Asunto(s)
Virus de Hepatitis/fisiología , Hepatitis Viral Humana , Interferones/uso terapéutico , Vacunas contra Hepatitis Viral/uso terapéutico , Antivirales/uso terapéutico , Femenino , Virus de Hepatitis/inmunología , Virus de Hepatitis/patogenicidad , Hepatitis Viral Humana/tratamiento farmacológico , Hepatitis Viral Humana/historia , Hepatitis Viral Humana/fisiopatología , Hepatitis Viral Humana/virología , Historia del Siglo XX , Humanos , Interferones/inmunología , Interferones/farmacología , Masculino , Inhibidores de la Síntesis del Ácido Nucleico/uso terapéutico , Vacunas contra Hepatitis Viral/inmunologíaRESUMEN
More than 90 years have passed since Peyton Rous reported that a tumor was transmitted between chickens like an infection disease. Currently the viruses are considered the second most important cause of cancer in humans and contribute to 10 to 20% of all cancer cases in the world, some of them being very common, like cervical and hepatocellular carcinomas. Human recognized cancer viruses include HPV, HBV, HCV, EBV, HHV-8 and HTLV-1. The knowledge of how viruses participate in the ethiopathogeny of cancer will allow fighting the disease with similar strategies than those that we use to control those infective agents now days. Great efforts are being initiated to decrease incidence of the neoplasms by preventing the initial infection or by prophylactic vaccination.
Asunto(s)
Neoplasias/virología , Predicción , Virus de Hepatitis/fisiología , Herpesvirus Humano 4/fisiología , Virus Linfotrópico T Tipo 1 Humano/fisiología , Humanos , Síndromes de Inmunodeficiencia/virología , Virus Oncogénicos/fisiología , Papillomaviridae/fisiologíaRESUMEN
Hepatitis viruses belong to different families and have in common a striking hepatotropism and restrictions for propagation in cell culture. The transmissibility of hepatitis is in great part limited to non-human primates. Enterically transmitted hepatitis viruses (hepatitis A virus and hepatitis E virus) can induce hepatitis in a number of Old World and New World monkey species, while the host range of non-human primates susceptible to hepatitis viruses transmitted by the parenteral route (hepatitis B virus, hepatitis C virus and hepatitis delta virus) is restricted to few species of Old World monkeys, especially the chimpanzee. Experimental studies on non-human primates have provided an invaluable source of information regarding the biology and pathogenesis of these viruses, and represent a still indispensable tool for vaccine and drug testing.
Asunto(s)
Cebidae , Cercopithecidae , Modelos Animales de Enfermedad , Virus de Hepatitis/patogenicidad , Hepatitis Viral Animal/transmisión , Animales , Virus de Hepatitis/inmunología , Virus de Hepatitis/fisiología , Hepatitis Viral Animal/virología , Replicación ViralRESUMEN
Hepatitis viruses belong to different families and have in common a striking hepatotropsin and restrictions for propagation in cell culture. The transmissibility of hepatitis is in great part limited to non-human primates. Enterically transmitted hepatitis viruses (hepatitis A virus and hepatitis E virus) can induce hepatitis in a number of OLD World and New Worls monkey species, while the host range of non-human primates susceptible to hepatitis viruses transmitted by the parenteral route (hepatitis B virus, hepatitis C virus and hepatitis delta virus) is restricted to few species of Old World monkeys, especially the chimpanzee. Experimental studies on non-human primates have provided an invaluable source of information regarding the biology and pathogenesis of these viruses, and represent a still indispensable tool for vaccine and drug testing.
Asunto(s)
Animales , Cebidae , Cercopithecidae , Modelos Animales de Enfermedad , Virus de Hepatitis/patogenicidad , Hepatitis Viral Animal/transmisión , Virus de Hepatitis/inmunología , Virus de Hepatitis/fisiología , Hepatitis Viral Animal/virología , Replicación ViralRESUMEN
Great advances has been achieved in the last 10 years in the study of acute and chronic viral hepatitis. The enigma of non-A non-B viral hepatitis was disclosed when C virus was identified and later when E virus was isolated. New viruses has been searched to explain non-A to non-E viral hepatitis, being reported recently G virus. Epidemiology and clinical aspects has been reviewed identifying unusual clinical forms: choletasic and relapsing hepatitis in HAV infection; escape mutants B virus hepatitis in HVB infection; and the silent evolution to chronicity in more than 70% of cases in HVC infection. Diagnostic techniques has been developed to asses serum antibodies and the virus itself. It is important to quantitate the viral particles in the serum before treatment. PCR technique has been used with good results. A and E virus do not remain in the host and permanent inmunity is obtained after infection is resolved. 10% of B and 80% of C viral hepatitis goes to chronicity. So far, the only drug used to treat chronic viral B, D and C hepatitis is interferon alfa, obtaining good response en 40%. Combinations with Rivabirin and increasing the dose, frequency and duration of interferon treatment are in study. lt is a recomendation to treat acute HCV infection with Interferon alfa to prevent chronicity. Vaccines against A and B virus are used, being included in childhood vaccination programs. No HVC vaccine has developed probably to constant virus mutancy. New chalenges are present in this field and in the identification of new hepatitis viruses.
Asunto(s)
Virus de Hepatitis/fisiología , Hepatitis Viral Humana/virología , Adulto , Anticuerpos Antivirales/sangre , Transmisión de Enfermedad Infecciosa , Femenino , Virus de Hepatitis/clasificación , Virus de Hepatitis/genética , Virus de Hepatitis/aislamiento & purificación , Hepatitis Viral Humana/diagnóstico , Hepatitis Viral Humana/prevención & control , Hepatitis Viral Humana/terapia , Hepatitis Viral Humana/transmisión , Humanos , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo , Vacunas contra Hepatitis ViralRESUMEN
Um provável novo agente de hepatopatia, da família Flaviviridae, provisoriamente denominado vírus da hepatite G (VHG), foi descoberto recentemente. Ele é transmitido principalmente por via parenteral, e é encontrado em politransfundidos, transplantados de fígado, rim e medula óssea, e portadores de hepatopatia esporádica ou pós-transfusional, aguda e crônica ou fulminante, muitas vezes associado aos vírus B e/ou C. As infecçöes exclusivas pelo VHG säo leves ou assintomáticas, embora possam persistir por muitos anos, e na maioria dos casos as aminotransferases säo sempre normais. Alguns pesquisadores acreditam que o novo vírus possa ser um mero acompanhante inocente de algum outro agente, viral ou näo, ainda näo identificado...
Asunto(s)
Humanos , Masculino , Femenino , Hepatitis/patología , Virus de Hepatitis/fisiología , Hepatopatías/inducido químicamenteRESUMEN
Os problemas de saúde relacionados à infecçao pelo vírus B da hepatite (HBV) sao imensos. A positividade para o antígeno de superfície do vírus B (HBsAg) pode significar:1)hepatite aguda, 2)hepatite crônica (persistente ou ativa) ou cirrose; 3)estado de portador sadio. Existem evidências de que a replicaçao viral ativa está associada com doença hepática progressiva. Ao contrário, a doença do portador que perde os marcadores da replicaçao viral usualmente permanece estática ou evolui lentamente. Atualmente, o alfa-interferon é o agente terapêutico que oferece a maior esperança para a seroconversao do antígeno e do vírus B (HBeAg) e perda sustentada do HBV DNA.
Asunto(s)
Humanos , Portador Sano , Antígenos de Superficie de la Hepatitis B , Hepatitis B/epidemiología , Brasil/epidemiología , Prevalencia , Virus de Hepatitis/fisiología , Replicación ViralRESUMEN
The aims of the study were to examine the knowledge of occupational hazards from blood-borne viruses, and practices related to cross-infection control in Brazil, by a survey of 947 Brazilian dental practitioners at a National Dental Congress in January 1990. Over 80% were aware that hepatitis B virus can be present in the oral cavity and constitutes an occupational hazard but their perceptions as to the hazards from other agents were at variance with the published evidence. Over 75% were aware of the existence of vaccines against hepatitis B virus but less than 60% appreciated the possible long-term hepatic sequelae of hepatitis B virus infection and, less than 40% were aware of the oncogenic potential. Less than 10% had been immunized against hepatitis B and only a further 30% intended to be vaccinated. Autoclaves were used by less than 10%: most appeared to use chemical means for disinfection of dental instruments. These results indicate the urgent need for a campaign to improve infection control procedures in Brazilian dental practice.