Fig. 3: The osteoarthritis lesions of knee joints were histologically analyzed in aged, osteoarthritic Dunkin-Hartley guinea pigs with vehicle control versus fludarabine intra-articular injection.

a, c The score of proteoglycan loss and modified Mankin score regarding osteoarthritis severity were calculated based on osteoarthritis scoring system. Modified Mankin score was calculated by adding together individual scores of cartilage structure, cellularity, tidemark, and osteophyte formation at 20x. Lateral tibia proteoglycan score 100 µm (n = 4, p = 0.0138, t = 5.196, df = 3); 200 µm (n = 5, p = 0.0402, t = 2.994, df = 4). Medial tibia proteoglycan score 100 µm (n = 5, p = 0.0161, t = 4.000, df = 4); 200 µm (n = 6, p = 0.0446, t = 2.666, df = 5). Medial tibia modified Mankin score 100 µm (n = 4, p = 0.0105, t = 5.745, df = 3); 200 µm (n = 5, p = 0.0189, t = 3.810, df = 4). b Toluidine blue stained images were used to determine proteoglycan content, as well as verify cellularity and tidemark at 20x microscopy. The black scale bar in (b): 500 µm for top panels, and 250 µm for lower panels. All points were plotted as individual values with error bars representing mean with SEM. Control: injection of equal volume of PBS; *p < 0.05.