Publications by authors named "Yahiro K"

is an important foodborne pathogen. Cholix cytotoxin (Cholix), produced by , is a novel eukaryotic elongation factor 2 (eEF2) adenosine diphosphate ribosyltransferase that causes host cell death by inhibiting protein synthesis. However, the role of Cholix in the infectious diseases caused by remains unclear.

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Unlabelled: imaging of bacterial infection models enables noninvasive and temporal analysis of individuals, enhancing our understanding of infectious disease pathogenesis. Conventional imaging methods for bacterial infection models involve the insertion of the bacterial luciferase LuxCDABE into the bacterial genome, followed by imaging using an expensive ultrasensitive charge-coupled device (CCD) camera. However, issues such as limited light penetration into the body and lack of versatility have been encountered.

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Article Synopsis
  • Endotoxins (LPS) are problematic in bacterial protein production, but researchers developed a method using a special bacterium that lacks LPS.
  • They successfully created endotoxin-free proteins, including functional green fluorescent protein and the cytokine TNF-α, and significantly reduced contamination levels.
  • This new system also enabled the production of a specific antibody targeting the coronavirus spike protein and a rheumatoid arthritis drug, showcasing its potential for future applications in biotechnology.
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  • The study focuses on understanding the function of the PmrAB two-component system (TCS) in resistance to colistin, a last-resort antibiotic, in extensively drug-resistant (XDR) Gram-negative bacteria.
  • Researchers conducted transcriptome analysis to identify the regulatory genes controlled by PmrAB, revealing its responsiveness to environmental factors like pH and metal ions (Fe, Zn, Al).
  • The findings highlight PmrAB's role in both environmental adaptation and the development of antibiotic resistance by modifying lipooligosaccharide (LOS) to mitigate toxicity and enhance resistance to colistin and polymyxin B.
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We identify a new class of distributional constraints defined as a union of symmetric M-convex sets, which can represent a wide range of real-life constraints in two-sided matching settings. Since M-convexity is not closed under union, a union of symmetric M-convex sets does not belong to this well-behaved class of constraints. Consequently, devising a fair and strategyproof mechanism to handle this new class is challenging.

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The aim of this study was to present a facile protocol for preparation of both enantiomerically pure forms of (Z)-1,5-octadien-3-ol with lipases and to identify the stereochemistry of oyster alcohol from Crassostrea gigas. The asymmetric hydrolysis of (±)-(Z)-1,5-octadien-3-yl acetate with CHIRAZYME L-2 afforded the (R)-alcohol with ≧99% ee in 37.8% conversion.

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Intracellular bacteria are able to survive and grow in host cells and often cause serious infectious diseases. The B subunit of the subtilase cytotoxin (SubB) found in enterohemorrhagic O113:H21 recognizes sialoglycans on cell surfaces and triggers the uptake of cytotoxin by the cells, meaning that Sub B is a ligand molecule that is expected to be useful for drug delivery into cells. In this study, we conjugated SubB to silver nanoplates (AgNPLs) for use as an antibacterial drug and examined their antimicrobial activity against intracellularly infecting ().

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Infection of mice with Citrobacter rodentium is a useful model for studying the pathogenicity of enteropathogenic and enterohemorrhagic Escherichia coli, pathogens that have a close association with humans. Here, we provide a protocol detailing the approaches for non-canonical inflammasome analysis in a mouse model of C. rodentium infection, including preparation of bacteria, oral administration of bacteria to mice, counting colony-forming units to quantify bacterial colonization, and analysis of expression and activation of inflammasome-related factors.

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  • * This study examined how colistin-resistant A. baumannii strains arise, showing that while colistin alone leads to LPS-deficient strains, combining it with other antibiotics results in strains with modified LPS.
  • * The findings indicate that LPS-deficient strains are less fit and more susceptible to other treatments, suggesting that LPS-modified strains are more prevalent in clinical settings, highlighting the urgent need to address colistin resistance in healthcare.
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Subtilase cytotoxin (SubAB) is a major virulence factor produced by eae-negative Shiga-toxigenic Escherichia coli (STEC) that can cause fatal systemic complications. SubAB binds to target cells through multivalent interactions between its B-subunit pentamer and receptor molecules such as glycoproteins with a terminal N-glycolylneuraminic acid (Neu5Gc). We screened randomized multivalent peptide libraries synthesized on a cellulose membrane and identified a series of tetravalent peptides that efficiently bind to the receptor-binding region of the SubAB B-subunit pentamer.

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Denosumab is a game-changing drug for giant cell tumor of bone (GCTB); however, its clinical biomarker regarding tumor ossification of GCTB has not been elucidated. In this study, we investigated the relationship between Wnt/β-catenin signaling and the ossification of GCTB and evaluated whether endogenous nuclear β-catenin expression predicted denosumab-induced bone formation in GCTB. Genuine patient-derived primary GCTB tumor stromal cells exhibited osteoblastic characteristics.

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Advances in drug delivery systems (DDSs) have enabled the specific delivery of drugs to target cells. Subtilase cytotoxin (SubAB) produced by certain enterohemorrhagic strains induces endoplasmic reticulum (ER) stress and suppresses nitric oxide generation in macrophages. We previously reported that modification of SubAB with poly(D,L-lactide-co-glycolic) acid (PLGA) nanoparticles (SubAB-PLGA NPs) increased intracellular uptake of SubAB and had an anti-inflammatory effect on macrophages.

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Bexarotene selectively activates retinoid X receptor, which is a commonly used anticancer agent for cutaneous T-cell lymphoma. In this study, we aimed to investigate the anticancer effect of bexarotene and its underlying mechanism in ovarian cancer in vitro. The ES2 and NIH:OVACAR3 ovarian cancer cell lines were treated with 0, 5, 10, or 20 µM of bexarotene.

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Subtilase cytotoxin (SubAB) is an AB toxin mainly produced by the locus of enterocyte effacement-negative Shiga-toxigenic (STEC) strain such as O113:H21, yet the contribution of SubAB to STEC infectious disease is unclear. We found that SubAB reduced activation of the STEC O113:H21 infection-induced non-canonical NLRP3 inflammasome and interleukin (IL)-1β and IL-18 production in murine macrophages. Downstream of lipopolysaccharide signaling, SubAB suppressed caspase-11 expression by inhibiting interferon-β/STAT1 signaling, followed by disrupting formation of the NLRP3/caspase-1 assembly.

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Article Synopsis
  • Dedifferentiated chondrosarcoma (DDCS) is a serious type of bone cancer that's hard to treat and not much is known about it.
  • Researchers found that a specific gene called PRKCZ is not working properly in DDCS because of DNA changes called methylation.
  • By using a drug called decitabine that can fix the issue with PRKCZ, they were able to help cancer cells die, which could lead to new treatments for DDCS.
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  • Locus for Enterocyte Effacement (LEE)-positive Shiga-toxigenic Escherichia coli (STEC) and LEE-negative STEC strains cause severe gastrointestinal diseases, like bloody diarrhea, with an increase in LEE-negative infections globally.
  • Subtilase cytotoxin (SubAB), released by some LEE-negative STEC strains, triggers apoptosis through endoplasmic reticulum (ER) stress by cleaving the chaperone protein BiP, but its apoptotic signaling pathway was previously unidentified.
  • This study reveals that SubAB induces the expression of KLHDC7B, which, when knocked down, reduces markers of apoptosis and suggests that KLHDC7B plays a crucial role in
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Background: Soft tissue sarcomas arise in the deep sites of the buttocks and lower extremities. Since a tourniquet is not applied during surgery for soft tissue sarcomas at such sites, excessive intraoperative blood loss may occur. Various devices, including LigaSure™ (Medtronic, Dublin, Ireland), are used as electrothermal bipolar vessel sealers.

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Pathogenic microorganisms produce various virulence factors, e.g., enzymes, cytotoxins, effectors, which trigger development of pathologies in infectious diseases.

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Osteosarcoma (OS) is the most common malignant bone tumor and often occurs in children. Chemotherapy with methotrexate, cisplatin, doxorubicin, and ifosfamide has greatly improved the prognosis of patients with OS, and most patients have been able to preserve their limbs. However, no progress has been made in the treatment for OS in the past few decades, and the prognosis of patients with metastasis and/or local recurrence remains poor.

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Shiga-toxigenic Escherichia coli (STEC) infection causes severe bloody diarrhea, renal failure, and hemolytic uremic syndrome. Recent studies showed global increases in Locus for Enterocyte Effacement (LEE)-negative STEC infection. Some LEE-negative STEC produce Subtilase cytotoxin (SubAB), which cleaves endoplasmic reticulum (ER) chaperone protein BiP, inducing ER stress and apoptotic cell death.

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Shiga-toxigenic Escherichia coli (STEC) is a major bacterium responsible for disease resulting from foodborne infection, including bloody diarrhea and hemolytic uremic syndrome. STEC produces important virulence factors such as Shiga toxin (Stx) 1 and/or 2. In the STEC family, some locus of enterocyte effacement-negative STEC produce two different types of cytotoxins, namely, Stx2 and subtilase cytotoxin (SubAB).

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Poly(D,L-lactide-co-glycolic) acid (PLGA) is a synthetic copolymer that has been used to design micro/nanoparticles as a carrier for macromolecules, such as protein and nucleic acids, that can be internalized by the endocytosis pathway. However, it is difficult to control the intracellular delivery to target organelles. Here we report an intracellular delivery system of nanoparticles modified with bacterial cytotoxins to the endoplasmic reticulum (ER) and anti-inflammatory activity of the nanoparticles.

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Subtilase cytotoxin (SubAB) is a member of bacterial AB toxin produced by certain enterohemorrhagic E. coli strains which cleaves host chaperone BiP in endoplasmic reticulum (ER), leading to ER stress-mediated cytotoxicity. Previous study suggested that protein disulfide isomerase (PDI), an enzyme which catalyzes the formation and breakage of disulfide bonds in proteins, regulates AB toxin such as cholera toxin by unfolding of A subunit, leading to its translocation into cytosol to induce disease.

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Background: Osteosarcoma (OS) is the most common malignant bone tumor and the prognosis of advanced cases is still poor. Recently, there have been several reports suggesting the relationship between innate immunity and OS, but the detailed mechanism is unknown. We demonstrate the relationship between OS and Toll-like receptor 4 (TLR4) which is one of the most important factors in innate immunity.

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Article Synopsis
  • Chondrosarcoma is a serious type of bone cancer that doesn't respond well to regular treatments like chemotherapy or radiation.
  • About half of the people with this cancer have a change in a gene called IDH, which makes the cancer worse by producing a harmful substance.
  • A new drug called DS-1001b shows promise by stopping the bad effects of the IDH change, helping to slow down cancer growth and possibly improve treatment options for patients.
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