Premature chromosome condensation assay for biodosimetry: studies with fission-neutrons.
Characterization of the premature chromosome condensation assay for radiation quality is needed. To that end, human lymphocytes were exposed in vitro to various doses of 250-kVp x rays (Y(D) = 4 keV microm(-1), Y(D) is the dose-mean lineal energy of the absorbed dose distribution, D(y), where y is defined as the energy deposited in a volume by a single event divided by the mean chord length of the volume) and to fission neutrons (Y(D) = 65 keV microm(-1)). The distribution of prematurely condensed chromosome and fragments following exposure to x rays or to neutrons were non-Poisson after repair at 37 degrees C for 24 h. Dose-response curves were constructed for the yield of excess prematurely condensed chromosome fragments as necessary for biodosimetry applications. The curves were fitted to a weighted linear model by the least-squares regression method. The neutron relative biological effectiveness (RBE) value was estimated to be 2.4 +/- 0.39.
Prasanna
P G
PG
Armed Forces Radiobiology Research Institute, Bethesda, MD 20889-5603, USA.
Kolanko
C J
CJ
Gerstenberg
H M
HM
Blakely
W F
WF
D000818:Animals; D016466:CHO Cells; D002877:Chromosomes, Human / Q000528:radiation effects*; D006224:Cricetinae; D005069:Evaluation Studies as Topic; D005214:Fast Neutrons; D006801:Humans; D066298:In Vitro Techniques; D018499:Linear Energy Transfer; D008214:Lymphocytes / Q000528:radiation effects; D011874:Radiometry / Q000379:methods*; D012062:Relative Biological Effectiveness