Tissue preparation and cell cultures
Synovial tissue specimens were obtained from seven patients with RA 			 undergoing synovectomy or joint replacement and from two nonarthritic 			 individuals. Immediately after surgery, one part of the tissue was embedded in 			 Tissue-Tek OCT medium (Miles, Elkhart, IN, USA), snap-frozen and stored at 			 -80°C, and a second was fixed in 4% buffered formalin for 6 h before 			 embedding in paraffin. Another portion was digested enzymatically and the 			 released cells were grown in Dulbecco's modified Eagle medium with 10% 			 foetal calf serum [7]. At confluence, cells were 			 harvested and half of them were used for complementary (c)DNA preparation. The 			 remaining cells were used to maintain the culture, as well as for growing cells 			 on chamber slides (Lab-Tek II; Nalge Nunc Int, Naperville, IL, USA) 48 h before 			 in situ hybridization.