Biomedical subjects
Publications and source records attributed to R Rappaport.
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Testicular responses to administration of human chorionic gonadotrophin (HCG) in 23 hypopituitary patients were compared to responses obtained in adequate control groups and correlated to basal plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels. Sixteen nonpubertal patients demonstrated a significantly diminished testosterone response (250 +/- 64 ng/100 ml, mean +/- SEM) along with low basal plasma FSH values (1.4 +/- 0.2 mU/ml) when compared to normal response (607 +/- 97 ng/100 ml) and normal FSH level (2.3 +/- 0.2 mU/ml), but with normal LH values. In 7 pubertal patients decreased testosterone responses to HCG (815 +/- 147 ng/100 ml) were observed with normal plasma FSH and LH values. Correlation between testosterone responses and FSH levels (r - 0.718, P less than 0.002) in the pre-pubertal hypopituitary patients was highly significant. No such correlation was observed between testosterone response and LH. The represent findings may a) give one explanation for the absence of response to HCG observed in some cases of hypopituitarism, b) give support to the hypothesis that FSH has a mediating role on LH-induced secretion of testosterone by the testis in human subjects.
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The mosaicism 45,X/46,XY,terrea(Y,Y)(pterpter)/47,XYY was observed in an 8-month-old child with male pseudohermaphroditism. The presence of a 47,XYY population points to a post-zygotic origin of the rearrangement. The loss of Yp material is in favor of localization of masculinization factor(s) to the proximal segment of Yq. Twenty-two relevant observations reported in the literature previously are discussed.
Precocious puberty has been reported as an important feature of the Silver-Russell syndrome. The present case refers to a boy entered puberty at the chronological age of 11 years and the bone age of 6 years 6/12. Criteria for precocious puberty in this syndrome are discussed by comparison with previously published cases, and it is concluded that abnormalities in clinical pubertal development are quite unusual in this syndrome.
A new case of the syndrome of "accelerated skeletal maturation, facial dysmorphism, failure to thrive and psychomotor retardation" is presented. The syndrome was noted in the neonatal period. The diagnosis can be readily suggested by the radiologist because ossification centers show exceptionally early maturation. This case history increases to at least five the number of cases so far reported following the initial publication by Marchall and al. in 1971. If the two cases described in 1974 by Weaver and al. (as a distinct entity) are also included then the total of cases reported rises to seven.
Understanding the process which established the cell division mechanism requires analysis of the role of the responding surface as well as that of stimulatory subsurface structures. Cell surface was altered by the expansion which occurs during exovate formation. Exovates appear on the surface of fertilized Arbacia lixula, Paracentrotus lividus and Echinarachnius parma eggs in response to extreme flattening. They result from cytoplasmic outflow initiated in a very restricted portion of the egg surface. Observations of the formation process in pigmented A. lixula eggs revealed that the original surface may be expanded about 100 fold as the exovate swells. When exovates formed 15-30 minutes after fertilization contain the mitotic apparatus, they divide synchronously with flattened controls. If nucleated exovates are established after the beginning of first cleavage, furrows appear in ten minutes. Exovates established after the beginning of second cleavage develop furrows four minutes after the entrance of the the mitsotic apparatus. Cytoplasm beneath damaged exovate surfaces sometimes develops partial constrictions independently of the surface in the plane the furrow would have occupied. These results suggest that normal surface structure is unnecessary for furrow establishment and function.
Evaluation of single-dose metyrapone tests in children with hypopituitarism; comparison with the prolonged metyrapone and insulin induced hypoglycaemia tests and their relationship with the etiology of hypopituitarism. Acta Paediatr Scand, 65:177, 1976.--Pituitary-adrenal reserve was evaluated in control and hypopituitary subjects by comparing the 8 a.m. plasma 11-deoxycorticoid response (11-DOCS) to a single midnight oral dose of metyrapone (short test) with 1) the 8 a.m. 11-DOCS increase under repeated oral doses of metyrapone (prolonged test) and 2) with the plasma corticoid response during arginine-insulin test. In the short and the prolonged metyrapone tests, the same response was obtained in 25 out of 27 patients. The short test was repeated in 22 patients and the 11-DOCS response did not show a significant difference. In 34 of 40 patients, the response to the short test was comparable to the response during the arginine-insulin test; only 3 patients with a normal 11-DOCS rise to the short test had a low response to insulin and vice versa. Among the low responders to the short test, the mean 11-DOCS value was significantly lower in subjects with operated craniopharyngiomas than in idiopathic hypopituitary patients (p less than 0.001). In the short test, the 8 a.m. baseline cortisol value was positively correlated with the 8 a.m. 11-DOCS response (p less than 0.001), the cortisol level allowing to predict the 11-DOCS response in 28 out of 53 patients. Thus, the short oral metyrapone stimulation was found to be a reliable test in hypopituitary children.
TSH, PRL and GH response to TSH releasing factor as well as basal T4 and T3 were evaluated in a group of patients with chronic renal failure undergoing chronic hemodialysis. Serum T4 and T3 were lower than normal. Basal TSH was normal as compared to control, but did not rise after TRF stimulation. Larger dosages of TRF did not correct this abnormal response. Basal PRL was higher than control and remained at the same level during the test. GH was stimulated by the TRF with a peak occurring 20 min after injection. This abnormal secretion was not blunted by T3 administration. TRF half-life measured in 3 patients was 4 min. These data indicate that 1) there is an abnormal response to TRF in chronic renal failure which does not seem to be due to an altered sensitivity to, or metabolism of TRF; and 2) there is an abnormal TSH secretion which may be responsible for the low T4 and T3 measured in these patients.
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Chondrocytes from epihyseal growth plate cartilage of prepubertal rabbits were cultured. Cells from the proliferative zone showed a very different adhesiveness: they did not stick to the flasks until the 8th to 10th days. They need more oxygen tension to develop and grew in small separated colonies. Each colony was composed by several layers of round or polygonal cells, metachromatic with toluidine blue and they were surrounded by one layer of fibroblastic-like cells. At the end of primary culture the colonies looked like "craters". Cells from the resting zone multiplied as monolayer culture identical to articular chondrocytes. The stage of differentiation of the two different kinds of cells is discussed.
Seventeen constitutionally short boys were studied throughout puberty. Nine received oxandrolone (0.1 mg/kg/day). Treatment was started before onset of puberty. Eight boys served as control subjects. No significant increase in linear growth or skeletal maturation was observed in the treated group. Likewise the peak height velocity was unchanged. Pubic hair developed similarly in both groups in relation to chronologic and skeletal age. The only significant difference was a diminution in testicular volume index during treatment after bone age of 12 years and until bone age of 14 6/12 years.