Neutrophil infiltration after repeated mild fluid percussion injury is reduced by the anti-CD11d treatment. (A) Photomicrographs of brain sections at the cortical injury site, or a comparable site in the sham-injured rats, immunostained by an anti-neutrophil antibody. The sections from sham-injured, 1B7 and anti-CD11d-treated rats at 72 h after injury are shown at lower power in panels 1 to 3 and higher power in panels 4 to 6. Scale bars = 100 μm. Scale bar in panel 3 refers to panels 1 to 3. Scale bar in panel 6 refers to panels 4 to 6. (B) MPO activity in brain homogenates in sham-injured groups (n = 6, both times), 1B7 groups (n = 7 and 6, respectively), and CD11d groups (n = 6 and 5 respectively) at 72 h and at 8 weeks post-injury. A.U., arbitrary units; *different from sham-injured group; #different from 1B7 group; all P ≤0.05 except that the gray *indicates P = 0.067. (C). Neutrophil protein, identified by western blotting in brain homogenates expressed as mean values ± standard error of the mean, with a representative autoradiogram shown above each set of histograms (n = 6 for each group).