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Background/Aims: To date, no reports have compared the diagnostic efficacy of narrow-band imaging (NBI) and i-scan for the histologic prediction of intermediate-to-large colorectal polyps. We aimed to compare the diagnostic accuracy of NBI and i-scan in predicting histology, and their inter-/intra-observer agreement.Methods: We performed a prospective, randomized study that included 66 patients (NBI, n=33 vs. i-scan, n=33) with colorectal polyps (size >10 mm but

The presence of atrophic gastritis (AG) and intestinal metaplasia (IM) is associated with an increased risk of gastric cancer (GC). Thus, the development of new strategies to improve AG/IM is essential for reducing the incidence of GC.We aimed to evaluate the efficacy of rebamipide for improving AG/IM.This was a prospective, randomized, pilot study from a single tertiary referral center. Fifty-three (rebamipide, n = 34 vs. placebo, n = 19) patients, who underwent endoscopic resection for gastric dysplasia or early GC, were analyzed. We obtained tissue samples from the antrum and corpus of the stomach, at the time of screening and 1-year later. The histologic grading of inflammation was performed by histopathologists RESULTS: The AG grade in the antrum improved significantly after rebamipide treatment (pre-administration, 1.870 ± 0.932 vs. post-administration, 1.430 ± 0.986; P = 0.013). Additionally, the severity of IM in the antrum was significantly improved (pre-administration, 1.750 ± 0.963 vs. post-administration, 1.370 ± 1.032; P = 0.038). The rebamipide subgroup analysis revealed that patients with no Helicobacter pylori (HP) infection showed significant improvements in AG in the antrum (pre-administration, 1.880 ± 1.040 vs. post-administration, 1.250 ± 0.894; P = 0.028) and IM in antrum (pre-administration, 1.840 ± 1.012 vs. post-administration, 1.180 ± 0.912; P = 0.020).This study demonstrated that the administration of rebamipide improves AG and IM in the antrum, especially in patients with HP non-infection (KCT0001915).

Helicobacter pylori (H. pylori) is the main cause of most gastroduodenal diseases. Triple therapy including two antibiotics, amoxicillin and clarithromycin, and a proton pump inhibitor given for a week has been recommended as the treatment of choice since the revision of the Korean H. pylori Clinical Practice Guidelines in 2013. However, antimicrobial resistance significantly decreased the cure rate of H. pylori eradication to 63.9%. Thus, the new H. pylori treatment regimen would be needed to increase the eradication rate in Korea. Recently, the update of clinical practice guideline for treatment of H. pylori was developed by conducting a meta-analysis. In this review, the recommended H. pylori eradication regimen in current 2020 guideline will be discussed. (Korean J Med 2021;96:13-21)

Background/Aim: Antimicrobial resistance significantly affects the cure rate of Helicobacter pylori (H. pylori) eradication. We evaluated the risk factor of failure in ultimate H. pylori eradication and assessed the efficacy of current regimens to overcome antibiotic resistance. Methods: Patients with H. pylori infection were prospectively enrolled in a single center. They were classified into 3 groups according to the previous history of H. pylori eradication, and antibiotic susceptibility was evaluated by culture and minimum inhibitory concentrations (MICs). Results: Ninety-seven patients were successfully cultured for H. pylori and 81 (83.5%), 7 (7.2%), and 9 (9.3%) were classified into primary resistance, 1st eradication failure, and 2nd or more eradication failure groups; the resistance to clarithromycin (CLA), metronidazole (MET), and levofloxacin increased in the 1st eradication failure (85.7, 57.1, and 42.9%) and 2nd or more eradication failure (88.9, 88.9, and 55.6%) groups. The prevalence of MDR was 21.0% (17/81), 57.1% (4/7), and 88.9% (8/9) in the primary, 1st eradication failure, and 2nd or more eradication failure groups, respectively. In multivariate analysis, dual CLA/MET resistance (CLA/MET-R) (OR = 31.432, 95% CI: 3.094–319.266, p = 0.004) was an independent risk factor for ultimate H. pylori eradication failure. In patients with dual CLA/MET-R, the eradication ratio of concomitant therapy was 57.1% (4/7), whereas that of bismuth-containing quadruple therapy was 27.3% (3/11) (p = 0.350). Conclusions: Dual CLA/MET-R was the main cause of failure in ultimate H. pylori eradication, and 7-day bismuth quadruple or concomitant regimen would not be suitable for H. pylori eradication in the dual CLA/MET-R group.

Background/Aims: Several clinical factors have been used to predict the response for concurrent chemoradiotherapy (CCRT); however, these factors are insufficient for prognostic predictions. We investigated clinical factors to assess wheth er they could be used to predict the response to CCRT and the survival of patients with esophageal cancer. Methods: Patients with esophageal cancer underwent CCRT from Janu ary 2005 to December 2015. Response to CCRT was clas sified as progressive disease (PD), stationary disease (SD), partial remission (PR), or complete remission (CR). Factors to predict the response to CCRT and patient survival were sub sequently investigated. Results: A total of 535 esophageal cancer patients underwent CCRT. Four hundred ninety-three patients were followed up, and patient outcomes were in vestigated. In the adjusted analysis, patients with advanced stage disease (relative risk [RR], 0.28 in stage III and 0.12 in stage IV compared to stage I), poor performance status, circumferential involvement (RR, 0.61), and male sex (RR, 0.31) were less likely to achieve CR. Advanced stage disease (hazard ratio [HR], 1.71 in stage III/IV), poor CCRT response (HR, 2.82 in PR, 4.47 in SD, 4.77 in PD compared to CR), and poor performance status (HR, 1.38 in ECOG 2-4) were found to increase mortality. Conclusions: Advanced stage disease, poor performance status, male sex, and circum ferential involvement were independent predictive factors for a poor response to CCRT. Advanced stage, poor perfor mance status, and poor CCRT response were independent factors for decreased survival. (Gut Liver 2020;14:450-458)

Background/Aims: The Internet is the main resource for health-related informa tion. The incidence of inflammatory bowel disease (IBD) is rapidly increasing in Asian countries. However, the quality of websites for IBD available in this region has not been evaluated. We aimed to evaluate the quality of the information on IBD obtained from Korean websites. Methods: Using the terms “Crohn’s disease” or “ulcerative colitis,” websites were selected from those obtained with the three most renowned search engines in Korea; 60 websites from the results of each engine were chosen. The websites were classified into institutional, commercial, charitable, supportive, or alter native medicine types according to the characteristics of each site. The websites were evaluated regarding content quality using the validated DISCERN instru ment and the Journal of the American Medical Association benchmarks. Results: The median score of all the websites according to the DISCERN instru ment was 32 (interquartile range, 25 to 47) out of 80, indicating an insufficient overall quality of information. The alternative medicine sites scored the lowest, whereas the institutional sites scored the highest (p < 0.05). The quality of infor mation was significantly different among the search engines (p = 0.028). The rank of appearance in the Google search result did not correlate with the quality level of the information. Conclusions: The quality of information on the Internet regarding IBD varied according to the website type and search engine. Accreditation and quality assur ance systems should be implemented for websites to ensure that the public and patients obtain accurate information on IBD.

Endoscopic submucosal dissection (ESD) is widely used for the treatment of colorectal neoplasia in patients who are candidates for endoscopic resection. In particular, pyogenic liver abscess (PLA), although rare, can occur. To our knowledge, there are no reports of PLA cases after ESD. Therefore, we report a rare case of PLA caused by ESD. A 76-year-old man was referred from a local clinic and admitted to our hospital for colonic ESD for a large polypoid mass. During colonoscopy, a 5-cm mass was seen in the cecum. ESD was performed. Four days after the procedure, he complained of myalgia and abdominal discomfort. Computed tomography revealed a 5.4- cm PLA in the medial segments of the liver. He was treated with antibiotics, and a percutaneous drainage catheter was inserted. Here, we report a very rare complication (PLA) after ESD. In conclusion, comprehensive awareness of the development of PLA is needed in ESD cases.

Background and Aims Post-EMR bleeding (PEB) is the most common adverse event after EMR. However, there are no established endoscopic methods for the prevention of PEB. This study aimed to investigate whether prophylactic endoscopic coagulation (PEC) using coagulation probes reduces the incidence of overall delayed PEB. Methods We performed a randomized controlled study of patients undergoing EMR for large (≥10 mm) sessile lesions and laterally spreading tumors. Patients were randomized 1:1 to the EMR with coagulation group (n = 285) or EMR (control) group (n = 285). Immediate bleeding during colon EMR or clean-based ulcer after EMR was excluded. Clinically significant PEB was defined as bleeding requiring endoscopic hemostasis, hospitalization, or a decrease in the hemoglobin level >2 g/dL. Results A total of 569 patients were analyzed. The incidence of overall PEB was significantly lower in the EMR with coagulation group than in the control group (12.6% [36/285] vs 18.7% [53/284], P = .048). However, this was largely because of a reduction in minor bleeding. There was no difference in clinically significant PEB (1.8% [5/285] vs 3.2% [9/284], P = .276). Rectal location was a risk factor associated with overall PEB (odds ratio, 1.256; 95% confidence interval, 1.12-1.41; P Conclusions Although this study found reduced PEB with prophylactic cautery of visible vessels, this was largely because of a reduction in minor bleeding with no benefit observed for clinically significant bleeding. Overall, PEB was more frequent with rectal lesions. (Clinical trial registration number: KCT0000779.)

Background/Aims The validity of 13C-urea breath test (13C-UBT) for Helicobacter pylori detection is influenced by atrophic gastritis. The aim of this study was to evaluate the effect of citric acid on the accuracy of 13C-Urea breath test after H. pylori eradication therapy in a region where atrophic gastritis is common. Methods In this prospective study, H. pylori-positive patients received 13C-UBT after H. pylori eradication regimen. They were classified into citric acid group and control group. To determine diagnostic accuracy of 13C-UBT, patients were offered invasive methods. Results A total of 1,207 who successfully took H. pylori-eradication regimen received UBT. They were assigned into the citric acid group (n=562) and the control group (n=645). The mean 13C-UBT value of the citric acid group was 10.3±26.4‰, which was significantly (p

Background/Aims Contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) is a promising imaging modality that can differentiate subepithelial tumors (SETs) by detecting the degree of enhancement. However, whether CEH-EUS alone can predict the malignancy risk of gastrointestinal stromal tumors (GISTs) remains unclear. This study aimed to evaluate the feasibility of CEH-EUS by using perfusion analysis software for distinguishing among SETs and predicting the malignancy risk of GISTs. Methods We retrospectively included patients with SETs who underwent preoperative CEH-EUS. In this study, 44 patients with histologically proven GISTs and benign SETs were enrolled. Perfusion analysis was performed using perfusion quantification software. Peak enhancement (PE), wash-in rate (WiR), wash-in perfusion index (WiPI), and wash-in and wash-out areas under the time-intensity curve (WiWoAUC) were calculated and compared between the GISTs and benign SETs. Results When we allocated the enrolled patients into the leiomyoma group and low- and high-grade malignancy GIST groups, significant statistical differences in PE (p

The inappropriate selection of patients with early gastric cancer (EGC) for endoscopic submucosal dissection (ESD) may lead to additional surgery because of a non-curative resection. This study was performed to assess the accuracy of clinical decisions in ESD for EGC. A total of 607 cases of EGC treated by ESD were prospectively enrolled from January 2011 to June 2014 at a single academic hospital. The 607 EGCs were divided into three groups (overestimated, same-estimated, and underestimated) based on pre-procedure endoscopic findings (indication) and pathological diagnosis after ESD (criteria). We evaluated the discrepancy rates between pre-procedure indication and pathological criteria, and then analyzed the pre-procedure factors that could influence the occurrence of the discrepancies. The absolute, expanded, and beyond the expanded indication has its accuracy on curability criteria in 87%, 77.6%, and 55.6% of cases, respectively. The ratio of overall indication-criteria discrepancies was 250/607 (41.2%). The curability was significantly lower in the underestimated group compared to the overestimated and same-estimated groups (41.6% vs. 94.6%, 94.4%, p

Mortality difference by age, sex, body mass index (BMI) in gastric cancer (GC) has been controversial. We evaluated sex-specific mortality by age and BMI. A total of 5961 patients diagnosed with GC from 2005 to 2013 in a single tertiary center were included and were followed until December 2017. The plot in goodness-of-fit-test by sex was crossed, so we performed sex-specific analysis. Overall mortality was lower in women than in men (adjusted hazard ratio [aHR], 0.72). Favor outcomes in women compared to men were observed among patients older than 60 yr (aHR, 0.64; 95% CI, 0.56–0.74), a BMI less than 25 kg/m2 (aHR, 0.69; 95% CI, 0.61–0.79), and stage I (aHR, 0.46; 95% CI, 0.38–0.56). In sex-specific analysis, mortality increased in age older than 60 yr in men, whereas it increased in both extreme ages (

Objective. The serum pepsinogen test has limitation in its predictive power as a noninvasive biomarker for gastric cancer screening. We aimed to investigate whether the combination of TFF3 and pepsinogen could be an effective biomarker for the detection of gastric cancer even in the early stages. Methods. In total, 281 patients with early gastric cancer (EGC), who underwent endoscopic submucosal dissection in Korea, and 708 healthy individuals from Japan were enrolled in the derivation cohort. The validation cohort included 30 Korean patients with EGC and 30 Korean healthy control blood donors. Serum TFF3 levels were examined using enzyme-linked immunosorbent assay. Results. Using a cutoff of 6.73 ng/mL in the derivation cohort, the sensitivity of the combination of tests for EGC detection was superior (87.5%) to that of TFF3 (80.4%) or pepsinogen test alone (39.5%). Similarly, in the validation cohort, the sensitivity of TFF3 plus pepsinogen was higher (90.4%) than that of TFF3 (80.0%) or pepsinogen test alone (33.3%). Conclusion. The combination of serum TFF3 and pepsinogen is a more effective noninvasive biomarker for gastric cancer detection compared with pepsinogen or TFF3 alone, even in EGC. This trial is registered with NCT03046745.

In 2011, the Korean Society of Neurogastroenterology and Motility (KSNM) published clinical practice guidelines on the management of irritable bowel syndrome (IBS) based on a systematic review of the literature. The KSNM planned to update the clinical practice guidelines to support primary physicians, reduce the socioeconomic burden of IBS, and reflect advances in the pathophysiology and management of IBS. The present revised version of the guidelines is in continuity with the previous version and targets adults diagnosed with, or suspected to have, IBS. A librarian created a literature search query, and a systematic review was conducted to identify candidate guidelines. Feasible documents were verified based on predetermined inclusion and exclusion criteria. The candidate seed guidelines were fully evaluated by the Guidelines Development Committee using the Appraisal of Guidelines for Research and Evaluation II quality assessment tool. After selecting 7 seed guidelines, the committee prepared evidence summaries to generate data exaction tables. These summaries comprised the 4 main themes of this version of the guidelines: colonoscopy; a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols; probiotics; and rifaximin. To adopt the core recommendations of the guidelines, the Delphi technique (ie, a panel of experts on IBS) was used. To enhance dissemination of the clinical practice guidelines, a Korean version will be made available, and a food calendar for patients with IBS is produced. (J Neurogastroenterol Motil 2018;24:197-215)

Endoscopic resection (ER) is the current standard of care for selected cases of gastric epithelial dysplasia or early gastric cancer because of its curative en bloc resectability and complete histopathological assessment of the specimen. Although ER provides many advantages to surgery, some adverse events, such as bleeding, perforation, and local recurrence, can occur during and after the procedure. Furthermore, negative pathological findings after ER cause concerns about the adequacy of the procedure and local recurrence after ER among endoscopists and patients. Several variant factors, such as complete removal of small gastric tumor lesions by using initial forceps biopsy, pathological inconsistencies between pathologists, and performing ER in the wrong area. Thus, endoscopists must consider these risk factors to avoid and manage negative pathological results.

Background and Aim rdxA and frxA mutations and enhancement of efflux pump have been suggested as the cause of metronidazole resistance in Helicobacter pylori. This study was performed to investigate the resistance mechanisms related to clinical eradication outcome, and to examine direct involvement of hefA in metronidazole-resistant isolates with intact rdxA and frxA. Methods A total of 53 H. pylori-positive patients who were treated with metronidazole-containing sequential or quadruple therapy from 2011 to 2015 were enrolled. The metronidazole susceptibility of H. pylori isolates was examined by agar dilution test. Mutations in rdxA and frxA, were analyzed with DNA sequencing, and impact of hefA on metronidazole resistance was examined with qRT-PCR, knockout and genetic complementation test for hefA. Results Seven mutation types of rdxA and/or frxA were found in H. pylori isolated from non-eradicated subjects. rdxA mutation was associated with eradication failure (P = 0.002), and nonsense mutation in rdxA reduced eradication efficacy (P = 0.009). hefA expression was significantly higher in resistant isolates (P < 0.001), especially in rdxA(-)frxA(-) as compared to rdxA(+)frxA(+) (P = 0.027). Resistant isolates with no mutation in rdxA and frxA became susceptible after hefA knockout. Genetic complementation for hefA recovered metronidazole resistance in all of three hefA knockout mutants. Conclusions These results suggest that rdxA mutations play a critical role in metronidazole resistance as well as the outcomes of eradication therapy. In addition, hefA seems to be directly involved in metronidazole resistance, which explains the resistance in clinical isolates with intact rdxA and frxA.

After endoscopic submucosal dissection (ESD) for early gastric cancer (EGC), negative pathological findings cause concern about the adequacy of the procedure and local recurrence after ESD. To investigate the incidence of local recurrence in cases with negative pathological findings after ESD for EGC and pathologically complete resection (CR) during long-term follow-up. We reviewed 453 patients who underwent ESD for ECG from January 2007 to December 2010, respectively. Of these patients, in 17 cases the pathology results confirmed no residual tumor (NRT), and in 421 cases they showed CR in the ESD specimen. Finally, 17 NRT and 358 CR cases were followed up during surveillance. Patient characteristics, endoscopic and pathological data were analyzed for risk factors of local recurrence. We also re-evaluated the pathology of the NRT group to identify hidden malignant cells in the previous ESD specimens. There was no difference between the two groups in terms of recurrence during follow-up surveillance (median 55.7 months). Late local recurrence of EGC was found in two cases (11.8%) in the NRT group, and three early local recurrences (5.6%) were found in the CR group. A review of the pathology in the NRT group revealed hidden malignant cells in five patients (29.4%). Even when the pathological report indicates NRT after ESD, it might be necessary to re-evaluate ESD specimens with a width

Helicobacter pylori infection and hyperplastic polyp are known to have strong connections, but there are not enough randomized controlled trial data. To evaluate the effect of H. pylori eradication on gastric hyperplastic polyp. This is an open-labeled, single-center, randomized controlled trial. Patients with hyperplastic polyp and current infection of H. pylori were randomly assigned to eradication or non-eradication groups. All participants underwent follow-up endoscopy to investigate the regression of gastric polyps. Gastric polyp regression was defined as the disappearance of polyps or a reduction of more than 50% in size. Thirty-two patients were randomized to eradication (n = 17) and non-eradication groups (n = 15). Final included patients were 14 in eradication group and 13 in non-eradication group. All patients showed polyp regression in eradication group, whereas no regression was observed in non-eradication group (P

Background The optimal endoscopic screening interval for early gastric cancer (EGC) detection still remains controversial. Thus, we performed this prospective study to clarify the optimal interval between endoscopic examinations for EGC detection. Methods A questionnaire survey for penultimate endoscopy and gastric cancer (GC) diagnosis interval was used; the findings were then analyzed. The patients were divided into two groups according to GC type and endoscopic examinations intervals. Results A total of 843 patients were enrolled. The endoscopic GC detection interval (P < 0.001), tumor location (P < 0.001), tumor size (P < 0.001), histology (P < 0.001), tumor stage (P < 0.001), and treatment modality (P < 0.001) showed significant differences in the univariate analysis between EGC and advanced gastric cancer (AGC). Endoscopic examination intervals below 2 years and 3 years were associated with higher proportions of EGC detection (adjusted odds ratio, 2.458 and 3.022, respectively) (P < 0.001). The patients with endoscopic examination to GC diagnosis interval of < 2 years showed significant differences in tumor size (P < 0.001), tumor stage (P < 0.001), and treatment modality (P < 0.001) compared to those with intervals of > 2 years and without screening. Similar results were observed in those with < 3-year intervals. Conclusion Triennial endoscopic screening might be as effective as biennial screening in increasing the detection rate of EGC and the risk of subsequent curable endoscopic resections., Graphical Abstract

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)

BACKGROUND The (13)C-urea breath test ((13)C-UBT) is a noninvasive method for diagnosing Helicobacter pylori (H. pylori) infection. The aims of this study were to evaluate the diagnostic validity of the (13)C-UBT cutoff value and to identify influencing clinical factors responsible for aberrant results. METHODS (13)C-UBT (UBiTkit; Otsuka Pharmaceutical, cutoff value: 2.5‰) results in the range 2.0‰ to 10.0‰ after H. pylori eradication therapy were compared with the results of endoscopic biopsy results of the antrum and body. Factors considered to affect test results adversely were analyzed. RESULTS Among patients with a positive (13)C-UBT result (2.5‰ to 10.0‰, n = 223) or a negative (13)C-UBT result (2.0‰ to < 2.5‰, n = 66) after H. pylori eradication, 73 patients (34.0%) were false positive, and one (1.5%) was false negative as determined by endoscopic biopsy. The sensitivity, specificity, false-positive rate, and false-negative rate for a cutoff value of 2.5‰ were 99.3%, 47.1%, 52.9%, and 0.7%, respectively, and positive and negative predictive values of the (13)C-UBT were 67.3% and 98.5%, respectively. Multivariate analysis showed that a history of two or more previous H. pylori eradication therapies (OR = 2.455, 95%CI = 1.299-4.641) and moderate to severe gastric intestinal metaplasia (OR = 3.359, 95%CI = 1.572-7.178) were associated with a false-positive (13)C-UBT result. CONCLUSION The (13)C-UBT cutoff value currently used has poor specificity for confirming H. pylori status after eradication, and this lack of specificity is exacerbated in patients that have undergone multiple prior eradication therapies and in patients with moderate to severe gastric intestinal metaplasia. In addition, the citric-free (13)C-UBT would increase a false-positive (13)C-UBT result.

BACKGROUND This study was conducted to evaluate the diagnostic validity of the (13)C-urea breath test ((13)C-UBT) in the remnant stomach after partial gastrectomy for gastric cancer. METHODS The (13)C-UBT results after Helicobacter pylori eradication therapy was compared with the results of endoscopic biopsy-based methods in the patients who have received partial gastrectomy for the gastric cancer. RESULTS Among the gastrectomized patients who showed the positive (13)C-UBT results (≥ 2.5‰, n = 47) and negative (13)C-UBT results (< 2.5‰, n = 114) after H. pylori eradication, 26 patients (16.1%) and 4 patients (2.5%) were found to show false positive and false negative results based on biopsy-based methods, respectively. The sensitivity, specificity, false positive rate, and false negative rate for the cut-off value of 2.5‰ were 84.0%, 80.9%, 19.1%, and 16.0%, respectively. The positive and negative predictive values were 44.7% and 96.5%, respectively. In the multivariate analysis, two or more H. pylori eradication therapies (odds ratio = 3.248, 95% confidence interval= 1.088-9.695, P = 0.035) was associated with a false positive result of the (13)C-UBT. CONCLUSIONS After partial gastrectomy, a discordant result was shown in the positive (13)C-UBT results compared to the endoscopic biopsy methods for confirming the H. pylori status after eradication. Additional endoscopic biopsy-based H. pylori tests would be helpful to avoid unnecessary treatment for H. pylori eradication in these cases.

Background Amoxicillin (Amx) is one of the most important antibiotics for eradication of Helicobacter pylori (H. pylori). Main determinants of genetically stable Amx resistance are mutations in the C-terminus of penicillin-binding protein 1A (pbp1A). However, contribution of individual mutation remains unclear. Methods 77 Amx-resistant (AmxR) and 77 Amx-susceptible (AmxS) H. pylori strains were isolated from gastric tissues, and DNA sequencing was performed to compare C-terminus sequences of pbp1A gene between AmxR and AmxS strains. Natural transformation of these mutated genes into amoxicillin-susceptible strains was performed. Results Among many mutations in pbp1A, D479E (OR: 37.4, 95% CI: 5.53-252.49, P

The gastric accommodation reflex is an important mechanism in gastric physiology. However, the aging-associated structural and functional changes in gastric relaxation have not yet been established. Thus, we evaluated the molecular changes of interstitial cell of Cajal (ICC) and neuronal nitric oxide synthase (nNOS) and the function changes in the corpus of F344 rats at different ages (6-, 31-, 74-wk and 2-yr). The proportion of the c-Kit-positive area in the submucosal border (SMB) and myenteric plexus (MP) layer was significantly lower in the older rats, as indicated by immunohistochemistry. The density of the nNOS-positive immunoreactive area also decreased with age in the SMB, circular muscle (CM), and MP. Similarly, the percent of nNOS-positive neuronal cells per total neuronal cells and the proportion of nNOS immunoreactive area of MP also decreased in aged rats. In addition, the mRNA and protein expression of c-Kit and nNOS significantly decreased with age. Expression of stem cell factor (SCF) and the pan-neuronal marker PGP 9.5 mRNA was significantly lower in the older rats than in the younger rats. Barostat studies showed no difference depending on age. Instead, the change of volume was significantly decreased by L-NG63-nitroarginine methyl ester in the 2-yr-old rats compared with the 6-wk-old rats (P = 0.003). Taken together, the quantitative and molecular nNOS changes in the stomach might play a role in the decrease of gastric accommodation with age.

Background: The Helicobacter felis (H. felis) mouse model has been developed for the research regarding pathogenesis of chronic gastritis and gastric cancer. The aim of this study was to investigate long-term H. felis colonization in the stomachs of C57BL/6 mice and subsequent histologic findings and inflammatory reactions including pro-inflammatory cytokines. Methods: Twenty-three female C57BL/6 mice at 4 weeks of age were gavaged with H. felis, and 13 control mice served as vehicle only. The mice were sacrificed at 4, 24, and 52 weeks after inoculation. The infection status and degree of inflammation were determined by culture and histopathology. The level of gastric mucosal myeloperoxidase (MPO), tumor necrosis factor alpha (TNF-α), and interleukin-1beta (IL-1β) were measured by ELISA. Results: The overall infection rate was 100%, as determined by the culture and histology. At 4, 24, and 52 weeks, the neutrophil and monocyte scores were significantly higher in infected mice than in control mice. At 24 weeks after inoculation, most of the infected mice showed mucosal atrophy with or without metaplasia, and a few showed focal dysplasia. Adenocarcinoma was observed in one mouse at 52 week post-infection. Gastric mucosal MPO and IL-1β levels were significantly higher in infected mice than those in control mice at 24 and 52 weeks. However, the expression of gastric mucosal TNF-α was not significantly different between the infected and control mice at any time-point. Conclusions: Long-term H. felis-infection in C57BL/6 mice provoked a severe inflammatory reaction and it progressed into atrophy, metaplasia, dysplasia and cancer. IL-1β might play an important role in the inflammatory response of mice to Helicobacter species.

Open converted cholecystectomy could occur in patients who planned for laparoscopic cholecystectomy after endoscopic removal of choledocholithiasis.To evaluate the risk factors associated with open converted cholecystectomy.The data for all patients who underwent cholecystectomy after endoscopic removal of choledocholithiasis were retrospectively reviewed. Factors predictive for conversion to open cholecystectomy were analyzed.The rate of open converted cholecystectomy was 15.7 %. In multivariate analysis, cholecystitis (OR 1.908, 95 % CI 1.390-6.388, p = 0.005), mechanical lithotripsy (OR 6.129, 95 % CI 1.867-20.123, p0.005), and two or more choledocholithiases (OR 2.202, 95 % CI 1.097-4.420, p = 0.026) revealed significant risk factors for conversion to open cholecystectomy. Analyzing the risk factors for open converted cholecystectomy according to duration from endoscopic stone removal to cholecystectomy (within 2 weeks, between 2 and 6 weeks, and beyond 6 weeks), acute cholangitis (OR 3.374, 95 % CI 1.267-8.988, p = 0.015), cholecystitis (OR 3.127, 95 % CI 1.100-8.894, p = 0.033), and mechanical lithotripsy (OR 17.504, 95 % CI 3.548-86.355, p0.005) were related to open converted cholecystectomy in ≤2 weeks group.For patients who need cholecystectomy after endoscopic removal of choledocholithiasis, endoscopic retrograde cholangiography-related factors predictive for open converted cholecystectomy are helpful in planning the appropriate timing of surgery.

Candida is a rare cause of infectious arthritis, and it can be found in infants and immunocompromised patients. Patients with maintenance hemodialysis are prone to opportunistic infections because of altered immunity, and frequent exposures to health-care associated infections. Herein, we report a case of candida arthritis of right shoulder with preceding fungemia in patients with maintenance hemodialysis. The diagnosis is based on the isolation of Candida Tropicalis from blood and synovial fluids of the shoulder joint. The patient has received intravenous fluconazole and arthroscopic surgical debridement. We then changed the fluconazole into amphotericin B due to the abnormal signs in the liver function tests, although the fluconazole successfully controlled fungemia and arthritis. To the best of our knowledge, this is the first case of candida arthritis in patients with maintenance hemodialysis in South Korea.

Gastric atypical cell (GAC), an indefinite pathologic finding, often requires repeated biopsy or other diagnostic treatments, such as endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or operation (OP). The aim of this study was to analyze the initial endoscopic and histologic findings of GAC and to discuss the necessity of EMR/ESD at establishing a correct diagnosis. This retrospective study enrolled 96 patients proven as GAC on index forceps biopsy. ESD (17/96, 17.7 %), EMR (5/96, 5.2 %), OP (20/96, 20.8 %), and other treatment or follow-up (54/96, 56.3 %) were performed. We analyzed the initial endoscopic and histologic characteristics of GAC lesions, predictive of neoplasm. After diagnostic modalities, the final pathologic diagnoses were cancer (36/96, 37.6 %), dysplasia (9/96, 9.4 %), and non-neoplasm (51/96, 53.0 %). In univariate analysis, age [odds ratio (OR) 1.04, 95 % confidence interval (CI) 1.01–1.07], lesion size of 10 mm or greater (OR 3.94, 95 % CI 1.61–9.61), lesion with depressed type (OR 2.50, 95 % CI 1.09–5.72), and presence of H. pylori (OR 2.83, 95 % CI 1.11–7.25) were risk factors for neoplasm. In multivariate analysis, lesion size of 10 mm or greater (OR 3.63, 95 % CI 1.23–10.66), lesion with depressed type (OR 2.86, 95 % CI 1.11–7.38) were independent risk factors for cancer. Considering the neoplastic risk of GAC, which could be missed on biopsy, more comprehensive tissue sampling via EMR/ESD might be necessary to establish a definite diagnosis.

Background As the prevalence of antibiotic resistance is increasing, the effectiveness of traditional Helicobacter pylori (H pylori) therapies is gradually declining. We aimed to evaluate the efficacy of tailored therapy (dual priming oligonucleotide [DPO]-based multiplex PCR) and previous antibiotic exposure survey predicting for antibiotic resistance. Materials and methods Patients with H pylori infection who did not receive previous treatment were enrolled. The patients were divided into four groups (no resistance [NR] group, clarithromycin resistance [CLA-R] group, metronidazole-resistant [MET-R] group, and CLA- and MET-resistant [Dual-R] group) based on the results of dual priming oligonucleotide (DPO) polymerase chain reaction (PCR) and previous antibiotic exposure survey, and they were treated with tailored therapy based on antibiotic susceptibility. Results Consecutive patients were distributed in the NR (n = 36, 70.6%), CLA-R (n = 9, 17.6%), and suspected MET-R (n = 6, 11.8%) group. The overall intention-to-treat/per-protocol eradication rate (ITT/PP) was 92.2%/94.0%. In the subgroup analysis, the ITT and PP of the NR, CLA-R, and MET-R groups were 94.4%/94.4%, 77.8%/87.5%, and 100.0%/100.0%, respectively. Total of 31 patients in all subgroups were evaluated for antibiotic resistance; five (16.1%), two (6.5%), and three (9.7%) participants showed CLA, MET, and dual resistance in culture-based susceptibility test. Compared with culture-based MIC test, the accuracy of DPO-based multiplex PCR in determining CLA resistance was 90.3%, while the accuracy of survey in determining MET resistance was only 77.4%. Conclusion A tailored therapy based on DPO-PCR and history of previous antibiotic use is useful in clinical practice and well correlated with culture-based susceptibility test.

In colonoscopic study, benign colorectal strictures with or without symptomatic pain are not rarely encountered. Benign colorectal stricture can be caused by a number of problems, such as anastomotic stricture after surgery, inflammatory bowel disease, postendoscopic submucosal dissection, diverticular disease, ischemic colitis, and so on. There are various modalities for the management of benign colorectal stricture. Endoscopic balloon dilatation is generally considered as the primary treatment for benign colorectal stricture. In refractory benign colorectal strictures, several treatment sessions of balloon dilatation are needed for successful dilatation. The self-expandable metal stent and many combined techniques are performed at present. However, there is no specific algorithmic modality for refractory benign colorectal strictures.

Although the pepsinogen I/II (PGI/II) ratio after Helicobacter pylori eradication is recovered at short-term follow-up, long-term follow-up studies of PGI/II are rare.A total of 773 patients with gastric cancer who underwent endoscopic resection and pepsinogen and H. pylori tests were enrolled. H. pylori was eradicated in these patients. Endoscopic and pepsinogen tests were performed every year. A low PGI/II ratio was defined as ≤3.The PGI/II ratio was higher in non-infected patients (n=275, 4.99) than infected patients (n=498, 3.53). After H. pylori eradication, the PGI/II ratio increased to 5.81 and 5.63 after 1 and 2 years (each p0.05). The PGI/II ratio in the non-eradication group decreased to 3.94 and 2.75 after 1 and 2 years. The PGI/II ratio in the H. pylori eradication group became similar to that of the H. pylori-negative group at 3 (4.48 vs. 4.34), 4 (4.88 vs. 4.34), and 5 years (4.89 vs. 4.23). The adjusted odds ratios for a lower PG I/II ratio in the non-eradication group compared to the eradication group were 4.78 (95% CI 2.15-10.67) after 1year and 8.13 (95% CI 2.56-25.83) after 2 years.After H. pylori eradication, the PGI/II ratio increased and was similar to that of H. pylori-negative controls for up to 5 years of follow-up.

The cure rates of Helicobacter pylori (H. pylori) eradication therapy using a proton pump inhibitor (PPI) and antimicrobial agents such as amoxicillin (AMX), clarithromycin (CAM), and metronidazole (MNZ) are mainly influenced by bacterial susceptibility to antimicrobial agents, and the eradication rates have gradually decreased because of the increased prevalence of H. pylori strains resistant to antimicrobial agents. The prevalence of antibiotic (e.g., CAM, MNZ, tetracycline, AMX, and furazolidone) resistance varies among different countries; it appears to be partly determined by geographical factors. Since the worldwide increase in the rate of antibiotic resistance represents a problem of relevance, local surveillance of antibiotic resistance assessed by H. pylori culture and antimicrobial susceptibility testing is warranted to guide clinicians in their choice of therapy. Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H. pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material. In the future, tailored therapy based on use of these techniques may allow for successful therapy for H. pylori infection.

The urea breath test (UBT) is a noninvasive, simple, and safe test which provides excellent accuracy both for the initial diagnosis of Helicobacter pylori infection and for the confirmation of its eradication after treatment (high sensitivity, 90–100 % and specificity, 90–100 %). This test is based on the organism’s urease activity, which liberates carbon dioxide (CO2) from urea and produces ammonia to buffer its acidic environment. Ingestion of labeled urea results in the production of labeled CO2 which then can be detected in the breath. Urea can be labeled with two different isotopes, 14C (the radioactive isotope) or 13C (the nonradioactive stable isotope). The methodology of the UBT have been changed including the dose of labeled urea used, the type of test meal, the time of breath collection, the cutoff values, and the equipment adopted to measure isotope enrichment. However, a definitive standardization of this test does not yet exist, and a unique and generally proposed cutoff level is not possible because it has to be adapted to different factors.

The effectiveness of Helicobacter pylori therapies has declined with an increase in antibiotic resistance. To overcome this problem, the efficacy of tailored H. pylori eradication therapy based on antimicrobial susceptibility testing was compared with that of empirical second-line rescue regimens.Patients who had persistent H. pylori infection after the first eradication were recommended to undergo culture for determining the minimal inhibitory concentration (MIC) via gastroscopy, which increased the cost by 300%. Fourteen-day esomeprazole, tripotassium dicitrate bismuthate, metronidazole and tetracycline (EBMT) therapy or esomeprazole, moxifloxacin and amoxicillin (MEA) therapy was performed according to the results of antibiotic susceptibility testing. In case of refusal to undergo culture, the participants were treated with either 14-day empirical EBMT or MEA regimen for second eradication after explaining the complexity, side effects and costs associated with each regimen. This trial was registered at ClinicalTrials.Gov (NCT 02349685).In the 219 patients included, the intention to treat (ITT) and per protocol (PP) eradication rates was 75.3% and 79.8% in the 14-day EBMT group (n = 89), 70.8% and 72.4% in the 14-day MEA group (n = 89) and 87.8% and 100.0% in the 14-day tailored therapy group (n = 41), respectively. Based on the PP analysis, the 14-day tailored therapy group showed a significantly higher eradication rate than the 14-day EBMT or MEA group (both p ≤ 0.001).Tailored therapy based on H. pylori culture and MIC test could be an option as a second-line eradication regimen in the presence of high level of antimicrobial resistance.