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Y Tabe

Publications and source records attributed to Y Tabe.

At least 19 recordsLinked to original sources
PubMed2006

Director-configurational transitions around microbubbles of hydrostatically regulated size in liquid crystals.

A high-pressure technique is introduced which allows a continuous variation of the inclusion size in liquid crystal colloids. We use a nematic liquid crystal host into which micrometer-sized gas bubbles are injected. By applying hydrostatic pressures, the diameter of these gas bubbles can be continuously decreased via compression and absorption of gas into the host liquid crystal, so that the director configurations around a single bubble can be investigated as a function of the bubble size. The theoretically predicted transition from a hyperbolic hedgehog to a Saturn-ring configuration, on reduction of the particle size below a certain threshold, is confirmed to occur at the radius of a few micrometers.

Journal Article↗
PubMed2001

Glycopeptide susceptibility profiles of nosocomial multiresistant Staphylococcus haemolyticus isolates.

We investigated 48 Staphylococcus haemolyticus isolates from patients and medical staff in terms of susceptibility to and in-vitro selection for vancomycin and teicoplanin in regard to their antibiotypes. On comparison of multiresistant S. haemolyticus isolates with non-multiresistant isolates, the geometric mean minimum inhibitory concentration (MIC) of vancomycin for multiresistant S. haemolyticus was 2.9 microg/ml, and that of teicoplanin was 18.0 microg/ml, both of which values were significantly greater than the corresponding mean MICs of vancomycin (2.0 microg/ml) and teicoplanin (4.7 microg/ml) for nonmultiresistant isolates. After agar selection, the mean of the highest teicoplanin concentration of selected plates for multiresistant S. haemolyticus was 97.1 microg/ml, which was significantly higher than that for nonmultiresistant isolates (57.8 microg/ml). However, the means' of the highest vancomycin concentrations after agar selection for multiresistant and nonmulti-resistant isolates were the same, at 7.4 microg/ml, with no colonies capable of growing in 32 microg/ml of vancomycin. There was no significant difference in glycopeptide susceptibility between oxacillin-resistant and oxacillin-susceptible isolates among nonmultiresistant S. haemolyticus. The geometric mean MICs of vancomycin for oxacillin-resistant and oxacillin-susceptible isolates were 2.1 microg/ml and 1.6 microg/ml, and those of teicoplanin were 4.4 microg/ml and 5.6 microg/ml, while the means of the highest concentrations of the selected plates of vancomycin were 8.6 microg/ml and 3.3 microg/ml, and those of teicoplanin were 52.8 microg/ml and 74.7 microg/ml, respectively. Multiresistant isolates showed significantly greater mean MICs of vancomycin and teicoplanin and higher teicoplanin concentration of the selected plates than nonmultiresistant isolates, irrespective of oxacillin resistance. These results indicate that methicillin resistance may not be related to reduced susceptibility to glycopeptide in S. haemolyticus, and that a multiresistant profile is associated more with a decreasing susceptibility to glycopeptides then with resistance to oxacillin. In this study, antibiotypes showed good concordance with pulsed-field gel electrophoresis typing results, with a sufficiently high discriminatory ability index, of 0.912. We consider that primary screening with antimicrobial susceptibility testing and antibiotyping, with attention to the multiresistant profile, would be useful for monitoring nosocomial S. haemolyticus colonization and infection.

Anti-Bacterial Agents↗
PubMed2000

[Epidemiological study on Staphylococcus epidermidis isolated from bloodstream and blood vessel catheter].

An epidemiological study on 35 strains of Staphylococcus epidermidis was conducted in Juntendo University Hospital between 1994 and 1996. The strains were isolated from blood and blood vessel catheters. Three epidemiological markers; PFGE type (pulsed-field gel electrophoresis using SmaI), biotype by STAPHYOGRAM and antibiotype (antibiotic resistant pattern) were used. There were 12 types in PFGE type, 6 types in biotype and 7 types in antibiotype. 1. The predominant types were PFGE type A (57.1%), biotype 1 (62.9%), and antibiotype I (resistant for oxacillin, ampicillin and gentamicin; 34.3%) in Juntendo University Hospital. 2. The strains with antibiotic V-VII (resistant for over 6 antibiotics) showed only PFGE type A and B. All strains with PFGE type B showed biotype 4-6 (negative nitrate reduction strain). 3. The strains having PFGE type A and B were isolated from various patient wards. The strains showing PFGE type A and antibiotype I were isolated from the pediatric ward. 4. There was no strain with PFGE type C or D in 1996. 5. Three patients in whom S. epidermidis was frequently isolated for a few months had the same types of PFGE type, biotype as well as antibiotype.

Blood↗
PubMed1998

Molecular characterization of epidemic multiresistant Staphylococcus haemolyticus isolates.

Fifty-five Staphylococcus haemolyticus specimens isolated from patients and neonatal intensive care unit staff were tested for susceptibility to 12 antimicrobial agents. There were 34 multidrug-resistant isolates which were resistant to oxacillin, ampicillin, cefazolin, cefmetazole, imipenem, and gentamicin. These isolates had a higher frequency of resistance to tobramicin and ofloxacin, and relatively high MICs (2 to 4 micrograms/mL) for vancomycin, although none of the isolates were vancomycin resistant. To investigate hospital-acquired colonization and infection by multiresistant S. haemolyticus, we examined all isolates by pulsed-field gel electrophoresis (PFGE) after SmaI and SstII digestion, and detected an endemic PFGE pattern in multiresistant isolates. The results suggested that local spread of multiresistant S. haemolyticus was hospital acquired, and that the hospital staffs functioned as a reservoir.

Ampicillin↗
PubMed1997

[Nationwide survey of susceptibilities of clinical isolates to antibacterial agents in 1992].

This study was conducted to investigate susceptibilities of clinical isolates to imipenem (IPM) and other antibacterial agents in 144 hospital laboratories throughout Japan from September to December of 1992. In this study, the isolates were identified and susceptibility tests were performed at individual laboratories. The susceptibility tests were performed using the disk dilution method recommended by NCCLS. S. aureus (including MRSA) strains were highly susceptible to arbekacin (ABK) and netilmicin (NTL). S. pneumoniae and H. influenzae were susceptible to most of the agents tested. E. faecalis were highly susceptible to penicillins and imipenem (IPM). P. aeruginosa showed high susceptibility to ceftazidime (CAZ), IPM and amikacin (AMK). Annual changes in antimicrobial susceptibility patterns over 5 years (1988-1992) were examined. The frequency of sensitive strains of S. aureus to methicillin (DMPPC) has slightly increased from 1991 to 1992. A moderate increases of PCG-insensitive S. pneumoniae was observed. B. fragilis group showed a slight increase in sensitivity to minocycline (MINO) but no yearly changes in IPM sensitivity was observed.

Anti-Bacterial Agents↗
PubMed1995

[Nationwide survey on susceptibilities of clinical isolates to antibacterial agents in 1991].

This study was conducted to investigate susceptibilities of clinical isolates to different antibacterial agents at 123 hospital laboratories throughout Japan from September to December of 1991. In this study, identifications and susceptibility testings were carried out at each hospital laboratory. The susceptibility testing were performed using the disk dilution method recommended by NCCLS. Staphylococcus aureus and CNS showed high or moderate resistance rates to methicillin (DMPPC). Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumoniae, Haemophilus influenzae, Proteus mirabilis were highly susceptible to many agents including beta-lactam antibiotics. Though Enterococcus faecalis was highly susceptible to ampicillin (ABPC), piperacillin (PIPC), imipenem (IPM), sulfamethoxazole-trimethoprim (ST) compounds, Enterococcus faecium was resistant to almost all antibacterial agents but to ST compounds. High susceptibility rates were observed for strains of Enterobacter cloacae to IPM, gentamicin (GM) and ofloxacin (OFLX) and for strains of Proteus vulgaris to latamoxef (LMOX), IPM, aztreonam (AZT), GM and OFLX. Serratia marcescens and Bacteroides fragilis group were highly susceptible only to IPM. Pseudomonas aeruginosa were sensitive to ceftazidime (CAZ), IPM, amikacin (AMK) and tobramycin (TOB). Pseudomonas cepacia was relatively susceptible only to CAZ. IPM showed strong antibacterial activity to many species except for S. aureus and CNS.

Bacteria↗
PubMed1994

[Susceptibilities of glucose non-fermentative gram-negative bacilli to antibiotics].

Glucose non-fermentative Gram-negative bacilli are important nosocomial pathogens. This study concerned with susceptibilities to antibacterial agents of strains of Glucose non-fermentative Gram-negative bacilli that were isolated from cultures of clinical materials at 123 hospital laboratories throughout Japan from September to December of 1991. The tests for susceptibilities were performed according to the disk dilution method recommended by NCCLS. The following bacteria were tested: Pseudomonas aeruginosa, Pseudomonas cepacia, Acinetobacter calcoaceticus, Alcaligenes spp., Alcaligenes xylosoxidans, Flavobacterium spp. and Xanthomonas maltophilia. The antibacterial agents tested were as follows: piperacillin (PIPC), ceftazidime (CAZ), aztreonam (AZT), imipenem (IPM), minocycline (MINO), gentamicin, amikacin (AMK) and ofloxacin (OFLX). 1. Eighty percent of the strains of P. aeruginosa and P. cepacia were sensitive to CAZ. More than ninety percent of the strains of A. calcoaceticus were sensitive to IPM, MINO, OFLX. To PIPC and IPM, about eighty percent of the strains of Alcaligenes spp. and A. xylosoxidans were sensitive. The strains of Flavobacterium spp. and X. maltophilia showed high sensitivities to MINO. 2. Annual changes in antimicrobial susceptibility patterns over 4 years (1988-1991) show that there has been a gradual increase in sensitive strains of P. aeruginosa to PIPC, CAZ and AMK. Sensitive strains of P. cepacia to AZT, IPM and MINO, and A. calcoaceticus to CAZ and MINO also have gradually increased. No yearly changes were observed in high sensitivity to MINO of the strains of Flavobacterium spp. and X. maltophilia.

Anti-Bacterial Agents↗