title: Cholesteatoma-associated pathogenicity:  potential role of lysosomal exoglycosidases.
abstract: The enzymatic profile of lysosomal exoglycosidases in middle ear cholesteatoma has not been well known. The assessment of glycoconjugate catabolism may contribute to a better understanding of cholesteatoma pathogenesis.
  
  
  OBJECTIVE
  The study aim was to evaluate catabolic processes of glycoproteins, glycolipids, and proteoglycans in cholesteatoma through outlining the concentration of N-acetyl-β-hexosaminidase (HEX), β-glucuronidase (GLUC), and β-galactosidase (GAL) activity as well as in serum of cholesteatoma patients and healthy volunteers.
  
  
  METHODS
  Acquired cholesteatomas (n = 25) and normal retroauricular skin specimens (n = 25) were taken during surgery as well as serum from cholesteatoma patients and healthy volunteers. HEX, GAL, and GLUC activity was assessed on basis of p-nitrophenol release from derivatives of the substrate (HEX: N-acetylglucosamine i N-acetylgalactosamine, GAL from galactose, and GLUC from glucuronide).
  
  
  RESULTS
  The mean concentration of activity of HEX 1142.39 pKat/ml, GAL 8.90 pKat/ml, and GLUC 14.06 pKat/ml was significantly higher compared with the concentration of enzyme activity in normal tissue: HEX 267.65 pKat/ml, GAL 3.44 pKat/ml, and GLUC 3.90 pKat/ml. In the serum of cholesteatoma patients, the mean concentration of enzyme activities were as follows: HEX 641.62 pKat/ml, GAL 4.55 pKat/ml, and GLUC 12.80 pKat/ml and were significantly higher compared with the concentration of HEX activity (215.75 pKat/ml), GAL (1.89 pKat/ml), and GLUC (5.51 pKat/ml) in the serum of the healthy control group. In cholesteatoma compared with the normal tissue, there is an increase of the glycoconjugate catabolism due to significantly higher concentration of HEX, GAL, and GLUC activity in cholesteatoma. Cholesteatoma causes systemic reaction due to the increase of HEX, GAL, and GLUC activity in patient serum.
authors.affiliation: Department of Otolaryngology, Medical University of Bialystok, Bialystok, Poland. Ewa.Olszewska@umwb.edu.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Olszewska
authors.forename: Joanna
authors.initials: J
authors.lastname: Jakimowicz-Rudy
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Knas
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Chilimoniuk
authors.forename: Jan Krzysztof
authors.initials: JK
authors.lastname: Pietruski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Sieskiewicz
mesh_terms: D000328:Adult; D018424:Cholesteatoma, Middle Ear / Q000201:enzymology* / Q000209:etiology; D005966:Glucuronidase / Q000097:blood*; D006801:Humans; D008247:Lysosomes / Q000201:enzymology*; D008875:Middle Aged; D012867:Skin / Q000201:enzymology; D001616:beta-Galactosidase / Q000097:blood*; D001619:beta-N-Acetylhexosaminidases / Q000097:blood*
chemical_list: D001616:beta-Galactosidase; D005966:Glucuronidase; D001619:beta-N-Acetylhexosaminidases