Background/Aims: Guide tube-assisted endoscopy for procedures that require repeated endoscopic access is safer and more effective than conventional endoscopy. However, its effectiveness has not been confirmed in animal studies. We assessed the usefulness of guide tube-assisted endoscopic procedures in an in vivo porcine model. Methods: Five different guide tube-assisted endoscopic procedures were performed by experienced endoscopists on a pig weighing 32 kg. To evaluate the efficacy of these procedures, we compared the endoscopic approach time when a guide tube was used to that when it was not. Additional endoscopic procedures using a guide tube were performed, including multiple foreign body extractions, multiple polypectomies, and multiple submucosal dissections. To evaluate safety, we compared the insertion force into the proximal esophagus between the guide tube and conventional overtube methods. Results: Using the endoscopic approach with a guide tube required a shorter average approach time to reach the three target lesions than when using the endoscopic approach without a guide tube (p<0.001). Compared to the conventional overtube method, the guide tube method produced a lower average resistance during insertion into the upper esophagus (p<0.001). Conclusions Guide tube-assisted endoscopic procedures are effective and safe for repeated endoscopic access in an in vivo porcine model.

Background/Aims: We developed a new endoscopic submucosal dissection (ESD) simulator and evaluated its efficacy and realism for use training endoscopists. Methods: An ESD simulator was constructed using polyvinyl alcohol hydrogel sheets and compared to a previous ESD simulator. Between March 1, 2020, and December 30, 2021, eight expert endoscopists from three different centers analyzed the procedure-related factors of the simulator. Five trainees performed gastric ESD exercises under the guidance of these experts. Results: Although the two ESD simulators provided overall favorable outcomes in terms of ESD-related factors, the new simulator had several benefits, including better marking of the target lesion’s limits (p<0.001) and overall handling (p<0.001). Trainees tested the usefulness of the new ESD simulator. The complete resection rate improved after 3 ESD training sessions (9 procedures), and the perforation rate decreased after 4 sessions (12 procedures). Conclusions We have developed a new ESD simulator that can help beginners achieve a high level of technical experience before performing real-time ESD procedures in patients.

Background/Aims: Fexuprazan is a novel potassium-competitive acid blocker that could be of benefit to patients with gastric mucosal injury. The aim of this study was to assess the 2-week efficacy and safety of fexuprazan in patients with acute or chronic gastritis. Methods: In this study, 327 patients with acute or chronic gastritis who had one or more gastric erosions on endoscopy and subjective symptoms were randomized into three groups receiving fexuprazan 20 mg once a day (q.d.), fexuprazan 10 mg twice a day (b.i.d.), or placebo for 2 weeks. The posttreatment assessments were the primary endpoint (erosion improvement rate), secondary endpoints (cure rates of erosion and edema and improvement rates of redness, hemorrhage, and subjective symptoms), and drug-related adverse events. Results: Among the patients, 57.8% (59/102), 65.7% (67/102), and 40.6% (39/96) showed erosion improvement 2 weeks after receiving fexuprazan 20 mg q.d., fexuprazan 10 mg b.i.d., and placebo, respectively. Both fexuprazan 20 mg q.d. and 10 mg b.i.d. showed superior efficacy to the placebo (p=0.017 and p<0.001, respectively). Likewise, both fexuprazan 20 mg q.d. and 10 mg b.i.d. also showed higher erosion healing rates than the placebo (p=0.033 and p=0.010, respectively). No difference was noted in the edema healing rate and the improvement rates for redness, hemorrhage, and subjective symptoms between the fexuprazan and placebo groups.No significant difference was noted in the incidence of adverse drug reactions. Conclusions Fexuprazan 20 mg q.d. and 10 mg b.i.d. for 2 weeks showed therapeutic efficacy superior to that of placebo in patients with acute or chronic gastritis (ClinicalTrials.gov identifier NCT04341454).

Background/Aims: Previous studies have reported the protective effects of tauroursodeoxycholic acid (TUDCA) on gastric epithelial cells in some animal models, but the precise mechanisms are unclear. This study examined the effects of TUDCA on NF-κB signaling in gastric epithelial cells. Moreover, the protective effects of TUDCA in experimental gastritis models induced by ethanol and NSAID were evaluated and compared with ursodeoxycholic acid (UDCA). Methods: After a pretreatment with TUDCA or UDCA, human gastric epithelial MKN-45 cells were stimulated with tumor necrosis factor (TNF)-α to activate NF-κB signaling. A real-time PCR (RT-PCR) for human interleukin (IL)-1 mRNA was performed. An electrophoretic mobility shift assay (EMSA) and immunoblot analyses were carried out. In murine models, after a pretreatment with TUDCA or UDCA, ethanol and indomethacin were administered via oral gavage. Macroscopic and microscopic assessments were performed to evaluate the preventive effects of TUDCA and UDCA on murine gastritis. Results: A pretreatment with TUDCA downregulated the IL-1α mRNA levels in MKN-45 cells stimulated with TNF-α, as assessed by RT-PCR. As determined using EMSA, a pretreatment with TUDCA reduced the TNF-α-induced NF-κB DNA binding activity. A pretreatment with TUDCA inhibited IκBα phosphorylation induced by TNF-α, as assessed by immunoblot analysis. TUDCA attenuated the ethanol-induced and NSAID-induced gastritis in murine models, as determined macroscopically and microscopically. Conclusions TUDCA inhibited NF-κB signaling in gastric epithelial cells and ameliorated ethanol- and NSAID-induced gastritis in murine models. These results support the potential of TUDCA for the prevention of gastritis in humans.

Purpose: The association of the initial serum ammonia level with in-hospital mortality in patients with acute glufosinate-ammonium herbicide poisoning was studied. Methods: This retrospective cohort study was conducted between March 2012 and August 2019 in the emergency department after glufosinate-ammonium herbicide poisoning. Survivors and non-survivors were analyzed using a Mann-Whitney U test and Fisher’s exact test. Multivariate logistic regression analysis was performed to determine the independent risk factors for mortality. Results: One hundred and six patients were enrolled; 11 died, yielding a mortality of 10.4%. The serum bicarbonate level was significantly lower in the non-survival group than the survival group. Age, serum ammonia, blood urea nitrogen, creatinine levels, SOFA score, and APACHE II score were significantly higher in the non-survival group than the survival group. Age, serum ammonia, and creatinine level were independent risk factors for mortality in multivariate logistic regression analysis. Conclusion The initial serum ammonia level is associated with mortality in patients with acute glufosinate herbicide poisoning.

Purpose: The association of the initial serum ammonia level with in-hospital mortality in patients with acute glufosinate-ammonium herbicide poisoning was studied. Methods: This retrospective cohort study was conducted between March 2012 and August 2019 in the emergency department after glufosinate-ammonium herbicide poisoning. Survivors and non-survivors were analyzed using a Mann-Whitney U test and Fisher’s exact test. Multivariate logistic regression analysis was performed to determine the independent risk factors for mortality. Results: One hundred and six patients were enrolled; 11 died, yielding a mortality of 10.4%. The serum bicarbonate level was significantly lower in the non-survival group than the survival group. Age, serum ammonia, blood urea nitrogen, creatinine levels, SOFA score, and APACHE II score were significantly higher in the non-survival group than the survival group. Age, serum ammonia, and creatinine level were independent risk factors for mortality in multivariate logistic regression analysis. Conclusion The initial serum ammonia level is associated with mortality in patients with acute glufosinate herbicide poisoning.

PURPOSE: With the emergence of next-generation sequencing (NGS) technology, profiling a wide range of genomic alterations has become a possibility resulting in improved implementation of targeted cancer therapy. In Asian populations, the prevalence and spectrum of clinically actionable genetic alterations has not yet been determined because of a lack of studies examining high-throughput cancer genomic data. MATERIALS AND METHODS: To address this issue, 1,071 tumor samples were collected from five major cancer institutes in Korea and analyzed using targeted NGS at a centralized laboratory. Samples were either fresh frozen or formalin-fixed, paraffin embedded (FFPE) and the quality and yield of extracted genomic DNA was assessed. In order to estimate the effect of sample condition on the quality of sequencing results, tissue preparation method, specimen type (resected or biopsied) and tissue storage time were compared. RESULTS: We detected 7,360 non-synonymous point mutations, 1,164 small insertions and deletions, 3,173 copy number alterations, and 462 structural variants. Fifty-four percent of tumors had one or more clinically relevant genetic mutation. The distribution of actionable variants was variable among different genes. Fresh frozen tissues, surgically resected specimens, and recently obtained specimens generated superior sequencing results over FFPE tissues, biopsied specimens, and tissues with long storage duration. CONCLUSION: In order to overcome, challenges involved in bringing NGS testing into routine clinical use, a centralized laboratory model was designed that could improve the NGS workflows, provide appropriate turnaround times and control costs with goal of enabling precision medicine.
Academies and Institutes ; Asian Continental Ancestry Group ; DNA ; Humans ; Korea ; Methods ; Paraffin ; Point Mutation ; Precision Medicine ; Prevalence

PURPOSE: There are few reports from Asian countries about the long-term results of aromatase inhibitor adjuvant treatment for breast cancer. This observational study aimed to evaluate the long-term effects of letrozole in postmenopausal Korean women with operable breast cancer. METHODS: Self-reported quality of life (QoL) scores were serially assessed for 3 years during adjuvant letrozole treatment using the Korean version of the Functional Assessment of Cancer Therapy-Breast questionnaires (version 3). Changes in bone mineral density (BMD) and serum cholesterol levels were also examined. RESULTS: All 897 patients received the documented informed consent form and completed a baseline questionnaire before treatment. Adjuvant chemotherapy was administered to 684 (76.3%) subjects, and 410 (45.7%) and 396 (44.1%) patients had stage I and II breast cancer, respectively. Each patient completed questionnaires at 3, 6, 12, 18, 24, 30, and 36 months after enrollment. Of 897 patients, 749 (83.5%) completed the study. The dropout rate was 16.5%. The serial trial outcome index, the sum of the physical and functional well-being subscales, increased gradually and significantly from baseline during letrozole treatment (p<0.001). The mean serum cholesterol level increased significantly from 199 to 205 after 36 months (p=0.042). The mean BMD significantly decreased from −0.39 at baseline to −0.87 after 36 months (p<0.001). CONCLUSION: QoL gradually improved during letrozole treatment. BMD and serum cholesterol level changes were similar to those in Western countries, indicating that adjuvant letrozole treatment is well tolerated in Korean women, with minimal ethnic variation.
Aromatase ; Asian Continental Ancestry Group ; Bone Density ; Breast Neoplasms* ; Breast* ; Chemotherapy, Adjuvant ; Cholesterol ; Consent Forms ; Female ; Humans ; Observational Study ; Quality of Life*

BACKGROUND: Iodine is an intrinsic element of thyroid hormone, which is essential for childhood growth and development. The Ideal Breast Milk (IBM) cohort study aims to evaluate the effects of maternal iodine status during pregnancy and lactation on maternal thyroid function, offspring growth and development, and offspring thyroid function. METHODS: The IBM cohort study recruited pregnant women from Seoul National University Hospital between June 2016 and August 2017, followed by enrollment of their offspring after delivery. For the maternal participants, iodine status is evaluated by urinary iodine concentration (UIC) and dietary records in the third trimester and at 3 to 4 weeks and 12 to 15 months postpartum. For the child participants, cord blood sampling and UIC measurements are performed at birth. At 3 to 4 weeks of age, UIC and breastmilk iodine concentrations are measured. At 12 to 15 months of age, growth and development are assessed and measurements of UIC, a thyroid function test, and ultrasonography are performed. RESULTS: A total of 198 pregnant women in their third trimester were recruited. Their mean age was 35.1±3.5 years, and 78 (39.4%) of them were pregnant with twins. Thirty-three (16.7%) of them had a previous history of thyroid disease. CONCLUSION: Korea is an iodine-replete area. In particular, lactating women in Korea are commonly exposed to excess iodine due to the traditional practice of consuming brown seaweed soup postpartum. The study of the IBM cohort is expected to contribute to developing guidelines for optimal iodine nutrition in pregnant or lactating women.
Breast* ; Child ; Cohort Studies* ; Cordocentesis ; Diet Records ; Female ; Growth and Development* ; Humans ; Infant ; Iodine* ; Korea ; Lactation* ; Milk, Human* ; Parturition ; Postpartum Period ; Pregnancy Trimester, Third ; Pregnancy* ; Pregnant Women ; Prospective Studies* ; Seaweed ; Seoul ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland* ; Twins ; Ultrasonography

BACKGROUND AND OBJECTIVES: Wall shear stress contributes to atherosclerosis progression and plaque rupture. There are limited studies for statin as a major contributing factor on whole blood viscosity (WBV) in patients with acute coronary syndrome (ACS). This study investigates the effect of statin on WBV in ACS patients. SUBJECTS AND METHODS: We prospectively enrolled 189 consecutive patients (mean age, 61.3±10.9 years; 132 males; ST-segment elevation myocardial infarction, n=52; non-ST-segment elevation myocardial infarction, n=84; unstable angina n=53). Patients were divided into two groups (group I: previous use of statins for at least 3 months, n=51; group II: statin-naïve patients, n=138). Blood viscosities at shear rates of 1 s-1 (diastolic blood viscosity; DBV) and 300 s-1 (systolic blood viscosity; SBV) were measured at baseline and one month after statin treatment. Rosuvastatin was administered to patients after enrollment (mean daily dose, 16.2±4.9 mg). RESULTS: Baseline WBV was significantly higher in group II ([SBV: group I vs group II, 40.8±5.9 mP vs. 44.2±7.4 mP, p=0.003], [DBV: 262.2±67.8 mP vs. 296.9±76.0 mP, p=0.002]). WBV in group II was significantly lower one month after statin treatment ([SBV: 42.0±4.7 mP, p=0.012, DBV: 281.4±52.6 mP, p=0.044]). However, low-density lipoprotein cholesterol level was not associated with WBV in both baseline (SBV: R2=0.074, p=0.326; DBV: R2=0.073, p=0.337) and after one month follow up (SBV: R2=0.104, p=0.265; DBV: R2=0.112, p=0.232). CONCLUSION: Previous statin medication is an important determinant in lowering WBV in patients with ACS. However, one month of rosuvastatin decreased WBV in statin-naïve ACS patients.
Acute Coronary Syndrome* ; Angina, Unstable ; Atherosclerosis ; Blood Viscosity* ; Cholesterol ; Follow-Up Studies ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Lipoproteins ; Male ; Myocardial Infarction ; Prospective Studies ; Rheology ; Rupture ; Rosuvastatin Calcium