Percentages of neutrophils observed along the EC borders.

After 24-hour TNF-α–treated ECs were washed, purified neutrophils (neutrophil to EC ratio, 1:1) were added to the wells and allowed to adhere for 1 to 15 minutes. After two washes, the cells were fixed and stained with silver stain as described in “Materials and methods.” The percentage of neutrophils observed along EC borders was measured. Data are expressed as mean ± SEM from 3 cell wells.