24 resultados para PORTAL-VEIN STENOSIS


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Objectives: Previous evidence supports a direct relationship between the calcium burden (volume) on post-contrast CT with the percent internal carotid artery (ICA) stenosis at the carotid bifurcation. We sought to further investigate this relationship by comparing non-enhanced CT (NECT) and digital subtraction angiography (DSA). Methods: 50 patients (aged 41-82 years) were retrospectively identified who had undergone cervical NECT and DSA. A 64-multidetector array CT (MDCT) scanner was utilised and the images reviewed using preset window widths/levels (30/300) optimised to calcium, with the volumes measured via three-dimensional reconstructive software. Stenosis measurements were performed on DSA and luminal diameter stenoses >40% were considered "significant". Volume thresholds of 0.01, 0.03, 0.06, 0.09 and 0.12 cm(3) were utilised and Pearson's correlation coefficient (r) was calculated to correlate the calcium volume with percent stenosis. Results: Of 100 carotid bifurcations, 88 were available and of these 7 were significantly stenotic. The NECT calcium volume moderately correlated with percent stenosis on DSA r=0.53 (p<0.01). A moderate-strong correlation was found between the square root of calcium volume on NECT with percent stenosis on DSA (r=0.60, p<0.01). Via a receiver operating characteristic curve, 0.06 cm(3) was determined to be the best threshold (sensitivity 100%, specificity 90.1%, negative predictive value 100% and positive predictive value 46.7%) for detecting significant stenoses. Conclusion: This preliminary investigation confirms a correlation between carotid bifurcation calcium volume and percent ICA stenosis and is promising for the optimal threshold for stenosis detection. Future studies could utilise calcium volumes to create a "score" that could predict high grade stenosis.

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There are no studies investigating the effect of the contrast infusion on the sensitivity and specificity of the main Doppler criteria of renal artery stenosis (RAS). Our aim was to evaluate the accuracy of these Doppler criteria prior to and following the intravenous administration of perfluorocarbon exposed sonicated albumin (PESDA) in patients suspected of having RAS. Thirty consecutive hypertensive patients (13 males, mean age of 57 ± 10 years) suspected of having RAS by clinical clues, were submitted to ultrasonography (US) of renal arteries before and after enhancement using continuous infusion of PESDA. All patients underwent angiography, and haemodynamically significant RAS was considered when ≥50%. At angiography, it was detected RAS ≥50% in 18 patients, 5 with bilateral stenosis. After contrast, the examination time was slightly reduced by approximately 20%. In non-enhanced US the sensitivity was better when based on resistance index (82.9%) while the specificity was better when based on renal aortic ratio (89.2%). The predictive positive value was stable for all indexes (74.0%–88.0%) while negative predictive value was low (44%–51%). The specificity and positive predictive value based on renal aortic ratio increased after PESDA injection respectively, from 89 to 97.3% and from 88 to 95%. In hypertensives suspected to have RAS the sensitivity and specificity of Duplex US is dependent of the criterion evaluated. Enhancement with continuous infusion of PESDA improves only the specificity based on renal aortic ratio but do not modify the sensitivity of any index.

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O SIBiUSP lançou em março de 2012 uma nova ferramenta de busca de conteúdos acadêmicos/científicos, o nome dado foi Portal de Busca Integrada. Esta ferramenta pertence à uma categoria de softwares intitulada de “Web Scale Discovery”, que permitem a integração de diversas e dispersas fontes de dados em uma única interface de busca e entrega de resultados. Dessa forma, apresentam-se aqui os processos de seleção e implantação desta solução.

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OBJECTIVE: During the neonatal and infancy periods, some chronic liver diseases may lead to progressive hepatic fibrosis, which is a condition that can ultimately result in the loss of organ function and severe portal hypertension necessitating hepatic transplantation. In a previous report, pharmacological interventions were demonstrated to modulate hepatic fibrosis induced by bile duct ligation in young rats. The administration of pentoxifylline or prednisolone, or the combination of both, resulted in reduced fibrogenesis in portal spaces. The objectives of the present study were to evaluate the expression of transforming growth factor β and vascular endothelial growth factor after bile duct ligation in young rats and to assess the effect of those same drugs on cytokine expression. METHODS: In this experimental study, 80 young rats (21 or 22 days old) were submitted either to laparotomy and common bile duct ligation or to sham surgery. The animals were allocated into four groups according to surgical procedure, and the following treatments were administered: (1) common bile duct ligation + distilled water, (2) sham surgery + distilled water, (3) common bile duct ligation + pentoxifylline, or (4) common bile duct ligation + prednisolone. After 30 days, a hepatic fragment was collected from each animal for immunohistochemical analysis using monoclonal antibodies against transforming growth factor β and vascular endothelial growth factor. Digital morphometric and statistical analyses were performed. RESULTS: The administration of pentoxifylline reduced the transforming growth factor β-marked area and the amount of transforming growth factor β expressed in liver tissue. This effect was not observed after the administration of prednisolone. There was a significant reduction in vascular endothelial growth factor expression after the administration of either drug compared with the non-treatment group. CONCLUSIONS: The administration of pentoxifylline to cholestatic young rats resulted in the diminished expression of transforming growth factor β and vascular endothelial growth factor in liver tissue. The administration of steroids resulted in the diminished expression of vascular endothelial growth factor only. These pathways may be involved in hepatic fibrogenesis in young rats submitted to bile duct ligation and exposed to pentoxifylline or prednisolone.

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El objeto de este poster es presentar la experiencia de manejamiento de un portal de revistas científicas de acceso abierto, en una universidad pública y que integra los editores científicos, profesores y bibliotecarios. Iniciativas de esta naturaleza tienen importancia estratégica para la consolidación y el fortalecimiento del Movimiento de Acceso Abierto en los países en desarrollo, puesto que ofrecen la oportunidad de se vivir plenamente una cultura de acceso abierto en todas las etapas de certificación del conocimiento. La experiencia de la Universidade de São Paulo, se convierte en relevante, ya que promueve la integración de los diversos actores involucrados en la producción de revistas científicas. El Portal de Revistas da USP (http://www.revistas.usp.br), lanzado en 2008, es una iniciativa del Departamento Técnico do Sistema Integrado de Bibliotecas de USP que tiene el Programa de Apoio às Publicações Científicas Periódicas da USP. Esta iniciativa, basada en los principios del Movimiento de Acceso Abierto, tiene como objetivo promover la visibilidad y la accesibilidad de las revistas científicas publicadas oficialmente por la USP. Considerase que las revistas cumplen con un doble papel, como objeto y también vehículo de comunicación. Con esto las inversiones para calificación de las revistas incluyen recursos informáticos para garantizar la interoperabilidad entre distintos sistemas de información (bases de datos, catálogos, repositorios etc.), sistemas de gestión editorial en línea (para agilizar la tramitación de los manuscritos y la disminución de la publicación); la formación de los equipos (técnicos y bibliotecarios), atribuición de nomes DOI (digital object identifier), software de verificación de plágio. En 2012 se cambió el software de gestión del Portal para Open Journal Systems - OJS por lo cual se reunió por la primera vez, en um mismo dominio web las revistas científicas editadas en USP. De las más de 100 revistas publicadas en el Portal 29 están en DOAJ, 27 en SciELO Brasil, 20 en Scopus, 11 en JCR entre outros. En el Portal hay revistas con distintos perfiles, unas más institucionales y otras de calidad internacional. Algunas revistas más antíguas y consolidadas se utilizan de distintos sistemas de gestión de los manuscriptos y en el Portal es como un espejo para garantizar la presencia en la Universidad. Con tantas y tan distintas publicaciones el OJS se presenta como una promisora herramienta para la gestión del Portal de Revistas. El OJS surge como un sistema para la gestión individual de revistas científicos y con los avances de las tecnologías y principalmente del uso por la comunidad se conviertió en herramienta de gestión de Portal. Para una mejor gestión del Portal se presenta algunas recomendaciones, basadas en la experiencia, y que podrán mejorar el trabajo de gestión del conjunto de las revistas: en la pantalla de creación de revistas se deberá incluir todos los datos del registro oficial en ISSN, sin posibilidad de edición por los editores-gerentes; en el listado general de revistas se podría incluir una indicación de las revistas que están en línea y las que están aún en configuración; clara identificación de las revistas vigentes y no-vigentes, una vinculación mas clara de las revistas que cambiaran su título y que están vigentes; una tabla para selección de fuentes de indización; edición de contenidos ya publicados solamente por el administrador del sistema; gestión centralizada del DOI y de la preservación digital en LOCKSS y un painel con los datos estadísticos (total de revistas, ediciones, estatísticas Counter, autores etc). Además el fortalecimiento y creación de centros de desarrollo de OJS en las Universidades Latinoamericanas podría impulsionar el uso del sistema en su totalidad por los editores de la región.

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Relata o estudo, a instalação e implantação de ferramenta de descoberta e entrega do Portal de Busca Integrada, para o Sistema Integrado de Bibliotecas da Universidade de São Paulo (SIBiUSP). Esta nova interface denominada Portal de Busca Integrada possibilita uma nova experiência de pesquisa científica ao usuário final pela recuperação de literatura em diferentes fontes de informação.

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O Portal de Revistas da USP apresenta-se como uma estratégia do Sistema Integrado de Bibliotecas, por meio de seu Programa de Apoio às Publicações Científicas Periódicas, para aumentar a visibilidade e acessibilidade das revistas científicas da Universidade de São Paulo. Para fazer parte deste Programa as revistas devem cumprir com critérios de qualidade, definidos por uma Comissão de Credenciamento, formada por professores e bibliotecários, e pautados em padrões internacionais. Atualmente 62 publicações estão credenciadas neste Programa.