The Effect of Oxygen on Impairment of the Proliferative Capacity of Human Cells in Culture by Ionizing Radiations of Different LET

Inactivation of Human Kidney Cells by High-Energy Monoenergetic Heavy-Ion Beams

“…using helium ions (23), and Todd, using lowenergy accelerated heavy ions (3), both demonstrated that the oxygen enhancement ratio (OER) for human kidney cells decreased to near unity at very high LET.…”

“…Human kidney T-l cells l (35) were used because of the abundance of data on their responses to x rays, gamma rays, neutrons, and most importantly, low-energy accelerated heavy ions (3,23). The cells were cultured as mono- In preparation for each experiment, a 0.2-ml volume of 1.7 x 10 5 exponentially growing cells was plated in a circular area approximately 2 cm in diameter at the center of special glass petri dishes.…”

Biological effects of radiation and related biochemical and physical studies. Proposal 1. Radiation studies theoretical investigation of LET spectra and dose relationship. Progress report, May 1, 1971--April 30, 1973

“…It rises to its maximum value at LET of about 100 kev per micron and decreases fast at still higher LET values (2,3,4). The details of this curve may change from one biological system to another, but its essential features remain the same.…”

New particles and their application in medicine

“…This is defined as the ratio of absorbed dose necessary to produce a given effect in hypoxic cells to that necessary to produce the same effect in oxygenated cells. Thus, the OER is large (i.e., between 2.5 and 3.0) for x rays and decreases with increasing LET, becoming close to one for high LET radiations (Barendsen et al, 1966).…”