Production of IL-1α, IL-8, and TNF-α by purified control and G-PBMC monocytes. Purified monocytes were isolated as described in Materials and Methods and cultured at 0.5 × 10⁶/mL in flat-bottom 96-well plates in the presence or absence of LPS (1 μg/mL). Supernatants from triplicate cultures were harvested after 24 hours, pooled, and cytokine levels were determined by ELISA. (*) Indicates a P value < .05 compared with control.