astrocytes, oligodandrocytes and ependymal cells
were in abundance in the treated groups as compared to the control group (Figs.
Later it was found that not only embryonic CNS but also adult CNS possess the ability to generate neurospheres forming cells in vitro, including neural epithelial progenitor (NEP) cells, radial glial cells, SVZ cells, and ependymal cells
, that clonigenically generate neurons, astrocytes and oligodendrocytes in vivo (16).
In this case, the ependyma is reconstituted by the transformation of the ependymal cells
into nonepithelial mesenchymal cells, which proliferate from both edges of the lesion to bridge the gap, then transform back into epithelial cells, while axons regenerate to make functional synapses.
Mild lymphocytic perivascular cuffing and loss of Purkinje cells were observed in the cerebrum and cerebellum, and virus antigen was detected in ependymal cells
and epithelium of the choroid plexus and in cerebellar Purkinje cells.
These tumors arise from the ependymal cells
of the central canal; hence, they are located centrally, as opposed to the eccentric location of astrocytomas (Table 2).
Occasionally, ependymal cells
of the spinal cord were also positive.
Immunohistologic analysis confirmed systemic infection and revealed influenza virus nucleocapsid protein in 1) ganglions of the adrenal medulla, 2) ependymal cells
of the central nervous system (associated with marked lymphocytic meningitis and perivascular cuffing), 3) thymus epithelia, and 4) epithelia of the exocrine pancreas (Figure 1).