CHAPTER 11 



Immediate Effects on Division, Morphology, and Viability 



of the Cell 



J. Gordon Carlson 



Department of Zoology and Entomology, The University of Tennessee, 1 and 

 Biology Division, Oak Ridge National Laboratory 2 



Introduction. Action of high-energy as compared with ultraviolet radiations. Meas- 

 urement of effect. High-energy radiations: Mitotic effects — Morphological effects — Cell 

 viability effects. Ultraviolet radiations: Mitotic effects — Cell morphology effects — 

 Viability effects. References. 



INTRODUCTION 



Among the earliest known effects of ionizing and ultraviolet radiations 

 on the living organism were their capacities to produce changes in cell 

 morphology that were frequently followed by death of the cell and to 

 reduce the mitotic activity in tissues. The last two decades have seen a 

 great increase in interest in this field and in the publication of papers deal- 

 ing with the results of research into these effects. As a natural conse- 

 quence, the subject of cytological effects has been subdivided in these 

 volumes into several topics, each delimited by somewhat arbitrary and 

 often overlapping boundary lines, more often than not determined by 

 the special interests and the particular points of view of the authors. The 

 subject matter of this chapter will be confined to a review of those radia- 

 tion-induced cytological effects that are ordinarily evident within a 

 single mitotic cycle of treatment. Omitted are such important subjects 

 as chromosome aberrations, protective agents, photorecovery, develop- 

 mental effects, physiological effects, and effects on microorganisms, which 

 are dealt with in other chapters. 



For discussions of certain aspects of the effects considered in this 

 chapter the reader is referred to reviews by Packard (1931), Duggar 

 (1936), Warren (1942), Lea (1946), Spear (1946), Giese (1947), Rajewsky 

 and Schon (1948), and Carlson (1950). 



1 Contribution No. 67 from the Department of Zoology and Entomology. 



2 Work performed under Contract No. W-7405-eng-26 for the Atomic Energy 

 Commission. 



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