Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003864 (arthritis)
 69,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The object of the present study was to define the optimal conditions for the quantitative determination of fibronectin in synovial fluid by laser nephelometry and to determine the diagnostic importance of this analysis in rheumatology. The results show that this technique is sensitive (threshold sensitivity is 70 mg/l if the sample is diluted 1/30 and 5 mg/l for a sample diluted to 1/2), accurate, reproducible (coefficient of variation less than 10%), specific, simple and rapid. The response is linear for dilutions from 1/30 to 1/240. Fibronectin P and fibronectin S were determined in 104 subjects who had contracted an arthropathy; 26 cases of rheumatoid polyarthritis, 43 mechanical arthropathies and 35 cases of non-rheumatoid arthritis. the plasma fibronectin does not vary significantly from one group of arthropathies to another but the mean value for the total population of arthropathies is significantly lower than that for a control group. In the synovial fluid the mean value for fibronectin in the patients with rheumatoid arthritis (583 + 76 mg/l) is very considerably higher than that in non-rheumatoid (379 + 58 mg/l) or mechanical (367 + 32 mg/l) arthritis patients. Thus, the determination of synovial fibronectin may provide useful information for the etiological diagnosis of inflammatory arthropathies.
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PMID:[Determination of synovial fibronectin by laser nephelometry. Its diagnostic value in rheumatology]. 387 77

We studied cell surface interactions between the fibronectin (FN)-containing extracellular matrix and the actin cytoskeleton of normal porcine synoviocytes in vitro, using electron microscopic methods. These type B synovial cells were distinguishable from dermal fibroblasts co-isolated from the same organism, because of their very long cellular processes and their ability to synthesize prostaglandin E2 after stimulation with interleukin-1. With plastic sections, we found end-to-end (tandem) and track-like (lateral) transmembrane associations of extracellular fibers and cortical 5-nm microfilaments localized along the attenuated synoviocyte processes in postconfluent cultures. Very similar FN-actin complexes, termed fibronexus (FNX), have been observed on cultured fibroblasts and on granulation tissue myofibroblasts in vivo. Using double-label immunoelectron microscopy with monospecific antibodies applied to ultrathin frozen sections of synoviocytes cut in situ, we proved that these FNX were indeed composed of associated FN and actin filaments. The striking finding of numerous FNX in cultured type B synoviocytes strongly suggests that the FNX is a major cell surface adhesion site in normal synovium, which may play an important role in pannus formation, connective tissue remodeling, and synoviocyte proliferation in patients with rheumatoid arthritis.
Arthritis Rheum 1985 Oct
PMID:Extracellular matrix-cytoskeletal interactions in rheumatoid arthritis. I. Immunoelectron microscopic analysis of the fibronexus at the adhesive surface of normal porcine type B synoviocytes in vitro. 390 32

Recent evidence suggests that fibronectin (Fn), a high molecular weight glycoprotein, may be used as an indicator protein in rats with adjuvant-induced arthritis. Rocket immunoelectrophoresis, using purified goat anti-rat Fn, provided a specific and sensitive means of measuring plasma Fn in rats during the development of various inflammatory disease states. It was shown that normal rat plasma Fn levels of approximately 400 micrograms/ml double within 24 hours after injection of adjuvant. Plasma Fn levels in this model of chronic systemic inflammatory joint disease were tracked for more than 4 months and remained significantly higher than normal. On the other hand, a carrageenan-induced inflammatory response in the pleural cavity of rats resulted in a large local accumulation of leukocytes, but no change in plasma Fn levels. A carrageenan-induced model of acute inflammation resulted in increased paw swelling within 6 hours and enhanced plasma Fn levels within 24 hours; plasma Fn levels returned to normal within 1 week. Quantitation of plasma Fn levels in the rat may provide a useful biochemical parameter for the study of chronic systemic inflammatory diseases.
Arthritis Rheum 1986 Mar
PMID:Fibronectin in acute and chronic inflammation. 396 15

Fibronectin promotes macrophage adherence and expression of Fc receptors, is chemotactic for fibroblasts, and is an opsonin for fibrin and denatured collagen. These properties suggest a role for fibronectin in the modulation of joint inflammation. Since structural modification of the fibronectin molecule has been shown to result in loss or de novo acquisition of opsonic and chemotactic activity, we determined the functional and immunochemical properties of fibronectin isolated from the inflamed joint. Eighty-six percent of synovial fluids obtained from patients with active rheumatoid arthritis (RA) contained fibronectin fragments, and 39% of the fluids no longer displayed the dimeric form. Compared with native fibronectin, RA peptides were as active in promoting synoviocyte chemotaxis and in glycosaminoglycan binding, but displayed lower affinity for fibrin and gelatin. Although comparable with intact protein in augmenting monocyte attachment to gelatin, the RA synovial fluid peptides did not augment monocyte attachment to fibrin. Analysis of whole synovial fluid and isolated fibronectins by enzyme immunoassay showed that the increased fibronectin immunoreactivity, previously reported in RA synovial fluid, measures intact and nearly intact protein and does not measure extensively degraded fragments.
Arthritis Rheum 1985 Jun
PMID:The immunoreactivity, ligand, and cell binding characteristics of rheumatoid synovial fluid fibronectin. 400 71

We examined fibronectin synthesis, secretion, and deposition in vitro by primary explants of rheumatoid synovium. Primary cultures initiated from tissue with monocytic infiltrates had higher levels of fibronectin synthesis; addition of dexamethasone at concentrations known to stimulate other tissue fibroblasts increased fibronectin synthesis and secretion. Newly synthesized fibronectin recovered from primary rheumatoid culture medium had a higher apparent molecular weight (240-245 kd), on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, compared with fibronectin recovered from passaged normal and rheumatoid cultures (230 kd). Primary rheumatoid explant cultures had a characteristic morphology which correlated with fibronectin deposition. Dense deposits of fibronectin extracellular matrix covered overlapping synoviocytes adjacent to esterase-positive mononuclear cells. Dexamethasone-treated cultures showed little fibronectin deposited as extracellular matrix and did not develop overlapping cellular networks. Characteristic patterns of fibronectin synthesis and deposition in primary rheumatoid cultures appear to result from interaction between fibroblastic and monocytic cells. This culture system may provide a model by which to study interactions between cells and extracellular matrix components that regulate synovial cell function.
Arthritis Rheum 1985 Sep
PMID:Synthesis, secretion, and deposition of fibronectin in cultured human synovium. 403 55

We studied the light microscopic, ultrastructural, and cytochemical characteristics of the temporomandibular joints of male ICR mice, from early neonatal life until they reached senescence, when spontaneous osteoarthritis is a common phenomenon. Aging of mandibular condylar cartilage was accompanied by decreasing total proteoglycan content and by an unmasking of collagen fibers, with no shift in collagen type. Fibronectin was also commonly present on the articular surface of specimens from old animals. Chondrocytes of aged mice contained an increased number of lysosomes, and their adjacent matrix vesicles reacted positively for acid phosphatase and arylsulfatase, but not for alkaline phosphatase. Such vesicles were also found to be devoid of calcium complexes and, thus, did not appear to be involved in the mineralization process. Similar age-related changes have been described in human mandibular condyles; hence, the male ICR mouse could serve as a useful model for studies of spontaneous osteoarthritis in the human mandibular joint.
Arthritis Rheum 1985 Sep
PMID:Morphologic and cytochemical changes in maturing and osteoarthritic articular cartilage in the temporomandibular joint of mice. 403 56

When rats were injected with Freund's adjuvant to induce arthritis, systemic disease as measured by swelling of the noninjected paw, was paralleled by a 100% rise in plasma fibronectin as measured by electroimmunoassay. When arthritic rats were given daily oral doses of nonsteroidal antiinflammatory drugs (NSAID), swelling of the noninjected rear paw was significantly less than that of the untreated arthritic controls. However, in all cases, plasma fibronectin (Fn) levels remained high in drug treated arthritic rats. Whether the NSAID was aspirin (100 mg/kg), phenylbutazone (10, 30, or 100 mg/kg) or indomethacin (0.3, 1 or 3 mg/kg) the pattern remained the same--reduced paw volume and unchanged high plasma Fn levels. Fn levels also remained unaltered in normal animals treated with drugs alone. Though NSAID diminish inflammation, clinical studies have shown that they do not halt disease progression. Our report shows that NSAID also fail to alter production of high levels of plasma Fn.
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PMID:The effect of antiinflammatory drugs on plasma fibronectin. 405 97

The presence of fibronectin on the surface of articular cartilage in rheumatoid arthritis (RA) was investigated. Cartilage samples were stained by the immunoperoxidase method using anti-human fibronectin antibody, and observed under light and electron microscopy. Fibronectin was present on the articular surface in 7 of 8 RA patients. The degree of staining varied greatly among the patients. Five of 8 patients were positive for fibronectin in 50% or more of the cartilage areas studied. In total, fibronectin was observed in RA. Fibronectin was not observed in cartilage samples of osteoarthritic joints or joints which were not diseased but had undergone trauma. Ultrastructurally, it was observed to be associated with collagen fibrils and amorphous substance in the matrix. The fibronectin-negative surface of the rheumatoid cartilage was usually thick ultrastructurally, compared with the fibronectin-positive surface, and the staining for fibronectin roughly correlated with decreased proteoglycans on the surface. The presence of fibronectin in the matrix appeared to be revealed by partial degradation of proteoglycans with proteolytic enzymes in the synovial fluid, as well as by the deposition of fibronectin onto the surface of rheumatoid cartilage. Fibronectin on the articular surface may play an important role in promoting pannus extension onto the articular surface in RA.
Arthritis Rheum 1984 Jun
PMID:Fibronectin on the surface of articular cartilage in rheumatoid arthritis. 620 43

Using 2-dimensional O'Farrell gel electrophoresis, we have mapped the proteins from undiluted plasma and serum which bind to monosodium urate (MSU) crystals. More than 30 crystal-associated polypeptides were visualized, including anionic and cationic species. Proteins increased on the crystals relative to plasma included C1q, C1-r, C1-s, fibronectin, fibrinogen, and kininogen. Crystal-bound polypeptides derived from IgG, albumin, and transferrin were recovered in decreased amounts relative to plasma. Direct evidence for activation of the complement and coagulation systems in plasma was provided by the identification of crystal-associated activation fragments of C1 and kininogen. Plasmas deficient in selected proteins (e.g., C1q and IgG) were used to define the role of these proteins in such activation events and confirmed activation of C1 in immunoglobulin-deficient plasma by MSU crystals. In summary, we have described a high resolution, semiquantitative approach to analyze protein binding to crystals, have documented the complexity of crystal-plasma protein interaction, and have provided direct evidence for the binding of coagulation system proteins and binding and activation of complement by MSU crystals, in whole plasma and IgG-deficient plasma.
Arthritis Rheum 1983 Jun
PMID:Plasma protein binding by monosodium urate crystals. Analysis by two-dimensional gel electrophoresis. 630 72

Normal synovial membranes and synovial membranes from patients with classic rheumatoid arthritis were investigated for the presence of fibrin and fibronectin by an indirect immunoperoxidase technique. In normal synovial membranes, fibronectin was found around the monolayer of the synovial lining cells. Staining was most intense on the surface and beneath the lining cells, but not detectable in the cytoplasm. Fibronectin was also found in the cytoplasm of the endothelial cells. No staining for fibrin was found in the normal synovial membrane. In synovial membranes from patients with rheumatoid arthritis, large amounts of fibronectin were found around the multilayer of synovial lining cells, in the cytoplasm of the endothelial cells, and in argyrophilic fiber-rich connective tissue. In superficial areas denuded of synovial lining cells, high amounts of fibronectin were found incorporated in fibrin. In some areas with noninjured synovial lining cells, fibrin was also found, but in this case no fibronectin was incorporated. No fibronectin was found in connective tissue in areas with infiltration of inflammatory cells. After treatment of normal and rheumatoid synovial membranes with hyaluronidase, fibronectin was still present around the lining cells but the staining was found to be more distinct. This study relates the presence of fibrin and fibronectin in the rheumatoid synovial membrane to the high amount of these proteins, recently described, in rheumatoid synovial fluid. It also suggests that fibronectin present in the synovial membrane is produced and secreted by the endothelial cells.
Arthritis Rheum 1983 Apr
PMID:Fibrin and fibronectin in rheumatoid synovial membrane and rheumatoid synovial fluid. 634 Jun 98


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