title: [The ultramicrostructure of secretory granules of mast cells in giant papillae of vernal keratoconjunctivitis patients].
abstract: OBJECTIVE
  To investigate the subtypes, extent of activation, and method of degranulation of mast cells (MCs) by observation of the ultramicrostructure of secretory granules from MCs in the giant papillae (GP) of patients with vernal keratoconjunctivitis (VKC).
  
  
  METHODS
  After informed consent, 8 giant papillae were obtained from 6 patients with severe VKC during treatment. The 168 collected MCs were observed by electron microscopy.
  
  
  RESULTS
  Thirty-eight percent of the MCs were degranulated (17% piecemeal and 21% anaphylactic degranulation). Among the non-degranulated MCs, 13% were TC type cells containing dense amorphous granules; 9% were T type cells containing scroll granules; 15% were transient cells containing both amorphous and scroll granules; and 25% were activated MCs containing particulate granules. Three patterns (separation from the cell membrane, exocytosis, and dissolution) of granule release were recognized.
  
  
  CONCLUSIONS
  The dynamics of MCs in GP were assessed from the ultramicrostructure of the secretory granules.
authors.affiliation: Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan. ebihara@med.juntendo.ac.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ebihara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Akira
authors.initials: A
authors.lastname: Murakami
mesh_terms: D000293:Adolescent; D000328:Adult; D003233:Conjunctivitis, Allergic / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000648:ultrastructure*; D022142:Secretory Vesicles / Q000648:ultrastructure