Hugo E. Scaglia

Bone Mineral Density and Bone Size in Men With Primary Osteoporosis and Vertebral Fractures

Abstract. The bone mineral density (BMD) at the lumbar spine, proximal femur, and total skeleton was evaluated in 38 men with primary osteoporosis and vertebral fractures. BMD of the patients was significantly reduced over all skeletal areas compared with controls. The Z-score of the lumbar spine (−2.8 ± 0.9) was less than that of the other areas (P < 0.001) except the legs (−2.5 ± 1.1) (p.n.s.) showing that bone loss had a tendency to be greater over the axial skeleton. Vertebral dimensions compared with age-matched controls were as follows: projected L2–L4 area (cm 2): 45.7 ± 5.6 versus 53.7 ± 3.6 (P < 0.001); vertebral width (cm): 4.37 ± 0.44 versus 4.90 ± 0.36 (P < 0.001). Serum biochemical parameters and testosterone levels were similar between osteoporotic and control men. We conclude that men with vertebral osteoporotic fractures have reduced vertebral BMD and vertebral dimensions compared with age-matched controls. Thus, these findings indicate that the achievement of a reduced bone size at the end of the growth period or a failure of periosteal increase during adult life is likely to contribute to the pathogenesis of the vertebral fractures observed in older men.

Analysis of the hypothalamic-pituitary-ovary axis in the neonatally-androgenized female rat

The administration of testosterone propionate (TP) in the female rat at the neonatal age has been used for several yr as a model to study anovulation during adulthood. The present work was designed in order to see whether some neuroendocrine parameters vary with age in this animal model. Hypothalamic LHRH content and LH-FSH anterior pituitary (AP) content and plasma levels were evaluated in samples taken from both neonatally-androgenized and littermate control female rats at different ages (15 to 100 days old). Additionally, we have studied pulsatile LH-FSH released in plasma and in vivo AP response to LHRH in both neonatally-androgenized and control female rats during adulthood. The results indicate that the neonatal TP treatment did not induce any change in hypothalamic LHRH content over development. Neonatally androgenized rats have decreased both LH-FSH AP content and plasma levels at the infantile age (15-day old). LH-FSH AP content remained reduced in samples taken up to the 30th day of age. Plasma LH-FSH levels on the day 30 of age were similar in both groups. TP-treated rats studied on the 100th day of age had: a) an altered pulsatile rhythm of gonadotropin release in plasma due to the decreased LH-FSH trough and average mean values, and to the diminished FSH peak amplitude values, as well as an increased LH:FSH ratio; and b) an impaired in vivo LHRH-induced LH-FSH release. In summary, the present study indicates that after the neonatal treatment with TP: 1) a reduction on both LH-FSH AP content and plasma levels is established at the infantile age, 2) a decreased pattern of pulsatile LH-FSH secretion in plasma is seen during adulthood, which is probably due, at least in part, to a decreased AP response to LHRH stimulation, and 3) although the synthesis of hypothalamic LHRH had not been altered over development, a modification of median eminence LHRH secretion into the portal blood must be not excluded. These results further suggest that the neonatal administration of TP could induce permanent sterility in the female rat by altering the AP function. Whether this treatment also alters other peripheral glands (ovary and/or adrenal) still remains unclear.

Failure of the Müllerian regression factor in two patients with complete androgen insensitivity syndrome

SummaryThe present paper describes the histological and endocrinologic features of 2 subjects with 46,XY karyotype affected by complete androgen insensitivity syndrome (AIS) with müllerian structures. Both patients had fallopian tubes, but only one had also uterus and presented a seminoma. Serum levels of luteinizing hormone, testosterone and estradiol were high or in the upper part of normal limits, whereas levels of follicle-stimulating hormone were normal. The association between AIS and the presence of müllerian structures observed in these 2 patients might be explained by an impaired synthesis of müllerian regression factor or by a failure in its mechanism of action.

Sleep-dependent hyperprolactinemia andCorpus luteum pathogenesis

SummaryThe results obtained in wake and sleep conditions by PRL determinations performed in 6 normoprolactinemic infertile women with determined by RIA in blood samples collected at 20-min intervals from 1800 to 0800. LPD has been previously demonstrated by endometrial biopsy, basal temperature and circulating progesterone determinations. PRL levels were also determined in 5 normal women used as control subjects under the same experimental conditions. The results obtained, expressed as means±SD of LPDvs. control group, were 15.9±4.6vs. 11.6±3.3 ng/ml (p>0.1) in wake conditions and 31.9±5.9vs. 21.4±5.7 ng/ml (p<0.01) in sleep conditions. PRL values during the highest pulse (HP) in sleep and wake conditions were 20.9±5.2vs. 17.0±3.3 ng/ml (p<0.1) and 51.1±17.1vs. 34.3±2.4 ng/ml (p<0.01), respectively. In 2 out of the 6 patients mean PRL values were 22.0 and 26.5 ng/ml during sleep, and 26.0 and 33.0 ng/ml during HP. These values were not statistically significant when compared with those obtained in the control group. The results obtained show that 4 out of the 6 patients with LPD and normal PRL levels in wake conditions had sleep-dependent hyperprolactinemia due to the pulses with a more significant amplitude. These findings suggest that in some cases sleep-induced hyperprolactinemia might be involved in LPD pathogenesis.

Determination of serum estriol levels using a125I-radioimmunoassay

SummaryA new method of radioimmunoassay (RIA) for serum estriol (E3) which utilizes125I-estriol as a tracer has been developed. This steroid was radioiodinated with chloramine T and purified by Sephadex LH-20 column chromatography. Two hundred and sixty-two samples from 130 normal pregnant patients at different stages of gestation were analysed. From 5 women, blood samples were drawn at 15 min intervals for 1 h. An increase in the circulating levels of E3 was observed throughout normal pregnancy and the results were widely distributed. The episodic fluctuations of E3 showed a variation of 13–20 ng/ml during the same 1-h sampling period. The quality control results showed the viability of this RIA in the determination of serum E3 utilizing the iodinated steroid as a tracer.

Radioimmunoassays of human luteinizing and follicle-stimulating hormones using the same radioactive tracer

SummaryThe National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK) provides the hFSH-I-3 preparation, to be employed as a tracer in the radioimmunoassay (RIA) of human follicle-stimulating hormone (hFSH). The contaminating LH contained in that preparation led us to study whether the iodination of such a material could render it a suitable tracer for RIA of both LH and FSH. hFSH-I-3 was labelled with125I by the chloramine-T method and was further purified on Sephadex G-75 column. The LH-RIA was performed using this preparation and anti-LH at a final dilution of 1:37,500, with a sensitivity of 3 mIU LH/ml (2nd international reference pattern). The method was validated by comparing the LH values obtained in different serum samples with those obtained using the standard RIA (125I-LH/anti-LH); the correlation coefficient (r) was equal to 0.9988. No LH overestimation due to the putative cross-reaction with FSH was found. This was demonstrated by testing serum samples containing high (>100 mIU/ml) and low (<10 mIU/ml) concentrations of FSH before and after the treatment with anti-LH. Under these conditions, serum samples from postmenopausal women, pregnant women, normal men and women in basal conditions and after the LH-RH administration, and from a patient with Klinefelter’s syndrome, were evaluated. In conclusion, NIDDK125I-hFSH-I-3 can be used as a tracer for the radioimmunological quantitation of both hLH and hFSH, which results not only inexpensive, but also allows to reduce the amount of the stored radioactive materials.

Prolactin, estriol and progesterone levels in frequent blood samples throughout normal pregnancy

SummaryThe 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 the 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.