Linked Life Data

8183993

Source:http://linkedlifedata.com/resource/pubmed/id/8183993

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-6-14
pubmed:abstractText
The micronucleus assay is a convenient, in situ method for observing cell damage resulting from exposure to clastogenic agents and has been widely used as a dosimeter of human exposure to radiation or chemicals. It also is a complement to the classic clonogenic cell survival assay in that it can be used to examine radiation damage vs dose as a function of cell type or radiation quality. Digitized imaging densitometry was conducted on CHO cells that have undergone one division and in which further cytokinesis was blocked to collect data on the distributions of percentage total cellular DNA per micronucleus and frequency of micronuclei per cell after gamma irradiation in G1 phase. Theoretical counterparts to both classes of distributions were generated by a Monte Carlo double-strand breakage (DSB) simulation to the CHO genome, followed by simulated repair of this initial damage using a Markov chain algorithm that assumes linear restitutions of single DSBs complete with quadratic, incomplete exchanges among pairs of DSBs. Micronuclei were presumed to consist of single acentric fragments (including fused acentric pairs). The empirical distributions, when compared to their fitted theoretical counterparts, suggest, inter alia, that: (1) a slight dependence of micronucleus size on dose exists, with a trend toward higher density in the 2-4% genome range, at the expense of the 0-2% range, with increasing dose; (2) the probability of exchange incompleteness is at least 20%; and (3) the dispersions of the micronucleus frequency distributions are progressively lower than their (essentially constant) counterparts with increasing dose. Suggested is a cooperative increase in the number of fragments per micronucleus with increasing dose. Beyond these specific results, however, it is clear that furthering the understanding of the connection between DNA aberrations and formation of micronuclei would further link these two large bodies of data.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0033-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
239-45
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
A Monte Carlo/Markov chain model for the association of data for chromosome aberrations and formation of micronuclei.
pubmed:affiliation
Joint Center for Radiation Therapy, Harvard Medical School, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article