The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Mara Mather - One of the best experts on this subject based on the ideXlab platform.
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Hormonal contraceptive phases matter: Resting-state functional connectivity of emotion-processing regions under stress
Neurobiology of stress, 2020Co-Authors: Padideh Nasseri, Alexandra Ycaza Herrera, Katherine Gillette, Sophia Faude, Jessica D. White, Ricardo Velasco, Mara MatherAbstract:Abstract Hormonal contraceptives (HCs) affect cognitive processes related to emotion processing, including emotional memory, fear extinction, and the cortisol response to stress. Despite the modulating role of HCs on the stress response in women and variance in Synthetic hormone levels across the HC cycle, little is known about the phase-related effects of HCs on the brain's response to stress. We investigated the effect of HC cycle phase on functional connectivity of memory- and emotion-related regions at rest after exposure to a stressor. Twenty HC users completed two sessions of resting-state functional magnetic resonance imaging after exposure to the cold pressor test, one during the hormone-present HC phase (when Synthetic Hormones are taken) and one during the hormone-absent HC phase (when Synthetic Hormones are not taken). Women showed higher functional connectivity between left amygdala and ventromedial prefrontal cortex during the hormone-present phase. During the hormone-absent phase, women showed higher coupling between left parahippocampus and right superior lateral occipital cortex. Our results suggest that the Synthetic Hormones contained in HCs may protect against the negative effects of stress on functional connectivity of emotional processing regions.
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Brain activity during a post-stress working memory task differs between the hormone-present and hormone-absent phase of hormonal contraception.
Neurobiology of stress, 2020Co-Authors: Alexandra Ycaza Herrera, Sophia Faude, Jessica D. White, Ricardo Velasco, Philipp C. Opitz, Ringo Huang, Mara MatherAbstract:Taking hormonal contraceptives (HCs) affects the magnitude of the hormonal stress response and cognition. HCs are usually administered in a monthly cycle with both Synthetic-hormone-containing and Synthetic-hormone-absent phases. The Synthetic Hormones contained in HCs affect a wide range of neurophysiological systems, suggesting that effects of the medication might only be observed during the Synthetic-hormone-containing phase of the HC cycle. To test this, women were seen twice, once during the hormone-present phase and once during the hormone-absent phase of the HC cycle. In each session, women performed an n-back working memory task to assess pre-stress performance outside of the magnetic resonance imaging scanner, were then exposed to cold pressor stress, and again completed the n-back task during functional magnetic resonance imaging. The free cortisol response to stress remained the same across the HC cycle. Women also performed comparably on the n-back task after stress exposure across the two phases. However, despite these similarities, women displayed greater disengagement of default mode network as task demands increased during the hormone-present phase only, a pattern more in line with working memory-related brain activation under non-stressful conditions reported in other studies. The results suggest that the Synthetic Hormones contained in HCs may mitigate stress-related disruptions of typical brain activation patterns during the hormone-present phase of the HC cycle, despite exhibiting comparable cortisol responses across the HC cycle. Additional research is required to determine the mechanisms contributing to, and the extent of, such mitigating effects.
Craig D. Adams - One of the best experts on this subject based on the ideXlab platform.
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removal of estrogenic activity of natural and Synthetic Hormones from a municipal wastewater efficiency of horseradish peroxidase and laccase from trametes versicolor
Chemosphere, 2008Co-Authors: M Auriol, Craig D. Adams, Y Filalimeknassi, R D Tyagi, Tanianoelia Noguerol, Benjamin PinaAbstract:Some researches studied the removal of steroid estrogens by enzymatic treatment, however none verified the residual estrogenicity after the enzymatic treatment at environmental conditions. In this study, the residual estrogenic activities of the key natural and Synthetic steroid estrogens were investigated following enzymatic treatment with horseradish peroxidase (HRP) and laccase from Trametes versicolor. Synthetic water and municipal wastewater containing environmental concentrations of estrone, 17beta-estradiol, estriol, and 17alpha-ethinylestradiol were treated. Liquid chromatography-mass spectrometry analysis demonstrated that the studied steroid estrogens were completely oxidized in the wastewater reaction mixture after a 1-h treatment with either HRP (8-10 U ml(-1)) or laccase (20 U ml(-1)). Using the recombinant yeast assay, it was also confirmed that both enzymatic treatments were very efficient in removing the estrogenic activity of the studied steroid estrogens. The laccase-catalyzed process seemed to present great advantages over the HRP-catalyzed system for up-scale applications for the treatment of municipal wastewater.
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Laccase-catalyzed conversion of natural and Synthetic Hormones from a municipal wastewater.
Water research, 2007Co-Authors: M Auriol, Y Filali-meknassi, Rajeshwar Dayal Tyagi, Craig D. AdamsAbstract:Abstract The Trametes versicolor-derived laccase-catalyzed oxidation of natural estrogens (estrone—E1; 17β-estradiol—E2; and estriol—E3) and a Synthetic estrogen (17α-ethinylestradiol—EE2) was studied in Synthetic water and municipal wastewater to optimize the process for steroid estrogen removal in wastewater. The optimal pH for each studied steroid estrogen oxidation was approximately 6 in Synthetic water. This research also focused on the wastewater matrix effect on developed enzymatic treatment. At pH 7.0 and 25±1 °C, the experiments showed that the laccase-catalyzed system for the removal of steroid estrogens was not significantly affected by the municipal wastewater matrix. Laccase activity of 20 U/ml was sufficient to achieve complete removal of studied steroid estrogens in both Synthetic water and municipal wastewater. Moreover, 1-hydroxy-benzotriazole, when used as a mediator, improved laccase-catalyzed system efficiency, thus decreasing the overall cost of the enzymatic system.
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Oxidation of natural and Synthetic Hormones by the horseradish peroxidase enzyme in wastewater.
Chemosphere, 2007Co-Authors: M Auriol, Y Filali-meknassi, Rajeshwar Dayal Tyagi, Craig D. AdamsAbstract:Steroid estrogens, including both natural estrogens (e.g., estrone - E1; 17beta-estradiol - E2; and estriol - E3) and Synthetic estrogens (e.g., 17alpha-ethinylestradiol - EE2), are known as endocrine-disrupting compounds. The objective of this research was to evaluate the feasibility of the enzymatic oxidation of estrogens and to optimize this process in municipal wastewater contaminated with steroid estrogens using horseradish peroxidase (HRP) and hydrogen peroxide. An initial HRP activity of 0.02 U ml(-1) was sufficient to completely remove EE2 from the Synthetic solution, although greater HRP doses (up to 0.06 U ml(-1)) were required to remove E1, E2 and E3. The optimal molar peroxide-to-substrate ratio was determined to be approximately 0.45. Based on the Michaelis-Menten kinetics, the HRP had an increasing reactivity with E1, E3, E2, and EE2, in increasing order. In real activated sludge process effluent, an HRP dose of 8-10 U ml(-1) was required to completely remove all of the studied estrogens, while only 0.032 U ml(-1) of HRP was necessary to treat Synthetic water containing the same estrogen concentrations.
Patrick Balaguer - One of the best experts on this subject based on the ideXlab platform.
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Estrogenic activity in water and sediments of a French river: contribution of alkylphenols.
Archives of environmental contamination and toxicology, 2003Co-Authors: Hélène Fenet, Elena Gomez, Arnaud Pillon, D. Rosain, Jean-claude Nicolas, Claude Casellas, Patrick BalaguerAbstract:Alkylphenols, known to possess estrogenic activity, have been found in the aquatic environment. In this study, we focused on the contribution of alkylphenols to total estrogenic activity in sediment and water extracts of French rivers. Four sites representing rural, agricultural, urban, and industrial watersheds were studied. The concentrations of alkylphenols in water and sediment were quantified by GC/MS. Estrogen-responsive reporter cell lines (MELN) have been used for investigating estrogenic activity at these sites. These observed activities were compared with activities mediated by known concentrations of alkylphenols. In water, the concentration of alkylphenols, from 0.06 to 0.550 microg x L(-1) and from < 0.001 microg x L(-1) to 0.077 microg x L(-1) for nonylphenols and 4t-octylphenol, respectively, were too low to contribute to the observed estrogenic activity. In sediment of the industrial, rural, and urban sites, the observed estrogenic activities could be explained in great part by the alkylphenol concentrations from 0.26 to 2.87 microg x g(-1) and from 0.005 microg x g(-1) to 0.49 microg x g(-1) for nonylphenols and 4t-octylphenol, respectively. In the agricultural site, the alkylphenols (0.022 microg x g(-1) of nonylphenols) poorly contribute to the observed estrogenic activity. Other compounds, such as natural and Synthetic Hormones, present in water and sediments could act additively in the overall activity.
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Estrogenic activity in water and sediments of a French river
Archives of Environmental Contamination and Toxicology, 2003Co-Authors: Hélène Fenet, Elena Gomez, Arnaud Pillon, D. Rosain, Jean-claude Nicolas, Claude Casellas, Patrick BalaguerAbstract:Alkylphenols, known to possess estrogenic activity, have been found in the aquatic environment. In this study, we focused on the contribution of alkylphenols to total estrogenic activity in sediment and water extracts of French rivers. Four sites representing rural, agricultural, urban, and industrial watersheds were studied. The concentrations of alkylphenols in water and sediment were quantified by GC/MS. Estrogen-responsive reporter cell lines (MELN) have been used for investigating estrogenic activity at these sites. These observed activities were compared with activities mediated by known concentrations of alkylphenols. In water, the concentration of alkylphenols, from 0.06 to 0.550 microg x L(-1) and from < 0.001 microg x L(-1) to 0.077 microg x L(-1) for nonylphenols and 4t-octylphenol, respectively, were too low to contribute to the observed estrogenic activity. In sediment of the industrial, rural, and urban sites, the observed estrogenic activities could be explained in great part by the alkylphenol concentrations from 0.26 to 2.87 microg x g(-1) and from 0.005 microg x g(-1) to 0.49 microg x g(-1) for nonylphenols and 4t-octylphenol, respectively. In the agricultural site, the alkylphenols (0.022 microg x g(-1) of nonylphenols) poorly contribute to the observed estrogenic activity. Other compounds, such as natural and Synthetic Hormones, present in water and sediments could act additively in the overall activity.
Salmijah Surif - One of the best experts on this subject based on the ideXlab platform.
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occurrence of Synthetic Hormones in sewage effluents and langat river and its tributaries malaysia
International Journal of Environmental Analytical Chemistry, 2013Co-Authors: Najat Ahmed Alodaini, Mohamad Pauzi Zakaria, Mohamad Ismail Yaziz, Salmijah Surif, Narayanan KannanAbstract:This study investigated for the first time the occurrence of selected Synthetic Hormones including 17α-ethinylestradiol, levonorgestrel, norethindrone and cyproterone acetate in Malaysian tropical waters. Samples were collected from the effluents of five sewage treatment plants (STPs) and at seven stations along the Langat River in Selangor, Malaysia, and its main tributaries. Samples were extracted by solid phase extraction (SPE) and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). In Langat river samples, only levonorgestrel and cyproterone acetate were found at 50% and 3.3% frequency. The concentrations detected for levonorgestrel ranged from less than the method detection limit (
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Multi-residue analytical method for human pharmaceuticals and Synthetic Hormones in river water and sewage effluents by solid-phase extraction and liquid chromatography–tandem mass spectrometry
Journal of chromatography. A, 2010Co-Authors: Najat Ahmed Al-odaini, Mohamad Pauzi Zakaria, Mohamad Ismail Yaziz, Salmijah SurifAbstract:Pollutants such as human pharmaceuticals and Synthetic Hormones that are not covered by environmental legislation have increasingly become important emerging aquatic contaminants. This paper reports the development of a sensitive and selective multi-residue method for simultaneous determination and quantification of 23 pharmaceuticals and Synthetic Hormones from different therapeutic classes in water samples. Target pharmaceuticals include anti-diabetic, antihypertensive, hypolipidemic agents, β2-adrenergic receptor agonist, antihistamine, analgesic and sex Hormones. The developed method is based on solid phase extraction (SPE) followed by instrumental analysis using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) with 30 min total run time. River water samples (150 mL) and (sewage treatment plant) STP effluents (100 mL) adjusted to pH 2, were loaded into MCX (3 cm(3), 60 mg) cartridge and eluted with four different reagents for maximum recovery. Quantification was achieved by using eight isotopically labeled internal standards (I.S.) that effectively correct for losses during sample preparation and matrix effects during LC-ESI-MS/MS analysis. Good recoveries higher than 70% were obtained for most of target analytes in all matrices. Method detection limit (MDL) ranged from 0.2 to 281 ng/L. The developed method was applied to determine the levels of target analytes in various samples, including river water and STP effluents. Among the tested emerging pollutants, chlorothiazide was found at the highest level, with concentrations reaching up to 865 ng/L in STP effluent, and 182 ng/L in river water.
Olivier Kah - One of the best experts on this subject based on the ideXlab platform.
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Looking for estrogen mimics using transgenic tg(cyp19a1b-GFP) zebrafish embryos
2012Co-Authors: Olivier Kah, Yann Le Page, Benjamin Piccini, Olivier Cardoso, E. Fetter, S. Scholz, Sok-keng Tong, Bon-chu Chung, François BrionAbstract:The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics : it is only expressed in radial glial progenitors in the brain of fish and it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or Synthetic Hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model represents a very powerful tool to screen and characterize compounds potentially acting as estrogens mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling to more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective.
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Screening Estrogenic Activities of Chemicals or Mixtures In Vivo Using Transgenic (cyp19a1b-GFP) Zebrafish Embryos
PLoS ONE, 2012Co-Authors: François Brion, Yann Le Page, Benjamin Piccini, Olivier Cardoso, Sok-keng Tong, Bon-chu Chung, Olivier KahAbstract:The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP (green fluorescent protein) under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics: (i) it is only expressed in radial glial progenitors in the brain of fish and (ii) it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or Synthetic Hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model presents a very powerful tool to screen and characterize compounds potentially acting as estrogen mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling for more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective.
