• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.382-392
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• 2017

Objectives: The purpose of this study is to obtain basic data on the development of a risk communication model through an investigation of risk perception for radon and identify effective risk communication channels. Methods: A questionnaire was used to evaluate differences in perception level according to respective communication channels. A chi-squared test was used to analyze the difference in pre- and post-risk communication by communication channel. One-way ANOVA was used to analyze the difference in the radon risk perception rate for each communication channel. Results: All of the communication channels resulted in increased radon risk perception, but there was no statistical difference between them in terms of perception (p>0.05). However, based on previous findings that it is effective to use a multi-channel approach, it is considered that communication channels based on duplicate avenues is most appropriate. Conclusions: It is expected that this study will be used as basic data to better understand the formation of public opinion about radon risk and to understand the social reaction to each risk factor.

• Journal of Gastric Cancer
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• v.17 no.3
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• pp.267-276
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• 2017

Purpose: Different esophagojejunostomy (EJ) reconstruction methods are used after totally laparoscopic total gastrectomy (TLTG), and none is considered a standard technique. This report describes a 2-layer hand-sewn EJ technique during TLTG; we also evaluated postoperative morbidity associated with this technique. Materials and Methods: This retrospective cohort study included all consecutive patients who underwent TLTG for gastric cancer (GC) from 2012 to 2016 at 2 affiliated teaching hospitals. All participating surgeons performed standardized intracorporeal 2-layer hand-sewn EJ. Results: We included 51 patients who underwent TLTG for GC and standardized EJ anastomosis. Twenty-seven (53%) were male, and the median age was 60 (36-87) years. The average operative time was $337{\pm}71minutes$ and intraoperative bleeding was $160{\pm}107mL$. There were no open conversions related to EJ. Postoperative morbidity was observed in 9 (17.0%) patients. There was no postoperative mortality. EJ leakage was observed in 2 patients (3.8%) and 1 patient (1.9%) developed EJ stenosis. Patients with leakage were managed non-operatively and the patient with stenosis required endoscopic dilation. The median length of hospital stay was 8 (6-29) days. Conclusions: Two-layer hand-sewn EJ during TLTG for GC is a feasible and safe technique. This method avoids a laparotomy for reconstruction and the disadvantages associated with laparoscopic introduction of mechanical staplers for EJ, and provides an alternative for alimentary tract reconstruction after TLTG.

• Journal of Ginseng Research
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• v.44 no.5
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• pp.717-724
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• 2020

Background: Malignant arrhythmias require drug therapy. However, most of the currently available antiarrhythmic drugs have significant side effects. Ginsenoside Rg2 exhibits excellent cardioprotective effects and appears to be a promising candidate for cardiovascular drug development. So far, the oral toxicity and antiarrhythmic effects of Rg2 have not been evaluated. Methods: Acute oral toxicity of Rg2 was assessed by the Limit Test method in mice. Subchronic oral toxicity was determined by repeated dose 28-day toxicity study in rats. Antiarrhythmic activities of Rg2 were evaluated in calcium chloride-induced arrhythmic rats. Antiarrhythmic mechanism of Rg2 was investigated in arrhythmic rats and H9c2 cardiomyocytes. Results: The results of toxicity studies indicated that Rg2 exhibited no single-dose (10 g/kg) acute oral toxicity. And 28-day repeated dose treatment with Rg2 (1.75, 3.5 and 5 g/kg/d) demonstrated minimal, if any, subchronic toxicity. Serum biochemical examination showed that total cholesterol in the high-dose cohort was dramatically decreased, whereas prothrombin time was increased at Day 28, suggesting that Rg2 might regulate lipid metabolism and have a potential anticoagulant effect. Moreover, pretreatment with Rg2 showed antiarrhythmic effects on the rat model of calcium chloride induced arrhythmia, in terms of the reduced duration time, mortality, and incidence of malignant arrhythmias. The antiarrhythmic mechanism of Rg2 might be the inhibition of calcium influx through L-type calcium channels by suppressing the phosphorylation of Ca²⁺/calmodulin-dependent protein kinase II. Conclusion: Our findings support the development of Rg2 as a promising antiarrhythmic drug with fewer side effects for clinical use.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.33.1-33.11
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• 2018

Background: Bimaxillary orthognathic surgery with maxillomandibular setback is often accompanied by changes in airway space. We analyzed the changes in airway space before and after surgery and assessed their association with obstructive sleep apnea. Methods: This study is based on the cohort of 13 adult patients (9 males, 4 females, average age 23.85 years) who underwent bimaxillary orthognathic surgery with maxillomandibular setback. We performed computed tomography and portable polysomnography before and after the surgery to assess changes in airway space and Apnea-Hypopnea Index (AHI) values (total, supine, non-supine). Results: The oropharyngeal airway volume decreased by 29% after the surgery, which was statistically significant (p < .05). The upper airway volume and hypopharyngeal airway volume were decreased, but not significantly (4 and 19%, respectively). The changes in airway surface area were statistically significant at all levels examined (p < .05). Changes in the maximum anteroposterior width of the airway were also significant at all levels (p < .05). However, the changes in maximum lateral width were only statistically significant at C2 level (p < .05). AHI values were increased after the surgery but not significantly at any position. Conclusions: Although bimaxillary surgery with maxillomandibular setback significantly reduces the airway space, it does not affect AHI values or induce obstructive sleep apnea.

• Molecules and Cells
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• v.41 no.2
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• pp.73-82
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• 2018

Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes groundbreaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

• 대한예방의학회:학술대회논문집
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• 1994.02b
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• pp.313-319
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• 1994

Phase I of the Trials of Hypertension Prevention was a multicenter, randomized, controlled trial designed to determine the efficacy of seven nonpharmacologic interventions in reducing blood pressure among persons with high-normal diastolic blood pressure. the initial goal for recruitment was to enroll 2,100 participants over a nine-month period. The yield from the first screening visit to randomization was 13% overall, with clinic-specific yields ranging from 4.5% to 31.7%. After five months of recruitment, approximately 60% of the goal for that point in the recruitment timetable had been randomized. Clinical centers falling short of their goals at that time altered their recruitment strategies and intensified their efforts, and centers that had exceeded their goals recruited additional participants. As a result, 2,182 participants, or 104\% of the goal for recruitment, were randomized over a 13-month period. Those clinics using a cohort, or wave, type of enrollment were most successful in achieving their recruitment goals within the prescribed timetable.

• Tuberculosis and Respiratory Diseases
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• v.78 no.2
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• pp.78-84
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• 2015

Background: Reports of therapeutic drug monitoring (TDM) for second-line medications to treat multidrug-resistant tuberculosis (MDR-TB) remain limited. Methods: A retrospective cohort from the Virginia state tuberculosis (TB) registry, 2009-2014, was analyzed for TDM usage in MDR-TB. Drug concentrations, measured at time of estimated peak ($C_{max}$), were compared to expected ranges. Results: Of 10 patients with MDR-TB, 8 (80%) had TDM for at least one drug (maximum 6 drugs). Second-line drugs tested were cycloserine in seven patients (mean $C_{2hr}$, $16.6{\pm}10.2{\mu}g/mL$; 4 [57%] below expected range); moxifloxacin in five (mean $C_{2hr}$, $3.2{\pm}1.5{\mu}g/mL$; 1 [20%] below); capreomycin in five (mean $C_{2hr}$, $21.5{\pm}14.0{\mu}g/mL$; 3 [60%] below); para-aminosalicylic acid in five (mean $C_{6hr}$, $65.0{\pm}29.1{\mu}g/mL$; all within or above); linezolid in three (mean $C_{2hr}$, $11.4{\pm}4.1{\mu}g/mL$, 1 [33%] below); amikacin in two (mean $C_{2hr}$, $35.3{\pm}3.7{\mu}g/mL$; 1 [50%] below); ethionamide in one ($C_{2hr}$, $1.49{\mu}g/mL$, within expected). Two patients died: a 38-year-old woman with human immunodeficiency virus/acquired immune deficiency syndrome and TB meningitis without TDM, and a 76-year-old man with fluoroquinolone-resistant (pre-extensively drug-resistant) pulmonary TB and low linezolid and capreomycin concentrations. Conclusion: Individual pharmacokinetic variability was common. A more standardized approach to TDM for MDR-TB may limit over-testing and maximize therapeutic gain.

• Tuberculosis and Respiratory Diseases
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• v.83 no.4
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• pp.303-311
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• 2020

Background: If the duration of mechanical ventilation (MV) is related with the intensive care unit (ICU) readmission must be clarified. The purpose of this study was to elucidate if prolonged MV duration increases ICU readmission rate. Methods: The present observational cohort study analyzed national healthcare claims data from 2006 to 2015. Critically ill patients who received MV in the ICU were classified into five groups according to the MV duration: MV for <7 days, 7-13 days, 14-20 days, 21-27 days, and ≥28 days. The rate and risk of the ICU readmission were estimated according to the MV duration using the unadjusted and adjusted analyses. Results: We found that 12,929 patients had at least one episode of MV in the ICU. There was a significant linear relationship between the MV duration and the ICU readmission (R²=0.85, p=0.025). The total readmission rate was significantly higher as the MV duration is prolonged (MV for <7 days, 13.9%; for 7-13 days, 16.7%; for 14-20 days, 19.4%; for 21-27 days, 20.4%; for ≥28 days, 35.7%; p<0.001). The analyses adjusted by covariables and weighted with the multinomial propensity scores showed similar results. In the adjusted regression analysis with a Cox proportional hazards model, the MV duration was significantly related to the ICU readmission (hazard ratio, 1.058 [95% confidence interval, 1.047-1.069], p<0.001). Conclusion: The rate of readmission to the ICU was significantly higher in patients who received longer durations of the MV in the ICU. In the clinical setting, closer observation of patients discharged from the ICU after prolonged periods of MV is required.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.393-407
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• 2019

Purpose: To identify the potential therapeutic role of postoperative radiotherapy (RT) in patients with locally advanced (stage II and stage III) gastric signet ring cell carcinoma (SRC). Materials and methods: Patients with locally advanced gastric SRC from the Surveillance, Epidemiology, and End Results program database between 2004 and 2012 were included in our study. Univariate and multivariate Cox proportional models were performed, and survival curves were generated to evaluate the prognostic effect of postoperative RT and surgery alone on SRC patients. Propensity score matching (PSM) was used to avoid selection bias among the study cohorts. Results: We found that patients with postoperative RT had better probability of survival compared with those who did not receive RT (overall survival [OS], P<0.001; cancer-specific survival [CSS], P<0.001). After PSM, analysis of both overall and CSS showed that patients who underwent postoperative RT had better prognosis than those receiving surgery alone in the matched cohort (OS, P=0.00079; CSS, P=0.0036). Multivariate Cox proportional model indicated that postoperative RT had better effect on prognosis compared with surgery alone with respect to both overall (hazard ratio [HR], 0.716; 95% confidence interval [95% CI], 0.590-0.87; P=0.001) and CSS (HR, 0.713; 95% CI, 0.570-0.890; P=0.003). Conclusions: Postoperative RT had better prognosis compared with surgery alone for both overall and CSS for patients with locally advanced gastric SRC.

• Genomics & Informatics
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• v.8 no.3
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• pp.150-158
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• 2010

Genome-wise association studies (GWASs) have become popular approaches to identify genetic variants associated with human biological traits. In this study, we applied Structural Equation Models (SEMs) in order to model complex relationships between genetic networks and traits as risk factors. SEMs allow us to achieve a better understanding of biological mechanisms through identifying greater numbers of genes and pathways that are associated with a set of traits and the relationship among them. For efficient SEM analysis for GWASs, we developed a procedure, comprised of four stages. In the first stage, we conducted single-SNP analysis using regression models, where age, sex, and recruited area were included as adjusting covariates. In the second stage, Fisher's combination test was conducted for each gene to detect significant genes using p-values obtained from the single-SNP analysis. In the third stage, Fisher's exact test was adopted to determine which biological pathways were enriched with significant SNPs. Finally, based on a pathway that was associated with the four traits in common, a SEM was fit to model a causal relationship among the genetic factors and traits. We applied our SEM model to GWAS data with four central obesity related traits: suprailiac and subscapular measures for upper body fat, BMI, and hypertension. Study subjects were collected from two Korean cohort regions. After quality control, 327,872 SNPs for 8842 individuals were included in the analysis. After comparing two SEMs, we concluded that suprailiac and subscapular measures may indirectly affect hypertension susceptibility by influencing BMI. In conclusion, our analysis demonstrates that SEMs provide a better understanding of biological mechanisms by identifying greater numbers of genes and pathways.