73 research outputs found
Analysis of Errors in Albedo Monte Carlo Calculation due to Errors in Albedo Data
The error analysis method, which enables one to make an estimation of errors in the streaming neutron flux due to errors in the albedo data in the albedo Monte Carlo calculation, is described. The proposed method is based on a perturbation model which follows the same neutron path as in the unperturbed case, and estimates the flux error as a deviation in the neutron weight each time a neutron has a collision. As an example of the application of the proposed method, neutron duct streaming problems in 2-m long concrete ducts are analyzed. The importance of neutron scattering in each energy group to the streaming neutron flux is quantitatively described by the method
Evaluation of the effect of oral appliance treatment on upper-airway ventilation conditions in obstructive sleep apnea using computational fluid dynamics
Objective: To evaluate the effect of oral appliance (OA) treatment on upper-airway ventilation conditions in patients with obstructive sleep apnea (OSA) using computational fluid dynamics (CFD).
Methods: Fifteen patients received OA treatment and underwent polysomnography (PSG) and computed tomography (CT). CT data were used to reconstruct three-dimensional models of nasal and pharyngeal airways. Airflow velocity and airway pressure measurements at inspiration were simulated using CFD.
Results: The apnea–hypopnea index (AHI) improved from 23.1 to 10.1 events/h after OA treatment. On CFD analysis, airflow velocity decreased at the retropalatal and epiglottis-tip levels, while airway pressure decreased at the retropalatal, uvular- and epiglottis-tip levels. The AHI of patients with OSA before OA treatment was correlated with airway pressure at the epiglottis-tip level.
Discussion: Treatment with OA improved the ventilation conditions of the pharyngeal airway and AHI. Results of CFD analysis of airway pressure and airflow velocity helped determine the severity and ventilatory impairment site of OSA, respectively
A Case of Obstetrical DIC Probably Due to Uterine Type of Amniotic Fluid Embolism during Cesarean Section
A 42-year-old woman diagnosed as marginal placenta previa underwent cesarean section and bilateral tubal ligation under general anesthesia in 37th gestational week. Uterine contraction after delivery was good, but atonic bleeding progressed during tubal ligation. Oxytocic drugs were ineffective. We suspected obstetrical DIC and started treatment for DIC immediately, but the bleeding lasted. After total hysterectomy, she had stable vital signs. She broke away from DIC immediately after surgery. Intraoperative findings were satisfied the criteria for clinical uterine type amniotic fluid embolism (AFE). Although AFE indicates a bad prognosis, we saved her without any sequelae
The Effect of Cranial Change on Oropharyngeal Airway and Breathing During Sleep
Mandibular micrognathia is one of the characteristics of obstructive sleep apnea syndrome. The purpose of this study was to assess the effects of bimaxillary surgery without maxillary advancement on the upper airway using computational fluid dynamics (CFD) results of comparing pre- and post-operative finite element model. Seven female patients with jaw deformity, who underwent two-jaw surgery (Le Fort1 osteotomy and bilateral sagittal split ramus osteotomy; BSSRO) were enrolled. Maxillary was moved for correcting occlusal plane and mandibular was moved to advancement. Pharyngeal airway space and breathing during sleep were evaluated, comparing the periods of 2 days before and 6 months after the operation. The cross-sectional area of the level of the hard palate (HP) and the level of the tip of the uvula (TU), and airway volume of total, HP-TU, and TP- the level of the base of the epiglottis (BE) were increased. AI and AHI in 2 days before and 6 months after were decreased. As the result of nasal ventilation condition, velocity of HP and TU in 2 days before and 6 months after were decreased. We think that it was revealed that movement of the maxilla without advancement did not affect to the morphology and function of airway
Cellular senescence in white matter microglia is induced during ageing in mice and exacerbates the neuroinflammatory phenotype
Cellular senescence, a state of irreversible cell-cycle arrest caused by a variety of cellular stresses, is critically involved in age-related tissue dysfunction in various organs. However, the features of cells in the central nervous system that undergo senescence and their role in neural impairment are not well understood as yet. Here, through comprehensive investigations utilising single-cell transcriptome analysis and various mouse models, we show that microglia, particularly in the white matter, undergo cellular senescence in the brain and spinal cord during ageing and in disease models involving demyelination. Microglial senescence is predominantly detected in disease-associated microglia, which appear in ageing and neurodegenerative diseases. We also find that commensal bacteria promote the accumulation of senescent microglia and disease-associated microglia during ageing. Furthermore, knockout of p16 INK4a, a key senescence inducer, ameliorates the neuroinflammatory phenotype in damaged spinal cords in mice. These results advance our understanding of the role of cellular senescence in the central nervous system and open up possibilities for the treatment of age-related neural disorders.Matsudaira T., Nakano S., Konishi Y., et al. Cellular senescence in white matter microglia is induced during ageing in mice and exacerbates the neuroinflammatory phenotype. Communications Biology 6, 665 (2023); https://doi.org/10.1038/s42003-023-05027-2
Single-Cell Analysis of the Multicellular Ecosystem in Viral Carcinogenesis by HTLV-1
成人T細胞白血病リンパ腫の多段階発がん分子メカニズムを解明 --難治性疾患の新規治療標的候補を複数同定--. 京都大学プレスリリース. 2021-09-07.Premalignant clonal expansion of human T-cell leukemia virus type-1 (HTLV-1)–infected cells occurs before viral carcinogenesis. Here we characterize premalignant cells and the multicellular ecosystem in HTLV-1 infection with and without adult T-cell leukemia/lymphoma (ATL) by genome sequencing and single-cell simultaneous transcriptome and T/B-cell receptor sequencing with surface protein analysis. We distinguish malignant phenotypes caused by HTLV-1 infection and leukemogenesis and dissect clonal evolution of malignant cells with different clinical behavior. Within HTLV-1–infected cells, a regulatory T-cell phenotype associates with premalignant clonal expansion. We also delineate differences between virus- and tumor-related changes in the nonmalignant hematopoietic pool, including tumor-specific myeloid propagation. In a newly generated conditional knockout mouse model recapitulating T-cell–restricted CD274 (encoding PD-L1) gene lesions found in ATL, we demonstrate that PD-L1 overexpressed by T cells is transferred to surrounding cells, leading to their PD-L1 upregulation. Our findings provide insights into clonal evolution and immune landscape of multistep virus carcinogenesis
Integrated genetic and clinical prognostic factors for aggressive adult T-cell leukemia/lymphoma
成人T細胞白血病リンパ腫(ATL)におけるゲノム情報と臨床情報を統合したリスクモデルを確立 --ATLの個別化医療を推進--. 京都大学プレスリリース. 2023-04-10.The prognosis of aggressive adult T-cell leukemia/lymphoma (ATL) is poor, and allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is a curative treatment. To identify favorable prognostic patients after intensive chemotherapy, and who therefore might not require upfront allo-HSCT, we aimed to improve risk stratification of aggressive ATL patients aged <70 years. The clinical risk factors and genetic mutations were incorporated into risk modeling for overall survival (OS). We generated the m7-ATLPI, a clinicogenetic risk model for OS, that included the ATL prognostic index (PI) (ATL-PI) risk category, and non-silent mutations in seven genes, namely TP53, IRF4, RHOA, PRKCB, CARD11, CCR7, and GATA3. In the training cohort of 99 patients, the m7-ATLPI identified a low-, intermediate-, and high-risk group with 2-year OS of 100%, 43%, and 19%, respectively (hazard ratio [HR] 5.46, p < 0.0001). The m7-ATLPI achieved superior risk stratification compared to the current ATL-PI (C-index 0.92 vs. 0.85, respectively). In the validation cohort of 84 patients, the m7-ATLPI defined low-, intermediate-, and high-risk groups with a 2-year OS of 81%, 30%, and 0%, respectively (HR 2.33, p = 0.0094), and the model again outperformed the ATL-PI (C-index 0.72 vs. 0.70, respectively). The simplified m7-ATLPI, which is easier to use in clinical practice, achieved superior risk stratification compared to the ATL-PI, as did the original m7-ATLPI; the simplified version was calculated by summing the following: high-risk ATL-PI category (+10), low-risk ATL-PI category (−4), and non-silent mutations in TP53 (+4), IRF4 (+3), RHOA (+1), PRKCB (+1), CARD11 (+0.5), CCR7 (−2), and GATA3 (−3)
Id2-, RORγt-, and LTβR-independent initiation of lymphoid organogenesis in ocular immunity
The eye is protected by the ocular immunosurveillance system. We show that tear duct–associated lymphoid tissue (TALT) is located in the mouse lacrimal sac and shares immunological characteristics with mucosa-associated lymphoid tissues (MALTs), including the presence of M cells and immunocompetent cells for antigen uptake and subsequent generation of mucosal immune responses against ocularly encountered antigens and bacteria such as Pseudomonas aeruginosa. Initiation of TALT genesis began postnatally; it occurred even in germ-free conditions and was independent of signaling through organogenesis regulators, including inhibitor of DNA binding/differentiation 2, retinoic acid–related orphan receptor γt, lymphotoxin (LT) α1β2–LTβR, and lymphoid chemokines (CCL19, CCL21, and CXCL13). Thus, TALT shares immunological features with MALT but has a distinct tissue genesis mechanism and plays a key role in ocular immunity
Gender-specific associations of vision and hearing impairments with adverse health outcomes in older Japanese: a population-based cohort study
BACKGROUND: Several epidemiological studies have shown that self-reported vision and hearing impairments are associated with adverse health outcomes (AHOs) in older populations; however, few studies have used objective sensory measurements or investigated the role of gender in this association. Therefore, we examined the association of vision and hearing impairments (as measured by objective methods) with AHOs (dependence in activities of daily living or death), and whether this association differed by gender. METHODS: From 2005 to 2006, a total of 801 residents (337 men and 464 women) aged 65 years or older of Kurabuchi Town, Gunma, Japan, participated in a baseline examination that included vision and hearing assessments; they were followed up through September 2008. Vision impairment was defined as a corrected visual acuity of worse than 0.5 (logMAR = 0.3) in the better eye, and hearing impairment was defined as a failure to hear a 30 dB hearing level signal at 1 kHz in the better ear. Information on outcomes was obtained from the town hall and through face-to-face home visit interviews. We calculated the risk ratios (RRs) of AHOs for vision and hearing impairments according to gender. RESULTS: During a mean follow-up period of 3 years, 34 men (10.1%) and 52 women (11.3%) had AHOs. In both genders, vision impairment was related to an elevated risk of AHOs (multi-adjusted RR for men and women together = 1.60, 95% CI = 1.05-2.44), with no statistically significant interaction between the genders. In contrast, a significant association between hearing impairment and AHOs (multi-adjusted RR = 3.10, 95% CI = 1.43-6.72) was found only in the men. CONCLUSION: In this older Japanese population, sensory impairments were clearly associated with AHOs, and the association appeared to vary according to gender. Gender-specific associations between sensory impairments and AHOs warrant further investigation
Increased Anion Channel Activity Is an Unavoidable Event in Ozone-Induced Programmed Cell Death
Ozone is a major secondary air pollutant often reaching high concentrations
in urban areas under strong daylight, high temperature and stagnant
high-pressure systems. Ozone in the troposphere is a pollutant that is
harmful to the plant. generation by salicylic and abscisic acids.
Anion channel activation was also shown to promote the accumulation of
transcripts encoding vacuolar processing enzymes, a family of proteases
previously reported to contribute to the disruption of vacuole integrity
observed during programmed cell death.-induced
programmed cell death. Because ion channels and more specifically anion
channels assume a crucial position in cells, an understanding about the
underlying role(s) for ion channels in the signalling pathway leading to
programmed cell death is a subject that warrants future investigation
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