Influence of CAM on NO production from NPFs in response to LPS stimulation. NPFs at a concentration of 5 × 105 cell/ml were stimulated with 1.0 μg/ml LPS in the presence of various concentrations of CAM. After 24 hours, culture supernatants were obtained and NO (NO2-/NO3-) levels were assayed by the Griess method. Data are the mean ± SE of five different subjects. CAM, clarithromycin; NO, nitric oxide; NPFs, nasal polyp fibroblasts; LPS, lipopolysaccharide.