An assay which measured neutrophil rolling on interleukin (IL)-1 beta-activated human umbilical vein endothelial cells (HUVECs) showed 50% reduction in the number of rolling neutrophils in the presence of 1 microM SLeX16BSA, whereas the level of free, monovalent SLeX oligosaccharide required to produce the same effect was approximately 0.3 mM.