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Biomedical subjects

U Serni

Publications and source records attributed to U Serni.

29 records · Page 2Linked to original sources
PubMed1993

The effects of methotrexate on normal and osteoarthritic lapine articular cartilage.

OBJECTIVE: The effects of methotrexate (MTX) on articular cartilage and its influence on the development of osteoarthritis (OA) lesions were tested in a lapine partial medial meniscectomy model. METHOD: Animals were divided into groups consisting of unoperated and operated rabbits that either received or did not receive MTX treatment. After 8 weeks knee articular condylar cartilage was examined for gross and histologic anatomy, active and total neutral metalloproteinases, tissue inhibitor of metalloproteinase (TIMP), DNA, uronic acid and hydroxyproline content. RESULTS: Carbon black retention and histologic scores revealed moderately severe changes in the OA animals with a tendency to less severe changes in OA animals receiving MTX. Unoperated animals receiving MTX had abnormal cartilage that displayed pitting and elevations in histologic score. Active and total neutral metalloproteinase and TIMP were elevated in both untreated and treated OA animals when compared to either unoperated or unoperated and treated animals. CONCLUSION: Articular cartilage with lesser amounts of neutral metalloproteinase and high amounts of TIMP levels often seen with other therapeutic modalities for OA, were not observed with MTX therapy. Our data suggest that MTX may have limited value in the treatment of OA.

Animals↗
PubMed1991

Chondrocyte physiopathology and drug efficacy.

After a brief exposition on the physiopathology of cartilage, and characteristic features of chondrocytes and proteoglycans (PGs) in osteoarthritis (OA), it is underlined how different molecules of GAGs and aggregated PGs added to the culture media can prevent damage and reduction of GAGs and fibril production in chondrocytes cultured with NSAIDs and corticosteroids. In animal models of OA, the local or general administration of GAGPS reduces the proteinase activity, the level of uronic acid in synovial fluid and the number of inflammatory cells in synovia. In the Pond-Nuki dog, GAGPS improves the cartilage surface. These favourable events can also occur in human OA, where it is, moreover, difficult to monitor the patients. For this purpose, patients must be selected in the first two stages of primary OA, and followed using NMR, the only device able to scan cartilage and subchondral bone, to determine their consistency and thickness, and to provide information on water content.

Animals↗
PubMed1990

Global safety of etodolac: reports from worldwide postmarketing surveillance studies.

Etodolac is a new nonsteroidal anti-inflammatory drug (NSAID) that has shown a favorable safety profile in clinical trials in osteoarthritis (OA) and rheumatoid arthritis (RA). Four postmarketing surveillance studies were conducted with patients who had OA and RA to further assess the safety of etodolac. One study also had patients with ankylosing spondylitis (AKS). These studies were conducted in Italy, Switzerland, the United Kingdom, and France. A total of 8334 patients received oral doses of 200 to 600 mg/day for periods ranging from 4 weeks to 1 year. The incidence of study events was low, 77% of the patients treated in these postmarketing surveillance studies reported no study events. Only 9% of all the patients treated withdrew from these studies because of adverse effects. Gastrointestinal events were the most commonly reported among the study events that did occur, as expected for an NSAID. These results further support the safety of etodolac that was previously established in clinical trials.

Administration, Oral↗
PubMed1990

Modulation of urokinase receptors on human synovial cells and osteoarthritic chondrocytes by diacetylrhein.

On the basis of both 125I-labelled urokinase-like plasminogen activator binding analysis and transmission electron microscopy of an urokinase-gold complex, we have shown the presence of specific receptors for human urokinase on the cell membrane of human synovial cells. By radio-ligand binding experiments we have shown the existence of similar receptors on the surface of human chondrocytes. In both cases the specific binding is attributable to interaction between the receptor and the A chain of the ligand, as previously shown in other cell model systems. Treatment of synoviocytes with 1,8-diacetoxy-anthraquinone-3-carboxylic acid (diacetylrhein) is able to reduce the number of surface urokinase receptors. At the same time the drug can reduce the fibrinolytic activity released into the culture medium of human synovial cells. Preliminary data indicate that chondrocytes from osteoarthritic patients have a larger number of urokinase receptors than chondrocytes of normal patients. Diacetylrhein can restore the receptor number to normal levels; the amount of urokinase in the synovial fluid of ostroarthritic patients is also reduced. We conclude that the use of this drug has the chance to significantly modify the natural history of osteoarthritis.

Anthraquinones↗
PubMed1988

Plasminogen activators and tiaprofenic acid in inflammation. A preliminary study.

Treatment with tiaprofenic acid appreciably reduced the level of plasminogen activators in the medium of 3T3-Balb mouse fibroblasts, as revealed by both a fibrin plate assay and amidolytic determination with chromogenic substrates. At the same time, tiaprofenic acid was able to inhibit the production of plasminogen activators induced by phorbol myristate acetate, a powerful inflammation and tumour promoter, added to the cell monolayers. By isolating the inhibitors of plasminogen activators it was possible to show that the decrease of fibrinolytic activity produced by tiaprofenic acid is not related to an increase of inhibitors. Rather, a decrease of activators seems to take place. Synovial fluid samples from 4 patients before and after treatment with tiaprofenic acid were also assayed for plasminogen activator activity by the fibrin lysis method. In 3 of the 4 cases a marked decrease after treatment was evident. The one unresponsive patient suffered from a para-neoplastic arthritis.

Animals↗
PubMedDate not supplied

[Cytokines].

Explore the source record for details and available documents.

Animals↗
PubMedDate not supplied

Antisense targeting of the urokinase receptor blocks urokinase-dependent proliferation, chemoinvasion, and chemotaxis of human synovial cells and chondrocytes in vitro.

Proliferation and invasion of synovial pannus in rheumatoid arthritis and cartilage remodeling in osteoarthritis are key events in development of disability of arthritic joints. The mechanisms that trigger these events are still poorly understood. The production of urokinase-type plasminogen activator (u-PA) by synovial cells and chondrocytes and the subsequent interaction of u-PA with its membrane receptor (u-PAR) is under the control of a variety of growth factors and cytokines released within the inflamed joints. Here we show that u-PA, on interaction with the specific receptor, regulates movement and invasion as well as proliferation of human synovial cells and chondrocytes. Targeting the urokinase receptor with an antisense oligonucleotide blocks the u-PA-dependent synoviocyte and chondrocyte proliferation and chemoinvasion, suggesting a possible use for this new class of drugs in the progression of the disease in rheumatoid arthritis and osteoarthritis.

Cartilage, Articular↗