Synovial fluid in an articulating joint contains proteins derived from the blood plasma and proteins that are produced by cells within the joint tissues, such as synovium, cartilage, ligament, and meniscus. The proteome composition of healthy synovial fluid and the cellular origins of many synovial fluid components are not fully understood. Here, we present a normative proteomics study using po...

Total IgM, IgA, and IgM-rheumatoid factor (RF) and IgA-RF were quantitated in the serum and synovial fluid of 35 seropositive and 8 seronegative rheumatoid arthritis (RA) patients, using a sensitive enzyme-linked immunosorbent assay (ELISA). Mononuclear cells isolated from peripheral blood and synovial fluid of three seropositive patients were also stimulated in vitro with phorbol myristat...

Studies on hyaluronate in normal human synovial fluid have been hindered by the high viscosity and small volume of fluid available. Reports on hyaluronate levels in normal synovial fluid, in which a number of different methods have been used, have shown discordant results (1-4). Several methods were used in the present study to determine the hyaluronate content of normal synovial fluid. Weighin...

Western blot of synovial fluid has been widely used for osteoarthritis (OA) research and diagnosis, but there is no ideal loading control for this purpose. Although β-actin is extensively used as loading control in western blot, it is not suitable for synovial fluid because it is not required in synovial fluid as a cytoskeletal protein. A good loading control for synovial fluid in OA studies sh...

Synovial fluid is present in all joint cavities, and protects the articular cartilage surfaces in large by lubricating the joint, thus reducing friction. Several studies have described changes in the protein composition of synovial fluid in patients with joint disease. However, the protein concentration, content, and synovial fluid volume change dramatically during active joint diseases and inf...

INTRODUCTION MicroRNAs (miRNAs), endogenous small noncoding RNAs regulating the activities of target mRNAs and cellular processes, are present in human plasma in a stable form. In this study, we investigated whether miRNAs are also stably present in synovial fluids and whether plasma and synovial fluid miRNAs could be biomarkers of rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS We...

Synovial fluid is a semidilute hyaluronate (HA) polymer solution, the rheology of which depends on HA-protein interactions, and lubricin is a HA-binding protein found in synovial fluid and at cartilage surfaces, where it contributes to boundary lubrication under load. Individuals with genetic deficiency of lubricin develop precocious joint failure. The role of lubricin in synovial fluid rheolog...

BACKGROUND Although relatively uncommon, spontaneous healing from a meniscus injury has been observed even within the avascular area. This may be the result of the existence of mesenchymal stem cells in synovial fluid. QUESTIONS/PURPOSES The purpose of this study was to investigate whether mesenchymal stem cells existed in the synovial fluid of the knee after meniscus injury. METHODS Synovi...