Manioc : Portail | resultats 101 - 120 pour la recherche: cultural minority

Voyages d'un naturaliste et ses observations faites sur les trois règnes de la nature : dans plusieurs ports de mer français, en Espagne, au continent de l'Amérique septentrionale, à Saint-Yago de Cuba et à St-Domingue, où l'auteur devenu le prisonnier de 40000 Noirs révoltés, et par suite mis en liberté par une colonne de l'armée française, donne des détails circonstanciés sur l'expédition du général Leclerc. Tome 1
Auteur(s) : Descourtilz, Michel Etienne (1777-1835)
Année de publication :

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Questions relatives à l'abolition de l'esclavage : instructions adressées à MM. les gouverneurs des colonies (circulaires du 18 juillet 1840) : avis des conseils coloniaux : délibérations et avis des conseils spéciaux
Auteur(s) : France. Ministère de la marine et des colonies (1790-1893)
Année de publication :

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La Guadeloupe. Renseignements sur l'Histoire, la Flore, la Faune, la Géologie, la Minéralogie, l'Agriculture, le Commerce, l'Industrie, la Législation, l'Administration. Tome III
Auteur(s) : Ballet, Jules (1825-1904)
Année de publication :

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Transgenic (cyp19a1b-GFP) zebrafish embryos as a tool for assessing combined effects of oestrogenic chemicals.
Auteur(s) : Petersen, Karina Fetter, Eva Kah, Olivier Brion, François Scholz, Stefan Tollefsen, Knut Erik
Auteurs secondaires : Institut de recherche, santé, environnement et travail [Rennes] (Irset) ; Université d'Angers (UA) - Université des Antilles et de la Guyane (UAG) - Université de Rennes 1 (UR1) - École des Hautes Études en Santé Publique [EHESP] (EHESP) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ) Institut National de l'Environnement Industriel et des Risques (INERIS)

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Endocrine disrupting chemicals and especially oestrogen receptor (ER) agonists have been extensively studied over the years due to their potential effects on sexual development and reproduction in vertebrates, notably fish. As ER agonists can exist as complex mixtures in the aquatic environment, evaluating the impact of combined exposure on oestrogenic effects has become increasingly important. Use of predictive models such as concentration addition (CA) and independent action (IA) has allowed assessment of combined estrogenic effects of complex multi-compound mixtures of ER agonists in various fish in vitro and in vivo experimental models. The present work makes use of a transgenic zebrafish strain, tg(cyp19a1b-GFP), which expresses the green fluorescent protein (GFP) under the control of the cyp19a1b (brain aromatase or aromatase B) gene to determine the oestrogenic potency of ER agonists alone or in mixtures. In these studies, tg(cyp19a1b-GFP) zebrafish embryos were exposed for four days (from one to five days post fertilization) to five different oestrogenic chemicals; 17α-ethinylestradiol (EE2), 17β-estradiol (E2), estrone (E1), bisphenol A (BPA) and 4-tert-octylphenol (OP), and three mixtures of up to four of these compounds. The mixture of BPA, OP and E2 was also tested with primary cultures of rainbow trout hepatocytes by analysing the ER-mediated induction of the oestrogenic biomarker vitellogenin in order to compare the performance of the two methods for assessing oestrogenic effects of complex mixtures. The three tested mixtures were predominantly acting in an additive manner on the expression of GFP. Additivity was indicated by the overlap of the 95% confidence interval of the concentration response curves for the observed data with the CA and IA prediction models, and model deviation ratios within a factor of two for a majority of the mixture concentrations. However, minor deviations determined as more than additive effects for the mixture of EE2, E1 and E2 and less than additive effects for the mixture of BPA, OP, EE2 and E1 were observed at the higher mixture concentrations tested. The successful prediction of additivity by CA and IA in tg(cyp19a1b-GFP) zebrafish embryos and deviations at high mixture concentrations seemed to correspond well to results obtained in the rainbow trout hepatocyte assay. The present results clearly show the usefulness of combining predictive modelling and use of in vitro bioassays for rapid screening of oestrogenic effects of complex mixtures and environmental samples.
ISSN: 0166-445X

hal-00877351
https://hal.archives-ouvertes.fr/hal-00877351
DOI : 10.1016/j.aquatox.2013.05.001
PUBMED : 23721851

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