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  • 1.
    Bergman, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Brandt, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Nordeman, Patrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Larhed, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Synthesis of 11C-Labelled Ureas by Palladium(II)-Mediated Oxidative Carbonylation2017In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 22, no 10, article id 1688Article in journal (Refereed)
    Abstract [en]

    Positron emission tomography is an imaging technique with applications in clinical settings as well as in basic research for the study of biological processes. A PET tracer, a biologically active molecule where a positron-emitting radioisotope such as carbon-11 has been incorporated, is used for the studies. Development of robust methods for incorporation of the radioisotope is therefore of the utmost importance. The urea functional group is present in many biologically active compounds and is thus an attractive target for incorporation of carbon-11 in the form of [C-11] carbon monoxide. Starting with amines and [C-11] carbon monoxide, both symmetrical and unsymmetrical C-11-labelled ureas were synthesised via a palladium(II)-mediated oxidative carbonylation and obtained in decay-corrected radiochemical yields up to 65%. The added advantage of using [C-11] carbon monoxide was shown by the molar activity obtained for an inhibitor of soluble epoxide hydrolase (247 GBq/mu mol-319 GBq/mu mol). DFT calculations were found to support a reaction mechanism proceeding through an C-11-labelled isocyanate intermediate.

  • 2. Bogdanović, Renée Marie
    et al.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Michler, Christina
    Russmann, Vera
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Windhorst, Albert D
    Lammertsma, Adriaan A
    de Lange, Elisabeth C
    Voskuyl, Rob A
    Potschka, Heidrun
    (R)-[(11)C]PK11195 brain uptake as a biomarker of inflammation and antiepileptic drug resistance: Evaluation in a rat epilepsy model2014In: Neuropharmacology, ISSN 0028-3908, E-ISSN 1873-7064, Vol. 85, p. 104-112Article in journal (Refereed)
    Abstract [en]

    Neuroinflammation has been suggested as a key determinant of the intrinsic severity of epilepsy. Glial cell activation and associated inflammatory signaling can influence seizure thresholds as well as the pharmacodynamics and pharmacokinetics of antiepileptic drugs. Based on these data, we hypothesized that molecular imaging of microglia activation might serve as a tool to predict drug refractoriness of epilepsy. Brain uptake of (R)-[(11)C]PK11195, a ligand of the translocator protein 18 kDa and molecular marker of microglia activation, was studied in a chronic model of temporal lobe epilepsy in rats with selection of phenobarbital responders and non-responders. In rats with drug-sensitive epilepsy, (R)-[(11)C]PK11195 brain uptake values were comparable to those in non-epileptic controls. Analysis in non-responders revealed enhanced brain uptake of up to 39% in different brain regions. The difference might be related to the fact that non-responders exhibited higher baseline seizure frequencies than responders indicating a more pronounced intrinsic disease severity. In hippocampal sections, ED1 immunostaining argued against a general difference in microglia activation between both groups. Our data suggest that TSPO PET imaging might serve as a biomarker for drug resistance in temporal lobe epilepsy. However, it needs to be considered that our findings indicate that the TSPO PET data might merely reflect seizure frequency. Future experimental and clinical studies should further evaluate the validity of TSPO PET data to predict the response to phenobarbital and other antiepileptic drugs in longitudinal studies with scanning before drug exposure and with a focus on the early phase following an epileptogenic brain insult.

  • 3. Chiotis, Konstantinos
    et al.
    Saint-Aubert, Laure
    Savitcheva, Irina
    Jelic, Vesna
    Andersen, Pia
    Jonasson, My
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Almkvist, Ove
    Wall, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Nordberg, Agneta
    Imaging in-vivo tau pathology in Alzheimer's disease with THK5317 PET in a multimodal paradigm2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, no 9, p. 1686-1699Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The aim of this study was to explore the cerebral distribution of the tau-specific PET tracer [(18)F]THK5317 (also known as (S)-[(18)F]THK5117) retention in different stages of Alzheimer's disease; and study any associations with markers of hypometabolism and amyloid-beta deposition.

    METHODS: Thirty-three individuals were enrolled, including nine patients with Alzheimer's disease dementia, thirteen with mild cognitive impairment (MCI), two with non-Alzheimer's disease dementia, and nine healthy controls (five young and four elderly). In a multi-tracer PET design [(18)F]THK5317, [(11)C] Pittsburgh compound B ([(11)C]PIB), and [(18)F]FDG were used to assess tau pathology, amyloid-beta deposition and cerebral glucose metabolism, respectively. The MCI patients were further divided into MCI [(11)C]PIB-positive (n = 11) and MCI [(11)C]PIB-negative (n = 2) groups.

    RESULTS: Test-retest variability for [(18)F]THK5317-PET was very low (1.17-3.81 %), as shown by retesting five patients. The patients with prodromal (MCI [(11)C]PIB-positive) and dementia-stage Alzheimer's disease had significantly higher [(18)F]THK5317 retention than healthy controls (p = 0.002 and p = 0.001, respectively) in areas exceeding limbic regions, and their discrimination from this control group (using the area under the curve) was >98 %. Focal negative correlations between [(18)F]THK5317 retention and [(18)F]FDG uptake were observed mainly in the frontal cortex, and focal positive correlations were found between [(18)F]THK5317 and [(11)C]PIB retentions isocortically. One patient with corticobasal degeneration syndrome and one with progressive supranuclear palsy showed no [(11)C]PIB but high [(18)F]THK5317 retentions with a different regional distribution from that in Alzheimer's disease patients.

    CONCLUSIONS: The tau-specific PET tracer [(18)F]THK5317 images in vivo the expected regional distribution of tau pathology. This distribution contrasts with the different patterns of hypometabolism and amyloid-beta deposition.

  • 4.
    Chow, Shiao Y.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Low-Pressure Radical C-11-Aminocarbonylation of Alkyl Iodides through Thermal Initiation2016In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 36, p. 5980-5989Article in journal (Refereed)
    Abstract [en]

    A radical C-11-aminocarbonylation protocol characterized by excellent substrate compatibility was developed to transform alkyl iodides into C-11-labelled amides, including the 11-HSD1 inhibitor [carbonyl-C-11]adamantan-1-yl(piperidin-1-yl)methanone. This protocol serves as a complementary extension of palladium-mediated C-11-aminocarbonylation, which is limited to the preparation of C-11-labelled compounds lacking beta-hydrogen atoms. The use of AIBN as a radical initiator and a low-pressure xenon-[C-11]CO delivery unit represents a simple and convenient alternative to previous radical C-11-carbonylation methodologies burdened with the need for a proprietary high pressure reactor connected to a light source.

  • 5.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Synthesis of 11C-labelled Alkyl Iodides: Using Non-thermal Plasma and Palladium-mediated Carbonylation Methods2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Compounds labelled with 11C (β+, t1/2 = 20.4 min) are used in positron emission tomography (PET), which is a quantitative non-invasive molecular imaging technique. It utilizes computerized reconstruction methods to produce time-resolved images of the radioactivity distribution in living subjects.

    The feasibility of preparing [11C]methyl iodide from [11C]methane and iodine via a single pass through a non-thermal plasma reactor was explored. [11C]Methyl iodide with a specific radioactivity of 412 ± 32 GBq/µmol was obtained in 13 ± 3% decay-corrected radiochemical yield within 6 min via catalytic hydrogenation of [11C]carbon dioxide (24 GBq) and subsequent iodination, induced by electron impact.

    Labelled ethyl-, propyl- and butyl iodide was synthesized, within 15 min, via palladium-mediated carbonylation using [11C]carbon monoxide. The carbonylation products, labelled carboxylic acids, esters and aldehydes, were reduced to their corresponding alcohols and converted to alkyl iodides. [1-11C]Ethyl iodide was obtained via palladium-mediated carbonylation of methyl iodide with a decay-corrected radiochemical yield of 55 ± 5%. [1-11C]Propyl iodide and [1-11C]butyl iodide were synthesized via the hydroformylation of ethene and propene with decay-corrected radiochemical yields of 58 ± 4% and 34 ± 2%, respectively. [1-11C]Ethyl iodide was obtained with a specific radioactivity of 84 GBq/mmol from 10 GBq of [11C]carbon monoxide. [1-11C]Propyl iodide was synthesized with a specific radioactivity of 270 GBq/mmol from 12 GBq and [1-11C]butyl iodide with 146 GBq/mmol from 8 GBq.

    Palladium-mediated hydroxycarbonylation of acetylene was used in the synthesis of [1-11C]acrylic acid. The labelled carboxylic acid was converted to its acid chloride and subsequently treated with amine to yield N-[carbonyl-11C]benzylacrylamide. In an alternative method, [carbonyl-11C]acrylamides were synthesized in decay-corrected radiochemical yields up to 81% via palladium-mediated carbonylative cross-coupling of vinyl halides and amines. Starting from 10 ± 0.5 GBq of [11C]carbon monoxide, N-[carbonyl-11C]benzylacrylamide was obtained in 4 min with a specific radioactivity of 330 ± 4 GBq/µmol.

    List of papers
    1. [C-11]methyl iodide from [C-11]methane and iodine using a non-thermal plasma method
    Open this publication in new window or tab >>[C-11]methyl iodide from [C-11]methane and iodine using a non-thermal plasma method
    2006 (English)In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 49, no 13, p. 1177-1186Article in journal (Refereed) Published
    Abstract [en]

    A method and an apparatus for preparing [C-11]methyl iodide from [C-11]methane and iodine in a single pass through a non-thermal plasma reactor has been developed. The plasma was created by applying high voltage (400 V/31 kHz) to electrodes in a stream of helium gas at reduced pressure. The [C-11]methane used in the experiments was produced from [C-11]carbon dioxide via reduction with hydrogen over nickel. [C-11]methyl iodide was obtained with a specific radioactivity of 412 +/- 32 GBq/mu mol within 6 min from approximately 24 GBq of [C-11]carbon dioxide. The decay corrected radiochemical yield was 13 +/- 3% based on [C-11]carbon dioxide at start of synthesis. [C-11]Flumazenil was synthesized via a N-alkylation with the prepared [C-11]methyl iodide.

    Keywords
    [C-11]methyl iodide, [C-11]methane, non-thermal plasma, specific radioactivity
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-94929 (URN)10.1002/jlcr.1135 (DOI)000242796700006 ()
    Available from: 2006-10-05 Created: 2006-10-05 Last updated: 2017-12-14Bibliographically approved
    2. Synthesis of [1-11C]ethyl iodide from carbon monoxide and its application in alkylation reactions
    Open this publication in new window or tab >>Synthesis of [1-11C]ethyl iodide from carbon monoxide and its application in alkylation reactions
    2004 (English)In: Journal of Labelled Compounds and Radiopharmaceuticals, ISSN 0362-4803, Vol. 47, no 11, p. 723-731Article in journal (Refereed) Published
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-94930 (URN)
    Available from: 2006-10-05 Created: 2006-10-05 Last updated: 2015-09-24
    3. Synthesis of [1-C-11]propyl and [1-C-11]butyl iodide from [C-11]carbon monoxide and their use in alkylation reactions
    Open this publication in new window or tab >>Synthesis of [1-C-11]propyl and [1-C-11]butyl iodide from [C-11]carbon monoxide and their use in alkylation reactions
    2006 (English)In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 49, no 12, p. 1105-1116Article in journal (Refereed) Published
    Abstract [en]

    A method to prepare [1-C-11]propyl iodide and [1-C-11]butyl iodide from [C-11]carbon monoxide via a three step reaction sequence is presented. Palladium mediated formylation of ethene with [C-11]carbon monoxide and hydrogen gave [1-C-11]propionaldehyde and [1-C-11]propionic acid. The carbonylation products were reduced and subsequently converted to [1-C-11]propyl iodide. Labelled propyl iodide was obtained in 58 +/- 4% decay corrected radiochemical yield and with a specific radioactivity of 270 +/- 33 GBq/mu mol within 15 min from approximately 12 GBq of [C-11]carbon monoxide. The position of the label was confirmed by C-13-labelling and C-13-NMR analysis. [1-C-11]Butyl iodide was obtained correspondingly from propene and approximately 8 GBq of [C-11]carbon monoxide, in 34 +/- 2% decay corrected radiochemical yield and with a specific radioactivity of 146 +/- 20 GBq/mu mol. The alkyl iodides were used in model reactions to synthesize [O-propyl-1-C-11]propyl and [O-butyl-1-C-11]butyl benzoate. Propyl and butyl analogues of etomidate, a (beta-11-hydroxylase inhibitor, were also synthesized.

    Keywords
    [C-11]carbon monoxide, [1-C-11]propyl iodide, [1-C-11]butyl iodide, carbonylation, formylation, alkylation
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-94931 (URN)10.1002/jlcr.1119 (DOI)000242335900009 ()
    Available from: 2006-10-05 Created: 2006-10-05 Last updated: 2017-12-14Bibliographically approved
    4. Synthesis of [11C]/[13C]acrylamides by palladium-mediated carbonylation
    Open this publication in new window or tab >>Synthesis of [11C]/[13C]acrylamides by palladium-mediated carbonylation
    2007 (English)In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 3, p. 455-461Article in journal (Refereed) Published
    Abstract [en]

    Two methods are presented for the synthesis of acrylamides labelled with C-11 (beta(+), t(1/2) = 20.4 min) and C-11 in the carbonyl position. In the first method, [1-C-11]acrylic acid is synthesised from [C-11]carbon monoxide by palladium-mediated hydroxy-carbonylation of acetylene. The labelled carboxylic acid is converted into the acyl chloride and subsequently treated with amine to yield N-benzyl[carbonyl(11)C]acrylamide, The second method utilizes [C-11]carbon monoxide in a palladium-mediated carbonylative cross-coupling of vinyl halides and amines. A higher radiochemical yield is achieved with the latter method and the amount of amine needed is decreased to 1/20. The C-11-labelled acrylamides were isolated in up to 81 % decay-corrected radiochemical yield. Starting from 10 +/- 0.5GBq of [C-11]carbon monoxide, N-benzyl[carbonyl-C-11]acrylamide was obtained in 4 min with a specific radioactivity of 330 +/- 4 GBq mu mol-(1). Co-labelling with C-11 and C-13 enabled confirmation of the labelled position by C-13 NMR spectroscopy.

    Keywords
    Carbonylation, Amides, Carbon monoxide, Isotopic labelling, Carbon-11, 11C, PET
    National Category
    Chemical Sciences
    Research subject
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-98592 (URN)10.1002/ejoc.200600700 (DOI)000243600100007 ()
    Available from: 2009-02-27 Created: 2009-02-27 Last updated: 2017-12-13Bibliographically approved
    5. [1-11C]Ethyl iodide and [1-11C]propyl iodide in the synthesis of two potential NK1-receptor ligands and initial PET-imaging
    Open this publication in new window or tab >>[1-11C]Ethyl iodide and [1-11C]propyl iodide in the synthesis of two potential NK1-receptor ligands and initial PET-imaging
    Show others...
    (English)Manuscript (Other academic)
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-94933 (URN)
    Available from: 2006-10-05 Created: 2006-10-05 Last updated: 2018-01-13
  • 6.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Single valve module for production and efficient transfer of [C-11]carbon monoxide to a disposable reaction vial2015In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 58, p. S303-S303Article in journal (Other academic)
  • 7.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Antoni, Gunnar
    Långström, Bengt
    Synthesis of [1-11C]ethyl iodide from carbon monoxide and its application in alkylation reactions2004In: Journal of Labelled Compounds and Radiopharmaceuticals, ISSN 0362-4803, Vol. 47, no 11, p. 723-731Article in journal (Refereed)
  • 8.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Antoni, Gunnar
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Synthesis of [1-C-11]propyl and [1-C-11]butyl iodide from [C-11]carbon monoxide and their use in alkylation reactions2006In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 49, no 12, p. 1105-1116Article in journal (Refereed)
    Abstract [en]

    A method to prepare [1-C-11]propyl iodide and [1-C-11]butyl iodide from [C-11]carbon monoxide via a three step reaction sequence is presented. Palladium mediated formylation of ethene with [C-11]carbon monoxide and hydrogen gave [1-C-11]propionaldehyde and [1-C-11]propionic acid. The carbonylation products were reduced and subsequently converted to [1-C-11]propyl iodide. Labelled propyl iodide was obtained in 58 +/- 4% decay corrected radiochemical yield and with a specific radioactivity of 270 +/- 33 GBq/mu mol within 15 min from approximately 12 GBq of [C-11]carbon monoxide. The position of the label was confirmed by C-13-labelling and C-13-NMR analysis. [1-C-11]Butyl iodide was obtained correspondingly from propene and approximately 8 GBq of [C-11]carbon monoxide, in 34 +/- 2% decay corrected radiochemical yield and with a specific radioactivity of 146 +/- 20 GBq/mu mol. The alkyl iodides were used in model reactions to synthesize [O-propyl-1-C-11]propyl and [O-butyl-1-C-11]butyl benzoate. Propyl and butyl analogues of etomidate, a (beta-11-hydroxylase inhibitor, were also synthesized.

  • 9.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Thibblin, Alf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Verbeek, Joost
    Vrije Univ Amsterdam, Med Ctr, Amsterdam, Netherlands..
    Windhorst, Albert D.
    Vrije Univ Amsterdam, Med Ctr, Amsterdam, Netherlands..
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    GMP compliant synthesis of [C-11]phenytoin by rhodium mediated [C-11]carbon monoxide carbonylation performed in disposable glass vials2015In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 58, p. S338-S338Article in journal (Other academic)
  • 10.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Ulin, Johan
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    [C-11]methyl iodide from [C-11]methane and iodine using a non-thermal plasma method2006In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 49, no 13, p. 1177-1186Article in journal (Refereed)
    Abstract [en]

    A method and an apparatus for preparing [C-11]methyl iodide from [C-11]methane and iodine in a single pass through a non-thermal plasma reactor has been developed. The plasma was created by applying high voltage (400 V/31 kHz) to electrodes in a stream of helium gas at reduced pressure. The [C-11]methane used in the experiments was produced from [C-11]carbon dioxide via reduction with hydrogen over nickel. [C-11]methyl iodide was obtained with a specific radioactivity of 412 +/- 32 GBq/mu mol within 6 min from approximately 24 GBq of [C-11]carbon dioxide. The decay corrected radiochemical yield was 13 +/- 3% based on [C-11]carbon dioxide at start of synthesis. [C-11]Flumazenil was synthesized via a N-alkylation with the prepared [C-11]methyl iodide.

  • 11.
    Eriksson, Jonas
    et al.
    VU University Medical Center Amsterdam.
    van den Hoek, Johan
    Windhorst, Albert D.
    Transition metal mediated synthesis using [11C]CO at low pressure - a simplified method for 11C-carbonylation2012In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 55, p. 223-228Article in journal (Refereed)
    Abstract [en]

    Transition metal mediated carbonylation with [11C]CO has proven a useful method to label a wide array of compounds in the carbonyl position. However, the general use in radiopharmaceutical synthesis has been hampered by the low solubility of carbon monoxide in most solvents and the resulting challenge to confine [11C]CO in low volume reaction vessels. This paper introduces a method that utilises xenon to transfer pre-concentrated [11C]CO to a sealed disposable glass vial containing carbonylation reagents. The high solubility of xenon in the organic solvent made it possible to confine the [11C]CO without utilising a pressure autoclave or chemical trapping additives. The utility of the method in 11C-carbonylation was investigated by conducting three model reactions, where [11C-carbonyl]N-benzylbenzamide, [11C-carbonyl]triclocarban and [11C-carbonyl]methyl nicotinate were afforded in decay corrected radiochemical yields of 71?+/-?6%, 42?+/-?15% and 29?+/-?10%, respectively. These promising results and the straight forward technical implementation suggest that 11C-cabonylation can become a viable mean to provide labelled carbonyl functionalities in routine radiopharmaceutical synthesis. Compounds labelled with short lived positron emitters are used in Positron Emission Tomography, a molecular imaging technology with applications in clinical diagnostics, clinical research and basic biomedical research.

  • 12.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Van Kooij, Rolph
    Schuit, Robert C.
    Froklage, Femke E.
    Reijneveld, Jaap C.
    Hendrikse, N. Harry
    Windhorst, Albert D.
    Synthesis of [3-N-11C-methyl]temozolomide via in situ activation of 3-N-hydroxymethyl temozolomide and alkylation with [11C]methyl iodide2015In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 58, no 3, p. 122-126Article in journal (Refereed)
    Abstract [en]

    Temozolomide is a chemotherapeutic drug that is mainly used in the treatment of primary glioblastoma multiforme and recurrent high-grade glioma. Here, we report an efficient good manufacturing practice compliant method for the synthesis of [3-N-11C-methyl]temozolomide from 3-N-hydroxymethyl temozolomide that cleaves off formaldehyde in situ and becomes activated towards alkylation with [11C]methyl iodide. The labelling method was developed for an on-going patient study in which the predictive value of [3-N-11C-methyl]temozolomide and positron emission tomography on the outcome of temozolomide treatment is being investigated. The precursor was reacted with [11C]methyl iodide in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in acetonitrile, heated at stepwise increasing temperature. Purification by semipreparative HPLC with pharmaceutical grade eluent and filtration gave approximately 10 mL sterile product solution ready for injection containing 1.55 ± 0.38 GBq (n = 5), the specific activity was 88 ± 25 GBq/μmol and the radiochemical purity was 98.5 ± 1.9%.13C-NMR spectroscopy confirmed the labelled position after colabelling with 11C and 13C.

  • 13.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Åberg, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Automation of the 'xenon method' and comparative study on C-11-carbonylation at ambient pressure versus high solvent pressure2013In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 56, no S1, p. S96-S96Article in journal (Other academic)
  • 14.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Åberg, Ola
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Synthesis of [11C]/[13C]acrylamides by palladium-mediated carbonylation2007In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 3, p. 455-461Article in journal (Refereed)
    Abstract [en]

    Two methods are presented for the synthesis of acrylamides labelled with C-11 (beta(+), t(1/2) = 20.4 min) and C-11 in the carbonyl position. In the first method, [1-C-11]acrylic acid is synthesised from [C-11]carbon monoxide by palladium-mediated hydroxy-carbonylation of acetylene. The labelled carboxylic acid is converted into the acyl chloride and subsequently treated with amine to yield N-benzyl[carbonyl(11)C]acrylamide, The second method utilizes [C-11]carbon monoxide in a palladium-mediated carbonylative cross-coupling of vinyl halides and amines. A higher radiochemical yield is achieved with the latter method and the amount of amine needed is decreased to 1/20. The C-11-labelled acrylamides were isolated in up to 81 % decay-corrected radiochemical yield. Starting from 10 +/- 0.5GBq of [C-11]carbon monoxide, N-benzyl[carbonyl-C-11]acrylamide was obtained in 4 min with a specific radioactivity of 330 +/- 4 GBq mu mol-(1). Co-labelling with C-11 and C-13 enabled confirmation of the labelled position by C-13 NMR spectroscopy.

  • 15.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Åberg, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Selvaraju, Ram K
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Eriksson, Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Strategy to develop a MAO-A-resistant 5-hydroxy-L-[beta-C-11]tryptophan isotopologue based on deuterium kinetic isotope effects2014In: EJNMMI Research, ISSN 2191-219X, E-ISSN 2191-219X, Vol. 4, no 1, article id 62Article in journal (Refereed)
    Abstract [en]

    Background

    The serotonin precursor 5-hydroxy-L-[β-11C]tryptophan ([11C]HTP) is in clinical use for localization of neuroendocrine tumors and has been suggested as a proxy marker for pancreatic islet cells. However, degradation by monoamine oxidase-A (MAO-A) reduces retention and the contrast to non-endocrine tissue.

    Methods

    A synthesis method was developed for 5-hydroxy-L-[β-11C2H]tryptophan ([11C]DHTP), an isotopologue of [11C]HTP, labeled with 11C and 2H at the β-position adjacent to the carbon involved in MAO-A decarboxylation. MAO-A-mediated degradation of [11C]DHTP was evaluated and compared to non-deuterated [11C]HTP.

    Results

    [11C]DHTP was synthesized with a radiochemical purity of >98%, radioactivity of 620 ± 190 MBq, and deuterium (2H or 2H2) incorporation at the β-position of 22% ±5%. Retention and resistance to MAO-A-mediated degradation of [11C]DHTP were increased in cells but not in non-human primate pancreas.

    Conclusions

    Partial deuteration of the β-position yields improved resistance to MAO-A-mediated degradation in vitro but not in vivo.

  • 16.
    Fang, Xiaotian T.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. PET Centre, Uppsala University Hospital, 751 85 Uppsala, Sweden.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. Uppsala University Hospital, 751 85 Uppsala, SwedenUppsala University Hospital, 751 85 Uppsala, Sweden.
    Yngve, Ulrika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. Uppsala University Hospital, 751 85 Uppsala, SwedenUppsala University Hospital, 751 85 Uppsala, Sweden.
    Cato, Linda
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Brain mGluR5 in mice with amyloid beta pathology studied with in vivo [(11)C]ABP688 PET imaging and ex vivo immunoblotting2017In: Neuropharmacology, ISSN 0028-3908, E-ISSN 1873-7064, Vol. 113, no Pt A, p. 293-300, article id S0028-3908(16)30459-2Article in journal (Refereed)
    Abstract [en]

    Alzheimer's disease (AD) is characterized by aggregation of amyloid beta (Aβ) into insoluble plaques. Intermediates, Aβ oligomers (Aβo), appear to be the mechanistic cause of disease. The de facto PET AD ligand, [(11)C]PIB, binds and visualizes Aβ plaque load, which does not correlate well with disease severity. Therefore, finding a dynamic target that changes with pathology progression in AD is of great interest. Aβo alter synaptic plasticity, inhibit long-term potentiation, and facilitate long-term depression; key mechanisms involved in memory and learning. In order to convey these neurotoxic effects, Aβo requires interaction with the metabotropic glutamate 5 receptor (mGluR5). The aim was to investigate in vivo mGluR5 changes in an Aβ pathology model using PET. Wild type C57/BL6 (wt) and AβPP transgenic mice (tg-ArcSwe), 4, 8, and 16 months old, were PET scanned with [(11)C]ABP688, which is highly specific to mGluR5, to investigate changes in mGluR5. Mouse brains were extracted postscan and mGluR5 and Aβ protofibril levels were assessed with immunoblotting and ELISA respectively. Receptor-dense brain regions (hippocampus, thalamus, and striatum) displayed higher [(11)C]ABP688 concentrations corresponding to mGluR5 expression pattern. Mice had similar uptake levels of [(11)C]ABP688 regardless of genotype or age. Immunoblotting revealed general decline in mGluR5 expression and elevated levels of mGluR5 in 16 months old tg-ArcSwe compared with wt mice. [(11)C]ABP688 could visualize mGluR5 in the mouse brain. In conclusion, mGluR5 levels were found to decrease with age and tended to be higher in tg-ArcSwe compared with wt mice, however these changes could not be quantified with PET.

  • 17. Fang, Yao-ren
    et al.
    Gao, Ying
    Ryberg, Per
    Eriksson, Jonas
    Department of Organic Chemistry, Institute of Chemistry.
    Kolodziejska-Huben, Magdalena
    Dybala-Defratyka, Agnieszka
    Madhavan, S
    Danielsson, Rolf
    Paneth, Piotr
    Matsson, Olle
    Westaway, Kenneht Charles
    Experimental and Theoretical Multiple Kinetic Isotope Effects for an SN2 Reaction. An Attempt to Determine Transition-State Structure and the Ability of Theoretical Methods to Predict Experimental Kinetic Isotope Effects2003In: Chemistry European Journal, no 9, p. 2696-2709Article in journal (Refereed)
  • 18. Fang, Yao-ren
    et al.
    MacMillar, Susanna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Kolodziejska-Huben, Magdalena
    Dybala-Defratyka, Agnieszka
    Paneth, Piotr
    Matsson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Westaway, Kenneth Charles
    The Effect of Solvent on the Structure of the Transition State for the SN2 Reaction between Cyanide Ion and Ethyl Chloride in DMSO and THF Probed with Six Different Kinetic Isotope Effects2006In: J. Org. Chem, no 71, p. 4742-4747Article in journal (Refereed)
    Abstract [en]

    The secondary a- and B-deuterium, the a-carbon, the nucleophile carbon, the nucleophile nitrogen, and the chlorine leaving group kinetic isotope effects forthe SN2 reaction between cyanide ion an dethyl chloride were determined in the very slightly polar solvent THF at 30 C. A comparison of these KIEs with those reported earlier for the same reaction in the polar solvent DMSO shows that the transition state in THF is only sligthly tighter with very slightly shorter NC-Ca-CI bonds. This minor change in transition state structure does not account for the different transition structures that were earlier suggested by interpreting the experimental KIEs and the gas-phase calculations, respectively. It therefore seems unlikely that the different transition states suggested by the two methods are due to the lack of appropriate solvent modeling in the theoretical calculations. Previously it was predicted that the transition state of SN2 reactions where the nucleophile and the leaving group have the same charge would be unaffected by a charge in solvent. The experimental KIEs support this view.

  • 19. Froklage, Femke E
    et al.
    Syvänen, Stina
    Leiden University.
    Hendrikse, N Harry
    Huisman, Marc C
    Molthoff, Carla Fm
    Tagawa, Yoshihiko
    Reijneveld, Jaap C
    Heimans, Jan J
    Lammertsma, Adriaan A
    Eriksson, Jonas
    VU University Medical Center Amsterdam.
    de Lange, Elizabeth Cm
    Voskuyl, Rob A
    [11C]Flumazenil brain uptake is influenced by the blood-brain barrier efflux transporter P-glycoprotein.2012In: EJNMMI research, ISSN 2191-219X, Vol. 2, p. 12-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: [11C]Flumazenil and positron emission tomography (PET) are used clinically to assess gamma-aminobutyric acid (GABA)-ergic function and to localize epileptic foci prior to resective surgery. Enhanced P-glycoprotein (P-gp) activity has been reported in epilepsy and this may confound interpretation of clinical scans if [11C]flumazenil is a P-gp substrate. The purpose of this study was to investigate whether [11C]flumazenil is a P-gp substrate.

    METHODS: [11C]Flumazenil PET scans were performed in wild type (WT) (n = 9) and Mdr1a/1b, (the genes that encode for P-gp) double knockout (dKO) (n = 10) mice, and in naive rats (n = 10). In parallel to PET scanning, [11C]flumazenil plasma concentrations were measured in rats. For 6 of the WT and 6 of the dKO mice a second, [11C]flumazenil scan was acquired after administration of the P-gp inhibitor tariquidar. Cerebral [11C]flumazenil concentrations in WT and Mdr1a/1b dKO mice were compared (genetic disruption model). Furthermore, pre and post P-gp-blocking cerebral [11C]flumazenil concentrations were compared in all animals (pharmacological inhibition model).

    RESULTS: Mdr1a/1b dKO mice had approximately 70% higher [11C]flumazenil uptake in the brain than WT mice. After administration of tariquidar, cerebral [11C]flumazenil uptake in WT mice increased by about 80% in WT mice, while it remained the same in Mdr1a/1b dKO mice. In rats, cerebral [11C]flumazenil uptake increased by about 60% after tariquidar administration. Tariquidar had only a small effect on plasma clearance of flumazenil.

    CONCLUSIONS: The present study showed that [11C]flumazenil is a P-gp substrate in rodents. Consequently, altered cerebral [11C]flumazenil uptake, as observed in epilepsy, may not reflect solely GABAA receptor density changes but also changes in P-gp activity.

  • 20. Golla, Sandeep S V
    et al.
    Boellaard, Ronald
    Oikonen, Vesa
    Hoffmann, Anja
    van Berckel, Bart N M
    Windhorst, Albert D
    Virta, Jere
    Haaparanta-Solin, Merja
    Luoto, Pauliina
    Savisto, Nina
    Solin, Olof
    Valencia, Ray
    Thiele, Andrea
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Schuit, Robert C
    Lammertsma, Adriaan A
    Rinne, Juha O
    Quantification of [18F]DPA-714 binding in the human brain: initial studies in healthy controls and Alzheimer's disease patients2015In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 35, no 5, p. 766-772Article in journal (Refereed)
    Abstract [en]

    Fluorine-18 labelled N,N-diethyl-2-(2-[4-(2-fluoroethoxy)phenyl]-5,7-dimethylpyrazolo[1,5-α]pyrimidine-3-yl)acetamide ([(18)F]DPA-714) binds to the 18-kDa translocator protein (TSPO) with high affinity. The aim of this initial methodological study was to develop a plasma input tracer kinetic model for quantification of [(18)F]DPA-714 binding in healthy subjects and Alzheimer's disease (AD) patients, and to provide a preliminary assessment whether there is a disease-related signal. Ten AD patients and six healthy subjects underwent a dynamic positron emission tomography (PET) study along with arterial sampling and a scan protocol of 150 minutes after administration of 250 ± 10 MBq [(18)F]DPA-714. The model that provided the best fits to tissue time activity curves (TACs) was selected based on Akaike Information Criterion and F-test. The reversible two tissue compartment plasma input model with blood volume parameter was the preferred model for quantification of [(18)F]DPA-714 kinetics, irrespective of scan duration, volume of interest, and underlying volume of distribution (VT). Simplified reference tissue model (SRTM)-derived binding potential (BPND) using cerebellar gray matter as reference tissue correlated well with plasma input-based distribution volume ratio (DVR). These data suggest that [(18)F]DPA-714 cannot be used for separating individual AD patients from healthy subjects, but further studies including TSPO binding status are needed to substantiate these findings.

  • 21. Golla, Sandeep S V
    et al.
    Boellaard, Ronald
    Oikonen, Vesa
    Hoffmann, Anja
    van Berckel, Bart N M
    Windhorst, Albert D
    Virta, Jere
    Te Beek, Erik T
    Groeneveld, Geert Jan
    Haaparanta-Solin, Merja
    Luoto, Pauliina
    Savisto, Nina
    Solin, Olof
    Valencia, Ray
    Thiele, Andrea
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Schuit, Robert C
    Lammertsma, Adriaan A
    Rinne, Juha O
    Parametric Binding Images of the TSPO Ligand 18F-DPA-714.2016In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 57, no 10, p. 1543-1547Article in journal (Refereed)
    Abstract [en]

    (18)F-labeled N,N-diethyl-2-(2-[4-(2-fluoroethoxy)phenyl]-5,7-dimethylpyrazolo[1,5-α]pyrimidine-3-yl)acetamide (DPA-714) is a radioligand for the 18-kDa translocator protein. The purpose of the present study was to identify the best method for generating quantitative parametric images of (18)F-DPA-714 binding.

    METHODS: Ninety-minute dynamic (18)F-DPA-714 PET scans with full arterial sampling from 6 healthy subjects and 9 Alzheimer disease (AD) patients were used. Plasma-input-based Logan graphical analysis and spectral analysis were used to generate parametric volume of distribution (VT) images. Five versions of Ichise, reference Logan, and 2 basis function implementations (receptor parametric mapping and simplified reference tissue model 2 [SRTM2]) of SRTM, all using gray matter cerebellum as the reference region, were applied to generate nondisplaceable binding potential (BPND) images.

    RESULTS: Plasma-input Logan analysis (r(2) = 0.99; slope, 0.88) and spectral analysis (r(2) = 0.99, slope, 0.93) generated estimates of VT that correlated well with values obtained using nonlinear regression. BPND values generated using SRTM2 (r(2) = 0.83; slope, 0.95) and reference Logan analysis (r(2) = 0.88; slope, 1.01) correlated well with nonlinear regression-based estimates.

    CONCLUSION: Both Logan analysis and spectral analysis can be used to obtain quantitatively accurate VT images of (18)F-DPA-714. In addition, SRTM2 and reference Logan analysis can provide accurate BPND images. These parametric images could be used for voxel-based comparisons.

  • 22.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Eriksson, Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Combined PET and microdialysis for in vivo estimation of drug blood-brain barrier transport and brain unbound concentrations2017In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 155, p. 177-186Article in journal (Refereed)
    Abstract [en]

    Methods to investigate blood-brain barrier transport and pharmacologically active drug concentrations in the human brain are limited and data translation between species is challenging. Hence, there is a need to further develop the read-out of techniques like positron emission tomography ( PET) for studying neuropharmacokinetics. PET has a high translational applicability from rodents to man and measures total drug concentrations in vivo. The aim of the present study was to investigate the possibility of translating total drug concentrations, acquired through PET, to unbound concentrations, resembling those measured in the interstitial fluid by microdialysis sampling. Simultaneous PET scanning and brain microdialysis sampling were performed in rats throughout a 60 min infusion of [N-methyl-C-11] oxycodone in combination with a therapeutic dose of oxycodone and during a 60 min follow up period after the end of infusion. The oxycodone concentrations acquired with PET were converted into unbound concentrations by compensating for brain tissue binding and brain intracellular distribution, using the unbound volume of distribution in brain (Vu, brain), and were compared to microdialysis measurements of unbound concentrations. A good congruence between the methods was observed throughout the infusion. However, an accumulating divergence in the acquired PET and microdialysis data was apparent and became more pronounced during the elimination phase, most likely due to the passage of radioactive metabolites into the brain. In conclusion, the study showed that PET can be used to translate non-invasively measured total drug concentrations into unbound concentrations as long as the contribution of radiolabelled metabolites is minor or can be compensated for.

  • 23.
    Jonasson, My
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Univ Uppsala Hosp, Med Phys, Uppsala, Sweden.
    Wall, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Chiotis, Konstantinos
    Karolinska Inst, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res, Translat Alzheimer Neurobiol, S-14157 Huddinge, Sweden.
    Saint-Aubert, Laure
    Karolinska Inst, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res, Translat Alzheimer Neurobiol, S-14157 Huddinge, Sweden.
    Wilking, Helena
    Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Sprycha, Margareta
    Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Borg, Beatrice
    Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Thibblin, Alf
    Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. Univ Uppsala Hosp, PET Ctr, Uppsala, Sweden.
    Nordberg, Agneta
    Karolinska Inst, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res, Translat Alzheimer Neurobiol, S-14157 Huddinge, Sweden.; Karolinska Univ, Huddinge Hosp, Dept Geriatr Med, Stockholm, Sweden.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Univ Uppsala Hosp, Med Phys, Uppsala, Sweden.
    Tracer kinetic analysis of (S)-18F-THK5117 as a PET tracer for assessing tau pathology.2016In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 57, no 4, p. 574-581Article in journal (Refereed)
    Abstract [en]

    Because a correlation between tau pathology and the clinical symptoms of Alzheimer's disease (AD) has been hypothesized, there is increasing interest in developing PET tracers that bind specifically to tau protein. The aim of this study was to evaluate tracer kinetic models for quantitative analysis and generation of parametric images for the novel tau ligand (S)-(18)F-THK5117.

    METHODS: 9 subjects (5 with AD, 4 with mild cognitive impairment) received a 90 min dynamic (S)-(18)F-THK5117 PET scan. Arterial blood was sampled for measurement of blood radioactivity and metabolite analysis. VOI-based analysis was performed using plasma-input models; single-tissue and two-tissue (2TCM) compartment models and plasma-input Logan, and reference tissue models; simplified reference tissue model (SRTM), reference Logan and standardised uptake value ratio (SUVr). Cerebellum grey matter was used as reference region. Voxel-level analysis was performed using basis function implementations of SRTM, reference Logan and SUVr. Regionally averaged voxel values were compared to VOI-based values from the optimal reference tissue model and simulations were made to assess accuracy and precision. In addition to 90 min, initial 40 and 60 min data were analysed.

    RESULTS: Plasma-input Logan distribution volume ratio (DVR)-1 values agreed well with 2TCM DVR-1 values (R2=0.99, slope=0.96). SRTM binding potential (BPND) and reference Logan DVR-1 values were highly correlated with plasma-input Logan DVR-1 (R2=1.00, slope≈1.00) while SUVr70-90-1 values correlated less well and overestimated binding. Agreement between parametric methods and SRTM was best for reference Logan (R2=0.99, slope=1.03). SUVr70-90-1 values were almost 3 times higher than BPND values in white matter and 1.5 times higher in grey matter. Simulations showed poorer accuracy and precision for SUVr70-90-1 values than for the other reference methods. SRTM BPND and reference Logan DVR-1 values were not affected by a shorter scan duration of 60 min.

    CONCLUSION: SRTM BPND and reference Logan DVR-1 values were highly correlated with plasma-input Logan DVR-1 values. VOI-based data analyses indicated robust results for scan durations of 60 min. Reference Logan generated quantitative (S)-(18)F-THK5117 DVR-1 parametric images with the greatest accuracy and precision, and with a much lower white matter signal than seen with SUVr-1 images.

  • 24.
    Lemoine, Laetitia
    et al.
    Karolinska Inst, Div Translat Alzheimer Neurobiol, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res,Novum, S-14157 Stockholm, Sweden.
    Saint-Aubert, Laure
    Karolinska Inst, Div Translat Alzheimer Neurobiol, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res,Novum, S-14157 Stockholm, Sweden.
    Marutle, Amelia
    Karolinska Inst, Div Translat Alzheimer Neurobiol, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res,Novum, S-14157 Stockholm, Sweden.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Univ Uppsala Hosp, PET Ctr, Ctr Med Imaging, Uppsala, Sweden.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Univ Uppsala Hosp, PET Ctr, Ctr Med Imaging, Uppsala, Sweden.
    Ghetti, Bernardino
    Indiana Univ Sch Med, Dept Pathol & Lab Med, Indianapolis, IN 46202 USA.
    Okamura, Nobuyuki
    Tohoku Univ, Sch Med, Dept Pharmacol, Sendai, Miyagi 980, Japan.
    Nennesmo, Inger
    Karolinska Univ Hosp, Dept Pathol, Stockholm, Sweden.
    Gillberg, Per-Göran
    Karolinska Inst, Div Translat Alzheimer Neurobiol, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res,Novum, S-14157 Stockholm, Sweden.
    Nordberg, Agneta
    Karolinska Inst, Div Translat Alzheimer Neurobiol, Dept Neurobiol Care Sci & Soc, Ctr Alzheimer Res,Novum, S-14157 Stockholm, Sweden; Karolinska Univ, Dept Geriatr Med, Huddinge Hosp, Stockholm, Sweden.
    Visualization of regional tau deposits using (3)H-THK5117 in Alzheimer brain tissue2015In: Acta neuropathologica communications, E-ISSN 2051-5960, Vol. 3, article id 40Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION:  The accumulation of neurofibrillary tangles, composed of aggregated hyperphosphorylated tau protein, starts spreading early in specific regions in the course of Alzheimer's disease (AD), correlating with the progression of memory dysfunction. The non-invasive imaging of tau could therefore facilitate the early diagnosis of AD, differentiate it from other dementing disorders and allow evaluation of tau immunization therapy outcomes. In this study we characterized the in vitro binding properties of THK5117, a tentative radiotracer for positron emission tomography (PET) imaging of tau brain deposits.

    RESULTS: Saturation and competition binding studies of (3)H-THK5117 in post-mortem AD brain tissue showed the presence of multiple binding sites. THK5117 binding was significantly higher in hippocampal (p < 0.001) and temporal (p < 0.01) tissue homogenates in AD compared to controls. Autoradiography studies with (3)H-THK5117 was performed on large frozen brain sections from three AD cases who had been followed clinically and earlier undergone in vivo (18)F-FDG PET investigations. The three AD cases showed distinct differences in regional THK5117 binding that were also observed in tau immunohistopathology as well as in clinical presentation. A negative correlation between in vivo (18)F-FDG PET and in vitro (3)H-THK5117 autoradiography was observed in two of the three AD cases.

    CONCLUSIONS: This study supports that new tau PET tracers will provide further understanding on the role of tau pathology in the diversity of the clinical presentation in AD.

  • 25.
    Lubberink, Mark
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Phys..
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Imaging Ctr..
    Lindskog, K.
    Uppsala Univ Hosp, Med Phys..
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Imaging Ctr..
    Sprycha, M.
    Uppsala Univ Hosp, Med Imaging Ctr..
    Daging, J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Uppsala Univ Hosp, Neurol..
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry. Uppsala Univ Hosp, Med Imaging Ctr..
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Imaging Ctr..
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala Univ Hosp, Neurol..
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging. Uppsala Univ Hosp, Med Imaging Ctr..
    Quantitative assessment of synaptic density using the SV2A ligand C-11-UCBA in humans2017In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 37, p. 74-74Article in journal (Other academic)
  • 26.
    Lubberink, Mark
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Jonasson, My
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Wall, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Chiotis, K.
    Karolinska Inst, Translat Alzheimer Neurobiol, Stockholm, Sweden..
    Saint-Aubert, L.
    Karolinska Inst, Translat Alzheimer Neurobiol, Stockholm, Sweden..
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Okamura, N.
    Tohoku Univ, Sch Med, Pharmacol, Sendai, Miyagi, Japan..
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Nordberg, A.
    Karolinska Inst, Translat Alzheimer Neurobiol, Stockholm, Sweden..
    Tracer kinetic analysis of [18f](s)-thk5117 as a pet tracer for tau pathology2016In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 36, no Suppl. 1, p. 16-17, article id 63Article in journal (Other academic)
  • 27.
    Lubberink, Mark
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Jonasson, My
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wall, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Chiotis, Konstantinos
    Saint-Aubert, Laure
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Okamura, Nobuyuki
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Nordberg, Agneta
    Tracer kinetic analysis of (S)-[F-18]THK5117 as a PET tracer for tau pathology2015Conference paper (Other academic)
  • 28. Mansor, Syahir
    et al.
    Yaqub, Maqsood
    Boellaard, Ronald
    Froklage, Femke E
    de Vries, Anke
    Bakker, Esther D M
    Voskuyl, Rob A
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Schwarte, Lothar A
    Verbeek, Joost
    Windhorst, Albert D
    Lammertsma, Adriaan A
    Parametric Methods for Dynamic (11)C-Phenytoin PET Studies.2017In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 58, no 3, p. 479-483Article in journal (Refereed)
    Abstract [en]

    In this study, the performance of various methods for generating quantitative parametric images of dynamic (11)C-phenytoin PET studies was evaluated. Methods: Double-baseline 60-min dynamic (11)C-phenytoin PET studies, including online arterial sampling, were acquired for 6 healthy subjects. Parametric images were generated using Logan plot analysis, a basis function method, and spectral analysis. Parametric distribution volume (VT) and influx rate (K1) were compared with those obtained from nonlinear regression analysis of time-activity curves. In addition, global and regional test-retest (TRT) variability was determined for parametric K1 and VT values. Results: Biases in VT observed with all parametric methods were less than 5%. For K1, spectral analysis showed a negative bias of 16%. The mean TRT variabilities of VT and K1 were less than 10% for all methods. Shortening the scan duration to 45 min provided similar VT and K1 with comparable TRT performance compared with 60-min data. Conclusion: Among the various parametric methods tested, the basis function method provided parametric VT and K1 values with the least bias compared with nonlinear regression data and showed TRT variabilities lower than 5%, also for smaller volume-of-interest sizes (i.e., higher noise levels) and shorter scan duration.

  • 29.
    Meyer Lundén, Karin
    Högskolan i Gävle.
    Forskare och parallellpublicering2009In: InfoTrend, ISSN 1653-0225, Vol. 63, no 4, p. 103-106Article in journal (Other (popular science, discussion, etc.))
  • 30.
    Meyer Lundén, Karin
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of ALM.
    Forskare och parallellpublicering: forskares syn på, kunskap om och användning av den 'gröna' vägen till open access2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To self-archive is to make research publications freely accessible by depositing them in an open digital archive or on a public website. The aim of this thesis is to explore what Swedish scientists think of self-archiving, what they know about it and how they make use of it, in order to understand why they do not self-archive more actively.

    A web survey was conducted which was answered by 296 scientists at the Swedish University of Agricultural Sciences (SLU). Results show that only 24 % have previous experience of self-archiving, but that a majority is willing to self-archive if there are no legal objections or if it is demanded by the research funder. The most important reasons why many scientists do not self-archive are that they feel uncertain about copyright issues and/or lack knowledge about self-archiving.

  • 31. Oprea-Lager, Daniela E
    et al.
    Vincent, Andrew D
    van Moorselaar, Reindert J A
    Gerritsen, Winald R
    van den Eertwegh, Alfons J M
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Boellaard, Ronald
    Hoekstra, Otto S
    Dual-Phase PET-CT to Differentiate [(18)F]Fluoromethylcholine Uptake in Reactive and Malignant Lymph Nodes in Patients with Prostate Cancer2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 10, p. e48430-Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To investigate whether time-trends of enhanced [(18)F]Fluoromethylcholine ([(18)F]FCH) in lymph nodes (LN) of prostate cancer (PCa) patients can help to discriminate reactive from malignant ones, and whether single time point standardized uptake value (SUV) measurements also suffice.

    PROCEDURES: 25 PCa patients with inguinal (presumed benign) and enlarged pelvic LN (presumed malignant) showing enhanced [(18)F]FCH uptake at dual-phase PET-CT were analyzed. Associations between LN status (benign versus malignant) and SUV(max) and SUV(meanA50), determined at 2 min (early) and 30 min (late) post injection, were assessed. We considered two time-trends of [(18)F]FCH uptake: type A (SUV early > SUV late) and type B (SUV late ≥ SUV early). Histopathology and/or follow-up were used to confirm the assumption that LN with type A pattern are benign, and LN with type B pattern malignant.

    RESULTS: Analysis of 54 nodes showed that LN status, time-trends, and 'late' (30 min p.i.) SUV(max) and SUV(meanA50) parameters were strongly associated (P<0.0001). SUV(max) relative difference was the best LN status predictor. All but one inguinal LN showed a decreasing [(18)F]FCH uptake over time (pattern A), while 95% of the pelvic nodes presented a stable or increasing uptake (pattern B) type.

    CONCLUSIONS: Time-trends of enhanced [(18)F]FCH uptake can help to characterize lymph nodes in prostate cancer patients. Single time-point SUV measurements, 30 min p.i., may be a reasonable alternative for predicting benign versus malignant status of lymph nodes, but this remains to be validated in non-enlarged pelvic lymph nodes.

  • 32. Peeters, Sarah G J A
    et al.
    Zegers, Catharina M L
    Lieuwes, Natasja G
    van Elmpt, Wouter
    Eriksson, Jonas
    VU Medical Center Amsterdam .
    van Dongen, Guus A M S
    Dubois, Ludwig
    Lambin, Philippe
    A Comparative Study of the Hypoxia PET Tracers [(18)F]HX4, [(18)F]FAZA, and [(18)F]FMISO in a Preclinical Tumor Model.2015In: International journal of radiation oncology, biology, physics, ISSN 1879-355X, Vol. 91, no 2, p. 351-9Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Several individual clinical and preclinical studies have shown the possibility of evaluating tumor hypoxia by using noninvasive positron emission tomography (PET). The current study compared 3 hypoxia PET tracers frequently used in the clinic, [(18)F]FMISO, [(18)F]FAZA, and [(18)F]HX4, in a preclinical tumor model. Tracer uptake was evaluated for the optimal time point for imaging, tumor-to-blood ratios (TBR), spatial reproducibility, and sensitivity to oxygen modification.

    METHODS AND MATERIALS: PET/computed tomography (CT) images of rhabdomyosarcoma R1-bearing WAG/Rij rats were acquired at multiple time points post injection (p.i.) with one of the hypoxia tracers. TBR values were calculated, and reproducibility was investigated by voxel-to-voxel analysis, represented as correlation coefficients (R) or Dice similarity coefficient of the high-uptake volume. Tumor oxygen modifications were induced by exposure to either carbogen/nicotinamide treatment or 7% oxygen breathing.

    RESULTS: TBR was stabilized and maximal at 2 hours p.i. for [(18)F]FAZA (4.0 ± 0.5) and at 3 hours p.i. for [(18)F]HX4 (7.2 ± 0.7), whereas [(18)F]FMISO showed a constant increasing TBR (9.0 ± 0.8 at 6 hours p.i.). High spatial reproducibility was observed by voxel-to-voxel comparisons and Dice similarity coefficient calculations on the 30% highest uptake volume for both [(18)F]FMISO (R = 0.86; Dice coefficient = 0.76) and [(18)F]HX4 (R = 0.76; Dice coefficient = 0.70), whereas [(18)F]FAZA was less reproducible (R = 0.52; Dice coefficient = 0.49). Modifying the hypoxic fraction resulted in enhanced mean standardized uptake values for both [(18)F]HX4 and [(18)F]FAZA upon 7% oxygen breathing. Only [(18)F]FMISO uptake was found to be reversible upon exposure to nicotinamide and carbogen.

    CONCLUSIONS: This study indicates that each tracer has its own strengths and, depending on the question to be answered, a different tracer can be put forward.

  • 33. Peeters, SarahG.J.A.
    et al.
    Dubois, Ludwig
    Lieuwes, NatasjaG.
    Laan, Dennis
    Mooijer, Martien
    Schuit, RobertC.
    Vullo, Daniela
    Supuran, ClaudiuT.
    Eriksson, Jonas
    VU University Medical Center Amsterdam.
    Windhorst, AlbertD.
    Lambin, Philippe
    [18F]VM4-037 MicroPET Imaging and Biodistribution of Two In Vivo CAIX-Expressing Tumor Models2015In: Molecular Imaging and Biology, ISSN 1536-1632, E-ISSN 1860-2002, p. 1-5Article in journal (Refereed)
  • 34.
    Poot, Alex J
    et al.
    VU University Medical Center, Amsterdam, the Netherlands.
    van der Wildt, Berend
    VU University Medical Center, Amsterdam, the Netherlands.
    Stigter-van Walsum, Marijke
    VU University Medical Center, Amsterdam, the Netherlands.
    Rongen, Marissa
    VU University Medical Center, Amsterdam, the Netherlands.
    Schuit, Robert C
    VU University Medical Center, Amsterdam, the Netherlands.
    Hendrikse, N Harry
    VU University Medical Center, Amsterdam, the Netherlands.
    Eriksson, Jonas
    VU University Medical Center, Amsterdam, the Netherlands.
    van Dongen, Guus A M S
    VU University Medical Center, Amsterdam, the Netherlands.
    Windhorst, Albert D
    VU University Medical Center, Amsterdam, the Netherlands.
    [(11)C]Sorafenib: Radiosynthesis and preclinical evaluation in tumor-bearing mice of a new TKI-PET tracer.:  2013In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 40, no 4, p. 488-497Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: Tyrosine kinase inhibitors (TKIs) like sorafenib are important anticancer therapeutics with thus far limited treatment response rates in cancer patients. Positron emission tomography (PET) could provide the means for selection of patients who might benefit from TKI treatment, if suitable PET tracers would be available. The aim of this study was to radiolabel sorafenib (1) with carbon-11 and to evaluate its potential as TKI-PET tracer in vivo. METHODS: Synthetic methods were developed in which sorafenib was labeled at two different positions, followed by a metabolite analysis in rats and a PET imaging study in tumor-bearing mice. RESULTS: [methyl-(11)C]-1 and [urea-(11)C]-1 were synthesized in yields of 59% and 53%, respectively, with a purity of >99%. The identity of the products was confirmed by coinjection on HPLC with reference sorafenib. In an in vivo metabolite analysis [(11)C]sorafenib proved to be stable. The percentage of intact product in blood-plasma after 45min was 90% for [methyl-(11)C]-1 and 96% for [urea-(11)C]-1, respectively. Due to the more reliable synthesis, further research regarding PET imaging was performed with [methyl-(11)C]-1 in nude mice bearing FaDu (head and neck cancer), MDA-MB-231 (breast cancer) or RXF393 (renal cancer) xenografts. Highest tracer accumulation at a level of 2.52±0.33%ID/g was observed in RXF393, a xenograft line extensively expressing the sorafenib target antigen Raf-1 as assessed by immunohistochemistry. CONCLUSION: In conclusion, we have synthesized [(11)C]sorafenib as PET tracer, which is stable in vivo and has the capability to be used as PET tracer for imaging in tumor-bearing mice.

  • 35. Postnov, Andrey
    et al.
    Froklage, Femke E
    van Lingen, Arthur
    Reijneveld, Jaap C
    Hendrikse, N Harry
    Windhorst, Albert D
    Schuit, Robert C
    Eriksson, Jonas
    VU university medical center Amsterdam.
    Lammertsma, Adriaan A
    Huisman, Marc C
    Radiation Dose of the P-Glycoprotein Tracer 11C-Laniquidar.2013In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 54, no 12, p. 2101-2103Article in journal (Refereed)
    Abstract [en]

    Resistance to current drug therapy is an important issue in the treatment of epilepsy. Inadequate access of central nervous system drugs to their targets in the brain may be caused by overexpression or overactivity of multidrug transporters, such as P-glycoprotein (P-gp), at the blood-brain barrier. Laniquidar, an inhibitor of P-gp, has been labeled with (11)C for use in PET studies of P-gp expression in humans. Given potential interspecies differences in biodistribution, the purpose of this study was to ensure safe use of (11)C-laniquidar by determining the dosimetry of (11)C-laniquidar using whole-body PET studies.

    METHODS: Six healthy volunteers were subjected to a series of 10 whole-body PET scans within approximately 70 min. Five blood samples were taken during the series.

    RESULTS: High uptake of (11)C-laniquidar was seen in liver, spleen, kidneys, and lung, whereas brain uptake was low. The effective dose for (11)C-laniquidar was 4.76 ± 0.13 and 3.69 ± 0.01 μSv·MBq(-1) for women and men, respectively.

    CONCLUSION: Biodistribution and measured effective dose indicate that (11)C-laniquidar is a safe tracer for PET imaging, with a total dose of about 2 mSv for a brain PET/CT protocol.

  • 36. Potschka, H.
    et al.
    Bogdanovic, R. M.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Michler, C.
    Russmann, V
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Windhorst, A. D.
    Lammertsma, A. A.
    de Lange, E. C.
    Voskuyl, R. A.
    Molecular Imaging of Inflammation Reveals Differences Between Drug-Resistant and Drug-Sensitive Animals in a Chronic Model of Temporal Lobe Epilepsy2014In: Epilepsia, ISSN 0013-9580, E-ISSN 1528-1167, Vol. 55, no Suppl. 2, p. 32-32Article in journal (Other academic)
  • 37.
    Roslin, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    De Rosa, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Deuther-Conrad, Winnie
    Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, 04318 Leipzig, Germany.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry.
    Brust, Peter
    Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, 04318 Leipzig, Germany.
    Larhed, Mats
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Synthesis and In Vitro Evaluation of 5-Substituted Benzovesamicol Analogs containing N-Substituted Amides as Potential Positron Emission Tomography Tracers for the Vesicular Acetylcholine Transporter2017In: Bioorganic & Medicinal Chemistry, ISSN 0968-0896, E-ISSN 1464-3391, Vol. 25, no 19, p. 5095-5106Article in journal (Refereed)
    Abstract [en]

    Herein, new ligands for the vesicular acetylcholine transporter (VAChT), based on a benzovesamicol scaffold, are presented. VAChT is acknowledged as a marker for cholinergic neurons and a positron emission tomography tracer for VAChT could serve as a tool for quantitative analysis of cholinergic neuronal density. With an easily accessible triflate precursor, aminocarbonylations were utilized to evaluate the chemical space around the C5 position on the tetrahydronaphthol ring. Synthesized ligands were evaluated for their affinity and selectivity for VAChT. Small, preferably aromatic, N-substituents proved to be more potent than larger substituents. Of the fifteen compounds synthesized, benzyl derivatives (+/-)-7i and (+/-)-7l had the highest affinities for VAChT. Compound (+/-)-7i was chosen to investigate the importance of stereochemistry for binding to VAChT and selectivity toward the sigma(1) and sigma(2) receptors. Enantiomeric resolution gave (+/-)-7i and (-)-7i, and the eutomer showed seven times better affinity. Although racemate (+/-)-7i was initially promising, the affinity of (-)-7i for VAChT was not better than 56.7 nM which precludes further preclinical evaluation. However, the nanomolar binding together with the ready synthesis of [C-11]-(+/-)-7i shows that (-)-7i can serve as a scaffold for future optimizations to provide improved C-11-labelled VAChT PET tracers.

  • 38.
    Stevens, Marc
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Chow, Chow
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Estrada, Sergio
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Asplund, Veronika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Bogdan, Mitran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Larhed, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Åberg, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Odell, Luke
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Synthesis of 11C-labelled Sulfonyl Carbamates via a Multicomponent Reaction Employing Sulfonyl Azides, Alcohols and [11C]CO2016In: ChemistryOpen, ISSN 2191-1363, Vol. 58, no 3, p. 566-573Article in journal (Refereed)
    Abstract [en]

    Herein we describe the development of new methodologyfocusing on 11C-labelling of sulfonyl carbamates in a multicomponentreaction comprising a sulfonyl azide, an alkyl alcohol and [11C]CO. Anumber of 11C-labelled sulfonyl carbamates were synthesised andisolated, and the developed methodology was then applied in thepreparation of a biologically active molecule. The target compoundwas obtained in 18±8% isolated radiochemical yield and wasevaluated for binding properties in a tumor cell assay, as well asundergoing in vivo biodistribution and imaging studies. Thisrepresents the first successful radiolabelling of C21, a non-peptideangiotensin II receptor subtype 2 agonist currently in clinical trials.

  • 39.
    Stevens, Marc Y.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Chow, Shiao Y.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Estrada, Sergio
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Asplund, Veronika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Larhed, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Åberg, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Synthesis of C-11-labeled Sulfonyl Carbamates through a Multicomponent Reaction Employing Sulfonyl Azides, Alcohols, and [C-11]CO2016In: ChemistryOpen, ISSN 2191-1363, Vol. 5, no 6, p. 566-573Article in journal (Refereed)
    Abstract [en]

    We describe the development of a new methodology focusing on C-11-labeling of sulfonyl carbamates in a multicomponent reaction comprised of a sulfonyl azide, an alkyl alcohol, and [C-11] CO. A number of C-11-labeled sulfonyl carbamates were synthesized and isolated, and the developed methodology was then applied in the preparation of a biologically active molecule. The target compound was obtained in 24 +/- 10% isolated radiochemical yield and was evaluated for binding properties in a tumor cell assay; in vivo biodistribution and imaging studies were also performed. This represents the first successful radiolabeling of a non-peptide angiotensin II receptor subtype 2 agonist, C21, currently in clinical trials for the treatment of idiopathic pulmonary fibrosis.

  • 40.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Advances in PET Imaging of P-Glycoprotein Function at the Blood-Brain Barrier.2013In: ACS Chemical Neuroscience, ISSN 1948-7193, E-ISSN 1948-7193, Vol. 4, no 2, p. 225-237Article, review/survey (Refereed)
    Abstract [en]

    Efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) restricts substrate compounds from entering the brain and may thus contribute to pharmacoresistance observed in patient groups with refractory epilepsy and HIV. Altered P-gp function has also been implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Positron emission tomography (PET), a molecular imaging modality, has become a promising method to study the role of P-gp at the BBB. The first PET study of P-gp function was conducted in 1998, and during the past 15 years two main categories of P-gp PET tracers have been investigated: tracers that are substrates of P-gp efflux and tracers that are inhibitors of P-gp function. PET, as a noninvasive imaging technique, allows translational research. Examples of this are preclinical investigations of P-gp function before and after administering P-gp modulating drugs, investigations in various animal and disease models, and clinical investigations regarding disease and aging. The objective of the present review is to give an overview of available PET radiotracers for studies of P-gp and to discuss how such studies can be designed. Further, the review summarizes results from PET studies of P-gp function in different central nervous system disorders.

  • 41. Syvänen, Stina
    et al.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Genchel, Tove
    Lindhe, Örjan
    Antoni, Gunnar
    Långström, Bengt
    [1-11C]Ethyl iodide and [1-11C]propyl iodide in the synthesis of two potential NK1-receptor ligands and initial PET-imagingManuscript (Other academic)
  • 42.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Genchel, Tove
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Pharmaceutical Biochemistry.
    Lindhe, Örjan
    Antoni, Gunnar
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Synthesis of two potential NK1-receptor ligands using [1-11C]ethyl iodide and [1-11C]propyl iodide and initial PET-imaging2007In: BMC Medical Imaging, ISSN 1471-2342, E-ISSN 1471-2342, Vol. 7, p. 6-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:

    The previously validated NK1-receptor ligand [O-methyl-11C]GR205171 binds with a high affinity to the NK1-receptor and displays a slow dissociation from the receptor. Hence, it cannot be used in vivo for detecting concentration changes in substance P, the endogenous ligand for the NK1-receptor. A radioligand used for monitoring these changes has to enable displacement by the endogenous ligand and thus bind reversibly to the receptor. Small changes in the structure of a receptor ligand can lead to changes in binding characteristics and also in the ability to penetrate the blood-brain barrier. The aim of this study was to use carbon-11 labelled ethyl and propyl iodide with high specific radioactivity in the synthesis of two new and potentially reversible NK1-receptor ligands with chemical structures based on [O-methyl-11C]GR205171.

    METHODS:

    [1-11C]Ethyl and [1-11C]propyl iodide with specific radioactivities of 90 GBq/μmol and 270 GBq/μmol, respectively, were used in the synthesis of [O-methyl-11C]GR205171 analogues by alkylation of O-desmethyl GR205171. The brain uptake of the obtained (2S,3S)-N-(1-(2- [1-11C]ethoxy-5-(3-(trifluoromethyl)-4H-1,2,4-triazol-4-yl)phenyl)ethyl)-2-phenylpiperidin-3-amine (I) and (2S,3S)-2-phenyl-N-(1-(2- [1-11C]propoxy-5-(3-(trifluoromethyl)-4H-1,2,4-triazol-4-yl)phenyl)ethyl)piperidin-3-amine (II) was studied with PET in guinea pigs and rhesus monkeys and compared to the uptake of [O-methyl-11C]GR205171.

    RESULTS:

    All ligands had similar uptake distribution in the guinea pig brain. The PET-studies in rhesus monkeys showed that (II) had no specific binding in striatum. Ligand (I) had moderate specific binding compared to the [O-methyl-11C]GR205171. The ethyl analogue (I) displayed reversible binding characteristics contrary to the slow dissociation rate shown by [O-methyl-11C]GR205171.

    CONCLUSION:

    The propyl-analogue (II) cannot be used for detecting changes in NK1-ligand levels, while further studies should be performed with the ethyl-analogue (I).

  • 43.
    Syvänen, Stina
    et al.
    Leiden University.
    Labots, Maaike
    Tagawa, Yoshihiko
    Eriksson, Jonas
    VU University Medical Center Amsterdam.
    Windhorst, Albert D
    Lammertsma, Adriaan A
    de Lange, Elizabeth C
    Voskuyl, Rob A
    Altered GABAA Receptor Density and Unaltered Blood-Brain Barrier Transport in a Kainate Model of Epilepsy: An In Vivo Study Using 11C-Flumazenil and PET.2012In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 53, no 12, p. 1974-1983Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to investigate if flumazenil blood-brain barrier transport and binding to the benzodiazepine site on the γ-aminobutyric acid A (GABA(A)) receptor complex is altered in an experimental model of epilepsy and subsequently to study if changes in P-glycoprotein (P-gp)-mediated efflux of flumazenil at the blood-brain barrier may confound interpretation of (11)C-flumazenil PET in epilepsy. METHODS: The transport of flumazenil across the blood-brain barrier and the binding to the benzodiazepine site on the GABA(A) receptors in 5 different brain regions was studied and compared between controls and kainate-treated rats, a model of temporal lobe epilepsy, with and without tariquidar pretreatment. In total, 29 rats underwent 2 consecutive (11)C-flumazenil PET scans, each one lasting 30 min. The tracer was mixed with different amounts of isotopically unmodified flumazenil (4, 20, 100, or 400 μg) to cover a wide range of receptor occupancies during the scan. Before the second scan, the rats were pretreated with a 3 or 15 mg/kg dose of the P-gp inhibitor tariquidar. The second scan was then obtained according to the same protocol as the first scan. RESULTS: GABA(A) receptor density, B(max), was estimated as 44 ± 2 ng⋅mL(-1) in the hippocampus and as 33 ± 2 ng⋅mL(-1) in the cerebellum, with intermediate values in the occipital cortex, parietal cortex, and caudate putamen. B(max) was decreased by 12% in kainate-treated rats, compared with controls. The radiotracer equilibrium dissociation constant, K(D), was similar in both rat groups and all brain regions and was estimated as 5.9 ± 0.9 ng⋅mL(-1). There was no difference in flumazenil transport across the blood-brain barrier between control and kainate-treated rats, and the effect of tariquidar treatment was similar in both rat groups. Tariquidar treatment also decreased flumazenil transport out of the brain by 73%, increased the volume of distribution in the brain by 24%, and did not influence B(max) or K(D), compared with baseline(.) CONCLUSION: B(max) was decreased in kainate-treated rats, compared with controls, but no alteration in the blood-brain barrier transport of flumazenil was observed. P-gp inhibition by tariquidar treatment increased brain concentrations of flumazenil in both groups, but B(max) estimates were not influenced, suggesting that (11)C-flumazenil scanning is not confounded by alterations in P-gp function.

  • 44.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Russmann, Vera
    Verbeek, Joost
    Eriksson, Jonas
    Department of Nuclear Medicine & PET Research, VU University Medical Center, Amsterdam, The Netherlands.
    Labots, Maaike
    Zellinger, Christina
    Seeger, Natalie
    Schuit, Robert
    Rongen, Marissa
    van Kooij, Rolph
    Windhorst, Albert D.
    Lammertsma, Adriaan A.
    de Lange, Elizabeth C.
    Voskuyl, Rob A.
    Koepp, Matthias
    Potschka, Heidrun
    [C-11]quinidine and [C-11]laniquidar PET imaging in a chronic rodent epilepsy model: Impact of epilepsy and drug-responsiveness2013In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 40, no 6, p. 764-775Article in journal (Refereed)
    Abstract [en]

    Introduction: To analyse the impact of both epilepsy and pharmacological modulation of P-glycoprotein on brain uptake and kinetics of positron emission tomography (PET) radiotracers [C-11]quinidine and [C-11]laniquidar.

    Methods: Metabolism and brain kinetics of both [C-11]quinidine and [C-11]laniquidar were assessed in naive rats, electrode-implanted control rats, and rats with spontaneous recurrent seizures. The latter group was further classified according to their response to the antiepileptic drug phenobarbital into "responders" and "non-responders". Additional experiments were performed following pre-treatment with the P-glycoprotein modulator tariquidar.

    Results: [C-11]quinidine was metabolized rapidly, whereas [C-11]laniquidar was more stable. Brain concentrations of both radiotracers remained at relatively low levels at baseline conditions. Tariquidar pre-treatment resulted in significant increases of [C-11]quinidine and [C-11]laniquidar brain concentrations. In the epileptic subgroup "non-responders", brain uptake of [C-11]quinidine in selected brain regions reached higher levels than in electrode-implanted control rats. However, the relative response to tariquidar did not differ between groups with full blockade of P-glycoprotein by 15 mg/kg of tariquidar. For [C-11]laniquidar differences between epileptic and control animals were only evident at baseline conditions but not after tariquidar pretreatment.

    Conclusions: We confirmed that both [C-11]quinidine and [C-11]laniquidar are P-glycoprotein substrates. At full P-gp blockade, tariquidar pre-treatment only demonstrated slight differences for [C-11]quinidine between drug-resistant and drug-sensitive animals.

  • 45. van Assema, Daniëlle ME
    et al.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rizzu, Patrizia
    van Swieten, John C
    Schuit, Robert C
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Scheltens, Philip
    Koepp, Matthias
    Lammertsma, Adriaan A
    van Berckel, Bart NM
    Blood-brain barrier P-glycoprotein function in healthy subjects and Alzheimer's disease patients: effect of polymorphisms in the ABCB1 gene2012In: EJNMMI Research, ISSN 2191-219X, E-ISSN 2191-219X, Vol. 2, article id 57Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: P-glycoprotein is a blood-brain barrier efflux transporter involved in the clearance of amyloid-beta from the brain and, as such, might be involved in the pathogenesis of Alzheimer's disease. P-glycoprotein is encoded by the highly polymorphic ABCB1 gene. Single-nucleotide polymorphisms in the ABCB1 gene have been associated with altered P-glycoprotein expression and function. P-glycoprotein function at the blood-brain barrier can be quantified in vivo using the P-glycoprotein substrate tracer (R)-[11C]verapamil and positron emission tomography (PET). The purpose of this study was to assess the effects of C1236T, G2677T/A and C3435T single-nucleotide polymorphisms in ABCB1 on blood-brain barrier P-glycoprotein function in healthy subjects and patients with Alzheimer's disease.

    METHODS: Thirty-two healthy subjects and seventeen patients with Alzheimer's disease underwent 60-min dynamic (R)-[11C]verapamil PET scans. The binding potential of (R)-[11C]verapamil was assessed using a previously validated constrained two-tissue plasma input compartment model and used as outcome measure. DNA was isolated from frozen blood samples and C1236T, G2677T/A and C3435T single-nucleotide polymorphisms were amplified by polymerase chain reaction.

    RESULTS: In healthy controls, binding potential did not differ between subjects without and with one or more T present in C1236T, G2677T and C3435T. In contrast, patients with Alzheimer's disease with one or more T in C1236T, G2677T and C3435T had significantly higher binding potential values than patients without a T. In addition, there was a relationship between binding potential and T dose in C1236T and G2677T.

    CONCLUSIONS: In Alzheimer's disease patients, C1236T, G2677T/A and C3435T single-nucleotide polymorphisms may be related to changes in P-glycoprotein function at the blood-brain barrier. As such, genetic variations in ABCB1 might contribute to the progression of amyloid-beta deposition in the brain.

  • 46. van der Doef, Thalia F
    et al.
    de Witte, Lot D
    Sutterland, Arjen L
    Jobse, Ellen
    Yaqub, Maqsood
    Boellaard, Ronald
    de Haan, Lieuwe
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Lammertsma, Adriaan A
    Kahn, René S
    van Berckel, Bart N M
    In vivo (R)-[(11)C]PK11195 PET imaging of 18kDa translocator protein in recent onset psychosis.2016In: NPJ schizophrenia, Vol. 2, article id 16031Article in journal (Refereed)
    Abstract [en]

    Evidence is accumulating that immune dysfunction is involved in the pathophysiology of schizophrenia. It has been hypothesized that microglia activation is present in patients with schizophrenia. Various in vivo and post-mortem studies have investigated this hypothesis, but as yet with inconclusive results. Microglia activation is associated with elevations in 18 kDa translocator protein (TSPO) levels, which can be measured with the positron emission tomography (PET) tracer (R)-[(11)C]PK11195. The purpose of the present study was to investigate microglia activation in psychosis in vivo at an early stage of the disease. (R)-[(11)C]PK11195 binding potential (BPND) was measured in 19 patients with recent onset psychosis and 17 age and gender-matched healthy controls. Total gray matter, as well as five gray matter regions of interest (frontal cortex, temporal cortex, parietal cortex, striatum, and thalamus) were defined a priori. PET data were analysed using a reference tissue approach and a supervised cluster analysis algorithm to identify the reference region. No significant difference in (R)-[(11)C]PK11195 BPND between patients and controls was found in total gray matter, nor one of the regions of interest. These findings suggest that microglia activation is not present in recent onset psychosis or that it is a subtle phenomenon that could not be detected using the design of the present study.

  • 47. Van der Veldt, A. A.
    et al.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Mathijssen, R. H.
    Loos, W. J.
    Eriksson, Jonas
    VU University Medical Center.
    Windhorst, A. D.
    Hendrikse, N. H.
    Postmus, P. E.
    Smit, E. F.
    Lammertsma, A. A.
    Towards Prediction of Efficacy of Chemotherapy: a Proof of Concept Study in Lung Cancer Patients Using [11C]docetaxel and Positron Emission Tomography2012In: European Journal of Cancer, ISSN 0959-8049, E-ISSN 1879-0852, Vol. 48, no S6, p. 75-76Article in journal (Other academic)
  • 48. van der Veldt, Astrid A. M.
    et al.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology. PET Centre, Uppsala University Hospital, Uppsala, Sweden.
    Bahce, Idris
    Walraven, Maudy
    de Boer, Michiel P.
    Greuter, Henri N. J. M.
    Hendrikse, N. Harry
    Eriksson, Jonas
    Department of Nuclear Medicine and PET Research, VU University Medical Center Amsterdam.
    Windhorst, Albert D.
    Postmus, Pieter E.
    Verheul, Henk M.
    Serne, Erik H.
    Lammertsma, Adriaan A.
    Smit, Egbert F.
    Rapid Decrease in Delivery of Chemotherapy to Tumors after Anti-VEGF Therapy: Implications for Scheduling of Anti-Angiogenic Drugs2012In: Cancer Cell, ISSN 1535-6108, E-ISSN 1878-3686, Vol. 21, no 1, p. 82-91Article in journal (Refereed)
    Abstract [en]

    Current strategies combining anti-angiogenic drugs with chemotherapy provide clinical benefit in cancer patients. It is assumed that anti-angiogenic drugs, such as bevacizumab, transiently normalize abnormal tumor vasculature and contribute to improved delivery of subsequent chemotherapy. To investigate this concept, a study was performed in non-small cell lung cancer (NSCLC) patients using positron emission tomography (PET) and radiolabeled docetaxel ([11C]docetaxel). In NSCLC, bevacizumab reduced both perfusion and net influx rate of [11C]docetaxel within 5 hr. These effects persisted after 4 days. The clinical relevance of these findings is notable, as there was no evidence for a substantial improvement in drug delivery to tumors. These findings highlight the importance of drug scheduling and advocate further studies to optimize scheduling of anti-angiogenic drugs.

  • 49. van der Veldt, Astrid A. M.
    et al.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Mathijssen, Ron H. J.
    Loos, Walter J.
    Herder, Gerarda J. M.
    Greuter, Henri N.
    Comans, Emile F. I.
    Rutten, Hugo B.
    Eriksson, Jonas
    VU University Medical Center Amsterdam.
    Windhorst, Albert D.
    Hendrikse, N. Harry
    Postmus, Pieter E.
    Smit, Egbert F.
    Lammertsma, Adriaan A.
    Toward Prediction of Efficacy of Chemotherapy: A Proof of Concept Study in Lung Cancer Patients Using [11C]docetaxel and Positron Emission Tomography2013In: Clinical Cancer Research, ISSN 1078-0432, E-ISSN 1557-3265, Vol. 19, no 15, p. 4163-4173Article in journal (Refereed)
    Abstract [en]

    Purpose:

    Pharmacokinetics of docetaxel can be measured in vivo using positron emission tomography (PET) and a microdose of radiolabeled docetaxel ([11C]docetaxel). The objective of this study was to investigate whether a [11C]docetaxel PET microdosing study could predict tumor uptake of therapeutic doses of docetaxel.

    Experimental Design:

    Docetaxel-naïve lung cancer patients underwent 2 [11C]docetaxel PET scans; one after bolus injection of [11C]docetaxel and another during combined infusion of [11C]docetaxel and a therapeutic dose of docetaxel (75 mg·m−2). Compartmental and spectral analyses were used to quantify [11C]docetaxel tumor kinetics. [11C]docetaxel PET measurements were used to estimate the area under the curve (AUC) of docetaxel in tumors. Tumor response was evaluated using computed tomography scans.

    Results:

    Net rates of influx (Ki) of [11C]docetaxel in tumors were comparable during microdosing and therapeutic scans. [11C]docetaxel AUCTumor during the therapeutic scan could be predicted reliably using an impulse response function derived from the microdosing scan together with the plasma curve of [11C]docetaxel during the therapeutic scan. At 90 minutes, the accumulated amount of docetaxel in tumors was less than 1% of the total infused dose of docetaxel. [11C]docetaxel Ki derived from the microdosing scan correlated with AUCTumor of docetaxel (Spearman ρ = 0.715; P = 0.004) during the therapeutic scan and with tumor response to docetaxel therapy (Spearman ρ = −0.800; P = 0.010).

    Conclusions:

    Microdosing data of [11C]docetaxel PET can be used to predict tumor uptake of docetaxel during chemotherapy. The present study provides a framework for investigating the PET microdosing concept for radiolabeled anticancer drugs in patients.

  • 50. Verbeek, Joost
    et al.
    Eriksson, Jonas
    VU University Medical Center Amsterdam.
    Syvänen, Stina
    Leiden University.
    Labots, Maaike
    de Lange, Elizabeth C M
    Voskuyl, Rob A
    Mooijer, Martinus P J
    Rongen, Marissa
    Lammertsma, Adriaan A
    Windhorst, Albert D
    [11C]phenytoin revisited: synthesis by [11C]CO carbonylation and first evaluation as a P-gp tracer in rats.2012In: EJNMMI Research, ISSN 2191-219X, E-ISSN 2191-219X, Vol. 2, no 1, p. 36-Article in journal (Refereed)
    Abstract [en]

    ABSTRACT: BACKGROUND: At present, several positron emission tomography (PET) tracers are in use for imaging Pglycoprotein (P-gp) function in man. At baseline, substrate tracers such as R-[11C]verapamil display low brain concentrations with a distribution volume of around 1. [11C]phenytoin is supposed to be a weaker P-gp substrate, which may lead to higher brain concentrations at baseline. This could facilitate assessment of P-gp function when P-gp is upregulated. The purpose of this study was to synthesize [11C]phenytoin and to characterize its properties as a P-gp tracer. METHODS: [11C]CO was used to synthesize [11C]phenytoin by rhodium-mediated carbonylation. Metabolism and, using PET, brain pharmacokinetics of [11C]phenytoin were studied in rats. Effects of P-gp function on [11C]phenytoin uptake were assessed using predosing with tariquidar. RESULTS: [11C]phenytoin was synthesized via [11C]CO in an overall decay-corrected yield of 22 +/- 4%. At 45 min after administration, 19% and 83% of radioactivity represented intact [11C]phenytoin in the plasma and brain, respectively. Compared with baseline, tariquidar predosing resulted in a 45% increase in the cerebral distribution volume of [11C]phenytoin. CONCLUSIONS: Using [11C]CO, the radiosynthesis of [11C]phenytoin could be improved. [11C]phenytoin appeared to be a rather weak P-gp substrate.

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