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M Colombani

Publications and source records attributed to M Colombani.

36 records · Page 2Linked to original sources
PubMedDate not supplied

Prolactin, estriol and progesterone levels in frequent blood samples throughout normal pregnancy (lack of prolactin pulsatile secretion).

The aim of this paper was to study the episodic fluctuations of circulating prolactin (PRL), estriol (E3) and progesterone (P4) concentrations throughout pregnancy. We examined 24 pregnant women; 21 were between the 28th and 40th week of gestation, and the other 3 in the 12th, 16th and 20th week of gestation. Blood samples were drawn every 5 min for half an hour, and every 15 min for one and a half hour. Blood samples were taken in two and three different weeks of gestation in 11 and 2 of the cases, respectively. Two normal non-pregnant women were also studied and used as controls. PRL, E3 and P4 were determined by radioimmunoassay in all the samples. The coefficients of variation of PRL values were 40 and 22.6%, respectively, in the two control women, 8, 12 and 9.8% in the pregnant women studied at the 12th, 16th and 20th week of gestation, respectively, while in the 21 cases studied during the third trimester the coefficient of variation was 8 +/- 3% (mean +/- SD). The coefficients of variation of the values obtained for E3 and P4 in women studied in he third trimester were 26 +/- 15 and 16 +/- 6% (Mean +/- SD), respectively. There was an increase in the average concentration of the three hormones in all the cases at two or three different weeks. We can conclude that E3 and P4 have a pulsatile secretion pattern throughout pregnancy, and that PRL looses its pulsatile secretion as from an early gestational age. Our results suggested that central mechanisms regulating PRL episodic fluctuations were altered during pregnancy.

Estriol↗
PubMedDate not supplied

Binding of prolactin by fetal human lung cell membrane fractions.

PRL binding capacity to cell membrane fraction was studied in lung tissues obtained from 4 human fetuses or newborn infants. One of the fetuses was a stillborn delivered at 33 weeks of gestation. The newborn infants died for unknown causes within 24 h after birth. The gestational age was 20, 39 and 41 weeks. The cell membrane fraction was prepared by ultracentrifugation. binding capacity and affinity constants were calculated according to athe Scatchard method. No significant specific binding of PRL to lung tissue from the stillborn fetus was observed, while for the other 3 newborn infants the binding capacity was 5.7, 7.4 and 9.6 fmol PRL bound/mg of membrane protein, respectively. The affinity constants were in the order of 10(10) M-1. these preliminary results show that human neonatal lung has receptors for PRL and suggest that PRL itself may be involved in the lung maturation.

Cell Membrane↗
PubMedDate not supplied

Heterogeneous results of serum testosterone obtained in multiple blood samples from women with idiopathic hirsutism in both basal and post-dexamethasone conditions.

Serum radioimmunoassayable testosterone (T), cortisol and luteinizing hormone (LH) were determined before and after dexamethasone (DXM) administration in 35 patients with idiopathic hirsutism (IH). Blood samples were taken at 15-min intervals during 1 hour in both basal and post-DXM conditions. Testosterone values obtained in 5 normal women in the same conditions during the early follicular phase were (mean +/- SD): baseline, 2.26 +/- 0.49 nmol/l; post-DXM, 0.80 +/- 0.35 nmol/l. Serum T levels in the whole group of patients with IH were significantly higher than those in the control group (mean +/- SD): baseline, 3.30 +/- 1.80nmol/l; post-DXM, 1.67 +/- 1.49nmol/l. Patients with IH were divided into 4 groups according to T results in the DXM test (mean +/- SD in both basal and post-DXM conditions, respectively): group 1 (n = 13) 1.67 +/- 0.66 and 0.62 +/- 0.35nmol/l; group 2 (n = 11) 3.89 +/- 1.63 and 3.09 +/- 1.49nmol/l; group 3 (n = 6) 3.96 +/- 1.46 and 0.87 +/- 0.73nmol/l; and group 4 (n = 5) 5.45 +/- 1.25 and 2.05 +/- 0.38nmol/l. In all cases, maximal adrenal inhibition, as judged by serum cortisol, was obtained. No LH modifications after DXM were obtained in any of the cases. Our results demonstrate that there is no common androgenic abnormality in IH. It is possible to obtain normal or high circulating T levels. The findings of this study also suggest that the adrenals, to ovary or both may be the sources of high T levels.

Adolescent↗