References of "Kohnen, Stéphane"
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See detailCharacterization of Black locust (Robinia pseudoacacia L.) heartwood extractives: identification of resveratrol and piceatannol
Sergent, Thérèse; Kohnen, Stéphane; Jourez, Benoît ULg et al

in Wood Science and technology (2014)

Robinia pseudoacacia L. heartwood is characterized by a very high natural durability. However, a significant difference was observed between the mature and juvenile heartwood, the latter presenting less ... [more ▼]

Robinia pseudoacacia L. heartwood is characterized by a very high natural durability. However, a significant difference was observed between the mature and juvenile heartwood, the latter presenting less durability against fungi decay, which could be attributed to lower extractive content. In order to elucidate this idea, extractives from mature and juvenile heartwoods of black locust trees were investigated. Results showed that extractive and phenolic contents were higher in mature than in juvenile heartwoods. The identification of phenolic compounds by UPLC–DAD–MS/MS revealed, for the first time, the presence of resveratrol and piceatannol. These two stilbenes as well as the flavonoid dihydrorobinetin were present at the highest level in mature heartwood, and as they are known antifungals, they could account for the great durability of mature heartwood. The stilbenes were detected in significant amounts particularly in mature heartwood where piceatannol reached a level tenfold higher than that reported for Japanese knotweed roots, the primary natural source of these stilbenes, whereas resveratrol level was comparable with reported values. As resveratrol and piceatannol receive increasing demand for nutraceutical, cosmetic and, possibly, pharmaceutical purposes, due to their beneficial health effects, this study underlines the use of R. pseudoacacia as a promising sustainable and economical source of resveratrol and piceatannol. [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 detailKit 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 (2010)

The present invention is related to a combined kit for sequential measurement of the enzymatically active fraction and total amount of an enzyme [(such as myeloperoxidase (MPO)] in a sample, and that find ... [more ▼]

The present invention is related to a combined kit for sequential measurement of the enzymatically active fraction and 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 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 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 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 detailMethod and kit for the measurement of neutrophil cell activation
Serteyn, Didier ULg; Deby-Dupont, Ginette; Franck, Thierry ULg et al

Patent (2006)

The present invention is related to methods and kits (or devices) for the measurement of equine myeloperoxidase (MPO), a specific enzyme of equine neutrophils, either in total [first method], or ... [more ▼]

The present invention is related to methods and kits (or devices) for the measurement of equine myeloperoxidase (MPO), a specific enzyme of equine neutrophils, either in total [first method], or specifically in its active form [second method]. Said methods and kits (or devices), used independently or in combination, find improved applications in the veterinary field and can be adapted for application in human health care. The concept of the second method is applicable to any other enzyme. [less ▲]

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See detailReactivity towards singlet oxygen of propofol inside liposomes and neuronal cells
Heyne, Belinda; Brault, Daniel; Fontaine-Aupart, Marie-Pierre et al

in Biochimica et Biophysica Acta - General Subjects (2005), 1724

Singlet oxygen (1O2), a reactive oxygen species, has been found to be implicated in many cellular events and pathological disorders.Herein, we investigated the reactivity of 1O2 towards the anaesthetic ... [more ▼]

Singlet oxygen (1O2), a reactive oxygen species, has been found to be implicated in many cellular events and pathological disorders.Herein, we investigated the reactivity of 1O2 towards the anaesthetic agent propofol (PPF) encapsulated within DMPC liposomes. By time resolved luminescence, the rate constant of 1O2 quenching by PPF was evaluated, depending on the location of the sensitizer. The nature of the oxidation product, resulting from the reaction of 1O2 with PPF, was determined using absorption and HPLC techniques. Finally, the in vitro protective effect of PPF towards the1O2-induced neuronal cell toxicity was evaluated in terms of cell viability. [less ▲]

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