Schematic diagrams of flow culture system and flow-based adhesion assay. (A) Flow culture system. Medium in the culture dish was constantly perfused at a chosen shear stress through the microslide containing HUVEC-1 and perfused for 30 seconds each hour at low shear stress through the microslide containing HUVEC-2. The 2 microslides received identical medium. (B) Flow-based adhesion assay. Either neutrophil suspension or wash buffer was perfused at a wall shear stress of 0.1 Pa through the microslide. HUVECs and neutrophils adhering to it were continually observed and recorded by phase-contrast videomicroscopy.