Studies of JC virus-induced nervous system tumors in the Syrian hamster: a review.

A review has been presented of the essential primary tumors of the nervous system, and of one secondary tumor of the brain, which has been obtained after JC virus inoculation of Syrian hamsters. These results have been compared with results obtained by other authors, testing different group B papovaviruses. Comparisons have also been made with neurooncogenicity results obtained with human adenovirus 12 in rodents and with JC virus in subhuman primates. The similarity of the phenotypically diverse JC virus-induced hamster tumors with human childhood of the nervous system and their usefulness for extended biologic research has been mentioned.

New world primates as a model of viral-induced astrocytomas.

Owl and squirrel monkeys are susceptible to the oncogenic effects of JCV. These species of New World monkeys can be safely inoculated intracerebrally. Care must be taken with owl monkeys since they have an inherited clotting abnormality. Incubation times for the development of tumors range from 14 to 30 months. Anorexia was the first clinical sign of tumor development. The clinical course is rapid with death within two to three days. This model provides a means for studying diagnostic, virological, immunological and therapeutic techniques which are applicable to human patients with astrocytomas.

Neuroradiological studies of JCV-induced astrocytomas in nonhuman primates.

Astrocytomas in nonhuman primates following JC virus inoculation provides a model which can be used to evaluate diagnostic and therapeutic techniques used in humans. The CT scan appearance of astrocytomas in nonhuman primates closely resembles that seen in humans. Our studies have shown that tumors may be detected in asymptomatic monkeys. Serial scans have shown astrocytomas to grow rapidly with breakdown of the blood-brain barrier. CT scanning has demonstrated the presence of tumor which was undetectable by gross examination at necropsy but confirmed by light microscopy. Studies are in progress to further define the radiological appearance of gliomas, to evaluate contrast-tagged anti-tumor antibodies as a diagnostic tool in evaluating gliomas by computerized tomography, and to evaluate metabolic parameters of actrocytomas by positron emission tomography.

Immunohistochemical demonstration of common antigen of polyomaviruses in routine histologic tissue sections of animals and man.

All polyomaviruses have a common antigen, which is located on the major capsid polypeptide (VPI). This antigen was demonstrated in routine histologic sections of formalin-fixed paraffin-embedded tissues by the peroxidase-antiperoxidase technic. Antiserum to the common determinant reacted with JC virus in oligodendrocytes of a patient who had progressive multifocal leukoencephalopathy, BK virus in bladder epithelium of a renal transplant patient, and K virus in endothelial cells of mouse lung. This method may be applicable to the screening of tissues for all polyomaviruses in diagnostic and investigative pathology.

Perinatal induction of medulloblastomas in Syrian golden hamsters by a human polyoma virus (JC).

Medulloblastomas, originating from cells of the internal granular layer of the cerebellum, developed in Syrian golden hamsters 3--6 months after inoculation at birth intracerebrally and sc with JC virus, a papovavirus isolated originally from a human case of the demyelinating disease progressive multifocal leukoencephalopathy. The lesion is compared with the human medulloblastoma of childhood. JC virus is the first infectious agent to produce such a neoplasm in any species.

Uhl's anomaly in the mink. Partial absence of the right atrial and ventricular myocardium.

Congenital marked hypoplasia of the right atrial and ventricular myocardium (Uhl's anomaly), without other cardiac anomalies, was observed at autopsy in a mink. The animal died unexpectedly without previous symptoms at the age of 2 years, suggesting that the cause of sudden death was acute congestive heart failure. This cause demonstrates that this malformation can occur in species other than man. Embryologically, this anomaly might be due to myocardial injury to the right cardiogenic fold at a relatively early stage of embryogenesis.

Susceptibility of mink to sheep scrapie.

A progressive, fatal spongiform polioencephalopathy was induced in mink intracerebrally inoculated with a suspension of brain from a Suffolk sheep with naturally acquired scrapie. The clinical signs and pathological lesions of the experimental disease were indistinguishable from transmissible mink encephalopathy, a disease of undetermined origin that occurs in mink.

Transmissible mink encephalopathy: experimental transmission to the squirrel monkey.

A progressive, fatal spongiform encephalopathy developed in three squirrel monkeys 11 months after inoculation with primate-passaged transmissible mink encephalopathy agent. The clinical symptoms and histopathologic and electron microscopic findings suggest that this naturally occurring disease of mink has been transmitted experimentally to squirrel monkeys.