Evening star., 1952-03-27


dreaded animal and plant diseases.
Now they are being trained like
soldiers to fight on mans side in
the cancer war.
This work at the Sioan-Ketter-
ing Institute for Cancer Research
here was described today at a
symposium arranged for science
writer's by the American Cancer
Society. Biologists have long rec
ognized the tendency of some OF
these infinitesimally minute hos
tile organisms to attack only one
kind of cell. An excellent example
is the poliomyelitis virus which
effects only certain kind OF motor
nerve cells. The object is to md,
or make, virus which will have
no effect 1on any normal cell but
will specialize on malignant cells.
Screening tests revealed one
virus which had some OF the de-
sired properties. Tissue OF a last
growing form of cancer was IN
iected in rats. When the animals
were infected with the virus OF
russian encephalitis cancer growth
would proceed normally for two
or three days and then stop
abruptly. Unfortunately this is one
of the most deadly Of all the VIRUS
diseases. 1t is largely restricted
TO Russia where its mortality rate
is about so per cent. All the IN
fected rats died in few days. 1t
probably never could be used with
man.
Several Isolated.
Now. however. three or four
other encephalitis-like organisms
have been isolated in the jungles
of equatorial Africa which are al
most as deadly to the cancer cells
and appear to have very little. ef-
feet on humans. per Sc. They act
against several. but not all. types
of cancer in the experimental set
I'D. This does not mean they neces-
sarily would work in actual treat
ment Of a patient.
Through a breeding tech
nioue two strains of the Russian
encephalitis virus have been pro-
duced-one with an increased
afinity for brain tissue and the
other with a greater avidlty 1or
cancer cells but little for nerve
cells. A few animals now are SUR
viying with greater and greater
doses-in one set Of experiments
100 million times the average
deadly dose of the original virus
The surviving animals are i'm
mune, both to the original virus
and the cancer.
Hope for Fierce Virus.
The real hope, however, lies in
finding, or breeding, some form OF
the Jungle viruseS which will at
tack cancer with greater fierce
ness.
About 20 human patients with
advanced forms of cancer which
would not respond to. any other
kind of treatment have been i'm
jected with these viruses. Virus
infection, as demonstrated by
fever, has been established in
about half the group. One pa
tient with a sub-acute form OF
lymphatic leukemia appears to
have been somewhat improved
and in other cases there is evil
dence that the virus prefers can
Ger to any other form of tissue
as it's food. The preferential ef-
fects, however, are hardly strong
enough to be useful.
May Be First Break.
At the same hospital was re-
ported what may be the first
major break of medical research
against acute leukemia, inevitably
fatal blood disease usually found
in children which runs it's course
in a few months. It is charac-
terized by an enormous increase
in the numbers of white blood
cells.
It now appears. according to
the report today. that the leu
kemic blood cell has a consider
ably greater need than normal
cells for two vitamins. both men,
bers of the B vitamin group
These are folio acid and the So
called citrovorum factor. Two
drugs have been synthesized
aminoteropterin and methopterin
which acts as antagonists to these
vitamins, preventing the cells
from making use of them.
Leukemic Cells Suffer.
The lukemic cells suffer worse
Remissions extending to a year
have been obtained by treatment
with these drugs. Then, according
to the report, life may be extend
ed for another period by treat
ment with the hormones, ACTE
and cortiSone.
Good results are obtained ir