References of "Franck, Thierry"
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See detailEffect of intensive exercise on plasmatic neutrophil elastase level in eventing and endurance horses
Lejeune, Jean-Philippe ULg; Sandersen, Charlotte ULg; Votion, Dominique ULg et al

in Equine Veterinary Journal. Supplement (2010), 48

Reasons for performing the study – Intensive exercise induces a systemic inflammatory response characterized by an increase of blood neutrophil count and myeloperoxidase (MPO) release. Neutrophil elastase ... [more ▼]

Reasons for performing the study – Intensive exercise induces a systemic inflammatory response characterized by an increase of blood neutrophil count and myeloperoxidase (MPO) release. Neutrophil elastase (NE) could also contribute to tissues lesions by their proteinase activities. Objective – To compare plasmatic NE concentrations before and after different forms of intensive exercise. Materials and Methods – EDTA blood samples were taken from 51 eventing horses (EvH) and 32 endurance horses (EndH) were sampled before the race (T0). Blood sampling was performed 2 h (T1) after completing either phase D of a one or two star eventing competition (n=51) or a 120 or 160 km endurance race (n=32). Plasmatic NE and MPO were measured by a specific equine ELISA. Neutrophil counts and creatine kinase (CK) levels were also measured. A Wilcoxon test for paired samples was used to compare mean values of neutrophils, CK, MPO and NE at T0 and T1 in EvH and in EndH. Correlations were calculated between all the 4 parameters in EvH and EndH. Results – At T0, mean NE levels were 14.43 ± 3.63 ng/ml for EvH and 11.7 ± 2.11 ng/ml for EndH. The competition induced a significant increase of NE levels in (58.57 ± 24.06 ng/mL) EvH and (95.74 ± 22.70 ng/mL) EndH (p < 0,05). NE was significantly (p < 0,0001) correlated to MPO in EvH (r = 0.293) and EndH (0.594) and to CK (r = 0.297) in EndH (p<0.0001). Neutrophils, CK and MPO were significantly increased between T0 and T1 in both types of horses. Conclusions – Significant increase of NE was observed after intense exercise with a significant correlation between NE and MPO. The huge variability in MPO and ELT, indicates, that not all horses show the same intensity of systemic inflammatory response. [less ▲]

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See detailAlterations in mitochondrial respiratory function in response to endurance training and endurance racing
Votion, Dominique ULg; Fraipont, Audrey ULg; Goachet, Anne-Gaëlle et al

in Equine Veterinary Journal. Supplement (2010), 42(38), 268-274

Objectives: To determine effects of training and racing on muscle oxidative phosphorylation (OXPHOS) and electron transport system (ETS) capacities in horses with high-resolution respirometry (HRR).

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See detailAMADEOX method : combination of various techniques to distinguish stoichiometric and anticatalytic activities of antioxidant molecules or natural extracts
Franck, Thierry ULg; Mouithys-Mickalad, Ange ULg; Kohnen, Stephan et al

in International Society of Antioxidants in Nutrition & Health, 5th International Conference on Polyphenols Applications, Bridging Bioefficacy to Innovations & Applications, October 29th-30th 2009, Malta (2009, October 29)

We developed an original method called AMADEOX (for « Action Modulatrice de l'Activité Des Enzymes Oxydantes ») able to distinguish stoichiometric, metabolic and anticatalytic activities of antioxidant ... [more ▼]

We developed an original method called AMADEOX (for « Action Modulatrice de l'Activité Des Enzymes Oxydantes ») able to distinguish stoichiometric, metabolic and anticatalytic activities of antioxidant molecules or natural extracts on stimulated neutrophils and purified myeloperoxidase (MPO), a key enzyme released by neutrophil and acting as one of the major ROS generating systems. [less ▲]

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See detailCombined method for the sequential measurement of (1) the enzymatically active fraction and (2) the total amount of an enzyme
Serteyn, Didier ULg; Deby-Dupont, Ginette; Franck, Thierry ULg et al

Patent (2009)

The present invention is related to a combined method and kit (or device) for the sequential measurement of the enzymatically active fraction and the total amount of an enzyme [(such as myeloperoxidase ... [more ▼]

The present invention is related to a combined method and kit (or device) for the sequential measurement of the enzymatically active fraction and the total amount of an enzyme [(such as myeloperoxidase (MPO)] in a sample, and that find improved applications in veterinary and human health fields. [less ▲]

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See detailRelationship between biochemical markers and radiographic scores in the evaluation of the osteoarticular status of Warmblood stallions
Verwilghen, Denis ULg; Busoni, Valeria ULg; Gangl, Monika et al

in Research in Veterinary Science (2009), 87(2), 319-28

Establishing the osteoarticular status of the horse is often performed by means of radiological screening of the animals. Widespread blood sampling could reveal to be an interesting alternative to this ... [more ▼]

Establishing the osteoarticular status of the horse is often performed by means of radiological screening of the animals. Widespread blood sampling could reveal to be an interesting alternative to this procedure which is time consuming and sometimes technically difficult. The aim of this study was to investigate the relationship between the radiological status of the horses and the levels of biochemical markers of cartilage degradation and synovial inflammation. A specific radiological scoring and classification system was therefore developed and applied on 63 stallions presented for studbook admission. Additionally, groups of horses were established according to the occurrence of osteochondrosis, degenerative joint disease and distal interphalangeal joint effusion. Insulin growth factor-I, myeloperoxidases, Coll2-1 and Coll2-1NO(2) were used as blood markers. The combination of the blood parameters did not seem to correlate with the used scoring system. Coll2-1NO(2) levels however tended to increase with poorer radiological class and this could therefore potentially be a useful predictor of the osteoarticular status in the horse. Coll2-1 levels were significantly higher in the degenerative joint disease group. A high percentage of horses with distal interphalangeal joint effusion was present in this study and was associated with decreased IGF-I and increased Coll2-1 levels. [less ▲]

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See detailA new easy method for specific measurement of active myeloperoxidase in human biological fluids and tissue extracts
Franck, Thierry ULg; Kohnen, Stephan; Zouaoui Boudjeltia, Karim et al

in Talanta (2009), 80

The SIEFED (“Specific Immunological Extraction Followed by Enzymatic Detection”) method already developed for the specific detection of the activity of equine myeloperoxidase (MPO) was adapted for the ... [more ▼]

The SIEFED (“Specific Immunological Extraction Followed by Enzymatic Detection”) method already developed for the specific detection of the activity of equine myeloperoxidase (MPO) was adapted for the specific measurement of active human MPO in biological fluids or tissue extracts. [less ▲]

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See detailEquine neutrophil elastase in plasma, laminar tissue, and skin of horses administered black walnut heartwood extract.
de la Rebière de Pouyade, Geoffroy ULg; Riggs, L. M.; Moore, J. N. et al

in Veterinary immunology and immunopathology (2009)

Laminitis is a local manifestation of a systemic inflammatory response that is characterized by neutrophil activation and movement of neutrophils into the laminar tissues. Given the evidence for the ... [more ▼]

Laminitis is a local manifestation of a systemic inflammatory response that is characterized by neutrophil activation and movement of neutrophils into the laminar tissues. Given the evidence for the involvement of neutrophils in the development of laminitis, we measured concentrations of neutrophil elastase, a serine protease released from the azurophilic granules of neutrophils, in plasma, skin and laminar tissues obtained from control horses and horses given black walnut heartwood extract (BWHE) to induce laminitis. Healthy horses (5-15 years old) were randomly assigned to 4 groups: 3 experimental groups given BWHE via nasogastric tube, and a control group given an equal volume of water. The experimental groups consisted of horses euthanized 1.5h (n=5), 3h (n=6) or 12h (n=10) after BWHE administration. Control horses (n=7) were euthanized 12h after intragastric administration of water. Plasma samples were collected in all horses of the control and 12h BWHE groups at 0, 1, 2, 3, 4, 6, 8, 10, and 12h after treatment, and laminar tissue and skin from the middle region of the neck were harvested at the time of euthanasia in all 1.5 and 3h BWHE horses, in 6 of the 12h BWHE horses and in 5 of the control horses. Plasma and tissue concentrations of neutrophil elastase were determined using an equine specific ELISA, and statistical significance was set at p<0.05. Plasma concentrations of neutrophil elastase in the BWHE group were significantly higher at 6 and 8h compared to the control group and at 8 and 10h compared to time 0. Concentrations of neutrophil elastase in skin and laminar tissue were significantly higher in the 3 and 12h BWHE groups compared to the control group. Concentrations of neutrophil elastase were significantly higher in the skin than in the lamina in the 12h BWHE horses. The administration of BWHE thus results in significant increases in the concentration of neutrophil elastase in the circulation, skin and laminar tissue. These results confirm a role for neutrophils in the developmental phase of laminitis, and the systemic nature of the inflammatory process. Furthermore, neutrophil elastase may play a key role in the disintegration of the hoof basal membrane and be a target for the development of new treatments for laminitis. [less ▲]

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See detailActivation of equine neutrophils by phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine induces a different response in reactive oxygen species production and release of active myeloperoxidase.
Franck, Thierry ULg; Kohnen, Stéphane; de la Rebière de Pouyade, Geoffroy ULg et al

in Veterinary Immunology and Immunopathology (2009)

Neutrophil (PMN) contribution to the acute inflammatory processes may lead to an excessive generation of reactive oxygen metabolites species (ROS) and secretion of granule enzymes. We compared the effects ... [more ▼]

Neutrophil (PMN) contribution to the acute inflammatory processes may lead to an excessive generation of reactive oxygen metabolites species (ROS) and secretion of granule enzymes. We compared the effects of either phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) in combination with a pre-treatment by cytochalasin B (CB) on the production of ROS and the release of total and active myeloperoxidase (MPO) by isolated equine PMNs. The ROS production was assessed by lucigenin dependent chemiluminescence (CL) and ethylene release by alpha-keto-gamma-methylthiobutyric acid (KMB) oxidation. In the supernatant of activated PMNs, total equine MPO was measured by ELISA and active MPO by the SIEFED (Specific Immunologic Extraction Followed by Enzymatic Detection) technique that allows for the study of the interaction of a compound directly with the enzyme. The stimulation of PMNs with CB-fMLP only modestly increased the release of MPO, but more than 70% of released MPO was active. PMA stimulation markedly increased the production of ROS and release of MPO, but more than 95% of released MPO was inactive. When PMNs were pre-incubated with superoxide dismutase (SOD) prior to PMA activation, the lucigenin enhanced CL, which is linked to the superoxide anion (O(2)(-)) production, was much more decreased than KMB oxidation, linked to the hydroxyl-like radical production. The addition of SOD prior to the activation of PMNs by PMA also limited the loss of the activity of released MPO. These results confirm the key role of O(2)(-) generation in the ROS cascade in PMN and reveal its critical role on MPO inactivation. [less ▲]

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See detailVariations of plasmatic concentrations of Insulin-like Growth Factor-I in post-pubescent horses affected with developmental osteochondral lesions.
Verwilghen, Denis ULg; Vander Heyden, Laurent ULg; Franck, Thierry ULg et al

in Veterinary Research Communications (2009)

Developmental osteochondral lesions are often encountered in the equine population and are a major cause of lameness. Different growth factors that act systemically as well as locally regulate the growth ... [more ▼]

Developmental osteochondral lesions are often encountered in the equine population and are a major cause of lameness. Different growth factors that act systemically as well as locally regulate the growth of cartilage. Among them is Insulin-like Growth Factor I that has been demonstrated to promote chondrocyte growth and differentiation and that has been shown to influence cartilage repair. The aims of this study were to investigate differences in circulating plasma levels of Insulin-like Growth Factor-I in post-pubescent horses affected with developmental osteochondral lesions compared to unaffected ones. Significantly higher values of circulating Insulin-like Growth Factor-I levels were found in the affected group (n = 82) compared to controls (n = 86). This result may still reflect an earlier imbalance in IGF-I levels from horses with developmental osteochondral lesions considering the aetiopathological link which has been made between IGF-I and the occurrence of osteochondrosis. However, other studies have shown increased expression of IGF-I after cartilage damage. The higher levels found in this study could be due to a healing response of the cartilage to the damage caused by the osteochondral lesions. [less ▲]

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See detailEffect de l'entraînement sur la fonction mitochondriale musculaire du cheval d'endurance
Votion, Dominique ULg; Fraipont, Audrey ULg; Franck, Thierry ULg et al

in 35eme Journee de la Recherche Equine, jeudi 26 fevrier 2009, Paris, France (2009)

Athletic ability of endurance horses is intimately linked to muscle oxidative capacity. Microbiopsies of triceps brachii (TB) and gluteus medius (GM) were collected before and after 10 weeks of training ... [more ▼]

Athletic ability of endurance horses is intimately linked to muscle oxidative capacity. Microbiopsies of triceps brachii (TB) and gluteus medius (GM) were collected before and after 10 weeks of training in 7 endurance horses to assess the feasibility of studying training effect with the use of microbiopsies. Oxygen consumption of permeabilized fibers was evaluated by high resolution respirometry (HRR) with a titration protocol that defines the activity of the mitochondrial complexes. Differences among muscles before and after training as well as training effect were assessed by Wilcoxon matched pairs test (P<0.05). No complications occurred following microbiopsies in any horse. The in situ oxidative capacity of the TB and GM increased with training. No difference was found between the TB and GM when one horse was excluded from the statistical analysis. Indeed, this horse showed signs of exercise intolerance before sampling (after the training period) which were associated to a low rate of respiration in GM but not in TB. Results of this study showed that HRR may be used to follow training effect and suggest that metabolic impairment might be detected with HRR. [less ▲]

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See detailIn vivo administration of acepromazine or promethazine to horse decreases the reactive oxygen species production response of subsequently isolated neutrophils to stimulation with phorbol myristate acetate
Péters, Fabrice; Franck, Thierry ULg; Pequito, Manuel et al

in Journal of Veterinary Pharmacology & Therapeutics (2009)

The previous experiments have shown that some phenothiazines have antioxidant and anti-inflammatory properties in vitro. In this study the inhibition of the production of reactive oxygen species (ROS) by ... [more ▼]

The previous experiments have shown that some phenothiazines have antioxidant and anti-inflammatory properties in vitro. In this study the inhibition of the production of reactive oxygen species (ROS) by neutrophils was studied in two groups of horses, which received a dose of 0.1 mg⁄ kg of either acepromazine or promethazine intravenously. Blood samples were collected before (T0) and 0.5, 1, 3 and 5 h after drug administration. The chemiluminescence (CML) response of neutrophils was measured ex vivo in the presence of luminol for a period of 10 min and the maximum CML value (peak value) recorded. There was a significant inhibition of the ROS production in the acepromazine treated group (49% inhibition) at 5 h after administration and in the promethazine group (24% inhibition) at 3 h after administration (P < 0.05 vs. T0). These findings are of therapeutic relevance in the use of phenothiazines in equine patients with inflammatory diseases where neutrophil activation and ROS production are implicated. [less ▲]

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See detailMethod for co-purification of equine neutrophil elastase and myeloperoxidase from a limited blood volume.
de la Rebière de Pouyade, Geoffroy ULg; Serteyn, Didier ULg; Deby, Ginette ULg et al

in Research in Veterinary Science (2009)

Neutrophil myeloperoxidase (MPO) and elastase can be released in severe inflammatory diseases and cause tissue injuries. Equine enzymes have already been individually purified from large blood quantities ... [more ▼]

Neutrophil myeloperoxidase (MPO) and elastase can be released in severe inflammatory diseases and cause tissue injuries. Equine enzymes have already been individually purified from large blood quantities. We describe the isolation of both enzymes from a same limited blood volume. Both MPO and elastase were extracted by crushing PMN isolated by centrifugation on a percoll-gradient from a 460ml blood collection. MPO and elastase were separated by an ionic exchange chromatography phase and further purified by gel filtration chromatography on Superdex 200 and 75, respectively. Enzymes were identified in the collected fractions by specific enzymatic assays. The final purity was verified by electrophoresis. Specific activity was improved to 19.92 and 34.3x for elastase (final yield: 340mug) and MPO (final yield: 130mug), respectively, during the procedure. Results show the possibility of isolating both enzymes from the same blood sample with a sufficient yield and purity for future studies on their implication and interaction during inflammatory diseases. [less ▲]

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See detailLes nouveaux outils d’investigation des myopathies « typiques » et atypique.
Votion, Dominique ULg; van Galen, Gaby; Deby-Dupont, Ginette et al

(2008, October)

This paper aims at describing new investigation tools that are currently under development. Oxymetry, electron spin resonance and myeloperoxidase assays may be applied on muscle sample taken by ... [more ▼]

This paper aims at describing new investigation tools that are currently under development. Oxymetry, electron spin resonance and myeloperoxidase assays may be applied on muscle sample taken by microbiopsy as well as on culture of myocytes. In a next future, these tools should improve our knowledge of the pathophysiological mechanisms involved in clinical and subclinical equine myopathies. [less ▲]

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See detailEquine frozen semen parameters in relation with total myeloperoxidase concentration
Ponthier, Jérôme ULg; Franck, Thierry ULg; Mottart, Evelyne et al

in Animal Reproduction Science (2008, September 15)

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See detailMyeloperoxidase Assay in Plasma and Peritoneal Fluid of Horses with Gastrointestinal Disease
Grulke, Sigrid ULg; Franck, Thierry ULg; Gangl, Monika et al

in Canadian Journal of Veterinary Research = Revue Canadienne de Recherche Vétérinaire (2008), 72(1), 37-42

Gastrointestinal disorders, especially strangulating intestinal obstructions, are still a major cause of illness and death in the horse. Circulating lipopolysaccharides may activate both neutrophils and ... [more ▼]

Gastrointestinal disorders, especially strangulating intestinal obstructions, are still a major cause of illness and death in the horse. Circulating lipopolysaccharides may activate both neutrophils and monocytes. The activated neutrophils release myeloperoxidase (MPO), a specific enzyme with strong oxidative activity. The aim of this study was to evaluate MPO concentrations in the plasma and peritoneal fluid (PF) of horses with colic and to check the hypothesis that these concentrations would be higher in a case of strangulating obstruction than in cases of nonstrangulating disease. By using a specific enzyme-linked immunosorbent assay for equine MPO, we determined the MPO concentrations in horses admitted to a clinic for colic. Horses with nonstrangulating or strangulating obstruction of the large intestine (NSLI or SLI), strangulating obstruction of the small intestine (SSI), or inflammatory bowel disease (IBD) were compared with healthy horses. The horses with SLI, SSI, or IBD had significantly higher MPO levels in plasma and PF than did those in the other 2 groups. The mean plasma level was significantly higher in the horses with NSLI than in the healthy horses. High MPO values in PF indicated necrotic bowel. These results show that neutrophil activation occurs during nonstrangulating and strangulating intestinal obstruction in horses and that the plasma and PF MPO concentrations may be a marker of the severity of the disease. [less ▲]

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See detailInhibitory effect of curcuminoids and tetrahydrocurcuminoids on equine activated neutrophils and myeloperoxidase activity
Franck, Thierry ULg; Kohnen, Stephan ULg; Grulke, Sigrid ULg et al

in Physiological Research (2008), 57(4), 577-587

In the horse, the inflammation response to various pathologies (intestinal strangulations, laminitis, etc.) involves an excessive stimulation of the polymorphonuclear neutrophils releasing reactive oxygen ... [more ▼]

In the horse, the inflammation response to various pathologies (intestinal strangulations, laminitis, etc.) involves an excessive stimulation of the polymorphonuclear neutrophils releasing reactive oxygen species (ROS) and myeloperoxidase (MPO). The aim of the present work was to study the effect of natural polyphenols, curcuminoids and tetrahydrocurcuminoids (THC) on isolated stimulated equine neutrophils and on the activity of purified MPO. The ROS production and the release of MPO by activated neutrophils were measured by chemiluminescence and ELISA techniques, respectively. The activity of purified MPO was measured by studying its nitration, chlorination or oxidation capacity and by using an original method called SIEFED allowing the study of drug interaction with the enzyme without interferences of the medium. Curcuminoids and THC had dose-dependent inhibitory effects on ROS production and MPO release by activated neutrophils and on purified MPO activity. We suggest that the higher efficacy of curcuminoids versus THC could be explained, at least partially, by its chemical structure: the conjugated double bounds and the plane structure of curcuminoids made easier the neutralization of the radical species generated by activated neutrophils and the interaction of the drug with the active site of MPO. These inhibitory effects of curcuminoids on the oxidant activity of equine neutrophils and on MPO activity open therapeutic perspectives in equine pathologies with excessive inflammatory reactions. [less ▲]

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See detailEffects of Unfractionated and Fractionated Heparins on Myeloperoxidase Activity and Interactions with Endothelial Cells: Possible Effects on the Pathophysiology of Equine Laminitis
de la Rebière de Pouyade, Geoffroy ULg; Franck, Thierry ULg; Dupont, Ginette ULg et al

in Veterinary Journal (2007), 178(1), 62-69

As heparins are sometimes used to prevent equine laminitis, the interactions between equine neutrophil myeloperoxidase (MPO), unfractionated (UFH) and fractionated low molecular weight (LMWH) heparins and ... [more ▼]

As heparins are sometimes used to prevent equine laminitis, the interactions between equine neutrophil myeloperoxidase (MPO), unfractionated (UFH) and fractionated low molecular weight (LMWH) heparins and digital endothelium have been investigated. The effects of the heparins on purified equine MPO activity were tested by immunocapture followed by enzymatic detection. Endothelium-MPO interactions were assessed by measuring total and active MPO uptake by arterial and venous digital endothelial cells in culture with or without the addition of heparins. A dose-dependent MPO inhibition by UFH and LMWH was seen, with the greatest reduction in MPO activity noted with the highest concentration of LMWH. The MPO capture was greater in arterial cells, but heparins better inhibited MPO capture in venous cells. The activity of cell-bound MPO was almost completely suppressed by the heparins, and no differences were observed between UFH and LMWH. The results confirm the anti-inflammatory properties of heparins and allow a better understanding of the potential role of MPO in laminitis. [less ▲]

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