Our clinical. . well as the animal is a narrow margir. .- tween the amount of » Seem to suggest that there 4°4I which will promote abnorml cell division (and perha;s promote neoplasm formation) and the dose of 1317 Bich Leukocytes in Man following 5 Aremalies of Chromosomes in Circula Voses The first published observations in this will Therdpeut: on chromosomal a following large doses of 131I far carcinoma of[tte thyroid ware made under this contract. These cbheervations were made follp 167 millicuries of 1311 for carcinomaof the thyroid. Not only was there BE - iy : : i acute dramatic rise in the incidence of anomiies (amounting to almost o shale of the circulating leukocytes cultured at the height of the rediation ¢ fect), but the pewliminary observations on that patient before the 167 curiks were given showed a higher than normal initial incidence of ancmmlies. This RE apparently attributable to residual effects from massive doses of 1311 that we had given six years before. Since that time, we have attespted similar opec include chromtids breaks in one leg of a chroncecme, which my be artifacts and to which (along with non-modal counts) we formerly attributed more s: iCance. David Satcher, aM.D., aspect of the work with FaeD. candidate, has been on the assistance of Dr. Neil Macintyre with whom we published the first work. ‘The significant feature of the Tha responsible investigator has recently spent five weeks in the 5 Eo is argha ; in the anmual review of the Marshallese eased to tik fallout from the thermonuclear devise detonated on Bikini in March 1954. he