Immunohistochemistry of core-binding factor alpha-1 (cbfa-1) staining. (a) control group at 6 days. (b) Experimental group at 6 days. (c) Control group at 10 days. (d) Experimental group at 10 days. (e) Scheme of the area (□) for pictures of a to d. At 6 days, cbfa-1 positive cells were found at the lower side in control group, but were also observed diffusely in the upper and lower sides in experimental group. At 10 days, cbfa-1 positive cells were observed at both the upper and lower sides in control group, and the number of cbfa-1 positive cells in experimental group was reduced