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See detailLes kératomes: lésions et traitements chez 19 chevaux
Salciccia, Alexandra ULg; de la Rebière de Pouyade, Geoffroy ULg; Bolen, Géraldine ULg et al

Conference (2012, October 12)

Introduction: Les kératomes, masses hyperplasiques de kératine, croissent entre la phalange distale (P3) et la paroi du sabot et provoquent des boiteries chez le cheval. La littérature comporte de ... [more ▼]

Introduction: Les kératomes, masses hyperplasiques de kératine, croissent entre la phalange distale (P3) et la paroi du sabot et provoquent des boiteries chez le cheval. La littérature comporte de nombreux rapports de cas isolés mais peu de séries cliniques. Matériel et méthodes: Les dossiers cliniques des cas de kératomes présentés depuis 2004 à la faculté de médecine vétérinaire de Liège ont été revus. Résultats: Vingt-trois kératomes ont été diagnostiqués sur 19 chevaux boiteux. Un cheval présentait 2 kératomes sur le même pied et 3 chevaux présentaient 2 kératomes sur des pieds différents. Sur les 22 pieds atteints, les lésions observées étaient: un abcès, souvent récidivant (18 cas), une déformation de la muraille (6 cas), une déviation de la ligne blanche (6 cas) et une seime (3 cas). Un kératome était situé sous la sole et 22 sous la muraille. La durée des symptômes variait de 2 semaines à 15 ans (plus d'un an sur 12 pieds). Sur les radiographies, une lyse par compression de P3 était visible en regard de 20 kératomes. Le cheval présentant 2 kératomes sur le même pied a été euthanasié. Trois kératomes ont été traités de manière conservative. Dix-huit kératomes (chez 16 chevaux) ont été excisés chirurgicalement dont 16 par avulsion complète de muraille, 1 par avulsion partielle de muraille et 1 par curetage d'une portion de sole. Aucune complication postopératoire n'a été observée dans 7/18 cas (39%). Les complications rencontrées étaient: une granulation excessive (10 cas), une douleur importante pendant plusieurs jours (5 cas), une légère infection (4 cas), un enfoncement de P3 en regard de la zone avulsée (2 cas) et une récidive (2 cas, dont 1 a été réopéré avec succès ultérieurement). Un cheval est encore en convalescence au moment de cette étude. Le suivi à long terme d’un cheval a été perdu. Des 14 chevaux repris dans l'évaluation postopératoire, 1 a été euthanasié pour une autre raison que le kératome, 3 chevaux ont gardé une boiterie résiduelle au trot et 10 chevaux ont récupéré leur niveau d'activité. Discussion: La littérature décrit les kératomes comme rares1. Or, 21% des chevaux de cette étude (4 chevaux sur 19) présentaient plusieurs kératomes. De plus, dans 54 % des cas, les symptômes duraient depuis plus d’un an. Dès lors, il apparait que les kératomes sont sous diagnostiqués ou le sont souvent tardivement. La chronicité et l’étendue des kératomes de cette étude n’a que très rarement permis leur résection par avulsion partielle de muraille, technique de choix dont les complications postopératoires sont moindres². Un diagnostic précoce par inspection minutieuse des sabots, particulièrement en cas d’abcès de pied récidivant permettrait une excision par une technique moins invasive, qui diminuerait la convalescence et les complications postopératoires. Bibliographie: 1. Sundberg, J.P. et al. Neoplasms of Equidae. Journal of American veterinary medical association, 1977, 170: 150-152. 2. Boys Smith SJ. et al. Complete and partial hoof wall resection for keratoma removal: postoperative complications and final outcome in 26 horses (1994-2004). Equine Veterinary Journal, 2006, 38 (2): 127-133. [less ▲]

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See detailIntérêt d’un système de traitement des plaies par pression négative chez le cheval : Etat des lieux et cas cliniques
de la Rebière de Pouyade, Geoffroy ULg; Salciccia, Alexandra ULg; Gougnard, Alexandra ULg et al

Conference (2012, October 12)

Les plaies traumatiques ou chirurgicales nécessitent souvent une cicatrisation par seconde intention lorsque la fermeture primaire n’est pas possible ou échoue. La fermeture assistée par le vide (Vacuum ... [more ▼]

Les plaies traumatiques ou chirurgicales nécessitent souvent une cicatrisation par seconde intention lorsque la fermeture primaire n’est pas possible ou échoue. La fermeture assistée par le vide (Vacuum Assisted Closure : VAC) est une méthode active et non invasive qui expose le lit de la plaie à une pression sub-atmosphérique locale afin de promouvoir sa cicatrisation. Elle stimule la granulation et la perfusion sanguine locale et réduit significativement l’œdème et la charge bactérienne.1 Cette technique s’est révélée efficace dans le traitement des plaies aiguës et chroniques chez l’homme. Chez le cheval, la méthode est encore peu décrite.2,3 Nous rapportons ici l’application et les effets de la thérapie des plaies par pression négative à travers les cas traités à la clinique vétérinaire universitaire de Liège depuis 2010. Les plaies étaient chirurgicalement débridées avant l’application du système VAC. Une mousse en polyuréthane était appliquée après avoir été adaptée à la géométrie de la plaie. Un champ plastique adhésif était alors apposé sur la plaie pour créer un environnement hermétique et un orifice d’1 cm2 était créé au centre du système pour appliquer la ventouse du tuyau d’aspiration. Cette ligne était alors raccordée à l’appareil d’aspiration contrôlée pour maintenir une pression continue de -125 mmHg dans la plaie. Quinze cas ont été recensés: 3 plaies intra-articulaires (au carpe, au coude et au grasset), 3 sur la face dorsale du canon postérieur, 2 sur la face dorsale du jarret, 1 sur la pointe du calcanéum, 2 sur l’encolure et 4 plaies de laparotomie infectées. Le traitement a accéléré la croissance du tissu de granulation, stimulé la contraction des plaies et favorisé la cicatrisation dans la majorité des cas (12/15). Les plaies apparaissaient aussi plus saines et présentaient moins de sécrétions lors des changements de bandages. Des résultats plus modérés ont été notés chez les 3 autres cas. Quelques complications mineures comme des irritations cutanées ont été observées. Le traitement de plaies contaminées nous a orientés vers l’usage d’une mousse de polyuréthane argenté mais d’autres types de matrice sont disponibles et permettent de modifier le comportement de la plaie. L’usage d’une mousse de polyvinyl Alcool s’est ainsi avéré efficace pour améliorer l’adhésion des greffons lors d’une greffe de peau chez le cheval.3 La principale limite du traitement réside dans la difficulté technique de maintenir la plaie sous vide lors d’atteinte de régions très mobiles comme les articulations. En conclusion, le système VAC semble très prometteur pour optimiser la qualité de la cicatrisation et réduire la durée de l’hospitalisation. 1 - Morykwas, M.J., Argenta, L.C., et al. Vacuum-assisted closure: a new method for wound control and treatment: animal studies and basic foundation. Ann. Plast. Surg. 1997, 38, 553-562 2 - Gemeinhardt K.D., Molnar J.A. Vacuum-assisted closure for management of a traumatic neck wound in a horse. Equine Vet. Educ. 2005, 17, 27-33 3 - Jordana M., Pint E., et al. The use of vacuum-assisted wound closure to enhance skin graft acceptance in a horse. Vlaams Diergeneeskundig Tijdschrift 2011, 80, 343-350 [less ▲]

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See detailSimultaneous measurement of protein-bound 3-chlorotyrosine and homocitrulline by LC-MS/MS after hydrolysis assisted by microwave: application to the study of myeloperoxidase activity during hemodialysis.
Delporte, Cedric; Franck, Thierry ULg; Noyon, Caroline et al

in Talanta (2012), 99

A high degree of uremia is common in patients with end-stage renal disease and has been linked to the development of chronic inflammation and cardiovascular diseases. In conditions where transplantation ... [more ▼]

A high degree of uremia is common in patients with end-stage renal disease and has been linked to the development of chronic inflammation and cardiovascular diseases. In conditions where transplantation is not possible, uremia can be reduced by hemodialysis although the repeated interventions have been implicated in loss of renal function, partially as a result of chronic inflammation and/or oxidative stress processes. In this context, it has been suggested that myeloperoxidase (MPO) can contribute to the oxidative stress during hemodialysis and to the cardiovascular risk. Protein damages due to MPO activity have never been assessed during hemodialysis although two of its reaction products, 3-chlorotyrosine and homocitrulline, are of interest. Indeed, the first one is a specific product of MPO activity and the formation of the second one could be catalyzed by MPO. In order to analyze these products in plasma proteins, a total hydrolysis method followed by liquid chromatography mass spectrometry analysis was developed. Different conditions of hydrolysis were tested and the optimized procedure was assessed for complete hydrolysis and artifactual chlorination. Finally, the method was used for analyzing 3-chlorotyrosine and homocitrulline in plasma proteins during a hemodialysis session in fifteen patients and data were related to measurements of MPO concentration and activity. Both increases in MPO activity and protein-bound 3-chlorotyrosine were observed, highlighting the involvement of MPO in oxidative stress during hemodialysis and further demonstrating the link between hemodialysis and cardiovascular diseases. [less ▲]

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See detailDoes the new water-soluble form of curcumin(NDS27) inhibit the oxidant response of stimulated neutrophils and HL-60 cells?
Derochette, Sandrine ULg; Franck, Thierry ULg; Deby-Dupont, Ginette et al

Poster (2012, September 07)

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) and the release of an oxidant enzyme, myeloperoxidase (MPO), to kill pathologic ... [more ▼]

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) and the release of an oxidant enzyme, myeloperoxidase (MPO), to kill pathologic agents. But, an excessive stimulation of PMNs is associated with development of inflammatory diseases. Neutrophils are prime targets to control inflammatory events and the therapeutic use of polyphenols is proposed to lower oxidative stress. The aim of this work was to study antioxidant effect of NDS27, a water-soluble form of curcumin, on stimulated equine PMNs and human promyelocytic leukemia cells (HL-60) which are less differenciated. 2',7'-Dichlorofluorescin diacetate and lucigenin were used to measure ROS production by activated HL-60 cells or PMNs. NDS27 (10-6 to 10-4 M) was pre-incubated with cells and eliminated before their activation to study its intracellular effects on ROS production. The effect of NDS27 on MPO activity released by the cells was determined by SIEFED. Likewise, the ability of NDS27 to enter into the cells was checked by HPLC on the cellular extracts.NDS27 significantly and dose-dependently inhibited the ROS production in both cell types without affecting their viability. Its intracellular effect showed higher efficiency for PMNs while its interaction with HL-60 cells remained better. The activity of MPO released by PMNs and HL-60 cells was decreased by NDS27 with a more efficient effect for PMNs. Our findings suggest that the greater efficiency of NDS27 in mature PMNs is not due to a better membrane permeability or a better interaction between membrane and NDS27, but rather to an inhibitory effect on the ROS production by the more mature cells, probably by targeting the enzymes implied in respiratory burst like MPO and NADPH oxidase. The modulatory effect of NDS27 towards oxidant activity of cells involved in immune and inflammatory response opens therapeutic perspectives to control pathologies with excessive inflammatory reactions. [less ▲]

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See detailRelationships between young stallions's temperament and their behavioral reactions during standardized veterinary examinations.
Peeters, Marie ULg; Verwilghen, Denis ULg; Serteyn, Didier ULg et al

in Journal of Veterinary Behavior: Clinical Applications and Research (2012), 7(5), 311-321

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See detailPhysical Fitness and Mitochondrial Respiratory Capacity in Horse Skeletal Muscle
Votion, Dominique ULg; Gnaiger, Erich; Lemieux, Hélène et al

in PLoS ONE (2012), 7(4), 1-12

We applied high-resolution respirometry and multiple substrate-uncoupler-inhibitor titration protocols to study mitochondrial physiology in small (1.0–2.5 mg) permeabilized muscle fibres sampled from ... [more ▼]

We applied high-resolution respirometry and multiple substrate-uncoupler-inhibitor titration protocols to study mitochondrial physiology in small (1.0–2.5 mg) permeabilized muscle fibres sampled from triceps brachii of healthy horses. The present investigation on horse skeletal muscle has tested the methodology used to study mitochondrial function in muscle microbiopsies by high-resolution respirometry to define reference protocols for horses (from sampling procedure to data analysis). [less ▲]

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See detailPossible intracellular effect of the new water-soluble form of curcumin (NDS27) on the oxidant response of stimulated neutrophils
Derochette, Sandrine ULg; Mouithys-Mickalad, Ange ULg; Deby-Dupont, Ginette et al

Poster (2012, April 18)

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) to kill pathologic agents. But, an excessive ROS production, called “oxidative ... [more ▼]

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) to kill pathologic agents. But, an excessive ROS production, called “oxidative stress” is associated with tissue damages and development of chronic or acute inflammatory diseases. PMNs are prime therapeutic targets to control inflammatory events associated to ROS production. Nowadays, there is a growing interest for the use of polyphenolic molecules to modulate the inflammatory response. The aim of this work was to study the antioxidant effect of NDS27 (1), a new highly water-soluble form of the polyphenolic molecule curcumin, on in vitro stimulated equine PMNs. NDS27 (10-6 to 10-4 M) was pre-incubated with cells and eliminated before their activation. The ability of NDS27 to enter into the cells was checked by HPLC from the cellular extracts. The intracellular ROS production by phorbol myristate acetate (PMA) stimulated PMNs was measured by fluorescence using 2’,7’-dichlorofluorescin diacetate. Lucigenin dependent chemiluminescence was used to measure extracellular ROS production. Additionally, the effect of NDS27 was tested on the activity of myeloperoxidase (MPO), a hemic enzyme contributing to the oxidant response of neutrophils. The activity of the released MPO by cytochalazine B (CB) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulated PMNs was measured by SIEFED (“Specific Immunologic Extraction Followed by Enzymatic Detection”) (2). The HPLC results showed that NDS27 enters into PMNs and interacts with their membrane. NDS27 significantly and dose-dependently inhibited the ROS production in neutrophils without affecting their viability. Likewise, the activity of MPO released by PMNs was lowered by NDS27. Overall, our findings demonstrate that the membrane of neutrophils is permeable to NDS27 or interacts with the drug, suggesting that its inhibitory effect on ROS production is mainly associated to an intracellular effect probably by acting on the enzymes implied in respiratory burst like NADPH oxidase and MPO. The modulatory effect of NDS27 towards the oxidant activity of cells involved in immune and inflammatory response open therapeutic perspectives to control equine or human pathologies with excessive inflammatory reactions. 1. Neven et al. 2011, Patent Application Publication: US2011/0257126 A1 2. Serteyn et al. 2005, European Patent Specification : EP1711817 B1 [less ▲]

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See detailSystemisch-entzuendliche Reaktion beim Hochleistungssportpferd
Sandersen, Charlotte ULg; Lejeune, Jean-Philippe ULg; Votion, Dominique ULg et al

Book published by Leipziger Blaue Hefte (2012)

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See detailMyeloperoxidase in Equine Semen: Concentration and Localization during Freezing Processing
Ponthier, Jérôme ULg; Desvals, Maud; Franck, Thierry ULg et al

in Journal of Equine Veterinary Science (2012), (32), 32-37

Myeloperoxidase (MPO) is a pro-oxidant enzyme contained in and released by neutro- phils during degranulation or after lysis. Post-thaw semen contains MPO, and concen- tration of this enzyme is associated ... [more ▼]

Myeloperoxidase (MPO) is a pro-oxidant enzyme contained in and released by neutro- phils during degranulation or after lysis. Post-thaw semen contains MPO, and concen- tration of this enzyme is associated with decreased motility. The aim of this study was to determine kinetics of MPO concentration during freezing, its origin, and its impact on frozenethawed semen. Forty ejaculates were used. Semen was frozen using the classical freezing procedure. MPO concentrations were assayed in fresh semen, after centrifuga- tion, and after cooling down to 4 C. Post-thaw MPO assay results and spermogram characteristics were determined. MPO immunocytochemistry was performed on 4 different ejaculates at each step of freezing procedure. MPO concentration increased after cooling down to 4 C and thawing compared with fresh semen. As temperature decreased, MPO was higher or tended to be higher in post-thaw poor quality samples. Nonsperm cells showed various degrees of MPO immunostaining and were observed as epithelial cells with nuclear pyknosis and keratinization. MPO immunostaining increased in medium and decreased in nonsperm cells during freezing. Our study shows that MPO concentration in equine semen increases when temperature decreases. We hypothesize that nonsperm cells present in fresh semen could release MPO. [less ▲]

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See detailEuropean outbreaks of atypical myopathy in grazing horses (2006-2009): Determination of indicators for risk and prognostic factors
Van Galen, Gaby ULg; Saegerman, Claude ULg; Marcilllaud Pitel, Christel et al

in Equine Veterinary Journal (2012), DOI: 10.1111/j.2042-3306.2012.00555.x

Appropriate management of atypical myopathy (AM) requires the establishment of an accurate diagnosis and prognosis. Furthermore, preventive measures to avoid AM need to be refined. The aims of the study ... [more ▼]

Appropriate management of atypical myopathy (AM) requires the establishment of an accurate diagnosis and prognosis. Furthermore, preventive measures to avoid AM need to be refined. The aims of the study were as follows: 1) to improve the diagnosis of AM; 2) to identify prognostic predictors; and 3) to refine recommended preventive measures based on indicators of risk factors. [less ▲]

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See detailComparison of the sedative and hemodynamic effects of acepromazine and promethazine in the standing horse.
Pequito, Manuel; Amory, Hélène ULg; Serteyn, Didier ULg et al

in Journal of Equine Veterinary Science (2012), 32(12), 1-6

The objective of this study was to compare the sedative and peripheral hemodynamic effects of acepromazine (ACP) and promethazine (PTZ) in the standing healthy horse. Nine healthy Warmblood horses ... [more ▼]

The objective of this study was to compare the sedative and peripheral hemodynamic effects of acepromazine (ACP) and promethazine (PTZ) in the standing healthy horse. Nine healthy Warmblood horses randomly received either intravenous ACP at 0.1 mg/kg or PTZ at 0.1, 0.2, and 0.3 mg/kg. A sedation score based on clinical examination was recorded, and systolic arterial blood pressure was noninvasively evaluated using a Doppler flow detector at the tail, just before and every 15 minutes until 60 minutes after drug injection. Hemodynamics of the median artery of the left forelimb was studied using Doppler ultrasonography just before and 45 minutes after injection of the drug, which allowed calculation of surface (SURF), diameter (DIAM), and circumference (CIRC) of the vessel and peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), volumetric flow (VF), and resistivity index (RI) of the blood flow. Regardless of the dose used, PTZ had lesser sedative and hypotensive effects than ACP at 0.1 mg/kg and did not induce significant variations in SURF, DIAM, CIRC, PSV, EDV, MV, VF, and RI of the studied standing horses. Conversely, the vasodilatory properties of ACP were illustrated by a significant increase in SURF, DIAM, CIRC, PSV, EDV, MV, and VF and a significant reduction of the RI. Unlike ACP, PTZ did not induce alterations on the morphology of the Doppler waveform. PTZ appears to have less sedative and peripheral vasodilator effects than ACP, thus it could be safer than ACP in patients suffering from hypotension. [less ▲]

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See detailAssessment of reactive oxygen species production in cultured equine skeletal myoblasts in response to conditions of anoxia followed by reoxygenation with or without exposure to peroxidases.
Ceusters, Justine ULg; Mouithys-Mickalad, Ange ULg; de la Rebière de Pouyade, Geoffroy ULg et al

in American Journal of Veterinary Research (2012), 73(3), 426-434

Objective—To culture equine myoblasts from muscle microbiopsy specimens, examine myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by reoxygenation, and assess the ... [more ▼]

Objective—To culture equine myoblasts from muscle microbiopsy specimens, examine myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by reoxygenation, and assess the effects of horseradish peroxidase (HRP) and myeloperoxidase (MPO) on ROS production. Animals—5 healthy horses (5 to 15 years old). Procedures—Equine skeletal myoblast cultures were derived from 1 or 2 microbiopsy specimens obtained from a triceps brachii muscle of each horse. Cultured myoblasts were exposed to conditions of anoxia followed by reoxygenation or to conditions of normoxia (control cells). Cell production of ROS in the presence or absence of HRP or MPO was assessed by use of a gas chromatography method, after which cells were treated with a 3,3′-diaminobenzidine chromogen solution to detect peroxidase binding. Results—Equine skeletal myoblasts were successfully cultured from microbiopsy specimens. In response to anoxia and reoxygenation, ROS production of myoblasts increased by 71%, compared with that of control cells. When experiments were performed in the presence of HRP or MPO, ROS production in myoblasts exposed to anoxia and reoxygenation was increased by 228% and 183%, respectively, compared with findings for control cells. Chromogen reaction revealed a close adherence of peroxidases to cells, even after several washes. Conclusions and Clinical Relevance—Results indicated that equine skeletal myoblast cultures can be generated from muscle microbiopsy specimens. Anoxia-reoxygenation– treated myoblasts produced ROS, and production was enhanced in the presence of peroxidases. This experimental model could be used to study the damaging effect of exercise on muscles in athletic horses. [less ▲]

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See detailRelationship between exercise-induced systemic inflammatory like reaction and racing performance in endurance horses
Serteyn, Didier ULg; Caudron, Isabelle ULg; Lejeune, Jean-Philippe ULg et al

in Comparative Exercise Physiology (2012), 8(3/4), 213218

This study showed that systemic inflammatory like reaction is not clearly related to performance but also to horse-related factors such as intinsic capacity or training.

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See detailAntioxidant and anti-inflammatory activities of Ribes nigrum extracts.
Tabart, Jessica ULg; Franck, Thierry ULg; Kevers, Claire ULg et al

in Food Chemistry (2012), 131(4), 1116-1122

Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce ... [more ▼]

Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce food supplement could also exhibit such interesting properties. <br />In the literature, various methods are often used and valid indicators of the antioxidant potential of dietary substances. However these assays do not provide evidence that antioxidants have in vivo or ex vivo activity when consumed. To obtain biologically relevant information, the antioxidant activities of the extracts were evaluated on cellular models implicating the measurement of blood haemolysis, the Cellular Antioxidant Activity on endothelial cells and the anti-inflammatory activities on isolated equine stimulated neutrophils and purified myeloperoxidase. <br />These tests generally showed that the blackcurrant leaf extract have the highest antioxidant and <br />anti-inflammatory (inhibition of MPO activity and ROS production on activated neutrophils) capacities correlated to the highest total phenolics content. [less ▲]

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See detailAntioxidant and anti-inflammatory like properties of benzoic acid analogs on the oxidant response of neutrophils: structure/redox potential relationship study.
Franck, Thierry ULg; Mouithys-Mickalad, Ange ULg; Robert, Thierry ULg et al

in Free Radical Biology & Medicine (2012), 53(supplement 1),

We investigated the antioxidant capacity of phenolic acid derivatives by measuring their capacity to prevent ABTS oxidation and evaluating their anti-inflammatory like-properties on the oxidant response ... [more ▼]

We investigated the antioxidant capacity of phenolic acid derivatives by measuring their capacity to prevent ABTS oxidation and evaluating their anti-inflammatory like-properties on the oxidant response of neutrophils, especially on superoxide anion production and the activity of myeloperoxidase (MPO), an oxidant enzyme present and released by the primary granules of neutrophils. The superoxide anion production by PMA-stimulated neutrophils was measured by lucigenin-enhanced chimiluminescence (CL) and the activity of MPO by SIEFED to study the potential interaction of a molecule with the enzyme without interferences due to medium. The antioxidant and anti-inflammatory activities of the phenolic compounds were correlated to their redox potentials measured by voltammetry method, and discussed in relation to their molecular structure. The ability of the phenolic molecules to decrease ABTS oxidation and CL production was inversely correlated to their redox potential increasing as follows: propyl gallate > gallic acid > caffeic acid > 3,4-dihydroxybenzoic acid > ferulic acid > syringic acid > 2,6-dihydroxybenzoic acid > salicylic acid > benzoic acid. The number of hydroxyl groups (3) and their position (catechol) were essential for the efficacy of the molecules as stoichiometric antioxidants or scavengers. On MPO activity, the inhibitory capacity of the molecules was not really correlated with their redox potential and increased as follows: gallic acid > caffeic acid > 2,6-dihydroxybenzoic acid > propyl gallate > ferulic acid = syringic acid > 3,4-dihydroxybenzoic acid = salicylic acid > benzoic acid. The number of OH groups and the elongation of the carboxyl group were essential for the inhibition of MPO activity, probably by facilitating the interaction with the MPO active site or structure. The redox potential measurement seems to be a good technique to select stoichiometric antioxidants, but not anti-catalytic ones. [less ▲]

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See detailPolyphenol Content and Modulatory Activities of Some Tropical Dietary Plant Extracts on the Oxidant Activities of Neutrophils and Myeloperoxidase
Tsumbu, César Ndele ULg; Deby-Dupont, Ginette; Tits, Monique ULg et al

in International Journal of Molecular Sciences (2012), 13(1), 628-650

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See detailIntriguing location of myeloperoxidase in the prostate: A preliminary immunohistochemical study.
Roumeguere, Thierry; Delree, Paul; Van Antwerpen, Pierre et al

in Prostate (2012), 72(5), 507-13

BACKGROUND: Myeloperoxidase (MPO) is a member of the peroxidase-cyclooxygenase superfamily, which is secreted from stimulated leucocytes at inflammatory sites. It is well known that MPO catalyses ... [more ▼]

BACKGROUND: Myeloperoxidase (MPO) is a member of the peroxidase-cyclooxygenase superfamily, which is secreted from stimulated leucocytes at inflammatory sites. It is well known that MPO catalyses oxidation reactions via the release of reactive halogenating and nitrating species and thus induces tissue damage. Several studies have already implicated MPO in the development of neoplasia. Chronic or recurrent prostatic inflammation has long been recognized as having the potential to initiate and promote the development of prostate cancer. The objective was to investigate whether MPO is present in the prostate. METHODS: Human prostate material was obtained from biopsies, transurethral resections of the prostate (TURP), prostatic adenomectomies, and retropubic radical prostatectomies. Twenty-nine slides of normal prostate tissue, benign prostatic hyperplasia (BPH), and prostate cancer were reviewed by a pathologist. Immunohistochemical analysis using MPO-specific human antibody was performed to detect MPO in the prostate tissue. RESULTS: Immunocytohistochemistry showed cellular colocalization of MPO in the secretory epithelial cells of the prostate with staining varying from light to strong intensity. Staining in the glandular apical snouts was often reinforced although staining of basal as well as of luminal glandular cells was also present. CONCLUSIONS: We identified, for the first time, the presence of MPO at the surface of prostatic epithelial cells. In view of the pro-oxidant properties of this enzyme, further research is needed to define whether MPO contributes to the development of prostatic lesions. Prostate 72:507-513, 2012. (c) 2011 Wiley Periodicals, Inc. [less ▲]

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