Linked Life Data

9374440

Source:http://linkedlifedata.com/resource/pubmed/id/9374440

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1997-12-4
pubmed:abstractText
Radioiodine ((131)I) induced a dose- and time-dependent increase in DNA single-strand breaks (DNA-ssb) in human (G0) mononuclear blood cells (MNC) in vitro. Incubation of MNC with 22MBq (131)I/ml at 4 degrees C caused a linear, time-dependent induction of DNA-ssb (increase in elution rate: 24.7 x 10(-3) h(-1) per 100 min incubation with (131)I). However, if MNC were incubated at 37 degrees C a decrease in the slope of the time effect curve was observed after about 300 min incubation with 22 or 30 MBq (131)I/ml. The goodness of fit of different regression models was assessed by Akaike's Information Criterion (AIC). The best fit was obtained for a non-linear model (y=a+bx+cx(0.5); AIC=53.5; where x is incubation time and y is elution rate), whereas other models including the linear regression model y=a+bx; AIC=38.6) were worse. As the total induction of DNA-ssb at 4 degrees C was constant with time, the decrease in the slope of the time effect curve (DNA-ssb versus time) at 37 degrees C can be interpreted as an increase in rejoining of DNA-ssb. Inhibition of both RNA and protein synthesis clearly increased the extent of DNA-ssb observable after incubation with (131)I. Thus, during continuous exposure of MNC to (131)I, proteins were synthesized which rejoined DNA-ssb. However, incubation of MNC with (131)I (44 MBq/ml) at 37 degrees C under conditions expected to lead to inhibition of RNA and/or protein synthesis still resulted in a decrease of the slope of the time effect curve, indicating a stimulation of DNA-ssb rejoining. Thus, we favour the hypothesis that the increase in the activity of DNA-ssb rejoining, besides de novo synthesis of repair enzymes, is also caused by a post-translational stimulation of DNA-repair enzymes and that this stimulation possibly is mediated by DNA-fragments.
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
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
607-13
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Increase in DNA single-strand break rejoining by continuous exposure of human mononuclear blood cells to radioiodine ((131)I) in vitro.
pubmed:affiliation
Institute of Toxicology, University of Mainz, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't