肝組織由来胆管系オルガノイドは脱細胞化肝臓の肝内胆管を再構築する

京都大学新制・課程博士博士(医学)甲第24198号医博第4892号京都大学大学院医学研究科医学専攻(主査)教授 川口 義弥, 教授 松田 秀一, 教授 小濱 和貴学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

Kinetics of denaturation and renaturation processes of double-stranded helical polysaccharide, xanthan, in aqueous sodium chloride

K. Terao and Y. Tomofuji. Kinetics of denaturation and renaturation processes of double-stranded helical polysaccharide, xanthan, in aqueous sodium chloride. SPring-8/SACLA Research Frontiers 2022, 78-79. (2023)

Kinetics of denaturation and renaturation processes of double-stranded helical polysaccharide, xanthan in aqueous sodium chloride

Circular dichroism (CD) and small-angle X-ray scattering (SAXS) measurements were made for three xanthan samples, a double helical polysaccharide, in 5 or 10 mM aqueous NaCl after rapid temperature change to investigate the kinetics of the conformational change between the ordered and disordered states. After the rapid heating, the CD signal mainly reflecting the carbonyl groups on the side chains quickly changed (<150 s) while the scattering intensity from SAXS around q (magnitude of the scattering vector) = 1 nm−1 changed more gradually, reflecting the main-chain conformation. The difference between CD and SAXS implies us the intermediate conformation which can be regarded as a loose double helix. The SAXS profile in the rapid cooling process showed that the loose double helical structure was constructed within 150 s, but the CD signal slowly changed with around 2 days to recover the native tight double helix.The definition of α in page 13 is incorrect. The right definition of α is the fraction of the double helix

Detection of Salivary miRNAs That Predict Chronic Periodontitis Progression: A Cohort Study

The aim of this two-year cohort study was to investigate salivary microRNAs (miRNAs) that predict periodontitis progression. A total of 120 patients who underwent supportive periodontal therapy were recruited. Unstimulated whole saliva was collected at baseline. Two years later, 44 patients were followed up (median age, 67.1 years) and divided into two groups: progression group (n = 22), with one or more sites with clinical attachment level (CAL) progression (>3 mm compared with baseline) or tooth extraction due to periodontitis progression; and the control group (n = 22), which did not exhibit CAL progression. In the microarray analysis of salivary miRNAs, hsa-miR-5571-5p, hsa-miR-17-3p, hsa-let-7f-5p, hsa-miR-4724-3p, hsa-miR-99a-5p, hsa-miR-200a-3p, hsa-miR-28-5p, hsa-miR-320d, and hsa-miR-31-5p showed fold change values = 2.0 in the progression group compared with the control group (p 0.7, indicating fair discrimination power. The expressions of salivary hsa-miR-5571-5p, hsa-let-7f-5p, hsa-miR-99a-5p, hsa-miR-28-5p, and hsa-miR-320d were associated with periodontitis progression in patients with chronic periodontitis. These salivary miRNAs may be new biomarkers for progression of periodontitis, and monitoring them may contribute to new diagnostics and precision medicine for periodontitis

Effects of Coffee Intake on Oxidative Stress During Aging-related Alterations in Periodontal Tissue

Background/aim: The purpose of this study was to determine the anti-aging effects of coffee intake on oxidative stress in rat periodontal tissue and alveolar bone loss. Materials and methods: Male Fischer 344 rats (8 weeks old) were randomized to four groups; the baseline group immediately sacrificed, the control group fed with normal powdered food for 8 weeks, and the experimental groups fed with powdered food containing 0.62% or 1.36% coffee components for 8 weeks. Results: Alveolar bone loss and gingival level of 8-hydroxydeoxyguanosine were significantly lower in the 1.36% coffee group than in the control group. Nuclear factor erythroid 2-related factor 2 translocation to the nucleus was significantly higher in the 1.36% coffee group than in the control group. Conclusion: Continuous intake of 1.36% coffee could prevent age-related oxidative stress in the periodontal tissue and alveolar bone loss, possibly by up-regulating the Nrf2 signaling pathway

Relationship between acetaldehyde concentration in mouth air and tongue coating volume

Objective Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehyde by oral microflora. The aim of this pilot study was to investigate the relationship between physiological acetaldehyde concentration and oral condition in healthy volunteers. Material and Methods Sixty-five volunteers (51 males and 14 females, aged from 20 to 87 years old) participated in the present study. Acetaldehyde concentration in mouth air was measured using a portable monitor. Oral examination, detection of oral Candida species and assessment of alcohol sensitivity were performed. Results Acetaldehyde concentration [median (25%, 75%)] in mouth air was 170.7 (73.5, 306.3) ppb. Acetaldehyde concentration in participants with a tongue coating status score of 3 was significantly higher than in those with a score of 1 (

Effects of hydrogen-rich water on aging periodontal tissues in rats

Oxidative damage is involved in age-related inflammatory reactions. The anti-oxidative effects of hydrogen-rich water suppress oxidative damage, which may aid in inhibiting age-related inflammatory reactions. We investigated the effects of drinking hydrogen-rich water on aging periodontal tissues in healthy rats. Four-month-old male Fischer 344 rats (n = 12) were divided into two groups: the experimental group (hydrogen-rich water treatment) and the control group (distilled water treatment). The rats consumed hydrogen-rich water or distilled water until 16 months of age. The experimental group exhibited lower periodontal oxidative damage at 16 months of age than the control group. Although protein expression of interleukin-1 beta did not differ, gene expression of Nod-like receptor protein 3 inflammasomes was activated in periodontal tissues from the experimental group as compared with the control group. Drinking hydrogen-rich water is proposed to have anti-aging effects on periodontal oxidative damage, but not on inflammatory reactions in healthy rats

Effects of self-efficacy on oral health behaviours and gingival health in university students aged 18- or 19-years-old

Aim Although self-efficacy is known to affect various health-related practises, few studies have clearly examined how self-efficacy correlates with oral health behaviors or the oral health condition. We examined the relationship between gingivitis, oral health behaviors and self-efficacy in university students. Material & Methods A total of 2,111 students (1,197 males, 914 females) aged 18 and 19 years were examined. The degree of gingivitis was expressed as the percentage of bleeding on probing (%BOP). Additional information was collected via a questionnaire regarding oral health behaviors (daily frequency of tooth-brushing, use of dental floss and regular check-up). Self-efficacy was assessed using the Self-Efficacy Scale for Self-care (SESS). Path analysis was used to test pathways from self-efficacy to oral health behaviors and %BOP. Results In the final structural model, self-efficacies were related to each other, and they affected oral health behaviors. Good oral health behaviors reduced dental plaque and calculus, and lower levels of dental plaque and calculus resulted in lower %BOP. Conclusion Higher self-efficacy correlated with better oral health behaviours and gingival health in university students. Improving self-efficacy may be beneficial for maintaining good gingival health in university students. To prevent gingivitis, the approach of enhancing self-efficacy in university students would be useful

Preventive effects of trehalose on osteoclast differentiation in rat periodontitis model

Aim Trehalose, which is a disaccharide formed by a 1,1 linkage of two glucose molecules, was suggested to have a suppressive effect on bone resorption. In this study, we examined the effects of topical application of trehalose on osteoclast differentiation in a rat periodontitis model. Material and Methods Rats were divided into four groups. One group received no treatment. In the other groups, experimental periodontitis was induced by ligature placement. These rats with experimental periodontitis received topical application of pure water (vehicle group), 30 mg/ml trehalose solution (30 mg/ml trehalose group) or 60 mg/ml trehalose solution (60 mg/ml trehalose group) to the gingival sulcus respectively. Results The vehicle group showed higher numbers of polymorphonuclear leucocytes, receptor activator of nuclear factor kappa B ligand (RANKL)-positive cells and osteoclasts compared with the no treatment group respectively. Trehalose-applied groups exhibited lower numbers of these cells compared with the vehicle group. Gene expressions of tumour necrosis factor-a, RANKL and toll-like receptor 4 were suppressed by trehalose. In addition, protein expressions of RANKL inducing pathway were less activated by trehalose. Conclusion Topical application of trehalose could suppress osteoclast differentiation by inactivation of RANKL inducing pathway in the rat periodontitis model

Redox-Active Protein Thioredoxin-1 Administration Ameliorates Influenza A Virus (H1N1)-Induced Acute Lung Injury in Mice

Objectives: Influenza virus infections can cause severe acute lung injury leading to significant morbidity and mortality. Thioredoxin-1 is a redox-active defensive protein induced in response to stress conditions. Animal experiments have revealed that thioredoxin-1 has protective effects against various severe disorders. This study was undertaken to evaluate the protective effects of recombinant human thioredoxin-1 administration on influenza A virus (H1N1)-induced acute lung injury in mice. Design: Prospective animal trial. Setting: Research laboratory. Subjects: Nine-week-old male C57BL/6 mice inoculated with H1N1. Intervention: The mice were divided into a vehicle-treated group and recombinant human thioredoxin-1-treated group. For survival rate analysis, the vehicle or recombinant human thioredoxin-1 was administered intraperitoneally every second day from day -1 to day 13. For lung lavage and pathological analyses, vehicle or recombinant human thioredoxin-1 was administered intraperitoneally on days 1, 1, and 3. Measurements and Main Results: Lung lavage and pathological analyses were performed at 24, 72, and 120 hrs after inoculation. The recombinant human thioredoxin-1 treatment significantly improved the survival rate of H1N1-inoculated mice, although the treatment did not affect virus propagation in the lung. The treatment significantly attenuated the histological changes and neutrophil infiltration in the lung of H1N1-inoculated mice. The treatment significantly attenuated the production of tumor necrosis factor-a and chemokine (C-X-C motif) ligand 1 in the lung and oxidative stress enhancement, which were observed in H1N1-inoculated mice. H1N1 induced expressions of tumor necrosis factor-a and chemokine (C-X-C motif) ligand 1 in murine lung epithelial cells MLE-12, which were inhibited by the addition of recombinant human thioredoxin-1. The recombinant human thioredoxin-1 treatment started 30 mins after H1N1 inoculation also significantly improved the survival of the mice. Conclusions: Exogenous administration of recombinant human thioredoxin-1 significantly improved the survival rate and attenuated lung histological changes in the murine model of influenza pneumonia. The protective mechanism of thioredoxin-1 might be explained by its potent antioxidative and anti-inflammatory actions. Consequently, recombinant human thioredoxin-1 might be a possible pharmacological strategy for severe influenza virus infection in humans. (Crit Care Med 2013; 41:171-181