Does the yield of radiation-induced chromosomal aberrations in first division human lymphocytes depend on the culture time?
The protracted exposure experiment produced results consistent with the G-function hypothesis that models the dose rate effect. Therefore the previous report of a marked departure from this model was not confirmed. The reports of aberration yields increasing with time of arrival at metaphase were confirmed. Possible explanations are discussed; the intercellular distributions of aberrations, or of doses to the cells or heterogeneous radiosensitivity of lymphocyte sub-populations. None alone seems sufficient quantitatively to explain the magnitude of the effect. The implications for biological dosimetry, which employs cultures times of approximately 48 h, are considered to be minor.
The Lewis lead is a simple and easy strategy to enhance atrial activity detection in wide QRS tachycardia.