tana
ie ih
Aeachaia aia cian aa VS a ath
Nh pet
8gt tad
gh he SNES pee (itgt Ade NT eter ow Sa
de gewees
esTg QE
OrsNtthre
Bah ene
Pa geSRLE
Cecio ad
ed
ial mal
*
rf
ce iusnieke sa Coeeee
ee
PieceseedaoeRete
"
atee.
—
UNCLASSIFIED
the anti-folics were negative, the dinitrophenol suppressed both processes. S
Penicillin and chioromycetin had no effect on CO? uptake, but d4pparently
altered the pattern in dark fixation by decreasing the amount ¢@f radio-
active malic acid.
Avreomycin also inhibited dark COpfixatio§
at high
Uptake of radioiodine in humans. Recent investigatioks at the
University of Jowa have been carried out to determine radioactive isotope
uptake by the thyroid of human embryos. Dosages of 100 to 200% microcuries
of radioactive iodine were given to pregnant women scheduled fbr therapeutic abortion. The embryos obtained were sectioned and autorad[ographed.
The human embryos showed thyroid uptake at four weeks, nearly pne month
sooner than was previously known. This finding is of primary Bmportance
to medicine in understanding transmission of this and other elbments
across the placental barrier; in studying the element uptake Oy the human
embryo; and in determining the amount of radioiodine which may be given
to pregnant women in terms of safety to the developing child.
Potassium absorption by tropical crops. A project hds been
initiated with the University of Puerto Rico Agricultural Expdriment
Station at Rio Piedras on the relative rates of absorption of fpotassium
from fertilizer and from soil.
Potassium is one of the majorfcrop ferti-
lizing elements; however, no data are available on the relatife absorption of potassium by tropical plants from fertilizer and fromJthe soil
to which the fertilizer is applied. Such knowledge will be of value in
the study of cation absorption by plants, and in determining fo what
extent the addition of fertilizer or plant nutrients to agrichltural
soils is beneficial.
Algae productivity in the Pacific. A cooperative cofhtract has
been executed with the University of Hawaii for research studies directed
toward the utilization and evaluation of isotope techniques
fpr determining algal productivity in the tropical Pacific. Research work recently
reported indicates that the productivity of the sea can be estimated from
measurements of COo fixation by sea water samples collected dqver a large
area. These studies are of interest in yielding significant information
relating to the mechanics, quantity, and rate of carbon-fixatfion through
photosynthesis by the marine algae.
The results are anticipqted to give
a better understanding of the potential productivity of the Werm seas,
and to extend the development of radioisotopes as useful toogJs in the
study of biological processes.
Antibody synthesis. In examining the incorporationfof radioisotopically labelled amino-acids into blood proteins, a res@arch group
at the University of Chicago has made certain observations that have inportant implications in regard to the body's immunological rfactions. The
relative time-patterns of the appearance of the labelled grofips in the
blood proteins generally,
as compared with antibodies produckkd in response
to injected egg albumin, suggest that the antibodies are not{formed merely
12
,
UNCLASSIFIED
DOE ARCHIVES
a
concentrations but accelerated it at lower concentrations. Te ranycin
had a similar effect. These results should aid in interpreting the nature
of both photosynthesis and the mode of action of antibiotics.