TABLE 1.

Effect of removal of nonadherent monocytes on PCA of cocultures of monocytes and bacterium-infected EC^a

Time of culture (h)b	PCA (mU of FXa/well) in cocultures of monocytes and EC infected with:
	S. aureus	S. sanguis	S. epidermidis
0 (no monocytes)	21.37 ± 14.0	1.67 ± 0.5	1.57 ± 0.8
1	24.28 ± 4.6	13.48 ± 2.9	23.45 ± 4.7
4	53.42 ± 18.5	27.31 ± 7.8	50.18 ± 15.5
6	76.68 ± 13.8	57.89 ± 7.1	91.99 ± 16.9

^aMonolayers of 2 × 10⁵ EC/well were incubated for 24 h with 4 × 10⁷ to 5 × 10⁷ organisms of the indicated bacterium, washed, and incubated for 1 h with 2.5 × 10⁵ monocytes. Then, nonadherent monocytes were removed by washing, EC with membrane-bound monocytes were cocultured for an additional period of time; and PCA was determined. Values represent the means ± standard deviations for three individual experiments. 

^bAt time zero, the levels of PCA were determined 24 h after bacterial infection just before the addition of monocytes. At 1 h of culture, nonadherent monocytes were removed and PCA was assessed 1 h after continuous incubation of bacterium-infected EC with monocytes. At 4 and 6 h after the addition of monocytes (i.e., 3 and 5 h, respectively, after the removal of nonadherent monocytes from the coculture, PCA was determined.