(26: [359][360][361][362][363][364][365] 1972)

PML, a rare form of subacute demyelinating disease of the human brain, is caused, in most instances, by JC virus, a new type of papova virus. Light microscopically, the lesions are characterized by hypertrophy of oligodendroglia with intranuclear inclusion and gigantic astroglia with bizarreshaped nuclei. Although viral particles have been found by many investigators, the use of autopsy material has limited the ultrastructural study of changes in the patient.This report concerns some new cytopathological changes based on an electron microscopic study of well fixed biopsy material. Oligodendroglia and astroglia were markedly hypertrophic, but were identified by the presence of abundant cytoplasmic microtubules and filaments, respectively. Intranuclear and intracytoplasmic virions were found in both cell types. The intranuclear virions were the typical round and filamentous forms, with diameters of 40 and 30 mμ, respectively. They were scattered randomly throughout the enlarged nuclei.

No abstract