Jae Gu Cho

Inhibitory effect of caffeic acid phenethyl ester (CAPE) on LPS-induced inflammation of human middle ear epithelial cells

Conclusions. The results suggest that the anti-inflammatory effect of caffeic acid phenethyl ester (CAPE) is due to its inhibition of tumor necrosis factor (TNF)-α expression and interleukin (IL)-8 production. The anti-inflammatory effect of CAPE is possibly through the inhibition of nuclear factor (NF)-κB via the suppression of inhibitor-κB-α (IκB-α) degradation. Objectives. CAPE is a biologically active component of propolis, a resinous material obtained from bee hives, which originates from conifer bark. The effect of CAPE on lipopolysaccharide (LPS)-induced inflammatory reactions is not known. The aim of this study was to evaluate the anti-inflammatory effect of CAPE on cultured human middle ear epithelial cells (HMEECs). Materials and methods. The effect of CAPE on LPS-induced TNF-α expression was evaluated in HMEECs by real-time reverse transcription polymerase chain reaction (RT-PCR). LPS-induced IL-8 production was determined by enzyme-linked immunosorbent assay (ELISA), and LPS-induced IκB-α degradation was followed by Western blot analysis. Results. CAPE significantly inhibited LPS-induced up-regulation of TNF-α in a dose-dependent manner. IL-8 production by LPS was significantly suppressed by the CAPE pretreatment. Furthermore, LPS-induced IκB-α degradation was suppressed by the CAPE pretreatment.

Effects of cigarette smoking on mucin production in human middle ear epithelial cells

OBJECTIVE Otitis media (OM) is the most common disease in preschool age children related to passive cigarette smoking as risk factor. In this study, we investigate whether the cigarette smoking can induce the inflammation in human middle ear epithelial cell, and cigarette smoke-induced inflammation can increase the expression of MUC5AC gene and protein that was known to play an important role in OM with effusion. METHODS After treatment of cigarette smoke solution (CSS) on immortalized human middle ear epithelial cells (HMEECs) with or without pretreatment by epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (AG1478), we observed expression of tumor necrosis factor-alpha (TNF-α), EGFR, MUC5AC mRNA by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and EGFR, MUC5AC protein by western blotting. RESULTS Treatment of CSS increased expression of TNF-α mRNA dose dependently. Treatment of CSS upregulated the EGFR and MUC5AC mRNA in a time-dependent manner. CSS-induced upregulation of EGFR and MUC5AC mRNA was suppressed by the pretreatment of AG1478. EGFR and MUC5AC proteins were upregulated by the treatment of CSS and suppressed by the pretreatment of AG1478. CONCLUSIONS Treatment of CSS on HMEECs increased the expression of MUC5AC mRNAs and proteins which play a major role in OM with effusion.

The Benefits and Risks of Prophylactic Central Neck Dissection for Papillary Thyroid Carcinoma: Prospective Cohort Study.

Objectives. This study evaluated the benefits of performing prophylactic central neck dissection (CND) with total thyroidectomy (TT) in management of papillary thyroid carcinoma (PTC) patients who were clinically node-negative at presentation. Methods. A total of 257 patients with stage T1 or T2 PTC and without preoperative evidence of lymph node involvement (N0) were enrolled in this prospective study. The patients were randomly assigned to two groups: (1) a total thyroidectomy (TT) group (n = 104) or (2) a TT plus CND group (n = 153). The two groups were compared for their perioperative data, complication rates, disease recurrence rates, and clinical outcomes. Results. The two groups of patients were similar in age, sex ratio, follow-up duration, and tumor size (P = 0.227, 0.359, 0.214, and 0.878, resp.). The two groups showed similar rates of disease recurrence (3.9% in the TT group versus 3.3% in the TT plus CND group); however, complications occurred more frequently in the TT plus CND group; especially transient hypocalcemia (P = 0.043). Conclusions. Patients treated with TT plus CND had a higher rate of complications with similar recurrence rate. We believe that CND may not be routinely recommended when treating patients with PTC.

Coblation vs. Electrocautery Tonsillectomy: A Prospective Randomized Study Comparing Clinical Outcomes in Adolescents and Adults

Objectives Coblation is operated in low temperature, so it is proposed that tonsillectomy with coblation involves less postoperative pain and allows accelerated healing of the tonsillar fossae compared with other methods involving heat driven processes. However, the results of the previous studies showed that the effect of coblation tonsillectomy has been equivocal in terms of postoperative pain and hemorrhage. Though, most of the previous studies which evaluated coblation tonsillectomy were performed in children. Recently, electrocautery tonsillectomy has been used most widely because of the reduced intraoperative blood loss and shorter operative time compared to other techniques. This prospective study compared intraoperative records and postoperative clinical outcomes in adolescents and adults following coblation and electrocautery tonsillectomies. Methods Eighty patients over 16 years of age with histories of recurrent tonsillitis were enrolled. The patients were randomly allocated into coblation (n=40) and electrocautery tonsillectomy groups (n=40). All operations were performed by one surgeon who was skilled in both surgical techniques. Intraoperative parameters and postoperative outcomes were checked. Results Postoperative pain and otalgia were not significantly different between the two groups; however, there was a tendency towards reduced pain and otalgia in the coblation group. More cotton balls for swabbing the operative field were used introoperatively in the electrocautery group (P=0.00). There was no significant difference in postoperative hemorrhage, wound healing, commencement of a regular diet, and foreign body sensation between the groups. Conclusion Only cotton use, which represented the amount of blood loss, was less in the coblation tonsillectomy group. Coblation tonsillectomy warrants further study with respect to the decreased postoperative pain and otalgia.

Differential expression of toll-like receptors 2 and 4 in rat middle ear

OBJECTIVE The epithelial cells of the middle ear and Eustachian tube must maintain an adequate mucosal defense system against various antigenic stimuli. Since toll-like receptors (TLRs) are known to play a critical role in mucosal defense, we investigated their expression in the mucosa of the tubotympanum, nasopharynx, and oral cavity of the rat. METHOD The expression of TLR2 and TLR4 was examined in the mucosa of the tubotympanum, nasopharynx and oral cavity of the rat using real time RT-PCR and Western blot analysis. RESULTS Transcripts for TLR2 and TLR4 were detected in the mucosa of the tubotympanum, nasopharynx, and oral cavity of the rat. The expression of TLR2 and TLR4 in the middle ear was increased more than in the other anatomical areas. Differential expression of these molecules at the protein level was confirmed by Western blot analysis. CONCLUSIONS Diverse expression of TLR2 and TLR4 in different parts of the tubotympanum and upper aerodigestive tract suggests region-specific functional modulation of the innate immune system. Differential expression of subtypes of the TLR in the normal physiology of the tubotympanum and upper aerodigestive tract also suggests that they may play a role in the pathophysiology of otitis media.

Does the kyphotic change decrease the risk of fall

Objectives Falls are a major problem in the elderly. Age-related degeneration of the human balance system increases the risk of falls. Kyphosis is a common condition of curvature of the upper spine in the elderly and its development occurs through degenerative change. However, relatively little is known about the effect of kyphotic changes on balance in the elderly. The aim of this study is to investigate the influence of kyphosis on the balance strategy through use of the motor control test (MCT) in computerized dynamic posturography. Methods Fifty healthy subjects who were not affected by other medical disorders that could affect gait or balance were enrolled in the study. By simulation of kyphotic condition through change of the angles of the line connecting the shoulder to the hip and the ankle axis by approximately 30°, the latency and amplitude of the MCT were measured in upright and kyphotic condition. Results In the kyphotic condition, latency was shortened in backward movement. In forward movement, latency was shortened only in large stimulation. The amplitude in forward movement was decreased in kyphotic condition. However, the change of amplitude was not significant in large intensity backward movement in the same condition. Conclusion Kyphotic condition decreases the latency of MCT, especially in backward movement. These findings imply that kyphotic condition may serve as a protective factor against falls.

Middle ear inflammation of rat induced by urban particles.

OBJECTIVE The aim of this study was to evaluate the histologic change of middle ear mucosa and the expression levels of epithelial sodium channel (ENaC) subunits and mucin production genes, after the injection of urban particulate matter (UPM) into the middle ear cavity of rats. METHODS Fifty pathogen-free, male Sprague Dawley rats were assigned to the study. Transtympanic injection of UPM solution (300μg/ml, 50μl) was made into the middle ear cavity of rats. Rats were sacrificed at day 1 (group1); day 3 (group2); day 5 (group3); and day 14 (group4) after the procedure. The expression levels of ENaC subunits (α, β and γ) and mucin producing genes (MUC5AC and MUC5B) were analyzed using semi-quantitative real-time reverse transcriptase-polymerase chain reaction. Thickness of middle ear mucosa was measured and analyzed. RESULT After transtympanic injection, the thickness of middle ear mucosa increased significantly on day 1, 3 and 5 (p<0.05) and was normalized on day 14, compared to the control group. Inflammatory changes observed in the middle ear mucosa were subepithelial widening, inflammatory cell infiltration and vascular space widening on day 1, 3 and 5. These changes had reverted to normal on day 14. The level of ENaC-α expression decreased 0.60 fold on day 1 (p<0.05), but was normalized thereafter. The level of ENaC-β and γ decreased 0.39 and 0.27 fold, respectively, on day 1, was normalized on days 3 and 5, and increased 2.30 and 2.47 fold on day 14, respectively (p<0.05). The level of MUC5AC expression increased 1.97-fold on day 1 (p<0.05) and 2.58-fold on day 5 (p<0.05), but was normalized on day 14. The level of MUC5B expression increased 5.4-fold on day 1, 3.14-fold on day 3, 3.85-fold on day 5, and 2.46-fold on day 14, respectively (p<0.05). CONCLUSION Transtympanic injection of UPM solution into the middle ear cavity of rat induced a characteristic inflammatory response and altered gene expression related with inflammation and mucin production. These findings provide a useful clue for the understanding of how air pollutants, particularly UPM, contribute to the development of otitis media.

Psoriasin (S100A7), an antimicrobial peptide, is increased in human middle ear cholesteatoma

Conclusion. Increased psoriasin in cholesteatoma epithelium may play a role in epithelial inflammatory response and differentiation. Objectives. Cholesteatoma is characterized by excessive keratinocyte differentiation leading to inflammation, granulation tissue, and osteolytic activity. Moreover, psoriasin may act as an antimicrobial peptide, stimulate granulocytes, and control keratinocyte differentiation. The purpose of this study was to investigate the differential expression patterns and the localization of psoriasin in cholesteatoma and in normal external auditory canal skin. Materials and methods. Expression levels of psoriasin mRNA were evaluated by real-time PCR and Western blotting. Cholesteatoma-affected and normal external auditory canal skin samples were immunostained with monoclonal antibody to psoriasin. Localization of immunoreactivity to psoriasin antibody was then compared. Results. By real-time PCR, expression levels of psoriasin mRNA in cholesteatoma were significantly higher than in normal external auditory canal skin, and this was confirmed by Western blotting. Immunohistochemical staining revealed that psoriasin protein is mainly expressed in the granular layer and in the upper parts of the spinous layer in cholesteatoma epithelium, but that it is expressed in the superficial layer of normal external auditory canal skin.

Expressions of Caspase‐14 in Human Middle Ear Cholesteatoma

Objectives: Cholesteatoma is characterized by an excessive proliferation and differentiation of keratinocytes with a progressive accumulation of keratin debris. Caspase‐14 is a novel regulator of keratinocyte terminal differentiation. The purpose of this study was to investigate the expression patterns and localizations of caspase‐ 14 in cholesteatoma and in normal external auditory canal (EAC) epithelium.

Analysis of Temporal Change in Voice Quality After Thyroidectomy: Single-institution Prospective Study

OBJECTIVES This study analyzed the temporal changes of voice quality after thyroidectomy and assessed the predictive perioperative parameters of postthyroidectomy voice disorder (PTVD). STUDY DESIGN This is a prospective cohort study. METHODS From March 2011 to July 2014, 559 patients who underwent thyroidectomy with or without central neck dissection were prospectively enrolled. All patients underwent prospective voice evaluation using the subjective and objective comprehensive battery of assessments, preoperatively and postoperatively at 1 week, 1 month, 3 months, 6 months, and 12 months. RESULTS Fundamental frequency (F0) was not significantly decreased during the postoperative follow-up. Maximal vocal pitch (MVP) and maximal intensity were not recovered, even at 1 year postoperatively, whereas the Grade, Roughness, Breathiness, Asthenia, Strain scale reached preoperative value at postoperative 3-6 months and voice handicap index at 1 year. Postoperative 1-month MVP was the best predictor for PTVD, and the cut-off value was 80% of preoperative value. Wide surgical extent and high preoperative F0 were the parameters that significantly correlated with PTVD (P = 0.021 and P < 0.001, respectively), and large tumor, higher preoperative MVP, and lower postoperative 1-month F0 were significantly associated with permanent PTVD (P = 0.028, P < 0.001, and P = 0.003, respectively). CONCLUSIONS Different recovery patterns of voice parameters should be considered in preoperative counseling. Intensive voice therapy may be needed for patients with the ability to produce higher pitch than normal preoperatively and wide surgical extent.