The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Daniel L Villeneuve - One of the best experts on this subject based on the ideXlab platform.
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comparison of fathead minnow ovary explant and h295r cell based steroidogenesis assays for identifying endocrine active chemicals
Ecotoxicology and Environmental Safety, 2007Co-Authors: Daniel L Villeneuve, Lindsey S Blake, Katie J Greene, Eric Higley, Elizabeth A Makynen, Gerald T. Ankley, John L. Newsted, John P GiesyAbstract:An in vitro steroidogenesis assay using H295R human adenocarcinoma cells has been suggested as a possible alternative to gonad explant assays for use as a Tier I screening assay to detect endocrine active chemicals capable of modulating steroid hormone synthesis. This study is one of the first to investigate the utility of the H295R assay for predicting effects and/or understanding mechanisms of action across species and tissues. Six chemicals, including one selective aromatase inhibitor (fadrozole), four fungicides (fenarimol, ketoconazole, prochloraz, and vinclozolin), and one herbicide (Prometon), were tested in both the H295R steroidogenesis assay, and an in vitro steroidogenesis assay using fathead minnow ovary explants. All six chemicals caused significant alterations in 17β-estradiol (E2) and/or testosterone (T) production in vitro. Effects of ketoconazole, prochloraz, and Prometon were similar in both assays. However, there were differences in the profile of responses for T for fadrozole and fenarimol, and for T and E2 for vinclozolin. In terms of sensitivity, steroid production in the H295R assay was most sensitive for detecting the effects of fadrozole, fenarimol, and prochloraz, but was less sensitive than the fathead minnow ovary explant assay to the effects of ketoconazole and vinclozolin. The H295R assay was consistently less variable (among replicates) than the fathead minnow ovary explant assay. However, the ovary explant assay was more predictive of in vivo effects of the six chemicals on fathead minnows than the H295R system. Further characterization of autoregulatory capacities, interaction of steroid-hormone receptor pathways with steroidogenesis, and metabolic capabilities of each system are needed for either system to provide clear and informative insights regarding a chemical's mechanism of action. Overall, however, results of this study suggest that both the H295R and fathead minnow ovary explant assays have utility for identifying endocrine-active chemicals in screening-type applications.
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evaluation of the methoxytriazine herbicide Prometon using a short term fathead minnow reproduction test and a suite of in vitro bioassays
Environmental Toxicology and Chemistry, 2006Co-Authors: Daniel L Villeneuve, Elizabeth A Makynen, Margaret B. Murphy, Michael D. Kahl, Kathleen M. Jensen, Brian C. Butterworth, Elizabeth J. Durhan, Ann Linnum, Richard L. LeinoAbstract:Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for Prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether Prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of Prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 microM), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor-mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 microg Prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 microg Prometon/L significantly increased female plasma testosterone concentrations, but the effect was not observed at greater concentrations. Overall, Prometon did not significantly reduce fecundity over the 21-d exposure, nor were other endpoints, including plasma vitellogenin and estradiol concentrations, brain and ovary aromatase activity, and male tubercle index, significantly affected. Evidence from our work suggests that Prometon may cause subtle endocrine and/or reproductive effects in fathead minnows, but no clear mechanism of action was observed. The relevance of these effects to hazard assessment for the pesticide is uncertain.
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Printed in the USA 0730-7268/06 $12.00 �.00 EVALUATION OF THE METHOXYTRIAZINE HERBICIDE Prometon USING A SHORT-TERM FATHEAD MINNOW REPRODUCTION TEST AND A SUITE OF IN VITRO BIOASSAYS
2006Co-Authors: Daniel L Villeneuve, Elizabeth A Makynen, Margaret B. Murphy, Michael D. Kahl, Kathleen M. Jensen, Brian C. Butterworth, Elizabeth J. Durhan, Ann Linnum, Richard L. Leino, Lawrence R. CurtisAbstract:Abstract—Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for Prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether Prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of Prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 �M), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor–mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 �g Prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 �g Prometon/
Robert J Gilliom - One of the best experts on this subject based on the ideXlab platform.
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major herbicides in ground water results from the national water quality assessment
Journal of Environmental Quality, 2001Co-Authors: Jack E Barbash, Dana W Kolpin, Gail P Thelin, Robert J GilliomAbstract:To improve understanding of the factors affecting pesticide occurrence in ground water, patterns of detection were examined for selected herbicides, based primarily on results from the National Water-Quality Assessment (NAWQA) program. The NAWQA data were derived from 2,227 sites (wells and springs) sampled in 20 major hydrologic basins across the USA from 1993 to 1995. Results are presented for six high-use herbicides--atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), cyanazine (2-[4-chloro-6-ethylamino-1,3,5triazin-2-yl]amino]-2-methylpropionitrile), simazine (2-chloro-4,6-bis-[ethylamino]-s-triazine), alachlor (2-chloro-N-[2,6-diethylphenyl]-N-[methoxymethyl]acetamide), acetochlor (2-chloro-N-[ethoxymethyl]-N-[2-ethyl-6-methylphenyl]acetamide), and metolachlor (2-chloro-N-[2-ethyl-6-methylphenyl]-N-[2-methoxylethyl]acetamide)--as well as for Prometon (2,4-bis[isopropylamino]-6-methoxy-s-triazine), a nonagricultural herbicide detected frequently during the study. Concentrations were <1 microg L(-1) at 98% of the sites with detections, but exceeded drinking-water criteria (for atrazine) at two sites. In urban areas, frequencies of detection (at or above 0.01 microg L(-1)) of atrazine, cyanazine, simazine, alachlor, and metolachlor in shallow ground water were positively correlated with their nonagricultural use nationwide (P < 0.05). Among different agricultural areas, frequencies of detection were positively correlated with nearby agricultural use for atrazine, cyanazine, alachlor, and metolachlor, but not simazine. Multivariate analysis demonstrated that for these five herbicides, frequencies of detection beneath agricultural areas were positively correlated with their agricultural use and persistence in aerobic soil. Acetochlor, an agricultural herbicide first registered in 1994 for use in the USA, was detected in shallow ground water by 1995, consistent with previous field-scale studies indicating that some pesticides may be detected in ground water within 1 yr following application. The NAWQA results agreed closely with those from other multistate studies with similar designs.
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occurrence of pesticides in shallow groundwater of the united states initial results from the national water quality assessment program
Environmental Science & Technology, 1998Co-Authors: Dana W Kolpin, Jack E Barbash, Robert J GilliomAbstract:The first phase of intensive data collection for the National Water-Quality Assessment (NAWQA) was completed during 1993−1995 in 20 major hydrologic basins of the United States. Groundwater land-use studies, designed to sample recently recharged groundwater (generally within 10 years) beneath specific land-use and hydrogeologic settings, are a major component of the groundwater quality as sessment for NAWQA. Pesticide results from the 41 land-use studies conducted during 1993−1995 indicate that pesticides were commonly detected in shallow groundwater, having been found at 54.4% of the 1034 sites sampled in agricultural and urban settings across the United States. Pesticide concentrations were generally low, with over 95% of the detections at concentrations less than 1 μg/L. Of the 46 pesticide compounds examined, 39 were detected. The compounds detected most frequently were atrazine (38.2%), deethylatrazine (34.2%), simazine (18.0%), metolachlor (14.6%), and Prometon (13.9%). Statistically significant rel...
Daqian Song - One of the best experts on this subject based on the ideXlab platform.
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vortex assisted solid phase extraction based on metal organic framework chitosan functionalized hydrophilic sponge column for determination of triazine herbicides in environmental water by liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2021Co-Authors: Yanxiao Jiang, Xinghua Wang, Ying Sun, Zucheng Qin, Fanghui Liang, Daqian SongAbstract:In the presented work, MIL-101(Cr) and chitosan were directly embedded on the skeleton of melamine sponge material using a simple and environmentally friendly method. Chitosan acts not only as an adhesive during the preparation of functionalized sponges, but also as an adsorption adjuvant in herbicide detection. Unlike other polymers, chitosan has excellent hydrophilicity and contains numerous adsorption sites; thus, it enables the sponge material to be used for determination of contaminants in an aqueous phase. Scanning electron microscopic (SEM) analysis showed that the coating material was uniformly distributed on the skeleton of melamine sponge. The prepared material was used as a sorbent in a vortex-assisted solid-phase extraction and combined with high performance liquid phase tandem mass spectrometry for the extraction and trace determination of six triazines in water samples (Atraton, Desmetryn, Prometon, Ametryn, Prometryn and Dimethametryn). Several parameters that affect the extraction efficiencies were investigated. Under the optimal conditions (MIL-101(Cr) loading, 150 mg; sample pH, 7; salt concentration, 0%; adsorption time, 3 min; desorption solvent, 1.5 mL acetonitrile; desorption time, 4 min), the proposed method was successfully used in the determination of trace triazines in five real water samples (drinking water, tap water, lake waters and river water), satisfactory recoveries were obtained in the range of 78.9%-118.6%. The limits of detection of the proposed method in detecting triazine herbicides in spiked water samples ranged from 0.014 to 0.045 ng mL-1.
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magnetic solid phase extraction of triazine herbicides from rice using metal organic framework mil 101 cr functionalized magnetic particles
Talanta, 2018Co-Authors: Li Liang, Xinghua Wang, Ying Sun, Huilan Piao, Yanxiao Jiang, Daqian SongAbstract:The metal-organic framework (MOF) functionalized magnetic graphene oxide/mesoporous silica composites (Fe3O4@SiO2-GO/MIL-101(Cr)) were synthesized and utilized as magnetic solid-phase extraction (MSPE) adsorbent for the extraction of seven triazine herbicides (terbuthylazine, secbumeton, terbumeton, atraton, atrazine, Prometon and trietazine) in rice samples. Several experimental parameters, including type and volume of extraction solvent, amount of MIL-101(Cr), extraction time, volume of desorption solvent and desorption time were investigated and optimized. The limits of detection (LODs) of seven triazine herbicides obtained by using the proposed MSPE method combined with high performance liquid chromatography (HPLC) were in the range of 0.010-0.080µgkg-1. The recoveries of the triazine herbicides in spiked rice samples ranged from of 83.9-103.5% with the relative standard deviations lower than 8.7%. The intra and inter-day (n = 6) precisions for all triazine herbicides at the spiked level of 100.0µgkg-1 were 1.4-5.9% and 2.6-7.8%, respectively.
Richard L. Leino - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the methoxytriazine herbicide Prometon using a short term fathead minnow reproduction test and a suite of in vitro bioassays
Environmental Toxicology and Chemistry, 2006Co-Authors: Daniel L Villeneuve, Elizabeth A Makynen, Margaret B. Murphy, Michael D. Kahl, Kathleen M. Jensen, Brian C. Butterworth, Elizabeth J. Durhan, Ann Linnum, Richard L. LeinoAbstract:Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for Prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether Prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of Prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 microM), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor-mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 microg Prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 microg Prometon/L significantly increased female plasma testosterone concentrations, but the effect was not observed at greater concentrations. Overall, Prometon did not significantly reduce fecundity over the 21-d exposure, nor were other endpoints, including plasma vitellogenin and estradiol concentrations, brain and ovary aromatase activity, and male tubercle index, significantly affected. Evidence from our work suggests that Prometon may cause subtle endocrine and/or reproductive effects in fathead minnows, but no clear mechanism of action was observed. The relevance of these effects to hazard assessment for the pesticide is uncertain.
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Printed in the USA 0730-7268/06 $12.00 �.00 EVALUATION OF THE METHOXYTRIAZINE HERBICIDE Prometon USING A SHORT-TERM FATHEAD MINNOW REPRODUCTION TEST AND A SUITE OF IN VITRO BIOASSAYS
2006Co-Authors: Daniel L Villeneuve, Elizabeth A Makynen, Margaret B. Murphy, Michael D. Kahl, Kathleen M. Jensen, Brian C. Butterworth, Elizabeth J. Durhan, Ann Linnum, Richard L. Leino, Lawrence R. CurtisAbstract:Abstract—Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for Prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether Prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of Prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 �M), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor–mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 �g Prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 �g Prometon/
Margaret B. Murphy - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the methoxytriazine herbicide Prometon using a short term fathead minnow reproduction test and a suite of in vitro bioassays
Environmental Toxicology and Chemistry, 2006Co-Authors: Daniel L Villeneuve, Elizabeth A Makynen, Margaret B. Murphy, Michael D. Kahl, Kathleen M. Jensen, Brian C. Butterworth, Elizabeth J. Durhan, Ann Linnum, Richard L. LeinoAbstract:Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for Prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether Prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of Prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 microM), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor-mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 microg Prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 microg Prometon/L significantly increased female plasma testosterone concentrations, but the effect was not observed at greater concentrations. Overall, Prometon did not significantly reduce fecundity over the 21-d exposure, nor were other endpoints, including plasma vitellogenin and estradiol concentrations, brain and ovary aromatase activity, and male tubercle index, significantly affected. Evidence from our work suggests that Prometon may cause subtle endocrine and/or reproductive effects in fathead minnows, but no clear mechanism of action was observed. The relevance of these effects to hazard assessment for the pesticide is uncertain.
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Printed in the USA 0730-7268/06 $12.00 �.00 EVALUATION OF THE METHOXYTRIAZINE HERBICIDE Prometon USING A SHORT-TERM FATHEAD MINNOW REPRODUCTION TEST AND A SUITE OF IN VITRO BIOASSAYS
2006Co-Authors: Daniel L Villeneuve, Elizabeth A Makynen, Margaret B. Murphy, Michael D. Kahl, Kathleen M. Jensen, Brian C. Butterworth, Elizabeth J. Durhan, Ann Linnum, Richard L. Leino, Lawrence R. CurtisAbstract:Abstract—Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for Prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether Prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of Prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 �M), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor–mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 �g Prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 �g Prometon/
