References of "Fillet, Marianne"
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See detailInfluence of the BGE composition on analyte response in CD-mediated NACE-MS
Servais, Anne-Catherine ULg; Fillet, Marianne ULg; Mol, Roelof et al

in Electrophoresis (2010), 31(7), 1157-1161

The influence of the BGE composition, including the addition of a single-isomer sulfated beta-CD derivative, on the ionization performance of the model compound carvedilol in NACE-ESI-MS was studied using ... [more ▼]

The influence of the BGE composition, including the addition of a single-isomer sulfated beta-CD derivative, on the ionization performance of the model compound carvedilol in NACE-ESI-MS was studied using an alternative infusion method. This approach employs voltage-induced infusion of the BGE containing the analyte, and takes into account the effects of variations in EOF and effective analyte mobility on the ESI-MS intensity. First, the optimal composition of the sheath liquid for CE-MS in terms of signal abundance and stability was determined. The BGE ammonium formate, acetate, and camphorsulfonate were found to have similar effects on analyte ionization. Addition of single-isomer sulfated beta-CD derivatives (available as sodium salt) to the BGE revealed that the anionic CD derivatives did not give rise to the same ionization suppression effect. This result can be attributed to differences in the dissociation state of these sodium salts. Finally, it is shown that information about chiral selectivity can also be obtained with the applied infusion method. [less ▲]

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See detailSeparation of propranolol enantiomers by CE using sulfated beta-CD derivatives in aqueous and non-aqueous electrolytes: Comparative CE and NMR study.
Servais, Anne-Catherine ULg; Rousseau, Anne ULg; Fillet, Marianne ULg et al

in Electrophoresis (2010), 31

Separations using CE employing non-aqueous BGE are already as well established as separations in aqueous buffers. The separation mechanisms in achiral CE with non-aqueous BGEs are most likely similar to ... [more ▼]

Separations using CE employing non-aqueous BGE are already as well established as separations in aqueous buffers. The separation mechanisms in achiral CE with non-aqueous BGEs are most likely similar to those in aqueous buffers. However, for the separation of enantiomers involving their interaction with chiral buffer additives, the interaction mechanisms might be very different in aqueous and non-aqueous BGEs. While the hypothesis regarding distinct mechanisms of enantiomer separations in aqueous and non-aqueous BGEs has been mentioned in several papers, no direct proof of this hypothesis has been reported to date. In the present study, the enantiomers of propranolol were resolved using CE in aqueous and non-aqueous methanolic BGEs with two single isomer sulfated derivatives of beta-CD, namely heptakis (2,3-diacetyl-6-sulfo)-beta-CD and heptakis (2,3-dimethyl-6-sulfo)-beta-CD. The enantiomer migration order of propranolol was inverted when an aqueous BGE was replaced with non-aqueous BGE in the case of heptakis (2,3-dimethyl-6-sulfo)-beta-CD but remained the same in the case of heptakis (2,3-diacetyl-6-sulfo)-beta-CD. The possible molecular mechanisms leading to this reversal of enantiomer migration order were studied by using nuclear overhauser effect spectroscopy in both aqueous and non-aqueous BGEs. [less ▲]

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See detailCapillary electrophoretic and nuclear magnetic resonance studies on the opposite affinity pattern of propranolol enantiomers towards various cyclodextrins
Servais, Anne-Catherine ULg; Rousseau, Anne ULg; Fillet, Marianne ULg et al

in Journal of Separation Science (2010), 33

In the present study the migration order of the propranolol enantiomers with various native CDs and neutral and charged CD derivatives was examined in capillary electrophoresis (CE). The reversal of the ... [more ▼]

In the present study the migration order of the propranolol enantiomers with various native CDs and neutral and charged CD derivatives was examined in capillary electrophoresis (CE). The reversal of the enantiomer migration order was observed due to sulfation of β-CD on its primary hydroxy groups. The structures of intermolecular selector-selectand temporary diastereomeric associates in solution were elucidated based on 1D rotating frame nuclear Overhauser effect spectroscopy (1D ROESY) experiments. Major structural differences were observed between the propranolol complexes with native β-CD and heptakis(6-O-sulfo)-β-CD. [less ▲]

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See detailFactors Influencing Cyclodextrin-Mediated Chiral Separations
Servais, Anne-Catherine ULg; Crommen, Jacques ULg; Fillet, Marianne ULg

in Chiral Separations by Capillary Electrophoresis (2010)

In this chapter, several factors likely to infl uence cyclodextrin (CD)-mediated enantioseparations, such as CD type and concentration, pH and ionic strength of the background electrolyte (BGE), addition ... [more ▼]

In this chapter, several factors likely to infl uence cyclodextrin (CD)-mediated enantioseparations, such as CD type and concentration, pH and ionic strength of the background electrolyte (BGE), addition of organic solvents, injection mode as well as temperature are discussed from a practical point of view and illustrated by examples. Finally, several types of dual systems including at least one CD are also presented. [less ▲]

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See detailAssociation of two single-isomer anionic CD in NACE for the chiral and achiral separation of fenbendazole, its sulphoxide and sulphone metabolites: Application to their determination after in vitro metabolism
Rousseau, Anne ULg; Gillotin, Florian; Chiap, Patrice ULg et al

in Electrophoresis (2010), 31

A NACE method was developed for the separation of fenbendazole (FBZ), a prochiral drug giving rise to chiral (oxfendazole or OFZ) and nonchiral (FBZ sulphone or FBZSO2) metabolites. First, the effect of ... [more ▼]

A NACE method was developed for the separation of fenbendazole (FBZ), a prochiral drug giving rise to chiral (oxfendazole or OFZ) and nonchiral (FBZ sulphone or FBZSO2) metabolites. First, the effect of the nature and the concentration of CD as well as that of the acidic BGE on the enantiomeric separation of OFZ were studied. OFZ enantiomers were completely resolved using a BGE made up of 10 mM ammonium formate and 0.5 M TFA in methanol containing 10 mM heptakis(2,3-di-O-acetyl-6-O-sulfo)-beta-CD and 10 mM heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-CD. Moreover, the NACE method was found to be particularly well suited to the simultaneous determination of FBZ, OFZ enantiomers, and FBZSO2. Thiabendazole was selected as an internal standard. The CD-NACE potential was then evaluated for in vitro metabolism studies using FBZ as a model case. The OFZ enantiomers and FBZSO2 could be detected after incubation of FBZ in the phenobarbital-induced male rat liver microsomes systems. [less ▲]

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See detailEnantioresolution of basic pharmaceuticals using cellulose tris(4-chloro-3-methylphenylcarbamate) as chiral stationary phase and polar organic mobile phases.
Dossou, Katina Sourou Sylvestre ULg; Chiap, Patrice ULg; Chankvetadze, Bezhan et al

in Journal of Chromatography. A (2009), 1216(44), 7450-5

A polysaccharide-based chiral stationary phase (Sepapak-4), with cellulose tris(4-chloro-3-methylphenylcarbamate) as chiral selector, has been investigated in liquid chromatography (LC). Its ... [more ▼]

A polysaccharide-based chiral stationary phase (Sepapak-4), with cellulose tris(4-chloro-3-methylphenylcarbamate) as chiral selector, has been investigated in liquid chromatography (LC). Its enantioresolution power was evaluated towards 13 basic amino-drugs with widely different structures and polarities, using polar organic mobile phases. After preliminary experiments, acetonitrile was selected as the main mobile phase component, to which a low concentration of diethylamine (0.1%) was systematically added in order to obtain efficient and symmetrical peaks. Different organic solvents were first added in small proportions (5-10%) to acetonitrile to modulate analyte retention. Polar organic modifiers were found to decrease retention and enantioresolution while hexane had the opposite effect, indicating normal-phase behaviour under these conditions. The addition of an organic acid (formic, acetic or trifluoroacetic acid) was found to strongly influence the retention of the basic amino drugs in these nonaqueous systems. The nature and proportion of the acidic additive in the mobile phase had also deep impact on enantioresolution. Therefore, the studied compounds could be subdivided in three groups in respect to the acidic additive used. All analytes could be enantioseparated in relatively short analysis times (10-20min) using these LC conditions. [less ▲]

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See detailBiomarker discovery in asthma-related inflammation and remodeling.
Quesada Calvo, Florence ULg; Fillet, Marianne ULg; De Seny, Dominique ULg et al

in Proteomics (2009), 9(8), 2163-2170

Asthma is a complex inflammatory disease of airways. A network of reciprocal interactions between inflammatory cells, peptidic mediators, extracellular matrix components, and proteases is thought to be ... [more ▼]

Asthma is a complex inflammatory disease of airways. A network of reciprocal interactions between inflammatory cells, peptidic mediators, extracellular matrix components, and proteases is thought to be involved in the installation and maintenance of asthma-related airway inflammation and remodeling. To date, new proteic mediators displaying significant activity in the pathophysiology of asthma are still to be unveiled. The main objective of this study was to uncover potential target proteins by using surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) on lung samples from mouse models of allergen-induced airway inflammation and remodeling. In this model, we pointed out several protein or peptide peaks that were preferentially expressed in diseased mice as compared to controls. We report the identification of different five proteins: found inflammatory zone 1 or RELM (FIZZ-1), calcyclin (S100A6), clara cell secretory protein 10 (CC10), Ubiquitin, and Histone H4. [less ▲]

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See detailStudy of the cholesterol extraction capacity of β-cyclodextrin and its derivatives, relationships with their effects on endothelial cell viability and on membrane models
Castagne, Delphine ULg; Fillet, Marianne ULg; Delattre, Luc ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2009), 63(3-4), 225-231

Endothelial cells (HUVEC) were treated with β-cyclodextrin and hydroxypropylated or methylated derivatives solutions in order to quantify their cholesterol extraction capacity. Non-toxic concentrations of ... [more ▼]

Endothelial cells (HUVEC) were treated with β-cyclodextrin and hydroxypropylated or methylated derivatives solutions in order to quantify their cholesterol extraction capacity. Non-toxic concentrations of cyclodextrins (CDs) were determined following methyl thiazol tetrazolium (MTT) assays, total protein measurements, morphological observations and trypan blue assays. The residual cholesterol content of cells was measured and the extraction power of CDs compared to results obtained by phase solubility diagrams. Cholesterol was extracted with a dose-response relationship, the lowest residual cholesterol content being obtained with β-CD at 10 mM. Low substituted derivatives (Crysmeb® and hydroxypropyl-β-CD) maintained liposomes integrity (as shown before), were the less cytotoxic and presented the lowest affinity for cholesterol contrary to methylated derivatives with degrees of substitution around 2. [less ▲]

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See detailProtéomique par SELDI-TOF-MS des maladies inflammatoires articulaires: identification des protéines S100 comme protéines d'intérêt
De Seny, Dominique ULg; Ribbens, Clio ULg; Cobraiville, Gaël ULg et al

in Revue Médicale de Liège (2009), 64(Spec No), 29-35

Clinical proteomics is a technical approach studying the entire proteome expressed by cells, tissues or organs. It describes the dynamics of cell regulation by detecting molecular events related to ... [more ▼]

Clinical proteomics is a technical approach studying the entire proteome expressed by cells, tissues or organs. It describes the dynamics of cell regulation by detecting molecular events related to diseases development. Proteomic techniques focus mainly on identification of new biomarkers or new therapeutic targets. It is a multidisciplinary approach using medical, biological, bioanalytical and bioinformatics knowledges. A strong collaboration between these fields allowed SELDI-TOF-MS proteomics studies to be performed at the CHU and the University of Liege, in GIGA-Research facilities. The aim of these studies was driven along three main axes of research related to the identification of biomarkers specific to a studied pathology, to a common biological pathway and, finally, to a treatment response. [less ▲]

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See detailNutrient digestibility of Mucuna (Mucuna pruriens var. utilis) bean in guinea fowl (Numida meleagris, L): Effects of heat treatment and levels of incorporation in diets.
Dahouda, M.; Toleba, S. S.; Youssao, A. K. I. et al

in British Poultry Science (2009), 50(5), 564-72

1. Mucuna pruriens var. utilis is a legume, the seeds of which are scarcely used in animal diets owing to their high content of 3,4-dihydroxy-L-phenylalanine (L-Dopa). 2. Experiments were conducted on ... [more ▼]

1. Mucuna pruriens var. utilis is a legume, the seeds of which are scarcely used in animal diets owing to their high content of 3,4-dihydroxy-L-phenylalanine (L-Dopa). 2. Experiments were conducted on guinea fowl to assess the effects of two types of heat processing (cooking and toasting) on chemical composition and nutrient digestibility of Mucuna seeds offered alone or incorporated at three concentrations (40, 120 or 200 g/kg) in complete diets. 3. Diets containing 200 g/kg seeds had more crude fibre and less ether extract. L-Dopa content increased with the amount of Mucuna inclusion. Cooking reduced markedly L-Dopa content while toasting had no effect. When fed alone, Mucuna seeds dramatically decreased feed intake. 4. Feed intake (FI) and body weight gain (BWG) were not influenced by the complete diets. Cooking significantly increased crude fibre digestibility. 5. It is suggested that cracked and cooked Mucuna bean can be incorporated at a safe level of 120 g/kg in complete diets for guinea fowl production. [less ▲]

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See detailThe proapoptotic C16-ceramide-dependent pathway requires the death-promoting factor Btf in colon adenocarcinoma cells.
Renert, Anne-Francoise; Leprince, Pierre ULg; Dieu, Marc et al

in Journal of Proteome Research (2009), 8(10), 4810-22

Ceramides are central molecules in sphingolipid metabolism. They are involved in the regulation of cancer-cell growth, differentiation, senescence and apoptosis. To better understand how these secondary ... [more ▼]

Ceramides are central molecules in sphingolipid metabolism. They are involved in the regulation of cancer-cell growth, differentiation, senescence and apoptosis. To better understand how these secondary messengers induce their biological effects, adenocarcinoma cells (HCT116) were treated with exogenous long-chain ceramides (C16-ceramide) in order to mimic endogenous sphingolipids. This treatment induced a decrease of cell viability partly due to apoptosis as shown by PARP cleavage and a decrease of pro-caspase 3. Two-dimensional differential in-gel electrophoresis (2D-DIGE) revealed the differential expression of 51 proteins in response to C16-ceramide. These proteins are notably involved in cell proliferation, apoptosis, protein transport and transcriptional regulation. Among them, the cell death-promoting factor Btf was found to be implicated in the apoptotic signal triggered by ceramide. In adenocarcinoma cells, Btf regulates apoptosis related proteins such as Mdm2, p53, BAX and pBcl-2 and thus plays an important role in the ceramide mediated cell death. These findings bring new insight into the proapoptotic ceramide-dependent signaling pathway. [less ▲]

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See detailEffect of the nature of the single-isomer anionic CD and the BGE composition on the enantiomeric separation of beta-blockers in NACE.
Rousseau, Anne ULg; Chiap, Patrice ULg; Oprean, Radu et al

in Electrophoresis (2009), 30(16), 2862-8

The separation of ten beta-blockers has been investigated in NACE systems using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-CD (HDMS-beta-CD) and heptakis(2,3-di-O-acetyl-6-O-sulfo)-beta-CD (HDAS-beta-CD ... [more ▼]

The separation of ten beta-blockers has been investigated in NACE systems using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-CD (HDMS-beta-CD) and heptakis(2,3-di-O-acetyl-6-O-sulfo)-beta-CD (HDAS-beta-CD). The influence on enantioresolution, mobility difference and selectivity of the nature of both anionic CD and BGE anion as well as their concentrations were studied by means of a multivariate approach. A D-optimal design with 25 experimental points was applied. For all studied analytes, the enantiomeric resolution was shown to be significantly influenced by both CD nature and concentration. Except for two compounds, HDAS-beta-CD was found to give higher enantioresolution values than HDMS-beta-CD. The best enantioseparation for all compounds was achieved in the presence of a high chiral selector concentration and for most of them at a low BGE anion concentration. For each investigated compound, operating conditions leading to the best enantiomeric resolution were deduced. A generic NACE system was then recommended, namely 10 mM ammonium acetate and 40 mM HDAS-beta-CD in methanol acidified with 0.75 M formic acid. This generic system was able to completely resolve the enantiomers of all beta-blockers, with a R(s) value of at least 4. Finally, the optimal conditions obtained modelling resolution, mobility difference and selectivity were compared. [less ▲]

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See detailCE-MS method development for peptides analysis, especially hepcidin, an iron metabolism marker.
Martin, Gaëlle ULg; Mansion, François ULg; Servais, Anne-Catherine ULg et al

in Electrophoresis (2009), 30(15), 2624-31

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the ... [more ▼]

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the addition of cyclodextrins or organic solvents in the BGE or the use of coated capillaries. Best results in terms of resolution, symmetry and efficiency were obtained with a BGE made of 500 mM ammonium acetate pH 4.5/ACN 70:30 v/v. Using the methodology of experimental design, BGE concentration, sheath liquid composition and MS-coupling parameters were then optimized in order to obtain the best signal intensity for hepcidin. Finally, a 225 mM BGE and a sheath liquid composed of isopropanol/water 80:20 v/v containing 0.5% v/v formic acid were selected as it constitutes the best compromise for selectivity, peak shape and sensitivity. [less ▲]

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See detailChallenges for Biomarker Discovery in Body Fluids Using SELDI-TOF-MS
De Bock, Muriel ULg; De Seny, Dominique ULg; Meuwis, Marie-Alice ULg et al

in Journal of Biomedicine & Biotechnology (2009)

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