113 research outputs found

    Spatiotemporal expression of TRPM4 in the mouse cochlea

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    The present study was conducted to elucidate the presence of the transient receptor potential cation channel subfamily M member 4, TRPM4, in the mouse inner ear. TRPM4 immunoreactivity (IR) was found in the cell body of inner hair cells (IHCs) in the organ of Corti in the apical side of marginal cells of the stria vascularis, in the apical portion of the dark cells of the vestibule, and in a subset of the type II neurons in the spiral ganglion. Subsequently, changes in the distribution and expression of TRPM4 in the inner ear during embryonic and postnatal developments were also evaluated. Immunohistochemical localization demonstrated that the emergence of the TRPM4-IR in IHCs occurs shortly before the onset of hearing, whereas that in the marginal cells happens earlier, at the time of birth, coinciding with the onset of endolymph formation. Furthermore, semiquantitative real-time PCR assay showed that expressions of TRPM4 in the organ of Corti and in the stria vascularis increased dramatically at the onset of hearing. Because TRPM4 is a Ca2+-activated monovalent-selective cation channel, these findings imply that TRPM4 contributes to potassium ion transport, essential for the signal transduction in IHCs and the formation of endolymph by marginal cells. © 2014 Wiley Periodicals, Inc

    Atomic-scale flattening of SiC surfaces by electroless chemical etching in HF solution with Pt catalyst

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    The authors present a method for flattening SiC surfaces with Pt as a catalyst in HF solution. The mechanism for flattening SiC surfaces is discussed. The flattened 4H-SiC (0001) surface is composed of alternating wide and narrow terraces with single-bilayer-height steps, which are induced by the rate difference of the catalytic reactions between adjacent terraces. Scanning tunneling microscopy images reveal a 1×1 phase on the terraces. The 1×1 phase is composed of coexisting of F- and OH-terminated Si atoms, which originate from the polarization of the underlying Si-C bonds. © 2007 American Institute of Physics.Kenta Arima, Hideyuki Hara, et al. "Atomic-scale flattening of SiC surfaces by electroless chemical etching in HF solution with Pt catalyst", Appl. Phys. Lett. 90(20), 202106 (2007) https://doi.org/10.1063/1.2739084

    Severe Hypomyelination and Developmental Defects Are Caused in Mice Lacking Protein Arginine Methyltransferase 1 (PRMT1) in the Central Nervous System

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    Protein arginine methyltransferase 1 (PRMT1) is involved in cell proliferation, DNA damage response, and transcriptional regulation. While PRMT1 is extensively expressed in the central nervous system (CNS) at embryonic and perinatal stages, the physiological role of PRMT1 was poorly understood. Here, to investigate the primary function of PRMT1 in the CNS, we generated CNS-specific PRMT1 knockout mice by Cre-loxP system. These mice exhibited post-natal growth retardation with tremors and most of them died in two weeks after birth. Brain histological analyses revealed the prominent cell reduction in the white matter tracts of the mutant mice. Furthermore, ultrastructural analysis demonstrated that myelin sheath was almost completely ablated in the CNS of these animals. In agreement with hypomyelination, we also observed that most major myelin proteins including MBP, CNPase, and MAG were dramatically decreased, although neuronal and astrocytic markers were preserved in the brain of CNS-specific PRMT1 knockout mice. These animals had reduced number of OLIG2+ oligodendrocyte lineage cells in the white matter. We found that expressions of transcription factors essential for oligodendrocyte specification and further maturation were significantly suppressed in the brain of the mutant mice. Our findings provide evidence that PRMT1 is required for CNS development, especially for oligodendrocyte maturation processes

    Impairment of starvation-induced and constitutive autophagy in Atg7-deficient mice

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    Autophagy is a membrane-trafficking mechanism that delivers cytoplasmic constituents into the lysosome/vacuole for bulk protein degradation. This mechanism is involved in the preservation of nutrients under starvation condition as well as the normal turnover of cytoplasmic component. Aberrant autophagy has been reported in several neurodegenerative disorders, hepatitis, and myopathies. Here, we generated conditional knockout mice of Atg7, an essential gene for autophagy in yeast. Atg7 was essential for ATG conjugation systems and autophagosome formation, amino acid supply in neonates, and starvation-induced bulk degradation of proteins and organelles in mice. Furthermore, Atg7 deficiency led to multiple cellular abnormalities, such as appearance of concentric membranous structure and deformed mitochondria, and accumulation of ubiquitin-positive aggregates. Our results indicate the important role of autophagy in starvation response and the quality control of proteins and organelles in quiescent cells

    A Clinico-pathological Study of Gastric Polyps Treated with Endoscopic Polypestomy

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    181 gastric polyps obtained by endoscopic polypectomy were studied clinico-pathologically. The polyps occurred most frequently in the lower portion, and the incidence of the polyps tended to increase with age. 91% (164/181) of the polyps were occupied by hyperplastic polyps, and 3 polyps and one polyp respectively with dysplastic and carcinomatous foci were detected in 164 hyperplastic polyps. Although hyperplastic polyps rarely transform into dysplasia or carcinoma, careful follow-up is recommended

    Histopathological evaluation of gastric mucosal environments in peptic ulcer using the endoscopic 5-point gastric biopsy method.

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    Although a strong association has been established between chronic Helicobacter pylori infection and peptic ulcers, the role of H. pylori is not necessarily causative because there are many patients infected with H. pylori who do not develop peptic ulcer. Therefore, we studied the relationship between the gastric mucosal environment and the development of peptic ulcers. We examined 165 endoscopic biopsy specimens from the gastric mucosa of 33 patients with peptic ulcers using the 5-point gastric biopsy method. The follow-up biopsies done within 3 weeks were well correlated with the first biopsy samples. We also reviewed the clinicohistopathological findings of 2250 endoscopic biopsy specimens from 450 patients with active gastric and/or duodenal ulcers. Over 90% of the patients with duodenal ulcer, with or without gastric ulcer, had no fundic gland atrophy, and a high incidence of intestinal metaplasia and pyloric mucosal atrophy was found in the patients with gastric ulcer. These findings suggest that patients with concomitant active gastric and duodenal ulcers exhibit severe atrophic changes in the antral mucosa but not in the fundic mucosa.</p

    PRMT1 Deficiency in Mouse Juvenile Heart Induces Dilated Cardiomyopathy and Reveals Cryptic Alternative Splicing Products

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    Protein arginine methyltransferase 1 (PRMT1) catalyzes the asymmetric dimethylation of arginine residues in proteins and methylation of various RNA-binding proteins and is associated with alternative splicing in vitro. Although PRMT1 has essential in vivo roles in embryonic development, CNS development, and skeletal muscle regeneration, the functional importance of PRMT1 in the heart remains to be elucidated. Here, we report that juvenile cardiomyocyte-specific PRMT1-deficient mice develop severe dilated cardiomyopathy and exhibit aberrant cardiac alternative splicing. Furthermore, we identified previously undefined cardiac alternative splicing isoforms of four genes (Asb2, Fbxo40, Nrap, and Eif4a2) in PRMT1-cKO mice and revealed that eIF4A2 protein isoforms translated from alternatively spliced mRNA were differentially ubiquitinated and degraded by the ubiquitin-proteasome system. These findings highlight the essential roles of PRMT1 in cardiac homeostasis and alternative splicing regulation

    <論文>Measuring individual differences of Self-as-We: Reliability and validity of revised version of the Self-as-We scale

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    We previously created an original scale to evaluate individual differences in Self-as-We, a holistic view of the self, based on the East Asian philosophy of self, which is distinct from the mainstream idea of self in Western philosophy (Watanabe, Murata, Takayama, Nakatani & Deguchi, 2020, in Japanese). One component of this scale, the Collective Action scale, has shown adequate reliability as well as usefulness in terms of its association with mental health (Murata, Watanabe & Deguchi, 2020, in Japanese). However, the response rate of “Neither agree nor disagree” was quite high, suggesting that it may have been difficult for survey participants to answer. Therefore, we developed a revised version of the Collective Action scale with modified wording to make it easier to answer and then tested its reliability and validity based on the responses of 1, 082 volunteers
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