Histological analysis of SKG mice on Day 35 (after 21 days of treatment). (A) The histological analysis was performed on their hind paw sections stained by hematoxylin and eosin. Tissues are shown at ×40 magnification. Representative results are shown. (B) Histological arthritis scores between the dimethyl sulfoxide- and trichostatin A-treated groups of SKG mice. Mice were killed on Day 35 (treatment for 21 days) and the histological arthritis scores were calculated on their left hind paw. Results are expressed as the mean ± SE (DMSO group: n = 8, TSA group: n = 8, P = 0.0004). CAS, clinical arthritis scores.