References of "Goblet, David"
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See detailAutomated synthesis of [18F] FBEM for labeling of thiol containing compounds
Paris, Jérôme ULg; Thonon, David ULg; Kaisin, Geoffroy ULg et al

Poster (2011, September 01)

[18F]FBEM, i.e. N-[2-(4-[18F]fluorobenzamido)ethyl]maleimide, is a useful synthon employed for the specific radiolabeling of thiol containing compounds, including peptides and proteins. The aim of the ... [more ▼]

[18F]FBEM, i.e. N-[2-(4-[18F]fluorobenzamido)ethyl]maleimide, is a useful synthon employed for the specific radiolabeling of thiol containing compounds, including peptides and proteins. The aim of the present work was to develop a fast, reproducible and fully automated synthesis of this compound in order to improve its availabilty as well as for obvious radioprotection matters. [less ▲]

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See detailUse of a beta microprobe system to measure arterial input function in PET via an arteriovenous shunt in rats
Warnock, Geoffrey ULg; Bahri, Mohamed Ali ULg; Goblet, David ULg et al

in European Journal of Nuclear Medicine and Molecular Imaging Research (2011), 1

Kinetic modeling of physiological function using imaging techniques requires the accurate measurement of the time-activity curve of the tracer in plasma, known as the arterial input function (IF). The ... [more ▼]

Kinetic modeling of physiological function using imaging techniques requires the accurate measurement of the time-activity curve of the tracer in plasma, known as the arterial input function (IF). The measurement of IF can be achieved through manual blood sampling, the use of small counting systems such as beta microprobes, or by derivation from PET images. Previous studies using beta microprobe systems to continuously measure IF have suffered from high background counts. In the present study, a light-insensitive beta microprobe with a temporal resolution of up to 1 s was used in combination with a pump-driven femoral arteriovenous shunt to measure IF in rats. The shunt apparatus was designed such that the placement of the beta microprobe was highly reproducible. The probe-derived IF was compared to that obtained from manual sampling at 5-s intervals and IF derived from a left ventricle VOI in a dynamic PET image of the heart. Probe-derived IFs were very well matched to that obtained by "gold standard" manual blood sampling, but with an increased temporal resolution of up to 1 s. The area under the curve (AUC) ratio between probe- and manually derived IFs was 1.07 ± 0.05 with a coefficient of variation of 0.04. However, image-derived IFs were significantly underestimated compared to the manually sampled IFs, with an AUC ratio of 0.76 ± 0.24 with a coefficient of variation of 0.32. IF derived from the beta microprobe accurately represented the IF as measured by blood sampling, was reproducible, and was more accurate than an image-derived technique. The use of the shunt removed problems of tissue-background activity, and the use of a light-tight probe with minimal gamma sensitivity refined the system. The probe/shunt apparatus can be used in both microprobe and PET studies. [less ▲]

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See detail[18F]fallypride binding in the mouse brain: test-retest and effects of registration
Bahri, Mohamed Ali ULg; Geuzaine, Annabelle ULg; Warnock, Geoffrey ULg et al

Conference (2011, January 17)

The quantification of in vivo receptor kinetics with PET tracer experiments is an intricate and challenging problem especially for small animals such as rats and mice. A test-retest scan is usually set up ... [more ▼]

The quantification of in vivo receptor kinetics with PET tracer experiments is an intricate and challenging problem especially for small animals such as rats and mice. A test-retest scan is usually set up in order to confirm an observed experimental effect or to examine the reliability of the experiment design. Inadequate processing of the image data may also mask small effects. The purpose of this study was to investigate the effect of image registration on [18F]fallypride binding potentials calculated from PET mouse test-retest data. Sub-optimal registration affected the quantification of in vivo receptor kinetics with [18F]fallypride. The absence of anatomical information in the [18F]fallypride image and the lack of a homogeneous tracer distribution, even during the earlier minutes of the scan, lead to erroneous automatic registration. A FDG scan after each [18F]fallypride test could improve registration as FDG provides a more homogeneous brain image. Variability in the data could also result from stress induced by anaesthesia or the experimental environment. [less ▲]

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See detailIN VIVO PET IMAGING OF THE EFFECT OF THE NMDA ANTAGONIST MEMANTINE ON GLUCOSE METABOLISM IN THE RODENT BRAIN
Warnock, Geoffrey ULg; Dedeurwaerdere, Stefanie; Bahri, Mohamed Ali ULg et al

Poster (2010, September)

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See detailTHE EFFECT OF BETA MICROPROBE IMPLANTATION ON THE BLOOD BRAIN BARRIER
Warnock, Geoffrey ULg; Dedeurwaardere, Stefanie; Bahri, Mohamed Ali ULg et al

Poster (2010, September)

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See detailAutomated radiosynthesis of [18F]MPPF derivatives for imaging 5-HT1A receptors
Goblet, David ULg; Thonon, David ULg; Plenevaux, Alain ULg et al

Poster (2010, May 30)

TOPIC: Molecular Neuroimaging: from Bench to Bedside Automated radiosynthesis of [18F]MPPF derivatives for imaging 5-HT1A receptors Introduction: Dysfunction of the cerebral serotoninergic system is ... [more ▼]

TOPIC: Molecular Neuroimaging: from Bench to Bedside Automated radiosynthesis of [18F]MPPF derivatives for imaging 5-HT1A receptors Introduction: Dysfunction of the cerebral serotoninergic system is implicated in numerous neurodegenerative disorders such as Alzheimer disease’s, dementia, depression, anxiety, schizophrenia, and Parkinson disease’s. The 5-HT1A serotonin receptors are involved in several physiological functions including sleep, mood, neurogenesis and learning [1]. Consequently, there have been huge efforts in finding ligands for this receptor. [11C]WAY-100635 is a high affinity radioligand used for quantifying serotonin 5-HT1A receptors with positron emission tomography. An 18F-labeled radioligand is advantageous because of higher specific activity and physical/nuclear properties (t1/2= 109 min, 97% of positron decay and positron energy of 635 keV maximum). [18F]MPPF, a selective 5-HT1A antagonist derived from WAY-100635, is currently one of the most successful PET ligand used for 5-HT1A receptor imaging [2]. However the affinity is lower then WAY-100635 and the amount of [18F]MPPF reaching the brain is relatively low since MPPF is a substrate for p-glycoprotein [3]. Methods: In order to improve the brain uptake of the radiotracer, a desmethylated analog has been developed in our lab and preliminary in vitro studies show positive results [4]. Nevertheless, the radiosynthesis take place in two steps as a protecting group removal is needed. A one step procedure with a MPPF derivative could be of very great interest. We have synthesized many MPPF derivatives in our lab (modification on the phenylpiperazine moiety) and developed an automated radiosynthesis procedure for the production of these radiotracers. [18F]MPPF was chosen as the model compound. We used a GE Healthcare FASTlabTM module and made modifications to the [18F]FDG synthesis sequence and cassette. [18F]MPPF was synthesized by coupling of [18F]FBA with the corresponding amine. After coupling, the crude solution was diluted with water and passed through a tC18 cartridge for prepurification. After elution, the [18F]MPPF was purified by semi-preparative HPLC. Results: Total synthesis time, including purification was approximately 100 min. [18F]FBA and [18F]MPPF were obtained at a corrected yield of 55% (n=20) and 25% (n=5) respectively. The radiochemical purity, checked by radio-TLC and UPLC, was >95%. Conclusions: We have developed an automated method for [18F]MPPF and derivatives production using a commercial synthesizer (FASTlabTM from GE Healthcare) and a conventional HPLC system resulting in good yields and high (radio)chemical purity. By simply switching the vial containing the modified amine, an 18F-labeled MPPF derivative could be obtained. Radiosynthesis is still under optimization and the radiotracers synthesized need to be tested as suitable 5-HT1A radioligands. Acknowledgement: This work was supported by the Fondation Rahier. References: [1] Filip M., Bader M. et Al, Pharmacol Rep. 2009 Sep-Oct; 61(5):761-77 [2] Aznavour N, Zimmer L. Et Al, Neuropharmacology. 2007 Mar; 52(3):695-707 [3] Laćan G., Plenevaux A. et Al, Eur J Nucl Med Mol Imaging. 2008 Dec;35(12):2256-66 [4] Defraiteur C., Plenevaux A. et Al., Br J Pharmacol. 2007 Nov; 152(6):952-8 [less ▲]

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See detail18F labelling of Insulin via click chemistry
Paris, Jérôme ULg; Mercier, Frédéric ULg; Thonon, David ULg et al

Poster (2010, May 27)

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See detailFast Production of Highly Reactive No-Carrier-Added [18F]Fluoride for the Labeling of Radiopharmaceuticals
Lemaire, Christian ULg; Aerts, Joël ULg; Voccia, Samuel et al

in Angewandte Chemie (International ed. in English) (2010), 49

The 18F labeling of radiopharmaceuticals requires nearly anhydrous solutions of [18F]fluoride. Aqueous K2CO3 is generally used to elute [18F]fluoride from an anion-exchange resin. Replacing aqueous K2CO3 ... [more ▼]

The 18F labeling of radiopharmaceuticals requires nearly anhydrous solutions of [18F]fluoride. Aqueous K2CO3 is generally used to elute [18F]fluoride from an anion-exchange resin. Replacing aqueous K2CO3 with strong organic bases, such as the phosphazene base P2Et enabled the recovery of highly reactive [18F]fluoride and avoided the azeotropic evaporation of water, which is very difficult on a microchip device. [less ▲]

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See detailFast production of highly concentrated reactive [18F] fluoride for aliphatic and aromatic nucleophilic radiolabelling
Aerts, Joël ULg; Voccia, Samuel; Lemaire, Christian ULg et al

in Tetrahedron Letters (2010), 51

The use of a polymeric solid support loaded with a long alkyl chain quaternary ammonium allows the rapid and efficient recovery of cyclotron produced [18F]F- from [18O]water to a low water content organic ... [more ▼]

The use of a polymeric solid support loaded with a long alkyl chain quaternary ammonium allows the rapid and efficient recovery of cyclotron produced [18F]F- from [18O]water to a low water content organic solution compatible with fast nucleophilic labelling of most precursors for PET radiopharmaceuticals in high yield. [less ▲]

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See detailDISPLACEMENT OF 18F-FALLYPRIDE BINDING WITH HALOPERIDOL IN A WITHIN-SUBJECT DESIGN USING A BETA MICROPROBE
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Cerebral Blood Flow & Metabolism (2009, October), 29(S1), 352-353

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See detailTIME-DEPENDENT PREFERENTIAL IN VIVO D2 OCCUPANCY BY AMISULPRIDE IN THE MEDIAL STRIATUM – CONTINUOUS MEASUREMENT USING A BETA MICROPROBE SYSTEM
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 105

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See detailUSE OF A BETA MICROPROBE SYSTEM AS AN AFFORDABLE TRANSLATIONAL TOOL COMPARED TO PET – EXAMPLES USING FDG AND 18F-FALLYPRIDE BINDING
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 55

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See detailTHE USEFULNESS OF AN ARTERIOVENOUS SHUNT COMBINED WITH A BETA MICROPROBE FOR THE MEASUREMENT OF INPUT FUNCTION IN RATS
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 106

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See detailModified Non-Ionic Solid Supports: a Way to High Activity Fluorine-18 Radiochemistry in Microfluidic Devices
Aerts, Joël ULg; Voccia, Samuel; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 12

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See detailCharacterization of 4-(2-hydroxyphenyl)-1-[2 '-[N-(2 ''-pyridinyl)-p-fluorobenzamido]ethyl]piperazine (p-DMPPF) as a new potent 5-HT1A antagonist
Defraiteur, Caroline ULg; Plenevaux, Alain ULg; Scuvée-Moreau, Jacqueline ULg et al

in British Journal of Pharmacology (2007), 152(6), 952-958

Background and purpose: The identification of potent and selective radioligands for the mapping of 5-HT receptors is interesting both for clinical and experimental research. The aim of this study was to ... [more ▼]

Background and purpose: The identification of potent and selective radioligands for the mapping of 5-HT receptors is interesting both for clinical and experimental research. The aim of this study was to compare the potency of a new putative 5-HT1A receptor antagonist, p-DMPPF, (4-(2-hydroxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-fluorobenzamido]-ethyl] piperazine) with that of the well-known 5-HT1A antagonists, WAY-100635(N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]-ethyl]-N-(2-pyridinyl) cyclohexanecarboxamide) and its fluorobenzoyl analogue, p-MPPF (4-(2-methoxyphenyl)-1-[2'-[N-(2''-pyridinyl)p-fluorobenzamido] ethyl] piperazine). Experimental approach: Single cell extracellular recordings of dorsal raphe (DR) neurones were performed in rat brain slices. The potency of each compound at antagonizing the effect of the 5-HT1A agonist, 8-OH-DPAT [8-hydroxy-2-(di-npropylamino)tetraline], was quantified using the Schild equation. The pharmacological profile of p-DMPPF was defined using competition binding assays. Key results: Consistently with a 5-HT1A receptor antagonist profile, incubation of slices with an equimolar (10 nM) concentration of each compound markedly reduced the inhibitory effect of 8-OH-DPAT on the firing rate of DR neurones, causing a significant rightward shift in its concentration-response curve. The rank order of potency of the antagonists was WAY-100635 > p-DMPPF >= p-MPPF. The sensitivity of DR neurones to the inhibitory effect of 8-OH-DPAT was found to be heterogeneous. The binding experiments demonstrated that p-DMPPF is highly selective for 5-HT1A receptors, with a K-i value of 7 nM on these receptors. Conclusions and implications: The potency of the new compound, p-DMPPF, as a 5-HT1A antagonist is similar to that of p-MPPF in our electrophysiological assay. Its selectivity towards 5-HT1A receptors makes it a good candidate for clinical development. [less ▲]

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