947 resultados para Arritmia ventricular compleja


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Este libro se basa en una investigación de campo entre los indfgenas Sionas y Secoyas del nororiente ecuatoriano en los aflos 1973 a 1975, y mi disertación docoral de 1976. Sin embargo, el presente texto ha sido aumentado con secciones nuevas, muchas correcciones y nuevas identificaciones de plantas y animales. Este libro no es solamente una descripción etnográfica de los Sionas y Secoyas, sino un estudio de su adaptación al medio ambiente de la floresa tropical y los ríos amazónicos. Se presentó información etnogáfica, pero siempre dentro de la estructura teórica de la ecologfa humana. A veces los datos presentados son muy técnicos (p. e., calorfas, tipos de suelos y los nombres cientfficos de la flora y la fauna). Espero que este aspecto no desanime a mis lectores. Los datos cientfficos revelan y documentan el conocimiento intimo elaborado del indígena acerca de la selva, y su adapación compleja a este ambierte.

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Uno de los aspectos clave para conocer la realidad de las personas con discapacidad, es sin duda el conocimiento de la magnitud y evolución del gasto público de las administraciones públicas en esta materia. En este documento, se presenta una estrategia metodológica de seguimiento y evaluación del gasto público en discapacidad en España, para su aplicación sistemática, de manera anual, a partir de 2015. La medición del gasto público en discapacidad es una tarea compleja, sobre la que el OED pretende propiciar un debate y reflexión conjunta a la que se invita a público e instituciones interesadas, con el objetivo último de alcanzar el mejor instrumento de medición posible.

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Coronary CT angiography is widely used in clinical practice for the assessment of coronary artery disease. Several studies have shown that the same exam can also be used to assess left ventricle (LV) function. LV function is usually evaluated using just the data from end-systolic and end-diastolic phases even though coronary CT angiography (CTA) provides data concerning multiple cardiac phases, along the cardiac cycle. This unused wealth of data, mostly due to its complexity and the lack of proper tools, has still to be explored in order to assess if further insight is possible regarding regional LV functional analysis. Furthermore, different parameters can be computed to characterize LV function and while some are well known by clinicians others still need to be evaluated concerning their value in clinical scenarios. The work presented in this thesis covers two steps towards extended use of CTA data: LV segmentation and functional analysis. A new semi-automatic segmentation method is presented to obtain LV data for all cardiac phases available in a CTA exam and a 3D editing tool was designed to allow users to fine tune the segmentations. Regarding segmentation evaluation, a methodology is proposed in order to help choose the similarity metrics to be used to compare segmentations. This methodology allows the detection of redundant measures that can be discarded. The evaluation was performed with the help of three experienced radiographers yielding low intraand inter-observer variability. In order to allow exploring the segmented data, several parameters characterizing global and regional LV function are computed for the available cardiac phases. The data thus obtained is shown using a set of visualizations allowing synchronized visual exploration. The main purpose is to provide means for clinicians to explore the data and gather insight over their meaning, as well as their correlation with each other and with diagnosis outcomes. Finally, an interactive method is proposed to help clinicians assess myocardial perfusion by providing automatic assignment of lesions, detected by clinicians, to a myocardial segment. This new approach has obtained positive feedback from clinicians and is not only an improvement over their current assessment method but also an important first step towards systematic validation of automatic myocardial perfusion assessment measures.

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Este estudo investiga a influência da interação imagem-texto de três álbuns ilustrados de língua inglesa no desenvolvimento do repertório linguístico de crianças pré-leitoras. Numa metodologia de estudo de caso, adotando uma abordagem qualitativa e socio construtivista num contexto real de educação pré-escolar, três grupos de crianças portuguesas foram filmados ao longo de várias sessões de leitura repetida em voz alta e em inglês, e de sessões de recontos trabalhados em pequenos grupos. Após a transcrição das gravações, o corpus resultante foi analisado com base numa teoria fundamentada de compreensão literária e em escalas de leitura emergente. Os resultados mostraram que as crianças adotaram uma postura fortemente analítica face aos álbuns, direcionando as suas respostas para as ilustrações e usando-as como apoio na construção de significados. Os resultados mostraram também que cada interanimação visual e verbal ofereceu diversas oportunidades para o uso das línguas em presença, o português e o inglês, tendo o formato e a estrutura inerentes a cada álbum contribuído de forma muito relevante para as respostas das crianças. Contudo, os álbuns com uma dinâmica imagem-texto mais complexa proporcionaram um maior envolvimento das crianças, provocando mais discussão em torno das ilustrações e criando mais oportunidades para mediação do uso da segunda língua. Os resultados revelaram ainda a importância da interação durante as leituras repetidas, na compreensão e na análise narrativa, num processo de desenvolvimento da linguagem. Com base nestes resultados, apontam-se conclusões, com implicações para os contextos educativos, quer ao nível da língua materna, quer ao nível da segunda língua, nomeadamente em relação: à seleção de álbuns e à valorização das ilustrações e ainda à importância de leituras repetidas em voz alta e à discussão realizada pelas crianças.

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INDICE DE LA OBRA ¿Qué significa ser indígena en el México de hoy? Los indígenas vistos desde afuera La ley y el gobierno frente a los indígenas Las identidades indígenas La gran pluralidad de los indígenas Las herencias históricas Las raíces prehispánicas Conquista y Colonia, las diferentes experiencias La vida de los indígenas en el México independiente El siglo XX Las comunidades indígenas: su vida política y social El territorio y la tierra Las formas de gobierno, una compleja historia Los sistemas de cargos Los consejos de ancianos Las asambleas comunitarias El consenso La comunidad y el exterior El trabajo comunitario Los sistemas jurídicos Cambios en la vida política Las realidades culturales indígenas Las lenguas indígenas hoy Lenguas indígenas y escritura Las lenguas indígenas y el español Las cosmovisiones indígenas Las religiones indígenas Las nuevas religiones La situación socioeconómica de los indígenas La agricultura de subsistencia y sus problemas Las formas de la marginación Género y marginación Las nuevas realidades socioeconómicas Los proyectos de desarrollo y las culturas indígenas Los indígenas y la nación, hoy y mañana Las sociedades indígenas en la encrucijada “Nunca más un México sin nosotros” La autonomía indígena ¿Problema indígena o problema nacional? Hacia un México verdaderamente plural

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Tese dout., Universidad de Huelva. Departamento de Economía Financiera, Contabilidad y Dirección de Operaciones.

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Cardiogenesis is a delicate and complex process that requires the coordination of an intricate network of pathways and the different cell types. Therefore, understanding heart development at the morphogenetic level is an essential requirement to uncover the causes of congenital heart disease and to provide insight for disease therapies. Mouse Cerberus like 2 (Cerl2) has been defined as a Nodal antagonist in the node with an important role in the Left-Right (L/R) axis establishment, at the early embryonic development. As expected, Cerl2 knockout mice (Cerl2-/-) showed multiple laterality defects with associated cardiac failure. In order to identify the endogenous role of Cerl2 during heart formation independent of its described functions in the node, we accurately analyzed animals where laterality defects were not present. We thereby unravel the consequences of Cerl2 lossof- function in the heart, namely increased left ventricular thickness due to hyperplasia of cardiomyocytes and de-regulated expression of cardiac genes. Furthermore, the Cerl2 mutant neonates present impaired cardiac function. Once that the cardiac expression of Cerl2 is mostly observed in the left ventricle until around midgestration, this result suggest a specific regulatory role of Cerl2 during the formation of the left ventricular myoarchitecture. Here, we present two possible molecular mechanisms underlying the cardiac Cerl2 function, the regulation of Cerl2 antagonist in activation of the TGFßs/Nodal/Activin/Smad2 signaling identified by increased Smad2 phosphorilation in Cerl2-/- hearts and the negative feedback between Cerl2 and Wnt/ß-catenin signaling in heart formation. In this work and since embryonic stem cells derived from 129 mice strain is extensively used to produce targeted mutants, we also present echocardiographic reference values to progressive use of juveniles and young adult 129/Sv strain in cardiac studies. In addition, we investigate the cardiac physiology of the surviving Cerl2 mutants in 129/Sv background over time through a follow-up study using echocardiographic analysis. Our results revealed that Cerl2-/- mice are able to improve and maintain the diastolic and most of systolic cardiac physiologic parameters as analyzed until young adult age. Since Cerl2 is no longer expressed in the postnatal heart, we suggest that an intrinsic and compensatory mechanism of adaptation may be active for recovering the decreased cardiac function found in Cerl2 mutant neonates. Altogether, these data highlight the role of Cerl2 during embryonic heart development in mice. Furthermore, we also suggest that Cerl2-/- may be an interesting model to uncover the molecular, cellular and physiological mechanisms behind the improvement of the cardiac function, contributing to the development of therapeutic approaches to treat heart failures.

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L’hypertrophie du ventricule gauche est une complication fréquente chez les gens souffrant de sténose aortique. Lorsque ces patients subissent un remplacement de la valve aortique, l’ampleur de la régression de l’hypertrophie dépend de plusieurs facteurs hémodynamiques qui sont peu ou pas modifiables. Dans ce travail, l’implication de la parathormone dans l’hypertrophie du ventricule gauche chez ces patients a été évaluée. Il s’agit d’une étude transversale comptant 195 patients recrutés 8±3,5 ans après leur chirurgie. La fonction et la masse ventriculaire gauche ont été évaluées par échocardiographie Doppler. Des mesures du niveau plasmatique de parathormone, de vitamine D, de calcium et de phosphate ont été obtenues. Les résultats démontrent que le niveau de parathormone est associé de façon indépendante et significative avec la masse ventriculaire gauche et l’hypertrophie du ventricule gauche. De plus, le niveau de vitamine D et la fonction rénale étaient en corrélation inverse avec le niveau de parathormone.

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Tese de doutoramento, Medicina (Pediatria), Universidade de Lisboa, Faculdade de Medicina, 2013

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In this study, we utilise a novel approach to segment out the ventricular system in a series of high resolution T1-weighted MR images. We present a brain ventricles fast reconstruction method. The method is based on the processing of brain sections and establishing a fixed number of landmarks onto those sections to reconstruct the ventricles 3D surface. Automated landmark extraction is accomplished through the use of the self-organising network, the growing neural gas (GNG), which is able to topographically map the low dimensionality of the network to the high dimensionality of the contour manifold without requiring a priori knowledge of the input space structure. Moreover, our GNG landmark method is tolerant to noise and eliminates outliers. Our method accelerates the classical surface reconstruction and filtering processes. The proposed method offers higher accuracy compared to methods with similar efficiency as Voxel Grid.

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The quantity of blood arriving at the left side of the heart oscillates throughout the breathing cycle due to the mechanics of breathing. Neurally regulated fluctuations in the length of the heart period act to dampen oscillations of the left ventricular stroke volume entering the aorta. We have reported that stroke volume oscillations but not spectral frequency variability stroke volume measures can be used to estimate the breathing frequency. This study investigated with the same recordings whether heart period oscillations or spectral heart rate variability measures could function as estimators of breathing frequency. Continuous 270 s cardiovascular recordings were obtained from 22 healthy adult volunteers in the supine and upright postures. Breathing was recorded simultaneously. Breathing frequency and heart period oscillation frequency were calculated manually, while heart rate variability spectral maximums were obtained using heart rate variability software. These estimates were compared to the breathing frequency using the Bland–Altman agreement procedure. Estimates were required to be \±10% (95% levels of agreement). The 95% levels of agreement measures for the heart period oscillation frequency (supine: -27.7 to 52.0%, upright: -37.8 to 45.9%) and the heart rate variability spectral maximum estimates (supine: -48.7 to 26.5% and -56.4 to 62.7%, upright: -37.8 to 39.3%) exceeded 10%. Multiple heart period oscillations were observed to occur during breathing cycles. Both respiratory and non-respiratory sinus arrhythmia was observed amongst healthy adults. This observation at least partly explains why heart period parameters and heart rate variability parameters are not reliable estimators of breathing frequency. In determining the validity of spectral heart rate variability measurements we suggest that it is the position of the spectral peaks and not the breathing

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Pain transmission at the spinal cord is modulated by descending actions that arise from supraspinal areas which collectively form the endogenous pain control system. Two key areas involved of the endogenous pain control system have a circunventricular location, namely the periaqueductal grey (PAG) and the locus coeruleus (LC). The PAG plays a crucial role in descending pain modulation as it conveys the input from higher brain centers to the spinal cord. As to the LC, it is involved in descending pain inhibition by direct noradrenergic projections to the spinal cord. In the context of neurological defects, several diseases may affect the structure and function of the brain. Hydrocephalus is a congenital or acquired disease characterized by an enlargement of the ventricles which leads to a distortion of the adjacent tissues, including the PAG and LC. Usually, patients suffering from hydrocephalus present dysfunctions in learning and memory and also motor deficits. It remains to be evaluated if lesions of the periventricular brain areas involved in pain control during hydrocephalus may affect descending pain control and, herein, affect pain responses. The studies included in the present thesis used an experimental model of hydrocephalus (the rat injected in the cisterna magna with kaolin) to study descending modulation of pain, focusing on the two circumventricular regions referred above (the PAG and the LC). In order to evaluate the effects of kaolin injection into the cisterna magna, we measured the degree of ventricular dilatation in sections encompassing the PAG by standard cytoarquitectonic stanings (thionin staining). For the LC, immunodetection of the noradrenaline-synthetizing enzyme tyrosine hydroxylase (TH) was performed, due to the noradrenergic nature of the LC neurons. In general, rats with kaolin-induced hydrocephalus presented a higher dilatation of the 4th ventricle, along with a tendency to a higher area of the PAG. Due to the validated role of detection the c-fos protooncogene as a marker of neuronal activation, we also studied neuronal activation in the several subnuclei which compose the PAG, namely the dorsomedial, dorsolateral, lateral and ventrolateral (VLPAG) parts. A decrease in the numbers of neurons immunoreactive for Fos protein (the product of activation of the c-fos protooncogene) was detected in rats injected with kaolin, whereas the remaining PAG subnuclei did not present changes in Fos-immunoreactive nuclei. Increases in the levels of TH in the LC, namely at the rostral parts of the nucleus, were detected in hydrocephalic animals. The following pain-related parameters were measured, namely 1) pain behavioural responses in a validated pain inflammatory test (the formalin test) and 2) the nociceptive activation of spinal cord neurons. A decrease in behavioral responses was detected in rats with kaolin-induced hydrocephalus was detected, namely in the second phase of the test (inflammatory phase). This is the phase of the formalin test in which the motor behaviour is less important, which is important since a semi-quantitative analysis of the motor performance of rats injected with kaolin indicates that these animals may present some motor impairments. Collectively, the results of the behavioral studies indicate that rats with kaolin-induced hydrocephalus exhibit hypoalgesia. A decrease in Fos expression was detected at the superficial dorsal layers of the spinal cord in rats with kaolin-induced hydrocephalus, further indicating that hydrocephalus decreases nociceptive responses. It remains to be ascertained if this is due to alterations in the PAG and LC in the rats with kaolin-induced hydrocephalus, which may affect descending pain modulation. It remains to be evaluated what are the mechanisms underlying the increased pain inhibition at the spinal dorsal horn in the hydrocephalus rats. Regarding the VLPAG, the decrease in neuronal activity may impair descending modulation. Since the LC has higher levels of TH in rats with kaolininduced hydrocephalus, which also appears to increase the noradrenergic innervation in the spinal dorsal horn, it is possible that an increase in the release of noradrenaline at the spinal cord accounts for pain inhibition. Our studies also determine the need to study in detail patients with hydrocephalus namely in what concerns their thresholds to pain and to perform imaging studies focused on the structure and function of pain control areas in the brain.

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Dissertação de Doutoramento em Saúde Pública;Especialidade em Política, Gestão e Administração

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Recentemente, surgiram alguns trabalhos que ressaltaram a importância do cálculo do volume da aurícula esquerda (VAE) como um marcador de eventos cardíacos adversos. Foi objectivo deste estudo avaliar a importância prognóstica deste parâmetro em doentes (dts) com deficiente função ventricular esquerda e correlacioná-lo com outros parâmetros clássicos de prognóstico – consumo de O2 (VO2 max) e pro-BNP (pBNP). Métodos: Analisou-se o volume da aurícula esquerda (VAE) por método de Simpson, numa população de 35 dts com cardiopatia dilatada (idiopática e isquémica) com fracção de ejecção (FE) 31±9,6% doentes (dts) eram de sexo masculino e a média de idades foi de 50,5±10,5 anos. Toda a população efectuou estudos de ecocardiografia convencional (incluindo avaliação por M-mode, bidimensional e Doppler), prova cardiorespiratória (VO2max) e doseamento de pro-BNP. O tempo médio de seguimento foi de 24 ± 4 meses, tendo-se considerado como eventos cardíacos (EC): internamento por insuficiência cardíaca, transplante e morte. Resultados: Dos parâmetros da ecocardiografia - o diâmetro da AE foi de 46,6±5,7mm, as dimensões do VE em diástole – 73,5±10mm e em sístole -58,9±11mm, a média da fracção de ejecção foi de 31±9,6%, o VAE foi de 78,6±33 ml, os volumes do VE foram de 214±82ml em diástole e de 153±75ml em sístole, 15 dts tinham padrão restritivo de enchimento ventricular (E/A>2), a média da área (Doppler cor) da insuficiência mitral foi de 4±3,3cm2, 14 dts tinham E/E’>15. O VO2 max médio foi de 20±5,8ml/kg/min e o pro-BNP de 3146±4629pg/mL. Para além da correlação de outros parâmetros clássicos ecocardiográficos com o prognóstico (volumes VE, FE e E/E’), o VAE e o volume indexado da AE (VAE/SC) mostraram uma correlação com o prognóstico (EC) com r=0,4 (p=0,02) que não se verificou para o diâmetro da AE (p=ns). Em relação à tolerância ao esforço, houve uma correlação inversa entre o diâmetro, o volume e o volume indexado da AE e o VO2max, com maior significado estatístico para o VAE e VAE/SC com r=-0,48, p=0,008. Quanto ao pro-BNP, quer o diâmetro, quer o VAE (ou volume indexado) tiverem o mesmo nível de significado estatístico (r=0,43; p=0,02). O valor predictivo de eventos (curvas ROC) para o VAE foi de 70ml e de 37ml/m2 para o VAE/m2. Conclusão: O volume da aurícula esquerda/volume indexado é um parâmetro ecocardiográfico com significado prognóstico em dts com deficiente função ventricular esquerda, correlacionando-se com a tolerância ao esforço e pro-BNP.