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See detailComparaison des outils bibliographiques et bibliométriques Web of Science et Scopus : rapport du groupe de réflexion mis en place par la Bibliothèque Interuniversitaire de la Communauté française de Belgique (BICfB)
Lerinckx, Dominique; Baguet, Muriel; Renaville, François ULg et al

Report (2011)

Depuis 2002, l'ensemble des membres de la BICfB souscrivent au Web of Science (WoS) de Thomson Reuters, plus précisément aux sous-bases Science Citation Index (SCI), Social Sciences Citation Index (SCCI ... [more ▼]

Depuis 2002, l'ensemble des membres de la BICfB souscrivent au Web of Science (WoS) de Thomson Reuters, plus précisément aux sous-bases Science Citation Index (SCI), Social Sciences Citation Index (SCCI) et Arts and Humanities Citation Index (A&HCI). Web of Science, partie du Web of Knowledge (WoK), est une base de données bibliographiques et d'analyse de citations renommée, au départ unique en son genre. Avec le Journal Citation Reports (JCR), elle est également beaucoup utilisée comme base de référence dans l'évaluation des chercheurs et de la recherche. En 2004, deux ressources concurrentes ont vu le jour. Il s'agit de Google Scholar (gratuit mais n'offrant pas autant de fonctionnalités) et de Scopus, un produit Elsevier. Aussi, lors de l'Assemblée générale de la BICfB du 4 mai 2010, les institutions ont décidé de constituer un groupe de réflexion interuniversitaire composé de membres issus des conseils ou administrations de la recherche, de bibliothèques et de représentants du F.R.S.-FNRS afin de comparer en profondeur ces outils. Ce rapport, présenté lors de l'AG du 7 juin 2011 de la BICfB, est le fruit du travail du groupe de réflexion. [less ▲]

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See detailDiffering in vitro biology of equine, ovine, porcine and human articular chondrocytes derived from the knee joint: an immunomorphical study.
Schulze-Tanzil, Gundula; Kohl, B.; Müller, R. D. et al

in Histochemistry & Cell Biology (2009), 131

For lack of sufficient human cartilage donors, chondrocytes isolated from various animal species are used for cartilage tissue engineering. The present study was undertaken to compare key features of ... [more ▼]

For lack of sufficient human cartilage donors, chondrocytes isolated from various animal species are used for cartilage tissue engineering. The present study was undertaken to compare key features of cultured large animal and human articular chondrocytes of the knee joint. Primary chondrocytes were isolated from human, porcine, ovine and equine full thickness knee joint cartilage and investigated flow cytometrically for their proliferation rate. Synthesis of extracellular matrix proteins collagen type II, cartilage proteoglycans, collagen type I, fibronectin and cytoskeletal organization were studied in freshly isolated or passaged chondrocytes using immunohistochemistry and western blotting. Chondrocytes morphology, proliferation, extracellular matrix synthesis and cytoskeleton assembly differed substantially between these species. Proliferation was higher in animal derived compared with human chondrocytes. All chondrocytes expressed a cartilage-specific extracellular matrix. However, after monolayer expansion, cartilage proteoglycan expression was barely detectable in equine chondrocytes whereby fibronectin and collagen type I deposition increased compared with porcine and human chondrocytes. Animal-derived chondrocytes developed more F-actin fibers during culturing than human chondrocytes. With respect to proliferation and extracellular matrix synthesis, human chondrocytes shared more similarity with porcine than with ovine or equine chondrocytes. These interspecies differences in chondrocytes in vitro biology should be considered when using animal models. [less ▲]

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See detailExamen échographique transcunéen post mortem de l'appareil podotrochléaire équin à l'aide des sondes linéaires et sectorielles
Schneider, Nicole ULg; Busoni, Valeria ULg; de la Rebière de Pouyade, Geoffroy ULg et al

in Annales de Médecine Vétérinaire (2008), 152

Ultrasound has become more common in the investigation of the podotrochlear apparatus in the horse and the use of more sensible scanheads improved the quality of the images. This study shows six examples ... [more ▼]

Ultrasound has become more common in the investigation of the podotrochlear apparatus in the horse and the use of more sensible scanheads improved the quality of the images. This study shows six examples of the ultrasound anatomy of the distal podotrochlear apparatus in the transcuneal view performed with three different scanheads. The presented transcuneal scans of the podotrochlear apparatus of an 18 months old warmblood foal have been established post mortem on isolated feet. Modus of registration was real-timemotion, linear- and sectorscanheads working at 7.5 (linear) and 7.5 (microconvex) and 3.5 (convex) MHz were used. The echoanatomic structures of the soft tissue and bony surfaces in the distal podotrochlear region are compared by six images. The combination of the different scanheads permits an improved complete visualisation in this area. Therefore these ultrasound pictures show that ultrasonography is an useful complementary investigation method that enables to precise the diagnosis [less ▲]

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See detailPlasma concentrations of a type II collagen-derived peptide and its nitrated form in growing ardenner sound horses and in horses suffering from juvenile digital degenerative osteoarthropathy
Lejeune, Jean-Philippe ULg; Serteyn, Didier ULg; Gangl, Monika et al

in Veterinary Research Communications (2007), 31(5), 591-601

Several breeds of draft horses suffer from degenerative digital osteoarthropathy, resulting in a reduced active lifespan. A group of 30 Ardenner horses was followed, in standardized conditions, from 15 to ... [more ▼]

Several breeds of draft horses suffer from degenerative digital osteoarthropathy, resulting in a reduced active lifespan. A group of 30 Ardenner horses was followed, in standardized conditions, from 15 to 28 months of age to detect the early manifestations of the disease. The severity of the disease was assessed according to a personal grading system including clinical and radiographic items. Coll 2-1, a peptide of the helical region of type II collagen, and its nitrated form (Coll 2-1 NO2) were assayed in blood plasma collected at 452 +/- 18 days, 504 +/- 20 days, 558 +/- 18 days, 613 +/- 19 days, 675 +/- 19 days, 752 +/- 21 days and 852 +/- 19 days of age. At the end of the follow-up period, 53.3% of Ardenner horses were affected by a degenerative digital osteoarthropathy. A significant effect (p < 0.05) of time, sex and pathology was observed for Coll 2-1 NO2. Variations of Coll 2-1 were not significant except for the time effect. The elevation of Coll 2-1 NO2 in the pathological group could indicate an inflammatory process during the growth of the affected horses, as nitration of tyrosine is mediated through reactive oxygen/nitrogen species and/or myeloperoxidase activity. Coll 2-1 NO2 appears to be an interesting early marker of cartilage degradation and oxidation in degenerative osteoarthropathy. [less ▲]

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See detailPathogénie cellulaire et moléculaire du stress oxydatif dans l'ostéo-arthropathie dégénérative équine
Schneider, Nicole ULg

Doctoral thesis (2007)

L’ostéo-arthropathie dégénérative affecte fréquemment les chevaux, et particulièrement le cheval de trait ardennais (Lejeune et al., 2002). Les nombreuses recherches consacrées à cette pathologie montrent ... [more ▼]

L’ostéo-arthropathie dégénérative affecte fréquemment les chevaux, et particulièrement le cheval de trait ardennais (Lejeune et al., 2002). Les nombreuses recherches consacrées à cette pathologie montrent un phénomène inflammatoire et un déséquilibre entre la production des enzymes dégradant le cartilage et l’intensité du processus de régénération (Landoni et al., 1996). On observe donc des dégâts à la surface du cartilage : f ibrillation, érosion, ulcération, formation d’ostéophytes, sclérose de l’os sous-chondral et remodelage ostéochondral (Reboul et al., 1996). Tous les éléments anatomiques sont concernés, avec une libération de médiateurs par les chondrocytes et les synoviocytes : cytokines, métalloprotéases, prostanoïdes (Cadore et Donabedian, 1997), leucotriènes, et espèces activées de l’oxygène et de l’azote (RNOS : reactive nitrogen and oxygen species). La formation des RNOS est souvent invoquée en relation avec des phénomènes d’anoxie-réoxygénation cycliques, liés au trauma ou à la surcharge articulaire, à un épanchement ou à un oedème de la capsule articulaire. Les travaux consacrés à la production des RNOS dans l’articulation l’attribuent habituellement aux chondrocytes et des observations biochimiques récentes ont révélé une augmentation des concentrations sanguines d’un produit oxydé caractéristique de la dégradation du cartilage, signe d’un métabolisme oxydant intra-articulaire (Lejeune et al., 2007). Peu de travaux sont consacrés à l’étude directe d’une production d’espèces radicalaires par les chondrocytes et les synoviocytes. L’objectif du travail était donc d’étudier la capacité des chondrocytes et des synoviocytes articulaires équins à produire des RNOS sous l’effet de l’anoxieréoxygénation. Il nécessitait la mise au point d’un modèle de culture des chondrocytes équins (Sanchez et al., 2002), d’un modèle de culture des synoviocytes équins (Georgescu et al., 1988) et d’un modèle de co-culture chondrocytes-synoviocytes pour imiter les interactions entre ces deux types cellulaires dans l’articulation où les chondrocytes matures sont nourris par diffusion à partir du liquide synovial à basse tension en oxygène (Grimshaw et Mason, 2000). Pour induire l’activité oxydante, nous avons soumis les cellules en culture à plusieurs cycles d’anoxie-réoxygénation, sur base de l’hypothèse qu’un traumatisme aigu ou chronique peut modifier le débit sanguin dans la membrane synoviale et initier des cycles d’anoxie-réoxygénation (par oedème et hypoxie tissulaire transitoire), avec une production intra-articulaire de RNOS, capables de déclencher des dommages tissulaires participant au développement de la pathologie articulaire. Pour tenir compte des conditions en oxygène existant dans l’articulation et du rôle du glucose ajouté au milieu de culture dans la résistance à l’anoxie, les chondrocytes ont été cultivés avec des concentrations variables en glucose (0, 1 et 4,5 g/l de milieu), combinées aux tensions d’oxygène de 1 % (hypoxie), 5 % (équivalent à la normoxie in vivo) et 21 % (condition hyperoxique prise comme référence par rapport à la littérature internationale). L’étude du métabolisme oxydant est effectuée en mesurant la consommation d’oxygène [oxymétrie mesurant la réponse mitochondriale (Mouithys- Mickalad et al., 2002)], la production globale de RNOS [estimée par la mesure de l’éthylène, produit par l’attaque d’un substrat par les RNOS (Deby-Dupont et al., 2005)] et la production d’espèces radicalaires [par résonance paramagnétique électronique (RPE) couplée au « spin trapping »] [less ▲]

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See detailPlasma concentration of insulin-like growth factor I (IGF-I) in growing Ardenner horses suffering from juvenile digital degenerative osteoarthropathy
Lejeune, Jean-Philippe ULg; Franck, Thierry ULg; Gangl, Monika et al

in Veterinary Research Communications (2007), 31(2), 185-195

Degenerative osteoarthropathy resulting in a reduced active lifespan was observed in Ardenner horses. In the context of joint biology, insulin-like growth factor I (IGF-I) is a potential candidate to ... [more ▼]

Degenerative osteoarthropathy resulting in a reduced active lifespan was observed in Ardenner horses. In the context of joint biology, insulin-like growth factor I (IGF-I) is a potential candidate to affect the anabolism of cartilage matrix molecules. A group of 30 Ardenner horses reared under standardized conditions from weaning were evaluated periodically from 15 to 28 months of age to detect the early manifestations of the disease. At the end of this period, horses were classified in two pathological groups related to the degree of interphalangeal degenerative osteoarthropathy based on clinical and radiographic evaluations: healthy (46.7%) and pathological (53.3%) horses. Seven sequential blood samples were taken from each horse (during the evaluation period) to study the variation of IGF-I plasma concentration. We tested the variations of the IGF-I plasma concentration during growth, and the effect of sex and of pathological classes. Significant variations were observed during the research period, with a maximum value corresponding to spring and a minimum in autumn. A significant reduction of the IGF-I plasma concentration was also observed in the pathological horses (433.5 +/- 19.5 ng/ml) compared to the healthy horses (493.9 +/- 18.2 ng/ml). An alteration in the level of this growth factor could induce a disregulation of the mechanisms involved in the local control of joint and bone tissue development. [less ▲]

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See detailOxygen consumption of equine articular chondrocytes: Influence of applied oxygen tension and glucose concentration during culture.
Schneider, Nicole ULg; Mouithys-Mickalad, Ange ULg; Lejeune, Jean-Philippe ULg et al

in Cell Biology International (2007), 31

We investigated the oxygen (O2) uptake of equine articular chondrocytes to assess their reactions to anoxia/re-oxygenation. They were cultured under 5% or 21% gas phase O2 and at glucose concentrations of ... [more ▼]

We investigated the oxygen (O2) uptake of equine articular chondrocytes to assess their reactions to anoxia/re-oxygenation. They were cultured under 5% or 21% gas phase O2 and at glucose concentrations of 0, 1.0 or 4.5 g/L in the culture medium (n = 3). Afterwards, the O2 consumption rate of the chondrocytes was monitored (oxymetry) before and after an anoxia period of 25 min. The glucose consumption and lactate release were measured at the end of the re-oxygenation period. The chondrocytes showed a minimal O2 consumption rate, which was hardly changed by anoxia. Independently from the O2 tension, glucose uptake by the cells was about 30% of the available culture medium glucose, thus higher for cells at 4.5 g/L glucose (n = 3). Lactate release was also independent from O2 tension, but lower for cells at 4.5 g/L glucose (n = 3). Our observations indicated that O2 consumption by equine chondrocytes was very low despite a functional mitochondrial respiratory chain, and nearly insensitive to anoxia/re-oxygenation. But the chondrocytes metabolism was modified by an excess of O2 and glucose. [less ▲]

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See detailA type II-collagen derived peptide and its nitrated form as new markers of inflammation and cartilage degradation in equine osteochondral lesions.
Gangl, Monika; Deberg, Michelle ULg; Lejeune, Jean-Philippe ULg et al

in Research in Veterinary Science (2007), 82

Markers of cartilage breakdown enable studying the degradation of cartilage matrix in equine joint pathologies. This study was designed to determine the levels of Coll2-1, a peptide of the triple helix of ... [more ▼]

Markers of cartilage breakdown enable studying the degradation of cartilage matrix in equine joint pathologies. This study was designed to determine the levels of Coll2-1, a peptide of the triple helix of type II collagen, and Coll2-1NO(2), its nitrated form in the plasma of healthy horses (controls; n=37) and horses suffering from osteochondrosis (n=34). Clinical and arthroscopic scores were attributed reflecting the severity of lesions and were related to the plasma levels of Coll2-1 and Coll2-1NO(2). The median of Coll2-1 was significantly higher in the control group, whereas the mean of Coll2-1NO(2) showed significant elevation in the pathological group. However, the measurement means of scoring classes did not vary significantly. The markers were able to differentiate the group of horses suffering from osteochondrosis from the group of healthy horses. The elevation of Coll2-1NO(2) in the pathological group indicates an inflammation, mediated through reactive oxygen species and/or increased myeloperoxidase activity. [less ▲]

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See detailLe rôle des synoviocytes dans l’articulation diarthrodiale enflammée
Schneider, Nicole ULg; Lejeune, Jean-Philippe ULg; Deby-Dupont, Ginette et al

in Annales de Médecine Vétérinaire (2007), 151

The degenerative osteoarthritis is a common source of disease in the horse, causing pain and leading finally to the destruction of the cartilage in the diarthrodial joints. The synovial membrane is a ... [more ▼]

The degenerative osteoarthritis is a common source of disease in the horse, causing pain and leading finally to the destruction of the cartilage in the diarthrodial joints. The synovial membrane is a constitutive element of the joint, but often neglected due to its less obvious alterations, despite its crucial role. This review of literature considers the embryology, the histology of synoviocytes in vivo and in vitro, gives information about the production of inflammatory mediators, degrading enzymes, free oxygen radicals, about the composition of the synovial fluid and the interaction with chondrocytes. The number of studies on equine synoviocytes in osteoarthritis is very restricted, therefore we included studies in other species and other types of joint diseases to achieve a more complete image of the complex, interdependent and mutual acting mechanisms. [less ▲]

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See detailSYNOVIOCYTES, NOT CHONDROCYTES, RELEASE FREE RADICALS AFTER CYCLES OF ANOXIA/RE-OXYGENATION
Schneider, Nicole ULg; Mouithys-Mickalad, Ange ULg; Lejeune, Jean-Philippe ULg et al

Poster (2007)

Introduction : An oxidant activity has been implicated in the onset of equine osteoarthritis. Most of the studies have been done on articular chondrocytes, but little is known about the role of ... [more ▼]

Introduction : An oxidant activity has been implicated in the onset of equine osteoarthritis. Most of the studies have been done on articular chondrocytes, but little is known about the role of synoviocytes. Objective : Our aim was to investigate if equine articular chondrocytes, primary synoviocytes or synoviocytes of a continuous cell line are able to produce free radicals after exposure to anoxia and re-oxygenation. Methods : By oxymetry and electron paramagnetic resonance (EPR), we investigated the effects of repeated anoxia/re-oxygenation (A/R) periods on the respiration and production of free radicals by synoviocytes (rabbit HIG-82 cell line and primary equine synoviocytes) and equine articular chondrocytes. Three periods of 20 min anoxia followed by re-oxygenation were applied to 10exp7 cells; O2 consumption was measured before anoxia and after each re-oxygenation. After the last A/R, cellular free radical formation was investigated by EPR spectroscopy with spin trapping technique (n = 3 for each cell line). Results : Both types of synoviocytes showed a high O2 consumption, which was slower after anoxia. By EPR with the spin trap POBN, we proved a free radical formation. Results were similar for equine and rabbit synoviocytes. For chondrocytes, we observed a low O2 consumption, unchanged by anoxia, and no free radical production. Conclusion : These observations suggest an oxidant activity of synoviocytes, potentially important for the onset of osteoarthritis. [less ▲]

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See detailRadiographic evolution of the forelimb digit in Ardenner horses from weaning to 28 months of age and its clinical significance
Lejeune, Jean-Philippe ULg; Schneider, Nicole ULg; Caudron, Isabelle et al

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (2006), 53(7), 364-370

Ossification of collateral cartilages is a common radiographic finding in draught horses and indication of a high frequency of interphalangeal osteo-arthropathy have been found in Ardenner horses. This ... [more ▼]

Ossification of collateral cartilages is a common radiographic finding in draught horses and indication of a high frequency of interphalangeal osteo-arthropathy have been found in Ardenner horses. This study first aimed at following the evolution of the digits of the forelimbs on radiographic images in a group of 32 Ardenner horses from weaning to 852 +/- 19 days and, secondly, at evaluating the clinical significance of the observed radiographic changes. At 250 +/- 21 days, only 23% of the horses presented a small separate ossification centre of collateral cartilages above the level of the distal sesamoid bone or at the level of the proximal half of the middle phalanx. At 852 +/- 19 days, 100% of the horses presented an ossification of collateral cartilages but at different stages and grades. The presence and the extent of the ossification of the lateral cartilages were not significantly associated with lameness. Phalanges changes appeared at the average age of 1 year and they were represented by entheseophytes on the dorsal surface of the middle and distal phalanges. The frequency of affected horses increased with age as well as the size of the entheseophytes. This may reflect mechanical stresses applied to the interphalangeal joints. A significant association with the presence of lameness was pointed out. The presence and the severity of phalanges changes could be of importance, in combination with a clinical examination, in improving the selection of horses able to assume work and/or leisure activities. [less ▲]

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See detailAnatomic variations and degenerative changes in the collateral cartilages and middle and distal phalanges of the forelimb in Ardenner colts
Lejeune, Jean-Philippe ULg; Audigie, Fabrice; Schneider, Nicole ULg et al

in Journal of Equine Veterinary Science (2006), 26(3), 102-112

The anatomic variations and the degenerative changes in the collateral cartilages and middle and distal phalanges in 6 Ardenner colts were characterized by radiography, scintigraphy, and magnetic ... [more ▼]

The anatomic variations and the degenerative changes in the collateral cartilages and middle and distal phalanges in 6 Ardenner colts were characterized by radiography, scintigraphy, and magnetic resonance imaging (MRI). The radiographic changes were assessed between the ages of 16.5 and 25 months. An anatomic variation of the middle and distal phalanges was demonstrated in some of the colts. MRI examination of the 6 colts revealed an association between the deep digital flexor tendon cross-sectional area and body weight as well as foot circumference. Also, a thin collateral sesamoidean (suspensory navicular) ligament was observed subjectively. The presence of an extensive ossification of the collateral cartilages of the foot was found in these young horses. The ossification was characterized by the existence of 2 separate ossification centers, which had a tendency to unite. The radiographic interphalangeal degenerative lesions seen appear as bone remodeling of the dorsal edges of the middle and distal phalanx, on the insertion sites of collateral ligaments of the distal interphalangeal joint, the digital extensor tendon, and the distal interphalangeal joint capsule. [less ▲]

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See detailHistology of two rice bodies isolated from the stifle of an adult draught horse stallion.
Schneider, Nicole ULg; Heimann, Marianne; Lejeune, Jean-Philippe ULg et al

in Journal of Veterinary Science (Suwon-si, Korea) (2006), 7(1), 83-5

In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most ... [more ▼]

In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most common finding in the equine species, whereas in humans rice bodies due to rheumatoid arthritis are more frequent. Herein we report a third type of floating body inside the stifle of an adult draught horse stallion, in macroscopic appearance similar to articular rice bodies known in humans. As revealed by histologic examination, the two particles consist of polypoid degenerated structures derived from synovial villi. Their formation was probably induced by ischemia. [less ▲]

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See detailDegenerative osteoarthropathy in horses: pathogeny and diagnostic
Lejeune, Jean-Philippe ULg; Schneider, Nicole ULg; Henrotin, Yves ULg et al

in Annales de Médecine Vétérinaire (2006), 150(3), 173-192

This work presents some important features of the normal articular structures and a definition of the degenerative osteo-arthropathy that points the involvement of all the joint structures. The pathogeny ... [more ▼]

This work presents some important features of the normal articular structures and a definition of the degenerative osteo-arthropathy that points the involvement of all the joint structures. The pathogeny of the pathology is tackled by the potential risk factors and by the cartilage-cartilage, synovium-cartilage and bone-cartilage cycles that lay particular emphasis on the interaction between the different joint structures. The diagnostic tools of the degenerative osteo-arthropathy like the conventional or recent imaging techniques (magnetic resonance imaging, scintigraphy and tomography) and the biomarkers of the cartilage and bone metabolisms are listed. The pathogeny of the degenerative osteo-arthropathy is complex and involves different factors. This disease is characterised by an imbalance between the anabolic and catabolic processes of the cartilage metabolism. Inflammation is also present and lead to the clinical signs. The synovitis, the liberation of degradation mediators, the mechanical stresses and/or the subchondral bone are part of the pathogeny at different degrees. The development of recent imaging techniques and the biomarkers of the cartilage and bone metabolisms allow the precise description of the lesions and give some additional information on the pathogeny of the osteo-arthropathy. These recent techniques raise new questions and allow the in-depth analysis of the study of the osteo-arthropathy. [less ▲]

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See detailSynoviocytes, not chondrocytes, release free radicals after cycles of anoxia/re-oxygenation
Schneider, Nicole ULg; Mouithys-Mickalad, Ange ULg; Lejeune, Jean-Philippe ULg et al

in Biochemical & Biophysical Research Communications (2005), 334(2), 669-673

By oxymetry and electron paramagnetic resonance (EPR), we investigated the effects of repeated anoxia/re-oxygenation (A/R) periods on the respiration and production of free radicals by synoviocytes ... [more ▼]

By oxymetry and electron paramagnetic resonance (EPR), we investigated the effects of repeated anoxia/re-oxygenation (A/R) periods on the respiration and production of free radicals by synoviocytes (rabbit HIG-82 cell line and primary equine synoviocytes) and equine articular chondrocytes. Three periods of 20 min anoxia followed by re-oxygenation were applied to 10(7)cells; O(2) consumption was measured before anoxia and after each re-oxygenation. After the last A/R, cellular free radical formation was investigated by EPR spectroscopy with spin trapping technique (n=3 for each cell line). Both types of synoviocytes showed a high O(2) consumption, which was slowered after anoxia. By EPR with the spin trap POBN, we proved a free radical formation. Results were similar for equine and rabbit synoviocytes. For chondrocytes, we observed a low O(2) consumption, unchanged by anoxia, and no free radical production. These observations suggest an oxidant activity of synoviocytes, potentially important for the onset of osteoarthritis. [less ▲]

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See detailSYNOVIOCYTES BUT NOT ARTICULAR CHONDROCYTES RELEASE FREE RADICALS AFTER REPETITIVE CYCLES OF ANOXIA/REOXYGENATION: AN ELECTRON SPIN RESONANCE STUDY.
Schneider, Nicole ULg; Lejeune, Jean-Philippe ULg; Mouithys-Mickalad, Ange ULg et al

Poster (2005)

Objective : We investigated if short recurrent periods of anoxia/reoxygenation (A/R), mimicking the in vivo conditions of hypoxia, could stimulate the production of free radicals by synoviocytes and ... [more ▼]

Objective : We investigated if short recurrent periods of anoxia/reoxygenation (A/R), mimicking the in vivo conditions of hypoxia, could stimulate the production of free radicals by synoviocytes and chondrocytes. Material and Methods : Synoviocytes (immortalised rabbit line HIG-82 and equine synoviocytes isolated from synovial membranes of the stifle joint) and chondrocytes (isolated from the same equine joint) were cultured for 48 hours. The respiration rate of the cells (107 cells/assay) was studied by oxymetry and the free radical production monitored by electron spin resonance (ESR) in the presence of the spin trap (-[-4-pyridyl 1-oxide]-N-tert butyl nitrone)/ethanol mixture (2%v/v). The A/R consisted of three periods of 20 minutes anoxia, each anoxia period being followed by re-oxygenation. Oxygen consumption by the cells was measured before starting the anoxia/reoxygenation cycles and after each reoxygenation. At the end of the last A/R period, the cells were transferred into the ESR flat cell and in the cavity, and the free radical formation was monitored. Results : The equine chondrocytes showed a low respiration rate, weakly affected by A/R and no production of free radicals (n=3). Synoviocytes showed a higher respiration rate (at least 20 times higher) which was affected by recurrent A/R (decrease of the slope of oxygen consumption), and a free radical production as evidenced by the appearance of the 4-POBN/EtOH adducts (n=6). Conclusions :These observations suggest that synoviocytes, but not chondrocytes, responded to repeated anoxia-reoxygenation conditions by the production of free radicals. Synoviocytes could thus be responsible for the production of free radicals in the joints, what could be an important factor in the onset of osteoarthritis. [less ▲]

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See detailViability of equine articular chondrocytes in alginate beads exposed to different oxygen tensions.
Schneider, Nicole ULg; Lejeune, Jean-Philippe ULg; Deby, Carol et al

in Veterinary Journal (2004), 168

Ischaemia and reperfusion are suspected to alter chondrocyte metabolism. Here, we studied the effects of three oxygen (O2) tensions on the viability of equine articular chondrocytes isolated from the ... [more ▼]

Ischaemia and reperfusion are suspected to alter chondrocyte metabolism. Here, we studied the effects of three oxygen (O2) tensions on the viability of equine articular chondrocytes isolated from the cartilage of the distal interphalangeal joint of horses. Chondrocytes were cultured in alginate beads under 1%, 5% or 21% gas phase O2 concentration for 14 days, cellular growth kinetics were measured (n=6), and the cells were observed by light microscopy after staining for necrotic and apoptotic cell detection. For information about the metabolic status, the intracellular adenosine triphosphate (ATP) content was measured. The number of chondrocytes remained stable for the first eight days, then decreased especially at 1% and 21% O2. At 21% O2, normal cells decreased and necrotic cells increased at the end of the 14 day-period. No significant variations were found at 5% O2 except for a decrease in necrotic cells at day 14. Most apoptotic cells were found at 1% O2 from days 5 to 11, and normal cells decreased during the same period. But an unexpected increase in normal cells and decrease in apoptotic cells were observed at day 14. The intracellular ATP content remained stable. It was concluded that, in a three-dimensional culture model of equine articular chondrocytes, O2 tension affected the viability of the cells after an 11-day period, with the most important effects observed at 21% and 1% O2 conditions. [less ▲]

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See detailStudie zur sonographischen Anatomie des Hufgelenks und der Hufrolle beim Pferd - ein Beitrag zur Diagnose der Podotrochlose
Schneider, Nicole ULg

Doctoral thesis (2003)

Ultrasound is becoming more common in the examination of the coffin joint and podotrochlear apparatus in horses. Purpose of this study is an approach to ultrasound anatomy of the coffin joint and ... [more ▼]

Ultrasound is becoming more common in the examination of the coffin joint and podotrochlear apparatus in horses. Purpose of this study is an approach to ultrasound anatomy of the coffin joint and detectable associated structures. Ultrasound is compared to photographs of dissected limbs to prove sensibility and reliability. Anatomy, artefacts, methods and other difficulties concerning realisation during an ultrasound imaging procedure of the distal interphalangeal joint and podotrochlear apparatus are discussed. This study is based on ten physiologic and seven pathologic reference sonograms, selected from patients at the Ecole Nationale Vétérinaire d’Alfort and the faculty of veterinary medicine of the university of Liège. Transcuneal views of the podotrochlear apparatus of an 18 months old foal have been established post mortem at the institute of veterinary diagnostic imaging at Liège. Modus of registration is real-time-motion, linear and sectorscanners working with 7,5 MHz are used. Echoanatomic documentation shows most of the soft tissue structures in the equine pastern in a reliable and sufficient way, some examples of pathologic alterations detected by ultrasound demonstrate that it is a suitable method to enrich informations achieved by common imaging procedures at the distal region of the equine limb. [less ▲]

Detailed reference viewed: 57 (3 ULg)
See detailEFFECTS OF O2 TENSION AND GLUCOSE CONCENTRATION ON THE CELLULAR RESPIRATION OF EQUINE ARTICULAR CHONDROCYTES IN CULTURE.
Schneider, Nicole ULg; Lejeune, Jean-Philippe ULg; Duyckaerts, Claire ULg et al

Poster (2003)

In vivo, articular chondrocytes are exposed to 5 to 10% O2. Chondrocytes are also suspected to produce reactive oxygen species when submitted to anoxia/re-oxygenation. We were interested to study the ... [more ▼]

In vivo, articular chondrocytes are exposed to 5 to 10% O2. Chondrocytes are also suspected to produce reactive oxygen species when submitted to anoxia/re-oxygenation. We were interested to study the effects of O2 and glucose variations on cellular respiration, glucose consumption and lactate production. Equine articular chondrocytes were cultured in suspension for 2 days under 5 or 21 % O2 in the gaseous phase, and with 0, 1.0 or 4.5 g/L glucose. The viable cells were then counted and the respiration rate (O2 consumption) of 10.106 cells was monitored by oxymetry for 2 hours; after oxymetry, glucose and lactate were measured in the medium (enzymatic assays). After 2 days, the cell viability was the best at 5% O2 and 1g/L glucose; it decreased at 4.5 g/L glucose and was the worst at 0g/L glucose, for the two O2 tensions (n=3). There was no obvious difference of the respiration rate between cells cultured at 5 and 21% O2, but respiration of chondrocytes was surprisingly low. When cells were submitted to 20 min anoxia at 0% O2, the O2 consumption was doubled at re-oxygenation for cells previously cultured at 21% O2. Glucose and lactate values found in the medium after oxymetry: lactate release in medium was similar (36.23 and 34.57 mg/L respectively) for cells cultured with 1g glucose and 5 or 21% O2 conditions; lactate values were low (2.03 and 8,63 mg/L respectively) for 4.5 g glucose and 5 or 21% O2. Glucose uptake was not different whatever the culture conditions. These results indicate a low cellular respiration with a lactate production linked to the glucose concentrationin the medium, and raise the question of the capacity of chondrocytes to produce ROS in vivo starting from the mitochondrial chain. [less ▲]

Detailed reference viewed: 24 (1 ULg)
See detailEffects of O2 tension and glucose concentration on the cellular respiration of equine articular chondrocytes in culture.
Schneider, Nicole ULg; Lejeune, Jean-Philippe ULg; Mouithys-Mickalad, Ange ULg et al

Poster (2003)

In vivo, articular chondrocytes are exposed to 5 to 10% O21,2. Chondrocytes are also suspected to produce reactive oxygen species when submitted to anoxia/re-oxygenation3,4. We were interested to study ... [more ▼]

In vivo, articular chondrocytes are exposed to 5 to 10% O21,2. Chondrocytes are also suspected to produce reactive oxygen species when submitted to anoxia/re-oxygenation3,4. We were interested to study the effects of O2 and glucose variations on cellular respiration, glucose consumption and lactate production. Equine articular chondrocytes were cultured in suspension for 2 days under 5 or 21 % O2 in the gaseous phase, and with 0, 1.0 or 4.5 g/L glucose. The viable cells were then counted and the respiration rate (O2 consumption) of 10.106 cells was monitored by oxymetry for 2 hours; after oxymetry, glucose and lactate were measured in the medium (enzymatic assays). After 2 days, the cell viability was the best at 5% O2 and 1g/L glucose; it decreased at 4.5 g/L glucose and was the worst at 0g/L glucose, for the two O2 tensions (n=3). There was no obvious difference of the respiration rate between cells cultured at 5 and 21% O2, but respiration of chondrocytes was surprisingly low. When cells were submitted to 20 min anoxia at 0% O2, the O2 consumption was doubled at re-oxygenation for cells previously cultured at 21% O2. Glucose and lactate values found in the medium after oxymetry : lactate release in medium was similar (36.23 and 34.57 mg/L respectively) for cells cultured with 1g glucose and 5 or 21% O2 conditions; lactate values were low (2.03 and 8,63 mg/L respectively) for 4.5 g glucose and 5 or 21% O2. Glucose uptake was not different whatever the culture conditions. These results indicate a low cellular respiration with a lactate production linked to the glucose concentration in the medium, and raise the question of the capacity of chondrocytes to produce ROS in vivo starting from the mitochondrial chain. [less ▲]

Detailed reference viewed: 25 (1 ULg)