Assessing Effects of Endocrine Disrupting Chemicals: Functional Outcomes of Exposure to Mixtures.
Notice bibliographique
Résumé
Complex mixtures contain compounds that differ in their biological actions that potentially act synergistically to affect physiological function. Further, birds vary in their vulnerability, utilize a range of lifetime reproductive strategies, and encounter a variety of contaminants especially with migration. It is critical to establish measurement end points responsive to the biological impacts in order to estimate potential risk to individuals and ultimately wildlife populations. We conducted a series of experiments to characterize the effects of polychlorinated biphenyl (PCB) mixtures in birds. Either single PCB congeners or complex PCB mixtures were administered by egg injection to tree swallows, Japanese quail, or chickens. Concentrations administered bracketed those found in eggs collected at the Upper Hudson River environs; comparisons were also made to chicks hatched from eggs collected from contaminated sites. Egg injections were conducted at 18% of embryonic development in field studies and were entirely at the nest sites, with return of eggs to the nest for the remainder of incubation. Samples were collected from hatchlings and measurement end points were chosen to assess target mechanisms. Results showed that PCB mixtures deleteriously impacted embryonic viability in a dose dependent manner. PCB 126 had the greatest impact, followed by the PCB mixtures. Interestingly, PCB 77 had little impact on embryonic development, with the exception of impaired heart development. The domestic chicken was most sensitive, followed by Japanese quail and tree swallows, with the latter two species being relatively similar in their vulnerability to these compounds. Embryonic exposure to the PCB mixtures had deleterious effects on the immune system, thyroid axis, and heart development. Quail raised in one of the laboratory studies showed impaired reproductive function and evidence of impacts on neuroendocrine regulatory systems. The biological impacts of PCBs varied with the congener; complex mixtures reflected the potency of relative proportions of the component congeners. Interestingly, in these and our other studies, it is clear that traditional methods for estimating potential toxicity by Toxic Equivalency Quotient (TEQ) do not accurately reflect the impacts observed in our studies. This may be due to non-aryl hydrocarbon receptor mediated action particularly in the case of endocrine disrupting compounds. We are considering additional methods to assess potential risk for these differing mechanisms of action. Acknowledgements: Research supported by EPA grants R826134010 (Star Grant) and R-82877801; Battelle contract for EPA-EDSTAC validation studies; and U.S. Fish and Wildlife Service. The conclusions and opinions presented here are those of the authors; they do not reflect the official position opinions of the funding agency or the Hudson River Trustees.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».