The Experts below are selected from a list of 29448 Experts worldwide ranked by ideXlab platform
John A. Katzenellenbogen - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and biological evaluation of a nonsteroidal Bromine-76-labeled androgen receptor ligand 3-[76Br]bromo-hydroxyflutamide
Nuclear medicine and biology, 2006Co-Authors: Ephraim E. Parent, Carl Jenks, Terry L. Sharp, Michael J. Welch, John A. KatzenellenbogenAbstract:Abstract Introduction Androgen receptors (ARs) are overexpressed in normal tissues and in most primary and metastatic prostate cancers. In our efforts to develop a nonsteroidal AR-specific imaging agent, we synthesized (±)-3-[ 76 Br]bromo-hydroxyflutamide ( 76 Br-3), an analog of hydroxyflutamide, the active metabolite of the AR antagonist ligand flutamide. Materials and Methods 76 Br-3 was synthesized in three steps, starting with commercially available compounds. Labeling of 76 Br-3 was achieved through the nucleophilic opening of an epoxide intermediate, and a labeled compound was obtained in high specific activity and good radiochemical yield. Results and Discussion (±)-3-Bromo-hydroxyflutamide has a significantly higher affinity for ARs compared to hydroxyflutamide, its parent compound. The androgen target-tissue uptake of 76 Br-3 in diethylstilbestrol-treated male rats was examined; however, AR-mediated uptake was minimal due most likely to the rapid metabolic debromination of the radiolabeled ligand. Conclusions This study is part of our first look at a novel class of nonsteroidal AR antagonists as positron emission tomography (PET) imaging agents, which are alternatives to steroidal AR agonist-based imaging agents. Although 76 Br-3 has a significant affinity for ARs, it showed limited promise as a PET imaging agent because of its poor target-tissue distribution properties.
Ephraim E. Parent - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and biological evaluation of a nonsteroidal Bromine-76-labeled androgen receptor ligand 3-[76Br]bromo-hydroxyflutamide
Nuclear medicine and biology, 2006Co-Authors: Ephraim E. Parent, Carl Jenks, Terry L. Sharp, Michael J. Welch, John A. KatzenellenbogenAbstract:Abstract Introduction Androgen receptors (ARs) are overexpressed in normal tissues and in most primary and metastatic prostate cancers. In our efforts to develop a nonsteroidal AR-specific imaging agent, we synthesized (±)-3-[ 76 Br]bromo-hydroxyflutamide ( 76 Br-3), an analog of hydroxyflutamide, the active metabolite of the AR antagonist ligand flutamide. Materials and Methods 76 Br-3 was synthesized in three steps, starting with commercially available compounds. Labeling of 76 Br-3 was achieved through the nucleophilic opening of an epoxide intermediate, and a labeled compound was obtained in high specific activity and good radiochemical yield. Results and Discussion (±)-3-Bromo-hydroxyflutamide has a significantly higher affinity for ARs compared to hydroxyflutamide, its parent compound. The androgen target-tissue uptake of 76 Br-3 in diethylstilbestrol-treated male rats was examined; however, AR-mediated uptake was minimal due most likely to the rapid metabolic debromination of the radiolabeled ligand. Conclusions This study is part of our first look at a novel class of nonsteroidal AR antagonists as positron emission tomography (PET) imaging agents, which are alternatives to steroidal AR agonist-based imaging agents. Although 76 Br-3 has a significant affinity for ARs, it showed limited promise as a PET imaging agent because of its poor target-tissue distribution properties.
Keith S Pentlow - One of the best experts on this subject based on the ideXlab platform.
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quantitative imaging of Bromine 76 and yttrium 86 with pet a method for the removal of spurious activity introduced by cascade gamma rays
Medical Physics, 2003Co-Authors: Bradley J Beattie, Ronald D Finn, Douglas J Rowland, Keith S PentlowAbstract:Positron Emission Tomography of Bromine-76 and yttrium-86 results in the detection of coincident events that are not strictly associated with annihilation photon pairs. Instead, these coincidences occur because prompt gamma rays emitted by these nuclides result in cascades of photons that are emitted within the timing window of the PET scanner. Pairs of detected photons from these cascades are not angularly correlated and therefore contain little information regarding the location of their source. Furthermore, these coincidences are not removed by correction procedures (e.g., randoms, scatter) routinely applied to PET data. If left uncorrected, the cascade coincidences will result in spurious apparent activity within the PETimages. A correction, applied within projection space, that removes the cascade coincidence signal from septa-in (i.e., two-dimensional) datasets is proposed and tested on phantom data.
Carl Jenks - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and biological evaluation of a nonsteroidal Bromine-76-labeled androgen receptor ligand 3-[76Br]bromo-hydroxyflutamide
Nuclear medicine and biology, 2006Co-Authors: Ephraim E. Parent, Carl Jenks, Terry L. Sharp, Michael J. Welch, John A. KatzenellenbogenAbstract:Abstract Introduction Androgen receptors (ARs) are overexpressed in normal tissues and in most primary and metastatic prostate cancers. In our efforts to develop a nonsteroidal AR-specific imaging agent, we synthesized (±)-3-[ 76 Br]bromo-hydroxyflutamide ( 76 Br-3), an analog of hydroxyflutamide, the active metabolite of the AR antagonist ligand flutamide. Materials and Methods 76 Br-3 was synthesized in three steps, starting with commercially available compounds. Labeling of 76 Br-3 was achieved through the nucleophilic opening of an epoxide intermediate, and a labeled compound was obtained in high specific activity and good radiochemical yield. Results and Discussion (±)-3-Bromo-hydroxyflutamide has a significantly higher affinity for ARs compared to hydroxyflutamide, its parent compound. The androgen target-tissue uptake of 76 Br-3 in diethylstilbestrol-treated male rats was examined; however, AR-mediated uptake was minimal due most likely to the rapid metabolic debromination of the radiolabeled ligand. Conclusions This study is part of our first look at a novel class of nonsteroidal AR antagonists as positron emission tomography (PET) imaging agents, which are alternatives to steroidal AR agonist-based imaging agents. Although 76 Br-3 has a significant affinity for ARs, it showed limited promise as a PET imaging agent because of its poor target-tissue distribution properties.
Terry L. Sharp - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and biological evaluation of a nonsteroidal Bromine-76-labeled androgen receptor ligand 3-[76Br]bromo-hydroxyflutamide
Nuclear medicine and biology, 2006Co-Authors: Ephraim E. Parent, Carl Jenks, Terry L. Sharp, Michael J. Welch, John A. KatzenellenbogenAbstract:Abstract Introduction Androgen receptors (ARs) are overexpressed in normal tissues and in most primary and metastatic prostate cancers. In our efforts to develop a nonsteroidal AR-specific imaging agent, we synthesized (±)-3-[ 76 Br]bromo-hydroxyflutamide ( 76 Br-3), an analog of hydroxyflutamide, the active metabolite of the AR antagonist ligand flutamide. Materials and Methods 76 Br-3 was synthesized in three steps, starting with commercially available compounds. Labeling of 76 Br-3 was achieved through the nucleophilic opening of an epoxide intermediate, and a labeled compound was obtained in high specific activity and good radiochemical yield. Results and Discussion (±)-3-Bromo-hydroxyflutamide has a significantly higher affinity for ARs compared to hydroxyflutamide, its parent compound. The androgen target-tissue uptake of 76 Br-3 in diethylstilbestrol-treated male rats was examined; however, AR-mediated uptake was minimal due most likely to the rapid metabolic debromination of the radiolabeled ligand. Conclusions This study is part of our first look at a novel class of nonsteroidal AR antagonists as positron emission tomography (PET) imaging agents, which are alternatives to steroidal AR agonist-based imaging agents. Although 76 Br-3 has a significant affinity for ARs, it showed limited promise as a PET imaging agent because of its poor target-tissue distribution properties.
