Differential expression of cathepsins B and L compared with matrix metalloproteinases and their respective inhibitors in rheumatoid arthritis and osteoarthritis: a parallel investigation by semiquantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry. - Keyszer,G.; Redlich,A.; Haupl,T.; Zacher,J.; Sparmann,M.; Engethum,U.; Gay,S.; Burmester,G.R. (Arthritis Rheum, 1998)