The ultrastructure of transmissible murine colonic hyperplasia.

Abstract

Transmissible murine colonic hyperplasia was examined ultrastructurally by sequential sampling after inoculation with the etiologic agent, Citobacter freundii. Light-microscopic changes in the descending colon of inoculated mice were correlated with scanning and transmission electron-microsopic findings. Bacteria were attached to the surface of the mucosa between 4 and 10 days after inoculation. Hyperplasia was most severe at 16 days and thereafter underwent regression. Regression was preceded by extrusion of infected cells from the surface mucosa and replacement by immature hyperplasia epithelium. Hyperplastic epithelium throughtout the crypt resembled undifferentiated crypt cells of controls. By 45 days, the mucosa had reverted to near normal structure. The results suggest that severe mucosal proliferation with minimal inflammatory change resulted from attachment of bacteria to the surface mucosal epithelium. The hyperplastic response appeared to be a defense mechanism of replacing infected cells with newly migrated, uninfected epithelium.

Full text

PDF

• 291
• 292
• 293
• 294
• 295
• …
• 313
• Next

Images in this article

Figure 15
on p.313

Figure 16
on p.313

Figure 4
on p.305

Figure 5
on p.305

Figure 6
on p.305

Figure 1
on p.303

Figure 2
on p.303

Figure 3
on p.303

Figure 8
on p.307

Figure 12
on p.311

Figure 13
on p.311

Figure 14
on p.311

Figure 9
on p.309

Figure 10
on p.309

Figure 11
on p.309

Figure 7
on p.306