• An Acylation-Finkelstein Approach to Radioiodination of Bioactives: The Role of Amide Group Anchimeric Assistance 

      Fjellaksel, Richard; Dugalic, Damir; Demissie, Taye Beyene; Riss, Patrick; Hjelstuen, Ole Kristian; Sundset, Rune; Hansen, Jørn H (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-28)
      Herein, we report a straightforward sequential acylation‐Finkelstein approach to achieve iodination of amine containing bioactives. The utility was demonstrated by successful radiolabelling with <sup>123</sup>I in high radiochemical yield. Moreover, microwave‐assisted Finkelstein reaction can be employed to enhance conversion and reaction rates to obtain the desired iodides. The method is of interest ...
    • Catalytic Intermolecular Functionalization of Benzimidazoles 

      Hansen, Jørn H; Fjellaksel, Richard (Peer reviewed; Chapter; Bokkapittel, 2019-06-25)
      This chapter describes contemporary strategies for selective catalytic intermolecular functionalization of the benzimidazole scaffold. Functionalization at nitrogen and position C-2 is well developed employing copper, palladium, rhodium, nickel, and cobalt catalysis. Direct CH activation is the predominant approach to C-2 functionalization. Nickel-based catalysts can activate C—O bonds in conjunction ...
    • Development and evaluation of gonadotropin releasing hormone antagonists as SPECT radiotracers 

      Fjellaksel, Richard (Doctoral thesis; Doktorgradsavhandling, 2018-05-24)
      The overall aim of the thesis was to evaluate the potential of gonadotropin releasing hormone receptor (GnRH-R) antagonists as radiotracers for the early detection and understanding of Alzheimer`s disease (AD). The molecular imaging field is a symbiosis between organic chemistry, radiochemistry, in vitro biology, as well as preclinical- and clinical trials, therefore an evaluation should involve all ...
    • Diagnostiske PET - radiofarmaka i Norge - klinisk bruk og utvikling 

      Johansen, Kurt Jonny; Fjellaksel, Richard (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-23)
      Hensikt - Formålet med denne artikkelen er å gi en oversikt over bruk og utvikling av PETradiofarmaka i Norge.<p> <p>Kunnskapsgrunnlag/Metode - Artikkelen bygger på innrapporterte tall over antall administrasjoner av radiofarmaka fra helseforetakene til Direktoratet for strålevern og atomsikkerhet (DSA). Det ble benyttet ikke-systematisk litteratursøk i PubMed og Google Scholar frem til ...
    • Discovery of a lead brain-penetrating gonadotropin-releasing hormone receptor antagonist with saturable binding in brain 

      Bekker, Roberto Bartholomeus Wilhelmus; Fjellaksel, Richard; Hjornevik, Trine; Nuruddin, Syed; Rafique, Waqas; Hansen, Jørn H; Sundset, Rune; Haraldsen, Ira Hebold; Riss, Patrick (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-16)
      We report the synthesis, radiosynthesis and biological characterisation of two gonadotropin‐releasing hormone receptor (GnRH−R) antagonists with nanomolar binding affinity. A small library of GnRH−R antagonists was synthesised in 20–67 % overall yield with the aim of identifying a high‐affinity antagonist capable of crossing the blood–brain barrier. Binding affinity to rat GnRH−R was determined by ...
    • Evaluation by metabolic profiling and in vitro autoradiography of two promising GnRH‐receptor ligands for brain SPECT imaging 

      Fjellaksel, Richard; Moldes-Anaya, Angel; Vasskog, Terje; Oteiza, Ana; Martin-Armas, Maria Montserrat; Hjelstuen, Ole Kristian; Hansen, Jørn H; Riss, Patrick; Sundset, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-18)
      The increased expression of gonadotropin releasing hormone receptor (GnRH‐R) in brain has been strongly linked to Alzheimer disease. Therefore, the development of radiolabeled imaging agents for GnRH‐R is relevant for early diagnosis of Alzheimer disease. We have recently disclosed the discovery of two promising compounds displaying nanomolar‐range affinity for the GnRH‐R. In the present study, a ...
    • First in vivo evaluation of a potential SPECT brain radiotracer for the gonadotropin releasing hormone receptor 

      Fjellaksel, Richard; Oteiza, Ana; Martin, armas maria montserrat; Riss, Patrick; Hjelstuen, Ole Kristian; Kuttner, Samuel; Hansen, Jørn H; Sundset, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-09)
      <p><i>Objectives</i>: In vivo evaluations of a gonadotropin releasing hormone-receptor single photon emission computed tomography radiotracer for non-invasive detection of gonadotropin releasing homone-receptors in brain.</p> <p><i>Results</i>: We have used a simple, robust and high-yielding procedure to radiolabel an alpha-halogenated bioactive compound with high radiochemical yield. Literature ...
    • Ny diagnostikk for Alzheimers i Nytt Senter 

      Fjellaksel, Richard; Hjelstuen, Ole Kristian; Sundset, Rune (Chronicle; Kronikk, 2015-04-23)
    • Radiography students´ experience using e-learning module in the subject nuclear medicine 

      Johansen, Kurt Jonny; Fjellaksel, Richard (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-24)
      Bachelor's degree in radiography is a high-tech health education. The subject nuclear medicine has been characterized by traditional and passive teaching methods with demotivated and inactive radiography students. As a tool to promote student activity, motivation, and learning, we developed and applied a new digital online teaching module in the subject nuclear medicine. In this study, we seek answers ...
    • Rapport - Workshop om fremtidens skredopplæring 

      Dassler, Tim; Skille, Tarjei Tveito; Pfuhl, Gerit; Fjellaksel, Richard (Research report; Forskningsrapport, 2023)
      2. november 2023 gjennomførte Norskred i samarbeid med Nortind, Den norske turistforeningen (DNT), Norsk fjellsportforum (NF) og UiT CARE – senter for snøskredforskning en workshop om fremtidens skredopplæring i Norge. Workshopen ble arrangert dagen før den nordiske skredkonferansen 2023 på Oppdal.<p> <p>Dagens modell for skredopplæring inneholder mange læringsmål og en kursstige som virker å ...
    • Small molecule piperazinyl-benzimidazole antagonists of the gonadotropin-releasing hormone (GnRH) receptor 

      Fjellaksel, Richard; Boomgaren, Marc; Sundset, Rune; Haraldsen, Ira Hebold; Hansen, Jørn H; Riss, Patrick (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-14)
      In this communication, we report the synthesis and characterization of a library of small molecule antagonists of the human gonadotropin releasing hormone receptor based upon the 2-(4-<i>tert</i>-butylphenyl)-4-piperazinyl-benzimidazole scaffold <i>via</i> Cu-catalysed azide alkyne cycloaddition. Our main purpose was to find a more soluble compound based on the WAY207024 lead with nanomolar potency ...
    • Stability evaluation of [ 18F]FDG: literature study, stability studies from two diferent PET centres and future recommendations 

      Holler, Jes Gitz; Renmælmo, Børge; Fjellaksel, Richard (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-24)
      Background: The need for a stability evaluation of [ <sup>18</sup>F]FDG is evident. The main purpose of this study was to make recommendations for determining the shelf life based on the available stability literature and our own two-centre stability studies.<p> <p>Results: We performed a non-systematic literature study to fnd the most relevant stability data for [ <sup>18</sup>F]FDG. The amount ...
    • Utøvelse og utvikling av radiografifaget i Norge. En kvalitativ studie 

      Egestad, Helen; Hofvind, Solveig Sand-Hanssen; Fjellaksel, Richard (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-18)
      Innledning - Økt arbeidstempo og mer krevende arbeidsoppgaver gjør at radiografer har behov for å videreutvikle kunnskaper og ferdigheter. Hensikten med studien var å undersøke hvordan norske radiografer opplever arbeidshverdagen og hvilke muligheter de har for å opprettholde og øke egen fagutvikling. <p> <p>Materiale og metode - Vi gjennomførte semistrukturerte intervjuer av ti radiografer fra ...