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Biomedical subjects

A Mizuno

Publications and source records attributed to A Mizuno.

At least 253 records · Page 14Linked to original sources
PubMed1988

Evaluation of a fluorescence polarization immunoassay procedure for quantitation of isepamicin, a new aminoglycoside antibiotic.

A fluorescence polarization immunoassay (FPIA) procedure for measuring isepamicin, a new aminoglycoside antibiotic, was evaluated. The range of the assay studied was from 0.3-50 micrograms/ml and the calibration curve can be stored for at least 32 days. There was no interference from hemoglobin (up to 400 mg/dl) and bilirubin (up to 20 mg/dl). Within-run precision on each 20 replicates at 5, 15, and 25 micrograms/ml yielded a coefficient of variation (CV) of 1.44-2.52%; between-run precision on analyses at 5, 15, and 25 micrograms/ml over five periods yielded a CV of 1.26-1.59%. Cross-reactivities of the assay system with tobramycin and amikacin were null, but that with gentamicin, of which isepamicin is a derivative, was approximately 14-29%. Data obtained by microbiological assay and FPIA and by high-performance liquid chromatography and FPIA correlated significantly, with coefficients of correlation being 0.980 (n = 70) and 0.965 (n = 39), respectively. The FPIA offers a rapid, efficient, and accurate system for therapeutic monitoring of isepamicin plasma levels.

Adult↗
PubMed1988

Restoration by xanthine of development of mouse embryos inhibited by mycophenolic acid.

Mouse embryos at the 1-cell stage were cultured in various concentrations of mycophenolic acid and xanthine. Mycophenolic acid at 10 and 2.5 micrograms/ml completely inhibited development to the morula and blastocyst stages, respectively. The addition of xanthine reversed the inhibitory effects of mycophenolic acid on the embryos but the reversal effect depended on the concentration of xanthine. Development was normal with a xanthine concentration of 25 micrograms/ml, even when an inhibitory concentration of mycophenolic acid was present. Embryo transfer experiments showed that the blastocysts formed in vitro in the presence of mycophenolic acid + xanthine could implant in foster mothers and develop normally to fetuses.

Animals↗
PubMed1988

Sexing of half-embryos produced by microsurgical bisection of mouse morulae and production of chimeric mouse of defined sex composition by aggregating two sexed half-embryos.

Using the halved morulae of mice obtained with microsurgical technique, the following two experiments were performed. 1) Sexing of half-embryos by chromosomal analysis and transfer of the half-embryos after determining the sex of the other monozygotic half. One half of the bisected embryo was cultured in Colcemid solution (0.04 micrograms/ml) to be ensured for chromosomal preparation. More than 50% (152/270) of the blastulated embryos from the halves could be sexed by direct sex chromosome analysis. Thirty-nine of the half-embryos of which the co-twin halves were sexed, were transplanted in to the uterine horns of 18 pseudopregnant mice, and twelve became pregnant. The autopsies of them on Day 18 to 20 of pregnancy, revealed the presence of 16 fetuses. The morphological sex of these fetuses thus obtained coincided completely with the previous judgement based on the chromosomal sexing. 2) Production of chimeras of defined sex composition by aggregating two half-morulae of defined sex. Out of 147 pairs of half-morulae of two different strains (ICR and C3H/He), which were replaced in pairs into empty zona pellucidae, 107 (72.8%) were aggregated successfully and developed in vitro into full expanding blastocysts of typical form. Among the 107 aggregate blastocysts, 31 were sexed for both component embryos by chromosomal analysis on the co-twin half-embryos. When these 31 blastocysts were transferred, 11 living offspring including 4 chimeras were obtained. Transfer of 12 male-male and 5 female-female aggregate blastocysts resulted in 8 males and 1 female, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Clinical evaluation of cefpodoxime proxetil in the treatment of skin and soft tissue infections. A double blind comparison of cefpodoxime proxetil and cefaclor].

In order to objectively evaluate the effectiveness, safety and usefulness of the new oral cephem cefpodoxime proxetil (CS-807, CPDX-PR) for the treatment of skin and soft tissue infections, a double-blind comparative study was undertaken using cefaclor (CCL) as the control drug. CPDX-PR and CCL were administered for 7 days at daily doses of 400 mg (divided into 2 portions) and 750 mg (divided into 3 portions), respectively. A total of 243 patients (118 in the CPDX-PR group and 125 in the CCL group) was treated in this study. The effectiveness, safety and usefulness were evaluated in 222 (106 in the CPDX-PR group and 116 in the CCL group), 234 (113 in the CPDX-PR group and 121 in the CCL group) and in 223 patients (107 in the CPDX-PR group and 116 in the CCL group), respectively. There were no differences in patients' backgrounds between the 2 groups, except for the presence or the absence of surgical treatments. The results we obtained are summarized below: 1. In the evaluation of clinical efficacy by the subcommittee, excellent, good, fair and poor efficacy were observed in 36, 43, 17 and 10 patients in the CPDX-PR group, respectively; the efficacy rate was, therefore, calculated to be 74.5%. As for the CCL group, respective results were observed in 50, 39, 17 and 10 patients, indicating an efficacy rate of 76.7%. There was no significant difference between the 2 groups. Improvement rates judged by physicians in charge were 80.2% in the CPDX-PR group and 88.8% in the CCL group. Moreover, no significant difference in diseases or severity were found between the 2 groups. 2. As for the bacteriological efficacy, the 2 groups showed high elimination rates, as 90.1% and 91.6% of the disease causing bacteria were eliminated in the CPDX-PR group and in the CCL group, respectively. Elimination rates in single infections with Staphylococcus aureus were determined to be 85.7% in the CPDX-PR group and 85.0% in the CCL group. 3. Although 6 patients in the CPDX-PR group and 2 patients in the CCL group developed side effects, which were mainly gastrointestinal symptoms, there was no significant difference in the incidence of side effects between the 2 groups. Abnormal laboratory values were found in 5 patients in the CPDX-PR group and 1 patient in the CCL group. 4. There was no significant difference in the usefulness between the 2 groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Abscess↗
PubMed1988

Laser Raman spectroscopic study of hereditary cataractous lenses in ICR/f-strain rat.

The lenses of ICR/f-strain rats with hereditary cataract were monitored in situ by laser Raman spectroscopy. The lenses used were within the age of 3-10 weeks before lens opacification became manifest. The reduction of protein SH group content and the increase of protein S-S bond content were observed in ICR/f rats in the precataractous stage. No significant change in the water content was observed.

Age Factors↗
PubMed1988

[Antibiotic susceptibility of bacteria isolated from surgical infection (second report)].

Isolated bacteria from infections in general surgery in 1984 and 1985 have been investigated to find bacterial composition and their susceptibilities to antibiotics in a joint research in which 6 university hospitals in Japan participated. A summary of findings from the investigation is as follows. 1. One hundred and seventy-two (1984) and 211 (1985) cases were included in the study. Cases in which bacteria were detected were 147 and 174 in the respective years. The detection rate was higher than 80% in either year. 2. Total numbers of strains isolated in 1984 and 1985 were 267 and 293, respectively; major sources of these strains were intraperitoneal infection exudates in either year. 3. The most frequent isolate from primary infection cases in both years was Escherichia coli (15-21%), followed by Bacteroides spp. and Staphylococcus spp., in that order. The most frequently isolated from postoperative infection cases were Enterococcus spp. (16-22%), followed by Pseudomonas spp. The diversity of isolated species, as well as the similarity of incidences of different species were noted in cases of postoperative infections. It is suspected that a certain species, even if its pathogenicity is essentially low, may become to be a causative organism once its number increases due to its survival through a perioperative prophylactic use of antibiotics, and also due to the decreased host resistance to infections caused by underlying diseases or surgical stress. 4. Staphylococcus spp. was the most frequent isolate from postoperative infections occurring after clean operations, while Enterococcus spp. and Pseudomonas aeruginosa were major isolates from infections after clean-contaminated operations. Isolates from infections occurring after contaminated operations included Enterococcus spp. greater than E. coli greater than Klebsiella pneumoniae, P. aeruginosa, Bacteroides spp. (1985). 5. In cases without the presence of clinical factors cause by depressed host defense, E. coli and Bacteroides spp. were major isolates, while in cases with the factors, a wide variety of bacterial population tended to be found. 6. Before an administration of antibiotics in primary infections, E. coli, Staphylococcus spp. Bacteroides spp. and Klebsiella spp. were most commonly isolated, while after a chemotherapy, Enterococcus spp. were the most frequent isolates, followed by P. aeruginosa during 1985. These findings reflected the antibacterial spectrum of cephems usually used in surgical field.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Bacterial Agents↗
PubMed1988

A fluorescence polarization immunoassay evaluated for quantifying astromicin, a new aminoglycoside antibiotic.

We evaluated a fluorescence polarization immunoassay (FPIA) procedure for measuring astromicin, a new aminoglycoside antibiotic. The calibration curve can be stored for at least 32 days without loss of accuracy. There were no interferences from hemoglobin (up to 4000 mg/L) or bilirubin (up to 200 mg/L), nor were there any cross-reactivities with amikacin, gentamicin, or tobramycin. Within-run precision (CV) for 20 replicates, each at concentrations of 5, 15, and 25 mg/L, was 1.25-2.11%. Between-run precision for these same concentrations, measured on five occasions, was 2.13-2.74%. Linear-regression analyses of data by FPIA (y) and HPLC (x) for plasma obtained from six healthy male volunteers who were given 200 mg of astromicin by 30-min intravenous infusion and for sera prepared by adding arbitrary amounts of astromicin showed highly significant correlations: r = 0.996 (n = 66), y = 0.96x - 0.48 mg/L and r = 0.981 (n = 59), y = 0.96x - 0.25 mg/L, respectively. This assay offers a rapid, efficient, and accurate system for therapeutic monitoring of astromicin in blood.

Adult↗
PubMed1987

Inter- and intramolecular disulfide bond formation and related structural changes in the lens proteins. A Raman spectroscopic study in vivo of lens aging.

Raman spectra have been measured for intact rat lens nuclei at various stages of aging in an attempt to gain further insight into age-related structural changes in the lens proteins, especially changes concerning protein sulfhydryl groups. Two Raman bands at 2579 and 2561 cm-1 were observed to be assignable to SH stretching modes of the cysteine residues. These bands have been attributed to "exposed" and "buried" sulfhydryl groups of the lens proteins, respectively, on the basis of a model compound study. The relative intensities of both SH stretching modes decreased with lens aging, and concurrently the intensity of a S-S stretching mode at 509 cm-1 due to disulfide bridges increased, suggesting that not only exposed but also buried protein sulfhydryl groups are converted to disulfide groups as a result of aging. The rate of the intensity decrease in the 2561 cm-1 band was similar to that in the 2579 cm-1 band. Therefore, it seems likely that the sulfhydryl groups in the two distinct environments are nearly equally subjected to the oxidation. Cysteine and cystine residues of the lens proteins gave their C-S stretching modes at 708 cm-1, indicating that they predominantly assume PC and/or PN conformers. The intensity ratio of a tyrosine doublet near 840 cm-1 (I832/I855) changed from approximately 0.86 to approximately 0.81 with the aging of the rat lens. This result implies that some tyrosine residues undergo a change in their hydrogen bonding environments during the course of aging. Of particular importance is that the relative intensity change of the tyrosine doublet with normal aging and that with cataract formation are in opposite directions.

Aging↗
PubMed1987

Effect of the enteroinsular axis on both the A- and B-cell response to arginine after oral glucose in man.

Studies were made on the effect of the enteroinsular axis on amino acid-induced insulin and glucagon secretion during hyperglycaemia in man. The responses of plasma immunoreactive insulin, C-peptide, and immunoreactive glucagon to arginine infusion were investigated in nine healthy subjects after induction of hyperglycaemia by an oral glucose load and by intravenous glucose infusion to produce similar glucose concentrations in the arterialised blood. The plasma immunoreactive insulin and C-peptide levels increased to higher levels after an oral glucose load than after an intravenous infusion of glucose. The incremental areas under the immunoreactive insulin and C-peptide curves during arginine infusion were significantly greater (p less than 0.01) after oral than after intravenous glucose administration. The plasma immunoreactive glucagon level was suppressed equally after oral and intravenous glucose loads. However, during subsequent arginine infusion, the plasma immunoreactive glucagon level rose more in the presence of hyperglycaemia induced by oral than intravenous glucose. The incremental area under the plasma immunoreactive glucagon curve during arginine infusion was 1.6-fold greater after glucose ingestion than after intravenous glucose infusion. These results suggest that the enteroinsular axis has a stimulatory effect on the responses of pancreatic A and B cells to arginine after oral glucose administration.

Administration, Oral↗