title: [The effect of frozen storage for amniotic membrane ultrastructure].
abstract: OBJECTIVE
  To observe the effect of frozen storage for amniotic membrane ultrastructure, and provide the experimental evidence for clinical use.
  
  
  METHODS
  The amniotic membranes of fresh-obtained and -80 degrees C frozen storage 30 d, 60 d, 90 d and 180 d were examined with transmission electron microscope, and the ultrastructural changes were observed.
  
  
  RESULTS
  The epithelium in the fresh-obtained amniotic membrane was observed as intact structure, abundant organelles in cytoplasm and intercellular contact with desmosome. A great quantity of collagen micro-fibrils were found in the stroma, and the light and shade striation were observed in the collagen micro-fibrils of fresh-obtained amniotic membrane. The epithelium degenerated and died gradually as the increase of frozen storage time. At the frozen storage of 90 days, the epithelial chromatin dissolved, organelles degenerated and mitochondrion vacuolated. At the frozen storage of 30 days and 60 days, the pattern of collagen micro-fibrils in stoma was similar to that in fresh-obtained amniotic membrane; At the frozen storage of 90 days, some of collagen micro-fibrils in stoma showed intumescence. At the frozen storage of 180 days, the number of collagen micro-fibrils in stoma decreased, and some of them showed intumescence and dissolvent.
  
  
  CONCLUSIONS
  Frozen storage can result in amniotic membrane epithelium death and collagen micro-fibrils intumescence and dissolvent.
authors.affiliation: Ophthalmology Department, Ruijin Hospital Affiliated Shanghai Second Medical University, Shanghai 200025, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhong
authors.forename: W
authors.initials: W
authors.lastname: Ye
authors.forename: X
authors.initials: X
authors.lastname: Shen
authors.forename: Y
authors.initials: Y
authors.lastname: Cheng
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: K
authors.initials: K
authors.lastname: Wang
mesh_terms: D000328:Adult; D000650:Amnion / Q000648:ultrastructure*; D001485:Basement Membrane / Q000648:ultrastructure; D003094:Collagen / Q000648:ultrastructure; D015925:Cryopreservation; D004847:Epithelial Cells / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D009926:Organ Preservation
chemical_list: D003094:Collagen