BACKGROUND/AIMS: Patient compliance and resistance to antibiotics are main factors determining the success of Helicobacter pylori eradication. This study provides basic data to verify the efficacy of currently implemented eradication therapy and reports changes in H. pylori resistance to all antibiotics used at Asan Medical Center, Seoul, Korea from 2004 to 2010. METHODS: We investigated the resistance rates to amoxicillin, clarithromycin, metronidazole, ciprofloxacin, and levofloxacin in 88, 100, and 47 strains isolated from adult patients without H. pylori eradication history in 2004, 2007, and 2010. RESULTS: The resistance rate to amoxicillin increased from 5.0% in 2007 to 10.6% in 2010. The resistance rate to clarithromycin increased from 10.2% in 2004 and 11.0% in 2007 to 14.8% in 2010. However, no difference was observed in the resistance rate to metronidazole, and strains resistant to tetracycline were not detected at all in this study. The resistance rates to quinolone lingered at 15-17% for 3 years. The non-resistant strains to antibiotics accounted for 56% of the total in 2004 and 62% in 2007. In contrast, a decreasing tendency was found for those strains in 2010 (43%). No significant differences were shown in the multi-drug resistance rate or the co-resistance rates of amoxicillin and clarithromycin over the 3 years. CONCLUSIONS: We showed increased resistance rates to clarithromycin and amoxicillin over the last 7 years, aligning with the results of previous studies performed domestically. Efforts are needed to inhibit the increase in resistant bacteria to maintain the effectiveness of eradication therapy.
Adult ; Amoxicillin ; Anti-Bacterial Agents ; Bacteria ; Chungcheongnam-do ; Ciprofloxacin ; Clarithromycin ; Drug Resistance, Microbial* ; Drug Resistance, Multiple ; Helicobacter pylori* ; Helicobacter* ; Humans ; Korea ; Levofloxacin ; Metronidazole ; Patient Compliance ; Seoul* ; Tetracycline

BACKGROUND/AIMS: We used 3-dimensional (3D) printing technology to create a new hemostasis simulator for the stomach and investigated its efficacy and realism in endoscopic hemostasis training. METHODS: A new stomach hemostasis simulator, with two hemostasis modules for hemoclipping and injection, was constructed using a 3D printer. Twenty-one endoscopists, including 11 first-year fellows (beginner group) and 10 faculty members (expert group), tested the performance of the simulator. We recorded and reviewed five training sessions and evaluated the simulator with questionnaires using a 7-point Likert scale. RESULTS: The mean evaluation score of the expert group was 6.3±0.5 for the hemoclipping module and 6.0±0.6 for the injection module. The expert group strongly agreed that endoscopic handling in the simulator was realistic and reasonable for hemostasis training. The mean procedure time for hemoclipping was 72.7±7.1 seconds for the beginner group and 19.7±1.2 seconds for the expert group. The mean procedure time for injection was 92.1±9.8 seconds for the beginner group and 36.3±2 seconds for the expert group. The procedure time of beginner group became shorter with repetition and was significantly lower by the fifth trial. CONCLUSIONS: A new 3D-printed hemostasis simulator is capable of hemostasis training and can very effectively train beginners before they perform the procedure in patients with gastrointestinal bleeding.
Education ; Endoscopy ; Hemorrhage ; Hemostasis ; Hemostasis, Endoscopic ; Humans ; Printing, Three-Dimensional ; Stomach

BACKGROUND: Antimicrobial resistance of Helicobacter pylori is considered as the main cause of failure of eradication therapy. Because resistance to metronidazole has been reported in 25.8% to 66.2% of H. pylori, a combination of proton pump inhibitors (PPI), amoxicillin, and clarithromycin is currently recommended as a primary therapy. We investigated the prevalence of antimicrobial resistance to the primary drugs and the impact of antimicrobial resistance on eradication rates. METHODS: Between May and August 2005, H. pylori isolates from 93 patients were tested for antimicrobial susceptibility at Asan Medical Center. Susceptibility tests of clarithromycin and amoxicillin were performed by the disk diffusion method and those of metronidazole and tetracycline by Etest (AB Biodisk, Solna, Sweden). The medical records of the patients were reviewed to collect the data such as demographic findings, previous and current eradication therapies, and bacteriological outcome. The appropriate therapy was defined as three-drug-combination including susceptible drugs only, or four-drug-combination including metronidazole in the case of metronidazole-resistance. RESULTS: Resistance rates to clarithromycin and metronidazole were 17.2% and 33.3%, respectively, but there was no resistance to tetracycline and amoxicillin. The eradication was successful in 32 of the 36 patients (88.9%) who received the appropriate therapy, but none of 4 patients who received an inappropriate therapy (P<0.01). CONCLUSIONS: Resistance to clarithromycin seemed to increase and contribute to the failure of eradication therapy. For the appropriate therapy of H. pylori infection, the susceptibility results should be reported before initiation of the eradication therapy.
Amoxicillin ; Chungcheongnam-do ; Clarithromycin ; Diffusion ; Helicobacter pylori* ; Helicobacter* ; Humans ; Medical Records ; Metronidazole ; Prevalence ; Proton Pump Inhibitors ; Tetracycline

Stricture frequently occurs after endoscopic submucosal dissection (ESD) for superficial esophageal carcinoma with near- or whole-circumferential mucosal defects, and post-ESD stricture is difficult to treat and usually requires multiple sessions of endoscopic balloon dilatation. Intralesional steroid injection has previously been used to prevent stricture; however, there have been few experiences with this method after near- or whole-circumferential ESD. We present a case of a single session of intralesional steroid injection performed immediately after near-circumferential ESD to prevent post-ESD stricture. After a follow-up period of 6 months, the patient showed good outcome without dysphagia.
Constriction, Pathologic* ; Deglutition Disorders ; Dilatation ; Esophageal Neoplasms* ; Esophageal Stenosis ; Follow-Up Studies ; Humans ; Injections, Intralesional

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.

About 90% of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphomas are strongly related to Helicobacter pylori infection. The eradication of the H. pylori by antibiotics leads to complete regression of the gastric MALT lymphoma in 80%of cases, and this is currently recommended as the first-line treatment for this tumor. However, no standard treatment for H. pylori-negative and H. pylori-eradication-resistant gastric MALT lymphomas has yet been devised. The association between H. pylori- negative MALT lymphoma and the t(11;18)(q21;q21) translocation, resulting in an API2-MALT1 chimera gene, was reported, and is now considered one of the possible causes of and a reliable predictive marker for unresponsiveness to H. pylori-eradication treatment in patients with low-grade gastric MALT lymphoma. We report a case of H. pylori-eradication-treatment-resistant low-grade gastric MALT lymphoma that was treated successfully with radiotherapy after recognizing the API2-MALT1 chimera gene.
Anti-Bacterial Agents ; Chimera ; Helicobacter ; Helicobacter pylori ; Humans ; Lymphoid Tissue ; Lymphoma ; Lymphoma, B-Cell, Marginal Zone

BACKGROUND/AIMS: The CYP2C19 polymorphism plays an important role in the metabolism of various proton-pump inhibitors. Several trials have produced conflicting data on eradication rates of Helicobacter pylori (H. pylori) among CYP2C19 genotypes. We investigated whether the CYP2C19 genotype affects the eradication rate of H. pylori by direct comparing the effects of lansoprazole- and rabeprazole-based triple therapies. METHODS: A total of 492 patients infected with H. pylori was randomly treated with either 30 mg of lansoprazole or 20 mg of rabeprazole plus 500 mg of clarithromycin and 1,000 mg of amoxicillin twice daily for 1 week. CYP2C19 genotype status was determined by a PCR-restriction-fragment-length polymorphism method. After 7 to 8 weeks, H. pylori status was evaluated by a C(13)-urea breath test. RESULTS: Four hundred and sixty-three patients were analyzed, and the eradication rate was 75.2% in a per-protocol analysis. Eradication rates for the lansoprazole regimen (n=234) were 73.8%, 80.7%, and 85.4% in the homozygous extensive (HomEM), heterozygous extensive (HetEM), and poor metabolizers (PM) groups, respectively (p=0.303). In the case of the rabeprazole regimen (n=229), the eradication rates were 68.6%, 73.0%, and 71.9% in the HomEM, HetEM, and PM groups, respectively (p=0.795). CONCLUSIONS: The efficacies of triple therapies that include lansoprazole or rabeprazole are not affected by CYP2C19 genetic polymorphisms.
2-Pyridinylmethylsulfinylbenzimidazoles ; Amoxicillin ; Breath Tests ; Clarithromycin ; Genotype ; Helicobacter ; Helicobacter pylori ; Humans ; Polymorphism, Genetic ; Prospective Studies

BACKGROUND/AIMS: MicroRNAs (miRNAs) regulate gene expression. We assess miRNA regulation by Helicobacter pylori infection and elucidate their role in H. pylori-infected gastric epithelial cells. METHODS: The relationship between miRNA expression and DNA methylation was examined. Cells were treated with the nuclear factor-kappaB (NF-κB) inhibitor Bay 11-7082 to determine the relationship between miRNA expression and NF-κB signal transduction. RESULTS: In the negative control cells infected with H. pylori 26695, the expression of six miRNAs was increased, whereas the expression of five miRNAs was decreased. The expression of upregulated miRNAs was increased when the host cells were treated with H. pylori and an NF-κB inhibitor. miR-127-5p, -155, and -181 were associated with increased interleukin 6 (IL-6) secretion in H. pylori infected cells treated with anti-miRNA. The expression of miR-155, -127-5p, -195, -216, -206, and -488 increased by approximately 3-fold following treatment with the methylation inhibitor Aza. CONCLUSIONS: We found novel miR-NAs in H. pylori-infected negative control cells using miRNA microarrays. Upregulated miRNA expression was inversely related to the transcription of NF-κB. miR-195 and miR-488 appear to play a pivotal role in controlling IL-6 activity in H. pylori infection. miRNA expression in H. pylori infection was affected by methylation.
Bays ; Cytokines ; DNA Methylation ; Epithelial Cells ; Gene Expression ; Helicobacter pylori* ; Helicobacter* ; Interleukin-6 ; Methylation ; MicroRNAs* ; NF-kappa B ; Signal Transduction

The apprenticeship-based training method (ABTM) is highly effective for gastrointestinal (GI) endoscopic training. However, the conventional ABTM has significant issues. Although many supplementary training methods (TMs) have been developed and utilized, they cannot entirely replace the ABTM, which remains the major TM strategy. Currently, new TM construction is crucial and necessary due to financial constraints, difficulty of obtaining sufficient training time due to patient safety-related regulations, and catastrophic damage caused by disasters such as the coronavirus disease 2019 pandemic. The simulator-based TM (SBTM) is widely accepted as an alternative to the ABTM, owing to the SBTM’s advantages. Since the 1960s, many GI endoscopy training simulators have been developed and numerous studies have been published on their effectiveness. While previous studies have focused on the simulator’s validity, this review focused on the accessibility of simulators that were introduced by the end of 2021. Although the current SBTM is effective in GI endoscopic education, extensive improvements are needed to replace the ABTM. Incorporating simulator-incorporated TMs into an improved ABTM is an attempt to overcome the incompleteness of the current SBTM. Until a new simulator is developed to replace the ABTM, it is desirable to operate a simulator-integrated and well-coordinated TM that is suitable for each country and institution.

Background/Aims: Although gastric neuroendocrine tumors (NETs) are uncommon neoplasms, their prevalence is increasing. The clinical importance of the World Health Organization (WHO) classification of gastric NETs, compared with NETs in other organs, has been underestimated.This study aimed to systematically evaluate the clinical and pathologic characteristics of gastric NETs based on the 2019 WHO classification and to assess the survival outcomes of patients from a single-center with a long-term follow-up. Methods: The medical records of 427 patients with gastric NETs who underwent endoscopic or surgical resection between January 2000 and March 2020 were retrospectively reviewed. All specimens were reclassified according to the 2019 WHO classification. The clinicopathologic characteristics, treatment, and oncologic outcomes of 139 gastric NETs were analyzed. Results: The patients’ median age was 53.0 years (interquartile range [IQR], 46.0 to 63.0 years). The median follow-up period was 36.0 months (IQR, 15.0 to 63.0 months). Of the patients, 92, 44, and 3 had grades 1, 2, and 3 NETs, respectively. The mean tumor size significantly increased as the tumor grade increased (p=0.025). Patients with grades 2 and 3 gastric NETs more frequently had lymphovascular invasion (29.8% vs 10.9%, p=0.005) and deeper tissue invasion (8.5% vs 0%, p=0.012) than those with grade 1 tumors. The overall disease-specific survival rate was 100%. Two patients with grades 2-3 gastric NETs experienced extragastric recurrence. Conclusions Although gastric NETs have an excellent prognosis, grade 2 or grade 3 gastric NETs are associated with a larger size, deeper invasion, and extragastric recurrence, which require active treatment.