title: Electron cytochemical determinations of periodic acid-reactive sites in Histoplasma capsulatum.
abstract: Electron cytochemical determinations of periodic acid-thiocarbohydrazide-silver proteinate (PATAg)-reactive sites in the vegetative and reproductive cells of the pathogenic dimorphic fungus Histoplasma capsulatum, are described an illustrated by electron micrographs. Ultrastructural sites of PATAg-reactive substances were detected at the plasma membrane, along various cytomembranes of the cytoplasm, and in aggregates of storage material believed to be partly composed of glycogen or a glycogen-like polymer. Cell walls were either minimally or negatively stained. The positive staining of PATAg-reactive sites was eliminated by use of the aldehyde-blocking agent sodium borohydride. The limiting membrane and matrix of Woronin bodies seen at the hyphal cell septum were devoid of PATAg reactivity.
mesh_terms: D001894:Borohydrides / Q000494:pharmacology; D002462:Cell Membrane / Q000032:analysis; D002473:Cell Wall / Q000032:analysis; D006651:Histocytochemistry; D006658:Histoplasma / Q000032:analysis* / Q000648:ultrastructure; D006834:Hydrazines; D008055:Lipids; D008854:Microscopy, Electron; D009940:Organoids / Q000032:analysis; D010503:Periodic Acid-Schiff Reaction; D012836:Silver Proteins; D013871:Thiones
chemical_list: D001894:Borohydrides; D006834:Hydrazines; D008055:Lipids; D012836:Silver Proteins; D013871:Thiones; C011368:thiocarbohydrazide; C025364:sodium borohydride