Histological analysis of the effect of local Ad-mIL-4 treatment inCIA. (a) Ankle joints of mice were isolated from CIA and same-agednormal DBA mice 28 days after adenovirus injection. Ankle joint tissues werestained with hematoxylin and eosin and showed 100× magnification.Particles of Ad-IL-4 or Ad-eGFP (5×108) were injected intoankle joints of mice with established CIA. (b) The joint tissue sectionswere evaluated in a blinded manner and scored as follows: 1, synovial cellproliferation, synovial hypertrophy with villus formation and/or fibrindeposition; 2, inflammation, synovitis and/or generalized inflammation; 3,cartilage disruption, chondrocyte degeneration and/or ruffling of cartilagesurface and/or dystrophic cartilage; and 4, joint destruction, cartilageerosion with abundant inflammation and pannus formation with bone erosion. Atotal of five joints per group were evaluated by at least two individuals in ablinded manner.