476
-
FLIEDNER, ANDREWS, CRONKITE AND BOND
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KARYOMERES IN ERYTHROBLASTS |
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% IO
{ PERCENT)
- “HIGH DOSE"
8 i
7
“LOW DOSE"
6
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2
—
4
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MITOTICALLY CONNECTED ABNORMALITIES
4
IN MYELOPOIESIS PER 100
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ERYTHROBLASTS
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WHOLE BODY IRRADIATION:
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22
DAYS AFTER !RRADIATION
Fig
ig. 3.—Frequency of “mitotically connected abnormalities” in the course of
counting 500 nucleated red cell precursors in marrow smears of persons exposed to
whole body irradiation.
quency of M. C. Abn. of myelocytic cells are shown in figure 3 together with
those of erythroblasts. Myelocytic abnormalities were observed in marrow
smears prepared 12 hours after whole body exposure (mainly abnormal mitoses) and were maximal on days 4 and 5. One value of each day was not in-
cluded. The smears were poor and only a few erythroblasts were found.
However, abnormal myelocytic cells of the types described were plentiful.
lf related to the few erythroblasts found, their frequency would be 100-200
per cent. Therefore, these somewhat misleading values were not included in
the graph. After 4 days, myelocytic abnormalities became less frequent and
had almost disappeared by the 16th day.
Of interest was the time sequence of the appearance of abnormalities at
different maturation levels. Forty-eight hours after the accident, all abnormalities described were found in promyelocytes, myelocytes and metamyelo-
cytes. In contrast, in the marrow smears of the 4th day after exposure, ab-
normal segmented granulocytes (giant cells, binucleated cells, and cells con-
taining karyomeres) were plentiful. This would suggest that the time from the
last myelocytic cell division (during which the abnormality presumably be-
came manifest) to the formation of abnormal segmented granulocytes was
between 2 and 4 days.
Abnormalities in myelocytic cells were found also in smears of the low
dose group after 4 days (fig. 3). However, they were much less frequent than
in smears of the high dose group. This may suggest a dose relationship for
such M. C. Abn.
Karyomeres were found also in lymphocytes, as shown in figure 2, on day
23 after exposure, but only in smears of two men of the high dose group.