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1.
Hepatology ; 67(6): 2113-2126, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29473975

RESUMO

Many direct-acting antiviral regimens have reduced activity in people with hepatitis C virus (HCV) genotype (GT) 3 infection and cirrhosis. The C-ISLE study assessed the efficacy and safety of elbasvir/grazoprevir (EBR/GZR) plus sofosbuvir (SOF) with and without ribavirin (RBV) in compensated cirrhotic participants with GT3 infection. This was a phase 2, randomized, open-label study. Treatment-naive participants received EBR/GZR + SOF + RBV for 8 weeks or EBR/GZR + SOF for 12 weeks, and peginterferon/RBV treatment-experienced participants received EBR/GZR + SOF ± RBV for 12 weeks or EBR/GZR + SOF for 16 weeks. The primary endpoint was HCV RNA <15 IU/mL 12 weeks after the end of treatment (sustained virologic response at 12 weeks [SVR12]). Among treatment-naive participants, SVR12 was 91% (21/23) in those treated with RBV for 8 weeks and 96% (23/24) in those treated for 12 weeks. Among treatment-experienced participants, SVR12 was 94% (17/18) and 100% (17/17) in the 12-week arm, with and without RBV, respectively, and 94% (17/18) in the 16-week arm. Five participants failed to achieve SVR: 2 relapsed (both in the 8-week arm), 1 discontinued due to vomiting/cellulitis (16-week arm), and 2 discontinued (consent withdrawn/lost to follow-up). SVR12 was not affected by the presence of resistance-associated substitutions (RASs). There was no consistent change in insulin resistance, and 5 participants reported serious adverse events (pneumonia, chest pain, opiate overdose, cellulitis, decreased creatinine). High efficacy was demonstrated in participants with HCV GT3 infection and cirrhosis. Treatment beyond 12 weeks was not required, and efficacy was maintained regardless of baseline RASs. CONCLUSION: Data from this study support the use of EBR/GZR plus SOF for 12 weeks without RBV for treatment-naive and peginterferon/RBV-experienced people with GT3 infection and cirrhosis (ClinicalTrials.gov NCT02601573). (Hepatology 2018;67:2113-2126).


Assuntos
Antivirais/uso terapêutico , Benzofuranos/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Imidazóis/uso terapêutico , Quinoxalinas/uso terapêutico , Ribavirina/uso terapêutico , Sofosbuvir/uso terapêutico , Adulto , Idoso , Combinação de Medicamentos , Feminino , Genótipo , Hepacivirus/genética , Hepatite C Crônica/complicações , Hepatite C Crônica/virologia , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade
2.
Liver Transpl ; 23(9): 1103-1112, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28544587

RESUMO

Concerns about an increased hepatocellular carcinoma (HCC) recurrence rate following direct-acting antiviral (DAA) therapy in patients with cirrhosis with a prior complete oncological response have been raised. Data regarding the impact of HCV treatment with DAAs on wait-list dropout rates in patients with active HCC and HCV-related cirrhosis awaiting liver transplantation (LT) are lacking. HCV-HCC patients listed for LT between January 2015 and May 2016 at Padua Liver Transplant Center were considered eligible for the study. After enrollment, patients were divided into 2 groups, depending on whether they underwent DAA treatment while awaiting LT or not. For each patient clinical, serological, and virological data were collected. HCC characteristics were radiologically evaluated at baseline and during follow-up (FU). For transplanted patients, pathological assessment of the explants was performed and recurrence rates were calculated. A total of 23 patients treated with DAAs and 23 controls were enrolled. HCC characteristics at time of LT listing were comparable between the 2 groups. Median FU was 10 and 7 months, respectively, during which 2/23 (8.7%) and 1/23 (4.3%) dropout events due to HCC progression were registered (P = 0.90). No significant differences in terms of radiological progression were highlighted (P = 0.16). A total of 9 out of 23 (39%) patients and 14 out of 23 (61%) controls underwent LT, and histopathological analysis showed no differences in terms of median number and total tumor volume of HCC nodules, tumor differentiation, or microvascular invasion. During post-LT FU, 1/8 (12.5%) DAA-treated patient and 1/12 (8.3%) control patient experienced HCC recurrence (P = 0.60). In conclusion, viral eradication does not seem to be associated with an increased risk of dropout due to neoplastic progression in HCV-HCC patients awaiting LT. Liver Transplantation 23 1103-1112 2017 AASLD.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/terapia , Doença Hepática Terminal/cirurgia , Cirrose Hepática/terapia , Neoplasias Hepáticas/terapia , Transplante de Fígado/efeitos adversos , Recidiva Local de Neoplasia/epidemiologia , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Listas de Espera , Idoso , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Progressão da Doença , Doença Hepática Terminal/virologia , Seguimentos , Hepacivirus/isolamento & purificação , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/sangue , Cirrose Hepática/complicações , Cirrose Hepática/virologia , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Pessoa de Meia-Idade , Invasividade Neoplásica/diagnóstico por imagem , Invasividade Neoplásica/patologia , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Recidiva Local de Neoplasia/virologia , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença
3.
Curr Opin Infect Dis ; 29(6): 625-631, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27673712

RESUMO

PURPOSE OF REVIEW: Directly acting antiviral drug (DAA) treatments represent a major advance in hepatitis C management, achieving virological cures in excess of 90%. When treatment failure occurs, it is mostly due to relapse with the emergence of resistance-associated variants. RECENT FINDINGS: Data from in-vitro studies and clinical trials have enabled characterization of the amino acid substitutions in antiviral drug targets that confer reduced susceptibility to DAAs. These resistance-associated substitutions (RASs) may exist prior to treatment, and are associated with, but do not inevitably result in, treatment failure. The most important RASs with current regimens occur in the NS5A protein of viral variants, which may persist for years after treatment. The optimal strategy is to prevent resistance through administering the best treatment, appropriately matched to patient and virological characteristics, for example the presence of cirrhosis, prior exposure to interferon and so on. SUMMARY: International treatment guidelines have been developed to select treatments, which may vary in duration and coadministration with ribavirin. Routine resistance testing prior to treatment of naive patients is not generally recommended. Next-generation DAAs will further reduce the emergence of RASs and, because of activity against RASs to currently used DAAs, will be used as rescue therapies for patients who have failed treatment.


Assuntos
Farmacorresistência Viral , Hepatite C Crônica/tratamento farmacológico , Antivirais/uso terapêutico , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/virologia , Humanos , Ribavirina/uso terapêutico , Falha de Tratamento , Proteínas não Estruturais Virais
5.
Liver Int ; 36(10): 1415-7, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27616335
6.
Liver Int ; 30(3): 463-71, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19912533

RESUMO

BACKGROUND: The circulatory dysfunction associated with cirrhosis is well described. Reduced systemic vascular resistance and high cardiac output are the main features of the hyperdynamic state, but involvement of the peripheral microcirculation in this process is poorly understood. Near infrared spectroscopy (NIRS) has been used to assess muscle tissue oxygenation (StO(2)) in haemorrhagic and septic shock. Vascular occlusion testing (VOT) can produce dynamic changes in StO(2) which represent tissue oxygen extraction, delivery, and hence, surrogate markers of microvascular function. AIMS: We aimed to investigate dynamic StO(2) changes in the peripheral microcirculation of patients with cirrhosis. METHODS: Thirty-five subjects were examined (25 cirrhosis, 10 healthy volunteers) with an InSpectra 650 StO(2) monitor and 15 mm thenar probe. Brachial VOT was applied at systolic blood pressure +50 mmHg for 3 min, in triplicate. Dynamic StO(2) parameters are reported for baseline, downslope, upslope, area over ischaemic curve, overshoot, area under recovery curve and recovery time. RESULTS: Patients with cirrhosis demonstrated significantly larger post-occlusive hyperaemic variables compared with volunteers: overshoot (17 vs 15%, P=0.009), area under recovery curve (25.1 vs 16.3 %/min, P<0.001) and recovery time (3.0 vs 2.2 min, P<0.001). Magnitude of change was also seen to increase with disease stage as defined by Child-Pugh score. Serial VOT revealed microcirculatory ischaemic adaptation in volunteers, which was absent in cirrhosis. CONCLUSIONS: NIRS can identify dynamic changes in muscle tissue oxygenation in cirrhosis which are compatible with microcirculatory vasodilatation. Ischaemic adaptation was seen in controls but not in patients with cirrhosis. NIRS techniques offer a novel approach to the assessment of peripheral vascular dysfunction in cirrhosis.


Assuntos
Cirrose Hepática/fisiopatologia , Microcirculação , Músculo Esquelético/irrigação sanguínea , Consumo de Oxigênio , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Feminino , Humanos , Hiperemia , Cirrose Hepática/metabolismo , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo
8.
J Health Psychol ; 23(11): 1405-1414, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-27458106

RESUMO

Development of psychiatric symptoms during interferon-alpha therapy may be influenced by psychological factors. We examined illness perceptions using the Revised Illness Perceptions Questionnaire in 55 patients with chronic hepatitis C virus infection, due to receive interferon-alpha. The Hospital Anxiety and Depression Scale was used to assess the development of symptoms. Negative identity, consequences and emotional representation beliefs were significantly associated with both higher depression and anxiety scores. Negative illness perceptions play a predictive role in the development of interferon-alpha-induced psychiatric symptoms.


Assuntos
Ansiedade/induzido quimicamente , Depressão/induzido quimicamente , Conhecimentos, Atitudes e Prática em Saúde , Hepatite C Crônica/tratamento farmacológico , Fatores Imunológicos/efeitos adversos , Interferon-alfa/efeitos adversos , Transtornos Mentais/induzido quimicamente , Adulto , Feminino , Humanos , Masculino
10.
Eur J Gastroenterol Hepatol ; 18(4): 333-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16538103

RESUMO

Patients with chronic hepatitis C virus (HCV) infection frequently describe neuropsychological symptoms. Although hepatic encephalopathy is the best established neurological association of HCV infection, there is a growing body of literature on cerebral dysfunction, occurring at an early stage of chronic HCV infection, well before the development of cirrhosis. In this review we describe recent studies that have documented mild, but significant neurocognitive impairment in HCV infection. These deficits in patients with minimal or absent liver disease do not appear to be attributable to a history of substance abuse, coexistent depression or hepatic encephalopathy. Recent studies employing in-vivo magnetic resonance spectroscopy have suggested that a biological mechanism associated with the virus may be responsible. The hypothesis that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment is supported by molecular virological studies of post-mortem brain tissue.


Assuntos
Encefalopatias/etiologia , Hepatite C Crônica/complicações , Encéfalo/metabolismo , Encefalopatias/diagnóstico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Infecções por HIV/complicações , Humanos , Espectroscopia de Ressonância Magnética
11.
World J Gastroenterol ; 12(19): 2969-78, 2006 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-16718775

RESUMO

Hepatic encephalopathy (HE) is a common neuro-psychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging (MRI) techniques provide a non-invasive means of assessment of changes in brain volume (coregistered MRI) and impaired brain function (fMRI), while proton magnetic resonance spectroscopy (1H MRS) detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.


Assuntos
Encéfalo/patologia , Encefalopatia Hepática/patologia , Imageamento por Ressonância Magnética/tendências , Espectroscopia de Ressonância Magnética/métodos , Astrócitos/patologia , Encéfalo/irrigação sanguínea , Química Encefálica , Edema Encefálico/patologia , Imagem de Difusão por Ressonância Magnética , Humanos , Falência Hepática/patologia , Imageamento por Ressonância Magnética/métodos , Fluxo Sanguíneo Regional , Água/análise
12.
Neuropsychopharmacology ; 41(10): 2502-11, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27067128

RESUMO

Owing to the unique opportunity to assess individuals before and after they develop depression within a short timeframe, interferon-α (IFN-α) treatment for chronic hepatitis C virus (HCV) infection is an ideal model to identify molecular mechanisms relevant to major depression, especially in the context of enhanced inflammation. Fifty-eight patients were assessed prospectively, at baseline and monthly over 24 weeks of IFN-α treatment. New-onset cases of depression were determined using the Mini International Neuropsychiatric Interview (MINI). Whole-blood transcriptomic analyses were conducted to investigate the following: (1) baseline gene expression differences associated with future development of IFN-α-induced depression, before IFN-α, and (2) longitudinal gene expression changes from baseline to weeks 4 or 24 of IFN-α treatment, separately in those who did and did not develop depression. Transcriptomics data were analyzed using Partek Genomics Suite (1.4-fold, FDR adjusted p⩽0.05) and Ingenuity Pathway Analysis Software. Twenty patients (34%) developed IFN-α-induced depression. At baseline, 73 genes were differentially expressed in patients who later developed depression compared with those who did not. After 4 weeks of IFN-α treatment, 592 genes were modulated in the whole sample, representing primarily IFN-α-responsive genes. Substantially more genes were modulated only in patients who developed depression (n=506, compared with n=70 in patients who did not), with enrichment in inflammation-, neuroplasticity- and oxidative stress-related pathways. A similar picture was observed at week 24. Our data indicate that patients who develop IFN-α-induced depression have an increased biological sensitivity to IFN-α, as shown by larger gene expression changes, and specific signatures both as predictors and as correlates.


Assuntos
Antivirais/efeitos adversos , Depressão , Interferon-alfa/efeitos adversos , Queratinas/sangue , Estresse Oxidativo/efeitos dos fármacos , Adulto , Análise de Variância , Estudos de Coortes , Biologia Computacional , Depressão/sangue , Depressão/induzido quimicamente , Depressão/diagnóstico , Depressão/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Hepatite C/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Inquéritos e Questionários
13.
AIDS ; 19 Suppl 3: S53-63, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16251829

RESUMO

Numerous studies have reported associations between chronic hepatitis C virus (HCV) infection and fatigue, depression and impairments in health-related quality of life, which are independent of the severity of liver disease. Although there are a large number of potential explanations for these symptoms, including a history of substance abuse and associated personality types, or the effect of the diagnosis of HCV infection itself, there has been recent interest in the possibility of a biological effect of HCV infection on cerebral function. There is emerging evidence of mild, but significant neurocognitive impairment in HCV infection, which cannot be wholly attributed to substance abuse, co-existent depression or hepatic encephalopathy. Impairments are predominantly in the domains of attention, concentration and information processing speed. Furthermore, in-vivo cerebral magnetic resonance spectroscopy studies in patients with hepatitis C and normal liver function have reported elevations in cerebral choline-containing compounds and reductions in N-acetyl aspartate, suggesting that a biological mechanism may underlie the cognitive findings. The recent detection of HCV genetic sequences in post-mortem brain tissue raises the intriguing possibility that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment.


Assuntos
Encéfalo/metabolismo , Transtornos Cognitivos/virologia , Hepatite C Crônica/psicologia , Depressão/virologia , Fadiga/virologia , Infecções por HIV/psicologia , Hepatite C Crônica/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Qualidade de Vida
14.
J Hepatol ; 49(3): 316-22, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18538439

RESUMO

BACKGROUND/AIMS: Abnormal cerebral metabolism and cognitive impairments have been reported in patients with chronic hepatitis C (HCV) but studies have failed to demonstrate a relationship between these findings. METHODS: Twenty-five HCV-positive patients with histologically-mild liver disease were studied with cerebral proton magnetic resonance spectroscopy (MRS), using acquisition parameters to quantify myo-inositol (mI) and other metabolites in frontal white matter (FWM). Patients underwent automated attention and working memory tests (Cognitive Drug Research test system). RESULTS: The mean mI/ creatine ratio in the HCV+ve patients (0.64, SD 0.21) was significantly higher (p=0.02) than in healthy controls (0.52, SD 0.10). On cognitive testing, the HCV+ve patients showed impairments in 2/4 composite scores, reflecting working memory and attention, compared to normative data from healthy volunteers (p<0.005) and HCV-ve controls (p=0.03). There was a significant association between elevated FWM mI/creatine and prolonged working memory reaction times (R=0.72, p=0.002). CONCLUSIONS: Elevated FWM mI/ creatine is a feature of HIV-related minor cognitive-motor disorder. It is associated with infection and immune activation of microglial cells. The similar findings in this study suggest that cerebral immune activation may also occur in HCV infection. This may underlie the mild neurocognitive impairment and neuropsychological symptoms observed in a proportion of patients.


Assuntos
Encéfalo/imunologia , Encéfalo/metabolismo , Creatina/metabolismo , Hepatite C Crônica/imunologia , Hepatite C Crônica/metabolismo , Imunidade/fisiologia , Inositol/metabolismo , Adulto , Atenção/fisiologia , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Cognição/fisiologia , Feminino , Humanos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Memória/fisiologia , Microglia/imunologia , Microglia/metabolismo , Pessoa de Meia-Idade , Prótons
15.
J Magn Reson Imaging ; 23(4): 459-64, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16506142

RESUMO

PURPOSE: To investigate variation in pH generated by different analysis techniques and to find the most robust method, 31P MR brain spectra were acquired in vivo. Three different methods were used to measure the chemical shift of inorganic phosphate (Pi) relative to phosphocreatine (PCr). MATERIALS AND METHODS: Eight healthy volunteers were scanned four times, and manual measurement of the chemical shift in a frequency domain spectrum using the manufacturer's software was compared with values produced by a frequency-domain analysis method (NMR1) and a prior-knowledge-based time-domain technique (MRUI). To explain the in vivo data, simulations of brain spectra, modified in ways typical of real variations in vivo, were produced and the pH was measured using manual measurement and MRUI. RESULTS: Different measurement techniques produced systematically different pH values, with manual measurement producing the lowest variability (manual measurement: pH = 6.999, CoV = 0.297; NMR1: pH = 7.042, CoV = 0.501; MRUI: pH = 7.036, CoV = 0.606). While MRUI more accurately measured the pH of unaltered simulations, it was systematically affected by altering the simulated spectra. Manual measurement was unaffected. CONCLUSION: Manual measurement produces the most consistent pH value, and there is no benefit in using more complex automated spectral fitting methods to measure the pH.


Assuntos
Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Fosfocreatina/metabolismo , Adulto , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Fosfatos/metabolismo , Isótopos de Fósforo
17.
Metab Brain Dis ; 19(3-4): 383-91, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15554429

RESUMO

Hepatic encephalopathy is the most obvious neurological consequence of chronic hepatitis C virus (HCV) infection. There are also case reports of HCV-associated cerebral vasculitis. This review is concerned with the possibility of an effect of HCV on cerebral dysfunction, occurring at an early stage of chronic infection, prior to the development of cirrhosis and unrelated to vasculitis. There is emerging evidence of mild, but significant neurocognitive impairment in HCV infection, which cannot be attributed to substance abuse, coexistent depression, or hepatic encephalopathy. In vivo magnetic resonance spectroscopy and neurophysiological studies have suggested that a biological mechanism may underlie these cognitive findings. The recent detection of HCV genetic sequences in postmortem brain tissue raises the intriguing possibility that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment.


Assuntos
Transtornos Cognitivos/virologia , Encefalite Viral/virologia , Hepatite C/complicações , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/fisiopatologia , Progressão da Doença , Encefalite Viral/diagnóstico , Encefalite Viral/fisiopatologia , Fadiga/fisiopatologia , Fadiga/virologia , Hepacivirus/genética , Encefalopatia Hepática/fisiopatologia , Encefalopatia Hepática/virologia , Humanos , Espectroscopia de Ressonância Magnética , Vasculite do Sistema Nervoso Central/fisiopatologia , Vasculite do Sistema Nervoso Central/virologia
18.
J Med Virol ; 70(1): 62-73, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12629645

RESUMO

To determine the pattern and significance of the HCV genetic heterogeneity before and during treatment with recombinant-2b or lymphoblastoid alpha-interferon, hypervariable region 1 (HVR-1) and NS5A quasispecies were characterised by cloning and sequencing in 12 HCV-1b-infected subjects. Patients were either responder-relapsers or non-responders to treatment. Extensive amino acid sequence analysis was applied to reveal the significance of HCV variation at key sites within HVR-1 and NS5A regions. Genetic complexity, genetic diversity, and the non-synonymous to synonymous substitution ratios of HVR-1 quasispecies decreased during treatment in responder-relapser patients only, and more markedly so following lymphoblastoid alpha-interferon. In non-responders, the HVR-1 quasispecies broadened. Amino acids G406 and Q409, which represent a major viral epitope, were highly conserved throughout treatment. Responder-relapser patients had a higher mutation frequency in NS5A than non-responders. Lymphoblastoid alpha-interferon promoted the selection of intermediate Interferon Sensitivity Determining Region (ISDR) sequences, whereas recombinant-2b alpha-interferon favoured maintenance or selection of conserved ISDR sequences. Variability upstream of the ISDR was associated with treatment response, but the amino acid substitutions conferring higher replicative ability to in vitro HCV replicons were absent in in vivo isolates. In conclusion, the pattern of HVR-1 quasispecies evolution correlates with the clinical response, and the conservation of specific amino acids may be useful for immune targeting in vivo. In responder-relapser patients, the initial HVR-1 evolution resembles that found in sustained responders. Variability within the entire NS5A, as opposed to a single region (ISDR), may have a role in influencing alpha-interferon treatment outcome. A differential effect of different alpha-interferon preparations on HCV quasispecies kinetics may exist.


Assuntos
Hepacivirus/genética , Hepatite C/virologia , Interferon-alfa/uso terapêutico , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , DNA Viral , Heterogeneidade Genética , Variação Genética , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Humanos , Dados de Sequência Molecular , Filogenia
19.
J Virol ; 78(10): 5170-83, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15113899

RESUMO

Reports of cerebral dysfunction in chronic hepatitis C virus (HCV) infection have led to the suggestion that HCV may infect the central nervous system (CNS). We used reverse transcription-PCR, cloning, and sequencing to define quasispecies for the HCV internal ribosomal entry site (IRES) and hypervariable region 1 (HVR1) in autopsy-derived brain, liver, lymph node, and serum samples. There was evidence of tissue compartmentalization of sequences in the brain in two patients, with between 24 and 55% of brain-derived IRES sequences absent from the serum, and significant phylogenetic and phenetic clustering of the brain and lymph node HVR1 sequences. The IRES initiates cap-independent translation of the viral polyprotein. Two unique brain-derived IRES mutations (C(204)-->A and G(243)-->A), which have previously been associated with lymphoid replication and altered translational efficiency in cell culture, were found in one patient. We used a dicistronic reporter vector to test whether brain-derived variants showed altered IRES-mediated translational efficiency, which might favor CNS infection. The translational efficiencies of the brain-derived IRES sequences were generally reduced compared to those of the master serum and liver sequences in rabbit reticulocyte cell lysates and two human cell lines, HuH7 (liver) and CHME3 (microglial). The C(204)-->A and G(243)-->A mutations showed preserved translational efficiency in HuH7 cells but reduced efficiency in CHME3 cells. Our data provide evidence that the CNS is a site of HCV replication, consistent with the recent demonstration of negative-strand HCV RNA in brain, and suggest that IRES polymorphisms may be important as a viral strategy of reduced translation to favor latency in the CNS.


Assuntos
Encéfalo/virologia , Hepacivirus/genética , Fígado/virologia , Biossíntese de Proteínas , Viremia/virologia , Sequência de Bases , Clonagem Molecular , Humanos , Dados de Sequência Molecular , RNA Viral/química , Ribossomos/fisiologia
20.
NMR Biomed ; 16(3): 168-76, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12884361

RESUMO

Prior knowledge is required when quantifying in vivo (31)P magnetic resonance spectra from the brain or liver. The prior knowledge system we have used models both the phosphomonoester and phosphodiester resonances as two peaks of equal linewidth and fixed relative chemical shift. The analysis of the data is carried out in the time domain, which allows the broad component of the spectra to be modelled. This prior knowledge method has been tested for analysis of in vivo (31)P MR spectra from the liver and brain and gives results consistent with other methods that are also used to analyse the spectra, but with reduced variability. This technique may be utilized for studies requiring serial MR spectroscopy examinations, before and after patient treatment.


Assuntos
Algoritmos , Química Encefálica , Fígado/química , Imageamento por Ressonância Magnética/métodos , Modelos Biológicos , Compostos de Fósforo/análise , Simulação por Computador , Humanos , Modelos Estatísticos , Isótopos de Fósforo , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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