Myung-Gu Kim

EMI shielding intrinsically conducting polymer/PET textile composites

Intrinsically conducting polymer(ICP)/PET textile composites were prepared by chemical and electrochemical polymerization of ICP on a PET fabric in sequence. We investigated the effects of the chemical or electrochemical polymerization conditions on the properties of resulting composites such as electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE). The ICP/PET composite prepared in this study was highly electrically conducting, showing 0.3 Ω-cm of the specific volume resistivity and about 35 dB of EMI SE over a wide frequency range.

Computed tomographic assessment of chronic rhinosinusitis with asthma.

Backgound The purpose of this study was to investigate differences in the extent of disease in patients with chronic rhinosinusitis (CRS) both with and without asthma. Methods Medical records and computed tomographic (CT) scans of 48 consecutive asthmatic patients and 523 nonasthmatic patients with CRS between April 1995 and December 2001 were reviewed, retrospectively. Each sinus in the ostiomeatal complex CT scans was assigned a score of 0–2 according to the extent of disease using the Lund-Mackay scoring system, and the ratios of the score of each sinus to the total score were analyzed for the difference between the asthmatic and nonasthmatic groups. A Mann-Whitney test was used for statistical evaluation, with p < 0.05 accepted as statistically significant. Results The ratios of ethmoid sinus score to total score were higher in asthmatic patients than in nonasthmatic patients (p < 0.001), and the ratios of the score of maxillary sinus to total score were lower in asthmatic patients than in nonasthmatic patients (p < 0.001). Conclusion Our study shows that the ethmoid sinus is the preferred site of CRS in patients with coexisting asthma.

Hearing Loss as a Function of Aging and Diabetes Mellitus: A Cross Sectional Study

Background Although hearing loss may be caused by various factors, it is also a natural phenomenon associated with the aging process. This study was designed to assess the contributions of diabetes mellitus (DM) and hypertension, both chronic diseases associated with aging, as well as aging itself, to hearing loss in health screening examinees. Methods This study included 37,773 individuals who underwent health screening examinations from 2009 to 2012. The relationships between hearing threshold and subject age, hearing threshold at each frequency based on age group, the degree of hearing loss and the presence or absence of hypertension and DM were evaluated. Results The prevalence of hearing loss increased with age, being 1.6%, 1.8%, 4.6%, 14.0%, 30.8%, and 49.2% in subjects in their twenties, thirties, forties, fifties, sixties, and seventies, respectively (p<0.05). Hearing value per frequency showed aging-based changes, in the order of 6000, 4000, 2000, 1000 and 500 Hz, indicating greater hearing losses at high frequencies. The degree of hearing loss ranged from mild to severe. Aging and DM were correlated with the prevalence of hearing loss (p<0.05). There was no statistically significant association between hearing loss and hypertension after adjusting for age and DM. Conclusions The prevalence of hearing loss increases with age and the presence of DM. Hearing loss was greatest at high frequencies. In all age groups, mild hearing loss was the most common form of hearing loss.

Objective usefulness of thin silastic septal splints after septal surgery.

Background Silastic splints have been used as effective tools for septal support, avoiding adhesion, and mucosal healing after septal surgery. Furthermore, although many surgeons insert septal splints, no well-designed trials exist to support their use. A randomized double-blinded controlled trial was performed. Methods We recruited 40 subjects who had undergone septoplasty only without sinus surgery or turbinoplasty. A silastic septal splint was inserted in one side of the nasal cavity at the end of each septoplasty, with the other side serving as a control. The splint side and control side were randomly selected. Nasal discomfort score (10-point scale) and mucosal status (grades 1–4) were surveyed in a blinded setting on postoperative days 7 and 14. Results Forty of 83 subjects fulfilled the enrollment criteria. On the 7th postoperative day there was no significant difference in nasal discomfort between the splint and control sides (6.2 ± 1.28 and 5.7 ± 1.27, respectively; p = 0.116), but the mucosal status was better on the splint side than on the control side (1.5 ± 0.51 and 2.5 ± 0.85; p < 0.001). At 14 days postoperatively, the symptom score (2.7 ± 1.06 versus 3.8 ± 1.25; p < 0.001) and mucosal status (1.5 ± 0.55 versus 1.9 ± 0.68; p = 0.013) were significantly better on the splint side compared with the control side. Conclusion Insertion of a silastic septal splint after septal surgery should be accepted as a routine procedure.

Role of Wnt signaling pathway in progression of sinonasal inverted papilloma to squamous cell carcinoma.

Background Sinonasal inverted papilloma (IP) is one of the most common benign tumors of the sinonasal area and malignant transformation has frequently been reported. However, the exact mechanism of the transition from benign lesion to malignancy is not known. The Wnt signaling pathway involves a network of multiple signaling glycoproteins that are known to play an important role in embryogenesis and carcinogenesis. Objective The purpose of this study was to evaluate the role of the Wnt pathway and signaling proteins in malignant transformation of IP to dysplasia and squamous cell carcinoma. Methods Expression of the Wnt signaling pathway proteins, including Wnt-1, beta-catenin, cyclin D1, and Dishevelled-1 (Dvl-1), were detected by immunohistochemistry by using 3-mm tissue core microarrays that consisted of 115 cores of IP tissue. Each of the IP cores was graded as I (prominent squamous metaplasia), II (inverted pattern), III (dysplasia), or IV (squamous cell carcinoma). The expression pattern of each protein and the correlation between the expression of each target protein and IP grade were evaluated. Results Membranous staining of beta-catenin showed a significant positive correlation with IP grade (ρ = 0.247, p < 0.001), as did staining of cyclin D1 (ρ = 0.365, p < 0.001), which showed a nuclear pattern and staining of Dvl-1 (ρ = 0.380, p < 0.001), which showed a membranous, cytoplasmic, and nuclear pattern. For Dvl-1, a nuclear expression pattern was more frequently observed in grade III and IV IP (p = 0.036). In the case of Wnt-1, cytoplasmic expression was observed; however, it did not show a significant correlation with IP grade (ρ = 0.141, p = 0.130). Conclusions Wnt signaling proteins, including beta-catenin, cyclin D1, and Dvl-1, may play crucial roles in the malignant transformation of IP.

Influence of Intranasal Epinephrine and Lidocaine Spray on Olfactory Function Tests in Healthy Human Subjects

Objective. Although topical decongestants and anesthetics are widely used in preparation for nasal endoscopy, no controlled trials have evaluated the effects of these agents on olfaction. Study Design. Randomized double-blinded controlled trial. Setting. Tertiary referral hospital. Materials and Methods. The authors recruited 72 healthy subjects and randomly assigned them to 1 of 4 groups (control, phenylephrine group, lidocaine group, and both agents). After baseline tests with the Korean version of Sniffin’ Stick Test II (KVSS II), topical agents were applied to each nostril. Fifteen minutes later, repeat tests were carried out. Pre- and postspray results of the olfactory tests were compared, and the differences among groups were analyzed. Results. The mean ± SD prespray KVSS II score of the study group was 30.2 ± 3.8, and there were no statistically significant differences among the study groups (P = .353). Mean ± SD pre- and postspray KVSS II scores were 29.0 ± 3.5 and 30.7 ± 3.7 (P = .128) in the control group, 30.6 ± 3.6 and 31.7 ± 3.3 (P = .262) in the phenylephrine group, and 31.4 ± 3.6 and 32.1 ± 3.1 (P = .557) in the lidocaine group, respectively. In the phenylephrine and epinephrine spray group, the mean ± SD pre- and postspray scores were 29.9 ± 4.4 and 31.3 ± 3.7 (P = .071), respectively. Conclusions. Neither topical intranasal phenylephrine nor lidocaine use affected the results of the olfactory test, even when the agents were used in combination.