Atlanta Georgian. [volume] (Atlanta, Ga.) 1912-1939, 1914-01-25

whether micro5e may be q cause of cancer
in addition to the other conditions mentioned.
We know, indeed, that to a certain extent, mi
cro-organisms call forth cell proliferation
abnormal growth. Thus the tubercle bacillus
may cause a limited growth of connective tbs.
sue and as especially Borrel has pointed out,
the organisms causing smallpox and vaccinia
may even produce a slight proliferation Of the
infected eptthelium. But In all those cases
the pronferation soon ceases and toxic sub.
stances produced by bacteria lead usually soon
to the death of great part OF the newly-formed
cells
Based on such considerations many attempts
have been made to prove the constant pres
ence of certain parasitic heterogeneous in
human cancer. Under the microscope It Is
possible to recognize in cancer cells certain
inclusions which usually absent in normal
tissues, and number of investigators claimed
such included bodies definitely as protocol
(among Others Thoma, Sjoebring, Leyden,
Gaylord and Eisen). Even the life cycle of
these protozoa was apparently determined by
some of these authors.
It could, however, be shown that similar
cell inclusions may originate otherwise, and
did in all probability therefore not represent
protocol Also bacteria (Doyon), mucor
(SchmidD, chytridiaciae (Bebla) and other
micro-organisms were held responsible 9th
ers (Sanfelice Leopold) believed yeast-like
organisms to be frequently demonstrabe in
human cancer; they cultivated some yeasts in
culture media and by injecting the organisms
into animals believed they had reproduced the
disease.
Careful studies by many investigators. how.
ever, could not confirm these interpretations.
In the case of yeasts 1t has, for instance, been
shown that although they occasionally occur
in cancers, they are on the whole rare and
do not reproduce the disease If injected into
animals (Busse, Nichols. Loeb, Moore and
Fleisher). They act in the body In a similar
inert FOREIGN ND
a yeast which we isolated from a sarcoma to
lead, after intravenous injections, to the
death of the animal through occlusion of
the kidney tubules, without ever producing
cancer
These persistent claims Of the discovery O,
a m1cro-organism as the cause OF cancer
which could in no case be substantated, led
in the case of many pathologists, especially OF
those mainly interested in the careful study
of the structure of pathological tissues, to
reaction, which induced them to deny the
possible Importance Of micro-organisms in the
causation Of cancer they were inclined to
hold on the whole the factors already estab-
ished as sufficient to explain the origin OF
cancer.
"On the other hand" concludes Professor
Loeb, a number Of experimental investigators,
without being able to accept as valid any of the
claims as to the discovery of a micro-organism
as the cause OF human cancer, always pointed
out the possibility that micro-organisms might
at least in a certain number, perhaps even in a
majority OF cases, be factor in the production
OF cancer, and tried to find new experimental
means to approach these problems. Accord.
ingly, on various occasions we pointed out
the possibility that ultramcroscopic perhaps
intracellular. heterogeneous might induce
body cells, under certain conditions, to pro.
liferate in such manner that cancer re-
suited. However, In no case of human cancer
has the causative significance of a micro-or-
ganism so far been proven. In certain kind
of animal cancer. however, this proof has re.
Gently been supplied by Peyton Rous, the