Linked Life Data

8551107

Source:http://linkedlifedata.com/resource/pubmed/id/8551107

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-2-22
pubmed:abstractText
We have investigated the properties of an in vitro cell survival assay that uses as its endpoint the ability to form polyploid cells (polykaryons) in the presence of cytochalasin B (CB). The criterion for survival is that a polykaryon-forming unit (PFU) must reach the arbitrary DNA content of at least 16C. The age-dependence of PFU sensitivity to 137Cs irradiation was determined using V79-379A cells synchronized at mitosis. Cells assayed as PFUs demonstrated much less variation in radiosensitivity with age than did clonogens, but the changes in curve shape were qualitatively similar. In both assays mitotic cells yielded an exponential survival curve while that obtained at 5 h (mid-late S) had a marked quadratic component. Owing to the small overall variation in PFU survival with age, at doses greater than about 25 Gy the surviving fraction at 5 h was lower than in mitosis. In both V79-379A and HeLa S3 cells, PFUs demonstrated a capacity for split-dose recovery and yielded recovery ratios at 2.6 at 50 Gy in V79 and 1.5 at 20 Gy in HeLa. Since these ratios were much lower than in clonogens at the same dose, we suggest that this is consistent with an association that we have previously demonstrated between PFU response and the clonogenic initial slope. In an attempt to clarify the DNA lesions to which PFUs may be sensitive, we determined PFU response following exposure to 254-nm UV irradiation. In contrast with ionizing radiation, PFU response to UV was very similar to that of clonogens. This suggests that following UV exposure the absence of cytokinesis in polykaryons may confer less protection than in the case of ionizing radiation, possibly due to fundamental differences in the spectrum of DNA lesions produced.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0955-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
68
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
647-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Variation in radiosensitivity due to cell age and split-dose recovery in polykaryons induced by cytochalasin.
pubmed:affiliation
Radiation Science Unit, Velindre Hospital NHS Trust, Cardiff, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't