The morphology of thioglycollate-stimulated peritoneal macrophages (A) and in vitro-differentiated bone marrow-derived macrophages (B) injected into MPS VII recipients are shown after Wright Giemsa staining. Dual histochemical staining for β-glucuronidase activity (diffuse red stain) and immunohistochemical staining for Mac-1 (black cell surface stain) of spleen sections from MPS VII mice 24 hours (C) and 15 days (D) after injection of peritoneal macrophages demonstrates the colocalization of the 2 markers (white arrows). Mac-1–positive spleen cells that are β-glucuronidase negative (solid arrows) are also seen. ([A] and [B], original magnification × 1,145; [C] and [D], original magnification × 467).