Abstract
Nude (nu/nu) mice bearing human tumour heterografts were affected with posterior paralysis and wasting. There was demyelination and infection of the oligodendrocytes of the spinal cord with a papovavirus. Similar virus particles and inclusion bodies were found in the bronchial epithelium, which showed histopathological changes. Similar changes were shown by the epithelia of the renal pelvis, ureter and choroid plexus. The virus was found in a transplantable human tumour, and evidence of spread by contact was also obtained. Intracerebral injection of spinal cord suspension from infected mice resulted in virus infected cutaneous carcinomata, demyelination with virus particles in the oligodendrocytes and posterior paralysis with wasting in adult nude mice. The suspension injected intraperitoneally into newborn Syrian hamsters produced tumours similar to those produced by murine polyoma. No evidence of infection was found in mice from the colony of origin. The virus was identified as murine polyoma Wild Type A2.