95 results on '"Tatsuro Yamamoto"'
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2. The Eleanor ncRNAs activate the topological domain of the ESR1 locus to balance against apoptosis
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Mohamed Osama Ali Abdalla, Tatsuro Yamamoto, Kazumitsu Maehara, Jumpei Nogami, Yasuyuki Ohkawa, Hisashi Miura, Rawin Poonperm, Ichiro Hiratani, Hideki Nakayama, Mitsuyoshi Nakao, and Noriko Saitoh
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Science - Abstract
Long term estrogen deprivation can result in apoptosis in breast cancer cells. Here, the authors show that this apoptosis is induced by the long-range chromatin interaction of loci containing the ESR1 and FOXO 3 genes, resulting in FOXO 3-mediated apoptosis.
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- 2019
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3. Circulating miRNA-1290 as a potential biomarker for response to chemoradiotherapy and prognosis of patients with advanced oral squamous cell carcinoma: A single-center retrospective study
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Hikaru Nakashima, Ryoji Yoshida, Akiyuki Hirosue, Kenta Kawahara, Junki Sakata, Hidetaka Arita, Tatsuro Yamamoto, Ryo Toya, Ryuji Murakami, Akimitsu Hiraki, Masanori Shinohara, Takaaki Ito, Yoshikazu Kuwahara, and Hideki Nakayama
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
MicroRNAs are a class of small, endogenous, noncoding 18- to 24-nucleotide-long RNAs that can regulate multiple processes related to cancer progression. However, their clinical value in patients with oral squamous cell carcinoma has not yet been fully explored. Therefore, the aim of this study was to investigate the clinical significance of circulating microRNAs in oral squamous cell carcinoma patients. The expression levels of circulating miR-1246 and miR-1290 in healthy volunteers and oral squamous cell carcinoma patients were examined by quantitative real-time polymerase chain reaction. The expression levels of both microRNAs in the radioresistant oral squamous cell carcinoma cell line (SAS-R) and the parent cell line (SAS) and in the conditioned medium obtained from these cell lines were also examined by quantitative real-time polymerase chain reaction. In addition, the correlations between circulating microRNA status and various clinicopathological features in 55 oral squamous cell carcinoma patients with locally advanced oral squamous cell carcinoma who underwent surgery following 5-fluorouracil-based chemoradiotherapy were examined. The expression level of miR-1290 was significantly lower in the plasma of oral squamous cell carcinoma patients than in that of healthy volunteers (p
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- 2019
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4. A framework of shape optimisation based on the isogeometric boundary element method toward designing thin-silicon photovoltaic devices.
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Toru Takahashi 0002, Tatsuro Yamamoto, Yuta Shimba, Hiroshi Isakari, and Toshiro Matsumoto
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- 2019
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5. Lamin A/C impairments cause mitochondrial dysfunction by attenuating PGC1α and the NAMPT-NAD+ pathway
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Scott Maynard, Arnaldur Hall, Panagiotis Galanos, Salvatore Rizza, Tatsuro Yamamoto, Helena Hagner Gram, Sebastian H N Munk, Muhammad Shoaib, Claus Storgaard Sørensen, Vilhelm A Bohr, Mads Lerdrup, Apolinar Maya-Mendoza, and Jiri Bartek
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Mice ,Progeria ,Sirtuin 1 ,Genetics ,Animals ,Humans ,Fibroblasts ,Lamin Type A ,NAD ,DNA, Mitochondrial ,Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ,Chromatin ,Mitochondria - Abstract
Mutations in the lamin A/C gene (LMNA) cause laminopathies such as the premature aging Hutchinson Gilford progeria syndrome (HGPS) and altered lamin A/C levels are found in diverse malignancies. The underlying lamin-associated mechanisms remain poorly understood. Here we report that lamin A/C-null mouse embryo fibroblasts (Lmna−/− MEFs) and human progerin-expressing HGPS fibroblasts both display reduced NAD+ levels, unstable mitochondrial DNA and attenuated bioenergetics. This mitochondrial dysfunction is associated with reduced chromatin recruitment (Lmna−/− MEFs) or low levels (HGPS) of PGC1, the key transcription factor for mitochondrial homeostasis. Lmna−/− MEFs showed reduced expression of the NAD+biosynthesis enzyme NAMPT and attenuated activity of the NAD+-dependent deacetylase SIRT1. We find high PARylation in lamin A/C-aberrant cells, further decreasing the NAD+ pool and consistent with impaired DNA base excision repair in both cell models, a condition that fuels DNA damage-induced PARylation under oxidative stress. Further, ATACsequencing revealed a substantially altered chromatin landscape in Lmna−/− MEFs, including aberrantly reduced accessibility at the Nampt gene promoter. Thus, we identified a new role of lamin A/C as a key modulator of mitochondrial function through impairments of PGC1 and the NAMPT-NAD+ pathway, with broader implications for the aging process.
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- 2022
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6. Mechanism Underlying Conflicting Drug-Drug Interaction Between Aprepitant and Voriconazole via Cytochrome P450 3A4-Mediated Metabolism.
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Masako Ishida, Takeshi Kumagai, Tatsuro Yamamoto, Hiroyuki Suzuki, Kuniaki Moriki, Masachika Fujiyoshi, Kiyoshi Nagata, and Miki Shimada
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DRUG interactions ,VORICONAZOLE ,ANTIEMETICS ,CYTOCHROME P-450 ,DRUG metabolism - Abstract
Background Voriconazole is an antifungal drug for which therapeutic monitoring is recommended to prevent side effects. Temporary administration of the antiemetic drug fosaprepitant remarkably decreases the plasma concentration of voriconazole from the therapeutic range. The ratio of the major metabolite voriconazole N-oxide to voriconazole exceeded that at any other time for a patient who started chemotherapy during voriconazole therapy. We attributed this unpredictable result to cytochrome P450 3A4 induced by aprepitant that was converted from fosaprepitant in vivo. Methods Concentrations of voriconazole and voriconazole N-oxide were measured using liquid chromatography-mass spectrometry/mass spectrometry in primary human hepatocytes after incubation with aprepitant. Aprepitant suppressed voriconazole N-oxide formation within 24 h, followed by a continuous increase. Levels of drug-metabolizing cytochrome P450 mRNA were measured using real-time PCR in primary human hepatocytes incubated with aprepitant. Results Cytochrome P450 3A4 and 2C9 mRNA levels increased ~4- and 2-fold, respectively, over time. Cytochrome P450 3A4 induction was confirmed using reporter assays. We also assessed L-755446, a major metabolite of aprepitant that lacks a triazole ring. Both compounds dose-dependently increased reporter activity; however, induction by L-755446 was stronger than that by aprepitant. Conclusion These results indicate that aprepitant initially inhibited voriconazole metabolism via its triazole ring and increased cytochrome P450 3A4 induction following L-755446 formation. The decrease in plasma voriconazole concentration 7 days after fosaprepitant administration was mainly attributed to cytochrome P450 3A4 induction by L-755446. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Inhibited maturation of astrocytes caused by maternal n-3 PUFA intake deficiency hinders the development of brain glial cells in neonatal rats
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Naomichi Nishimura, Ayako Yamamoto, Hiroki Tanabe, and Tatsuro Yamamoto
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chemistry.chemical_classification ,medicine.medical_specialty ,Nutrition and Dietetics ,Glial fibrillary acidic protein ,Medicine (miscellaneous) ,Biology ,Somatosensory system ,Oligodendrocyte ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Cerebral cortex ,Internal medicine ,Lactation ,medicine ,biology.protein ,Gestation ,Polyunsaturated fatty acid ,Astrocyte - Abstract
The brain is rich in long-chain PUFA, which play an essential role in its development and functions. Here, we examined the impact of maternal n-3 PUFA intake deficiency during gestation and lactation on the development of glial cells in the pup’s developing cerebral cortex. In addition, using myelination as indicator and the anti-myelin basic protein as measurement to establish the relationship between the number of glial fibrillary acidic protein (GFAP)-positive cells and the development of oligodendrocytes, we determined the myelination state of the somatosensory cortex at postnatal day 14. Rat dams were fed either a control (Cont) or an n-3 PUFA-deficient (Def) diet for 60 d (acclimatisation: 14 d; gestation: 21 d; and lactation: 21 d). Pups lactated from dams throughout the experiment. The distribution pattern of astrocytes in pups on postnatal day 7 was immunohistochemically analysed using GFAP and brain lipid binding protein (BLBP) as markers for mature astrocytes and astrocyte-specific radial glial cells, respectively. It was observed that, when compared with Cont pups, GFAP-positive cells decreased, BLBP-positive cells increased and myelinated structures were sparser in the somatosensory cortices of Def pups. In the open field test on postnatal day 21, behavioural parameters did not differ between groups. Our results indicated that inhibited maturation of astrocytes caused by maternal n-3 PUFA deficiency hindered the development of brain glial cells of neonatal rats; hence, maternal n-3 PUFA intake during the gestation and lactation periods may have been crucial for the brain cell composition of pups.
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- 2021
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8. A Case of Significant Fluctuation of Prothrombin Time-international Normalized Ratio with Change, and Cancellation of the Transluminal Nutrient Preparation under Warfarin Administration
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Naruhito Matsumoto, Yukiko Miyoshi, Tatsuro Yamamoto, and Miki Shimada
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- 2021
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9. Colonic Hydrogen Generated from Fructan Diffuses into the Abdominal Cavity and Reduces Adipose mRNA Abundance of Cytokines in Rats
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Naomichi, Nishimura, Hiroki, Tanabe, Misato, Adachi, Tatsuro, Yamamoto, and Michihiro, Fukushima
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- 2013
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10. A case of Rosai-Dorfman disease initially suspected to be cervical lymph node metastasis after surgery for tongue cancer
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Tatsuro Yamamoto, Hideki Nakayama, Akiyuki Hirosue, Yuki Murahashi, Syunsuke Gohara, and Nozomu Takahashi
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medicine.medical_specialty ,medicine.anatomical_structure ,Tongue ,business.industry ,medicine ,Cancer ,General Medicine ,Radiology ,Lymph node metastasis ,medicine.disease ,business ,Rosai–Dorfman disease - Published
- 2021
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11. Development of a New Method for Simultaneous Quantitation of Plasma Concentrations of Voriconazole and Voriconazole N-Oxide Using Column- Switching LC-MS/MS and Its Application in Therapeutic Drug Monitoring.
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Tatsuro Yamamoto, Masako Ishida, Nao Kodama, Yusuke Saiki, Masachika Fujiyoshi, and Miki Shimada
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VORICONAZOLE ,DRUG monitoring ,LIQUID chromatography ,PHARMACOKINETICS ,TANDEM mass spectrometry - Abstract
Background Voriconazole therapy for fungal infections usually continues for several years and is often administered on an outpatient basis. Maintaining the voriconazole plasma concentration in the therapeutic range is highly important for effective therapy; however, it is difficult to obtain sufficient information to assess the voriconazole concentration in outpatients. Therefore. we developed a method to simultaneously measure the plasma concentrations of voriconazole and its major metabolite, voriconazole V-oxide, to obtain rapid results after outpatient blood collection and before medical consultation and to attain a better understanding of adherence and the drug-drug interactions of voriconazole. Methods Fifty microliters of patient plasma was deproteinized with methanol, injected into the liquid chromatography-tandem mass spectrometry system, and purified using an online column. Separation was achieved on an InertSustain C18 column (2.1 mm id x 50 mm, 2 μm) with a mobile phase of 30:70 (0.1% formic acid in water:methanol) at a flow rate of 0.2 mL/min. Detection was performed using electrospray ionization in positive ion multiple reaction monitoring mode. Results The analysis time was 4 min. The calibration curve was linear, in the range of 0.1 μg/mL to 20 μg/mL for voriconazole and 0.05 μg/mL to 10 μg/mL for voriconazole V-oxide, with a coefficient of determination at R² > 0.999. Conclusion There is no need to dilute the patient's plasma even if the concentration of voriconazole is near the upper limit of measurement. Furthermore, the short measurement-time could immediately inform physicians of the patient's voriconazole concentration during ambulatory medical care. Simultaneous measurement of voriconazole and voriconazole V-oxide may also be useful for the immediate adjustment of voriconazole dosage in outpatients and would help us to understand adherence or drug-drug interactions in plasma voricon-azole concentrations. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Inhibited maturation of astrocytes caused by maternal
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Tatsuro, Yamamoto, Ayako, Yamamoto, Hiroki, Tanabe, and Naomichi, Nishimura
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The brain is rich in long-chain PUFA, which play an essential role in its development and functions. Here, we examined the impact of maternal
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- 2021
13. Non-coding RNAs and chromatin domains
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Noriko Saitoh and Tatsuro Yamamoto
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RNA, Untranslated ,Chromosomal Proteins, Non-Histone ,Cell Cycle Proteins ,Computational biology ,Biology ,Chromosomes ,Transcriptome ,03 medical and health sciences ,0302 clinical medicine ,Transcription (biology) ,medicine ,Animals ,Humans ,Gene ,030304 developmental biology ,Cell Nucleus ,0303 health sciences ,Cohesin ,RNA ,Cell Biology ,Chromatin Assembly and Disassembly ,Chromatin ,medicine.anatomical_structure ,CTCF ,Nucleus ,030217 neurology & neurosurgery ,Transcription Factors - Abstract
Large-scale transcriptome analyses have identified a variety of non-coding RNAs (ncRNAs) that are not translated into proteins. Many of them are in the nucleus, where they associate with chromatin and regulate its structure and function. Interphase chromosomes are intricately folded into multiple layers and composed of domains. Recent studies using Hi-C technologies have identified a mega-base self-associating chromatin domain: the topologically associating domain (TAD). The domain boundaries are demarcated with the chromatin regulatory proteins CTCF and cohesin, which are often bound to or recruited by ncRNAs. Some ncRNAs form RNA clouds in the nucleus and coordinate the transcription of multiple genes in a chromatin domain. In this review, we describe the emerging link between long ncRNAs and chromatin domains in the nucleus.
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- 2019
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14. Risk factors for clozapine-induced central nervous system abnormalities in Japanese patients with treatment-resistant schizophrenia
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Masafumi Kodama, Yoshiki Kishi, Tatsuro Yamamoto, Takashi Yoshio, Yuji Yada, Kazuhiro Matsuo, Shusuke Uekusa, Kei Moriyama, and Kohei Kitagawa
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medicine.medical_specialty ,Lithium (medication) ,Electroencephalography ,Nervous System Malformations ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Risk Factors ,Internal medicine ,medicine ,Humans ,Clozapine ,General Psychology ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,General Medicine ,Odds ratio ,medicine.disease ,Confidence interval ,030227 psychiatry ,Psychiatry and Mental health ,Schizophrenia ,Concomitant ,medicine.symptom ,business ,Myoclonus ,030217 neurology & neurosurgery ,medicine.drug ,Antipsychotic Agents - Abstract
The purpose of this study was to assess the risk factors for clozapine-induced central nervous system (CNS) abnormalities (i.e., electroencephalogram [EEG] abnormalities, myoclonus, and seizures). We retrospectively analyzed data from 106 patients with schizophrenia who received clozapine treatment through our hospital. A review of the EEG recordings showed that 71 of these patients (67.0 %) developed CNS abnormalities after initiating clozapine treatment. EEG abnormalities, myoclonus, and seizures occurred in 53.8 %, 38.7 %, and 8.5 % of the patients, respectively. Multivariate logistic regression analysis showed that the risk factors for clozapine-induced CNS abnormalities were concomitant lithium usage (odds ratio, 4.560; 95 % confidence interval, 1.750-11.900) and shorter illness durations before clozapine initiation (odds ratio, 0.796; 95 % confidence interval, 0.649-0.976). However, plasma clozapine levels and the usage of antiepileptics did not exhibit associations with the risks of CNS abnormalities. Clinicians should monitor their patients for incident CNS abnormalities when administering lithium in combination with clozapine regardless of plasma clozapine levels or the usage of antiepileptics. This is especially true for patients with short illness durations.
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- 2021
15. Novel method of whole lung lavage therapy using biphasic cuirass ventilator for pulmonary alveolar proteinosis; the retrospective observational study
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Takuro Sakagami, Takayuki Jodai, Hidenori Ichiyasu, Tatsuro Yamamoto, Toshiki Kimura, Chieko Yoshida, Shinichiro Okamoto, Tatsuhiro Isimura, and Daisuke Tamanoi
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business.industry ,Anesthesia ,Medicine ,Retrospective cohort study ,Whole lung lavage ,business ,Pulmonary alveolar proteinosis ,medicine.disease - Published
- 2020
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16. Endocrine therapy-resistant breast cancer model cells are inhibited by soybean glyceollin I through Eleanor non-coding RNA
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Koji Ochiai, Toshiro Matsui, Mitsuyoshi Nakao, Mitsuru Kumabe, Masatoshi Shinagawa, Tatsuro Yamamoto, Tadatoshi Yamashita, Hiroaki Tachiwana, Chiyomi Sakamoto, and Noriko Saitoh
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0301 basic medicine ,Magnetic Resonance Spectroscopy ,RNA, Untranslated ,Pterocarpans ,Cell ,Estrogen receptor ,lcsh:Medicine ,Apoptosis ,Breast Neoplasms ,Article ,Mass Spectrometry ,03 medical and health sciences ,chemistry.chemical_compound ,Transcription (biology) ,Glyceollin I ,medicine ,Humans ,RNA, Messenger ,lcsh:Science ,Cell Proliferation ,Multidisciplinary ,Chemistry ,Cell growth ,lcsh:R ,RNA ,Polyphenols ,food and beverages ,Estrogens ,030104 developmental biology ,medicine.anatomical_structure ,Receptors, Estrogen ,Cancer cell ,Cancer research ,MCF-7 Cells ,Female ,lcsh:Q ,Soybeans ,Estrogen receptor alpha - Abstract
Long-term estrogen deprivation (LTED) of an estrogen receptor (ER) α-positive breast cancer cell line recapitulates cancer cells that have acquired estrogen-independent cell proliferation and endocrine therapy resistance. Previously, we have shown that a cluster of non-coding RNAs, Eleanors (ESR1 locus enhancing and activating non-coding RNAs) formed RNA cloud and upregulated the ESR1 gene in the nuclei of LTED cells. Eleanors were inhibited by resveratrol through ER. Here we prepared another polyphenol, glyceollin I from stressed soybeans, and identified it as a major inhibitor of the Eleanor RNA cloud and ESR1 mRNA transcription. The inhibition was independent of ER, unlike one by resveratrol. This was consistent with a distinct tertiary structure of glyceollin I for ER binding. Glyceollin I preferentially inhibited the growth of LTED cells and induced apoptosis. Our results suggest that glyceollin I has a novel role in LTED cell inhibition through Eleanors. In other words, LTED cells or endocrine therapy-resistant breast cancer cells may be ready for apoptosis, which can be triggered with polyphenols both in ER-dependent and ER-independent manners.
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- 2018
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17. Longitudinal changes and body composition assessment using bioelectrical impedance in elderly patients with mild disequilibrium and different care needs
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Akira Kubo, Kaho Miura, Shohei Hayashi, Kazuya Goto, Tatsuro Yamamoto, and Momoko Kashiwazaki
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030506 rehabilitation ,medicine.medical_specialty ,business.industry ,Elderly with mild disequilibrium ,Disequilibrium ,Muscle mass ,Physical Therapy, Sports Therapy and Rehabilitation ,030229 sport sciences ,Body composition ,Trunk ,03 medical and health sciences ,0302 clinical medicine ,Physical therapy ,Medicine ,Original Article ,medicine.symptom ,Level of care ,0305 other medical science ,business ,Whole body ,Bioelectrical impedance analysis ,Rehabilitation interventions - Abstract
[Purpose] This study involved performing longitudinal measurements of muscle mass in elderly patients with mild disequilibrium using a body composition meter. The rate of change and characteristics were determined according to the level of care needed. [Participants and Methods] Bioelectrical impedance was used to measure body composition in 20 elderly females in Care Needs Category 1 (n=10) and 2 (n=8); body composition was measured every 3 months for 1 year. [Results] Compared to Category 1, the muscle mass at each body site was lower in Category 2 and the muscle mass of the whole body and thighs in Category 2 decreased throughout the year. [Conclusion] Muscle mass in elderly patients needing assistance depended on the level of care, as suggested by the decrease in muscle mass in the whole body and thighs in Category 2 over time. In addition, effective rehabilitation intervention for the trunk is important.
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- 2018
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18. Enhanced Expression of IGFBP-3 Reduces Radiosensitivity and Is Associated with Poor Prognosis in Oral Squamous Cell Carcinoma
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Hikaru Nakashima, Ryo Toya, Akiyuki Hirosue, Sho Kawaguchi, Junki Sakata, Kenta Kawahara, Yuka Nagao, Yoshikazu Kuwahara, Manabu Fukumoto, Ryoji Yoshida, Masashi Nagata, Tatsuro Yamamoto, Ryuji Murakami, Keisuke Yamana, Shunsuke Gohara, Hidetaka Arita, Yuichiro Matsuoka, and Hideki Nakayama
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0301 basic medicine ,Cancer Research ,DNA repair ,DNA damage ,medicine.medical_treatment ,lcsh:RC254-282 ,Article ,03 medical and health sciences ,0302 clinical medicine ,Medicine ,Radiosensitivity ,DNA-PKcs ,Gene knockdown ,business.industry ,Growth factor ,IGFBP-3 ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,oral squamous cell carcinoma ,stomatognathic diseases ,030104 developmental biology ,Oncology ,radiosensitivity ,030220 oncology & carcinogenesis ,Cancer research ,Immunohistochemistry ,business ,Chemoradiotherapy - Abstract
Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3) modulates various cell functions through IGF-dependent or independent mechanisms. However, its biological roles in the radiosensitivity of oral squamous cell carcinoma (OSCC) remain largely unknown. The purpose of this study was to determine the clinical significance and molecular mechanisms of the association between IGFBP-3 and OSCC radiosensitivity. We performed an immunohistochemical analysis of IGFBP-3 in 52 OSCC specimens from patients treated with preoperative chemoradiotherapy and surgery (phase II study). Associations between IGFBP-3 expression and clinicopathological features were also evaluated. In addition, we examined the effects of IGFBP-3 on post-X-ray irradiation radiosensitivity and DNA damage in vitro. High IGFBP-3 expression was significantly correlated with poor chemoradiotherapy responses and prognosis. With IGFBP-3 knockdown, irradiated OSCC cells exhibited significantly higher radiosensitivity compared with that of control cells. Moreover, IGFBP-3 depletion in OSCC cells reduced phosphorylation of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), which is required for DNA double-strand break repair during non-homologous end joining. These findings indicate that IGFBP-3 may have a significant role in regulating DNA repair and is be a potential biomarker for predicting clinical response to radiotherapy and prognosis in OSCC.
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- 2020
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19. Nucleosome destabilization by nuclear non-coding RNAs
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Reo Maruyama, Risa Fujita, Michiaki Hamada, Tatsuro Yamamoto, Mitsuyoshi Nakao, Hitoshi Kurumizaka, Noriko Saitoh, Yuichi Ichikawa, Hiroaki Tachiwana, Yasuhiro Arimura, Liying Yang, Saori Fujiwara, and Yuka Sakata
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RNA, Untranslated ,Medicine (miscellaneous) ,Biochemical assays ,General Biochemistry, Genetics and Molecular Biology ,Article ,Cell Line ,Histones ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Chromatin analysis ,Transcription (biology) ,Transcriptional regulation ,Nucleosome ,Humans ,lcsh:QH301-705.5 ,Gene ,In Situ Hybridization, Fluorescence ,030304 developmental biology ,Cell Nucleus ,0303 health sciences ,biology ,Chemistry ,Protein Stability ,Fluorescence in situ hybridization ,RNA ,Chromatin Assembly and Disassembly ,Chromatin ,Cell biology ,Nucleosomes ,Histone ,lcsh:Biology (General) ,Genetic Loci ,biology.protein ,Long non-coding RNAs ,Nucleic Acid Conformation ,General Agricultural and Biological Sciences ,030217 neurology & neurosurgery ,DNA - Abstract
In the nucleus, genomic DNA is wrapped around histone octamers to form nucleosomes. In principle, nucleosomes are substantial barriers to transcriptional activities. Nuclear non-coding RNAs (ncRNAs) are proposed to function in chromatin conformation modulation and transcriptional regulation. However, it remains unclear how ncRNAs affect the nucleosome structure. Eleanors are clusters of ncRNAs that accumulate around the estrogen receptor-α (ESR1) gene locus in long-term estrogen deprivation (LTED) breast cancer cells, and markedly enhance the transcription of the ESR1 gene. Here we detected nucleosome depletion around the transcription site of Eleanor2, the most highly expressed Eleanor in the LTED cells. We found that the purified Eleanor2 RNA fragment drastically destabilized the nucleosome in vitro. This activity was also exerted by other ncRNAs, but not by poly(U) RNA or DNA. The RNA-mediated nucleosome destabilization may be a common feature among natural nuclear RNAs, and may function in transcription regulation in chromatin., The Eleanor cluster of non-coding RNAs is localised upstream of estrogen receptor-α (ESR1) gene locus in estrogen-deprived breast cancer cells. Fujita et al find that RNA fragments of Eleanor2 and of other non-coding RNAs are able to destabilise nucleosomes in vitro, suggesting a role in transcriptional regulation.
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- 2020
20. Gene regulation by non-coding RNAs in the 3D genome architecture
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Noriko Saitoh, Tatsuro Yamamoto, and Hiroaki Tachiwana
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Computational biology ,Biology ,Genome ,X-inactivation ,03 medical and health sciences ,0302 clinical medicine ,X Chromosome Inactivation ,Genetics ,Animals ,Humans ,Epigenetics ,Gene ,030304 developmental biology ,Regulation of gene expression ,Cell Nucleus ,0303 health sciences ,Cell Differentiation ,Chromatin ,Histone ,biology.protein ,XIST ,RNA, Long Noncoding ,030217 neurology & neurosurgery ,Developmental Biology - Abstract
Appropriate gene expression is essential for producing the correct amount of proteins at the right time, which is critical for living organisms. In the three-dimensional (3D) space of the nucleus, genomes are folded into higher order chromatin structures that are intimately associated with epigenetic factors, including histone modifications and nuclear long non-coding RNAs (lncRNAs). LncRNAs regulate transcription for both activation and repression, either in cis or in trans. Many ncRNAs are expressed in development-specific, differentiation-specific, and disease-specific manners, suggesting that they are critical regulators for organ generation and maintenance. In this review, we mainly describe the following ncRNAs: Xist, involved in X chromosome inactivation, Firre, which serves as a platform for trans-chromosomal associations, and UMLILO and ELEANORS, which co-regulate genes involved in the immune response and breast cancer, respectively. These ncRNAs are gene regulators in the context of the 3D genome structure.
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- 2020
21. HMGA2 Contributes to Distant Metastasis and Poor Prognosis by Promoting Angiogenesis in Oral Squamous Cell Carcinoma
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Masashi Nagata, Akiyuki Hirosue, Nozomu Takahashi, Hikaru Nakashima, Junki Sakata, Masafumi Nakamoto, Akimitsu Hiraki, Yuichiro Matsuoka, Kenta Kawahara, Hidetaka Arita, Takuya Nakamura, Ryoji Yoshida, Tatsuro Yamamoto, Masanori Shinohara, Masatoshi Hirayama, and Hideki Nakayama
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Adult ,Male ,HMGA2 ,Angiogenesis ,Fibroblast growth factor ,Catalysis ,Article ,Metastasis ,Inorganic Chemistry ,lcsh:Chemistry ,chemistry.chemical_compound ,angiogenesis ,Medicine ,Humans ,metastasis ,Clinical significance ,Neoplasm Invasiveness ,Physical and Theoretical Chemistry ,Molecular Biology ,lcsh:QH301-705.5 ,Spectroscopy ,Aged ,Aged, 80 and over ,biology ,Neovascularization, Pathologic ,business.industry ,Organic Chemistry ,HMGA2 Protein ,General Medicine ,Middle Aged ,medicine.disease ,Phenotype ,Computer Science Applications ,Vascular endothelial growth factor ,oral squamous cell carcinoma ,stomatognathic diseases ,chemistry ,lcsh:Biology (General) ,lcsh:QD1-999 ,Cancer research ,biology.protein ,Carcinoma, Squamous Cell ,Immunohistochemistry ,Female ,Mouth Neoplasms ,prognosis ,business - Abstract
The highly malignant phenotype of oral squamous cell carcinoma (OSCC), including the presence of nodal and distant metastasis, reduces patient survival. High-mobility group A protein 2 (HMGA2) is a non-histone chromatin factor that is involved in advanced malignant phenotypes and poor prognosis in several human cancers. However, its biological role in OSCC remains to be elucidated. The purpose of this study was to determine the clinical significance and role of HMGA2 in the malignant potential of OSCC. We first investigated the expression pattern of HMGA2 and its clinical relevance in 110 OSCC specimens using immunohistochemical staining. In addition, we examined the effects HMGA2 on the regulation of vascular endothelial growth factor (VEGF)-A, VEGF-C, and fibroblast growth factor (FGF)-2, which are related to angiogenesis, in vitro. High expression of HMGA2 was significantly correlated with distant metastasis and poor prognosis. Further, HMGA2 depletion in OSCC cells reduced the expression of angiogenesis genes. In OSCC tissues with high HMGA2 expression, angiogenesis genes were increased and a high proportion of blood vessels was observed. These findings suggest that HMGA2 plays a significant role in the regulation of angiogenesis and might be a potential biomarker to predict distant metastasis and prognosis in OSCC.
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- 2019
22. Rational conversion of chromophore selectivity of cyanobacteriochromes to accept mammalian intrinsic biliverdin
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Takahiro Nakajima, Tatsuro Yamamoto, Hirokazu Kawagishi, Takatsugu Miyazaki, Yuka Takeda, Keita Miyake, Yoshibumi Ueda, Enoch Y. Park, Yuto Kuwasaki, Kazushi Suzuki, Moritoshi Sato, Masahiko Ikeuchi, Keiji Fushimi, Rei Narikawa, and Jae-Hoon Choi
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0301 basic medicine ,Steric effects ,Models, Molecular ,bilin ,Green Fluorescent Proteins ,Cyanobacteria ,Photoreceptors, Microbial ,Protein Engineering ,Transfection ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Phycocyanobilin ,Chlorocebus aethiops ,Molecule ,Animals ,Multidisciplinary ,Biliverdin ,030102 biochemistry & molecular biology ,Biliverdine ,Optical Imaging ,Chromophore ,Fluorescence ,Recombinant Proteins ,030104 developmental biology ,chemistry ,Liver ,PNAS Plus ,Covalent bond ,COS Cells ,Biophysics ,Cyanobacteriochrome ,in vivo imaging - Abstract
Because cyanobacteriochrome photoreceptors need only a single compact domain for chromophore incorporation and for absorption of visible spectra including the long-wavelength far-red region, these molecules have been paid much attention for application to bioimaging and optogenetics. Most cyanobacteriochromes, however, have a drawback to incorporate phycocyanobilin that is not available in the mammalian cells. In this study, we focused on biliverdin (BV) that is a mammalian intrinsic chromophore and absorbs the far-red region and revealed that replacement of only four residues was enough for conversion from BV-rejective cyanobacteriochromes into BV-acceptable molecules. We succeeded in determining the crystal structure of one of such engineered molecules, AnPixJg2_BV4, at 1.6 Å resolution. This structure identified unusual covalent bond linkage, which resulted in deep BV insertion into the protein pocket. The four mutated residues contributed to reducing steric hindrances derived from the deeper insertion. We introduced these residues into other domains, and one of them, NpF2164g5_BV4, produced bright near-infrared fluorescence from mammalian liver in vivo. Collectively, this study provides not only molecular basis to incorporate BV by the cyanobacteriochromes but also rational strategy to open the door for application of cyanobacteriochromes to visualization and regulation of deep mammalian tissues.
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- 2019
23. Sufficient intake of high amylose cornstarch maintains high colonic hydrogen production for 24 h in rats
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Tatsuro Yamamoto, Hiroki Tanabe, and Naomichi Nishimura
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Male ,0301 basic medicine ,Time Factors ,food.ingredient ,Colon ,Starch ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,Rats, Sprague-Dawley ,Excretion ,03 medical and health sciences ,chemistry.chemical_compound ,food ,Amylose ,medicine ,Animals ,Large intestine ,Food science ,Resistant starch ,Molecular Biology ,Hydrogen production ,030109 nutrition & dietetics ,Dose-Response Relationship, Drug ,Chemistry ,Organic Chemistry ,General Medicine ,Diet ,Rats ,030104 developmental biology ,medicine.anatomical_structure ,Digestion ,Fermentation ,Oxidative stress ,Hydrogen ,Biotechnology - Abstract
Colonic hydrogen (H2) can suppress oxidative stress and damage in the body. We examined the minimum requirement of high amylose cornstarch (HAS) to maintain high colonic H2 production for 24 h. Ileorectostomized and sham-operated rats were fed a control diet supplemented with or without 20% HAS for 7 days. Colonic starch utilization was determined. Next, rats were fed the control diet with or without 10% or 20% HAS for 14 or 28 days, respectively. Breath and flatus H2 excretion for 24 h was measured. 1.04 g of resistant fraction in HAS was utilized for 24 h by colonic bacteria. High H2 excretion was not maintained for 24 h in rats fed the 10% HAS diet, from which only 0.89 g of resistant starch was estimated to be delivered. High colonic H2 production for 24 h would be maintained by delivering more HAS to the large intestine than is utilized.
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- 2017
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24. Circulating miRNA-1290 as a potential biomarker for response to chemoradiotherapy and prognosis of patients with advanced oral squamous cell carcinoma: A single-center retrospective study
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Akiyuki Hirosue, Ryo Toya, Hideki Nakayama, Takaaki Ito, Ryoji Yoshida, Kenta Kawahara, Akimitsu Hiraki, Tatsuro Yamamoto, Hikaru Nakashima, Masanori Shinohara, Junki Sakata, Yoshikazu Kuwahara, Hidetaka Arita, and Ryuji Murakami
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Oncology ,Adult ,Male ,medicine.medical_specialty ,Single Center ,Disease-Free Survival ,Internal medicine ,Cell Line, Tumor ,microRNA ,medicine ,Biomarkers, Tumor ,Humans ,Basal cell ,RC254-282 ,Aged ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Cancer ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Retrospective cohort study ,Cell Differentiation ,General Medicine ,Chemoradiotherapy ,Middle Aged ,medicine.disease ,Prognosis ,Circulating MicroRNA ,stomatognathic diseases ,MicroRNAs ,Potential biomarkers ,Carcinoma, Squamous Cell ,Female ,Mouth Neoplasms ,Fluorouracil ,business - Abstract
MicroRNAs are a class of small, endogenous, noncoding 18- to 24-nucleotide-long RNAs that can regulate multiple processes related to cancer progression. However, their clinical value in patients with oral squamous cell carcinoma has not yet been fully explored. Therefore, the aim of this study was to investigate the clinical significance of circulating microRNAs in oral squamous cell carcinoma patients. The expression levels of circulating miR-1246 and miR-1290 in healthy volunteers and oral squamous cell carcinoma patients were examined by quantitative real-time polymerase chain reaction. The expression levels of both microRNAs in the radioresistant oral squamous cell carcinoma cell line (SAS-R) and the parent cell line (SAS) and in the conditioned medium obtained from these cell lines were also examined by quantitative real-time polymerase chain reaction. In addition, the correlations between circulating microRNA status and various clinicopathological features in 55 oral squamous cell carcinoma patients with locally advanced oral squamous cell carcinoma who underwent surgery following 5-fluorouracil-based chemoradiotherapy were examined. The expression level of miR-1290 was significantly lower in the plasma of oral squamous cell carcinoma patients than in that of healthy volunteers (p
- Published
- 2019
25. Isomaltodextrin, a highly branched α-glucan, increases rat colonic H2 production as well as indigestible dextrin
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Hiroki Tanabe, Naomichi Nishimura, and Tatsuro Yamamoto
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0301 basic medicine ,Firmicutes ,030209 endocrinology & metabolism ,Biology ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,Microbiology ,Excretion ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Food science ,Molecular Biology ,Glucan ,chemistry.chemical_classification ,030109 nutrition & dietetics ,Fructooligosaccharide ,Organic Chemistry ,General Medicine ,biology.organism_classification ,chemistry ,High amylose ,Dextrin ,Oxidative stress ,Biotechnology - Abstract
Colonic hydrogen (H2) protects against inflammation-induced oxidative stress. We examined the effect of a new highly branched α-glucan, isomaltodextrin (IMD), on colonic H2 production in rats. Rats were fed a 16.7% IMD, 8.8% indigestible dextrin (ID), or 10.4% high amylose cornstarch diet (Expt. 1), were fed diets containing 3.3–16.7% IMD (Expt. 2), or were fed diets containing 16.7% IMD or 5.2% fructooligosaccharide (FOS) (Expt. 3), for 14 days. Compared with the control group, feeding IMD or other α-glucans dose dependently and significantly increased H2 excretion and portal H2 concentration. The ability of IMD to increase H2 production was not inferior to that of FOS. The cecal Firmicutes/Bacteroidetes ratio in the IMD group was 5–14% of that in the control group. The cecal abundance of bifidobacteria was significantly greater in the IMD group than in the control group. Taken together, IMD, as well as other α-glucans, significantly increased colonic H2 production in a dose-dependent manner.
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- 2016
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26. Transplantation of High Hydrogen-Producing Microbiota Leads to Generation of Large Amounts of Colonic Hydrogen in Recipient Rats Fed High Amylose Maize Starch
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Ryo Inoue, Tatsuro Yamamoto, Erika Komori, Naomichi Nishimura, Hiroki Tanabe, and Yumi Sasaki
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0301 basic medicine ,resistant starch ,food.ingredient ,Starch ,Colon ,medicine.medical_treatment ,030106 microbiology ,Firmicutes ,antioxidant effect ,lcsh:TX341-641 ,medicine.disease_cause ,Diet, High-Fat ,Zea mays ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,food ,RNA, Ribosomal, 16S ,Ruminococcus ,medicine ,Animals ,Food science ,Resistant starch ,hydrogen ,microbiota transplantation ,rats ,Saline ,Bifidobacterium ,Nutrition and Dietetics ,biology ,Bacteroidetes ,Sequence Analysis, DNA ,Fecal Microbiota Transplantation ,biology.organism_classification ,Gastrointestinal Microbiome ,Transplantation ,030104 developmental biology ,chemistry ,Amylose ,Bacteroides ,lcsh:Nutrition. Foods and food supply ,Oxidative stress ,Food Science - Abstract
The hydrogen molecule (H2), which has low redox potential, is produced by colonic fermentation. We examined whether increased hydrogen (H2) concentration in the portal vein in rats fed high amylose maize starch (HAS) helped alleviate oxidative stress, and whether the transplantation of rat colonic microbiota with high H2 production can shift low H2-generating rats (LG) to high H2-generating rats (HG). Rats were fed a 20% HAS diet for 10 days and 13 days in experiments 1 and 2, respectively. After 10 days (experiment 1), rats underwent a hepatic ischemia–reperfusion (IR) operation. Rats were then categorized into quintiles of portal H2 concentration. Plasma alanine aminotransferase activity and hepatic oxidized glutathione concentration were significantly lower as portal H2 concentration increased. In experiment 2, microbiota derived from HG (the transplantation group) or saline (the control group) were orally inoculated into LG on days 3 and 4. On day 13, portal H2 concentration in the transplantation group was significantly higher compared with the control group, and positively correlated with genera Bifidobacterium, Allobaculum, and Parabacteroides, and negatively correlated with genera Bacteroides, Ruminococcus, and Escherichia. In conclusion, the transplantation of microbiota derived from HG leads to stable, high H2 production in LG, with the resultant high production of H2 contributing to the alleviation of oxidative stress.
- Published
- 2018
27. Human induced-pluripotent stem cell-derived hepatocyte-like cells as an in vitro model of human hepatitis B virus infection
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Hiroyuki Mizuguchi, Koichi Watashi, Tatsuro Yamamoto, Kazuo Takayama, Takaji Wakita, Yasuhito Tanaka, Masashi Tachibana, Seiji Mitani, Fuminori Sakurai, and Sayuki Iijima
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0301 basic medicine ,Hepatitis B virus ,Cellular differentiation ,Induced Pluripotent Stem Cells ,Organic Anion Transporters, Sodium-Dependent ,Biology ,medicine.disease_cause ,Article ,Cell Line ,Viral Proteins ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Induced pluripotent stem cell ,Multidisciplinary ,Symporters ,Nucleoside analogue ,virus diseases ,Cell Differentiation ,Hep G2 Cells ,Entecavir ,Hepatitis B ,medicine.disease ,Virology ,digestive system diseases ,030104 developmental biology ,Cell culture ,Host-Pathogen Interactions ,Hepatocytes ,RNA, Viral ,030211 gastroenterology & hepatology ,Stem cell ,medicine.drug - Abstract
In order to understand the life cycle of hepatitis B virus (HBV) and to develop efficient anti-HBV drugs, a useful in vitro cell culture system which allows HBV infection and recapitulates virus-host interactions is essential; however, pre-existing in vitro HBV infection models are often problematic. Here, we examined the potential of human induced-pluripotent stem (iPS) cell-derived hepatocyte-like cells (iPS-HLCs) as an in vitro HBV infection model. Expression levels of several genes involved in HBV infection, including the sodium taurocholate cotransporting polypeptide (NTCP) gene, were gradually elevated as the differentiation status of human iPS cells proceeded to iPS-HLCs. The mRNA levels of these genes were comparable between primary human hepatocytes (PHHs) and iPS-HLCs. Following inoculation with HBV, we found significant production of HBV proteins and viral RNAs in iPS-HLCs. The three major forms of the HBV genome were detected in iPS-HLCs by Southern blotting analysis. Anti-HBV agents entecavir and Myrcludex-B, which are a nucleoside analogue reverse transcriptase inhibitor and a synthetic pre-S1 peptide, respectively, significantly inhibited HBV infection in iPS-HLCs. These data demonstrate that iPS-HLCs can be used as a promising in vitro HBV infection model.
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- 2017
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28. Improved electron injection from silver electrode for all solution-processed polymer light-emitting diodes with Cs2CO3:conjugated polyelectrolyte blended interfacial layer
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Tatsuro Yamamoto, Hirotake Kajii, and Yutaka Ohmori
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chemistry.chemical_classification ,Materials science ,General Chemistry ,Polymer ,Condensed Matter Physics ,Polymer light emitting diodes ,Cathode ,Electronic, Optical and Magnetic Materials ,law.invention ,Solution processed ,Biomaterials ,Conjugated polyelectrolyte ,Chemical engineering ,chemistry ,law ,Electron injection ,Materials Chemistry ,Organic chemistry ,Electrical and Electronic Engineering ,Layer (electronics) ,Diode - Abstract
This study demonstrates the incorporation of a Cs 2 CO 3 :conjugated polyelectrolyte blended interfacial layer between the emissive layer and a silver (Ag) cathode, for realizing all-solution processed polymer light-emitting diodes. For a device with poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) as the emissive layer, this approach improves the maximum luminance of approximately 80,000 cd/m 2 and maximum current efficiency of 10.6 cd/A. It is clarified that the interfacial layer prevents Ag nanoparticles from penetrating into the emissive layer, resulting in yellow–green emission from F8BT. We also demonstrate the possibility of all-solution processed polymer light-emitting diodes utilizing solution-processed Cs 2 CO 3 :conjugated polyelectrolyte interfacial layer and Ag nano-ink.
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- 2014
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29. An Investigation of Task-based Language Teaching in Elementary School
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Tatsuro, YAMAMOTO and Gerard, MARCHESSEAU
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TBLT ,CLT ,ComputingMilieux_COMPUTERSANDEDUCATION ,Foreign Language Education - Abstract
Task-based Language Teaching has been popular for a number of years in English as a second or foreign language programs. This research investigates the effectiveness of tasks in elementary school Foreign Language Activities classes in Japan. First, classes were observed over a two-month period to investigate how often, and how tasks are employed currently in the elementary school setting. Then, the researchers taught two different groups of students, administering tasks to an experimental group and a non-task-based lesson to a control group to observe students’ attitudes towards Task-based Language Teaching. Observing English classes, it was found that tasks are frequently employed by teachers and are well-received by students. When the researchers gave a task-based lesson as compared to a non-task-based lesson, however, the results were mixed.
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- 2014
30. Photoconversion and Fluorescence Properties of a Red/Green-Type Cyanobacteriochrome AM1_C0023g2 That Binds Not Only Phycocyanobilin But Also Biliverdin
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Rei Narikawa, Tatsuro Yamamoto, Moritoshi Sato, Takahiro Nakajima, Masahiko Ikeuchi, Yuki Aono, Keiji Fushimi, and Ni-Ni-Win
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0301 basic medicine ,Microbiology (medical) ,Acaryochloris marina ,lcsh:QR1-502 ,GFP ,Microbiology ,lcsh:Microbiology ,Green fluorescent protein ,03 medical and health sciences ,chemistry.chemical_compound ,Phycocyanobilin ,Botany ,optogenetics ,Original Research ,Biliverdin ,030102 biochemistry & molecular biology ,biology ,Phytochrome ,Chromophore ,biology.organism_classification ,Fluorescence ,live cell imaging ,chemistry ,near-infrared fluorescence ,Biophysics ,linear tetrapyrrole ,Cyanobacteriochrome - Abstract
Cyanobacteriochromes (CBCRs) are distantly related to the red/far-red responsive phytochromes. Red/green-type CBCRs are widely distributed among various cyanobacteria. The red/green-type CBCRs covalently bind phycocyanobilin (PCB) and show red/green reversible photoconversion. Recent studies revealed that some red/green-type CBCRs from chlorophyll d-bearing cyanobacterium Acaryochloris marina covalently bind not only PCB but also biliverdin (BV). The BV-binding CBCRs show far-red/orange reversible photoconversion. Here, we identified another CBCR (AM1_C0023g2) from A. marina that also covalently binds not only PCB but also BV with high binding efficiencies, although BV chromophore is unstable in the presence of urea. Replacement of Ser334 with Gly resulted in significant improvement in the yield of the BV-binding holoprotein, thereby ensuring that the mutant protein is a fine platform for future development of optogenetic switches. We also succeeded in detecting near-infrared fluorescence from mammalian cells harboring PCB-binding AM1_C0023g2 whose fluorescence quantum yield is 3.0%. Here the PCB-binding holoprotein is shown as a platform for future development of fluorescent probes.
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- 2016
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31. Suppressive Effect of High Hydrogen Generating High Amylose Cornstarch on Subacute Hepatic Ischemia-reperfusion Injury in Rats
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Naomichi Nishimura, Shuhachi Kiriyama, Tatsuro Yamamoto, Yumi Sasaki, and Hiroki Tanabe
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medicine.medical_specialty ,Pathology ,Antioxidant ,food.ingredient ,antioxidant ,Hydrogen ,medicine.medical_treatment ,Immunology ,chemistry.chemical_element ,Applied Microbiology and Biotechnology ,Microbiology ,ischemia-reperfusion ,food ,Internal medicine ,medicine ,Large intestine ,Resistant starch ,Alanine ,business.industry ,Gastroenterology ,Hindgut ,medicine.disease ,Note ,high amylose cornstarch ,Endocrinology ,medicine.anatomical_structure ,chemistry ,large intestine ,hydrogen ,High amylose ,business ,Reperfusion injury ,Food Science - Abstract
We examined whether feeding high hydrogen generating resistant starch could suppress subacute hepatic ischemia-reperfusion injury. Rats were fed a control diet with or without 20% high amylose cornstarch (HAS) supplementation for 14 days. On day 12, rats were subject to ischemia-reperfusion treatment. Portal hydrogen concentration was higher in the HAS group compared with the control group. Increased plasma alanine and aspartate aminotransferase activities due to ischemia-reperfusion treatment tended to decrease, and a significant reduction was observed by HAS feeding when compared with the control group. In conclusion, HAS, which enhances hydrogen generation in the hindgut, alleviated subacute hepatic ischemia-reperfusion injury.
- Published
- 2012
32. Characterization of heterotopic cell clusters in the hippocampus of the rat after prenatal treatment of methylazoxymethanol acetate
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Toshio Terashima, Tatsuro Yamamoto, Hideaki Imai, and Kozo Sugioka
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Embryology ,Methylazoxymethanol acetate ,biology ,Cell ,Hippocampus ,General Medicine ,Anatomy ,Hippocampal formation ,Embryonic stem cell ,Cell biology ,White matter ,chemistry.chemical_compound ,medicine.anatomical_structure ,nervous system ,chemistry ,Cerebral cortex ,Pediatrics, Perinatology and Child Health ,medicine ,biology.protein ,Antibody ,Developmental Biology - Abstract
Prenatal exposure of methylazoxymethanol acetate, a DNA methylating agent, to pregnant rats on embryonic day 15 is known to produce hippocampal malformation and laminar disorganization of the cerebral cortex. However, there are few studies to demonstrate developmental processes of abnormal structures in the hippocampus. In the present study, we examined complete serial sections of rat brains on postnatal day 0 to 2, which pretreated with methylazoxymethanol acetate on embryonic day 15. At birth, massive cellular clusters were found under the white matter of the cerebral cortex and then, a part of these clusters entered into the hippocampal CA1 sector on postnatal day 2. These ectopic cellular clusters in the CA1 were immunoreactive to anti-calbindin antibody, suggesting that the origin of these cellular clusters is equivalent to that of the cortical layer II/III neurons. Next, we injected FluoroGold into the lateral septal nucleus to examine hippocampo-septal projection. FluoroGold-labeled neurons were scattered in the ectopic cellular cluster, implying that CA1 pyramidal neurons project normally to the lateral septal nucleus. In conclusion, a majority of neurons found in the ectopic cellular cluster caused by prenatal methylazoxymethanol treatment is derived from cortical neurons, and some intrinsic pyramidal neurons in the CA1 of hippocampus are scattered throughout the ectopic cellular cluster.
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- 2012
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33. Raw Chinese yam (Dioscorea opposita) promotes cecal fermentation and reduces plasma non-HDL cholesterol concentration in rats
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Tatsuro Yamamoto, Hiroki Tanabe, Michihiro Fukushima, and Naomichi Nishimura
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Male ,Very low-density lipoprotein ,food.ingredient ,Chinese_yam ,Medicine (miscellaneous) ,Butyrate ,Bile Acids and Salts ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Cecum ,Feces ,food ,medicine ,Animals ,Food science ,Cooking ,RNA, Messenger ,Resistant starch ,Cholesterol 7-alpha-Hydroxylase ,fermentation ,chemistry.chemical_classification ,Nutrition and Dietetics ,Cholesterol ,Dioscorea ,Anticholesteremic Agents ,Short-chain fatty acid ,cholesterol ,Starch ,resistant_starch ,Fatty Acids, Volatile ,rats ,Plant Tubers ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Gene Expression Regulation ,Liver ,Propionate ,Fermentation ,Carrier Proteins - Abstract
We examined the effects of raw Chinese yam (Dioscorea opposita), containing resistant starch (RS), on lipid metabolism and cecal fermentation in rats. Raw yam (RY) and boiled yam (BY) contained 33.9% and 6.9% RS, respectively. Male Sprague-Dawley rats were fed a cholesterol-free, control (C) diet supplemented with or without 15 and 30 g of RY or BY/100 g for 3 wk. Plasma total cholesterol concentrations in the tail vein of rats fed the 30% RY diet were significantly lower than in the C group throughout the feeding period. Compared with the C group, non-HDL concentrations in arterial plasma in the 30% RY group was significantly reduced. Liver cholesterol concentration in rats fed the 30% RY diet was significantly higher compared with those fed the C diet. Hepatic cholesterol 7α-hydroxylase mRNA and fecal bile acid excretion were significantly higher in the BY, but not the RY group, compared with the C group. Fecal cholesterol excretion in the 30% RY group was greater compared with the C group. Hepatic microsomal triacylglycerol transfer protein mRNA was significantly lower in the 30% RY group compared with the C group. Cecal pools of acetate, propionate and butyrate were 113-257%, 181-476% and 410-789% greater in the RY group compared with the C group. These results suggest raw yam is effective as a source of RS and facilitates production of short chain fatty acid (SCFA), especially butyrate, in the rat cecum. In addition, RY has a plasma-cholesterol lowering effect, possibly due to the inhibited release of VLDL.
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- 2011
34. Pectin and high-amylose maize starch increase caecal hydrogen production and relieve hepatic ischaemia–reperfusion injury in rats
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Naomichi, Nishimura, Hiroki, Tanabe, Yumi, Sasaki, Yui, Makita, Misako, Ohata, Saori, Yokoyama, Mami, Asano, Tatsuro, Yamamoto, and Shuhachi, Kiriyama
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Male ,medicine.medical_specialty ,food.ingredient ,Pectin ,Hepatic Veno-Occlusive Disease ,Medicine (miscellaneous) ,medicine.disease_cause ,Zea mays ,Maize starch ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,food ,Ischemia ,Internal medicine ,medicine ,Animals ,Large intestine ,Resistant starch ,Cecum ,Alanine ,Nutrition and Dietetics ,Starch ,Glutathione ,Rats ,Oxidative Stress ,Prebiotics ,Endocrinology ,medicine.anatomical_structure ,Liver ,Biochemistry ,chemistry ,Reperfusion Injury ,Fermentation ,Seeds ,Pectins ,Amylose ,Oxidation-Reduction ,Oxidative stress ,Hydrogen - Abstract
We investigated whether the feeding of high H2-generating dietary fibre and resistant starch (RS) could suppress hepatic ischaemia–reperfusion (IR) injury, which results from oxidative stress, in rats fed a pectin (Pec) or high-amylose maize starch (HAS) diet. Male Sprague–Dawley rats were fed a control (C) diet, with or without Pec (0–5 % Pec) or HAS (0–30 % HAS) supplementation for 7 d. Portal H2concentration showed a significant dose-dependent increase with the amount of Pec or HAS supplementation. Plasma alanine and aspartate aminotransferase activities remarkably increased in the C rats (5 % cellulose) due to IR treatment, while it decreased significantly or showed tendencies to decrease in 5 % Pec and 20 % HAS diet-fed rats. The hepatic oxidised glutathione (GSSG):total glutathione ratio increased significantly in IR rats maintained on the C diet compared with sham-operated rats. On the other hand, reduced glutathione (GSH):total glutathione and GSH:GSSG ratios decreased significantly. The GSSG:total glutathione ratio that increased due to IR treatment decreased significantly on HAS and Pec intake, while GSH:total glutathione and GSH:GSSG ratios increased significantly. Hepatic sinusoids of IR rats fed the C diet were occluded, but those of IR rats fed the Pec diet were similar to those in the sham-operated rats. In conclusion, we found that Pec or HAS, which enhance H2generation in the large intestine, alleviated hepatic IR injury. The present study demonstrates another physiological significance of dietary fibre and RS.
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- 2011
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35. Kinetics of polymorphonuclear leukocytes in an experimental hypopyon model
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Hiroshi Goto, Hideki Mori, Shinya Okada, Kouji Fujita, Naoyuki Yamakawa, Akio Ishikawa, and Tatsuro Yamamoto
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Pathology ,medicine.medical_specialty ,Anterior Chamber ,Neutrophils ,Hypopyon ,Lesion progression ,Rats, Sprague-Dawley ,Cellular and Molecular Neuroscience ,Imaging, Three-Dimensional ,Ascites ,Animals ,Medicine ,business.industry ,Uveitis, Suppurative ,medicine.disease ,Sensory Systems ,Rats ,Disease Models, Animal ,Kinetics ,Ophthalmology ,Immunology ,medicine.symptom ,business ,Infiltration (medical) ,Tomography, Optical Coherence ,Uveitis - Abstract
Regarding the process of uveitis development, many past studies have used the experimental autoimmune uveoretinitis (EAU) and other animal models to observe histologically the infiltration of inflammatory cells and the process of lesion progression. However, no detailed study of the process of clearance of infiltrated inflammatory cells from the eye has been reported. The purpose of this study was to investigate the process of clearance of polymorphonuclear leukocytes (PMNs) using an experimental hypopyon model. PMNs obtained from ascites of SD rat were injected into the anterior chamber of SD rats. The process of PMNs clearance was evaluated by serial photography and 3D optical coherence tomography (3D-OCT), and histological changes were observed simultaneously. The hypopyon heights regressed from 1.04±0.06 mm at 1h (day 0) to 0.45±0.07 mm at day 1, and 0 mm at day 3 after PMNs injection. When the hypopyon heights at the three time points were compared, significant differences were found between groups (P0.05). The hypopyon volumes also decreased from 1.46±0.07 mm(3) at 1h to 1.16±0.09 mm(3) at 2h, and 0.83±0.04 mm(3) at 3h after PMN injection. When the hypopyon volumes at the three time points were compared, significant differences were found between groups (P0.05). Light micrographs of inferior segment of the eyeball revealed dense PMNs in the chamber angle at 1h after PMNs injection and many PMNs in the iris stroma and vessels, as well as at the episcleral and subconjunctival tissues around limbus at 3h and day 1 after PMNs injection. Light micrographs of superior segment of the eyeball at 3h after injection revealed PMNs in the episcleral and subconjunctival vessels. Electron micrographs of inferior segment of the eyeball at 3h after PMNs injection revealed dense PMNs with slightly condensed nuclei in the anterior chamber, as well as in the iris stroma and vessels. In conclusion, in the experimental hypopyon model, PMNs injected into the anterior chamber were cleared from the eye mainly through the iris stroma and vessels, as well as the episcleral and subconjunctival tissues around limbus.
- Published
- 2010
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36. Histological study in the brain of the reelin/Dab1-compound mutant mouse
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Toshio Terashima, Ayako Okuyama-Yamamoto, Tatsuro Yamamoto, and Tomiyoshi Setsu
- Subjects
Yotari ,Heterozygote ,Cell Adhesion Molecules, Neuronal ,Pyramidal Tracts ,Hippocampus ,Nerve Tissue Proteins ,Mice ,symbols.namesake ,Reeler ,medicine ,Animals ,Reelin ,Horseradish Peroxidase ,Extracellular Matrix Proteins ,biology ,Serine Endopeptidases ,Brain ,General Medicine ,DAB1 ,Molecular biology ,Mice, Inbred C57BL ,Neuroanatomical Tract-Tracing Techniques ,Reelin Protein ,medicine.anatomical_structure ,nervous system ,Cytoarchitecture ,Cerebral cortex ,Mutation ,Nissl body ,symbols ,biology.protein ,Anatomy ,Neuroscience ,Signal Transduction - Abstract
The Reelin (Reln)-deficient mouse (reeler) and the Dab1-deficient mouse (yotari) are autosomal recessive mutant mice characterized by cerebellar ataxia. Previously, we reported that Reelin and Dab1 proteins have slightly different functions during the development of the cerebral cortex. To analyze the functional roles of Reelin and Dab1 proteins in detail, we attempted to generate a reelin/Dab1 compound-mutant mouse by breeding heterozygote reeler and yotari mice. We examined the cytoarchitecture of the cerebral and cerebellar cortices and the hippocampus of wild-type (Reln ( +/+ ); Dab1 ( +/+ )), double-heterozygote (Reln ( rl/+ ); Dab1 ( yot/+ )), reeler (Reln ( rl/rl ); Dab1 ( +/+ ), Reln ( rl/rl ); Dab1 ( yot/+ )), yotari (Reln ( +/+ ); Dab1 ( yot/yot ), Reln ( rl/+ ); Dab1 ( yot/yot )), and double-compound-deficient (Reln ( rl/rl ); Dab1 ( yot/yot )) mice. Nissl staining demonstrated that no abnormality was recognized in the mice of reelin/Dab1 double-heterozygote (Reln ( rl/+ ); Dab1 ( yot/+ )). The reelin/Dab1-compound mutant mouse (Reln ( rl/rl ); Dab1 ( yot/yot )) showed histological abnormalities in the cerebral and cerebellar cortices and the hippocampus, in addition to those of reeler and yotari mice. We injected HRP into the lumbar cord of these animals with various gene compositions to examine the distribution pattern of corticospinal tract (CST) neurons. CST neurons of the reelin/Dab1-compound mutant mice were not confined to layer V, but scattered throughout the motor cortex. This quantitative and statistical analysis shows that the distribution pattern of CST neurons of the reelin/Dab1-compound mutant mouse differs from those of either of the reeler or yotari counterparts. Taken together, although Reelin/Dab1 signal transduction is a primary cascade in neurons during developmental periods, other signaling cascades (e.g., the Cdk-5/Dab1 pathway) may lie in a parallel fashion to Reelin/Dab1 signal transduction.
- Published
- 2009
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37. Interfacial Shear Strength Evaluation of Jute/Poly(Lactic Acid)
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Tatsuro Yamamoto, Satoshi Kobayashi, and Asami Nakai
- Subjects
Materials science ,Compressive strength ,Bundle ,Ultimate tensile strength ,technology, industry, and agriculture ,Shear stress ,Fiber bundle ,Molding (process) ,Test method ,Composite material ,Pure shear - Abstract
In order to evaluate the interfacial shear strength between fiber bundle and matrix of jute/poly(lactic acid) (PLA), a fiber bundle pull-out test method is proposed. Shear stress distribution was calculated based on the parabolic shear-lag analysis. Fiber bundle pull-out tests were conducted to evaluate the effects of molding condition on the interfacial shear strength. The interfacial shear strength increased with increasing molding temperature up to 185°C. Then gradual decrease in the interfacial shear strength with molding temperature was observed. Similar tendency was also observed in the effect of molding time, whereas the interfacial shear strength decreased with increasing molding pressure. Comparing the result of the tensile tests in the previous study, interfacial shear strength has corelations with tensile strength.
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- 2009
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38. Roles of long noncoding RNAs in chromosome domains
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Saori, Tomita, Mohamed Osama Ali, Abdalla, Saori, Fujiwara, Tatsuro, Yamamoto, Hirotaka, Iwase, Mitsuyoshi, Nakao, and Noriko, Saitoh
- Subjects
Cell Nucleus ,Histones ,Animals ,Humans ,RNA, Long Noncoding ,Chromatin ,Chromosomes - Abstract
The cell nucleus is highly organized and functionally compartmentalized. Double-stranded naked DNA is complexed with core histones and assembled into nucleosomes and chromatin, which are surrounded by nuclear domains composed of RNAs and proteins. Recently, three-dimensional views of chromosome organization beyond the level of the nucleosome have been established and are composed of several layers of chromosome domains. Only a small portion of the human genome encodes proteins; the majority is pervasively transcribed into noncoding RNAs whose functions are under intensive investigation. Importantly, the questions of how nuclear retained noncoding RNAs play roles in orchestrating the chromatin structure that have been addressed. We discuss the novel noncoding RNA clusters, Eleanors, which are derived from a large chromatin domain. They accumulate at the site of their own transcription to form RNA clouds in the nucleus, and they activate gene expression in the chromatin domain. Noncoding RNAs have emerging roles in genome regulation that are integrated into the spatial organization of chromatin and the nucleus. WIREs RNA 2017, 8:e1384. doi: 10.1002/wrna.1384 For further resources related to this article, please visit the WIREs website.
- Published
- 2016
39. Sufficient intake of high amylose cornstarch maintains high colonic hydrogen production for 24 h in rats
- Author
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Naomichi Nishimura, Tanabe, Hiroki, and Tatsuro Yamamoto
- Abstract
Colonic hydrogen (H2) can suppress oxidative stress and damage in the body. We examined the minimum requirement of high amylose cornstarch (HAS) to maintain high colonic H2 production for 24 h. Ileorectostomized and sham-operated rats were fed a control diet supplemented with or without 20% HAS for 7 days. Colonic starch utilization was determined. Next, rats were fed the control diet with or without 10% or 20% HAS for 14 or 28 days, respectively. Breath and flatus H2 excretion for 24 h was measured. 1.04 g of resistant fraction in HAS was utilized for 24 h by colonic bacteria. High H2 excretion was not maintained for 24 h in rats fed the 10% HAS diet, from which only 0.89 g of resistant starch was estimated to be delivered. High colonic H2 production for 24 h would be maintained by delivering more HAS to the large intestine than is utilized. High production of colonic H2 can be maintained over a 24-h period when sufficient amounts of HAS (>1 g) are delivered to the large intestine as a fermentation substrate.
- Published
- 2016
- Full Text
- View/download PDF
40. Effect of soy resistant protein on fermentation and microbiota in the large intestine
- Author
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Naomichi, Nishimura and Tatsuro, Yamamoto
- Subjects
soy_resistant_protein ,microbiota ,rat ,fermentation ,large_intestine - Published
- 2007
41. 817 Experimental Study on Fatigue Strength of Dental Composite Resin in Ethanol Solution
- Author
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Hiroki Takimoto, Izuru Nishikawa, and Tatsuro Yamamoto
- Subjects
Materials science ,Dental composite resin ,Composite material ,Fatigue limit - Published
- 2007
- Full Text
- View/download PDF
42. Isomaltodextrin, a highly branched α-glucan, increases rat colonic H₂ production as well as indigestible dextrin
- Author
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Naomichi, Nishimura, Hiroki, Tanabe, and Tatsuro, Yamamoto
- Subjects
Male ,Rats, Sprague-Dawley ,Colon ,Polysaccharides ,Dextrins ,Animals ,Hydrogen ,Rats - Abstract
Colonic hydrogen (H2) protects against inflammation-induced oxidative stress. We examined the effect of a new highly branched α-glucan, isomaltodextrin (IMD), on colonic H2 production in rats. Rats were fed a 16.7% IMD, 8.8% indigestible dextrin (ID), or 10.4% high amylose cornstarch diet (Expt. 1), were fed diets containing 3.3-16.7% IMD (Expt. 2), or were fed diets containing 16.7% IMD or 5.2% fructooligosaccharide (FOS) (Expt. 3), for 14 days. Compared with the control group, feeding IMD or other α-glucans dose dependently and significantly increased H2 excretion and portal H2 concentration. The ability of IMD to increase H2 production was not inferior to that of FOS. The cecal Firmicutes/Bacteroidetes ratio in the IMD group was 5-14% of that in the control group. The cecal abundance of bifidobacteria was significantly greater in the IMD group than in the control group. Taken together, IMD, as well as other α-glucans, significantly increased colonic H2 production in a dose-dependent manner.
- Published
- 2015
43. Rational conversion of chromophore selectivity of cyanobacteriochromes to accept mammalian intrinsic biliverdin.
- Author
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Keiji Fushimi, Takatsugu Miyazaki, Yuto Kuwasaki, Takahiro Nakajima, Tatsuro Yamamoto, Kazushi Suzuki, Yoshibumi Ueda, Keita Miyake, Yuka Takeda, Jae-Hoon Choi, Hirokazu Kawagishi, Park, Enoch Y., Masahiko Ikeuchi, Moritoshi Sato, and Rei Narikawa
- Subjects
CHROMOPHORES ,BILIVERDIN ,PHOTORECEPTORS ,CRYSTAL structure ,COVALENT bonds - Abstract
Because cyanobacteriochrome photoreceptors need only a single compact domain for chromophore incorporation and for absorption of visible spectra including the long-wavelength far-red region, these molecules have been paid much attention for application to bioimaging and optogenetics. Most cyanobacteriochromes, however, have a drawback to incorporate phycocyanobilin that is not available in the mammalian cells. In this study, we focused on biliverdin (BV) that is a mammalian intrinsic chromophore and absorbs the far-red region and revealed that replacement of only four residues was enough for conversion from BV-rejective cyanobacteriochromes into BV-acceptable molecules. We succeeded in determining the crystal structure of one of such engineered molecules, AnPixJg2_BV4, at 1.6 Å resolution. This structure identified unusual covalent bond linkage, which resulted in deep BV insertion into the protein pocket. The four mutated residues contributed to reducing steric hindrances derived from the deeper insertion. We introduced these residues into other domains, and one of them, NpF2164g5_BV4, produced bright near-infrared fluorescence from mammalian liver in vivo. Collectively, this study provides not only molecular basis to incorporate BV by the cyanobacteriochromes but also rational strategy to open the door for application of cyanobacteriochromes to visualization and regulation of deep mammalian tissues. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Changes inreelinexpression in the mouse olfactory bulb after chemical lesion to the olfactory epithelium
- Author
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Akinori Miki, Ayako Okuyama-Yamamoto, Toshio Terashima, and Tatsuro Yamamoto
- Subjects
Olfactory system ,medicine.medical_specialty ,Tyrosine 3-Monooxygenase ,Cell Adhesion Molecules, Neuronal ,Gene Expression ,Nerve Tissue Proteins ,Lesion ,Mice ,Reeler ,Olfactory Mucosa ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,Reelin ,Astringents ,Extracellular Matrix Proteins ,biology ,General Neuroscience ,Serine Endopeptidases ,Olfactory Pathways ,DAB1 ,Denervation ,Olfactory Bulb ,Zinc Sulfate ,Nerve Regeneration ,Olfactory bulb ,Mice, Inbred C57BL ,Reelin Protein ,Endocrinology ,medicine.anatomical_structure ,nervous system ,Nerve Degeneration ,biology.protein ,Olfactory ensheathing glia ,medicine.symptom ,Olfactory epithelium - Abstract
To explore the functional roles of Reelin in the adult olfactory system, we examined changes in the expression of reelin mRNA and Reelin protein in the olfactory bulb (OB) of adult mice after a chemical lesion to the olfactory epithelium. Following intranasal irrigation with 2% zinc sulphate solution, animals were perfused at various times between 5 and 40 days post-lesion. The expression of reelin mRNA in mitral cells in the OB was slightly reduced at 5 days post-lesion, completely abolished by 20 days, but restored almost to the normal level at 40 days post-lesion. Similarly, the expression of Reelin protein in mitral cells of the deafferented OB also recovered, although not to the normal level. No recovery of either reelin mRNA or Reelin immunoreactivity was seen in the periglomerular cells and external tufted cells. The expression profile of reelin mRNA and Reelin protein in the OB coincided with the time course of degeneration and regeneration of olfactory nerves, as indicated by anterograde labeling of olfactory nerves with WGA-HRP. These results suggest that expression of reelin mRNA in the adult OB is regulated by olfactory inputs.
- Published
- 2005
- Full Text
- View/download PDF
45. Missplicing resulting from a short deletion in thereelin gene causesreeler-like neuronal disorders in the mutant shaking rat Kawasaki
- Author
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Masaharu Ogawa, Satoshi Kikkawa, Yayoi Ikeda, Kazuyo Misaki, Toshio Terashima, Tatsuro Yamamoto, Haruo Okado, and Peter L. Woodhams
- Subjects
Cerebellum ,DNA, Complementary ,Cell Adhesion Molecules, Neuronal ,Blotting, Western ,DNA Mutational Analysis ,Molecular Sequence Data ,Mutant ,Nerve Tissue Proteins ,Biology ,medicine.disease_cause ,Rats, Mutant Strains ,Reeler ,medicine ,Animals ,RNA, Messenger ,Reelin ,Rats, Wistar ,Gait Disorders, Neurologic ,In Situ Hybridization ,Neurons ,Extracellular Matrix Proteins ,Mutation ,Base Sequence ,General Neuroscience ,Serine Endopeptidases ,Brain ,food and beverages ,Blotting, Northern ,DAB1 ,Immunohistochemistry ,Molecular biology ,Rats ,Reelin Protein ,medicine.anatomical_structure ,nervous system ,Cerebral cortex ,Cerebellar cortex ,biology.protein ,Gene Deletion - Abstract
The shaking rat Kawasaki (SRK) is an autosomal recessive mutant that exhibits reeler-like abnormal locomotor behaviors. The murine reeler mutants arise from several mutations in the specific gene called reelin, which result in defects of Reelin expression or secretion in the cerebral cortex and other regions of CNS. To address the issue of whether the SRK mutation also arises from a mutation in reelin, we analyzed the reelin gene in SRK. Northern analysis of reelin mRNA from normal rats showed that rat reelin was expressed as a approximately 12-kb transcript in both the cerebrum and the cerebellum, whereas reelin expression was markedly reduced in the SRK brains. In situ hybridization analysis showed that reelin mRNA in the SRK brains was expressed in Cajal-Retzius cells in the marginal zone of the cerebral cortex and outer granular cells in the cerebellar cortex in similar manners to normal controls, but its expression was considerably reduced. On Western blotting and immunohistochemical analyses using antibodies specific for the Reelin protein, no immunoproduct was recognized in the cerebral and cerebellar cortices. From the cDNA sequences, we found a 64-base heterologous sequence in SRK reelin, which contains a termination codon in the reading frame. Furthermore, genomic DNA analysis revealed that a 10-base deletion, which contains a predicted splice donor site, occurred in the SRK genomic reelin gene, resulting in "read through" into the following intron in SRK. Thus, the SRK mutation is another type of mutation that lacks expression of the functional Reelin protein and, therefore, causes the reeler phenotype.
- Published
- 2003
- Full Text
- View/download PDF
46. Ectopic corticospinal tract and corticothalamic tract neurons in the cerebral cortex ofyotari andreeler mice
- Author
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Tatsuro Yamamoto, Katsuhiko Mikoshiba, Toshio Terashima, and Shunsuke Sakakibara
- Subjects
Yotari ,Cell Adhesion Molecules, Neuronal ,Organogenesis ,Molecular Sequence Data ,Pyramidal Tracts ,Nerve Tissue Proteins ,Axonal Transport ,Mice ,Mice, Neurologic Mutants ,Reeler ,Thalamus ,Cell Movement ,Cortex (anatomy) ,Neural Pathways ,medicine ,Animals ,Reelin ,Horseradish Peroxidase ,Cerebral Cortex ,Neurons ,Extracellular Matrix Proteins ,Pyramidal tracts ,Base Sequence ,biology ,General Neuroscience ,Serine Endopeptidases ,DAB1 ,Reelin Protein ,medicine.anatomical_structure ,nervous system ,Cerebral cortex ,Corticospinal tract ,biology.protein ,Neuroscience - Abstract
Reeler and yotari mice, which are mutant for Reelin or Dab1, respectively, show disorders of cerebral cortical lamination. We injected horseradish peroxidase (HRP) into the upper lumbar enlargement to label corticospinal tract (CST) neurons and wheat germ agglutinin-conjugated HRP (WGA-HRP) into the ventral lateral nucleus of the thalamus to label corticothalamic tract (CTT) neurons in both 19-day-old yotari and reeler mice with the aim of discovering whether or not they show differences in the distribution pattern of layer V or layer VI neurons. Similar injections of tracers were made in normal controls. HRP-labeled CST neurons, which were exclusively distributed in layer V of the normal cortex, were radially scattered in the cortex of both mutants, but those in reeler were more deeply distributed than in yotari. WGA-labeled CTT neurons, which were mainly located in layer VI in the normal cortex, were superficially distributed just beneath the pia mater in both reeler and yotari cortex. The present quantitative study shows that the distribution pattern of layer V neurons, but not layer VI neurons, differs between reeler and yotari mice, suggesting that the Reelin and Dab1 proteins may play different roles in the migration and cell positioning of layer V neurons.
- Published
- 2003
- Full Text
- View/download PDF
47. Retrograde labeling of mouse spinal descending tracts by a recombinant adenovirus
- Author
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Toshio Terashima, Tatsuro Yamamoto, Haruo Okado, Ken-ichi Nibu, and Yasuhiro Tsukamoto
- Subjects
Time Factors ,Histology ,Ependymal Cell ,Microinjections ,Genetic Vectors ,Gene Expression ,Biology ,Adenoviridae ,law.invention ,Mice ,Neurons, Efferent ,law ,Ependyma ,Escherichia coli ,medicine ,Animals ,Horseradish Peroxidase ,Fixative ,Staining and Labeling ,Small volume ,Gene Transfer Techniques ,Anatomy ,beta-Galactosidase ,Spinal cord ,Axons ,Staining ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Lac Operon ,Spinal Cord ,Corticospinal tract ,Axoplasmic transport ,Recombinant DNA ,Feasibility Studies - Abstract
The present study tested whether a gene-transfer based upon the retrograde axonal transport of the lacZ adenovirus is effective in the spinal descending tracts of the adult mouse. A small volume of a replication-defective recombinant adenovirus encoding E. coli beta-galactosidase was injected into the upper lumbar cord, and, seven days later, the mice were transcardially perfused by a fixative solution. X-gal staining of coronal or sagittal sections of the spinal cord and the brain revealed that many sites of origin for rubrospinal, vestibulospinal, and reticulospinal tracts were retrogradely labeled, whereas few of the corticospinal tract neurons were retrogradely labeled. Ependymal cells surrounding the central canal of the spinal cord, which were located far from the injection site, showed a high expression of beta-galactosidase activity. Motoneurons around the injection site were strongly stained by X-gal staining, and their axons in the ventral root were anterogradely labeled. Afferent fibers in the dorsal root were labeled by the transganglionic transport of beta-galactosidase. To examine the efficacy of the uptake and retrograde transport of HRP and adenovirus, we injected a mixed solution of 10% HRP and recombinant adenovirus. The number of HRP-labeled corticospinal neurons overwhelmed the number of X-gal stained ones, while the numbers of HRP-labeled rubrospinal and subcoeruleus-spinal neurons were smaller in comparison with the numbers of beta-galactosidase-positive counterparts. The present study revealed that the origins for the spinal descending tracts except for corticospinal neurons could be efficiently gene-transferred by the retrograde infection of a recombinant adenovirus. Such a difference in efficacy of retrograde infection among the spinal descending tracts is practically important when an adenovirus-mediated gene transfer is designed to treat certain neurological diseases affecting the spinal descending tracts.
- Published
- 2003
- Full Text
- View/download PDF
48. Successful esophageal bypass surgery in a patient with a large tracheoesophageal fistula following endotracheal stenting and chemoradiotherapy for advanced esophageal cancer: case report
- Author
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Masayuki Watanabe, Masaaki Iwatsuki, Tatsunori Miyata, Yoshifumi Baba, Yoshihiro Ikuta, Yohei Nagai, Shiro Iwagami, Tatsuro Yamamoto, Chiyo Furushou, and Hideo Baba
- Subjects
medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Tracheoesophageal fistula ,Gastroenterology ,Stent ,Achalasia ,Case Report ,Tracheobronchial stent ,Airway obstruction ,medicine.disease ,Tracheal tube ,Surgery ,Esophageal bypass ,Bypass surgery ,Cardiothoracic surgery ,medicine ,business ,Chemoradiotherapy - Abstract
A 63-year-old man with esophageal achalasia for more than 20 years complained of respiratory distress. He was admitted as an emergency to the referral hospital three months previously. Computed tomography revealed tracheobronchial stenosis due to advanced esophageal cancer with tracheal invasion. He underwent tracheobronchial stenting and chemoradiotherapy. A large tracheoesophageal fistula (TEF) developed after irradiation (18 Gy) and chemotherapy, and he was unable to eat. Thereafter, he was referred to our hospital, where we performed esophageal bypass surgery using a gastric conduit. A percutaneous cardiopulmonary support system was prepared due to the risk of airway obstruction during anesthesia. A small-diameter tracheal tube inserted into the stent achieved ordinary respiratory management. No anesthesia-related problems were encountered. Oral intake commenced on postoperative day 9. He was discharged on postoperative day 23 and was able to take in sustenance orally right up to the last moment of his life. Esophageal bypass under general anesthesia can be performed in patients with large TEF with sufficient preparation for anesthetic management.
- Published
- 2012
- Full Text
- View/download PDF
49. [Treatment of chronic pain]
- Author
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Tatsuro, Yamamoto
- Subjects
Analgesics, Opioid ,Cognitive Behavioral Therapy ,Humans ,Neuralgia ,Nerve Block ,Chronic Pain - Published
- 2014
50. Dual labeling with 5-bromo-2'-deoxyuridine and 5-ethynyl-2'-deoxyuridine for estimation of cell migration rate in the small intestinal epithelium
- Author
-
Mami Asano, Takeshi Tsuruta, Naomichi Nishimura, Kei Sonoyama, and Tatsuro Yamamoto
- Subjects
Male ,medicine.medical_treatment ,Intraperitoneal injection ,Cell ,Biology ,chemistry.chemical_compound ,Cell Movement ,5-Ethynyl-2'-deoxyuridine ,Intestine, Small ,medicine ,Animals ,Intestinal Mucosa ,Rats, Wistar ,Staining and Labeling ,Cell growth ,Cell migration ,Cell Biology ,Molecular biology ,Intestinal epithelium ,Deoxyuridine ,Epithelium ,Rats ,medicine.anatomical_structure ,chemistry ,Bromodeoxyuridine ,Developmental Biology - Abstract
Small intestinal epithelium is a self-renewing system in which the entire sequence of cell proliferation, differentiation, and removal is coupled to cell migration along the crypt-villus axis. We examined whether dual labeling with different thymidine analogues, 5-bromo-2'-deoxyuridine (BrdU) and 5-ethynyl-2'-deoxyuridine (EdU), can be used to estimate cell migration rates on the villi of small intestines in rats. Rats received a single intraperitoneal injection of BrdU and EdU within a time interval, and signals in tissue sections were examined by immunohistochemistry and the "click" reaction, respectively. We successfully observed BrdU- and EdU-positive cells on the epithelium with no cross-reaction. In addition, we observed an almost complete overlapping of BrdU- and EdU-positive cells in rats administered simultaneously with BrdU and EdU. By calculating the cell migration rate by dividing the distance between the median cell positions of the distribution of BrdU- and EdU-positive cells by the time between the injection of BrdU and EdU, we estimated approximately 9 and 5 μm/h for the cell migration rates on the villi in the jejunum and ileum, respectively. We propose that dual labeling with BrdU and EdU within a time interval, followed by detecting with immunohistochemistry and the click reaction, respectively, is useful to estimate accurately the cell migration rate in the intestinal epithelium in a single animal.
- Published
- 2014
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