Marcadores séricos do metabolismo ósseo no hipertireoidismo felino

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Consenso brasileiro para a abordagem clínica e tratamento do hipotireoidismo subclínico em adultos: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

INTRODUÇÃO: O hipotireoidismo subclínico (HSC), definido por concentrações elevadas do TSH em face de níveis normais dos hormônios tireoidianos, tem elevada prevalência no Brasil, particularmente entre mulheres e idosos. Embora um número crescente de estudos venha associando o HSC com maior risco de doença arterial coronariana e de mortalidade, não há ensaio clínico randomizado sobre o benefício do tratamento com levotiroxina na redução dos riscos e o tratamento permanece controverso. OBJETIVO: Este consenso, patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia e desenvolvido por especialistas brasileiros com vasta experiência clínica em tireoide, apresenta recomendações baseadas em evidências para uma abordagem clínica do paciente com HSC no Brasil. MATERIAIS E MÉTODOS: Após estruturação das questões clínicas, a busca das evidências disponíveis na literatura foi realizada inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO - Lilacs. A força da evidência, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão e a experiência brasileira. RESULTADOS: Os temas abordados foram definição e diagnóstico, história natural, significado clínico, tratamento e gestação, que resultaram em 29 recomendações para a abordagem clínica do paciente adulto com HSC. CONCLUSÃO: O tratamento com levotiroxina foi recomendado para todos os pacientes com HSC persistente com níveis séricos do TSH > 10 mU/L e para alguns subgrupos especiais de pacientes.

Consenso brasileiro para o diagnóstico e tratamento do hipertireoidismo: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

INTRODUÇÃO: O hipertireoidismo é caracterizado pelo aumento da síntese e liberação dos hormônios tireoidianos pela glândula tireoide. A tireotoxicose refere-se à síndrome clínica decorrente do excesso de hormônios tireoidianos circulantes, secundário ao hipertireoidismo ou não. Este artigo descreve diretrizes baseadas em evidências clínicas para o manejo da tireotoxicose. OBJETIVO: O presente consenso, elaborado por especialistas brasileiros e patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia, visa abordar o manejo, diagnóstico e tratamento dos pacientes com tireotoxicose, de acordo com as evidências mais recentes da literatura e adequadas para a realidade clínica do país. MATERIAIS E MÉTODOS: Após estruturação das questões clínicas, foi realizada busca das evidências disponíveis na literatura, inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO - Lilacs. A força das evidências, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão. RESULTADOS: Foram definidas 13 questões sobre a abordagem clínica inicial visando ao diagnóstico e ao tratamento que resultaram em 53 recomendações, incluindo investigação etiológica, tratamento com drogas antitireoidianas, iodo radioativo e cirurgia. Foram abordados ainda o hipertireoidismo em crianças, adolescentes ou pacientes grávidas e o manejo do hipertireoidismo em pacientes com oftalmopatia de Graves e com outras causas diversas de tireotoxicose. CONCLUSÕES: O diagnóstico clínico do hipertireoidismo, geralmente, não oferece dificuldade e a confirmação diagnóstica deverá ser feita com as dosagens das concentrações séricas de TSH e hormônios tireoidianos. O tratamento pode ser realizado com drogas antitireoidianas, administração de radioiodoterapia ou cirurgia de acordo com a etiologia da tireotoxicose, as características clínicas, disponibilidade local de métodos e preferências do médico-assistente e paciente.

Concentrações plasmáticas de cortisol, hormônios tiroídeanos, metabólitos lipídicos e temperatura corporal de cabras alpinas submetidas ao estresse térmico

The objective of this work was to determine the plasma concentrations of cortisol, thyroid hormone, lipids metabolites and corporal temperature or lactating Alpine goats submitted to heat stress. Six lactating Alpine goats were allotted randomly in a crossover experimental design for two groups: thermoneutral conditions or thermal stress. An adaptation period of 28 days was followed by Four-periods of 14 days each, when the animals submitted to thermal stress were exposed to the average temperature of 33.84 degrees C; THI of 86.20; BGT of 36.18 and BT of 32.11 degrees C from 8:00 am to 5:00 pm, including simulated solar radiation from 10:00 am to 3:00 pm. There were no differences between the groups in the plasma concentrations of cortisol, thyroid hormones (T-3-triiodothyronine and T-(4) tiroxine), and lipid metabolites (cholesterol and HDL). Rectal temperature was higher during thermal stress when compared to the group of animals in thermoneutral conditions. The goats maintained the thyroid plasma hormone concentrations, when exposed to repealed and intermittent stress, in spite of the occurrence of hypertermia during heat stress.

Effect of thermal conditioning during embryonic development on aspects of physiological responses of broilers to heat stress

The purpose of the present study was to investigate the effect of thermal conditioning, (through exposure to heat stress), during pre-hatch development on some physiological responses of post-hatch broilers to a post-natal heat stress challenge. Exposure to heat stress at this stage, we hope, may possibly induce epigenetic heat adaptation. Incubating eggs were exposed to temperature of 39.0degreesC for 2 h from Day 13 to 17 of incubation. At 33, 35, 37, 39, 41 and 43 d of age, the broilers hatched from these eggs were housed individually in open-circuit respiration cells. The climatic chambers were set to 22degreesC and increased to 30degreesC for 4 h. O-2 consumption and CO2 production of each chicken was monitored continuously in order to calculate the heat production. Blood samples were obtained before and during the 4 h heat stress. Thermal conditioning during incubation did not affect the plasma T-4, corticosterone, glucose, uric acid and CK concentrations. Temperature challenge, decreased plasma T-3 of broilers of both groups but the decrease was greater in pre-conditioned broilers compared with controls. A similar trend was observed for triglycerides. These changes did not affect total heat production. Since decreased T3 and triglyceride levels are part of the mechanisms for thermoregulation, these suggest that thermal conditioning during incubation can improve the broiler chicken capability for thermotolerance at later post-hatch age. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

THE ESSENTIAL ROLE OF ZINC IN GROWTH

Zinc is known to play a relevant role in growth and development. The basic mechanisms of action of this trace element are intimately linked to the structure and action of countless enzymes involved in many different metabolic processes. In this respect, when zinc specifically acts on cartilage growth it is involved in multiple enzymatic reactions which make this a multifactorial event. Thus, we may divide the actions of zinc into three distinct types: 1) action on taste and smell acuity, appetite regulation, and food consumption and regulation; 2) action on DNA and RNA synthesis stimulating a) cell replication and differentiation of chondrocytes, osteoblasts and fibroblasts; b) cell transcription culminating in the synthesis of somatomedin-C (liver), alkaline phosphatase, collagen and osteocalcin (bone), and c) protein, carbohydrate and lipid metabolism, that is intimately related to the mechanisms of smell, taste, appetite, and food consumption and utilization; 3) action on hormonal mediation by participating in a) GH synthesis and secretion in somatomammotroph cells, b) the action of GH on liver somatomedin-C production, and c) somatomedin-C activation in bone cartilage. In addition to these multiple functions, zinc also interacts with other hormones somehow related to bone growth such as testosterone, thyroid hormones, insulin, and vitamin D-3.On the basis of the above considerations, we conclude that the integration of these mechanisms contributes to the perfect physiological functioning of bone. Tn the presence of zinc deficiency, this homeostasis is impaired, causing the weight-height deficiency detected in several species studied, the human species in particular.

The effect of timing of thermal conditioning during incubation on embryo physiological parameters and its relationship to thermotolerance in adult broiler chickens

Previously, we reported that thermal conditioning at 39degreesC on days 13-17 of incubation of broiler eggs enabled thermotolerance during post-hatch growth (J. Therm. Biol. 28 (2003) 133). Tolerance to a temperature of 30degreesC was accompanied by changes in thyroid hormones and metabolic parameters. In the current study, we determined the mechanism of epigenetic heat adaptation during embryonic age by measuring blood physiological parameters that may be associated with the ultimate effects of thermal conditioning. Hatching eggs from Ross breeders were subjected to heat treatment of 39degreesC at days 13, 14, 15, 16 and 17 of incubation for 2 h per day. Control eggs were incubated at 37.6degreesC. Samples of eggs were withdrawn on each day of thermal conditioning and at internal pipping (IP) to obtain blood samples from embryos. The remaining eggs were weighed at day 18 and transferred to hatchers. The timing of IP, external pipping (EP) and hatching were monitored every 2 h. At hatch, chicks were weighed and hatchability was determined. Blood samples were obtained from samples of day-old chicks. T3, T4, corticosterone, pCO(2), pO(2) levels were determined in the blood. Blood pH was measured and T3/T4 ratios were calculated. Heat conditioning significantly increased corticosterone and pO(2) levels and blood pH but depressed pCO(2) at day 14. These were followed by a significant depression of T4 level on day 15. Remarkably, at day 16, all these parameters were back to normal as in the control embryos. Hatching was delayed by thermal conditioning probably as a result of the depressed corticosterone levels at IP. Hatchability was also lower in the heat-treated group but 1-day old chick weights were comparable to those of the controls. The result suggests that epigenetic thermal conditioning involves changes in these physiological parameters and probably serve as a method for epigenetic temperature adaptation since the same mechanisms are employed for coping with heat during post-embryonic growth. It also suggests that days 14-15 may be the optimal and most sensitive timing for evoking this mechanism during embryonic development. The adverse effects of heat treatment observed in this study may have been due to the continued exposure to heat until day 17. Fine-tuning thermal conditioning to days 14-15 only may improve these production parameters. (C) 2003 Elsevier Ltd. All rights reserved.

Transtorno bipolar do humor e gênero

Although the bipolar disorder (BD) occurs almost with the same frequency in both genders, the phenomenology and the outcome of the illness differ between them. Nevertheless, there is evidence that women with BD show, more than men, delayed beginning, especially in their fifth decade, more rapid cycling outcome, more depressive episodes, more dysphoric mania, more mixed states and more BD type II. Even so, the findings are not always consistent. Although the risk of comorbidities in BD includes, for both the sorts, excessive alcoholic consumption and drugs, bipolar men would have greater probability of being alcohol dependent, of not seeking treatment and of committing suicide. Suggested hypotheses to explain such differences vary from those centered in cultural or psychological aspects to those that focus on the steroids hormones, and other hormones such as cortisol, thyroid hormones and even on the cerebral anatomy. The reproductive cycle (menstrual cycle, pregnancy and menopause) influences on the BD phenomenology and its relevance to the therapeutical options in the treatment of the BD in women are presented in the last part of this review. Further investigations must to be done in order to clarify this controversy. However, up to now the data indicate that estrogen therapy is not to be primarily indicated to prevent depression, Alzheimer disease or cognition impairment.

Homeostase do cálcio e marcadores do metabolismo ósseo no hipertireoidismo felino - Revisão

Hyperthyroidism is the most frequent endocrine disease in old-aged cats. It is a illness provoked by the excess of circulating thyroid hormones. Hyperthyroidism causes alteration in bone metabolism with predominance of activity resorption. The evaluation of bone metabolism can be made by measuring serum and urinary markers of bone metabolism or bone mineral densitometry. Osteoblasts are responsible cells for bone formation while the osteoclasts are for resorption. In physiological situation osteoblastic and osteoclastic activities are in balance. Markers of bone formation express the osteoblastic activity and markers of the osseous resorption the osteoclástica activity. Markers of bone turnover are important in the diagnosis and prognostic of muscle-skeletal disease, as well as in the accompaniment of therapy. It is fundamental do carry on studies on the influence of feline hyperthyroidism on markers of bone formation and resorption in bone turnover to comprise pathophysiologic mechanism of bone alterations.

Mensuração do tamanho cardíaco em radiografias de gatos com hipertireoidismo experimental

Feline hyperthyroidism (thyrotoxicosis) is now recognised as the most common endocrine disease of the domestic cat. Feline hyperthyroidism cause multisystemic disorder associated with incresead circulating concentrations of the thyroid hormones, tri-iodothyronine (T3) and thyroxine (T4). Cardiovascular abnormalities in cats with spontaneous hyperthyroid have been described. Objective to determine heart size of progressing experimental thyrotoxicosis of 19 cats, using a vertebral scale system (VHS). The lateral, dorsoventral e ventrodorsal radiographs thoracic were measured using a vertebral scale system. Lateral radiographs thoracic to efficient develop that DV and VD. The VHS method is easy to use, allows objective assesment of heart size in cats hyperthyroid, and may be helpful to identify cardiomegaly and heart size progressing.

Polineuropatia associada a hipotireoidismo em cães: Relato de seis casos

Six Doberman Pinscher, between six and eight years of age, were presented to the Veterinary Hospital from Faculty of Veterinary Science of The University of Buenos Aires. Neurological examination revealed tetraparesis with inability to walk, decreased muscle tonus and myotatic reflexes in all dogs. Serum cholesterol levels, creatine kinase and alkaline phosphatase activities were mildly to markedly elevated, and tibial motor nerve conduction velocities were slow in all dogs. Basal measurements of free T4 and TSH were determined by radioimmunoassay. Although fT4 values were within normal range, in all dogs TSH values were elevated. Based on this results, hypothyroidism was diagnosed and a supplementation therapy was established with oral levothyroxine (T4). Two weeks after treatment has been started, all patients had an improvement in clinical signs, and within a month gait became normal, as well as muscular tonus and spinal reflexes.

Chronic alcohol intake upregulates hepatic expression of carotenoid cleavage enzymes and PPAR in rats

Excessive and chronic alcohol intake leads to a lower hepatic vitamin A status by interfering with vitamin A metabolism. Dietary provitamin A carotenoids can be converted into vitamin A mainly by carotenoid 15,15′-monooxygenase 1 (CMO1) and, to a lesser degree, carotenoid 9′10′-monooxygenase 2 (CMO2). CMO1 has been shown to be regulated by several transcription factors, such as the PPAR, retinoid X receptor, and thyroid receptor (TR). The regulation of CMO2 has yet to be identified. The impact of chronic alcohol intake on hepatic expressions of CMO1 and CMO2 and their related transcription factors are unknown. In this study, Fischer 344 rats were pair-fed either a liquid ethanol Lieber-DeCarli diet (n = 10) or a control diet (n = 10) for 11 wk. Hepatic retinoid concentration and expressions of CMO1, CMO2, PPARγ, PPARα, and TRβ as well as plasma thyroid hormones levels were analyzed. We observed that administering alcohol decreased hepatic retinoid levels but increased mRNA concentrations of CMO1, CMO2, PPARγ, PPARα, and TRβ and upregulated protein levels of CMO2, PPARγ, and PPARα. There was a positive correlation of PPARγ with CMO1(r = 0.89; P<0.0001) and both PPARγ and PPARα with CMO2 (r = 0.72, P< 0.001 and r = 0.62, P< 0.01, respectively). Plasma thyroid hormone concentrations did not differ between the control rats and alcohol-fed rats. This study suggests that chronic alcohol intake significantly upregulates hepatic expression of CMO1 and, to a much lesser extent, CMO2. This process may be due to alcohol-induced PPARγ expression and lower vitamin A status in the liver. © 2010 American Society for Nutrition.

Efeito do genótipo paterno e sistemas de pastejo no desenvolvimento fetal e nas características ao nascimento de bovinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tirotoxicose experimental em gatos: estudo ultra-sonográfico das alterações hepáticas e suas correlações com os níveis séricos das enzimas hepáticas, dos hormônios tiroideos e achados histológicos e citológicos

Pós-graduação em Medicina Veterinária - FMVZ

Influência do hormônio tireoidiano e da restrição alimentar sobre dano de DNA em animais obesos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)