Fig. 2

Mean + standard deviation PGE₂ and chemokine (CCL2 and CXCL1) levels normalized for weight in the nucleus pulposus (NP) and annulus fibrosus (AF) per Pfirrmann grade (a, b, c) and per herniation (d, e, f). a. PGE₂ levels expressed as pg/mg wet weight in grade I NP samples were significantly lower compared with grade II, III, and IV + V NP samples. c, b and c. CCL2 and CXCL1 levels normalized for weight did not significantly change with degeneration. d. PGE₂ levels did not significantly differ in the NP and AF between the three herniation groups. e. CXCL1 levels did not significantly differ between herniation groups. f. CCL2 levels normalized for weight in the NP from extruded samples were significantly higher compared with the AF of these samples and the NP from protruded samples. No significant differences were shown between treatment (no treatment, NSAID < 1 wk, NSAID > 1 wk, corticosteroids (cort) < 1 wk, cort > 1 wk, other) groups, hence these groups are not shown separately. ** Indicate significant difference at a 99 % confidence level