904 
GENETIC AND BIOLOGICAL EFFECTS OF RADIATION 
5. Bender, M. A., and Brewen, J. G. Factors In- 
fluencing chromosome aberration yields in the 
human peripheral leukocyte system. Mutat. Res. 
8:383, 1969. 
6. Evans, H. J. International Review Cytology. T. H. 
Bourne and J. F. Danielli, Academic Press, New 
York, 1961. 
7. Giles, N. H. Radiation Biology, Ed. A. Hollaender 
McGraw-Hill, New York, 1954. 
8. Wolff, S. Some postirradiation phenomena that 
affect the induction of chromosome aberrations. J. 
Comp. Cell Physiol. 58:151, Suppl. I. 1961. 
9. Brewen, J. G. Cell-cycle and radiosensitivity of the 
chromosomes of human leukocytes. Int. J. Had. Biol. 
9:391, 1965. 
10. ZiRKLE, R. E. and Bloom, W. Irradiation of parts 
of individual cells. Science 117:487, 1953. 
11. Rogers, R. W., and von Borstel, R. C. Alpha-part- 
icle bombardment of the Habrobracon Egg. I. Sensi- 
tivity of the nucleus. Rad. Res. 7:484, 1957. 
12. Puck, T. T., and Marcus, P. I. Action of X-rays on 
mammalian cells. J. Exptl. Med. 103:653, 1956. 
13. Puck, T. T., Morkovin, D., Marcus, P. I., and 
CiECiURA, S. J. Action of X-rays on mammalian 
cells. II. Survival curves of cells from normal 
human tissues. J. Exptl. Med. 106:485. 1957. 
14. Skarsgard, L. D., Kihlman, B. A., Parker, L., 
PiYARA, C. M., and Richardson, S. Survival chromo- 
some abnormalities, and recovery in heavy ion and 
X irradiated cells. Rad. Res. Supplement 7:208, 
1967. 
15. Parsons, D. F. An electron microscope study of 
radiation damage in the mouse oocyte. J. Cell. Biol. 
14:31, 1962. 
16. Neary, G. J., Preston, R. J., and Savage, J. R. 
Chromosome aberrations and the theory of RBE. 
III. Evidence from experiments with soft X-rays, 
and a consideration of the effects of hard X-rays. 
Int. J. Rad. Biol. 12:317, 1967. 
17. Giles, N. H., Jr. Radiation induced chromosome 
aberrations in Tradescantia in radiobiology. Ed. 
A. Hollaender, McGraw Hill, 713, 1954. 
18. Chu, E. H. Y., Giles, W. 'H., and Passano, K. Types 
and frequencies of human chromosome aberrations 
induced by X-rays. Proc. Nat. Acad. Sci., U.S. 
47:830, 1961. 
19. Wolff, S. Some post irradiation phenomena that 
affect the induction of chromosome aberrations. 
J. Comp. Cell Physiol. 50:151, Suppl. I. 1961. 
20. Sax, K. Effect of centrifuging upon production of 
chromosomal aberrations by X-rays. Proc. Nat. 
Acad. Sci., U.S. 29:18, 1943, 
21. Sax., K. The time factor in X-ray production of 
chromosome aberrations. Proc. Nat. Acad. Sci., 
U.S. 25: 225, 1939. 
22. Zirkel, R. E. The radiobiological importance of 
linear energy transfer in radiation biology. Ed. A. 
Hollaender, McGraw Hill, p. 713, 1954. 
23. Deschner, E. E., and Gray, L. H. Influence of 
oxygen tension on X-ray induced chromosomal 
damage in Ehrlich Ascites tumor cells irradiated 
in vitro and in vivo. Rad. Res. 11:115, 1959. 
24. Wolff, S., and Luippold, H. E. The Biochemical 
Aspects of Chromosome Rejoining in Progress in 
Radiobiology. Proc. 4th Int. Conf. Radiobiol., held 
in Cambridge 1955. Eds. Mitchell, Holmes and 
Smith, Oliver and Boyd, 1956. 
25. Wolff, S., and Scott, D. Repair of radiation in- 
duced damage to chromosomes. Exp. Cell Res. 
55:9, 1969. 
26. Yu, C. K., and Sinclair, W. K. Mitotic delay and 
chromosomal aberrations induced by X-rays in 
synchronized Chinese hamster cells in vitro. J. Nat. 
Cancer Inst. 39:619, 1967. 
27. Sasaki, M. S., and Norman, A. Selection against 
chromosome aberrations in human lymphocytes. 
Nature 214:5023, 1967. 
28. GOH, K., and Sumner, H. Breaks in normal human 
chromosomes : Are they induced by a transferable 
substance in the plasma of persons exposed to total 
body irradiation? Rad. Res. 35:171, 1968. 
29. LiTTLEFiELD, L. G., HoLLOWELL, J. G., and POOL, 
W. H. Chromosomal abarrations induced by plasma 
from irradiated patients: On indirect effect of 
X-radiation. Radiol. 93:879, 1969. 
30. Stich, H. F. Radiomimetric effect of oncogenic 
and nonocogenic human and simian adenoviruses. 
Symp, of Rad. Ind. Cancer, Athens, p. 21, 1969. 
DISCUSSION 
Marvin Goldman, University of California, 
Davis: (Inaudible). 
Dr. Hungate : The techniques v^^ere as identi- 
cal as we could possibly make them. In other 
w^ords, in both cases, forty-five hours v^^as used 
and I'm sure that what you're probably alluding 
to is that one has no basic assurance that the 
time of selection is appropriate to maximize 
the observation of the event. We have not taken 
time to look at the spectrum of the cell cycle. 
