RESUMO
UNLABELLED: Experimental models of hepatic encephalopathy (HE) are limited by difficulties in objectively monitoring neuronal function. There are few models that examine a well-defined neuronal pathway and lack the confounding effects of anesthetics. Motor-evoked potentials (MEPs) assess the function of the motor tract, which has been shown to be impaired in patients with cirrhosis. MEPs were elicited by cranial stimulation (central) and compound motor action potential by sciatic nerve stimulation (peripheral) in several models of HE in the rat. The experiments were performed using subcutaneous electrodes without anesthetics. Brain water content was assessed by gravimetry, brain metabolites were measured by magnetic resonance spectroscopy, and amino acids in microdialysates from the frontal cortex were analyzed by high-performance liquid chromatography. Abnormalities of MEP were observed in acute liver failure (ALF) induced by hepatic devascularization in relation to the progression of neurological manifestations. Similar disturbances were seen in rats with portocaval anastomosis after the administration of blood or lipopolysaccharide, but were absent in rats with biliary duct ligation. Hypothermia (≤35°C) and mannitol prevented the development of brain edema in acute liver failure, but only hypothermia avoided the decrease in the amplitude of MEP. Disturbances of MEP caused by the administration of blood into the gastrointestinal tract in rats with portocaval anastomosis were associated with an increase in ammonia, glutamine, and glutamate in brain microdialysate. CONCLUSION: Assessment of MEP in awake rats is a valid method to monitor HE in models of ALF and precipitated HE. This method shows the lack of efficacy of mannitol, a therapy that decreases brain edema, and relates disturbances of the function of the motor tract to ammonia and its metabolites.
Assuntos
Potencial Evocado Motor , Encefalopatia Hepática/fisiopatologia , Animais , Edema Encefálico/prevenção & controle , Potencial Evocado Motor/efeitos dos fármacos , Encefalopatia Hepática/etiologia , Falência Hepática Aguda , Masculino , Manitol/uso terapêutico , Derivação Portocava Cirúrgica/efeitos adversos , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: fewer than half of patients infected with hepatitis C virus (HCV) achieve sustained viral clearance after peginterferon alfa/ribavirin (Peg-IFN/RBV) therapy. AIMS: thalidomide posses anti-inflammatory and immunomodulatory properties through inhibition of tumor necrosis factor and costimulatory effect on human CD8+ T cells. METHODS: we started a prospective, open label trial of retreatment of very-difficult-to-treat genotype 1 chronic hepatitis C patients (CHC) patients, who had failed to respond to the (Peg-IFN/RBV), with a triple therapy consisting in these same antivirals plus thalidomide 200 mg/day (the TRITAL study). RESULTS: none of the eleven patients fulfilling the inclusion criteria and included in the trial reached complete early virological response or sustained virological response. Viral load decline after 12 weeks of triple therapy thalidomide-based retreatment did not differ from viral dynamics during the first course. The triple therapy was well tolerated and only one patient developed mild bilateral neuropathy. CONCLUSIONS: thalidomide addition to standard therapy is tolerated and did not increase the SVR rate in very-difficult-to-treat genotype 1 CHC patients. Different schedules are warranted to improve attempting retreatment of non responder CHC patients.
Assuntos
Antivirais/uso terapêutico , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Fatores Imunológicos/uso terapêutico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Talidomida/uso terapêutico , Viremia/tratamento farmacológico , Adulto , Antivirais/administração & dosagem , Quimioterapia Combinada , Feminino , Genes Virais , Genótipo , Hepacivirus/classificação , Hepacivirus/isolamento & purificação , Hepatite C Crônica/virologia , Humanos , Fatores Imunológicos/administração & dosagem , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/administração & dosagem , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Ribavirina/administração & dosagem , Terapia de Salvação , Talidomida/administração & dosagem , Resultado do Tratamento , Carga Viral , Viremia/virologiaRESUMO
Antecedentes: menos de la mitad de los pacientes con hepatitis C logra eliminar el virus de manera sostenida después de la terapia con peginterferón alfa y ribavirina (Peg-IFN/RBV). Objetivos: la talidomida posee propiedades antiinflamatorias e inmunomoduladoras a través de la inhibición del TNF-α y al efecto estimulador sobre las células T CD8+. Métodos: se inició un estudio prospectivo y abierto de re-tratamiento de pacientes con hepatitis crónica C genotipo 1, no respondedores al tratamiento con Peg-IFN/RBV, mediante triple terapia añadiendo a los mismos antivirales 200 mg/día de talidomida. Resultados: ninguno de los once pacientes que fueron incluidos en el ensayo consiguió respuesta viral completa en la semana 12 ni respuesta viral sostenida. La dinámica viral en las 12 primeras semanas de tratamiento no difirió de la dinámica viral durante el primer curso de tratamiento. La triple terapia fue bien tolerada y solo un paciente desarrolló neuropatía bilateral autolimitada. Conclusiones: añadir talidomida al tratamiento estándar fue bien tolerado pero no incrementó la tasa de respuesta viral sostenida en pacientes con hepatitis C genotipo 1 no respondedores previos(AU)
Background: fewer than half of patients infected with hepatitis C virus (HCV) achieve sustained viral clearance after peginterferon alfa/ribavirin (Peg-IFN/RBV) therapy. Aims: thalidomide posses anti-inflammatory and immunomodulatory properties through inhibition of tumor necrosis factor and costimulatory effect on human CD8+ T cells. Methods: we started a prospective, open label trial of retreatment of very-difficult-to-treat genotype 1 chronic hepatitis C patients (CHC) patients, who had failed to respond to the (Peg-IFN/RBV), with a triple therapy consisting in these same antivirals plus thalidomide 200 mg/day (the TRITAL study). Results: none of the eleven patients fulfilling the inclusion criteria and included in the trial reached complete early virological response or sustained virological response. Viral load decline after 12 weeks of triple therapy thalidomide-based retreatment did not differ from viral dynamics during the first course. The triple therapy was well tolerated and only one patient developed mild bilateral neuropathy. Conclusions: thalidomide addition to standard therapy is tolerated and did not increase the SVR rate in very-difficult-to-treat genotype 1 CHC patients. Different schedules are warranted to improve attempting retreatment of non responder CHC patients(AU)