Figure 4.

Macrophage foam cell formation assessed by Oil Red O staining. The uptake of oxidized HDL by macrophages treated with (A) HDL only, (B) HDL oxidized with Porphyromonas gingivalis, and (C) HDL oxidized with CuSO₄ was determined by light microscopy (scale bar=200 μm).

HDL: high-density lipoprotein.