Clinical performance of fecal calprotectin, lactoferrin, and hemoglobin for evaluating the disease activity of IBD and detecting colorectal tumors.

Background and Aim: Recently, noninvasive fecal markers have been used as indicators of intestinal inflammation in patients with inflammatory bowel disease (IBD). We conducted a clinical validation study to measure fecal calprotectin (Cp), lactoferrin (Lf), and hemoglobin (Hb) levels using an all-in-one kit in patients with IBD and colorectal tumors and aimed to clarify the utility of these fecal markers. Methods: In this study, 104 patients were analyzed, including 25 patients with ulcerative colitis (UC), 20 with Crohn's disease (CD), 48 with colorectal tumors, and 13 healthy controls (HC). Of the 48 patients with colorectal tumors, 14 had invasive cancer. We validated the utility of fecal Cp, Lf, and Hb levels by simultaneously measuring fecal markers in patients with IBD and colorectal tumors. Results: Fecal Cp and Lf had almost equivalent abilities in detecting clinical remission in patients with UC; however, fecal Cp was slightly superior to Lf. Regarding colorectal tumors, fecal Cp and Lf levels tended to be higher in patients with adenomas and colorectal cancer than in HCs. Although fecal Hb alone had the best sensitivity and specificity for detecting colorectal cancer, it had relatively low sensitivity for detecting advanced neoplasms and colorectal cancer. Conclusion: Fecal Cp and Lf can be used as almost equivalent biomarkers to assess the clinical activity in patients with UC. Fecal Hb is the most useful marker for screening colorectal cancer; however, adding fecal Cp and Lf may compensate for the low sensitivity of detecting for advanced colorectal tumors based on Hb alone.

Effectiveness and Persistency of Ustekinumab Treatment for Ulcerative Colitis: A Phoenix retrospective Cohort Study.

Background: Real-world data regarding ustekinumab (UST) for ulcerative colitis (UC) particularly in biologics-naïve patients is currently limited. This study aimed to elucidate the real-world effectiveness and safety of UST for UC. Methods: Overall, 150 patients with UC treated with UST from March 2020 to January 2023 were enrolled across 7 referral hospitals. To assess the clinical efficacy and persistence of UST, retrospective analyses were conducted from weeks 8 to 56. Predictive factors concerning the response and persistence of UST were examined through univariate and multivariate analyses. Results: Of the 150 patients, 125 received UST for remission induction, including 36% biologics-naïve. The response and remission rates were 72.8% and 56.0% at week 8 and 73.2% and 63.4% at week 56, respectively. Biologics-naïve patients represented higher response and remission rates at week 8 (84.4% and 73.3%) than those with biologics exposure (66.2% and 46.2%). Patients with prior antitumor necrosis factor (anti-TNF) and vedolizumab (VDZ) exposure had relatively lower response and remission rates (34.5% and 24.1%, respectively). The 1-year cumulative persistence rate was 84.0%. Multivariate analysis revealed that the chronic continuous type and prior anti-TNF and VDZ exposure were negative predictive factors for week 8 responsiveness. Clinical response at week 8 was a predictor of 1-year persistence. Adverse event incidence remained notably low at 6.4%. Conclusions: This study highlights the safety and effectiveness of UST as an induction and maintenance therapy for UC. Chronic continuous type and previous anti-TNF and VDZ exposure negatively contributed to short-term effectiveness, whereas short-term effectiveness provided good persistency.

Change in systemic steroid use and surgery rate in patients with inflammatory bowel disease: a Japanese real-world database analysis.

BACKGROUND: Corticosteroids are recommended only for induction of remission in inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD). This study aimed to evaluate the change in pharmacologic treatment use, particularly systemic corticosteroids, over approximately 30 years, and the impact of biologics on IBD treatment since their appearance in the 2000s. METHODS: This retrospective study conducted in Japan used data from the Phoenix cohort database (January 1990 to March 2021). Patients with disease onset at age ≥ 10 years who received treatment for UC or CD between January 1990 and March 2021 were included. Outcome measures were change in IBD treatments used, total cumulative corticosteroid doses, initial corticosteroid dose, duration of corticosteroid treatment, and surgery rate. RESULTS: A total of 1066 and 579 patients with UC and CD, respectively, were included. In UC, the rate of corticosteroid use as initial treatment was relatively stable regardless of the year of disease onset; however, in CD, its rate decreased in patients who had disease onset after 2006 (before 2006: 14.3-27.8% vs. after 2006: 6.6-10.5%). Compared with patients with disease onset before biologics became available, cumulative corticosteroid doses in both UC and CD, and the surgery rate in CD only, were lower in those with disease onset after biologics became available. CONCLUSIONS: Since biologics became available, corticosteroid use appears to have decreased, with more appropriate use. Furthermore, use of biologics may reduce surgery rates, particularly in patients with CD. UMIN Clinical Trials Registry; UMIN000035384.

Effectiveness and Factors Associated with Response to Golimumab in Japanese Patients with Ulcerative Colitis in Real Clinical Practice: The Phoenix Study.

Introduction: There have been limited reports on the clinical efficacy of golimumab (GLM) in Japanese patients with ulcerative colitis (UC) in real clinical practice. This study aimed to explore the real-life effectiveness and factors associated with response to GLM in Japanese patients with UC. Methods: This observational, retrospective, multicenter study was conducted in hospitals with expertise in inflammatory bowel disease treatment. Sixty-three patients treated with GLM and active UC were included in the analysis. Clinical remission (CR) (partial Mayo (pMayo) score ≤2) in the induction and maintenance phases after GLM treatment and associated factors were evaluated. Results: The proportion of patients achieving CR in the induction and maintenance phases was 41.3% (26/63) and 46.0% (29/63, the last observation carried forward method was used for patients who discontinued treatment for reasons other than inadequate response), respectively. The median pMayo score was 5 (interquartile range (IQR): 4-6) at baseline, 3 (IQR: 1-5) in the induction phase, and 1 (IQR: 0-3) in the maintenance phase. Hemoglobin, platelet, and C-reactive protein levels changed, consistent with the pMayo score. Multivariate logistic analysis revealed that biologic-naive status was an independent factor associated with CR in the induction (p = 0.0200) and maintenance (p = 0.0459) phases, and a disease duration of >60 months until GLM initiation was associated with CR in the induction phase (p = 0.0427). Conclusions: The effectiveness of GLM in daily clinical practice has been confirmed in Japanese patients with active UC. Biologic-naive patients responded more to GLM in the induction and maintenance phases, and patients with disease duration of >60 months until initiation of GLM were more responsive in the induction phase.

A new two-dimensional luminescent Ag12 cluster-assembled material and its catalytic activity for reduction of hexacyanoferrate(III).

Silver cluster-assembled materials (SCAMs) have garnered significant interest as promising platforms for different functional explorations. Their atomically precise structures, intriguing chemical/physical properties, and remarkable luminescent capabilities make them highly appealing. However, the properties of these materials are primarily determined by their structural architecture, which is heavily influenced by the linker molecules used in their assembly. The choice of linker molecules plays a pivotal role in shaping the structural characteristics and ultimately determining the unique properties of SCAMs. To this end, the first SCAM with an intriguing (3,6)-connected kgd topology, [Ag12(StBu)6(CF3COO)6(TPBTC)6]n (termed TUS 3), TPBTC = benzene-1,3,5-tricarboxylic acid tris-pyridin-4-ylamide, has been synthesized by reticulating C6-symmetric Ag12 cluster cores with C3-symmetric tripodal pyridine linkers. Due to the structutural architecture of the linker molecule, TUS 3 posseses a luminescent porous framework structure where each two-dimensional (2D) layers are non-covalently linked with each other to form a three dimensional (3D) framework and ultimately offers uniaxial open channels. The compact mesoporous structural architecture not only gives the excellent surface area but also offers impressive stability of this material even in water medium. Taking advantage of these properties, TUS 3 shows brilliant catalytic activity in the reduction of hexacyanoferrate(III) using sodium borohydride in aqueous solutions.

Regional Transcriptomics and Proteomics of Pharmacokinetics-Related Genes in Human Intestine.

The intestine is an organ responsible for the absorption and metabolism of orally administered drugs. To predict pharmacokinetics behavior in the small intestine, it is necessary to examine the human intestinal expression profiles of the genes related to drug absorption, distribution, metabolism, and excretion (ADME). In this study, to obtain more accurate expression profiles in various regions of the human intestine, biopsy samples were collected from endoscopically noninflamed mucosa of the duodenum, jejunum, ileum, colon, and rectum from Japanese including Crohn's disease or ulcerative colitis patients, and both RNA-seq and quantitative proteomics analyses were performed. We also analyzed the expression of drug-metabolizing enzymes (cytochromes P450 (CYPs) and non-CYP enzymes), drug transporters, and nuclear receptors. Overall, the mRNA expression levels of these ADME-related genes correlated highly with the protein expression levels. The characteristics of the expression of ADME-related genes differed significantly between the small and large intestines, including the expression levels of CYP enzymes, which were higher and lower in the small and large intestines, respectively. Most CYPs were expressed dominantly in the small intestine, especially the jejunum, but were rarely expressed in the large intestine. On the other hand, non-CYP enzymes were expressed in the large intestine but at lower expression levels than in the small intestine. Moreover, the expression levels of drug metabolizing enzyme genes differed even between the proximal and distal small intestine. Transporters were expressed most highly in the ileum. The data in the present study will enhance understanding of the intestinal ADME of drug candidates and would be useful for drug discovery research.

Carbon Nitride Loaded with an Ultrafine, Monodisperse, Metallic Platinum-Cluster Cocatalyst for the Photocatalytic Hydrogen-Evolution Reaction.

For the realization of a next-generation energy society, further improvement in the activity of water-splitting photocatalysts is essential. Platinum (Pt) is predicted to be the most effective cocatalyst for hydrogen evolution from water. However, when the number of active sites is increased by decreasing the particle size, the Pt cocatalyst is easily oxidized and thereby loses its activity. In this study, a method to load ultrafine, monodisperse, metallic Pt nanoclusters (NCs) on graphitic carbon nitride is developed, which is a promising visible-light-driven photocatalyst. In this photocatalyst, a part of the surface of the Pt NCs is protected by sulfur atoms, preventing oxidation. Consequently, the hydrogen-evolution activity per loading weight of Pt cocatalyst is significantly improved, 53 times, compared with that of a Pt-cocatalyst loaded photocatalyst by the conventional method. The developed method is also effective to enhance the overall water-splitting activity of other advanced photocatalysts such as SrTiO3 and BaLa4 Ti4 O15 .

Promoting Photocatalytic Carbon Dioxide Reduction by Tuning the Properties of Cocatalysts.

Suppressing the amount of carbon dioxide in the atmosphere is an essential measure toward addressing global warming. Specifically, the photocatalytic CO2 reduction reaction (CRR) is an effective strategy because it affords the conversion of CO2 into useful carbon feedstocks by using sunlight and water. However, the practical application of photocatalyst-promoting CRR (CRR photocatalysts) requires significant improvement of their conversion efficiency. Accordingly, extensive research is being conducted toward improving semiconductor photocatalysts, as well as cocatalysts that are loaded as active sites on the photocatalysts. In this review, we summarize recent research and development trends in the improvement of cocatalysts, which have a significant impact on the catalytic activity and selectivity of photocatalytic CRR. We expect that the advanced knowledge provided on the improvement of cocatalysts for CRR in this review will serve as a general guideline to accelerate the development of highly efficient CRR photocatalysts.

An older patient with active ulcerative colitis and coronavirus disease 2019 (COVID-19) pneumonia successfully treated with the combination of anti-TNFα therapy and azathioprine.

A 77-year-old patient with ulcerative colitis (UC) was transferred to our department because of worsening bloody diarrhea and abdominal pain, which was consistent with a UC flare. Two days after admission, she complained of cough and high fever. The polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was positive, and a computed tomography showed pneumonia in the left lobe, consistent with coronavirus disease 2019 (COVID-19) pneumonia. However, frequent bloody diarrhea and abdominal pain due to the UC flare persisted; therefore, an additional immunosuppressive agent needed to be considered. We initiated infliximab biosimilar (IFX-BS), and her abdominal symptoms improved. However, they deteriorated after the second IFX-BS infusion. After confirming that the patient was negative for SARS-CoV-2 by PCR, we administered a combination of azathioprine and IFX-BS. The combination treatment improved her intestinal symptoms without worsening COVID-19 pneumonia. She has remained in remission for over a year since her discharge.

[Report on a new remote collaborative medical care system -construction and operation of a remote collaborative medical care network for inflammatory bowel disease using information and communication technology in Hokkaido].

Inflammatory bowel disease (IBD) comprises 2 major types-ulcerative colitis (UC) and Crohn's disease (CD). A remote collaborative medical care fee has been established for patients with suspected intractable diseases since 2020. Remote collaborative medical care is a type of telemedicine wherein a hospital specialist for intractable diseases, the patient, and an attending physician at a community hospital communicate via video calls. In IBD cases, however, treating patients who have already been diagnosed with severe or intractable diseases is difficult. As a part of the Hokkaido Intractable Disease Medical Care System Development Project, we have started providing free remote collaborative medical care services for all IBD patients, including those with a confirmed diagnosis and attending regional hospitals. We set up the telemedicine system using Microsoft365, a commercial cloud, and Nextcloud, a PaaS, to ensure robust security and enable rapid and massive sharing of medical details by information and communication technology. Since April 2021, we have examined 27 patients (36 times). Among these patients, 5 patients from regional hospitals were undiagnosed (1 patient of suspected CD, 3 patients of suspected IBD unclassified (IBD-U), and 1 patient of undiagnosed enteritis). Twenty-two patients from regional hospitals had a confirmed diagnosis (17 UC and 5 CD patients). Eight patients required a second time remote collaborative medical care, and 1 patient required a third time remote collaborative medical care. There was no equipment failure such as communication failure or system trouble, and all patients could be examined smoothly. The maintenance cost of the telemedicine system was 2500yen/month per hospital. Among all cases receiving remote collaborative medical care, 86% were consultations for refractory or severe active cases with a confirmed diagnosis of IBD. At present, the remote collaborative medical care fee for diagnosed patients is not permitted. Since remote collaborative medical care has the potential to correct regional disparities in medical standards, there is an urgent need to review the criteria for remote collaborative medical care fees.

Development and Functionalization of Visible-Light-Driven Water-Splitting Photocatalysts.

With global warming and the depletion of fossil resources, our fossil fuel-dependent society is expected to shift to one that instead uses hydrogen (H2) as a clean and renewable energy. To realize this, the photocatalytic water-splitting reaction, which produces H2 from water and solar energy through photocatalysis, has attracted much attention. However, for practical use, the functionality of water-splitting photocatalysts must be further improved to efficiently absorb visible (Vis) light, which accounts for the majority of sunlight. Considering the mechanism of water-splitting photocatalysis, researchers in the various fields must be employed in this type of study to achieve this. However, for researchers in fields other than catalytic chemistry, ceramic (semiconductor) materials chemistry, and electrochemistry to participate in this field, new reviews that summarize previous reports on water-splitting photocatalysis seem to be needed. Therefore, in this review, we summarize recent studies on the development and functionalization of Vis-light-driven water-splitting photocatalysts. Through this summary, we aim to share current technology and future challenges with readers in the various fields and help expedite the practical application of Vis-light-driven water-splitting photocatalysts.

Extensive mucosal sloughing of the small intestine and colon in a patient with severe COVID-19.

Patients with coronavirus disease 2019 (COVID-19) primarily cause respiratory symptoms. However, gastrointestinal (GI) symptoms can also occur. The endoscopic characteristics of the GI tract in COVID-19 patients remain unclear. We herein report a 62-year-old male with severe COVID-19 who needed multidisciplinary treatment, including extracorporeal membrane oxygenation (ECMO). Despite the improvement in his respiratory status, GI bleeding developed. Capsule endoscopy and colonoscopy revealed extensive mucosal sloughing in the lower intestinal tract. Additionally, we performed a comprehensive analysis of the mRNA expression levels of various proinflammatory cytokines in the intestinal mucosal tissues. The results suggested a significant elevation of IL-6, which could be involved in the pathophysiology of the GI involvement in COVID-19. Further investigation with more clinical data, including endoscopic findings and molecular analyses, will contribute to a comprehensive understanding of COVID-19-associated GI injury.

Interim analysis of a multicenter registry study of COVID-19 patients with inflammatory bowel disease in Japan (J-COSMOS).

BACKGROUND: The spread of coronavirus disease 2019 (COVID-19) had a major impact on the health of people worldwide. The clinical background and clinical course of inflammatory bowel disease (IBD) among Japanese patients with COVID-19 remains unclear. METHODS: This study is an observational cohort of Japanese IBD patients diagnosed with COVID-19. Data on age, sex, IBD (classification, treatment, and activity), COVID-19 symptoms and severity, and treatment of COVID-19 were analyzed. RESULTS: From 72 participating facilities in Japan, 187 patients were registered from June 2020 to October 2021. The estimated incidence of COVID19 in Japanese IBD patients was 0.61%. The majority of IBD patients with COVID-19 (73%) were in clinical remission. According to the WHO classification regarding COVID-19 severity, 93% (172/184) of IBD patients had non-severe episodes, while 7% (12/184) were severe cases including serious conditions. 90.9% (165/187) of IBD patients with COVID-19 had no change in IBD disease activity. A logistic regression analysis stepwise method revealed that older age, higher body mass index (BMI), and steroid use were independent risk factors for COVID-19 severity. Six of nine patients who had COVID-19 after vaccination were receiving anti-tumor necrosis factor (TNF)-α antibodies. CONCLUSION: Age, BMI and steroid use were associated with COVID-19 severity in Japanese IBD patients.

Multicenter, cross-sectional, observational study on Epstein-Barr viral infection status and thiopurine use by age group in patients with inflammatory bowel disease in Japan (EBISU study).

BACKGROUND: The Epstein-Barr virus (EBV) infection status in patients with inflammatory bowel disease (IBD), particularly those using thiopurines, may be associated with the risk of lymphoproliferative disorder and hemophagocytic lymphohistiocytosis. This was the first multicenter survey of EBV infection in Japanese patients with IBD. Factors related to the EBV infection status were also investigated. METHODS: Five tertiary institutions in Japan participated in this study to examine pediatric and adult patients with IBD. Serum EBV anti-viral capsid antigen (VCA) IgG, EBV anti-VCA IgM, and anti-EBV nuclear antigen-antibody were measured in 495 patients with IBD. The patients' information was obtained from their medical records. Prior EBV infection was defined as anti-VCA IgM negativity and anti-VCA IgG positivity (UMIN000033004). RESULTS: The patients' median age was 25 years (range 0-92 years). Of the 495 patients, nine were anti-VCA IgM-positive and 354 were anti-VCA IgG-positive (seroprevalence: 72.8%). The proportion of patients with prior EBV infection was 0% for those aged < 5 years, < 60% for those aged < 30 years, and > 90% for those aged > 30 years. The proportion of EBV-uninfected patients using thiopurines was 28.4% (52/183) for all patients and 51.8% (44/85) for pediatric patients. Age was significantly associated with anti-VCA IgG seropositivity (p < 0.01, odds ratio: 0.902, 95% confidence interval: 0.880-0.925). No cases of lymphoproliferative disorder, hemophagocytic lymphohistiocytosis, or chronic active EBV infection were reported. CONCLUSIONS: Approximately 30% of Japanese patients with IBD were EBV-uninfected, including those using thiopurines. Age was a significant factor for anti-VCA IgG seropositivity.

Monolayer platform using human biopsy-derived duodenal organoids for pharmaceutical research.

The human small intestine is the key organ for absorption, metabolism, and excretion of orally administered drugs. To preclinically predict these reactions in drug discovery research, a cell model that can precisely recapitulate the in vivo human intestinal monolayer is desired. In this study, we developed a monolayer platform using human biopsy-derived duodenal organoids for application to pharmacokinetic studies. The human duodenal organoid-derived monolayer was prepared by a simple method in 3-8 days. It consisted of polarized absorptive cells and had tight junctions. It showed much higher cytochrome P450 (CYP)3A4 and carboxylesterase (CES)2 activities than did the existing models (Caco-2 cells). It also showed efflux activity of P-glycoprotein (P-gp) and inducibility of CYP3A4. Finally, its gene expression profile was closer to the adult human duodenum, compared to the profile of Caco-2 cells. Based on these findings, this monolayer assay system using biopsy-derived human intestinal organoids is likely to be widely adopted.

Gastrointestinal involvement in a patient with familial Mediterranean fever mimicking Crohn's disease: a case report.

Familial Mediterranean fever (FMF) in gastrointestinal involvement has been considered rare, but resent reports suggest that FMF causes enterocolitis which is similar endoscopic findings to inflammatory bowel disease. The clinical characteristics and endoscopic findings of FMF with enterocolitis remain unclear. Here, we report a case of an FMF patient who had enterocolitis with stricture of the terminal ileum whose endoscopic and clinical features mimicked Crohn's disease. A 23-year-old man who was diagnosed with FMF 10 years ago presented with abdominal pain and diarrhea. Colonoscopy showed terminal ileitis and aphthous colitis; however, these findings, including the histopathology, did not confirm Crohn's disease. Therefore, we diagnosed FMF with enterocolitis and administered anti-interleukin-1ß monoclonal antibody (canakinumab). The patient's symptoms improved with treatment, but after 1 year, lower abdominal pain recurred. Colonoscopy revealed a stricture of the terminal ileum. Endoscopic balloon dilation relieved his symptoms. At present, he has been followed up without surgical treatment by endoscopic balloon dilation every 6 month. Clinicians should be aware that FMF accompanied with enterocolitis may resemble Crohn's disease.

Successful hemostasis of bleeding gastric inflammatory fibroid polyp by endoscopic treatment in a patient with severe COVID-19.

The coronavirus disease-2019 (COVID-19) has rapidly become a pandemic, resulting in a global suspension of non-emergency medical procedures such as screening endoscopic examinations. There have been several reports of COVID-19 patients presenting with gastrointestinal symptoms such as diarrhea and vomiting. In this report, we present a case of successful hemostasis of bleeding gastric inflammatory fibroid polyp by endoscopic treatment in a patient with severe COVID-19. The case was under mechanical ventilation with extracorporeal membrane oxygenation (ECMO), and the airway was on a closed circuit. This indicates that COVID-19 is associated with not only lung injury but also intestinal damage, and that proper protective protocols are essential in guaranteeing the best outcomes for patients and clinical professionals during this pandemic.

The characteristics of gastrointestinal symptoms in patients with severe COVID-19: a systematic review and meta-analysis.

Although primarily a respiratory illness, several studies have shown that COVID-19 causes elevation of liver enzymes and various gastrointestinal (GI) symptoms. The aim of this study was to undertake a systematic review and meta-analysis to determine whether the presence of gastrointestinal (GI) symptoms contributed toward COVID-19 severity, and identify the GI symptoms characteristic of severe COVID-19. We conducted a literature search of PubMed from December 1, 2019, to June 30, 2020, and identified all reports with GI symptoms reported. A meta-analysis comparing the severity of COVID-19 with the presence of liver enzyme elevation and GI symptoms was performed using RevMan version 5.4. Pooled data from 15,305 unique reverse transcriptase-polymerase chain reaction positive COVID-19 patients from 44 studies were analyzed. We found that the severe COVID-19 patients significantly had abdominal pain compared to the non-severe COVID-19 patients (OR = 2.70, 95% CI 1.17-6.27, Z = 2.32, p = 0.02, I2 = 0%) by analyzed 609 patients of 4 studies who reported both abdominal pain and COVID-19 severity. However, there was no significant difference in the incidence of diarrhea, nausea, or vomiting between the two groups. Thus, this systematic review and meta-analysis demonstrated that abdominal pain could be characteristic of severe COVID-19 infections. Compared with other viral infections that primarily infect the respiratory system, patients with COVID-19 have a slightly lower frequency of diarrheal symptoms with abdominal pain. However, to confirm this, further studies with COVID-19 patients across various countries and ethnicities are required.

Stress distribution analysis of oral mucosa under soft denture liners using smoothed particle hydrodynamics method.

This study aims to simulate the stress distributions of oral mucosa under different soft denture liners using the smoothed particle hydrodynamics (SPH) method. The Young's modulus and viscosity of denture liners composed of silicone (Sofreliner Super Soft and Sofreliner Tough Medium, Tokuyama Dental), acrylic (Vertex Soft, Vertex Dental), and a tissue conditioner (Visco-gel, Dentsply Sirona) were measured using a creep meter. A numerical simulation model that represents the stress distribution of oral mucosa under soft denture liners was also developed using the SPH method. The oral mucosa was divided into four regions: A) buccal border, B) buccal shelf, C) crest of residual ridge, and D) lingual border. For each region, the von Mises stress (hereafter, referred to as "Mises stress") of the oral mucosa was calculated. Based on a creep test, Sofreliner Super Soft and Sofreliner Tough Medium silicone liners showed an elastic behavior, whereas Vertex Soft acrylic liner and Visco-gel tissue conditioner showed a viscoelastic behavior. In addition, Sofreliner Super Soft and Visco-gel exhibited a large strain. The numerical simulation revealed that the mean Mises stress was the highest in region A and lowest in region D. Vertex Soft acrylic liners resulted in a statistically lower Mises stress on the oral mucosa compared to the other three soft denture liners. Different soft denture liner materials lead to different stress distributions on the oral mucosa. The acrylic soft denture liners cause a lower Mises stress on the oral mucosa than the silicon soft denture liners. This suggests that acrylic soft denture liners would be more effective for manufacturing painless dentures than silicone soft denture liners.