Fisiologia endocrina del lactante. / Endocrine physiology in infancy

El lactante ofrece peculiariadades en su fisiologia hormonal que no son vistas a ninguna otra edad. Se efectua una revision de las acciones, produccion y regulacion de aquellas hormonas que muestran caracteristicas especiales en este periodo de la vida. Es en la etapa de recien nacido, cuando ocurren cambios dramaticos y rapidos en la velocidad de secrecion y nivel serico de varias hormonas, especialmente de las involucradas en el metabolismo energetico. La hormona de crecimiento, la triyodotironina y la tiroxina, en el recien nacido se encuentran en niveles mas altos que los observados en ninos mayores.El mantenimiento de niveles sericos adecuados de calcio en los primeros dias, de vida es muy importante. Sin embargo, normalmente se encuentra cierto grado de hipoparatiroidismo e hipercalcitoninemia, los cuales pueden ser de importancia en la etiologia de la hipocalcemia en el recien nacido, especialmente en el pequeno para edad gestacional y en el prematuro.Otras hormonas que no muestran caracteristicas especiales en esta edad, son revisadas ligeramente o no mencionadas

[Growth in children with diabetes insipidus]. / Crecimiento estatural en ninos con diabetes insípida.

Commercial preparations of vasopressin for the treatment of diabetes insipidus are not available in Mexico. Besides, the hormone is useless in the nephrogenic variety. In the department of Endocrinology at the Hospital Infantil de Mexico, a preparation containing hydrochlorothiazide, aminopyrine and potassium chloride, which reduces urinary volumes in about two thirds, is employed in all varieties of the disease. Growth in stature was investigated in 44 patients under treatment, attending the Endocrine Outpatient Clinic since 1967 for a period of 2 to 12 years. Clinical material included 29 males and 15 females. There were 23 idiopathic, 7 histiocytosis, 5 nephrogenic, 4 craniopharyngiomas, 2 psychogenic polydipsia, 2 traumatic and 1, as a sequel of tuberculous meningoencephalitis. Six idiopathic, 2 nephrogenic, 2 traumatic, 1 histiocytosis, and 1 psychogenic proceeded between percentiles 3 and 97, parallel to the nearest line of reference along the whole period of study. Two nephrogenic, 2 histiocytosis, 1 psychogenic, 1 post-meningoencephalitis and 14 idiopathic, grew below the third percentile, but parallel to it. One nephrogenic, 4 histiocytosis, 4 craniopharyngioma and 3 idiopathic progressively departed from the initial centile. Two of the latter had growth hormone deficiency, and 1 had been very irregularly treated. It is concluded that the therapy employed limits stature impairment but does not produce catch-up growth. Accordingly, it is proposed that the treatment of diabetes insipidus should be started as early as possible, and that if progress in stature is appreciably deteriorated, the presence of additional pathology should be suspected.

[Cervical cryptothyroidism. Report of 2 cases]. / Criptotiroidismo cervical Presentación de dos casos

Two cases of abnormality in the normal embrionary migration of the thyroid gland are reported with hyoid and sublingual location. Both cases where misdiagnosed and operated as thyroglossal cysts. The methods of treatment are reviewed and emphasis is placed on the convenience to make gammagraphic studies in patients with a mid-line cervical mass.

[Relationships between thyrotropin, growth hormone and insulin in hypothyroidism]. / Estudios sobre las relaciones entre tirotrofina y hormona de crecimiento e insulina en hipotiroidismo

Since growth hormone has been found to be inhibited in many cases of untreated primary hypothyroidism, we tried to investigate whether the high thyrotropin levels or the lack of thyroid hormones is the responsible factor. Six primary hypothyrotic patients were kept euthyroid by means of high and constant doses of thyroid extract. Growth hormone immunoassays were performed before and after three days of thyrotropin stimulation. Immunoassayable insulin was also investigated under the same experimental conditions. Although a moderate inhibition of growth hormone after thyrotopin stimulation was observed, the magnitude of this inhibition was not as marked as it has bee described in untreated primary hypothyrotics. There was no difference in insulin production before and after thyrotropin administration.

[Intravenous and oral glucose: production of insulin and growth hormone in the newborn infant]. / Glucosa oral y endovenosa: producción de insulina y de hormona de crecimiento en el recién nacido

Insulin production in response to intravenous and high and low oral glucose administration was investigated in 15 healthy fasting newborns. Results show that in spite of the fact that the highest blood glucose was obtained by the intravenous load, the highest insulin levels corresponded to the high oral glucose. The lowest blood glucose levels were found in the cases who received the low oral doses. The amounts of circulating insulin in this group were not significantly different from those in the group with I.V. glucose. In two of the groups where growth hormone was measured, the known paradoxixal increase in response to administered glucose was observed.