Publications by authors named "Ohkura K"

Grafting carbon-based nanomaterials (CNMs) with polyglycerol (PG) improves their application potentials in biomedicine and electronics. Although "grafting from" method offers advantages over "grafting to" one in terms of operability and versatility, little is known about the reaction process of glycidol with the surface groups onto CNMs. By using graphene oxide (GO) as a multi-functional model material, we examined the reactivity of the surface groups on GO toward glycidol molecules via a set of model reactions.

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Anginosus group streptococci (AGS) are opportunistic pathogens that reside in the human oral cavity. The β-hemolytic strains of subsp. (SAA) produce streptolysin S (SLS), a streptococcal peptide hemolysin.

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Background/aim: Acetyl glucose adducts (UTX-114, -115, and -116) were prepared from gefitinib, and their characteristics (e.g., anticancer activity, structural property) were analyzed.

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Neuroevolution is a promising approach for designing artificial neural networks using an evolutionary algorithm. Unlike recent trending methods that rely on gradient-based algorithms, neuroevolution can simultaneously evolve the topology and weights of neural networks. In neuroevolution with topological evolution, handling crossover is challenging because of the competing conventions problem.

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A 69-year-old female was presented with a history of sigmoid colon cancer, uterine cancer, and intrahepatic carcinomas. After computed tomography revealed a disseminated nodule located in the peritoneum, colonoscopy demonstrated a rather flat-to-slightly elevated lesion with a depressed area located in the ascending colon. The flat component showed color similar to its surrounding area, and the depressed area showed redness and an expanded appearance.

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Anginosus group streptococci (AGS) are opportunistic human pathogens of the oral cavity. The β-hemolytic subgroup of Streptococcus anginosus subsp. anginosus secretes streptolysin S (SLS) and exhibits not only hemolytic activity but also cytotoxicity toward cultured human cell lines.

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Background/aim: Interaction analysis between modeled human sodium/glucose cotransporter 2 (hSGLT2) and antidiabetic C-glycoside drugs, such as canagliflozin, dapagliflozin, ipragliflozin, empagliflozin, tofogliflozin, and luseogliflozin was performed.

Materials And Methods: The hSGLT2 was modeled using the X-ray data of Vibrio parahaemolyticus SGLT2 (protein data bank ID=2XQ2) as a template. Conformational analyses of C-glycosides were performed using CAChe-Conflex.

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Anginosus group streptococci (AGS) are opportunistic pathogens of the human oral cavity; however, their pathogenicity has not been discussed in detail. Oral streptococci live in the gingival sulcus, from where they can easily translocate into the bloodstream due to periodontal diseases and dental treatment and cause hazardous effects on the host through their virulence factors. Streptolysin S (SLS), a pathogenic factor produced by β-hemolytic species/strains belonging to AGS, plays an important role in damaging host cells.

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Article Synopsis
  • A specific strain of bacteria, Nm-76, produces a unique cholesterol-dependent cytolysin (CDC) called discoidinolysin (DLY), which is different from other known CDCs and has not been previously characterized.
  • Phylogenetic analysis and experiments with gene-deletion mutant strains revealed that DLY can lyse human cells and facilitate the aggregation of human erythrocytes and intercellular associations.
  • DLY's dual role as both a cytolysin and an agent promoting cell interactions may contribute significantly to the pathogenicity of strain Nm-76, making it a potential virulence factor.
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Background/aim: Boron tracedrugs possess global molecular tracking abilities and localized destructive power. We investigated the molecular properties of synthesized boron tracedrugs, including UTX-51, and their interactions with the advanced glycation end-product (AGE)-related protein bovine serum albumin (BSA).

Materials And Methods: A conformational analysis of the compounds used in the present study was performed using CAChe (Fujitsu Inc.

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Background/aim: Efficient drug encapsulation and regulation of drug release are important factors for sustained drug release and application for release-controlled anti-cancer and anti-inflammatory drug delivery. In the present study, a direct evaluation system for drug-release from model carrier (e.g.

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Type B aortic dissection (TBAD) is a rare but catastrophic complication of endovascular aneurysm repair (EVAR). We report two cases of TBAD occurring in the perioperative period of EVAR. The intraoperative and postoperative courses were unremarkable.

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Streptococcus pseudopneumoniae (SPpn) is a relatively new species closely related to S. pneumoniae (SPn) and S. mitis (SM) belonging to the Mitis group of the genus Streptococcus (MGS).

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Background: From the design and synthesis of enantiomers, we can expect to obtain two compounds with different pharmacokinetics and pharmacological activities at the same time, which is thought to lead to the development of efficient anticancer agents. Chiral-2-nitroimidazole TX-2036 derivatives exhibit stereo-configuration (R- and S-configuration)-dependent tyrosine kinase inhibitory activity, and the activity of the tyrosine kinase domain of EGF receptor (EGFR-tyk) is suppressed. In order to clarify the reason why the effects on EGFR-tyk activity differ depending on stereoisomers, we tried to analyze the interaction between each TX-2036 derivative and EGFR-tyk.

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Introduction: Although liver biopsy is the gold standard for the diagnosis of nonalcoholic steatohepatitis (NASH), it has several problems including high invasiveness and sampling errors. Therefore, the development of alternative methods to overcome these disadvantages is strongly required. In this study, we evaluated the potential use of our tracer targeting thymidine phosphorylase (TYMP), 5-[I]iodo-6-[(2-iminoimidazolidinyl)methyl]uracil ([I]IIMU) for the diagnosis of NASH.

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Background/aim: The stereo-configuration (R-, S-configuration) of chiral-2-nitroimidazole derivatives alters their radiosensitizing activity. This study aimed at examining the molecular features of these enantiomers by molecular simulation techniques.

Materials And Methods: A series of 2-nitroimidazole-based radiosensitizer TX-2036 molecules were synthesized, and their profiles were examined using molecular structural analysis such as conformation analysis, molecular orbital analysis, and electrostatic potential analysis.

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Streptococcus anginosus subsp. (SAA) is one of the opportunistic pathogens in humans that inhabits the oral cavity. The type strain of SAA, NCTC10713, showed clear β-hemolysis on blood agar plates, and the sole β-hemolytic factor revealed two streptolysin S (SLS) molecules.

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Aim: We previously reported that stroke-prone spontaneously hypertensive rat/Ezo (SHRSP/Ezo) has high validity as an attention deficit/hyperactivity disorder (AD/HD) animal model, based on its behavioral phenotypes, such as inattention, hyperactivity, and impulsivity. Fronto-cortical dysfunction is implicated in the pathogenesis of AD/HD. In this study, we investigated prefrontal cortex (PFC) function in SHRSP/Ezo rats by electrophysiological methods and radioreceptor assay.

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Background/aim: Sugar molecules are often used as a tool to structurally modify chemical compounds. The features of synthesized sugar-conjugated TX-1877 derivatives were herein examined.

Materials And Methods: The molecular stabilities (reactivity) and hydrophobicities of sugar (e.

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Objectives: To prevent haemodynamic stroke during cardiovascular surgery in patients with carotid stenosis, we routinely evaluated magnetic resonance angiography and selectively evaluated brain perfusion single-photon emission computed tomography with acetazolamide challenge. Off-pump surgery was preferred when cerebral blood flow reserve was impaired. This strategy's usefulness was investigated.

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Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to treat inflammation and pain. In the present study, we examined the effects of celecoxib, a cyclooxygenase-2 (COX-2)-selective NSAID, on rat liver mitochondrial function. Celecoxib dose-dependently induced mitochondria swelling, which was not suppressed by cyclosporine A (CsA).

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A 71-year-old woman was diagnosed with sick sinus syndrome (SSS) upon her cardiogenic cerebral embolism and underwent pacemaker implantation. Active fixation leads were positioned at the right atrial appendage and ventricular septum. Twenty-one days later at her routine checkup, she was asymptomatic and there were no signs of cardiac tamponade or pacing failure.

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Introduction: In-DTPA-d-Phe-octreotide scintigraphy is an important method of detecting neuroendocrine tumors. We previously reported that a new derivative of In-DTPA-d-Phe-octreotide, In-DTPA-d-Phe-Asp-d-Phe-octreotide, accomplished the reduction of prolonged renal accumulation of radioactivity. The aim of this study was to evaluate the tumor accumulation of In-DTPA-d-Phe-Asp-d-Phe-octreotide in vitro and in vivo by comparing it with In-DTPA-d-Phe-octreotide.

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Background: To date, two cyclo-oxygenase (COX) isoforms, COX1 and COX2, have been identified. In the present study, the COX-inhibitory activities of TX-1123 derivatives with the 2-hydroxyarylidene-4-cyclopentene-1,3-dione structure were examined, and the binding profiles of TX-1123 to COXs were analyzed using docking simulations.

Materials And Methods: X-Ray data on COX1 [protein data bank (PDB) ID=1PGG] and COX2 (PDB ID=3LN1) were used for molecular interactive simulations.

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Introduction: Radiolabeled octreotide derivatives have been studied as diagnostic and therapeutic agents for somatostatin receptor-positive tumors. To prevent unnecessary radiation exposure during their clinical application, the present study aimed to develop radiolabeled peptides which could reduce radioactivity levels in the kidney at both early and late post-injection time points by introducing a negative charge with an acidic amino acid such as L-aspartic acid (Asp) at a suitable position in In-DTPA-conjugated octreotide derivatives.

Methods: Biodistribution of the radioactivity was evaluated in normal mice after administration of a novel radiolabeled peptide by a counting method.

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