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Biomedical subjects

Z Hochberg

Publications and source records attributed to Z Hochberg.

At least 127 records · Page 7Linked to original sources
PubMed1987

Psychosexual outcome of assigned females and males with 46,XX virilizing congenital adrenal hyperplasia.

Seven genotypic female (46,XX) patients with congenital adrenal hyperplasia, four reared as girls and three reared as boys were evaluated at 16-26 years of age with psychological interviews and testing. A small penis in the three young men produced a practical and psychological barrier that severely injured their personality. In spite of some degree of pre-adolescent tomboyism and a somewhat injured body image, the girls adjusted to their feminine gender identity. It is concluded that in cases of both early and late diagnosis, the genotypic female sex should be preferred.

Adaptation, Psychological↗
PubMed1987

Long-term intracaval calcium infusion therapy in end-organ resistance to 1,25-dihydroxyvitamin D.

Two boys aged six and four with the syndrome of hereditary resistance to 1,25-dihydroxyvitamin D3 with rickets alopecia and growth retardation are presented. After unsuccessful therapeutic trials with pharmacologic doses of vitamin D or its active metabolites, the patients were treated by long-term intracaval infusions of calcium through an implantable catheter. A total of 0.5 to 0.9 g of elemental calcium was infused daily for 18 months and the serum calcium concentration was maintained at 9 to 10 mg/dl. Bone pain subsided within one week of treatment. Serum phosphorus, immunoreactive parathyroid hormone, and 1,25-dihydroxyvitamin D concentrations and alkaline phosphatase activity were normalized within four to nine months. Radiographs of the knees and hands revealed progressive healing of rickets with complete resolution after one year of treatment. The patients gained 12 cm and 8 cm per year in height as compared with 3 cm and 2 cm, respectively, in the previous year. A transilial bone biopsy obtained from one patient prior to treatment revealed severe osteomalacia associated with osteitis fibrosa. A follow-up biopsy examined after 12 months of therapy showed almost complete healing of osteomalacia and normal mineralization. These observations indicate the following: (1) Long-term intracaval calcium infusions are an effective mode of therapy for these patients, and (2) When adequate serum calcium and phosphorus concentrations are maintained, healing of rickets and normal growth rate could be achieved even in the absence of a normal 1,25-dihydroxyvitamin D3 receptor-effector system.

Biopsy↗
PubMed1987

Myeloid progenitors from the bone marrow of patients with vitamin D resistant rickets (type II) fail to respond to 1,25(OH)2D3.

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), has been shown to enhance the growth of human granulocyte/macrophage haemopoietic progenitors in vitro and to induce these cells to differentiate along the monocyte/macrophage pathway. In order to evaluate the relationship between specific receptors for 1,25(OH)2D3 and the role of 1,25(OH2D3 in the regulation of haemopoietic cell differentiation, we examined the effect of haemopoietic cell differentiation, we examined the effect of 1,25(OH)2D3 on the in vitro growth and differentiation patterns of marrow myeloid progenitor cells from two patients with 1,25(OH)2D3 resistant rickets, resulting from defective receptors to vitamin D. A significant rise in the frequency of myeloid colonies in control marrow cell cultures was induced by 2 X 10(-9) to 2 X 10(-7)M 1,25(OH)2D3. This rise reached a plateau at 2 X 10(-9)_2 X 10(-8) M 1,25(OH)2D3, resulting in a maximal 54 +/- 9% increase in colony numbers. In contrast, no stimulatory effect could be detected when 1,25(OH)2D3 was added to cultured marrow cells from the patients with 1,25(OH)2D3 resistance. Analysis of colony composition revealed that 2 X 10(-8) and 2 X 10(-7) M, 1,25(OH)2D3 induced a 50 +/- 26% increase in the frequency of colonies composed only of monocytes/macrophages in control, but not in the patients' marrow cell cultures. The effect of 2 X 10(-8) and 2 X 10(-7) M 1,25(OH)2D3 on progenitor cell differentiation towards monocytes/macrophages was also observed in marrow cell suspension cultures. Whereas 1,25(OH)2D3 induced a 81-136% increase in the frequency of monocytes in control marrow cells, no effect could be detected on the generation of mature monocytes in marrow cells of the 1,25(OH)2D3 resistant patients. Our results show that marrow granulocyte/macrophage progenitor cells from patients with 1,25(OH)2D3 resistance fail to respond to 1,25(OH)2D3. We thus demonstrate that the effect of 1,25(OH)2D3 on the proliferation and differentiation of haemopoietic progenitor cells is mediated through its binding to specific cytoplasmic receptors.

Bone Marrow↗
PubMed1987

Post-obstructive urinary concentrating defect. A case study in the role of prostaglandins.

A child with post-obstructive urinary concentrating defect was studied for the possible pathophysiological role of prostaglandins and an eventual therapeutic approach. Increased urinary excretion of prostaglandins was corrected by indomethacin, with resultant increased nephrogenous cyclic AMP and partial improvement in the concentrating defect. The addition of a thiazide restored urinary concentration. These results add clinical support to the conception of the important role of prostaglandins in the mechanism of post-obstructive hyposthenuria. This therapeutic regimen is advocated for prolonged post-obstructive concentrating defect.

Child, Preschool↗
PubMed1987

Interrelated calcium ion and cyclic AMP inhibition of placental lactogen secretion by cultured human term trophoblast.

Calcium ion has been shown to have a negative regulatory effect on the secretion of human placental lactogen (hPL). We report an inhibitory effect of cyclic AMP on hPL secretion in a model system of cultured human term trophoblast. Similar results were obtained by modulation of cyclic AMP-phosphodiesterase. The effects of ionophore A23187 and cyclic AMP were non-additive. In searching for the sequence of the common pathway, we found that the ionophore A23187 reduced cyclic AMP concentration and that the inhibitory effect of cyclic AMP was abolished by verapamil, a calcium channel blocker, and by trifluoperazine, a calcium-calmodulin inhibitor. Cyclic AMP seems to mobilize intracellular calcium, and the latter, by way of a calcium-calmodulin complex, modulates the secretion of hPL.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1987

Prostatic ejaculate in assigned males with 46,XX congenital adrenal hyperplasia.

Two assigned males with 46,XX congenital virilizing adrenal hyperplasia due to 11 beta-hydroxylase deficiency reported an ejaculation of thick fluid. Chemical analysis revealed that the fluids bore a resemblance to normal prostatic fluids. Extreme virilization in utero seems to have produced both complete virilization of external genitalia and development of a prostate.

Adrenal Hyperplasia, Congenital↗
PubMed1986

The dual effect of calcium on aromatization by cultured human trophoblast.

To study the effect of calcium ion on aromatization of an androgenic precursor to estradiol by the placenta, cultured term trophoblasts were used as a model system. Secretion of estradiol into the culture medium was regarded as indicating aromatization, since cells cultured with no androgenic precursors produced only insignificant amounts of estradiol. EGTA, verapamil and ionophore A23187 inhibited aromatization, while trifluoperazine, an inhibitor of the calcium-calmodulin complex, interfered with the stimulatory effect of cyclic AMP on aromatization. We conclude that calcium ion has an essential role in the aromatization of 4-androstene-3,17-dione to estradiol. The calcium-calmodulin complex is required for activation of aromatase by cyclic AMP. However, when flooded with calcium by ionophore A23187, the trophoblast is unable to effectively buffer calcium, and aromatization is inhibited.

Androstenedione↗
PubMed1986

Low-set osmotic threshold for vasopressin release in a patient with prolactinoma.

This report describes a 38-year-old patient with prolactinoma, without adrenal or thyroid insufficiency, with syndrome of inappropriate secretion of vasopressin due to downward resetting of the hypothalamic osmoreceptors. Random measurements of plasma and urine osmolality revealed an inappropriately high urine osmolality for a given plasma osmolality. Simultaneous plasma vasopressin levels were within normal limits. Urine dilution after water load was normal. During infusion of hypertonic saline, the osmotic threshold was demonstrated at plasma osmolality of 267 mosmol/kg, which is markedly lower than the normal 287.3 +/- 3.3 mosmol/kg. Thirst sensation seemed to be intact. The defect in the osmoreceptor function might have been induced by the tumor mass or by chronic hyperprolactinemia.

Adrenocorticotropic Hormone↗
PubMed1986

Requirement of mineralocorticoid in congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency.

Marginal salt loss occurs in patients with congenital adrenal hyperplasia due to 11 beta-hydroxylase (11-OHase) deficiency treated with dexamethasone and is accompanied by increased PRA. The present study was undertaken to evaluate the effect of the stimulated renin-angiotensin system on pituitary-adrenal suppression. Seven patients with 11-OHase deficiency were subjected to a series of treatments with dexamethasone, cortisol, and combined cortisol and 9 alpha-fluorohydrocortisone. The latter combination suppressed PRA and sodium excretion, and produced better control of the pituitary-adrenal axis, as measured by plasma ACTA and serum 11-deoxycortisol. We conclude that in children with 11-OHase deficiency, PRA needs to be monitored, and when it is elevated, mineralocorticoid replacement is indicated.

Adolescent↗
PubMed1986

Osmotic threshold for vasopressin release in hyperprolactinemic patients.

Eleven patients with chronic hyperprolactinemia were tested to determine their osmotic threshold by isovolemic infusion of 5% NaCl. The results obtained demonstrate no statistical difference from known values in healthy volunteers. No linear correlation was found between levels of blood prolactin and the osmotic threshold, except for 1 patient who represents downward resetting of the hypothalamic osmoreceptors. The average time elapsed from the maximal dilution point to the osmotic threshold in hyperprolactinemia was found to be significantly shorter than in the normal population. We conclude that prolactin does not appear to participate in the osmotic regulation in man.

Adolescent↗
PubMed1985

Growth and pubertal development in patients with congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency.

To evaluate growth and pubertal development in patients with congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency, data were collected retrospectively from the charts of 24 patients, 15 girls and nine boys. Growth before diagnosis was characterized by a rapid acceleration in the second half of the first year of life, with rapid advancement of bone age. Final height was severely compromised in all the patients, regardless of age at diagnosis and quality of therapeutic control. Onset of puberty was precocious in male patients and normal in female patients. In this respect, treatment with hydrocortisone acetate proved to be superior to cortisone acetate or prednisone.

Adolescent↗
PubMed1985

Hypocalcaemia induced by glucocorticoids in a child with hypoparathyroidism treated with 1-alpha-hydroxyvitamin D3.

Glucocorticoids tend to lower the intestinal absorption of calcium, leading to a negative calcium balance. A 7-year-old girl with hypoparathyroidism was maintained as normocalcaemic on 1-alpha-hydroxyvitamin D3 (1 alpha D3) and calcium gluconate lactate. During an episode of aplastic anaemia she was treated with prednisolone, with a subsequent dramatic fall of serum calcium despite 1 alpha D3 treatment and serum 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in the high-normal range. Glucocorticoids seem to have interfered directly with cellular events responsible for intestinal absorption of calcium.

Anemia, Aplastic↗
PubMed1985

Isolated ACTH deficiency with transitory GH deficiency.

A nine-year-old girl, who presented with a severe hypoglycemic coma, proved to have isolated ACTH deficiency, a finding previously reported in only two children. On the initial evaluation, before any treatment, GH did not respond to provocative stimuli. On replacement therapy with hydrocortisone, normal linear growth was observed. Repeated testing while on glucocorticoids replacement four years after the initial attack revealed normal GH response to stimulation test. It is suggested that cortisol deficiency was responsible for the severe hypoglycemic coma and subnormal GH response. A similar mechanism is speculated for the normal growth observed in some patients with apparent deficiency of anterior pituitary hormones, including GH. The possibility of permanent ACTH deficiency and transitory GH deficiency following hypophysitis is discussed.

Adrenocorticotropic Hormone↗
PubMed1985

The effect of inhibitors on insulin regulation of hormone secretion by cultured human trophoblast.

The effect of insulin in physiological concentrations on hormone secretion by human term trophoblast cell culture was studied in relation to insulin control of glucose transport and utilization. Specific inhibitors to these 2 functions were added to the culture, either alone to test for a dose response or with insulin. 2-Deoxy-D-glucose, which inhibits glycolysis, did not change the pattern of response of estradiol and placental lactogen (hPL) secretion to insulin. Phloridzin, an inhibitor of glucose transport, interfered with the stimulatory effect of insulin on hPL secretion, but stimulated insulin inhibition of estradiol secretion when added by itself. The results indicate that hPL response to insulin is dependent on glucose transport, but is independent of glycolysis. Estradiol response is dependent on glucose transport, but is independent of glycolysis.

Cells, Cultured↗
PubMed1985

Normal plasma-urine osmolality relationship in preterm infants on positive pressure mechanical ventilation.

Mechanical ventilation with positive pressure has been implicated in the inappropriate release of vasopressin. To examine whether such a phenomenon occurs in infancy, 26 preterm neonates with Respiratory Distress Syndrome were studied. Simultaneous urine and plasma were collected for osmolality determination during mechanical ventilation with positive end expiratory pressure of 4-8 cmH2O. Results were plotted onto our previously described nomogram. The data show normal distribution of plasma to urine osmolality ratio in 25 out of 26 infants. These results do not support the common belief that positive pressure mechanical ventilation in the newborn with RDS provokes inappropriate secretion of vasopressin.

Humans↗
PubMed1985

Defective binding and function of 1,25-dihydroxyvitamin D3 receptors in peripheral mononuclear cells of patients with end-organ resistance to 1,25-dihydroxyvitamin D.

Lectin-induced DNA synthesis by peripheral mononuclear cells from 17 normal donors was inhibited (40-60%) by 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) at physiological concentrations (10(-10)-10(-9) M). The lymphocytes acquire specific receptors for 1,25(OH)2D3 upon activation by the lectins. This process precedes the inhibitory effect of 1,25(OH)2D3. We studied lymphocytes from six patients from four different kindreds with the syndrome of hereditary end-organ resistance to 1,25(OH)2D (the so-called vitamin D-dependent rickets type II). In five patients (three kindreds) peripheral blood mononuclear cells did not acquire receptors for 1,25(OH)2D3 upon phytohemagglutinin-induced activation. Moreover, in contrast to normal lymphocytes, the mitogenic stimulation of these patients' lymphocytes by phytohemagglutinin and concanavalin A was not inhibited by 1,25(OH)2D3. Activated lymphocytes of the sixth patient from a fourth kindred exhibited normal binding of [3H]1,25(OH)2D3 but the hormone failed to inhibit the mitogenic stimulation. A similar pattern of the vitamin D effector system was previously observed in fibroblasts cultured from skin biopsies of the same group of patients. The conclusions from these findings are: (a) the inhibition of mitogenic stimulation by 1,25(OH)2D3 is mediated by specific functional receptors to the hormone; and (b) the receptors for 1,25(OH)2D3 in mononuclear cells are probably controlled genetically by the same mechanisms as the effector system in well-characterized target organs of the hormone, such as intestine and kidney.

Adolescent↗
PubMed1985

Does 1,25-dihydroxyvitamin D participate in the regulation of hormone release from endocrine glands?

The presence of receptors for 1,25-dihydroxyvitamin D3 in the pituitary, pancreas, testis, and ovary has raised the question of a possible direct role for 1,25-dihydroxyvitamin D (1,25(OH)2D) in the regulation of hormone synthesis and secretion. To evaluate this problem, six children with the syndrome of resistance to 1,25(OH)2D with rickets and alopecia underwent dynamic tests of insulin, TSH, PRL, GH, and testosterone secretion. Oral glucose loading resulted in normal glucose curves, subnormal peak insulin responses of 12-20 microU/ml in three hypocalcemic patients, and normal peak serum insulin values of 30-40 microU/ml in two normocalcemic patients. Basal serum, TSH, PRL, T4, and T3 concentrations were normal in all patients. Peak serum TSH values after TRH were 11-17 and 16-32 microU/ml in the hypo- and normocalcemic patients, respectively. The PRL response to TRH stimulation in either hypocalcemic or normocalcemic patients was normal [mean 26.2 +/- 5.1 (SD) ng/ml]. Peak serum GH levels were greater than 8 ng/ml in all five patients studied after one or more of the various stimuli. Serum testosterone concentrations after hCG stimulation were normal in the three patients studied (4.1-8.0 ng/ml). Thus, in children with resistance to 1,25(OH)2D, we could find no significant abnormalities in hormone secretion from the pituitary, pancreas, and testis apart from those presumably due to the hypocalcemia itself.

Calcitriol↗