References of "Fillet, Marianne"
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See detailOptimization of micro-HPLC peak focusing for the detection and quantification of low hepcidin concentrations.
Mansion, François ULg; Chiap, Patrice ULg; Houbart, Virginie ULg et al

in Journal of Separation Science (2011), 34(15), 1820-1827

Micro-high-performance liquid chromatography is a miniaturized, economic and ecological chromatographic system allowing the use of reduced size chromatographic columns. Coupled with electrospray ... [more ▼]

Micro-high-performance liquid chromatography is a miniaturized, economic and ecological chromatographic system allowing the use of reduced size chromatographic columns. Coupled with electrospray ionization tandem mass spectrometry, this technique can be used to detect and quantify low concentrations of peptides. In this study, hepcidin was used as the model compound and analysed using octadecylsilica stationary phase by means of a gradient elution mode at a flow rate of 4 muL/min. Several parameters were studied to optimize peak focusing. Using the methodology of experimental design, the mobile-phase gradient conditions and the sample composition were optimized in order to maximize the sensitivity and minimize retention time. Stability of the target peptide in solution was also demonstrated. [less ▲]

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See detailEspectroscopia aplicada
Ziemons, Eric ULg; Frederich, Michel ULg; Fillet, Marianne ULg et al

Scientific conference (2011, May)

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See detailidentification of new parterns of the NOD2 protein
Lecat, Aurore ULg; Di Valentin, Emmanuel ULg; Fillet, Marianne ULg et al

Poster (2011, January 27)

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See detailEvaluation of chlorine containing cellulose-based chiral stationary phases for the LC enantioseparation of basic pharmaceuticals using polar non-aqueous mobile phases.
Dossou, Katina S. S.; CHIAP, Patrice ULg; Servais, Anne-Catherine ULg et al

in Journal of Separation Science (2011), 34(6), 617-22

The discrimination ability of three cellulose-based chiral stationary phases (CSPs) was evaluated towards the enantiomers of basic drugs, using ACN as the main solvent in polar organic mobile phases. The ... [more ▼]

The discrimination ability of three cellulose-based chiral stationary phases (CSPs) was evaluated towards the enantiomers of basic drugs, using ACN as the main solvent in polar organic mobile phases. The study was focused on CSPs containing cellulose tris(3-chloro-4-methylphenylcarbamate) (3-Cl-4-MePC), cellulose tris(4-chloro-3-methylphenylcarbamate) (4-Cl-3-MePC) or cellulose tris(3,5-dichlorophenylcarbamate) (3,5-diClPC) as the chiral selector. The behaviour of these CSPs was studied systematically in order to investigate the influence of the presence and position of the chlorine substituents on the phenylcarbamate moieties on the retention and resolution of the enantiomers. The evaluation was made with three different generic mobile phases, namely ACN/0.1%DEA/0.1% TFA (DEA, diethylamine), ACN/0.1%DEA/0.2% FA and ACN/0.1%DEA/0.2%AcA, deduced from the previous study. The nature of the acidic additive and of the chiral selector was found to be particularly important for the retention and enantioresolution of these basic compounds. High-resolution values could be obtained for most studied enantiomers with these CSPs, clearly demonstrating the interest of using them in combination with polar organic mobile phases. However, significant differences in enantioresolution between the CSPs have been observed for many compounds, indicating that these phases seem to be quite complementary. [less ▲]

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See detailDevelopment and validation of a LC method for the enantiomeric purity determination of S-ropivacaine in a pharmaceutical formulation using a recently commercialized cellulose-based chiral stationary phase and polar non-aqueous mobile phase.
Dossou, Katina Sourou Sylvestre; CHIAP, Patrice ULg; Servais, Anne-Catherine ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2011), 54(4), 687-93

Ropivacaine is the first enantiomerically pure long-acting local anaesthetic used for surgical anaesthesia and post-operative pain relief. A liquid chromatographic (LC) method using acetonitrile as the ... [more ▼]

Ropivacaine is the first enantiomerically pure long-acting local anaesthetic used for surgical anaesthesia and post-operative pain relief. A liquid chromatographic (LC) method using acetonitrile as the main solvent and cellulose tris(4-chloro-3-methylphenylcarbamate) coated on silica as chiral stationary phase was successfully developed and applied for the enantiomeric purity determination of S-ropivacaine in a pharmaceutical formulation (Naropin((R))). The key role played by the acidic additive (trifluoroacetic acid or formic acid) in the enantioseparation of basic drugs in these LC systems was demonstrated by the reversal of ropivacaine enantiomers elution order observed when both acids were compared. In order to elute the enantiomeric impurity (R-ropivacaine) before S-ropivacaine, formic acid (FA) was selected. The temperature and the percentages of acidic additive and hexane in the mobile phase were found to significantly influence the retention and resolution of these enantiomers. The optimized mobile phase consisted of ACN/0.1% DEA/0.2% FA/5% hexane (v/v/v/v). The temperature was set at 35 degrees C to avoid the interference from a peak system related to the presence of water in the sample on ropivacaine enantiomers. The LC method was then fully validated applying the strategy based on total measurement error and accuracy profiles. The accuracy profile obtained by linear regression after square root transformation was selected, the acceptance limits being settled at +/-10% for the intended use of this analytical method. The relative bias was lower than 1.5%, while the RSD values for repeatability and intermediate precision were both below 1.0%. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be about 0.2 and 1.0 mug/mL, respectively, corresponding to 0.02 and 0.1% of the enantiomeric impurity in S-ropivacaine. [less ▲]

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See detailDiscovery and biochemical characterisation of four novel biomarkers for osteoarthritis.
DE SENY, Dominique ULg; Sharif, Mohammed; Fillet, Marianne ULg et al

in Annals of the Rheumatic Diseases (2011), 70(6), 1144-52

OBJECTIVE: Knee osteoarthritis (OA) is a heterogeneous, complex joint pathology of unknown aetiology. Biomarkers have been widely used to investigate OA but currently available biomarkers lack specificity ... [more ▼]

OBJECTIVE: Knee osteoarthritis (OA) is a heterogeneous, complex joint pathology of unknown aetiology. Biomarkers have been widely used to investigate OA but currently available biomarkers lack specificity and sensitivity. Therefore, novel biomarkers are needed to better understand the pathophysiological processes of OA initiation and progression. METHODS: Surface enhanced laser desorption/ionisation-time of flight-mass spectrometry proteomic technique was used to analyse protein expression levels in 284 serum samples from patients with knee OA classified according to Kellgren and Lawrence (K&L) score (0-4). OA serum samples were also compared to serum samples provided by healthy individuals (negative control subjects; NC; n=36) and rheumatoid arthritis (RA) patients (n=25). Proteins that gave similar signal in all K&L groups of OA patients were ignored, whereas proteins with increased or decreased levels of expression were selected for further studies. RESULTS: Two proteins were found to be expressed at higher levels in sera of OA patients at all four K&L scores compared to NC and RA, and were identified as V65 vitronectin fragment and C3fpeptide. Of the two remaining proteins, one showed increased expression (unknown protein at m/z of 3762) and the other (identified as connective tissue-activating peptide III protein) was decreased in K&L scores >2 subsets compared to NC, RA and K&L scores 0 or 1 subsets. CONCLUSION: The authors detected four unexpected biomarkers (V65 vitronectin fragment, C3f peptide, CTAP-III and m/z 3762 protein) that could be relevant in the pathophysiological process of OA as having significant correlation with parameters reflecting local inflammation and bone remodelling, as well as decrease in cartilage turnover. [less ▲]

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See detailPotential Therapeutic Target Discovery by 2D-DIGE Proteomic Analysis in Mouse Models of Asthma
QUESADA CALVO, Florence ULg; Fillet, Marianne ULg; Renaut, Jenny et al

in Journal of Proteome Research (2011), 10(9), 4291-4301

As asthma physiopathology is complex and not fully understood to date; it is expected that new key mediators are still to be unveiled in this disease. The main objective of this study was to discover ... [more ▼]

As asthma physiopathology is complex and not fully understood to date; it is expected that new key mediators are still to be unveiled in this disease. The main objective of this study was to discover potential new target proteins with a molecular weight >20 kDa by using two-dimensional differential in-gel electrophoresis (2D-DIGE) on lung parenchyma extracts from control or allergen-exposed mice (ovalbumin). Two different mouse models leading to the development of acute airway inflammation (5 days allergen exposure) and airway remodeling (10 weeks allergen exposure) were used. This experimental setting allowed the discrimination of 33 protein spots in the acute inflammation model and 31 spots in the remodeling model displaying a differential expression. Several proteins were then identified by MALDI-TOF/TOF MS. Among those differentially expressed proteins, PDIA6, GRP78, Annexin A6, hnRPA3, and Enolase display an increased expression in lung parenchyma from mice exposed to allergen for 5 days. Conversely, Apolipoprotein A1 was shown to be decreased after allergen exposure in the same model. Analysis on lung parenchyma of mice exposed to allergens for 10 weeks showed decreased calreticulin levels. Changes in the levels of those different mediators were confirmed by Western blot and immunohistochemical analysis. Interestingly, alveolar macrophages isolated from lungs in the acute inflammation model displayed enhanced levels of GRP78. Moreover, intratracheal instillation of anti-GRP78 siRNA in allergen-exposed animals led to a decrease in eosinophilic inflammation and bronchial hyperresponsiveness. This study unveils new mediators of potential importance that are up- and down-regulated in asthma. Among up-regulated mediators, GRP-78 appears as a potential new therapeutic target worthy of further investigations. [less ▲]

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See detailDetermination of enantiomeric purity of S-amlodipine by chiral LC with emphasis on reversal of enantiomer elution order.
Dossou, Katina ULg; Edorh, P. A.; Chiap, Patrice ULg et al

in Journal of Separation Science (2011), 34

An LC method was developed and prevalidated for the enantiomeric purity determination of S-amlodipine in polar organic solvent chromatography using a chlorine-containing cellulose-based chiral stationary ... [more ▼]

An LC method was developed and prevalidated for the enantiomeric purity determination of S-amlodipine in polar organic solvent chromatography using a chlorine-containing cellulose-based chiral stationary phase (CSP). The concentration of formic acid (FA) (0.01-0.2%) in the mobile phase containing acetonitrile as the main solvent was found to influence the elution order of amlodipine enantiomers as well as the enantioresolution. A reversal of the enantiomer elution order of amlodipine was only observed with chiral stationary phases with both electron-withdrawing (chloro) and electron-donating groups (methyl) on the phenyl moieties of the chiral selector, namely cellulose tris(3-chloro-4-methylphenylcarbamate) and cellulose tris(4-chloro-3-methylphenylcarbamate). The highest enantioresolution (R(s) : 4.1) value was obtained at the lowest FA concentration (0.01%) using cellulose tris(4-chloro-3-methylphenylcarbamate) as the chiral selector and the enantiomeric impurity, R-amlodipine, eluted first under these conditions. Therefore, the mobile phase selected for the prevalidation of the method consisted of ACN/0.1% DEA/0.01% FA and the temperature was set at 25 degrees C. The method was prevalidated by means of the strategy based on the total measurement error and the accuracy profile. The method was found to be selective and the limit of quantification was found to be about 0.05% for R-amlodipine, while the limit of detection was close to 0.02%. [less ▲]

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See detailPre-study and in-study validation of a SPE-LC-MS-MS method for the determination of 5-S-cysteinyldopa, a melanoma biomarker, in human plasma.
Martin, Gaelle; Mansion, François ULg; Houbart, Virginie ULg et al

in Talanta (2011), 84(2), 280-6

The incidence of malignant melanoma has increased over the past decades, particularly in Caucasian population. This disease presents defavourable prognosis in terms of survey, especially when detection ... [more ▼]

The incidence of malignant melanoma has increased over the past decades, particularly in Caucasian population. This disease presents defavourable prognosis in terms of survey, especially when detection occurs at the metastatic phase. Reliable analytical methods for biomarker determination are thus an interesting tool in pathology detection and follow-up. In this context, a method using SPE-LC-ESI-MS-MS for the determination of 5-S-cysteinyldopa (5-SCD) in human plasma was optimized. The presence of matrix effect was investigated in details while 5-SCD stability was studied according to FDA requirements for the validation of bioanalytical methods. Pre-study and in-study validations of the entire method were then successfully performed by applying the approach based on total measurement error and accuracy profiles over a concentration ranges from 1.6 to 200 ng/ml. Good results with respect to accuracy, trueness and precision were obtained. The maximum risk of observing future measurements falling outside the acceptance limits during routine analysis was also estimated. [less ▲]

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See detailGeneric systems for the enantioseparation of basic drugs in NACE using single-isomer anionic CDs
Rousseau, Anne ULg; Gillotin, Florian; Chiap, Patrice ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2011), 54

The enantioseparation of ten basic drugs was evaluated in NACE systems using heptakis(2-O-methyl-3-O-acetyl-6-O-sulfo)-β-CD (HMAS-β-CD). For this purpose, a D-optimal design with 21 experimental points ... [more ▼]

The enantioseparation of ten basic drugs was evaluated in NACE systems using heptakis(2-O-methyl-3-O-acetyl-6-O-sulfo)-β-CD (HMAS-β-CD). For this purpose, a D-optimal design with 21 experimental points was applied. Four antifungal agents (econazole, isoconazole, miconazole, sulconazole), three local anesthetics (bupivacaine, mepivacaine and prilocaine), two sympathomimetics (salbutamol and terbutaline) and one β-blocker (carvedilol) were selected as basic model analytes. The influence on the enantiomeric resolution of anionic CD and BGE anion concentrations as well as the BGE anion nature was investigated. For all studied analytes, the enantiomeric resolution was shown to be significantly influenced by the CD concentration. Based on the observed results, a generic NACE system was recommended, namely 20 mM HMAS-β-CD and 10 mM ammonium camphorSO3- in methanol acidified with 0.75 M formic acid. Moreover, this NACE system was compared to previous conditions with heptakis(2,3-di-O-methyl-6-O-sulfo)-β-CD (HDMS-β-CD) or heptakis(2,3-di-O-acetyl-6-O-sulfo)-β-CD (HDAS-β-CD). Finally, two generic systems using either HDAS-β-CD or HMAS-β-CD were proposed and evaluated for the enantioseparation of ketamine and norketamine after incubation of ketamine in phenobarbital-induced male rat liver microsomes systems. [less ▲]

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