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Biomedical subjects

Y Mizuguchi

Publications and source records attributed to Y Mizuguchi.

At least 91 records · Page 5Linked to original sources
PubMed1984

Gonorrhoea caused by a mixture of penicillinase-positive and -negative gonococci: a case report.

A 23-year-old unmarried man was infected with gonorrhoea from a prostitute in Fukuoka City and was treated with ampicillin which resulted in failure. By a rapid iodometric test it was found that the isolates before the treatment were penicillinase-negative. After the ampicillin treatment, however, the isolates turned to penicillinase-positive but were, in fact, a mixture of penicillinase-positive and penicillinase-negative gonococcal strains. Treatment by spectinomycin and doxycycline resulted in failure but the gonorrhoea was cured by ribostamycin.

Adult↗
PubMed1984

Petite induction in Saccharomyces cerevisiae by ethidium analogs. Action on mitochondrial genome.

Petite induction of ethidium analogs was examined in both resting and growing yeast cells. All of the analogs used in these experiments were active in dividing cells of Saccharomyces cerevisiae; only the parent ethidium bromide was mutagenic under resting conditions. Incorporation of adenine into mitochondrial DNA appeared to be prevented completely by ethidium and partially inhibited by other analogs. Treatment of growing cells with analogs affected fragmentation of pre-existing DNA as seen by the loss of a mitochondrial antibiotic resistance marker. The rates of elimination of the marker were different; ethidium generated greater loss than the monoamino analogs (3-amino and 8-amino-); and the deaminated analog was least effective. However, in resting yeast the marker was partially eliminated only with treatment of the parent ethidium. The degradation of the mitochondrial DNA by exposure to ethidium compounds was confirmed by agarose gel electrophoresis. Electrophoretic patterns of the mitochondrial DNA treated with each of the analogs under growing conditions and only with ethidium under resting conditions showed degradation of the mitochondrial DNA.

Cell Cycle↗
PubMed1984

Antibiotic susceptibility of Legionella pneumophia Philadelphia-1 in cultured guinea-pig peritoneal macrophages.

The effect of antimicrobial agents on the intracellular multiplication of Legionella pneumophila in cultured guinea-pig peritoneal macrophages was measured. Beta-lactam antibiotics at concentrations 5 to 400 times the MIC in vitro did not inhibit the intracellular growth of the organism. Gentamicin inhibited the growth considerably but failed to eliminate the organism from the phagocytic mixture. Chloramphenicol or tetracycline at 10 micrograms ml-1 (40 or 5 times the MIC in vitro respectively) did not eliminate the organism. At a higher concentration (30 micrograms ml-1), however, these drugs eliminated the bacterium from the mixture. Only erythromycin and rifampin were effective in killing the organism at very low concentration (1 microgram ml-1). Intracellular multiplication of L. pneumophila was observed clearly by light microscopy using Wright-Giemsa staining.

Animals↗
PubMed1984

Isolation and characterization of a filamentous phage, Vf33, specific for Vibrio parahaemolyticus.

Phage Vf33, a filamentous phage about 1,400 nm long and 7 nm wide, specific for Vibrio parahaemolyticus, was isolated and characterized. The buoyant density of Vf33 in CsCl was 1.292 g/cm3. As with other filamentous phages, the lytic activity of Vf33 was resistant to heating below 80 C and to treatment with diethylether, acetone or methanol but sensitive to chloroform. The nucleic acid of this phage is single-stranded circular DNA 8.4 kb in size. The viral genome was converted to a double-stranded replicative form in the host-cell. Among the strains tested, only V. parahaemolyticus strains possessing K38 antigen was sensitive to the phage.

Bacteriophages↗
PubMed1983

[Structure-function characterization of phenanthridinium compounds as mutagens in salmonella and yeast].

The relation between the mutagenic activities and chemical structure of phenanthridinium derivatives were tested by using Salmonella typhimurium strain TA 98 and yeast Saccharomyces cerevisiae. The 3,8-diamino analog and amino-azido isomers caused frameshift type mutation in Salmonella. However, mutagenicity was severely reduced for the diazido analog, and mutagenic activities of monoamino and monoazido analogs were minimal. The deaminated analog was not mutagenic. Diamino analog and two amino-azido isomers induced mitochondrial mutation of yeast in both resting and growing conditions. Two monoamino and deaminated analogs were mutagenic only in growing yeast but not in resting cells. Two monoazido and diazido analogs were less mutagenic even in the growing conditions.

Mitochondria↗
PubMed1983

[Fatal Vibrio vulnificus infection in a patient with aplastic anemia].

The patient was a 59-year-old man who had been in hospital suffering from aplastic anemia with transfusion hemosiderosis. Sudden onset of weakness, shaking chills and headache was observed after his staying out overnight on July 25, 1981. His temperature was 39.3 degrees C and he complained of abdominal pain and abdominal distension. His blood pressure dropped to a dangerous level and tonic convulsions that had begun in the upper body gradually extended to the whole body and he died 23 hours after his return. V. vulnificus was isolated by the blood culture performed before death. During his stay away from the hospital, he had eaten raw cuttlefish, which was considered to be the source of infection. V. vulnificus is one of the halophilic marine vibrios and is isolated frequently in summertime from the sea foods and sea water near Japan. It has been disclosed that the presence of underlying diseases such as liver cirrhosis, hemochromatosis can predispose a person to fatal sepsis by V. vulnificus. In this case, besides leukocytopenia, the presence of hemosiderosis induced by many transfusions was considered to be a major cause leading to the fulminating course of the disease.

Anemia, Aplastic↗
PubMed1983

Electron microscopic observations of cell division in Mycobacterium vaccae V1.

Cell division of Mycobacterium vaccae was initiated by deposition of new wall material in the cross wall. The surface layers of the old wall remained continuous until septum formation was complete. Subsequently, rupture of the outer cell wall layers occurred circumferentially, leaving rings on the cell wall. The two daughter cells remained connected with each other at the new pole and bent to form V-shaped structures at the connecting point.

Cell Division↗
PubMed1983

Mechanism of antibiotic resistance in Mycobacterium intracellulare.

The mechanism of resistance of Mycobacterium intracellulare strain 103 and other clinical isolates to a variety of drugs including aminoglycoside and peptide antibiotics was investigated. Enzymatic inactivation of aminoglycoside and peptide antibiotics could not be demonstrated. Ribosomes of the strain were found to be sensitive to the antibiotics. The levels of resistance of strain 103 and other clinical isolates decreased dramatically when the culture medium was changed from Dubos agar to Tween 80-containing agar. These results suggest that a permeability barrier is the reason for naturally occurring resistance in M. intracellulare.

Aminoglycosides↗
PubMed1983

Epidemiology and treatment of gonorrhoea caused by penicillinase-producing strains of Neisseria gonorrhoeae in Fukuoka, Japan.

Thirty strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) were detected by a rapid iodometric method out of 206 strains isolated from patients with gonorrhoea between January and December 1981. Of the 30 patients, five of the nine women were prostitutes and 14 of the 21 men were infected by prostitutes in or around Fukuoka City, with the exception of one who was infected in Formosa. Treatment with ampicillin or amoxycillin resulted in failure whereas treatment with spectinomycin was successful.

Adolescent↗
PubMed1983

An improved method for the preparation of mycobacterial spheroplasts and the mechanism involved in the reversion to bacillary form: electron microscopic and physiological study.

An efficient method is described for preparing spheroplasts and protoplasts by treating bacillary cells of Mycobacterium smegmatis with precise concentrations of L-glycine (followed by lysozyme). This improved procedure was widely applicable to many rapidly growing mycobacteria by selecting the concentrations of glycine suitable for the individual strains used. The process of reversion of spheroplasts to original bacillary form on solid and in liquid media, as revealed by electron microscopy, appeared to involve the formation of an internal elementary or initial body with subsequent budding from the spheroplast. The internal membrane systems appeared to function in the induction of initial bodies and in the maturation of elementary bodies to become dividing forms. Possible mechanisms involved in the development of bacilli from spheroplasts are discussed.

Bacteriological Techniques↗
PubMed1982

Spheroplast formation of Mycobacterium smegmatis and morphological aspects of their reversion to the bacillary form.

Cell wall-deficient forms (spheroplasts) of Mycobacterium smegmatis strain P53 were prepared by combined treatment with glycine, lysozyme, and lytic enzyme no. 2 as the spheroplasting agents. Quantitative mass conversion to spherical forms was effected by pretreatment of the intact cells with 1.2% glycine in nutrient broth, followed by transfer to spheroplasting medium containing the above agents. Two apparent modes of reversion to the bacillary form were observed under electron microscopy. The first one was initiated by budding from the spheroplasts. The buds gradually elongated to become the mycelial form, which showed branching, septation, and fragmentation. The second resulted from the intracellular formation of tiny cells, possibly the elementary bodies, and their release from the spheroplasts.

Cell Membrane↗
PubMed1982

Antibiotic sensitivity patterns of penicillinase-positive and penicillinase-negative strains of Neisseria gonorrhoeae isolated in Fukuoka, Japan.

Penicillinase production and minimum inhibitory concentrations (MICs) of penicillin G, amoxycillin, doxycycline, and spectinomycin were studied for 155 gonococcal strains isolated in Fukuoka, Japan, between April and December 1981. Of 155 isolates, 25 (16.1%) strains were identified as penicillinase-producing Neisseria gonorrhoeae (PPNG) by a rapid iodometric test. The antibiotic sensitivity of 130 penicillinase-negative (non-PPNG) and 25 PPNG strains was compared. The mean MIC of penicillin G for non-PPNG strains was 0.65 microgram/ml. Twenty-five PPNG strains had MICs of penicillin G between 6.25 and greater than 100 micrograms/ml. The susceptibility to amoxycillin and doxycycline of PPNG strains was significantly lower than that of non-PPNG strains. All the strains proved to be sensitive to spectinomycin. The MICs of four antibiotics for non-PPNG strains were significantly correlated.

Amoxicillin↗
PubMed1981

Plasmid deoxyribonucleic acid and translucent-to-opaque variation in Mycobacterium intracellulare 103.

After treatment with mitomycin D and other antibacterial agents, a translucent, smooth-colony-forming mycobacterium, isolated from sputum and designated as Mycobacterium intracellulare strain 103, gave rise to variants forming opaque colonies. These opaque variants were more sensitive streptomycin, kanamycin, viomycin, and rifampin than were the wild-type translucent variants. Plasmid deoxyribonucleic acids taken from translucent strain cells and from cells of certain opaque variants were analyzed by agarose gel electrophoresis. Two plasmids of molecular weights of approximately 2 x 10(6) and 50 x 10(6), respectively, were found in the wild-type translucent cells; one of them, the 2 x 10(6)-molecular-weight plasmid, was always missing from deoxyribonucleic acids of the opaque variant cells. The results suggested that translucent colonial appearance and antibiotic resistance of the strain are plasmid-determined functions.

Anti-Bacterial Agents↗