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Biomedical subjects

J M Wit

Publications and source records attributed to J M Wit.

209 records · Page 12Linked to original sources
PubMed1981

Reinstitution of mineralocorticoid therapy in congenital adrenal hyperplasia. Effects on control and growth.

The results of reintroduction of mineralocorticoid substitution therapy (9-alpha-fluorohydrocortisone) in five children with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency are described. All children had shown a salt-losing syndrome in infancy, but were off mineralocorticoids during several years; at the start of this study they all had elevated plasma renin activity (PRA). Four of them had increased and fluctuating pregnanetriol excretion during the year preceding reintroduction of mineralocorticoids, indicating poor control despite substantial substitution with hydrocortisone: 26 +/- 1.9 mg/m2/day (mean +/- S.E.M.). Reintroduction of mineralocorticoid therapy at ages 5.0-9.4 years resulted in a marked improvement of control, significant reduction in hydrocortisone requirements (to 17.6 +/- 1.4 mg/m2/day) and improvement in linear growth. The data suggest that, in all children with CAH and elevated PRA, continuation throughout childhood of mineralocorticoid therapy in addition to glucocorticoid therapy is necessary for optimal control and linear growth.

17-Ketosteroids↗
PubMed1979

Serum somatomedin activity and cartilage metabolism in acutely fasted, chronically malnourished, and refed rats.

Serum somatomedin activity (SM-act) and cartilage metabolism were compared in acutely fasted, marasmic (M), and marasmic kwashiorkor (MK) rats. SM-act was estimated in the porcine bioassay. In vitro uptake of [35S]sulfate and [3H]methylthymidine in costal cartilage of the experimental animals during an incubation in medium immediately after sacrifice, called endogenous activity, and the effect of incubation in 20% normal human plasma after a preincubation of 22 h in medium only, called plasma responsiveness", were determined. Acutely fasted rats had lowered SM-act and a circulating heat-labile inhibitor. Endogenous activity and responsiveness of cartilage were depressed. MK rats (fed ad libitum a 0.5% casein, isocaloric food) showed a profound depression of growth and cartilage endogenous activity despite only partially reduced SM-act and increased responsiveness. M rats received normal food and were pair-fed with MK rats, consuming approximately 0.08 g/g BW . day. They showed very depressed SM-act and low endogenous activity, and responsiveness was increased, though less than in the MK rats. On refeeding M rats, SM-act and cartilage responsiveness increased, followed by an increase of endogenous activity. Catch-up growth was best related to [3H]methylthymidine incorporation by cartilage (endogenous activity). In conclusion, these two types of experimental chronic malnutrition induce a more diversified pattern than does acute fasting. During malnutrition, cartilage metabolism does not reflect bioassayable SM-act of serum but rather the other effects of the nutritional insult. On refeeding, the expected relationship of SM-act and cartilage metabolism is rapidly restored.

Animals↗
PubMedDate not supplied

Pubertal development and growth after total-body irradiation and bone marrow transplantation for haematological malignancies.

UNLABELLED: Pubertal development after total-body irradiation (TBI) was investigated in 40 children (21 boys) treated with allogeneic bone marrow transplantation (BMT) for haematological malignancies at a mean age of 11.3 years. The mean age at the last visit was 19.0 years. Twenty-five patients (15 boys) were prepubertal at BMT. Data on secondary sexual characteristics, the pituitary-gonadal axis and longitudinal growth were retrospectively collected from the medical records. In boys not receiving additional testicular irradiation (n = 19), penile growth and pubic hair development was normal and all had serum testosterone levels within the adult range. The majority of them, however, had incidental elevations of LH, suggesting minor Leydig cell damage. Testicular volume at last measurement was small (mean: 10.5 ml) and serum FSH levels were elevated in all boys, with normalisation in only one, suggesting severe impairment of reproductive gonadal function. Of the ten girls who received BMT before puberty, six had a spontaneous onset of puberty and menarche; the four other girls needed hormonal substitution therapy. Recovery of gonadal function after cessation of substitution was seen in one girl, who became pregnant but had a spontaneous abortion. Decrease in height SDS was seen in the majority of patients and was positively correlated with male gender and lower age at the time of BMT. CONCLUSION: Careful monitoring of both gonadal function and growth after bone marrow transplantation and total body irradiation is warranted in order to detect disturbances early and ensure normal pubertal development in children treated for haematological malignancies.

Adolescent↗
PubMedDate not supplied

Adult height corrected for shrinking and secular trend.

BACKGROUND: If in growth studies on adults of different ages and generations height standard deviation scores (SDS) is to be calculated, individual heights should be compared with the average height for that generation (corrected for secular trend) at that age (corrected for shrinking). AIM: To generate mathematical formulas for calculating adult height SDS corrected for shrinking and secular trend. SUBJECTS AND METHODS: Decline of height by age was modelled based on data derived from the Baltimore Longitudinal Study of Aging. Based on mean height of Dutch conscripts in 1917 and data from four consecutive nationwide growth studies (1955, 1965, 1980 and 1997), and assuming a constant male-female difference of 13 cm, the secular trend was modelled over 80 years. The average coefficient of variation was calculated from the last three Dutch nationwide growth studies. RESULTS: Height at 21 years of age can be estimated as current height t 0.042*(age - 21) -0.0015*(age - 21)2 for males, and current height + 0.039*(age - 21) + 0.0019*(age - 21)2 for females. Mean height of 21-year-olds between 1917 and 1997 is characterized by linear regression. The coefficient of variation was close to 3.8%. Adult height SDS is calculated by the equation (A - B)/(0.038B), where A is the estimated individual height at 21 years and B is the average height of 21-year-olds in that generation. CONCLUSION: For studies on adult height at various ages and in various generations, these equations can be used to reduce experimental noise.

Adult↗
PubMedDate not supplied

Longitudinal analysis of growth in children with idiopathic short stature.

In this study the growth curves of 229 children (145 boys, 84 girls ) with idiopathic short stature (ISS) were analysed in three ways: (1) we compared the results of longitudinal modelling by means of Karlberg's ICP model with those of a cross-sectional analysis; (2) we studied to what extent an individual changes his/her height standard deviation score (SDS) position during childhood; and (3) we constructed height velocity curves for children with ISS using Cole's LMS method, and compared these with the British references. During childhood the difference between the average longitudinal and the cross-sectional height curves was less than 1 cm and the spread was almost identical. The average change in height SDS during childhood was not different from zero, indicating that in general growth of children with ISS was well canalized. The individual change in height SDS position during childhood was within 0.6 SDS for a follow-up of 1 year, increasing to 1.9 SDS for a follow-up of 7 years. During childhood mean height velocity was about 1 cm/year lower than that of the British reference. With respect to the pubertal growth spurt the maximum height velocity took place 1 year later, and was 0.6 cm/year lower than the British reference in boys as well as girls. We conclude that spontaneous growth of children with ISS adequately described by a cross-sectional curve.

Body Height↗
PubMedDate not supplied

Intra- and inter-observer variability in the assessment of testicular descent.

Measurements of the distance between the testis and the pubic tubercle have been used to differentiate retractile testes from "real" cryptorchidism and to measure the effect of therapy. The intra- and inter-observer variation of these measurements was determined in 21 boys with incompletely descended testes treated with placebo. Patients were investigated in supine and squatting position, before and during moderate caudal traction. In squatting position the average distance is 20 mm greater than in supine position. The intra-observer SD is approximately 10 mm. It is doubtful if quantitative measurements can be used to define retractile testes. The wide prediction intervals should be taken into account in interpreting results of therapy.

Administration, Intranasal↗
PubMedDate not supplied

Two-year results of treatment with methionyl human growth hormone in children with Turner syndrome. Dutch Growth Hormone Working Group.

Methionyl growth hormone (somatrem) in a daily dosage of 4 IU/m2 body surface area was administered to 16 girls with Turner syndrome. Low dose ethinyl estradiol (0.1 microgram/kg body weight) was added in girls aged 13 years or more. Mean (SD) height velocity increased from 3.4 (0.9) to 7.2 (1.7) and 5.3 (1.3) cm/year in the first and second year, respectively. Bone age advanced 1.8 years over 2 years and predicted adult height was increased. Apart from the occurrence of anti-GH antibodies there were no side effects. In conclusion, somatrem is an efficacious and safe therapy for short stature in Turner syndrome over a period of 2 years. Longer follow-up is needed before conclusions about its effect on final height can be drawn.

Adolescent↗
PubMedDate not supplied

A nationwide cohort study on Creutzfeldt-Jakob disease among human growth hormone recipients.

OBJECTIVE: In 1991, a Dutch patient who had been treated from 1963 to 1969 with human-derived growth hormone died of Creutzfeldt-Jakob disease (CJD). This study was performed to investigate whether among other Dutch human growth hormone recipients there were clinically suspected cases of iatrogenic CJD. METHODS: In a retrospective cohort study, all patients (n = 564) treated with human-derived growth hormone before May 1985 and recorded in the Dutch National Growth Registry were followed up until January 1995 for a clinical diagnosis of CJD. For this purpose, all human growth hormone recipients were linked to a database of the Foundation for Health Care Information comprising hospital discharges with a clinical diagnosis of iatrogenic CJD. Linkage of the two databases was performed on the basis of date of birth and gender. Subsequently, verification of patient's name and initials of the positively matched pairs took place. RESULTS: Linkage provided 37 positively matched pairs concerning 29 individual patients. After verification, no name from the hospital discharge records corresponded to the names of the human growth hormone recipients. CONCLUSIONS The follow-up of 564 Dutch human growth hormone recipients, who had been treated with human growth hormone until 1985 did not establish any clinically suspected case of iatrogenic CJD. Future cases, however, can still emerge due to the potentially long incubation period of prion diseases.

Adult↗
PubMedDate not supplied

Influence of growth hormone treatment on pubertal timing and pubertal growth in children with idiopathic short stature. Dutch Growth Hormone Working Group.

We studied the influence of recombinant human growth hormone (rhGH) on pubertal timing and pubertal growth in children with idiopathic short stature (ISS), and evaluated whether this was different between children with and without intra-uterine growth retardation (IUGR). Twenty-six (18 M, 6 IUGR; 'treated') subjects were treated with rhGH (6-7 days/week, dosage: 14-28 IU/m2 per week [i.e. 0.2-0.3 mg/kg per week]). Fifty-eight subjects (31 M, 9 IUGR; 'controls') were not treated. All subjects attained final height. Prepubertal height gain was significantly larger in the treated children compared to control children (M: 0.66 SDS, 95% confidence interval [CI] 0.41 to 0.92; F. 0.92 SDS, CI 0.58 to 1.26). Pubertal height gain, peak height velocity and duration of puberty were similar for the treated and control subjects. rhGH advanced the age at peak height velocity by 0.7 years (CI 0.3 to 1.0) in boys, and the age at onset of puberty by 1.1 years (CI 0.3 to 1.9) in girls. The gain in final height was 2-3 cm. Age and height SDS at start were the most important predictors for pubertal height gain, total height gain and final height in a multivariate regression analysis. Total height gain of treated subjects with IUGR was less than that of treated subjects without IUGR. In conclusion, rhGH did not affect pubertal growth in children with ISS, and slightly improved their final height. rhGH treatment should be started early to improve height as much as possible before the onset of puberty.

Age Factors↗
PubMedDate not supplied

Efficacy of long-term growth hormone treatment in Turner's syndrome. European Study Group.

The efficacy of long-term growth hormone treatment and the optimal treatment modalities in Turner's syndrome are still controversial. Studies have shown widely divergent results. While there is still need for results of randomized controlled trials, large uncontrolled trials remain a valuable source of preliminary information. This study of 136 girls with Turner's syndrome (TS) from the European Lilly Turner Study shows that the treatment regimens followed by girls with TS who start GH treatment at a relatively late age (12.9 +/- 2.2 yr) lead at best to a small average gain in final height. Mean gain over initial projected final height was 3.7-4.7 cm, depending on the chosen Turner-specific height-for-age reference data. There was a considerable variation in gains over initial projected final height (range -10.6 to +17.2 cm), which may be partly explained by the existence of good and bad responders. Whether there is a genetic/molecular basis for this and how responsiveness can best be predicted remains an important challenge.

Adolescent↗