Fig. 3.

Vascular growth factor expression in articular cartilage and bone. (A) VEGF-positive cells (brown) in vascular channels (RA, PM and OA), and in bone marrow spaces (RA). (B) PDGF-positive cells (brown). Vascular channels displaying PDGF-B-positive cells within the matrix and adherent to the bone surface in RA and OA, but not PM. (C) Chondrocytes displaying VEGF immunoreactivity in deep (RA) and superficial (OA) articular cartilage, but not in PM. Tissue morphology is revealed by combined transmitted and fluorescent light (blue/white: cartilage, bone; yellow: background) (A and B) or by haematoxylin counterstain (C). Scale bar = 100 microns.