466
Fliedner, Cronkite, Bond and Andrews, Mitotic Activity and Cytology
containing only one nucleus which was considerably larger than nuclei of normal
cells of similar maturation stages. Since under normal conditions, the nuclear vo-
lume in red and white cell precursors decreases with the steps of nuclear division
and cytoplasmic maturation4: 5, the size of the nucleus with a normal chromatin
pattern indicates the compartment. An inhibition of nuclear division but undisturbed maturation gives rise to giant cells.
Summary
The findings presented in five men exposed to mixed neutron-gammaradiation, resulting in severe depression of blood cell formation, indicate that there are
significant abnormalities in the mitotic figures and in cells during interphase.
The percentage of abnormalinterphase cells is not high and such abnormalities
must be looked for carefully. The presence in the bone marrow within a few hours
after radiation exposure of nuclear swelling, chromatin dissociation, nuclear
and cytoplasmic maturation without nuclear division, atypical mitoses with
chromosomalstickiness, fragmentation, and loss of chromosomes indicate severe
damage to the marrow. The dose in our cases was not severe
significant karyorrhexis and karyolysis resulting in immediate
believed that serial bone marrow examinations within the first
certain radiation exposure mayaid in a better assessmentofthe
and prognosis after radiation accidents.
enough to cause
cell death. It is
3 days after unclinical situation
References
1. Brucer, M.: The acute radiation syndrome. Report of the Oak Ridge Institute of Nuclear
Studies, April 1959.
2. FLIEDNER, T.M.; Cronxrrz,E. P.; Bonn, V.P.; Rusmt, J.R. and Anprews G.: The mitotic
index of human bone marrowin healthy individuals and irradiated human beings. Acta
haemat. 22: 65-78 (1959).
3. Furepner, T.M.; Bonn, V.P. and Cronxire, E.P.: The effect of total-body irradiation on
H® thymidine incorporation into DNA of bone marrow cells. Proc. 9th Int. Congr.
Radiology, Munich 1959.
4. WEIcKER, H.: Die hemi-homoplastische Teilung des Proerythroblasten die Lésung des
Stammzellenproblems der Erythropoese. Folia haemat. 74: 49-64 (1956).
5. Furepner, T.M.; Cronxrre, E.P. and Bonn, V.P.: Die Proliferationsdynamik der Blut-
zellenbildung, autoradiographisch untersucht mit tritiummarkiertem Thymidin. Schweiz.
med. Wschr. 89: 1061-1067 (1959).
6. Cronxire, E.P. and Bonp, V.P.: Radiation injury in man. Its chemical and biological
basis, pathogenesis and therapy (in press).
7. Japa, J.: A study of the mitotic activity of normal human bone marrow. Brit. J. exp. Path.
23: 272-276 (1942).
8. Unpritz, E.: Personal communication and discussion remarks. Schweiz. med. Wschr. 87:
1124 (1957).
9. Forp, C.E. and Hamerton, J.L.: Acolchicine, hypotonic citrate squash sequence for mam-
erya
—
weet
Sante
malian chromosomes. Stain Technol. 31: 247-251 (1956).
10. Marguarp, M.: Die Réntgenpathologie der Mitose. Z. Botanik 31; 572-593 (1937).