_ VII - BIOLOGY AND MEDICINE
Research Activities (UNCLASSIFIED)
Total body scintillation counter for human subjects.
e Los
.
counter
Alamos Scientific Laboratory has developed a large scintillati
for recording the total body load of radioactivity. The: ‘subje
is placed
within the cylindrical counter, so that essentially all emanatfons arising
from radioactive disintegrations anywhere in the body are recoywded. The
instrument is sufficiently sensitive to measure the natural le
activity in tissues of persons who have never been exposed to
radiological hazard. Any appreciable increase in activity abo
natural level is therefore easily detected.
Cardiac effluography with radioisotopes.
At Tulane Un
an apparatus has been developed which permits a novel use of r
in the analysis of the fundamental processes in heart action,
a turtle which has been previously injected with tracer potass
chief inorganic ion in the heart muscle) is removed from the agi
connected to a pipeline providing a constant supply of a physi
salt solution.
As the heart beats, some of its potassium ion,
the tracer, is released from the heart muscle cells into the c
circulation and is carried out by the circulating fluid. The
(the "effluograph") provides a continuous collection of this f
moving paper strip, with sufficient resolution that it is poss ble to separate as many as 17 samples per second for counting of the rad oactivity
of the released potassium isotope.
This technique has provide the first
means of following the release of potassium accompanying a sin le cardiac
contraction.
The time-course of the phenomenon is being correJated with
that of the electrocardiogram and of the contraction itself infJan effort
to achieve a better understanding of the basic processes which|connect
these three aspects of the heart's action.
It is hoped in thefmear future
to extend these studies to mammelian hearts and to the behaviof of biologically active ions other than potassium.
The action of cardiag drugs may
also be elucidated by this means.
-ARCHIVES
Use of waste fission preducts for control of trichi
University of Michigan researcn group has been investigating t e radiosensitivity of the trichina larva.
The larvae were exposed bo
ected pork or rat muscle, and uiter removal, to tap water. im