987 resultados para Ectopic thyroid


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El objetivo de esta investigación es describir la calidad de vida y la calidad del sueño en los pacientes con diagnóstico de Síndrome de Apnea Hipoapnea del sueño, mediante el uso de un grupo de cuestionarios para obtener datos demográficos, la evaluación del grado de somnolencia diurna percibida, la percepción de la calidad del sueño y la percepción de la calidad de vida relacionada con la salud con encuestas en sus respectivas versiones validadas para Colombia.

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Introducción y objetivos: El conocimiento de la anatomía de las venas pulmonares y de la aurícula izquierda es fundamental para la planeación y prevención de posibles complicaciones durante la ablación de las venas pulmonares, procedimiento realizado para el manejo de la fibrilación auricular. Este estudio pretende caracterizar la anatomía (tamaño y forma) de las venas pulmonares y determinar las variantes anatómicas más comunes de las mismas. Métodos: Se analizaron 277 estudios de angioresonancia tridimensional y tomografía computarizada realizados previo al procedimiento de aislamiento de venas pulmonares. Se evaluaron los diámetros de la aurícula izquierda, de los ostia de las venas pulmonares y se determinaron la presencia de venas pulmonares comunes, accesorias y ramificaciones tempranas. Resultados: 75% de nuestros pacientes presentaron la anatomía normal de dos venas pulmonares derechas y dos izquierdas. En un 10,1% de los casos se encontraron venas supernumerarias y en un 11,2% se encontró un tronco común. En un 61% de los pacientes se encontraron ramas ostiales, las cuales en un 39,4% de los casos se presentaron en la vena pulmonar inferior derecha. Conclusiones: La evaluación de la morfología de la aurícula derecha y las venas pulmonares por medio de angioresonancia o tomografía computarizada, es necesaria para la realización de ablación por radiofrecuencia dada la alta frecuencia de variantes anatómicas y presencia de ramas ostiales.

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: Los métodos imagenológicos para evaluar los nódulos tiroideos han sido motivo de estudio en las últimas décadas, especialmente la ecografía sobresale sobre las otras modalidades diagnósticas por su accesibilidad, portabilidad, y seguridad. A pesar de ello, las características ecográficas de cada nódulo han sido objeto de controversia en cuanto a su potencial detección de malignidad o benignidad. Se presenta un estudio de concordancia entre el estudio citopatológico y la ecografía para la caracterización nódulos tiroideos de naturaleza maligna y benigna, y su análisis de pruebas diagnósticas. Metodología: Se realizó un estudio descriptivo de concordancia con estudio de pruebas diagnósticas anidado. Se escogieron todos los pacientes con nódulos tiroideos a quienes se les realizó ecografía y estudio citopatológico de la lesión y se estudiaron los hallazgos ecográficos para evaluar su potencial diagnóstico para malignidad. Se incluyeron un total de 100 pacientes con nódulos tiroideos potencialmente malignos. La concordancia entre la ecografía en modo B y el estudio citopatológico fue moderada (índice kappa 0.55). La característica con mayor potencial para detectar malignidad fue la presencia de Microcalcificaciones (sensibilidad 75%, especificidad 92%).

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El diagnóstico de cáncer de tiroides se ha incrementado y las posibilidades de detección de una enfermedad subclínica son altas, toda vez que disponemos de herramientas de detección más sensibles y de fácil acceso. Por ende, el clínico requiere conocer la historia natural del nódulo tiroideo y del carcinoma papilar de tiroides de bajo riesgo para brindar a su paciente el mejor tratamiento basado en la evidencia clínica. El objetivo de esta revision es reconocer los elementos clínicos que han condicionado el aumento inusitado de casos de cáncer de tiroides. Conclusión: El sobrediagnóstico del cáncer de tiroides es una realidad, que se posibilita por el uso extendido de biopsia por aspiración con aguja fina ((BACAF)) después de la detección de un nódulo tiroideo, en gran parte de manera incidental, sin acarrear la mayoría de las veces un mejor pronóstico después de su tratamiento.

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O Hipertiroidismo Felino é uma endocrinopatia emergente em felinos geriátricos nos últimos 20 anos. É caracterizada pela elevada produção de hormonas tiróideias, originando sinais clínicos multisistémicos por vezes inespecíficos, tornando o seu diagnóstico um desafio. O diagnóstico é estabelecido maioritariamente com base no aumento da concentração sérica de tiroxina (T4) total e no quadro clínico. O tratamento pode ser realizado através de três modalidades distintas, o maneio médico, a tiroidectomia e a radioterapia. A sua etiologia permanece desconhecida, sendo considerada actualmente uma doença multifactorial, com elevada incidência e prevalência em diversos Países, como EUA, Reino Unido e Alemanha. A sua incidência em Portugal é desconhecida. Actualmente os factores de risco mais preponderantes são a idade geriátrica, e o contacto com químicos goitrogénicos presentes no alimento ou no ambiente. A raça europeu comum apresenta maior predisposição para o desenvolvimento da doença, as raças Himalaia e Siâmes apresentam menor risco. O presente estudo foi realizado com os objectivos de determinar a incidência de hipertiroidismo felino na região de Aveiro entre Outubro de 2010 e Janeiro de 2012 e os seus potenciais factores de risco. A incidência de hipertiroidismo em animais com idade ≥ 8 anos foi 7,69% e 9,84% em animais com idade ≥ 10 anos. Gatos mais geriátricos, assim como animais do sexo masculino apresentam maior predisposição ao desenvolvimento da doença.

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Unlike most domestic livestock species, sheep are widely known as an animal with marked seasonality of breeding activity. The annual cycle of daily photoperiod has been identified as the determinant factor of this phenomenon, while environmental temperature, nutritional status, social interactions, lambing date and lactation period are considered to modulate it. The aim of this paper is to review the current state of knowledge of the reproductive seasonality in sheep. Following general considerations concerning the importance of seasonal breeding as a reproductive strategy for the survival of species, the paper describes the manifestations of seasonality in both the ram and the ewe. Both determinant and modulating factors are developed and special emphasis is given to the neuroendocrine base of photoperiodic regulation of seasonal breeding. Other aspects such as the role of melatonin, the involvement of thyroid hormones and the concept of photorefractoriness are also reviewed. (C) 2003 Elsevier Science B.V. All rights reserved.

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One of the largest contributions to biologically available nitrogen comes from the reduction of N-2 to ammonia by rhizobia in symbiosis with legumes. Plants supply dicarboxylic acids as a carbon source to bacteroids, and in return they receive ammonia. However, metabolic exchange must be more complex, because effective N-2 fixation by Rhizobium leguminosarum bv viciae bacteroids requires either one of two broad-specificity amino acid ABC transporters (Aap and Bra). It was proposed that amino acids cycle between plant and bacteroids, but the model was unconstrained because of the broad solute specificity of Aap and Bra. Here, we constrain the specificity of Bra and ectopically express heterologous transporters to demonstrate that branched-chain amino acid (LIV) transport is essential for effective N-2 fixation. This dependence of bacteroids on the plant for LIV is not due to their known down-regulation of glutamate synthesis, because ectopic expression of glutamate dehydrogenase did not rescue effective N-2 fixation. Instead, the effect is specific to LIV and is accompanied by a major reduction in transcription and activity of LIV biosynthetic enzymes. Bacteroids become symbiotic auxotrophs for LIV and depend on the plant for their supply. Bacteroids with aap bra null mutations are reduced in number, smaller, and have a lower DNA content than wild type. Plants control LIV supply to bacteroids, regulating their development and persistence. This makes it a critical control point for regulation of symbiosis. MICROBIOLOGY

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The ascidian Ciona intestinalis, a marine invertebrate chordate, is an emerging model system for developmental and evolutionary studies. The endostyle, one of the characteristic organs of ascidians, is a pharyngeal structure with iodine-concentrating and peroxidase activities and is therefore considered to be homologous to the follicular thyroid of higher vertebrates. We have previously reported that a limited part of the endostyle (zone VII) is marked by the expression of orthologs of the thyroid peroxidase (TPO) and thyroid transcription factor-2 (TTF-2/FoxE) genes. In this study, we have identified the Ciona homolog of NADPH oxidase/peroxidase (Duox), which provides hydrogen peroxide (H2O2) for iodine metabolism by TPO in the vertebrate thyroid. Expression patterns assessed by in situ hybridization have revealed that Ciona Duox (Ci-Duox) is predominantly expressed in the dorsal part of zone VII of the endostyle. Furthermore, two-color fluorescent in situ hybridization with Ci-Duox and Ciona TPO (CiTPO) has revealed that the ventral boundary of the Ci-Duox domain of expression is more dorsal than that of CiTPO. We have also characterized several genes, such as Ci-Fgf8/17/18, 5HT7, and Ci-NK4, which are predominantly expressed in the ventral part of zone VII, in a region complementary to the Ci-Duox expression domain. These observations suggest that, at the molecular level, zone VII has a complex organization that might have some impact on the specification of cell types and functions in this thyroid-equivalent element of the ascidian endostyle.

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The virulence factor IpgD, delivered into nonphagocytic cells by the type III secretion system of the pathogen Shigella flexneri, is a phosphoinositide 4-phosphatase generating phosphatidylinositol 5 monophosphate (PtdIns(5) P). We show that PtdIns(5) P is rapidly produced and concentrated at the entry foci of the bacteria, where it colocalises with phosphorylated Akt during the first steps of infection. Moreover, S. flexneri-induced phosphorylation of host cell Akt and its targets specifically requires IpgD. Ectopic expression of IpgD in various cell types, but not of its inactive mutant, or addition of short-chain penetrating PtdIns(5) P is sufficient to induce Akt phosphorylation. Conversely, sequestration of PtdIns(5) P or reduction of its level strongly decreases Akt phosphorylation in infected cells or in IpgD-expressing cells. Accordingly, IpgD and PtdIns(5) P production specifically activates a class IA PI 3-kinase via a mechanism involving tyrosine phosphorylations. Thus, S. flexneri parasitism is shedding light onto a new mechanism of PI 3-kinase/Akt activation via PtdIns(5) P production that plays an important role in host cell responses such as survival.

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The endostyle of invertebrate chordates is a pharyngeal organ that is thought to be homologous with the follicular thyroid of vertebrates. Although thyroid-like features such as iodine-concentrating and peroxidase activities are located in the dorsolateral part of both ascidian and amphioxus endostyles, the structural organization and numbers of functional units are different. To estimate phylogenetic relationships of each functional zone with special reference to the evolution of the thyroid, we have investigated, in ascidian and amphioxus, the expression patterns of thyroid-related transcription factors such as TTF-2/MoxE4 and Pax2/5/8, as well as the forkhead transcription factors FoxQ1 and FoxA. Comparative gene expression analyses depicted an overall similarity between ascidians and amphioxus endostyles, while differences in expression patterns of these genes might be specifically related to the addition or elimination of a pair of glandular zones. Expressions of Ci-FoxE and BbFoxE4 suggest that the ancestral FoxE class might have been recruited for the formation of thyroid-like region in a possible common ancestor of chordates. Furthermore, coexpression of FoxE4, Pax2/5/8, and TPO in the dorsolateral part of both ascidian and amphioxus endostyles suggests that genetic basis of the thyroid function was already in place before the vertebrate lineage. (c) 2005 Wiley-Liss, Inc.

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A series of experiments was conducted to examine the mechanism by which removal of the thyroid glands in seasonally suppressed rams brings about rapid testicular growth. In the first experiment, thyroidectomy at the nadir of the testicular cycle (late winter) initiated testis growth without any detectable change in the extent of spermatogenesis compared with sham-operated controls. The serum concentration of FSH, but not LH, was also markedly increased by thyroidectomy. In the second experiment, serum FSH concentration was again increased by thyroidectomy in late winter but there was no effect of thyroidectomy on LH concentration, LH pulses (measured in frequent blood samples) or testosterone concentration. Furthermore, there was no evidence of a change in central dopaminergic inhibition of GnRH, as measured by the pulsatile LH response to an i.m. injection of the dopaminergic D-2 agonist bromocriptine or antagonist sulpiride. The rapid increase in FSH concentration occurred despite a markedly increased serum inhibin A concentration in thyroidectomized rams. Therefore, the efficacy of inhibin feedback was examined by testing the FSH-suppressive effect of an inhibin preparation (5 ml charcoal-stripped bovine follicular fluid i.v.) in long-term thyroidectomized and thyroid intact castrated rams. Bovine follicular fluid suppressed FSH concentrations in control rams as expected but in marked contrast, was completely without effect in thyroidectomized animals. In castrated rams, the FSH concentration was only marginally increased by thyroidectomy, indicating that there is a major component of the mediation of the effects of thyroidectomy that is testicular in origin. It was concluded that a reduction in the ability of endogenous inhibin to inhibit FSH release at the pituitary, rather than a hypothalamic mechanism, is the primary cause of the stimulation of testis growth by thyroidectomy.

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Anthocyanins are flavonoid pigments imparting red, blue, or purple pigmentation to fruits, flowers and foliage. These compounds are powerful antioxidants in vitro, and are widely believed to contribute to human health. The fruit of the domestic apple (Malus x domestica) is a popular and important source of nutrients, and is considered one of the top ‘functional foods’—those foods that have inherent health-promoting benefits beyond basic nutritional value. The pigmentation of typical red apple fruits results from accumulation of anthocyanin in the skin. However, numerous genotypes of Malus are known that synthesize anthocyanin in additional fruit tissues including the core and cortex (flesh). Red-fleshed apple genotypes are an attractive starting point for development of novel varieties for consumption and nutraceutical use through traditional breeding and biotechnology. However, cultivar development is limited by lack of characterization of the diversity of genetic backgrounds showing this trait. We identified and cataloged red-fleshed apple genotypes from four Malus diversity collections representing over 3,000 accessions including domestic cultivars, wild species, and named hybrids. We found a striking range of flesh color intensity and pattern among accessions, including those carrying the MYB10 R 6 allele conferring ectopic expression of a key transcriptional regulator of anthocyanin biosynthesis. Although MYB10 R 6 was strongly associated with red-fleshed fruit among genotypes, this allele was neither sufficient nor required for this trait in all genotypes. Nearly all red-fleshed accessions tested could be traced back to ‘Niedzwetzkyana’, a presumed natural form of M. sieversii native to central Asia.