Western blot analysis of CA1 expression in synovial membranes from AS, RA and OA patients. (A) Western blotting of CA1 in AS, RA and OA synovial tissues (n = 5 for each disease). The molecular weight is indicated with arrows. Sample loading was normalized using GADPH. (B) The CA1 signal was normalized to the GADPH signal. The expression levels are expressed as the mean ± SEM. CA1 was expressed at a significantly higher level in AS synovial tissue than in RA and OA synovial tissues.