The relationship between a comprehensive index of prosperity and suicide rates in former Soviet countries, including a comparison with European and Asian countries: Discussion from a new perspective.

Investigations of suicide in countries of the former Soviet Union, which broke into 15 different countries in the early 1990s, require examinations of a combination of economic, social, and health factors. It is important to address these factors individually and to examine the various composite indicators for each. Moreover, it would be worthwhile to explore the potential applicability of a comprehensive worldwide index. We analyzed data from nine of the former Soviet countries for which both the annual suicide rate and the Global Competitiveness Index (GCI) were available for the years 2006-2017. We determined the precise relationships between the suicide rate and the GCI during this period in these nine countries as well as in nine countries with high suicide rates in Europe and Asia. The results indicated the following: (i) In six of the nine former Soviet countries with complete data, the suicide rate showed a relationship with the GCI. Notably, this relationship was inverse in all but one country. (ii) Among the nine European and Asian countries with high suicide rates, three exhibited a correlation between the suicide rate and the GCI. Measures to prevent suicide should be devised especially in countries of the former Soviet Union through collaboration among multiple fields and organizations, as necessary, with particular attention paid to countries with worse or worsening GCI values.

Detailed Superiority of the CAD EYE Artificial Intelligence System over Endoscopists for Lesion Detection and Characterization Using Unique Movie Sets.

Objectives: Detailed superiority of CAD EYE (Fujifilm, Tokyo, Japan), an artificial intelligence for polyp detection/diagnosis, compared to endoscopists is not well examined. We examined endoscopist's ability using movie sets of colorectal lesions which were detected and diagnosed by CAD EYE accurately. Methods: Consecutive lesions of ≤10 mm were examined live by CAD EYE from March-June 2022 in our institution. Short unique movie sets of each lesion with and without CAD EYE were recorded simultaneously using two recorders for detection under white light imaging (WLI) and linked color imaging (LCI) and diagnosis under blue laser/light imaging (BLI). Excluding inappropriate movies, 100 lesions detected and diagnosed with CAD EYE accurately were evaluated. Movies without CAD EYE were evaluated first by three trainees and three experts. Subsequently, movies with CAD EYE were examined. The rates of accurate detection and diagnosis were evaluated for both movie sets. Results: Among 100 lesions (mean size: 4.7±2.6 mm; 67 neoplastic/33 hyperplastic), mean accurate detection rates of movies without or with CAD EYE were 78.7%/96.7% under WLI (p<0.01) and 91.3%/97.3% under LCI (p<0.01) for trainees and 85.3%/99.0% under WLI (p<0.01) and 92.6%/99.3% under LCI (p<0.01) for experts. Mean accurate diagnosis rates of movies without or with CAD EYE for BLI were 85.3%/100% for trainees (p<0.01) and 92.3%/100% for experts (p<0.01), respectively. The significant risk factors of not-detected lesions for trainees were right-sided, hyperplastic, not-reddish, in the corner, halation, and inadequate bowel preparation. Conclusions: Unique movie sets with and without CAD EYE could suggest it's efficacy for lesion detection/diagnosis.

Analysis of the characteristics of coexisting lesions in colorectal cancer patients in an international study: A subgroup analysis of the ATLAS trial.

INTRODUCTION: We investigated coexisting lesion types in patients with invasive colorectal cancer (CRC) in a multinational study for comprehending the adenoma-carcinoma and serrated pathway about the development of CRC. METHODS: We retrospectively reviewed 3050 patients enrolled in the international randomized controlled trial (ATLAS study) to evaluate the colorectal polyp detection performance of image-enhanced endoscopy in 11 institutions in four Asian countries/regions. In the current study, as a subgroup analysis of the ATLAS study, 92 CRC patients were extracted and compared to 2958 patients without CRC to examine the effects of age, sex, and coexisting lesion types (high-grade adenoma [HGA], low-grade adenoma with villous component [LGAV], 10 adenomas, adenoma ≥10 mm, sessile serrated lesions [SSL], and SSL with dysplasia [SSLD]). Additional analyses of coexisting lesion types were performed according to sex and location of CRC (right- or left-sided). RESULTS: A multivariate analysis showed that HGA (odds ratio [95%confidence interval] 4.29 [2.16-8.18]; p<0.01), LGAV (3.02 [1.16-7.83], p=0.02) and age (1.04 [1.01-1.06], p=0.01) were independently associated with CRC. According to sex, the coexisting lesion types significantly associated with CRC were LGAV (5.58 [1.94-16.0], p<0.01) and HGA (4.46 [1.95-10.20], p<0.01) in males and HGA (4.82 [1.47-15.80], p<0.01) in females. Regarding the location of CRC, SSLD (21.9 [1.31-365.0], p=0.03) was significant for right-sided CRC, and HGA (5.22 [2.39-11.4], p<0.01) and LGAV (3.46 [1.13-10.6], p=0.02) were significant for left-sided CRC. CONCLUSIONS: The significant coexisting lesions in CRC differed according to sex and location. These findings may contribute to comprehending the pathogenesis of CRC.

Airborne Suspended Particulate Matter and the Prevalence of Allergic Conjunctivitis in Japan.

Background This study aimed to examine the association of suspended particulate matter (SPM) with outpatient attendance for allergic conjunctivitis. Methodology The information on air pollution, encompassing total hydrocarbons, non-methane hydrocarbons, methane, carbon monoxide, nitrogen oxide, nitric oxide, oxidants, and SPM alongside data concerning daily weather conditions such as temperature, wind speed, and humidity, was gathered. Subsequently, the weekly mean values for outpatient visits, air pollution, and weather parameters were computed. Results The number of outpatient visits for allergic conjunctivitis was significantly associated with SPM levels (r = 0.70, p = 0.0037), oxidant levels (r = 0.70, p = 0.0038), wind speed (r = 0.48, p = 0.0472), and humidity (r = 0.77, p = 0.0009) from January to March, as well as SPM levels (r = 0.53, p = 0.0309) and carbon monoxide (r = 0.56, p = 0.0230) from April to June. Multivariate analysis showed that SPM (odds ratio = 1.37, p = 0.0161) and wind velocity (odds ratio = 1.52, p = 0.0038) were significant predictors of the number of outpatient visits from January to December. Conclusions SPM levels were the only independent predictor of outpatient visits for allergic conjunctivitis, suggesting that SPM contributes to the pathophysiology of this condition.

Prevalence of colonoscopy in Japan using a large-scale health claims data compared to esophagogastroduodenoscopy.

OBJECTIVE: Prevalence of colonoscopy (CS) is an important countermeasure against colorectal cancer (CRC). In this study, we used large-scale data for a comparison of CS with esophagogastroduodenoscopy (EGD) in Japan. METHODS: This was a retrospective descriptive study. Commercially anonymized patient data were collected from various health insurance societies (JMDC, Inc. Tokyo, Japan) generated from the insurance registry, receipts (inpatient, outpatient, and prescription), and health checkup data. The data also included healthy subjects who had never been examined in a hospital. The data of 2,760,048 persons who were 50-75 years old during January 2012-December 2019 were extracted from the original data source. The annual rate, the prevalence rate (frequency of those undergoing at least one endoscopy during the period), and the percentage of repeaters (undergoing endoscopy at least twice during the period) of CS were calculated and compared to those of EGD. RESULTS: The annual rates in 2012/2015/2019 were 3.4%/4.5%/5.3% for CS, respectively, and increased gradually from 2012 to 2019. Those rates were 7.0%/7.9%/7.4% for EGD, respectively, and did not increase. The prevalence rates of CS and EGD were 25.3% and 36.2%, respectively, among the 137,246 participants over 8 years. The prevalence rates of individuals in their 50 s/60 s/70 s were 23.0%/25.9%/31.4% for CS and 33.0%/37.6%/40.7% for EGD, respectively. The proportions of males/females were 27.9%/20.7% for CS, and 36.4%/35.8% for EGD, respectively. The repeat rates of CS and EGD were 40.3% and 44.8%, respectively, over 8 years. CONCLUSIONS: Using large-scale data, we determined the status of CS and EGD in Japan.

Generation of Dopamine Transporter (DAT)-mCherry Knock-in Rats by CRISPR-Cas9 Genome Editing.

Midbrain dopaminergic neurons respond to rewards and have a crucial role in positive motivation and pleasure. Electrical stimulation of dopaminergic neurons and/or their axonal fibers and arborization has been often used to motivate animals to perform cognitive tasks. Still, the electrical stimulation is incompatible with electrophysiological recordings. In this light, optical stimulation following artificial expression of channelrhodopsin-2 (ChR2) in the cell membrane has been also used, but the expression level of ChR2 varies among researchers. Thus, we attempted to stably express ChR2 fused with a red fluorescence protein, mCherry, in dopaminergic neurons. Since dopamine transporter (DAT) gene is known as a marker for dopaminergic neurons, we inserted ChR2-mCherry into the downstream of the DAT gene locus of the rat genome by clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR-Cas9) genome editing and created DAT-ChR2-mCherry knock-in rats. Immunohistochemistry showed that ChR2-mCherry was expressed in dopaminergic neurons in homozygote knock-in rats, whereas whole-cell recordings revealed that ChR2-mCherry-positive neurons did not fire action potentials upon blue light stimulation, indicating that ChR2 was not functional for optogenetics. Nevertheless, fluorescent labeling of dopaminergic neurons mediated by mCherry could help characterize them physiologically and histologically.

Efficacy of Glycicumarin and Isoliquiritigenin in Suppressing Colonic Peristalsis in Both an Animal Model and a Clinical Trial.

Patients with diarrhea-predominant irritable bowel syndrome (IBS-D) show excessive peristalsis, and antispasmodic agents may be useful therapeutic agents. There are few reports on the use of Kampo medicines for the treatment of IBS-D. Shakuyakukanzoto (SKT) is a Kampo medicine that is effective against abdominal pain. We examined the relationship between SKT and intestinal peristalsis in an animal model and a prospective study. In the animal model, SKT and its components were administered from the serosal side of the colon and colonic peristalsis was evaluated using intraluminal pressure and spatiotemporal mapping before and after the administration of SKT and its components. In this clinical trial, we used abdominal ultrasonography (US) to obtain long-axis images of the sigmoid colon of 11 patients. The frequency of intestinal peristalsis was measured using US in five patients with SKT and six patients without medication after the ingestion of a test meal. The primary outcome was the frequency of peristalsis. The Clinical Trial Registry Website (Trial No. UMIN-CTR; UMIN000051547). In the animal model, peony did not suppress peristalsis frequency, but SKT (p = 0.005) and glycyrrhiza (p = 0.001) significantly suppressed peristalsis frequency compared with saline and peony. Among the glycyrrhiza components, glycycoumarin and isoliquiritigenin suppressed the peristalsis frequency compared to dimethyl sulfoxide (control) (p = 0.001, 0.01, respectively). In a clinical trial, peristalsis was significantly suppressed after oral administration in patients taking SKT (p = 0.03). Administration of SKT was found to inhibit colonic peristalsis, with glycicumarin and isoliquiritigenin being particularly relevant among its components.

Unified picture of vibrational relaxation of OH stretch at the air/water interface.

The elucidation of the energy dissipation process is crucial for understanding various phenomena occurring in nature. Yet, the vibrational relaxation and its timescale at the water interface, where the hydrogen-bonding network is truncated, are not well understood and are still under debate. In the present study, we focus on the OH stretch of interfacial water at the air/water interface and investigate its vibrational relaxation by femtosecond time-resolved, heterodyne-detected vibrational sum-frequency generation (TR-HD-VSFG) spectroscopy. The temporal change of the vibrationally excited hydrogen-bonded (HB) OH stretch band (ν=1→2 transition) is measured, enabling us to determine reliable vibrational relaxation (T1) time. The T1 times obtained with direct excitations of HB OH stretch are 0.2-0.4 ps, which are similar to the T1 time in bulk water and do not noticeably change with the excitation frequency. It suggests that vibrational relaxation of the interfacial HB OH proceeds predominantly with the intramolecular relaxation mechanism as in the case of bulk water. The delayed rise and following decay of the excited-state HB OH band are observed with excitation of free OH stretch, indicating conversion from excited free OH to excited HB OH (~0.9 ps) followed by relaxation to low-frequency vibrations (~0.3 ps). This study provides a complete set of the T1 time of the interfacial OH stretch and presents a unified picture of its vibrational relaxation at the air/water interface.

Granulomatous pneumonia in a cow infected with Toxoplasma gondii.

We report a confirmed case of Toxoplasma gondii infection in the lungs of a cow exhibiting respiratory symptoms. At slaughter, white nodules were discovered in lung tissue, accompanied by enlarged hilar lymph nodes. Histological examination revealed the disappearance of alveolar structures in nodular areas, replaced by granulomas containing inflammatory cells. Immunohistochemical staining with anti-T. gondii antibody and nucleotide sequencing of 18S rDNA confirmed T. gondii infection. However, the link between T. gondii and observed symptoms remains unclear. Various factors, including host genetics, underlying diseases, infection route, and exposure level, may contribute to these uncommon symptoms. Although T. gondii infections in cattle are traditionally considered asymptomatic, our study suggests the possible existence of clinical symptoms associated with Toxoplasma infection. Beef cattle are generally not assumed to be a relevant source of human T. gondii infection; however, sporadic transmission by infected edible beef to humans cannot be completely excluded and deserves further studies.

Prognostic value of moderate or massive ascites in patients with advanced gastric cancer.

Advanced gastric cancer is a highly aggressive malignancy. The available literature does not provide the prognostic value of ascites based on their degree, because most clinical trials exclude patients who present with massive ascites. Therefore, this study examined whether the presence or degree of ascites has a prognostic value in 124 patients with advanced gastric cancer. The degree of ascites was assessed using computed tomography and classified as none, small, moderate or massive. The overall survival (OS) was compared based on the presence or degree of ascites. Furthermore, a Cox proportional hazards analysis was performed to ascertain the predictors of OS. The cumulative 1-year and 2-year OS rates in patients without ascites were 43.5 and 20.2%, respectively, whereas those in patients with ascites were 29.1 and 13.6%, respectively (P=0.116). The cumulative 1-year and 2-year OS rates in patients without moderate or massive ascites were 39.5 and 20.9%, respectively; however, those in patients with moderate or massive ascites were 28.0 and 4.0%, respectively (P=0.027). Multivariate analysis showed that diffuse-type [hazard ratio (HR), 1.532; 95% confidence interval (CI), 1.002-2.343; P=0.049], moderate or massive ascites (HR, 2.153; 95% CI, 1.301-3.564; P=0.003) and chemotherapy (HR, 0.189; 95% CI, 0.101-0.352; P<0.001) were significant predictive factors of OS. In conclusion, the present study indicated that moderate or massive ascites may influence the OS of patients with advanced gastric cancer.

Short- and long-term outcomes of endoscopic submucosal dissection and laparoscopic and endoscopic cooperative surgery for superficial non-ampullary duodenal epithelial tumors.

BACKGROUND AND AIMS: This retrospective study aimed to compare the short- and long-term outcomes of endoscopic submucosal dissection and laparoscopic and endoscopic cooperative surgery in patients with superficial non-ampullary duodenal epithelial tumors. PATIENTS AND METHODS: We investigated consecutive patients with SNADETs > 10 mm in size who underwent ESD (ESD group) or LECS (LECS group) between January 2015 and March 2021. The data was used to analyze the clinical course, management, survival status, and recurrence between the two groups. RESULTS: A total of 113 patients (100 and 13 in the ESD and LECS groups, respectively) were investigated. The rates of en bloc resection and curative resection were 100% vs. 100% and 93.0% vs. 77.0% in the ESD and LECS groups, respectively, with no significant difference. The ESD group had shorter resection and suturing times than the LECS group, but there were no significant difference after propensity score matching. There were also no differences in the rates of postoperative adverse event (7.0% vs. 23.1%; P = 0.161). The 3-year overall survival (OS) rate was high in both the ESD and LECS groups (97.6% vs. 100%; P = 0.334). One patient in the ESD group experienced recurrence due to liver metastasis; however, no deaths related to SNADETs were observed. CONCLUSION: ESD and LECS are both acceptable treatments for SNADETs in terms of a high OS rate and a low long-term recurrence rate, thereby achieving a comparable high rate of curative resection. Further studies are necessary to compare the outcomes of ESD and LECS for SNADETs once both techniques are developed further.

D-alanine inhibits murine intestinal inflammation by suppressing IL-12 and IL-23 production in macrophages.

BACKGROUND AND AIMS: Free D-amino acids, which have different functions from L-amino acids, have recently been discovered in various tissues. However, studies on the potential interactions between intestinal inflammation and D-amino acids are limited. We examined the inhibitory effects of D-alanine on the pathogenesis of intestinal inflammation. METHODS: We investigated serum D-amino acid levels in 40 patients with ulcerative colitis and 34 healthy volunteers. For 7 d, acute colitis was induced using dextran sulfate sodium in C57BL/6J mice. Plasma D-amino acid levels were quantified in mice with dextran sulfate sodium-induced colitis, and these animals were administered D-alanine via intraperitoneal injection. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression in the colonic mucosa was measured using real-time PCR. In vitro proliferation assays were performed to assess naïve CD4+ T cell activation under Th-skewing conditions. Bone marrow cells were stimulated with mouse macrophage-colony stimulating factor to generate mouse bone marrow-derived macrophages. RESULTS: Serum D-alanine levels were significantly lower in patients with ulcerative colitis than in healthy volunteers. Dextran sulfate sodium-treated mice had significantly lower plasma D-alanine levels than control mice. D-alanine-treated mice had significantly lower disease activity index than control mice. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression levels were significantly lower in D-alanine-administered mice than in control mice. D-alanine suppressed naïve T cell differentiation into Th1 cells in vitro and inhibited the production of IL-12p35 and IL-23p19 in bone marrow-derived macrophages. CONCLUSIONS: Our results suggest that D-alanine prevents dextran sulfate sodium-induced colitis in mice and suppresses IL-12p35 and IL-23p19 production in macrophages.

Abnormality in GABAergic postsynaptic transmission associated with anxiety in Bronx waltzer mice with an Srrm4 mutation.

The homozygous Bronx waltzer (bv) mouse, which shows hearing impairment, also exhibits anxiety accompanied by a reduction in cortical parvalbumin (PV)-positive GABAergic interneurons. Recently, a mutation in splicing factor Ser/Arg repetitive matrix 4 (Srrm4) was found in bv mice. However, the cellular consequences of the Srrm4 mutation for anxiety remain unknown. Here, we tested our hypothesis that bv mutant primarily affects interneurons through a cell-intrinsic pathology that leads to a reduction of interneurons and consequently causes anxiety. We found that the anxiety becomes apparent at 6 weeks of age in bv/bv mice. However, in situ hybridization revealed that Srrm4 is not expressed in interneurons, but rather dominates in pyramidal neurons. In addition, the PV-positive GABAergic interneurons were not reduced in number in the bv/bv cortex when anxiety became evident. However, electrophysiological abnormality of GABAergic transmission from interneurons was concomitantly present. Pharmacological blockage of GABAA receptors revealed increased excitability in bv/bv mice, although no gross change occurred in the expression of an Srrm4-downstream gene, Kcc2, which regulates chloride flux upon GABAergic transmission. These findings suggest that the bv-associated Srrm4 mutation mainly involves post-synaptic GABAergic transmission in the central nervous system, which may be associated with the anxiety phenotype in bv/bv mice.

Efficacy of hemostatic gel for perioperative bleeding and prevention of delayed bleeding of cold snare polypectomy under anticoagulant.

Background and Aim: A hemostatic gel, PuraStat (3-D Matrix, Tokyo, Japan), is used for various gastrointestinal hemostasis. In this study, we analyzed the efficacy of PuraStat for perioperative bleeding (POB) and prevention of delayed bleeding (DB) to colorectal cold snare polypectomy (CSP) with continuous anticoagulant. Methods: This was a single-center, retrospective study. Subjects were lesions of 2-9 mm under continuous anticoagulant from 2021 to 2023 and treated with PuraStat for POB. The definition of POB was bleeding which did not stop spontaneously by 1.0-1.5 min after resection and needed hemostasis. Successful hemostasis was defined as cessation of bleeding within 1.0-1.5 min after spraying PuraStat and the rate of it and risk factors of POB were analyzed. For comparison, cases receiving previous CSP without PuraStat were extracted from all cases with CSP (2018-2021), and POB and DB rate (DBR) were analyzed after propensity score matching. Results: One hundred twenty-two lesions (91: direct oral anticoagulant (DOAC), 31: warfarin) with anticoagulant were analyzed and the rate of successful hemostasis with PuraStat was 92.6% (DOAC/warfarin: 93.4%/80.6%, P = 0.01). The rate of DB was 0.0%. Multivariate analysis showed that significant risk factors about unsuccessful hemostasis for POB with PuraStat were lesion size 8-9 mm (P < 0.01), warfarin (P = 0.01), and combination of antiplatelet (P = 0.01). Regarding the comparison about CSP with/without PuraStat, the clipping rate and DBR were 8.5%/94.9% (P < 0.01) and 0%/1.7% (P = 1.0). Conclusion: The effects of PuraStat for POB and DB in colorectal CSP with continuous anticoagulant were acceptable.

Kudoa tanakai n. sp. (Myxozoa: Myxosporea: Multivalvulida), a new kudoid species with spheroid myxospores from the scalpel sawtail (Actinopterygii: Prionurus scalparum) from western Japan.

We describe a new kudoid species, Kudoa tanakai n. sp., in the scalpel sawfish, Prionurus scalprum (Actinopterygii: Acanthuriformes: Acanthuridae), from the natural water around western Japan. The plasmodia were filamentous, localized in pseudocysts in the myofibers of the trunk muscles. The occurrence of plasmodia in the trunk muscle showed no site preference. Its myxospores were spheroid, measuring 6.6-7.6 (7.0) µm by 5.8-6.9 (6.3) µm in apical view (width) and 5.7-6.6 (6.2) in length (n = 30), with four shell valves and a corresponding number of spheroid polar capsules. Shell valves lacked apical protrusions, but scanning electron microscopy revealed that one of the four shell valves had two semi-lunar flaps at its apical terminus. Nucleotide sequencing of the small and large subunit ribosomal RNA genes of the present isolate showed phylogenetic affinities to kudoid species characterized by spheroid myxospores, such as K. musculoliquefaciens, K. hemiscylli, and K. carcharhini, but was molecularly and morphometrically distinct from these and other kudoid species. For direct comparison, Kudoa hemiscylli was collected from the Pacific spadenose shark, Scoliodon macrorhynchos (Elasmobranchii: Carcharhiniformes: Carcharhinidae), in the South China Sea off Guangdong Province, China, and the myxospore surface of the species was observed using scanning electron microscopy. Our study describes the new host and distribution record of this kudoid species originally described from a variety of elasmobranchs in the Australian Coral Sea.

Conventional versus underwater endoscopic resection for superficial non-ampullary duodenal epithelial tumours.

BACKGROUND AND OBJECTIVE: Several endoscopic resection methods have been developed as less invasive treatments for superficial non-ampullary duodenal epithelial tumours. This study aimed to compare outcomes of conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours, including resection depth and rate of the muscularis mucosa contained under the lesion. METHODS: This single-centre retrospective cohort study conducted from January 2009 to December 2021 enrolled patients who underwent conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours and investigated their clinicopathological outcomes using propensity score matching. RESULTS: Of the 285 superficial non-ampullary duodenal epithelial tumours, 98 conventional endoscopic mucosal resections and 187 underwater endoscopic mucosal resections were included. After propensity score matching, 64 conventional endoscopic mucosal resections and 64 underwater endoscopic mucosal resections were analysed. The R0 resection rate was significantly higher in underwater endoscopic mucosal resection cases than in conventional endoscopic mucosal resection cases (70.3% vs. 50.0%; P = 0.030). In the multivariate analysis, a lesion diameter > 10 mm (odds ratio 7.246; P = 0.001), being in the 1st-50th treatment period (odds ratio 3.405; P = 0.008), and undergoing conventional endoscopic mucosal resection (odds ratio 3.617; P = 0.016) were associated with RX/R1 resection. Furthermore, in underwater endoscopic mucosal resection cases, the R0 rate was significantly higher for lesions diameter ≤10 mm than >10 mm, and was significantly higher in the 51st-treatment period than in the 1st-50th period. Conventional endoscopic mucosal resection and underwater endoscopic mucosal resection cases showed no significant difference in resection depth and muscularis mucosa containing rate. CONCLUSIONS: Underwater endoscopic mucosal resection may be more acceptable than conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours ≤ 10 mm. A steep early learning curve may be acquired for underwater endoscopic mucosal resection. Large multicentre prospective studies need to be conducted to confirm the effectiveness of underwater endoscopic mucosal resection.