Fig. 4

A TNF-α staining of osteochondral specimens. A, F, K: Normal saline injected knees; B-D, G-I, L-N: 20μg/kg to 40μg/kg SDF-1 injected knees; E, J, O: surgical knees. Scale bars = 500 μm. B The percentages of TNF-α positive cells were randomly counted using three fields. Data were measured as mean ± standard error of the mean. (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, and ns: no significant difference)