Effect of anti-CD18 antibodies on leukocyte-endothelium interaction (LEI) and contusion volume. (A) The number of rolling leukocytes in the cerebral venules 14 h after controlled cortical impact (CCI) was not affected by the administration of anti-CD18 antibodies compared to control IgG. (C) In contrast, the number of adherent leukocytes was reduced by approximately two-thirds by anti-CD18 antibodies relative to control IgG. (B,D) Qualitatively similar results were observed 14 h after CCI with respect to rolling and adhering aggregates in the cerebral venules after the administration of either anti-CD18 antibodies or control IgG. (E) Nevertheless, treatment with anti-CD18 antibodies had no effect on the expansion of the secondary lesion, measured 24 h after CCI.