Histopathological changes in the liver of tree shrew with persistent HBV-infection. A. Hydropic degeneration, fatty degeneration and acidophilic degeneration (arrow) in some hepatocytes. HE staining, 200×. The insert image visualizes the apoptotic cells (arrow) confirmed by TUNEL assay. TUNEL staining, 400×. B. Ballooning degeneration in hepatocytes (arrow). HE staining, 200×. C. Ground-glass-like hepatocytes in animal A1 who was HBV-infected for more than 6 years (arrow). HE staining, 100× and 400× respectively. D. The ground-glass-like hepatocytes were proved to be HBsAg-positive (arrow). Immunohistochemical staining for HBsAg, 100× and 400× respectively. E. Portal tracts were infiltrated with densely packed lymphocytes (arrow), accompanied with bile duct proliferation. HE staining, 100×. The insert image visualizes the CD3-positive lymphocytes. Immunohistochemical staining for CD3, 400×. F. Minor histopathological changes in one animal of group B. HE staining, 200 ×.