Keiko Yamamoto

Goals: We identified prognostic factors for mortality after Suspected small bowel bleeding (SSBB) and evaluated the impact of severe anemia and other clinical factors on patient survival. Background: SSBB is characterized by an inability to identify the cause of bleeding despite esophagogastroduodenoscopy and colonoscopy. Study: This retrospective observational study included patients aged ≥20 years with SSBB who underwent capsule endoscopy (CE) at Hokkaido University Hospital in Japan from April 2015 to March 2022. Patient characteristics, blood transfusion history, CE results, blood test results, and post-CE mortality events were collected from electronic medical records. Results: CE was performed in 99 patients to investigate the causes of SSBB, identifying bleeding sources in 40.4%. Over a median follow-up of 35 months (range: 0 to 94), mortality occurred in 34 cases. The overall 3-year survival rate was 71.1%. Multivariate analysis identified hemoglobin levels HR )=9.75; 95% CI: 1.26-75.15; P =0.003] and end-stage cancer ( HR =4.94; 95% CI: 2.02-12.10; P HR =5.07; 95% CI: 1.10-23.03; P =0.037) remained an independent predictor of mortality. The overall 5-year survival rates for patients without small bowel tumors and end-stage cancer in the groups with hemoglobin levels of ≥8.0 g/dL and <8.0 g/dL were 89.0% and 56.8%, respectively. Conclusion: Hemoglobin levels <8.0 g/dL significantly predict mortality in patients with SSBB.

Background There is a consensus that identifying the distal end of the palisade vessels (DEPV) is important for diagnosing gastroesophageal junction (GEJ). However, optimum observation methods have not been established. This study investigated the use of effective image-enhanced endoscopy (IEE) for DEPV detection. Methods One hundred endoscopic images in 20 cases of columnar metaplastic mucosa of the GEJ recorded with white-light imaging (Olympus-WLI and Fujifilm-WLI) and IEEs (narrow-band imaging; RDI1/2/3, red dichromatic imaging; texture and color enhancement imaging 1/2; blue-laser imaging; and LCI, linked color imaging) from two manufacturers were extracted and evaluated by 10 evaluators. Up to 24 radial straight lines from the center of the lumen were placed on the image, and the evaluators placed markings according to confidence level (high, low, and not detectable) at the DEPV locations. The detectability and reproducibility at the rate of the confidence level and coefficient of variance of markings among the evaluator were analyzed. Results In total, 15,180 markings were obtained. In terms of detectability, RDI1 (49.4%), RDI2 (53.0%), RDI3 (54.1%), TXI2 (49.7%), and LCI (34.6%) had a significantly higher rate of high confidence among the IEEs in each manufacturer. By contrast, Olympus-WLI (40.6%), Fujifilm-WLI (17.6%), narrow-band imaging (15.9%), and blue laser imaging (9.8%) presented with a significantly lower rates of high confidence. Regarding reproducibility, RDI3 and LCI had the lowest coefficient of variance for each manufacturer. Conclusions RDI and LCI could be reliable modalities for detecting DEPVs in the columnar metaplastic mucosa of the GEJ zone.

Background Anastomotic leakage (AL) after gastrointestinal surgery remains a challenging complication that requires surgical or non-surgical treatment. Although various therapeutic endoscopic techniques are available, no definitive interventions exist. We developed a therapeutic endoscopic submucosal injection method using novel gel-forming mixed solutions to close AL and evaluated the elasticity of the developed hydrogel. The safety and efficacy of the injection method were explored in porcine AL models. Methods We developed a novel gel-forming solution, and the formed gel lasted approximately one week within the gastrointestinal wall. An indentation test evaluated the elasticity of the novel hydrogel. After the confirmation of AL on porcine anterior gastric walls, sodium alginate was endoscopically injected into the submucosal layer around the leakage site circularly, followed by a calcium lactate/chitosan-based solution. After that, the outcomes data were collected, and histopathological effectiveness was evaluated. Results The increased sodium alginate elasticity with the addition of calcium lactate/chitosan-based solution facilitated long-lasting gel formation. Four pigs with AL underwent this intervention consecutively. Each endoscopic injection was completed in less than 5 min. No significant complications were observed for 3 weeks after the intervention. All AL sites were macroscopically healed. Histopathologic findings at 3 weeks showed that the wall defect was filled with collagen fibers that had grown around the site of the muscle layer tear. No tissue necrosis was observed. Conclusion This preclinical study demonstrated that the therapeutic injection method for gastroenterological AL using gel-forming solutions could be an alternative endoscopic treatment, especially in patients with severe conditions or comorbidities. The optimal target of this treatment is small size and early AL without poor blood flow or intense hypertrophic scar lesions.

Multiple development of esophageal squamous-cell carcinoma is explained by field cancerization and is associated with alcohol consumption and smoking. We investigated the association between the development of second primary esophageal squamous-cell carcinoma after endoscopic resection for esophageal squamous-cell carcinoma and genetic polymorphisms related to alcohol and nicotine metabolism. The study group comprised 56 patients with esophageal squamous-cell carcinoma after endoscopic resection. The main variables were the following: (i) cumulative incidence and total number of second primary esophageal squamous-cell carcinoma according to genetic polymorphisms in alcohol dehydrogenase 1B, aldehyde dehydrogenase 2 and cytochrome P450 2A6; and (ii) risk factors of second primary esophageal squamous-cell carcinoma identified using a multivariate Cox proportional-hazards model. The frequencies of alcohol dehydrogenase 1B, aldehyde dehydrogenase 2 and cytochrome P450 2A6 genetic polymorphisms in the buccal mucosa were analyzed. The median follow-up was 92.8 months (range: 2.7–134.2). Slow-metabolizing alcohol dehydrogenase 1B was associated with a higher 7-year cumulative incidence of second primary esophageal squamous-cell carcinoma (fast-metabolizing alcohol dehydrogenase 1B vs slow-metabolizing alcohol dehydrogenase 1B: 20.5% vs 71.4%, P = 0.006). Slow-metabolizing alcohol dehydrogenase 1B (relative risk [95% confidence interval]: 3.17 [1.49–6.73]), inactive aldehyde dehydrogenase 2 (2.17 [1.01–4.63]) and poorly-metabolizing cytochrome P450 2A6 (4.63 [1.74–12.33]) had a significantly higher total number of second primary esophageal squamous-cell carcinoma per 100 person-years. In the multivariate Cox proportional-hazards model, slow-metabolizing alcohol dehydrogenase 1B was a significant risk factor of the development of second primary esophageal squamous-cell carcinoma (hazard ratio 9.92, 95% confidence interval: 2.35–41.98, P = 0.0018). Slow-metabolizing alcohol dehydrogenase 1B may be a significant risk factor for the development of second primary esophageal squamous-cell carcinoma. In addition, inactive aldehyde dehydrogenase 2 and poorly-metabolizing cytochrome P450 2A6 may be important factors.

Background and Aim: Optical biopsy using endocytoscopy for superficial nonampullary duodenal epithelial tumors (SNADETs) is practical; however, a diagnostic algorithm has not been established. The aim of this study was to determine correlations of endocytoscopic findings of SNADETs with histology using computer analysis and to establish an algorithm.Methods: Endocytoscopic images and histological images of duodenal lesions from 70 patients were retrospectively collected. The numbers of glands and densely stained areas with methylene blue (DSMs) per 1 mm² and the percentage of DSMs per screen in endocytoscopy were determined. Moreover, correlations in DSMs and glands between endocytoscopy and histological images were analyzed. Histopathological diagnoses were assessed according to the revised Vienna classification. The primary outcome was correlation between the number of glands in endocytoscopy and that in histology. Finally, a diagnostic algorithm for endoscopic intervention of SNADETs with a statistical program command was established.Results: The number of glands in endocytoscopic images was correlated with that in histopathological images (ρ 0.64, P < 0.001). There were significant differences in the mean number of glands between category 4/5 and category 3 (P = 0.03) and the mean percentage of DSMs between category 4/5 and category 1 (P < 0.001). When the cutoffs for the number of glands and percentage of DSMs were set at 47 per 1 mm² and 20.8% in one screen, respectively, the area under the ROC curve was 0.89.Conclusions: Endocytoscopic images of SNADETs reflect histopathological atypia, and computer analysis provides a practical diagnostic algorithm for endoscopic intervention.

The emergence of primary and acquired treatment resistance significantly reduces the clinical utility of many effective targeted therapies. Both genetic and epigenetic mechanisms of drug resistance have been reported in literature; however, whether these mechanisms are stochastically selected in individual tumors or governed by a predictable underlying principle is unknown.Here, we report that one can predict a priori the resistance mechanism that will arise in individual SMO inhibitor (SMOi)-resistant SHH medulloblastoma (MB), based on different CSC phenotypes in each tumor. We show that the dependence of cancer stem cells (CSCs), not bulk tumor cells, on the targeted pathway (sonic hedgehog (SHH) pathway) determines the molecular mechanism of resistance in individual tumors. Using both spontaneous (Fsmo;GFAP-cre) and transplantable (Ptch+/-;p53) mouse models of SHH MB treated with a Smoothened inhibitor, sonidegib/LDE225, we show that genetic-based resistance occurs only when the CSCs depend on the targeted pathway. In contrast, SHH MBs containing SHH-dependent bulk tumor cells but SHH-independent CSCs (SI-CSCs), acquire resistance through epigenetic reprogramming. Mechanistically, we discovered that the elevated proteasome activity in SMOi-resistant SI-CSC MBs alters the tumor cell maturation trajectory through enhanced degradation of specific epigenetic regulators, including the histone acetylation machinery. Consequently, SMOi-resistant SI- SMOi-resistant SI-CSC exhibit a global reduction of H3K9Ac, H3K14Ac, H3K56Ac, H4K5Ac, and H4K8Ac marks and gene expression changes. These results provide new insights into how selective pressure on distinct tumor cell populations contributes to different mechanisms of resistance to targeted therapies and implicate histone acetylation in the process. This information can be clinically exploited to understand responses and resistance to SMOis and other targeted therapies. Citation Format: Joshy George, Yaohui Chen, Nourhan Abdelfattah, Keiko Yamamoto, Scott Adamson, Jong Min Choi, Brad Rybinski, Anuj Srivastava, Parveen Kumar, Min Gyu Lee, David S. Baskin, Wen Jiang, Betty Y. Kim, William Flavahan, Jeffrey H. Chuang, Sung Yun Jung, Kyuson Yun. Cancer stem cells, not bulk tumor cells, predict mechanisms of resistance to SMO inhibitors in SHH medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3961.

Ono S, et al. J Gastric Cancer. 2022 Feb;22:e2. https://doi.org/10.5230/jgc.2022.22.e2

Introduction: Animal tests of cosmetic ingredients and products have been banned in the EU since 2013. However, in Japan, the application of new quasi-drugs requires the generation of 24-hour data on primary and cumulative skin irritation by animal testing. Such data are unreliable because an ingredient predicted as nonirritating after short exposure (4 hours), based on the Organization for Economic Co-operation and Development (OECD) test guidelines (TG)404, may cause irritation after a longer application period in human skin irritation tests. With insufficient data to draw conclusions about the irritation potential of an ingredient, there remains a high probability of skin irritation occurrence after extended exposure to the ingredient. Materials and Methods: This study assessed whether the skin irritation caused by quasi-drugs and cosmetic products can be evaluated in a step-by-step manner. Results: A workflow was developed considering several key steps such as the component characteristics based on physicochemical properties or the ingredient category based on existing information from animal tests and human patch test results, and its utility was assessed using the reconstructed human epidermis (RhE) test (OECD TG439), animal testing, the human patch test, and the human cumulative skin irritation test. Conclusion: The RhE test and the aforementioned human skin tests can be employed to evaluate test substances that cause weak or nonskin irritation categorized as “harmless ingredients”—thereby avoiding animal testing.

The most likely cause of lower-leg swelling is prolonged sitting, which sometimes induces deep vein thrombosis, also known as, economy class syndrome. We aimed to clarify the influence of intake of 4^G-α-glucopyranosyl hesperidin (G-Hsp) beverage on the lower-leg swelling caused by 6 h of sitting in six healthy women. All subjects ingested 100 mL of G-Hsp or Placebo beverages with 100 mL of mineral water after 10 min of rest in a chair. Subsequently, subjects were requested to sit in the chair in a relaxed position for 6 h with two breaks to walk for urination. Calf water content measured by impedance plethysmography, calf circumference, and calf skin temperature by infrared thermography were measured, along with assessment of calf swelling sensation on a visual analog scale. Increase in ankle % circumference was significantly less after the G-Hsp ingestion (101.8 ± 1.5%) than after placebo (103.3 ± 0.8%; P = 0.004). A significant difference was found between percent circumference after the G-Hsp and the placebo, that is, the calf swelling after the placebo was significantly larger (P = 0.043). A gradual increase in skin temperature at the lower limb was observed after G-Hsp ingestion, while there was no change after placebo. Gravity-induced calf and ankle swelling resulted by prolonged sitting can be ameliorated by oral ingestion of hesperidin-derived G-Hsp through production of nitric oxide. It might be helpful in preventing economy-class syndrome caused by enforced sitting for a long duration.

Background: It is still difficult to detect and diagnose early adenocarcinoma of the esophagogastric junction (EGJ) using conventional endoscopy or image-enhanced endoscopy. A glutamylprolyl hydroxymethyl rhodamine green (EP-HMRG) fluorescent probe that can be enzymatically activated to become fluorescent after the cleavage of a dipeptidyl peptidase (DPP)-IV-specific sequence has been developed and is reported to be useful for the detection of squamous cell carcinoma of the head and neck, and esophagus; however, there is a lack of studies that focuses on detecting EGJ adenocarcinoma by fluorescence molecular imaging. Therefore, we investigated the visualization of early EGJ adenocarcinoma by applying EP-HMRG and using clinical samples resected by endoscopic submucosal dissection (ESD).Methods: Fluorescence imaging with EP-HMRG was performed in 21 clinical samples resected by ESD, and the fluorescence intensity of the tumor and non-tumor regions of interest was prospectively measured. Immunohistochemistry was also performed to determine the expression of DPP-IV.Results: Fluorescence imaging of the clinical samples showed that the tumor lesions were visualized within a few minutes after the application of EP-HMRG, with a sensitivity, specificity, and accuracy of 85.7, 85.7, and 85.7%, respectively. However, tumors with a background of intestinal metaplasia did not have a sufficient contrast-to-background ratio since complete intestinal metaplasia also expresses DPP-IV. Immunohistochemistry measurements revealed that all fluorescent tumor lesions expressed DPP-IV.Conclusions: Fluorescence imaging with EP-HMRG could be useful for the detection of early EGJ adenocarcinoma lesions that do not have a background of intestinal metaplasia.