Objective: A sex difference in fetal and neonatal pituitary±gonadal function has been well documented. The aim of the following study was to determine sex differences and patterns of basal LH/FSH in the neonatal period. Design: Peripheral venous blood was obtained from 164 healthy full term newborns (91 males, 73 females) for clinically indicated laboratory examinations. Results: In male newborns, LH values were initially low (days 1±5), increased between days 6 and 10, and reached maximum levels between days 16 and 20. Levels of FSH were initially low (days 1±5), increased between days 6 and 10 and reached maximum levels between days 11 and 15. In female newborns, LH levels were generally lower than in newborn boys; levels were initially low, then increased between days 11 and 15 and reached maximum levels at the end of the newborn period. FSH values were generally higher than in newborn boys; there were initially low values with a ®rst peak between days 11 and 15 and a second peak between days 21 and 28. Conclusions: LH values in male newborns were higher and exceeded values in female newborns, whereas FSH values in female newborns exceeded male newborn values. Male newborns do not exhibit any peaks of LH and FSH activity, whereas female newborns exhibit two FSH peaks during this period.

In adults, selenium supplementation decreases thyroid peroxidase antibody (TPO Ab) concentrations in patients with autoimmune thyroiditis (AIT). Our aim in this study was to investigate if selenium supplementation decreased TPO Ab and thyroglobulin antibody (Tg Ab) concentrations in children with AIT. Forty-nine patients (33 females) with newly diagnosed AIT and hypothyroidism were randomized to daily oral therapy with levothyroxine alone (group A, n = 18), levothyroxine plus 100 µg sodium-selenite (group B, n = 13), or levothyroxine plus 200 µg sodium-selenite (group C, n = 18). Mean age at diagnosis was 12.2 ± 2.2 years. All 49 patients needed a mean levothyroxine dose of 1.6 ± 0.5 µg/kg body weight to lower TSH to the treatment goal of 1–2 µU/ml, with no significant difference between groups. At study entry and after 12 months, TPO Ab concentrations were comparable in all three groups. Tg Ab concentrations decreased significantly after 12 months in group A and group C (p = 0.03 and p = 0.01), but not in group B (p = 0.06). It is our conclusion that selenium supplementation with sodium-selenite does not decrease TPO Ab concentrations in children and adolescents, neither given in the reduced dose of 100 µg daily nor given in the “adult” supplementation dose of 200 µg daily.

No abstract

By means of 3 endurance exercises, the effect of a several-hour intensive somatic stress on the changes of the Sm-C/IGF-I concentration was tested during, immediately after and on the day following the exercise. Exp. 1: Marathon with 17 male sportsmen in 2 groups with different glucose supply. Exp. 2: 45-km crosscountry run with 41 males. Exp. 3: Three 20-km runs with 8 young females at intervals of 3 months. In the marathon, no significant changes of the Sm-C/IGF-I concentration were found between the start, half distance and final values. The exogenous glucose supply (continuous or discontinuous) had also no effect. The tendency of a slight decrease of the Sm-C/IGF-I concentration by 0.14 U/ml (p greater than 0.05) was observed between start and finish in the 45 km crosscountry run lasting one hour longer. In the three 20-km runs, reproducible, slightly increased levels were measured at the end, whereas a decrease to the initial value or even below was detected on the following day (p greater than 0.05). The insignificant alterations of the Sm-C/IGF-I concentration measured in the 3 variants of races show that neither the hormonal changes stimulating the Sm-C/IGF-I synthesis (e.g. increase of GH and prolactin) nor inhibiting factors (energy deficiency) clearly dominate during strenuous exercises. The binding of carrier protein prevents great variations of the Sm-C/IGF-I level even under the condition of 3- to 4-hour extreme endurance exercises.

To investigate biological rhythms of the thyroid gland circannual oscillations of thyroxine (T4), triiodothyronine (T3), and thyrotropin (TSH) were compared in serum samples of untreated young male Wistar-rats with the circannual changes of thyroid weights and with the relative proportion of colloid, epithelium, and interstitium of the thyroids. Animals were kept under standard environmental conditions, however, lighting conditions simulated the natural day-night changes. Thyroid weights, T4, T3, and TSH showed a statistically significant circannual rhythm with maxima in winter and spring and minima in summer and autumn. The same circannual patterns were observed in the proportion of epithelium and interstitium of the thyroids, while the colloid exhibited an inverse circannual pattern. These data were verified by biomathematical methods, like locally adjusted functional approximation, analysis of variance, and Spearman rank correlation. Our results represent an example for the concordance between functional and morphometrical changes in the course of circannual oscillations. Furthermore, these data confirm our earlier results describing higher T4-levels in the winter time (short-day) and lower serum titers in the summer time (long-day).