Mean (± SEM) leukocyte counts in human endotoxemia. Total leukocyte counts (A), neutrophils (B), and monocytes (C). Placebo (○) or G-CSF (5 μg/kg; •) was administered 2 hours -b e f o r e e n d o t o x i n c h a l l e n g e -(group 1) or 24 hours before endotoxin challenge (group 2).