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Biomedical subjects

Z Josefsberg

Publications and source records attributed to Z Josefsberg.

At least 37 records · Page 2Linked to original sources
PubMed1988

When should hydrocortisone therapy be instituted in children with hypopituitarism?

The records of 72 pediatric and adolescent patients with multiple hypothalamic and/or pituitary hormone deficiencies of nontumoral origin who were followed up for years and receiving somatotropin, thyroxine, and sex hormones at the appropriate age have been reviewed. According to their corticotropin-releasing factor-corticotropin-cortisol (CAC) axis function as evaluated by basal plasma cortisol levels and the response of cortisol to insulin hypoglycemia and to corticotropin-releasing factor, the patients were divided into three groups: group 1 (n = 25), patients with multiple hypothalamic and/or pituitary hormone deficiencies with normal CAC axis; group 2 (n = 38), patients with partial CAC deficiency without cortisol replacement therapy (hydrocortisone); and group 3 (n = 9), patients with CAC deficiency receiving hydrocortisone therapy (5 to 10 mg/d). Repeated CAC axis evaluation in patients of group 2 over years revealed a progressive decrease in the basal and stimulated cortisol levels with age and pubertal advancement. Despite the low cortisol levels and the low cortisol response to insulin hypoglycemia, these patients did not have clinical symptoms until the end of puberty when nine of 24 patients complained of abdominal pain, weakness, or anorexia. Linear growth, which was followed up in all patients at regular intervals, showed a lower growth velocity and irregular growth in response to somatotropin treatment in the patients receiving low doses of hydrocortisone (group 3 patients when compared with group 2 patients not receiving hydrocortisone).

Adolescent↗
PubMed1987

Greater efficiency of human growth hormone therapy in children below five years of age with growth hormone deficiency. A 5-year follow-up study.

The effect of human growth hormone (hGH) therapy was studied in 39 prepubertal children with growth hormone deficiency (24 with isolated growth hormone deficiency; 15 with multiple pituitary hormone deficiencies) who had been treated for 2-5 years. They were divided into two groups according to age at the initiation of therapy: group A (n = 21), 0.7-4.8 years (mean chronological age, 2.9 +/- 1.4 years, and bone age, 1.2 +/- 0.9 years); group B (n = 18), 5.2-9.9 years (mean chronological age, 7.4 +/- 1.3 years, and bone age, 4.0 +/- 1.5 years). hGH was given at an initial dose of 2-4 IU 3 times/week, raised to 4-6 IU 3 times/week when growth velocity slowed. In the first year, the mean height SDS gain was 1.7 for group A and 0.8 for group B, and in the second year, 1.1 and 0.1, respectively. Subsequently this remained consistent. Bone age advancement was significantly slower in the younger group (3.8 vs. 5.8 years during 5 years) although this group had a greater catch-up response to therapy. It is concluded that hGH therapy is significantly more effective in achieving normalization of height when treatment is initiated at an early age.

Age Factors↗
PubMed1986

Responsiveness of pituitary hGH to GRH1-44 in juveniles with obesity.

The response of plasma hGH to an iv bolus injection of GRH1-44 (1 microgram/kg) was studied in 14 obese juveniles with a mean overweight of 4.7 +/- 0.05 standard deviation score (SDS). Two patterns of response were observed: in all 7 adolescents with 'simple' obesity not related to any particular disorder (group A) the response was good (a mean of 11.8 +/- 2.4 ng/ml) whereas in 6 of the 7 juveniles suffering from syndromes associated with obesity (group B) the response was poor (a mean of 3.2 +/- 1.4 ng/ml). This divergence in response could not be related to a difference in the degree of overweight. These results indicate that in group B with syndromes associated with obesity there may also be a pituitary impairment in addition to the hypothalamic defect.

Adolescent↗
PubMed1985

Some properties of the plasma hGH activity in patients with Laron-type dwarfism determined by a radioreceptor assay using human liver tissue.

A radioreceptor assay for human growth hormone (hGH) using the 100,000-g pellet of human liver tissue homogenates obtained from a 13-year-old male donor of a kidney transplantation is described. The dilution curves of the plasma hGH of 6 patients with Laron-type dwarfism (LTD) as well as those of the plasma hGH from 1 normal child and 2 acromegalic patients were all found to be parallel to the standard curve, suggesting that in the LTD syndrome the circulating hGH is biologically active.

Acromegaly↗
PubMed1985

Absence of down-regulation of insulin receptors in human breast cancer cells (MCF-7) cultured in serum-free medium: comparison with epidermal growth factor.

MCF-7 cells were cultured either in RPMI-1640 medium containing 10% fetal calf serum (FCS) or in a serum-free (SF) medium supplemented with insulin, epidermal growth factor (EGF) and transferrin. Binding studies were performed with 125I-insulin or 125I-EGF. In the FCS containing culture, down-regulation was seen for insulin receptors (47%), and for the EGF receptors (75%). Using cells grown in the serum-free medium we could not demonstrate down-regulation of the insulin receptors, while the EGF receptors were down-regulated to the same extent (74%). The number of binding sites per cell was about twice as much in cells cultured in FCS as that in SF medium. No significant differences were observed for receptor affinity of insulin or EGF in cells grown in both media. The rate of internalization of insulin or EGF into cells was similar in both culture conditions. The mechanism in which only EGF but not insulin demonstrated receptor down-regulation in SF medium remains unknown.

Cell Division↗
PubMed1985

Comparison of metabolic and psychological parameters during continuous subcutaneous insulin infusion and intensified conventional insulin treatment in type I diabetic patients.

Two methods of insulin treatment--intensified conventional therapy (ICT) of three to four daily injections and continuous s.c. insulin infusion (CSII)--were compared in nine patients with insulin-dependent diabetes mellitus (mean age +/- SD 29.4 +/- 5.6 years; duration of diabetes 14.6 +/- 2.9 years). Patients followed each regimen for 3 to 4 months. Under both regimens hemoglobin A1 (HbA1) levels were lower than those recorded previously, but under CSII the mean HbA1 and glucose levels were significantly lower than under ICT (7.8 +/- 0.1 vs. 8.9 +/- 0.2% for HbA1 and 136 +/- 40 vs. 155 +/- 60 mg/dl for blood glucose, P less than 0.001). There was no difference in the frequency of blood glucose levels less than 60 mg/dl, but under CSII hypoglycemic symptoms appeared at lower glucose levels. There was no marked difference between the two regimens regarding scores for depression and anxiety and other psychological parameters, but patients who chose to continue treatment with CSII following completion of the study had previously manifested a significantly higher degree of distress symptoms, which had been reduced during the study. CSII was preferred by some patients because of the superior metabolic control achieved and the greater flexibility in time and size of meals permitted, but was rejected by others because of technical failures and bulkiness of the device. It is concluded that metabolic control can be improved by either regimen, but external pumps must be further miniaturized and technical failures eliminated before CSIII is acceptable to larger numbers of patients.

Adult↗
PubMed1984

Binding of epidermal growth factor (EGF) and insulin to human liver microsomes and Golgi fractions.

Microsomes and Golgi fractions were isolated from 13 human liver samples without local malignancy. Binding of insulin to microsomes (per cent per 0.5 mg protein) was 14.4 +/- 7.9% with two classes of receptors: K1 = 1.4 nM, R1 = 0.28 pmol/mg; K2 = 8.1 nM, R2 = 0.62 pmol/mg. The binding was insignificantly lower than in rats. Binding of EGF was only 3.4 +/- 1.7% with two classes of receptors: K1 = 1.4 nM, R1 = 0.06 pmol/mg; K2 = 10.8 nM, R2 = 0.22 pmol/mg; the binding was much lower than in rats (26.3 +/- 5.8%). Binding of insulin to Golgi fraction (per cent per 0.1 mg protein) was 5.5 +/- 0.4% with straight line Scatchard plot; Kd = 5.6 nM, Ro = 3.06 pmol/mg; it was only half of that found in rats. In one case of hepatoma, the binding of insulin to microsomes was normal but that of EGF very low.

Aged↗
PubMed1984

Plasma growth hormone response to oral clonidine as compared to insulin hypoglycemia in obese children and adolescents.

The response of plasma growth hormone (hGH) to a single oral dose of clonidine (0.15 mg/m2) was compared with that obtained with insulin hypoglycemia (ITT) induced by administration of double the usual dose (0.2 U/kg i.v.) in 13 obese subjects aged 5-17 years (7 males, 6 females) with a subscapular skinfold greater than 20 mm and a weight greater than 2 SD of the median. Six healthy subjects (3 males, 3 females), aged 8-14 years who served as controls received the usual dose of 0.1 U/kg i.v. in the ITT. Clonidine induced an increase of more than 10 ng/ml in the plasma hGH levels in 10 (4 males, 6 females) of the 13 obese subjects and in all of the healthy controls, with peak levels ranging from 14.3 to 31.0 ng/ml (m +/- SD 21.0 +/- 5.2 ng/ml); the ITT elicited a similar rise in only 6 of the 13 subjects and 3 of the healthy controls, with peak levels ranging from 9.8 to 20.0 ng/ml (m +/- SD 14.4 +/- 4.5 ng/ml). Clonidine decreased plasma insulin levels in all the obese female subjects (by a mean of 65%) whereas in the obese males the insulin pattern was variable. There was no change in blood glucose levels following the administration of clonidine; during the ITT all subjects showed a decrease to less than 50 mg/dl. Blood pressure decreased by a mean of 20 mmHg during the clonidine test. This study demonstrates that clonidine is a more effective hGH stimulus than insulin induced hypoglycemia in normal and in obese children and that the lower hGH secretion of the obese is confirmed by the clonidine test.

Adolescent↗
PubMed1984

Effects of the hepatocarcinogen 2-acetylaminofluorene on insulin binding to microsomal and Golgi fractions of rat liver cells.

Adult male Fischer rats fed the hepatocarcinogen 2-acetylaminofluorene [(2-AAF) CAS: 53-96-3; N-fluoren-2-yl-acetamide] at 0.02% showed a sharp decrease in the insulin binding to the Golgi fraction of the liver cells: from 10.0% specific binding per 0.1 mg protein in control animals to 5.9% after only 2 days and to 1.5% after 21 days of feeding 2-AAF. A less pronounced and slower decrease was observed in the microsomal fraction: from 19.1% specific binding per 0.5 mg protein in controls to a nadir of 10.8% after 46 days. The low binding of insulin to both fractions was observed for the 85 days of the experiment and persisted also in the animals fed 2-AAF for 90-107 days and then taken off the carcinogen for 30-75 days. The decrease in binding was due to the apparent decrease in the number of receptors. Neither 2-AAF nor its metabolites N-hydroxy-2-AAF (CAS: 53-95-2; N-fluoren-2-yl-acetohydroxamic acid) and N-acetoxy-2-AAF (CAS: 6098-44-8; N,O-diacetyl-N-fluoren-2-yl-hydroxylamine) influenced the insulin binding to the microsomes when added to the reaction mixture in vitro.

2-Acetylaminofluorene↗
PubMed1984

Effect of 2-acetylaminofluorene on the binding of epidermal growth factor to microsomal and Golgi fractions of rat liver cells.

The livers of rats fed the hepatocarcinogen 2-acetylaminofluorene (0.02%) with chow showed a sharp decrease in the binding of epidermal growth factor to microsomes and Golgi fractions. The binding to the latter decreased from 15.3% specific binding per 0.1 mg protein in controls to 9.4% after 2 days and reached a nadir of 0.8% after 21 days. The binding to microsomes decreased from 26.3% specific binding per 0.5 mg protein in the controls to 17.4% after 4 days and reached a nadir of 7.5% after 46 days. The low binding which persisted until the end of the experiment (85 days) was due to the apparent decrease in the number of receptors without significant changes in their affinity. Also, there was only partial recovery in rats fed 2-acetylaminofluorene for 90 to 107 days and taken off the carcinogen for 30 to 75 days. In vitro, neither 2-acetylaminofluorene nor its metabolites hydroxy- and acetocy -2-acetylaminofluorene significantly decreased epidermal growth factor binding to the isolated microsomal fraction.

2-Acetylaminofluorene↗
PubMed1983

Fenfluramine inhibits insulin secretion and potentiates glucagon release by the perfused rat pancreas.

Fenfluramine, an anorectic used in the treatment of obesity, in a final concentration of 1 mM strongly inhibited both phases of insulin release by the perfused rat pancreas. Insulin secretion resumed promptly after cessation of the drug infusion. This concentration of the drug markedly increased glucagon output. The blockade of alpha-adrenergic receptors and the use of antiserotonin agents did not alter the inhibitory effect of fenfluramine on insulin secretion. It is concluded that in the perfused rat pancreas 1 mM fenfluramine acutely inhibits glucose-induced insulin secretion and potentiates glucagon output. The direct effect of fenfluramine on insulin secretion is not related to alpha-adrenergic activity, nor is it mediated by serotonin.

Animals↗
PubMed1983

Histopathological features of the skin in hypopituitarism and Laron-type dwarfism.

Skin biopsies from children and adolescents with various syndromes of somatomedin deficiency revealed changes in structure and in distribution of the dermal elastin fibers as compared with a group of seven healthy control subjects. In 18 patients with isolated growth hormone deficiency (IGHD) and in 11 with multiple pituitary hormone deficiencies (MPHD), the number of elastin fibers was reduced; the individual fibers were shorter and slimmer than usual, and frequently arranged in groups dispersed in various directions. Skin biopsies from six patients with Laron-type dwarfism (LTD) revealed mostly thickened elastin fibers, frequently arranged in irregular bundles, but the number of elastin fibers was normal in prepubertal patients and reduced only in postpubertal patients. The reduction of elastin fibers in these patients was less prominent than in IGHD. The finding of more numerous elastin fibers in LTD than in IGHD is suggestive of a direct nonsomatomedin-mediated effect of human growth hormone on skin elastogenesis.

Adolescent↗
PubMed1981

Occurrence of four types of growth hormone-related dwarfism in Israeli communities.

Data are presented on 121 dwarfed patients belonging to 98 Israeli families with 4 types of dwarfism related to deficiency or in activity of human growth hormone (hGH): isolated growth hormone deficiency (IGHD), partial hGH deficiency (pIGHD), multiple pituitary hormone deficiencies (MPHD) and Laron-type dwarfism (LTD). These series are believed to comprise most of the dwarfs of these types in Israel; however, their distribution among the various ethnic communities varies greatly: LTD (15 families) is confined to a few communities of Oriental Jews; only 3 of 30 families with IGHD, but 7 of 10 families with pIGHD, are Ashkenazi, whereas the clinic distribution of 42 families with MPHD corresponds roughly to that of the general population. These data seem to reflect the role of genetic factors in the etiology of the various types of dwarfism: the stronger the genetic component, the greater is its deviation from random occurrence among the various communities.

Dwarfism, Pituitary↗