[Prevalence of endemic goiter among school children of central and southern Chile]. / Prevalencia de bocio endémico en escolares del centro y sur de Chile.

The prevalence of endemic goiter was evaluated during 1986 in 1,015 school age children from basic public schools of Santiago and Temuco, Chile. The prevalence of goiter, defined by WHO's standards was 7.6% as a whole, without differences related to children's geographical origin. A greater prevalence of goiter, in females than in males, which increased with age, was detected. Prevalence of endemic goiter decreased from year 1982 to year 1986 from 18.8% to 7.4% in similar samples of school children from Santiago. This change may be due to preventive iodination of table salt.

[Etiology of growth retardation in children of adolescent mothers]. / Etiología del retraso estatural en hijos de adolescentes.

The influence of some nutritional and hormonal factors in the growth failure detected in children of teenage mothers belonging to medium-low socioeconomic level (SEL) was studied. They were compared with children of mothers older than twenty years of the name SEL. Only growth retarded children of teenage mothers had significant delay in bone age, compared with chronological age (14.8 +/- 4.1 vs 18.2 +/- 2.2 months respectively). Children with growth failure had significantly lower plasma Zn (85.7 +/- 13.3 vs 94.6 +/- 17.9 micrograms/dl), Cu (106.2 +/- 32.5 vs 122.0 +/- 13.8 micrograms/dl) and hemoglobin (Hb) (11.7 +/- 2.1 vs 12.8 +/- 2.1 micrograms/dl) levels. No differences in plasmatic levels of thyrotropin, thyroid hormones and response of growth hormone to L-Dopa stimulation were detected in comparison with those of children with normal stature. We concluded that etiological factors of growth failure were similar in children of teenage and adult mothers according to the parameters analyzed. The increased prevalence of growth failure in children of teenage mothers may be due to a greater impact of the analyzed factors.

Histological maturation of astroglial cells in the archicortex of young hypothyroid rats.

The maturation of fibrous astrocytes was studied in the archicortex (hippocampus) of rats rendered hypothyroid by perinatal administration of propylthiouracil (PTU). A decrease in the number of protoplasmic processes and end-feet in fibrous astrocytes from the cortical molecular layer was observed. The diameter of the perikaryon and length of the prolongations were also decreased. In animals rehabilitated after weaning, the diameter of the perikaryon and length of protoplasmic processes returned to normal while that of number of prolongations per astroglial cell remained unchanged. It is postulated that hypothyroidism induced immediately after birth impairs differentiation of astroglia in the archicortex of the rat brain, probably as a response secondary to altered neuronal and capillary development.

[Effects of iodine deficiency during intrauterine and early postnatal life on DNA synthesis in liver and brain of rats]. / Effectos del déficit de yodo durante la vida intrauterina y postnatal precoz en la síntesis de ADN en hígado y encéfalo de ratas.

Iodine deficiency during intrauterine and early postnatal life of the rat produces a transient decrease in the DNA content of brain and cerebellum, which is spontaneously recovered without replacement therapy. Results of the study revealed that DNA synthesis measured through thymidine-H3 incorporation to DNA, was increased at 21 days of life in liver, brain and cerebellum, indicative of a higher activity of DNA synthesis. This prolongation of the critical period of brain cell multiplication in iodine deficient rats, suggests, therefore, an alteration of brain maturation.

Efectos del deficit de yodo durante la vida intrauterina y postnatal precoz en la sintesis de ADN en higado y encefalo de ratas. / Effects of iodine deficiency during intrauterine and early postnatal life on DNA synthesis in liver and brain of rats

El deficit de yodo durante la vida pre y postnatal temprana de la rata, produce un descenso transitorio en el contenido de ADN en cerebro y cerebelo. Este se recupera espontaneamente, sin que medie una terapia de reemplazo, debido a una prolongacion del periodo critico de multiplicacion celular. Los resultados del estudio revelaron un aumento transitorio de la captacion de timidina radiactiva al 21o dia en el higado, cerebro y cerebelo, indicativo de una mayor actividad de sintesis y desplazamiento del periodo critico. Estos hallazgos sugieren, por lo tanto, un dano del sistema nervioso por deficit precoz de yodo durante el embarazo

[Sex hormones binding globulin in lying-in women and their newborn infants with intrauterine malnutrition]. / Globulina ligante de hormonas sexuales en puérperas y sus recién con desnutrición intrauterina.

The purpose of this research was to study the binding capacity of estrogens to the sex hormone-binding globulin (SHBG) in mothers and their intrauterine malnourished newborns. Blood samples were obtained from mothers at delivery, and from babies, of the umbilical cord. SHBG was measured according to the method of Mickelson and Petra. It was found in mothers of malnourished babies that the binding capacity of serum protein to dehydrotestosterone (DHT) was significantly decreased in comparison to the controls (10.63 +/- 1.61 vs 13.25 +/- 2.18 micrograms DHT/dl serum, respectively), whereas it was significantly increased in intrauterine malnourished newborns (1.01 +/- 0.24 vs 0.77 +/- 0.18, respectively). These results suggest that SHBG decrease in mothers of intrauterine malnourished newborns occurs due to a decrease in the production of fetal adrenal hormone precursors and may, therefore, be a compensating mechanism to increase placental flow.

Globulina ligante de hormonas sexuales en puerperas y sus recien nacidos con desnutricion intrauterina. / Sex hormone binding globulin in lying-in women and their newborn infants with intrauterine malnutrition

Se estudio la capacidad de union de los estrogenos a la globulina ligante serica en puerperas y sus recien nacidos que presentaban desnutricion intrauterina. Las muestras de sangre se obtuvieron de vena periferica dentro de las tres primeras horas post-parto en las madres, y del cordon umbilical en los recien nacidos. La globulina ligante se midio de acuerdo a la tecnica de Mickelson y Petra. Se encontro que las madres de recien nacidos desnutridos tenian disminuida la capacidad de union de la dehidrotestosterona (DHT) a la globulina serica, en comparicion a las madres de recien nacidos adecuados para su edad gestacional (10.63 +/- 1.61 vs 19.25 +/- 2.18 ug DHT/dl suero, respectivamente) mientras que los recien nacidos desnutridos la tenian aumentada en contraste con los recien nacidos adecuados para su edad gestacional (1.01 +/- 0.24 vs 0.77 +/- 0.18, respectivamente). Estos resultados sugieren que por descenso en la produccion de los precursores adrenales fetales de estrogenos, las madres de recien nacidos desnutridos in utero tienen disminuida la globulina ligante de hormonas sexuales, lo que podria ser un mecanismo compensatorio para aumentar el flujo placentario

Histological maturation of astroglial cells in the archicortex of early malnourished rats.

The maturation of fibrous astrocytes was studied in the archicortex (hippocampus) of rats subjected to early postnatal malnutrition. A decrease in the number of protoplasmic processes and end-feet in fibrous astrocytes from the cortical molecular layer was observed. In animals refed after weaning the number of protoplasmic processes returned to normal while that of end-feet remained unchanged. The diameter of the perikaryon was reduced. It is postulated that early malnutrition, induced immediately after birth, impairs differentiation of astroglia in the archicortex of the rat brain, probably as a response secondary to altered neuronal and capillary development.