X-IRRADIATION AND DELAYED MYELOMALACIA 



TABLE I 

 Experimental Rats 



237 



pulling itself by its forelimbs with the hind limbs cliat:L;inu helplessly behind. 

 Complete loss of sphincter control of bladder and rectum resulted in the 

 hind charters becoming permanently wet and soiled. The "paralyzed"" rats 

 were allowed to surxive for a few days up to 28 days beiore being sacrificed 

 for neuropatholosic study lable I ' . 



Pathologic Findings 



As a routine survey for lesions and their extent and distribution, the spinal 

 cord was fixed in situ in the \ertebral cokmin with its sin rounding skeletal 

 muscles. Subsequent to fixation and decalcification, the column was sliced 

 trans\ersely throughout its entire length in 1-2 mm pieces. The caudal 

 surface of each slice was sectioned and stained with hematoxylin and eosin. 

 Usually this amounted to 28 or more blocks i including usually 3 of the 

 brain i being cut from each rat. The distribution of the lesions was plotted 

 for each rat as in Fig. 5. We do not include any detailed reference to 

 examination of the spinal cord of the many rats irradiated and killed at 

 inter\als from 1 dav to 1 month, or to extensive histologic and histochemical 

 work on embedded and frozen sections. The spinal cords from nonirradiated 

 control rats were also studied. 



As might be expected from the variability of the latent period and the 

 time allowed between on.set of signs and sacrifice, there was some varia- 

 bility in extent of damage to the spinal cord. 



