Figure 2  .

(A) Effects of three different concentrations of ferric citrate on the spontaneous PGE₂ production by human synovial cells in a time course study. Data are the mean (SEM) of five experiments. * p < 0.05 compared with medium alone. (B) Effects of three different concentrations of ferric citrate on the PGE₂ production by human synovial cells with stimulation by 1 ng/ml IL1β in a time course study. Data are the mean (SEM) of five experiments. * p < 0.05, ** p < 0.01 compared with medium alone.