8 resultados para Androgen Levels

em DI-fusion - The institutional repository of Université Libre de Bruxelles


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Hypogammaglobulinemia (hypo-Ig) and low mannose binding protein (MBP) levels might be involved in the infectious risk in renal transplantation. In 152 kidney transplant recipients treated with calcineurin inhibitors (CNI) and mycophenolate mofetil (MMF), during the first year, we prospectively recorded the incidence of hypogammaglobulinemia, and low MBP levels. Their influence on infectious complications was evaluated in 92 patients at 3 and 12 months (T3 and T12). The proportion of deficiency increased significantly: hypo-IgG: 6% (T0), 45% (T3), and 30% (T12) (P < 0.001); hypo-MBP: 5%, 11%, and 12% (P = 0.035). Hypo-IgG at T3 was not associated with an increased incidence of first-year infections. A significantly higher proportion of patients with combined hypogammaglobulinemia [IgG+ (IgA and/or IgM)] at T3 and with isolated hypo-IgG at T0 developed infections until T3 compared with patients free of these deficits (P < 0.05). Low MBP levels at T3 were associated with more sepsis and viral infections. Hypogammaglobulinemia is frequent during the first year after renal transplantation in patients treated with a CNI and MMF. Hypo-IgG at T0 and combined Igs deficts at T3 were associated with more infections. MBP deficiency might emerge as an important determinant of the post-transplant infectious risk.

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Background: Anti-Müllerian hormone (AMH), secreted by the granulosa cells of preantral and small antral follicles, has been described as a potential marker of the ovarian reserve. The aim of this prospective study is to investigate the variations of AMH during the menstrual cycle in a young selected population of normo-ovulatory women and to analyse the correlation with other cyclic hormones. Methods: Twenty healthy volunteers from 19 to 35 years old, with regular menstrual cycles (26-31 days), normal ovulation (day 10-16), normal hormonal profile and normal body mass index (18-26 kg/m2) were recruited. AMH, inhibin B, LH, FSH, estradiol and progesterone were measured on days 3, 7, 10, 11, 12, 13, 14, 15, 16, 18, 21 and 25 of a spontaneous cycle. Results: AMH serum levels, either expressed by cycleday or aligned according to the ovulation day, did not show any significant variations during the menstrual cycle. Conclusions: No significant fluctuation of the AMH level during the menstrual cycle was observed. Therefore, this hormone is particularly interesting for clinical evaluation of the ovarian reserve as it may be used at any time during the cycle. © The Author 2007.

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info:eu-repo/semantics/nonPublished

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To understand how a signaling molecule's activities are regulated, we need insight into the processes controlling the dynamic balance between its synthesis and degradation. For the Ins(1,3,4,5,6)P5 signal, this information is woefully inadequate. For example, the only known cytosolic enzyme with the capacity to degrade Ins(1,3,4,5,6)P5 is the tumour-suppressor PTEN [J.J. Caffrey, T. Darden, M.R. Wenk, S.B. Shears, FEBS Lett. 499 (2001) 6 ], but the biological relevance has been questioned by others [E.A. Orchiston, D. Bennett, N.R. Leslie, R.G. Clarke, L. Winward, C.P. Downes, S.T. Safrany, J. Biol. Chem. 279 (2004) 1116 ]. The current study emphasizes the role of physiological levels of PTEN in Ins(1,3,4,5,6)P5 homeostasis. We employed two cell models. First, we used a human U87MG glioblastoma PTEN-null cell line that hosts an ecdysone-inducible PTEN expression system. Second, the human H1299 bronchial cell line, in which PTEN is hypomorphic due to promoter methylation, has been stably transfected with physiologically relevant levels of PTEN. In both models, a novel consequence of PTEN expression was to increase Ins(1,3,4,5,6)P5 pool size by 30-40% (p<0.01); this response was wortmannin-insensitive and, therefore, independent of the PtdIns 3-kinase pathway. In U87MG cells, induction of the G129R catalytically inactive PTEN mutant did not affect Ins(1,3,4,5,6)P(5) levels. PTEN induction did not alter the expression of enzymes participating in Ins(1,3,4,5,6)P5 synthesis. Another effect of PTEN expression in U87MG cells was to decrease InsP6 levels by 13% (p<0.02). The InsP6-phosphatase, MIPP, may be responsible for the latter effect; we show that recombinant human MIPP dephosphorylates InsP6 to D/L-Ins(1,2,4,5,6)P5, levels of which increased 60% (p<0.05) following PTEN expression in U87MG cells. Overall, our data add higher inositol phosphates to the list of important cellular regulators [Y. Huang, R.P. Wernyj, D.D. Norton, P. Precht, M.C. Seminario, R.L. Wange, Oncogene, 24 (2005) 3819 ] the levels of which are modulated by expression of the highly pleiotropic PTEN protein.

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The most potent steroid in human prostatic carcinoma LNCaP cells, i.e. dihydrotestosterone (DHT), has a biphasic stimulatory effect on cell proliferation. At the maximal stimulatory concentration of 0.1 nM DHT, analysis of cell kinetic parameters shows a decrease of the G0-G1 fraction with a corresponding increase of the S and G2 + M fractions. In contrast, concentrations of 1 nM DHT or higher induce a return of cell proliferation to control levels, reflected by an increase in the G0-G1 fraction at the expense of the S and especially the G2 + M fractions. Continuous labeling for 144 h with the nucleotide analogue 5'-bromodeoxyuridine shows that the percentage of cycling LNCaP cells rises more than 90% after treatment with stimulatory concentrations of DHT, whereas in control cells as well as in cells treated with high concentrations of the androgen, this value remains below 50%. Although LNCaP cells do not contain detectable estrogen receptors, the new pure steroidal antiestrogen EM-139 not only reversed the stimulation of cell proliferation and cell kinetics induced by stimulatory doses of DHT but also inhibited basal cell proliferation.

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Although steroid hormones are known to play a predominant role in the regulation of cell growth in hormone-sensitive cancers, their mechanisms of action, especially their interaction with growth factors and/or growth inhibitors, is poorly understood. We have recently observed that the effects of androgens and estrogens on the expression of the major protein found in human breast gross cystic disease fluid, protein-24, are opposite to their respective action on cell proliferation in human breast cancer cell lines. Somewhat surprisingly, the recent elucidation of the amino acid sequence of this progesterone binding protein reveals that this tumor marker is apolipoprotein D (apo D), a member of a superfamily of lipophilic ligand carrier proteins. The present study was designed to determine whether apo D is secreted by human prostate cancer cells and could thus be a new marker of steroid action in these cancer cells, and whether the sex steroid-induced stimulation of apo D secretion coincides with inhibition of cell proliferation. We took advantage of the biphasic pattern of the effect of steroids on the proliferation of the human prostate cancer LNCaP cell line, which offers the opportunity to discriminate between positive and negative steroid receptor-regulated cell growth processes. A 10-day exposure to low concentrations of dihydrotestosterone and testosterone caused a potent stimulation of LNCaP cell proliferation, whereas incubation with higher concentrations of these androgens led to a progressive decrease in cell proliferation towards basal levels. The biphasic action of androgens was also observed on apo D secretion, the effects on apo D secretion being inversely related to their action on LNCaP cell proliferation. Similar opposite biphasic effects were also observed with 9 other steroids, thus indicating that the stimulation of secretion of this new biochemical marker coincides with inhibition of cell proliferation in LNCaP human prostatic cancer cells.