Treatment of Keloids With Imiquimod: A Possible Mechanism via the Upregulation of Matrix-Metalloproteinase-1

the surgery, a synovial fluid aspirate was obtained from the involved joint, by injecting and then aspirating 2 cc of normal saline two times over the course of 5-10 seconds. Confirmation of correct placement into the joint space was the characteristic “bounce back” on the plunger of the syringe following release of pressure from the injection. Asymptomatic volunteer subjects also underwent synovial fluid aspirate collection for comparison purposes. The synovial fluid specimens were stored in at 70 degrees Celsius for future protein analysis. Two different proteome approaches were used for protein profiling. In the patient group, 2-dimensional gel electrophoresis was performed on the specimens, followed by mass spectrometry to identify proteins of the synovial fluid from patients. Due to limitations in the amount of fluid recovered from the asymptomatic group, liquid chromatography-coupled tandem mass spectrometry was used to generate protein profiles of synovial fluid from controls, which is very sensitive and capable of identifying small amounts of proteins. Method of Data Analysis: The study population included 19 patients who underwent TMJ arthroscopy and synovial fluid aspirate collection on 27 joints (bilateral 8 patients, unilateral 11 patients) over a period of 21 months. The mean age was 39 years, the female:male ratio was 15:4, and the mean duration of symptoms was 22 months. Synovial fluid aspirate samples were obtained from 13 asymptomatic volunteers under local anesthesia using the same technique as described for the patients. The control group had a mean age of 27 years and a female:male ratio of 6:7. The protein profile of the pooled synovial fluids of patients was compared to synovial fluids of the asymptomatic group. Results: Arthroscopic pathology that was identified in the patient group included synovitis (24/27 joints), adhesions (23/27 joints), anterior disc displacement (18/ 27), osteoarthritis (8/27 joints), and disc perforation (2/27 joints). 2-D based mass spectrometry of synovial fluids from this patient population permitted the identification of 26 individual proteins. The asymptomatic synovial fluids yielded identification of 30 different proteins. There were 8 proteins that were common to both groups (alpha-1-antitrypsin, alpha2 HS glycoprotein, transthyretin precursor, alpha-1-B-glycoprotein, hemopexin precursor, transferrin, hemoglobin beta chain, and hemoglobin alpha chain). The patient synovial fluids yielded identification of 18 proteins that were not present in the control group. The protein profile of the patient group included transthyretin and haptoglobin which are acute phase proteins that have been shown to be directly involved in the inflammatory process in the synovial fluids of joints with rheumatoid arthritis. Complement component C9, as well as many other pro-inflammatory mediators, was also present in the diseased synovial fluids. Conclusion: Mass spectrometry proteomics can be used to identify very small quantities of proteins in the