Effect of short-term OPG treatment on leukocyte/endothelial cell adhesion. Endothelial monolayers were exposed to PMNs in the absence or presence of recombinant OPG (0.5 ng/mL) for the indicated times before scoring the number of adherent PMNs. Cell adhesion in untreated control culture was set as unity. Values are mean ± SD of triplicate determinations of 3 separate experiments. ∗, P > .05 versus control.