References of "Plenevaux, Alain"
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See detailRadiochemical synthesis and tissue distribution of p-[F-18]DMPPF, a new 5-HT1A ligand for PET, in rats
Defraiteur, Caroline; Lemaire, Christian ULg; Luxen, André ULg et al

in Nuclear Medicine & Biology (2006), 33(5), 667-675

Several studies have demonstrated the potential of p-[F-18]MPPF as a radiophanilaceutical to study the 5-HT1A receptor family in animals and humans. A structural modification leading to a higher ... [more ▼]

Several studies have demonstrated the potential of p-[F-18]MPPF as a radiophanilaceutical to study the 5-HT1A receptor family in animals and humans. A structural modification leading to a higher radioactive signal at an equipotent dose would greatly enhance this potential. With this goal, the desmethylated 4-(2'-methoxyphenyl)-1-[2'-[N-(2"-pyridinyl)-p-fluorobenzamidolethyl]-piperazine (p-MPPF), identified as p-DMPPF, was synthesized, labeled with fluorine-18 and evaluated through ex vivo tissue distribution in rats. The new compounds p-DMPPF, p-DMPPNO2, MEM-p-MPPF and MEM-p-MPPNO2 were isolated and fully identified (H-1 and C-13 NMR, LC-MS). The final compound, p-[F-18]DMPPF, was obtained ready for injection, with an overall radiochemical yield of 10% (EOB corrected) within 90 min and a specific activity of 62 GBq/mu mol. Tissue distributions showed that the carbon-fluorine bond was stable in vivo and that this compound could cross the blood-brain barrier. For kidney, lung, heart, spleen, bone, testicle, liver and muscle, the percentage of injected dose per gram of tissue obtained with p-[F-18]DMPPF was of the same order of magnitude as that of p-[F-18]MPPF. The amount of radioactivity reaching the brain was much higher (approximately fivefold at 60 min) for p-[F-18]DMPPF compared with p-[F-18]MPPF, which was taken as reference. The distribution and specificity were in total agreement with the known localization of 5-HT1A receptors in rats. The radioactivity increase was more important for specific tissues (hippocampus and frontal cortex) than for cerebellum or striatum, leading to better contrast (hippocampus/cerebellum=5.8 at 60 min). The levels of metabolites found in plasma showed that p-[F-18]DMPPF appears to be less metabolized than p-[F-18]MPPF. p-[F-18]DMPPF deserves further evaluation as a radiopharmaceutical candidate. (c) 2006 Elsevier Inc. All rights reserved. [less ▲]

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See detailSynthesis of anhydro-muramic acid derivatives as substrates for MurNAc amidase
Mercier, Frédéric; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

Poster (2006, May 17)

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See detailDEVELOPPEMENT D'INHIBITEURS SELECTIFS DE LA TRYPTOPHANE HYDROXYLASE
Giacomelli, Fabrice ULg; Luxen, André ULg; Lemaire, Christian ULg et al

Conference (2006, February 03)

Comprendre la façon dont le cerveau travaille et en particulier le mode de communication de ses cellules est un rêve que beaucoup de chercheurs caressent. A l’heure actuelle, une des rares certitudes à ... [more ▼]

Comprendre la façon dont le cerveau travaille et en particulier le mode de communication de ses cellules est un rêve que beaucoup de chercheurs caressent. A l’heure actuelle, une des rares certitudes à son sujet est qu’un de ses modes de transmission d’informations utilise des « messagers » chimiques appelés neurotransmetteurs. Parmi ceux-ci, la sérotonine (5-HT) revêt une importance particulière. En effet, la 5-HT est impliquée dans de nombreuses fonctions (apprentissage, locomotion, sommeil,…) et pathologies (dépressions, démences, schizophrénies,…). Dès lors, l'étude in vivo chez l'homme des neurones sérotoninergiques ainsi que la quantification de la vitesse de biosynthèse de la 5-HT sont des domaines d'études fondamentaux pour lesquels la tomographie à émission de positons (TEP) constitue un outil de choix. Pour mener à bien ces différentes expérimentations, deux stratégies sont envisageables : - L’emploi d'un traceur capable de suivre la chaîne métabolique du tryptophane conduisant à la 5-HT tout en évitant les autres voies métaboliques. - L’utilisation d'un inhibiteur de la TrpOH (enzyme limitant du processus). Dans le cadre de cette présentation, nous nous intéresserons plus particulièrement à la deuxième stratégie. [less ▲]

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See detailSynthesis of protected meso-diaminopimelic acid.
Teller, N.; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

Poster (2005, October 10)

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See detailSynthesis of anhydro-muranic acid derivatives as substrates for MurNAc amidase.
Mercier, F.; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

Poster (2005, October 10)

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See detailRadiochemical Synthesis of OCH2F-[18F]MPPF a New Analogue of p-[18F]MPPF for the Study of 5-HT1A Receptors.
Defraiteur, C.; Lemaire, Christian ULg; Luxen, André ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2005), 48

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See detailEx Vivo Evaluation of p-[18F]D-MPPF for the Study of 5-HT1A Receptors.
Defraiteur, C.; Lemaire, Christian ULg; Luxen, André ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2005), 48

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See detailNew Methods For Halogenation of [18F]Fluorinated Benzyl Derivatives.
Kech, C.; Lemaire, Christian ULg; Brichard, L. et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2005), 48

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See detailHighly enantioselective synthesis of no-carrier-added 6-[18F]Fluoro-L-dopa by chiral phase-transfer alkylation
Lemaire, Christian ULg; Gillet, Steve; Guillouet, Stéphane et al

in European Journal of Organic Chemistry (2004), (13), 2899-2904

[F-18]Fluoro-L-dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived ... [more ▼]

[F-18]Fluoro-L-dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived from a Cinchona alkaloid served as phase-transfer catalyst for the enantioselective alkylation of a glycine derivative. The active methylene group of this Schiff-base substrate was deprotonated with cesium hydroxide and rapidly alkylated by the 2-[F-18]fluoro-4,5-dimethoxybenzyl halide (X = Br, I). The reaction proceeded with high yield (> 90%) at 0 degreesC or room temperature in various solvents such as toluene or dichloromethane. Preparation of the [F-18]alkylating agent on a solid support was developed. After labelling, the labeled [F-18]fluoroveratraldehyde was trapped on a (t)C18 cartridge and then converted on the cartridge into the corresponding benzyl halide derivatives by addition of aqueous sodium borohydride and gaseous hydrobromic or -iodic acid. Hydrolysis and purification by preparative HPLC made 6-[F-18]fluoro-L-dopa ready for human injection in a 25-30% decay-corrected radiochemical yield in a synthesis time of 100 min. The product was found to be chemically, radiochemically and enantiomerically pure (ee > 95%). (C) Wiley-VCH Verlag GmbH [less ▲]

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See detailTissue distribution and metabolism of D-p-[18F]MPPF in rats.
Defraiteur, C.; Muroni, S.; Lemaire, Christian ULg et al

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (2004), 45(S2), 444

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See detailRadiochemical Synthesis of p-[18F]Desmethyl-MPPF (p-[18F]D-MPPF) for the Study of 5-HT1A Receptors
Defraiteur, Caroline; Plenevaux, Alain ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2003, August), 46(S1), 157

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See detailRadiosynthèses d'antagonistes des récepteurs 5-HT1A.
Defraiteur, C.; Plenevaux, Alain ULg; Lemaire, Christian ULg et al

Poster (2003, June 13)

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See detailMise au point de sondes pour l'étude du système sérotoninergique par tomographie à émission de positons (TEP)
Giacomelli, Fabrice ULg; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

Poster (2003, June 13)

La quantification de la vitesse de biosynthèse de la sérotonine ainsi que l'étude in vivo chez l'homme sont, du fait de l'implication cruciale des neurones sérotoninergiques dans de nombreuses fonctions ... [more ▼]

La quantification de la vitesse de biosynthèse de la sérotonine ainsi que l'étude in vivo chez l'homme sont, du fait de l'implication cruciale des neurones sérotoninergiques dans de nombreuses fonctions et pathologies cérébrales, des domaines d'études fondamentaux pour lesquels la TEP constitue un outil de choix. Ces différentes expérimentations peuvent être conduites suivant deux optiques: (i) emploi d'un traceur capable de suivre la chaîne métabolique du tryptophane conduisant à la sérotonine tout en évitant les autres voies métaboliques. (ii) utilisation d'un inhibiteur de la tryptophane hydroxylase (TPOH), enzyme limitante du processus. [less ▲]

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See detailRadiosynthèse de dérivés du 7-[18F]fluoroindole
Otabashi, Muhammad ULg; Giacomelli, Fabrice ULg; Lemaire, Christian ULg et al

Poster (2003, June 13)

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See detailRadiosynthesis of 7-[18F]fluoroindole derivatives.
Otabashi, Muhammad ULg; Giacomelli, Fabrice ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2003), 46

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See detailSimple device for the radiosynthesis of [carbonyl-11C]amides, esters and ketones using carbon-11 monoxide.
Brichard, L.; Del Fiore, G.; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2003), 46

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See detailSynthesis of [18F]fluorinated a-methyl-a-amino acids by phase transfer catalysis for potential PET application.
Wouters, L.; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2003), 46

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See detailDevelopment and evaluation of an automated atlas-based image analysis method for microPET studies of the rat brain.
Rubins, Daniel J.; Melega, William P.; Lacan, Goran et al

in NeuroImage (2003), 20(4), 2100-18

An automated method for placement of 3D rat brain atlas-derived volumes of interest (VOIs) onto PET studies has been designed and evaluated. VOIs representing major structures of the rat brain were ... [more ▼]

An automated method for placement of 3D rat brain atlas-derived volumes of interest (VOIs) onto PET studies has been designed and evaluated. VOIs representing major structures of the rat brain were defined on a set of digitized cryosectioned images of the rat brain. For VOI placement, each PET study was registered with a synthetic PET target constructed from the VOI template. Registration was accomplished with an automated algorithm that maximized the mutual information content of the image volumes. The accuracy and precision of this method for VOI placement was determined using datasets from PET studies of the striatal dopamine and hippocampal serotonin systems. Each evaluated PET study could be registered to at least one synthetic PET target without obvious failure. Registration was critically dependent upon the initial position of the PET study relative to the synthetic PET target, but not dependent on the amount of synthetic PET target smoothing. An evaluation algorithm showed that resultant radioactivity concentration measurements of selected brain structures had errors=2% due to misalignment with the corresponding VOI. Further, radioligand binding values calculated from these measurements were found to be more precise than those calculated from measurements obtained with manually drawn regions of interest (ROIs). Overall, evaluation results demonstrated that this atlas-derived VOI method can be used to obtain unbiased measurements of radioactivity concentration from PET studies. Its automated features, and applicability to different radioligands and brain regions, will facilitate quantitative rat brain PET assessment procedures. [less ▲]

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