
further observations of the lymphomas
of african children
during 1963, cytopathogenic, filtrable agents were frequently encountered in
cultures of embryonic human kidney cells following their inoculation with
supernatant fluids from primary human amnion cultures which had previously been
exposed to extracts of tumors and other specimens from east african children
with malignant lymphomas of the kind described by burkitt and others.  the
results seemed noteworthy because they suggested an intimate association
between the agents and the disease, and also because of the nature of the
isolations which involved two phenomena, an initial induction of a peculiar
spindling and twisting of the amnion cells
(fig. 1) and subsequently destructive changes
in kidney cells inoculated with fluid from such altered amnion cultures.  the
direct inoculation of embryonic kidney cells with extracts of tumors or bone
marrow never caused cytopathogenic effects nor did the isolated, transmissible
agents have the capacity to induce the amnion lesions.  nevertheless,
the two effects were closely associated and clearly related to the specimens.
the cytopathogenic agents were later cultivated on protein-rich media and
found to have the characteristics of mycoplasma.  they failed to induce
tumors in a variety of animals, and serologic tests in which they served as
antigen gave suggestive but inconclusive evidence of a relationship to the
disease.  the mycoplasma also failed to induce the amnion lesions caused by
the specimens.
