Chronic cholesterol depletion by lovastatin suppresses MUC5AC gene expression in human airway epithelial cells.

BACKGROUND: We recently showed that acute cholesterol depletion in the plasma membrane of NCI-H292 cells by methyl-ß-cyclodextrin suppressed IL-1beta-induced MUC5AC gene expression. Because cholesterol depletion is clinically used as an antihypersecretory method, chronic cholesterol depletion by lovastatin is more rational and safe than acute depletion. Therefore, we sought to investigate whether chronic cholesterol depletion by lovastatin is feasible and, if so, suppresses the expression of GMUC5AC in NCI-H292 cells. We also considered whether this alteration of MUC5AC expression is related to IL-1 receptor and mitogen-activated protein kinase (MAPK) activity. METHODS: After NCI-H292 cells were pretreated with 10 µM of lovastatin for 1 hour, 10 ng/mL of IL-1ß was added and cotreated with lovastatin for 24 hours. MUC5AC mRNA expression was then determined by real-time polymerase chain reaction. Cholesterol depletion by lovastatin was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK, and p38 MAPK was analyzed by Western blot. RESULTS: Cholesterol in the plasma membrane was significantly depleted by lovastatin treatment for 24 hours. IL-1beta0-induced MUC5AC mRNA expression was decreased by lovastatin and this decrease occurred IL-1 receptor specifically. Lovastatin suppressed the activation of p38 MAPK but not ERK1/2 in cells activated with IL-1beta. This result suggests that lovastatin-mediated suppression of IL-1beta-induced MUC5AC mRNA operated only viathe p38 MAPK-dependent pathway. CONCLUSION: Chronic cholesterol depletion in the plasma membrane of NCI-H292 cells may be considered an antihypersecretory method, because it effectively inhibits mucin gene expression of human airway epithelial cells.

Phonatory outcome of 585 nm/pulsed-dye laser in the management of glottic leukoplakia.

OBJECTIVE: Vocal cord mucosectomy using pulsed-dye laser was assessed for its ability to completely remove lesions without deterioration of vocal quality in cases of vocal cord leukoplakia. To confirm the validity of a pulsed-dye laser, we retrospectively analyzed the treatment outcomes of patients who received surgery preceded by pulsed-dye laser and compared these with the outcomes of patients who received vocal cord mucosectomy using CO2 laser. METHODS: Between February 2007 and June 2012, 36 patients were enrolled. Seventeen patients received vocal cord treatment with a CO2 laser and 19 patients received operation with a pulsed-dye laser. To evaluate voice status, acoustic wave form analysis and electroglottography were done, and voice handicap index was measured before and after the operation. RESULTS: The entire lesion was removed in all patients. Compared to preoperative vocal parameters, the postoperative values for jitter were only improved in the pulsed-dye laser group. On stroboscopic findings, a diminution or lack of mucosal wave was observed in more CO2 laser cases than pulsed-dye laser cases. Significant improvement in voice handicap index results was only observed in the pulsed-dye laser group. CONCLUSION: Although long-term results with more patients are required to establish the validity of pulsed-dye laser, this study confirmed the merits of pulsed-dye laser for the en-bloc removal of vocal cord leukoplakia and improved voice outcome.

Clinical characteristics of vocal polyps with underlying sulcus vocalis.

OBJECTIVE: This study aims to find a correlation between vocal fold polyps and sulcus vocalis and to investigate the character of such vocal fold polyps associated with sulcus vocalis. STUDY DESIGN: Retrospective clinical research. METHODS: A retrospective review of 280 patients who have been admitted and operated under general anesthesia for vocal fold polyps at a tertiary care medical center from March 2009 to July 2012 was performed. RESULTS: The patients were classified into two groups. Group A (18 patients) was defined as patients who have been diagnosed with vocal polyps coexisting with sulcus vocalis. Group B (262 patients) was designated to the rest of the patients who have been solely diagnosed with vocal fold polyps. The prevalence of an underlying sulcus vocalis associated with vocal polyps in the studied population overall was 6.4% (18/280). Considering the recurrence rate of vocal fold polyps in each group, it was 16.7% (three patients) in group A and 3.1% (eight patients) in group B. In general, there was an improvement in the voice quality after the operation in both groups. The degree of improvement was less substantial in group A rather than group B. CONCLUSION: When dealing with patients who have been diagnosed as vocal fold polyps, the possibility of coexisting sulcus vocalis should always be considered, and if diagnosed simultaneously, management of vocal polyps and sulcus vocalis must be sought for a better voice outcome and to reduce the chance of recurrence of vocal polyps.