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Biomedical subjects

E Vignon

Publications and source records attributed to E Vignon.

At least 91 records · Page 5Linked to original sources
PubMed1993

Characterization of gangliosides from normal and osteoarthritic human articular cartilage.

OBJECTIVE: Glycosphingolipids (GSLs) are biologically active molecules in the physiology and pathology of cells. Since changes in GSLs might be associated with the impaired metabolism of articular cartilage in osteoarthritis (OA), we investigated gangliosides from normal and OA human cartilage. METHODS: OA and control cartilage was obtained from patients with hip OA and femoral neck fracture, respectively. Gangliosides were extracted and quantified by determining their lipid-bound sialic acid concentration. Major gangliosides were identified by immuno-detection on thin-layer plates, purified by high performance liquid chromatography, and analyzed for their carbohydrate, fatty acid, and long-chain base composition. RESULTS: The total ganglioside content of OA cartilage was decreased by 40% (per mg of DNA). Major gangliosides, GM3 and GD3, separated into 3 on thin-layer chromatography bands. All were decreased except for the lowest migrating band of GM3, which was increased 5-fold. This ganglioside had the same carbohydrate moiety and fatty acids as the other two, but differed by a long-chain base composed mainly of C20-sphingosine. CONCLUSION: OA cartilage is characterized by a decrease in all gangliosides except GM3, which demonstrates a large increase in the lowest band. These results indicate that there are changes in the biochemical composition of chondrocyte membranes in OA. The causes and roles of these changes remain to be determined.

Aged↗
PubMed1993

Metalloprotease activity, phospholipase A2 activity and cytokine concentration in osteoarthritis synovial fluids.

Collagenase, stromelysin and phospholipase A2 (PLA2) activity as well as interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha) and interleukin 6 (IL-6) concentration were determined in the knee joint synovial fluid (SF) of 26 patients with osteoarthritis (OA) and with rheumatoid arthritis (RA). Collagenase and stromelysin were detected in 80.7 and 69.2% of OA SF, respectively. When present, the mean activity of both enzymes was approximately two times lower in OA than in RA SF. PLA2 activity was present in all SF with no significant difference between OA and RA SF. IL-1 beta, TNF alpha and IL-6 were found in 0, 96.1 and 84.6% of OA SF, respectively. Mean TNF alpha and IL-6 concentration was also lower in OA than in RA SF. Metalloprotease activity correlated weakly with IL-6 level and enzymatic activities were unrelated with TNF alpha in OA SF.

Adult↗
PubMed1993

[Measurement of the hip joint space using automatic digital image analysis].

Joint surface area (JSA) and mean joint space width (MJSW) at the hip were measured using a ICMS-Techline computer program to analyze digitalised frontal weight-bearing roentgenograms of the pelvis. With this technique, the portion of joint space studied is always the same in a given patient and is enclosed within an acute ECS angle whose apex C is the center of the head of the femur and whose ends E and S are the lateral rim of the acetabulum and the highest point of the homolateral sacral wing respectively. ECS varies across individuals but remains constant in a given hip. Twenty hips were included in the first part of the study. For each hip, three roentgenograms were taken at five-minute intervals by three different radiologists who used their own constants (settings, position of the subject). JSA and MJSW are determined five times on each film by two different observers who had no information on the films under study. The interobserver coefficient of variation (CV) was 4.7% for JSA and 3.3% for MJSW. Intra-observer CVs were 2.97 and 3.54% for MJSW and 4.32% and 5.13% for JSA. There was a very close correlation between MJSW and JSA (r = 0.87, p < 0.0001). MJSW was then determined for roentgenograms of 30 hips with osteoarthritis. Results were compared with the values obtained using Lequesne's method of joint space measurement at the site of maximum narrowing. Measurements were performed in a double-blind fashion by two observers. The correlation coefficient was r = 0.89 (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Serum hyaluronic acid in osteoarthritis].

In this prospective study, serum hyaluronate (SH) was assayed using a radiometric method (Pharmacia) in 73 osteoarthritis patients and 39 controls. All assays were performed between 8 h 00 and 9 h 00 a.m. because SH levels exhibit circadian variations. SH levels were significantly higher in patients with osteoarthritis than in controls (92 +/- 66 micrograms/l and 39 +/- 21 micrograms/l, respectively, p = 0.0001). Among 50 patients with osteoarthritis, including 29 with knee involvement and 21 with hip involvement, SH levels were not correlated with morning stiffness, duration of symptoms, Lequesne's algofunctional index, erythrocyte sedimentation rate, C-reactive protein, severity of roentgenographic changes in the affected knee or hip, disease extension, or severity. The lack of any relationship between changes in SH levels and Lequesne's is index values in 25 patients or between SH levels and joint space narrowing evaluated retrospectively in 16 patients, as well as the prompt return to high SH levels after arthroplasty and synovectomy in 14 patients with hip joint osteoarthritis, suggest that this potential marker is not useful for monitoring osteoarthritis in a single joint.

Adult↗
PubMed1992

Effect of non-steroidal anti-inflammatory drugs (NSAIDS) on glycosyltransferase activity from human osteoarthritic cartilage.

The effect of non-steroidal anti-inflammatory drugs (NSAIDs) on the activity of glycosyltransferases required for the synthesis of the polysaccharide chains of proteoglycans, was studied in human osteoarthritic cartilage in vitro. Using exogenous acceptors, salicylate and indomethacin suppressed the activity of glucuronyl- and xylosyltransferases in a concentration-dependent manner, but had little effect on N-acetylgalactosaminyl- and galactosyltransferases. When used at a concentration derived from the values found in the synovial fluid, salicylate, indomethacin and chloroquine significantly suppressed the activity of glucuronyl- and xylosyltransferases, while tiaprofenic acid, paracetamol (acetaminophen), floctafenine, ketoprofen, ibuprofen and tenoxicam had no effect on the enzymes. An alteration of some glycosyltransferases could explain the reported suppressive effect of some NSAIDs on cartilage proteoglycan synthesis.

Aged↗
PubMed1991

Calmodulin-dependent collagenase and proteoglycanase activities in chondrocytes from human osteoarthritic cartilage.

Chondrocyte metalloproteinases appear to play a major role in the development of osteoarthritis. The intracellular post-traductional mechanisms regulating collagenase and proteoglycanase are not known. Calmodulin antagonists including phenothiazine and sulfonamide derivatives significantly increased proteoglycanase activity and decreased collagenase activity. H-7, a specific inhibitor of protein kinase C, had no effect on the two metalloproteinase activities, and calmodulin was ineffective in in vitro assays upon metalloproteinase activities. We postulate that collagenase and proteoglycanase activities are controlled by calmodulin-dependent regulation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Serotonin-stimulated phospholipase A2 and collagenase activation in chondrocytes from human osteoarthritic articular cartilage.

We have previously described several receptors on the chondrocyte membrane. In an attempt to further characterize the coupling mechanisms of serotoninergic receptors, here we examined the involvement of serotonin in the phospholipase A2 activity. Serotonin dose-dependently stimulated phospholipase A2. This activation enhanced collagenase type II activity and had no effect on proteoglycanase activity.

Aged↗
PubMed1991

In vitro effect of nonsteroidal antiinflammatory drugs on proteoglycanase and collagenase activity in human osteoarthritic cartilage.

The effects of several nonsteroidal antiinflammatory drugs, used at concentrations achievable in synovial fluid, on human osteoarthritic (OA) cartilage metallo-protease activity in vitro was studied. Acetaminophen and ketoprofen had no effect; sodium salicylate, indomethacin, and diclofenac slightly decreased proteoglycanase activity. Piroxicam and tenoxicam suppressed proteoglycanase activity by 48.2% and 68.3%, respectively, and suppressed collagenase activity by 19.1% and 36.8%, respectively. Use of these NSAIDs may help to decrease cartilage catabolism in patients with OA.

Acetaminophen↗
PubMed1991

[Serum hyaluronic acid and phospholipase A2 in an arthritic population].

Serum hyaluronic acid (HA) and A2 phospholipase (A2PL) activity were measured by radioimmunoassay (Pharmacia) and using a specific phospholipid substrate respectively, as potential markers of osteoarthritic synovitis. With neither age, treatment nor sample time taken into consideration, the concentration of HA (micrograms/ml) was 585 +/- 1,054 in rheumatoid arthritis, 379 +/- 409 in knee osteoarthrosis, 272 +/- 384 in hip osteoarthrosis, 131 +/- 144 in low back pain and 44 +/- 23 in osteoporosis, with no significant difference between the groups. HA was nevertheless found to be significantly higher in knee osteoarthrosis patients than in normal controls, when samples were drawn at the same time of day. Physical exercise (pedalling), as well as 20 hours lying flat and an intra-articular injection of corticosteroids did not cause any significant variation in serum HA levels in knee osteoarthrosis patients, in contrast to 20 hours of rest in the controls. A2PL activity was significantly higher in osteoarthrosis patients than in the controls, decreased with rest and corticosteroids and was not dependent upon sample time.

Aged↗
PubMed1991

[Hexosaminidase and alkaline phosphatase in cartilage and chondrocyte cultures obtained from normal and arthritic rabbit joints].

Hexosaminidase and alkaline phosphatase activities were studied in a rabbit model of osteoarthritis. Enzyme activities were determined in cartilage slices and cultures of chondrocytes from normal and arthritic joints. Alkaline phosphatase activity was increased in cartilage slices from rabbits with osteoarthritis, as compared with normal cartilage, whereas no difference was seen for hexosaminidase activity. Alkaline phosphatase activity was not found in chondrocyte cultures. Hexosaminidase activity was significantly higher in chondrocytes from joints with arthritis, as compared with chondrocytes from normal joints, regardless of the mode of expression of results (enzyme activity normalized for cell protein content of for number of cells). Chondrocyte hexosaminidase activity can be proposed as an enzyme marker for osteoarthritis in chondrocyte culture models.

Alkaline Phosphatase↗
PubMed1991

Study of an inhibitor of plasminogen activator (tranexamic acid) in the treatment of experimental osteoarthritis.

The effects of tranexamic acid, an inhibitor of plasminogen activator, were evaluated in a rabbit model of osteoarthritis induced by section of the knee joint anterior cruciate ligament. Prophylactic treatment administered intramuscularly thrice weekly for 12 or 24 weeks significantly reduced cartilage destructive lesions, increased cartilage hypertrophy but did not prevent changes in cartilage water and proteoglycan content. A suppression of synovial membrane stromelysin and collagenase activity was found while phospholipase A2 activity was unaffected.

Animals↗
PubMed1991

[Effects of naproxen (naprosyne) on the metabolism of arthrotic cartilage in man in vivo].

Degradative enzyme (proteoglycanase and collagenase) as well as proteoglycan synthesis enzyme (glycosyl-transferase) activity was studied in osteoarthritic fibrillated cartilage. Proteoglycanase activity was significantly lower in 10 patients with hip osteoarthritis treated with Naproxen (1 g/daily for 4 weeks) than in 10 patients treated with acetaminophen. Synthesis enzyme activity was similar in both groups. The results which confirm in vitro studies suggest that naproxen has not toxic effect on human osteoarthritic cartilage and could rather be beneficial.

Acetaminophen↗
PubMed1991

[Association of lumbar canal stenosis and ankylosing vertebral hyperostosis. Results of a multicenter study].

The authors report data collected in a study of the association of narrow lumbar canal and vertebral hyperostosis. Five centres (Montpellier, Toulouse, Lille, Lyons and Paris) participated in this cooperative study which was both retrospective and prospective. Grid case forms were sent to homogenise the date provided. Two hundred and sixty nine cases of symptomatic lumbar canal stenosis were collected; 89 (33 per cent) had hyperostosis. Hyperostosis was definite in 74 cases and probable in 15 other cases. Certain radiological and/or CT scan morphological factors seen frequently in the hyperostosis patients group led us to undertake a second study in 2 of the 5 centres (Montpellier and Toulouse) in order to identify their specificity. Twenty eight items were adopted and studied by 3 different evaluators (2 rheumatologists and one radiologist) in the X-ray films and CT scan documents of 100 patients with acquired lumbar canal stenosis with or without hyperostosis (46 and 54 cases respectively). The most discriminative appearances, which we suggest as diagnostic criteria of narrow lumbar canal with hyperostosis concern anterior and/or posterolateral marginal somatic bone proliferations on the non-articular surfaces of the posterior apophyses and ossifications of the posterior joint capsule and of the ligaments (ligamentum flavum--posterior longitudinal ligament--supraspinous ligament). Four of these 6 criteria are necessary to make the diagnosis of lumbar stenosis with hyperostosis. The radiological and CT scan appearances of lumbar hyperostosis appear to differ from ordinary degenerative changes of osteoarthrosis and hyperostosis may be held responsible for compression of the dural cul-de-sac.

Humans↗
PubMed1991

[Cytokines, prostaglandin E2, phospholipase A and metalloproteases in synovial fluid in osteoarthritis].

Concentrations of prostaglandin E2, interleukin 1 beta, interleukin 6 and tumor necrosis factor alpha, phospholipase A2, collagenase and proteoglycanase activity were determined in synovial fluid from 26 patients with osteoarthrosis of the knee and 10 with rheumatoid arthritis. Osteoarthrosis synovial fluid was characterised by the absence of interleukin 1 beta while tumour necrosis factor alpha and interleukin 6 were present in relatively large amounts, by a very high phospholipase A2 activity contrasting with a very low concentration of prostaglandin E2, and by a collagenase/proteoglycanase activity only slightly less constant and high as in rheumatoid arthritis. In osteoarthrosis patients, the interleukin 6 concentration, but not that of tumor necrosis factor alpha, was correlated with the collagenase and proteoglycanase activity of synovial fluid.

Adult↗