title: Effects of time on ultrastructural integrity of parathyroid tissue before cryopreservation.
abstract: BACKGROUND
  Cryopreservation of parathyroid tissue is used in the surgical treatment of secondary hyperparathyroidism. After surgical resection, the tissue is temporarily maintained in a cell culture solution until it arrives at the specialized laboratory where the cryopreservation process will take place. The present study evaluates the time that the human hyperplastic parathyroid gland tissue can wait before cryopreservation, based on parathyroid cell ultrastructural integrity.
  
  
  METHODS
  This prospective study included 11 patients who underwent total parathyroidectomy with heterotopic autotransplantation and cryopreservation of parathyroid tissue fragments. Part of the tissue was kept in cell culture solution at 4 °C. Five time periods between 2 and 24 h were defined, and parathyroid fragments were kept in the solution for that length of time. At the end of each period, the fragments were removed from the transport solution, fixed, and prepared for ultrathin sections.
  
  
  RESULTS
  Of the 11 cases studied, 10 showed ultrastructural findings consistent with cellular viability in tissue fragments that remained in the transport solution up to 12 h. Electron microscopy revealed that cell adhesion and the integrity of plasma membranes, nuclei, and mitochondria were preserved in one case for up to 24 h. Changes in mitochondrial structure represented the most constant ultrastructural damage seen in the cases studied, in addition to the presence of edema and cell vacuoles.
  
  
  CONCLUSIONS
  Analysis of the ultrastructure of hyperplastic parathyroid gland tissue showed that ultrastructural integrity was in most cases properly maintained in fragments stored up to 12 h in a cell culture solution at 4 °C.
authors.affiliation: Department of Head and Neck Surgery, University of Sao Paulo Medical School, Sao Paulo, Brazil. csantaritta@yahoo.com.br
authors.forename: Carlos Eduardo Santa Ritta
authors.initials: CE
authors.lastname: Barreira
authors.forename: Cláudio Roberto
authors.initials: CR
authors.lastname: Cernea
authors.forename: Lenine Garcia
authors.initials: LG
authors.lastname: Brandão
authors.forename: Melani Ribeiro
authors.initials: MR
authors.lastname: Custódio
authors.forename: Elia Tamaso Espin Garcia
authors.initials: ET
authors.lastname: Caldini
authors.forename: Fábio Luiz
authors.initials: FL
authors.lastname: de Menezes Montenegro
mesh_terms: D000328:Adult; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D015925:Cryopreservation; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000601:surgery; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D008928:Mitochondria / Q000648:ultrastructure; D010280:Parathyroid Glands / Q000637:transplantation / Q000648:ultrastructure*; D016105:Parathyroidectomy; D011446:Prospective Studies; D013048:Specimen Handling / Q000379:methods*; D013997:Time Factors