Human plasma-cell-membrane glycoprotein 1 and homolog of progressive ankylosis expression in cartilage with/without calcification. Examples of normal cartilage without calcification and mildly degraded cartilage containing carbonated apatite crystals. (A) Safranin-O staining and immunohistochemistry (IHC) staining of human plasma-cell-membrane glycoprotein 1 (PC-1) and homolog of progressive ankylosis (ANKH). (B) Quantitative expression of PC-1 and ANK according to the presence or not of calcium-containing crystals. Immunohistochemistry analysis was performed by two researchers who were blinded to Fourier-transform infrared spectroscopy results. The number of chondrocytes expressing PC-1 or ANKH is relative to the total number of chondrocytes. CC = calcium-containing crystals.
Nguyen et al. Arthritis Research & Therapy 2013 15:R103 doi:10.1186/ar4283