Fig. 5. Development of amyloid in foie gras-treated vs control (untreated) IL-6 transgenic mice. Twenty-eight 8-week-old H-2/h (*) and 15 MT-1/h (+) IL-6 mice were injected or gavaged with foie gras extracts (red arrow) and another five (H-2/h) were given PBS (filled circle). Both treated and control animals were euthanized 2 months later (blue arrow). Additionally, 12 untreated H-2/h IL-6 mice were euthanized at 8 months of age (open circle). Tissues were obtained at necropsy, and the appearance of amyloid was documented by the presence of green birefringent deposits in Congo red-stained specimens, as evidenced by polarizing microscopy.