112,096 research outputs found
Graziella : valse brillante pour piano : op. 50 : piano / par Adolphe Botte ; [couv. ornée par] A. V.
No full textTitre uniforme : Botte, Adolphe (1823-18..). Compositeur. [Graziella. Op. 50]Valses (piano) -- +* 1800......- 1899......+:19e siècle:Piano, Musique de -- +* 1800......- 1899......+:19e siècle
Progettazione,sintesi e caratterizzazione di peptici ad azione dismetabolica sugli insetti.
No full textromatase and testosterone receptor in the liver of the female green frog, Rana esculenta.
No full textIn the green frog, Rana esculenta, a peculiar feature of female reproductive endocrinology is an high level of circulating testosterone. Although several hypotheses have been set out to explain this phenomenon, the testosterone specific roles in female anuran have not been yet fully explored. This study results propose a testosterone implication in liver vitellogenin synthesis control, since in ovariectomized frogs the hormone induces an increase of circulating vitellogenin. The testosterone action could depend on its local conversion to 17beta-estradiol by aromatase which is present in frog liver tissue. Liver aromatase activity ranges from 7.5 to 26 fmoles E2 formed/mg protein/h and results higher as long as liver is engaged in vitellogenin synthesis. Aromatase activity seems depend on testosterone since it decreases after ovariectomy and is restored by testosterone injection in ovariectomized frogs. In green frog liver, testosterone binding molecules are present both in cytosol and nuclei. These molecule binding properties (Kd and Bmax in nM range; t 1/2 = 85 min; specificity) are in line with those of testosterone receptor of other lower vertebrate target tissue. In liver nuclei, testosterone receptor level undergoes modification throughout the sexual cycle which almost coincides with that of plasma testosterone level and liver aromatase activity. This could indicate that the testosterone induction of liver aromatase in frogs is via the testosterone receptor, as reported for aromatase of mammalian brain tissues
The BH-bulge relation for Narrow-Line Seyfert 1 and Seyfert 1
No full textWe have studied a sample of NLS1 in order to understand thoroughly these active galaxies. Our preliminary results suggest that a BH-bulge relation exists also for NLS1 but conclusions are still in conflict. M(Black Hole) - M(Bulge) and MBH - σ let us think of opposite scenarios about the nature of NLS1. We show that, in order to make clear if NLS1 do fill the lower ranges of the BH-bulge relation, it is necessary a direct measure of the stellar velocity dispersion in the nuclei of these galaxies
Progettazione,sintesi e caratterizzazione di peptici ad azione dismetabolica sugli insetti.
No full textPROSTAGLANDIN-F2-ALPHA AND PLASMATIC SEXUAL STEROIDS IN FEMALE GREEN FROG, RANA-ESCULENTA
No full textA POSSIBLE INVOLVEMENT OF PROSTAGLANDIN-E2 IN THE REPRODUCTION OF FEMALE CRESTED NEWT, TRITURUS-CARNIFEX
No full textPlasma prostaglandin E2 (PGE2), prostaglandin F2-alpha (PGF2-alpha), and sex steroid hormones (progesterone, androgens, and 17-beta-estradiol) were determined in the female crested newt, Triturus carnifex, during the annual reproductive cycle. In vivo experiments were carried out to study the effects of PGE2 and PGF2-alpha on plasma sex steroid hormones during prereproduction, reproduction, and postreproduction; simultaneously, in vitro experiments were performed to study the effects of these two prostaglandins on sex steroid hormones ovarian release. The effects of one week's captivity on PGE2, PGF2-alpha and sex steroid hormones were also evaluated. The PGE2 plasma level was low from October to December, then it rapidly increased to peak in March, after which it soon fell to reach its minimum value in May. Plasma PGF2-alpha and sex steroid hormones showed similar trends to those found in previous studies. From December to April, the PGE2 plasma values were negatively correlated to those of PGF2-alpha and positively to those of androgens; PGF2-alpha plasma values were positively correlated to those of estradiol. PGE2 in vivo treatment increased plasma progesterone and decreased 17-beta-estradiol in April, while PGF2-alpha induced the opposite effects in the same month; PGE2 increased androgens in January and March, and PGF2-alpha increased androgens in April. The in vitro experiments were in agreement. These results suggest that PGE2 and PGF2-alpha play opposite role(s) in the reproductive processes of the female Triturus carnifex. PGE2 could be involved in the reproduction processes through androgen secretion, while PGF2-alpha in the ending of reproduction through estradiol increas
Plasma prostaglandin F2 alpha in the male Triturus carnifex (Laur.) during the reproductive annual cycle and effects of exogenous prostaglandin on sex hormones.
No full textPlasma patterns of prostaglandin F2 alpha (PGF2 alpha) and sex hormones (progesterone, androgens and 17 beta-estradiol) have been studied in the male crested newt, Triturus carnifex (Laur.), during the sexual cycle. The effects of exogenous PGF2 alpha on sex steroids have also been observed. In addition, effects of one week's captivity are reported. The patterns of plasma sex hormones, during the annual cycle, are consistent with the results previously reported for the same newt species. PGF2 alpha plasma level peaks in April, is low in summer, and progressively increases during autumn to peak again in December. The April PGF2 alpha peak coincides with a plasma estradiol increase and with an androgens drop. In April-collected newts, moreover, PGF2 alpha treatment induces a significant estradiol increase. These findings lead us to suppose that at the end of the breeding season (April) a PGF2 alpha-dependent estradiol synthesis occurs which could be implied in reproductive period termination. In several vertebrates, including some amphibian species, in fact, chronic administration of estradiol results in a strong inhibition of testicular endocrine tissue activity. The putative role of PGF2 alpha-dependent estradiol production in the gonadal regulation in amphibia living in temperate zones is discussed. The autumn PGF2 alpha increase has been tentatively related to the recovery gonadal processes and secondary sexual character development
Effects of short postcapture confinement on plasma reproductive hormone and corticosterone profiles in rana esculenta during the sexual cycle
No full textThe effects of short-term confinement (24 hours) on the plasma levels of gonadal hormones and corticosterone have been evaluated in Rana esculenta, which is widely used in amphibian reproductive physiology studies. A 24-h confinement has been chosen since this is the time that usually elapses from frog capture to utilization. Although short confinement does not influence the morphological aspect of gonads, genital tracts (oviduct in the female) and secondary sexual characters (thumbpads in the male), it causes a significant decrease of testosterone in both sexes, and of progesterone and estradiol in the female only. The confinement effects vary depending on the sexual cycle phase, but plasma hormonal patterns during the year are, on the whole, maintained. Plasma hormonal drop in captive frogs is coupled with an increase of circulating corticosterone, the administration of which strengthens the captivity effects. The results were considered to support the fact that, like in other vertebrates, plasma hormonal changes in short-term confined frogs depend on a stress-related increase of circulating corticosterone. This hormone, in fact, inhibits sex hormone synthesis and/or release either by a local action on the gonads or by a depression of hypothalamus-pituitary axis. Capture effects, therefore, should be considered in any study of relationships between circulating sex hormone profiles and gonadal activity during the annual cycle. © 1990 Taylor & Francis Group, LLC
- …
