blood. The acceptable technology must not introduce toxicities into the blood supply nor result in neoantigen formation and subsequent antibody production. Several promising pathogen-inactivation technologies are being developed and tested, and others are currently in use, but all of them have limits. Pathogen-reduction promises an additional ,layer of protection' from infectious agents and has the potential to impact the safety of blood transfusions worldwide. [source] Molecular, immunological and clinical properties of mutated hepatitis B virusesJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2002C. Kreutz Abstract Hepatitis B virus (HBV) is at the origin of severe liver diseases like chronic active hepatitis, liver cirrhosis and hepatocellular carcinoma. There are some groups of patients with high risk of generation of HBV mutants: infected infants, immunosupressed individuals (including hemodialysis patients), patients treated with interferon and lamivudine for chronic HBV infection. These groups are the target for molecular investigations reviewed in this paper. The emergence of lamivudine- or other antiviral-resistant variants, rises concern regarding long term use of these drugs. Infection or immunization with one HBV subtype confers immunity to all subtypes. However, reinfection or reactivation of latent HBV infection with HBV mutants have been reported in patients undergoing transplant and those infected with HIV. Mutations of the viral genome which are not replicative incompetent can be selected in further course of infection or under prolonged antiviral treatment and might maintain the liver disease. Four open reading frames (ORF) which are called S-gene, C-gene, X-gene and P-gene were identified within the HBV genome. Mutations may affect each of the ORFs. Mutated S-genes were described to be responsible for HBV-infections in successfully vaccinated persons, mutated C-genes were found to provoke severe chronic liver diseases, mutated X-genes could cause serious medical problemes in blood donors by escaping the conventional test systems and mutated P-genes were considered to be the reason for chemotherapeutic drug resistance. This paper reviews molecular, immunological and clinical aspects of the HBV mutants. [source] Prediction of response to treatment of chronic hepatitis B with pegylated interferon in the PhilippinesJOURNAL OF MEDICAL VIROLOGY, Issue 2 2010Dorothy M. Agdamag Abstract The response marker for interferon has not been investigated fully for hepatitis B viruses (HBVs) in the Philippines where novel subtypes B5 and C5 were recognized recently. The prediction parameters for interferon treatment were assessed, with emphasis on the mutation patterns in the basal core promoter and precore regions in patients with chronic hepatitis B. Seventeen HBeAg-positive patients were stratified according to response to treatment with pegylated interferon based on HBe seroconversion and HBV load. Intra-patient distributions of wild-type strains (A1762, G1764) and variants (T1762, A1764) were analyzed using HBV-DNA amplification and subsequent molecular cloning. The rate of variants (T1762, A1764) harbored by a patient was higher among responders (41.2% and 31% per person on average) than among non-responders (2.4% and 2.4%) to treatment with pegylated interferon at the baseline, respectively (P,<,0.05). The rate of variants (T1762, A1764) harbored by responders (41.2% and 31%) decreased to 1.7% and 1.7%, and wild-type strains (A1762, G1764) conversely became majority (98.3% and 98.3%) after treatment with pegylated interferon, respectively. HBV strains harbored by two of six responders and a patient with lower baseline load (1.0,×,104,copies/ml) showed genotype shift from A to other genotypes, where genotype A disappeared preferentially after the loss of HBeAg and genotypes B and C formed a major population. These results suggest that the HBV variants (T1762, A1764) and HBV genotype A in the Philippines have an advantage in the response to pegylated interferon. These results warrant a large-scale examination for further precise prediction of the response to treatment with interferon. J. Med. Virol. 82:213,219, 2010. © 2009 Wiley-Liss, Inc. [source] Distinct patterns of evolution between respiratory syncytial virus subgroups A and B From New Zealand isolates collected over thirty-seven years,JOURNAL OF MEDICAL VIROLOGY, Issue 10 2006James W. Matheson Abstract Respiratory syncytial virus (RSV) is the most important cause of viral lower respiratory tract infections in infants and children worldwide. In New Zealand, infants with RSV disease are hospitalized at a higher rate than other industrialized countries, without a proportionate increase in known risk factors. The molecular epidemiology of RSV in New Zealand has never been described. Therefore, we analyzed viral attachment glycoprotein (G) gene sequences from 106 RSV subgroup A isolates collected in New Zealand between 1967 and 2003, and 38 subgroup B viruses collected between 1984 and 2004. Subgroup A and B sequences were aligned separately, and compared to sequences of viruses isolated from other countries during a similar period. Genotyping and clustering analyses showed RSV in New Zealand is similar and temporally related to viruses found in other countries. By quantifying temporal clustering, we found subgroup B viruses clustered more strongly than subgroup A viruses. RSV B sequences displayed more variability in stop codon usage and predicted protein length, and had a higher degree of predicted O-glycosylation site changes than RSV A. The mutation rate calculated for the RSV B G gene was significantly higher than for RSV A. Together, these data reveal that RSV subgroups exhibit different patterns of evolution, with subgroup B viruses evolving faster than A. J. Med. Virol. 78:1354,1364, 2006. © 2006 Wiley-Liss, Inc. [source] Seroepidemiology of hepatitis A, B, C, and E viruses infection among preschool children in TaiwanJOURNAL OF MEDICAL VIROLOGY, Issue 1 2006Jye-Bin Lin Abstract Taiwan was a hyperendemic area for hepatitis A and B viruses (HAV and HBV) infection before late 1980s. To study the seroprevalence of hepatitis A, B, C, and E viruses (HCV and HEV) infection among preschool children in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and 2 aboriginal areas randomly selected through stratified sampling. Serum specimens of 2,538 preschool children were screened for the hepatitis A, C, and E antibodies by a commercially available enzyme immunoassay and for HBV markers by radioimmunoassay methods. The multivariate-adjusted odd ratios (OR) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. Females had a statistically significantly higher HAV seroprevalence than males. The seroprevalence of HCV infection increased significantly with age. The larger the sibship size, the higher the seroprevalence of HBV infection. Aboriginal children had a significantly higher seroprevalence of HBV and HEV infection and lower seroprevalence of HCV infection than non-aboriginal children. A significantly higher seroprevalence of HBV infection was found in rural children than urban children. There was no significant association between serostatus of HAV and HEV infection and between serostatus of HBV and HCV infection among preschool children in Taiwan. The poor environmental and hygienic conditions in the aboriginal areas might play a role in infection with HBV and HEV. J. Med. Virol. 78:18,23, 2006. © 2005 Wiley-Liss, inc. [source] Measurement of HIV RNA in patients infected by subtype C by assays optimized for subtype B results in an underestimation of the viral loadJOURNAL OF MEDICAL VIROLOGY, Issue 2 2004Bat-Sheva Gottesman Abstract Quantitation assays of HIV-1 RNA used currently were designed and optimized for subtype B viruses. However, infection with non-B HIV viruses has become more common worldwide. Unfortunately, little information is available regarding the suitability of these assays for measurement of viral load in specific non-B subtypes. The performance of two commercial HIV-1 RNA quantitation assays was evaluated in 82 HIV subtype C-infected patients and in 43 HIV-1 subtype B-infected patients. Blood samples were tested by the Amplicor HIV-1 Monitor Assay, Version 1.5, and by the nucleic acid sequence-based amplification HIV-1 assay (NucliSens). The results were compared by using a paired, two-tailed Student's t -test; the difference between the assays was found to be significant only for subtype C. Discordant results (>0.5 log difference) between the two assays were detected in 39% of subtype C samples, compared to 23.2% of subtype B samples. In all cases in which a discordant result was detected, the lower results were obtained by the NucliSens assay. Discordant results between CD4 and viral load (CD4,<,200 cells/ml with a viral load <5,000 copies/ml) were observed in eight of the subtype C-infected patients when a viral load was measured by NucliSens (9.7%), compared to three patients (3.6%) when measured by the Amplicor assay. In conclusion, in patients with HIV subtype C infection, measurement of HIV RNA by the NucliSens assay resulted in a significant underestimation of the viral load as compared to the Amplicor assay. As a consequence, such an underestimation may result in sub-optimal care of patients infected with HIV subtype C. J. Med. Virol. 73:167,171, 2004. © 2004 Wiley-Liss, Inc. [source] Sequencing of human-viral DNA junctions in hepatocellular carcinoma from patients with HCV and occult HBV infectionJOURNAL OF MEDICAL VIROLOGY, Issue 4 2003Akihiro Tamori Abstract DNA of free hepatitis B viruses (HBV) has been detected in the liver of patients infected with hepatitis C virus (HCV). It is unknown whether HBV DNA is integrated into such livers; if so, it may affect hepatocarcinogenesis. Hepatocellular carcinomas (HCCs) from 34 patients without HBV surface antigen (HBsAg) and with anti-HCV, and from 7 patients with HBsAg and without anti-HCV as controls, were examined, using the cassette-ligation,mediated polymerase chain reaction and primers based on HBV DNA sequence. In the controls, HBV DNA had been integrated into human DNA of all HCCs. On the basis of HBV DNA in tumor tissue, 23 of the 34 patients with anti-HCV had occult infection. Junctions between human DNA and HBV DNA were detected in 10 of the 34 patients without HBsAg and with anti-HCV. HBV DNA was integrated into chromosome 11q in 4 of the 10 HCCs with junctions. The DNA to either side of the human-viral junctions was sequenced. Clinically, the mean tumor size of these 10 HCCs was 39 mm; that of the 24 HCCs without integrated HBV was 25 mm. The surrounding tissue was cirrhotic in 2 of the 10 former HCCs and in 16 of the latter 24 HCCs. In conclusion, integrated HBV was detected in some patients with HCV infection; in these patients, the integrated DNA was associated with accelerated hepatocarcinogenesis. J. Med. Virol. 69:475,481, 2003. © 2003 Wiley-Liss, Inc. [source] Rapid and Sustained Immune Response Against Hepatitis A and B Achieved With Combined Vaccine Using an Accelerated Administration ScheduleJOURNAL OF TRAVEL MEDICINE, Issue 1 2007Bradley A. Connor MD Background Combined hepatitis A and B vaccine administered on an accelerated schedule provides a rapid immune response against both hepatitis A and B viruses, which might be especially relevant for individuals who need protection quickly. Methods A prospective, open-label, randomized study to compare the immunogenicity and reactogenicity of the combined hepatitis A and B vaccine Twinrix (GlaxoSmithKline Biologicals, Rixensart, Belgium) (,720 EL.U/mL inactivated hepatitis A antigen and 20 ,g/mL recombinant hepatitis B surface antigen [HBsAg]) administered at 0, 7, 21 to 30 days, and 12 months compared with concurrent administration of Havrix [GlaxoSmithKline Biologicals, Rixensart, Belgium (,1440 EL.U/mL inactivated hepatitis A antigen)] at 0 and 12 months, and Engerix-B [GlaxoSmithKline Biologicals, Rixensart, Belgium (20 ,g/mL recombinant HBsAg)] at 0, 1, 2, and 12 months in seronegative healthy adults. Results At month 13, the anti-hepatitis B seroprotection rates (>10 mIU/mL) for the combined vaccine compared to the monovalent hepatitis B vaccine were 96.4% (95% CI: 92.7,98.5) and 93.4% (95% CI: 89.0,96.4), respectively. The anti-hepatitis A seroconversion rates were 100% in both groups (95% CI: 98.1,100). At day 37, the anti-hepatitis A seroconversion rates were similar in both groups (98.5% for combined vaccine, 98.6% for the monovalent vaccine group), but the combined vaccine resulted in a statistically significantly ( p < 0.001) better anti-hepatitis B seroprotection compared to monovalent hepatitis B vaccine, 63.2% versus 43.5%, respectively. The reactogenicity profile was similar in both study groups. Conclusions The combined hepatitis A and B vaccine administered on an accelerated schedule was at least as immunogenic and as well tolerated as the corresponding monovalent vaccines. [source] Broad-spectrum antiviral effect of Agrimonia pilosa extract on influenza virusesMICROBIOLOGY AND IMMUNOLOGY, Issue 1 2010Woo-Jin Shin ABSTRACT Influenza virus continues to emerge and re-emerge, posing new threats for humans. Here we tested various Korean medicinal plant extracts for potential antiviral activity against influenza viruses. Among them, an extract of Agrimonia pilosa was shown to be highly effective against all three subtypes of human influenza viruses including H1N1 and H3N2 influenza A subtypes and influenza B virus. The EC50 value against influenza A virus, as tested by the plaque reduction assay on MDCK cells, was 14,23 ,g/ml. The extract also exhibited a virucidal effect at a concentration of 160,570 ng/ml against influenza A and B viruses when the viruses were treated with the extract prior to plaque assay. In addition, when tested in embryonated chicken eggs the extract exhibited a strong inhibitory effect in ovo on the H9N2 avian influenza virus at a concentration of 280 ng/ml. Quantitative RT-PCR analysis data showed that the extract, to some degree, suppressed viral RNA synthesis in MDCK cells. HI and inhibition of neuraminidase were observed only at high concentrations of the extract. And yet, the extract's antiviral activity required direct contact between it and the virus, suggesting that its antiviral action is mediated by the viral membrane, but does not involve the two major surface antigens, HA and NA, of the virus. The broad-spectrum antiviral activity of Agrimonia pilosa extract on various subtypes of influenza viruses merits further investigation as it may provide a means of managing avian influenza infections in poultry farms and potential avian-human transmission. [source] Chimeric adenoviral vectors incorporating a fiber of human adenovirus 3 efficiently mediate gene transfer into prostate cancer cellsTHE PROSTATE, Issue 4 2010Miho Murakami Abstract BACKGROUND We have developed a range of adenoviral (Ad) vectors based on human adenovirus serotype 5 (HAdV-5) displaying the fiber shaft and knob domains of species B viruses (HAdV-3, -11, or -35). These species B Ads utilize different cellular receptors than HAdV-5 for infection. We evaluated whether Ad vectors displaying species B fiber shaft and knob domains (Ad5F3Luc1, Ad5F11Luc1, and Ad5F35Luc1) would efficiently infect cancer cells of distinct origins, including prostate cancer. METHODS The fiber chimeric Ad vectors were genetically generated and compared with the original Ad vector (Ad5Luc1) for transductional efficiency in a variety of cancer cell lines, including prostate cancer cells and primary prostate epithelial cells (PrEC), using luciferase as a reporter gene. RESULTS Prostate cancer cell lines infected with Ad5F3Luc1 expressed higher levels of luciferase than Ad5Luc1, as well as the other chimeric Ad vectors. We also analyzed the transductional efficiency via monitoring of luciferase activity in prostate cancer cells when expressed as a fraction of the gene transfer in PrEC cells. In the PC-3 and DU145 cell lines, the gene transfer ratio of cancer cells versus PrEC was once again highest for Ad5F3Luc1. CONCLUSION Of the investigated chimeric HAdV-5/species B vectors, Ad5F3Luc1 was judged to be the most suitable for targeting prostate cancer cells as it showed the highest transductional efficiency in these cells. It is foreseeable that an Ad vector incorporating the HAdV-3 fiber could potentially be used for prostate cancer gene therapy. Prostate 70: 362,376, 2010. © 2009 Wiley-Liss, Inc. [source] Treatment of epidemic and pandemic influenza with neuraminidase and M2 proton channel inhibitorsCLINICAL MICROBIOLOGY AND INFECTION, Issue 1 2003J. S. Oxford A small armentarium of anti-influenza drugs now exists, and includes the M2 blockers (amantadine and rimantadine) and the neuraminidase inhibitors (Relenza and Tamiflu). The neuraminidase inhibitors have certain advantages, including a broader spectrum of antiviral activity, including influenza A and B viruses. On the other hand, there is now much clinical experience with the M2 blockers, and these drugs are inexpensive. It is clear that influenza in different community groups needs to be managed in specific and targeted ways. For example, in the over-65-years and at-risk groups, vaccination will remain a mainstay of disease prevention. However, up to 40% of those in these groups may fail to receive vaccine, and therefore the antivirals can be used therapeutically, or, in defined circumstances, as prophylactics. At present, influenza is hardly managed in the community. The infrequent global outbreaks, pandemics, present further problems. The more extensive use of the two classes of antivirals, and also vaccines, in the important interpandemic years will provide a very significant investment in health benefits in the face of a new pandemic virus in an otherwise completely vulnerable population. [source] | |||||||||||||