RESUMEN
There is a considerable controversy about whether western Amazonia was ever covered by marine waters during the Miocene [23 to 5 Ma (million years ago)]. We investigated the possible occurrence of Miocene marine incursions in the Llanos and Amazonas/Solimões basins, using sedimentological and palynological data from two sediment cores taken in eastern Colombia and northwestern Brazil together with seismic information. We observed two distinct marine intervals in the Llanos Basin, an early Miocene that lasted ~0.9 My (million years) (18.1 to 17.2 Ma) and a middle Miocene that lasted ~3.7 My (16.1 to 12.4 Ma). These two marine intervals are also seen in Amazonas/Solimões Basin (northwestern Amazonia) but were much shorter in duration, ~0.2 My (18.0 to 17.8 Ma) and ~0.4 My (14.1 to 13.7 Ma), respectively. Our results indicate that shallow marine waters covered the region at least twice during the Miocene, but the events were short-lived, rather than a continuous full-marine occupancy of Amazonian landscape over millions of years.
RESUMEN
La distribución geográfica del carcinoma hepatocelular (CHC) depende de la incidencia y prevalencia de sus agentes etiológicos en los diferentes lugares. Esto ha llevado a la realización de un mapa que muchas veces puede coincidir con las características de dichas entidades causales; las más importantes son la hepatitis B, la hepatitis C e incluso el alcohol en algunas regiones del mundo. Las estadísticas informadas en cuanto a raza, edad y sexo también dependen mucho de estas causas, y por eso en algunos casos los datos pueden ser similares, pero bien vale la pena recordarlos.
The geographical distribution of hepatocellular carcinoma (HCC) depends on the incidence and prevalence of related etiological agents in different places. This has led to the creation of a map upon which the characteristics of these causal entities can often be matched. The most important are hepatitis B, hepatitis C and even alcohol in some regions. The statistics are also reported in terms of race, age and sex and are heavily relied upon in these cases as well. In some cases the data may be similar which is well worth remembering.
Asunto(s)
Humanos , Hepacivirus , Virus de la Hepatitis B , Factores Protectores , Factores de RiesgoRESUMEN
La hepatitis autoinmune es una entidad que se puede presentar en forma asintomática, como hepatitis aguda o como cirrosis hepática; el diagnóstico se basa en criterios clínicos, de laboratorio basados en niveles elevados de inmunoglobulina G y autoanticuerpos y en criterios histológicos como la hepatitis de interfase, la presencia de células plasmáticas e infiltrado linfocitario, en casos de difícil diagnóstico se pueden utilizar los sistemas de puntuación original o modificado. El tratamiento se basa en la utilización de inmunosupresores como corticoides y azatioprina que cambiaron la historia natural de la enfermedad.
Autoimmune hepatitis is a condition which can be asymptomatic or can present as acute hepatitis or liver cirrhosis. Diagnosis is based on clinical criteria and laboratory criteria. Laboratory criteria include elevated levels of immunoglobulin G and/or autoantibodies and histological criteria such as hepatitis interface, the presence of plasma cells and lymphocytic infiltrate. In difficult to diagnose cases original or modified scoring systems can be used. Treatment is based on the use of immunosuppressants such as corticosteroids and azathioprine that have changed the natural history of disease.