尾﨑 隼人

Objective In general, surface ulceration in gastric gastrointestinal stromal tumor (GIST) is considered a malignant feature; however, the mechanism underlying its formation has not been evaluated in detail. In this study, we analyzed the factors involved in ulceration using resected specimens of gastric GIST. Methods A total of 48 samples were retrospectively analyzed. We examined the association of surface ulceration of gastric GIST with the MIB-1 labeling index, mitotic number, tumor size, endoscopic ultrasound (EUS) findings and growth pattern on computed tomography (CT). Results The proportion of men was significantly higher in the ulceration group than in the non-ulceration group (p=0.04146), whereas age was not significantly different between the groups. Tumor was significantly larger in the ulceration group than in the non-ulceration group (p=0.0048). There was no correlation between tumor size and ulcer number. The MIB-1 index was not related to ulceration, nor were EUS findings. The number of mitotic cells tended to be higher in the ulceration group than in the non-ulceration group (p=0.05988). Intraluminal growth pattern was strongly associated with ulceration (p=0.00019). After a multivariate analysis, the growth pattern was the only factor associated with ulceration of gastric GIST. Conclusion Although formation of surface ulceration in gastric GIST was partially associated with the degree of malignancy, the growth pattern was the most important factor associated with ulceration in gastric GIST.

BACKGROUND: The management of bleeding during endoscopic submucosal dissection (ESD) is critical and related to the procedure time. We collaborated on a new image enhancement algorithm with parameter optimization for clinical use being developed by FUJIFILM Co. and processed white light image data offline to evaluate the effectiveness of this technology. This study aims to evaluate the clinical usefulness of this technology. METHODS: Eighteen video scenes of bleeding points from 5 gastric ESDs were selected and processed by the new image enhancement algorithm. The time until a bleeding point was found, visibility of a bleeding point and color abnormality of the submucosal layer were evaluated by ESD experts, ESD trainees, and endoscopy trainees. The color differences between the bleeding point and the surroundings in CIE- L*a*b* color space were calculated in the original and enhanced images. RESULTS: The time until a bleeding point was found in the enhanced videos was significantly shorter than that in the original videos (11.10 seconds vs. 13.85 seconds) (P=0.017). On a 5-point (-2 to +2) Likert scale of visibility, the enhanced image was slightly superior to the original (+0.45), and the appearance of the submucosa was comparable between images (+0.14). The color difference among the bleeding areas on the enhanced images were significantly larger than that on the original images (10.93 vs. 8.36). CONCLUSION: This novel image enhancement algorithm emphasizes the color difference between a bleeding point and the surrounding area, which would help find bleeding points faster during ESD for the less experienced endoscopists.

Gastric endoscopic submucosal dissection (ESD) is increasingly performed in patients receiving antithrombotic therapy. Second-look endoscopy (SLE) has been performed empirically in several clinical settings. We investigated whether SLE omission was associated with an increased risk of postESD bleeding in all patients, including those administered antithrombotic agents. Between July 2016 and June 2018, 229 patients were treated with a clinical pathway for gastric ESD that involved SLE on the day after ESD (SLE group). Between September 2018 and May 2020, 215 patients were treated using a clinical pathway that did not include SLE (nonSLE group). We retrospectively compared the incidence of postESD bleeding among the propensity score-matched cohorts and determined the risk factors for postESD bleeding using multivariate analysis. The propensity score-matched cohorts showed no significant differences in the incidence of postESD bleeding between the SLE (3.2%) and nonSLE (5.1%) groups. Multivariate analysis revealed that the presence of lesions in the lower gastric body (adjusted odds ratio [OR] 2.17, 95% confidence interval [CI] 1.06-4.35, P.03) was a significant risk factor for postESD bleeding during admission, whereas resected specimen size ≥ 40 mm (adjusted OR 3.21, 95% CI 1.19-8.19, P.02) and antiplatelet therapy (adjusted OR 4.16, 95% CI 1.47-11.80, P.007) were significant risk factors after discharge. Complete omission of SLE after gastric ESD does not increase postESD bleeding in clinical practice.

Recurrent Clostridioides difficile infection (rCDI) is a frustrating condition that may affect a person's quality of life for months. Microbiome-based therapy such as fecal microbiota transplantation (FMT) has been effective for the treatment of rCDI by correcting the imbalance of the gut microbiota. Appropriate antibiotic treatment is recommended for at least two recurrences before offering FMT. Here, we report the case of a 92-year-old woman who experienced five recurrences of Clostridioides difficile infection (CDI) (six episodes in total) complicated by dementia and delirium, both of which were dramatically improved by FMT, which was associated with alterations in fecal microbiota and the metabolome. Analyses of whole microbial communities and metabolomic analyses were performed on stool specimens collected from the patient on the first episode, the third episode, the day of FMT (before FMT), and 2, 8, and 23 weeks after the FMT and from the donor. The patient had various fecal dysbioses on the first and third episodes and on the day of FMT. Two weeks after FMT, diversity of the gut bacteriome as well as the virome increased dramatically and was reflected in a positive clinical outcome for this patient. Metabolomic analysis revealed that short-chain fatty acids, which have been reported to be associated with improved memory function, were increased after FMT.