Publications by authors named "Yoko Masuda"

Enhancing nitrogen (N) fixation in rice plants can reduce N fertilizer application and contribute to sustainable rice production, particularly under low-N conditions. However, detailed microbial and metabolic characterization of N fixation in rice stems, unlike in the well-studied roots, has not been investigated. Therefore, the aim of this study was to determine the active N-fixing sites, their diazotroph communities, and the usability of possible carbon sources in stems compared with roots.

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Dissimilatory nitrate reduction to ammonium (DNRA), driven by nitrate-ammonifying bacteria, is an increasingly appreciated nitrogen-cycling pathway in terrestrial ecosystems. This process reportedly generates nitrous oxide (NO), a strong greenhouse gas with ozone-depleting effects. However, it remains poorly understood how NO is produced by environmental nitrate-ammonifiers and how to identify DNRA-derived NO.

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Paddy fields are a major emission source of the greenhouse gas methane. In the present study, the addition of ferrihydrite to xylan-amended paddy soil microcosms suppressed methane emissions. PCR-based and metatranscriptomic ana-lyses revealed that the addition of ferrihydrite suppressed methanogenesis by heterogeneous methanogens and simultaneously activated Geobacteraceae, the most abundant iron-reducing diazotrophs.

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Background: Biological nitrogen fixation is a fundamental process sustaining all life on earth. While distribution and diversity of N-fixing soil microbes have been investigated by numerous PCR amplicon sequencing of nitrogenase genes, their comprehensive understanding has been hindered by lack of de facto standard protocols for amplicon surveys and possible PCR biases. Here, by fully leveraging the planetary collections of soil shotgun metagenomes along with recently expanded culture collections, we evaluated the global distribution and diversity of terrestrial diazotrophic microbiome.

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Forty-eight strains were isolated from soils and sediments in Japan. Among them, six representative strains, designated W79, W786, Red222, Red802, Red803, and Red804, were subjected to the taxonomic classification. These six strains are Gram-stain-negative, non-spore-forming, rod-shaped, and facultative anaerobic bacterium that can reduce ferric iron.

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Biological nitrogen fixation (BNF) is important to sustain nitrogen fertility of paddy soil and rice yield, while could be affected by nitrogen fertilization. Iron-reducing bacteria, Anaeromyxobacter and Geobacter, are newly found diazotrophic bacteria predominant in paddy soil. Experimental field of this study is a long-term (35 years) nitrogen fertilized (6.

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Three bacterial strains (Red232, Red267 and Red630) were isolated from paddy soils sampled in Japan. Cells of these strains were Gram-stain-negative, facultative anaerobic, long rod-shaped with monotrichous flagella or pilus-like structures for motility, and formed red colonies on agar plates. Phylogenetic trees based on 16S rRNA gene and multiple single-copy gene sequences showed that the three strains formed a cluster with the type strains of species, independent from any other strain genera.

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The application of iron powder stimulated the growth of iron-reducing bacteria as a respiratory substrate and enhanced their nitrogen (N)-fixing activity in flooded paddy soils. High N fertilization (urea) in the flooded paddy soils has caused adverse environmental impacts such as ammonia (NH) volatilization, nitrous oxide (NO) emissions, and nitrate (NO) leaching. This study aims to investigate the effects of N fertilization rates in combination with an iron amendment on rice yields and N losses from flooded paddy fields.

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Nitrogen fixation, a distinct process incorporating the inactive atmospheric nitrogen into the active biological processes, has been a major topic in biological and geochemical studies. Currently, insights into diversity and distribution of nitrogen-fixing microbes are dependent upon homology-based analyses of nitrogenase genes, especially the gene, which are broadly conserved in nitrogen-fixing microbes. Here, we report the pitfall of using as a marker of microbial nitrogen fixation.

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is a recently proposed order comprising members who originally belonged to the well-known family , which is a key group in terrestrial ecosystems involved in biogeochemical cycles and has been widely investigated in bioelectrochemistry and bioenergy fields. Previous studies have illustrated the taxonomic structure of most members in this group based on genomic phylogeny; however, several members are still in a pendent or chaotic taxonomic status owing to the lack of genome sequences. To address this issue, we performed this taxonomic reassignment using currently available genome sequences, along with the description of two novel paddy soil-isolated strains, designated Red51 and Red69, which are phylogenetically located within this order.

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Distant metastasis is the most important prognostic factor for head and neck cancer. This report presents the case of a 50-year-old man with distant metastasis of tongue carcinoma to the vastus lateralis muscle which presented to Nihon University Itabashi Hospital, Tokyo, Japan. Tumourectomy was performed with a diagnosis of tongue carcinoma (cT2N0M0, Stage II).

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Bacteria in the family Geobacteraceae have been proven to fill important niches in a diversity of anaerobic environments and global biogeochemical processes. Here, three bacterial strains in this family, designated Red875, Red259, and Red421 were isolated from river sediment and paddy soils in Japan. All of them are Gram-staining-negative, strictly anaerobic, motile, flagellum-harboring cells that form red colonies on agar plates and are capable of utilizing Fe(III)-NTA, Fe(III) citrate, ferrihydrite, MnO, fumarate, and nitrate as electron acceptors with acetate, propionate, pyruvate, and glucose as electron donors.

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Nitrous oxide (NO) is an important greenhouse gas and an ozone-depleting substance. Due to the long persistence of NO in the atmosphere, the mitigation of anthropogenic NO emissions, which are mainly derived from microbial NO-producing processes, including nitrification and denitrification by bacteria, archaea, and fungi, in agricultural soils, is urgently necessary. Members of mesofauna affect microbial processes by consuming microbial biomass in soil.

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Background: Following ankle sprains, some patients complain of their ankles "giving way," characterized by functional instability with no positive findings in traditional stress tests. The calcaneofibular ligament (CFL) may contribute to the stabilization of the subtalar and talocrural joints, and some functional instability may be due to CFL insufficiency. We aimed to clarify and quantitatively assess CFL insufficiency with three-dimensional stress computer tomography (CT) using the Pronation-External Rotation Stress Test (PERST).

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Three bacterial strains, designated Red330, Red736 and Red745, were isolated from forest and paddy soils in Japan. Strains Red330, Red736 and Red745 are flagella-harbouring and strictly anaerobic bacteria forming red colonies. A 16S rRNA gene sequence-based phylogenetic tree showed that all three strains were located in a cluster, including the type strains of species, which were recently separated from the genus within the family .

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Biological nitrogen fixation is an essential reaction in a major pathway for supplying nitrogen to terrestrial environments. Previous culture-independent analyses based on soil DNA/RNA/protein sequencing could globally detect the nitrogenase genes/proteins of (in the class ), commonly distributed in soil environments and predominant in paddy soils; this suggests the importance of in nitrogen fixation in soil environments. However, direct experimental evidence is lacking; there has been no research on the genetic background and ability of to fix nitrogen.

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Article Synopsis
  • Bacteria from a specific family are crucial for biogeochemical processes in soil and freshwater environments.
  • Three iron-reducing bacterial strains (Red96, Red100, Red88) were isolated from Japanese paddy fields and pond sediments, showing unique properties like being anaerobic, rod-shaped, and red-pigmented.
  • Phylogenetic and genomic analysis revealed that these strains form a distinct cluster, differentiating them from other species in the family, leading to the conclusion that they represent a new genus and three novel species, with proposed names for each strain.
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Trichoblastic infundibular cyst (TBIC) was previously reported as a unique keratinous cystic lesion, which was characterized by the papillary projections of follicular germinative-like cells emanating from the cyst wall. Here, we report three additional cases of this cyst and discuss the pathogenesis of this unique entity. In all cases, a unilocular cyst contained keratin, and the cyst wall was composed of squamous epithelium.

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Article Synopsis
  • Researchers isolated and characterized four new strains of ferric reducing bacteria from paddy soils in Japan, indicating their significant role in the biogeochemical cycle.
  • The isolated strains (S43, Red53, S62, Red111) are Gram-negative, strictly anaerobic, and motile, showcasing distinct genomic and chemotaxonomic features compared to known species.
  • These findings propose the classification of these strains as new species in a new genus, along with reclassification of certain existing bacteria based on phylogenetic and genomic data.
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Article Synopsis
  • The study explores how a fragrant environment (FE) containing α-pinene affects tumor growth in melanoma mice, revealing a ~40% reduction in tumor size.
  • Exposure to the FE led to decreased leptin levels and increased sympathetic nervous activity, while certain immune cells (B cells, CD4 T cells, CD8 T cells, and natural killer cells) were found to be more abundant.
  • These findings suggest that the FE may enhance immune response and activate key neurohormonal pathways, potentially offering a mechanism for how environmental factors can influence cancer outcomes.
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Waterlogged paddy soils possess anoxic zones in which microbes actively induce reductive nitrogen transformation (RNT). In the present study, a shotgun RNA sequencing analysis (metatranscriptomics) of paddy soil samples revealed that most RNT gene transcripts in paddy soils were derived from Deltaproteobacteria, particularly the genera Anaeromyxobacter and Geobacter. Despite the frequent detection of the rRNA of these microbes in paddy soils, their RNT-associated genes have rarely been identified in previous PCR-based studies.

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Certain interindividual differences affecting the efficacy of drug treatment and adverse drug reactions are caused by genetic variants, and their phenotypic effects differ among ethnic groups. In this study, we used whole exome sequencing (WES) systematically to identify germline mutations that influence the activities of drug-metabolizing enzymes, as well as that of a transporter. We analyzed DNA isolated from blood samples from 2,042 Japanese patients with diverse cancers.

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Background Tris-acryl gelatin microspheres (TAGM) and gelatin sponge particles (GS) have been used in uterine artery embolization (UAE) for leiomyoma. No direct comparisons of both embolic agents have been reported. Purpose To compare the outcomes of UAE with TAGM with those of UAE with GS for uterine leiomyoma.

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Synopsis of recent research by authors named "Yoko Masuda"

  • - Yoko Masuda's research primarily focuses on the interactions of bacteria involved in nitrogen cycling and their effects on greenhouse gas emissions in agricultural ecosystems, particularly in paddy fields, highlighting pathways like dissimilatory nitrate reduction to ammonium (DNRA) and biological nitrogen fixation.
  • - Recent findings indicate that the introduction of ferrihydrite can activate iron-reducing diazotrophs while suppressing methane emissions, suggesting potential strategies for mitigating greenhouse gas output from rice paddies.
  • - Masuda's work also emphasizes the importance of metagenomic analyses in understanding the distribution and activity of nitrogen-fixing microbiomes, revealing previously overlooked prokaryotic drivers of nitrogen transformation processes in soils.