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Repair of clustered DNA damage caused by high LET radiation in human fibroblastsIt has recently been demonstrated experimentally that DNA damage induced by high LET radiation in mammalian cells is non-randomly distributed along the DNA molecule in the form of clusters of various sizes. The sizes of such clusters range from a few base-pairs to at least 200 kilobase-pairs. The high biological efficiency of high LET radiation for induction of relevant biological endpoints is probably a consequence of this clustering, although the exact mechanisms by which the clustering affects the biological outcome is not known. We discuss here results for induction and repair of base damage, single-strand breaks and double-strand breaks for low and high LET radiations. These results are discussed in the context of clustering. Of particular interest is to determine how clustering at different scales affects overall rejoining and fidelity of rejoining of DNA double-strand breaks. However, existing methods for measuring repair of DNA strand breaks are unable to resolve breaks that are close together in a cluster. This causes problems in interpretation of current results from high LET radiation and will require new methods to be developed.
Document ID
20040088975
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Rydberg, B.
(Lawrence Berkeley National Laboratory, Life Sciences Division Berkeley, CA 94720, United States)
Lobrich, M.
Cooper, P. K.
Chatterjee, A.
Date Acquired
August 21, 2013
Publication Date
July 1, 1998
Publication Information
Publication: Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)
Volume: 14 Suppl 1
ISSN: 1120-1797
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: DE-AC03-76SF00098
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Radiation Health
Non-NASA Center

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