ABSTRACT
Abstract: Sex hormones play a major role during pubertal growth. Estradiol (E2) and testosterone (T) levels progressively increase during puberty and in the presence of growth hormone (GH), growth velocity increases. Understanding the interactions between sex hormones and GH, may optimize the treatment of pubertal children with growth disorders. The aim of our study was to investigate possible molecular mechanisms which might potentiate longitudinal growth during puberty due to E 2or T combined with GH. We evaluated the GH/JAK2/STAT5 signaling pathway in the human hepatoma cell line HEPG2. Our results suggest that sex hormones potentiate the GH signaling pathway in a dose dependent fashion. Relatively low concentrations of E 2associated with GH induce a substantial activation of the GH pathway, whereas relatively high concentrations of T associated with GH produce a similar effect. These findings are concordant with the physiology of the pubertal growth spurt, which is an early event in girls (when E 2 circulating levels are low), and a late event in boys (when T circulating levels are high).
Resumen: Las hormonas sexuales, modulan el crecimiento durante la pubertad. Los niveles de estradiol (E2) y testosterona (T) aumentan progresivamente durante la pubertad y en combinación con la hormona de crecimiento (GH), producen un incremento en la velocidad de crecimiento en este período conocido como el "estirón puberal". El estudio de la interacción entre las hormonas sexuales y la GH, es de gran importancia para optimizar el tratamiento de niños(as) con alteraciones del crecimiento durante la pubertad. El objetivo de nuestro estudio fue investigar los posibles mecanismos que podrían potenciar el crecimiento longitudinal durante la pubertad, en especial las interacciones entre E 2o T en combinación con GH. Se evaluó la activación de la vía de señalización GH/JAK2/STAT5 frente al estímulo combinado con estas hormonas en cultivos celulares de hepatoma humana HEPG2. Nuestros resultados sugieren que existe un efecto potenciador de las hormonas sexuales sobre la vía de señalización de GH. Observamos que concentraciones relativamente bajas de E2 junto con GH producen una clara activación de la vía de señalización para GH, mientras que concentraciones relativamente altas de T junto con GH producen una activación similar. Estos hallazgos son concordantes con la fisiología del estirón puberal, que es más precoz en niñas (cuando los niveles circulantes de E2 son bajos), y más tardíos en varones (cuando los niveles circulantes de T son altos).
Subject(s)
Humans , Testosterone/physiology , Growth Hormone/physiology , Estradiol/physiology , STAT5 Transcription Factor/physiology , Janus Kinase 2/physiology , PubertyABSTRACT
Polycystic ovarian syndrome (PCOS) is a lifelong disorder characterized by hyperandrogenism and ovulatory dysfunction, with a wide spectrum of clinical symptoms and signs. Three different sets of diagnostic criteria have been established in order to define this disease in adult women, but there is controversy regarding the use of these criteria in adolescence. During puberty, the adult criteria for ovulatory dysfunction does not seem applicable, because an irregular menstrual pattern and a decreased ovulatory rate is a physiologic event during this period of life. Also, a higher prevalence of polycystic ovarian morphology (PCOM) may be observed during this period, so PCOM is not a useful criterion to define PCOS in young women. These findings suggest that a key factor to diagnose to PCOS during adolescence is hyperandrogenism. In addition, since PCOM is not clearly associated with hyperandrogenism during this period of life, the term "polycystic ovarian syndrome" during adolescence creates confusion and may be misleading.
A síndrome dos ovários policísticos (SOP) é uma desordem que afeta pacientes por toda a vida e é caracterizada por hiperandrogenismo e disfunção ovariana, com um amplo leque de sintomas e sinais clínicos. Três diferentes conjuntos de critérios diagnósticos foram estabelecidos para definir essa doença em mulheres adultas, mas existem controvérsias relacionadas ao uso desses critérios na adolescência. Durante a puberdade, o critério de disfunção ovariana usado em adultos não parece aplicável, porque um padrão menstrual irregular e uma menor taxa de ovulação são eventos fisiológicos nesse período da vida. Além disso, uma maior prevalência de morfologia ovariana policística (MOP) pode ser observada nesse período, de forma que a MOP não é um critério útil para se definir a SOP em mulheres jovens. Esses achados sugerem que o hiperandrogenismo é um fator-chave para o diagnóstico da SOP na adolescência. Além disso, como a MOP não está claramente associada com o hiperandrogenismo durante esse período da vida, o termo "síndrome dos ovários policísticos" durante a adolescência cria confusão e pode ser errôneo.
Subject(s)
Adolescent , Female , Humans , Diagnostic Techniques, Obstetrical and Gynecological/standards , Hyperandrogenism/diagnosis , Polycystic Ovary Syndrome/diagnosis , Age Factors , Risk Factors , Terminology as TopicSubject(s)
Humans , Adolescent , Female , Diabetes Mellitus, Type 1 , Puberty , Gonadotropin-Releasing Hormone , Hyperandrogenism , Menarche , Menstruation DisturbancesABSTRACT
Background: Congenital hypopituitarism is an uncommon cause of hypophyseal insufficiency It is less common than growth hormone deficiency which has an incidence of 1:4.000 to 1:8.000 Uve newborns. Early diagnosis ofthis condition is important to prevent impairment of cognitive function, poor growth and alterations in metabolic profile in these patients. Aim: To report 23 patients diagnosed with congenital hypopituitarism. Material and methods: Retrospective review of clinical records of 23 patients (12 males) with congenital hypopituitarism, diagnosed during a 21 years period. In a group of 16 patients a molecular study was performed searching for mutations in HESX1, PROP-1 or POUF-1. Results: Short stature was the most frequent sign at the first evaluation, followed by neonatal hypoglycemia and presence of nistagmus, strabismus, atrophic optic nerve or malformations in the middle Une showed in CNS imaging, suggesting septo-optic-dysplasia. All male patients diagnosed during neonatal period, exhibited micropenis. CNS images showed isolated hypophyseal hypoplasia or associated to an ectopic neurohypophysis in most patients. No patient in the subgroup subjected to molecular analysis had any of the mutations in the searched genes. Conclusions: The diagnosis of hypopituitarism must be based on clinical grounds, speciaUy when hypoglycemia, prolonged jaundice, micropenis or midline alterations are found in the neonatal period.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Hypopituitarism/congenital , Hypopituitarism/genetics , Follow-Up Studies , Homeodomain Proteins/genetics , Hypopituitarism/diagnosis , Mutation , Retrospective Studies , Transcription Factor Pit-1/genetics , Transcription Factors/geneticsABSTRACT
Background: A decline in the age of menarche was observed from early 1900s to the 1970s. However, it is not known if a further decline ocurred thereafter. Aim: To evaluate the age of menarche in girls from Santiago, Chile and its relationship with body mass index (BMI) and socioeconomic status. Material and Methods: We studied 1302 healthy girls aged 7 to 19 years. Age of menarche was evaluated through a questionnaire to the patient and her parents. Kaplan-Meier curves were used to determine age of menarche and Cox regression analysis was employed to evaluate the effect of the type of school and BMI on the age of menarche. Results: The mean age at menarche was 12.7±0.04 years. Girls from public and private schools had their period at 12.5±0.1 and 13.05±0.05 years respectively. A negative correlation between z scores for BMIand age of menarche was observed (r-0.3: p =0.001). Girls whose menarche occurred before 11.5 years had higher z scores for BMI and a larger proportion were overweight, compared to girls who had menarche later. Cox regression analysis showed that after adjusment for BMI, age of menarche was similar in both types of schools. Conclusions: Age of menarche is ocurring three months earlier in girls from public schools, which is associated with higher z scores for BMI. Type of school, a marker of socio-economic status in Chile, affects timing of menarche due to differences in body mass index.
Subject(s)
Adolescent , Child , Female , Humans , Body Mass Index , Menarche/physiology , Obesity/physiopathology , Social Class , Kaplan-Meier Estimate , Age of Onset , Chile , Proportional Hazards Models , Surveys and QuestionnairesABSTRACT
La deficiencia de hormona de crecimiento (GH) provoca un severo retraso de crecimiento y una diversidad de efectos multisistémicos. El individuo con deficiencia de GH no tratado obtiene una talla final de alrededor de 4 SD bajo la media, y si es tratada en forma tardía o utilizando dosis de GH insuficientes, su talla final es alrededor de -2 SD bajo la media. El estirón puberal de los niños con deficiencia de GH no tratados es alrededor de la mitad de lo observado en adolescentes normales. En estudios más recientes se ha documentado que si la deficiencia de GH es tratada con dosis adecuadas administradas en forma diaria se obtienen tallas finales de alrededor de -1,0 SD y a veces se puede alcanzar la talla esperada de acuerdo a los antecedentes genéticos de los pacientes. Por lo tanto, el tratamiento con GH de niños deficientes tiende a corregir el déficit de talla de dichos pacientes, pero no existe mucha información sobre las repercusiones psicosociales de dicho tratamiento. En este artículo, revisaremos someramente los efectos multisistémicos de la deficiencia de GH para luego profundizar en el impacto psicosocial de la deficiencia de GH y en su respuesta al tratamiento con dicha hormona
Subject(s)
Humans , Child Development , Failure to Thrive/psychology , Growth Hormone/deficiency , Failure to Thrive/drug therapy , Failure to Thrive/etiology , Family Relations , Quality of Life , Self Concept , Sickness Impact Profile , Social AdjustmentABSTRACT
El tema de esta conversación es hipotiroidismo en la infancia. Nuestro entrevistado es el doctor Fernando Cassorla, brillante ex alumno del Curso de Pediatría en la Universidad de Chile; ex residentte en el Albany Medical College de los Estados Unidos de Norteamérica durante dos años y luego especializado en Endocrinología Infantil otros 3 años, en la Universidad de Pennsylvania. Actualmente se desempeña como Investigador Senior en el National Institute of Child Health, and Human Development Bethesda, Maryland, USA. Antes de iniciar esta conversación, deseamos sintetizar las razones que tenemos para elegir este tema, señalando que en nuestra experiencia pediátrica han influido tres factores que consideramos de extraordinaria importancia para preocuparnos del problema. El primero de estos factores, es que la mayoría de los enfermos que nos ha correspondido observar en los hospitales de niños con este trastorno hipotiroidismo , han concurrido cuando la sintomatología y signología estaba muy avanzada, con grave retardo mental, difícil de reparar. El segundo factor, es el conocimiento que en la actualidad se tiene acerca de la incidencia relativamente elevada (1 en 3.000 a 1 en 4.000 nacimientos) de hipotiroidismo congénito, lo que obviamente es digno de tenerse presente. El tercer factor lo constituye la posibilidad que se pueda hacer un diagnóstico precoz, basado en el reconocimiento de manifestaciones clínicas en el período del recién nacido y consecuentemente, la instalación de un tratamiento oportuno, que evite el deterioro mental que acompaña a estos cuadros