PubMed Health⌕ Search

Biomedical subjects

J M Gertner

Publications and source records attributed to J M Gertner.

16 recordsLinked to original sources
PubMed1992

Growth hormone actions on fat distribution and metabolism.

The secretion of growth hormone (GH) and the mass and distribution of body fat are linked through a complex series of interactions. There is increasing evidence that a GH/fat cycle exists and that elements of this cycle may possess regulatory functions. The essential elements of the cycle are: (1) GH-deficient individuals are often obese and lose body fat when they are treated; GH is lipolytic in vitro and causes an acute release of free fatty acids (FFA) when administered in vivo; (3) circulating FFA inhibit the pituitary release of GH by most secretagogues, including growth hormone releasing hormone, and (4) the obese state is characterized by a defect in GH release which can be reversed by weight loss.

Adipose Tissue↗
PubMed1992

Insulin insensitivity in adrenal hyperplasia due to nonclassical steroid 21-hydroxylase deficiency.

To determine whether hyperandrogenism caused by an inborn error of adrenal steroidogenesis could produce insulin resistance, we examined insulin sensitivity in females with 21-hydroxylase deficiency. Minimal modelling was used to analyze the results of tolbutamide-modified, frequently sampled, iv glucose tolerance testing. Insulin sensitivity [Si; (min-1) (microU/mL)-1] was plotted against body mass index (BMI; defined as kilograms per m2). Six patients with nonclassical 21-hydroxylase deficiency (mean age, 27 yr; mean BMI, 23.2) underwent testing. None of these patients was in active puberty, nor was any patient being treated with glucocorticoids at the time of the study. Twelve eumenorrheic nonhyperandrogenic young adult female control subjects (mean age, 27 yr; mean BMI, 22.4) were also tested. The basal 17-hydroxyprogesterone concentration, but not the total serum testosterone level, was significantly different in the two groups (mean +/- SEM, 11,987 +/- 2,761 vs. 4,059 +/- 802 pmol/L; P < 0.05). As a group the patients' Si values were significantly lower than those of the controls (mean +/- SEM, 4.1 +/- 0.6 vs. 9.7 +/- 1.2; P < 0.05). There was no correlation between Si and basal serum 17-hydroxyprogesterone, testosterone, delta 4-androstenedione, or dehydroepiandrosterone. We conclude that chronic hypersecretion of androgen precursors due to an inborn error of metabolism can induce a reduction in insulin sensitivity.

Adolescent↗
PubMed1979

[Urinary excretion of cAMP after PTH injection in patients with hypohyperparathyroidism (author's transl)].

The urinary excretion of cyclic adenosine monophosphate (cAMP) and phosphate in response to an intravenous injection of 200 U.I. PTH in two women with hypohyperparathyroidism was studied. PTH activity was previously verified. Both patients were under treatment with vitamin D and their plasma calcium and phosphate levels were normal at the time of the study. Basal values for urinary excretion of cAMP were 2.25 nmol/min in one patient and 4.2 nmol/min in the other. Maximum excretion after PTH injection were 6.4 nmol/min and 5.5 nmol/min respectively. Basal values for urinary excretion of phosphate were 0.32 mg/min in the first patient and 0.18 mg/min in the second. After PTH injection the peak values were 0.73 mg/min and 0.35 mg/min respectively. These results pointed out the existence of a renal resistance to PTH which, unlike what happens in other similar patients, cannot be corrected with the administration of vitamin D.

Cyclic AMP↗
PubMed1979

Impaired parathyroid response to induced hypocalcemia in thalassemia major.

Ethylene diamine tetra-acetic acid-induced hypocalcemia was used as provocative test of parathyroid reserve in eight normocalcemic patients with thalassemia major (age 8 to 26 years) and five young adult control subjects (age 22 to 35). In response to an intravenous infusion of disodium EDTA (50 mg/kg), serum immunoreactive parathyroid hormone rose by 1.97 +/- 1.93 (SD) microliterEq/ml in the patients, controls showing a rise of 10.6 +/- 3.6 microliterEq/ml (t = 5.46, P less than 0.001). There was no relationship between parathyroid response and total iron burden as measured by serum ferritin- or desferrioxamine-induced urinary iron excretion. Impairment of parathyroid reserve is common in transfused patients with thalassemia major and may serve as a marker of significant iron overload.

Adolescent↗
PubMed1979

Parathyroid function and vitamin D metabolism during human growth hormone replacement.

Changes in calcium and phosphorus metabolism were studied in nine children with GH deficiency before and during human GH replacement therapy. Parathyroid function and serum concentrations of physiologically important vitamin D metabolites were examined to determine their relationship to changes in mineral metabolism. By comparison with pretreatment values, the GH-treated children showed significant increases in growth rate and renal tubular phosphate reabsorption and a significant decrease in urinary calcium excretion after a standardized oral load. There was no significant change in serum concentrations of parathyroid hormone, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, or 24,25-dihydroxyvitamin D or in nephrogenous cAMP excretion. Although GH has been proposed as a regulator of vitamin D metabolism, the present study demonstrates that the anabolic changes in calcium and phosphorus metabolism accompanying GH therapy are not mediated via changes in parathyroid hormone or vitamin D status.

Adolescent↗
PubMed1979

Pulsatile subcutaneous nocturnal administration of GnRH by portable infusion pump in hypogonadotropic hypogonadism: initiation of gonadotropin responsiveness.

GnRH was administered subcutaneously in hourly pulses for 10 consecutive nights to two immature males with Kallmann's Syndrome using a portable, battery-operated infusion pump adapted for home use. Pulsatile GnRH produced a progressive increase in urinary gonadotropin excretion, a significant increase in mean basal plasma FSH, pulsatile LH release, and an increased LH response to a standard 3 hour GnRH infusion test. One subject developed a striking increment in plasma testosterone in response to GnRH pulses, as well as a biphasic LH response to the 3 hour infusion.

Adolescent↗
PubMed1978

Normocalcaemic pseudohypoparathyroidism with unusual phenotype.

We describe a boy who presented at 4 years of age with radiological hyperparathyroidism, osteosclerosis, and necrosis of the femoral heads. Plasma biochemistry was normal but the parathyroid hormone (PTH) level was very high. He was deaf and had an unusual facies but did not have the phenotype of Albright's hereditary osteodystrophy. Plasma and urine cyclic AMP reponses to bovine PTH were markedly subnormal. Vitamin D produced sustained hypercalcaemia and a fall in plasma phosphorus. After four hyperplastic parathyroid glands were removed he became hypocalcaemic and plasma phosphorus rose. After operation he remained unresponsive to exogenous PTH; We suggest that he had a form of pseudohypoparathyroidism without the phenotype of Albright's hereditary osteodystrophy and with some residual skeletal and renal responsiveness to PTH.

Bone and Bones↗
PubMed1977

25-Hydroxycholecalciferol absorption in steatorrhoea and postgastrectomy osteomalacia.

Post-absorption levels of 25-hydroxy vitamin D (25-OHD) after oral administration of 25-hydroxycholecalciferol (25-OHD3) were measured in 11 subjects. Five had presented with steatorrhoea of various causes while six had post-gastrectomy osteomalacia. Post-absorption levels of 25-OHD were low in four of the patients with steatorrhoea but normal in five of those with post-gastrectomy osteomalacia. There was a significant inverse correlation between peak post-absorption 25-OHD levels and faecal fat excretion. All patients with active post-gastrectomy osteomalacia had subnormal baseline plasma 25-OHD levels, which indicates that the condition is due to a deficiency of vitamin D. Only two of the patients with osteomalacia had estimated dietary vitamin D intakes ofer 1-75 microng/day. These findings suggest that an oral 25-OHD absorption test may be a valuable measure of small intestinal function and that poor dietary vitamin D intake rather than impaired absorption of the vitamin may be the major cause of post-gastrectomy osteomalacia.

Adult↗
PubMed1977

1alpha-hydroxyvitamin D3 in the treatment of nutritional and metabolic rickets and osteomalacia.

Five patients with nutritional osteomalacia or rickets and six children with rickets unresponsive to physiological doses of vitamin D were treated with 1alpha-hydroxyvitamin D3 (1alpha-OHD3). Patients with nutritional osteomalacia responded to 1--2 microgram/day of 1alpha-OHD3. The most striking findings were rises in plasma calcium and, in one case, a decrease in faecal calcium. In some cases there was a rise in plasma phosphorus, alkaline phosphatase remained unchanged. There was radiological healing. In three patients with cystinosis and one with hypophosphataemia and Barrter's syndrome 2 microgram of 1alpha-OHD3 produced healing of rickets. Plasma phosphate rose on treatment, possibly by a suppression of parathyroid activity. The response to such low doses of 1alpha-OHD3 suggests impaired 1alpha-hydroxylation of 25-hydroxyvitamin D in these patients. A patient with intestinal malabsorption was resistant to high doses of 1alpha-OHD3 by mouth but responded to parenteral administration. A boy with osteopetrosis and the biochemical changes of rickets was resistant to large doses of 1alpha-OHD3 presumably because of failure of osseous response.

Adolescent↗
PubMed1977

25-Hydroxyvitamin D levels in patients treated with high-dosage ergo- and cholecalciferol.

25-Hydroxyvitamin D (25-OHD) levels were measured in 39 patients with metabolic bone disease or hypoparathyroidism who had been treated with a constant high dose of vitamin D2 or D3 for at least 12 weeks. Plasma 25-OHD levels rose with increasing dosage, the relationship between dose and plasma level being approximately linear whether or not the dose was expressed on a weight-corrected basis. A therapeutic range of 25-OHD to be expected when patients with these conditions are treated with vitamin D has been established. There may be certain exceptions in which plasma 25-OHD levels within the range are associated with either an inadequate response to treatment or, conversely, the hypercalcaemia of vitamin D toxicity. There was no correlation between plasma calcium level and 25-OHD concentration in the group of patients studied. There was also no difference between the dose/25-OHD relationship of patients treated with vitamin D2 and that of patients receiving vitamin D3. Ten patients were started on treatment with large doses of vitamin D during the period of the study. The rate of rise of plasma 25-OHD was followed during treatment. The incremental rise in 25-OHD was calculated at the end of the first week of treatment in terms of dose per unit body weight. The rate of rise of plasma 25-OHD level was highly correlated with the dose used. Plasma 25-OHD levels after one weeks' treatment were only 15-20% of the expected steady-state level on the same dosage. The importance of a high priming dose when a rapid response is needed is thus emphasised.

Adolescent↗
PubMed1976

1-Alpha-hydroxycholecalciferol in the treatment of hypocalcaemic psychosis.

Two patients with profound hypocalcaemia due to uraemia and hypoparathyroidism respectively presented with alterations of mental state as their dominant symptom. 1-Alpha-hydroxycholecalciferol (1-alpha-OHD3) was chosen as the principal therapy because of its potency and rapid action. In both patients the plasma calcium was restored towards normal and the symptoms relieved within a very short period. The cases illustrate the role of 1-alpha-OHD3 in severe hypocalcaemia due to two different causes and provide experience on which to base treatment regimes for future patients similarly afflicted.

Calcium↗
PubMed1976

Hypophosphataemic osteomalacia in fibrous dysplasia.

We describe three patients with fibrous dysplasia of bone in whom there was evidence of hypophosphataemic osteomalacia or rickets. Two of the patients had polyostotic fibrous dysplasia and osteomalacia. The third was a child with fibrous dysplasia of the facial and cranial bones and rickets. In all cases the manifestations of osteomalacia or rickets were controlled with large doses of vitamin D. In the child the rickets and hypophosphataemia ceased when most of the bone affected by fibrous dysplasia was surgically resected. Previously reported cases of the association between fibrous dysplasia and hypophosphataemic osteomalacia are reviewed. We suggest that these cases are analogous to the syndrome of 'tumour rickets' where hypophosphataemia appears to be due to the presence of a mesenchymal tumour and regresses when the tumour is removed.

Adult↗