935 resultados para ANTI-HEPATITIS C VIRUS


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The heat shock protein Hsp90 is known as an essential component of several signal transduction pathways and has now been identified as an essential host factor for hepatitis B virus replication. Hsp90 interacts with the viral reverse transcriptase to facilitate the formation of a ribonucleoprotein (RNP) complex between the polymerase and an RNA ligand. This RNP complex is required early in replication for viral assembly and initiation of DNA synthesis through a protein-priming mechanism. These results thus invoke a role for the Hsp90 pathway in the formation of an RNP.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Neuropsychiatric complications are common in patients with chronic hepatitis C undergoing treatment with interferon alpha. These side effects include alterations of mood, cognition, and neuroendocrine function and are unpredictable. In a number of neurological disorders characterized by neuropsychiatric symptoms and cognitive dysfunction, inheritance of an apolipoprotein E (APOE) epsilon4 allele is associated with adverse neuropsychiatric outcomes. The authors present evidence that the APOE genotype may influence a patient's neuropsychiatric response to interferon alpha treatment. The inheritance of APOE genotypes was examined in 110 patients with chronic hepatitis C treated with interferon alpha. A retrospective investigation was conducted by assessing the rates of psychiatric referral and neuropsychiatric symptoms experienced during treatment along with other complaints indicating psychological distress. A highly statistically significant association was seen between APOE genotypes and interferon-induced neuropsychiatric symptoms. Patients with an epsilon4 allele were more likely to be referred to a psychiatrist and had more neuropsychiatric symptoms during antiviral treatment than those without an epsilon4 allele. Additionally, patients with an epsilon4 allele were more likely to experience irritability or anger and anxiety or other mood symptoms. These data demonstrate that an individual's APOE genotype may influence the neuropsychiatric response to antiviral therapy with interferon alpha. Prospective studies evaluating the importance of APOE in susceptibility to interferon alpha-induced neuropsychiatric complications are needed. Moreover, pathways involving APOE should be considered in understanding the pathophysiology of interferon alpha-induced neuropsychiatric complications.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Sustained virological response (SVR) is the primary objective in the treatment of chronic hepatitis C (CHC). Results from a recent clinical trial of patients with previously untreated CHC demonstrate that the combination of peginterferon alpha-2a and ribavirin produces a greater SVR than interferon alpha-2b and ribavirin combination therapy. However, the cost-effectiveness of peginterferon alpha-2a plus ribavirin in the U.S. setting has not been investigated. METHODS: A Markov model was developed to investigate cost-effectiveness in patients with CHC using genotype to guide treatment duration. SVR and disease progression parameters were derived from the clinical trials and epidemiologic studies. The impact of treatment on life expectancy and costs were projected for a lifetime. Patients who had an SVR were assumed to remain virus-free for the rest of their lives. In genotype 1 patients, the SVRs were 46% for peginterferon alpha-2a plus ribavirin and 36% for interferon alpha-2b plus ribavirin. In genotype 2/3 patients, the SVRs were 76% for peginterferon alpha-2a plus ribavirin and 61% for interferon alpha-2b plus ribavirin. Quality of life and costs were based on estimates from the literature. All costs were based on published U.S. medical care costs and were adjusted to 2003 U.S. dollars. Costs and benefits beyond the first year were discounted at 3%. RESULTS: In genotype 1, peginterferon alpha-2a plus ribavirin increases quality-adjusted life expectancy (QALY) by 0.70 yr compared to interferon alpha-2b plus ribavirin, producing a cost-effectiveness ratio of $2,600 per QALY gained. In genotype 2/3 patients, peginterferon alpha-2a plus ribavirin increases QALY by 1.05 yr in comparison to interferon alpha-2b plus ribavirin. Peginterferon alpha-2a combination therapy in patients with HCV genotype 2 or 3 is dominant (more effective and cost saving) compared to interferon alpha-2b plus ribavirin. Results weighted by genotype prevalence (75% genotype 1; 25% genotype 2 or 3) also show that peginterferon alpha-2a plus ribavirin is dominant. Peginterferon alpha-2a and ribavirin remained cost-effective (below $16,500 per QALY gained) under sensitivity analyses on key clinical and cost parameters. CONCLUSION: Peginterferon alpha-2a in combination with ribavirin with duration of therapy based on genotype, is cost-effective compared with conventional interferon alpha-2b in combination with ribavirin when given to treatment-naive adults with CHC.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background/Aims: Peginterferon alfa-2a plus ribavirin improves sustained virological responses compared with interferon alfa-2b and ribavirin, or peginterferon alfa-2a alone in chronic hepatitis C. We examined the impact of these treatments on health related quality of life (HRQOL). Methods: Patients (n = 1121) were randomized to peginterferon alfa-2a weekly plus ribavirin or placebo, or interferon alfa-2b thrice weekly plus ribavirin. HRQOL was assessed with the SF-36 Health Survey and Fatigue Severity Scale (FSS). Results: Patients receiving peginterferon alfa-2a plus ribavirin reported better HRQOL than those receiving interferon alfa-2b plus ribavirin. These differences were statistically significant for three SF-36 domains and both FSS scores (p < = 0.05). Patients receiving peginterferon alfa-2a plus placebo had the least impairment; adding ribavirin significantly decreased five domains of the SF-36 and both FSS scores. Sustained virological response was associated with improvement at follow-up on all SF-36 and FSS scores. Conclusions: The effects of combination therapy on HRQOL and fatigue are less with peginterferon alfa-2a plus ribavirin than interferon alfa-2b plus ribavirin. Each medication in combination therapy with interferon and ribavirin, affects patients' quality of life differently. Understanding the relationship of specific therapeutic options to HRQOL may help physicians minimize the impact of therapy on HRQOL. (C) 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The mechanisms for progressive fibrosis and exacerbation by steatosis in patients with chronic hepatitis C (HCV) are still unknown. We hypothesized that proliferative blockade in HCV-infected and steatotic hepatocytes results in the default activation of hepatic progenitor cells (HPC), capable of differentiating into both biliary and hepatocyte lineages, and that the resultant ductular reaction promotes portal fibrosis. To study this concept, 115 liver biopsy specimens from subjects with HCV were scored for steatosis, inflammation, and fibrosis. Biliary epithelium and HPC were decorated by cytokeratin 7 immunoperoxidase, and the replicative state of hepatocytes was assessed by p21 and Ki-67 immunohistochemistry. A ductular reaction at the portal interface was common. There was a highly significant correlation between the area of ductular reaction and fibrosis stage (r = 0.453, P < .0001), which remained independently associated after multivariate analysis. HPC numbers also correlated with fibrosis (r = 0.544, P < .0001) and the ductular area (r = 0.624, P < .0001). Moreover, steatosis correlated with greater HPC proliferation (r = 0.372, P = .0004) and ductular reaction (r = 0.374, P < .0001) but was not an obligate feature. Impaired hepatocyte replication by p21 expression was independently associated with HPC expansion (P = .002) and increased with the body mass index (P < .001) and lobular inflammation (P = .005). In conclusion, the strong correlation between portal fibrosis and a periportal ductular reaction with HPC expansion, the exacerbation by steatosis, and the associations with impaired hepatocyte replication suggest that an altered regeneration pathway drives the ductular reaction. We believe this triggers fibrosis at the portal tract interface. This may be a stereotyped response of importance in other chronic liver diseases.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Aim: To rapidly quantify hepatitis B virus (HBV) DNA by real-time PCR using efficient TaqMan probe and extraction methods of virus DNA. Methods: Three standards were prepared by cloning PCR products which targeted S, C and X region of HBV genome into pGEM-T vector respectively. A pair of primers and matched TaqMan probe were selected by comparing the copy number and the Ct values of HBV serum samples derived from the three different standard curves using certain serum DNA. Then the efficiency of six HBV DNA extraction methods including guanidinium isothiocyanate, proteinase K, NaI, NaOH lysis, alkaline lysis and simple boiling was analyzed in sample A, B and C by real-time PCR. Meanwhile, 8 clinical HBV serum samples were quantified. Results: The copy number of the same HBV serum sample originated from the standard curve of S, C and X regions was 5.7 × 104/ mL, 6.3 × 102/mL and 1.6 × 103/mL respectively. The relative Ct value was 26.6, 31.8 and 29.5 respectively. Therefore, primers and matched probe from S region were chosen for further optimization of six extraction methods. The copy number of HBV serum samples A, B and C was 3.49 × 109/mL, 2.08 × 106/mL and 4.40 × 107/mL respectively, the relative Ct value was 19.9, 30 and 26.2 in the method of NaOH lysis, which was the efficientest among six methods. Simple boiling showed a slightly lower efficiency than NaOH lysis. Guanidinium isothiocyanate, proteinase K and NaI displayed that the copy number of HBV serum sample A, B and C was around 105/ mL, meanwhile the Ct value was about 30. Alkaline failed to quantify the copy number of three HBV serum samples, Standard deviation (SD) and coefficient variation (CV) were very low in all 8 clinical HBV serum samples, showing that quantification of HBV DNA in triplicate was reliable and accurate. Conclusion: Real-time PCR based on optimized primers and TaqMan probe from S region in combination with NaOH lysis is a simple, rapid and accurate method for quantification of HBV serum DNA. © 2006 The WJG Press. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hepatitis C infection (HCV) continues to disproportionately affect Hispanics/Latinos in the United States. Hispanic/Latino intravenous drug users (IDUs), because of their risky injection and sexual behaviors, are prone to HCV infection and rapid transmission of the virus to others via several routes. With a prevalence rate of approximately 75% among IDUs, it is imperative that transmission of HCV be prevented in this population. This study aims to examine the associations between demographic, injection and sexual risk factors to HCV infection in a group Hispanic/Latino IDUs in Miami-Dade County, Florida. Preliminary unadjusted results in this sample reveal that age (OR=4.592, p=0.004), weekly injection (OR=5.171, p=0.000), daily injection frequency (OR=3.856, p=0.000) and use of a dirty needle (OR=2.320, p= 0.006) were all significantly associated with HCV infection. Being born outside the U.S. was significantly negatively associated with HCV infection (OR=0.349, p=0.004). Additionally, having two or more sex partners in the past three months (OR=0.472, p=0.014) was negatively associated with HCV infection. After adjusting for all other variables, older age (AOR=7.470, p=0.006), weekly injection (AOR=3.238, p=0.007) and daily injection frequency (AOR=2.625, p=0.010) were all significantly associated with HCV infection. Being born outside the U.S. (AOR=0.369, p=0.019) was a significant protective factor for HCV infection, along with having two or more sex partners in the past three months (AOR=0.481, p=0.037). When analyzing the significant variables in a backward regression model, having 2 or more sex partners in the past three months was not significant at the p

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Occult hepatitis B infections are becoming a major global threat, but the available data on its prevalence in various parts of the world are often divergent. Objective: This study aimed to detect occult hepatitis B virus in hepatitis B surface antigen-negative serum using anti-HBc as a marker of previous infection. Patient and Methods: A total of 1000 randomly selected hepatitis B surface antigen-negative sera from blood donors were tested for hepatitis B core antibody and hepatitis B surface antibody using an ELISA and nested polymerase chain reaction was done using primers specific to the surface gene (S-gene). Results: Of the 1000 samples 55 (5.5%) were found to be reactive, of which 87.3% (48/55) were positive for hepatitis B surface antibody, indicating immunity as a result of previous infection however, that does not exclude active infection with escaped mutant HBV. Nested PCR results showed the presence of hepatitis B viral DNA in all the 55 samples that were positive for core protein, which is in agreement with the hepatitis B surface antibody result. Conclusion: This study reveals the 5.5% prevalence of occult hepatitis B among Malaysian blood donors as well as the reliability of using hepatitis B core antibody in screening for occult hepatitis B infection in low endemic, low socioeconomic settings.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hepatitis C infection (HCV) continues to disproportionately affect Hispanics/Latinos in the United States. Hispanic/Latino intravenous drug users (IDUs), because of their risky injection and sexual behaviors, are prone to HCV infection and rapid transmission of the virus to others via several routes. With a prevalence rate of approximately 75% among IDUs, it is imperative that transmission of HCV be prevented in this population. This study aims to examine the associations between demographic, injection and sexual risk factors to HCV infection in a group Hispanic/Latino IDUs in Miami-Dade County, Florida. Preliminary unadjusted results in this sample reveal that age (OR=4.592, p=0.004), weekly injection (OR=5.171, p=0.000), daily injection frequency (OR=3.856, p=0.000) and use of a dirty needle (OR=2.320, p= 0.006) were all significantly associated with HCV infection. Being born outside the U.S. was significantly negatively associated with HCV infection (OR=0.349, p=0.004). Additionally, having two or more sex partners in the past three months (OR=0.472, p=0.014) was negatively associated with HCV infection. After adjusting for all other variables, older age (AOR=7.470, p=0.006), weekly injection (AOR=3.238, p=0.007) and daily injection frequency (AOR=2.625, p=0.010) were all significantly associated with HCV infection. Being born outside the U.S. (AOR=0.369, p=0.019) was a significant protective factor for HCV infection, along with having two or more sex partners in the past three months (AOR=0.481, p=0.037). When analyzing the significant variables in a backward regression model, having 2 or more sex partners in the past three months was not significant at the p

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The concept of zoonotic hepatitis E in industrialized countries has emerged with the discovery of swine strains of hepatitis E virus (HEV) genotype 3, closely related to human HEV. Different routes of zoonotic HEV transmission have been recognized, including contact with infected pigs. Workers occupationally exposed to swine (WOES) have been considered a risk group for HEV infection, but contradictory results have been reported. In the present study, we searched for anti-HEV IgG in WOES (butchers, slaughterhouse workers, veterinarians and pig farmers; n = 114) and in the general population (n = 804) in order to investigate the potential occupational risk of zoonotic HEV infection in this work group. A significantly higher (p = 0.008) anti-HEV IgG seroprevalence was found in WOES (30.7 %) when compared with the general population (19.9 %). Multivariate analysis showed that having professions with exposure to pigs for more than 16.5 years was a risk factor for being positive for anti-HEV IgG (aOR of 5.4, 95 % CI 1.9-15.6, p = 0.002). To our knowledge, this is the first study on the prevalence of anti-HEV IgG in WOES in Portugal, also showing increased probability for infection in this group.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Hepatitis B virus (HBV) can be classified into nine genotypes (A-I) defined by sequence divergence of more than 8% based on the complete genome. This study aims to identify the genotypic distribution of HBV in 40 HBsAg-positive patients from Rondonia, Brazil. A fragment of 1306 bp partially comprising surface and polymerase overlapping genes was amplified by PCR. Amplified DNA was purified and sequenced. Amplified DNA was purified and sequenced on an ABI PRISM (R) 377 Automatic Sequencer (Applied Biosystems, Foster City, CA, USA). The obtained sequences were aligned with reference sequences obtained from the GenBank using Clustal X software and then edited with Se-Al software. Phylogenetic analyses were conducted by the Markov Chain Monte Carlo (MCMC) approach using BEAST v.1.5.3. Results: The subgenotypes distribution was A1 (37.1%), D3 (22.8%), F2a (20.0%), D4 (17.1%) and D2 (2.8%). Conclusions: These results for the first HBV genotypic characterization in Rondonia state are consistent with other studies in Brazil, showing the presence of several HBV genotypes that reflects the mixed origin of the population, involving descendants from Native Americans, Europeans, and Africans.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The complete nucleotide sequence of the genomic RNA from the insect picorna-like virus Drosophila C virus (DCV) was determined. The DCV sequence predicts a genome organization different to that of other RNA virus families whose sequences are known. The single-stranded positive-sense genomic RNA is 9264 nucleotides in length and contains two large open reading frames (ORFs) which are separated by 191 nucleotides. The 5' ORF contains regions of similarities with the RNA-dependent RNA polymerase, helicase and protease domains of viruses from the picornavirus, comovirus and sequivirus families. The 3' ORF encodes the capsid proteins as confirmed by N-terminal sequence analysis of these proteins. The capsid protein coding region is unusual in two ways: firstly the cistron appears to lack an initiating methionine and secondly no subgenomic RNA is produced, suggesting that the proteins may be translated through internal initiation of translation from the genomic length RNA. The finding of this novel genome organization for DCV shows that this virus is not a member of the Picornaviridae as previously thought, but belongs to a distinct and hitherto unrecognized virus family.