Ionising radiation, with the contribution of telomere shortening, induces DNA double-strandbreaks that result in chromosome end fusion, nucleoplasmic bridges (NPBs) and chromosomeaberrations (ChAbs) as well as dicentric chromosomes. In order to investigate the chromosomaldamage induced by occupational ionising radiation at low exposure levels, and to find earlymarkers of health hazard, peripheral lymphocytes of occupationally exposed hospital workerswere cytogenetically analysed. Results showed a significant difference in the frequency of ChAbs inexposed subjects relative to controls. A significant number of NPBs between nuclei of binucleatedcultured lymphocytes from exposed subjects were also observed, as well as a consistent amountof acrocentric chromosomes with associations of their short arms. Excluding confounding factors,the frequencies of all these three biological endpoints differed significantly in exposed subjectsfrom those in controls. Because the absence of telomeres and/or their short length could be acommon root for both the findings, we utilised fluorescence in situ hybridisation technique withtelomeric repeat as probe to demonstrate that, in exposed subjects, chromatin of short arms ofinvolved acrocentric chromosomes did not exhibit a telomeric shortening but appeared stronglydecondensed. This finding suggests that NPBs and telomeric acrocentric association should beregarded as early markers of exposure to low levels of ionising radiation and their increase shouldbe seen as an early warning for the health of the involved workers.
|Numero di pagine||7|
|Stato di pubblicazione||Published - 2014|
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