Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-1-5
pubmed:abstractText
Ionizing radiations deposit a wide range of energies in and around DNA and this leads to a corresponding spectrum of complexity of the lesions induced. The relationships between the amount of energy deposited and the yields and types of damage induced are important in modelling the physical and chemical stages of radiation effect and linking them to biological outcome. To study these relationships experimentally, plasmids were mounted as a monolayer and exposed in vacuum to near-monoenergetic photons from the Daresbury Synchrotron. After irradiation, the DNA was washed off and assayed for single-(ssb) and double-strand breaks (dsb) using agarose gel electrophoresis. Dose-effect relationships for ssb and dsb induction were obtained at various energies in the range 8-25 eV. The initial responses in the low-dose region allowed damage yields to be estimated. However, a common feature is that the responses showed energy-dependent plateaus at higher doses as if a fraction of the DNA were shielded. Various measures were taken both to minimize and to correct for this effect. The data appear to show that the yields of ssb and dsb increase only slowly with photon energies > 10 eV, with a suggestion of similar threshold energies for both lesions. In the energy range covered, the yield of ssb is 12-20-fold greater than that of dsb. The data indicate that ssb and dsb may have a common precursor in this system. Earlier work with low-energy electrons showed that at 25 eV ssb were induced but no dsb were detected.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0955-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
569-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Action spectra for single- and double-strand break induction in plasmid DNA: studies using synchrotron radiation.
pubmed:affiliation
Cancer Research Campaign Gray Laboratory, Mount Vernon Hospital, Northwood, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't