{"entity": "researcher", "timestamp": "2026-05-12T22:12:19.098Z", "family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "affiliations": ["Department of Surgical Sciences Uppsala University Uppsala Sweden", "Department of Medical Physics Uppsala University Hospital Uppsala Sweden"], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400"}}, "publications": [{"entity": "publication", "iuid": "2880f6e723fd451eb14e6f2abec59a80", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/2880f6e723fd451eb14e6f2abec59a80.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/2880f6e723fd451eb14e6f2abec59a80"}}, "title": "Quantification of aromatase binding in the female human brain using [11 C]cetrozole positron emission tomography.", "authors": [{"family": "Jonasson", "given": "My", "initials": "M"}, {"family": "Nordeman", "given": "Patrik", "initials": "P"}, {"family": "Eriksson", "given": "Jonas", "initials": "J", "orcid": "0000-0003-0241-092X", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/71cd42cbc17b4eb092c0ea4d452477e9.json"}}, {"family": "Wilking", "given": "Helena", "initials": "H"}, {"family": "Wikstr\u00f6m", "given": "Johan", "initials": "J"}, {"family": "Takahashi", "given": "Kayo", "initials": "K"}, {"family": "Niwa", "given": "Takashi", "initials": "T"}, {"family": "Hosoya", "given": "Takamitsu", "initials": "T"}, {"family": "Watanabe", "given": "Yasuyoshi", "initials": "Y"}, {"family": "Antoni", "given": "Gunnar", "initials": "G"}, {"family": "Sundstr\u00f6m Poromaa", "given": "Inger", "initials": "I", "orcid": "0000-0002-2491-2042", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/32a89a8ec1084ec3b4f523622f7f2fbb.json"}}, {"family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}}, {"family": "Comasco", "given": "Erika", "initials": "E", "orcid": "0000-0002-2174-2068", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/4f10cd12fd8e4c529264697930ac87b7.json"}}], "type": "journal article", "published": "2020-11-00", "journal": {"title": "J Neurosci Res", "issn": "1097-4547", "issn-l": "0360-4012", "volume": "98", "issue": "11", "pages": "2208-2218"}, "abstract": "Aromatase, the enzyme that in the brain converts testosterone and androstenedione to estradiol and estrone, respectively, is a putative key factor in psychoneuroendocrinology. In vivo assessment of aromatase was performed to evaluate tracer kinetic models and optimal scan duration, for quantitative analysis of the aromatase positron emission tomography (PET) ligand [11 C]cetrozole. Anatomical magnetic resonance and 90-min dynamic [11 C]cetrozole PET-CT scans were performed on healthy women. Volume of interest (VOI)-based analyses with a plasma-input function were performed using the single-tissue and two-tissue (2TCM) reversible compartment models and plasma-input Logan analysis. Additionally, the simplified reference tissue model (SRTM), Logan reference tissue model (LRTM), and standardized uptake volume ratio model, with cerebellum as reference region, were evaluated. Parametric images were generated and regionally averaged voxel values were compared with VOI-based analyses of the reference tissue models. The optimal reference model was used for evaluation of a decreased scan duration. Differences between the plasma-input- and reference tissue-based methods and comparisons between scan durations were assessed by linear regression. The [11 C]cetrozole time-activity curves were best described by the 2TCM. SRTM nondisplaceable binding potential (BPND ), with cerebellum as reference region, can be used to estimate [11 C]cetrozole binding and generated robust and quantitatively accurate results for a reduced scan duration of 60 min. Receptor parametric mapping, a basis function implementation of SRTM, as well as LRTM, produced quantitatively accurate parametric images, showing BPND at the voxel level. As PET tracer, [11 C]cetrozole can be employed for relatively short brain scans to measure aromatase binding using a reference tissue-based approach.", "doi": "10.1002/jnr.24707", "pmid": "32761874", "labels": {"Erika Comasco": null, "SciLifeLab Fellow": null}, "xrefs": [], "notes": [], "created": "2020-11-20T09:21:42.211Z", "modified": "2024-10-24T08:55:30.257Z"}, {"entity": "publication", "iuid": "6cf7565d0e724ae691db1eca82d0fd58", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/6cf7565d0e724ae691db1eca82d0fd58.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/6cf7565d0e724ae691db1eca82d0fd58"}}, "title": "[11C]5-Hydroxy-tryptophan model for quantitative assessment of in vivo serotonin biosynthesis, retention and degradation in the endocrine pancreas.", "authors": [{"family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}}, {"family": "Eriksson", "given": "Olof", "initials": "O", "orcid": "0000-0002-2515-8790", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/85991bf00e4b4a26ab15599d25c58601.json"}}], "type": "journal article", "published": "2020-10-15", "journal": {"title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "volume": "10", "issue": "5", "pages": "226-234", "issn-l": "2160-8407"}, "abstract": "[11C]5-Hydroxy-tryptophan ([11C]5-HTP) is a Positron Emission Tomography marker for serotonergic biosynthesis and degradation, with use in imaging of neuroendocrine tumors and recently also the endocrine pancreas in diabetes. In order to further develop [11C]5-HTP as a quantitative in vivo tool for understanding the mechanisms of serotonin signaling in human pancreas, we aimed to develop a kinetic modeling approach sensitive for changes in serotonin biosynthesis, retention and degradation. Cynomolgus monkeys were examined by [11C]5-HTP PET/CT, either at baseline (n=9) or following intravenous pretreatment with 3 mg/kg carbidopa (Dopa Decarboxylase inhibitor, n=3) or 2 mg/kg clorgyline (Monoamine Oxidase-A inhibitor, n=5). The dynamic tissue uptake was analysed by a 2-tissue compartment model including an efflux mechanism from the second tissue compartment (2TC kloss), which theoretically reproduces the known processing of 5-HTP in neuroendocrine cells. The 2TC kloss model could accurately describe all three modes of tissue kinetics depending on the pretreatment regiment. Rate constant k3 (corresponding to DDC activity) and the macro-parameter Flux (Ki) was decreased (P<0.05) by carbidopa pretreatment, while k2 (corresponding to cellular washout of intact [11C]5-HTP) was increased (P<0.05). The efflux parameter kloss (corresponding to MAO-A activity) was decreased (P<0.05) by pretreatment of clorgyline, while the macro-parameter Flux/Efflux ratio (Ki/kloss) was increased (P<0.0001). We present a compartment model analysis method that can quantitatively assess in vivo pharmacological interactions with several of the key enzymatic steps of the serotonergic biosynthesis in pancreas.", "doi": null, "pmid": "33224618", "labels": {"SciLifeLab Fellow": null, "Olof Eriksson": null}, "xrefs": [{"db": "pmc", "key": "PMC7675115"}], "notes": [], "created": "2023-05-14T14:53:47.354Z", "modified": "2025-12-01T13:35:52.000Z"}, {"entity": "publication", "iuid": "828640fda961421082598ddb6c3a6cc6", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/828640fda961421082598ddb6c3a6cc6.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/828640fda961421082598ddb6c3a6cc6"}}, "title": "Dosimetry of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in rodents, pigs, non-human primates and human - repeated scanning in human is possible.", "authors": [{"family": "Selvaraju", "given": "Ram Kumar", "initials": "RK"}, {"family": "Bulenga", "given": "Thomas N", "initials": "TN"}, {"family": "Espes", "given": "Daniel", "initials": "D", "orcid": "0000-0001-8843-7941", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/80736c5043194099992841a2a2a161f9.json"}}, {"family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}}, {"family": "S\u00f6rensen", "given": "Jens", "initials": "J"}, {"family": "Eriksson", "given": "Barbro", "initials": "B"}, {"family": "Estrada", "given": "Sergio", "initials": "S"}, {"family": "Velikyan", "given": "Irina", "initials": "I", "orcid": "0000-0002-3732-8857", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/947ae561cd794e5b94c6736880620287.json"}}, {"family": "Eriksson", "given": "Olof", "initials": "O", "orcid": "0000-0002-2515-8790", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/85991bf00e4b4a26ab15599d25c58601.json"}}], "type": "journal article", "published": "2015-02-15", "journal": {"title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "volume": "5", "issue": "3", "pages": "259-269", "issn-l": "2160-8407"}, "abstract": "Quantitative PET imaging with [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 has potential use in diabetes and cancer. However, the radiation dose to the kidneys has been a concern for the possibility of repeated imaging studies in humans. Therefore, we investigated the dosimetry of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 based on the biodistribution data in rats, pigs, non-human primates (NHP) and a human.Organ distribution of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in rats (Male Lewis; n=12; 30, 60, and 80 min) was measured ex vivo. The dynamic uptake of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in the abdomen was assessed by PET/CT scanning of pigs (male; n = 4, 0-60 min), NHP (Female; cynomolgus; n=3; 0-90 min), and human (female; n=1; 0-40, 100, 120 min).The organ distribution data in each species were extrapolated to those of a human, assuming similar distribution between the species. Residence times were assessed by trapezoidal approximation of the kinetic data. Organ doses (mGy/MBq) and the whole body effective dose (mSv/MBq), was extrapolated by using the OLINDA/EXM 1.1 software. The extrapolated human whole body effective dose was 0.017 \u00b1 0.004 (rats), 0.014 \u00b1 0.004 (pigs), 0.017 \u00b1 0.004 (NHP), and 0.016 (human) mSv/MBq. The absorbed dose to the kidneys was limiting:0.33 \u00b1 0.06 (rats), 0.28\u00b10.05 (pigs), 0.65 \u00b1 0.11 (NHP), and 0.28 (human) mGy/MBq, which corresponded to the maximum yearly administered amounts of 455 (rat), 536 (pig), 231 (NHP), and 536 (human) MBq before reaching the yearly kidney limiting dose of 150 mGy. More than 200 MBq of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 can be administered yearly in a human, allowing for repeated (2-4 times) scanning. This potentially enables longitudinal clinical PET imaging studies of the GLP-1R in the pancreas, transplanted islets, or insulinoma.", "doi": null, "pmid": "26069859", "labels": {"Olof Eriksson": null, "SciLifeLab Fellow": null}, "xrefs": [{"db": "pmc", "key": "PMC4446394"}], "notes": [], "created": "2020-10-06T13:53:32.732Z", "modified": "2025-11-17T09:33:25.651Z"}]}