Search PubMed⌕ Search

Biomedical subjects

J M Wit

Publications and source records attributed to J M Wit.

At least 163 records · Page 9Linked to original sources
PubMed1991

Placebo-controlled, double-blind, cross-over trial of growth hormone treatment in prepubertal children with chronic renal failure.

Stunted growth is a serious problem for children with chronic renal failure (CRF) despite normal endogenous growth hormone secretion and normal or elevated plasma concentrations of insulin-like growth factors (IGF) I and II. Biosynthetic growth hormone (GH) was given to 20 prepubertal children (eleven boys, nine girls; mean age 9.5 years, range 4-16) with CRF and severe growth retardation in a placebo-controlled, double-blind, cross-over trial. 6 months of subcutaneous injection of GH (4 IU/m2 per day) was either preceded or followed by 6 months of placebo injection. The patients had a full examination every 3 months. Sixteen children completed the study. Height velocity improved significantly with GH therapy (p less than 0.0001) and placebo (p less than 0.04), but the GH-induced height-velocity increase exceeded that of placebo by 2.9 cm per 6 months. There was a positive relationship between prestudy height velocity and height-velocity increase. Bone maturation was not affected. GH caused a significant increase in IGF-I and a moderate increase in IGF-II plasma concentrations. The pretreatment elevation of IGF-binding protein-1 decreased by almost 50% during GH therapy, while IGF-binding protein-3 increased significantly in concentration, although this increase was significantly smaller than the GH-induced increase in IGF-I. Fructosamine, lipid, and parathyroid concentrations remained constant. Renal function deterioration did not accelerate. Impressive height-velocity increase can be achieved with GH therapy in children with CRF and growth retardation without changes in renal function. Bone maturation appears unaffected suggesting improved final height. Treatment is best started before growth retardation becomes considerable.

Adolescent↗
PubMed1991

A neonate with idiopathic hyperaldosteronism.

A boy with functional abnormalities of the gastro-intestinal tract, hyponatraemia, hypokalaemia and hypertension is described. All symptoms developed within the first 2 months of life. Increased aldosterone levels were associated with suppressed values in the renin-angiotensin system. The diagnosis of idiopathic hyperaldosteronism was made because of adrenal hyperplasia and the failure to suppress aldosterone to undetectable levels with glucocorticoids. Treatment with spironolactone alone, or in combination with either intravenous dopamine or ibopamine orally, amiloride, enalapril, hydralazine or clonidine corrected serum potassium values but failed to normalize blood pressure and to correct plasma renin activity and plasma aldosterone. However, the combination of spironolactone with nifedipine decreased blood pressure. Abnormal gastro-intestinal motility was corrected by low doses of oral magnesium hydroxide. To assess intracellular calcium homeostasis, the patient's peripheral blood mononuclear cells were incubated with increasing concentrations of calcium. As these cells failed to maintain physiological calcium concentration, a defect in intracellular calcium homeostasis was suspected.

Aldosterone↗
PubMed1991

Testosterone esters advance skeletal maturation more than growth in short boys with chronic renal failure and delayed puberty.

Four young males with chronic renal failure and absent or stagnant puberty were treated with testosterone esters. Endocrine evaluation before therapy showed low plasma follicle stimulating hormone (FSH) levels and relatively high luteinizing hormone (LH). Following therapy skeletal maturation accelerated more than growth velocity, resulting in a lower predicted adult height. In three patients osteoporosis increased or rickets developed. Testosterone therapy was effective in developing sex characteristics, but endogenous pubertal development was not stimulated. Growth velocity was increased, but the effect on growth was more than outweighed by bone age acceleration.

Adult↗
PubMed1991

Immunologic studies in Turner syndrome before and during treatment with growth hormone. The Dutch Growth Hormone Working Group.

Immunologic studies of 14 girls with Turner syndrome were done before and during treatment with biosynthetic growth hormone (GH). Compared with control subjects, the patients before treatment had a decreased CD4/CD8 ratio and an increased number of cells bearing the natural killer cell marker CD16; serum immunoglobulin levels were within the normal range. During GH treatment some of the girls had a slight reduction in the percentage of CD20+ B cells, but we observed no impairment of B lymphocyte function as demonstrated by the normal in vivo antibody response to the primary antigen Helix Pomatia hemocyanin, administered 6 months after the start of GH treatment. The number of CD16+ natural killer cells returned to normal. Although the number of children with thyroid antibodies increased from two before treatment to five after 1 year, no conclusion about an adverse effect of GH is warranted, because the phenomenon might be part of the natural course of the disease. We conclude that girls with Turner syndrome have minor changes in some immunologic measurements and that GH treatment resulted in some alterations that have no effect on immune function.

Adolescent↗
PubMed1990

Premature thelarche: a possible adverse effect of cimetidine treatment.

An 18-month-old girl is reported in whom marked unilateral breast enlargement occurred after 4 weeks of cimetidine therapy. After withdrawal of the drug the enlargement rapidly disappeared. This observation points to cimetidine as a possible cause of premature thelarche. Cimetidine, a selective H2 receptor blocking agent, is known to cause gynaecomastia in males. This effect seems related to elevated plasma oestrogens, gonadotropins, or to binding of the drug to androgen receptors. Ranitidine, a much more potent selective H2 receptor blocker, does not cause gynaecomastia and seems therefore preferable to cimetidine.

Breast↗
PubMed1990

Sexual precocity induced by ovarian follicular cysts. Is autoimmunity involved?

A 2-year-old girl presented with gonadotrophin-independent precocious puberty due to ovarian follicles. Central precocious puberty was excluded by several GnRH-tests and overnight LH sampling. There were no signs of McCune-Albright syndrome. An ovarian tumour was excluded by laparotomy and biopsies. Abdominal sonography demonstrated follicles occurring mostly in the left, sometimes in the right, ovary. Immunoglobulin G (IgG) purified from the patient's serum was capable of stimulating DNA synthesis in granulosa cells of rat ovarian segments kept in organ culture. Since FSH had a similar in-vitro action it is hypothesized that this patient's IgG mimics the action of FSH.

Animals↗
PubMed1990

Twenty-four-hour plasma growth hormone (GH) profiles, urinary GH excretion, and plasma insulin-like growth factor-I and -II levels in prepubertal children with chronic renal insufficiency and severe growth retardation.

We studied 24-h plasma GH profiles, maximal GH responses to arginine provocation and insulin-like growth factor-I (IGF-I) and IGF-II levels in plasma in 22 euthyroid prepubertal children (mean age, 9.5 yr) with chronic renal insufficiency (glomerular filtration rate, less than 20 mL/min.1.73 m2) and severe growth retardation [mean (+/- SD) height SD score (SDS), -2.8 (1.1)]. The 24-h GH profiles were analyzed using the Pulsar program. Girls had significantly higher 24-h GH secretion than boys (P less than 0.004). Children with end-stage nephrotic syndrome had higher baseline GH levels and total area under the curve (AUCo) than patients with dysplastic kidneys (P less than 0.05), while the area under the curve above baseline (AUCb) was similar in all types of renal diseases. The type of treatment (conservative, peritoneal, hemodialysis) did not significantly influence the 24-h GH secretion. No correlation was found between 24-h GH profiles and age, height SDS for chronological age, height velocity SDS for bone age, and weight for height. Fourteen children showed a normal 24-h GH profile, defined as a GH profile with well defined, regular GH peaks returning to baseline GH levels and a distinct day and night pattern (AUCb, 90-300 micrograms/L.24 h). Four children had low profiles, with GH peaks below 10 micrograms/L, returning to baseline GH levels and occurring almost exclusively during the night (AUCb, less than 90 micrograms/L.24 h). The remaining four children had elevated 24-h GH profiles, with GH peaks on top of elevated baseline GH levels of more than 3 micrograms/L (AUCb, 35-205 micrograms/L.24 h; AUCo greater than 300 micrograms/L.24 h). In all patients 24-h urinary GH and beta 2-globulin excretion was 100-1000 times higher than that in controls. The urinary GH excretion correlated significantly with all characteristics of the 24-h GH profiles (r = 0.57-0.59; P less than 0.05). The maximal GH response during the arginine tolerance test was normal in 66% of the children. The mean (+/- SD) SDS for bone age for the IGF-I plasma levels was +1.1 (1.9), and that for IGF-II was +3.6 (3.4). IGF-I levels correlated significantly with the AUCb, maximum GH, and GH peak characteristics of the 24-h GH profiles (r = 0.05-0.73; P less than 0.02-0.001). IGF-II levels did not show any correlation with the characteristics of the endogenous GH secretion.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Insulinomas in MEN-I patients: early detection and treatment of insulinomas in patients with the multiple endocrine neoplasia syndrome type-I.

In the multiple endocrine neoplasia syndrome type I (MEN-I syndrome), periodic screening of patients and their close relatives may improve prognosis and life expectancy. Although there is diffuse involvement of the pancreas with microadenomatosis, insulinomas in the MEN-I syndrome usually occur as single tumours. This is illustrated here by two patients with insulinomas and the MEN-I syndrome. Preoperative localization of the tumours was achieved accurately by digital subtraction angiography combined with dynamic computerized tomography after a bolus injection of contrast medium. At present, two and three years after elective surgery both patients are asymptomatic. The early detection and treatment of insulinomas is extremely important because of the high risk of cerebral damage associated with late diagnosis. Periodic investigation of MEN-I family members can promote the early diagnosis and treatment of insulinomas, especially in young patients, whose life expectancy and quality of life may be improved.

Adolescent↗
PubMed1990

Plasma lipids and apoproteins, body fat distribution and body fatness in early pubertal children.

Besides body fatness, the body fat distribution is associated with coronary risk in adults, but little has been reported on this aspect in children. This study describes body fatness, body fat distribution (waist-to-hip ratio, WHR) and the plasma lipid and apoprotein profile (TC, HDL-C, LDL-C, TG, apo A-I and apo B) in 60 boys (age 10.8 +/- 0.1 year; mean +/- s.e.m.) and 64 girls (age 10.2 +/- 0.1 year), all caucasian. To avoid interference by the large changes in plasma sex hormone levels during puberty, only pre- and early pubertal children (Tanner stages of genital c.q. breast development 1 or 2) participated. Physical and sports activity was scored in hours per week using a questionnaire. The boys were taller than the girls (146.2 +/- 0.7 vs 143.2 +/- 0.9 cm; ANOVA, P less than or equal to 0.05) and their WHR was larger (0.88 +/- 0.01 vs 0.83 +/- 0.01; ANOVA, P less than or equal to 0.05). The boys spent 8.0 +/- 0.4 hours weekly on physical and sports activities, the girls 5.5 +/- 0.3 (ANOVA, P less than or equal to 0.05). The plasma lipid and apoprotein profiles were similar in both groups. Body fatness was significantly associated with the lipid and apoprotein profile, although in different ways in boys and girls. In boys there was a relationship with TG (r = 0.49), with apo B (r = 0.33) and with the apo A-I to apo B ratio (r = -0.24); in girls with TG (r = 0.25), HDL-C (r = -0.39), apo A-I (r = -0.28) and with the HDL-C to TC ratio (r = -0.31); P less than 0.05 for all correlations. A regional component of the subcutaneous fatmass, assessed by the partial correlations of the individual skinfold thicknesses with the plasma lipid and apoprotein profile after controlling for body fatness, was lacking in these early and prepubertal children. The WHR was associated with TC (r = 0.35), LDL-C (r = 0.32), apo B (r = 0.36) and with apo A-I/apo B (r = -0.34) in the girls after controlling for body fatness. Although closer investigation into the validity of the WHR as a measure of fat distribution in children is needed, the tentative conclusion is that in pre- and early pubertal girls the WHR has an impact on the plasma lipid and apoprotein profile similar to that seen in adults. It is suggested that in boys these relationships develop later in puberty.

Adipose Tissue↗
PubMed1989

The offspring of mothers with anorexia nervosa: a high-risk group for undernutrition and stunting?

Seven children from three families presented with stunting and low weight-for-height. Their mothers had a history of anorexia nervosa (AN). Evidence was gathered that the children were nourished insufficiently, possibly in combination with psychosocial deprivation. Low growth hormone secretion was documented in three cases. With the increasing ability to induce fertility in anorectic women one should be aware of the effects of maternal AN on the offspring.

Adult↗
PubMed1989

Effects of two years of methionyl growth hormone therapy in two dosage regimens in prepubertal children with short stature, subnormal growth rate, and normal growth hormone response to secretagogues. (Dutch Growth Hormone Working Group).

Thirty short, slowly growing children with normal plasma growth hormone response to standard provocation tests were randomly assigned to a group (n = 20) undergoing therapy with methionyl growth hormone, 2 IU/m2 subcutaneously once daily, (group 1) or a control group (n = 10, group 2). The mean (+/- SD) height velocity increment in group 1 was 3.0 +/- 1.9 cm/yr in the first year, compared with -0.2 +/- 0.7 cm/yr in group 2. Of the 18 children who completed the first year of treatment, 12 had a height velocity increment of more than 2 cm/yr and 11 of them continued treatment for a second year (group 1A). The remaining six children also reached height velocities greater than the mean for bone age, but because of a low height velocity increment they were termed nonresponders and their growth hormone dosage was increased to 4 IU/m2/day (group 1B). Of the 10 children in the control group, seven received authentic biosynthetic growth hormone in the second year of the study (group 2); the remaining three received no therapy (group 3). The mean height velocities (measured in centimeters per year) before and during the first and second years of therapy were 3.6, 7.6, and 6.1 in group 1A; 5.7, 6.9, and 7.3 in group 1B; 4.2, 4.0, and 6.7 in group 2; and 5.0, 4.9, and 5.2 in group 3. The effect of doubling the dosage was a further increase of 1.9 cm/yr. Bone age advance paralleled growth acceleration, resulting in an unchanged height standard deviation score for bone age and ambiguous results on final height prediction. Growth hormone therapy in such short children appears to be safe and efficacious in increasing growth velocity for 2 years, but its efficacy in terms of increasing final height is uncertain.

Age Determination by Skeleton↗
PubMed1989

A controlled trial of methionyl growth hormone therapy in prepubertal children with short stature, subnormal growth rate and normal growth hormone response to secretagogues. Dutch Growth Hormone Working Group.

Thirty short and slowly growing children with normal plasma growth hormone (GH) responses to standard provocation tests were randomly assigned to either a group (n = 20) undergoing treatment with methionyl GH (somatrem), 2 IU per m2 body surface s.c. daily, or a control group (n = 10). Twelve out of 18 children who completed the first year of treatment showed a height velocity increment of more than 2 cm/year. The mean (SD) growth velocity of the treatment group increased by 3.0 (1.9) cm/year over the first year, compared with -0.2 (0.7) cm/year in the control group. Neither parameters of endogenous GH secretion nor plasma IGF-I levels showed a significant correlation with the growth response. Of the auxological variables studied, pre-treatment growth velocity (r = -0.8) and the short-term height velocity increment (r = 0.7-0.9) showed significant correlations with the growth response in the first year of treatment. Somatrem therapy was without side effects, except in one child who developed anti-GH antibodies in combination with a poor growth response.

Body Height↗
PubMed1989

Total deficiency of growth hormone and prolactin, and partial deficiency of thyroid stimulating hormone in two Dutch families: a new variant of hereditary pituitary deficiency.

Four out of 10 children in two unrelated families presented with a total pituitary growth hormone (GH) and prolactin deficiency and a partial thyrotropin (TSH) deficiency. The GH gene was intact in family I. The pituitaries, visualized by magnetic resonance imaging, were normal. All children responded well to GH and L-thyroxine therapy. Baseline plasma somatostatin and its peak response to arginine infusion were elevated in family I and they had a milder TSH deficiency than family II. Plasma insulin showed a poor response to arginine infusion. This hereditary combination of pituitary deficiencies suggests a deficiency of a common positive transcription factor.

Adult↗
PubMed1989

Gastric drip feeding in patients with glycogen storage disease type I: its effects on growth and plasma lipids and apolipoproteins.

In 19 patients with a deficiency of glucose-6-phosphatase and 1 patient with a deficiency of glucose-6-phosphate translocase, the effect of nocturnal gastric drip feeding (GDF) on growth and plasma lipids and apolipoproteins was studied. The effect on growth was estimated by determining the height standard deviation score (SDS) of the patients and comparing its changes (delta SDS) over 4-, 2-, and 1-y periods before and 1-, 2-, 5-, and 8-y periods after the institution of GDF. The effect of GDF on plasma lipids and apolipoproteins was investigated by following the concentrations of triglycerides, cholesterol, and apolipoproteins A-I, A-II, B, C-I, C-II, C-III, and E. Growth caught up significantly or remained in the normal range in 14 patients. They were defined as responders to GDF. In the other six patients, growth caught up insufficiently or showed a further deceleration. They were defined as nonresponders to GDF. GDF had only a temporary and marginal effect on plasma lipids and apolipoproteins, but after 5-8 y, the levels of plasma triglycerides, cholesterol, apolipoprotein, B, C-I, C-II, C-III, and E increased further in both responders and nonresponders, whereas apolipoproteins A-I and A-II decreased in nonresponders. There were minor differences in the levels of lipids and apolipoproteins between responders and nonresponders without any discernible trends during the first years of GDF.(ABSTRACT TRUNCATED AT 250 WORDS)

Antiporters↗