Fig. (1).

Light and electron microscopic observations of lymphoid follicles and lymphoepithelial lesions.

a: Lymphoid follicle (L) observed in the fundic mucosa of a mouse infected for 6 months. Toluidine blue-stained Epon (x100).

b: Lymphoepithelial lesion in the stomach of a mouse infected for 6 months. Toluidine blue-stained Epon (x600).

c: Invasion of a lymphocyte between fundic glandular cells in a mouse infected for 6 months (x3000).

d: Accumulation of centrocyte-like cells in a lymphoid follicle (x2000).