Publications by authors named "Akira Imatani"

Background: The patients taking direct oral anticoagulants (DOACs) are at high risk for developing ischemic stroke and delayed bleeding in upper gastrointestinal endoscopic submucosal dissection (ESD). We aimed to identify the optimal DOAC based on both adverse events in upper gastrointestinal ESD.

Methods: A retrospective population-based cohort study was conducted using the Diagnosis Procedure Combination database in Japan.

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A 68-year-old woman was diagnosed with leiomyosarcoma (LMS) based on preoperative biopsy of the gastric body. As tumor invasion confined to the submucosa with no breaking of the submucosal layer was confirmed on endoscopic ultrasonography (EUS), the patient underwent endoscopic submucosal dissection (ESD) for gastric LMS, resulting in complete tumor resection. No apparent recurrence was observed in the 2.

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Chronic infection of is considered the principal cause of gastric cancers, but evidence has accumulated regarding the impact of tobacco smoking and alcohol consumption on the development of gastric cancers. Several possible mechanisms, including the activation of nicotinic acetylcholine receptors, have been proposed for smoking-induced gastric carcinogenesis. On the other hand, local acetaldehyde exposure and ethanol-induced mucosal inflammation have been proposed as the mechanisms involved in the development of gastric cancers in heavy alcohol drinkers.

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Article Synopsis
  • Endoscopic hemostasis is crucial for treating gastrointestinal bleeding but traditionally involves high-risk training on real patients; a new simulator, "Medical Rising STAR-Ulcer type," offers a safer practice option.
  • A study with 50 gastroenterology residents showed significant improvements in success rates for clipping hemostasis after simulation training, with rates rising from 64% to 86%.
  • Trainees reported enhanced self-confidence and proficiency post-training, appreciating structured learning while also noting some limitations of the simulator and the importance of ongoing skill development.
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  • ERCP (Endoscopic Retrograde Cholangiopancreatography) and EST (Endoscopic Sphincterotomy) are critical but risky procedures, highlighting the need for safer training methods, particularly for inexperienced learners.
  • A new simulator model was created to help trainees practice these procedures using real endoscopic tools and aligned with skills assessed by the Bethesda ERCP Skill Assessment Tool (BESAT).
  • The simulator received positive feedback from 30 gastroenterology trainees, showing a significant increase in satisfaction after use, indicating its effectiveness in enhancing training experiences.
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Background: Recent epidemiological studies suggested correlation between gastric cancer (GC) and periodontal disease.

Aims: We aim to clarify involvement of lipopolysaccharide of Porphyromonas gingivalis (Pg.), one of the red complex periodontal pathogens, in the GC development.

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Objective The use of a proton pump inhibitor (PPI) reduces rebleeding and mortality in patients with upper gastrointestinal bleeding (UGIB). Vonoprazan is a novel oral agent with strong and sustained acid-inhibitory activity. We clarified the effect of vonoprazan compared with oral PPIs in such patients.

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The expression of T-box transcription factor 3 (TBX3) has been identified in various cancers, including gastric cancers. Its role in breast cancers and melanomas has been intensively studied, and its contribution to the progression of cancers through suppressing senescence and promoting epithelial-mesenchymal transition has been reported. Recent reports on the role of TBX3 in gastric cancers have implied its involvement in gastric carcinogenesis.

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Unlabelled: Aging is a risk factor for cancers in various organs. Recent advances in the organoid culturing system have made it viable to investigate the influence of aging utilizing these mini organs. In this study, we aimed to examine the implications of aging for gastric carcinogenesis.

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Some patients present gastro-duodenal eosinophilia without abdominal symptoms. Nine cases with gastro-duodenal eosinophilia were seen at the Tohoku University Hospital between January 2011 and June 2022. Seven (78%) patients had a background of allergic or hyper-eosinophilic disease.

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An unidentified cause of functional dyspepsia (FD) is closely associated with medication resistance. Acid suppression is a traditional and preferential method for the treatment of FD, but the efficacy of this treatment varies between epigastric pain syndrome (EPS) and postprandial syndrome (PDS): it is efficient in the former but not much in the latter. Transepithelial electrical resistance (TEER), a surrogate of mucosal barrier function, was measured under pH 3 and pH 5 acidic conditions using duodenal biopsy specimens obtained from the patients with EPS and PDS and asymptomatic healthy controls.

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Aging is considered a risk factor for various diseases including cancers. In this aging society, there is an urgent need to clarify the molecular mechanisms involved in aging. Wnt signaling has been shown to play a crucial role in the maintenance and differentiation of tissue stem cells, and intensive studies have elucidated its pivotal role in the aging of neural and muscle stem cells.

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  • The study investigates how alcohol consumption may contribute to the development of esophageal squamous cell carcinoma (ESCC) by examining the role of NRF2, a protective factor against cancer, in the esophageal mucosa.
  • Researchers analyzed biopsy samples from 20 ESCC patients and 20 patients without ESCC to compare the effects of acetaldehyde and ethanol exposure on mRNA levels of NRF2 target genes and transepithelial electrical resistance (TEER).
  • Results indicated that while TEER did not significantly change between groups, mRNA levels of NRF2 target genes decreased more in ESCC patients after alcohol exposure, particularly among those with certain genetic and clinical risk factors, suggesting a disruption in NRF2's protective role related to
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  • Endoscopic submucosal dissection (ESD) is a minimally invasive method for treating upper gastrointestinal tumors, but it can lead to serious complications like intraoperative perforation and delayed bleeding.
  • To prevent these complications, techniques like traction-assisted ESD and the use of prediction models (BEST-J score) for delayed bleeding have been developed, along with the medication vonoprazan.
  • Despite advancements, duodenal ESD remains challenging due to higher complication rates, necessitating improved devices, specific techniques for prevention, and ongoing research for standardization.
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A 69-year-old woman with multiple neuroendocrine neoplasms (NENs) was referred to our hospital. Although she had extreme hypergastrinemia (11,675 pg/mL), no findings that indicated types I to III gastric NENs were found. Although gastric corpus atrophy was suspected on conventional white-light imaging, findings on magnifying endoscopy with narrow-band imaging indicated no severe atrophy.

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Blue light imaging (BLI) and narrow-band imaging (NBI) are two modalities that enable narrow-band light observation. We aimed to compare the diagnostic ability of magnifying endoscopy with BLI (ME-BLI) and NBI (ME-NBI) for determining the invasion depth of superficial esophageal squamous cell carcinoma (SESCC) by the Japanese Esophageal Society's intrapapillary capillary loop (IPCL) classification. We enrolled 81 patients between 2014 and 2018, and the still endoscopic images for diagnosing the invasion depth at the same part in ME-BLI and ME-NBI were registered.

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Barrett's esophagus arises in the process of wound healing in distal esophageal epithelium damaged by gastroesophageal reflux disease. Differentiation of fibroblast into myofibroblasts, a smooth muscle cell-like phenotype and tissue contraction are crucial processes in wound healing. No study has evaluated mechanism by which luminal esophageal nitric oxide (NO) affect Rho-associated coiled coil-forming protein kinase (Rho-ROCK) signaling pathway, a key factor of tissue contraction, in stromal fibroblasts to develop Barrett's esophagus.

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Objective Linked-color imaging (LCI), a new technology for image-enhanced endoscopy, emphasizes the color of the mucosa, and its practicality in the detection of early gastric and colon cancers has been reported. However, whether or not LCI is useful for the diagnosis of Barrett's adenocarcinoma (BA) has been unclear. In this study, we explored whether or not LCI enhances the color difference between a BA lesion and the surrounding mucosa.

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Objectives: Although many patients with early gastric cancers (EGCs) die of non-gastric cancer-related causes, the association of the risk categories of lymph node metastasis (LNM) with all-cause mortality remains unclear. We aimed to clarify the predictors of early and late mortality, separately.

Methods: Patients with endoscopic resection or gastrectomy for EGCs between 2003 and 2017 were retrospectively enrolled.

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Background: With the ongoing growth of the aged population, the number of elderly patients suffering from gastric cancer has increased in Japan. Since the frequency of lymph node metastasis (LNM) in patients after endoscopic submucosal dissection (ESD) with endoscopic curability (eCura) C-2 for early gastric cancer (EGC) is relative low, the following question can be raised: "Is additional gastrectomy required for elderly patients with such criteria for ESD?"

Summary: For therapeutic decision-making after ESD with eCura C-2, the risk of all-cause mortality and impaired quality of life (QoL) should thus be evaluated. Risk stratification of LNM and gastric cancer-specific mortality was established by the eCura system; however, it remains unclear how much these categories and treatment selection affect all-cause mortality.

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Background: Delayed bleeding is the major adverse event in upper gastrointestinal endoscopic treatment (UGET). We aimed to investigate the efficacy of vonoprazan, which is the novel strong antisecretory agent, to reduce the risk for delayed bleeding in comparison with proton pump inhibitors (PPIs) in UGET.

Methods: This retrospective population-based cohort study used the Diagnosis Procedure Combination database in Japan.

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A 66-year-old man with a history of diabetes and dilated cardiomyopathy underwent the implantation of a ventricular assist device (VAD) at the age of 62. He suffered from epigastralgia for a month and then visited our hospital with complaints of severe epigastralgia and hematemesis. A physical examination revealed abdominal distension without rigidity.

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In esophageal squamous cell carcinoma (ESCC) comprising 90% of cases with esophageal cancer, endoscopic resection (ER) is recommended for patients with negligible risk of ESCC-related mortality. In fact, a main cause of death in patients underwent ER is not ESCC. We thus aimed to clarify the predictors for early and late mortality among patients underwent ER of ESCC between 2005 and 2018 at our institution.

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A 72-year-old man without any symptoms was referred to our hospital. Esophagogastroduodenoscopy revealed an elevated esophageal lesion that was covered with normal mucosa. The examination of biopsy specimens from the lesion revealed amyloid light-chain (AL) (λ) type amyloid deposits, but there were no amyloid deposits elsewhere in the gastrointestinal tract.

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