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Biomedical subjects

Y Okawa

Publications and source records attributed to Y Okawa.

At least 55 records · Page 3Linked to original sources
PubMed1996

Therapeutic effect of the quinolone prodrug prulifloxacin against experimental urinary tract infections in mice.

The in vitro antibacterial activity of prulifloxacin (CAS 123447-62-1, NM441), a new quinoline prodrug, against clinical isolates from urinary tract infections was investigated. In addition, it was compared with ofloxacin (CAS 82419-36-1), levofloxacin (CAS 100986-85-4), ciprofloxacin urinary tract infections in mice, as well as its pharmacokinetics. 1. The antibacterial activity of NM394 (6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H-[1,3]thiazeto[3,2- a]quinoline-3-carboxylic acid), an active metabolite of prulifloxacin, against gram-positive clinical isolates was inferior to that of levofloxacin and tosufloxacin, and equal to that of ofloxacin and ciprofloxacin. Against gram-negative clinical isolates, the activity of NM394 was superior to that of the reference drugs. 2. The therapeutic effect of prulifloxacin on experimental urinary tract infection with Escherichia coli in mice was equal to that of tosufloxacin and ciprofloxacin and superior to that of ofloxacin and levofloxacin. Its therapeutic effect on Pseudomonas aeruginosa infection was equal to that of tosufloxacin and ciprofloxacin, and superior to that of ofloxacin. Against urinary tract infection with olfloxacin-resistant Enterobacter cloacae, prulifloxacin was the most effective of all the drugs tested. 3. The maximal serum concentration of prulifloxacin was slightly higher than that of ciprofloxacin, and the area under the curve (AUC) for prulifloxacin was 1/4 that of ofloxacin, levofloxacin and tosufloxacin. The maximal concentration and AUC of prulifloxacin in lung and kidney were slightly higher than the corresponding values for ciprofloxacin but only 1/2 to 1/4 of the values for ofloxacin, levofloxacin and tosufloxacin. In conclusion, prulifloxacin (NM394) showed potent antibacterial activity against clinical isolates and potent therapeutic efficacy against experimental infection in spite of its lower AUCs compared with the reference drugs. These findings suggest that prulifloxacin may be a useful drug in the treatment of urinary tract infections.

Animals↗
PubMed1995

Detection of beta-1,2-mannosyltransferase in Candida albicans cells.

A particulate insoluble fraction from Candida albicans J-1012 (serotype A) strain cells was obtained as the residue after extracting a 105,000 x g pellet of cell homogenate with 1% Triton X-100. Incubation of this fraction with a mannopentaose, Man beta 1-->2Man alpha 1-->(2Man alpha 1-->)(2)2Man (alpha beta Man5), in the presence of GDP-mannose followed by high performance liquid chromatography showed the formation of a mannohexaose. Analysis of the product by 1H NMR indicates that alpha beta Man5 was changed to Man beta 1-->2Man beta 1-->2Man alpha 1-->(2Man alpha 1-->)2 2Man (alpha beta Man6). This beta-1,2-mannosyltransferase (ManTase) II activity was completely inhibited by Zn2+ and was not restored by the addition of EDTA. The corresponding enzyme fraction from C. albicans NIH B-792 (serotype B) strain cells, the mannan of which does not possess both the alpha beta Man5 and alpha beta Man6 side chains, also exhibited the same beta-1,2-ManTase II activity.

Candida albicans↗
PubMed1995

Dental health indicator based on a questionnaire.

Dentistry has lacked an effective indicator of the impact of dental problems on a person's daily life. Subjective factors in dental health need to be included in order to improve current indicators. The purpose of this research was to develop a new type of indicator recorded from a questionnaire which takes account of subjective factors in dental health. The indicator we constructed has the following advantages. 1. Calculation process is simple in practice. 2. The indicator values range from 0 to 100, with values closer to 100 indicating a more favorable condition for the individual. 3. The distribution of indicator values is similar to the normal distribution. 4. The score of each item is reflected on the indicator, suggesting the individual's characteristics in terms of dental health. 5. Although it is principally an indicator for individuals, it can also be applied to groups. This study will also provide a model for the preparation of a dental health indicator.

Adult↗
PubMed1994

Temperature-dependent change of serological specificity of Candida albicans NIH A-207 cells cultured in yeast extract-added Sabouraud liquid medium: disappearance of surface antigenic factors 4, 5, and 6 at high temperature.

The cells of Candida albicans NIH A-207 strain (A-strain) cultivated in YSLM at high temperatures (37 and 40 degrees C) did not undergo agglutination with the factor sera 4, 5, and 6 in a commercially available factor serum kit, 'Candida Check', and formed a grape-like shape. The mannans isolated from the cells had lost their reactivity against the factor sera in ELISA. It was also revealed by 1H NMR analysis that the mannans contained neither a phosphate group nor a beta-1,2-linked mannopyranose unit, although these mannans increased the non-reducing terminal alpha-1,3-linked mannopyranose unit. The cells and the mannans prepared by cultivation at such high temperatures followed by 27 degrees C in the same medium entirely recovered the reactivity with the factor sera.

Agglutination Tests↗
PubMed1994

Anti-oral microbial activity of isoflavonoids in root bark of Ormosia monosperma.

From the root bark of Ormosia monosperma, 10 isoflavonoids including two new compounds 7,4'-dihydroxy-6",6"-dimethylpyrano-(2",3":5,6)-8-(3-methyl-1,3- butadienyl)isoflavone, named ormosidin, and dalbergion 4'-O-beta-D-glucopyranoside, were isolated. These structures were confirmed by spectroscopic analysis. 2,3-Dihydroauriculatin, one of the compounds isolated, showed moderate activities against oral-microbial organisms (Streptococcus mutans, Prophyromonas gingivalis and Actinomyces actinomycetemcomitans).

Anti-Infective Agents↗
PubMed1993

High frequency of etoposide (VP-16)-related secondary leukemia in children with non-Hodgkin's lymphoma.

PATIENTS AND METHODS: We report patients who were treated for non-Hodgkin's lymphoma (NHL) or Ki-1 antigen-positive (Ki-1) lymphoma with a T-8801 protocol that included etoposide (VP-16) and behenoylcytosine arabinoside. RESULTS: Secondary acute myeloid leukemia (AML) developed in 5 of 38 NHL and Ki-1 lymphoma patients, and the cumulative risk at 4 years was 18.4%. The median time from the initiation of the chemotherapy to the development of AML was 21 months (range, 13-30). Four patients had a FAB M5 morphology, and one had FAB M2. In four of five examined cases, chromosomal alterations involving the long arm of chromosome 11 were demonstrated at the time of development of AML. None of the 46 NHL patients who we treated with another protocol (B-8801), using significantly higher cumulative doses of VP-16 than in the case of the patients with T-8801 and a different schedule of VP-16 administration, developed secondary AML. CONCLUSIONS: The risk of secondary AML possibly related to the use of VP-16 given twice weekly.

Adolescent↗
PubMed1993

Prevalence of root caries in a Japanese adult population aged 20-59 years.

The purpose of the present study was to investigate the prevalence of root caries in an adult population in Japan. A total of 770 company employees aged 20-59 were examined in 1990. The subjects were all dentate and had 27.2 present teeth on the average. The proportion of gingival recession in this population ranged from 20.1% for the 20-29 year old group to 75.2% for the 50-59 year old group, with an average of 44.0%. In the present study, 3.2% of the subjects showed one or more active root caries. The prevalence of active root caries ranged from 0.4% at age 20-29 to 7.1% at age 50-59. The proportion of persons with active root caries and/or root fillings ranged from 1.3% at age 20-29 to 36.3% at age 50-59. The percentage of subjects with active and/or inactive caries and/or root fillings varied from 3.1% at age 20-29 to 43.4% at age 50-59. The prevalence of active root caries in the subjects at risk (with gingival recession) was 7.4% on the average and ranged from 2.2% at age 20-29 to 9.4% at age 50-59. The percentage of persons with active root caries and/or root fillings in the subjects at risk ranged from 6.7% at age 20-29 to 48.2% at age 50-59. The mean number of teeth with active root lesions was 0.09 per person, and the mean number of teeth with root fillings was 1.25 at age 50-59.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Site-specific CPITN score and periodontal disease activity assessed by the paper BANA assay.

The purpose of this study was to examine the association between site-specific periodontal conditions assessed by CPITN and BANA test results. A total of 161 Japanese company employees aged 18-59 were examined for their periodontal conditions at mesio-buccal and mid-lingual sites of the maxillary right and mandibular left first molars using CPITN. Code 2 (calculus) was divided into Code 2+ and Code 2- by the presence or absence of bleeding. Plaque samples were collected from the examined sites with a scaler and placed on BANA reagent cards. The results indicated a close relationship between site-specific CPITN Codes and the BANA test results except at sites designated Code 2-. The proportion of sites with strong-positive reactions were 19.0% for Code 0, 21.4% for Code 2-, 29.9% for Code 1, 37.0% for Code 2+ and 50.0% for Code 3. These data indicated that the teeth given higher CPITN Codes tend to have higher risks for periodontal disease. From these results, it was concluded that the site-specific CPITN score is a good indicator of periodontal disease activity and that a higher priority for treatment should be given to the sites with pocket formation (Code 3 and Code 4) and/or gingival bleeding (Code 1 and Code 2+).

Adolescent↗
PubMed1992

Sequential nuclear magnetic resonance assignment of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of the pathogenic yeast Candida albicans NIH B-792 strain.

The H-1 and H-2 signals of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of Candida albicans NIH B-792 strain by mild acid hydrolysis were assigned by a sequential NMR assignment method that combines two-dimensional 1H-1H correlated spectroscopy (COSY) and two-dimensional nuclear Overhauser enhancement and exchange spectroscopy (NOESY). The results indicated that the H-1 and H-2 of each beta-1,2-linked mannopyranose unit show largely different signals compared with those of the alpha-linked ones and that the correlation between linkages and signals could not be explained by a conventional additivity rule. Furthermore, a regular proportional downfield shift of the H-1 signal was observed in the order of the mannose unit from the reducing terminal except those of the reducing and nonreducing terminal positions. Although the 1H NMR spectra of these oligosaccharides were complicated due to the presence of a large portion of the beta-anomer from the reducing terminal mannose unit, reduction of the oligosaccharides with NaBH4 to the corresponding alcohols gave simple and more readily interpretable 1H NMR spectra. Unexpectedly, however, a shift of H-1 signals by this reduction occurred not only on the second mannose unit but also on the third and fourth mannose units from the modified reducing terminal group of each oligosaccharide alcohol. This result indicates that the reducing terminal mannose unit is able to affect up to the fourth mannose unit from the reducing terminal. The presence of a long-distance interresidue NOE also suggests that the beta-1,2-linked mannooligosaccharides have a compactly folded conformation in solution.

Alcohols↗
PubMed1992

Production of anti-peptide specific antibody in mice following immunization with peptides conjugated to mannan.

In order to investigate the usefulness of polysaccharides as carriers for the induction of antibody to synthetic peptides, peptides representing residues 139-147 of the surface antigen of hepatitis B and residues 129-140 of the pre-S2 region of the protein were coupled to mannan and dextran via an aminocaproic spacer molecule. Of the two conjugates studied, only mannan was useful as a carrier for the efficient production of anti-peptide antibodies.

Aminocaproates↗
PubMed1992

Model analysis of enzyme monolayer- and bilayer-modified electrodes: the transient response.

The transient responses of enzyme monolayer- and bilayer-modified electrodes were theoretically analyzed. The response was numerically simulated with parameters used in the foregoing paper. The transient process consists of three elementary steps: enzymatic reaction step, substrate and mediator consumption step, and charge-carrying mediator accumulation step. Contributions of the parameters to these elementary steps and the overall response were examined. Experimental observations are successfully interpreted in terms of the theoretical results.

Biosensing Techniques↗
PubMed1992

Augmentation of host resistance to Candida albicans infection in ascites tumor-bearing mice.

We found that the number of peripheral blood polymorphonuclear leukocytes (PMN) dramatically increased in both sarcoma 180 (S-180) and MM-46 mammary carcinoma (MM-46) ascites tumor-bearing mice, and mice required a remarkable resistance to Candida albicans infection via intravenous route. When the resistance was determined by number of cells of C. albicans in the kidney, a significant decrease in the number of fungal cells was observed in the kidneys of infected ascites tumor-bearing mice. An increase of active oxygen levels of PMN from ascites tumor-bearing mice was observed, suggesting that this factor is important in developing of resistance in ascites tumor-bearing mice. Additionally, a culture supernatant of tumor cells co-cultivated with bone-marrow cells in vitro increased the number of granulocytes and macrophages differentiated from the bone-marrow cells.

Animals↗
PubMed1992

Decline in caries prevalence in 6-14-year-old schoolchildren during 1975-85 in Shizuoka, Japan.

The purpose of this study was to examine changes in caries prevalence during 1975-85 in Japanese schoolchildren who did not have an apparent change in fluoride exposure. A total of 2872 schoolchildren aged 6-14 yr in two primary schools and one junior high school in Shizuoka city, Japan, were examined in 1985. The caries prevalence in 1985 was then compared with data which had been collected in a longitudinal survey on schoolchildren in the same primary and junior high schools by Katayama in 1970-75. The results indicated that DMFT and DMFS indices in 1985 were significantly lower than those in 1970-75 in all the examined ages (P < 0.01). The DMFT indices at age 12 were 3.60 in 1985 and 5.47 in 1970-75. Remarkable decreases in DMFT at age 12 were observed in maxillary incisors (50%), followed by maxillary molars (24%) and mandibular molars (22%). The decline in caries prevalence in the examined area may be mainly attributed to several factors other than use of fluoride, such as changes in dietary pattern, an increasing dental awareness and promotion of dental health care. But the percentage decrease per annum of DMFT index at age of 12 in the examined population was relatively low (-4.1%) in comparison with other industrial countries. Comparing the results with data from national dental surveys, it can be considered that rural areas in Japan do not exhibit a similar decline of caries prevalence as in Shizuoka city, but there will be a lot of districts exhibiting significant reduction in caries prevalence in the near future.

Adolescent↗
PubMed1991

Structural study on a phosphorylated mannotetraose obtained from the phosphomannan of Candida albicans NIH B-792 strain by acetolysis.

A mixture of phosphorylated manno-oligosaccharides was isolated from the acid-stable domain of phosphomannan of Candida albicans NIH B-792 strain (serotype B) by acetolysis and was fractionated on a column of Bio-Gel P-2 equilibrated with 50 mM pyridine-CH3COOH buffer, pH 5.0. A monophosphorylated mannotetraose was isolated as the major constituent. Structural analyses of this phosphate-containing tetraose and its reduction product with NaBH4 by 1H, 13C, and two-dimensional homonuclear Hartmann-Hahn NMR spectroscopies, subsequently, gave results consistent with the structure described below (where Manp represents the mannopyranose unit): [formula: see text] It was unexpected that the major phosphorylated branch in the acid-stable domain of the parent phosphomannan of this C. albicans strain is a relatively short mannotetraosyl residue containing solely alpha-1,2-linked mannopyranose units, and a phosphate group as a 6-O-ester on the intermediary unit adjacent to the nonreducing terminal group. These findings indicate that the size of the major phosphorylated branch of this phosphomannan is the same as that of Saccharomyces cerevisiae.

Candida albicans↗
PubMed1991

Structural determination of D-mannans of pathogenic yeasts Candida stellatoidea type I strains: TIMM 0310 and ATCC 11006 compared to IFO 1397.

The structures of the cell-wall D-mannans of pathogenic yeasts of Candida stellatoidea Type I strains, IFO 1397, TIMM 0310, and ATCC 11006, were investigated by mild acid and, alkaline hydrolysis, by digestion with the Arthrobacter GJM-1 strain exo-alpha-D-mannosidase, and by acetolysis. The modified D-mannans and their degradation products were studied by 1H- and 13C-n.m.r. analyses. D-Manno-oligosaccharides released by acid treatment from the parent D-mannans were identified as the homologous beta-(1----2)-linked D-manno-oligosaccharides from biose to hexaose, whereas those obtained by alkaline degradation were the homologous alpha-(1----2)-linked D-mannobiose and D-mannotriose. The acid- and alkali-modified D-mannans lacking 1H-n.m.r. signals above 4.900 p.p.m. [corresponding to beta-(1----2)-linked D-mannopyranose units] were acetolyzed with 10:10:1 (v/v) Ac2O-AcOH-H2SO4, and the resultant D-manno-oligosaccharides were also analyzed. It was found that the longest branches of these D-mannans, corresponding to hexaosyl residues, had the following structures: alpha-D-Manp-(1----3)-alpha-D-Manp-(1----2)-alpha-D-Manp+ ++-(1----2)-alpha-D-Manp- (1----2)-alpha-D-Manp-(1----2)-D-Man and alpha-D-Manp-(1----2)-alpha-D-Manp-(1----3)-alpha-D-Manp+ ++-(1----2)-alpha-D-Manp- (1----2)-alpha-D-Manp-(1----2)-D-Man. These results indicate that the D-mannans of C. stellatoidea Type I strains possess structures in common with the D-mannans of Candida albicans serotype B strain (see ref. 4) containing phosphate-bound beta-(1----2)-linked oligo-D-mannosyl residues.

Candida↗
PubMed1991

Candida albicans serotype A strains grow in yeast extract-added Sabouraud liquid medium at pH 2.0, elaborating mannans without beta-1,2 linkage and phosphate group.

Cultivation of three Candida albicans strains, NIH A-207, J-1012, and NIH B-792, abbreviated as A-, J-, and B-strains, respectively, in yeast extract-enrich Sabouraud liquid medium at pH 2.0 provided the following findings, i.e., the two former strains belonging to serotype A were able to grow in this medium in almost the same rates as those in the same medium of pH 5.9, while B-strain cells did not proliferate under the former condition. The cells of A- and J-strains cultivated at pH 2.0 did not undergo agglutination with the factor serum 6 in a commercially available factor serum kit, Candida Check, corresponding to C. albicans serotype A-specific epitope. It was also revealed by 1H-13C correlation spectra of the mannans isolated from the cells of A- and J-strains contained neither phosphate group nor beta-1,2-linked mannopyranose unit, although these mannans retained non-reducing terminal alpha-1,3 linked mannopyranose units, providing a substantiating evidence that the serotype A-specific epitope contains a non-reducing terminal beta-1,2-linked mannopyranose unit.

Candida albicans↗