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See detailValidation of a two-plate microbiological method for screening antibiotic residues in shrimp tissue
Pham Kim, Dang ULg; Degand, Guy ULg; Danyi, Sophie ULg et al

in Analytica Chimica Acta (2010), 672

Microbiological inhibition screening tests could play an important role to detect residues of antibiotics in the different animal food products, but very few are available for the aquaculture products in ... [more ▼]

Microbiological inhibition screening tests could play an important role to detect residues of antibiotics in the different animal food products, but very few are available for the aquaculture products in general, and for shrimps in particular. A two-plate microbiological method to screen shrimp for residues of the most commonly used antibiotics has been developed and validated according to criteria derived from the European Commission Decision 2002/657/CE. Bacillus subtilis was used as a sensitive strain to target antibiotics. Culture conditions on Petri plates (pH of medium) were selected to enhance the capacity of antibiotic detection. Antibiotic residues were extracted from shrimps using acetonitrile/acetone (70/30, v/v) before application on Petri plates seeded with B. subtilis. The method was validated using spiked blank tissues as well as antibiotic treated shrimps with enrofloxacin and tetracycline, two antibiotics often found to be used in shrimp production. For tetracyclines and (fluoro)quinolones, the detection capability was below the maximum residue limit (MRL), while it was around the MRL for sulfonamides. The specificity of the microbiological screening was 100% in all cases while the sensitivity and accuracy was 100% in almost all cases. The capacity of the method to detect contaminated samples was confirmed on antibiotic treated shrimps, analyzed in parallel with a confirmatory method (Liquid Chromatography coupled to mass spectrometry (LC–MS)). [less ▲]

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See detailAdaptation of a microbiological method for screening antimicrobial residues in shrimp tissue
Pham Kim, Dang ULg; Degand, Guy ULg; Danyi, Sophie ULg et al

in Book of abstracts - 4th International Symposium on Recent Advances in Food Analysis (RAFA 2009) (2009, November 04)

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See detailSolubilisation and binding characteristics of a recombinant beta(2)-adrenergic receptor expressed in the membrane of Escherichia coli for the multianalyte detection of beta-agonists and antagonists residues in food-producing animals
Danyi, Sophie ULg; Degand, Guy ULg; Duez, Colette ULg et al

in Analytica Chimica Acta (2007), 589(2), 159-165

The number of substances with beta-agonistic activity, illegally introduced in meat production or in sports doping as anabolic or beta-blocking agents is increasing. Analytical methods suited for their ... [more ▼]

The number of substances with beta-agonistic activity, illegally introduced in meat production or in sports doping as anabolic or beta-blocking agents is increasing. Analytical methods suited for their multianalyte detection are thus necessary. In this perspective, receptor assays were developed. The research activities undertaken in this study describe the solubilisation of a recombinant human beta(2)-adrenergic receptor produced in the inner membrane of genetically modified Escherichia coli, using the detergent n-dodecyl-beta-D-maltoside. Its potential to detect the presence of beta-agonists or beta-blockers in biological samples was evaluated. The solubilised beta(2)-adrenergic receptor retained its binding affinity in a radio-receptor assay based on the competition for the binding to receptors between a ligand (beta-agonist or antagonist) and the radioligand [I-125]iodocyanopindolol. The IC50 values ranged from 5 +/- x 10(-8) M (clenbuterol) to 8 +/- 2 x 10(-6) M (isoxsuprine) for the beta-agonists tested and from 1.5 +/- 0.2 x 10(-10) M (carazolol) to 1.2 +/- 0.2 x 10(-5) M (metoprolol) for the beta-blockers tested. It was shown to have a lower limit of detection than a radio-receptor assay using the solubilised beta(2)-adrenoceptor expressed in a mammalian cell line. The solubilised recombinant human beta(2)-adrenoreceptor expressed in E. coli would be a useful tool to develop non radioactive multianalyte screening methods. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailDevelopment of non radioactive multi-analyte methodes based on the use of a recombinant human beta2-agonists and antagonists residues in food-producing animals
Danyi, Sophie ULg; Degand, Guy ULg; Granier, Benoît et al

in Proceedings Euroresidue V conference on residues of veterinary drugs in food (2004, May)

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See detailInvestigations on PrP and PrPres in porcine brain and in stimufol preparations
Degand, Guy ULg; Remy, Benoit; Fotsing, Lucas ULg et al

in Proceedings: 20th Annual Meeting A.E.T.E (2004)

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See detailChronic mastitis-affected cows display lower lipoxin levels than acute mastitis-affected cows
Boutet, Philippe ULg; Bureau, Fabrice ULg; Degand, Guy ULg et al

in Pflügers Archiv : European Journal of Physiology (2004), 447

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See detailChronic mastitis-affected cows display lower lipoxin levels than acute mastitis-affected cows
Boutet, Philippe ULg; Bureau, Fabrice ULg; Degand, Guy ULg et al

in Recueil "Le Médecin Vétérinaire du Québec" (2004), 34(1 et 2), 160

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See detailImbalance between lipoxin A(4) and leukotriene B-4 in chronic mastitis-affected cows
Boutet, Philippe ULg; Bureau, Fabrice ULg; Degand, Guy ULg et al

in Journal of Dairy Science (2003), 86(11), 3430-3439

Persistent accumulation of inflammatory cells in the udder, with neutrophils being the predominant cell type, is a characteristic feature of chronic mastitis in dairy cows. Leukotriene (LT) B-4 is a ... [more ▼]

Persistent accumulation of inflammatory cells in the udder, with neutrophils being the predominant cell type, is a characteristic feature of chronic mastitis in dairy cows. Leukotriene (LT) B-4 is a potent chemotactic agent, known to induce recruitment and accumulation of neutrophils in the bovine mammary gland. The LTB4-stimulated neutrophil functional responses are closely opposed by lipoxin (LX) A(4), which promotes the resolution of inflammation. We thus hypothesized that the chronic inflammation of the udder could be associated with an unfavorable ratio between these two eicosanoids and that the persistence of neutrophil accumulation could be due to an increase in LTB4 synthesis and/or an impaired LXA(4) production. In an attempt to verify this hypothesis, we first measured LXA(4), LTB4, and their ratio in the milk of healthy and acute and chronic mastitis-affected quarters. Next, we studied the relationships between these variables and the degree of udder inflammation as assessed by somatic cell count measurement. The LTB4 concentration was low in healthy quarters, drastically increased in acute mastitis, and reached intermediate levels in chronic mastitis-affected quarters. However, whereas LXA(4) concentration was highly increased in acute mastitis, healthy and chronic quarters had similarly low values. The LXA(4):LTB4 ratio was thus significantly lower in chronic mastitis-affected cows. The LTB4 concentrations measured in chronic quarters were highly correlated to somatic cell count and to milk neutrophil and macrophage numbers. A weaker correlation was observed between LXA(4) and these variables. For both eicosanoids, the highest correlation was observed with the number of neutrophils. These results show the existence of an LXA(4):LTB4 imbalance in chronic mastitis-affected cows because of low LXA(4) concentrations. Further studies are needed to determine whether administration of LX or stable analogs could have therapeutic potential in the control of chronic bovine mastitis. [less ▲]

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See detailEffect of nutritional antioxidant supplementation on systemic and pulmonary antioxidant status, airway inflammation and lung function in heaves-affected horses
Kirschvink, Nathalie; Fievez, Laurence ULg; Bougnet, V. et al

in Equine Veterinary Journal (2002), 34

An oxidant/antioxidant imbalance in favour of oxidants has been identified as playing a decisive role in the pathogenesis of chronic inflammatory airway diseases. Nutritional antioxidant supplementation ... [more ▼]

An oxidant/antioxidant imbalance in favour of oxidants has been identified as playing a decisive role in the pathogenesis of chronic inflammatory airway diseases. Nutritional antioxidant supplementation might reduce oxidative damage by enhancement of the antioxidant defence, thereby modulating inflammatory processes. In a placebo-controlled, blind study, it was tested whether a dietary antioxidant supplement administered for 4 weeks would improve lung function and reduce airway inflammation in heaves-affected horses. Eight horses in clinical remission of heaves were investigated at rest and after a standardised exercise test before and after treatment with an antioxidant supplement (consisting of a mixture of natural antioxidants including vitamins E and C and selenium from a variety of sources) or placebo (oatfeed pellets without additive). Pulmonary function and exercise tolerance were monitored; systemic and pulmonary lining fluid uric acid, glutathione and 8-epi-PGF(2alpha) were analysed, and bronchoalveolar lavage (BAL) cytology and inflammatory scoring of the airways were performed. The antioxidant treatment significantly improved exercise tolerance and significantly reduced endoscopic inflammatory score. Plasma uric acid concentrations were significantly reduced, suggesting downregulation of the xanthine-dehydrogenase and xanthine-oxydase pathway. Haemolysate glutathione showed a nonsignificant trend to increase, while plasma 8-epi-PGF(2alpha) remained unchanged. Pulmonary markers and BAL cytology were not significantly affected by antioxidant supplementation. The present study suggests that the antioxidant supplement tested modulated oxidant/antioxidant balance and airway inflammation of heaves-affected horses [less ▲]

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See detailAdaptation to multiday ozone exposure is associated with a sustained increase of bronchoalveolar uric acid.
Kirschvink, Nathalie; Fievez, Laurence ULg; Bureau, Fabrice ULg et al

in Free Radical Research (2002), 36(1), 23-32

The phenomenon of ozone tolerance is described, but the underlying mechanisms remain unknown. We tested whether adaptation to multiday ozone exposure was related to an upregulated pulmonary antioxidant ... [more ▼]

The phenomenon of ozone tolerance is described, but the underlying mechanisms remain unknown. We tested whether adaptation to multiday ozone exposure was related to an upregulated pulmonary antioxidant defence. Six calves were exposed to 0.75 ppm ozone, 12 h day(-1) for seven consecutive days. Pulmonary function tests and bronchoalveolar lavage (BAL) were performed before, after the first (D1), third (D3) and seventh (D7) exposure. Differential cell count, total proteins, 8-epi-PGF2alpha, glutathione and uric acid were determined in BAL. Dynamic lung compliance and arterial oxygen tension were significantly decreased and lung oedema impaired pulmonary function on D1. By repeating ozone exposures, progressive functional adaptation occurred. Ozone induced a significant increase of BAL neutrophil percentage on D1. On D3 and D7, neutrophil percentage was progressively decreased, but remained significantly elevated. BAL total proteins were significantly increased on D1 and decreased progressively until D7. 8-Epi-PGF2alpha was significantly increased on D1 and was returned to baseline on D3 and D7, whilst glutathione significantly increased on D3 and returned to baseline on D7. Uric acid was increased ten-fold on D1. On D3, uric acid was increased six-fold and was persistently elevated at D7. This study suggests that ozone adaptation of functional and inflammatory variables is accompanied with sustained BAL uric acid elevation. [less ▲]

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See detailEffect of chronic airway inflammation and exercise on pulmonary and systemic antioxidant status of healthy and heaves-affected horses
Kirschvink, Nathalie; Smith, N.; Fievez, Laurence ULg et al

in Equine Veterinary Journal (2002), 34(6), 563-571

In heaves-affected horses the relation between oxidant status, airway inflammation (AI) and pulmonary function (PF) is unknown. The oxidant status of blood and pulmonary epithelial lining fluid (PELF) of ... [more ▼]

In heaves-affected horses the relation between oxidant status, airway inflammation (AI) and pulmonary function (PF) is unknown. The oxidant status of blood and pulmonary epithelial lining fluid (PELF) of healthy (H, n = 6) and heaves-affected horses in clinical remission (REM, n = 6) and in crisis (CR, n = 7) was assessed at rest, during and after standardised exercise test by measurement of reduced and oxidised glutathione, glutathione redox ratio [GRR%]; uric acid and 8-epi-PGF2alpha. Oxidant status was related to PF parameters (mechanics of breathing and arterial blood gas tension) and Al parameters (bronchoalveolar lavage [BAL] neutrophil % and AI score). Haemolysate glutathione was significantly different between groups and was correlated with PF and AI parameters; GRR in PELF was increased during CR and was correlated with PF and AI parameters. Exercise induced an increase of plasma uric acid that was significantly higher both in REM and CR. PELF 8-epi-PGF2alpha was significantly increased in CR and correlated with PF and AI parameters. These results suggest that oxidative stress occurring in heaves is correlated with PF and AI and may be locally assessed by PELF glutathione status, uric acid and 8-epi-PGF2alpha. Systemic repercussions are reflected by assay of GSH in resting horses and by uric acid in exercising horses. [less ▲]

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See detailB2 agonists cross the bovine placenta
Boutet, Philippe ULg; Uysterpruyst, C. H.; Degand, Guy ULg et al

in Pflügers Archiv : European Journal of Physiology (2001), 442(R41),

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See detailAntioxidant vitamin cocktail does not improve calves'lung function and airway inflammation in ozone-induced pulmonary disease
Kirschvink, Nathalie; Jacqmot, Olivier ULg; Fievez, Laurence ULg et al

in Pflügers Archiv : European Journal of Physiology (2001), 442(R42),

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See detailReceptors as screening tools in the detections of hormones. Applications in the control of meat production
Maghuin-Rogister, Guy ULg; Baise, Etienne ULg; Carpeaux, Rudy et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (1999), 4(1), 21-22

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See detailNew approach for the detection of growth promotors residues in animal products
Scippo, Marie-Louise ULg; Helbo, Vincent; Degand, Guy ULg et al

in Third meeting on animal productions. Biotechnologies: society stake. Proceedings of the study day held in Gembloux (Belgium) the 28 January 1998 (1998)

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See detailIdentification des vaches laitières traitées à la somatotropine bovine
Scippo, Marie-Louise ULg; Degand, Guy ULg; Duyckaerts, Anne et al

in Annales de Médecine Vétérinaire (1997), 141(5), 381-390

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See detailIdentification of the dairy cows treated with bovine somatotropine (BST): criteria to discriminate the treated animals from the non-treated ones
Scippo, Marie-Louise ULg; Degand, Guy ULg; Maghuin-Rogister, Guy ULg

in Second meeting on animal productions. The milk channel], Centre de Recherches Agronomiques, Gembloux (Belgium); Faculte Universitaire des Sciences Agronomiques de Gembloux (Belgium).- Gembloux (Belgium), 1997. p. Q3 (1997)

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See detailAntipeptide antibody against the bovine IGF-BP-2 : application to the detection of BST-treated cows
Scippo, Marie-Louise ULg; Degand, Guy ULg; Duyckaerts, Anne et al

in Food & Agricultural Immunology (1996), 8

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