Second, because of the small size of blubber samples, we could detect only two dioxin-like PCBs (congeners 118 and 156), and we did not analyze other CYP1A1-inducing PHAHs
Our present study tested the hypothesis that a mixture of 18 PHAHs acts in a dose-additive manner.
Results demonstrate a very wide range of effective doses of PHAHs that decrease TH concentrations.
This strain of mouse is highly sensitive to PHAH toxicity (Shen et al.
Because beluga have a systemic response to PHAH contaminants at low doses, toxic effects may be expected in Arctic populations.
The negative correlation between PHAHs and allergic responses in adolescents suggested that exposure may entail alterations in the immune status.
We calculated dose-effect relations in individual subjects between the biomarkers of immunologic effects and those reflecting exposure to PHAHs, using multiple linear regression for continuous outcomes or logistic regression for categorical variables.
1) were grown to confluence in 96-well view plates and exposed in triplicate to the PHAH samples and TCDD standards for 24 hr, using DMSO (0.
PHAH body burdens were determined in human serum and follicular fluid obtained from infertile women attending one of the collaborating Centers for Reproductive Medicine.
There is evidence that some of the toxicity of these pHAHs may be directly due to CYP1A activity; for example, CYP1A2 knockout mice are resistant to liver damage and uroporphyria when exposed to TCDD (Smith et al.
This result is in general agreement with other studies showing the reduction of early-life-stage toxicity of pHAHs when CYP1A activity or AHR-mediated signaling was decreased (Cantrell et al.
The term "dioxins" is used for members of the PHAHs
that are structurally related (have similar halogen substitution patterns), are persistent and bioaccumulative, and have a common spectrum of biologic responses mediated via binding to a specific high-affinity cellular protein, the aryl hydrocarbon (Ah) receptor (Van den Berg et al.