MOLOKHIA, ROBINSON, HUFFMAN AND NORMAN 
917 
1-3 (A) 
4-5 (B) 
II u It n li H 
6-12 and X (C) 
it i> ii 
— - 
13-15 to) 
It li . 
II H <l it , 
' — y 
16-18 (E) 
19-20 (F) 
I »» -i. 
21-22 ondY (G) 
Figure 6. — Karyotyping of male chimpanzee #191-71. 
Forty eight normal chromosomes, (oil immersion field 
X 1000 Giemsa stain) 
involved acute high dosage exposures. The de- 
crease of abnormal cells with time is probably 
related to the fact that damaged cells would 
have difficulty completing normal mitosis and 
therefore would end in what Kaplan termed 
"mitotic suicide". However, the decrease in ab- 
normal forms may be more apparent than real 
since the loss of a fragment during a later cell 
division may make a cell appear normal unless 
a full karyotype is made. It is also possible that 
abnormal cells are selectively destroyed by the 
reticuloendothelial system. 
Although the most important chromosomes 
from the point of view of long-term human 
radiation hazard are those of the germ cells 
(the meiotic chromosomes), these were not ana- 
lyzed in the current study. However, if chromo- 
somal abnormalities had affected the germ cells, 
they would have been passed on to the next 
generation. Monitoring of the offspring from 
irradiated parent dogs showed good mitotic 
activity and normal karyotyping. 
It is essential to ensure that aberration fre- 
quencies are determined only during first divi- 
sion cells. According to Sasaki and Norman.^^ 
this would necessitate the use of cultures grown 
for about 48 hours at 37° C because by 72 hours, 
some cells reach their second or third in vitro 
division which alters the observed frequency 
of aberrations. However, since the 72-hour pe- 
riod of culture was used in the beginning of 
this long-term study, it was retained to facili- 
tate comparisons. 
In conclusion, transient chromosomal aber- 
rations were noted in a colony of radioisotope 
bearing canines three months after implanta- 
tion. Later studies of this group and of radio- 
isotope-bearing primates showed normal chro- 
mosomal morphology. Studies of offspring 
suggested that no chromosomal abnormalities 
were transmitted or effected. 
SUMMARY 
Radioactive capsules simulating the dose rates 
for proposed and developing implantable arti- 
ficial hearts were implanted in eight adult dogs 
and three adult primates. Serial hematologic 
profiles, lymphocyte cultures and chromosomal 
morphologic studies were carried out for three 
years to determine the effects of intracorporeal 
radiation. Nine Puppies, sired by a capsule- 
bearing father and subjected to irradiation 
from the mother's capsule during gestation, 
were also studied. No changes in blood values 
were detected. Chromosomal abnormalities were 
observed in four dogs, three months after source 
implantation, but later studies revealed normal 
chromosomal morphology in all animals and 
their offspring. 
REFERENCES 
1. Norman, J. C, Covelli, V. H., Bernhard, W. F. 
and Spira, J. Implantable nuclear fuel capsules for 
an artificial heart. Trans. Amer. Soc. Artif. Int. 
Organs. 14:204, 1968. 
2. Sandberg, G. W., Jr., Huffman, F. N. and 
Norman, J. C. Experimental observations of intra- 
corporeal strontium 90-americium 241 /beryllium 
sources simulating radiation fields from nuclear- 
powered artificial hearts. Ann. Thorac. Surg. 9:401, 
1970. 
