PMID- 9729276
OWN - NLM
STAT- MEDLINE
DCOM- 19981002
LR  - 20190702
IS  - 0027-5107 (Print)
IS  - 0027-5107 (Linking)
VI  - 404
IP  - 1-2
DP  - 1998 Aug 3
TI  - Kinetics of the formation of chromosome aberrations in X-irradiated human 
      lymphocytes, using PCC and FISH.
PG  - 55-65
AB  - In order to study the initial frequencies and define kinetics of the formation of 
      chromosomal exchanges in X-irradiated human lymphocytes, the premature chromosome 
      condensation (PCC) technique was employed in combination with fluorescence in 
      situ hybridization (FISH) with a composite probe for human chromosome 8 and a 
      pan-centromeric probe for the whole genome. Human lymphocytes were X-irradiated 
      (0.5, 1, 2, 3, 4 and 6 Gy), fused with mitotic Chinese hamster ovary (CHO) cells 
      immediately or 1, 3, 6, 12 and 18 h after irradiation. Immediately after 
      irradiation chromosomal breaks, dicentrics and translocations showed a linear 
      dose-response. Unrejoined chromosome breaks were the most frequent types of 
      aberrations (about 85%) observed. About 15% of total aberrations were chromosome 
      exchanges of 65% of these were translocations and 35% were dicentrics. The 
      chromosomal exchanges initially observed were mostly incomplete, with no complex 
      exchanges at doses of 1 and 2 Gy, at higher doses (3-6 Gy) complex exchanges were 
      observed and their frequencies increased with increasing post incubation time. 
      Following different recovery times, repair kinetics of breaks for different doses 
      of irradiation was studied. The shapes of the curves obtained for breaks as well 
      as chromosome exchanges were linear-quadratic. The linear yield component, alpha, 
      is formed entirely in the fast process that can be manifested in the early 
      plateau, while component beta developed slowly in the subsequent hours. The 
      kinetics of breaks rejoining was exponential, almost 50% of breaks rejoined after 
      1 h and at 18 h about 20% of breaks remained. At low doses of 1 and 2 Gy most of 
      the exchanges were formed immediately and at higher doses, the frequency of 
      exchanges increased with kinetics similar to that observed for the rejoining of 
      breaks. However, the kinetics was different for different doses of irradiation. 
      The frequency of dicentrics increased at doses above 2 Gy following 3 h recovery 
      time, but for the translocations effect was pronounced even at 1 h recovery time. 
      The frequency of incomplete exchanges (i.e., terminal translocations) decreased 
      with post irradiation time and at 18 h was 30-40% less than the frequency 
      obtained immediately after irradiation. The increase in the total translocations 
      as a function of time between irradiation and fusion was due to a rapid increase 
      in complete exchanges (i.e., reciprocal translocations). The frequency of ring 
      chromosomes immediately after irradiation, also increased linearly, however, it 
      was 3-5 times lower than dicentrics and remained almost constant in number for 
      different doses and at different post-irradiation times.
CI  - Copyright 1998 Elsevier Science B. V.
FAU - Darroudi, F
AU  - Darroudi F
AD  - MGC, Department of Radiation Genetics and Chemical Mutagenesis, University of 
      Leiden Medical Centre, Wassenaarseweg 72, 2333 AL Leiden, Netherlands. 
      darroudi@rullf2.medfac.leidenuniv.nl
FAU - Fomina, J
AU  - Fomina J
FAU - Meijers, M
AU  - Meijers M
FAU - Natarajan, A T
AU  - Natarajan AT
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Mutat Res
JT  - Mutation research
JID - 0400763
SB  - IM
MH  - Animals
MH  - CHO Cells
MH  - Cell Fusion/radiation effects
MH  - Chromosome Aberrations/*genetics
MH  - Chromosome Breakage/genetics
MH  - Chromosomes/*radiation effects
MH  - Cricetinae
MH  - Dose-Response Relationship, Radiation
MH  - Humans
MH  - In Situ Hybridization, Fluorescence
MH  - Kinetics
MH  - Lymphocytes/*radiation effects
MH  - Translocation, Genetic/genetics
MH  - X-Rays
EDAT- 1998/09/05 00:00
MHDA- 1998/09/05 00:01
CRDT- 1998/09/05 00:00
PHST- 1998/09/05 00:00 [pubmed]
PHST- 1998/09/05 00:01 [medline]
PHST- 1998/09/05 00:00 [entrez]
AID - S0027-5107(98)00095-5 [pii]
AID - 10.1016/s0027-5107(98)00095-5 [doi]
PST - ppublish
SO  - Mutat Res. 1998 Aug 3;404(1-2):55-65. doi: 10.1016/s0027-5107(98)00095-5.