Dae Han Chung

Hearing Abilities at Ultra-High Frequency in Patients with Tinnitus

Objectives To compare tinnitus patients who have normal hearing between 250 Hz and 8 kHz with normal controls with regard to the ability of each group to hear extended high-frequency pure tone thresholds. Methods We enrolled 18 tinnitus patients, each of whom had a threshold of HL <25 dB and threshold differences of <10 dB between ears at frequencies of 250 and 500 Hz and 1, 2, 4, and 8 kHz. We also enrolled age- and gender-matched normal volunteers (10 ears), for each patient. Extended high frequency pure tone audiometry was performed, and the mean hearing thresholds at 10, 12, 14, and 16 kHz of each tinnitus ear were compared with those of the 10 age- and sex-matched normal ears. Results Of the 18 patients with tinnitus, 12 had significantly increased hearing thresholds at more than one of the four high frequencies, compared with the normal group. When we assessed results according to frequency, we found that 8 patients had decreased hearing ability at 10 kHz, 10 at 12 kHz, 8 at 14 kHz, and 4 at 16 kHz. Conclusion Some patients with tinnitus who have normal hearing below 8 kHz have decreased hearing ability at extended high-frequencies. Thus, the proportion of patients with tinnitus who have normal hearing over the entire audible range is smaller than in previous reports.

Advantages of Intraoral Removal Over Submandibular Gland Resection for Proximal Submandibular Stones: A Prospective Randomized Study

To compare surgical outcomes after intraoral removal of proximal submandibular stones versus traditional submandibular gland (SMG) resection.

A Polymorphism (rs1801018, Thr7Thr) of BCL2 is Associated with Papillary Thyroid Cancer in Korean Population

Objectives Among the apoptosis signals, B-cell CLL/lymphoma 2 (BCL2) is a well-known regulator of apoptosis with anti-apoptotic properties. We investigated here whether single nucleotide polymorphisms (SNPs) of the BCL2 were associated with host susceptibility of papillary thyroid cancer (PTC) occurrence and clinicopathologic parameters. Methods Ninety-two PTC patients and 222 control subjects were recruited. One promoter SNP (rs2279115, -938A/C) and one synonymous SNP (rs1801018, Thr7Thr) in the BCL2 gene were selected and genotyped using direct sequencing. Multiple logistic regression models were performed to evaluate odds ratios, 95% confidence intervals, and P-values. Results rs1801018 of the BCL2 gene was not associated with the development of PTC. In the clinicopathologic features, rs1801018 SNP was associated with the number and location. The G allele frequency of rs1801018 in PTC patients with multifocality (13.3%) was about four-fold higher than that in PTC patients with unifocality (3.4%). The G allele frequency of rs1801018 in PTC patients with both lobes (15.4%) was increased by about five-fold, compared to PTC patients with one lobe (3.2%). Conclusion The results suggest that synonymous SNP rs1801018 and the G allele of the BCL2 gene may be associated with the multifocality and bilaterality of PTC in Korean population.

PDGFRA promoter polymorphisms are associated with the risk of papillary thyroid cancer.

Platelet-derived growth factor (PDGF) acts as a regulator in cancer development and progression. We investigated whether single nucleotide polymorphisms (SNPs) of platelet-derived growth factor receptor α polypeptide (PDGFRA) and platelet-derived growth factor receptor β polypeptide (PDGFRB) genes are associated with papillary thyroid cancer (PTC) in a Korean population. Two promoter SNPs (rs6554162, -1309A/G and rs1800812, -635G/T) of PDGFRA and one promoter SNP (rs3828610, -202A/C) of PDGFRB were genotyped using direct sequencing in 93 PTCs and 212 controls. Genetic data were analyzed using the SNPAnalyzer Pro, SNPStats and Haploview programs. Two promoter SNPs (rs6554162 and rs1800812) in PDGFRA revealed significant differences between PTC and controls (for rs6554162, p=0.0018 in the codominant model and p=0.0005 in the dominant model; for rs1800812, p=0.016 in the codominant model and p=0.007 in the dominant model). In the analysis of allele frequency, we also found that the A allele of rs6554162 (p=0.004) and the T allele of rs1800812 (p=0.029) were associated with PTC. Additionally, by haplotype analysis, the GG and AT haplotypes consisting of rs6554162 and rs1800812 were associated with PTC (GG, p=0.0033; AT, p=0.0270). However, rs3828610 in PDGFRB showed no significant difference between PTC and controls. The results suggest that PDGFRA promoter SNPs (rs6554162 and rs1800812) may be associated with the risk of PTC.

Association of the Oncostatin M Receptor Gene Polymorphisms with Papillary Thyroid Cancer in the Korean Population

Objectives To investigate the association between papillary thyroid cancer (PTC) and single nucleotide polymorphisms (SNPs) of oncostatin M receptor (OSMR) in the Korean population. Methods Retrospective case-control study was done. Eighty-five patients with PTC and 287 controls were studied. One missense SNP (rs2278329, Asp553Asn) and one promoter SNP (rs2292016, -100 G/T) of the OSMR gene were genotyped by direct sequencing. Genetic data were analyzed using the SNPStats, Helixtree, and SNPAnalyzer Pro. PTC patients were dichotomized and compared with respect to the clinicopathologic characteristics. Results There was no association between genotypes and allele frequencies of OSMR SNPs (rs2278329 and rs2292016) and PTC susceptibility. SNP rs2278329 was significantly associated with tumor size (dominant model; P=0.028; odds ratio [OR], 2.71; 95% confidence interval [CI], 1.12 to 6.57). The A allele was higher in sizes large than 1 cm (32.5% vs. 16.7%; P=0.018; OR, 2.41; 95% CI, 1.17 to 4.98). Regarding the number of tumors, we found no significant association with genotype, however, the A allele was higher in patients with multifocaltiy (33.3% vs. 19.1%; P=0.040; OR, 2.12; 95% CI, 1.03 to 4.34). Conclusion The results suggest that OSMR polymorphism rs2278329 is associated with clinicopathologic characteristics of the tumor growth and multifocality development.