Read by QxMD icon Read


Hema S Krishnan, Vadim Bernard-Gauthier, Michael Stephen Placzek, Kenneth Dahl, Vidya Narayanaswami, Elijahu Livni, Zhen Chen, Jing Yang, Thomas Lee Collier, Chongzhao Ran, Jacob M Hooker, Steven H Liang, Neil Vasdev
Dyshomeostasis or abnormal accumulation of metal ions such as copper, zinc and iron have been linked to the pathogenesis of multiple neurodegenerative disorders including Alzheimer's disease (AD) and Huntington's disease (HD). 5,7-Dichloro-2-((dimethylamino)methyl)quinolin-8-ol, PBT2, is a second generation metal protein-attenuating compound that has recently advanced in Phase II clinical trials for the treatment of AD and HD based on promising preclinical efficacy data. Herein, we report the first radiosynthesis and preclinical positron emission tomography (PET) neuroimaging evaluation of [11C]PBT2 in rodents and nonhuman primates...
January 3, 2018: Molecular Pharmaceutics
Fadi Zarrad, Boris D Zlatopolskiy, Philipp Krapf, Johannes Zischler, Bernd Neumaier
In a recent contribution of Scott et al., the substrate scope of Cu-mediated nucleophilic radiofluorination with [18F]KF for the preparation of 18F-labeled arenes was extended to aryl- and vinylstannanes. Based on these findings, the potential of this reaction for the production of clinically relevant positron emission tomography (PET) tracers was investigated. To this end, Cu-mediated radiofluorodestannylation using trimethyl(phenyl)tin as a model substrate was re-evaluated with respect to different reaction parameters...
December 15, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Michele Iori, Pier C Capponi, Sara Rubagotti, Luca Rosario Esposizione, Johanna Seemann, Riccardo Pitzschler, Thorsten Dreger, Debora Formisano, Elisa Grassi, Federica Fioroni, Annibale Versari, Mattia Asti
In spite of the hazard due to the radiation exposure, preparation of (90)Y- and (177)Lu-labelled radiopharmaceuticals is still mainly performed using manual procedures. In the present study the performance of a commercial automatic synthesizer based on disposable cassettes for the labelling of (177)Lu- and (90)Y-DOTA-conjugated biomolecules (namely, DOTATOC and PSMA-617) was evaluated and compared to a manual and a semiautomated approach. The dose exposure of the operators was evaluated as well. More than 300 clinical preparations of both (90)Y- and (177)Lu-labelled radiopharmaceuticals have been performed using the three different methods...
2017: Contrast Media & Molecular Imaging
Christopher M Waldmann, Adrian Gomez, Phillip Marchis, Sean T Bailey, Milica Momcilovic, Anthony E Jones, David B Shackelford, Saman Sadeghi
PURPOSE: The aim of this study was the automated synthesis of the mitochondrial membrane potential sensor 4-[(18)F]fluorobenzyl-triphenylphosphonium ([(18)F]FBnTP) on a commercially available synthesizer in activity yields (AY) that allow for imaging of multiple patients. PROCEDURES: A three-pot, four-step synthesis was implemented on the ELIXYS FLEX/CHEM radiosynthesizer (Sofie Biosciences) and optimized for radiochemical yield (RCY), radiochemical purity (RCP) as well as chemical purity during several production runs (n = 24)...
September 13, 2017: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
Kenneth Dahl, Johan Ulin, Magnus Schou, Christer Halldin
A new method for the reduction of no-carrier-added [(11) C]carbon dioxide into [(11) C]carbon monoxide ([(11) C]CO) is described, in which the reductant (zinc) is supported on fused silica particles. Using this setup, which allows for a reduction temperature (485°C) well above the melting point for zinc (420°C), radiochemical yields of up to 96% (decay-corrected) were obtained. A slight decrease in radiochemical yield was observed upon repeated [(11) C]CO productions (93 ± 3%, n = 20). The methodology is convenient and efficient and provides a straightforward path to no-carrier-added production of [(11) C]CO...
September 4, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Ya-Yao Huang, Chia-Ling Tsai, Hsiang-Ping Wen, Kai-Yuan Tzen, Ruoh-Fen Yen, Chyng-Yann Shiue
INTRODUCTION: [(18)F]Fluoromethylcholine ([(18)F]FCH) is a potent tumors imaging agent. In order to fulfill the demand of pre-clinical and clinical studies, we have developed an automated high yield one-pot synthesis of this potent tumors imaging agent. METHODS: [(18)F]FCH was synthesized using a modified TRACERlab FxFN module. Briefly, dibromomethane (10% in CH3CN) was fluorinated with K[(18)F]/K 2.2.2 in a glassy carbon reaction vessel at 120°C for about 5min to generate [(18)F]fluorobromomethane ([(18)F]FBM)...
July 15, 2017: Applied Radiation and Isotopes
Lidia Matesic, Annukka Kallinen, Ivan Greguric, Giancarlo Pascali
INTRODUCTION: The production of (18)F-radiotracers using continuous flow microfluidics is under-utilized due to perceived equipment limitations. We describe the dose-on-demand principle, whereby the back-to-back production of multiple, diverse (18)F-radiotracers can be prepared on the same day, on the same microfluidic system using the same batch of [(18)F]fluoride, the same microreactor, the same HPLC column and SPE cartridge to obtain a useful production yield. METHODS: [(18)F]MEL050, [(18)F]Fallypride and [(18)F]PBR111 were radiolabeled with [(18)F]fluoride using the Advion NanoTek Microfluidic Synthesis System...
September 2017: Nuclear Medicine and Biology
Carlotta Taddei, Salvatore Bongarzone, Antony D Gee
The development of a fast and novel methodology to generate carbon-11 carbon monoxide ([(11) C]CO) from cyclotron-produced carbon-11 carbon dioxide ([(11) C]CO2 ) mediated by a fluoride-activated disilane species is described. This methodology allows up to 74 % conversion of [(11) C]CO2 to [(11) C]CO using commercially available reagents, readily available laboratory equipment and mild reaction conditions (room temperature). As proof of utility, radiochemically pure [carbonyl-(11) C]N-benzylbenzamide was successfully synthesized from produced [(11) C]CO in up to 74 % radiochemical yield (RCY) and >99 % radiochemical purity (RCP) in ≤10 min from end of [(11) C]CO2 delivery...
June 7, 2017: Chemistry: a European Journal
Enrico Raffaele Fantoni, Diego Dal Ben, Simonetta Falzoni, Francesco Di Virgilio, Simon Lovestone, Antony Gee
BACKGROUND: The P2X7 receptor has been shown to play a fundamental role in the initiation and sustenance of the inflammatory cascade. The development of a novel fluorine-18 PET tracer superior and with a longer half-life to those currently available is a promising step towards harnessing the therapeutic and diagnostic potential offered by this target. Inspired by the known antagonist A-804598, the present study outlines the design via molecular docking, synthesis and biological evaluation of the novel P2X7 tracer [(18)F]EFB...
December 2017: EJNMMI Research
Christian Brand, Valerie A Longo, Mike Groaning, Wolfgang A Weber, Thomas Reiner
PURPOSE: The folate receptor (FR) has emerged as an interesting diagnostic and therapeutic drug target with many potential applications in oncologic and inflammatory disorders. It was therefore the aim of this study to develop a folate-derived Ga-68-based positron emission tomography (PET) imaging tracer that is straightforward to radiolabel and could be broadly used in clinical studies. We validated its target binding affinity and specificity and compared it to [(99m)Tc]EC20, the folate single-photon emission computed tomography (SPECT) imaging tracer that has been most extensively studied clinically so far...
February 13, 2017: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
Archana Mukherjee, Suresh Subramanian, Rajwardhan Ambade, Bhaurao Avhad, Ashutosh Dash, Aruna Korde
Intra-arterial injection of (131)I Lipiodol is an effective treatment option for primary hepatocellular carcinoma as it delivers high radiation dose to liver tumor tissue with minimal accumulation in adjacent normal tissue. The present article demonstrates design, fabrication, and utilization of a semiautomated radiosynthesis module for preparation of (131)I labeled Lipiodol. The radiolabeling method was standardized for preparation of patient dose of (131)I labeled Lipiodol radiochemical yield (RCY); radiochemical purity (RCP) and pharmaceutical purity of the product were determined using optimized procedures...
February 2017: Cancer Biotherapy & Radiopharmaceuticals
Lauren Radford, Fabio Gallazzi, Lisa Watkinson, Terry Carmack, Ashley Berendzen, Michael R Lewis, Silvia S Jurisson, Dionysia Papagiannopoulou, Heather M Hennkens
INTRODUCTION: A somatostatin receptor (SSTR)-targeting antagonist peptide (sst2-ANT) was radiolabeled with (99m)Tc tricarbonyl via a tridentate [N,S,N]-type ligand (L) to develop a radiodiagnostic agent, (99m)TcL-sst2-ANT, for imaging of SSTR-expressing neuroendocrine tumors. METHODS: Receptor affinity was assessed in vitro with the nonradioactive analogue, ReL-sst2-ANT, via a challenge experiment in AR42J cells with (125)I-SS-14 as the competing radioligand. Preparation of (99m)TcL-sst2-ANT was achieved via reaction of [(99m)Tc(CO)3(H2O)3](+) with L-sst2-ANT...
April 2017: Nuclear Medicine and Biology
Pradeep K Garg, Rachid Nazih, Yanjun Wu, Ravi Singh, Sudha Garg
We report the synthesis and preclinical evaluation of a (11)C-labeled probe to target melanoma using PET. Methods: The target compound 4-(11)C-methoxy N-(2-diethylaminoethyl) benzamide (4-(11)C-MBZA) was prepared via the (11)C-methylation of 4-hydroxy N-(2-diethylaminoethyl) benzamide (4-HBZA). The in vitro binding was performed using B16F1 (melanoma cells), MCF-10A (breast epithelial cells), and MDA-MB 231 (breast cancer cells). The internalization studies were conducted using B16F1 cells. In vivo biodistribution and small-animal PET imaging were performed in mice bearing B16F1 melanoma tumor xenografts...
May 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Wenjie Zhang, Zhengxin Cai, Lin Li, Jim Ropchan, Keunpoong Lim, Nabil E Boutagy, Jing Wu, John C Stendahl, Wenhua Chu, Robert Gropler, Albert J Sinusas, Chi Liu, Yiyun Huang
Reactive oxygen species (ROS) play important roles in cell signaling and homeostasis. However, an abnormally high level of ROS is toxic, and is implicated in a number of diseases. Positron emission tomography (PET) imaging of ROS can assist in the detection of these diseases. For the purpose of clinical translation of [(18)F]6-(4-((1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-5-methyl-5,6-dihydrophenanthridine-3,8-diamine ([(18)F]DHMT), a promising ROS PET radiotracer, we first manually optimized the large-scale radiosynthesis conditions and then implemented them in an automated synthesis module...
December 9, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Marc Pretze, Dominic Franck, Falk Kunkel, Erich Foßhag, Carmen Wängler, Björn Wängler
Two different strategies for the nucleophilic radiosynthesis of [(18)F]F-DOPA were evaluated regarding their applicability for an automated routine production on an Ecker&Ziegler Modular-Lab Standard module. Initially, we evaluated a promising 5-step synthesis based on a chiral, cinchonidine-derived phase-transfer catalyst (cPTC) being described to give the product in high radiochemical yields (RCY), high specific activities (AS) and high enantiomeric excesses (ee). However, the radiosynthesis of [(18)F]F-DOPA based on this strategy showed to be highly complex, giving the intermediate products as well as the final product in insufficient yields for automatization...
February 2017: Nuclear Medicine and Biology
James Kelly, Alejandro Amor-Coarasa, Anastasia Nikolopoulou, Dohyun Kim, Clarence Williams, Shashikanth Ponnala, John W Babich
PURPOSE: Current clinical imaging of PSMA-positive prostate cancer by positron emission tomography (PET) mainly features (68)Ga-labeled tracers, notably [(68)Ga]Ga-PSMA-HBED-CC. The longer half-life of fluorine-18 offers significant advantages over Ga-68, clinically and logistically. We aimed to develop high-affinity PSMA inhibitors labeled with fluorine-18 as alternative tracers for prostate cancer. METHODS: Six triazolylphenyl ureas and their alkyne precursors were synthesized from the Glu-urea-Lys PSMA binding moiety...
April 2017: European Journal of Nuclear Medicine and Molecular Imaging
Pu Zhang, Rongqiang Zhuang, Zhide Guo, Xinhui Su, Xiaoyuan Chen, Xianzhong Zhang
A convenient and quantitative radioiodination method by copper-mediated cross-coupling of aryl boronic acids was developed. The mild labeling conditions, ready availability of the boronic acid substrate, simple operation, broad functional group tolerance and excellent radiochemical yield (RCY) make this a practical strategy for radioiodine labeling without further purification.
November 14, 2016: Chemistry: a European Journal
Christian Drerup, Johannes Ermert, Heinz H Coenen
Nitric oxide (NO), an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS) and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible) or nNOS (neuronal) are of great interest for decoding neurodestructive key factors, and (18)F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((3-fluorophenethylamino)methyl)phenoxy)methyl)-4-methylpyridin-2-amine (10) lends itself as suitable compound to be (18)F-labelled in no-carrier-added (n...
September 1, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Benjamin H Rotstein, Lu Wang, Richard Y Liu, Jon Patteson, Eugene E Kwan, Neil Vasdev, Steven H Liang
Synthesis of non-activated electron-rich and sterically hindered (18)F-arenes remains a major challenge due to limitations of existing radiofluorination methodologies. Herein, we report on our mechanistic investigations of spirocyclic iodonium(III) ylide precursors for arene radiofluorination, including their reactivity, selectivity, and stability with no-carrier-added [(18)F]fluoride. Benchmark calculations at the G2[ECP] level indicate that pseudorotation and reductive elimination at iodine(III) can be modeled well by appropriately selected dispersion-corrected density functional methods...
July 1, 2016: Chemical Science
Alex Khoshnevisan, Krisanat Chuamsaamarkkee, Mehdi Boudjemeline, Alex Jackson, Gareth E Smith, Antony D Gee, Gilbert O Fruhwirth, Philip J Blower
Anion transport by the human sodium-iodide symporter (hNIS) is an established target for molecular imaging and radionuclide therapy. Current radiotracers for PET of hNIS expression are limited to (124)I(-) and (18)F-BF4(-) We sought new (18)F-labeled hNIS substrates offering higher specific activity, higher affinity, and simpler radiochemical synthesis than (18)F-BF4(-) METHODS: The ability of a range of anions, some containing fluorine, to block (99m)TcO4(-) uptake in hNIS-expressing cells was measured. SO3F(-) emerged as a promising candidate...
January 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"