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Historia natural de la infección por el VHC Natural history of hepatitis C virus infection  [cached]
J. Uriz,R. Briz
Anales del Sistema Sanitario de Navarra , 2004,
Abstract: El curso generalmente indolente, lento y prolongado de la infección por el virus de la hepatitis C ha limitado la realización de estudios que valoren su historia natural. Dichos estudios han tenido como objetivo la probabilidad de muerte por enfermedad hepática, cirrosis hepática (compensada o descompensada) y/o hepatocarcinoma, o el desarrollo de una fibrosis hepática importante (substrato anatomopatológico indispensable para el desarrollo de las complicaciones de la cirrosis hepática). A pesar de sus posibles limitaciones, los resultados de estos estudios demuestran que la infección crónica por VHC sigue generalmente un curso evolutivo benigno, sobre todo si ésta acontece en pacientes jóvenes (<50 a os), sin otros factores agravantes de una posible hepatopatía (alcohol, coinfección por otros virus, inmunosupresión) y si ésta se valora en los primeros 10-20 a os de infección. Actualmente, no es posible identificar con exactitud aquellos pacientes con infección por el VHC con mayor riesgo de desarrollar una enfermedad hepática clínicamente relevante. Sin embargo, es probable que aquellos sujetos con transaminasas elevadas (>2 veces el valor normal) e importante actividad necroinflamatoria (necrosis periportal) y fibrosis en la biopsia hepática presenten un curso evolutivo más agresivo que aquellos con transaminasas normales y biopsia hepática casi normal. The generally indolent, slow and protracted course of hepatitis C virus infection has limited the realisation of studies that evaluate its natural history. The aim of such studies has been the probability of death through hepatic disease, hepatic cirrhosis (compensated or decompensated), and/or hepatocarcinoma, or the development of a significant hepatic fibrosis (essential anatamopathological substrate for the development of the complications of hepatic cirrhosis). In spite of their possible limitations, the results of these studies show that chronic hepatitis C virus infection generally follows a benign evolutionary course, above all if this occurs in young patients (<50 years of age), without other aggravating factors of a possible hepatopathy (alcohol, coinfection by other viruses, immunosuppression) and if this is evaluated in the first 10-20 years of infection. At present, it is not possible to identify with precision those patients with HCV infection with a greater risk of developing a clinically relevant hepatic disease. However, it is likely that those subjects with high transaminases (> 2 times the normal value) and significant necroinflammatory activity (periportal necrosis) and fibrosis in
Historia natural de la infección por el virus de la hepatitis C
Arús Soler,Enrique;
Revista Cubana de Medicina , 2006,
Abstract: the acute stage of infection goes by inadvertently in most of the patients. the disease has a marked trend of evolution towards chronicity and it evolves very slowly. the chronic persistence of the virus ranges from 54 to 86 % of the cases. the evolution towards liver cirrhosis fluctuates between 2.6 and 42 % of the cases, depending on the study method used to evaluate the natural history. the youngest patients at the moment of infection and the females had the lowest progression rates. the coinfection with hivand hbv favor a rapid progression. some associated diseases as the non-alcoholic steatohepatitis, type ii diabetes mellitus, obesity, and the increase of the iron deposit in the liver have also been related to a rapid progression. alcoholism plays an important role on accelerating the course of the disease to liver cirrhosis and to hepatocellular carcinoma. the transfusion-acquired infection has been considered as a fibrosis-accelerating factor.
The Natural History of Hepatitis C Virus (HCV) Infection  [cached]
Chen Stephen L.,Morgan Timothy R.
International Journal of Medical Sciences , 2006,
Abstract: Hepatitis C virus (HCV) is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma, as well as the most common indication for liver transplantation in many countries. Although the incidence of hepatitis C infection has dramatically decreased during the past decade, the worldwide reservoir of chronically infected persons is estimated at 170 million, or 3% of the global population. There is much controversy surrounding the natural history of hepatitis C infection. The rate of chronic HCV infection is affected by a person's age, gender, race, and viral immune response. Approximately 75%-85% of HCV-infected persons will progress to chronic HCV infection, and are at risk for the development of extrahepatic manifestations, compensated and decompensated cirrhosis, and hepatocellular carcinoma (HCC). The rate of progression to cirrhosis is highly variable, and is influenced by several factors, including the amount of alcohol consumption, age of initial HCV infection, degree of inflammation and fibrosis on liver biopsy, HIV and HBV coinfection, and comordid conditions. An estimated 10%-15% of HCV-infected persons will advance to cirrhosis within the first 20 years. Persons with cirrhosis are at increased risk of developing HCC. An understanding of the natural history of hepatitis C is essential to effectively manage, treat, and counsel individuals with HCV infection.
Aproximación terapéutica a la hepatitis por virus C Therapeutic approach to hepatitis for virus C  [cached]
Víctor Idrovo
Revista Colombiana de Gastroenterologia , 2006,
Abstract: La hepatitis C (VHC) es producida por un virus RNA perteneciente a la familia de los flavivirus, y fue identificado en 1989. Es responsable del desarrollo de hepatitis aguda la cual se autolimita en un 20 a 30% de casos, pero hasta en 70 a 80% evoluciona a infección crónica, con riesgo de cirrosis y hepatocarcinoma después de varias décadas de infección. La progresión a cirrosis es frecuentemente silenciosa hasta que se presentan las complicaciones de una enfermedad hepática avanzada, como la hipertensión portal, la insuficiencia hepática y el hepatocarcinoma. Las alternativas terapéuticas contra la hepatitis C han mejorado significativamente en los últimos a os, lográndose respuestas virológicas sostenidas cercanas al 60% si se logra una adecuada adherencia al tratamiento. A continuación se presenta una revisión general y concisa sobre la hepatitis C con el fin de entender mejor la epidemiología, historia natural, diagnóstico, pronóstico y tratamiento de esta infección. Hepatitis C (HCV) is caused by a small RNA virus that belongs to the flaviviridae family that was identified in 1989. HCV produces acute hepatitis, which is self-limited in approximately 20 to 30% of cases. However, it will progress to chronic disease in 70 to 80%, with the potential risk of developing cirrhosis and hepatocellular carcinoma (HCC) after several decades of infection. Progression to cirrhosis is usually silent until complications of advanced disease develop, such as portal hypertension, liver insufficiency, and HCC. Treatment options for HCV have improved significantly in recent years, with sustained virologic responses that reach up to 60% if optimize adherence to therapy is achieved. The following article about HCV is a general and concise review about the epidemiology, natural history, diagnosis, prognosis, and treatment options for this viral infection.
Is natural history really dead?: Toward the rebirth of natural history Está realmente muerta la historia natural?: Hacia el renacimiento de la Historia Natural
MARY F WILLSON,JUAN J ARMESTO
Revista chilena de historia natural , 2006,
Abstract: In recent years natural history has been derided by some scientists as an old-fashion endeavor that does not follow the model of "hard" science and therefore should be considered "dead" and replaced by modern ecology, evolutionary biology, and conservation biology. We contend that natural history has much to offer to contemporary scientists and that it has a primary role in the creative process of generating novel hypotheses and designing significant field experiments and observations En a os recientes, la historia natural ha sido desacreditada por científicos que la consideran un modelo obsoleto de ciencia y que, en consecuencia, se trataría de una disciplina "muerta" que ha sido reemplazada por la ecología moderna, la biología evolutiva y la biología de la conservación. Argumentamos aquí que la historia natural tiene mucho que ofrecer a los científicos contemporáneos y que juega un rol principal en el proceso de creación de hipótesis y en el dise o acertado de observaciones y experimentos de campo
De Rocinante al rinoceronte: la historia natural y el 'Quijote'  [PDF]
Fernando Pardos
Panace@ : Revista de Medicina, Lenguaje y Traducción , 2005,
Abstract: Este trabajo pretende, siquiera someramente, ofrecer una panorámica general de la situación de las ciencias biológicas, entonces historia natural , en los tiempos del 'Quijote'. Y ello tanto en Europa, con figuras como Fuchs o Gessner, como en Espa a, con los Laguna, Fernández, Oviedo y Acosta, entre otros. Se analizan las relaciones e influencias mutuas entre la historia natural y la Corona, con su doble papel impulsor y represor. Otro tanto con la Iglesia, parte fundamental del Estado y rectora y garante de la pureza del pensamiento, científico o no. No se intenta presentar de forma exhaustiva o pormenorizada cuantos animales y plantas aparecen en el 'Quijote', sino analizar algunos detalles desde el prisma de un biólogo. Así, se intenta esclarecer la relación entre las cigüe as y las lavativas, la presencia de cuervos y murciélagos en la cueva de Montesinos, los nombres comunes de los animales en la época, las sabogas de Sancho, las hayas que nunca existieron o los azores y la cetrería. Y qué sabía Teresa Panza, mujer de Sancho, de los avestruces? Así, a través del 'Quijote', se intenta vislumbrar al menos cuál era el conocimiento que la sociedad en general tenía, a caballo entre los siglos XVI y XVII, de lo que hoy llamamos biodiversidad. -------------------------------------------- From Rocinante to rhinoceros: natural history and 'Don Quixote'. This article seeks to offer a sweeping overview of the status of the biological sciences —or "natural history," as they were then called— when 'Don Quixote' was written. Its aim is to cover Europe, with figures such as Fuch or Gessner, as well as Spain, with the Lagunas, Fernandez, Oviedo, and Acosta, among others. The interactions and mutual influences between natural history and the monarchy, in its dual role as promoter and suppressor, are examined. The same is done with the Church, which was a fundamental component of the State and the overseer and guarantor of "purity" of thought in general, scientific and otherwise. There is no attempt to give an exhaustive or minute account of the animals and plants that appear in 'Don Quixote', but only to analyze certain details from a biologist's point of view. Thus, an effort is made to explain the relationship between storks and enemas, the presence of ravens and bats in the cave of Montesinos, the common names of animals at the time, Sancho's shads, the beeches that never existed, or the hawks and the falconry. And what did Teresa Panza, Sancho's wife, know about ostriches? The idea is to have a glimpse, by looking at 'Don Quixote', of at least what was kno
Un relevo generacional en la historia natural espa ola. La Gasca y Graells: del científico liberal al naturalista isabelino
Aragón, Santiago
Asclepio : Revista de Historia de la Medicina y de la Ciencia , 2006,
Abstract: This article analyzes the Mariano de la Paz Graells' education in Barcelone, before he held the chair of zoology at the Natural History Museum in Madrid. Furthermore, some unpublished letters exchanged between Graells and Mariano La Gasca, his mentor, are studied. The subjet of the correspondence is nepotism. El artículo aporta información sobre la formación de Mariano de la Paz Graells en Barcelona, antes de ocupar la cátedra de zoología del Gabinete de Historia Natural de Madrid. Además, se estudia una correspondencia inédita entre Graells y su protector, Mariano La Gasca. Los papeles hablan de nepotismo.
Historia natural de la hepatitis por virus C (VHC)  [cached]
Patricia Alvarez,Raúl E Pi?a
Revista Colombiana de Gastroenterologia , 2012,
Abstract:
Epidemiología e historia natural de la hepatitis B  [cached]
Víctor Idrovo Cubides,Carmen Yanette Suárez Q,Patricia álvarez Quintero
Revista Colombiana de Gastroenterologia , 2009,
Abstract:
En los márgenes del Imperio Espa ol y de la Historia natural: Félix de Azara colector (1787-1789)  [cached]
Marcelo Fabián Figueroa
Prohistoria , 2011,
Abstract: Este trabajo estudia la recolección de aves realizada por Félix de Azara durante sus viajes como demarcador de la Expedición de la América Meridional. Focaliza en especial las prácticas de recolección de especímenes y su posterior envío al Real Gabinete de Historia Natural de Madrid entre 1787 y 1789. Pretende explicar los dispositivos científicos y administrativos usados por la Historia natural los cuales fueron herramientas usadas por la administración colonial y explicar una actividad que tuvo amplia difusión en el virreinato del Río de la Plata . This paper focuses the collecting practices developed by Félix de Azara during his journeys as surveryor of the Expedición de la América Meridional. It identifies the collected birds and their shipping to the Royal Cabinet of Natural History of Madrid between 1787 and 1789. It hopes to explains the scientific and administrative mechanisms used by the Natural History which was a tool of colonial government, on one hand, and explains an activity which was common in the viceroyalty of River Plate, on the other one.
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