«~
§
=
and how many cells possessed nuclei that were preparing for mitosis.
some instances the rats were also given minute trace doses of 131f to
test the function of the thyroid before they were sacrificed.
The
In
radio-
autographs: for tritiated thymidine were not prepared until the 1f1r had
completely decayed. Some animals were killed early in the courselof the
experiments to gather additional data on the supramaximal surge of DNA
formation that had been observed in previous experiments two months after
the 131] was given.
Body weights, thyroid weights and thyroid fusction,
as measured by 131r uptake, as well as grcss changes in thyroids,|are all
being determined at the time of sacrifice.
The longest of these experiments hare been in progress for about
1*
years, Intervals thus far selected for sacrifice have been 34 mouths, .
9 months, 1 year and 1% years. They will be sacrificed at 2 year$ end
2% years. It is hoped that the intervals elected for sacrifice
give
radioautographs at the time when the first signs of the developmest
of
neoplasms occur. ne ine reprlammebegin to develop. it is anticigated
that clusters of cells which repre sent incipient tumors aene
displ
different proclivity for synthesizing DMA. At the time of the
pro=
gress report no gross tumors had appeared in animals that had bee sacrificed. At the end of one year5 sacrificed animals showed some
gqul axi-
ties in the thyroid.
Ra
hse were not as good as they
shquld have
been for interveetation of teitsum in nuclear DNA. New radicautogrepl
have just been completed and srenot particular
arly revealirg, probably be—cause the nodular areas are not sufficiently distinct. Tissues oljtainec
at 18 months show 4 examples of more irregularity in each series.
autographs are in preparetion on these tissues.
Radio-=
It is interesting that
the irregularities sre developing in the gland a little more feq
mtly in
the animals given 131r alone than in Lily plus chronic aduinistratlion of
azcithyroid drug. It now seens apparent that there should be a thir
series of animals thet are such younger than either of these two deries
when 131r is given, i.e., weanling rats.
Chromosome Abnomalities in
Circulating
Leukocytes of Patients
ated with
Several years ago we solicited the assistance of Professor Ne
Macintyre of this University in the study of chromosomal anomalies in
circulating white ceils in a patient treated with large doses of e+I.
In our comprehensive review two years ago, we described our observations
the very high incidence of chromosomal anomalies in a patribnt
whom we had given several very large doses of 13511 end had
died in
to
great detail. These observations were published several yeats agofas the
first American publication of its kind, In those studies we found] that a
high incidence of anomalies Gk years after the last of a total of +75
millicuries of 1312,
With the very extensive experience in
chros
preparation am interpretation by Dr. Macintyre and his associates ‘it
seemed appropriate to carry these observations futher and look for] anomalies
in individualswho had received doses of 8 to 15 millicuries of 131f
as
of 8 to 12, sxples of blood during a two week period following a
tteatment
treatment for hyperthyroidism. In the meantime observations have beer
reported by others who have used one or two observations on each of several
patients rather than a series of cbservations on each patient to prove
unquestionably that a change had taken place and to observe a sequence of
changes, It has been ow policy to make multiple cultures from a §eries
aaan
a