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In recent years, it became evident that the hypothalamo-pituitary-gonadal axis is functioning in boys already between the neonatal period and the onset of puberty. With sensitive techniques, testosterone and gonadotropines have been detected in the plasma and urine of prepubertal boys. It is now believed that, during this period of life, the axis is active, but that either the feedback mechanisms are adjusted to a different level, the hypothalamic centers being more sensitive to androgens and keeping the testicular androgen production low, or that the gonads are more refractory to the effect of gonadotropins.

The androgen levels in biological fluids from normal prepubertal boys are extremely low. It is therefore impossible to distinguish the basal values of children with defective steroid production from those of normal children. Recently, several investigators have, however, shown that stimulation of the testicular interstitial cells is possible, if human chorionic gonadotropin is administered for several

Abstract

The frequency of hypoglycemia in 165 children with primary adrenal insufficiency, 118 of whom had Congenital Adrenal Hyperplasia and 47 Addison's Disease, was 18 %. Half of the hypoglycemic episodes occurred in the neonatal period. Hypoglycemia was isolated in 13 children, revealing the disease in 4 newborns with Congenital Adrenal Hypoplasia and in a boy with 11 B Hydroxylase deficiency.

Basal plasma cortisol levels were significantly lower in those of subjects who experienced hypoglycemia ( 47.1 ± 28.6 ng/ml vs. 106.0 ± 86.6 ng/ml, p< 0.001). A significant correlation ( p < 0.001) was found between the plasma concentration of glucose and cortisol at time of hypoglycemia.

Yoshibayashi M, Kamiya T. Saito Y. Nakao K, Nishioka K, Temma S, Itoh H, Shirakami G, Matsuo H. Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth. Eur J Endocrinol 1995;133:207–9. ISSN 0804–4643

The aim of the present study is to establish the normal range and to determine the developmental changes of plasma brain natriuretic peptide (BNP) concentrations in children. We measured plasma BNP concentrations as well as atrial natriuretic peptide (ANP) concentrations in 58 healthy children from birth to adolescence and in the umbilical vein of 20 healthy neonates using highly sensitive immunoradiometric assays. The plasma BNP concentration was the highest at 0 days of age and descended through maturation to be almost constant and to be at the adult level at 3 months of age. The plasma BNP concentration at 0 days of age (56.7 ± 49.6 fmol/ml; mean±sd) was 25 to 30 times higher than the adult level and 21 times higher than that in the umbilical vein (2.7 ± 1.4fmol/ml), The plasma ANP concentration at 0 days of age was not significantly different from that in the umbilical vein. The ratio of BNP to ANP was also the highest at 0 days of age (1.39 ± 0.72) and decreased through maturation to be at the adult level at 3 months of age. Thus, the plasma BNP concentration in healthy subjects showed a marked, rapid and preferential increase immediately after birth, suggesting that BNP has a physiological role distinct from that of ANP in the perinatal circulatory changes from fetus to neonate.

Muneo Yoshibayashi, Department of Pediatrics, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565, Japan

Abstract.

¹²⁵I Computed Tomography (CT) allows for the selective determination of trabecular and compact bone mineral parameters in the radius. Using this technique the effects of high dose oestrogen treatment in 11 tall girls, and of high dose testosterone treatment in 5 tall boys were monitored. In both groups trabecular bone density (TBD) increased steadily during treatment at a rate of about 1% per month. Also in both groups the compact bone mineral increased steadily. These results are compared with those from a cross sectional study on 49 normal children and 36 normal adults, in whom TBD was found to be independent of age and sex, so that the increases in TBD in both treatment groups can be attributed directly to the influence of the sex hormones. Since the compact bone mineral is higher in adults than in children it cannot yet be decided whether the increases seen in the treated patients are related to the sex hormone treatment, or reflect only the normal development of the bone during adolescence.

The presentation made by Dr. Verbickij is important in several respects. First, it is an excellent piece of work on the immunology of pregnancy. Next, it shows how a model can be established in a non-human primate to facilitate research on clinical problems.

There has been a great amount of interest in the immunology of pregnancy in recent years. The stimulus to much of the early research was the development of methods to prevent rhesus haemolytic disease in human neonates. We are all familiar with the great progress being made in these studies following the introduction of the use of anti-Rh serum (Clarke 1968). There has been a significant reduction in the incidence of afflicted children, and this progress seems bound to continue as more experience is gained on the best ways of using the antiserum.

Yet there are still many cases of sensitised mothers carrying foetuses at risk of

Abstract. Total parathyroidectomy is required to cure neonatal primary hyperparathyroidism (NPH) as any parathyroid remnant quickly becomes hyperplastic, causing recurrent hypercalcaemia. We present a patient with NPH who had total removal of his eutopic parathyroid glands but continued to have parathyroid hormone secretion from presumed ectopic parathyroid tissue. Hypercalcaemia initially recurred but normal calcium homeostasis was established as the child grew older. We postulate that the underlying defect in NPH is decreased sensitivity to the serum ionic calcium feedback inhibition at the parathyroid receptor level and that this sensitivity can improve with age.

Abstract. In this paper we describe methods for the early aetiological diagnosis of congenital hypothyroidism, using beside the classical T₄, T₃ and TSH plasma concentrations, four additional parameters in plasma and urine. The first one is thyroglobulin (Tg). In normal children of more than one year of age and in adults, 5–35 ng/ml plasma is found, in neonates 2–3 weeks old, this level is 10–250 ng/ml. In patients with a stimulated thyroid gland, as in primary congenital hypothyroidism, plasma Tg levels increase. High Tg values are found in iodine deficiency and in organification defects. In the absence of the thyroid gland plasma Tg is undetectable. Low to normal levels are found in cases with hypoplasia of the gland. In patients with a disturbed synthesis of Tg, resulting in Tg deficiency of the gland, plasma Tg levels vary from undetectable to normal. The PBI-T₄ plasma difference, which is caused by circulating abnormal iodoproteins is the second parameter. The products of thyroidal breakdown processes of the abnormal iodoproteins are excreted in the urine and used as the third parameter. We found that the excretion of this low molecular weight iodinated material (LOMWIOM) was increased only in Tg-deficient patients.

If the neonate is found to be hypothyroid, thyroid hormone substitution must be given immediately. Blood and urine sampling can be done just before or even directly after starting the therapy. The measurements extended with the determination of the total iodine excretion (fourth parameter) can be carried out within 1 week. With these additional methods it appeared to be possible to distinguish between several types of congenital hypothyroidism in neonates found by screening.