The fine structure of intracranial neoplasms induced by the inoculation of avian sarcoma virus in neonatal and adult rats.

Abstract

Groups of F-344 rats were inoculated with the Bratislava-77 strain of avian sarcoma virus (B-77 ASV) within 24 hours of birth, at 9 days of age, or between 97 and 119 days of age. Intracranial tumors developed in each age group. Multiple tumors with mixed histologic patterns developed in rats inoculated at 1 or 9 days of age. Solitary tumors with a uniform histologic pattern developed in rats inoculated as adults. On the basis of light and electron microscopic study, the majority of tumors in each age group were classified as astrocytomas and divided into either poorly differentiated, gemistocytic, pilocytic, or polymorphic varieties. The polymorphic astrocytomas were most common among neonatally inoculated rats, while the pilocytic astrocytomas were most common among rats inoculated as adults. Ultrastructural characteristics of astrocytes, including gap junctions and 7- to 9-nm filaments, were present in the majority of tumors in each age groups. Astrocytomas induced in adult rats were remarkable for the presence of extensive basement membrane alone the astrocytic cell surfaces. Intracytoplasmic virus-like particles (R particles) were common in the tumor cells. These virus-like particles are morphologically distinct from C-type B-77 ASV, and no morphologic evidence of C-type virus replication was observed in any of the tumors.

Full text

PDF

• Previous
• 149
• …
• 152
• 153
• 154
• …
• 176
• Next

Images in this article

Figure 16
on p.175

Figure 17
on p.175

Figure 1
on p.167

Figure 2
on p.167

Figure 18
on p.176

Figure 3
on p.168

Figure 4
on p.168

Figure 5
on p.168

Figure 6
on p.168

Figure 7
on p.169

Figure 8
on p.169

Figure 9
on p.170

Figure 10
on p.171

Figure 11
on p.173

Figure 12
on p.173

Figure 13
on p.173

Figure 14
on p.174

Figure 15
on p.174