[Prevalence of endemic goiter among school children of central and southern 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.

[Etiology of growth retardation in children of adolescent mothers].

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.

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.

[Effects of iodine deficiency during intrauterine and early postnatal life on DNA synthesis in liver and brain of rats].

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.

[Sex hormones binding globulin in lying-in women and their newborn infants with intrauterine malnutrition].

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.

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.