Histological grading of joint lesions in the knee joint of rats developing antigen-induced arthritis. (a) Cartilage score. (b) Bone score. Data are expressed as mean ± standard error of the mean of five independent samples. ‡P < 0.05 in comparison with day 0. Representative sections of contralateral (saline-injected) (c) and arthritic (mBSA-injected) (d) knees 14 days after arthritis induction (safranin O-fast green staining, magnification 4×). D, day; h, hour; mBSA, methylated bovine serum albumin.