Histopathological changes in liver of tree shrew with chronic HBV-infection. Tree shrews were inoculated with HBV and sequential liver biopsies were obtained. HE-stained liver biopsies from representative chronically HBV-infected animals are depicted. Left: Biopsy was collected from animal 90-1 at 2.5 years post HBV inoculation and shows scattered or focally accumulated inflammatory mononuclear cells (arrows), ×200. Right: Biopsy was collected from animal 97-1 at 48 weeks post HBV inoculation and shows a proliferative focus (arrow) which is composed of transparent hepatocytes. ×400.