title: Kinetics of 5-aminolevulinic acid-induced fluorescence in organ cultures of bronchial epithelium and tumor.
abstract: BACKGROUND
  5-Aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PPIX) fluorescence improves the differentiation of tumor and normal tissue in the bladder, skin and brain.
  
  
  OBJECTIVE
  The kinetics of 5-ALA-induced protoporphyrin IX (PPIX) fluorescence in organ cultures of normal human bronchial epithelium and cocultures of bronchial epithelium and tumor have been studied.
  
  
  METHODS
  Cultured biopsies of bronchial epithelium were exposed for 5 or 15 min, or continuously to 5-ALA. PPIX fluorescence was quantified for up to 300 min by spectroscopy. Cocultures of normal bronchial epithelium and a non-small-cell lung cancer cell line (EPLC-32M1) were incubated with 5-ALA. Space-resolved fluorescence microscopy was used to quantify PPIX fluorescence kinetics in the tumor and normal epithelium.
  
  
  RESULTS
  In cultures of normal epithelium, PPIX fluorescence kinetics were shown to depend on the duration of exposure to 5-ALA. There was a trend to higher fluorescence intensities with longer exposure times. In cocultures of bronchial epithelium and tumor, increases of fluorescence intensity were significantly greater in the tumor. Best tumor/normal tissue fluorescence ratios were found between 110 and 160 min after exposure to 5-ALA.
  
  
  CONCLUSIONS
  Data obtained in this coculture system of bronchial epithelium and tumor is valuable to optimize modalities of fluorescence bronchoscopy for the diagnosis of early bronchial carcinoma.
authors.affiliation: Department of Pneumology, Medizinische Klinik Innenstadt, Ludwig Maximilians University of Munich, Germany.
authors.forename: Fernando
authors.initials: F
authors.lastname: Gamarra
authors.forename: Simon
authors.initials: S
authors.lastname: Wagner
authors.forename: Salah
authors.initials: S
authors.lastname: Al-Batran
authors.forename: Irmgard
authors.initials: I
authors.lastname: Maier
authors.forename: Mirna
authors.initials: M
authors.lastname: Castro
authors.forename: Hubert
authors.initials: H
authors.lastname: Hautmann
authors.forename: Albrecht
authors.initials: A
authors.lastname: Bergner
authors.forename: Reinhold
authors.initials: R
authors.lastname: Baumgartner
authors.forename: Rudolf Maria
authors.initials: RM
authors.lastname: Huber
mesh_terms: D000622:Aminolevulinic Acid; D000704:Analysis of Variance; D001980:Bronchi / Q000166:cytology; D001984:Bronchial Neoplasms / Q000175:diagnosis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology; D018920:Coculture Techniques; D004847:Epithelial Cells / Q000502:physiology; D005453:Fluorescence; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms; D008856:Microscopy, Fluorescence; D009924:Organ Culture Techniques; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX