Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Copper-64 (T 1/2 = 12.7 h) is an intermediate-lived positron-emitting radionuclide that is a useful radiotracer for positron emission tomography (PET) as well as a promising radiotherapy agent for the treatment for cancer. Currently, copper-64 suitable for biomedical studies is produced in the fast neutron flux trap (irradiation of zinc with fast neutrons) at the Missouri University Research Reactor. Access to the fast neutron flux trap is only possible on a weekly basis, making the availability of this tracer very limited. In order to significantly increase the availability of this intermediate-lived radiotracer, we have investigated and developed a method for the efficient production of high specific activity Cu-64 using a small biomedical cyclotron. It has been suggested that it may be possible to produce Cu-64 on a small biomedical cyclotron utilizing the 64Ni(p,n)64Cu nuclear reaction. We have irradiated both natural nickel and enriched (95% and 98%) Ni-64 plated on gold disks. Nickel has been electroplated successfully at thicknesses of approximately 20-300 mm and bombarded with proton currents of 15-45 microA. A special water-cooled target had been designed to facilitate the irradiations on a biomedical cyclotron up to 60 microA. We have shown that it is possible to separate Cu-64 from Ni-64 and other reaction byproducts rapidly and efficiently by using ion exchange chromatography. Production runs using 19-55 mg of 95% enriched Ni-64 have yielded 150-600 mCi of Cu-64 (2.3-5.0 mCi/microAh) with specific activities of 94-310 mci/microgram Cu. The cyclotron produced Cu-64 had been used to radiolabel PTSM [pyruvaldehyde bis-(N4-methylthiosemicarbazone), used to quantify myocardial, cerebral, renal, and tumor blood flow], MAb 1A3 [monoclonal antibody MAb to colon cancer], and octreotide. A recycling technique for the costly Ni-64 target material has been developed. This technique allows the nickel eluted off the column to be recovered and reused in the electroplating of new targets with an overall efficiency of greater than 90%.
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PMID:Efficient production of high specific activity 64Cu using a biomedical cyclotron. 908 Apr 73

Laparoscopic colectomy for curable colon cancer may result in the development of abdominal wall implants because of disseminated disease and the favorable environment of the wound site for cell implantation. Injection of disaggregated human GW39 colon cancer cells into the hamster peritoneum represents a model of tumor spillage that may occur during dissection, manipulation, resection, and extraction of tumor during surgery in the clinical setting. Using this well-established animal model, we tested the efficacy of (64)Cu-pyruvaldehyde-bis(N(4)-methylthiosemicarbazone) ((64)Cu-PTSM) in inhibiting tumor cell implantation in trocar wound sites. Anesthetized hamsters had four 5-mm trocars inserted through the anterior abdominal wall. GW39 cells ( approximately 3.2 x 10(4) cells in 0.5 ml) were injected into the peritoneum through a midline incision. Ten min later, hamsters were randomized to receive 5, 3, or 1 mCi of (64)Cu-PTSM through the same midline incision. High-resolution magnetic resonance imaging and microPET were used to monitor tumor volume and morphology after surgery. After 7 weeks, animals were sacrificed, and trocar and midline wounds were harvested for macroscopic and histological analysis. No macroscopic tumor was found in any of the group treated with 5 mCi of (64)Cu-PTSM, whereas 96% of the wound sites in the group treated with saline had macroscopic tumor growth (P < 0.001). This study demonstrates the therapeutic potential of (64)Cu-PTSM in inhibiting cancer cell implantation and growth at doses well below the maximum tolerated dose, with no signs of toxicity to the hamsters.
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PMID:Copper-64-pyruvaldehyde-bis(N(4)-methylthiosemicarbazone) for the prevention of tumor growth at wound sites following laparoscopic surgery: monitoring therapy response with microPET and magnetic resonance imaging. 1180 94