ABSTRACT
We have histochemically evaluated the LAP, AP and ANE activities of the human appendix in 100 surgical specimens. The mucosa has been particularly investigated for its different aspects during inflammatory conditions. Two main facts have been ascertained: the subepithelial location of macrophages, and the AP and ANE activities of two groups of cells in the germinal centers. Subepithelial macrophages show conspicuous AP activity that correlates with the degree of inflammatory response and of exposure to luminal antigens. In the germinal centers, AP and ANE activities disclose two further groups of positive cells, probably the same cells reacting to both technics. One group is rooted to the core of the germinal center; the other to the intermediate area between the germinal center and the follicular mantle.