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Biomedical subjects

X Chevalier

Publications and source records attributed to X Chevalier.

At least 37 records · Page 2Linked to original sources
PubMed1998

Factors linked to disease activity in a French cohort of patients with spondyloarthropathy.

OBJECTIVE: To identify risk factors associated with disease activity, in a group of patients with spondyloarthropathy (SpA) living in France. METHODS: Patients fulfilling the ESSG or Amor criteria for SpA were enrolled in a cross sectional multicenter study. Disease activity was assessed using a French version of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Univariate and multivariate analyses were used to identify a link between BASDAI and disease characteristics, genetic factors, and environmental factors such as infectious events, mental stress, working conditions, and dietary factors. RESULTS: We studied 293 patients. On multivariate analysis, BASDAI appeared to be mainly linked to disease duration (negative correlation), the absence of sacroiliitis, and the "frequency of meals taken out of home" (negative correlation). CONCLUSION: Disease activity in a French population of patients with SpA appeared to be linked mainly to a shorter disease duration and a peripheral pattern of arthritis, as well as to dietary habits. The underlying links between this last environmental factor and disease activity remained hypothetical and could only reflect a nontested social factor.

Adult↗
PubMed1997

Upregulation of enzymatic activity by interleukin-1 in osteoarthritis.

Osteoarthritis is a slow progressive disease characterized by destruction of the articular cartilage. The degradation of extracellular matrix components is mainly mediated by a family of enzymes, the metalloproteinases (MMPs), which are active at neutral pH. Interleukin-1 (IL-1) is a small peptide, active in autocrine and paracrine fashions. In vitro IL-1 increases the production of MMPs and inhibits the synthesis of collagen type II and proteoglycans. Its role in osteoarthritis is based on several findings: IL-1 is detectable in the synovial fluid and in the cartilage matrix of osteoarthritic joints; in vivo its deleterious actions can be reproduced by intra-articular injection of recombinant IL-1; biochemical changes observed in the cartilage matrix from osteoarthritic joints resemble those induced in vitro by IL-1; finally, antagonists of IL-1 are capable in vivo of preventing or at least diminishing the degradation of cartilage matrix components in several models of experimental arthritis. Interleukin-1 appears to be a main factor mediating cartilage matrix destruction. However, its role in human osteoarthritis, although highly probable, remains to be determined.

Cartilage, Articular↗
PubMed1997

Macrophage targeting with 99mTc-labelled J001 for scintigraphic assessment of experimental osteoarthritis in the rabbit.

The potential of scintigraphy with technetium 99m-labelled J001 (99mTc-J001) to detect synovitis was studied in 15 rabbits with osteoarthritis (OA) of the right knee (section of cruciate ligaments), in five sham-operated rabbits and in four non-operated rabbits. J001 is a non-pyrogenic, acylated poly (1,3) galactoside isolated from the membrane of a non-pathogenic strain of Klebsiella pneumoniae which is able to bind selectively to macrophages via the binding to CD11b and CD14 molecules. The results of 99mTc-J001 scintigraphy were compared with those of scintigraphy with 99mTc-labelled methylene diphosphonate (99mTc-MDP) and GC-APG (a derivative of J001 unable to bind macrophages in vitro). The mean scintigraphic ratios (diseased healthy knee) of 99mTc-J001 were significantly higher in OA rabbits than in sham- and non-operated rabbits, from as early as day 18 until day 90. 99mTc-J001 scintigraphy demonstrated earlier increased uptake than 99mTc-MDP scintigraphy. The mean scintigraphic ratios of 99mTc-J001 were significantly higher than those of 99mTc-GC-APG (which remained normal) in OA rabbits. The normal scintigraphic ratios of 99mTc-J001 in sham-operated and non-operated rabbits, as well as of 99mTc-GC-APG in OA rabbits, suggested that the increased uptake demonstrated with 99mTc-J001 in OA rabbits, as early as day 18 corresponded to imaging of synovitis via elective macrophage targeting. These results showed that 99mTc-J001 scintigraphy should be a specific method of detecting synovitis in OA.

Animals↗
PubMed1997

Misleading clinical aspects of hydroxyapatite deposits: a series of 15 cases.

OBJECTIVE: To study the characteristics of radiographs in diagnosis of hydroxyapatite deposits in sites other than the shoulders and hips. METHODS: We reviewed the records of patients hospitalized during the last 3 years whose final diagnosis was apatite deposits in sites other than the shoulders and hips. RESULTS: Ten women and 5 men were studied. The initial presentation mimicked septic arthritis or periarticular soft tissue abscess in 12 patients, corresponding to calcifications in the fingers (6), toes (2), wrists (2), elbow (1), and ankle (1). One patient presented with a spontaneous coccygeal pain (precoccygeal deposit), one with a pseudotumoral process of the thigh (paradiaphyseal calcification), and one with acute cervical pain and dysphagia (longus coli muscle calcification). Complete clinical healing was observed after an average of 4.9 days; 11 patients used nonsteroidal antiinflammatory drugs (NSAID), 2 used colchicine, one used oral steroids, and one had brief antibiotic therapy and used NSAID. CONCLUSION: Initial clinical aspects of apatite deposits in sites other than the shoulders and hips can often be misleading, especially by mimicking an infectious process. Careful analysis of immediate radiographic films can help to rapidly ascertain the diagnosis and thus avoid useless investigations or treatment.

Adult↗
PubMed1997

Evaluation of a French version of the Bath Ankylosing Spondylitis Disease Activity Index in patients with spondyloarthropathy.

OBJECTIVE: To develop a French version of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and to determine its metric properties in patients with all forms of spondyloarthropathies (SpA). METHODS: A French version of BASDAI was obtained after a translation and back-translation process. Patients fulfilling the European Spondylarthropathy Study Group or Amor criteria for SpA were included. BASDAI of Day 0, Day 1, and, when treatment was changed, Day 8, and other clinical and biological disease activity variables were recorded, along with assessment of disease activity by the physician or the patient. Scalability, reproducibility, sensitivity to change, internal consistency and redundancy, and construct validity of the index were assessed. RESULTS: We studied 293 patients. Good scalability, reproducibility, construct, and internal validity were observed for BASDAI. Sensitivity to change could not be assessed. CONCLUSION: The French version of BASDAI exhibited good metric properties in patients with all forms of SpA, confirming its utility in further clinical research in SpA. However, sensitivity to changes due to drug therapy remains to be assessed.

Adult↗
PubMed1997

Is a biological marker for osteoarthritis within reach?

Identification of a biological marker for osteoarthritis is a important research priority. A good biological marker would be sensitive to changes in the severity of cartilage destruction. Data from the literature suggest that hyaluronate and cartilage oligomeric matrix protein are more likely to meet this criterion than keratan sulfate, cytokines, or phospholipase A2. Baseline hyaluronate levels and their increase during the first year of follow-up predicted radiographic changes in knee osteoarthritis, and baseline cartilage oligomeric matrix protein levels predicted radiological changes in hip osteoarthritis. Circulating metalloproteinase levels may also deserve to be investigated. Identification of a single predictive marker is probably an unrealistic goal. Current research is focusing on combinations of several markers capable of providing information on the extent of cartilage degradation and anabolism, on subchrondral bone metabolism, and on reactive changes in the synovial membrane.

Animals↗
PubMed1996

Increased expression of the Ed-B-containing fibronectin (an embryonic isoform of fibronectin) in human osteoarthritic cartilage.

Fibronectin is non-collagenous protein which accumulates in osteoarthritic cartilage. The presence of fibronectin and its specific isoform containing the B sequence, Ed-B fibronectin (B.Fn), was studied in normal and osteoarthritic human cartilage using immunohistochemical and biochemical assays, with a specific monoclonal antibody. Results showed substantial amounts of B.Fn in osteoarthritic cartilage, especially in the superficial and middle layers. Western blot analysis confirmed the presence of B.Fn with a molecular mass of 220 and 55 kDa. In contrast, in normal cartilage, expression of B.Fn was extremely low. In conclusion, the expression of a specific isoform of fibronectin during the osteoarthritic process suggests that this isoform might have specific functions in extracellular matrix remodelling.

Aged↗
PubMed1996

Proteoglycan-degrading activity associated with the 40 kDa collagen-binding fragment of fibronectin.

The osteoarthritis (OA) process is characterized by the progressive destruction of articular cartilage. There is a loss of cartilage proteoglycan content and disorganization of the collagen network, as well as an increase in other non-collagenous protein such as fibronectin (Fn). Increased proteolytic activity may lead to the degradation of native Fn and generation of Fn proteolytic fragments. Among them, the 45 kDa collagen-binding Fn fragment can be autoactivated in vitro into a 40 kDa fragment. This 40 kDa fragment induces an average of 30% of proteoglycan release per day from human OA cartilage explants and can degrade proteoglycan using dead cartilage sections. Proteoglycan-degrading activity related to the 40 kDa Fn fragment was decreased up to 66% by fetal calf serum (10%), but was not prevented by protein synthesis inhibitors (cycloheximide or actinomycin D). The action of this 40 kDa Fn fragment was greater on OA than on normal cartilage. This study suggests that enzymatic activity induced by the 40 kDa collagen-binding fragment of Fn might be involved in cartilage matrix turnover.

Cartilage↗
PubMed1996

Production of binding proteins and role of the insulin-like growth factor I binding protein 3 in human articular cartilage explants.

The aim of this study was to determine the production of insulin-like growth factor binding proteins (IGFBP) and the role of the IGFBP-3 in human normal (n = 2) and osteoarthritic (OA) articular cartilage (n = 14) explants. Binding proteins were studied in the medium by Western ligand blotting and Western blotting. Proteoglycan synthesis under insulin-like growth factor I (IGF-I) stimulation was studied after a pulse of 35SO4(2-) in the presence or absence of added IGFBP-3. Osteoarthritic explants released a doublet of IGFBPs with a 39/43 kDa Mr corresponding to the binding protein 3. Constitutive production from unstimulated OA cartilage was higher than from normal cartilage. IGF-I induced a 20-fold increase and IL-1 a 2-fold increase in IGFBP-3 release. A minor band around 30 kDa was also detectable. Studies of proteoglycan (PG) synthesis showed that the majority of OA cartilage explant samples responded weakly to IGF-I (100 ng/ml) stimulation (+33%), while the others were high responders (+180%). Co-incubation of IGF-I with recombinant (r) IGFBP-3 did not affect the rate of PG synthesis. However, while pre-incubation with rIGFBP3 for 72 h did not change the rate of PG synthesis in the high-responder group, it strongly increased PG synthesis in the low-responder group. This study demonstrates that the ability of IGF-I to enhance proteoglycan synthesis varied among the OA samples and may in part be dependent on the local level of IGFBP-3. This implies pathophysiological considerations in the limits of IGF-I action during the OA process.

Aged↗
PubMed1996

Influence of interleukin 1 beta on tenascin distribution in human normal and osteoarthritic cartilage: a quantitative immunohistochemical study.

OBJECTIVE: To determine the influence of IL-1 beta on the presence and the distribution of tenascin in matrix of human normal and osteoarthritic cartilage explants. METHODS: Cartilage was grown in organotypic culture with or without IL-1 beta (10 ng ml1). Tenascin antigen was detected on cryopreserved cartilage sections by immunohistochemical techniques with a monoclonal antibody directed against all tenascin isoforms (BC-4), and then quantified by video imaging densitometry. RESULTS: Tenascin was present in normal cartilage explants and increased in osteoarthritic cartilage explants. Treatment of normal and osteoarthritic cartilage explants with IL-1 beta (10 ng ml-1) induced an increase in tenascin content, which was particularly high in normal cartilage and predominated in the superficial layers of damaged cartilage. There was no obvious correlation between proteoglycan loss and presence of tenascin. CONCLUSIONS: In human normal and osteoarthritic cartilage explants, the presence and the distribution of tenascin are influenced by IL-1 beta.

Aged↗
PubMed1996

Presence of ED-A containing fibronectin in human articular cartilage from patients with osteoarthritis and rheumatoid arthritis.

OBJECTIVE: To determine whether normal (fetal and adult) and osteoarthritic (OA) and rheumatoid arthritic (RA) cartilage express a specific isoform of fibronectin, the extra domain A (ED-A) containing fibronectin (EDA+Fn). METHODS: Presence of fibronectin (EDA+Fn and native molecule) in cartilage matrix was studied using immunohistochemical assays with specific monoclonal antibodies. Fibronectins were identified by Western blots, in synovial fluids (SF) and cartilage extracts. RESULTS: EDA+Fn was either moderately present in the surface zone or undetectable in normal cartilage, while it was increased in OA cartilage surface. In one OA cartilage sample, EDA+Fn was localized in the matrix distant from the cartilage surface (patches of staining) and its presence was confirmed by immunoblotting. In RA cartilage EDA+Fn was present in the pericellular areas of the different layers. By Western blots, the presence of EDA+Fn was confirmed in OA SF (2/3) and RA SF (3/3) (with different patterns of fragmentation). CONCLUSION: EDA+Fn generally accumulates in the surface zone of OA cartilage, where it may play a role in extracellular matrix remodelling. Its presence was more abundant in SF and in cartilage from patients with RA.

Aged↗