2022
Radiochemical Synthesis and Evaluation of 3‑[11C]Methyl-4-aminopyridine in Rodents and Nonhuman Primates for Imaging Potassium Channels in the CNS
Sun Y, Guehl N, Zhou Y, Takahashi K, Belov V, Dhaynaut M, Moon S, Fakhri G, Normandin M, Brugarolas P. Radiochemical Synthesis and Evaluation of 3‑[11C]Methyl-4-aminopyridine in Rodents and Nonhuman Primates for Imaging Potassium Channels in the CNS. ACS Chemical Neuroscience 2022, 13: 3342-3351. PMID: 36417797, PMCID: PMC9732819, DOI: 10.1021/acschemneuro.2c00364.Peer-Reviewed Original ResearchConceptsRegional brain time-activity curvesBrain time-activity curvesOne-tissue compartment modelBlood-brain barrierConsistent with <i>inNonhuman primatesTime-activity curvesPositron emission tomographySpinal cord injuryDemyelinated neuronsNeurological symptomsPotassium channelsNeuronal conductionBrain uptakeEmission tomographyStille cross-couplingMultiple sclerosisCord injurySlow kineticsBrain permeabilityTraumatic brainMyelin sheathStronger binding affinityNeuronsBrainDesign, Synthesis, and Characterization of [18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2
Yuan G, Dhaynaut M, Guehl N, Afshar S, Huynh D, Moon S, Iyengar S, Jain M, Pickett J, Kang H, Ondrechen M, Fakhri G, Normandin M, Brownell A. Design, Synthesis, and Characterization of [18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Journal Of Medicinal Chemistry 2022, 65: 9939-9954. PMID: 35802702, PMCID: PMC9434700, DOI: 10.1021/acs.jmedchem.2c00593.Peer-Reviewed Original ResearchConceptsPositive allosteric modulatorsMetabotropic glutamate receptor 2Glutamate receptor 2Cu-mediated radiofluorinationPET imaging ligandsReceptor 2High molar activityExcellent radiochemical purityGloSensor assayPositron emission tomography radiotracersClasses of positive allosteric modulatorsNon-human primatesJNJ-46356479Radiochemical yieldBrain heterogeneityAllosteric modulatorsBrain uptakeMGluR2Molar activityLigandBrainBrain permeabilityImaging ligandsBinding kineticsMetabotropic
2021
Synthesis and Characterization of [18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2
Yuan G, Guehl N, Zheng B, Qu X, Moon S, Dhaynaut M, Shoup T, Afshar S, Kang H, Zhang Z, El Fakhri G, Normandin M, Brownell A. Synthesis and Characterization of [18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Molecular Imaging And Biology 2021, 23: 527-536. PMID: 33559035, PMCID: PMC8277681, DOI: 10.1007/s11307-021-01586-0.Peer-Reviewed Original ResearchConceptsNon-human primatesIn vivo PET imaging studiesNucleus accumbensGlutamate receptor 2PET imaging ligandsImaging ligandsParietal cortexBrain regionsPET imaging studiesPET radioligandIn vivo PET imaging experimentsVolume of distributionMGluR2C57BL/6 J micePET imaging experimentsPET studiesBrainSprague-Dawley ratsAlzheimer's diseaseBrain permeabilityPre-treatment studyImaging studiesDisordersRat studiesReversible kinetics
2020
Synthesis and Characterization of Fluorine-18-Labeled N‑(4-Chloro-3-((fluoromethyl‑d 2)thio)phenyl)picolinamide for Imaging of mGluR4 in Brain
Wang J, Qu X, Shoup T, Yuan G, Afshar S, Pan C, Zhu A, Choi J, Kang H, Poutiainen P, Fakhri G, Zhang Z, Brownell A. Synthesis and Characterization of Fluorine-18-Labeled N‑(4-Chloro-3-((fluoromethyl‑d 2)thio)phenyl)picolinamide for Imaging of mGluR4 in Brain. Journal Of Medicinal Chemistry 2020, 63: 3381-3389. PMID: 32081008, PMCID: PMC7261135, DOI: 10.1021/acs.jmedchem.0c00201.Peer-Reviewed Original ResearchConceptsDrug-like propertiesMethylthio analoguePotential ligandsMetabolic stabilityPositron emission tomographyRadiochemical yieldMolar activityDose-dependent blocking effectPositron emission tomography imaging studiesMethylthioPAM activityBrain regionsMale Sprague Dawley ratsLigandEx vivo biodistribution studiesRadiosynthesisSprague Dawley ratsBrainMGluR4SynthesisAnaloguesEmission tomographyImaging studies
2017
Tau and amyloid β proteins distinctively associate to functional network changes in the aging brain
Sepulcre J, Sabuncu M, Li Q, Fakhri G, Sperling R, Johnson K. Tau and amyloid β proteins distinctively associate to functional network changes in the aging brain. Alzheimer's & Dementia 2017, 13: 1261-1269. PMID: 28366797, PMCID: PMC5623176, DOI: 10.1016/j.jalz.2017.02.011.Peer-Reviewed Original ResearchConceptsAging brainFunctional connectivityAlzheimer's disease-related pathologyCognitively normal individualsPositron emission tomography scanHyperconnected regionsFunctional network changesMisfolded tauDisease-related pathologyBrain areasEmission tomography scanAmyloid-bFunctional reorganizationB proteinHuman brainNeuronal circuitsTauBrainNeuronal functionNegative associationAmyloidCortical patternsNetwork changesElderly subjectsPositive association
2016
Discovery of a Highly Selective Glycogen Synthase Kinase‐3 Inhibitor (PF‐04802367) That Modulates Tau Phosphorylation in the Brain: Translation for PET Neuroimaging
Liang S, Chen J, Normandin M, Chang J, Chang G, Taylor C, Trapa P, Plummer M, Para K, Conn E, Lopresti‐Morrow L, Lanyon L, Cook J, Richter K, Nolan C, Schachter J, Janat F, Che Y, Shanmugasundaram V, Lefker B, Enerson B, Livni E, Wang L, Guehl N, Patnaik D, Wagner F, Perlis R, Holson E, Haggarty S, Fakhri G, Kurumbail R, Vasdev N. Discovery of a Highly Selective Glycogen Synthase Kinase‐3 Inhibitor (PF‐04802367) That Modulates Tau Phosphorylation in the Brain: Translation for PET Neuroimaging. Angewandte Chemie International Edition 2016, 55: 9601-9605. PMID: 27355874, PMCID: PMC4983481, DOI: 10.1002/anie.201603797.Peer-Reviewed Original ResearchConceptsGlycogen synthase kinase-3Tau phosphorylationPET neuroimagingPET imaging studiesModulation of tau phosphorylationNon-human primatesRegulate multiple cellular processesModulates tau phosphorylationMultiple cellular processesBrainBrain permeabilityImaging studiesCellular processesDisplaceable bindingKinase-3Discovery of a Highly Selective Glycogen Synthase Kinase‐3 Inhibitor (PF‐04802367) That Modulates Tau Phosphorylation in the Brain: Translation for PET Neuroimaging
Liang S, Chen J, Normandin M, Chang J, Chang G, Taylor C, Trapa P, Plummer M, Para K, Conn E, Lopresti‐Morrow L, Lanyon L, Cook J, Richter K, Nolan C, Schachter J, Janat F, Che Y, Shanmugasundaram V, Lefker B, Enerson B, Livni E, Wang L, Guehl N, Patnaik D, Wagner F, Perlis R, Holson E, Haggarty S, Fakhri G, Kurumbail R, Vasdev N. Discovery of a Highly Selective Glycogen Synthase Kinase‐3 Inhibitor (PF‐04802367) That Modulates Tau Phosphorylation in the Brain: Translation for PET Neuroimaging. Angewandte Chemie 2016, 128: 9753-9757. DOI: 10.1002/ange.201603797.Peer-Reviewed Original Research
2014
Evaluating Structural Symmetry of Weighted Brain Networks via Graph Matching
Hu C, El Fakhri G, Li Q. Evaluating Structural Symmetry of Weighted Brain Networks via Graph Matching. Lecture Notes In Computer Science 2014, 17: 733-740. PMID: 25485445, DOI: 10.1007/978-3-319-10470-6_91.Peer-Reviewed Original ResearchConceptsAttention deficit hyperactivity disorderNetwork symmetryBrain networksType of Attention Deficit Hyperactivity DisorderWeighted brain networksConsistent with former findingsDeficit hyperactivity disorderRs-fMRI networksResting state fMRISymmetry levelInattentive typeHyperactivity disorderBrain areasSymmetryStructural symmetryBrain connectivityFunctional networksResting stateLarger thresholdsBrainFMRIHigher levelsGraph matchingNode pairsNormal subjects
2007
Comparison of Brain PET and Sequential and Simultaneous Dual-isotope SPECT for Estimation Tasks in Normal and Parkinson Subjects
Trott C, Fakhri G. Comparison of Brain PET and Sequential and Simultaneous Dual-isotope SPECT for Estimation Tasks in Normal and Parkinson Subjects. 2007, 5: 3616-3620. DOI: 10.1109/nssmic.2007.4436906.Peer-Reviewed Original ResearchDopamine transporterEarly stages of PDDual-isotope SPECTStages of PDSequential SPECTDisease stageSimultaneous dual-isotope studyStriatal sizeBrain functionImprove patient managementEstimation taskDual-isotope studiesBrain PETDopamineClinical symptomsParkinson's diseasePatient managementSPECT imagesSpecific bindingMotor functionSPECTBrainEarly detectionActivity concentrationsIdentical physiological conditions