17 results on '"Kamo T."'
Search Results
2. Structural insights into Influenza A virus RNA polymerase PB1 binding to nuclear import host factor RanBP5.
- Author
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Uchikubo-Kamo T, Ishimoto N, Umezawa H, Hirohama M, Ono M, Kawabata H, Kamata K, Ohki M, Yoshida H, Park JH, Tame JRH, Kawaguchi A, and Park SY
- Subjects
- Humans, Nucleocytoplasmic Transport Proteins metabolism, Nucleocytoplasmic Transport Proteins chemistry, Models, Molecular, Cryoelectron Microscopy, Nuclear Proteins metabolism, Nuclear Proteins chemistry, DNA-Directed RNA Polymerases metabolism, DNA-Directed RNA Polymerases chemistry, Binding Sites, beta Karyopherins, Viral Proteins metabolism, Viral Proteins chemistry, Viral Proteins genetics, Active Transport, Cell Nucleus, Influenza A virus metabolism, Influenza A virus genetics, Protein Binding
- Abstract
The genome of influenza A viruses consists of eight RNA segments that form a heterotrimer, and the viral genome undergoes transcription and replication in the nucleus. Thus, during infection, newly synthesized RNA polymerase subunits must be imported into the nucleus. Although several models have been proposed for this process, the consensus is that the RNA polymerase subunits PB1 and PA form a dimer in the cytoplasm and are transported into the nucleus by Ran binding protein 5 (RanBP5). The PB2 subunit undergoes separate transport to complete the nuclear import. However, the molecular mechanism of nuclear import by host factors and their interactions with proteins are largely unknown. Here we present the structural analysis of the RanBP5 and PB1 NLS domain complex by cryo-EM at 3.2 Å resolution. The pattern shows that the NLS domain of PB1 does not exist in a secondary structure and interacts with RanBP5 in a wrapped state. In addition, biochemical analyses of the mutant have identified critical amino acid sites involved in complex binding. The results suggest a stepwise assembly of influenza virus structural components regulated by nuclear import mechanisms and host factor binding, with important implications for drug discovery research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
3. ARDS clinical practice guideline 2021.
- Author
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Tasaka S, Ohshimo S, Takeuchi M, Yasuda H, Ichikado K, Tsushima K, Egi M, Hashimoto S, Shime N, Saito O, Matsumoto S, Nango E, Okada Y, Hayashi K, Sakuraya M, Nakajima M, Okamori S, Miura S, Fukuda T, Ishihara T, Kamo T, Yatabe T, Norisue Y, Aoki Y, Iizuka Y, Kondo Y, Narita C, Kawakami D, Okano H, Takeshita J, Anan K, Okazaki SR, Taito S, Hayashi T, Mayumi T, Terayama T, Kubota Y, Abe Y, Iwasaki Y, Kishihara Y, Kataoka J, Nishimura T, Yonekura H, Ando K, Yoshida T, Masuyama T, and Sanui M
- Subjects
- Adult, Child, Humans, Prone Position, Respiration, Artificial, Tidal Volume, Extracorporeal Membrane Oxygenation, Respiratory Distress Syndrome therapy
- Abstract
Background: The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021., Methods: The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method., Results: Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4-8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO
2 (PaO2 ) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D); we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D); we suggest against routinely implementing NO inhalation therapy (GRADE 2C); and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D)., Conclusions: This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jrs.or.jp/publication/jrs_guidelines/). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries., Competing Interests: Conflict of Interest All committee members and panelists submitted disclosure forms of financial and academic conflict of interest (COI) prior to being requested to participate in individual activities. If panelists have any COI concerning each CQ, other panelists were assigned to replace the vacancy. All COI were collected according to the guideline written by Japanese Society of Intensive Care Medicine. Detailed information of COI and the roles in creating this clinical guideline are summarized in Additional file 7., (Copyright © 2022 [The Author/The Authors]. Published by Elsevier B.V. All rights reserved.)- Published
- 2022
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4. A comprehensive study on the oxidative pyrolysis of epoxy resin from fiber/epoxy composites: Product characteristics and kinetics.
- Author
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Ma C, Sánchez-Rodríguez D, and Kamo T
- Abstract
Thermal treatment has been the most feasible process to recycle valuable carbon fibers and obtain fuel and chemicals from waste fiber/epoxy composites. The present work studied the oxidative pyrolysis behaviors of epoxy resin from fiber/epoxy composites using a thermogravimetric apparatus and a fixed-bed reactor, respectively. The effects of various O
2 concentrations on the thermal behaviors of epoxy resin were investigated and the product characteristics were analyzed. Furthermore, a multi distributed activation energy model (multi-DAEM) was first developed to determine the oxidative pyrolysis kinetics of epoxy resin under various atmospheres. Results showed that the degradation behaviors of epoxy resin were largely altered by the O2 concentrations. High O2 concentrations accelerated the primary decomposition of epoxy resin and shifted the oxidation of resin residue into lower temperatures. High contents of methylcyclohexene and phenolic derivatives were detected in liquid products. In air atmosphere, high yields of CO and CO2 were generated and distributed in several stages. The kinetic analysis indicated that the multi-DAEM method can well explain the oxidative pyrolysis behaviors of epoxy resin. A minimum six-reaction fitting process can perfectly simulate the oxidative pyrolysis of epoxy resin. The predictions for various O2 concentrations were in good agreement with the experimental tests., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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5. Effect of steam-iron reaction on product characteristics and debromination during pyrolysis of epoxy-printed circuit boards.
- Author
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Ma C and Kamo T
- Abstract
In this work, the effect of steam and Fe powders on the pyrolysis of epoxy-printed circuit boards (e-PCBs) is in the focus of interest. It was found that higher yields of oil and gas were obtained at 600 °C in steam atmosphere than these obtained in N
2 atmosphere. Due to the interactions of Fe powders and steam, the highest yield of H2 was obtained at 600 °C, accounting for 12.2 mmol g-1 . In terms of the oil products, a high amount of phenol was produced in steam atmosphere, whereas an increased yield of single ring aromatic compounds was obtained, due to the dehydroxylation reactions promoted by steam-iron reaction. In steam atmosphere, the amount of organobromine compounds was greatly reduced. Fe powders removed most of organobromine compounds and HBr from oils. However, the bromine fixing ability of Fe powders was declined at 700 °C, leading to an increase in the content of inorganic bromine in liquid products. The characterization of spent Fe powders showed that the oxidation reactions of Fe powders with steam proceeded during the experiment, whereas the reduction reactions could be promoted at higher temperatures., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
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6. Efficacy of Carotid Endarterectomy for Mild (<50%) Symptomatic Carotid Stenosis with Unstable Plaque.
- Author
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Kashiwazaki D, Shiraishi K, Yamamoto S, Kamo T, Uchino H, Saito H, Akioka N, Kuwayama N, Noguchi K, and Kuroda S
- Subjects
- Aged, Aged, 80 and over, Carotid Stenosis drug therapy, Computed Tomography Angiography methods, Female, Humans, Intraoperative Care, Ischemic Attack, Transient etiology, Magnetic Resonance Angiography, Male, Middle Aged, Multimodal Imaging, Platelet Aggregation Inhibitors therapeutic use, Postoperative Complications etiology, Prospective Studies, Stroke etiology, Treatment Outcome, Carotid Stenosis surgery, Endarterectomy, Carotid methods, Plaque, Atherosclerotic surgery
- Abstract
Background: Carotid endarterectomy (CEA) is known to reduce stroke risk in patients with symptomatic, moderate to severe carotid stenosis but has no apparent impact in patients with symptomatic, mild (less than 50%) carotid stenosis. However, recent development of noninvasive imaging modalities has shown that a certain subgroup of patients are at high risk for further ischemic events despite antiplatelet therapy. This study, therefore, aimed to clarify the patients' clinical features and explore the impact of CEA for them., Methods: This prospective cohort study included 74 patients who underwent CEA for symptomatic carotid stenosis between April 2012 and December 2016. Of these, 16 (22%) had mild (less than 50%) carotid stenosis. Their demographic, radiologic, intraoperative, and pathologic findings were precisely analyzed, and their outcome after CEA was examined for 38.5 ± 13.3 months., Results: Of these 16 patients, 12 had already been treated with antiplatelets against previous ischemic cerebrovascular or coronary artery diseases. Plaque magnetic resonance imaging revealed that all patients had vulnerable plaque, including lipid-rich plaque (n = 6) and intraplaque hemorrhage (n = 10). Intraoperative observations confirmed this. Histologic analysis revealed that inflammatory cells and fragile angiogenesis were widely found in the specimens. Only 1 patient experienced transient (less than 30 days) neurologic deficit after CEA, and none of them repeated cerebrovascular events during the follow-up period., Conclusions: It is not rare the patients who are at high risk for subsequent ischemic events because of vulnerable plaque despite mild (less than 50%) carotid stenosis. Magnetic resonance imaging is quite useful to noninvasively detect such vulnerable plaque. CEA is a promising procedure to treat these patients., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
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7. Anti-inflammatory roles of mesenchymal stromal cells during acute Streptococcus pneumoniae pulmonary infection in mice.
- Author
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Asami T, Ishii M, Namkoong H, Yagi K, Tasaka S, Asakura T, Suzuki S, Kamo T, Okamori S, Kamata H, Zhang H, Hegab AE, Hasegawa N, and Betsuyaku T
- Subjects
- Animals, Culture Media, Conditioned metabolism, Culture Media, Conditioned pharmacology, Cytokines metabolism, Ligands, Lung metabolism, Lung microbiology, Lung pathology, Macrophages immunology, Macrophages metabolism, Male, Mice, Inbred C57BL, Neutrophils immunology, Pneumonia, Pneumococcal immunology, Streptococcus pneumoniae pathogenicity, Toll-Like Receptors immunology, Mesenchymal Stem Cell Transplantation methods, Mesenchymal Stem Cells immunology, Pneumonia, Pneumococcal therapy
- Abstract
Background: Pneumonia is the fourth leading cause of death worldwide, and Streptococcus pneumoniae is the most commonly associated pathogen. Increasing evidence suggests that mesenchymal stromal cells (MSCs) have anti-inflammatory roles during innate immune responses such as sepsis. However, little is known about the effect of MSCs on pneumococcal pneumonia., Methods: Bone marrow-derived macrophages (BMDMs) were stimulated with various ligands in the presence or absence of MSC-conditioned medium. For in vivo studies, mice intranasally-inoculated with S. pneumoniae were intravenously treated with MSCs or vehicle, and various parameters were assessed., Results: After stimulation with toll-like receptor (TLR) 2, TLR9 or TLR4 ligands, or live S. pneumoniae, TNF-α and interleukin (IL)-6 levels were significantly decreased, whereas IL-10 was significantly increased in BMDMs cultured in MSC-conditioned medium. In mice, MSC treatment decreased the number of neutrophils in bronchoalveolar lavage fluid (BALF) after pneumococcal infection, and this was associated with a decrease in myeloperoxidase activity in the lungs. Levels of proinflammatory cytokines, including TNF-α, IL-6, GM-CSF and IFN-γ, were significantly lower in MSC-treated mice, and the bacterial load in the lung after pneumococcal infection was significantly reduced. In addition, histopathologic analysis confirmed a decrease in the number of cells recruited to the lungs; however, lung edema, protein leakage into the BALF and levels of the antibacterial protein lipocalin 2 in the BALF were comparable between the groups., Conclusions: These results indicate that MSCs could represent a potential therapeutic application for the treatment of pneumonia caused by S. pneumoniae., (Copyright © 2018 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
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8. The Japanese version of the Posttraumatic Diagnostic Scale: Validity in participants with and without traumatic experiences.
- Author
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Itoh M, Ujiie Y, Nagae N, Niwa M, Kamo T, Lin M, Hirohata S, and Kim Y
- Subjects
- Adolescent, Adult, Female, Humans, Japan, Male, Middle Aged, Reproducibility of Results, Self Report, Sensitivity and Specificity, Young Adult, Psychiatric Status Rating Scales standards, Psychometrics instrumentation, Stress Disorders, Post-Traumatic diagnosis
- Abstract
The Posttraumatic Diagnostic Scale (PDS) is a brief, self-report questionnaire developed for the diagnostic screening and assessment of the severity of posttraumatic stress disorder (PTSD); the PDS is based on the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders (4th edition; DSM-IV). We investigated the validity and reliability of the Japanese version of the PDS in a clinical (n=109) and a non-clinical (n=116) sample, recruited from an outpatient psychiatric facility and a university student population, respectively. The Japanese versions of the PDS and the Clinician-Administered PTSD Scale (CAPS/DSM-IV) were administered to the participants. The Japanese PDS's diagnostic sensitivity and specificity exceeded 90%. The correlation between the severity scores assessed by the Japanese PDS and the CAPS was also high (r=0.92). The findings suggest that the Japanese version of the PDS is useful for diagnostically screening PTSD and assessing symptom severity., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
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9. Simultaneous neuron- and astrocyte-specific fluorescent marking.
- Author
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Schulze W, Hayata-Takano A, Kamo T, Nakazawa T, Nagayasu K, Kasai A, Seiriki K, Shintani N, Ago Y, Farfan C, Hashimoto R, Baba A, and Hashimoto H
- Subjects
- Animals, Astrocytes cytology, Biomarkers metabolism, Brain cytology, Brain metabolism, Cell Nucleus metabolism, Cloning, Molecular, Genetic Vectors, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, Hippocampus cytology, Histones genetics, Histones metabolism, Lentivirus genetics, Male, Mice, Neurons cytology, Primary Cell Culture, Promoter Regions, Genetic, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Astrocytes metabolism, Biochemistry methods, Fluorescent Dyes metabolism, Neurons metabolism
- Abstract
Systematic and simultaneous analysis of multiple cell types in the brain is becoming important, but such tools have not yet been adequately developed. Here, we aimed to generate a method for the specific fluorescent labeling of neurons and astrocytes, two major cell types in the brain, and we have developed lentiviral vectors to express the red fluorescent protein tdTomato in neurons and the enhanced green fluorescent protein (EGFP) in astrocytes. Importantly, both fluorescent proteins are fused to histone 2B protein (H2B) to confer nuclear localization to distinguish between single cells. We also constructed several expression constructs, including a tandem alignment of the neuron- and astrocyte-expression cassettes for simultaneous labeling. Introducing these vectors and constructs in vitro and in vivo resulted in cell type-specific and nuclear-localized fluorescence signals enabling easy detection and distinguishability of neurons and astrocytes. This tool is expected to be utilized for the simultaneous analysis of changes in neurons and astrocytes in healthy and diseased brains., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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10. Structural basis for the specific recognition of the major antigenic peptide from the Japanese cedar pollen allergen Cry j 1 by HLA-DP5.
- Author
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Kusano S, Kukimoto-Niino M, Satta Y, Ohsawa N, Uchikubo-Kamo T, Wakiyama M, Ikeda M, Terada T, Yamamoto K, Nishimura Y, Shirouzu M, Sasazuki T, and Yokoyama S
- Subjects
- Animals, Binding Sites, Cryptomeria chemistry, Crystallography, X-Ray, HLA-DP alpha-Chains genetics, HLA-DP beta-Chains genetics, Humans, Hydrogen Bonding, Models, Molecular, Phylogeny, Protein Binding, Protein Interaction Domains and Motifs, Protein Structure, Secondary, Sf9 Cells, Spodoptera, Antigens, Plant chemistry, HLA-DP alpha-Chains chemistry, HLA-DP beta-Chains chemistry, Peptide Fragments chemistry, Plant Proteins chemistry
- Abstract
The major allergen, Cry j 1, was isolated from Japanese cedar Cryptomeria japonica (Cry j) pollen and was shown to react with immunoglobulin E antibodies in the sera from pollinosis patients. We previously reported that the frequency of HLA-DP5 was significantly higher in pollinosis patients and the immunodominant peptides from Cry j 1 bound to HLA-DP5 to activate Th2 cells. In the present study, we determined the crystal structure of the HLA-DP5 heterodimer in complex with a Cry j 1-derived nine-residue peptide, at 2.4Å resolution. The peptide-binding groove recognizes the minimal peptide with 10 hydrogen bonds, including those between the negatively charged P1 pocket and the Lys side chain at the first position in the peptide sequence. We confirmed that HLA-DP5 exhibits the same Cry j 1-binding mode in solution, through pull-down experiments using structure-based mutations of Cry j 1. We also identified the characteristic residues of HLA-DP5 that are responsible for the distinct properties of the groove, by comparing the structure of HLA-DP5 and the previously reported structures of HLA-DP2 in complexes with pDRA of the self-antigen. The comparison revealed that the HLA-DP5·pCry j 1 complex forms several hydrogen bond/salt bridge networks between the receptor and the antigen that were not observed in the HLA-DP2·pDRA complex. Evolutionary considerations have led us to conclude that HLA-DP5 and HLA-DP2 represent two major groups of the HLA-DP family, in which the properties of the P1 and P4 pockets have evolved and acquired the present ranges of epitope peptide-binding specificities., (Copyright © 2014. Published by Elsevier Ltd.)
- Published
- 2014
- Full Text
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11. Lateral pressure change on phase transitions of phosphatidylcholine/diolein mixed membranes.
- Author
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Kamo T, Handa T, and Nakano M
- Subjects
- Egg Yolk chemistry, Fluorescence, Phase Transition, Pressure, Diglycerides chemistry, Phosphatidylcholines chemistry
- Abstract
In this work, the changes in the lateral pressure in mixed membranes of egg yolk phosphatidylcholine (EPC) and a nonlamellar-forming lipid diolein (DO) were investigated with respect to increasing DO content. Several fluorescence techniques were employed to probe transitions of EPC/DO lipid mixtures from lamellar to inverted hexagonal via bicontinuous cubic phases. Excimer fluorescence of dipyrenyl phospholipids revealed that the lateral pressure in the acyl chain region of the EPC/DO mixed membrane increased with the mole fraction of DO (X(DO)) in the lamellar phase and further increased almost linearly up to X(DO)=0.2 through the lamellar-to-cubic phase transition. Water penetration into the acyl chain region, as determined by fluorescence lifetime experiments, decreased linearly with increasing X(DO) until the cubic phase was formed. These results suggest that the acyl chain packing becomes tighter by the incorporation of DO in the lamellar phase and that it does not alter during the lamellar-to-cubic phase transition. Only the packing of the headgroup region was found to increase during the transition to the cubic phase, as detected by the fluorescence lifetime of dansyl phosphatidylethanolamine, which localizes in this region. Through the cubic-to-hexagonal transition, headgroup packing was increased further, and the acyl chain packing was in turn loosened. These results suggest that the acyl chain packing stress induced by the incorporation of DO is released not by the lamellar-to-cubic phase transition but by the cubic-to-hexagonal transition., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
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12. Preventive effect of chemical peeling on ultraviolet induced skin tumor formation.
- Author
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Abdel-Daim M, Funasaka Y, Kamo T, Ooe M, Matsunaka H, Yanagita E, Itoh T, and Nishigori C
- Subjects
- Animals, Cyclooxygenase 2 analysis, Dinoprostone blood, Female, Genes, p53, Mice, Mice, Hairless, Neoplasms, Radiation-Induced metabolism, Neoplasms, Radiation-Induced pathology, Skin Aging drug effects, Skin Aging radiation effects, Skin Neoplasms metabolism, Skin Neoplasms pathology, Chemexfoliation, Glycolates therapeutic use, Neoplasms, Radiation-Induced prevention & control, Salicylic Acid therapeutic use, Skin Neoplasms prevention & control, Trichloroacetic Acid therapeutic use, Ultraviolet Rays adverse effects
- Abstract
Background: Chemical peeling is one of the dermatological treatments available for certain cutaneous diseases and conditions or improvement of cosmetic appearance of photoaged skin., Objectives: We assessed the photochemopreventive effect of several clinically used chemical peeling agents on the ultraviolet (UV)-irradiated skin of hairless mice., Methods: Chemical peeling was done using 35% glycolic acid dissolved in distilled water, 30% salicylic acid in ethanol, 10% or 35% trichloroacetic acid (TCA) in distilled water at the right back of UV-irradiated hairless mice every 2 weeks in case of glycolic acid, salicylic acid, and 10% TCA and every 4 weeks in case of 35% TCA for totally 18 weeks after the establishment of photoaged mice by irradiation with UVA+B range light three times a week for 10 weeks at a total dose of 420 J/cm(2) at UVA and 9.6 J/cm(2) at UVB. Tumor formation was assessed every week. Skin specimens were taken from treated and non-treated area for evaluation under microscopy, evaluation of P53 expression, and mRNA expression of cyclooxygenase (COX)-2. Serum level of prostaglandin E(2) was also evaluated., Results: All types of chemical peeling reduced tumor formation in treated mice, mostly in the treated area but also non-treated area. Peeling suppressed clonal retention of p53 positive abnormal cells and reduced mRNA expression of COX-2 in treated skin. Further, serum prostaglandin E(2) level was decreased in chemical peeling treated mice., Conclusions: These results indicate that chemical peeling with glycolic acid, salicylic acid, and TCA could serve tumor prevention by removing photodamaged cells., (Copyright © 2010 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
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13. Limited distribution of natural cyanamide in higher plants: occurrence in Vicia villosa subsp. varia, V. cracca, and Robinia pseudo-acacia.
- Author
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Kamo T, Endo M, Sato M, Kasahara R, Yamaya H, Hiradate S, Fujii Y, Hirai N, and Hirota M
- Subjects
- Cyanamide metabolism, Gas Chromatography-Mass Spectrometry methods, Robinia metabolism, Seasons, Seeds chemistry, Seeds growth & development, Species Specificity, Vicia metabolism, Cyanamide analysis, Robinia chemistry, Vicia chemistry
- Abstract
Cyanamide (NH2CN) has recently been proven to be a natural product, although it has been synthesized for over 100 years for agricultural and industrial purposes. The distribution of natural cyanamide appears to be limited, as indicated by our previous investigation of 101 weed species. In the present study, to investigate the distribution of natural cyanamide in Vicia species, we monitored the cyanamide contents in V. villosa subsp. varia, V. cracca, and V. amoena during their pre-flowering and flowering seasons. It was confirmed that V. cracca was superior to V. villosa subsp. varia in accumulating natural cyanamide, and that V. amoena was unable to biosynthesize this compound under laboratory condition examined. The localization of cyanamide in the leaves of V. villosa subsp. varia seedlings was also clarified. In a screening study to find cyanamide-biosynthesizing plants, only Robinia pseudo-acacia was found to contain cyanamide among 452 species of higher plants. We have investigated 553 species to date, but have so far found the ability to biosynthesize cyanamide in only three species, V. villosa subsp. varia, V. cracca and R. pseudo-acacia.
- Published
- 2008
- Full Text
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14. Direct quantitative determination of cyanamide by stable isotope dilution gas chromatography-mass spectrometry.
- Author
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Hiradate S, Kamo T, Nakajima E, Kato K, and Fujii Y
- Subjects
- Gas Chromatography-Mass Spectrometry standards, Nitriles chemistry, Reproducibility of Results, Sensitivity and Specificity, Cyanamide analysis, Gas Chromatography-Mass Spectrometry methods, Indicator Dilution Techniques, Isotopes chemistry, Vicia chemistry
- Abstract
Cyanamide is a multifunctional agrochemical used, for example, as a pesticide, herbicide, and fertilizer. Recent research has revealed that cyanamide is a natural product biosynthesized in a leguminous plant, hairy vetch (Vicia villosa). In the present study, gas chromatography-mass spectrometry (GC-MS) equipped with a capillary column for amines was used for direct quantitative determination of cyanamide. Quantitative signals for ((14)N(2))cyanamide, ((15)N(2))cyanamide (internal standard for stable isotope dilution method), and m-(trifluoromethyl)benzonitrile (internal standard for correcting errors in GC-MS analysis) were recorded as peak areas on mass chromatograms at m/z 42 (A(42)), 44 (A(44)), and 171 (A(IS)), respectively. Total cyanamide content, ((14)N(2))cyanamide plus ((15)N(2))cyanamide, was determined as a function of (A(42)+A(44))/A(IS). Contents of ((14)N(2))cyanamide and ((15)N(2))cyanamide were then calculated by multiplying the total cyanamide content by A(42)/(A(42)+A(44)) and A(44)/(A(42)+A(44)), respectively. The limit of detection for the total cyanamide content by the GC-MS analysis was around 1ng. The molar ratio of ((14)N(2))cyanamide to ((15)N(2))cyanamide in the injected sample was equal to the observed A(42)/A(44) value in the range from 0.1 to 5. It was, therefore, possible to use the stable isotope dilution method to quantify the natural cyanamide content in samples; i.e., the natural cyanamide content was derived by subtracting the A(42)/A(44) ratio of the internal standard from the A(42)/A(44) ratio of sample spiked with internal standard, and then multiplying the resulting difference by the amount of added ((15)N(2))cyanamide (SID-GC-MS method). This method successfully gave a reasonable value for the natural cyanamide content in hairy vetch, concurring with the value obtained by a conventional method in which cyanamide was derivatized to a photometrically active compound 4-cyanimido-1,2-naphthoquinone and analyzed with reversed-phase HPLC (CNQ-HPLC method). The determination range of cyanamide in the SID-GC-MS method was almost the same as that in the CNQ-HPLC method; however, the SID-GC-MS method was much simpler than the CNQ-HPLC method.
- Published
- 2005
- Full Text
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15. Revised chirality of the acyl group of 8'-O-(3-hydroxy-3-methylglutaryl)-8'-hydroxyabscisic acid.
- Author
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Kamo T, Hirai N, Matsumoto C, Ohigashi H, and Hirota M
- Subjects
- Chromatography, High Pressure Liquid, Molecular Structure, Stereoisomerism, Abscisic Acid analogs & derivatives, Abscisic Acid chemistry
- Abstract
8'-O-(3-Hydroxy-3-methylglutaryl)-8'-hydroxyabscisic acid is a stable conjugate of the first metabolite of abscisic acid, 8'-hydroxyabscisic acid, that is spontaneously isomerized to phaseic acid. The chirality of the 3-hydroxy-3-methylglutaryl group of the conjugate was revised to S based on an HPLC analysis of the diastereomer derived from mevalonolactone obtained by reduction of the conjugate with lithium borohydride., (Copyright 2004 Elsevier Ltd.)
- Published
- 2004
- Full Text
- View/download PDF
16. Isolation and localization of type IIb Na/Pi cotransporter in the developing rat lung.
- Author
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Hashimoto M, Wang DY, Kamo T, Zhu Y, Tsujiuchi T, Konishi Y, Tanaka M, and Sugimura H
- Subjects
- Animals, Animals, Newborn, Blotting, Northern, Cloning, Molecular, DNA, Complementary chemistry, DNA, Complementary genetics, DNA, Complementary isolation & purification, Female, Gene Expression Regulation, Developmental, In Situ Hybridization, Lung embryology, Lung growth & development, Male, Molecular Sequence Data, RNA genetics, RNA metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Rats, Rats, Wistar, Sequence Analysis, DNA, Sodium-Phosphate Cotransporter Proteins, Sodium-Phosphate Cotransporter Proteins, Type II, Sodium-Phosphate Cotransporter Proteins, Type IIb, Carrier Proteins genetics, Lung metabolism, Symporters
- Abstract
Differential display analysis of rat lung at different developmental stages identified a fragment, HG80, which appeared on embryonic day 16.5 and thereafter. A full-length cDNA derived from a cDNA library of newborn rat lung probed with HG80 was the rat counterpart of sodium-dependent phosphate transporter type IIb and was designated rNaPi IIb. In situ hybridization showed that rNaPi IIb was expressed in type II alveolar cells, suggesting a role in the synthesis of surfactant in the alveoli. The time-dependent changes in localization of this gene in the developing lung and its possible use as a type II pneumocyte marker are discussed.
- Published
- 2000
- Full Text
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17. A biosynthetic intermediate of phytoalexins in banana fruits.
- Author
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Kamo T, Kato N, Hirai N, Tsuda M, Fujioka D, and Ohigashi H
- Abstract
Phytoalexins of Musa balbisiana [BBB] cv Saba sa Hapon and cv Mundo fruits were compared with those of M. acuminata [AAA] cv Buñgulan fruits. Phytoalexins induced by wound and inoculation of Colletotrichum musae in these two cultivars were the same as those of Buñgulan. In the course of analysis of the phytoalexins, 2-phenyl-1,8-naphthalic anhydride, 2-(4'-methoxyphenyl)-1,8-naphthalic anhydride, and 1,2,3,4-tetrahydro-6,7-dihydroxy-1-(4'-hydroxycinnamyliden)naphthalen-2-one were found as new phytoalexins of banana fruits. This latter compound is probably a biosynthetic intermediate of phenylphenalenones in banana fruits.
- Published
- 1998
- Full Text
- View/download PDF
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