A Note on the Spread of Poliomyelitis Virus in Monkeys

Abstract

Jungeblut and Spring 1 transected the spinal cords of 2 monkeys at the level of the first lumbar vertebra and then injected them intracerebrally with poliomyelitis virus. One animal developed a condition which might have been poliomyelitis, but when separate emulsions, made from the upper and lower parts of the cord, were injected into other monkeys, the disease was not reproduced. Postmortem autolysis prevented a positive histological diagnosis. The second animal developed poliomyelitis. Histologically, there was an absence of lesions considered typical for poliomyelitis in sections taken from the lumbar cord, while those obtained from the cervical area were positive. Injections of an emulsion made from the upper or cervical section of the cord of this monkey reproduced the disease, while an emulsion made from the lower or lumbar section did not do so when injected into another animal.

Previously 2 I reported that when the virus of poliomyelitis was injected into the sciatic nerves of Macacus rhesus monkeys, the disease was produced in the cervical area even though the cord had been transected and removed in the region of thoracic X. The only connection between the upper and lower parts of the cord was by way of the sympathetic nerve fibers.

In these animals, the pathological picture of the distal or lumbar sections of the cord showed complete tissue degeneration, practically an autolysis in all but one specimen as well as a diffuse, but sparse, round cell infiltration and a few leucocytes. There was neither dilatation of nor cuffing about the capillaries. In the one specimen from the lumbar area referred to in the foregoing report, there was slight cellular degeneration, a relative decrease in the number of neurones in the anterior horn cell area and the same diffuse, but sparse, round cell infiltration. There was a lack of capillary dilatation and cuffing. The capillaries in the proximal or cervical sections of the cord were dilated and had cuffing about the vessels. There was also a generalized infiltration of round cells and anterior horn cell degeneration. The cells seen in the cervical cord sections took the contrasting stains, while the whole section from the lumbar cord, save for the lymphocytes present, was a pinkish red.