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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1995-1-30
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pubmed:abstractText |
To improve tumor:tissue ratios in immunoscintigraphy, a three-step targeting method has been developed. The reagents used were (a) a radioactive, low molecular weight chelate prepared from ionic gallium and a phenolic polyaminocarboxylic acid, which can be labeled either with the single-photon emitter 67Ga or with the short-lived positron emitter 68Ga (t1/2 = 68 min); (b) a bispecific monoclonal antibody (bs-mAb) synthesized from the F(ab)2 fragment of the 1.1ASML antibody specific for the glycoprotein CD44v associated with a rat pancreas carcinoma cell line and the F(ab') fragment of an antibody specific for the gallium chelate; and (c) the nonradioactive gallium chelate covalently coupled to transferrin, which served as a high molecular weight blocker to prevent binding of the radioactive gallium chelate to bs-mAbs in the circulation. Targeting experiments in tumor-bearing nude mice with different doses of bs-mAbs, blocker, and 67Ga chelate were adjusted to maximize tumor to tissue contrasts and tumor uptake. Compared with the biodistribution of the 131I-labeled, native 1.1ASML antibody 24 h postinjection, a schedule using 100 pmol bs-mab 24 h later 100 pmol blocker, 15 min later 16 pmol 67Ga chelate, 1 h later examination, increased tumor:blood and tumor: liver ratios by a factor of 5 while keeping the localization of radioactivity in the tumor constant (10.1% injected dose/g). High-contrast images using either 67Ga or 68Ga were obtained within 1 h. The targeting method described enables the use of the short-lived positron emitter 68Ga and thus allows the combination of an improved immunoscintigraphy and positron emission tomography.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0008-5472
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
55
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
115-23
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:7805020-Animals,
pubmed-meshheading:7805020-Antibodies, Bispecific,
pubmed-meshheading:7805020-Chelating Agents,
pubmed-meshheading:7805020-Female,
pubmed-meshheading:7805020-Gallium Radioisotopes,
pubmed-meshheading:7805020-Mice,
pubmed-meshheading:7805020-Mice, Nude,
pubmed-meshheading:7805020-Neoplasms, Experimental,
pubmed-meshheading:7805020-Tomography, Emission-Computed,
pubmed-meshheading:7805020-Transferrin
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pubmed:year |
1995
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pubmed:articleTitle |
Multistep tumor targeting in nude mice using bispecific antibodies and a gallium chelate suitable for immunoscintigraphy with positron emission tomography.
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pubmed:affiliation |
Department of Diagnostic and Therapeutic Radiology (FS5), German Cancer Research Center, Heidelberg.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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