Figure 7.

Immunohistochemical Analysis of Defects Where Partial Bridging Occurred

(A–F) As confirmed in (A), although some new bone was formed in the defect, bridging was incomplete. In addition to new bone, the defect contained cartilage, fibrous tissue, and areas that appeared to be undergoing endochondral ossification (B, stained with SOFG). Chondrocytes within the cartilage were GFP⁻, whereas cells in areas undergoing endochondral ossification and cells within fibrous tissue contained both GFP⁺ and GFP⁻ cells (C–E). Both GFP⁺ cells (example indicated by red arrowhead) and GFP⁻ cells (example indicated by black arrowhead) were present in the newly formed bone (D and E). Certain blood vessels were lined with GFP⁺ cells (insert, C, red arrowhead). (A) and (C)–(E) were stained with anti-GFP antibody. Isotype controls were negative for GFP staining (F). N, new bone; F, fibrous tissue; EO, endochondral ossification.