Promotion of endometriosis in mice by polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls.

Previous studies showed exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) enhances the development of endometriotic lesions. In this study we examined the effects of other polyhalogenated aromatic hydrocarbons on endometriotic proliferation. B6C3F1 female mice were treated via oral gavage a total of five times, with 3 weeks between each dosing, with 0, 1, 3, or 10 micrograms 2,3,7,8,-TCDD/kg body weight (bw); 3 or 30 mg 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153)/kg bw; 100, 300, or 1000 micrograms 3,3',4,4',5-pentachlorobiphenyl (PCB 126)/kg bw; 10, 30, or 100 micrograms 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF)/kg bw; or 2 or 20 mg 1,3,6,8-TCDD/kg at 10 ml/kg bw. Endometriosis was surgically induced during the week of the second dosing. Three weeks following the final dose, the mice were euthanized and endometriotic lesions, whole body, liver, ovaries, uterine horn, and thymus were weighted, and lesion diameters were measured. Lesions, uterine horns, and ovaries were fixed for histopathology and livers were processed for measurement of ethoxyresorufin O-deethylase (EROD) activity. Both 2,3,7,8-TCDD (1 and 3 micrograms/kg bw) and 4-PeCDF (100 micrograms/kg bw) significantly enhanced the growth of endometrial lesions. No statistically significant increase in endometriotic lesion size was detected in animals treated with either PCB 126 or with the highest dose of 2,3,7,8-TCDD, possibly due to the effects of histologically observed ovarian toxicity. The nondioxin-like compounds, PCB 153 and 1,3,6,8-TCDD, produced no observable effects on endometriosis. Hepatic EROD activity was significantly induced by 2,3,7,8-TCDD, 4-PeCDF, and PCB 126, but not by PCB 153 or 1,3,6,8-TCDD. The results of this study provide preliminary support for the hypothesis that halogenated aromatic hydrocarbon-promoted endometriosis may be Ah receptor mediated

Are Differences in Exposure to a Multicomponent School-Based Intervention Associated With Varying Dietary Outcomes in Adolescents?

Multicomponent interventions are recommended for health behavior change among adolescents. However, it is difficult to disentangle the effects of multiple intervention components. This article reports outcomes associated with varying levels of exposure to a school-based nutrition intervention, Teens Eating for Energy and Nutrition at School (TEENS). Four incremental exposureswere possible: (1) control group, (2) school environment interventions only, (3) classroom plus environment interventions, and (4) peer leaders plus classroom plus environment interventions. Patterns suggesting dose response were observed, with peer leaders reporting the largest increases in fruit, vegetable, and lower fat food consumption. Students exposed to classroom plus environment interventions also improved, whereas students exposed only to school environment interventions showed trends toward choosing lower fat foods and declining fruit intake and no change in vegetable intake. Control students’ choices remained stable. Future studies may investigate mechanisms for peer leaders’ changes, maximizing curriculum effectiveness, and improving environmental interventions