72 research outputs found

    Cardiomyocyte culture with in vivo functions

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    Rationale Diabetes causes cardiac dysfunction, and understanding of its mechanism is still incomplete. One reason could be limitations in modeling disease conditions by current in vitro cardiomyocyte culture. Emerging evidence suggests that the mechanical properties of the microenvironment affect cardiomyocyte function. Nevertheless, the impact of high glucose on cardiomyocytes cultured on substrates whose stiffness matches that of the heart (approximately 15 kPa) is untested. Objective To test the hypothesis that cardiomyocytes cultured in microenvironments that mimic the mechanical properties of those for cardiomyocytes in vivo may reproduce the pathophysiology characteristics of diabetic cardiomyocytes ex vivo, such as the morphological appearance, ROS accumulation, mitochondrial dysfunction, apoptosis and insulin-stimulated glucose uptake. Methods and results Isolated neonatal rat cardiomyocytes were seeded on 15 kPa polyacrylamide (PAA) gels, whose stiffness mimics that of heart tissues, or on glass coverslips, which represent conventional culture devices but are unphysiologically stiff. Cells were then cultured at 5 mM glucose, corresponding to the normal blood glucose level, or at high glucose levels (10 to 25 mM). Cytoskeletal disorganization, ROS accumulation, attenuated mitochondrial membrane potential and attenuated ATP level caused by high glucose and their reversal by a ROS scavenger were prominent in cells on gels, but not in cells on coverslips. The lack of response to ROS scavenging could be attributable to enhanced apoptosis in cells on glass, shown by enhanced DNA fragmentation and higher caspase 3/7 activity in cells on glass coverslips. High-glucose treatment also downregulated GLUT4 expression and attenuated insulin-stimulated glucose uptake only in cells on 15 kPa gels. Conclusion Our data suggest that a mechanically compliant microenvironment increases the susceptibility of primary cardiomyocytes to elevated glucose levels, which enables these cells to serve as an innovative model for diabetic heart research

    シボウ サイボウ ノ カガク

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    Adipose tissue secretes a variety of bioactive molecules (adipocytokines) that directlycontribute to the development of life-style related diseases, such as diabetes, hypertension,and cardiovascular diseases. TNF-α is a well - known inhibitor of insulin signaling and PAI(plasminogen activator inhibitor) - 1 contributes to thrombus formation. Adiponectin has anaction both insulin sensitivity and anti - atherogenic action. Interestingly, low plasmaadiponectin concentrations were observed in patients with obesity, coronary artery disease(CAD), and type 2 diabetes. Adiponectin from the plasma adhered to the injured arteryand suppressed the endothelial expression of adhesion molecules, the proliferation ofvascular smooth muscle cells, and the transformation of macrophage to foam cells. Thesefindings support that accumulation of fat produces not only insulin resistance but alsoatherosclrosis in obese subjects

    Approach to novel functional foods for stress control : 3. Establishment of stress-resistant rat model and its mechanism

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    A stress-resistant rat model was introduced. SPORTS (Spontaneously-Running-Tokushima-Shikoku) rats showed significantly shorter time of immobility in the forced swim test compared to control Wister rats. Increase norepinephrine concentration secondary to decreased activity of monoamine oxidase A (MAOA) in hippocampus was observed in this model rats. This model rats are considered to be useful for studying the mechanism of psychological stress

    コウウンドウセイ モデル ラット SPORTS ノ カイバ ニオケル ノルエピネフリン ドウタイ ト ジハツ ウンドウリョウ

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    Reduced physical exercise activity contributes to the development of several metabolic disorders including obesity, type 2 diabetes and hypertension. Especially in the developed countries, many people choose not to be active physically, possibly because of a reduced motivation to participate in exercise activities. Thus, augmentation of exercise motivation and subsequent increase in the physical activity would reduce an incidence of these metabolic disorders. In order to clarify the psychological mechanisms responsible for an increased exercise activity, we have generated and established a line of SPORTS (Spontaneously-Running-Tokushima-Shikoku) rat for high levels of voluntary wheel running. Male SPORTS rats run voluntarily in the running wheel almost six times longer than control Wistar rats. Here we examined the relation of the running activity of SPORTS rat with the hippocampal norepinephrine (NE) system including the levels of NE, adrenergic receptors, and degradation enzymes for monoamines. In the hippocampus of SPORTS rats, the level of NE in extracellular fluid was augmented, whereas the level in the homogenate of the whole tissue was decreased even for sedentary conditions. The level of striatal dopamine has not altered in both groups. The protein expression and the activity levels of monoamine oxidase A (MAOA), a critical enzyme for the degaradation of NE, were decreased in the hippocampus of SPORTS rats to increase extracellular NE level. Thus, inhibition of oxidase activity in normal Wistar rats markedly increased wheel running activity. Our results indicate that the hippocampal NE determines the neural basis of the psychological regulation of exercise behavior in SPORTS rats. Modulation of NE transmission in the hippocampus will be a good method for enhancing the exercise behavior both in clinical patients and in healthy humans

    Laser-driven multi-MeV high-purity proton acceleration via anisotropic ambipolar expansion of micron-scale hydrogen clusters

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    強力なレーザーを使ってエネルギーがそろった純度100%の陽子ビーム発生に成功 --レーザー駆動陽子ビーム加速器の実現へ向けて大きく前進--. 京都大学プレスリリース. 2022-10-13.Multi-MeV high-purity proton acceleration by using a hydrogen cluster target irradiated with repetitive, relativistic intensity laser pulses has been demonstrated. Statistical analysis of hundreds of data sets highlights the existence of markedly high energy protons produced from the laser-irradiated clusters with micron-scale diameters. The spatial distribution of the accelerated protons is found to be anisotropic, where the higher energy protons are preferentially accelerated along the laser propagation direction due to the relativistic effect. These features are supported by three-dimensional (3D) particle-in-cell (PIC) simulations, which show that directional, higher energy protons are generated via the anisotropic ambipolar expansion of the micron-scale clusters. The number of protons accelerating along the laser propagation direction is found to be as high as 1.6 ±0.3 × 10⁹/MeV/sr/shot with an energy of 2.8 ±1.9 MeV, indicating that laser-driven proton acceleration using the micron-scale hydrogen clusters is promising as a compact, repetitive, multi-MeV high-purity proton source for various applications

    A System for Worldwide COVID-19 Information Aggregation

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    The global pandemic of COVID-19 has made the public pay close attention to related news, covering various domains, such as sanitation, treatment, and effects on education. Meanwhile, the COVID-19 condition is very different among the countries (e.g., policies and development of the epidemic), and thus citizens would be interested in news in foreign countries. We build a system for worldwide COVID-19 information aggregation (http://lotus.kuee.kyoto-u.ac.jp/NLPforCOVID-19 ) containing reliable articles from 10 regions in 7 languages sorted by topics for Japanese citizens. Our reliable COVID-19 related website dataset collected through crowdsourcing ensures the quality of the articles. A neural machine translation module translates articles in other languages into Japanese. A BERT-based topic-classifier trained on an article-topic pair dataset helps users find their interested information efficiently by putting articles into different categories.Comment: Poster on NLP COVID-19 Workshop at ACL 2020, 4 pages, 3 figures, 7 table

    心不全を合併した心房細動患者のカテーテルアブレーション後の長期予後 : 左室駆出率に基づいた心不全のサブタイプ間における比較

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    Aims: Heart failure (HF) prognosis has been reported similar in patients with preserved vs. reduced left ventricular ejection fraction (LVEF). This study compared the long-term prognosis of HF patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). Methods and results: Among 5010 patients undergoing RFCA in Kansai Plus AF registry, 656 patients (13.1%) with a documented history of HF were enrolled in the study before RFCA. The primary endpoint was a composite of all-cause death, HF hospitalization, and stroke or systemic embolism. Patients with reduced (<40%), mid-range (40-49%), and preserved (≥50%) LVEF were 98 (14.9%), 107 (16.3%), and 451 (68.8%) patients, respectively. The prevalence of ischaemic heart disease and cardiomyopathies was higher among patients with reduced as compared with preserved LVEF (27.6% vs. 10.0%, P < 0.05 and 36.7% vs. 15.3%, P < 0.05, respectively). The median follow-up period was 2.9 years. The 3-year cumulative risk for the primary endpoint was higher in patients with reduced LVEF (32.7%) compared to those with mid-range (11.7%) or preserved (11.6%) LVEF (P < 0.001). Reduced LVEF was the most significant independent risk factor for primary endpoint (hazard ratio, 2.83; 95% confidence interval 1.74-4.61, P < 0.001). The 3-year arrhythmia recurrence rate was similar among the groups (48.2%, 42.8%, and 47.3%, respectively, P = 0.75). Conclusion : This study raises hypothesis that patients with HFrEF and AF had approximately three times higher risk for a composite of all-cause death, HF hospitalization, and stroke or systemic embolism after AF ablation compared with patients with HFmrEF or HFpEF.博士(医学)・甲第802号・令和3年12月21日Copyright: © Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021.This is a pre-copyedited, author-produced version of an article accepted for publication in Europace following peer review. The version of record "Europace Online ahead of print (2021 Aug 31;euab201) is available online at: https://doi.org/10.1093/europace/euab201.発行元が定める登録猶予期間終了の後、本文を登録予定(2022.08

    C9orf72-derived arginine-rich poly-dipeptides impede phase modifiers

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    Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-β2 (Kapβ2) at 1:1 ratio. The nuclear magnetic resonances of Kapβ2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapβ2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration

    Diminished Medial Prefrontal Activity behind Autistic Social Judgments of Incongruent Information

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    Individuals with autism spectrum disorders (ASD) tend to make inadequate social judgments, particularly when the nonverbal and verbal emotional expressions of other people are incongruent. Although previous behavioral studies have suggested that ASD individuals have difficulty in using nonverbal cues when presented with incongruent verbal-nonverbal information, the neural mechanisms underlying this symptom of ASD remain unclear. In the present functional magnetic resonance imaging study, we compared brain activity in 15 non-medicated adult males with high-functioning ASD to that of 17 age-, parental-background-, socioeconomic-, and intelligence-quotient-matched typically-developed (TD) male participants. Brain activity was measured while each participant made friend or foe judgments of realistic movies in which professional actors spoke with conflicting nonverbal facial expressions and voice prosody. We found that the ASD group made significantly less judgments primarily based on the nonverbal information than the TD group, and they exhibited significantly less brain activity in the right inferior frontal gyrus, bilateral anterior insula, anterior cingulate cortex/ventral medial prefrontal cortex (ACC/vmPFC), and dorsal medial prefrontal cortex (dmPFC) than the TD group. Among these five regions, the ACC/vmPFC and dmPFC were most involved in nonverbal-information-biased judgments in the TD group. Furthermore, the degree of decrease of the brain activity in these two brain regions predicted the severity of autistic communication deficits. The findings indicate that diminished activity in the ACC/vmPFC and dmPFC underlies the impaired abilities of individuals with ASD to use nonverbal content when making judgments regarding other people based on incongruent social information

    Human+AI Crowd Task Assignment Considering Result Quality Requirements

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    This paper addresses the problem of dynamically assigning tasks to a crowd consisting of AI and human workers. Currently, crowdsourcing the creation of AI programs is a common practice. To apply such kinds of AI programs to the set of tasks, we often take the ``all-or-nothing'' approach that waits for the AI to be good enough. However, this approach may prevent us from exploiting the answers provided by the AI until the process is completed, and also prevents the exploration of different AI candidates. Therefore, integrating the created AI, both with other AIs and human computation, to obtain a more efficient human-AI team is not trivial. In this paper, we propose a method that addresses these issues by adopting a ``divide-and-conquer'' strategy for AI worker evaluation. Here, the assignment is optimal when the number of task assignments to humans is minimal, as long as the final results satisfy a given quality requirement. This paper presents some theoretical analyses of the proposed method and an extensive set of experiments conducted with open benchmarks and real-world datasets. The results show that the algorithm can assign many more tasks than the baselines to AI when it is difficult for AIs to satisfy the quality requirement for the whole set of tasks. They also show that it can flexibly change the number of tasks assigned to multiple AI workers in accordance with the performance of the available AI workers
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