[Properties of the cell surface of normal and malignant cells: investigations on polysialic acid and terminal sialic acid residues in specific linkages].

Data are reported to demonstrate the usefulness of a monoclonal anti-polysialic acid antibody for (i) the visualization of immature and mature neural elements in human teratomas, and (ii) the distinction of small cell lung carcinoma from bronchial carcinoids as well as squamous cell and adenocarcinomas of the lung. Lectins which discriminate between the various types of sialylated sequences, such as the Sambucus nigra L. I lectin specific for Neu5Ac alpha 2,6 Gal/GalNAc and the leukoagglutinin from Maackia amurensis (MAL) specific for Neu5Ac alpha 2,3 Gal beta 1,4 GlcNAc have been applied to the study of human colonic mucosa. The Neu5Ac alpha 2,3 Gal beta 1,4 GlcNAc sequence was detectable in normal and transitional mucosa and carcinomas, whereas the Neu5Ac alpha 2,6 Gal/GalNAc sequence was found in carcinomas. The lectin Amaranthin reacts with Gal beta 1,3 GalNAc-alpha (the T antigen) and NeuAc alpha 2,3 Gal beta 1,3 GalNAc-alpha (the cryptic T antigen). It stained normal and transitional colonic mucosa as well as carcinoma. The reactivity was solely due to the cryptic T antigen and indicates that the T antigen may not represent a general carcinoma autoantigen.