165 research outputs found

    Solution properties of amylose tris(3,5-dimethylphenylcarbamate) and amylose tris(phenylcarbamate): Side group and solvent dependent chain stiffness in methyl acetate, 2-butanone, and 4-methyl-2-pentanone

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    Five amylose tris(3,5-dimethylphenylcarbamate) (ADMPC) samples ranging in weightaverage molecular weight M w from 1.7 × 10 4 to 3.4 × 10 5 were studied by light and small-angle X-ray scattering, sedimentation equilibrium, and viscometry in methyl acetate (MEA), 2-butanone (MEK), and 4-methyl-2-pentanone (MIBK) at 25 °. Seven amylose tris(phenylcarbamate) (ATPC) samples whose M w ranges between 2 × 10 4 and 3×10 6 were also investigated in MEK at 25 °. The radii of gyration, particle scattering functions, and intrinsic viscosities determined as a function of M w were analyzed in terms of the cylindrical wormlike chain model mainly to determine the Kuhn segment length λ -1 and the contour length h (or the helix pitch) per residue. While the obtained h values (0.36-0.38 nm) of ADMPC are quite insensitive to the solvents, the λ -1 value not only is 1.5-3 times larger than that of ATPC in the corresponding solvent but also significantly increases with an increase of the molar volume of the solvent, and it reaches 73 nm in MIBK, which is the highest value for previously investigated phenylcarbamate derivatives of polysaccharides. This high stiffness is most likely due to the steric hindrance of the solvent molecules H-bonding with the NH groups of the polymer. © 2010 American Chemical Society.Tsuda M., Terao K., Nakamura Y., et al. Solution properties of amylose tris(3,5-dimethylphenylcarbamate) and amylose tris(phenylcarbamate): Side group and solvent dependent chain stiffness in methyl acetate, 2-butanone, and 4-methyl-2-pentanone. Macromolecules, 43(13), 5779-5784, June 11, 2010. Copyright © 2010, American Chemical Society. https://doi.org/10.1021/ma1006528

    An All-Recombinant Protein-Based Culture System Specifically Identifies Hematopoietic Stem Cell Maintenance Factors.

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    Hematopoietic stem cells (HSCs) are considered one of the most promising therapeutic targets for the treatment of various blood disorders. However, due to difficulties in establishing stable maintenance and expansion of HSCs in vitro, their insufficient supply is a major constraint to transplantation studies. To solve these problems we have developed a fully defined, all-recombinant protein-based culture system. Through this system, we have identified hemopexin (HPX) and interleukin-1α as responsible for HSC maintenance in vitro. Subsequent molecular analysis revealed that HPX reduces intracellular reactive oxygen species levels within cultured HSCs. Furthermore, bone marrow immunostaining and 3D immunohistochemistry revealed that HPX is expressed in non-myelinating Schwann cells, known HSC niche constituents. These results highlight the utility of this fully defined all-recombinant protein-based culture system for reproducible in vitro HSC culture and its potential to contribute to the identification of factors responsible for in vitro maintenance, expansion, and differentiation of stem cell populations

    Hemosiderin Detection inside the Mammillary Bodies Using Quantitative Susceptibility Mapping on Patients with Wernicke-Korsakoff Syndrome

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    Hemorrhage inside the mammillary bodies (MMBs) is known to be one of the findings of Wernicke encephalopathy. Brain MRI of two patients with Wernicke-Korsakoff syndrome (WKS) demonstrated high susceptibility values representing hemosiderin deposition in MMBs by using quantitative susceptibility mapping (QSM). QSM provided additional information of susceptibility values to susceptibility-weighted imaging in diagnosis of WKS

    Hematopoietic stem cell-derived Tregs are essential for maintaining favorable B cell lymphopoiesis following posttransplant cyclophosphamide

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    Posttransplant cyclophosphamide (PTCy) is associated with a low incidence of chronic graft -versus-host disease (cGVHD) following hematopoietic stem cell (HSC) transplantation. Previous studies have shown the important roles of B cell immunity in cGVHD development. Here, we investigated the long-term reconstitution of B lymphopoiesis after PTCy using murine models. We first demonstrated that the immune homeostatic abnormality leading to cGVHD is characterized by an initial increase in effector T cells in the bone marrow and subsequent B and Treg cytopenia. PTCy, but not cyclosporine A or rapamycin, inhibits the initial alloreactive T cell response, which restores intra-bone marrow B lymphogenesis with a concomitant vigorous increase in Tregs. This leads to profound changes in posttransplant B cell homeostasis, including decreased B cell activating factors, increased transitional and regulatory B cells, and decreased germinal center B cells. To identify the cells responsible for PTCy-induced B cell tolerance, we selectively depleted Treg populations that were graft or HSC derived using DEREG mice. Deletion of either Treg population without PTCy resulted in critical B cytopenia. PTCy rescued B lymphopoiesis from graft-derived Treg deletion. In contrast, the negative effect of HSC-derived Treg deletion could not be overcome by PTCy, indicating that HSC-derived Tregs are essential for maintaining favorable B lymphopoiesis following PTCy. These findings define the mechanisms by which PTCy restores homeostasis of the B cell lineage and reestablishes immune tolerance

    Low-grade B-cell lymphoma presenting primarily in the bone marrow

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    Cases of low-grade B-cell lymphoma presenting primarily in the bone marrow are rare, and its clinicopathology remains unclear. We retrospectively examined patients with low-grade B-cell lymphoma presenting primarily in the bone marrow. Fourteen patients met the inclusion criteria, including 5 with lymphoplasmacytic lymphoma (LPL), 3 with chronic lymphocytic leukemia/small lymphocytic lymphoma, 2 with follicular lymphoma (FL), and 4 with low-grade B-cell lymphoma not otherwise specified (LGBCL-NOS). The median age was 69.5 years (range, 42-89 years), and a slight male predominance was noted (9 men and 5 women, 1.8: 1). Immunohistochemically, all cases were positive for CD20. One case was positive for CD138. Both cases of FL were positive for CD10 and B-cell lymphoma 2 (BCL-2), and immunoglobulin heavy locus (IgH)/B-cell lymphoma 2 rearrangement was observed by fluorescence in situ hybridization. The myeloid differentiation primary response gene (88) leucine to proline mutation was observed in 3 of 5 LPL, 1 of 2 FL, and 2 of 4 LGBCL-NOS patients. Paraproteinemia was observed in 10 patients; IgM and IgG paraproteinemia were observed in 6 and 3 patients, respectively. In this patient series, 3 patients had died at a median follow-up of 36.5 months; the cause of death of 1 LPL patient was malignant lymphoma itself. Thus, low-grade B-cell lymphoma presenting primarily in the bone marrow has various subtypes, and approximately one-third of the patients had LGBCL-NOS. The immunophenotypic features and myeloid differentiation primary response gene (88) leucine to proline mutation data of LGBCL-NOS suggested that some cases present with characteristics similar to those of LPL or marginal zone lymphoma

    Pure-strategy Nash equilibria on competitive diffusion games

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    Development of a Multifunctional Lightweight Membrane with a High Specific Power Generation Capacity

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    As a lighter power generation system, Japan Aerospace Exploration Agency (JAXA) and Sakase Adtech Corp. are developing a demonstrator component named “Harvesting Energy with Lightweight Integrated Origami Structure” (HELIOS), which is a deployable lightweight membrane structure. HELIOS has solar arrays on its surface and demonstrates the technology which enables higher specific power generation capacity compared to the conventional solar array panels. The membrane also has communication antennas, showing the potency of lightweight membrane’s multifunctionality such as large data transmitting by 5G antennas and high-resolution observation by interferometer antennas. This paper presents the component’s concept and design, and the expected achievements

    Analysis of gut microbiome, host genetics, and plasma metabolites reveals gut microbiome-host interactions in the Japanese population

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    Interaction between the gut microbiome and host plays a key role in human health. Here, we perform a metagenome shotgun-sequencing-based analysis of Japanese participants to reveal associations between the gut microbiome, host genetics, and plasma metabolome. A genome-wide association study (GWAS) for microbial species (n = 524) identifies associations between the PDE1C gene locus and Bacteroides intestinalis and between TGIF2 and TGIF2-RAB5IF gene loci and Bacteroides acidifiaciens. In a microbial gene ortholog GWAS, agaE and agaS, which are related to the metabolism of carbohydrates forming the blood group A antigen, are associated with blood group A in a manner depending on the secretor status determined by the East Asian-specific FUT2 variant. A microbiome-metabolome association analysis (n = 261) identifies associations between bile acids and microbial features such as bile acid metabolism gene orthologs including bai and 7β-hydroxysteroid dehydrogenase. Our publicly available data will be a useful resource for understanding gut microbiome-host interactions in an underrepresented population.Tomofuji Yoshihiko, Kishikawa Toshihiro, Sonehara Kyuto, et al. Analysis of gut microbiome, host genetics, and plasma metabolites reveals gut microbiome-host interactions in the Japanese population. Cell Reports 42, 113324 (2023); https://doi.org/10.1016/j.celrep.2023.113324
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