title: Subcellular particles in synovial fluids and synovial cells.
abstract: Membranous particles of mycoplasma-like appearance (100 to 300 nm in diameter) and non-membranous particles which are viral-like (20 to 80 nm in diameter) were observed in negatively-stained preparations of synovial fluid pellets from patients with rheumatoid arthritis (RA), osteoarthrosis (OA) or psoriatic arthritis (PA). The incidence of positive fluids were: membranous particles--22/28 (RA), 7/11 (OA), 1/3 (PA); non-membranous particles--12/28 (RA), 1/11 (OA), 1/3 (PA). Eight of the RA fluids, one OA and one PA fluid were positive for both types of particle. The observation of an increased frequency of viral-like particles in RA synovial fluids compared to OA and PA fluids is of possible aetiological interest. Viral-like particles were also observed in the nuclei of rheumatoid synovial macrophage syncytia by electron microscopy of ultra-thin sections of cultured cells.
mesh_terms: D001168:Arthritis / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000473:pathology; D006801:Humans; D002479:Inclusion Bodies / Q000648:ultrastructure*; D007181:Inclusion Bodies, Viral / Q000648:ultrastructure; D008264:Macrophages / Q000648:ultrastructure*; D010003:Osteoarthritis / Q000473:pathology; D011565:Psoriasis / Q000473:pathology; D013582:Synovial Fluid / Q000166:cytology*