935 resultados para ENDOCRINOLOGY


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Medullary thyroid carcinoma (MTC) originates in the thyroid parafollicular cells and represents 3-4% of the malignant neoplasms that affect this gland. Approximately 25% of these cases are hereditary due to activating mutations in the REarranged during Transfection (RET) proto-oncogene. The course of MTC is indolent, and survival rates depend on the tumor stage at diagnosis. The present article describes clinical evidence-based guidelines for the diagnosis, treatment, and follow-up of MTC. The aim of the consensus described herein, which was elaborated by Brazilian experts and sponsored by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism, was to discuss the diagnosis, treatment, and follow-up of individuals with MTC in accordance with the latest evidence reported in the literature. After clinical questions were elaborated, the available literature was initially surveyed for evidence in the MedLine-PubMed database, followed by the Embase and Scientific Electronic Library Online/Latin American and Caribbean Health Science Literature (SciELO/Lilacs) databases. The strength of evidence was assessed according to the Oxford classification of evidence levels, which is based on study design, and the best evidence available for each question was selected. Eleven questions corresponded to MTC diagnosis, 8 corresponded to its surgical treatment, and 13 corresponded to follow-up, for a total of 32 recommendations. The present article discusses the clinical and molecular diagnosis, initial surgical treatment, and postoperative management of MTC, as well as the therapeutic options for metastatic disease. MTC should be suspected in individuals who present with thyroid nodules and family histories of MTC, associations with pheochromocytoma and hyperparathyroidism, and/or typical phenotypic characteristics such as ganglioneuromatosis and Marfanoid habitus. Fine-needle nodule aspiration, serum calcitonin measurements, and anatomical-pathological examinations are useful for diagnostic confirmation. Surgery represents the only curative therapeutic strategy. The therapeutic options for metastatic disease remain limited and are restricted to disease control. Judicious postoperative assessments that focus on the identification of residual or recurrent disease are of paramount importance when defining the follow-up and later therapeutic management strategies.

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We collected data on plasma levels of testosterone+5a-dihydrotestosterone (T+DHT) and corticosterone (CORT) from adult female green sea turtles (Chelonia mydas) from southern Queensland during distinct stages of their reproductive cycle. Those females capable of breeding in a given year had elevated plasma steroid levels (T+DHT 0.91 +/- 0.08; CORT 1.05 +/- 0.29 ng/ml), associated with follicular development, until courtship began in October. At the beginning of the nesting season in November plasma levels of 2 CORT were related to when the female first nested (r(2) = 0.06; F = 10.45; P = 0.01). However, they were not correlated with the number of clutches a female laid in that season (F = 3.65; P = 0.08). We repeatedly sampled 23 turtles over the nesting season and profiled changes in steroids immediately following oviposition of each clutch. Levels of T+DHT (range 0.41-0.58 ng/ml) and CORT (range 2.13-2.81 ng/ml) were similar through the early stages of the nesting season and inter-nesting period, and declined to near basal levels (T+DHT 0.37 +/- 0.03 and CORT 1.85 +/- ng/ml) following the last clutch for the season. Steroid hormone levels were also low (T+DHT 0.38 +/- 0.16; CORT 0.46 +/- 0.21 ng/ml) in four independent post-breeding (atretic) females; samples for these females were taken at a time when body condition was presumably at the lowest for the season. Subtle changes in the nesting environment, such as variation in nesting habitat or the time of night that nesting occurred, were associated with a small and slow CORT increase. We suggest CORT is increased in nesting females to assist in lipid transfer to prepare the ovarian follicles and/or the reproductive organs for ovulation.

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Patients with diabetes are at risk of early renal function decline. Therefore, kidney function needs monitoring at least once per year. Once the glomerular filtration rate (GFR) is less than 60 ml/min, the pharmacokinetics of antidiabetic drugs may be altered. Sulfonylurea and glinide therapies are associated with a risk of hypoglycaemia which is increased in the presence of renal impairment. Most sulfonylureas must be discontinued once GFR is <60 ml/min. Some glinides may be continued beyond this threshold, in particular repaglinide, which may be used in dialysis patients. In the absence of comorbidities, metformin can be continued at lower doses until a GFR of 45 ml/min, but must be withdrawn in case of dehydration or during the administration of a nephrotoxic drug including dye for radiological investigations. Glitazones may worsen water and sodium retention in patients with renal impairment. The pharmacokinetics of all DPP-IV inhibitors except linagliptin are altered with impaired renal function. Only sitagliptin, saxagliptin and linagliptin may be used in advanced kidney disease, but experience is as yet very limited. GLP-1 agonists are contraindicated in moderate to advanced kidney disease.

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By this study we seek the expectable range of waist circumference (WC) for every degree of body mass index (BMI), which will serve to studies targeting ascertaining the health risk. We studied 2,932 patients (39.6% men and 60.4% women, between 18 and 96 years ) of the same ethnic group who consecutively attended outpatient departments of our clinics between 2000 and 2004. BMI correlated linearly with the WC (cc: 0.85; p < 0.001). The men, the obese, and diabetics were older (p < 0.001). BMI was greater in women and WC in men. The women had a greater WC if they had diabetes (p < 0.01), being equal to diabetic males. The men had greater WC when they had diabetes (p < 0.001). Waist at risk was detected (men > or = 102 cm and women > or = 88 cm) in 94.3% of the obese, in 32.3% of overweight patients, in 3.8% of patients with BMI < 25, in 84.3% of diabetics, and in 72.6% of patients without diabetes. We made graphic standardisation of WC with regard to BMI, and we calculated the percentiles 10, 25, 50, 75 and 90, grouping in ranges of 2 kg/m(2) of BMI. The diabetic patients are grouped in ranges of 4 kg/m(2). As conclusion we present a standardisation of the WC measurement of patients attended to in our Endocrinology and Nutrition practices distributed in percentiles as a clinically usable tool to define the ranges of WC for every BMI value.

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Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily like the steroid, thyroid, or retinoid hormone receptors, which are ligand-activated transcription factors regulating gene expression. PPARs mediate the induction of the enzymes of the peroxisomal and microsomal fatty-acid oxidation pathways by hypolipidemic drugs such as clofibrate and are probably also involved in the gene expression of other lipid-metabolism-associated proteins that are controlled by fibrate hypolipidemic drugs. That PPARs play an important role in the regulation of lipid metabolism is reinforced by the discovery of their activation by physiologic concentrations of fatty acids. This observation raises the question of whether fatty acids are ligands of PPARs, which would imply that nutritional fatty acids can act like hormones.

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This short perspective explores some ways in which new genomic methodologies impact the study of endocrine signaling. Emphasis is put on the impact of studying species which are not molecular biology models. This opens the door to using knowledge molecular endocrinology in areas of biology as distant as conservation biology, as well as enriching endocrinology with information from biodiversity and natural variation.

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Puberty is a remarkable developmental process with the activation of the hypothalamic-pituitary-gonadal axis culminating in reproductive capacity. It is accompanied by cognitive, psychological, emotional, and sociocultural changes. There is wide variation in the timing of pubertal onset, and this process is affected by genetic and environmental influences. Disrupted puberty (delayed or absent) leading to hypogonadism may be caused by congenital or acquired etiologies and can have significant impact on both physical and psychosocial well-being. While adolescence is a time of growing autonomy and independence, it is also a time of vulnerability and thus, the impact of hypogonadism can have lasting effects. This review highlights the various forms of hypogonadism in adolescence and the clinical challenges in differentiating normal variants of puberty from pathological states. In addition, hormonal treatment, concerns regarding fertility, emotional support, and effective transition to adult care are discussed.

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The growing demand for quality prawn seed from the farmers‘ and entrepreneurs, coupled with uncertainity of their availability from nature at the appropriate time in required quantities has prompted‘ research on problems connected with prawn seed production. Endocrine control of reproduction in the penaeid shrimp _P_. monodon has been investigated in detail by adopting a comprehensive approach to the problem. The major aspects of the study included in depth investigations of the cytological details of the reproductive and neuroendocrine organs in correlation with the process of gonadal maturation. Based on the conclusions drawn from such ultrastructural studies various endocrine manipulations were carried out to see their effects on gonadal maturation. Besides that studies on the reproductive quality of male P_. monodon and the cryopreservation of spermatophores form a part of the present investigation. The shrimp 3; Inonodon used in the present study were collected from the offshore waters of Cochin, Madras and Mandapam and from the culture ponds of Vypeen Island near Cochin (Kerala) . The entire investigation on the cytological aspects were carried out using standard histological and electron-microscopic methods. Endocrine manipulations and cryopreservation studies is also carried out using the standard methods.

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The present investigation has been carried out to understand the process and events leading to maturation of the ovary and testis in the Indian white prawn Penaeus indicus. The study includes the classification of the ovarian maturity stages based on its colour, gonadosomatic index, oocyte diameter and morphological changes in the oocyte. Further the process of oogenesis has been investigated using light and electron microscopic techniques. A histochemical study of the ovary has also been carried out to determine the sequence in which yolk substances are synthesized or sequestered in the oocytes and also to elicit the nature of the penaeid yolk material. The process of spermatogenesis and the development of the spermatophore has been studied in detail using light and electron microscopic methods. In addition a brief histochemical study on the testis was also made to understand the nature of the organic reserves in the sperm cells.