77 research outputs found

    Multiple myeloma with high adenosine deaminase expression

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    A 50-year-old man with immunoglobulin A type multiple myeloma (MM) was referred to our hospital after bortezomib therapy. He had high alkaline phosphatase and lactate dehydrogenase levels. Computed tomography showed osteolytic and osteoblastic bone lesions. Response to salvage chemotherapy was temporary, and he developed a right pleural effusion with high adenosine deaminase (ADA) levels. He died from bleeding associated with a pelvic bone fracture 9 months later. ADA mRNA expression and ADA secretion of the MM cells from the patient were higher than those from myeloma cell lines tested. Clinical relevance of high ADA expression in MM cells is warranted

    Effects of Different Types of Dietary Fibers on Fermentation by Intestinal Flora

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    Purpose: A treatment for chronic constipation is dietary fiber intake. This study aimed to determine the effects of different types of dietary fibers on the microbiota in the large intestine. Methods: Nine healthy volunteers participated in this study. Breath hydrogen test was used to determine the dietary fiber fermentations. The presence of hydrogen in the breath indicates intestinal bacterial activities. Participants fasted overnight and ate white bread (200 g) with 10 g of each type of dietary fiber: (1) cellulose, (2) soy fiber, (3) guar gum, and (4) control (without any dietary fiber). Samples were collected before and every 1 hour after eating, for 8 h. Another test compared the effects between cellulose and guar gum with a loaded food, which activates intestinal fermentation, and samples were collected using the same methods. Results: During 8 h of measurements, breath hydrogen concentration in the soy fiber group were higher than that of the control, but were not significantly different. Changes in the guar gum group were similar to those in the control. However, breath hydrogen concentrations in the cellulose group did not increase even after eating white bread that caused large intestinal fermentation 2.9 ± 0.7 ppm, which was significantly lower than that of the guar gum group (7.4 ± 1.7 ppm, p < 0.01). In the study with a well-fermented food intake, cellulose reduced breath hydrogen concentrations, but its difference with that of the guar gum group was statistically non-significant. Conclusion: Cellulose might have a suppressive effect on large intestinal fermentation. Therefore, this compound may be beneficial in treating chronic constipation

    Development of ethnographic digital collections

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    Περιέχει το πλήρες κείμενοΟι λαογραφικές συλλογές αποτελούν πολύτιμη πηγή μελέτης, εξερεύνησης και αξιολόγησης των εθνικών στερεοτύπων των διαφόρων διαμερισμάτων μιας χώρας, δεδομένου ότι στις συλλογές είναι καταχωρημένα ανόθευτα και πηγαία τα εγχώρια εθνοχαρακτηριστικά τους. Κατά κύριο λόγο η λαογραφία αναφέρεται στους μύθους, τα τραγούδια, τη μουσική, τα έθιμα, τη χειροτεχνία, την ενδυμασία, την αρχιτεκτονική και την προφορική παράδοση μιας κοινότητας. Η ιδιαιτερότητα και η ποικιλία ενός τομέα όπως της λαογραφίας δικαιολογεί απόλυτα την ύπαρξη συλλογών και υπο-συλλογών σύνθετης δομής και σημασιολογίας, όπως αυτές που αναφέρουμε παραπάνω. Επομένως η ανάπτυξη ψηφιακών συλλογών απαιτεί τη διατήρηση των στοιχείων που χρειάζονται για: (α) την περιγραφή του περιεχομένου της κάθε συλλογής χωριστά και (β) τη σωστή απεικόνιση της δομής των αντικειμένων στο εσωτερικό αυτής. Στόχος της εργασίας αυτής είναι η παρουσίαση μιας μεθοδολογίας για την ανάπτυξη ενός περιγραφικού μοντέλου μεταδεδομένων για λαογραφικές συλλογές. Το μοντέλο θα αποτελέσει βασικό εργαλείο για την περιγραφή του ψηφιοποιημένου λαογραφικού υλικού, την πρόσβαση σε αυτό από κατανεμημένους χρήστες και φυσικά την επικοινωνία του με άλλα συστήματα. Επιπλέον θα συμβάλλει στη διασύνδεση σύνθετων συλλογών και των αντικειμένων που περιλαμβάνουν είτε σημασιολογικά, είτε χρονικά, είτε θεματικά είτε με οποιονδήποτε άλλο τρόπο απαιτεί η φύση των συλλογών και οι ανάγκες των χρηστών

    Cryo-EM structures of human zinc transporter ZnT7 reveal the mechanism of Zn²⁺ uptake into the Golgi apparatus

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    クライオ電子顕微鏡により、ゴルジ体の亜鉛輸送体による亜鉛輸送機構の全容を解明 細胞の亜鉛恒常性維持機構の理解に大きな進展. 京都大学プレスリリース. 2023-08-29.Zinc ions (Zn²⁺) are vital to most cells, with the intracellular concentrations of Zn²⁺ being tightly regulated by multiple zinc transporters located at the plasma and organelle membranes. We herein present the 2.2-3.1 Å-resolution cryo-EM structures of a Golgi-localized human Zn²⁺/H+ antiporter ZnT7 (hZnT7) in Zn²⁺-bound and unbound forms. Cryo-EM analyses show that hZnT7 exists as a dimer via tight interactions in both the cytosolic and transmembrane (TM) domains of two protomers, each of which contains a single Zn²⁺-binding site in its TM domain. hZnT7 undergoes a TM-helix rearrangement to create a negatively charged cytosolic cavity for Zn²⁺ entry in the inward-facing conformation and widens the luminal cavity for Zn²⁺ release in the outward-facing conformation. An exceptionally long cytosolic histidine-rich loop characteristic of hZnT7 binds two Zn²⁺ ions, seemingly facilitating Zn²⁺ recruitment to the TM metal transport pathway. These structures permit mechanisms of hZnT7-mediated Zn²⁺ uptake into the Golgi to be proposed

    Structure of SARS-CoV-2 membrane protein essential for virus assembly

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    新型コロナウイルスのウイルス形成に必須の膜タンパク質の構造を解明. 京都大学プレスリリース. 2022-08-08.The coronavirus membrane protein (M) is the most abundant viral structural protein and plays a central role in virus assembly and morphogenesis. However, the process of M protein-driven virus assembly are largely unknown. Here, we report the cryo-electron microscopy structure of the SARS-CoV-2 M protein in two different conformations. M protein forms a mushroom-shaped dimer, composed of two transmembrane domain-swapped three-helix bundles and two intravirion domains. M protein further assembles into higher-order oligomers. A highly conserved hinge region is key for conformational changes. The M protein dimer is unexpectedly similar to SARS-CoV-2 ORF3a, a viral ion channel. Moreover, the interaction analyses of M protein with nucleocapsid protein (N) and RNA suggest that the M protein mediates the concerted recruitment of these components through the positively charged intravirion domain. Our data shed light on the M protein-driven virus assembly mechanism and provide a structural basis for therapeutic intervention targeting M protein

    Evaluation of the Pichia pastoris expression system for the production of GPCRs for structural analysis

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    <p>Abstract</p> <p>Background</p> <p>Various protein expression systems, such as <it>Escherichia coli </it>(<it>E. coli</it>), <it>Saccharomyces cerevisiae </it>(<it>S. cerevisiae</it>), <it>Pichia pastoris </it>(<it>P. pastoris</it>), insect cells and mammalian cell lines, have been developed for the synthesis of G protein-coupled receptors (GPCRs) for structural studies. Recently, the crystal structures of four recombinant human GPCRs, namely β<sub>2 </sub>adrenergic receptor, adenosine A<sub>2a </sub>receptor, CXCR4 and dopamine D3 receptor, were successfully determined using an insect cell expression system. GPCRs expressed in insect cells are believed to undergo mammalian-like posttranscriptional modifications and have similar functional properties than in mammals. Crystal structures of GPCRs have not yet been solved using yeast expression systems. In the present study, <it>P. pastoris </it>and insect cell expression systems for the human muscarinic acetylcholine receptor M2 subtype (CHRM2) were developed and the quantity and quality of CHRM2 synthesized by both expression systems were compared for the application in structural studies.</p> <p>Results</p> <p>The ideal conditions for the expression of CHRM2 in <it>P. pastoris </it>were 60 hr at 20°C in a buffer of pH 7.0. The specific activity of the expressed CHRM2 was 28.9 pmol/mg of membrane protein as determined by binding assays using [<sup>3</sup>H]-quinuclidinyl benzilate (QNB). Although the specific activity of the protein produced by <it>P. pastoris </it>was lower than that of Sf9 insect cells, CHRM2 yield in <it>P. pastoris </it>was 2-fold higher than in Sf9 insect cells because <it>P. pastoris </it>was cultured at high cell density. The dissociation constant (Kd) for QNB in <it>P. pastoris </it>was 101.14 ± 15.07 pM, which was similar to that in Sf9 insect cells (86.23 ± 8.57 pM). There were no differences in the binding affinity of CHRM2 for QNB between <it>P. pastoris </it>and Sf9 insect cells.</p> <p>Conclusion</p> <p>Compared to insect cells, <it>P. pastoris </it>is easier to handle, can be grown at lower cost, and can be expressed quicker at a large scale. Yeast, <it>P. pastoris</it>, and insect cells are all effective expression systems for GPCRs. The results of the present study strongly suggested that protein expression in <it>P. pastoris </it>can be applied to the structural and biochemical studies of GPCRs.</p
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