Survey-Based Analysis of the Clinical Treatment Status of Irritable Bowel Syndrome in Korea.

BACKGROUND: The quality-of-life of patients with irritable bowel syndrome is low; incorrect diagnosis/treatment causes economic burden and inappropriate consumption of medical resources. This survey-based study aimed to analyze the current status of irritable bowel syndrome treatment to examine differences in doctors' perceptions of the disease, and treatment patterns. METHODS: From October 2019 to February 2020, the irritable bowel syndrome and Intestinal Function Research Study Group of the Korean Society of Neurogastroenterology and Motility conducted a survey on doctors working in primary, secondary, and tertiary healthcare institutions. The questionnaire included 37 items and was completed anonymously using the NAVER platform (a web-based platform), e-mails, and written forms. RESULTS: A total of 272 doctors responded; respondents reported using the Rome IV diagnostic criteria (amended in 2016) for diagnosing and treating irritable bowel syndrome. Several differences were noted between the primary, secondary, and tertiary physicians' groups. The rate of colonoscopy was high in tertiary healthcare institutions. During a colonoscopy, the necessity of random biopsy was higher among physicians who worked at tertiary institutions. 'The patient did not adhere to the diet' as a reason for ineffectiveness using low-fermentable oligo-, di-, and mono-saccharides, and polyols diet treatment was higher among physicians in primary/secondary institutions, and 'There are individual differences in terms of effectiveness' was higher among physicians in tertiary institutions. In irritable bowel syndrome constipation predominant subtype, the use of serotonin type 3 receptor antagonist (ramosetron) and probiotics was higher in primary/secondary institutions, while serotonin type 4 receptor agonist was used more in tertiary institutions. In irritable bowel syndrome diarrhea predominant subtype, the use of antispasmodics was higher in primary/secondary institutions, while the use of serotonin type 3 receptor antagonist (ramosetron) was higher in tertiary institutions. CONCLUSION: Notable differences were observed between physicians in primary/secondary and tertiary institiutions regarding the rate of colonoscopy, necessity of random biopsy, the reason for the ineffectiveness of low-fermentable oligo-, di-, and mono-saccharides, and polyols diet, and use of drug therapy in irritable bowel syndrome. In South Korea, irritable bowel syndrome is diagnosed and treated according to the Rome IV diagnostic criteria, revised in 2016.

Rebamipide for the Improvement of Gastric Atrophy and Intestinal Metaplasia: A Prospective, Randomized, Pilot Study.

BACKGROUND: 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. AIMS: We aimed to evaluate the efficacy of rebamipide for improving AG/IM. METHODS: 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). CONCLUSIONS: This study demonstrated that the administration of rebamipide improves AG and IM in the antrum, especially in patients with HP non-infection (KCT0001915).

Xenopus chip for single-egg trapping, in vitro fertilization, development, and tadpole escape.

Xenopus laevis is highly suitable as a toxicology animal model owing to its advantages in embryogenesis research. For toxicological studies, a large number of embryos must be handled simultaneously because they very rapidly develop into the target stages within a short period of time. To efficiently handle the embryos, a convenient embryo housing device is essential for fast and reliable assessment and statistical evaluation of malformation caused by toxicants. Here, we suggest 3D fabrication of single-egg trapping devices in which Xenopus eggs are fertilized in vitro, and the embryos are cultured. We used manual pipetting to insert the Xenopus eggs inside the trapping sites of the chip. By introducing a liquid circulating system, we connected a sperm-mixed solution with the chip to induce in vitro fertilization of the eggs. After the eggs were fertilized, we observed embryo development involving the formation of egg cleavage, blastula, gastrula, and tadpole. After the tadpoles grew inside the chip, we saved their lives by enabling their escape from the chip through reverse flow of the culture medium. The Xenopus chip can serve as an incubator to induce fertilization and monitor normal and abnormal development of the Xenopus from egg to tadpole.

Dual Clarithromycin and Metronidazole Resistance Is the Main Cause of Failure in Ultimate Helicobacter pylori Eradication.

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.

Helicobacter pylori Eradication Regressed Gastric Hyperplastic Polyp: A Randomized Controlled Trial.

BACKGROUND: Helicobacter pylori infection and hyperplastic polyp are known to have strong connections, but there are not enough randomized controlled trial data. AIMS: To evaluate the effect of H. pylori eradication on gastric hyperplastic polyp. METHOD: 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. RESULTS: 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 < 0.001). Disappearance of polyp (n = 7) and decrease in size (n = 7) were observed in eradication group. In non-eradication group, no change (n = 5), increase of size (n = 5), and increase of number (n = 3) were observed. Mean regression time was 6.8 months, and disappearance time was 9.8 months. In non-eradication group, hyperglycemia was noted in 50% of progression group but not noted in no change group (P = 0.057). CONCLUSIONS: H. pylori eradication induced regression of hyperplastic polyp, and persistent H. pylori infection was related to progression of gastric polyp. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03065868.

Prophylactic endoscopic coagulation to prevent delayed post-EMR bleeding in the colorectum: a prospective randomized controlled trial (with videos).

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 < .001). 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.).

Efficacy of tailored therapy for Helicobacter pylori eradication based on clarithromycin resistance and survey of previous antibiotic exposure: A single-center prospective pilot study.

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.

Endoscopic Indication of Endoscopic Submucosal Dissection for Early Gastric Cancer Is Not Compatible with Pathologic Criteria in Clinical Practice.

BACKGROUND: 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. METHODS: 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. RESULTS: 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 < 0.001). In multivariate analysis examining the predictive factors for discrepancies in the 598 EGCs with absolute/expanded indications, the endoscopic size ≥ 20 mm [odds ratio (OR) 2.493, confidence interval (CI) 1.546-4.022, p < 0.001], presence of ulcers (OR 1.712, CI 1.070-2.738, p = 0.025), patient age < 60 years (OR 1.689, CI 1.044-2.733, p = 0.033), and undifferentiated type EGC on forceps biopsy (OR 5.397, CI 2.027-14.369, p = 0.001) were all associated with discrepancies. CONCLUSIONS: Indication judged by pre-procedural endoscopy is not sufficiently accurate to be used as a good measurement for post-procedural criteria.

rdxA, frxA, and efflux pump in metronidazole-resistant Helicobacter pylori: Their relation to clinical outcomes.

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 quantitative real-time reverse transcription polymerase chain reaction, 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.

Specific mutations of penicillin-binding protein 1A in 77 clinically acquired amoxicillin-resistant Helicobacter pylori strains in comparison with 77 amoxicillin-susceptible strains.

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 < .001), and T593 mutation (OR: 32.0, 95% CI: 4.04-252.86, P < .001) independently contributed to Amx resistance in H. pylori strains. In the transformation experiment, T593 mutations were identified in their transformants showing Amx resistance. However, PCR product of D479E was not inserted into recipient (ATCC 43504) resulting in transformation failure. CONCLUSION: Amx resistance is associated with various substitutions in pbp1A and T593 mutation contributes to Amx resistance of H. pylori.

Long-Term Outcome After Endoscopic Submucosal Dissection for Early Gastric Cancer in Non-neoplastic Pathology Results.

BACKGROUND: 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. AIM: 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. METHODS: 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. RESULTS: 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%). CONCLUSIONS: Even when the pathological report indicates NRT after ESD, it might be necessary to re-evaluate ESD specimens with a width <2 mm, and long-term endoscopic surveillance should be routinely used for detecting local EGC recurrence after ESD.

Comparison of the efficacy of culture-based tailored therapy for Helicobacter pylori eradication with that of the traditional second-line rescue therapy in Korean patients: a prospective single tertiary center study.

OBJECTIVE: 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. MATERIAL AND METHODS: 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). RESULTS: 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). CONCLUSIONS: 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.

The Diagnostic Validity of Citric Acid-Free, High Dose (13)C-Urea Breath Test After Helicobacter pylori Eradication in Korea.

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.

Risk factors of open converted cholecystectomy for cholelithiasis after endoscopic removal of choledocholithiasis.

BACKGROUND: Open converted cholecystectomy could occur in patients who planned for laparoscopic cholecystectomy after endoscopic removal of choledocholithiasis. AIM: To evaluate the risk factors associated with open converted cholecystectomy. PATIENTS AND METHODS: 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. RESULTS: 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, p < 0.005), 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, p < 0.005) were related to open converted cholecystectomy in ≤2 weeks group. CONCLUSIONS: 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.

Endoscopic resection as a first therapy for gastric epithelial atypia: is it reasonable?

BACKGROUND AND AIMS: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

A tailored approach for endoscopic treatment of small rectal neuroendocrine tumor.

INTRODUCTION: Resection of rectal neuroendocrine tumors (NETs) less than 1 cm in diameter can be performed using various endoscopic techniques. Endoscopic mucosal resection (EMR) traditionally had suboptimal complete resection rate compared to endoscopic submucosal resection with band ligation (ESMR-L). However, the previous studies did not consider the characteristics of rectal NETs. The aim of our study is to compare the efficacy of ESMR-L and EMR using tailored approach according to the characteristics of rectal NETs. METHODS: 82 rectal NETs in 77 patients treated by ESMR-L (n = 48) or EMR (n = 34) between September 2007 and October 2012 were retrospectively analyzed. ESMR-L was used for flat-type tumors or tumors with non-lifting sign after submucosal injection. Conventional EMR was used for elevated-type tumors or tumors with well-lifting sign after submucosal injection. RESULTS: The pathological complete resection rate was higher in the ESMR-L group (45 lesions, 93.8%) compared with the EMR group (30 lesions, 88.2%); however, this difference was not significant (p = 0.441). Overall complication did not differ significantly between the ESMR-L group and the EMR group (p = 0.774). There was one case of a remnant lesion in the ESMR-L group, which was managed by EMR after circumferential pre-cutting (EMR-P), and no recurrence has been detected in either the ESMR-L or EMR group. CONCLUSIONS: ESMR-L and EMR procedures could have a similar excellent complete resection rate, if we select the endoscopic resection technique according to the characteristics of the small rectal NETs.

A Multicenter Survey of Percutaneous Endoscopic Gastrostomy in 2019 at Korean Medical Institutions.

Background/Aims: : This study aimed to review the indications, methods, cooperation, complications, and outcomes of percutaneous endoscopic gastrostomy (PEG). Methods: : Questionnaires were sent to 200 hospitals, of which 62 returned their questionnaires, with a response rate of approximately 30%. Descriptive statistics were calculated to analyze the responses to the questionnaires. Results: : In 2019, a total of 1,052 PEGs were performed in 1,017 patients at 62 hospitals. The main group who underwent PEG was older adult patients with brain disease, particularly stroke. Nutritional supply was an important purpose of the PEG procedure. "The pull method" was the most commonly used for initial PEG insertion. The complications related to PEG were mostly mild, with leakage being the most common. Patients who underwent PEG procedures were primarily educated regarding the post-procedure management and complications related to PEG. Preoperative meetings were skipped at >50% of the institutions. Regarding the cooperation between the nutrition support team (NST) and the physician performing PEG, few endoscopists answered that they cooperated with NST before and after PEG. Moreover, the rate of NST certification obtained by physicians performing PEG and the frequency of attendance at NST-related conferences were relatively low. Conclusions: : This study shows a similar trend to that found in the previous PEG guidelines. However, it covers new aspects, including team-based work for PEG procedure, nutrition support, and education for patients and guardians. Therefore, each medical institution needs to select an appropriate method considering the medical environment and doctor's abilities.

Optimization of spot-size converter for low polarization dependent loss of waveguide photodetector.

We present an optimization of spot-size converter (SSC) of waveguide photodetector (PD) for small polarization dependent loss (PDL). Beam-propagation method simulation gives responsivity for each polarization and SSC structure. From the calculated responsivity data, optimum structure of SSC is determined that can be implemented with a sufficient process tolerance. We confirm the optimization by measuring PDL of waveguide PD designed according to the structure obtained through the simulation.

Genetic landscape and PD-L1 expression in Epstein-Barr virus-associated gastric cancer according to the histological pattern.

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer. This study aims to investigate genomic and clinicopathological characteristics of EBVaGC according to the histological pattern. We retrospectively collected 18 specimens of surgically resected EBVaGCs. Whole-exome sequencing was performed for all cases. Moreover, PD-L1 expression and tumor-infiltrating lymphocyte (TIL) percentage were investigated. Among 18 EBVaGCs, 10 cases were of intestinal histology, 3 were of poorly cohesive histology, and the remaining 5 were of gastric carcinoma with lymphoid stroma histology. Whole-exome sequencing revealed that EBVaGCs with intestinal histology harbored pathogenic mutations known to frequently occur in tubular or papillary adenocarcinoma, including TP53, KRAS, FBXW7, MUC6, ERBB2, CTNNB1, and ERBB2 amplifications. One patient with poorly cohesive carcinoma histology harbored a CDH1 mutation. Patients with EBVaGCs with intestinal or poorly cohesive carcinoma histology frequently harbored driver mutations other than PIK3CA, whereas those with EBVaGCs with gastric carcinoma with lymphoid stroma histology lacked other driver mutations. Moreover, the histological pattern of EBVaGCs was significantly associated with the levels of TILs (P = 0.005) and combined positive score (P = 0.027). In conclusion, patients with EBVaGCs with different histological patterns exhibited distinct genetic alteration, PD-L1 expression, and degree of TILs.

Ten-day tegoprazan-based concomitant therapy as a first-line treatment for Helicobacter pylori eradication.

BACKGROUND/AIMS: Tegoprazan, a novel potassium-competitive acid blocker, has shown rapid action and gastric acid inhibition. In this study, we evaluated the efficacy of a tegoprazan-based, nonbismuth-containing quadruple (concomitant) therapy for the primary eradication of Helicobacter pylori. METHODS: We conducted a prospective, single-arm, single-center, primitive study to verify the efficacy of a 10-day tegoprazan- based (50-mg dose) concomitant therapy, including amoxicillin (1,000-mg dose), clarithromycin (CLA; 500-mg dose), and metronidazole (MET; 500-mg dose) twice daily as a first-line treatment for H. pylori eradication. RESULTS: We tested consecutive cultures for antibiotic susceptibility and minimum inhibitory concentrations. We enrolled 84 participants; 79 (94.0%) completed first-line therapy. The overall intention-to-treat and per-protocol eradication rates were 90.5% (95% confidence interval [CI], 82.1-95.8) and 96.2% (95% CI, 83.4-97.6), respectively. Of the 73 participants evaluated for antibiotic resistance, 19 (26.0%), 32 (42.5%), and 8 (11.0%) exhibited CLA, MET, and CLA and MET dual resistance, respectively. Of these, 39 participants (66.1%) exhibited successful eradication after the therapeutic regimen despite antibiotic resistance. CONCLUSION: The 10-day tegoprazan-based concomitant therapy may be an effective first-line treatment for eradicating H. pylori.