Ymdd
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Natural YMDD motif mutations in treatment naïve patients with chronic hepatitis B in Huzhou of eastern China
Braz J Infect Dis. Publicado em: 2016-12
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2. YMDD motif mutations in chronic hepatitis B antiviral treatment naïve patients: a multi-center study
OBJECTIVE: This study aimed to determine the natural prevalence of variants of tyrosine-methionine-aspartic acid-aspartic acid (YMDD) motif in patients with chronic hepatitis B (CHB), and to explore its relation with demographic and clinical features, hepatitis B virus (HBV) genotypes, and HBV DNA levels. METHODS: A total of 1,042 antiviral treatment naïve
Brazilian Journal of Infectious Diseases. Publicado em: 2012-06
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3. Genotipagem do vírus da hepatite B de pacientes crônicos com resistência ao tratamento com lamivudina na Cidade de Ribeirão Preto, Estado de São Paulo
INTRODUÇÃO: Lamivudina é um análogo de nucleosídeo clinicamente utilizado para o tratamento da infecção crônica pela hepatite B. Entretanto, o principal problema do uso prolongado da lamivudina é o desenvolvimento de resistência viral ao tratamento. Mutações no motivo YMDD no gene da DNA polimerase do vírus da hepatite B estão associados com a
Revista da Sociedade Brasileira de Medicina Tropical. Publicado em: 2010-06
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4. The emergence of YMDD mutants precedes biochemical flare by 19 weeks in lamivudine-treated chronic hepatitis B patients: an opportunity for therapy reevaluation
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
Brazilian Journal of Medical and Biological Research. Publicado em: 29/10/2007
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5. Fatores preditivos para resposta da Lamivudine na hepatite crônica B
INTRODUÇÃO: A Lamivudina tem-se mostrado útil no tratamento da hepatite crônica pelo vírus B (HC-VHB). OBJETIVO: Investigar os fatores preditivos da resposta à Lamivudina na HC-VHB. MATERIAL E MÉTODOS: Estudo prospectivo com Lamivudina em 35 pacientes com HC-VHB e evidência de multiplicação viral, independentemente do resultado do AgHBe. Administro
Revista do Instituto de Medicina Tropical de São Paulo. Publicado em: 2000-08
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6. Kinetic Analysis of Wild-Type and YMDD Mutant Hepatitis B Virus Polymerases and Effects of Deoxyribonucleotide Concentrations on Polymerase Activity
Mutations in the YMDD motif of the hepatitis B virus (HBV) DNA polymerase result in reduced susceptibility of HBV to inhibition by lamivudine, at a cost in replication fitness. The mechanisms underlying the effects of YMDD mutations on replication fitness were investigated using both a cell-based viral replication system and an in vitro enzyme assay to exami
American Society for Microbiology.
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7. Long-Term Follow-Up Study of Chinese Patients with YMDD Mutations: Significance of Hepatitis B Virus Genotypes and Characteristics of Biochemical Flares
We sought to examine the role of hepatitis B virus (HBV) genotypes in virological breakthroughs and biochemical flares in patients with YMDD mutations during lamivudine therapy. Virologic breakthroughs (i.e., the reappearance of HBV DNA as determined by bDNA assay) and biochemical flares (mild flares = alanine aminotransferase [ALT] between 2 and 10 times th
American Society for Microbiology.
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8. A novel Met-to-Thr mutation in the YMDD motif of reverse transcriptase from feline immunodeficiency virus confers resistance to oxathiolane nucleosides.
Variants of feline immunodeficiency virus (FIV) that possess a unique methionine-to-threonine mutation within the YMDD motif of reverse transcriptase (RT) were selected by culturing virus in the presence of inhibitory concentrations of (-)-beta-L-2',3'-dideoxy-5-fluoro-3'-thiacytidine [(-)-FTC]. The mutants were resistant to (-)-FTC and (-)-beta-L-2',3'-dide
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9. In vitro enzymatic activity of human immunodeficiency virus type 1 reverse transcriptase mutants in the highly conserved YMDD amino acid motif correlates with the infectious potential of the proviral genome.
Reverse transcriptases contain a highly conserved YXDD amino acid motif believed to be important in enzyme function. The second amino acid is not strictly conserved, with a methionine, valine or alanine occupying the second position in reverse transcriptases from various retroviruses and retroelements. Recently, a 3.5-A (0.35-nm) resolution electron density
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10. Wild-Type and YMDD Mutant Murine Leukemia Virus Reverse Transcriptases Are Resistant to 2′,3′-Dideoxy-3′-Thiacytidine
The antiretroviral nucleoside analog 2′,3′-dideoxy-3′-thiacytidine (3TC) is a potent inhibitor of wild-type human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). A methionine-to-valine or methionine-to-isoleucine substitution at residue 184 in the HIV-1 YMDD motif, which is located at the RT active site, leads to a high level of resis
American Society for Microbiology.
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11. Monitoring the Emergence of Hepatitis B Virus Polymerase Gene Variants during Lamivudine Therapy Using the LightCycler
Treatment of chronic hepatitis B virus (HBV) infection with lamivudine is associated with the appearance in the circulation of HBV variants with mutations in the YMDD (tyrosine, methionine, aspartate, aspartate) motif of the polymerase gene. Fluorometric real-time PCR with the LightCycler assay was used for the detection of resistant variants. Differences in
American Society for Microbiology.
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12. Subunit-Specific Analysis of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase In Vivo
The human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) is a heterodimer comprised of two structurally distinct subunits (p51 and p66). Since p51 and p66 are derived from the same coding region, subunit-specific structure-function studies of RT have been conducted exclusively by in vitro biochemical approaches. To study RT subunit function
American Society for Microbiology.