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Biomedical subjects

C Vilser

Publications and source records attributed to C Vilser.

7 recordsLinked to original sources

[Assessment of skeletal age using a new ultrasound method].

PURPOSE: Determination of skeletal development in children is important. The most used evaluation method is to study left hand X-ray based on the standards depicted by Greulich and Pyle. The aim of our study was to compare the accuracy of a new sonographically based method with the standard method. MATERIAL AND METHODS: 160 consecutive evaluated children and adolescents (77 male, 83 female) who received a X-ray of the left hand were evaluated. Ultrasound examination of the same hand was performed on the same day using the BonAge system (Sunlight Medical Ltd., Israel). This system evaluates the relationship between the velocity of the wave (speed of sound) passing thorough the distal radial and ulna epiphysis and growth, using gender- and ethnicity-based algorithms. Three experienced investigators (U1-U3) analysed the X-ray and assigned bone age scores based on the Greulich and Pyle atlas (G and P). The investigators were blinded to the calendary age (CA) of the patient and also for the BonAge result. Correlation between BonAge system results and G and P was performed using SPSS 12.0.1. RESULTS: In 152 patients BonAge measurement could be performed successfully. The correlation between the three investigators using the G and P method was between 0.977 and 0.980; correlation between the BonAge system and the investigators (U1-U3) was 0.902 and 0.920. The paired t-test showed no significant differences between the BonAge system and the three investigators and also for the comparison between U1 and U2. There were significant differences between U1 vs. U3 and U2 vs. U3 (p < 0.05). DISCUSSION: The BonAge device demonstrates the ability to produce an sufficient assessment of bone age using an ultrasound method. The results are correlated with conventional skeletal age evaluation using the G and P method. Advantages of the ultrasound device are objectivity, lack of ionizing radiation, and easy accessibility. In the case of first investigation X-ray is necessary to look for dissociated skeletal age, dysplasia, and mineralisation.

Adolescent↗

Insulin-like growth factor I correlations to changes of the hormonal status in puberty and age.

IGF-I is considered to be one of the most important growth factors during puberty. Information concerning its correlation to thyroid hormones (T3, T4), adrenal and sex steroids is limited to puberty and the elderly. The presented study included 455 subjects (among them 259 children) ranging in age from newborn to 100 years. Serum IGF-I concentrations increase from childhood to the end of puberty (2 years earlier in girls). There are close positive correlations between IGF-I concentrations and age, height and weight and between IGF-I and estradiol or testosterone concentration in girls and boys respectively, and the DHEA-S level in boys during puberty. Correlations also exist with T3, aldosterone and 17 OH-progesterone in boys and girls in the pubertal stages I-V and with T4 in stages I-IV. Compared to 20-30 year-old subjects IGF-I concentrations amounted to 59% after 60 years, 43% in men and 54% in women after 70 years and 29% after 90 years. It is suggested that increasing adrenal DHEA-S concentrations stimulate IGF-I synthesis and by means of gonadal steroidogenesis, increase the pubertal GH secretion and the further pubertal IGF-I increase. The low IGF-I concentrations in patients > 60 years reflect the more catabolic metabolism of the elderly.

Adolescent↗

Stimulation of nitrogen and whole-body protein metabolism in growth hormone-deficient children by recombinant human growth hormone: relationship to growth.

The effect of a mammalian-cell-derived recombinant human growth hormone (rhGH) on nitrogen and whole-body protein metabolism was assessed in 12 children with complete growth hormone (GH) deficiency. All the patients received single oral doses of 15N-glycine (95 atom % 15N), 20 mg/kg body weight, prior to and following 7 days of treatment with rhGH, 1.7 IU/m2 body surface area (BSA) per day, administered subcutaneously. Prior to rhGH, mean urinary 15N-nitrogen excretion was 42.8 +/- 8% of the administered dose, which fell significantly to 22.8 +/- 7% during rhGH administration (p < 0.0001). Stimulation of protein metabolism by rhGH resulted in a protein net gain rate of 1.1 +/- 0.4 g/kg/day, which was significantly higher than the 0.6 +/- 0.5 g/kg/day rate seen prior to rhGH (p < 0.001). In patients subsequently placed on daily subcutaneous injections of rhGH 1.7 IU/m2 BSA, mean height velocity standard deviation score (HV SDS) for chronological age significantly increased from -3.8 +/- 2.6 to +8.5 +/- 3.1 and +3.3 +/- 2.2, during the 1st and 2nd years of treatment, respectively. However, there was no correlation between the long-term response to rhGH treatment and the short-term changes in nitrogen or protein metabolism in GH-deficient children.

Adolescent↗

Thyroid hormone metabolism under extreme body exercises.

In two runs over a distance of 75 km and 45 km as well as in a marathon (42.2 km), the thyroid hormones (T4, T3 and TSH in all runs and rT3 in two of them) were determined before and after the runs. The performance of the runners was analyzed, with their age considered in the analysis. We found that the changes of thyroid hormones are characterized by individual differences. Younger runners and those with better performances had significantly higher T4 serum concentrations and unaltered T3 and TSH concentrations, whereas older sportsmen and those with worse performances reacted to the stressful stimulus with a significant decrease of T4, T3 and TSH. This response was interpreted as an exhaustion reaction, i.e. reduced adaptation responses of thyroid hormone metabolism. Therefore, these investigations provide an assessment of the state of fitness, the optimization of training and the avoidance of damage caused by overly stressful physical exercise

Adult↗