Detección de anticuerpos contra el virus de la hepatitis C en donantes de sangre voluntarios / Detection of antibodies against hepatitis C virus in volunteer blood donors

Introducción: las pruebas de detección de anticuerpos contra el virus de la hepatitis C en donantes de sangre han servido para la identificación de enfermos y son un elemento importante para interrumpir la transmisión por esta vía. Objetivo: describir el comportamiento de la detección de anti-HVC en el municipio de Artemisa entre los años 2006-2010 e identificar las principales alteraciones clínicas en los pacientes con prueba de detección de ARN positiva. Métodos: se realizó un estudio ecológico de series temporales. El universo estuvo conformado por los 162 pacientes pertenecientes al municipio Artemisa a los cuales, en las donaciones de sangre, se les detectó positividad para en anti-VHC según método de ELISA (UMELISA). La información se obtuvo a través de la base de datos del Banco de Sangre Territorial de San Antonio de los Baños entre el 1º de enero de 2006 y el 31 de diciembre de 2010. Resultados: de las 8 057 donaciones de sangre realizadas en el período; el 2,01 por ciento resultaron positivas. Se demostró el comportamiento estacional, la variación cíclica de la serie cronológica y una tendencia creciente. Se identificaron los meses de septiembre, junio y noviembre como los de mayor incidencia. La relación hombre/mujer fue de 13:1, predominando el sexo masculino entre los donantes anti-HVC positivos con el 94,7 por ciento. Se detectó el ácido nucleico del virus C por biopsia hepática en 41 casos comprendidos entre los 41 y 45 años predominantemente. El 95,1 por ciento de los enfermos presentaron transaminasas normales, antecedentes de instrumentaciones percutáneas y cambios histológicos compatibles con una hepatitis crónica en el momento del diagnóstico. Conclusiones: se confirma la utilidad del pesquisaje del anti-HVC para la planificación de los recursos de salud en el territorio y para la identificación de enfermos con distintos grados de lesión hepática, a pesar de estar asintomáticos y con transaminasas normales(AU)

Introduction: Tests for antibodies to the hepatitis C virus in blood donors have been used to identify patients and it is an important element in disrupting transmission by this route. Objective: The objective of the present investigation was to describe the behavior of the detection of anti-HVC in Artemisa municipality between 2006-2010 years and to identify the main clinical alterations in the patients with positive RNA detection test. Methods: An ecological study of time series was carried out. The universe was 162 patients resident in Artemisa municipality, to whom, in blood donations, they were detected positivity for anti-HCV according to the ELISA method (UMELISA). The information was obtained through the database of the Territorial Blood Bank of San Antonio de los Baños between January 1, 2006 and December 31, 2010. Results: In this period 8057 blood donations were made; 2.01 percent were positive. The seasonal behavior, the cyclical variation of the chronological series and an increasing tendency were demonstrated. The months of September, June and November were identified as months with highest incidence. The male-to-female ratio was 13: 1, with male sex predominating among anti-HVC positive donors with 94.7 percent. Nucleic acid of C virus was detected by liver biopsy in 41 cases between 41 and 45 years old predominantly. The 95.1 percent of the patients presented normal transaminases, a history of percutaneous instrumentation and histological changes compatible with chronic hepatitis at the time of diagnosis. Conclusions: The usefulness of anti-HVC screening for the planning of health resources in the territory and for the identification of patients with different degrees of liver injury, despite being asymptomatic and with normal transaminases, is confirmed(AU)

Hepatopatología para gastroenterólogos y hepatólogos. Tercera parte: patología de la enfermedad hepática necroinflamatoria crónica / Hepatology for Gastroenterologists and Hematologists. Part Three: pathology of chronic necroinflammatory liver disease

En la interpretación de una biopsia hepática, las enfermedades necroinfl amatorias hepáticas están entre laspatologías halladas más a menudo, y en el estudio histopatológico es habitual enfrentarse a varias preguntasal respecto: ¿Qué es? ¿Qué tan grave es la enfermedad? ¿Qué es lo que el clínico espera? Se buscará eneste artículo dar respuesta a tales preguntas.

Necroinfl ammatory liver diseases are one of the most frequently encountered pathologies when interpreting a liver biopsy. In a histopathological study, we faced several questions including: What is it? How severe is the illness? And what does the clinician expect? This article attempts to answer these questions.

Perfil epidemiológico dos pacientes portadores do vírus da imunodeficiência humana (HIV) coinfectados com o vírus da hepatite C (HCV) no ambulatório de DST/Aids da cidade de Criciúma / Epidemiological profile of patients with human immunodeficiency virus (HIV) coinfected with hepatitis C virus (HCV) in the clinic of DST/Aids city of Criciúma

Introdução: a coinfecção HIV/HCV representa um problema de saúde pública, dificultando o tratamento tanto do HIV quanto da hepatite C, pela maior hepatotoxicidade. Por compartilharem via de transmissão similar, é frequente encontrar a coinfecção HCV em pacientes HIV-positivo. Objetivo: conhecer o perfil epidemiológico dos pacientes portadores de HIV que estão coinfectados pelo vírus da hepatite C no ambulatório de DST/aids da Cidade de Criciúma-SC. Métodos: trata-se de um estudo retrospectivo, descritivo, documental e exploratório em que foram avaliados prontuários de 97 pacientes que frequentavam o ambulatório de DST/aids de Criciúma no período de janeiro de 2007 a dezembro de 2009. Resultados: de uma amostra de 97 prontuários analisados, 25% dos pacientes eram do sexo feminino e 75%, do sexo masculino. A média de idade entre as mulheres foi: 43,29 ± 9,888 DP e em homens:42,61 ± 23,364 DP. Quanto à situação sexual, 74% eram heterossexuais, 9%, homossexuais, 8%, ignorados, 6%, bissexuais e 3%, profissionais do sexo.Com relação à situação de risco, 30% eram usuários de droga intravenosa, 2%, hemofílicos e 68%, ignorados. No tocante à prática sexual, 65% tinham múltiplos parceiros, 16%, parceiro fixo, 15%, ignorados, 3%, parceiro com HIV/aids, 1%, múltiplos parceiros e parceiro com HIV/aids. Conclusão: a coinfecção HIV/HCV ocorre com mais frequência nos homens, já que esses pacientes estão mais expostos que as mulheres a fatores de risco. A via de transmissão sexual pode ter alguma importância na transmissão de HCV, pelo menos no presente estudo. Porém, ainda são necessários estudos subsequentes que possam confirmar essa hipótese levantada com o atual estudo.

Introduction: HIV/HCV coinfection represents a public health issue, complicating the treatment of both HIV and hepatitis C through increased hepatotoxicity. By sharing similar route of transmission coinfection of HCV in HIV positive patients is often found. Objective: to know the epidemiological profile of patients with HIV who are coinfected with hepatitis C virus in the clinic of STD/aids in the city of Criciúma, SC. Methods: this documentaryis a retrospective, descriptive and exploratory study that evaluated charts of 97 patients who attended in the STD/aids clinic in Cricíuma from jan/2007 todec/2009. Results: from a sample of 97 files reviewed, 25% of patients were female and 75% male. The average age among women was: 43.29 ± 9.888SD and men: 42.61 ± 23.364 SD. As for the sexual situation 74% were heterosexual, homosexual 9%, 8% ignored, 6% bisexual, 3% were sex workers.In relation to risk 30% were intravenous drug users, hemophiliacs 2% and 68% ignored. Regarding sexual practices, 65% had multiple partners, 16%steady partner, 15% ignored, 3% partner with HIV/aids, 1% partner with multiple partners and HIV/aids. Conclusion: coinfection HIV/HCV occurs morefrequently in males, since these patients are more susceptible than women to risk factors. The route of sexual transmission may have some importance in the transmission of HCV, at least in this study. However, subsequent studies that can confirm this hypothesis with the current study are needed.

La tolerancia inmunológica a 50 años del premio nobel en medicina y fisiología: una perspectiva como mecanismo de respuesta inmune frente a patógenos: [revisión] / Immune tolerance at 50 years from the nobel prize in medicine and physiology: a perspective as a mechanism of immune response against pathogens: [review]

El sistema inmune es responsable de proteger al organismo contra agentes extraños mediante el desarrollo de un repertorio de receptores, capaces de reconocer antígenos de toda etiología, diferenciando moléculas propias de extrañas, estableciendo además fundamentos para la identidad biológica del individuo. Para ello dispone de una red compleja de mecanismos celulares y moleculares que son los responsables de la llamada tolerancia inmune. La regulación de la interacción entre el sistema inmune y los antígenos que eventualmente puede conducir al desarrollo de tolerancia, es crítica tanto en condiciones fisiológicas como en diferentes estados de patología. Desde las primeras descripciones de Medawar, las cuales mostraron que el fenómeno de tolerancia es adquirido y central para la homeóstasis del sistema inmune, un número importante de mecanismos se han propuesto para explicar la tolerancia inmune. Sin embargo, un mecanismo único de autotolerancia ha surgido: la generación de linfocitos T reguladores antígeno específicos, también conocidos como células T reguladoras (Treg), de origen central o periférico. Esta subpoblación de linfocitos con funciones supresoras ha mostrado un papel muy importante no solo en el control de enfermedades autoinmunes, sino además en la inmunopatogenia de enfermedades infecciosas crónicas, ya sean inducidas por el patógeno como mecanismo de escape o por el hospedador para mitigar el daño tisular consecuencia de la activación de la respuesta inmune. Esta revisión tiene como propósito actualizar los conceptos modernos en tolerancia inmune, con especial énfasis en el papel de las células Treg en la tolerancia inducida durante el curso de infecciones crónicas.

The immune system has the capability of protection against infectious disease which is accomplished by an enormous repertoire of receptors specifically reactive to foreign antigens, but it is tolerant to self-antigens, establishing biological identity. The ability to discriminate between self and non-self is a central property of the immune system, by using complex network of cellular and molecular mechanisms in order to prevent autoimmunity; this function is called immune tolerance. Thus, the Interaction between immune system and antigens is required for the generation of tolerance and it is critical in different physiological and pathological conditions in order to limit the damage to self tissues. Since Medawar description, who showed that the tolerance is an acquired property playing a central role in the homeostasis, several mechanism has been proposed to explain it. It is accepted today that an important group of antigen specific cells called regulatory T cell, both natural and induced, are critical as a unifying mechanism to maintain self-tolerance. These suppressor lymphocyte subpopulations had shown to play an important role not only by controlling autoimmune disease but also in the pathogenesis of many chronic infectious diseases, either manipulated by the microorganism to escape from the immune system, or induced by the host to reduce inflammatory damage. This review has the intention of updating about modern concepts in immune tolerance mechanisms, with special emphasis played by Treg cell in the tolerance which is unquestionable induced during the course of chronic infections diseases.

Perfil epidemiologico de la infección por el virus de la hepatitis C en la región central de Argentina / Molecular epidemiology pattern of hepatitis C virus infection in central region of Argentina

La presencia de RNA-HCV y la distribución de genotipos se detectaron mediante técnicas moleculares (RT-nested PCR y RFLP) en 310 muestras de individuos de la región centro de Argentina. Se halló 11,8% de coinfección HCV/HIV, con mayor prevalencia de genotipo 1 (73%). La distribución de los genotipos 1 y 2 entre individuos monoinfectados fue de 49,4% y 43,9%, respectivamente. El análisis de regresión logística multivariado mostró que la edad y el uso de drogas endovenosas (UDEV) condicionó la distribución de genotipos. El genotipo 2 se halló frecuentemente entre adultos mayores y su diseminación no se pudo asociar a ninguna vía de transmisión. El genotipo 1 se lo halló principalmente en adultos jóvenes y asociados al UDEV. El notable incremento de genotipo 1, homogéneamente distribuido en todas las edades posee importantes implicancias en las decisiones terapéuticas, considerando que posee baja respuesta a laterapia antiviral.

Pruebas complementarias a la problemática del diagnóstico de la infección por los virus B y C en donantes de sangre / Complementary tests for the problem of B and C virus infection diagnosis in blood donors

El objetivo de este trabajo es determinar si las transaminasas hepáticas tienen valor como pruebas complementarias que orienten el diagnóstico de hepatitis B y C, en donantes de sangre con anticuerpos positivos por el método ELISA a estas infecciones virales; teniendo en cuenta que las pruebas confirmatorias como el inmunoensayo recombinante (RIBA) o la prueba de ácidos nucleicos por técnicas moleculares como PCR (RNA HCV) para hepatitis C y DNA viral (PCR) para hepatitis B no se realizan aún en nuestro país debido a sus elevados costos. Se busca sumar esfuerzos en salud pública desde los bancos de sangre debido a la trascendencia de llegar a un diagnóstico en los donantes seropositivos, que hayan sido captados en el tamizaje, para prevenir la propagación de estas hepatitis. Se realizaron pruebas serológicas para hepatitis C, anticuerpos frente al antígeno del core de la hepatitis B y determinaciones de los niveles de GPT o ALT (Transaminasa Glutámica Pirúvica o Alanina Amino Transferasa), GOT o AST (Transaminasa Glutámico Oxalacética o Aspartato Amino Transferasa) en 236 donantes de sangre seropositivos para hepatitis B y C del Banco de Sangre del Hospital de Clínicas de la Universidad Nacional de Asunción-Paraguay. Las transaminasas elevadas fueron clasificadas de acuerdo a los marcadores serológicos positivos para hepatitis B y C, encontrándose niveles elevados en un 13.9% de individuos con anti-HBc, 40% en individuos con anti HCV y 2 de 7 casos en individuos con serología positiva para ambos marcadores serológicos. Casi la mitad de los donantes con marcador serológico positivo para anti HCV presentan elevación de las transaminasas.

The aim of this study was to determine if liver transaminases had value as complementary tests to orientate the diagnosis of hepatitis B and C in blood donors with positive antibody to these viral infections by the EIA method, considering that confirmatory tests such as the recombinant immunoassay (RIBA) or nucleic acid test by molecular techniques such as PCR (HCV RNA) for hepatitis C and viral DNA (PCR) for hepatitis B are not performed in our country due to their high costs. We are looking for joining efforts in public health from the blood banks due to the importance of reaching a diagnosis of seropositive donors who have been detected in the screening to prevent the spread of hepatitises. Serologic tests for hepatitis C, antibodies against the core antigen of hepatitis B and determinations of the levels of ALT or GPT (Alanine aminotransferase or Glutamic pyruvic transaminase), AST or GOT (Aspartate aminotransferase or Glutamic oxalacetic transaminase) were carried out in 236 blood donors seropositive for hepatitis B and C of the Blood Bank of the Hospital de Clinicas, National University of Asuncion, Paraguay. Elevated transaminases were classified according to the positive serological markers for hepatitis B and C finding high levels in 13.9% in donors with anti-HBc, 40% in donors with anti HCV and two of seven cases in donors with positive serology for both serological markers. Almost half of the donors with positive serologic marker for anti HCV had elevated transaminases.

Soroprevalência da hepatite C em pacientes hemodialisados / Hepatitis C serum prevalence in hemodialyzed patients

Os objetivos deste estudo foram estimar a soroprevalência da infecção pelo vírus da hepatite C em um centro de diálise da grande Recife; e associar a soropositividade para o vírus da hepatite C em relação a alguns fatores de risco. Foram analisados 250 pacientes com idade variando de 17 a 92 anos e de ambos os sexos. Dados epidemiológicos desses pacientes foram obtidos para a determinação dos fatores de riscos para esta infecção. A pesquisa de anticorpos anti-HCV foi realizada pelo ELISA de 4ª geração. Foi observado que em relação aos fatores de riscos, como o tempo de hemodiálise, número e período das transfusões de hemocomponentes, foi encontrada uma associação estatisticamente significante (p< 0,05). A prevalência encontrada foi baixa (8,4 por cento) em relação a outros estudos do Brasil. Entretanto, seriam necessários mais estudos em outros centros a fim de estimar a real prevalência para infecção pelo vírus da hepatite C em pacientes submetidos a hemodiálise em Pernambuco.

The objectives of this study were to estimate the serum prevalence of hepatitis C virus (HCV) infection in a dialysis center in the greater Recife region, and to correlate HCV serum positivity with some risk factors. Analyses were performed on 250 patients of both sexes, with ages ranging from 17 to 92 years old. Epidemiological data on these patients were obtained in order to determine the risk factors for this infection. Anti-HCV antibodies were investigated using fourth-generation ELISA. Statistically significant associations (p < 0.05) were observed in relation to the risk factors of hemodialysis duration, number of blood component transfusions and time taken for transfusions. The prevalence was low (8.4 percent) in relation to other Brazilian studies. However, more studies in other centers are needed in order to estimate the real prevalence of HCV infection among patients undergoing hemodialysis in the State of Pernambuco.

Auditory Feedback and The Plasticity of Vocal Learning in Songbirds / 生物化学与生物物理进展

Songbirds and humans both rely critically on auditory feedback for learning and maintaining accurate vocalizations. During vocal learning, juvenile songbirds learn to sing by using auditory feedback to match their variable song patterns to a memorized tutor model. During song maintaining, adult songbirds monitor the integrality and accuracy of its song on-line according to auditory feedback. This form of learning requires auditory-vocal integration. The output of songs and the information of auditory feedback are integrated in some areas of the bird's brain, and then direct next vocal activity. In recent years, the lateral magnocellular nucleus of the anterior neostriatum (LMAN) has been demonstrated that it is necessary for feedback-dependent song decrystallization, and LMAN neurons exhibit highly selective responses to auditory presentation of the bird's own song (BOS). Moreover, the discovery of mirror neurons in the high vocal centre (HVC) also provides a significant clue for further study in songbirds. Here the progress of auditory feedback and the plasticity of vocal learning in songbirds are reviewed in recent years.