ABSTRACT
Foram estudados os efeitos do excesso da tiroxina materna associado ao hipertireoidismo pós-natal sobre o crescimento ósseo e o perfil proliferativo e angiogênico das cartilagens. Dezesseis ratas Wistar adultas foram distribuídas nos grupos tratados com L-tiroxina e controle. A prole do grupo tratado recebeu L-tiroxina do desmame até 40 dias de idade. Ao desmame, foi realizada dosagem plasmática de T4 livre nas mães. Na prole, foram realizados: dosagem plasmática de T3 total e T4 livre, morfometria das tireoides, mensuração do comprimento e largura do fêmur. Nas cartilagens, foi avaliada a expressão imuno-histoquímica e gênica de CDC-47, VEGF, Flk-1, Ang1, Ang2 e Tie2. As médias entre grupos foram comparadas pelo teste T de Student. As concentrações de T4 livre das mães tratadas e de T3 total e T4 livre da prole foram significativamente mais elevadas. A largura do fêmur foi menor nos animais tratados. Houve também redução da imunoexpressão de CDC-47 e de VEGF e dos transcritos gênicos para VEGF e Ang1 nas cartilagens. Conclui-se que o excesso de tiroxina materna associado ao hipertireoidismo pós-natal reduz a largura da diáfise femoral, a proliferação celular e a expressão de VEGF e de Ang1 nas cartilagens de crescimento de ratos.(AU)
The effects of excess of maternal thyroxine associated with postnatal hyperthyroidism at bone growth and proliferative and angiogenic profile of cartilage were studied. Sixteen adult Wistar rats were divided into treated and control groups. The offspring of the treated group received L-thyroxine from weaning to 40 days-old. At weaning, plasma assay of free T4 was measurement on female rats. In the offspring, the following assessments were performed: measurement of total T3 and free T4, histomorphometry analysis of the thyroid, measurement of body weight and length and width of the femur. In femoral growth cartilage, immunostaining of CDC-47, gene or protein expression of VEGF, Flk-1, Ang1, Ang2 and Tie2 were evaluated. Data were analyzed using Student's t-test. Free T4 was significantly higher in treated rats and total T3 and free T4 were significantly higher in offspring. The width of the femur was significantly lower in treated animals. There was lower immunoreactivity of CDC-47, VEGF and lower expression of gene transcripts for VEGF and Ang1. We concluded that the excess maternal thyroxine associated with postnatal hyperthyroidism reduces the width of the femoral shaft, the cell proliferation and gene and protein expression of VEGF and gene expression of Ang1 on the growth cartilage in rats.(AU)
Subject(s)
Animals , Rats , Bone Development , Growth Plate/abnormalities , Hyperthyroidism/congenital , Neovascularization, Physiologic , Thyroxine/adverse effectsABSTRACT
Introducción: El hipertiroidismo es una patología tiroidea poco frecuente en neonatos, relacionada con el antecedente materno de enfermedad de Graves, y por lo tanto con el paso transplacentario de inmunoglobulinas estimulantes del receptor de TSH. Presentación de casos: Reportamos dos casos de sexo femenino, que se presentaron en el Hospital Universitario de Santander. El primero de los casos se manifestó en la primera semana; el segundo caso se presentó tardíamente después del primer mes de vida. Los síntomas que presentaron en común fueron taquicardia persistente e hiperactividad. En uno de los casos la presentación clínica fue confundida con una infección bacteriana, debido a la presencia de fiebre. Se confirma el diagnóstico con los niveles de TSH muy suprimidos y T4 libre elevada, al menos al doble del límite superior. Los dos casos observaron medicamentos antitiroideos y propanolol con buena evolución clínica y de laboratorios; no se observamos complicaciones a corto o largo plazo como arritmias o craneosinostosis. Discusión: El hipertiroidismo congénito es una patología poco frecuente y siempre debe ser sospechado en recién nacidos de madres con antecedente de enfermedad de Graves, sus manifestaciones pueden presentarse prenatalmente o postnatalmente, y su diagnóstico y tratamiento deben ser oportunos para evitar secuelas a largo plazo o incluso la muerte.
Introduction: Hyperthyroidism is a thyroidal pathology infrequent in neonates related with maternal history of Graves' disease, and therefore with the transplacental passage of stimulating TSH receptor immunoglobulins. Case report: We report two female gender cases at Hospital Universitario Santander, one of the two cases became manifest during the first week of life, and the other took longer time after the first month of life, as it can happen. Symptoms in common were persistent tachycardia and hyperactivity; one of the cases was mistaken for bacterial infection arising from fever. Diagnose was confirmed of highly suppressed TSH levels and high Free T4, at least twice the limit level. Both cases were treated for some time with antithyroid drugs and ß-blockers, showing good clinical and lab evolution; no complications like arrhythmias or craneosynostosis were observed. Discussion: Congenital hyperthyroidism is a rare condition and should always be suspected in infants of mothers with Graves' disease, its manifestations may occur prenatally or postnatally, and their diagnosis and treatment should be timely to avoid long-term sequelae or death.
ABSTRACT
Monogenic disorder is a single gene disorder resulted of a single mutated gene. Monogenic disorder has benefits in early diagnosis and precious prediction of disease course. Furthermore, monogenic disorder could provide an informative knowledge to the understanding of related pathophysiology. Thyroid monogenic disorder could occur in various steps, such as thyroid development, hormonogenesis, TSH-receptor signaling, thyroid hormone transport and end organ response. Here, we reviewed of congenital hypothyroidism, congenital hyperthyroidism and thyroid hormone resistance syndrome.
Subject(s)
Congenital Hypothyroidism , Early Diagnosis , Hyperthyroidism , Thyroid Gland , Thyroid Hormone Resistance SyndromeABSTRACT
Objetivo: Relatar a importância de suspeitar e reconhecer o quadro clínico do hipertireoidismo congênito, dado sua infrequência. Descrição: Os autores relatam um caso de hipertireoidismo congênito diagnosticado em recém-nascido de parto normal com 32 semanas, o qual permaneceu internado por prematuridade, baixo peso de nascimento (sem necessidade de suporte ventilatório), vômitos e dificuldade para ganhar peso. A criança se apresentava taquicárdica, com aspecto de desnutrido e exoftalmia. Foi diagnosticada doença de Graves materna com aproximadamente 29 semanas de gestação, sendo iniciado seu tratamento com propiltiouracil e cloridrato de propranolol. Comentários: Concluímos que a suspeita clínica e o diagnóstico pré-natal de doença de Graves materna evitam danos ao feto e possibilitam adequado tratamento e acompanhamento ainda durante a gestação. O tratamento com propiltiouracil ainda é o melhor para a gestante e para reduzir complicações.
Subject(s)
Humans , Male , Female , Pregnancy , Infant, Newborn , Prenatal Care , Graves Disease/diagnosis , Graves Disease/therapy , Hyperthyroidism/diagnosis , Hyperthyroidism/therapy , Child Health ServicesABSTRACT
Objective Gene linkage would be processed in order to make sure if an autosomal dominant congenital hyperthyroidism family has genetic linking relationship with the known hyperthyroidism disease genes,TSHR or THRB.Methods Microsatellite marked gene linkage was done with the use of three microsatellite markers,D14S74,D3S2338 and D3S1266,whose chromosomal locations were very close to TSHR or THRB gene,and the results were analyzed by Genemapper 3.5 Software.Results LOD scores of the three markers were all less than 1,revealing that there were no linking relationships between TSHR or THRB gene and this hyperthyroidism family,further reflecting this family might have a new disease gene other than TSHR and THRB.Conclusion There might be new disease genes responsible for autosomal dominant congenital hyperthyroidism.