Enhanced molecular recognition with longer chain crosslinkers in molecularly imprinted polymers for an efficient separation of TR active substances.

Molecular imprinting technology has been widely studied as a technique to obtain molecular recognition by artificial means. Selecting functional monomers or polymerization conditions plays a key role to optimize molecularly imprinted polymer (MIP) synthesis. To date, there have been few reports well exploiting the effect of crosslinkers. Here, in this study, we synthesized the MIPs using poly(ethyleneglycol) dimethacrylate with different units of ethylene oxide (n = 1 to 23) as crosslinkers to observe the molecular recognition abilities. The MIPs were attached to the surface of mono-dispersed polymer beads. The obtained spherical MIPs and non-imprinted polymers were filled in a column for high performance liquid chromatography. Then the retention selectivity toward TR active substances was evaluated. The result revealed that the recognition ability did not improve regardless of the amount of ethylene oxide. With the crosslinker (n = 9), extremely high retention selectivity was observed, which provides at most around ten times as large imprinting factors in comparison with other MIPs. Interestingly, we obtained the highest recognition ability at around polymerization temperature from the evaluation of the recognition ability toward temperature shift using the MIP (n = 9). In general, hydrogen bonding based on MIPs provides high recognition ability at low temperature, whereas, this study indicates that the use of flexible crosslinkers may enable the synthesis of MIPs that precisely memorize the conditions of polymerization. Lastly, we simultaneously analyzed the TR active substances using the column filled with MIPs (n = 9). The result showed relatively linear correlation between the retention strength of each substance and phycological activity toward TR obtained by yeast assay. Therefore, we can conclude that an induced fit like the receptor emerged by constructing the flexible molecular recognition field.

Rapid and Highly Efficient Purification of Extracellular Vesicles Enabled by a TiO2 Hybridized Spongy-like Polymer.

We developed a novel purification medium of extracellular vesicles (EVs) by constructing a spongy-like monolithic polymer kneaded with TiO2 microparticles (TiO2-hybridized spongy monolith, TiO2-SPM). TiO2-SPM was applied in a solid-phase extraction format and enabled simple, rapid, and highly efficient purification of EVs. This is due to the high permeability caused by the continuous large flow-through pores of the monolithic skeleton (median pore size; 5.21 µm) and the specific interaction of embedded TiO2 with phospholipids of the lipid bilayers. Our method also excels in efficiency and comprehensiveness, collecting small EVs (SEVs) from the same volume of a cell culture medium 130.7 times more than typical ultracentrifugation and 4.3 times more than affinity purification targeting surface phosphatidylserine by magnetic beads. The purification method was completed within 1 h with simple operations and was directly applied to serum SEVs. Finally, we demonstrated flexibility toward the shape and size of our method by depleting EVs from fetal bovine serum (FBS), which is a necessary process to prevent contamination of culture cell-derived EVs with exogenous FBS-derived EVs. Our method will eliminate the tedious and difficult purification processes of EVs, providing a universal purification platform for EV-based drug discovery and pathological diagnosis.

Efficient Selective Adsorption of SARS-CoV-2 via the Recognition of Spike Proteins Using an Affinity Spongy Monolith.

Since the outbreak of COVID-19, SARS-CoV-2, the infection has been spreading to date. The rate of false-negative result on a polymerase chain reaction (PCR) test considered the gold standard is roughly 20%. Therefore, its accuracy poses a question as well as needs improvement in the test. This study reports fabrication of a substrate of an anti-spike protein (AS)-immobilized porous material having selective adsorption toward a spike protein protruding from the surface of SARS-CoV-2. We have employed an organic polymer substrate called spongy monolith (SPM). The SPM has through-pores of about 10 µm and is adequate for flowing liquid containing virus particles. It also involves an epoxy group on the surface, enabling arbitrary proteins such as antibodies to immobilize. When antibodies of the spike protein toward receptor binding domain were immobilized, selective adsorption of the spike protein was observed. At the same time, when mixed analytes of spike proteins, lysozymes and amylases, were flowed into an AS-SPM, selective adsorption toward the spike proteins was observed. Then, SARS-CoV-2 was flowed into the BSA-SPM or AS-SPM, amounts of SARS-CoV-2 adsorption toward the AS-SPM were much larger compared to the ones toward the BSA-SPM. Furthermore, rotavirus was not adsorbed to the AS-SPM at all. These results show that the AS-SPM recognizes selectively the spike proteins of SARS-CoV-2 and may be possible applications for the purification and concentration of SARS-CoV-2.

Rational Supramolecular Strategy via Halogen Bonding for Effective Halogen Recognition in Molecular Imprinting.

Halogen bonding is a highly directional interaction and a potential tool in functional material design through self-assembly. Herein, we describe two fundamental supramolecular strategies to synthesize molecularly imprinted polymers (MIPs) with halogen bonding-based molecular recognition sites. In the first method, the size of the σ-hole was increased by aromatic fluorine substitution of the template molecule, enhancing the halogen bonding in the supramolecule. The second method involved sandwiching hydrogen atoms of a template molecule between iodo substituents, which suppressed competing hydrogen bonding and enabled multiple recognition patterns, improving the selectivity. The interaction mode between the functional monomer and the templates was elucidated by 1H NMR, 13C NMR, X-ray absorption spectroscopy, and computational simulation. Finally, we succeeded in the effective chromatographic separation of diiodobenzene isomers on the uniformly sized MIPs prepared by multi-step swelling and polymerization. The MIPs selectively recognized halogenated thyroid hormones via halogen bonding and could be applied to screening endocrine disruptors.

Classification of Extracellular Vesicles Based on Surface Glycan Structures by Spongy-like Separation Media.

Extracellular vesicles (EVs) are lipid bilayer vesicles that enclose various biomolecules. EVs hold promise as sensitive biomarkers to detect and monitor various diseases. However, they have heterogeneous molecular compositions. The compositions of EVs from identical donor cells obtained using the same purification methods may differ, which is a significant obstacle for elucidating objective biological functions. Herein, the potential of a novel lectin-based affinity chromatography (LAC) method to classify EVs based on their glycan structures is demonstrated. The proposed method utilizes a spongy-like monolithic polymer (spongy monolith, SPM), which consists of poly(ethylene-co-glycidyl methacrylate) with continuous micropores and allows an efficient in situ protein reaction with epoxy groups. Two distinct lectins with different specificities, Sambucus sieboldiana agglutinin and concanavalin A, are effectively immobilized on SPM without impacting the binding activity. Moreover, high recovery rates of liposomal nanoparticles as a model of EVs are achieved due to the large flow-through pores (>10 µm) of SPM compared to a typical agarose gel. Finally, lectin-immobilized SPMs are employed to classify EVs based on the surface glycan structures and demonstrate different subpopulations by proteome profiling. This is the first approach to clarify the variation of protein contents in EVs by the difference of surface glycans via lectin immobilized media.

Selective Separation of Thyroid-Hormone-Receptor-Binding Substances Using Molecularly Imprinted Polymers.

To date, an identification protocol for endocrine disruptors that bind to the thyroid hormone receptor (TR) has not been established. A method for screening and identifying TR-binding substances is highly required due to the existence of unknown TR-binding substances from the environment. Here, we conceived a chromatographic method using a molecularly imprinted polymer (MIP) to create a novel screening protocol for the endocrine disruptors. A receptor-imitating MIP was prepared using N-acetylthyroxine (AcetylT4) and 4-vinylpyridine as a pseudo-template and a functional monomer, respectively, based on the existing molecular recognition mechanism of the TR. The receptor-imitating MIP provided molecular recognition ability for all the TR-binding substances that were employed in this study. The prepared MIPs were packed into a high-performance liquid chromatography column for the simultaneous analysis of TR-binding and non-binding substances. The former was strongly retained, while the latter was not. The presence or absence of TR-binding/non-binding activity resulted in successful dichotomous separation. Additionally, the surface imprinting technique was applied to improve the separation performance of the MIP packing material. MIP-coated uniformly sized silica-based particles of 5 µm were successfully prepared, and the MIP-coated silica column enabled more efficient dichotomous separation of TR-binding and non-binding substances.

Identification by Liquid Chromatography-Tandem Mass Spectrometry and Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry of the Contributor to the Thyroid Hormone Receptor Agonist Activity in Effluents from Sewage Treatment Plants.

3,3',5-Triiodothyroacetic acid (TRIAC) was identified as a major contributor to the activity of thyroid hormone receptor (TR) agonists in environmental water. TRIAC contributed 60-148% of the TR-agonist activity in effluents from sewage treatment plants (STPs). Meanwhile, the contributions of 3,5,3'-triiodothyronine (T3), 3,3',5,5'-tetraiodothyronine (T4), and analogues were <1%. TRIAC concentrations in the range of 0.30-4.2 ng/L are likely enough to cause disruption of the thyroid system in living aquatic organisms. The origin of TRIAC in the STP effluents was investigated by analyzing both STP influents and effluents. Relatively high concentrations of T3 and T4 (2.5 and 6.3 ng/L, respectively) were found only in the influents. TRIAC was identified only in the effluents. These findings suggested that T3 and T4 in STP influents were potentially converted into TRIAC during activated sludge treatment or by other means. The evaluation of TRIAC at relevant environmental concentrations by in vivo assays and an appropriate treatment to reduce the TR activity in sewage are needed.

Pirfenidone prevents esophageal stricture by inhibiting nucleotide binding oligomerization domain like receptor protein 3 inflammasome activation.

BACKGROUND AND AIM: Esophageal injury often results in a scar, leading to refractory strictures. The NLRP3 inflammasome activates caspase-1, causing the maturation of interleukin (IL)-1ß. Here, we aimed to investigate the preventive effect of pirfenidone (PFD), an antifibrotic drug, on esophageal stricture after ulcer healing and studied its mechanism by focusing on the activation of the NLRP3 inflammasome. METHODS: Esophageal ulcers were induced in rats via the local application of acetic acid in the serosa. PFD was intraperitoneally administered to the rats 3 days after ulcer induction. The effect of PFD on esophageal stricture after ulcer healing was assessed by esophagography on day 9. The protein levels of mature caspase-1 and IL-1ß were assessed by western blotting. RESULTS: The ulcers fully developed 3 days after induction and were almost scarred by day 9 with severe strictures. PFD promoted ulcer healing and attenuated fibrotic collagen in the submucosa by suppressing the increase in NLRP3, cleaved caspase-1, and mature IL-1ß expression, improving stricture rate (PFD vs vehicle = 55% vs 81%). Exogenous IL-1ß abolished the therapeutic effects of PFD on ulcer healing and stricture formation. Furthermore, NLRP3 and caspase-1 inhibitors mimicked the effects of PFD on ulcer healing and stricture formation, with suppression of the increase in cleaved caspase-1 and mature IL-1ß proteins and expression of fibrosis-related molecules including transforming growth factor (TGF)-ß1. CONCLUSION: The NLRP3 inflammasome promotes esophageal stricture formation following ulcer healing, and PFD exerts potential prophylactic activity against strictures, possibly via the inhibition of the NLRP3/IL-1ß/TGF-ß1 axis.

Interferon-α exerts proinflammatory properties in experimental radiation-induced esophagitis: Possible involvement of plasmacytoid dendritic cells.

AIMS: Radiation-induced esophagitis, experienced during radiation therapy for lung cancer and head and neck cancer, is a major dose-limiting side effect of the treatment. This study aimed to elucidate the role of interferon-α (IFN-α) in radiation-induced esophagitis. MAIN METHODS: C57BL/6 mice were exposed to 10 and 25Gy of single thoracic irradiation. Esophageal mucosal damage and inflammatory reactions were assessed for 5 days after irradiation. KEY FINDINGS: Irradiation induced esophagitis, characterized by reduction in the thickness of epithelial layer, upregulation of proinflammatory cytokines and chemokines, infiltration of inflammatory cells into the esophageal mucosa, and apoptosis of epithelial cells. Irradiation upregulated the level of gene expression for IFN-α in the esophageal tissue, and the neutralizing antibody against IFN-α ameliorated radiation-induced esophageal mucosal damage, while administration of IFN-α receptor agonist (RO8191) had an inverse effect. Depletion of plasmacytoid dendritic cells (pDCs) by anti-CD317 antibody or pharmacological inactivation with bortezomib suppressed radiation-induced mucosal inflammation and damage, accompanied by decrease in IFN-α expression level. SIGNIFICANCE: These findings suggest that IFN-α and pDCs exert proinflammatory properties in the pathophysiology of radiation-induced esophagitis.

Selective Recovery of Estrogenic Endocrine Disruptors from 48 Environmental Samples Using a Substrate for Activity-Specific Concentration.

hER-MIP is a molecularly imprinted polymer (MIP) that has been shown to selectively collect human estrogen receptor (hER) binding active substances. However, environmental samples contain various chemicals depending on the location and regional differences, and the hER binding activity depends on the sample type. Thus, the general applicability of hER-MIP to actual environmental samples must be elucidated. In this study, 48 environmental samples were collected and screened with hER-MIP, and a yeast assay was performed to evaluate the adsorption characteristics of the samples according to the adsorption and elution fractions. The results showed that hER-MIP collects hER binding active substances almost selectively but does not collect constitutive androstane receptor (CAR) binding active substances selectively. CAR binding activity was detected in the adsorbed fraction because several hER binding active substances also demonstrate CAR binding activity.

Eosinophilic esophagitis and asymptomatic esophageal eosinophilia display similar immunohistological profiles.

Patients with asymptomatic esophageal eosinophilia (aEE) do not exhibit clinical symptoms because of esophageal dysfunction, although they have endoscopic and histological findings similar to those of eosinophilic esophagitis (EoE). The cause of the symptoms and the differences between aEE and EoE are unclear. The aim of this study is to determine whether aEE and EoE are same disease entities by comparing immune-related tissue biomarkers using immunohistological staining. Esophageal biopsy specimens from 61 patients, including 18 with aEE and 43 with EoE, were analyzed. Immunofluorescence staining was performed to quantify the immune-related tissue biomarkers such as major basic protein, eosinophil-derived neurotoxin, eotaxin-3, and immunoglobulin G4. Data are presented as median (interquartile range). There were no significant differences in clinical, endoscopic, or histological features, between patients with aEE and EoE, with the exception of body mass index. There were no significant differences in all immune-related tissue biomarkers between both groups. In conclusions, EoE and aEE displayed similar immunohistological profiles. Hence, they may be similar disease entities with some common pathogenic mechanisms. Our findings suggest that patients with aEE also have histopathological esophageal inflammation.

Protective role of resolvin D1, a pro-resolving lipid mediator, in nonsteroidal anti-inflammatory drug-induced small intestinal damage.

Resolvin D1, a specialized pro-resolving lipid mediator produced from docosahexaenoic acid by 15- and 5-lipoxygenase, exerts anti-inflammatory effects driving to the resolution of inflammation. The present study aimed to elucidate its role in small intestinal damage induced by nonsteroidal anti-inflammatory drug (NSAID). Indomethacin was administered orally to C57BL/6J male mice, which were sacrificed 24 h later to collect small intestine specimens. Before administration of indomethacin, mice were subjected to intraperitoneal treatment with resolvin D1 or oral administration of baicalein, a 15-lipoxygenase inhibitor. Small intestinal damage induced by indomethacin was attenuated by pretreatment with resolvin D1. Furthermore, resolvin D1 reduced the gene expression levels of interleukin-1ß, tumor necrosis factor-α, and CXCL1/keratinocyte chemoattractant. Conversely, the inhibition of 15-lipoxygenase activity by baicalein increased the expression of genes coding for these inflammatory cytokines and chemokine, leading to exacerbated small intestinal damage, and reduced the concentration of resolvin D1 in the small intestinal tissue. Exogenous treatment with resolvin D1 negated the deleterious effect of baicalein. 15-lipoxygenase was mainly expressed in the epithelium and inflammatory cells of the small intestine, and its gene and protein expression was not affected by the administration of indomethacin. Inhibition of the resolvin D1 receptor, lipoxin A4 receptor /formyl peptide receptor 2, by its specific inhibitors Boc-1 and WRW4 aggravated indomethacin-induced small intestinal damage. Collectively, these results indicate that resolvin D1 produced by 15-lipoxygenase contributes to mucoprotection against NSAID-induced small intestinal damage through its anti-inflammatory effect.

Gastrointestinal endoscopic practice during COVID-19 pandemic: a multi-institutional survey.

Introduction. An on-going coronavirus disease 2019 (COVID-19) has become a challenge all over the world. Since an endoscopy unit and its staff are at potentially high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we conducted a survey for the management of the gastrointestinal endoscopic practice, personal protective equipment (PPE), and risk assessment for COVID-19 during the pandemic at multiple facilities.Methods. The 11-item survey questionnaire was sent to representative respondent of Department of Gastroenterology, Osaka City University Hospital, and its 19 related facilities.Results. A total of 18 facilities submitted valid responses and a total of 373 health care professionals (HCPs) participated. All facilities (18/18: 100%) were screening patients at risk for SARS-CoV-2 infection before endoscopy. During the pandemic, we found that the total volume of endoscopic procedures decreased by 44%. Eleven facilities (11/18: 61%) followed recommendations of the Japan Gastroenterological Endoscopy Society (JGES); consequently, about 35%-50% of esophagogastroduodenoscopy and colonoscopy were canceled. Mask (surgical mask or N95 mask), face shield/goggle, gloves (one or two sets), and gown (with long or short sleeves) were being used by endoscopists, nurses, endoscopy technicians, and endoscope cleaning staff in all the facilities (18/18: 100%). SARS-CoV-2 infection risk assessment of HCPs was conducted daily in all the facilities (18/18: 100%), resulting in no subsequent SARS-CoV-2 infection in HCPs.Conclusion. COVID-19 has had a dramatic impact on the gastrointestinal endoscopic practice. The recommendations of the JGES were appropriate as preventive measures for the SARSCoV-2 infection in the endoscopy unit and its staff.

Rebamipide ameliorates indomethacin-induced small intestinal damage and proton pump inhibitor-induced exacerbation of this damage by modulation of small intestinal microbiota.

Non-steroidal anti-inflammatory drugs (NSAIDs) induce small intestinal damage. It has been reported that rebamipide, a mucoprotective drug, exerts a protective effect against NSAID-induced small intestinal damage; however, the underlying mechanism remains unknown. In this study, we investigated the significance of the small intestinal microbiota in the protective effect of rebamipide against indomethacin-induced small intestinal damage in mice. A comprehensive analysis of the 16S rRNA gene sequencing revealed an alteration in the composition of the small intestinal microbiota at the species level, modulated by the administration of rebamipide and omeprazole. The transplantation of the small intestinal microbiota of the mice treated with rebamipide suppressed the indomethacin-induced small intestinal damage. Omeprazole, a proton pump inhibitor, exacerbated the indomethacin-induced small intestinal damage, which was accompanied by the alteration of the small intestinal microbiota. We found that the transplantation of the small intestinal microbiota of the rebamipide-treated mice ameliorated indomethacin-induced small intestinal damage and the omeprazole-induced exacerbation of the damage. These results suggest that rebamipide exerts a protective effect against NSAID-induced small intestinal damage via the modulation of the small intestinal microbiota, and that its ameliorating effect extends also to the exacerbation of NSAID-induced small intestinal damage by proton pump inhibitors.

NOD-Like Receptor Family Pyrin Domain-Containing 3 Inflammasome Activation Exacerbates 5-Fluorouracil-Induced Small Intestinal Mucositis via Interleukin-1ß Activation.

BACKGROUND AND AIM: 5-Fluorouracil (5-FU) is an anticancer agent that induces intestinal mucositis, which causes diarrhea and dehydration. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is responsible for inflammatory response activation via caspase-1 cleavage and subsequent interleukin-1ß (IL-1ß) and IL-18 activation and secretion. The objective of this study was to determine the role of the NLRP3 inflammasome in 5-FU-induced small intestinal mucositis. METHODS: Small intestinal mucositis was induced in wild-type, NLRP3-/-, and caspase-1-/- mice by intraperitoneal injection of 5-FU. Some mice received intraperitoneal injection of a caspase-1 inhibitor, recombinant IL-1ß or IL-18, or neutralizing antibody against IL-1ß. RESULTS: Mice treated with 5-FU developed small intestinal mucositis with diarrhea and body weight loss, characterized by a decrease in villus height and the villus height-to-crypt depth ratio. These histological changes peaked on day 3 and were accompanied by an increase in mRNA expression of NLRP3 and IL-1ß and protein expression of cleaved caspase-1 and mature IL-1ß. Mature IL-18 protein expression was not affected by 5-FU administration. NLRP3-/- mice exhibited less severe 5-FU-induced mucositis, and this phenotype was mimicked by genetic depletion or pharmacological inhibition of caspase-1. Small intestinal mucositis was aggravated by exogenous IL-1ß and neutralized by IL-1ß antibody treatment. Administration of exogenous IL-18 or anti-IL-18 antibody did not affect any parameters associated with mucositis. NLRP3, cleaved caspase-1, and IL-1ß were expressed by inflammatory cells (mainly macrophages) in the lamina propria and damaged epithelial cells. CONCLUSIONS: NLRP3 inflammasome activation may exacerbate 5-FU-induced small intestinal mucositis via IL-1ß maturation.

Successful Eradication of Helicobacter pylori Could Prevent Metachronous Gastric Cancer: A Propensity Matching Analysis.

BACKGROUND AND AIM: Helicobacter pylori is the leading cause of gastric cancer, but it is still uncertain whether eradicating H. pylori in early gastric cancer (EGC) patients who underwent endoscopic resection can prevent metachronous gastric cancer (MGC). This study aimed to investigate the effect of H. pylori eradication to prevent MGC after endoscopic submucosal dissection (ESD). METHODS: In this propensity-matched retrospective observational study, 770 patients with EGC who received ESD were enrolled. The outcome was the incidence of MGC; this was compared between the persistent and eradicated groups. RESULTS: MGC was detected in 27 patients (7.8%) during a median period of 39.0 months (range 26.0-64.0). After propensity matching, 126 pairs of patients in each group were analyzed. The 5-year cumulative incidence rates of MGC were 13.2 and 3.9% in the persistent and eradicated groups, respectively (p= 0.021, log-rank test). On multivariate analysis, H. pylori eradication prevented MGC significantly (hazard ratio [HR] 0.32; p = 0.029). The results remained robust after inverse probability of treatment weighting analysis (HR 0.30; p = 0.020). CONCLUSIONS: Successful H. pylori eradication could prevent MGC after ESD for EGC.

Safety of Endoscopic Mucosal Resection Using a Bipolar Snare for Superficial Nonampullary Duodenal Epithelial Tumors and the Predictive Factors of Piecemeal Resection.

INTRODUCTION: Endoscopic mucosal resection for small superficial nonampullary duodenal epithelial tumors is a noninvasive treatment; however, perforations can occur. Bipolar snares can reduce the risk of perforation due to small tissue damage. Currently, only few studies have reported endoscopic mucosal resection for small superficial nonampullary duodenal epithelial tumors using a bipolar snare and the effect of preoperative findings. OBJECTIVE: To investigate (1) resectability and adverse events of endoscopic mucosal resection using a bipolar snare for small superficial nonampullary duodenal epithelial tumors and (2) the predictions of piecemeal resection. METHODS: Between 2007 and 2017, 89 patients with 107 lesions underwent endoscopic mucosal resection using a bipolar snare. Among them, 88 lesions of 77 patients were evaluated. The primary outcome was the incidence of en bloc resection and R0 resection and adverse events. Risk factors associated with piecemeal resection, including preoperative lesion findings, were also examined. RESULTS: The incidence rates of en bloc and R0 resections were 85.2 and 48.9%, respectively. Neither intraoperative or delayed perforations nor procedure-related mortality was noted. The nonlifting sign after submucosal injection was associated with an increase in piecemeal resection (odds ratio: 20.3, 95% confidence interval: 2.53-162; p = 0.005). CONCLUSION: Endoscopic resection for small superficial nonampullary duodenal epithelial tumors can cause perforation; however, endoscopic mucosal resection using a bipolar snare can be a safe treatment option as it does not cause perforations. The nonlifting sign after submucosal injection is a predictive factor for piecemeal resection.

Predictive factors for difficult endoscopic submucosal dissection for esophageal neoplasia including failure of en bloc resection or perforation.

BACKGROUND: Endoscopic submucosal dissection (ESD) is accepted as the standard treatment for early-stage esophageal neoplasia. However, esophageal perforation may occur, leading to mediastinitis and pneumothorax, which occasionally require emergency surgery. Moreover, failure of en bloc resection causes local recurrence. However, studies on the predictors of such difficulties during ESD are limited. Hence, we evaluated the predictors associated with the difficulty of ESD for esophageal neoplasia including failure of en bloc resection or perforation. METHODS: Data of 549 consecutive patients who were treated with ESD between May 2004 and March 2016 at a single institution were retrospectively studied. Exclusion criteria were the presence of metachronous esophageal neoplasia or missing data. The primary outcome was determining the predictors associated with the difficulty of ESD for esophageal neoplasia including failure of en bloc resection or perforation. RESULTS: Altogether, 543 patients with 736 lesions were evaluated. Failure of en bloc resection occurred in 6 patients (1.1%) with 6 lesions, and perforation occurred in 11 patients (2.0%) with 11 lesions (1.5%). Multivariate logistic regression analysis showed that large lesion diameter (odds ratio [OR] 1.49; 95% confidence interval [CI] 1.21-1.84; p < 0.001) and previous chemoradiotherapy (OR 5.24; 95% CI 1.52-18.06; p = 0.009) were independent predictive factors. CONCLUSIONS: Larger lesions and previous chemoradiotherapy for esophageal cancer increased the risk for failure of en bloc resection or perforation in patients who underwent esophageal ESD.

Role of nucleotide binding oligomerization domain-like receptor protein 3 inflammasome in stress-induced gastric injury.

BACKGROUND AND AIM: The inflammasomes promote pro-caspase-1 cleavage, leading to processing of pro-interleukin (IL)-1ß into its mature form. We investigated the role of the IL-1ß and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in gastric injury in mice receiving water-immersion restraint stress (WIRS), focusing on the cyclooxygenase (COX)-2/prostaglandin (PG) E2 axis. METHODS: To induce gastric injury, the mice were placed in a restraint cage and immersed in the water bath to the level of the xiphoid process. Protein levels of mature caspase-1 and IL-1ß were assessed by western blotting. RESULTS: Water-immersion restraint stress induced gastric injury with increase in IL-1ß expression by activation of NLRP3 inflammasome. Exogenous IL-1ß attenuated the injury, whereas anti-IL-1ß neutralizing antibody and IL-1ß receptor antibody aggravated it. NLRP3-/- and caspase-1-/- mice enhanced the injury with reducing of mature IL-1ß, and this aggravation was reduced by exogenous IL-1ß supplementation. Toll-like receptor 4-/- mice were hyporesponsive to WIRS in terms of mature IL-1ß production. Rabeprazole attenuated the injury with preventing inflammasome activation. WIRS injured the stomach with promotion of COX-2 mRNA and PGE2 production, and exogenous IL-1ß enhanced these molecules, while IL-1ß immunoneutralization exerted opposite effect. PGE2 supplementation abolished the hypersensitivity in NLRP3-/- and caspase-1-/- mice through negative regulation of inflammatory cytokines. CONCLUSION: These results suggest that NLRP3 inflammasome-derived IL-1ß plays a protective role in stress-induced gastric injury via activation of the COX-2/PGE2 axis. Toll-like receptor 4 signaling and gastric acid may be involved in NLRP3 inflammasome activation.

Long-term persistence of gastric dysbiosis after eradication of Helicobacter pylori in patients who underwent endoscopic submucosal dissection for early gastric cancer.

BACKGROUND: Gastric microbiome, other than Helicobacter pylori, plays a role in the tumorigenesis of gastric cancer (GC). Patients who undergo endoscopic submucosal dissection for early GC have a high risk of developing metachronous GC even after successful eradication of H. pylori. Thus, we investigated the microbial profiles and associated changes in such patients after the eradication of H. pylori. METHODS: A total of 19 H. pylori-infected patients with early GC who were or to be treated by endoscopic resection, with paired biopsy samples at pre- and post-eradication therapy, were retrospectively enrolled. Ten H. pylori-negative patients were enrolled as controls. Biopsy samples were analyzed using 16S rRNA sequencing. RESULTS: H. pylori-positive patients exhibited low richness and evenness of bacteria with the deletion of several genera, including Blautia, Ralstonia, Faecalibacterium, Methylobacterium, and Megamonas. H. pylori eradication partially restored microbial diversity, as assessed during a median follow-up at 13 months after eradication therapy. However, post-eradication patients had less diversity than that in the controls and possessed a lower abundance of the five genera mentioned above. The eradication of H. pylori also altered the bacterial composition, but not to the same extent as that in controls. The microbial communities could be clustered into three separate groups: H. pylori-negative, pre-eradication, and post-eradication. CONCLUSION: Changes in dysbiosis may persist long after the eradication of H. pylori in patients with a history of GC. Dysbiosis may be involved in the development of both primary and metachronous GC after the eradication of H. pylori in such patients.