Figure 3From: Urokinase, a constitutive component of the inflamed synovial fluid, induces arthritisImmunohistochemical staining of an arthritic knee joint injected with low molecular weight urokinase plasminogen activator. (a) Abundance of mononuclear cells expressing Mac-1 (red–brown colour) in the inflamed synovial tissue. Original magnification × 20. (b) Arthritic knee joint stained with irrelevant goat IgG. JC, joint cavity; C, cartilage; ST, synovial tissue.Back to article page