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Biomedical subjects

J M Wit

Publications and source records attributed to J M Wit.

At least 181 records · Page 10Linked to original sources

The effect of human growth hormone therapy on skinfold thickness in growth hormone-deficient children.

Skinfold thickness (ST) was measured in 43 children with various forms of growth hormone (GH) deficiency during the first year of GH therapy. The average (and SEM) initial ST, expressed as standard deviation score (SDS) was 1.17 (0.25) for subscapular, 0.63 (0.18) for triceps, and 0.40 (0.21) for biceps ST. During therapy the average decrease is 1 SD. Children in the pubertal age group and those with partial GH deficiency showed smaller decreases. A larger decrease of triceps ST was associated with lower GH and insulin peaks, and lower age, bone age and initial weight-for-height. Some correlations between ST decrease and growth response in the first year were significant, but still too low to allow of reliable predictions. The same was true for other clinical parameters. These data indicate that a chronic lack of GH leads to unequal fat distribution, possibly due to different sensitivities to GH in the trunk and extremities. The variability of ST responses to GH therapy limits clinical applications.

Adolescent↗

Excessive growth in a child with craniopharyngioma and growth hormone deficiency.

In a 5-year-old boy presenting with clumsiness and excessive growth, a large craniopharyngioma was diagnosed. Biochemically, there was a deficiency of growth hormone, a hypothalamic hypothyroidism and hypocorticalism, a thyroxine binding globulin elevation, an abnormal gonadotropin secretion and a mild hyperprolactinaemia. After removal of the tumour growth stopped almost completely. Plasma insulin-like growth factor (IGF)-I was in the lower normal range. Plasma IGF-II decreased after tumour removal. It is speculated that the tumour produced a growth factor causing excessive growth.

Child, Preschool↗

In vivo and in vitro studies in a 46, XY phenotypically female infant with 17-ketosteroid reductase deficiency.

A 46, XY phenotypically female infant with 17-ketosteroid reductase (17-KSR) showed normal plasma androgens for chromosomal sex shortly after birth, but did not show the physiologic testosterone rise. One intramuscular injection with human chorionic gonadotropin resulted in high ratios between androstenedione/testosterone and dehydroepiandrosterone/delta 5-androstenediol, confirming the diagnosis. In spermatic vein plasma similarly elevated ratios were found. A urinary steroid profile revealed elevated levels of metabolites of 17-OH-progesterone and androstenedione. In vitro studies in testicular tissue showed a decreased capacity of 17-ketosteroid reductase, the reduction capacity being more affected than the oxidation capacity. The activity of 3 beta-hydroxysteroid-dehydrogenase was slightly increased. The serial analysis of plasma androgens provides more insight in the natural history of 17-ketosteroid reductase.

17-Hydroxysteroid Dehydrogenases↗

Heterozygotes for 17 alpha-hydroxylase deficiency can be detected with a short ACTH test.

A short ACTH test was performed in the six parents, and four siblings, of three cases with 17 alpha-hydroxylase deficiency. Baseline steroid levels were all normal in female heterozygotes but in males 17 alpha-hydroxyprogesterone levels were elevated. After ACTH-stimulation, plasma levels of corticosterone were elevated in five obligate heterozygotes and 18-hydroxydeoxycorticosterone levels were increased in four of them. Two of the four siblings had biochemical signs of heterozygosity. The short ACTH test appears to be an efficient method for detecting heterozygosity, but the abnormalities found are more heterogeneous than previously suggested.

Adolescent↗

Methionyl human growth hormone in Turner's syndrome.

Sixteen girls with Turner's syndrome aged 7.9-15.2 years (bone ages 7.0-11.8 years) were given methionyl growth hormone (somatrem) 4 IU/m2 body surface daily, corresponding to 0.9 IU/kg/week. During one year of treatment their mean (SD) height velocity increased from 3.4 (0.9) to 7.2 (1.7) cm/year and height prediction from 148.2 (4.4) to 150.0 (4.4) cm. All the girls except one had a height velocity increment of more than 2 cm/year and these velocities are above the age references for girls with Turner's syndrome. The girl with a low growth response had antibodies against growth hormone with high binding capacity (3.7 U/l). The height velocity increment was inversely correlated with age and bone age, but this might be partly due to the somewhat higher dosage/m2 body surface and kg body weight that the younger patients were given because of the rounding off of the dose. The better results of our study compared with those of other workers who used similar dosages but did not give the drug as often suggest that giving it daily might have increased the growth response as it does in children deficient in growth hormone.

Adolescent↗

Fetal treatment for thyrotoxicosis in non-thyrotoxic pregnant women.

Euthyroid or even hypothyroid pregnant women without antithyroid medication but with a history of treatment for thyrotoxicosis, almost always a subtotal strumectomy, may still produce thyroid-stimulating immunoglobulins. This can induce fetal and neonatal thyrotoxicosis. Without treatment this results in a high fetal and neonatal mortality and morbidity. Fetal treatment by administering antithyroid drugs during pregnancy improves this prognosis remarkably. A case is described, the literature is reviewed and guidelines for diagnosis and treatment are presented.

Adult↗

A phenotypic male with true hermaphroditism and a 46,XX/46,XY/47,XXY karyotype.

A phenotypic boy presenting with gynaecomastia showed a mixed karyotype of 46,XX/46,XY/47,XXY. The left gonad was normally descended into the scrotum, but proved to be an ovary without any testicular structures. After left gonadectomy, plasma androgen and estrogen levels showed that the right gonad only contained testicular tissue. Seven patients with this form of triple mosaicism have been described but the clinical features are strikingly different among the described cases.

Adolescent↗

Comparison of short-term lower leg growth with statural growth in children treated with growth promoting substances.

Lower leg growth was determined by knemometry in 11 children with short stature, before and during therapy with growth promoting drugs. The growth response of lower leg length was determined by comparing growth velocities over periods of 6 weeks. The growth response of total body height was determined by comparing the growth velocity during 3 months of therapy with the growth velocity over 1 year before therapy. Significant knemometric growth responses were always associated with positive height responses, but smaller knemometric responses were associated with positive as well as negative height responses.

Anthropometry↗

Assessment of the usefulness of weekly knemometric measurements in growth studies.

In 31 healthy children the variability of lower leg length growth over 12 weekly measuring sessions, each consisting of 6 measurements, was assessed with a knemometer. The average SD of 6 measurements was 0.12 mm. In many cases not only a rising trend, but also a zig-zag pattern was observed. The linear regression was not significant (p greater than 0.05) in 1 child. The average (+/- SD) lower leg length velocity (LV) was 0.36 +/- 0.14 mm/week, and the average statural growth velocity 1.27 +/- 0.54 mm/week. The median ratio was 3.3. The range of both velocities was greater than the range of annual height velocities. When LV over the first 6 weeks was compared with LV over the next 6 weeks, a significant difference was found in 5 children. If the effect of growth-promoting or -inhibiting drugs were to be analyzed over such periods, a difference of 0.37 mm/week over two 6-week-periods would be necessary for significance at a 5% level. This would be equivalent with a statural growth response of at least 6.3 cm/year. In conclusion, short-term knemometric growth response cannot be used as a reliable predictor of long-term statural growth response.

Anthropometry↗

Short-term effect on growth of two doses of GRF 1-44 in children with growth hormone deficiency: comparison with growth induced by methionyl-GH administration.

In a double-blind study 12 prepubertal children with idiopathic growth hormone (GH) deficiency were treated with growth hormone releasing factor (GRF) 1-44 in a dosage of 7.5 or 15 micrograms/kg body weight, administered once a day subcutaneously. With 7.5 micrograms/kg the average growth velocity increased from 2.5 to 4.6 cm/year, an insufficient response. With the higher dosage the average growth velocity increased from 2.7 to 7.0 cm/year, a similar increase as observed with GH therapy in subsequent periods. In 3 of the 6 children treated with the higher dose appropriate catch-up growth was observed. The growth response of the lower leg length was not always consistent with the statural growth response.

Body Height↗

[Obese children and their treatment].

Retrospectively the data were analyzed of 188 children treated for obesity. The mean age at which obesity begins is 5,5 years, but the mean age at which medical help is sought is 9,5 years. In 78% of these children one or both parents were obese. The mean caloric value of the pretreatment feeding pattern was 924 kJ (220 kCal) less than the reference quantities for age. Thirty-nine percent of cases stopped visiting the clinic themselves. Mean weight loss is 10% of the median weight-for-height. No differences were found between the results of various therapeutical regimens.

Anthropometry↗

Thyroid-stimulating immunoglobulins and thyroid function tests in two siblings with neonatal thyrotoxicosis.

Thyroid function and serum TSI levels in two siblings with neonatal thyrotoxicosis are described. The first infant was treated with exchange transfusion and potassium iodide. The second infant was treated with intrauterine propylthiouracil followed by potassium iodide. In contrast to the first infant, the second infant had no clinical sign of neonatal thyrotoxicosis. He also had lower TSI levels with a biological half-life of 5 days. Only one of three assays showed some TSI activity in breast milk.

Adult↗