Objective. To investigate the correlation between joint disease and the composition of chondroitin sulfate in the joint fluid, unsaturated disaccharide isomers of chondroitin 4-sulfate (.1di-4S) and chondroitin 6-sulfate (.1di·6S) were measured in joint fluids obtained from patients with osteoarthritis (OA), rheumatoid arthritis (RA), or traumatic arthritis (TA).Methods. These pathologic joint fluids were digested with chondroitinase ABC, and the .1di·4S and .1di·6S produced were determined by high performance liquid chromatography combined with fluorometry.Results. Total content of .1di-4S plus .1di·6S was 71.8 ± 30.0 nmoles/ml (mean ± SD) in OA, 55.4 ± 29.3 nmoles/ml in RA, and 211 ± 149 nmoles/ml in TA joint fluids. The ratio of .1di·6S to .1di·4S was 3.81 ± 0.992 in OA, 1.13 ± 0.527 in RA, and 5.75 ± 2.46 in TA joint fluids. Differences between groups were statistically significant.Conclusion. These results strongly suggest that the levels of chondroitin sulfate isomers and the .1di-6S: .1di·4S ratio in joint fluid reflect the proteoglycan metabolism of joint tissues, particularly of articular cartilage; hence, they could be used to diagnose joint diseases

Objectives-It has been shown previously that hyaluronic acid (HA) has an analgesic action on bradykinin induced pain in the knee joints of rats. This study further clarifies the effects of the molecular weight of HA and its mechanism of action in the same model using HA Conclusions-HA with a molecular weight of greater than 40 kilodaltons produced an analgesic effect, and HA of 860 and 2300 kilodaltons produced high and longlasting analgesia. These effects of HA appear to be caused by the interaction between HA and HA receptors.

Graft implantation is one of the more popular procedures for repairing cartilage defects; however, sacrifices of the donor site have been an issue. Mesenchymal stem cells (MSCs) are a fascinating source for regenerative medicine because they can be harvested in a less invasive manner and are easily isolated and expanded, with multi-potentiality including chondrogenesis. MSCs can be isolated from various adult mesenchymal tissues including synovium. Here, we attempted to form cartilage from the composites of synovium-derived MSCs with collagen gel in vitro. After 21 days of culture, the composites had increased their cartilage matrix, as demonstrated by toluidine blue staining and immunohistochemistry for type II collagen. The composites consisting of 5 x 10(7) and 10(8) cells/ml in gel were richer in proteoglycans than those consisting of lower cell densities. After 1 day, MSCs/gel composites contracted and the diameter decreased by 30%; however, they were stable thereafter. Round cells with short processes producing collagen fibrils showing a similar morphology to that of chondrocytes were seen in the composites by transmission electron microscopy. During composite culture, chondroitin sulfate and mRNA expression for cartilage-related genes increased, demonstrating cartilage maturation. Using an optimized method, we obtained cartilage discs with a diameter of 7 mm and a thickness of 500 microm. Our procedure should thus make it possible to produce a large cartilage matrix in vitro. The tissue engineering of autologous cartilage from the composites of synovium-derived MSCs with collagen gel in vitro for transplantation may be a future alternative to graft implantation for patients with cartilage defects.

IntroductionOsteoarthritis is influenced by genetic and environment factors, including mechanical stress; however, the relationship between running and the development of osteoarthritis remains a matter of controversy. We investigated whether osteoarthritic change could be obtained in a rat strenuous running model, whether serum keratan sulfate in rats could be detected by HPLC and was associated with onset or progression of osteoarthritis, and whether hyaluronan injection suppressed development of osteoarthritis and elevation of serum keratan sulfate.MethodsWistar rats were forced to run 30 km in 6 weeks on a treadmill machine. Articular cartilage of the knees was evaluated macroscopically and immunohistologically. Serum keratan sulfate was examined every week by HPLC. The effect of weekly knee injection of hyaluronan was also investigated.ResultsCartilage surfaces stained with India ink became irregular, metachromasia by safranin-O staining appeared to be almost lost, and Mankin's score significantly worsened after 30 km of running. Serum keratan sulfate in rats was detected by HPLC and transiently increased (peaked at 3 to 4 weeks) along with depletion of keratan sulfate in cartilage tissue. Hyaluronan treatment suppressed morphological progression of osteoarthritis and elevation of serum keratan sulfate.ConclusionRat strenuous running induced osteoarthritis. Serum keratan sulfate was associated with progression of osteoarthritis. Weekly intraarticular injection of hyaluronan controlled the development of osteoarthritis, and the effect was reflected by serum keratan sulfate.