Comparison of the VEGF content of synovial fluid (as determined by ELISA) from healthy (Con) or OA patients. The level of VEGF is strongly increased in the synovial fluid of OA patients. Results are shown as mean ± standard error of the mean; n = 5 (Con) and n = 8 (OA). * p < 0.05. Con, control; OA, osteoarthritis; VEGF, vascular endothelial growth factor.