Mononuclear cells derived from the bone marrow and isolated by density gradient.
Bone marrow (50 ml) was harvested from the posterior iliac crest. Bone marrow mononuclear cells were isolated by density gradient using Ficoll-Paque Plus, washed with heparinized saline containing human serum albumin (5%) and filtered through a 100-µm nylon mesh to remove cell aggregates.