Pseudomorphic amorphization of three-dimensional superlattices through morphological transformation of nanocrystal building blocks.

Nanocrystal (NC) superlattices (SLs) have been widely studied as a new class of functional mesoscopic materials with collective physical properties. The arrangement of NCs in SLs governs the collective properties of SLs, and thus investigations of phenomena that can change the assembly of NC constituents are important. In this study, we investigated the dynamic evolution of NC arrangements in three-dimensional (3D) SLs, specifically the morphological transformation of NC constituents during the direct liquid-phase synthesis of 3D NC SLs. Electron microscopy and synchrotron-based in situ small angle X-ray scattering experiments revealed that the transformation of spherical Cu2S NCs in face-centred-cubic 3D NC SLs into anisotropic disk-shaped NCs collapsed the original ordered close-packed structure. The random crystallographic orientation of spherical Cu2S NCs in starting SLs also contributed to the complete disordering of the NC array via random-direction anisotropic growth of NCs. This work demonstrates that an understanding of the anisotropic growth kinetics of NCs in the post-synthesis modulation of NC SLs is important for tuning NC array structures.

Comparison of treatment outcomes between endoscopic submucosal dissection with the needle-type knife and insulated-tip knife for superficial esophageal neoplasms.

Our study aimed to compare the treatment outcomes between endoscopic submucosal dissection (ESD) with an insulated-tip knife (ESD-IT) and a needle-type knife (ESD-N) for large superficial esophageal neoplasms, as no study of this kind has been previously reported. We used the dataset of a multicenter, randomized controlled trial that compared conventional ESD (C-ESD) and traction-assisted ESD (TA-ESD) for superficial esophageal neoplasms. We compared the procedural outcomes between ESD-IT and ESD-N in a post hoc analysis and conducted sub-analyses based on traction assistance and electrical knife type. We included 223 (EST-IT, n = 169; ESD-N, n = 54) patients with no significant differences in baseline characteristics. The operator handover rate due to ESD difficulties was significantly higher in ESD-N (ESD-IT = 0.6% vs. ESD-N = 13.0%, P = 0.001), while the injection volume was significantly higher in ESD-IT than in ESD-N (40.0 vs. 20.5 mL, P < 0.001). Other outcomes were comparable between both groups (procedural time: 51.0 vs. 49.5 minute, P = 0.89; complete resection: 90.5% vs. 90.7%, P > 0.99; and complication rate: 1.8% vs. 3.7%, P = 0.60 for ESD-IT and ESD-N, respectively). In the sub-analyses, the handover rate was significantly lower with TA-ESD than with C-ESD for ESD-N (3.2% vs. 26.1%, P = 0.034), and a significantly smaller injection volume was used in TA-ESD than in C-ESD for ESD-IT (31.5 vs. 47.0 mL, P < 0.01). ESD with either endoscopic device achieved favorable treatment outcomes with low complication rates. The handover rate in ESD-N and the injection volume in ESD-IT improved with the traction method.

Clinicopathological and molecular characterization of early gastric adenocarcinoma in Helicobacter pylori-uninfected patients: emphasis on differentiated gastric adenocarcinoma.

BACKGROUND: Recently, Helicobacter pylori (HP)-uninfected gastric mucosal cancer has been reported; however, the clinicopathological and molecular features of HP-uninfected gastric cancer have not been elucidated. METHODS: We evaluated the clinicopathological, immunohistochemical, and genetic alterations in HP-uninfected early gastric adenocarcinoma using next-generation sequencing (NGS). RESULTS: Among 968 primary early gastric carcinomas, 64 (6.6%) were HP-uninfected gastric adenocarcinoma and were pathologically classified as gastric adenocarcinoma of fundic-gland type (GA-FG, n = 39), differentiated gastric adenocarcinoma (DGA, n = 16), and signet-ring cell carcinoma (SRCC, n = 9). Based on the expression profile of the mucin core protein, DGAs were classified into a gastrointestinal phenotype showing either MUC5AC or MUC6 expression and MUC2 or CD10 expression simultaneously (n = 5), and a gastric phenotype (n = 11) showing either MUC5AC or MUC6 expression. All DGAs with a gastrointestinal phenotype shared similar endoscopic characteristics, such as reddish depressed lesions in the antrum. In contrast, DGAs with a gastric phenotype exhibited several distinct endoscopic features, including a raspberry-shaped appearance and whitish flat-elevated appearance; the former expressed only MUC5AC and the latter exhibited co-expression of MUC5AC and MUC6. Among 16 HP-uninfected DGAs, seven were subjected to NGS. APC was recurrently mutated in DGA (42.9%) and was enriched in DGAs with a gastrointestinal phenotype (75%). CONCLUSIONS: Overall, HP-uninfected gastric adenocarcinomas showed distinct clinicopathologic and endoscopic characteristics. Furthermore, HP-uninfected DGAs, especially those with a gastrointestinal phenotype, may be characterized by recurrent APC mutations.

In Situ Control of Crystallinity of 3D Colloidal Crystals by Tuning the Growth Kinetics of Nanoparticle Building Blocks.

Colloidal crystals (CCs) constructed from inorganic nanoparticle (NP) building blocks exhibit properties that cannot be realized from isolated NPs or corresponding bulk counterparts. Because the arrangement of NPs in CCs is crucial in the CC's collective properties, development of a procedure to modulate the assembly of NP constituents is important. We demonstrate rapid formation of nickel (phosphide) CCs with tunable crystallinity through van der Waals force-driven spontaneous self-assembly of NPs in a facile one-pot colloidal synthesis. The quantity of size-regulating reagent (tri-n-octylphosphine) modulates the assembly of NPs from ordered close-packed to a disordered configuration in CCs. Synchrotron-based in situ small-angle X-ray scattering revealed that the size uniformity of the NPs determines the crystallinity of CCs, indicating the importance of regulating the growth kinetics of NPs during the synthesis. Our work will be useful for universal scalable preparation of CCs from a variety of materials and structures, with tunable concerted properties.

Inter-element miscibility driven stabilization of ordered pseudo-binary alloy.

An infinite number of crystal structures in a multicomponent alloy with a specific atomic ratio can be devised, although only thermodynamically-stable phases can be formed. Here, we experimentally show the first example of a layer-structured pseudo-binary alloy, theoretically called Z3-FePd3. This Z3 structure is achieved by adding a small amount of In, which is immiscible with Fe but miscible with Pd and consists of an alternate L10 (CuAu-type)-PdFePd trilayer and Pd-In ordered alloy monolayer along the c axis. First-principles calculations strongly support that the specific inter-element miscibility of In atoms stabilizes the thermodynamically-unstable Z3-FePd3 phase without significantly changing the original density of states of the Z3-FePd3 phase. Our results demonstrate that the specific inter-element miscibility can switch stable structures and manipulate the material nature with a slight composition change.

Pivotal trial of a biodegradable stent for patients with refractory benign esophageal stricture.

OBJECTIVE: Benign esophageal strictures (BES) cause dysphagia and decrease patients' quality of life. Although mechanical dilation is the standard of care for BES, in some patients, dysphagia is unrelieved despite repeated procedures. The biodegradable stent was developed to resolve refractory BES, with reported favorable outcomes, but it is unapproved in Japan. Thus, we evaluated the safety and efficacy of the biodegradable stent (BDS) for patients with refractory BES for regulatory approval. METHODS: This was a nonrandomized single-arm prospective trial conducted at eight institutions. We included patients with BES after ≥ 5 times of dilation or ≥ one time of radial incision and cutting whose dysphagia score (DS) was 2 or worse and an endoscope could not admit. The primary endpoint was the proportion of patients whose DS improvement of ≤ 1 was maintained at 3 months. RESULTS: Thirty patients (median age: 69 years, male/female: 27:3) were enrolled and treated; BDS placement failed in 1 patient. Fourteen patients maintained their DS improvement until 3 months after placement (proportion of DS improvement at 3 months 46.7% [95% CI: 28.3-65.7]), and the median dysphagia-free survival was 98 days [95% CI: 68-123]. Most adverse events could be managed conservatively; however, a patient with BES after chemoradiotherapy (CRT) developed an esophago-left atrium fistula and died approximately 4 months after stent placement. CONCLUSION: The BDS was effective for refractory BES and the safety was acceptable. However, the indication for this procedure in patients RECEIVING CRT for esophageal cancer should be carefully considered.

Endoscopic findings of Helicobacter pylori gastritis in children and young adults based on the Kyoto classification of gastritis and age-associated changes.

BACKGROUND AND AIM: We aimed to evaluate endoscopic findings of Helicobacter pylori (H. pylori)-positive children and young adults based on the Kyoto classification, and to examine if there are age-associated changes in H. pylori-positive gastritis. METHODS: H. pylori-positive patients under 40 years old who underwent upper gastrointestinal endoscopy from 1 April 2009 to 15 February 2017 were included. Subjects were classified into the Pediatric (<20 years) and Young adult groups (20-39 years). The patients' endoscopic photographs were retrospectively re-evaluated based on the Kyoto classification. We compared endoscopic findings between the two groups and examined alterations in the findings of H. pylori-associated gastritis in 5-year age groups. RESULTS: Forty-three and 163 subjects were classified into the Pediatric and Young adult groups, respectively. In the Pediatric group, nodularity was seen in the majority (93.0%); other endoscopic findings in order of decreasing frequency included mucosal swelling (32.6%), spotty redness (25.6%), diffuse redness (18.6%), and atrophy (9.3%). In the Young adult group, endoscopic findings included atrophy (66.9%), mucosal swelling (49.7%), spotty redness (39.3%), nodularity (31.9%), and diffuse redness (30.3%). The difference in prevalence of nodularity or atrophy between the two groups reached statistical significance (P < 0.0001 each). The rate of nodularity decreased with increasing age in the Young adult group. The rate of atrophy was 33% in young adult patients aged 20-24, and the rate increased to >65% in patients over age 25. CONCLUSION: H. pylori-positive children had endoscopic findings besides nodularity based on the Kyoto classification. The prevalence of atrophy increased in patients over age 20.

Gastric epithelial neoplasm of fundic-gland mucosa lineage: proposal for a new classification in association with gastric adenocarcinoma of fundic-gland type.

BACKGROUND: Gastric adenocarcinoma of fundic-gland type (GA-FG) is a rare variant of gastric neoplasia. However, the etiology, classification, and clinicopathological features of gastric epithelial neoplasm of fundic-gland mucosa lineage (GEN-FGML; generic term of GA-FG related neoplasm) are not fully elucidated. We performed a large, multicenter, retrospective study to establish a new classification and clarify the clinicopathological features of GEN-FGML. METHODS: One hundred GEN-FGML lesions in 94 patients were collected from 35 institutions between 2008 and 2019. We designed a new histopathological classification of GEN-FGML using immunohistochemical analysis and analyzed via clinicopathological, immunohistochemical, and genetic evaluation. RESULTS: GEN-FGML was classified into 3 major types; oxyntic gland adenoma (OGA), GA-FG, and gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM). In addition, GA-FGM was classified into 3 subtypes; Type 1 (organized with exposure type), Type 2 (disorganized with exposure type), and Type 3 (disorganized with non-exposure type). OGA and GA-FG demonstrated low-grade epithelial neoplasm, and GA-FGM should be categorized as an aggressive variant of GEN-FGML that demonstrated high-grade epithelial neoplasm (Type 2 > 1, 3). The frequent presence of GNAS mutation was a characteristic genetic feature of GEN-FGML (7/34, 20.6%; OGA 1/3, 33.3%; GA-FG 3/24, 12.5%; GA-FGM 3/7, 42.9%) in mutation analysis using next-generation sequencing. CONCLUSIONS: We have established a new histopathological classification of GEN-FGML and propose a new lineage of gastric epithelial neoplasm that harbors recurrent GNAS mutation. This classification will be useful to estimate the malignant potential of GEN-FGML and establish an appropriate standard therapeutic approach.

[Celiac disease:a case report detailing clinical and pathological improvement with a gluten-free diet].

Celiac disease has a morbidity of 0.2 to 1% in Europe and the United States (US), but appears to be extremely rare in Japan with only a few case reports. This report details a Japanese woman with celiac disease diagnosed by histopathological findings and the improvement of her clinical symptoms on a gluten-free diet. The woman was in her 60s and presented with diarrhea, abdominal pain, and vomiting which were repeatedly exacerbated over several weeks. Therefore, she was referred to our hospital for a detailed examination and treatment. Upper gastrointestinal endoscopy revealed a crude granular mucosa with an erythematous color in the duodenum. No special findings were noted on colonoscopy or capsular endoscopy. Histopathological findings of the duodenum noted villous atrophy, crypt hyperplasia, and lymphocytic infiltration within the surface epithelium, which were suspicious for celiac disease. A gluten-free diet was started which resulted in improved clinical symptoms. Repeat endoscopic imaging and histopathological findings after initiation of the gluten-free diet demonstrated improved small bowel villous atrophy. In this case, appropriate testing had ruled out inflammatory bowel disease, amyloidosis, infectious enteritis, parasitic disease, and allergies. Although anti-gliadin antibody (AGA) and anti-tissue transglutaminase antibody (ATTGA) were serologically negative, and HLA typing was HLA-DQ6, the patient was ultimately diagnosed as having celiac disease based on the characteristic pathological findings and clinical course. In many cases of celiac disease reported in Japan, serum antibodies such as AGA and ATTGA have not been detected, and HLA testing has been negative for DQ2 or DQ8. Therefore, it is possible that celiac disease in Japan might have different genetic and immunological characteristics than the disease in the US and Europe. In the future, additional cases with histology and molecular biological analysis are necessary to test this hypothesis.

Dynamic diagnosis of early gastric cancer with microvascular blood flow rate using magnifying endoscopy (with video): A pilot study.

BACKGROUND AND AIM: Magnifying endoscopy (ME) diagnostic algorithm for early gastric cancer (EGC) relies on qualitative features such as microvascular (MV) architecture and microsurface structure; however, it is a "static" diagnostic algorithm that uses still images. ME can visualize red blood cell flow within subepithelial microvessels in real time. Here, we evaluated the utility of using the MV blood flow rate in combination with ME for the diagnosis of EGC as a retrospective study. METHODS: Patients with differentiated-type EGC (n = 10) or patchy redness (n = 10) underwent ME with blue laser imaging. The mean MV blood flow rates of EGC, patchy redness, and background mucosa were calculated by the mean movement distance of one tagging red blood cell using split images of ME with blue laser imaging videos. We compared the mean MV blood flow rate between EGC, patchy redness, and background mucosa and also calculated the MV blood flow imaging ratio (inside lesion/background mucosa) between EGC and patchy redness. RESULTS: Mean MV blood flow rate was significantly lower in EGC (1481 µm/s; range 1057-1762) than in patchy redness (3859 µm/s; 2435-5899) or background mucosa (4140.6 µm/s; 2820-6247) (P < 0.01). The MV blood flow imaging ratio was significantly lower in EGC (0.39; 0.27-0.62) than in patchy redness (0.90; 0.78-1.1) (P < 0.01). CONCLUSIONS: Dynamic diagnosis with MV blood flow rate using ME may be useful for the differential diagnosis of EGC and patchy redness. Endoscopic assessment of dynamic processes within the gastric mucosa may facilitate the diagnosis of EGC.

Synthesis of mesoscopic particles of multi-component rare earth permanent magnet compounds.

Multielement rare earth (R)-transition metal (T) intermetallics are arguably the next generation of high-performance permanent magnetic materials for future applications in energy-saving and renewable energy technologies. Pseudobinary Sm2Fe17N3 and (R,Zr)(Fe,Co,Ti)12 (R = Nd, Sm) compounds have the highest potential to meet current demands for rare-earth-element-lean permanent magnets (PMs) with ultra-large energy product and operating temperatures up to 200°C. However, the synthesis of these materials, especially in the mesoscopic scale for maximizing the maximum energy product ( B H m a x ), remains a great challenge. Nonequilibrium processes are apparently used to overcome the phase-stabilization challenge in preparing the R-T intermetallics but have limited control of the material's microstructure. More radical bottom-up nanoparticle approaches based on chemical synthesis have also been explored, owing to their potential to achieve the desired composition, structure, size, and shape. While a great achievement has been made for the Sm2Fe17N3, progress in the synthesis of (R,Zr)(Fe,Co,Ti)12 magnetic mesoscopic particles (MMPs) and R-T/T exchange-coupled nanocomposites (NCMs) with substantial coercivity ( H c ) and remanence ( M r ) , respectively, remains marginal.

Long-term relapse-free treatment with endoscopic submucosal dissection combined with magnifying narrow-band imaging for a pregnant patient with flat-type condyloma acuminatum: a case report.

Condyloma acuminatum, in the form of genital warts, usually results from an infection by human papillomavirus, one of the most common causes of sexually transmitted diseases. It develops after an incubation period of 3 weeks to 8 months after infection; flat lesions are significantly rare. Condyloma acuminatum is prevalent in the genitals, particularly in the anus of immunodeficient patients. This also occurs in women during menstrual period and pregnancy. Although a common treatment option for rectal and anal lesions, surgical resection is highly invasive and results in a high rate of recurrence. Recently, endoscopic submucosal dissection has been performed for anorectal lesions, but data on its long-term follow-up are not available. We report the case of an immunocompromised patient due to pregnancy who remained recurrence-free 27 months after en-bloc resection by endoscopic submucosal dissection, with adequate visualisation of the flat lesion's safety margin, combined with magnifying narrow-band imaging.

Multibending scope use for reduction of perforation risks in endoscopic submucosal dissection.

AIMS: To identify areas that are difficult to access by the single scope at the time of endoscopic submucosal dissection (ESD) and examine the effectiveness, en-bloc, R0 resection, and perforation rate after changing to multibending scope at the same site. MATERIAL AND METHODS: When the direct visualization of the submucosal layer became impossible with Q260J or in the position where the device became vertical and peeling became impossible in parallel, we decided to change to the multibending 2TQ260M scope to record the position where the change was effective and the perforation rate. RESULTS: A total of 315 lesions were studied. Of the 12 sites, ESD was completed using the Q260J alone at four sites. The 2TQ260M scope was used with greater frequency at the fornix (88.9%) and on the line of the lesser curvature of the stomach (37.1%). In the cases with observed perforations (0.9%), the submucosal layer was not elevated due to the adhesion caused by strong fibrosis. None of the cases involving the change to 2TQ260M was ineffective, nor were perforations observed, and all resected specimens were en-bloc and R0 resections. CONCLUSIONS: The success rate of this scope may help clinicians perform ESD with greater understanding.

Application of artificial intelligence using a convolutional neural network for diagnosis of early gastric cancer based on magnifying endoscopy with narrow-band imaging.

BACKGROUND AND AIM: Magnifying endoscopy with narrow-band imaging (ME-NBI) has made a huge contribution to clinical practice. However, acquiring skill at ME-NBI diagnosis of early gastric cancer (EGC) requires considerable expertise and experience. Recently, artificial intelligence (AI), using deep learning and a convolutional neural network (CNN), has made remarkable progress in various medical fields. Here, we constructed an AI-assisted CNN computer-aided diagnosis (CAD) system, based on ME-NBI images, to diagnose EGC and evaluated the diagnostic accuracy of the AI-assisted CNN-CAD system. METHODS: The AI-assisted CNN-CAD system (ResNet50) was trained and validated on a dataset of 5574 ME-NBI images (3797 EGCs, 1777 non-cancerous mucosa and lesions). To evaluate the diagnostic accuracy, a separate test dataset of 2300 ME-NBI images (1430 EGCs, 870 non-cancerous mucosa and lesions) was assessed using the AI-assisted CNN-CAD system. RESULTS: The AI-assisted CNN-CAD system required 60 s to analyze 2300 test images. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the CNN were 98.7%, 98%, 100%, 100%, and 96.8%, respectively. All misdiagnosed images of EGCs were of low-quality or of superficially depressed and intestinal-type intramucosal cancers that were difficult to distinguish from gastritis, even by experienced endoscopists. CONCLUSIONS: The AI-assisted CNN-CAD system for ME-NBI diagnosis of EGC could process many stored ME-NBI images in a short period of time and had a high diagnostic ability. This system may have great potential for future application to real clinical settings, which could facilitate ME-NBI diagnosis of EGC in practice.

Endoscopic and Clinicopathological Features of Superficial Non-Ampullary Duodenal Tumor Based on the Mucin Phenotypes.

AIMS: We aimed to clarify the endoscopic/clinicopathological features of superficial non-ampullary duodenal epithelial tumors (SNADETs) based on their mucin phenotypes. METHODS: We analyzed 62 SNADET lesions and classified them based on mucin phenotypic expression. Endoscopic and clinicopathological findings were compared according to mucin phenotypes. RESULTS: Eleven lesions had the gastric phenotype (GP) and 43 lesions had the intestinal phenotype (IP). All GP lesions were located in the first portion of the duodenum, while most IP lesions (72.1%) were located in the second portion (p < 0.01). Tumor size was significantly larger in the GP than in the IP group (14.4 mm vs. 10.2 mm, p < 0.05). Reddish color (72.7% in GP vs. 37.2% in IP, p < 0.05), type 0-I (72.7% vs. 11.6%, p < 0.01), lobular/granular pattern (81.8% vs. 4.7%, p < 0.01), and category 4/5 in Vienna classification (81.8% vs. 30.2%, p < 0.01) were observed significantly more often in the GP than in the IP group. Regarding findings of magnifying endoscopy with narrow-band imaging (M-NBI), white opaque substance (22.2% in GP vs. 89.7% in IP, p < 0.01) and light blue crest (0% vs. 43.6%, p < 0.05) were significantly less frequently observed in the GP group. Oval-shaped marginal epithelium (66.7% vs. 17.9%, p < 0.01), dense pattern (55.6% vs. 2.6%, p < 0.01), and dilatation of the intervening part (100% vs. 12.8%, p < 0.01) were more frequently observed in the GP group. CONCLUSIONS: SNADETs showed distinct endoscopic/clinicopathological features according to the mucin phenotype. Tumor location, coloration, macroscopic type, and endoscopic findings including M-NBI are useful to distinguish the mucin phenotypes of SNADETs.

Association between the severity of constipation and sarcopenia in elderly adults: A single-center university hospital-based, cross-sectional study.

The aim of the present study was to investigate the association between the severity of constipation and sarcopenia in elderly adults. We conducted a single-center university hospital-based, retrospective cross-sectional study of consecutive outpatients aged ≥65 years from 2017 to 2020. Patients were included in the study if all of the following information were available from medical records: Patient's profile (age, sex, body mass index), laxative/prokinetics use, evaluation of sarcopenia, nutritional status, and questionnaires concerning the severity of constipation [Constipation Scoring System (CSS)], abdominal symptom-related quality of life (QOL) (Izumo scale) and stool shape [Bristol Stool Form Scale (BSFS)]. Multiple regression analysis of risk factors for high CSS score was performed. The results revealed that of the 310 eligible study subjects, [149 men (48.1%) and 161 women (51.9%); mean age, 75.7±6.1 years; mean body mass index, 23.0±3.6 kg/m2], sarcopenia was noted in 83 cases (26.8%). The CSS score was significantly higher in the sarcopenia group than that noted in the non-sarcopenia group (4.9±4.9 vs. 3.6±3.6, P=0.009). The CSS score was significantly associated with the albumin level (r=-0.148), lymphocyte count (r=-0.118), CONUT score (r=0.130), reflux-related QOL score (r=0.155), upper abdominal pain-related QOL score (r=0.171), fullness-related QOL score (r=0.299), constipation-related QOL score (r=0.615), diarrhea-related QOL score (r=0.235) and BSFS score (r=-0.114). In multiple regression analysis, independent predictors for CSS score were sarcopenia [standardized partial regression coefficient (ß)=0.107, P=0.032], constipation-related QOL score (ß=0.537, P<0.001), laxative/prokinetics use (ß=0.211, P<0.001) and BSFS score (ß=-0.098, P=0.031) (R2=0.436). In conclusion, sarcopenia, constipation-related QOL score, laxative/prokinetics use and BSFS score are associated with the severity of constipation in elderly adults.

Clinicopathological and Endoscopic Features of Raspberry-Shaped Gastric Cancer in Helicobacter pylori-Uninfected Patients.

BACKGROUND: Gastric adenocarcinoma of foveolar type (GA-FV) is a raspberry-shaped gastric cancer (RSGC) and garners much attention as H. pylori (Hp)-uninfected gastric cancer. However, the classification and clinicopathological and endoscopic features of RSGCs in Hp-uninfected patients are poorly defined. We designed a new histopathological classification of RSGC and compared them via endoscopic and clinicopathological characteristics. SUMMARY: From 996 patients with early gastric cancers resected by endoscopy in our hospital, we studied 24 RSGC lesions from 21 (2.4%) Hp-uninfected patients. RSGCs were classified into 3 histological types as follows: GA-FV (n = 19), gastric adenocarcinoma of fundic gland type (GA-FG, n = 2), and gastric adenocarcinoma of fundic gland mucosa type (GA-FGM, n = 3). Most of the lesions were found at the greater curvature of the upper or middle third of the stomach. GA-FV lesions were homogeneously reddish and frequently accompanied with a whitish area around the tumor and an irregular microvascular (MV) pattern; these features were confirmed histopathologically by the presence of homogeneous neoplastic foveolar epithelium with foveolar hyperplasia around the tumors. GA-FG lesions might be heterogeneously reddish with a submucosal tumor shape and regular MV pattern; these were confirmed by the presence of covered or mixed nonneoplastic epithelium on deeper regions of tumors. GA-FGM lesions might be homogeneously reddish and occasionally had a submucosal tumor shape and irregular MV pattern; these were confirmed by the presence of homogeneous neoplastic foveolar epithelium on deeper regions of the tumors. Key Messages: RSGCs in Hp-uninfected patients are classified into 3 histopathological types. For accurate diagnosis of RSGCs, it may be necessary to fully understand endoscopic features of these lesions based on these histological characteristics and to take a precise biopsy.

Randomized controlled study on the effects of triple therapy including vonoprazan or rabeprazole for the second-line treatment of Helicobacter pylori infection.

BACKGROUND AND AIM: Inhibition of gastric acid secretion is important for eradicating Helicobacter pylori. Vonoprazan (VPZ) is a strong, long-lasting inhibitor of gastric acid secretion. Studies that examined the effectiveness of VPZ-based triple therapy in second-line treatment have been performed. However, there have been no randomized controlled studies to compare the effect between VPZ-based triple therapy and proton pump inhibitor (PPI)-based triple therapy in second-line treatment, and it is not known which is more effective between VPZ-based and PPI-based therapies. This study aimed to compare the effectiveness of second-line triple therapies including VPZ or rabeprazole (RPZ) as the PPI. METHODS: Eligible patients with H. pylori infection who failed first-line triple therapy were assigned randomly to the VPZ [VPZ40 mg/day, amoxicillin (AMPC) 1500 mg/day, metronidazole (MNZ) 500 mg/day] or RPZ (RPZ20 mg/day, AMPC1500 mg/day, MNZ500 mg/day) group. A 13C-urea breath test result of less than 2.5% was considered as successful eradication. RESULTS: In total, 46 and 41 patients were analyzed as intention to treat (ITT) and per protocol (PP), respectively. Eradication rates in the VPZ and RPZ groups were 73.9% [95% confidence interval (CI) 51.6-89.8%] and 82.6% (95% CI 61.2-95.0%) based on ITT analysis, respectively (p = 0.72). Based on PP analysis, the eradication rates in the VPZ and RPZ groups were 89.5% (95% CI 66.9-98.7%) and 86.4% (95% CI 65.1-97.1%), respectively (p = 1.00). Two patients in the VPZ group and one in the RPZ group discontinued treatment due to side effects (p = 1.00). CONCLUSION: There were no significant differences in efficacy and safety between second-line therapies including VPZ or RPZ.

Diagnostic limitations of magnifying endoscopy with narrow-band imaging in early gastric cancer.

Background and study aims Magnifying endoscopy with narrow band imaging (M-NBI) has made a huge contribution to endoscopic diagnosis of early gastric cancer (EGC). However, we sometimes encountered false-negative cases with M-NBI diagnosis (i. e., M-NBI diagnostic limitation lesion: M-NBI-DLL). However, clinicopathological features of M-NBI-DLLs have not been well elucidated. We aimed to clarify the clinicopathological features and histological reasons of M-NBI-DLLs. Patients and methods In this single-center retrospective study, M-NBI-DLLs were extracted from 456 EGCs resected endoscopically at our hospital. We defined histological types of M-NBI-DLLs and analyzed clinicopathologically to clarify histological reasons of M-NBI-DLLs. Results Of 456 EGCs, 48 lesions (10.5 %) of M-NBI-DLLs were enrolled. M-NBI-DLLs was classified into four histological types as follows: gastric adenocarcinoma of fundic-gland type (GA-FG, n = 25), gastric adenocarcinoma of fundic-gland mucosal type (GA-FGM, n = 1), differentiated adenocarcinoma (n = 14), and undifferentiated adenocarcinoma (n = 8). Thirty-nine lesions of M-NBI-DLLs were H. pylori -negative gastric cancers (39/47, 82.9 %). Histological reasons for M-NBI-DLLs were as follows: 1) completely covered with non-neoplastic mucosa (25/25 GA-FG, 8/8 undifferentiated adenocarcinoma); 2) well-differentiated adenocarcinoma with low-grade atypia (1/1 GA-FGM, 14/14 differentiated adenocarcinoma); 3) similarity of surface structure (10/14 differentiated adenocarcinoma); and 4) partially covered and/or mixed with a non-neoplastic mucosa (1/1 GA-FGM, 6/14 differentiated adenocarcinoma). Conclusions Diagnostic limitations of M-NBI depend on four distinct histological characteristics. For accurate diagnosis of M-NBI-DLLs, it may be necessary to fully understand endoscopic features of these lesions using white light imaging and M-NBI based on these histological characteristics and to take a precise biopsy.