Figure 5.

Nerve growth factor (NGF) protein levels in the culture supernatant of synovial CD14‐negative and ‐positive fractions. NGF concentrations in the culture supernatants of CD14‐negative (white bars) and ‐positive cells (black bars) treated with or without human recombinant tumour necrosis factor (TNF)‐α and interleukin (IL)‐1β were examined by enzyme‐linked immunosorbent assay (ELISA). NGF concentration was normalized to the number of cells in each well. Data represent mean ± standard error (s.e.) (n = 10). ^aStatistical difference between CD14‐negative (white bars) and ‐positive cells (black bars) under the same conditions; ^bstatistical difference between cytokine‐stimulated and non‐stimulated cells in each fraction.