References of "Lemaire, Christian"
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See detailp-[18F]MPPF, 5-HT1A antagonist: comparison to [3H]8-OH-DPAT with autoradiography
Plenevaux, Alain ULg; Weissmann, D.; Lemaire, Christian ULg et al

in Society for Neuroscience / Abstracts (1999)

p-MPPF 4-(2’-methoxyphenyl)-1-[2’-[N-(2’’-pyridinyl)-p-fluorobenzamido] ethyl]piperazine is the para-fluorobenzoyl analog of the highly selective 5-HT1A antagonist WAY-100635. The one step procedure used ... [more ▼]

p-MPPF 4-(2’-methoxyphenyl)-1-[2’-[N-(2’’-pyridinyl)-p-fluorobenzamido] ethyl]piperazine is the para-fluorobenzoyl analog of the highly selective 5-HT1A antagonist WAY-100635. The one step procedure used to label p-MPPF with fluorine-18 (cyclotron produced positron emitter of 110 min half-life) leads to a radiopharmaceutical compound easily prepared on a large scale. The preliminary evaluations conducted in rats and cats are good reason to consider p-[18F]MPPF as an interesting reversible radioligand to study the 5-HT1A receptor family in humans with positron emission tomography (PET). In this paper we report a careful comparison between p-[18F]MPPF and [3H]8-OH-DPAT with autoradiography and quantitative densitometry in the same animal. All experiments were conducted in Sprague Dawley male rats. For p-[18F]MMPF, the results were obtained ex-vivo after an intravenous injection of high specific activity radioligand (0.8-1.5 Ci/µmol) in vigil (no anesthesia), free moving and unstressed animals. For the purpose, permanent cannulation of the posterior vena cava were realized at least four days in advance. The [3H]8-OH-DPAT results were obtained in vitro on adjacent coronal sections to the one used for the p-[18F]MPPF autoradiography. Quantitative densitometry was employed to compare the values obtained in relevant brain structures (frontal cortex, lateral septum, hippocampus, dorsal raphe, entorhinal cortex and cerebellum). The plot of the p-[18F]MPPF values obtained for each structure against the [3H]8-OH-DPAT results displayed a significant linear correlation. These results demonstrate that from a qualitative as well as quantitative point of view, the binding of p-[18F]MPPF is totally comparable to the one of [3H]8-OH-DPAT. Supported by grants from INSERM/CGRI and FNRS Belgium. [less ▲]

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See detailSynthesis and in vivo evaluation of 6-fluoro-a-methyl-L-tryptophan.
Lambin, D.; Tadino, V.; Olynyk, C. et al

in American Chemical Society / Abstracts (1999)

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See detailSolid phase extraction : An alternative to the use of rotary evaporators for solvent removal in the rapid formulation of PET radiopharmaceuticals
Lemaire, Christian ULg; Plenevaux, Alain ULg; Aerts, Joël ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1999), 42(1), 63-75

Solid phase extraction (SPE) was used for the formulation of several radiopharmaceuticals. The method involves dilution of the previously purified HPLC compound with water, trapping of the activity on an ... [more ▼]

Solid phase extraction (SPE) was used for the formulation of several radiopharmaceuticals. The method involves dilution of the previously purified HPLC compound with water, trapping of the activity on an SPE bed, washing off the support, elution of the radiopharmaceutical with a small volume of ethanol (<1 mL) and dilution with sterile isotonic saline solution. Recovery of the radiopharmaceuticals was always higher than 97%. Two different methods of automation were developed for the formulation of [11C] and [18F]radiopharmaceuticals. In all cases, organic solvent levels in the injectable solution were below the recommended limits. This fast (3-6 min.) and easy to automate process can be considered as an alternative to the conventional methods (rotary evaporators). Copyright © 1999 John Wiley [less ▲]

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See detailMetabolism of no-carrier-added 2-[18F]fluoro-L-tyrosine in free mooving rats.
Aerts, Joël ULg; Plenevaux, Alain ULg; Lemaire, Christian ULg et al

in Society for Neuroscience / Abstracts (1998), 24

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See detailHigh-yield radiosynthesis and preliminary in vivo evaluation of p-[18F]MPPF, a fluoro analog of WAY-100635.
Le Bars, Didier; Lemaire, Christian ULg; Ginovart, N. et al

in Nuclear Medicine & Biology (1998), 25(4), 343-50

No-carrier-added 4-[18F]fluoro-N-[2-[1-(2-methoxyphenyl)-1 piperazinyl]ethyl-N-2-pyridinyl-benzamide (p-[18F]MPPF) was synthesized by nucleophilic substitution of the corresponding nitro compound in the ... [more ▼]

No-carrier-added 4-[18F]fluoro-N-[2-[1-(2-methoxyphenyl)-1 piperazinyl]ethyl-N-2-pyridinyl-benzamide (p-[18F]MPPF) was synthesized by nucleophilic substitution of the corresponding nitro compound in the presence of Kryptofix 222 and K2CO3 by microwave heating (3 min, 500 W) using a remotely controlled radiosynthesis. Baseline separation of p-[18F]MPPF from the nitro derivative was performed on a semipreparative HPLC C18 column. After Sep-Pak formulation, the radiopharmaceutical was obtained with a radiochemical yield of 25% (EOS) in about 70 min. Specific radioactivity averaged between 1-5 Ci/micromol EOS. Labelling of the ortho and meta derivatives was also attempted. Brain uptake of p-[18F]MPPF was studied with PET on fluothane-anesthetized cats. Following intravenous injection of p-[18F]MPPF, high accumulation of radioactivity was observed in the hippocampus and cerebral cortex. Low levels of radioactivity were observed in cerebellum. At 30 min, the mean hippocampus/cerebellum and cortex/cerebellum ratios were 5 and 3.8, respectively. The accumulation of the tracer was blocked by prior administration of reference WAY-100635, demonstrating the specificity of the ligand. [less ▲]

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See detailMétabolisme du p-[18]MPPF (antagoniste 5-HT1A) chez le rat
Plenevaux, Alain ULg; Aerts, Joël ULg; Lemaire, Christian ULg et al

Poster (1997, May 29)

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See detailMétabolisme de la 6-fluoro-L-tyrosine chez le rat
Aerts, Joël ULg; Plenevaux, Alain ULg; Lemaire, Christian ULg et al

Poster (1997, May 29)

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See detailLe p-[18F]MPPF: un nouveau ligand pour l'étude par TEP des récepteurs 5-HT1A
Ginovart, Nathalie; Le Bars, Didier; Lemaire, Christian ULg et al

Poster (1997, May 25)

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See detailMicrowave improved synthesis of p-[18F]MPPF, 5-HT1A antagonist and PET sudies on cat brain.
Le Bars, D.; Ginovart, N.; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40

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See detailSynthesis of a fluorinated analogue of L-threo-3-(3,4-dihydroxyphenyl)serine: 6-fluoro-L-threo-DOPS.
Lambin, D.; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40

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See detailSynthesis of [18F]FDG with alkaline hydrolysis on a low polarity solid phase support.
Lemaire, Christian ULg; Damhaut, Ph.; Lauricella, Benjamino ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40

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See detailMetabolism of no carrier added 2-[18F]fluoro-L-tyrosine in free moving rats.
Aerts, Joël ULg; Plenevaux, Alain ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40

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See detailTissue distribution, autoradiography and metabolism in rats of p-[18F]MPPF: 5-HT1A antagonist.
Plenevaux, Alain ULg; Aerts, Joël ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1997), 40

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See detailHigh yield radiosynthesis of p-[F-18]MPPF, 5-HT1A antagonist, and PET studies in cat brain.
Le Bars, D.; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (1997), 38

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See detailEvaluation of p-[F-18]MPPF, 5-HT1A antagonist, in rats: tissue distribution, autoradiography and metabolism.
Plenevaux, Alain ULg; Aerts, Joël ULg; Lemaire, Christian ULg et al

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (1997), 38

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See detailNo-carrier-added asymmetric synthesis of alpha-methyl-alpha-amino acids labelled with fluorine-18
Damhaut, Philippe; Lemaire, Christian ULg; Plenevaux, Alain ULg et al

in Tetrahedron (1997), 53(16), 5785-5796

Various [18F]fluoro aromatic α-methyl-L-amino acids 11 have been synthesized with high enantiomeric purity (ee > 97%). These new radiopharmaceuticals for Positron Emission Tomography (PET), potential ... [more ▼]

Various [18F]fluoro aromatic α-methyl-L-amino acids 11 have been synthesized with high enantiomeric purity (ee > 97%). These new radiopharmaceuticals for Positron Emission Tomography (PET), potential inhibitors of enzymatic functions, were regiospecifically labelled by nucleophilic substitution on trimethylammoniumbenzaldehyde triflate precursors 9. The [18F]fluoro aromatic aldehydes 12 obtained were easily converted to the corresponding [18F]fluorobenzyl halides [13 (X = 1)]. After alkylation of the lithium enolate of (2S,5S)-l-tert-Boc-2-tert-butyl-3,5-dimethyl-imidazolidin-4-one 2, the adducts were cleaved to give, after HPLC purification, various [18F]fluoro-α-methyl amino acid analogs with radiochemical yields of 10% (End of Bombardment, EOB) after a synthesis time of 120 min. The corresponding [19F]fluorinated amino acids 4 and [19F]fluoro intermediates were also prepared. [less ▲]

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See detailCombined study of cerebral glucose metabolism and [11C] methionine accumulation in probable Alzheimer's disease using positron emission tomography
Salmon, Eric ULg; Grégoire, M. C.; Delfiore, Guy et al

in Journal of Cerebral Blood Flow & Metabolism (1996), 16(3), 399-408

There is a characteristic decrease in glucose metabolism in associative frontal and temporo-parietal cortices of patients suffering from Alzheimer's disease (AD). The decrease in metabolism might result ... [more ▼]

There is a characteristic decrease in glucose metabolism in associative frontal and temporo-parietal cortices of patients suffering from Alzheimer's disease (AD). The decrease in metabolism might result from local neuronal loss or from a decrease of synaptic activity. We measured in vivo [11C]methionine accumulation into proteins with positron emission tomography (PET) to assess cortical tissue loss in AD. Both global regional activity and compartmental analysis were used to express [11C]methionine accumulation into brain tissue. Glucose metabolism was measures with [18F]fluorodeoxyglucose and autoradiographic method. Combined studies were performed in 10 patients with probable AD, compared to age-matched healthy volunteers. There was a significant 45% decrease of temporo-parietal glucose metabolism in patients with AD, and frontal metabolism was lowered in most patients. Temporo-parietal metabolism correlated to dementia severity. [11C]methionine incorporation into temporo-parietal and frontal cortices was not significantly decreased in AD. There was no correlation with clinical symptoms. Data suggest that regional tissue loss, assessed by the decrease of [11C]methionine accumulation, is not sufficient to explain cortical glucose hypometabolism, which reflects, rather, reduced synaptic connectivity. [less ▲]

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See detailEnantioselective syntheses of no-carrier-added (nca) (S)-4-chloro-2 F-18 fluorophenylalanine and (S)-(alpha-methyl)-4-chloro-2 F-18 fluorophenylalanine
Al-Darwich, M. J.; Plenevaux, Alain ULg; Lemaire, Christian ULg et al

in Journal of Fluorine Chemistry (1996), 80(2), 117-124

(S)-4-Chloro-2-fluorophenylalanine and (S)-( a-methyl)-4-chloro-2-fluorophenylalanine were synthesized and labeled with no carrier added (n.c.a.) fluorine-18 through a radiochemical synthesis relying on ... [more ▼]

(S)-4-Chloro-2-fluorophenylalanine and (S)-( a-methyl)-4-chloro-2-fluorophenylalanine were synthesized and labeled with no carrier added (n.c.a.) fluorine-18 through a radiochemical synthesis relying on the highly enantioselective reaction between 4-chloro-2-[18F] fluorobenzyl iodide and the lithium enolate of (2s) -1-( tert-butyloxycarbonyl) -2-( tert-butyl)-3-methyl- 1,3-imidazolidine-4-one for (S) -4-chloro-2- [18F] fluorophenylalanine and (2S,5S)-1-( tert-butyloxycarbonyl) -2-( tert-butyl) -3,5-dimethyl- 1,3-imidazolidine-4-one for (S) -( a-methyl) -4-chloro-2- [18F] fluorophenylalanine. Quantities of about 20-25 mCi were obtained at the end of synthesis, ready for injection after hydrolysis and high performance liquid chromatography (HPLC) purification, with a radiochemical yield of 17%-20% corrected to the end of bombardment after a total synthesis time of 90-105 min from [18F] fluoride. The enantiomeric excesses were shown to be 97% or more for both molecules without chiral separation and the radiochemical and chemical purities were 98% or better. [less ▲]

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See detailFluorine-18 labeling of radiopharmaceuticals for PET studies: main aspects and problems encountered in chemical syntheses
Lemaire, Christian ULg

in Emran, A (Ed.) Chemists' Views of Imaging Centers (1995)

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