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Search Results: 1 - 10 of 204714 matches for " Ramiro D. Almeida "
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Diabetes Alters KIF1A and KIF5B Motor Proteins in the Hippocampus
Filipa I. Baptista, Maria J. Pinto, Filipe Elvas, Ramiro D. Almeida, António F. Ambrósio
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065515
Abstract: Diabetes mellitus is the most common metabolic disorder in humans. Diabetic encephalopathy is characterized by cognitive and memory impairments, which have been associated with changes in the hippocampus, but the mechanisms underlying those impairments triggered by diabetes, are far from being elucidated. The disruption of axonal transport is associated with several neurodegenerative diseases and might also play a role in diabetes-associated disorders affecting nervous system. We investigated the effect of diabetes (2 and 8 weeks duration) on KIF1A, KIF5B and dynein motor proteins, which are important for axonal transport, in the hippocampus. The mRNA expression of motor proteins was assessed by qRT-PCR, and also their protein levels by immunohistochemistry in hippocampal slices and immunoblotting in total extracts of hippocampus from streptozotocin-induced diabetic and age-matched control animals. Diabetes increased the expression and immunoreactivity of KIF1A and KIF5B in the hippocampus, but no alterations in dynein were detected. Since hyperglycemia is considered a major player in diabetic complications, the effect of a prolonged exposure to high glucose on motor proteins, mitochondria and synaptic proteins in hippocampal neurons was also studied, giving particular attention to changes in axons. Hippocampal cell cultures were exposed to high glucose (50 mM) or mannitol (osmotic control; 25 mM plus 25 mM glucose) for 7 days. In hippocampal cultures incubated with high glucose no changes were detected in the fluorescence intensity or number of accumulations related with mitochondria in the axons of hippocampal neurons. Nevertheless, high glucose increased the number of fluorescent accumulations of KIF1A and synaptotagmin-1 and decreased KIF5B, SNAP-25 and synaptophysin immunoreactivity specifically in axons of hippocampal neurons. These changes suggest that anterograde axonal transport mediated by these kinesins may be impaired in hippocampal neurons, which may lead to changes in synaptic proteins, thus contributing to changes in hippocampal neurotransmission and to cognitive and memory impairments.
Complicaciones en la evolución precoz del infarto agudo del miocardio en la Unidad de Cuidados Intensivos Complications in the precocious evolution of the aute myocardial infarct at the Intensive Care Unit
Jorge Félix Nú?ez Martínez,Mario Héctor Almeida Alfonso,Ramiro Guedez Díaz,Roberto Gómez Castellanos
Revista M??dica Electr?3nica , 2009,
Abstract: Se realizó un estudio en la Unidad de Cuidados Intensivos del Hospital Militar “Dr. Mario Mu oz Monroy” de Matanzas de los pacientes con diagnóstico de Infarto Agudo del Miocardio no tormbolizados que en algún momento de su evolución hospitalaria presentaron complicaciones, durante el período comprendido desde julio del 2003 hasta junio del 2006. Nuestro universo estuvo dado por 113 pacientes que fueron caracterizados a través de un modelaje confeccionado al respecto y representando nuestros resultados en tablas estadísticas utilizándose como método el porcentaje, la prueba de Chi cuadrado y el intervalo confidencial cuando se requirió. En los resultados se determinó que las complicaciones eléctricas fueron las más frecuentes y las clínicas las más letales presentándose generalmente en las primeras 24 horas, el shock cardiogénico y el Infarto Agudo del Miocardio anterior extenso fueron los índices de mal pronóstico más frecuentes. La mortalidad general del estudio fue del 25.7 %. At the Intensive Care Unit of the Military Hospital “Dr Mario Mu oz Monroy” of Matanzas, we performed a study of the patients with diagnostic of Acute Myocardial Infarct that were not treated with thrombolysis presenting complications at some moment of their hospital evolution, during the period from July 2003 to June 2006. Our universe was composed by 113 patients that were characterized through forms designed for that; our results were represented in statistical tables using the percentage as a method, the Chi-square test and the confidential interval when it was required. In the results we determined that electrical complications were the most frequent, and the clinical ones the most lethal, generally presented during the first 24 hours; cardiogenic shock and extensive anterior Acute Myocardial Infarct were the most frequent indexes of bad prognosis. General mortality of the study was 25.7 %.
Complicaciones en la evolución precoz del infarto agudo del miocardio en la Unidad de Cuidados Intensivos
Nú?ez Martínez,Jorge Félix; Almeida Alfonso,Mario Héctor; Guedez Díaz,Ramiro; Gómez Castellanos,Roberto; la Rosa Guerra,Héctor;
Revista M??dica Electr?3nica , 2009,
Abstract: at the intensive care unit of the military hospital “dr mario mu?oz monroy” of matanzas, we performed a study of the patients with diagnostic of acute myocardial infarct that were not treated with thrombolysis presenting complications at some moment of their hospital evolution, during the period from july 2003 to june 2006. our universe was composed by 113 patients that were characterized through forms designed for that; our results were represented in statistical tables using the percentage as a method, the chi-square test and the confidential interval when it was required. in the results we determined that electrical complications were the most frequent, and the clinical ones the most lethal, generally presented during the first 24 hours; cardiogenic shock and extensive anterior acute myocardial infarct were the most frequent indexes of bad prognosis. general mortality of the study was 25.7 %.
Una solución al problema inverso en geomagnetismo
Díaz Ramiro L.
Earth Sciences Research Journal , 1992,
Abstract: Un tema importante en geofísica, es el problema inverso en geomagnetismo. En este trabajo se propone un método para resolverlo, que consiste en hallar la solución de un sistema móvil de ecuaciones no lineales a lo largo de un perfil magnético. Conociendo los datos de anomalías magnéticas y por medio de un programa que ejecuta un proceso iterativo eficiente, se determina la estructura bidimensional bajo el perfil muestreado. An interesting aspect in Geophysics is the inverse problem in Geomagnetism. This paper proposes a method for solving it. So, the objective is to solve a mobil system of non linear equations along a magnetic profile. From knowed magnetic anomalies and using an efficient iterative process, it is possible to find a bidimensional structure below a sample profile.
Algunos algoritmos para filtros digitales en el procesamiento de información electromagnética
Díaz C. Ramiro
Earth Sciences Research Journal , 2000,
Abstract: EI proceso de análisis de se ales en prospección electromagnética, ha sido trabajado desde diferentes puntos de vista y varios autores han planteado diferentes metodologías. EI objeto de este artículo es plantear algunos algoritmos para filtros digitales basados en el análisis de Fourier. En el trabajo se muestran las facilidades del uso del dominio de la frecuencia en el análisis de se ales en prospeccion electromagnética. The signal processing in electromagnetic prospecting have been worked from several points of view and several authors there is expounding several methodologies. The object of this paper is to expound some algorithms for digital filters based on the Analysis of Fourier. In the work the facilities of the use of the frequency domain in the signal processing are shown.
AXIOLOGIA E éTICA PROPOSICIONAL SEGUNDO CARNAP: PELA ANáLISE LóGICA
Ramiro D lio null
Eidos , 2008,
Abstract: On this article, I explain the critical position to ethic in relation to logic analysis foundation from the "Viena Circle". However, there are conditions to carrie out the application from the verificability principle of language philosophy, by the thinking of R. Carnap, and the deontic logic plays a very important role to the bioethical foundations.
Role of the Proteasome in Excitotoxicity-Induced Cleavage of Glutamic Acid Decarboxylase in Cultured Hippocampal Neurons
Márcio S. Baptista,Carlos V. Melo,Mário Armel?o,Dennis Herrmann,Diogo O. Pimentel,Graciano Leal,Margarida V. Caldeira,Ben A. Bahr,Mário Bengtson,Ramiro D. Almeida,Carlos B. Duarte
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010139
Abstract: Glutamic acid decarboxylase is responsible for synthesizing GABA, the major inhibitory neurotransmitter, and exists in two isoforms—GAD65 and GAD67. The enzyme is cleaved under excitotoxic conditions, but the mechanisms involved and the functional consequences are not fully elucidated. We found that excitotoxic stimulation of cultured hippocampal neurons with glutamate leads to a time-dependent cleavage of GAD65 and GAD67 in the N-terminal region of the proteins, and decrease the corresponding mRNAs. The cleavage of GAD67 was sensitive to the proteasome inhibitors MG132, YU102 and lactacystin, and was also abrogated by the E1 ubiquitin ligase inhibitor UBEI-41. In contrast, MG132 and UBEI-41 were the only inhibitors tested that showed an effect on GAD65 cleavage. Excitotoxic stimulation with glutamate also increased the amount of GAD captured in experiments where ubiquitinated proteins and their binding partners were isolated. However, no evidences were found for direct GADs ubiquitination in cultured hippocampal neurons, and recombinant GAD65 was not cleaved by purified 20S or 26S proteasome preparations. Since calpains, a group of calcium activated proteases, play a key role in GAD65/67 cleavage under excitotoxic conditions the results suggest that GADs are cleaved after ubiquitination and degradation of an unknown binding partner by the proteasome. The characteristic punctate distribution of GAD65 along neurites of differentiated cultured hippocampal neurons was significantly reduced after excitotoxic injury, and the total GAD activity measured in extracts from the cerebellum or cerebral cortex at 24h postmortem (when there is a partial cleavage of GADs) was also decreased. The results show a role of the UPS in the cleavage of GAD65/67 and point out the deregulation of GADs under excitotoxic conditions, which is likely to affect GABAergic neurotransmission. This is the first time that the UPS has been implicated in the events triggered during excitotoxicity and the first molecular target of the UPS affected in this cell death process.
Operadores diferenciales en el análisis de se ales en geofísica
Díaz Campos Ramiro I.
Earth Sciences Research Journal , 2000,
Abstract: EI objetivo de este artículo es mostrar la utilidad que tienen los operadores vectoriales en el análisis e interpretación de información en Geofísica. Con éste propósito, se plantean algunos filtros digitales y se sugiere una metodología para su implementación mediante el análisis de un muestreo de campo magnético total. The objective of this paper is show the utility that have the vectorial operators in the analysis and interpretation of information in Geophysics. With this purpose, they come some digital filters and suggested a methodology for their application by means of the analysis of a map of magnetic total field.
Relación entre susceptibilidad magnética y contenido de minerales pesados en un depósito aluvial
Díaz C. Ramiro L.
Earth Sciences Research Journal , 1993,
Abstract: A partir de observaciones realizadas en una perforación a orillas del Rio Nechi en el Noreste Antioque o, se muestra la relación directa que existe entre el contenido de minerales en el dep6sito aluvial y la susceptibilidad magnética, relación que se explica por la semejanza en algunas propiedades físicas de dichos minerales. Mediante un análisis del Espectro de Energía, se verifican estas relaciones. A direct relationship between heavy minerals contents and magnetic susceptibility in an alluvial deposit has been observed in samples taken in a bore hole made at the shore of the Nechi river in NE of the Antioquia Department. These results are explained by the similarity of physical properties of these minerals. Analysis of energy spectrum has verified these relations.
Una técnica para la estimación de la densidad y el monitoreo de poblaciones de Inambú Común (Nothura maculosa) en ambientes de pastizal
Crego,Ramiro D.; Macri,Ivana N.;
El hornero , 2009,
Abstract: in this paper we present a technique to estimate densities and quantitatively evaluate population trends of spotted nothura (nothura maculosa) in grasslands habitats. we evaluated spotted nothura density in the hills of tandil, buenos aires province, using two techniques: line transects with variable width and strip transects. for the latter, we also evaluated the assumption that the probability of detecting an individual within the strip was 1. density values obtained with both techniques were similar (1.20 ind/ha for variable width transects, and 1.16 ind/ha for strip transects). we did not find significant differences among frequencies of individuals detected at different distances within the strip. we conclude that strip transects constitute a robust and efficient technique to evaluate, with a minimum cost, population trends of spotted nothura in grasslands and agricultural habitats. our density estimates are among the highest reported for buenos aires province, suggesting that the hills of tandil could represent a refuge for this species.
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