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Biomedical subjects

E Menini

Publications and source records attributed to E Menini.

At least 55 records · Page 3Linked to original sources

Comparative studies in two cases of testicular feminization syndrome, one with and the other without the fluorescent distal band q12 of the Y.

In two patients with testicular feminization syndrome, one Yq12-positive and the other Yq12-negative, we compared phenotype, gonadal histology and ultrastructure, in vivo steroid response of the testes to the administration of exogenous gonadotropin during adrenal suppression, and of the adrenal gland to ACTH. The assumption that the constitutive Y heterochromatin could function as a regulator of steroid biosynthesis and metabolism, with or without effect at other levels, was not firmly supported by the observations reported here. However, further studies along this line may help elucidate the biologic role of this portion of the Y chromosome in humans.

Adrenal Glands↗

Four cases of pregnancy with low estrogen production due to placental enzymatic deficiency.

4 cases of normal pregnancies associated with low estriol excretion and resulting in healthy infants are described, in which by in vitro studies on the placentas a steroid 3-sulfatase deficiency was found in 3 cases and a lack of activity of the aromatizing system was found in the 4th case. A reduced activity of the aromatizing system was also shown in one of the cases affected by steroid 3-sulfatase defect. The placental 3 beta-hydroxysteroid dehydrogenase, delta 4,5-isomerase system was measured in 3 cases and results were normal. The repetition of the specific lack of steroid 3-sulfatase was observed in 2 successive pregnancies of the same patient (case T.C.). It is interesting to note that, at variance with other reports, this patient delivered 2 fetuses, both female.

3-Hydroxysteroid Dehydrogenases↗

Serum prolactin response to thyrotropin-releasing hormone and metoclopramide in patients with prolactin-secreting tumors before and after transsphenoidal surgery.

Seven female patients with amenorrhea, galactorrhea, and hyperprolactinemia were examined before and after selective transsphenoidal removal of a PRL-secreting microadenoma. Before adenomectomy, metoclopramide (MCP; 10 mg orally) and TRH (200 micrograms iv) did not increase PRL blood levels in any of the seven patients. On the contrary, after oral administration of 10 mg MCP, a positive response was noted in a group of eight lactating women 3 days postpartum. After surgery, serum PRL level returned to normal in all patients. A positive PRL response to MCP and TRH was found in six of the seven patients 1 month after surgery. One patient, who had the lowest PRL level, failed to show a PRL increase after both stimuli. These findings indicate that hypothalamic pituitary function can be restored to normal after transsphenoidal removal of PRL-secreting pituitary tumors.

Adenoma↗

Effects of dehydroepiandrosterone and 16 alpha-hydroxydehydroepiandrosterone on the reduction of glucose to glucitol by the human placenta.

The metabolism of glucose by subcellular preparations of human full term placentae has been investigated. It has been shown that in the presence of NADPH two transformation products can be detected of which one has been identified as glucitol. The effects of dehydroepiandrosterone and 16alpha-hydroxydehydroepiandrosterone on the reduction of glucose to glucitol have also been studied. It has been found that at a concentration of DHA 1.2 X 10(-4)M, the reduction of glucose is strongly inhibited (35-51%), while at a concentration of DHA 5.8 X 10(-6)M this reaction is stimulated by 13 +/- 2.3%. 16alpha-hydroxyepiandrosterone at concentrations ranging from 1.2 X 10(-4)M to 3 X 10(-6)M inhibits the formation of glucitol from 63% to 9%.

Dehydroepiandrosterone↗

Serum levels and biochemical characterization of oestradiol-17 beta dehydrogenase in umbilical cord blood.

The properties of the enzyme oestradiol-17 beta dehydrogenase from human umbilical cord serum have beem compared with those of oestradiol-17 beta dehydrogenase present in the maternal peripheral blood. On the basis of studies on stability, specificity, optimum pH, rate of enzymic reaction and Km determinations it can be concluded that oestradiol-17 beta dehydrogenase in the umbilical cord arteries has an activity between 5 and 15 times higher than in the umbilical cord vein and about 65% of the activity of the enzyme present in the maternal peripheral blood. The present results strongly suggest that in pregnancy the enzyme oestradiol-17 beta dehydrogenase is elaborated not only by the placenta but also by the foetus.

Blood↗

Enchancement of deficient pituitary response to luteinizing hormone releasing hormone in patients with primary amenorrhea.

Although the absence of pituitary response to the luteinizing hormone releasing hormone (LHRH) test has been considered proof of a lesion primarily localized at the pituitary level, the possibility exists that an absent pituitary response may represent only the effect of a chronic deficiency of hypothalamic secretion. To verify this hypothesis, 4 patients with primary amenorrhea, hypogonadotropic hypogonadism, and deficient or absent responses to a 25 mug LHRH rapid IV test were treated with 400 mug LHRH infused in 7 hours during each of 3 successive days. The finding that patients with deficient LH responses to a rapid LHRH test became normally responsive to a second equivalent test after a slow and prolonged treatment with the decapeptide suggests that, in these patients, besides a lesion at the pituitary level, a primary defect at the hypothalamic or higher centers may also be suspected.

Adolescent↗

[Comparison of chemical and radiochemical methods in determination of steroid hormones].

While in some cases steroids can be measured directly in serum or plasma by radioimmunoassay (RIA), in other cases, especially when analyses are carried out in urine, the samples must be processed before RIA can be performed. The operations involved in the preparation of urinary or blood extracts suitable for the RIA of steroid hormones are examined and compared in terms of practicability with the analytical procedures currently used for the chemical determination of the same steroids or their metabolites.

17-Hydroxycorticosteroids↗

The indirect analysis of 17-oxosteroid glucosiduronates and sulphates in human urine.

1. An analytical procedure has been developed for the determination of urinary 17-oxosteroid sulphates and 11-deoxy-17-oxosteroid glucosiduronates. 2. By submitting urine to the following operations: (a) extraction of the 17-oxosteroid conjugates into chloroform (in the presence of pyridinium sulphate), (b) solvolysis (in the absence of acid) of the steroid sulphates, (c) separation of the steroid glucosiduronates, (d) hydrolysis of the glucosiduronates, (e) oxidation with tert.-butyl chromate of the liberated steroids and (f) analysis of the final extracts by gas-liquid chromatography, the 17-oxosteroid conjugates are converted into and measured as androstanediones and androstane-(ene)triones. 3. Values for the daily excretion of 17-oxosteroid glucosiduronates and sulphates in normal men and women are given.

Chromatography, Gas↗

Ovarian and peripheral steroid hormones in a case of Sertoli-Leydig cell tumor.

The clinical course, histology, and steroid secretion of a 59-year-old postmenopausal woman with a 4-yr history of virilizing well-differentiated Sertoli-Leydig cell tumor of the right ovary are reported. Hormone secretion was examined by measuring peripheral and ovarian venous gradients and pre-and postoperative levels of some delta 4 and delta 5 steroids, estrogens, gonadotropins and Sex Hormone Binding Globulin levels. The preoperative responsiveness to ACTH, dexamethasone and hCG is also reported. The results are consistent with a Sertoli-Leydig cell tumor producing mainly testosterone and, to a lesser degree, androstenedione, progesterone, estrone and 17 alpha-hydroxyprogesterone. The tumor hormone secretion may be in part responsive to hCG.

Adrenocorticotropic Hormone↗

Effects of progesterone administration on follicle-stimulating hormone and prolactin release in estrogen treated eugonadal adult men.

In order to investigate the modulatory effect of steroids on FSH secretion in vivo, we studied 16 human males, aged 51-81 years, affected by prostatic carcinoma. They were given estradiol or E2 plus progesterone (P), added at different times during E2 treatment. Daily blood samples were collected in order to determine LH, FSH, and PRL levels; moreover, blood samples were collected at 2 h intervals for 12 h on the day of P administration. We observed the expected biphasic effect on LH secretion, whereas daily basal FSH levels, during E2 treatment, decreased gradually and progressively from the first day until the end of the study. FSH levels exhibited, after P administration, wide fluctuations, with peak levels observed from 2 to 6 h after P in 4 of 6 patients studied (at 72 h during E2 treatment). A clear trend toward FSH increase was also observed in 3 out of 5 patients in whom P was administrated 96 h after starting E2 administration. In this case, FSH increases were delayed, becoming evident between 8th and 10th h after P injection. Finally, during E2 administration basal PRL levels showed a progressive increase, which was significant in all three groups. In conclusion, these data confirm the biphasic effects of estrogen administration on LH secretion in eugonadal adult human males; while estrogens alone showed an inhibitory effect on FSH secretion, the addition of P induced also a positive action, resulting in a clear FSH peak in some patients tested. The time course of E2 and P administration seems to be critical for the hormone response pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗