Cholesteatoma-associated pathogenicity: potential role of lysosomal exoglycosidases.

UNLABELLED: 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-ß-hexosaminidase (HEX), ß-glucuronidase (GLUC), and ß-galactosidase (GAL) activity as well as in serum of cholesteatoma patients and healthy volunteers. STUDY DESIGN: 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.

[Possible involvement of hexosaminidase in vocal polyps--preliminary report]. / Rola heksozaminidazy w polipach faldów glosowych--doniesienie wstepne.

UNLABELLED: Vocal fold polyp is usually a result of the injury of the vocal cords. It often appears after vocal overuse or misuse causing trauma in vocal fold mid-membranous and wound formation. THE AIM OF THE STUDY was to assess the activity of hexosaminidase in vocal fold polyps in the comparison to the control tissue. MATERIAL AND METHODS: Vocal polyps (n=8) were collected from 8 patients during direct laryngoscopy. Specimens of normal vocal folds were obtained from 8 cadavers (n=8) served as controls. Specimens were immediately frozen in -80 degrees C. To assess hexosaminidase activity, release of p-nitrophenol from p-nitrophenol derivatives was used. RESULTS: We observed statistical differences between the activity of investigated enzyme in all vocal folds specimens compared with that in normal tissue homogenates. However the activity of HEX achieved a low level. Mean release of HEX from the activated cells in vocal fold specimens was 1.073 nkat/g wet tissue compared with 0.766 nkat/g wet tissue in normal cadaveric vocal fold homogenates. CONCLUSIONS: Low activity of HEX in vocal fold polyps suggests that inflammation may not be a primary factor in the development of the disease and other mechanism should likely be considered in the pathogenesis of vocal fold polyps.