Search PubMed⌕ Search

Biomedical subjects

R Rapaport

Publications and source records attributed to R Rapaport.

47 records · Page 3Linked to original sources
PubMed1987

Effects of human growth hormone on immune functions: in vitro studies on cells of normal and growth hormone-deficient children.

We have studied the in vitro effects of human growth hormone on cell surface markers and mitogenic responses of peripheral blood lymphocytes (PBL) of normal and growth hormone-deficient children before, during and after treatment with growth hormone. Growth hormone resulted in a decrease in B cell expression but it did not affect expression of T cell subsets. Growth hormone depressed the proliferation of PBL of normal and untreated growth hormone-deficient children. The proliferative responses to phytohemagglutinin (PHA) versus PHA with growth hormone were not statistically different, though the responses of most normal and on treatment children were diminished by the addition of growth hormone. PBL derived from growth hormone-deficient children during treatment with human growth hormone exhibited significantly greater spontaneous proliferation then the PBL of normal children. Growth hormone further significantly enhanced their proliferation. PHA and PHA with growth hormone resulted in significantly greater proliferation of these patients' PBL when compared to those of normal children. We demonstrated that human growth hormone had substantial in vitro effects on immune functions. These effects, some of which depend on the treatment status of the children, may need to be considered in the clinical use of human growth hormone.

Child↗
PubMed1986

Suppression of immune function in growth hormone-deficient children during treatment with human growth hormone.

Inasmuch as growth hormone is known to interact with the immune system, we studied immune functions including immunoglobulins, cell surface markers, mitogen responses, and polymorphonuclear cell function in eight children with growth hormone deficiency, ages 1 to 17 years, before and during treatment with human growth hormone for 12 to 16 months. Before treatment immune functions were normal in all children. Treatment with human growth hormone did not significantly affect serum immunoglobulins, polymorphonuclear cell function, or percent T cells. However, percent B cells decreased to subnormal levels in seven of seven patients. T helper/suppressor ratios decreased in all patients, to subnormal values in seven of eight patients; and mitogen responses decreased to below normal in all. The decline of percent B cells was transient in all patients, of T helper/suppressor ratios in seven of eight, and mitogen responses in five of eight patients. In vitro incubation of lymphocytes with growth hormone resulted in no changes in cell surface markers or mitogen responses. Although the depression of immune functions resulted in no increased rate of infections during the observation period, we do not know the possible effects of prolonged treatment and therefore caution against the indiscriminate use of human growth hormone. The effects of biosynthetically obtained growth hormone on immune function remain to be determined.

Adolescent↗
PubMed1983

Congenital adrenal hypoplasia: two new cases.

Two male adolescents with the X-linked form of congenital adrenal hypoplasia are described. Both grew slowly during childhood and adolescence and did not undergo pubertal development because of hypogonadotropic hypogonadism associated with the congenital adrenal hypoplasia. The severely delayed bone age in childhood is probably due to the adrenal androgen deficiency and suggests a role of these hormones in the prepubertal skeletal maturation. The failure of gonadotropin secretion still remains unexplained. A hypothalamic defect has been suggested, but further studies are necessary to clarify this hypothesis.

Adolescent↗
PubMed1981

The 21-hydroxylase activity in the glomerulosa and fasciculata of the adrenal cortex in congenital adrenal hyperplasia.

In the two clinical syndromes of congenital adrenal hyperplasia due to a 21-hydroxylation defect of adrenal steroidogenesis, the simple virilizing and the salt-wasting forms, the 21-hydroxylase activity was studied considering the zona fasciculata and the zona glomerulosa of the adrenal cortex as two separate glands under different regulation. To test this hypothesis, we stimulated adrenal steroidogenesis by ACTH infusion or dietary sodium restriction in eight patients with congenital adrenal hyperplasia (four patients with the simple virilizing form and four with the salt-wasting form of congenital adrenal hyperplasia) and in six normal children. Both the 17-hydroxy and 17-deoxy pathways of adrenocortical steroid biosynthesis were examined by measuring serum concentrations of 17-hydroxyprogesterone, cortisol, progesterone, deoxycorticosterone, corticosterone, and aldosterone and the excretion of free deoxycorticosterone, 18-hydroxydeoxycorticosterone, corticosterone, 18-hydroxycorticosterone, cortisol, and aldosterone. We considered the steroids 18-hydroxycorticosterone and aldosterone to be primarily of zona glomerulosa origin. These studies indicated that the zona fasciculata of both the salt-wasting and the simple virilizing forms is defective in 21-hydroxylation of 17-hydroxy and 17-deoxy steroids. The zona glomerulosa demonstrated deficient 21-hydroxylation only in the salt-wasting form, whereas in the simple virilizing form, the glomerulosa was spared this defect.

Adrenal Cortex↗
PubMed1980

New studies of the 11 beta-hydroxylase and 18-hydroxylase enzymes in the hypertensive form of congenital adrenal hyperplasia.

Studies in four children with congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency provide evidence for two separate 11 beta-hydroxylating systems in the adrenal zona fasciculata and zona glomerulosa. In addition, these studies support the proposal that the adrenal 11 beta- and 18-hydroxylating activities are related and may involve the same enzyme protein and catalytic site. In the untreated or poorly treated state, despite elevation of deoxycorticosterone (DOC) and tetrahydrodeoxycorticosterone, urinary free 18-hydroxy-DOC was in the low normal range and did not increase normally with ACTH. PRA and urinary free 18-hydroxycorticosterone (18-OHB), tetrahydroaldosterone (TH Aldo), and pH 1 aldosterone were suppressed in the untreated and ACTH periods. Glucocorticoid administration suppressed plasma ACTH, and urinary tetrahydro-DOC and free DOC excretion decreased to the normal range. Concomitantly, there was a rise in PRA accompanied by parallel increase in urinary 18-OHB, urinary TH Aldo, and pH 1 aldosterone. While on dexamethasone, a low sodium diet (10 meq/day) resulted in prompt sodium retention, with a further rise in PRA and urinary 18-OHB, TH Aldo, and pH 1 aldosterone. These studies indicate the presence of both an 11 beta- and an 18-hydroxylase deficiency in the zona fasciculata and normal 11 beta- and 18-hydroxylase function in the zona glomerulosa, suggesting that these two enzymatic functions are related and that separate enzyme systems are present in the two zones.

Adolescent↗
PubMedDate not supplied

Wide field scanning slit in vivo confocal microscopy of flattening-induced corneal bands and ridges.

We used a wide field scanning slit confocal microscope to examine the response of the in vivo human cornea to flattening. Flattening-induced effects consisted of (1) anterior corneal mosaic, which appeared as a meshwork of intersecting stromal and Bowman's layer bands with overlying epithelial ridges; (2) deep and middle stromal bands, which were narrower than and unrelated in position to the anterior corneal mosaic; and (3) posterior surface ridges. The posterior surface ridges projected posteriorly into the anterior chamber consisted of endothelium, Descemet's membrane, and posterior stroma, and were unrelated in position to posterior stromal bands. Confocal microscopy is a promising modality in the examination of the cornea and its response to mechanical stress.

Cornea↗
PubMedDate not supplied

Non-insulin dependent diabetes mellitus in a prepubertal child with Prader-Willi syndrome.

Diabetes mellitus has only rarely been reported in prepubertal children with Prader-Willi syndrome. All reported children have required insulin therapy. We report the development of a previously unrecognized association of non-insulin dependent diabetes mellitus in an obese 6 year-old child with Prader-Willi syndrome. She has never developed ketosis or acidosis, and she has been treated with oral hypoglycemic medication.

Child↗
PubMedDate not supplied

Long-term treatment with GHRH [1-44] amide in prepubertal children with classical growth hormone deficiency.

A cohort of 20 GH deficient prepubertal patients were treated with GHRH [1-44] 10 micrograms/kg or 20 micrograms/kg twice daily for up to four years (5 patients). GHRH treatment resulted in sustained improvement in height velocity. The mean prepubertal height velocity was 3.57 +/- 1.05 cm/yr pretreatment; 8.49 +/- 1.45 cm/yr at year 1; 6.86 +/- 1.45 cm/yr at year 2; 6.22 +/- 0.74 cm/yr at year 3; and 6.16 +/- 0.97 cm/yr at year 4. IGF-I levels increased and remained within normal range. The difference between the children's and the parents' Ht SD scores significantly diminished from a pretreatment difference of -2.43 to -0.48 after four years of treatment. No adverse effects were noted during treatment. We conclude that twice-daily GHRH [1-44] treatment in a small group of prepubertal GH deficient children resulted in sustained improvement in height and growth velocity, and achieved height SDS approaching closely those of their parents.

Adolescent↗