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This study aims to provide research results through empirical analysis on how customers’ reactions on social media affect the present and future value of a company. This research selected Korean KOSPI-listed companies that actually own and operate YouTube channels, and collected data through text mining the comments on YouTube videos with high views. In addition, the TF-IDF value was calculated, keywords were extracted, and keywords were classified into three groups through topic modeling. The characteristics of the three groups could be transformed into a “current-oriented topic” as advertising promotion content focused on fun or interest; a “future-oriented topic” as critical content pointing out problems, and a “neutral topic” as content of a neutral attitude toward companies. This study uses a regression analysis model to perform an empirical analysis by setting a company’s YouTube-related variable as an independent variable and setting a company’s current value and future value-related variable as a dependent variable. The results of this research are as follows. First, this paper found that companies that directly operate and manage YouTube accounts currently have lower corporate value than those that do not. Second, this study also found that companies which directly operate and manage YouTube accounts have higher future corporate value than those that do not. Third, the results showed that if a customer simply mentions interesting content or advertising/promotion-related content through corporate YouTube comments, the current corporate value may be improved in the short term, but in the long term, it has a negative effect on future corporate value. Fourth, the results of this research also presented that if a customer criticizes a company or points out a company’s problems through YouTube comments, the current corporate value decreases due to damage to the company’s image, but it was found that the future corporate value increases. Fifth, this paper found that neutral content, not just for fun and interest, nor for constructive criticism or dissatisfaction with the company, was not related to the company’s current and future corporate value. The contributions and expected effects of this paper are as follows. First of all, this paper provides useful information through research results which shows that companies are more advantageous in improving future corporate value from a long-term perspective by strategically operating social media directly. In addition, the research results of this study objectively demonstrated through YouTube channels that it is more helpful for companies in the long run to respond well to customer complaints and negative opinions, and to implement policies that continuously manage customer opinions. Finally, the research method used in this paper, that is, the research methodology that conducted empirical analysis through quantification of unstructured tax data, is expected to provide guidelines for many scholars to expand the scope of data available for empirical research in the future.

Increased bone marrow adiposity is widely observed in patients with obesity and osteoporosis and reported to have deleterious effects on bone formation. Dracunculin (DCC) is a coumarin isolated from Artemisia spp. but, until now, has not been studied for its bioactive potential except antitrypanosomal activity. In this context, current study has reported the anti-adipogenic effect of DCC in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). DCC dose-dependently inhibited the lipid accumulation and expression of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) in hBM-MSCs induced to undergo adipogenesis. To elucidate its action mechanism, the effect of DCC on Wnt/β-catenin and AMPK pathways was examined. Results showed that DCC treatment activated Wnt/β-catenin signaling pathway via AMPK evidenced by increased levels of AMPK phosphorylation and Wnt10b expression after DCC treatment. In addition, DCC treated adipo-induced hBM-MSCs exhibited significantly increased nuclear levels of β-catenin compared with diminished nuclear PPARγ levels. In conclusion, DCC was shown to be able to hinder adipogenesis by activating the β-catenin via AMPK, providing potential utilization of DCC as a nutraceutical against bone marrow adiposity.

Background/Aims To examine whether visceral adiposity serves as a risk factor for colorectal cancer (CRC) and colorectal adenomas. Methods Two hundred healthy subjects, 200 patients with colorectal adenoma, and 151 patients with CRC (46 with early-stage and 105 with advanced-stage cancers) were enrolled at a tertiary referral hospital. All subjects underwent colonoscopy, and had laboratory data, and computed tomography (CT) scan available for abdominal fat measurement. An abdominal CT scan taken 1 to 4 years (mean interval, 20.6 months) before the diagnosis of CRC was also available in the 42 CRC patients. Results The mean areas of visceral adipose tissue (VAT) areas in the control, adenoma, early- and advanced-stage CRC groups were 94.6, 116.8, 110.4, and 99.7 cm2, respectively (P0.05). The risk of both adenoma and CRC positively correlated with fasting plasma glucose levels (P for trend

This research examines the association between CEO messages and current and future corporate value on the websites of fashion companies. The research methods of this paper are as follows: First, we extract the fashion firm samples among companies listed in Korea’s KOSPI and KOSDAQ in 2020. Second, CEO messages’ text data on the homepage of the fashion companies are obtained by hand-collecting. The repeated words with high TF-IDF values are selected as keywords using text-mining techniques. Third, the CEO messages of the fashion firms are classified with one of finance, customer, internal management process, learning and growth, and corporate social standpoints by the SBSC framework. This research investigates through regression analysis whether firms that emphasize certain factors affect their future or current corporate value. As an additional test, using social network analysis, CONCOR analysis, and 2SLS analysis, the paper checks the objectivity and robustness of the empirical results. The results of this paper are as follows: The first finding presents that all the standpoints of the CEO messages of fashion firms had no significant association with current company value. These results imply that CEO messages posted on the company homepage are generally expressed from a long-term standpoint, and a long time is needed to realize their visions or goals expressed in the CEO message to actually effect corporate value. The second finding shows that the future firm value can be improved as firms mention more words related to the corporation’s social responsibility among CEO messages of the company homepages disclosed by fashion companies. This result implies that if a fashion firm shows its vision and goals related to corporate social responsibility and makes an effort to achieve them, the company value will be increased in the future. The results of the additional tests support the fact that there is a significant positive association between the mention of social responsibility in the CEO message of the company’s website and future firm value. The contributions of this study are as follows: First, on research topics in the field of accounting, this study utilizes text mining and the SBSC framework and quantified qualitative data to perform empirical analysis. Introducing this new and innovative methodology contributes to the development of convergence research. Second, the results of this study suggest that the contents of the company’s CEO message contain symbolic and implicit important information. In particular, this study proved through empirical analysis that companies’ effort and achievement related to social responsibility help increase corporate value in the long run.

Natural bioactive substances are promising lead compounds with beneficial effects on various health problems including osteoporosis. In this context, the goal of this study was to investigate the effect of myricetin 3-O-β-D-galactopyranoside (M3G), a glycoside of a known bioactive phytochemical myricetin, on bone formation via osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). The hBM-MSCs were induced to differentiate into osteoblasts and adipocytes in the presence or absence of M3G and the differentiation markers were analyzed. Osteoblastogenesis-induced cells treated with M3G exhibited stimulated differentiation markers: cell proliferation, alkaline phosphatase (ALP) activity, and extracellular mineralization. In terms of intracellular signaling behind the stimulatory effect of M3G, the expression of RUNX2 and osteopontin transcription factors were upregulated. It has been shown that M3G treatment increased the activation of Wnt and BMP as a suggested mechanism of action for its effect. On the other hand, M3G treatment during adipogenesis-inducement of hBM-MSCs hindered the adipogenic differentiation shown as decreased lipid accumulation and expression of PPARγ, SREBP1c, and C/EBPα, adipogenic transcription factors. In conclusion, M3G treatment stimulated osteoblast differentiation and inhibited adipocyte differentiation in induced hBM-MSCs. Osteoblast formation was stimulated via Wnt/BMP and adipogenesis was inhibited via the PPARγ pathway. This study provided necessary data for further studies to utilize the therapeutic potential of M3G against osteoporosis via regulation of bone marrow stromal cell differentiation.

A nosocomial outbreak of severe acute respiratory syndrome-coronavirus-2 occurred in two general wards. One outbreak had pre-symptomatic transmission and was linked epidemiologically with an index case. The other outbreak was associated with early detection failure in a crowded room. Notably, adherence to appropriate mask wearing was not confirmed in the hospital outbreak. Confirmed cases were moved into isolation rooms, and contacts were quarantined. Quarantined cases were tested regularly and facilitated early termination of the hospital outbreak., Graphical Abstract

Background and aims Resting heart rate is an independent predictor of colorectal cancer (CRC) development and CRC-related mortality. However, little is known about the relationship between resting heart rate and colorectal adenoma development. We aimed to investigate this association in a population who underwent screening colonoscopy. Methods Among 39,021 patients who underwent both electrocardiogram and screening colonoscopy during routine health examinations at the Seoul National University Bundang Hospital, Health Promotion Center, Korea from January 2014 to July 2019, 1,344 patients had advanced adenoma. We performed 1:1 propensity score (PS) matching to establish a control group that mitigated the confounding effects of age and sex. We performed multivariate logistic regression analyses to identify the independent risk factors of advanced adenoma development. Results Resting heart rate was significantly higher in the advanced adenoma group than in the control group. The prevalence of advanced polyp increased across the quartiles of resting heart rate. Patients with higher resting heart rates were more likely to be older, smokers, and have increased blood pressure and DM and less likely to engage in active exercises than those with lower resting heart rates. Patients with higher resting heart rates had higher serum glucose, triglyceride, hemoglobin A1C, and insulin levels and lower high-density lipoprotein cholesterol levels. Patients with resting heart rate in the highest quartile (≥71 bpm) still showed significantly increased odds ratio (OR) of advanced adenoma development (OR: 1.379, 95% confidence interval: 1.099–1.731, p = 0.006). Conclusions High resting heart rate was a meaningful independent risk factor of advanced adenoma development.

BACKGROUND AND PURPOSE This study aimed to determine the long-term effects of vagus nerve stimulation (VNS) treatment on suicidality, mood-related symptoms, and quality of life (QOL) in patients with drug-resistant epilepsy (DRE). We also investigated the relationships among these main effects, clinical characteristics, and VNS parameters. METHODS Among 35 epilepsy patients who underwent VNS implantation consecutively in our epilepsy center, 25 patients were recruited to this study for assessing the effects of VNS on suicidality, mood-related symptoms, and QOL. The differences in these variables between before and after VNS treatment were analyzed statistically using paired t-tests. Multiple linear regression analyses were also performed to determine how the patients' demographic and clinical characteristics influenced the variables that showed statistically significant changes after long-term VNS treatment. RESULTS After VNS, our patients showed significant improvements not only in the mean seizure frequency but also in suicidality, depression, and QOL. The reduction in depression was associated with the improvement in QOL and more-severe depression at baseline. The reduction in suicidality was associated with higher suicidality at baseline, smaller changes in depression, and less-severe depression at baseline. Improved QOL was associated with lower suicidality at baseline. CONCLUSIONS This study found that VNS decreased the mean seizure frequency in patients with DRE, and also improved their depression, suicidality, and QOL. These results provide further evidence for therapeutic effect of VNS on psychological comorbidities of patients with DRE.

Natural bioactive substances are promising lead compounds with beneficial effects on various health problems including osteoporosis. In this context, the goal of this study was to investigate the effect of myricetin 3-O-β-D-galactopyranoside (M3G), a glycoside of a known bioactive phytochemical myricetin, on bone formation via osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). The hBM-MSCs were induced to differentiate into osteoblasts and adipocytes in the presence or absence of M3G and the differentiation markers were analyzed. Osteoblastogenesis-induced cells treated with M3G exhibited stimulated differentiation markers: cell proliferation, alkaline phosphatase (ALP) activity, and extracellular mineralization. In terms of intracellular signaling behind the stimulatory effect of M3G, the expression of RUNX2 and osteopontin transcription factors were upregulated. It has been shown that M3G treatment increased the activation of Wnt and BMP as a suggested mechanism of action for its effect. On the other hand, M3G treatment during adipogenesis-inducement of hBM-MSCs hindered the adipogenic differentiation shown as decreased lipid accumulation and expression of PPARγ, SREBP1c, and C/EBPα, adipogenic transcription factors. In conclusion, M3G treatment stimulated osteoblast differentiation and inhibited adipocyte differentiation in induced hBM-MSCs. Osteoblast formation was stimulated via Wnt/BMP and adipogenesis was inhibited via the PPARγ pathway. This study provided necessary data for further studies to utilize the therapeutic potential of M3G against osteoporosis via regulation of bone marrow stromal cell differentiation.

Background/Aims Neuronal degeneration and changes in interstitial cells of Cajal (ICCs) are important mechanisms of age-related constipation. This study aims to compare the distribution of ICCs and neuronal nitric oxide synthase (nNOS) with regard to age-related changes between the ascending colon (AC) and descending colon (DC) in 6-, 31-, and 74-week old and 2-year old male Fischer-344 rats. Methods The amount of fecal pellet and the bead expulsion times were measured. Fat proportion in the muscle layer of the colon was analyzed by hematoxylin and eosin staining. Proto-oncogene receptor tyrosine kinase (KIT) and neuronal nitric oxide synthase (nNOS) expression were analyzed with Western blotting and immunohistochemistry. Isovolumetric contractile measurements and electrical field stimulation were used to assess smooth muscle contractility. Results Colon transit and bead expulsion slowed with senescence. Fat in the muscle layer accumulated with age in the AC, but not in the DC. The proportion of KIT-immunoreactive ICCs in the submucosal and myenteric plexus was higher in the DC than in the AC, and it declined with age, especially in the AC. In contrast, the proportion of NOS-immunoreactive neurons in the myenteric plexus was higher in the AC than in the DC, and both decreased in older rats. Nitric oxide levels declined with age in the DC. Muscle strip experiments showed that the inhibitory response mediated by nitric oxide in the circular direction of the DC was reduced in 2-year old rats. Conclusion The AC and DC differ in their distribution of ICCs and nNOS, and age-related loss of nitrergic neurons more severely affects the DC than the AC.

Effects of the structural characteristics of MgTi0.95(Sn0.05-xZrx)O3 (0 ≤ x ≤ 0.04) and Mg(Ti0.99-xSnx)Zr0.01O3 (0 ≤ x ≤ 0.06) on microwave dielectric properties were investigated. Complete solid solutions consisting of single-phased ilmenite structures with overall compositions of Mg(Ti0.99-xSnx)Zr0.01O3 and MgTi0.95(Sn0.05-xZrx)O3 (x ≤ 0.03) were obtained. However, a secondary phase was detected in MgTi0.95(Sn0.05-xZrx)O3 specimens at x = 0.04. The temperature coefficient of resonant frequency (TCF) of the specimens was affected by distortion of the Ti-site octahedra. The dielectric constants (K) of the specimens were affected by the theoretical dielectric polarizabilities of constituent ions of the ilmenite structure. The quality factor (Qf) was dependent on the Ti-site bond valence, which was a function of the bond strength between the cation and oxygen ion in the oxygen octahedron. The quality factors of MgTi0.95(Sn0.02Zr0.03)O3 and Mg(Ti0.95Sn0.04)Zr0.01O3 improved owing to the well-ordered structure, which was confirmed by analysis of Raman spectra.

Background/Aims: The aim of this study was to evaluate the effect of the synthetic S-allyl-L-cysteine (SAC) PMK-S005 on gastric acid secretion, inflammation, and antioxidant enzymes in aging rats. Methods: The rats were divided into four groups at 31 weeks of age and were continuously fed a diet containing a vehicle control, PMK-S005 (5 or 10 mg/kg), or lansoprazole (5 mg/kg). Gastric acid secretion and connective tissue thickness of the lamina propria were evaluated at 74 weeks and 2 years of age. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and COX-2 levels were measured by using enzyme-linked immunosorbent assays (ELISAs) or Western blot assays. Levels of antioxidant enzymes, including heme oxyganase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), were also measured. Results: As the rats aged, gastric acid secretion significantly decreased, and the connective tissue of the lamina propria increased. However, 74-week-old rats in the PMK-S005 group exhibited greater levels of gastric acid secretion than those of the control and lansoprazole groups. The increase of TNF-α, IL-1β, and COX-2 expression in 74-week and 2-year-old control rats were inhibited by PMK-S005. In addition, the decrease in HO-1 and NQO-1 protein expression that occurred with aging was inhibited by PMK-S005 in the 74-week-old rats. Conclusions: These results suggest that PMK-S005 has therapeutic potential as an antiaging agent to ameliorate age-related gastric acid secretion, inflammation, and oxidative stress in the stomach. (Gut Liver 2016;10:749-756)

The dependence of the microwave dielectric properties of the glass-ceramic composite 0.9CaMgSi₂O 6 -0.1MgSiO₃ on the crystallization behaviour was investigated as functions of the TiO₂ content and heat-treatment temperature. The crystallization behaviour of the specimens was evaluated via a combination of the Rietveld and reference-intensity ratio methods. For specimens with a TiO₂ content of up to 1 wt.%, a monoclinic diopside phase was formed, whereas a secondary TiO₂ phase was formed with further increases in the TiO₂ content. The quality factor (Qf) of the specimens was strongly dependent on the degree of crystallization. The highest Qf value was obtained with a TiO₂ content of 0.5 wt.%, which was improved by increasing the heat-treatment temperature. The dielectric constant (K) was affected by the size of the crystallites and the TiO₂ content. The temperature coefficient of the resonant frequency (TCF) was nearly constant for all of the specimens, regardless of the TiO₂ content or heattreatment temperature.

Background: Not much is known about the role of gastric microbiota except for Helicobacter pylori in human health and disease. In this study, we aimed to detect human gastric microbiota in both gastric mucosa and gastric juice by barcoded 454-pyrosequencing of the 16S rRNA gene and to compare the results from mucosa and juice. Methods: Gastric biopsies and stomach juices were collected from 4 subjects who underwent standard endoscopy at Seoul National University Bundang Hospital. Gastric microbiota of antral mucosa, corpus mucosa samples, and gastric fluids were analyzed by barcoded 454-pyrosequencing of the 16S rRNA gene. The analysis focused on bacteria, such as H. pylori and nitrosating or nitrate-reducing bacteria. Results: Gastric fluid samples showed higher diversity compared to that of gastric mucosa samples. The mean of operational taxonomic units was higher in gastric fluid than in gastric mucosa. The samples of gastric fluid and gastric mucosa showed different composition of phyla. The composition of H. pylori and Proteobacteria was higher in mucosa samples compared to gastric fluid samples (H. pylori, 66.5% vs. 3.3%, P = 0.033; Proteobacteria, 75.4% vs. 26.3%, P = 0.041), while Actinobacteria, Bacteroidetes, and Firmicutes were proportioned relatively less in mucosa samples than gastric fluid. However there was no significant difference. (Actinobacteria, 3.5% vs. 20.2%, P = 0.312; Bacteroidetes, 6.0% vs. 14.8%, P = 0.329; Firmicutes, 12.8% vs. 33.4%, P = 0.246). Conclusions: Even though these samples were small, gastric mucosa could be more effective than gastric fluid in the detection of meaningful gastric microbiota by pyrosequencing.

The microwave dielectric properties of MgTiO3 ceramics with isovalent substitutions of ( ( Li 1 / 4 1 + B 3 / 4 5 + ) 4 + , ( Mg 1 / 3 2 + B 2 / 3 5 + ) 4 + , and ( Al 1 / 2 3 + B 1 / 2 5 + ) 4 + (B=Nb5+ or Ta5+)) at the Ti-site were investigated. All isovalent-substituted MgTiO3 ceramics showed single phases of ilmenite structure with rhombohedral symmetry. Specimens with B=Ta5+ showed higher quality factors (Qf) and lower dielectric constants (K) than those with B=Nb5+, because of the high degree of average covalency in the ceramics. The Qf values of specimens substituted with (Mg1/3B2/3)4+ at the Ti-site were higher than those of other isovalent-substituted MgTiO3 ceramics, because of the high Ti-site bond strength of (Mg1/3B2/3)4+. Because (Li1/4B3/4)4+ displayed the largest dielectric polarizability of the substituting species, MgTiO3 ceramics substituted (Li1/4B3/4)4+ at the Ti-site showed the largest K value. The substituted specimens showed lower temperature coefficients of the resonant frequencies (TCF) than the pure MgTiO3 ceramics, because of the increased Ti-site octahedral distortion. The relationships between the microstructures and microwave dielectric properties of MgTiO3 ceramics were also discussed.

Objective: To determine the effect of Lentinula edodes extract on ultraviolet (UV) A and UVB-induced changes in matrix metalloproteinase (MMP) and type I procollagen expression using human immortalized HaCaT keratinocytes. Methods: Lentinula edodes ethanol extract (LEE) was obtained by extraction with 80% ethanol for 4 h at 80 °C. Effect of LEE on UV-induced alteration on the expression and production of MMPs and type I procollagen in keratinocytes was investigated using ELISA, RT-PCR, and Western blotting assay. To determine the underlying mechanism of LEE-mediated effects, mitogen-activated protein kinase (MAPK) and activator protein 1 signaling pathways were analysed by Western blotting assay. Results: LEE significantly inhibited the expression of MMP-1 and MMP-9 and increased the expression of type I procollagen in UVA and UVB-irradiated HaCaT keratinocytes. The phosphorylation levels of p38 were significantly inhibited by LEE whereas it did not affect c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation. Suppression of p38 phosphorylation was also accompanied by downregulation of UVA and UVB-induced increase in c-Fos. Conclusions: LEE effectively inhibits the expression of MMP-1 and MMP-9 and increases type I procollagen production through the p38 MAPK/c-Fos signaling pathway in UVA and UVB-irradiated HaCaT keratinocytes. This findings suggest that Lentinula edodes may be developed as a cosmetic material to suppress UV exposuremediated skin aging.

Background/aims Functional dyspepsia (FD) is one of the most common gastrointestinal disorders, and FD imposes social and economic burden worldwide. The aim of this study is to identify the prevalence and risk factors of FD in health check-up population in tertiary centers in Korea. Methods A nationwide multicenter prospective study was performed at 9 tertiary healthcare centers in Korea between September 2016 and June 2017. A total of 2525 subjects were investigated based on endoscopic findings and questionnaires with the Rome III criteria, and Helicobacter pylori serology (IgG). Results A total of 1714 subjects without organic disease were enrolled. The mean (± SD) age was 51.5 (± 12.7) years, and 917 patients (53.5%) were female. The proportion of H. pylori seropositivity was 51.0% (874/1714). The prevalence of FD was 10.3% (176/1714), and the subtypes of postprandial distress syndrome alone, epigastric pain syndrome alone, and postprandial distress syndrome-epigastric pain syndrome overlap were 4.8%, 3.0%, and 2.5%, respectively. Multivariate analysis showed that female gender (OR, 1.58; 95% CI, 1.14-2.21) and education below college level (OR, 1.45; 95% CI, 1.01-2.07) were related to FD. Multivariate analysis based on age 60 showed female gender as a significant (OR, 2.90; 95% CI, 1.06-7.94) factor in the group ≥ 60 years. Conclusions The prevalence of FD was 10.3% in the health check-up population in Korea. Female sex and education below college level were risk factors for FD. Female sex is a risk factor for FD in old age, underscoring the need for close attention in this age group.

Effects of the partial substitution of divalent and/or tetravalent cations for Mg 2+ and/or Ti 4+ on the structural characteristics and dielectric properties of MgTiO 3 -based ceramics [MgTiO 3 (MT), (Mg 0.95 Zn 0.05 )TiO 3 (MZT), Mg(Ti 0.95 Sn 0.05 )O 3 (MTS), (Mg 0.95 Zn 0.05 )(Ti 0.95 Sn 0.05 )O 3 (MZTS)] were investigated at microwave frequencies. Among these MgTiO 3 -based ceramics with single-phase ilmenite structure, the MZTS showed the largest unit cell volume owing to the larger ionic radii of Sn 4+ (0.69 A) and Zn 2+ (0.74 A) in comparison to Ti 4+ (0.605 A) and Mg 2+ (0.72 A), respectively. The quality factor ( Qf ) of the MZTS showed the highest value among all the MgTiO 3 -based ceramics investigated; this is because of the strong bond strength at the Ti site, confirmed by Raman spectroscopy analysis and the high average covalency originated from the small difference in electronegativity between the cation and oxygen ion in the oxygen octahedra. The dielectric constant ( K ) of MgTiO 3 -based ceramics was affected by the dielectric polarizability of the composing ions. The relationship between the microstructure and microwave dielectric properties was also discussed.

AIM: To compare characteristics and prognosis of gastric cancer based on age. METHODS: A retrospective study was conducted on clinical and molecular data from patients (n = 1658) with confirmed cases of gastric cancer in Seoul National University Bundang Hospital (Seoul, South Korea) from 2003 to 2010 after exclusion of patients diagnosed with lymphoma, gastrointestinal stromal tumor, and metastatic cancer in the stomach. DNA was isolated from tumor and adjacent normal tissue, and a set of five markers was amplified by polymerase chain reaction to assess microsatellite instability (MSI). MSI was categorized as high, low, or stable if ≥ 2, 1, or 0 markers, respectively, had changed. Immunohistochemistry was performed on tissue sections to detect levels of expression of p53, human epidermal growth factor receptor (HER)-2, and epidermal growth factor receptor. Statistical analysis of clinical and molecular data was performed to assess prognosis based on the stratification of patients by age (≤ 45 and > 45 years). RESULTS: Among the 1658 gastric cancer patients, the number of patients with an age ≤ 45 years was 202 (12.2%; 38.9 ± 0.4 years) and the number of patients > 45 years was 1456 (87.8%; 64.1 ± 0.3 years). Analyses revealed that females were predominant in the younger group (P < 0.001). Gastric cancers in the younger patients exhibited more aggressive features and were at a more advanced stage than those in older patients. Precancerous lesions, such as atrophic gastritis and intestinal metaplasia, were observed less frequently in the older than in the younger group (P < 0.001). Molecular characteristics, including overexpression of p53 (P < 0.001), overexpression of HER-2 (P = 0.006), and MSI (P = 0.006), were less frequent in gastric cancer of younger patients. Cancer related mortality was higher in younger patients (P = 0.048), but this difference was not significant after adjusting for the stage of cancer. CONCLUSION: Gastric cancer is distinguishable between younger and older patients based on both clinicopathologic and molecular features, but stage is the most important predictor of prognosis.

Background/Aims: Controversy exists regarding the characteristics of Helicobacter pylori infection-negative gastric cancer (HPIN-GC). The aim of this study was to evaluate clinicopathologic features of HPIN-GC compared to H. pylori infection-positive gastric cancer (HPIP-GC) using a comprehensive analysis that included genetic and environmental factors. Methods: H. pylori infection status of 705 resectable gastric cancer patients was determined by the rapid urease test, testing for anti-H. pylori antibodies, histologic analysis and culture of gastric cancer tissue samples, and history of H. pylori eradication. HPIN-GC was defined as gastric cancer that was negative for H. pylori infection based on all five methods and that had no evidence of atrophy in histology or serology. Results: The prevalence of HPIN-GC was 4% (28/705). No significant differences with respect to age, sex, smoking, drinking, family history of gastric cancer or obesity were observed between the two groups. HPIN-GC tumors were marginally more likely to involve the cardia (14.3% for HPIN-GC vs 5.3% for HPIP-GC, p=0.068). The Lauren classification, histology, and TNM stage did not differ according to H. pylori infection status. Microsatellite instability was not different between the two groups, but p53 overexpression in HPIN-GC was marginally higher than in HPIP-GC (56.0% for HPIN-GC vs 37.0% for HPIP-GC, p=0.055). Conclusions: The prevalence of HPIN-GC was extremely low, and its clinicopathologic characteristics were similar to HPIP-GC. (Gut Liver 2016;10:212-219)

Little is known about the time course of aging on interstitial cells of Cajal (ICC) of colon. The aim of this study was to investigate the change of morphology, ICC, and neuronal nitric oxide synthase (nNOS)-immunoreactive cells in the aged rat. The proximal colon of 344 Fischer rats at four different ages (6, 31, 74 wk, and 2 yr) were studied. The immunoreactivity of c-Kit, nNOS, anti-protein gene product 9.5, and synaptophysin were counted after immunohistochemistry. The c-kit, stem cell factor (ligand of Kit), and nNOS mRNA were measured by real-time PCR. c-Kit and nNOS protein were assessed by Western blot. Isovolumetric contractile force measurement and electrical field stimulation (EFS) were conducted. The area of intramuscular fat deposition significantly increased with age after 31 wk. c-Kit-immunoreactive ICC and nNOS-immunoreactive neurons and nerve fibers significantly declined with age. mRNA and protein expression of c-kit and nNOS decreased with aging. The functional study showed that the spontaneous contractility was decreased in aged rat, whereas EFS responses in the presence of atropine and l-NG-Nitroarginine methyl ester were increased in aged rat. In conclusion, the decrease of proportion of proper smooth muscle, the density of ICC and nNOS-immunoreactive neuronal fibers, and the number of nNOS-immunoreactive neurons during the aging process may explain the aging-associated colonic dysmotility.

Background/aims The relationship between halitosis and gastroesophageal reflux disease (GERD) remains controversial. The aim of this study was to investigate an association between subjective and objective halitosis and GERD. Methods The subjects were enrolled from participants who visited a health promotion center at Seoul National University Bundang Hospital. For diagnosis of halitosis, a questionnaire was requested, and volatile sulfur compounds (VSCs) were measured by Halimeter. Self-conscious halitosis was defined as halitosis perceived by himself or herself. Informed halitosis was defined as hal-itosis perceived by others. Objective halitosis was defined when mean VSCs values were > 100 parts per billion. GERD was defined based on a questionnaire and endoscopy, including erosive esophagitis and non-erosive reflux disease (NERD). Results A total of 54 subjects (male:female = 33:21) with mean age of 46.0 ± 11.4 years were analyzed. The mean VSCs values were not significantly different between presence and absence of self-conscious halitosis (P = 0.322), but significantly different be-tween presence and absence of informed halitosis (P = 0.021). Informed halitosis was associated with objective halitosis (P = 0.039). GERD, erosive esophagitis and NERD did not correlate with objective halitosis (P = 0.556, 0.206 and 0.902, re-spectively). In multivariable analysis, the relationship between objective halitosis and GERD symptoms including chest pain, heart burn, acid regurgitation, epigastric pain, hoarseness, globus sensation and coughing was not significant. Besides, GERD was not associated with self-conscious halitosis, informed halitosis and objective halitosis, respectively. Conclusions GERD might not be associated with self-conscious, informed halitosis and objective halitosis indicated by Halimeter results. Informed halitosis could be correlated with objective halitosis determined by the Halimeter.(J Neurogastroenterol Motil 2014;20:483-490).

Background/Aims This study evaluated the effect of Helicobacter pylori eradication on functional dyspepsia (FD), and the relationship between the changes of histological gastritis and FD symptom responses.

Background/Aims Concerns that proton pump inhibitors (PPIs) diminish the efficacy of clopidogrel could hamper the appropriate prescription of PPIs. We evaluated the influence of pantoprazole on the antiplatelet effect of clopidogrel compared with ranitidine, which is regarded as safe, after stratification of the population according to the presence of a cytochrome (CYP) 2C19 polymorphism in Korea. Methods Forty patients who underwent dual antiplatelet therapy were randomized to receive pantoprazole (n=20) or ranitidine (n=20). Platelet aggregation was evaluated by impedance aggregometry at baseline (D0) and 8 days after acid-lowering treatments (D9). CYP2C19 was genotyped by polymerase chain reaction-restriction fragment length polymorphism. Results After co-treatment, the percentage of clopidogrel low-response was 11.1% (2/18) in the pantoprazole group and 10.5% (2/19) in the ranitidine group (p=0.954). The impedance values with adenosine diphosphate stimulus after acid-lowering treatments did not significantly differ between the two groups. In a multiple regression analysis, only ST-elevation myocardial infarction was marginally associated with a reduced antiplatelet effect (odds ratio, 12.07; 95% confidence interval, 0.84 to 173.78). However, pantoprazole use did not affect the antiplatelet effect after correction for the CYP2C19 polymorphism. Conclusions This study showed that pantoprazole does not increase platelet aggregation in patients receiving dual antiplatelet therapy (ClinicalTrials.gov number: NCT02733640).

Objective Cervical spondylosis and shoulder disorders share with neck and shoulder pain. Differentiating between the two can be challenging and patient with combined pathologies is less likely to have pain improvement even after successful cervical operation. We investigated clinical characteristics of the patients who were diagnosed as cervical spondylosis however, were turned out to have shoulder disorders or the patients whose pain was solely originated from shoulder. Methods Between January 2008 and October 2009, the patients presenting neck and shoulder pain with diagnosis of cervical spondylosis were enrolled. Among them, the patients who met following inclusion criteria were grouped into shoulder disorder group and the others were into cervical spondylosis group. Inclusion criteria were as follows. (1) To have residual or unresponsive neck and shoulder pain despite of optimal surgical treatment due to concomitant shoulder disorders. (2) When the operation was cancelled for the reason that shoulder and neck pain was proved to be related with unrecognized shoulder disorders. The authors retrospectively reviewed and compared clinical characteristics, level of pathology, diagnosis of cervical spondylosis and shoulder disorders. Results A total of 96 patients were enrolled in this study. Shoulder disorder group was composed of 15 patients (15.8%) and needed additional orthopedic treatment. Cervical spondylosis group was composed of 81 patients (84.2%). There was no significant differences in mean age, sex ratio and major diagnosis in both shoulder disorder and cervical spondylosis group (p=0.33, 0.78, and 0.68 respectively). However, the distribution of pathologic levels was found to be significantly different (p=0.03). In shoulder disorder group, the majority of lesions (15 of 19 levels, 78.9%) were located at the level of C4-5 (36.8%) and C5-6 (42.1%). On the other hand, in cervical spondylosis group, C5-6 (39.0%) and C6-7 (37.1%) were the most frequently observed level of lesions (80 of 105 levels, 16.1%). Conclusion It is very important for spine surgeons to perform a complete history taking and physical examination using the special tests, and to discover the underlying shoulder disorders causing of symptom in treatment of cervical spondylosis presenting neck and shoulder pain.

A hepatitis B virus (HBV) vaccine has been developed using a new adjuvant and HBV surface antigens produced from a CHO cell line. The purified HBV surface antigens are composed of L protein, M protein, and S protein in a mixture of 20- and 40-nm-diameter particles and filamentous forms. This HBV surface antigen, formulated with L-pampo, a proprietary adjuvant, induced 10 times more antibody than the same antigen with alum and was capable of inducing strong immune responses in three different HBV transgenic mice. In spite of the presence of a large amount of HBV antigen in the blood, no antibody against HBV surface antigen was normally detected in these transgenic mice. After immunization, the HBV antigen was also cleared from the blood.

Fusion is the cornerstone in the treatment of an unstable degenerative lumbar spinal disease. Various techniques have been developed. Amongst these techniques exists the oblique lumbar interbody fusion (OLIF), which is the ante-psoas approach. Adequate restoration of disc height with large cages placed in the intervertebral space, indirect decompression, and correction of sagittal and coronal alignment can be achieved with OLIF procedure with the advantage of minimal risk for the psoas muscle and lumbar plexus. Nevertheless, this technique entails complications directly associated with the anatomical location where the fusion takes place. This surgical area is a window between the left lateral border of the aorta, or the left common iliac artery, and the anterior belly of the left psoas muscle. Vascular complications associated with the injury of the main vessels, segmental artery or iliolumbar vein of the lumbar spine have been reported, as well as urologic lesions due to ureter transgression, amongst others. Although these complications have been described in the literature, an article that complements this information with technical advice for its avoidance is yet to be published. This article is a review of the most frequent complications associated with the OLIF procedure in L2-L5 lumbar levels, as well as a description of technical strategies for the prevention of such complications.

Background: Atrophic gastritis is a precancerous condition, which can be diagnosed by several methods. However, there is no consensus for the standard method. The aim of this study was to evaluate the correlations among endoscopic, histologic, and serologic findings for the diagnosis of atrophic gastritis. Methods: From March 2003 to August 2013, a total of 2,558 subjects were enrolled. Endoscopic atrophic gastritis was graded by Kimura-Takemoto classification and histological atrophic gastritis was assessed by updated Sydney system. Serological assessment of atrophic gastritis was based on serum pepsinogen test. Results: The serum pepsinogen I/II ratio showed a significant decreasing nature when the extent of atrophy increased (R2=0.837, P

Background The increasing trend of antibiotic resistance requires effective second-line Helicobacter pylori (H. pylori) treatment in high prevalence area of H. pylori. The aim of our study was to evaluate the reinfection rate of H. pylori after second-line treatment that would determine the long-term follow up effect of the rescue therapy. Methods A total of 648 patients who had failed previous H. pylori eradication on standard triple therapy were randomized into two regimens: 1, esomeprazole (20 mg b.i.d), tripotassium dicitrate bismuthate (300 mg q.i.d), metronidazole (500 mg t.i.d), and tetracycline (500 mg q.i.d) (EBMT) or 2, moxifloxacin (400 mg q.d.), esomeprazole (20 mg b.i.d), and amoxicillin (1000 mg b.i.d.) (MEA). At four weeks after completion of eradication therapy, H. pylori tests were performed with 13C urea breath test or invasive tests. In patients who maintained continuous H. pylori negativity for the first year after eradication therapy, H. pylori status was assessed every year. For the evaluation of risk factors of reinfection, gender, age, clinical diagnosis, histological atrophic gastritis or intestinal metaplasia were analyzed. Results The recrudescence rate of the EBMT was 1.7% and of the MEA group 3.3% (p = 0.67). The annual reinfection rate of H. pylori of EBMT was found to be 4.45% and the MEA group 6.46%. Univariate analysis (Log-rank test) showed no association with any clinical risk factor for reinfection. Conclusions The long-term reinfection rate of H. pylori stayed low in both of bismuth-containing quadruple therapy and moxifloxacin-based triple therapy; thus reinfection cannot affect the choice of second-line treatment. Trial registration Clinical Trial Registration Number NCT01792700

BACKGROUND/AIMS Cochinchina momordica seed extract (SK-MS10) has a gastric protective effect. We aimed to assess the effect of SK-MS10 on gastric acid secretion with morphologic changes in the aged rat. METHODS Acid secretions were evaluated in the male F344 rats of four different ages (6-, 31-, 74-week, and 2-year). The 31-week-old rats were divided to three groups and continuously administered chow containing vehicle, SK-MS10 and lansoprazole, respectively. At the age of 74 weeks and 2 years, basal and stimulated acid was measured and the expression of mRNA and protein of H(+)-K(+)-ATPase were determined. The area of connective tissue of lamina propria was measured. RESULTS Basal and stimulated gastric acid significantly decreased and connective tissue of lamina propria increased with age. The expression of mRNA and protein of H(+)-K(+)-ATPase significantly decreased with age. However, 74-week-old rats in the SK-MS10 group had higher stimulated gastric acid secretion than those in the vehicle and lansoprazole groups. In 2-year-old rats of SK-MS10 group, there was no increase of connective tissue. CONCLUSIONS As SK-MS10 kept the capacity of acid secretion as well as connective tissue area to comparable to young rats, it might valuable to perform further research regarding mechanism of SK-MS10 as an antiaging agent in the stomach.

Background/Aims There has been no report regarding the regression of Barrett's esophagus (BE) by continuous treatment of proton pump inhibitor (PPI). The aim of this study was to determine the regression rate of BE by PPI and predictable markers related to regression. Methods Thirty-five patients diagnosed as BE were consecutively enrolled and most of them took continuous PPI. The 25 patients underwent endoscopic surveillance and received biopsy. If the specialized intestinal metaplasia (SIM) was lost at any point of surveillance and did not recur, the case was regarded as the regression group. The proportion of SIM was graded and the mucin phenotype was decided using immunohistochemistry for MUC2, MUC5AC and MUC6. To assess the cell proliferation indexes and the degree of intestinal maturation, immunohistochemistry for Ki67 and CDX2 were performed. Results The regression of BE occurred in the 11 (44%) patients. The clinical and demographic factors showed no difference between the regression (n = 11) and persistence group (n = 14). The lower grade of SIM (P < 0.001) and gastric predominant mucin phenotype (P = 0.018) were more frequent, and the number of Ki67 positive cell per gland (P = 0.008) and the mean extent of CDX2 (P = 0.022) were lower in the regression group than in the persistence group. Conclusions The regression of BE by PPI treatment was frequent in Korea. The immunohistochemical detection of mucin phenotype, grade of SIM, Ki67 and CDX2 expression in Barrett's mucosa could be useful as a predictable marker for regression of SIM in BE.

Background/aims Colonic diverticular bleeding cases account for 30-40% of the lower gastrointestinal bleeding, among which, 3-5% appear to be massive bleeding. The purpose of this study was to evaluate the risk factors for colonic diverticular bleeding diagnosed by colonoscopic examination. Methods Among the 1,003 patients, who were identified to have colonic diverticulosis including sleeding by diverticulitis and diverticular bleeding coding search, 216 patients had diverculosis, and they were divided into two groups: one with diverticular bleeding, and the other without bleeding. We evaluated the potential risk factors for diverticular bleeding, based on age, gender, location of diverticulum, comorbidities related to atherosclerosis, smoking, alcohol and medications, and compared them between both groups. Results Among the 216 patients, we observed colonic diverticular bleeding in 35 patients (16.2%). The mean age of the bleeding group was significantly older than that of non-bleeding group. No difference was observed regarding gender ratio. Right colonic diverticula were common in both groups, but there were higher proportion of patients with bleeding in bilateral diverticuosis. Old age, bilateral diverticulosis, presence of atherosclerosis related diseases (hypertension, diabetes mellitus, ischemic heart disease, obesity), use of aspirin, NSAIDs and calcium channel blocker, increased the risk of bleeding. In a multivariate analysis, use of aspirin and bilateral diverticulosis were identified as independent risk factors for colonic diverticular bleeding. Conclusions Since the patients who took aspirin and/or had bilateral colonic diverticulosis increased the risk of bleeding from divertuculi. As such, caution and education of patients are required.

Background/Aims This study evaluated the effect of Helicobacter pylori eradication on functional dyspepsia (FD), and the relationship between the changes of histological gastritis and FD symptom responses. Methods A total of 213 FD patients diagnosed by Rome III criteria were consecutively enrolled. H. pylori tests and gastritis grade by the Sydney system were performed before and 1 year after the proton pump based-eradication therapy for 7 days. Serum levels of pepsinogen, and genetic polymorphisms IL-6, IL-8 and IL-10 were investigated. Results Total of 91 patients completed the 1 year follow-up. When the response rate of dyspepsia was compared at 1 year between the non-eradicated group (n = 24) and eradicated group (n = 67), each group showed complete response of 62.5% and 62.7%; satisfactory response (≥ 50%) of 0.0% and 19.4%; partial response (< 50%) of 12.5% and 11.9%; and refractory response of 25.0% and 6.0%, respectively (P = 0.015). In addition, the responder group (complete + satisfactory response) at 1 year showed improvement of activity and chronic inflammation in both the antrum and corpus (all P < 0.001). Multivariate analysis showed that H. pylori eradication (OR, 5.81; 95% CI, 1.07-31.59) and symptom improvement at 3 month (OR, 28.90; 95% CI, 5.29-157.82) were associated with the improvement of dyspepsia at 1 year. Among the successfully eradicated FD patients (n = 67), male (P = 0.013) and higher initial BMI (P = 0.016) were associated with the improvement of dyspepsia at 1 year. Conclusions H. pylori eradication improved FD symptoms, as well as gastritis at 1 year, suggesting that inflammation mediates FD.

BACKGROUND/AIMS The aim of this study was to compare polyethylene glycol (PEG) 4 L, split method of PEG 4 L and PEG 2 L plus sodium phosphate (NaP) in the aspect of bowel preparation quality, safety, patients' compliance and preference. METHODS Total 249 subjects were prospectively enrolled and received bowel preparation for colonoscopy from August to October in 2010; PEG 4 L (93 subjects), split method of 4 L PEG (74 subjects) and PEG 2 L plus NaP 90 mL group (82 subjects). To investigate the completion, preference for bowel preparation and safety, a questionnaire survey was conducted before colonoscopy. RESULTS There were no significant intergroup differences in the aspect of completion of preparation, cecal intubation time and success rate. Satisfaction and preference were higher in PEG 2 L plus NaP 90 mL and split method of 4 L PEG compared with PEG 4 L. In the aspect of the bowel preparation quality PEG 4 L showed significantly higher quality in the morning colonoscopy (p

Background/Aims: In spite of the improvement of medical treatment for the peptic ulcer disease (PUD), PUD is still one of the common upper gastrointestinal diseases. The purpose of this study was to evaluate the risk factors and general characteristics of Korean patients diagnosed as PUD at a single third referral center. Methods: A total of 310 patients, diagnosed as PUD through endoscopy during one year of 2007 at Seoul National University Bundang Hospital were, retrospectively, evaluated regarding age, gender, Helicobacter pylori (H. pylori) positivity, clinical manifestations, comorbidities and medications. In addition, PUD was analyzed in the aspect of ulcer location, type of visit, gastrointestinal bleeding, and age. Results: The mean age was 61.5 years old (48.1% over 65) and 208 (66.7%) patients were men. The rate of H. pylori infection was 47.8%, and any ulcerogenic medication history such as antiplatelet agents and NSAIDs was found to be 21.0% (65 patients). The rate of idiopathic peptic ulcer without evidence of H. pylori and NSAIDs was found to be 40.6% (126 patients). Among 310 PUD patients, bleeding symptoms such as melena, hematemesis and hematochezia occurred in 110 patients (35.5%). Conclusions: PUD was more prevalent in the elderly patients and frequently associated with bleeding. Substantial proportion of PUD patients had neither H. pylori infection nor history of ulcerogenic medications, suggesting of increasing prevalence of idiopathic PUD. (Korean J Gastroenterol 2012;59:338-346)

Hepatosplenic candidiasis is also called chronic disseminated candidiasis and usually seen in patients with hematologic malignancies who have just recovered from an episode of neutropenia. Gastric candidiasis most commonly present as a mucosal lesion such as an ulcer or erosions, but other gastric lesion is very rare. We experienced a case of gastric candidiasis which presented as gastric subepithelial mass in a 60-year old woman who had undergone the 2nd consolidation chemotherapy due to acute myeloid leukemia. The pathologic diagnosis was confirmed by fine needle aspiration of the gastric subepithelial mass under the guidance of endoscopic ultrasonography.

The sap ofAcer monohas been called ‘bone-benefit-water’ in Korea because of its mineral and sugar content. In particular, the calcium concentration of the sap ofA. monois 37·5 times higher than commercial spring water. In the current study, we examined whetherA. monosap could improve or prevent osteoporosis-like symptoms in a mouse model. Male mice (3 weeks old) were fed a low-calcium diet supplemented with 25, 50 or 100 %A. monosap, commercial spring water or a high calcium-containing solution as a beverage for 7 weeks. There were no differences in weekly weight gain and food intake among all the groups. Mice that were given a low-calcium diet supplemented with commercial spring water developed osteoporosis-like symptoms. To assess the effect of sap on osteoporosis-like symptoms, we examined serum calcium concentration, and femur density and length, and carried out a histological examination. Serum calcium levels were significantly lower in mice that received a low-calcium diet supplemented with commercial spring water (the negative control group), and in the 25 % sap group compared to mice fed a normal diet, but were normal in the 50 and 100 % sap and high-calcium solution groups. Femur density and length were significantly reduced in the negative control and 25 % sap groups. These results indicate that a 50 % sap solution can mitigate osteoporosis-like symptoms induced by a low-calcium diet. We also examined the regulation of expression of calcium-processing genes in the duodenum and kidney. DuodenalTRPV6and renalcalbindin-D9kwere up-regulated dose-dependently by sap, and the levels of these factors were higher than those attained in the spring water-treated control. The results demonstrate that the sap ofA. monoameliorates the low bone density induced by a low-calcium diet, most likely by increasing calcium ion absorption.

Background/Aims Bismuth-containing quadruple and moxifloxacin-based triple regimens are recommended as second-line therapy for Helicobacter pylori infection. The aim of this study was to compare the efficacy of each regimen. Methods From August 2004 to October 2012, a total of 949 patients (mean age, 54.32±12.08 years; male, 49.4%) who failed H. pylori eradication with a standard triple regimen were included. Patients treated with a bismuth-containing quadruple regimen for 7 and 14 days were designated as 7-BMT and 14-BMT, respectively, and those treated with a moxifloxacin-based triple regimen for 7 and 14 days were designated as 7-MA and 14-MA, respectively. H. pylori eradication was confirmed using the 13C-urea breath test, rapid urease test or histology. Results The eradication rates by 7-BMT, 14-BMT, 7-MA, and 14-MA were 66.4% (290/437), 71.1% (113/159), 53.1% (51/96), and 73.5% (189/257), respectively, by intention-to-treat analysis (ITT) and 76.5% (284/371), 83.8% (109/130), 55.6% (50/90), and 80.6% (187/232), respectively, by per-protocol analysis (PP). The eradication rates were higher in 14-BMT than 7-BMT by the ITT and PP analyses (p=0.277 and p=0.082, respectively). The 14-BMT and 14-MA treatments showed similar efficacies by ITT and PP (p=0.583 and p=0.443, respectively). Conclusions The 7-BMT, 14-BMT, and 14-MA treatments showed similar and suboptimal efficacies. In both regimens, extending the duration of treatment may be reasonable considering the high level of antibiotic resistance in Korea.