Ulcerative colitis-associated neoplasms often harbor poor prognostic histologic components with low detection by biopsy.

Background/Aims: Poorly differentiated adenocarcinoma, signet-ring cell carcinoma, and mucinous adenocarcinoma (por/sig/muc), which are considered to be histologic subtypes with a poor prognosis, occur more frequently with colitis-associated cancer than with sporadic tumors. However, their invasiveness and manifestations are unclear. This study aimed to determine the prevalence of the por/sig/muc component in ulcerative colitis-associated neoplasms (UCANs) and its association with invasiveness and to clarify its clinicohistologic and endoscopic features. Methods: This retrospective observational study included patients diagnosed with ulcerative colitis-associated high-grade dysplasia or adenocarcinoma from 1997 to 2022 who were divided according to the presence or absence of a por/sig/muc component. Results: Thirty-five patients had UCAN with a por/sig/muc component and 66 had UCAN without this component. The 5-year survival rate was significantly lower in the por/sig/muc group than in the tub group (67% vs. 96%, P= 0.001), which was attributed to disease above stage III and depth to below the subserosa. Biopsy-based diagnosis before resection detected a por/sig/muc component in only 40% of lesions (14/35). Lesions with a por/sig/muc component were prevalent even in the early stages: stage 0 (4/36, 11%), I (8/20, 40%), II (7/12, 58%), III (10/14, 71%), and IV (6/8, 75%). Conclusions: This is the first investigation that shows UCANs with a por/sig/muc component tended to be deeply invasive and were often not recognized preoperatively. Endoscopists should be aware that UCAN often has a por/sig/muc component that is not always recognized on biopsy, and the optimal treatment strategy needs to be carefully considered.

Organoid Medicine for Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting inflammatory disease of the gastrointestinal tract with an unknown etiology, and its incidence is increasing worldwide. Recent advances in immunomodulatory therapeutic agents such as biologics and small-molecule inhibitors have improved the prognosis of patients with IBD. However, some patients are refractory and resistant to these immunomodulatory therapies, and new therapies are needed. Given the importance of the intestinal epithelium in IBD pathogenesis, the difficulty of culturing intestinal epithelial cells (IECs) for long periods remains an obstacle in IBD research. Over the past 15 years, intestinal stem cells have been identified, and the in vivo microenvironment, called the niche, required for their maintenance has been elucidated, making the permanent culture of IECs possible. Recapitulating the niche in vitro, the intestinal epithelium forms 3-dimensional structures called organoids that simulate the intestinal epithelium in vivo. The intestinal epithelium plays an important role in the intestinal barrier and immunomodulatory functions and serves as a physical structure that separates the intestinal lumen from the body. Recent studies have revealed that functional disruption of the intestinal epithelium is closely related to the pathogenesis of IBD, and IBD research using organoids has attracted attention. In this review, we discuss the application of adult tissue-derived organoids culture technology to elucidate the pathogenesis of IBD and to develop novel therapies, including regenerative treatments.

Visible-Light-Responsive Oxyhalide PbBiO2Cl Photoelectrode: On-Site Flux Synthesis on a Fluorine-Doped Tin Oxide Electrode.

The performance of photoelectrodes is hugely affected by the preparation method. Although a flux synthesis is useful to endow semiconductor particles with the desired properties such as high crystallinity, there are only a few reports on its application to photoelectrode fabrication, probably because relatively high temperatures are necessary. In the present study, we introduce a new concept for on-site flux synthesis of semiconductor crystals on a commonly used fluorine-doped tin oxide (FTO) substrate; a seed layer is predeposited and then treated with an appropriate flux containing other required elements at a right temperature lower than the limit temperature of FTO but sufficiently high to transform the seed layer to the target material with the aid of flux. Here, an oxyhalide PbBiO2Cl, one of the promising semiconductors for achieving visible-light water splitting, is selected as a target material. Combination of a BiOCl seed layer and the NaCl-PbCl2 flux containing other precursors enables the seed layer to transform into PbBiO2Cl crystals even at 450 °C. The thickness of the PbBiO2Cl layer can be controlled by changing the thickness of the BiOCl seed layer for efficient photon-to-current conversion. Owing to a good contact at the semiconductor-substrate interfaces as well as the high quality of PbBiO2Cl crystals, the flux-synthesized PbBiO2Cl photoelectrode shows a significantly improved PEC performance compared with those prepared from the particulate PbBiO2Cl samples via the conventional squeegee method. In addition, the present PbBiO2Cl photoelectrodes exhibit both anodic and cathodic photoresponses with substantially high current values depending on the applied potentials; the unusual phenomenon is affected by the conditions in flux-assisted synthesis. The present study provides a new and effective way for fabricating efficient photoelectrodes of various semiconductors on various substrates and a possible option to control their morphologies and p/n types for further improvement in performance.