Normal human monocytes were isolated , carefully washed , and incubated for 36 to 48 h in fetal bovine serum-containing medium .
normal human monocytes were isolated , carefully washed , and incubated for 36 to 48 h in fetal bovine serum-containing medium .
O B-cell_type I-cell_type O O O O O O O O O O O O O O B-other_organic_compound I-other_organic_compound I-other_organic_compound I-other_organic_compound O