0000000000292139
AUTHOR
Padmakar V Kulkarni
UTSW Small Animal Positron Emission Imager
A Small Animal Imager (SAI) for PET has been designed, built, tested in phantoms, and applied to investigations in mice and rats. The device uses principles based on gamma-ray induced scintillation in crossed fiber optic detectors connected to Position Sensitive Photomultiplier Tubes (PSPMT). Each detector consists of an epoxied stack of 28 layers of 135 round 1 mm BCF-10 scintillating plastic fibers. The overlap region forms a 13.5times13.5times2.8 cm3 detector volume. Scintillating light from the fibers is detected by two (X and Y directions) Hamamatsu R-2486 PSPMTs with 16 anode wires in each of two orthogonal directions. A centroid-finding algorithm gives the position of a light cluster…
Vascular imaging of solid tumors in rats with a radioactive arsenic-labeled antibody that binds exposed phosphatidylserine.
Abstract Purpose: We recently reported that anionic phospholipids, principally phosphatidylserine, become exposed on the external surface of vascular endothelial cells in tumors, probably in response to oxidative stresses present in the tumor microenvironment. In the present study, we tested the hypothesis that a chimeric monoclonal antibody that binds phosphatidylserine could be labeled with radioactive arsenic isotopes and used for molecular imaging of solid tumors in rats. Experimental Design: Bavituximab was labeled with 74As (β+, T1/2 17.8 days) or 77As (β−, T1/2 1.6 days) using a novel procedure. The radionuclides of arsenic were selected because their long half-lives are consistent w…
A new method for radiochemical separation of arsenic from irradiated germanium oxide.
Abstract Radioarsenic labelled radiopharmaceuticals could be a valuable asset to Positron Emission Tomography (PET). In particular, the long half-lives of 72 As ( T 1/2 =26 h) and 74 As ( T 1/2 =17.8 d) allow to investigate slow physiological or metabolical processes, like the enrichment and distribution of antibodies in tumor tissue. This work describes the direct production of no-carrier-added (nca) arsenic isotopes *As, with *=71, 72, 73, 74 or 77, the reaction to [*As]AsI 3 and its radiochemical separation from the irradiated solid germanium oxide via polystyrene-based solid-phase extraction. The germanium oxide target, irradiated at a cyclotron or a nuclear reactor, is dissolved in con…
A no-carrier-added72Se/72As radionuclide generator based on solid phase extraction
Summary72As-labelled radiopharmaceuticals could be a valuable resource for Positron Emission Tomography (PET). In particular, the long half-life of72As (T1/2= 26 h) facilitates the observation of long-term physiological or metabolic processes, such as the enrichment and distribution of antibodies in tumor tissue. This work describes the primary radiochemical separation of no-carrier-added (nca)72Se from cyclotron irradiated germanium targets and the development of a polystyrene type solid-phase extraction based72Se/72As radionuclide generator, avoiding the addition of any selenium carrier. The irradiated germanium target is dissolved in HFconcand selenium is reduced with hydrazine dihydroch…