Enhancing Origin Prediction: Deep Learning Model for Diagnosing Premature Ventricular Contractions with Dual-Rhythm Analysis Focused on Cardiac Rotation.

BACKGROUND: Several algorithms can differentiate inferior axis premature ventricular contractions (PVCs) originating from the right side and left side on 12-lead electrocardiograms (ECGs). However, it is unclear whether distinguishing the origin should rely solely on PVC or incorporate sinus rhythm (SR). AIMS: We compared the Dual-Rhythm model (incorporating both SR and PVC) to the PVC model (using PVC alone), and quantified the contribution of each ECG lead in predicting the PVC origin for each cardiac rotation. METHODS: This multicenter study enrolled 593 patients from 11 centers-493 from Japan and Germany, and 100 from Belgium, which used as the external validation dataset. Using a hybrid approach combining a Resnet50-based convolutional neural network and a Transformer model, we developed two variants-the PVC and Dual-Rhythm models-to predict PVC origin. RESULTS: In the external validation dataset, the Dual-Rhythm model outperformed the PVC model in accuracy (0.84 vs. 0.74, respectively; p < 0.01), precision (0.73 vs. 0.55, respectively; p < 0.01), specificity (0.87 vs. 0.68, respectively; p < 0.01), area under the receiver operating characteristic curve (0.91 vs. 0.86, respectively; p = 0.03), and F1-Score (0.77 vs. 0.68, respectively; p = 0.03). The contributions to PVC origin prediction were 77.3% for PVC and 22.7% for the SR. However, in patients with counterclockwise rotation, SR had a greater contribution in predicting the origin of right-sided PVC. CONCLUSIONS: Our deep learning-based model, incorporating both PVC and SR morphologies, resulted in a higher prediction accuracy for PVC origin. Considering SR is particularly important for predicting right-sided origin in patients with counterclockwise rotation.

Association of pancreatic atrophy patterns with intraductal extension of early pancreatic ductal adenocarcinoma: a multicenter retrospective study.

BACKGROUND: Focal pancreatic parenchymal atrophy (FPPA) and upstream pancreatic atrophy (UPA) may indicate the presence of early pancreatic cancer. In early pancreatic cancer, the tumor occasionally spreads laterally along the main pancreatic duct, presenting challenges in determining the extent of surgical resection. This study aimed to investigate the association of pancreatic atrophy pattern and intraductal cancer extension. METHODS: Thirty-two patients with early-stage pancreatic cancer who underwent surgery at five participating centers were enrolled. Pancreatic atrophy was defined as the narrowing of parenchyma compared to the surrounding parenchyma and was classified as either FPPA (partial atrophy surrounding the pancreatic duct stenosis) or UPA (global atrophy caudal to the site of duct stenosis). Intraductal cancer extension was defined as an extension exceeding 10 mm. RESULTS: Preoperative computed tomography revealed FPPA, UPA, and no parenchymal atrophy in 13, 13, and 6 patients. Cases with FPPA or UPA showed significantly longer cancer extensions than those without atrophy (P = 0.005 and P = 0.03, respectively). Intraductal cancer extension was present in all but one case of FPPA. 69% (9/13) of the cases with UPA showed intraductal cancer extension, whereas cases without atrophy showed no intraductal cancer extension. Importantly, two patients with FPPA or UPA showed positive resection margins during surgery and three patients with FPPA or UPA showed recurrence in the remnant pancreas. CONCLUSIONS: The presence of FPPA and UPA indicates lateral cancer extension in early-stage pancreatic cancer. Preoperative assessment of the pancreatic parenchyma may provide valuable insights for determining the extent of surgical resection.

Roles of Atrial Arrhythmias in Triggering Torsade de Pointes in Patients With Acquired Long-QT Syndrome.

BACKGROUND: Little is known about the role of atrial arrhythmias (AAs) in triggering Torsade de Pointes (TdP) in patients with long-QT syndrome (LQTS). The aim of this study was to examine the contribution of AAs to the development of TdP in acquired LQTS patients. METHODS: The initiation patterns of 81 episodes of TdP obtained from 34 consecutive acute acquired LQTS patients (14 men, median age, 69 years; median QTc, 645.5 ms) with documented TdP were analyzed. The initiation mode of TdP was divided into 3 categories: (1) preceding short-long sequence (SLS); (2) sudden R-on-T phenomenon without preceding SLS; and (3) increased atrial rate. The patients were divided into 2 groups based on the presence or absence of AAs-induced TdP; AAs-induced (n=18) and non-AAs-induced (n=16) groups. The association of clinical/ECG characteristics and TdP frequency after initiating conventional therapy with AAs-induced TdP was evaluated. The groups were compared using the Mann-Whitney U test or Fisher exact test. RESULTS: AAs-induced group comprised 52.9% (18/34) of the patients studied. TdP was preceded by AAs-initiated SLSs in 41.2% (14/34) of the patients and was directly induced by R-on-T AAs (AAs coincidentally encountered a vulnerable repolarizing region during the T wave) in 23.5% (8/34). AAs triggered 48 (59.3%) of the 81 TdP episodes. AAs-initiated SLSs in 67.8% (40/59) of the SLS-induced TdP episodes. R-on-T AAs accounted for 23.5% (19/81) of the TdP episodes. AAs-induced group experienced TdP after initiating therapy more frequently than non-AAs-induced group (2.5 versus 1 event, P=0.008). AAs-induced group exhibited macroscopic T-wave alternans more frequently than non-AAs-induced group (6 versus 0, P=0.02). CONCLUSIONS: AAs play a key role in triggering TdP in more than half of patients with acute acquired LQTS and can increase TdP frequency after initiating therapy. Thus, AAs are not benign but rather can be life-threatening in patients with acute acquired LQTS.

Direct catalytic oxidation of rice husk lignin with hydroxide nanorod-modified copper foam and muconate production by engineered Pseudomonas sp. NGC7.

For the direct alkaline oxidation of rice husk lignin, we developed a copper foam-based heterogeneous catalyst that offers advantages in its recovery after the reaction mixture. The depolymerized products were utilized for muconate production by an engineered Pseudomonas sp. NGC7-based strain. A hydroxide nanorod-modified copper foam was prepared by the surface oxidation of copper foam, followed by alkaline oxidation of rice husk lignin over the catalyst. The catalyst was easily separated from the cellulosic residues in the reaction mixture, and the residues were then recovered by filtration. The resulting lignin stream was composed of a variety of aromatic monomers containing p-hydroxyphenyl, guaiacyl, and syringyl compounds. The catabolic activity of Pseudomonas sp. NGC7 was demonstrated to be more suitable for muconate production from a mixture comprising 4-hydroxybenzoate (a typical p-hydroxyphenyl compound), vanillate (a guaiacyl compound), and syringate (a syringyl compound), owing to its natural ability to grow on syringate. Thus, it was applied to produce muconate from a rice husk lignin stream prepared through hydroxide nanorod-modified copper foam-catalyzed alkaline oxidation by conferring the genes responsible for converting the acetophenone derivatives to their corresponding aromatic acids and protocatechuate decarboxylase to an NGC7-based strain deficient in protocatechuate 3,4-dioxygenase and muconate cycloisomerase. As a result, the engineered NGC7-based muconate-producing strain produced muconate selectively from the rice husk lignin stream at 93.7 mol% yield.

Effective degradation of various bacterial toxins using ozone ultrafine bubble water.

Infectious and foodborne diseases pose significant global threats, with devastating consequences in low- and middle-income countries. Ozone, derived from atmospheric oxygen, exerts antimicrobial effects against various microorganisms, and degrades fungal toxins, which were initially recognized in the healthcare and food industries. However, highly concentrated ozone gas can be detrimental to human health. In addition, ozonated water is unstable and has a short half-life. Therefore, ultrafine-bubble technology is expected to overcome these issues. Ultrafine bubbles, which are nanoscale entitles that exist in water for considerable durations, have previously demonstrated bactericidal effects against various bacterial species, including antibiotic-resistant strains. This present study investigated the effects of ozone ultrafine bubble water (OUFBW) on various bacterial toxins. This study revealed that OUFBW treatment abolished the toxicity of pneumolysin, a pneumococcal pore-forming toxin, and leukotoxin, a toxin that causes leukocyte injury. Silver staining confirmed the degradation of pneumolysin, leukotoxin, and staphylococcal enterotoxin A, which are potent gastrointestinal toxins, following OUFB treatment. In addition, OUFBW treatment significantly inhibited NF-κB activation by Pam3CSK4, a synthetic triacylated lipopeptide that activates Toll-like receptor 2. Additionally, OUFBW exerted bactericidal activity against Staphylococcus aureus, including an antibiotic-resistant strain, without displaying significant toxicity toward human neutrophils or erythrocytes. These results suggest that OUFBW not only sterilizes bacteria but also degrades bacterial toxins.

Prescription Pattern of Anamorelin; a Therapeutic Agent for Cancer Cachexia.

Background: The commercial availability of anamorelin, Japan's first therapeutic agent for cancer cachexia in 2021, led to an investigation into its prescription patterns at Toyama University Hospital. Objective: We aimed to analyze anamorelin prescription trends and outcomes among cancer cachexia patients. Methods: A retrospective study from July 2021 to December 2022 examined 88 cases, assessing demographics, cancer types, prescription locations, and meal intake changes. Results: Anamorelin usage was predominant during chemotherapy, especially for pancreatic cancer in outpatient settings. Approximately 30% experienced increased meal intake. Chemotherapy-initiated cases had a longer median duration (55 days) compared with best supportive care only cases (12 days). Conclusion: Anamorelin demonstrated significant prescription patterns, particularly during chemotherapy for pancreatic cancer in outpatient settings, suggesting potential efficacy enhancements when administered with chemotherapy in cancer cachexia management. The study underscores the importance of tailored approaches to optimize anamorelin's therapeutic benefits.

Utility of Contrast-Enhanced Harmonic Endoscopic Ultrasonography to Diagnose Pancreaticobiliary Maljunction.

BACKGROUND: Detection of a common channel outside the duodenal wall is important in diagnosing pancreaticobiliary maljunction (PBM). The present study evaluated the utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) in diagnosing PBM. METHODS: This single-center retrospective study enrolled 45 patients who were diagnosed with PBM or high confluence of pancreatobiliary ducts (HCPBD) between January 2007 and December 2021. The diagnostic sensitivities of contrast-enhanced computed tomography (CE-CT), magnetic resonance imaging (MRI), and CH-EUS for diagnosing PBM were analyzed. Imaging findings were evaluated by two reviewers blinded to the clinicopathological results. RESULTS: Based on diagnostic criteria, 33 patients were diagnosed with PBM and 12 with HCPBD. Compared with the patients with HCPBD, those with PBM had significantly longer common channel (12.5 mm vs. 8.1 mm, P = 0.018) and common bile duct (13.0 mm vs. 8.6 mm, P = 0.049) lengths. The κ-coefficients for differentiating PBM and HCPBD were 0.871 between CE-CT and MRI, 0.330 between CE-CT and CH-EUS, and 0.611 between MRI and CH-EUS. The diagnostic sensitivity of CH-EUS (95.2%) was higher than that of CE-CT (83.3%) and MRI (82.8%), although the differences were not statistically significant. CONCLUSION: CH-EUS may be useful for the diagnosis of PBM.

Difference in reaction mechanism between ZnZrOx and InZrOx for CO2 hydrogenation.

Oxide solid-solution catalysts, such as Zn-doped ZrO2 (ZnZrOx) and In-doped ZrO2 (InZrOx), exhibit distinctive catalytic capabilities for CH3OH synthesis via CO2 hydrogenation. We investigated the active site structures of these catalysts and their associated reaction mechanisms using both experimental and computational approaches. Electron microscopy and X-ray absorption spectroscopy reveal that the primary active sites are isolated cations, such as Zn2+ and In3+, dissolved in tetragonal ZrO2. Notably, for Zn2+, decomposition of the methoxy group, which is an essential intermediate in CH4 synthesis, is partially suppressed because of the relatively high stability of the methoxy group. Conversely, the methyl group strongly adsorbs on In3+, facilitating the conversion of the methoxy species into methyl groups. The decomposition of CH3OH is also suggested to contribute to CH4 synthesis. These results highlight the generation of CH4 as a byproduct of the InZrOx catalyst. Understanding the active site structure and elucidating the reaction mechanism at the atomic level are anticipated to contribute significantly to the future development of oxide solid-solution catalysts.

Hereditary hemorrhagic telangiectasia with hepatic arteriovenous shunt diagnosed due to liver damage.

A 53-year-old woman was diagnosed with liver dysfunction in August 20XX. Computed tomography (CT) revealed multiple hepatic AV shunts, and she was placed under observation. In March 20XX + 3, she developed back pain, and CT performed during an emergency hospital visit showed evidence of intrahepatic bile duct dilatation. She was referred to our gastroenterology department in May 20XX + 3. We conducted investigations on suspicion of hereditary hemorrhagic telangiectasia (HHT) with hepatic AV shunting based on contrast-enhanced CT performed at another hospital. HHT is generally discovered due to epistaxis, but there are also cases where it is diagnosed during examination of liver damage.

Photodynamic Therapy With Resveratrol and an Nd:YAG Laser for Enterococcus faecalis Elimination.

BACKGROUND/AIM: Enterococcus faecalis is the leading cause of endodontic treatment failures. Despite various conventional disinfection approaches, microorganisms often persist in root canals. Photodynamic therapy (PDT) is an adjunct antimicrobial strategy employing a nontoxic photosensitizer (PS) and light source. This study evaluated the antimicrobial effect of PDT using an Nd:YAG laser and resveratrol (RSV) with or without pigment, and confirmed that RSV is nontoxic as a PS. MATERIALS AND METHODS: We employed laser irradiation at a 3W output power, using RSV and red pigment as the PS, on an E. faecalis bacterial solution. Subsequently, colony-forming units were quantified. The impact of RSV on osteoblasts was measured using an MTT assay. RESULTS: E. faecalis counts declined after laser irradiation. The combined application of laser irradiation with RSV, red pigment, or both showed a reduction compared to no irradiation and control groups without RSV and red pigment. The 50% cytotoxic concentration against osteoblast cells from mice incubated with RSV for 48 h was 162 µM. The value with RSV and laser was 201 µM and that with RSV and red pigment was 199 µM. The value with RSV, laser and red pigment was 357 µM. CONCLUSION: The combination of Nd:YAG laser irradiation and RSV as the PS with pigment was efficacious for E. faecalis elimination without inducing any toxic effects on osteoblasts. This combination holds potential as a root canal irrigation strategy.

A Case of an Splenic Artery Aneurysm and Focal Nodular Hyperplasia Associated with an Abdominal Vascular Abnormality of Hereditary Hemorrhagic Telangiectasia.

In October 2021, a 51-year-old woman developed a skin rash. Abdominal computed tomography revealed a large splenic artery aneurysm and an intrahepatic portovenous shunt. As her splenic artery aneurysm was at risk of rupture, she was referred to the Kindai University Hospital and underwent coiling surgery. In October 2023, approximately two years after she had been initially referred, contrast-enhanced ultrasound revealed findings suggestive of focal nodular hyperplasia. No reports have confirmed the occurrence of liver masses in patients with hereditary hemorrhagic telangiectasia, which is considered to be an interesting finding when investigating the mechanism of tumor development.

Hemophagocytic lymphohistiocytosis induced by nivolumab/ipilimumab combination therapy: A case of lung adenocarcinoma that responded to early steroid pulse therapy.

BACKGROUND: Immune checkpoint inhibitors have been reported to have excellent therapeutic effects on various malignant tumors. However, immune-related adverse events can occur, targeting various organs. CASE PRESENTATION: A 49-year-old male with lung carcinoma was started on carboplatin + pemetrexed + nivolumab (every 3 weeks) + ipilimumab (every 6 weeks), and nivolumab/ipilimumab was administered in the 3rd course. Subsequently, fever and fatigue developed, and grade 3 liver damage was also noted, so he was admitted to Kindai University Hospital. A bone marrow aspirate examination was performed on the third day of illness, and a definitive diagnosis of hemophagocytic lymphohistiocytosis (HLH) was made. It was determined that immediate therapeutic intervention was necessary, and pulse therapy with methylprednisolone was started on the third day of illness. After 3 days of pulse treatment, a rapid recovery of platelet values, a decrease in ferritin levels, and a decrease in lactate dehydrogenase were observed. Subjective symptoms such as fever and fatigue also quickly improved. CONCLUSION: Early diagnosis and treatment for HLH resulted in a positive response. The number of HLH cases may increase in the future due to the expansion of immune checkpoint inhibitor indications.

Appetite and family and friends network among community-dwelling older adults: A cross-sectional study.

OBJECTIVES: The aim of this study was to investigate the stronger correlate of appetite-family or friend networks-in community-dwelling older adults, given that undernutrition can impair physical function, increase mortality, and be influenced by social networks. METHODS: A cross-sectional study was conducted in Kasugai City, Aichi Prefecture, and Nara City, Nara Prefecture, Japan, between August 2019 and March 2023. The analysis included 119 participants (women: 79%, mean age: 76.5 ± 5.6 y). A multiple regression analysis was performed, using the scores from the Japanese version of the Simplified Nutritional Appetite Questionnaire (SNAQ-J) as the dependent variable and family network and friend network as the independent variables. The analysis included social participation, living alone status, sex, age, body mass index, skeletal muscle mass index, grip strength, walking speed, and the Japanese version of the 15 Geriatric Depression Scale score as covariates to examine their relationship with appetite. RESULTS: The mean value of the SNAQ-J score of the participants was 15.4 ± 1.2. Seven participants (6%) had a loss of appetite. Family network was significantly associated with appetite (B = 0.121, ß = 0.266, P <0.05; 95% condidence interval [CI], 0.030-0.212). In the single regression analysis, the friend network was significantly associated with the total score of the SNAQ-J (B = 0.115, P <0.001; 95% CI, 0.052-0.177); however, this association was not observed in the multiple regression analysis (B = 0.002, ß = 0.006, P = 0.954; 95% CI, -0.074-0.078). CONCLUSION: Appetite was associated with family networks. Among social networks, focusing on family networks may help prevent the loss of appetite in older adults in Japan.

ERCP using balloon-assisted endoscopes versus EUS-guided treatment for common bile duct stones in Roux-en-Y gastrectomy.

BACKGROUND AND AIMS: We compared ERCP using a balloon-assisted endoscope (BE-ERCP) with EUS-guided antegrade treatment (EUS-AG) for removal of common bile duct (CBD) stones in patients with Roux-en-Y (R-Y) gastrectomy. METHODS: Consecutive patients who had previous R-Y gastrectomy undergoing BE-ERCP or EUS-AG for CBD stones in 16 centers were retrospectively analyzed. RESULTS: BE-ERCP and EUS-AG were performed in 588 and 59 patients, respectively. Baseline characteristics were similar, except for CBD diameter and angle. The technical success rate was 83.7% versus 83.1% (P = .956), complete stone removal rate was 78.1% versus 67.8% (P = .102), and early adverse event rate was 10.2% versus 18.6% (P = .076) in BE-ERCP and EUS-AG, respectively. The mean number of endoscopic sessions was smaller in BE-ERCP (1.5 ± .8 vs 1.9 ± 1.0 sessions, P = .01), whereas the median total treatment time was longer (90 vs 61.5 minutes, P = .001). Among patients with biliary access, the complete stone removal rate was significantly higher in BE-ERCP (93.3% vs 81.6%, P = .009). Negative predictive factors were CBD diameter ≥15 mm (odds ratio [OR], .41) and an angle of CBD <90 degrees (OR, .39) in BE-ERCP and a stone size ≥10 mm (OR, .07) and an angle of CBD <90 degrees (OR, .07) in EUS-AG. The 1-year recurrence rate was 8.3% in both groups. CONCLUSIONS: Effectiveness and safety of BE-ERCP and EUS-AG were comparable in CBD stone removal for patients after R-Y gastrectomy, but complete stone removal after technical success was superior in BE-ERCP.

Reductions in liver enzymes are associated with anti-hyperglycaemic and anti-obesity effects of tofogliflozin in people with type 2 diabetes: Post-hoc analyses.

AIMS: How the pathology of type 2 diabetes (T2D), including hyperglycaemia and obesity, affects liver enzymes has not been clinically demonstrated. Thus, we compared time courses of gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT) with those of fasting plasma glucose (FPG) and body weight (BW) during treatment with the SGLT2 inhibitor tofogliflozin for T2D. MATERIALS AND METHODS: We post-hoc analysed preexisting data on 1046 people with T2D administered tofogliflozin or placebo for 24 weeks in four tofogliflozin studies. First, time courses of percent changes in variables during the intervention were analysed using a mixed effect model to explore the similarity of the time courses and to evaluate time-treatment interactions. Second, clinical factors related to the percent changes in GGT and ALT were clarified using multivariate analyses. RESULTS: GGT levels and FPG values rapidly and significantly decreased via tofogliflozin as early as week 4, with decreases maintained until week 24. Conversely, BW and ALT decreased progressively until week 24. Time courses of FPG (p = .365, time-treatment interaction) and GGT (p = .510) reductions were parallel between tofogliflozin and placebo from weeks 4 to 24, while BW and ALT reductions (p < .001, respectively) were not. Reductions in GGT at week 24 were associated with reductions in FPG and BW at week 24, whereas ALT reductions were only associated with reductions in BW. CONCLUSIONS: Reductions in GGT and ALT were associated with the anti-hyperglycaemic and anti-obesity effects of tofogliflozin, respectively, in people with T2D. Therefore, GGT and ALT may be surrogate markers for hyperglycaemia and obesity in T2D.

True diagnostic ability of EUS-guided fine-needle aspiration/biopsy sampling for small pancreatic lesions ≤10 mm and salvage diagnosis by pancreatic juice cytology: a multicenter study.

BACKGROUND AND AIMS: The diagnostic performance of EUS-guided fine-needle aspiration/biopsy sampling (EUS-FNAB) for pancreatic ductal adenocarcinoma (PDAC) ≤10 mm in diameter is relatively low. Pancreatic juice cytology (PJC) has gained attention because of its high sensitivity for small PDACs. We aimed to clarify the diagnostic ability of EUS-FNAB and the salvage ability of PJC for PDAC ≤10 mm. METHODS: Data obtained from attempted EUS-FNAB for patients with EUS-confirmed pancreatic tumors ≤10 mm (excluding pancreatic metastases/malignant lymphomas) were retrospectively analyzed. Patients who experienced technical failure or had a negative EUS-FNAB result and had a strong likelihood of PDAC based on imaging characteristics underwent PJC. PDAC was diagnosed using resected histologic specimens, EUS-FNAB-positive tumor growth on the imaging examination, or additional EUS-FNAB-positive results after increase in tumor size. The primary endpoint was the diagnostic ability of EUS-FNAB for PDAC ≤10 mm. The salvage ability of PJC was also assessed. RESULTS: Overall, 86 of 271 patients with pancreatic tumors ≤10 mm who underwent attempted EUS-FNAB were diagnosed with PDAC. The technical success rate, sensitivity, specificity, and accuracy of EUS-FNAB for PDAC ≤10 mm were 80.8%, 82.3%, 94.9%, and 91.3%, respectively. Among the 35 PDAC patients who experienced technical failure or false-negative results of EUS-FNAB, 26 (74.3%) were correctly diagnosed using salvage PJC. CONCLUSIONS: The true success rate and sensitivity of EUS-FNAB for PDAC ≤10 mm were relatively low. When EUS-FNAB for a pancreatic lesion ≤10 mm strongly suspected to be PDAC is unsuccessful or yields a negative result, PJC is recommended. (Clinical trial registration number: UMIN000049965.).

The effects of exposure to O2- and HOCl-nanobubble water on human salivary microbiota.

Nanobubbles of gas remain dissolved in water for longer periods than ordinary bubbles, and exhibit unique physicochemical and biological properties. As a result, nanobubble water (NBW) is finding widespread use many applications, such as cleaning in the industry and purification of lake water. The ozone NBW (O3-NBW), in particular, has been used in clinical dentistry; however, it has several disadvantages, including the instability of ozone, which is spontaneously converted to molecular oxygen (O3 to O2), and its broad range of antibacterial activity, which can disrupt the oral microbiota. Therefore, the use of NBW in dental medicine requires greater evaluation. Here, we examined the effects of oxygen and hypochlorite NBW (O2-NBW and HOCl-NBW, respectively) on the microbiota in human saliva in 16 male patients (35-75 years old; median: 53.5 years) using multiple assays, including next generation sequencing analysis. 16S rRNA gene sequencing revealed no significant changes in both alpha-diversity and beta-diversity. Principal Coordinate Analysis (PCoA) revealed two subclusters in both unweighted and weighted UniFrac distances. Overall, the results revealed that HOCl-NBW exposure of saliva may lead to inhibition or delay in oral biofilm formation while maintaining the balance of the oral microbiome. These results can lead to the development of a novel type of mouthrinse for prevention of oral infectious diseases.

Palatal microbiota associated with membranous substances in older Japanese individuals undergoing tube feeding in long-term care: A cross-sectional study.

Objective: Tube feeders are prone to membranous substance formation on the palate, and those with membranous substances have a risk of fever, with the probable involvement of their oral bacteria. However, the palatal microbiota of those with membranous substances has not been elucidated. Therefore, we evaluated the differences in palatal microbiota between tube-fed individuals with and without membranous substances to clarify the microbiota. Materials and methods: This study included 19 participants aged 65 years who required tube feeding. The participants' characteristics were collected from nursing records and oral examinations. If membranous materials were found on the palate, a specimen was collected. Membranous substances were defined as keratotic degeneration observed under a microscope. Additionally, we performed a comprehensive microbiome analysis by extracting DNA from the samples and performing 16 S rRNA gene sequencing. Finally, we compared the participant demographics and oral microbiota between patients with and without membranous substances. Results: A total of 11 participants had membranous substances associated with "mouth dryness" (p < 0.001) and "constant mouth opening" (p = 0.020). Palatal microbiota differed between those with and without membranous substances. Among the bacteria with a relative abundance greater than 1.0%, the abundance of Streptococcus (p = 0.007), Fusobacterium (p = 0.041), Streptococcus agalactiae (p = 0.009), and Fusobacterium nucleatum subsp. vincentii (p = 0.026) was significantly higher in the membranous substance group than in the non-membranous substance group. Conclusions: The palatal microbiota of individuals undergoing tube feeding differed depending on the presence or absence of membranous substances. Membrane substance formation associated with dry mouth purportedly alters the palatal microbiota. Streptococcus, Fusobacterium, S. agalactiae, and F. nucleatum subsp. vincentii were more abundant in the oral microbiota of patients with membranous substances. Thus, preventing this formation may help in controlling the growth of these microbes.