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Biomedical subjects

X Chevalier

Publications and source records attributed to X Chevalier.

At least 19 recordsLinked to original sources
PubMed2006

A material decoy of biological media based on chitosan physical hydrogels: application to cartilage tissue engineering.

The cartilage tissue has a limited self-regenerative capacity. Tissue-engineering represents a promising trend for cartilage repair. The present study was aimed to develop a biomaterial formulation by combining fragments of chitosan hydrogel with isolated rabbit or human chondrocytes. We first reported the properties of the constructs elaborated with rabbit chondrocytes and pure chitosan physical hydrogels with defined molecular weight, acetylation degree and polymer concentration. Morphological data showed that chondrocytes were not penetrating the hydrogels but tightly bound to the surface of the fragments and spontaneously formed aggregates of combined cell/chitosan. A significant amount of neo-formed cartilage-like extracellular matrix (ECM) was first accumulated in-between cells and hydrogel fragments and furthermore was widely distributed within the neo-construct. The optimal biological response was obtained with hydrogel fragments concentrated at 1.5% (w/w) of polymer made from a chitosan with a degree of acetylation between 30 and 40%. Such hydrogels were then mixed with human chondrocytes. The phenotype of the cells was analyzed by using chondrocytic (mRNA expression of mature type II collagen and aggrecan as well as secretion of proteoglycans of high molecular weight) and non chondrocytic (mRNA expression of immature type II collagen and type I collagen) molecular markers. As compared with human chondrocytes cultured without chitosan hydrogel which rapidly dedifferentiated in primary culture, cells mixed with chitosan rapidly loose the expression of type I and immature type II collagen while they expressed mature type II collagen and aggrecan. In these conditions, chondrocytes maintained their phenotype for as long as 45 days, thus forming cartilage-like nodules. Taken together, these data suggest that a chitosan hydrogel does not work as a scaffold, but could be considered as a decoy of cartilage ECM components, thus favoring the binding of chondrocytes to chitosan. Such a biological response could be described by the concept of reverse encapsulation.

Acetylation↗
PubMed2001

Hemarthrosis: an unusual complication of type 1 neurofibromatosis.

Type 1 neurofibromatosis is one of the most common autosomal-dominant disorders and often includes orthopedic manifestations. We report the case of a 48-year-old woman with hemarthrosis caused by a popliteal cyst infiltrated by a diffuse neurofibroma associated with angiodysplasia. Surgical resection of this tumor was followed by postoperative hemorrhagic complications.

Female↗
PubMed2001

Iliac vein thrombosis complicating SAPHO syndrome: MRI and histologic features of soft tissue lesions.

Subclavian and superior vena cava obstruction complicating SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis) syndrome has been described. We report the first case to our knowledge of iliac vein thrombosis complicating lumbar vertebral osteitis due to SAPHO syndrome. Lumbar MRI demonstrated a large tissue mass anterior to the involved vertebras and surrounding the right iliac vein. Histology of the mass showed aseptic inflammation.

Acquired Hyperostosis Syndrome↗
PubMed2001

Tissue inhibitor of metalloprotease-1 (TIMP-1) serum level may predict progression of hip osteoarthritis.

OBJECTIVE: To determine the predictive value of serum levels of TIMP-1 and hyaluronic acid in a 1 year prospective study in hip osteoarthritis (OA). METHODS: Twenty-nine patients with OA of the hip were enrolled in a 1-year prospective study (median follow-up, 13 months). Biochemical analysis was used to assess TIMP-1 and hyaluronic acid at entry and at the end of the study. Radiographic evaluation with an assisted computed program was performed to calculate progression of joint space narrowing. Statistical tests served to determine correlations between observed serum levels and radiograph joint space narrowing. RESULTS: Among the 29 patients, 10 showed joint space narrowing greater than 0.6 mm per year. The initial concentration of TIMP-1 as well as delta value of variation in serum levels of TIMP-1 (difference between TIMP-1 concentration at entry and at the end) correlated with the progression of joint space narrowing. A cut-off value of 600 ng/ml of TIMP-1 allowed the patients who progressed slowly from those who progressed more rapidly. Hyaluronic acid serum level was not predictive of evolution. CONCLUSION: TIMP-1 serum level may serve to predict the evolution of patients with hip OA.

Adult↗
PubMed2001

Reliability, validity, and sensitivity to change of the Cochin hand functional disability scale in hand osteoarthritis.

OBJECTIVE: To assess the reliability, validity and sensitivity to change of the Cochin hand functional scale in hand osteoarthritis (OA). BACKGROUND: The Cochin hand functional disability scale has been validated in rheumatoid arthritis. DESIGN: Patients with hand OA according to Altman's criteria were included. Impairment outcome measures (VAS of pain, hand score of tenderness, clinical hand score of impairment, Kallman's radiographic scale), functional disability measures [Cochin scale, Revel's functional index (RFI), Dreiser's functional index (DFI)] and patients' perceived handicap (VAS) were recorded twice, at baseline and at a 6-month follow-up visit. Interobserver reliability was assessed using the intraclass correlation coefficient (ICC) and the Bland and Altman method. Construct (convergent and divergent) validity was investigated using the Spearman rank correlation coefficient and a factor analysis was performed. Sensitivity to change was assessed using the effect size (ES) and the standardized response mean (SRM), and the non-parametric Spearman rank correlation coefficient (r) was used to assess the correlation between quantitative variable changes and patient's overall opinion. RESULTS: 89 patients (8 males, mean age 63 years) were included. Interobserver reliability was excellent (ICC=0.96). The Bland and Altman method showed no systematic trend. Correlations of the Cochin scale score with RFI (r=0.86), DFI (r=0.87), VAS of handicap (r=0.67), VAS of pain (r=0.54), tenderness (r=0.51), clinical impairment (r=0.32), and Kallman's radiographic scale (r=0.13) indicated a good construct validity. Factor analysis extracted four main factors, accounting for 65% of the total variance. 51 patients were evaluated at the 6-month visit. The Cochin scale score had worsened with SRM and ES values of -0.26 and -0.17 respectively. Changes in the score had one of the highest correlation (r=0.47) with the patient's overall opinion. CONCLUSION: The Cochin hand functional disability scale which was first developed to assess the rheumatoid hand can be used to evaluate functional disability in hand OA.

Adult↗
PubMed2001

Impaired redox status and cytochrome c oxidase deficiency in patients with polymyalgia rheumatica.

OBJECTIVE: To evaluate redox status and muscular mitochondrial abnormalities in patients with polymyalgia rheumatica (PMR). METHODS: Prospective evaluation of deltoid muscle biopsy in 15 patients with PMR. Fifteen subjects matched for age and sex, with histologically normal muscle and without clinical evidence of myopathy, were used as controls. Cryostat sections of muscle were processed for conventional dyes, cytochrome c oxidase (COX), usual histochemical reactions, and Sudan black. A total of 300-800 fibres was examined in each case. Blood lactate, pyruvate, and lactate/pyruvate ratio were determined in all patients. RESULTS: Ragged red fibres were found in eight patients with PMR and accounted for 0-0.5% of fibres. Focal COX deficiency was found in 14 (93%) of 15 patients and in nine (60%) of 15 controls. COX deficient fibres were more common in patients with PMR (range 0-2.5%; mean 0.9%) than in controls (range 0-1.2%; mean 0.3%) (paired t test, p=0.001). Seven (47%) of 15 patients had high blood lactate levels (1.50-2.60 mmol/l) or high blood lactate/pyruvate ratios (22-25). CONCLUSIONS: PMR is associated with mitochondrial abnormalities not solely related to the aging process.

Aged↗
PubMed2001

Immunohistological study of entheses in spondyloarthropathies: comparison in rheumatoid arthritis and osteoarthritis.

OBJECTIVE: To determine which inflammatory cell types are present in entheses from patients with spondyloarthropathy (SpA) compared with patients with rheumatoid arthritis (RA) or osteoarthritis (OA). METHODS: Enthesis specimens were obtained during orthopaedic procedures in eight patients with SpA, four with RA, and three with OA. After decalcification, the lymphocyte subsets (CD3, CD4, CD8, CD20) in the bone marrow component of each enthesis were measured by an immunohistochemical technique. RESULTS: Oedema and an inflammatory infiltrate were present in all the SpA specimens, being clearly predominant in the bone marrow component of the entheses. The density of all cell types in the bone marrow was significantly higher in the SpA group than in the two other groups. The cell type CD3+ showed the greatest difference between the SpA and RA groups, being increased fivefold in the SpA group. Within the SpA group, CD3+ cells were considerably more numerous than CD20+ cells-a difference from the RA group-and the predominant T cells were CD8+. CONCLUSION: Persistent oedema with an inflammatory infiltrate composed predominantly of CD8+ cells was noted in the entheses of patients with SpA, being predominant in the bone marrow. These results suggest that CD8+ cells may have a key role in local inflammation in SpAs.

Adult↗
PubMed2000

Methodology for the assessment of treatments in hand osteoarthritis.

OBJECTIVE: To perform a review of methods in clinical trials of hand OA and outline a set of guidelines. METHODS: Methods related to assessing treatment in hand OA were classified as those obtaining general consensus and those on which there was disagreement and need for further work. RESULTS: It was agreed that criteria validated for trials in knee and hip OA must be re-evaluated for hand OA; and that populations studied, trial parameters and evaluation tools should meet criteria established herein. Consensus was not reached or further work is required regarding functional index, daily or weekly questionnaire, hand(s) taken into account, scoring system and consideration of aesthetic damage. CONCLUSION: New therapeutic trials are needed in hand OA. Guidelines for future trials are given. International

Hand Deformities, Acquired↗
PubMed1999

Increased Ed-B fibronectin plasma levels in spondyloarthropathies: comparison with rheumatoid arthritis patients and a healthy population.

OBJECTIVE: To determine, for the first time, plasma levels of general fibronectin (Fn) and two spliced isoforms, Ed-A and Ed-B, in patients with spondyloarthropathy (SpA) in comparison with rheumatoid arthritis (RA) patients and healthy volunteers (HV). METHODS: Plasmas (EDTA) as well as clinical data, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were collected in two groups of 10 patients fulfilling the European Spondylarthropathy Study Group criteria for SpA or the 1987 American College of Rheumatology criteria for RA. Plasmas of 21 blood donors served as controls. Plasma levels of Fns were determined by using an in-house immunocapture ELISA, using monoclonal antibodies (MAbs) against general Fn and its isoforms. RESULTS: Total Fn plasma levels were significantly higher in the SpA group (mean+/-S.D.=1387+/-569 mg/l) than in the RA group (684+/-196 mg/l; P=0.02) and in HV (303+/-211 mg/l; P<0.0001). Ed-A Fn levels appeared higher in SpA (23+/-10.4 mg/l) and RA (32.5+/-16.5 mg/l) groups than in the HV group (2.8+/-0.9 mg/l; P=0.0003 and P<0.0001, respectively), without a significant difference between SpA and RA groups. Ed-B Fn levels were higher in SpA (6.9+/-2.1 mg/l) than in RA (3.2+/-1.9 mg/l; P=0. 02) and HV (1.1+/-0.8 mg/l; P=0.0003) groups. No significant correlation was observed in SpA patients between each Fn level and clinical activity, ESR or CRP levels. CONCLUSIONS: This study showed an increase in plasma levels of Fn and Ed-B Fn in SpA patients compared with RA patients and HV, which could not be attributed solely to systemic inflammation. It may be hypothesized that Ed-A and Ed-B Fn might reflect local turnover in inflamed tissues, and that Ed-B Fn might be particularly involved in the musculoskeletal inflammatory process of SpA.

Adult↗
PubMed1998

Unusual CD3+, CD4+ large granular lymphocyte expansion associated with a solid tumor.

Large granular lymphocyte proliferation has been reported in association with rheumatoid arthritis. We report an unusual association between a pleural mesothelioma and an unusual form of large granular proliferation of CD3+, CD4+, CD8-, CD56+ cells. This case sheds light on the possible causal relationship between these 3 conditions.

Bone Neoplasms↗