Development of a LC-UV-MS analytical method for aldehydes formed during fatty acids degradation

Poster (2012)

Étude de l’évolution de l’oxydation lipidique du Tilapia du Nil (Oreochromis niloticus) conservé à température ambiante (30°C) et à (4°C), en Algérie.

Poster (2012)

Development of a LC-UV-MS analytical method for malondialdehyde.

Poster (2011)

Mise au point d'une stratégie analytique pour le contrôle des résidus d'acide oxolinique dans la chair du Tilapia "Oreochromis niloticus". Scientific Day of the Faculty of Veterinary Medicine, Liège, 9 December 2011.

Poster (2011)

Optimisation of a new two-plate screening method for the detection of antibiotic residues in meat

in International Journal of Food Science & Technology (2011), 46

STUDY OF THE STABILITY OF POLYUNSATURATED FATTY ACIDS IN PORK MEAT AFTER STORAGE AND COOKING.

Poster (2010)

Adaptation of a microbiological method for screening antimicrobial residues in shrimp tissue

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

Solubilisation 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

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 ▲]

Chronic mastitis-affected cows display lower lipoxin levels than acute mastitis-affected cows

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

Imbalance between lipoxin A(4) and leukotriene B-4 in chronic mastitis-affected cows

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 ▲]