Consulta: subjectFacets:"Hepatitis B virus"
Registros recuperados: 23
Data/hora: 08/06/2024 17:26:29

Decrease in hepatitis B prevalence among blood donors in Central-West Brazil
Provedor de dados: Journal of Venomous Animals and Toxins Including Tropical Diseases
Autores: Lindenberg,Andréa de Siqueira Campos; Motta-Castro,Ana Rita Coimbra; Puga,Marco Antonio; Ortiz Tanaka,Tayana Serpa; Torres,Marina Sawada; Fernandes-Fitts,Sonia Maria; Cunha,Rivaldo Venancio.
Background The aim of the present study was to estimate hepatitis B virus seroprevalence among first-time blood donors in the city of Campo Grande, Mato Grosso do Sul State, in the central-western region of Brazil. Findings A retrospective analysis of first-time voluntary blood donor records, from January 2010 to December 2010, was conducted at the Hematology Center of Mato Grosso do Sul. The prevalence of the HBsAg and anti-HBc serological markers and their respective 95% confidence intervals were calculated. Chi-square analysis was performed between the seroprevalence previously found in 2001 and the one determined by the current study. Results were considered statistically significant if p &lt; 0.05. Among 8,840 subjects, 269 (3.04%, 95% CI: 2.7-3.4)...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Hepatitis B virus; Prevalence; Blood donors.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992013000100402

Prevalence of mutations in HBV DNA polymerase gene associated with nucleos(t)ide resistance in treatment-naive patients with Chronic Hepatitis B in Central China
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Zhao,Youyun; Wu,Jianhua; Sun,Lijun; Liu,Guangzhong; Li,Bo; Zheng,Yi; Li,Xiaodong; Tao,Junxiu.
Abstract  Objective There are a lot of disagreements in the studies on hepatitis B virus (HBV) DNA polymerase mutation rate associated with nucleos(t)ide analogues (NAs) in treatment-naive chronic hepatitis B (CHB) patients. This is the first study aimed to investigate the prevalence of spontaneous HBV resistance mutations in Central China.  Methods This study included treatment-naive patients with CHB from June 2012 to May 2015 receiving care at the Institute of Liver Disease in Central China. All patients completed a questionnaire covering different aspects, such as family medical history, course of liver disease, medication history, alcohol use, among others. Mutations in HBV DNA polymerase associated with NAs resistance were detected using INNO-LiPA...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Chronic hepatitis B; Viral resistance mutations.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702016000200173

Theories about evolutionary origins of human hepatitis B virus in primates and humans
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Souza,Breno Frederico de Carvalho Dominguez; Drexler,Jan Felix; Lima,Renato Santos de; Rosário,Mila de Oliveira Hughes Veiga do; Netto,Eduardo Martins.
Introduction:The human hepatitis B virus causes acute and chronic hepatitis and is considered one of the most serious human health issues by the World Health Organization, causing thousands of deaths per year. There are similar viruses belonging to the Hepadnaviridae family that infect non-human primates and other mammals as well as some birds. The majority of non-human primate virus isolates were phylogenetically close to the human hepatitis B virus, but like the human genotypes, the origins of these viruses remain controversial. However, there is a possibility that human hepatitis B virus originated in primates. Knowing whether these viruses might be common to humans and primates is crucial in order to reduce the risk to humans.Objective:To review the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Hepadnaviridae; Non-human primates; Evolutionary origins.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702014000500535

Detection of hepatitis B virus A1762T/G1764A mutant by amplification refractory mutation system
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Wang,Yong-Zhong; Zhu,Zhen; Zhang,Hong-Yu; Zhu,Min-Zhi; Xu,Xin; Chen,Chun-Hua; Liu,Long-Gen.
OBJECTIVE: To study the role of hepatitis B virus with A1762T/G1764A double mutation in liver cirrhosis and hepatocellular carcinoma, and create a sensitive, fast, accurate assay for detection of A1762T/G1764A double mutation.METHODS: We developed an accurate and fast real-time amplification refractory mutation system to detect A1762T/G1764A double mutation. Cloned hepatitis B virus genome was used as a control. Assay sensitivity was determined by serial dilution and mixed template experiments. Specificity was determined by cross experiments with wild and mutant hepatitis B virus. Fifty clinical samples were tested by the real-time amplification refractory mutation system and the results were compared with sequencing.RESULTS: The real-time amplification...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Basal core promoter mutations; Amplification refractory mutation system; PCR.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702014000300261

Hepatitis B virus genotypes, precore mutations, and basal core promoter mutations in HBV-infected Chinese patients with persistently normal alanine aminotransferase and low serum HBV-DNA levels
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Shi,Ming; Zhang,Yong; Zhang,Jing; Liu,Wei; Xing,Lu.
Hepatitis B virus (HBV) genotype and precore and basal core promoter (BCP) mutants in the patients with persistently normal alanine aminotransferase (ALT) and low serum HBV-DNA levels are unclear. The aim of this study was to determine HBV genotypes, precore and BCP mutations, and their association with chronic hepatitis and liver fibrosis in HBV-infected patients with persistently normal ALT, and low serum HBV-DNA levels in northeast China. Patients (n = 89) with normal ALT and serum HBV-DNA levels below 20000 IU/mL but detectable with real-time PCR were included in this study. HBV genotypes were determined by real-time PCR. The precore and BCP mutations were detected by sequencing. All the patients had biopsy results. Of the 89 patients, 11 (12.4%) were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Genotype; Mutation; Alanine transaminase.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000100009

Occult B infection in the Brazilian northeastern region: a preliminary report
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Almeida,Delvone; Tavares-Neto,José; Trepo,Christian; Almeida,Alessandro; Mello,Caroline; Chemin,Isabelle; Paraná,Raymundo.
A sentinel study on viral hepatitis is currently being carried out in the village of Cavunge in a semiarid rural region of the state of Bahia, northeastern Brazil. This study has identified individuals in whom anti-HBc IgG was the only serological marker for hepatitis B virus (HBV). This serological pattern may constitute evidence of occult HBV infection. This study Investigated the possibility of occult hepatitis B virus infection in individuals in a rural community who tested positive for anti-HBc IgG alone. A cross-sectional population-based study. ELISA III was performed on serum samples to test for serological viral markers, and ultrasensitive PCR (US-PCR) was used to assess viremia. Among the 1,536 serum samples, 3.6% (n=55) were positive for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anti-HBc alone; Hepatitis B virus; Occult hepatitis B; Ultrasensitive PCR.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702008000400010

Expression of Hepatitis B virus surface antigen (HBsAg) from genotypes A, D and F and influence of amino acid variations related or not to genotypes on HBsAg detection
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Araujo,Natalia M.; Vianna,Carlos O. A.; Moraes,Marcia T. B.; Gomes,Selma A.
The impact of hepatitis B virus (HBV) genotypes on the sensitivity of surface antigen (HBsAg) detection assays has been poorly investigated. Here, plasmids carrying consensus or variant coding sequences for HBV surface proteins from genotypes A, D and F, were constructed. HBsAg levels were evaluated in medium and extracts of transfected CHO cells by a commercial polyclonal-based assay. We show that HBsAg detection values of consensus forms from genotypes D and F were, respectively, 37% and 30% lower than those obtained by genotype A. However, the presence of two single variations, T143M in genotype A, and T125M in genotype D, produced a decrease of 44% and an increase of 34%, respectively, on HBsAg mean values in comparison with their consensus forms. In...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Surface antigen; Amino acid variations; Transfection.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702009000400005

Absence of occult hepatitis B among blood donors in southern Brazil
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Wolff,Fernando Herz; Fuchs,Sandra Costa; Brandão,Ajacio BM.
BACKGROUND: Occult hepatitis B virus (HBV) infection is characterized by the detection of HBV DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). The reported prevalence of occult hepatitis B varies markedly among populations and according to the sensitivity of the HBV DNA assay. The aim of the present study was to describe the prevalence of occult hepatitis B among HCV-infected and non-infected blood donors in Porto Alegre, Southern Brazil, using a highly sensitive real time polymerase chain reaction (PCR) method. METHODOLOGY: Between 1995 and 1997 a sample of 178 blood donors with two positive anti-HCV ELISA tests were consecutively selected as cases, and 356 anti-HCV negative donors were selected as controls....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B; Hepatitis B virus; Blood donors; Seroepidemiologic studies.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702011000200012

Novel fluoronucleoside analog NCC inhibits lamivudine-resistant hepatitis B virus in a hepatocyte model
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Zhang,Jingmin; Wang,Yafeng; Peng,Youmei; Qin,Chongzhen; Liu,Yixian; Li,Jingjing; Jiang,Jinhua; Zhou,Yubing; Chang,Junbiao; Wang,Qingduan.
ABSTRACT Antiviral drug resistance is the most important factor contributing to treatment failure using nucleos(t)ide analogs such as lamivudine for chronic infection with hepatitis B virus (HBV). Development of a system supporting efficient replication of clinically resistant HBV strains is imperative, and new antiviral drugs are needed urgently to prevent selection of drug-resistant HBV mutants. A novel fluorinated cytidine analog, NCC (N-cyclopropyl-4′-azido-2′-deoxy-2′-fluoro-β-d-cytidine), was recently shown to strongly inhibit human HBV in vitro and in vivo. This study was designed to evaluate the antiviral activity of NCC against lamivudine-resistant HBV. We generated a stable cell line encoding the major pattern of lamivudine-resistant mutations...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: N-cyclopropyl-4′-azido-2′-deoxy-2′-fluoro-β-D- cytidine; Hepatitis B virus; HepG2.RL1 cells; Lamivudine-resistant; RtL180M/M204V.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702018000600477

Distribution of HBV subgenotypes in Ribeirão Preto, Southeastern Brazil: a region with history of intense Italian immigration
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Chachá,Silvana Gama Florencio; Gomes-Gouvêa,Michele Soares; Malta,Fernanda de Mello; Ferreira,Sandro da Costa; Villanova,Márcia Guimarães; Souza,Fernanda Fernandes; Teixeira,Andreza Correa; Passos,Afonso Dinis da Costa; Pinho,João Renato Rebello; Martinelli,Ana de Lourdes Candolo.
Abstract Hepatitis B virus (HBV) is distributed worldwide, with geographical variations regarding prevalence of the different genotypes. The aim of this study was to determine the HBV genotypes and subgenotypes circulating in Southeast Brazil and compare the genetic sequences found with HBV sequences previously described in the world. Sequences from 166 chronic HBV carriers were analyzed using the fragment constituted by 1306 base pairs comprising surface and polymerase regions of the HBV genome. The sequences obtained were submitted to phylogenetic analysis. HBV subgenotypes A1, A2, D1-D4, F2a, and F4 were found. HBV genotype D was the most frequent, found in 99 patients (58.4%). Within this group, subgenotype D3 was the most prevalent, in 73 patients...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Genotype; Phylogenetics; Intra-familial transmission.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702017000400424

Compositional changes of PBL population in patients with chronic hepatitis B virus infection
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Alireza,Khabiri; Mohsen,Abolhassani; Sudabeh,Aslani; Hiedeh,Darabi; Farideh,Bagheri; Mohammad-Hossein,Alimohammadian.
In this report we have analysed the peripheral blood lymphocyte of several patients with chronic hepatitis B virus infection with flow cytometry. Based on the presence and absence of the HBeAb, patients were divided into two groups. In both, all the patients were HBsAg positive with normal range of serum alanine aminotranferase (23.9 ± 17.8). We have found that the immunophenotypic profiles of patients were different from healthy donors with significant decrease in CD3+ T cells, specially CD8+ T cells and a siginificant increase in the CD19+ B cells. The differences were seen in other subset of T cells (CD4+) or NK cells (CD56+/CD16+ ) and HLA-DR markers were not significant. When the phenotypic profiles of both groups were compared with each other, such...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Chronic HBV infection; HBsAg; HBeAg; HBeAb; Lymphocyte subset; Flow cytometry.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702001000600009

Hepatitis B virus infection among institutionalized mentally ill patients in Brazil
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Moraes,Tatiane Cinquini; Fiaccadori,Fabíola Souza; Souza,Menira; Almeida,Tâmera Nunes Vieira; Cunha,Marielton dos Passos; Castro,Ítalo de Araújo; Cardoso,Divina das Dôres de Paula.
ABSTRACT  OBJECTIVES:  The main objective was to evaluate HBV infection and occult HBV infection (OBI) cases in mentally ill patients based on serological and molecular profiles.  MATERIAL AND METHODS:  Serum samples of 333 long-stay mentally ill patients were tested for the prevalence of HBV markers by serological (ELISA) and molecular (PCR) assays. The PCR products were sequenced to determine viral genotypes.  RESULTS:  It was observed a global prevalence of 12.9% (43/333) for HBV infection markers, considering HBsAg and/or anti-HBc positivity. Fourteen samples tested positive for anti-HBs alone. All samples positive (n= 57) for any HBV serological markers were tested for HBV-DNA and six were positive: HBsAg/anti-HBc (n = 1), anti-HBc/anti-HBs (n = 1),...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Hepatitis B virus; Occult infection; Prevalence; Mental illness.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702015000600643

Coexistence of low levels of HBsAg and high levels of anti-HBs may increase risk of hepatocellular carcinoma in chronic hepatitis B patients with high HBV load
Provedor de dados: Brazilian Journal of Infectious Diseases
Autores: Jin,Zi-zheng; Jin,Fang-fang; Liu,Xin; Liu,Ning; Wen,Feng; Lou,Jin-li.
ABSTRACT  Objective: The clinical significance of coexistence of HBsAg/anti-HBs in chronic hepatitis B (CHB) patients remains controversial. This study was aimed to assess the association of this serological pattern with hepatocellular carcinoma (HCC) in patients with CHB.  Methods: In this cross-section study, 206 CHB patients with coexistence of HBsAg/anti-HBs and 206 CHB patients with HBsAg alone were included to evaluate the risk of HCC development by logistic regression analysis. In addition, a retrospective cohort of 260 patients with CHB was recruited to estimate the cumulative incidence of HCC by Kaplan-Meier analysis.  Results: The serological pattern of coexistence of HBsAg/anti-HBs, with high levels of ("High") HBsAg/low levels of ("Low")...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; HBsAg; Hepatocellular carcinoma.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702019000500343

Prevalence of serological markers of hepatitis B virus in pregnant women from Paraná State, Brazil
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Bertolini,D.A.; Pinho,J.R.R.; Saraceni,C.P.; Moreira,R.C.; Granato,C.F.H.; Carrilho,F.J.
The prevalence of hepatitis B virus (HBV) in Brazil increases from South to North but moderate to elevated prevalence has been detected in the Southwest of Paraná State. The prevalence of serological markers of HBV was evaluated in 3188 pregnant women from different counties in Paraná State and relevant epidemiological features were described. The prevalence of HBV markers in pregnant women for the state as a whole was 18.5% (95% CI = 17.2-19.9), ranging from 7.2% in Curitiba to 38.5% in Francisco Beltrão. The endemicity of HBV marker prevalence in pregnant women was intermediate in Cascavel, Foz do Iguaçu, and Francisco Beltrão, and low in Curitiba, Londrina, Maringá, and Paranaguá. Multiple logistic regression showed that HBV marker prevalence increased...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Brazil; Serological markers; Pregnant women.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000800011

Overexpression of Fc receptor-like 1 associated with B-cell activation during hepatitis B virus infection
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Wang,Ke; Pei,Hao; Huang,Biao; Yang,Run-Lin; Wu,Hang-Yuan; Zhu,Xue; Zhu,Lan.
The role of B cells in the pathogenesis of hepatitis B virus (HBV) infection has not been explored in depth. In the present study, the activation status of B cells from peripheral blood of healthy controls (N = 20) and patients with acute hepatitis B (AHB, N = 15) or chronic hepatitis B (CHB, N = 30) was evaluated by measuring the expression levels of B-cell activation markers CD69 and CD86, using quantitative real-time PCR and flow cytometry. Moreover, the potential mechanism underlying B-cell activation during HBV infection was further investigated by analyzing the expression profile of FCRL1, an intrinsic activation molecule of B cells. An elevation in the levels of B-cell activation markers including CD69 and CD86 was observed in the AHB patients...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; B-cell activation; Fc receptor-like 1; Gene expression.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200002

Occult hepatitis B virus infection in liver transplant patients in a Brazilian referral center
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Ferrari,T.C.A.; Xavier,M.A.P.; Vidigal,P.V.T.; Amaral,N.S.; Diniz,P.A.; Resende,A.P.; Miranda,D.M.; Faria,A.C.; Lima,A.S.; Faria,L.C.
Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Occult hepatitis B virus infection; Hepatitis B virus; HBV DNA; Liver transplantation.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014001100990

The emergence of YMDD mutants precedes biochemical flare by 19 weeks in lamivudine-treated chronic hepatitis B patients: an opportunity for therapy reevaluation
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: França,P.H.C.; Coelho,H.S.M.; Brandão,C.E.; Segadas,J.A.; Quintaes,R.F.; Carrilho,F.J.; Ono-Nita,S.; Mattos,A.A.; Tovo,C.; Gouvea,V.S.; Sablon,E.; Vanderborght,B.O.M.
Given the loss of therapeutic efficacy associated with the development of resistance to lamivudine (LMV) and the availability of new alternative treatments for chronic hepatitis B patients, early detection of viral genotypic resistance could allow the clinician to consider therapy modification before viral breakthrough and biochemical relapse occur. To this end, 28 LMV-treated patients (44 ± 12 years; 24 men), on their first therapy schedule, were monitored monthly at four Brazilian centers for the emergence of drug resistance using the reverse hybridization-based INNO-LiPA HBV DR assay and occasionally sequencing (two cases). Positive viral responses (HBV DNA clearance) after 6, 12, and 18 months of therapy were achieved by 57, 68, and 53% of patients,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B; Antiviral therapy; Lamivudine; Drug resistance; YMDD variants; Hepatitis B virus.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001200003

Hepatitis B virus subgenotype C2- and B2-associated mutation patterns may be responsible for liver cirrhosis and hepatocellular carcinoma, respectively
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Chen,Y.M.; Wu,S.H.; Qiu,C.N.; Yu,D.J.; Wang,X.J.
The objective of this study was to examine hepatitis B virus (HBV) subgenotypes and mutations in enhancer II, basal core promoter, and precore regions of HBV in relation to risks of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) in Southeast China. A case-control study was performed, including chronic hepatitis B (CHB; n=125), LC (n=120), and HCC (n=136). HBV was genotyped by multiplex polymerase chain reaction and subgenotyped by restriction fragment length polymorphism. HBV mutations were measured by DNA sequencing. HBV genotype C (68.2%) predominated and genotype B (30.2%) was the second most common. Of these, C2 (67.5%) was the most prevalent subgenotype, and B2 (30.2%) ranked second. Thirteen mutations with a frequency &gt;5% were detected....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Genotype; Core promoter; Precore; Mutation; Advanced liver disease.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000700614

A polymerase chain reaction-based assay to identify genotype F of hepatitis B virus
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Moraes,M.T.B.; Niel,C.; Gomes,S.A.
We have developed a polymerase chain reaction (PCR) assay which distinguishes genotype F from the other genotypes of hepatitis B virus (HBV). The method was used to characterize HBV strains isolated in urban areas of the Brazilian Amazon. DNA was amplified in 54 of a total of 78 HBsAg-positive serum samples, using universal, non-genotype-specific primers. Only 4 (7.4%) were identified as genotype F by our genotype-specific PCR assay. This proportion is notably lower than that previously reported in Argentina, Venezuela, Peru, and Central America.
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Hepatitis B virus; Genotype F; Subtype adw4; Polymerase chain reaction; Brazil.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000100006

Absence of hepatitis B virus DNA in patients with hepatitis C and non-A-E hepatitis in the State of São Paulo, Brazil
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Souza,L.O.; Pinho,J.R.R.; Carrilho,F.J.; da Silva,L.C.
Occult hepatitis B virus (HBV) infection has been reported as cases in which HBV DNA was detected despite the absence of any HBV serological markers or in cases in which anti-HBc antibody was the sole marker. The aim of the present study was to determine, using the polymerase chain reaction (PCR), whether HBV infection occurs in hepatitis C and non-A-E hepatitis patients without serological evidence of hepatitis B infection in São Paulo State. Two different populations were analyzed: 1) non-A-E hepatitis patients, including 12 patients with acute and 50 patients with chronic hepatic disorders without serological evidence of infection with known hepatitis viruses; 2) 43 patients previously diagnosed as hepatitis C with positive results for anti-HCV and HCV...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Hepatitis B virus; Non-A-E hepatitis; Polymerase chain reaction.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004001100011

Prevalence of the precore G1896A mutation in Chinese patients with e antigen negative hepatitis B virus infection and its relationship to pre-S1 antigen
Provedor de dados: Brazilian Journal of Microbiology
Autores: Zhang,Jing; Xu,Wei-Jia; Wang,Qing; Zhang,Yong; Shi,Ming.
This study investigated the prevalence of the precore G1896A mutation in Chinese patients with hepatitis B e antigen (HBeAg) negative HBV infection and its relation to serum HBV pre-S1 antigen. The overall prevalence of the precore G1896A mutation was 72.6% in HBeAg-negative Chinese patients with detectable serum HBV DNA. The prevalence of the precore G1896A is significantly higher in Chinese HBeAg-negative patients with chronic hepatitis B than that in inactive HBV carriers with detectable serum HBV DNA. Serum pre-S1 and the precore G1896A mutation were simultaneously detected in most of Chinese HBeAg-negative patients.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Precore mutation; Pre-S1.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000400031

Cloning and high-level expression of Thermus thermophilus RecA in E. coli: purification and novel use in HBV diagnostics
Provedor de dados: Brazilian Journal of Microbiology
Autores: Sundarrajan,Sudarson; Rao,Sneha; Padmanabhan,Sriram.
ABSTRACT We studied the role of Thermus thermophilus Recombinase A (RecA) in enhancing the PCR signals of DNA viruses such as Hepatitis B virus (HBV). The RecA gene of a thermophilic eubacterial strain, T. thermophilus, was cloned and hyperexpressed in Escherichia coli. The recombinant RecA protein was purified using a single heat treatment step without the use of any chromatography steps, and the purified protein (&gt;95%) was found to be active. The purified RecA could enhance the polymerase chain reaction (PCR) signals of HBV and improve the detection limit of the HBV diagnosis by real time PCR. The yield of recombinant RecA was ∼35 mg/L, the highest yield reported for a recombinant RecA to date. RecA can be successfully employed to enhance detection...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: RecA; Hepatitis B virus; DNA virus; Thermus thermophilus.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000400848

Seroprevalence of Hepatitis B and C markers at the population level in the municipality of Caxias do Sul, southern Brazil
Provedor de dados: Brazilian Journal of Microbiology
Autores: Menegol,Débora; Spilki,Fernando Rosado.
Chronic viral hepatitis are main public health problems worldwide. Data about the seroprevalence to Hepatitis B and C viruses (HBV e HCV) at the population level are scarce on Brazil and especially for the Southern region of the country. The seroprevalence to HBV and HBC antigens was evaluated on a large portion of the population of the municipality of Caxias do Sul (427,858 inhabitants), Brazil. A total of 60,604 individual serum samples collected from 2008 to 2011 were screened for HBV surface antigen (HBsAg) and for antibodies against HBsAg; anti HCV antibodies were measured by ELISA (Enzyme Linked Immunosorbent Assay). Overall, 1.63% of the individuals were positive for HBsAg and 1.43% showed seropositivity to HCV. From the total, 31,749 samples were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hepatitis B virus; Hepatitis C virus; Seroprevalence.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000400030