title: The structure of filaments of normal and psoriatic horny cells.
abstract: The structure of single filaments of horny cells of normal and psoriatic epidermis was studied in the electron microscopy in situ and in filaments reconstituted from urea extracts by dialysis, against low ionic strength buffer. It was found that both in situ and reconstituted filaments consist of 20 A protofibrils. In filaments of normal horny cells the protofibrils seem to form a rope-like structure while in those of psoriatic horny cells protofibrils appear randomly arranged. The filaments reconstituted from extracts of psoriatic scales range in width from 90 to 500 A, indicating a defect in lateral assembly of protofibrils. Numerous small particles are detectable at high magnification in extracts of both normal and psoriatic horny cells, which are about 20 A wide and 200 A long. These particles are consisted to be the basic structural units from which the protofibrils are formed, by end-to-end junctions.
mesh_terms: D002145:Callosities / Q000473:pathology; D003599:Cytoskeleton / Q000648:ultrastructure*; D004817:Epidermis / Q000648:ultrastructure*; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008854:Microscopy, Electron; D011565:Psoriasis / Q000473:pathology*
chemical_list: D007633:Keratins