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Biomedical subjects

M Vanderschueren-Lodeweyckx

Publications and source records attributed to M Vanderschueren-Lodeweyckx.

At least 37 records · Page 2Linked to original sources
PubMed1992

Thyroid dyshormonogenesis: severe hypothyroidism after normal neonatal thyroid stimulating hormone screening.

We report four children who presented no evidence of primary hypothyroidism in the neonatal period, either clinically (normal growth velocity) or biochemically (normal plasma levels of thyroid stimulating hormone and/or thyroid hormone). However, in early childhood, these children developed severe hypothyroidism due to dyshormonogenesis. We conclude that apparently normal thyroid function in the neonatal period does not preclude the development of severe hypothyroidism due to thyroid dyshormonogenesis later in childhood.

Age Factors↗
PubMed1992

Hyperthyroidism accelerates growth in Turner's syndrome.

Graves' disease in a girl with Turner's syndrome (karyotype 46,Xdel(Xp)) is described. Hyperthyroidism led to a pronounced acceleration of height velocity. During treatment with methimazole and L-thyroxine, height velocity normalized. The patient also developed spontaneous puberty with a clear-cut pubertal growth spurt. Final height, however, did not appear to be influenced either by Graves' disease or by spontaneous puberty.

Child↗
PubMed1992

Serum levels of immunoreactive inhibin, FSH, and LH in human infants at preterm and term birth.

Serum levels of immunoreactive inhibin, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were determined in 112 fetal cord blood samples obtained at birth between 26 and 40 weeks of gestation. High levels of inhibin immunoreactivity were detected in all samples. Between the gestational age of 26 and 28 weeks, the levels (mean +/- SE) were higher (p less than 0.05) in male (21.6 +/- 1.0 U/ml; n = 12) than in female (12.8 +/- 0.2 U/ml; n = 12) fetuses. With ongoing gestation, the serum inhibin immunoreactivity decreased and was found to be similar in male (12.1 +/- 0.3 U/ml; n = 13) and female (9.1 +/- 0.7 U/ml; n = 8) fetuses at term. Serum FSH and LH levels were elevated at the beginning of the 3rd trimester of pregnancy and decreased with ongoing gestation to undetectable values at term birth. Between 26 and 32 weeks of gestation, the FSH levels were higher in females (p less than 0.02), whereas the LH levels were higher in males (p less than 0.01). These observations suggest that in the human fetus the pituitary-gonadal axis is active and presents sexual dimorphism; both characteristics are pronounced early during the 3rd trimester of gestation and decrease towards term.

Female↗
PubMed1992

Serum growth hormone-binding proteins in the human fetus and infant.

Growth hormone-binding protein (GH-BP) levels were studied in cord serum of 69 human infants born after 24 to 41 wk of gestation and in serum of 14 infants aged 1 to 3 mo. GH-BP levels were measured by HPLC-gel filtration of serum incubated overnight with 125I-hGH. The radioactive elution profile revealed two small 125I-hGH peaks of high molecular weight and a large peak, corresponding to monomeric 125I-hGH. The first peak of high molecular weight was variable, showed some of the characteristics (high molecular weight, displaceability by a large excess of unlabeled hGH) of the described low affinity, high capacity GH-BP, and did not correlate with gestational age or birth weight (peak I-BP). The second peak was identified as 125I-hGH bound to the high affinity, low capacity GH-BP (peak II-BP). Mean +/- SD specific binding of 125I-hGH to this peak was significantly (p less than 0.0001) different between preterm infants (3.1 +/- 1.1%; n = 51), term infants at birth (4.2 +/ 1.1%; n = 18), and 1- to 3-mo-old infants (8.5 +/- 1.6%; n = 14). To evaluate the effect of intrauterine nutritional state, the ponderal index (weight/lengths) was calculated. Peak II-BP levels were lower (p less than 0.05) in infants with the ponderal index less than 2.35 (2.8 +/- 1.0%; n = 20) than in those with the ponderal index between 2.35 and 2.65 (3.4 +/- 1.2%; n = 29) or greater than 2.65 (3.8 +/- 1.2%; n = 20).(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1992

Cellular processing of growth hormone in IM-9 cells: evidence for exocytosis of internalized hormone.

IM-9 cells extensively internalize [125I]human (h) GH at physiological temperatures, yet little is known regarding the final destination of internalized hormone and its receptor. We studied this by first binding [125I]hGH to the cell surface at 4 C, and then following its fate during a subsequent incubation at 30 C in isotope-free medium. Cell-associated radioactivity decreased with time at 30 C, with a biphasic pattern suggestive of a rapid (but minor) and a slow component. The kinetics of the latter were critically influenced by NH4Cl and were abolished at 20 C. Intracellular (acid-resistant) [125I]hGH first increased with time at 30 C until it reached a maximum after 1 h, then declined continuously upon prolonged incubation. The radioactivity released by the cells was recovered in the medium as both trichloroacetic acid-precipitable material and trichloroacetic acid-soluble fragments. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, one major band migrating with an estimated mol wt of 22,000 was identified, presumably corresponding to intact [125I]hGH. These data suggest exocytosis of intact hormone via recycling endosomes and degradation in the lysosomes, respectively. Computer modelling was consistent with two intracellular compartments acting partially in series and probably corresponding to these two organelles. When analyzed by computer curve fitting, this model accurately described the kinetics of [125I]hGH internalization. So, receptor-mediated endocytosis and subsequent exocytosis are part of the GH pathway in IM-9 cells. In as much as they reflect pathways of GH receptors, these processes contribute to receptor down-regulation and could provide an explanation for release into the medium of the high affinity GH-binding protein.

Cell Line↗
PubMed1992

Serum growth hormone (GH)-binding protein and insulin-like growth factor-I levels in Turner's syndrome before and during treatment with recombinant human GH and ethinyl estradiol.

Serum levels of GH-binding protein (GH-BP) and insulin-like growth factor-I (IGF-I) were measured in 14 adolescent girls with Turner's syndrome (TS) before and during treatment with recombinant human GH (rhGH) and oral ethinyl estradiol (EE2). Before treatment, the mean +/- SE GH-BP level in TS patients was 33.2 +/- 2.0%; this was higher (P < 0.05) than that in bone age-matched (27.9 +/- 1.1%; n = 13) or chronological age-matched (28.1 +/- 0.8%; n = 17) control girls. The mean +/- SE IGF-I level in TS girls (283 +/- 26 micrograms/L) was comparable to that in bone age-matched controls (255 +/- 17 micrograms/L), but lower (P < 0.005) than that in chronological age-matched pubertal controls (568 +/- 35 micrograms/L). In 7 TS girls treated with daily sc injections of rhGH in a dose of 0.8 U/kg.week for 18 months, serum levels of IGF-I increased from 330 +/- 39 to 707 +/- 48 micrograms/L after 3 months of treatment and remained elevated for the entire observation period (P < 0.002). In contrast, GH-BP levels did not change significantly. In 7 other TS girls, puberty was induced after 2 yr of daily sc injections with rhGH (1 U/kg.week) by adding 100 ng/kg.day EE2, orally, during ongoing rhGH therapy. During 18 months of pubertal induction, serum GH-BP levels increased gradually from 31.4 +/- 2.7% at the start of EE2 treatment to a maximum of 49.2 +/- 0.8% after 1 yr (P < 0.001). Serum IGF-I levels, in contrast, did not change significantly. These results show that in adolescent TS patients 1) pretreatment serum GH-BP levels are higher than in bone age-matched or chronological age-matched control girls, and IGF-I levels are similar to those in bone age-matched but lower than those in chronological age-matched controls; 2) during rhGH treatment GH-BP levels do not change, whereas IGF-I levels increase significantly; and 3) oral EE2 treatment during ongoing rhGH treatment increases GH-BP levels markedly, but does not modify IGF-I levels.

Adolescent↗
PubMed1991

Growth hormone treatment of Turner syndrome patients with insufficient growth hormone response to pharmacological stimulation tests.

Growth before and during treatment with biosynthetic human growth hormone (hGH) was studied in 13 patients with Turner syndrome (TS) and a growth hormone (GH) response of less than 10 micrograms/l to two standard provocative tests. During 1 year of treatment with hGH (0.15 IU/kg per day) height velocity (mean +/- SD) increased significantly (P less than 0.001) from 3.7 +/- 1.8 cm/year to 7.6 +/- 1.5 cm/year. The auxological data in these girls before and during treatment with hGH were similar to those observed in TS patients with a normal response of GH to pharmacological stimuli. It is concluded that in girls with Turner syndrome GH testing should only be performed when height velocity is below the Turner norm. In TS patients with residual growth potential a clinically significant growth acceleration can be obtained with a higher-than-replacement dose of hGH, i.e. 0.15 IU/kg per day, regardless of GH testing.

Adolescent↗
PubMed1991

Effect of growth hormone therapy on thyroid status of girls with Turner's syndrome.

The effect of recombinant human growth hormone (rhGH) administration on thyroid function was studied in 14 girls with Turner's syndrome for 18 months. All patients were euthyroid and had no documented GH deficiency. Treatment with rhGH, administered as daily subcutaneous injections in a dose of 0.15 IU/kg/day, led to a decrease of serum T4 levels from 124 +/- 4 (mean +/- SEM) to 106 +/- 4 nmol/l (P less than 0.05) after 6 months of therapy. Thereafter serum T4 levels returned progressively to baseline levels. Serum TBG levels increased consistently from 21.9 +/- 0.5 to 24.4 +/- 0.9 mg/l (P less than 0.05) after 3 months. Serum T3 and TSH levels did not change significantly during rhGH administration. The T3/T4 ratio (x 100) increased from 1.9 +/- 0.1 to 2.2 +/- 0.1 (P less than 0.05) after 6 months of treatment and returned thereafter to baseline levels. The observed changes in T3/T4 ratio demonstrated a striking parallelism with the changes in height velocity and plasma IGF-I levels. We conclude that rhGH treatment results in a transient alteration of the thyroid status in girls with Turner's syndrome. The functional importance of this phenomenon, in particular its role in the concomitant growth acceleration, remains to be established.

Adolescent↗
PubMed1991

Growth hormone deficiency in a girl with the Cohen syndrome.

A girl with the Cohen syndrome and isolated growth hormone deficiency is described. Treatment with biosynthetic human growth hormone resulted in marked catch up growth to normal stature. It is concluded that growth hormone deficiency should be ruled out in patients with the Cohen syndrome and small stature.

Abnormalities, Multiple↗
PubMed1991

Measuring growth hormone activity through receptor and binding protein assays.

In most of the children with short stature, no organic basis can be found, which has led to the suggestion that some cases of growth failure may be due to an immunoreactive but bioinactive growth hormone (GH). In order to compare GH immunoreactivity and bioactivity (measured as receptor binding ability), a radioreceptor assay allowing the measurement of GH levels in human serum was developed using cultured human lymphocytes and 125I-labeled human GH purified by high-performance liquid chromatography. Serum samples were obtained after pharmacological stimulation with either insulin, glucagon or GRF from 19 healthy control subjects and 114 patients with various growth disturbances, aged 2.3-24.8 years. In general, there was a good correlation between the GH levels measured by the two methods, the RRA-GH levels being lower than the RIA-GH levels at all times irrespective of the stimulation test. In all the groups studied, most of the individual RRA/RIA ratios were within normal limits. It is concluded that the presence of an abnormal (bioinactive) GH molecule is extremely rare in patients with short stature.

Adolescent↗
PubMed1991

Growth hormone (GH) treatment in short normal children: absence of influence of time of injection and resistance to GH autofeedback.

Forty prepubertal subjects (25 boys and 15 girls) with idiopathic short stature, aged 3.8-14.6 yr, were randomly allocated to receive sc injections of recombinant human GH (hGH) 6 days/week at a dose of 3 IU (1.25 mg)/m2.day either in the morning or in the evening. After 6 months of therapy, each subject was switched over to the other schedule of injection. After 12 months, treatment was stopped, and the subjects were followed for 6 months. For the whole group, regardless of the time of injection, height velocity (centimeters per yr) was 4.3 +/- 0.9 before hGH treatment, 8.3 +/- 1.9 during the first 6 months of treatment, and 6.9 +/- 1.6 during the last 6 months of treatment. Thirty-three of 38 subjects (87%) who completed 12 months of therapy presented an increase in height velocity greater than 2 cm/yr. Two patients (5%) developed antibodies to hGH and were among the nonresponders. There was no significant difference in growth response according to the schedule of injections. GH-releasing hormone (GHRH) testing was performed before and after 6 and 12 months of hGH therapy. When the last hGH injection was performed 12 h before the GHRH test, there was a 36% decrease in the maximum GH response (P less than 0.01) and a 33% decrease (P less than 0.01) in the GH secretory area compared to those before therapy. When the last hGH injection was performed 24 h or more before the GHRH test, no significant differences were observed. Insulin-like growth factor-I levels were not significantly different when measured 12 or 24 h after hGH. During the 6 months after discontinuation of hGH therapy, catch-down growth was observed in 44% of the subjects. We conclude that the schedule of injection does not influence the growth response, which wanes after 6 months; this waning effect is not related to declining insulin-like growth factor-I levels or GH autofeedback, suggesting a peripheral mechanism. Likewise, the catch-down phenomenon after hGH is discontinued is not related to a persistent diminution of pituitary responsiveness to GHRH.

Antibody Formation↗
PubMed1991

Age and height at diagnosis in Turner syndrome: influence of parental height.

Age and height at diagnosis was studied in 100 patients with Turner syndrome: 41 with the 45,X karyotype and 59 with various other karyotypes. In 15 patients diagnosis was made at birth. In the remaining patients median age at diagnosis was 12.9 years in those with 45,X karyotype and 11.6 years in the others. Mean +/- SD height standard deviation score at diagnosis was -3.2 +/- 0.9 for the patients with 45,X karyotype and -2.8 +/- 0.9 for the others. A significantly negative correlation was found between age and height standard deviation score at diagnosis (r = - .51; P less than .005). Corrected mid parental height was significantly correlated with height standard deviation score at diagnosis (r = .49; P less than .005), but not with age at diagnosis (r = -.08). It is concluded that although Turner syndrome is a congenital disorder, the diagnosis is usually made too late, at a chronological age when a marked height deficit is present. To make an early diagnosis, a cytogenetic examination should be recommended for all girls with height more than 2 SD below the mean for age or more than 2 SD below corrected mid parental height.

Adolescent↗
PubMed1990

Linear growth in patients with Turner syndrome: influence of spontaneous puberty and parental height.

Growth data on 100 patients with Turner syndrome are reported. Seventeen had spontaneous puberty. Between the ages 11 and 13 years, height and height velocity were higher in these girls than in those with induced puberty. Final adult height, however, was not different. Patients disomic for Xp chromosome were taller than the monosomic ones, and the majority of them had spontaneous puberty. Significant positive correlations were found between height of Turner syndrome patients and corrected mid parental height, mother's height and father's height from the age of 6 years. It is concluded that in patients with Turner syndrome spontaneous puberty and parental height should be accounted for in the evaluation of linear growth.

Adolescent↗
PubMed1990

Exercise therapy and hypocaloric diet in the treatment of obese children and adolescents.

Fourteen obese children and adolescents were treated with a combined therapy of low calorie diet and exercise and their progress compared to that of 11 obese children treated with diet only. Children treated with combination therapy were encouraged to perform aerobic exercises daily, for a period of time which was calculated to consume approximately 250 kcal per exercise session. After 4 months of therapy, a significantly (P less than 0.05) larger decrease of % overweight was observed in the group of children treated with diet and exercise (-25 +/- 13.5%) than in those treated with diet only (-15.8 +/- 10.5%). Treatment compliance was better in the group treated with diet and exercise than in the group which followed a low calorie diet only. We think that unsupervised exercise therapy can be successfully combined with a low calorie diet in the treatment of childhood obesity.

Adolescent↗
PubMed1990

Recombinant human growth hormone treatment in short children with chronic renal disease, before transplantation or with functioning renal transplants: an interim report on five European studies.

Growth retardation is common in children with chronic renal disease. Final adult height is often reduced, even in children with a functioning renal transplant. The five European studies considered here aim to investigate the efficacy and safety of recombinant human growth hormone therapy (rhGH) in two groups of short children with chronic renal disease. The first group comprises 29 prepubertal children with preterminal chronic renal failure (i.e. before renal transplantation), and the second group comprises 39 prepubertal and pubertal children with functioning renal transplants. The median bone age retardation in the groups at the start of treatment was between 2.2 and 3.7 years; this did not change during the first year of treatment. This interim report concentrates on patients who have been treated for at least 1 year (i.e. 22 children from the first group, and 28 children from the transplant group (15 prepubertal and 13 pubertal children). The median height velocity increased from 4.8 cm/year to 10.0 cm/year in the first group (the chronic renal failure group), from 2.6 cm/year to 6.2 cm/year in prepubertal children with renal transplants and from 3.8 cm/year to 6.7 cm/year in pubertal children with renal transplants. The corresponding changes in height velocity SDS were from -1.3 to 5.1 for the chronic renal failure group and -2.8 to 2.3 for the prepubertal children with renal transplants. Renal function declined in the chronic renal failure group but this decline corresponded to expected progression of the disease. Some of the children with renal transplants showed a decreased renal function, which in most cases was explained by non-compliance or chronic rejection.

Adolescent↗