Yoshikazu Hirai

ORCID: 0000-0003-0835-7314
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About
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Research Areas
  • Helicobacter pylori-related gastroenterology studies
  • Advanced MEMS and NEMS Technologies
  • Advanced Surface Polishing Techniques
  • Mechanical and Optical Resonators
  • 3D Printing in Biomedical Research
  • Microfluidic and Capillary Electrophoresis Applications
  • Advancements in Photolithography Techniques
  • Nanofabrication and Lithography Techniques
  • Galectins and Cancer Biology
  • Veterinary medicine and infectious diseases
  • Advanced biosensing and bioanalysis techniques
  • Photonic and Optical Devices
  • Nanowire Synthesis and Applications
  • Microfluidic and Bio-sensing Technologies
  • Silicon and Solar Cell Technologies
  • Force Microscopy Techniques and Applications
  • Acoustic Wave Resonator Technologies
  • Atomic and Subatomic Physics Research
  • Diamond and Carbon-based Materials Research
  • Neuroscience and Neural Engineering
  • Innovative Microfluidic and Catalytic Techniques Innovation
  • Bacteriophages and microbial interactions
  • Advanced ceramic materials synthesis
  • Carbon Nanotubes in Composites
  • RNA Interference and Gene Delivery

Kyoto University
2016-2025

National Institutes for Quantum Science and Technology
2025

Ritsumeikan University
2003-2024

Kyoto Katsura Hospital
2013-2023

Kyoto College of Medical Science
2022

Tamano General Medical College
2018-2021

Jichi Medical University
2009-2019

Kake Educational Institution
2019

Material Sciences (United States)
2016

University of Fukui
2016

Non-alcoholic fatty liver disease (NAFLD) afflicts a significant percentage of the population; however, no effective treatments have yet been established because unsuitability in vitro assays and animal experimental models. Here, we present an integrated-gut-liver-on-a-chip (iGLC) platform as human model gut-liver axis (GLA) by co-culturing gut cell lines interconnected via microfluidics closed circulation loop, for initiation progression NAFLD treatment with free acids (FFAs) 1 7 days,...

10.1038/s42003-023-04710-8 article EN cc-by Communications Biology 2023-03-23

Abstract Helicobacter pylori is a major etiological agent in gastroduodenal disorders. In this study, we isolated 36 polyphenols and 4 terpenoids from medicinal plants, investigated their antibacterial activity against H. vitro . All hydrolyzable tannins tested demonstrated promising Monomeric revealed especially strong activity. Other compounds minimal with few exceptions. A monomeric tannin, Tellimagrandin I time‐ dose‐dependent bactericidal On the other hand, did not affect viability of...

10.1111/j.1348-0421.2004.tb03521.x article EN Microbiology and Immunology 2004-04-01

A chloroform-methanol-extracted lipid of Helicobacter pylori was studied. Three kinds glycolipids, accounting for about 25% (wt/wt) the total lipid, were detected and identified to be cholesteryl glucosides. The structures two them determined cholesteryl-alpha-D-glucopyranoside cholesteryl-6-O-tetrade-canoyl-alpha-D-glucopyranoside, plausible structure third one as cholesteryl-6-O-phosphatidyl-alpha-D-glucopyranoside. Cholesteryl glucosides are very rare in animals bacteria. Furthermore,...

10.1128/jb.177.18.5327-5333.1995 article EN Journal of Bacteriology 1995-09-01

Integrated Heart/Cancer on a Chip (iHCC) is promising microfluidic platform that allows the culture of different cell types separately and application closed-medium circulation to reproduce side effects doxorubicin heart <italic>in vitro</italic>.

10.1039/c7ra07716e article EN cc-by-nc RSC Advances 2017-01-01

Binding of the purified type C 7S (neurotoxin), 12S and 16S botulinum toxins to epithelial cells ligated small intestine or colon guinea pig (in vivo test) pre-fixed gastrointestinal tissue sections vitro was analysed. The toxin bound intensely microvilli in both tests, but did not bind stomach colon. neurotoxin Absorption assessed by determining titre sera pigs 6-8 h after intra-intestinal administration toxins. When [1 x 10(5) minimum lethal dose (MLD)] injected, 200-660 MLD ml-1 detected...

10.1099/00221287-143-12-3841 article EN Microbiology 1997-12-01

The antibacterial properties of five kinds antimicrobial-finished textile products (AFTPs) were examined against Staphylococcus aureus, including methicillin-resistant (MRSA) strains and Pseudomonas aeruginosa, under wet dry conditions. Textile containing Ag. Zn. ammonium Zeolite chitosan found to be effective methicillin-sensitive S. aureus (MSSA) for up 6 hr incubation conditions, MRSA 24 only Under however, all AFTPs ineffective one strain. When organic matter was added the mixture, still...

10.1111/j.1348-0421.2002.tb02661.x article EN Microbiology and Immunology 2002-02-01

The lipid and fatty acid profiles of eight Helicobacter spp. (H. nemestrinae, H. acinonyx, canis, sp. strain CLO-3, "H. rappini" [Flexispira rappini], pametensis, Bird-B, Bird-C) the five additional species pylori, felis, muridarum, mustelae, fennelliae) were analyzed compared. A heterologous profile was observed among spp., on that basis could be divided into two groups. Group had 19-carbon cyclopropane (19:0cyc) tetradecanoic (14:0) as major acids, group B characteristically lacked 19:0cyc...

10.1128/jb.178.7.2065-2070.1996 article EN Journal of Bacteriology 1996-04-01

Bacillus cereus (B. cereus) is a pathogen in opportunistic infections. Here we show that sphingomyelinase (Bc-SMase) virulence factor for septicemia. Clinical isolates produced large amounts of Bc-SMase, grew vivo, and caused death among mice, but ATCC strains isolated from soil did not. A transformant the strain carrying recombinant plasmid containing Bc-SMase gene with E53A, which has little enzymatic activity, Administration an anti-Bc-SMase antibody immunization against prevented by...

10.1371/journal.pone.0038054 article EN cc-by PLoS ONE 2012-06-06

This paper presents a systematic study on novel 3D (three-dimensional) UV (ultraviolet) lithography apparatus for thick photoresist and process simulation microstructuring. In order to realize wide variety of microstructures, the developed proximity adopts 'moving mask lithography' concept which was originally proposed by authors deep x-ray lithography. Furthermore, propose new practical profile approach adopting 'fast marching method' consider dissolution vector in development process. A...

10.1088/0960-1317/17/2/003 article EN Journal of Micromechanics and Microengineering 2006-12-22

Abstract This study demonstrated that the vitamin D 3 decomposition product VDP1 exerts an antibacterial action against Helicobacter pylori but not other bacteria. Treatment with induced a collapse of cell membrane structures H. and ultimately lysed bacterial cells. A unique dimyristoyl phosphatidylethanolamine in lipid compositions contributed to interaction In separate experiments, had no influence on viability human cancer lines MKN45 T47D lacked any -like hormonal latter. both 1 H 13 C...

10.1038/srep08860 article EN cc-by Scientific Reports 2015-03-09

The past morphological studies on individual corneocytes have so far mainly focused their two-dimensional characteristics, particularly projected area, which been widely employed for the estimation of turnover rate stratum corneum because practical use. However, sometimes a poor correlation has reported between area and actually measured time corneum. objective present study is to perform detailed three-dimensional measurements with atomic force microscope. Through analyses obtained data, we...

10.1034/j.1600-0846.2002.00348.x article EN Skin Research and Technology 2002-11-01

Summary Background Large‐scale studies of rabeprazole‐based Helicobacter pylori eradication therapy have not been reported in Japan. Aims To evaluate H. by with reference to antibiotic susceptibility, CYP2C19 genotype, and rabeprazole clarithromycin dosages. Methods From 35 centres 479 ‐positive patients gastric or duodenal ulcer were randomized four treatment groups: Group 1 (10 mg + 750 amoxicillin 200 twice daily for 7 days); 2 mg, 400 mg); 3 (20 mg) 4 mg). Results Eradication rates 86%...

10.1111/j.1365-2036.2007.03298.x article EN Alimentary Pharmacology & Therapeutics 2007-02-26

Helicobacter pylori is a unique bacterial species that assimilates various steroids as membrane lipid components. Our group has recently found, however, certain may impair the viability of H. pylori. In this study, we go on to reveal estradiol, androstenedione, and progesterone (PS) all have potential inhibit growth Of these three steroid hormones, demonstrated most effective anti-H. action. 17α-hydroxyprogesterone caproate (17αPSCE), synthetic derivative, had much stronger action than...

10.1111/j.1574-6968.2011.02239.x article EN FEMS Microbiology Letters 2011-02-09

Helicobacter pylori infects the human stomach and is closely linked with development of gastric cancer. When detected, this pathogen can be eradicated from using wide-spectrum antibiotics. However, year by year, H. strains resistant to antibacterial action antibiotics have been increasing. The new substances effective against drug-resistant urgently required. Our group has recently identified extremely selective bactericidal effects in...

10.1002/lipd.12043 article EN Lipids 2018-04-01

The lipids of different species Helicobacter (H.felis, H. muridarum, mustelae, fennelliae, and cinaedi) were studied. Different types cholesteryl glucosides found in all the studied except cinaedi. total amount varied from 14.8% mustelae to 33.1% felis. their distribution are cholesteryl-6-O-acyl-alpha-D-glucopyranoside (cholesteryl-6-O-tetradecanoyl-alpha-D-glucopyranoside felis cholesteryl-6-O-dodecanoyl-alpha-D-glucopyranoside muridarum), cholesteryl-alpha-D-glucopyranoside (H. felis,...

10.1128/jb.177.18.5334-5337.1995 article EN Journal of Bacteriology 1995-09-01

Detection of biological weapons is a primary concern in force protection, treaty verification, and safeguarding civilian populations against domestic terrorism. One great the detection Bacillus anthracis, causative agent anthrax. Therefore, there pressing need to develop novel methods for rapid, simple, precise B. anthracis. Here, we report that C-terminal region gamma-phage lysin protein (PlyG) binds specifically cell wall anthracis recombinant corresponding this (positions, 156-233),...

10.1111/j.1348-0421.2007.tb03894.x article EN Microbiology and Immunology 2007-02-01

One of the unique features Helicobacter pylori is its ability to assimilate free-cholesterol (FC) into membranes. Via FC assimilation, H. strengthens membrane lipid barrier and/or evades host immune system. No previous studies, however, have investigated uptake mechanisms cell. Phosphatidylethanolamine (PE) most prevalent component bacteria, including pylori, but function PE remains unclear. We were therefore interested in (HpPE) and interaction with cholesterols. The isolated from underwent...

10.1128/jb.00105-12 article EN Journal of Bacteriology 2012-03-09

Abstract It is crucial to monitor healthcare workers’ radiation exposure, especially given the increasing reliance on X-ray imaging technologies. In response new evidence that threshold for lens opacity lower than previously thought, International Commission Radiological Protection (ICRP) has revised annual dose limit exposure of eye. After revision eye limit, survey dosemeter wearing rate was conducted in Japan. The result showed despite presence monitoring protocols, among workers still...

10.1093/rpd/ncaf061 article EN Radiation Protection Dosimetry 2025-06-05

<h3>BACKGROUND</h3> Development of gastric mucosa associated lymphoid tissue (MALT) lymphoma is thought to be closely with host immune reactions to<i>Helicobacter pylori</i>. <h3>AIM</h3> To investigate humoral responses in patients MALT antigens shared by <i>H pylori</i> and human epithelial cells. <h3>METHODS</h3> Sera were obtained from positive (n = 11) or other gastroduodenal diseases (peptic ulcer, n 40; non-ulcer dyspepsia, 20) from<i>H negative healthy control subjects 10)....

10.1136/gut.45.1.20 article EN Gut 1999-07-01
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