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Mitchell S. Kostich - One of the best experts on this subject based on the ideXlab platform.
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A computational model of the hypothalamic - pituitary - gonadal axis in female fathead minnows (Pimephales promelas) exposed to 17α-ethynylestradiol and 17β-trenbolone
BMC Systems Biology, 2011Co-Authors: Zhenhong Li, Jayne V. Brian, Kevin J Kroll, Kathleen M Jensen, Edward F Orlando, James M. Lazorchak, Maria S Sepulveda, Mitchell S. KostichAbstract:Background: Endocrine disrupting chemicals (e.g., estrogens, androgens and their mimics) are known to affect reproduction in fish. 17a-ethynylestradiol is a synthetic estrogen used in birth control pills. 17b-trenbolone is a relatively stable metabolite of trenbolone acetate, a synthetic androgen used as a growth promoter in livestock. Both 17a-ethynylestradiol and 17b-trenbolone have been found in the aquatic environment and affect fish reproduction. In this study, we developed a physiologically-based computational model for female fathead minnows (FHM, Pimephales promelas), a small fish species used in ecotoxicology, to simulate how estrogens (i.e., 17a-ethynylestradiol) or androgens (i.e., 17b-trenbolone) affect reproductive endpoints such as plasma concentrations of steroid hormones (e.g., 17b-estradiol and testosterone) and vitellogenin (a precursor to egg yolk proteins). Results: Using Markov Chain Monte Carlo simulations, the model was calibrated with data from unexposed, 17aethynylestradiol-exposed, and 17b-trenbolone-exposed FHMs. Four Markov chains were simulated, and the chains for each calibrated model parameter (26 in total) converged within 20,000 iterations. With the converged parameter values, we evaluated the model’s predictive ability by simulating a variety of independent experimental data. The model predictions agreed with the experimental data well. Conclusions: The physiologically-based computational model represents the hypothalamic-pituitary-gonadal axis in adult female FHM robustly. The model is useful to estimate how estrogens (e.g., 17a-ethynylestradiol) or androgens (e.g., 17b-trenbolone) affect plasma concentrations of 17b-estradiol, testosterone and vitellogenin, which are important determinants of fecundity in fish.
Patricio Soaresdasilva - One of the best experts on this subject based on the ideXlab platform.
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effect of eslicarbazepine acetate on the pharmacokinetics of a combined Ethinylestradiol levonorgestrel oral contraceptive in healthy women
Epilepsy Research, 2013Co-Authors: Amilcar Falcao, Luis Almeida, Patricio Soaresdasilva, Teresa G. Nunes, Helena Gama, Manuel VazdasilvaAbstract:Summary Objective To investigate the effect of once-daily (QD) eslicarbazepine acetate (ESL) 800mg and 1200mg administration on pharmacokinetics of a combined Ethinylestradiol/levonorgestrel oral contraceptive (OC) in women of childbearing potential. Methods Two two-way, crossover, two-period, randomized, open-label studies were performed in 20 healthy female subjects, each. In one period (ESL+OC period), subjects received ESL 800mg QD in one study and ESL 1200mg QD in the other study, for 15 days; concomitantly with the Day 14 ESL dose, an oral single dose of 30μg Ethinylestradiol and 150μg levonorgestrel was administered. In the other period (OC alone), a single dose of 30μg Ethinylestradiol and 150μg levonorgestrel was administered. Three weeks or more separated the periods. An analysis of variance (ANOVA) was used to test for differences between pharmacokinetic parameters of 30μg Ethinylestradiol and 150μg levonorgestrel following ESL+OC and OC alone, and 90% confidence intervals (90%CI) for the ESL+OC/OC alone geometric mean ratio (GMR) were calculated. Results ESL significantly decreased the systemic exposure to both Ethinylestradiol and levonorgestrel. GMR (90%CI) for AUC 0–24 of Ethinylestradiol were 68% (64%; 71%) following 1200mg ESL and 75% (71%; 79%) following 800mg ESL. GMR (90%CI) for AUC 0–24 of levonorgestrel were 76% (68%; 86%) following 1200mg ESL and 89% (82%; 97%) following 800mg ESL. Conclusions A clinically relevant dose-dependent effect of ESL administration on the pharmacokinetics of Ethinylestradiol and levonorgestrel was observed. Therefore, to avoid inadvertent pregnancy, women of childbearing potential should use other adequate methods of contraception during treatment with ESL, and, in case ESL treatment is discontinued, until CYP3A4 activity returns to normal.
Tasuku Harada - One of the best experts on this subject based on the ideXlab platform.
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efficacy and safety of a flexible extended regimen of Ethinylestradiol drospirenone for the treatment of dysmenorrhea a multicenter randomized open label active controlled study
International Journal of Women's Health, 2017Co-Authors: Mikio Momoeda, Masami Kondo, Joerg Elliesen, Masanobu Yasuda, Shigetomo Yamamoto, Tasuku HaradaAbstract:Background Dysmenorrhea is a common condition in women, which is characterized by menstrual pain. Low-dose estrogen/progestin combined oral contraceptives have been shown to reduce the severity of dysmenorrhea symptoms, and a 28-day cyclic regimen of Ethinylestradiol/drospirenone (28d regimen) is approved for this indication in Japan. Aim The aim of this study was to assess the safety and efficacy of a flexible extended regimen of Ethinylestradiol/drospirenone (flexible regimen) in Japanese women with dysmenorrhea. Methods This multicenter, open-label study was performed in Japanese women with dysmenorrhea who, after a baseline observational phase, were randomized to receive Ethinylestradiol 20 μg/drospirenone 3 mg in a flexible regimen (one tablet each day for 24-120 days followed by a 4-day tablet-free interval) or in the standard 28d regimen (one tablet each day for 24 days, followed by 4 days of placebo tablets for six cycles). The primary endpoint was the number of days with dysmenorrhea of at least mild intensity over a 140-day evaluation period. Dysmenorrhea scores, bleeding patterns, and other pain-related parameters were also assessed. Results A total of 216 women (mean age 29.7 years) were randomized to the flexible regimen (n=108) or 28d regimen (n=108) and 212 were included in the full analysis sets (flexible regimen, n=105; 28d regimen, n=107). Women in the flexible-regimen group reported a mean of 3.4 fewer days with dysmenorrheic pain than women in the 28d-regimen group, with similar decreases in disease severity reported in both treatment groups. According to the investigators, 64.8% and 59.4% of women in the flexible-regimen and 28d-regimen treatment groups had "very much improved" or "much improved" disease, while 54.3% and 50.9% of patients reported being "very much satisfied" or "much satisfied" with their treatment, respectively. Conclusion In Japanese women with dysmenorrhea, a flexible extended regimen of Ethinylestradiol/drospirenone decreased the number of days with dysmenorrheic pain versus the traditional 28d regimen.
Zhenhong Li - One of the best experts on this subject based on the ideXlab platform.
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A computational model of the hypothalamic - pituitary - gonadal axis in female fathead minnows (Pimephales promelas) exposed to 17α-ethynylestradiol and 17β-trenbolone
BMC Systems Biology, 2011Co-Authors: Zhenhong Li, Jayne V. Brian, Kevin J Kroll, Kathleen M Jensen, Edward F Orlando, James M. Lazorchak, Maria S Sepulveda, Mitchell S. KostichAbstract:Background: Endocrine disrupting chemicals (e.g., estrogens, androgens and their mimics) are known to affect reproduction in fish. 17a-ethynylestradiol is a synthetic estrogen used in birth control pills. 17b-trenbolone is a relatively stable metabolite of trenbolone acetate, a synthetic androgen used as a growth promoter in livestock. Both 17a-ethynylestradiol and 17b-trenbolone have been found in the aquatic environment and affect fish reproduction. In this study, we developed a physiologically-based computational model for female fathead minnows (FHM, Pimephales promelas), a small fish species used in ecotoxicology, to simulate how estrogens (i.e., 17a-ethynylestradiol) or androgens (i.e., 17b-trenbolone) affect reproductive endpoints such as plasma concentrations of steroid hormones (e.g., 17b-estradiol and testosterone) and vitellogenin (a precursor to egg yolk proteins). Results: Using Markov Chain Monte Carlo simulations, the model was calibrated with data from unexposed, 17aethynylestradiol-exposed, and 17b-trenbolone-exposed FHMs. Four Markov chains were simulated, and the chains for each calibrated model parameter (26 in total) converged within 20,000 iterations. With the converged parameter values, we evaluated the model’s predictive ability by simulating a variety of independent experimental data. The model predictions agreed with the experimental data well. Conclusions: The physiologically-based computational model represents the hypothalamic-pituitary-gonadal axis in adult female FHM robustly. The model is useful to estimate how estrogens (e.g., 17a-ethynylestradiol) or androgens (e.g., 17b-trenbolone) affect plasma concentrations of 17b-estradiol, testosterone and vitellogenin, which are important determinants of fecundity in fish.
Stefano Venturoli - One of the best experts on this subject based on the ideXlab platform.
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polycystic ovary syndrome and cardiovascular risk in young patients treated with drospirenone Ethinylestradiol or contraceptive vaginal ring a prospective randomized pilot study
Fertility and Sterility, 2010Co-Authors: Cesare Battaglia, Nicola Persico, Fulvia Mancini, Raffaella Fabbri, Fabio Facchinetti, Paolo Busacchi, Stefano VenturoliAbstract:Objective To compare the effects of a pill containing drospirenone with those of a combined contraceptive vaginal ring on the lipid and carbohydrate metabolism and on the surrogate markers of arterial function. Setting Bologna University School of Medicine. Patient(s) Thirty-seven women with polycystic ovary syndrome (PCOS) were randomly submitted to drospirenone + Ethinylestradiol (group I; n=19) or combined contraceptive vaginal ring (group II; n=18) therapy. The duration of the study was 6 months. Intervention(s) The effect of treatments was assessed after 6 months of therapy. Main Outcome Measure(s) Utero-ovarian ultrasound analysis and color Doppler evaluation of uterine and stromal ovarian arteries. In addition, analysis of brachial artery flow-mediated vasodilatation and 24-hour ambulatory blood pressure monitoring were performed. Fasting blood samples were drawn for testing biochemical and hormonal parameters and nitrites/nitrates. Result(s) Both treatments improved hirsutism, hyperandrogenemia, and ultrasound and color Doppler ovarian parameters. Both drospirenone + Ethinylestradiol or contraceptive vaginal ring induced a slight but significant increase of diurnal and 24-hour blood pressure. Although both therapies worsened the lipid profile, the oral pill administration was associated with a more evident increase of circulating triglycerides. The 6-month treatment with the vaginal ring significantly improved the area under the curve for glucose, insulin, and C-peptide, whereas the drospirenone + Ethinylestradiol pill induced an increase in the insulinogenic index and homeostatic model assessment estimate for insulin resistance values. Conclusion(s) Vaginal hormonal contraception appears to be preferable to oral Ethinylestradiol + drospirenone administration in hyperinsulinemic patients with PCOS.