Figure 2.

Hepatic lesions in dipin-treated mice. A: Liver morphology in a PBS-treated mouse 13 weeks after hepatectomy. BD, bile duct. B: Liver morphology in a dipin-treated MUP-uPA mouse 15 weeks after hepatectomy. Dipin-induced abnormalities include hepatocytomegaly, frequent nuclear inclusions (arrows), and oval cells (arrowheads). BD, bile duct. C: Immunohistochemical staining with A6 monoclonal antibody of MUP-uPA liver collected 15 weeks after dipin treatment. In contrast to hepatocytes, oval cells and bile epithelial cells contain A6 antigen and stain dark brown. Arrowheads mark the edge of a focus of small hepatocytes. D–F: Endogenous focus of small hepatocytes. D and E: Adjacent sections of a small hepatocyte focus stained with H&E (D) and immunohistochemically with antiserum to β-gal (E). F: A separate focus (arrowheads) incubated with X-gal. Nuclear fast red counterstain. Hepatocytes in endogenous foci do not contain β-gal. G–I: Donor-derived focus of small hepatocytes. G and H: Adjacent sections of a small hepatocyte focus stained with H&E (G) and immunohistochemically with antiserum to β-gal (H). I: A separate focus (arrowheads) incubated with X-gal. Nuclear fast red counterstain. Hepatocytes in donor-derived foci contain β-gal that is detectable both immunohistochemically (brown stain, H) and histochemically (blue stain, I). Although blue staining in the focus in I appears to be less intense than staining in adjacent donor-derived parenchyma, this likely reflects the smaller size of hepatocyte nuclei in this focus. Fixation: C, F, and I, frozen tissue; all others, paraformaldehyde-fixed, paraffin-embedded tissue. Size bars: F and I, 200 μm; all others, 100 μm.