Influence of CAM (A) and M-4 (B) on iNOS production in NPFs after LPS stimulation. NPFs at a concentration of 5 × 105 cells/ml were stimulated 1.0 μg/ml LPS in the presence of various concentrations of CAM and M-4. After 12 hours, NPFs were collected and iNOS levels were assayed by ELISA. Data are the mean ± SE of five different subjects. iNOS, inducible nitric synthase; NPFs, nasal polyp fibroblasts; LPS, lipopolysaccharide; CAM, clarithromycin; ELISA, enzyme-linked immunosorbent assay.