Beitrag zum Verständnis der biologischen Wirksamkeit des Auger-Elektronen emittierenden Radionuklids $^{125}$I in menschlichen Zellen
Beitrag zum Verständnis der biologischen Wirksamkeit des Auger-Elektronen emittierenden Radionuklids $^{125}$I in menschlichen Zellen
The Auger-electron-emitter $^{125}$I was positioned in different compartments of human cellsby the use of three carrier molecules ($^{125}$I-iododeoxyuridine for DNA-incorporation, $^{125}$I-antipyrine for distribution throughout the whole cell, and Na$^{125}$I for extracellular positioning)and the...
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Personal Name(s): | Zerhusen, Sandra (Corresponding author) |
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Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
2001
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Physical Description: |
119 p. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Berichte des Forschungszentrums Jülich
3882 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
The Auger-electron-emitter $^{125}$I was positioned in different compartments of human cellsby the use of three carrier molecules ($^{125}$I-iododeoxyuridine for DNA-incorporation, $^{125}$I-antipyrine for distribution throughout the whole cell, and Na$^{125}$I for extracellular positioning)and the effects were compared with those of $^{137}$Cs-$\gamma$-radiation. With regard to a clinicalapplication in the adjuvant radiotherapy of tumors, all experiments were carried out underphysiological conditions. The two dominant biological endpoints were clonogenic survivaland molecular DNA damage measured by the alkaline comet assay.In a comparison of the carrier molecules $^{125}$IUdR demonstrated the most radiotoxic effectwhereas $^{125}$I-antipyrine was obviously less effective. Na $^{125}$I hardly produced any biologicaleffect. The declining radiotoxicity of the $^{125}$I-labeled carrier molecules was explained bythe increasing distance of the $^{125}$I-decay site from the DNA. A strong correlation was foundbetween increasing DNA damage and reduced colony-forming ability.The biological effects of $^{125}$I were compared with those of the reference radiation $^{137}$Cs-$\gamma$,but only for $^{125}$I-antipyrine, which distributed its energy nearly homogeneously throughoutthe cell, was a dose calculation possible. A quantitative assessment of the biologicalefficacy for $^{125}$IUdR was made for the first time by efficacy factors focusing on a definiteendpoint. Efficacy factors of 24 - 28 were found for $^{125}$IUdR relative to the 37%-survivingfraction and compared with $^{137}$Cs-$\gamma$-radiation. |