Research / Clinical Summary

Jamie Milligan, PhD Research Scientist, Radiology Contact by Email

The unique aspect of the biologically significant DNA damage associated with ionizing radiation is that this damage is clustered. It is, therefore, qualitatively distinct from that produced by UV radiation, or chemicals such as alkylating agents.

The long term goals of Dr. Milligan's work are to clarify the radiation chemical mechanisms by which DNA damage is introduced by ionizing radiation and by which it may be processed, modified, or repaired. This provides a means to evaluate the ability of cellular systems to cope with this damage.

Applications to human health include defining the causes of individual variation in radiosensitivity (for example the role of anti-oxidants in protecting against radiation damage) and the development of mechanistic models for risk estimation of cancer etiology by low dose and low dose rate exposures.

Dr. Milligan's program examines the mechanism of DNA damage by ionizing radiation using a plasmid model system. Recently they have been investigating electron transfer reactions involving phenols and indoles which serve as models for the amino acids tyrosine and tryptophan. Residues of these amino acids present in DNA binding proteins may be able to repair oxidative DNA damage before it is trapped in a stable form.