Argentaffin and argyrophil cells in the appendix

Treatment of clinical experimental allergic encephalomyelitis in the rat using fragments and combinations of monoclonal antibodies

We reported previously that two different anti-CD4 monoclonal antibodies (W3/25, MRC OX35) were effective in treating experimental allergic encephalomyelitis in the Lewis rat whereas anti-I-A antibody was ineffective. Further studies with other monoclonal antibodies and fragments have now been performed. Anti-I-E antibody was ineffective in shortening the disease duration even when used in combination with anti-I-A antibody. Anti-CD2 (T11) antibody was marginally effective, shortening the duration of disease by only one day on the average. Combination of anti-CD4 antibody with anti-CD2 antibody did not improve the recovery time over the use of anti-CD4 antibody alone. On the other hand, the F (ab')2 fragment of the anti-CD4 antibody was as effective in the treatment of disease as the intact antibody molecule, indicating that it was sufficient to block the CD4 molecules on the cell surface of the EAE effector cells in order to affect the disease course.

Neuroendocrine cells in intestinal lamina propria. Detection with antibodies to chromogranin A

This study details immunohistochemical experiments showing the location of chromogranin A-containing cells within the lamina propria of rat and human gut. The presence of this marker confirms the presence of neuroendocrine type cells in the lamina propria.

Ultrastructural study on an appendiceal carcinoid tumor showing intra-nerve fiber growth

Ultrastructural and immunohistochemical studies on an appendiceal carcinoid tumor in a 53-year-old man disclosed an intimate association of nerves and tumor cells. Electron microscopy revealed that the tumor nests were composed of neurosecretory cells containing neurosecretory granules and peripherally-located Schwann cells encasing axons. Some tumor nests were continuous with nerve fibers invested in the common basal lamina. These findings suggest that at least some carcinoid tumors of the appendix show intra-nerve fiber growth, and that the neurosecretory cells might be present in the nerve fibers from the beginning or infiltrated into the nerve fibers at a very early stage of neoplastic transformation.

On the possible origin of extra-epithelial enterochromaffin cells by budding from the crypts of Lieberkuhn

This study was undertaken to test Pierre Masson's still unconfirmed theory that extra-epithelial enterochromaffin cells in the gut arise in adult life by budding from the crypts of Lieberkuhn under conditions of low grade inflammation. Appendices (900) were reviewed and 19 were selected for serial section study because in random sections they showed lateral fusion of the crypts, one of the key features described by Masson. Ten specimens without crypt fusion served as controls. Sixteen of the 19 study specimens and one of the control specimens showed budding, averaging one bud in every 88 sections. Most buds were in direct contact with Schwann cells in the adjacent lamina propria and 45 per cent of them contained enterochromaffin cells. There was also histologic evidence linking buds and lateral crypt fusion to low grade inflammation. Masson's ideas are, therefore, confirmed insofar as the existence of buds and their relationship to enterochromaffin cells, Schwann cells, and inflammation is concerned. The actual separation of buds from the crypts to form extra-epithelial enterochromaffin cells has yet to be proved.