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Biomedical subjects

I Yano

Publications and source records attributed to I Yano.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Bactericidal effect of chlorine on strains of Legionella species].

We have previously reported that the hot water of 17 (42.5%) out of 40 thermal baths were contaminated with legionellae. Our recent investigation revealed that legionellae inhabited 39 (66.1%) of the 59 thermal bath water, and their viable counts were at the level of 10(4) CFU/100 ml in 5 baths and 10(5) CFU/100 ml in another 5. Accordingly, the bactericidal effects of free chlorine on 102 strains of 22 Legionella species were tested, in order to find a method of controlling legionellae in thermal bath water. The test strains were the type strains of 22 species, 35 strains of 4 species from patients with Legionella pneumonia in Japan, and 45 strains of 4 species from thermal bath water. Viable cells of all 102 strains suspended at the concentration of 10(5) CFU/100 ml in sodium hypochloride solution with 0.4 mg/l free chlorine became undetectable within 15 min.

Balneology↗
PubMed1994

Separation and partial characterization of soluble fatty acid alpha-hydroxylase from Sphingomonas paucimobilus.

The crude extracts from Sphingomonas paucimobilus containing 2-hydroxy fatty acid-rich sphingolipids were found to oxidize [1-14C]-myristate to 2-hydroxymyristate in the presence of NADH. The myristate-oxidation activity was partially purified about 290-fold from the cell-free extracts by ammonium sulfate fractionation and hydroxylapatite chromatography. When laurate, myristate, and palmitate were used as the substrates, the reaction products were identified as the corresponding 2-hydroxy fatty acids by gas-chromatography (GC), HPLC, and GC-mass spectrometry. The enzyme preparation required NADH and molecular oxygen for its alpha-hydroxylation activity, suggesting that the bacterial alpha-hydroxylation is typical of monooxygenase reactions. Of fatty acids tested, myristate was the most efficient substrate.

Bacteria↗
PubMed1994

Predictive performance of the Bayesian analysis: effects of blood sampling time, population parameters, and pharmacostatistical model.

The present paper reports theoretical equations for the predictive performance of the Bayesian forecasting method. The precision of parameter estimates and predicted concentrations for an individual was described by general equations with the aid of a variance-covariance matrix of parameter estimates that involved the Bayes theorem. The equations were applied to assess the predictive performance of the one-point Bayesian method in association with blood sampling time, the population parameters, and the pharmacostatistical model. The simulation study showed that the prediction error in parameter estimates essentially depended upon the sampling time but the magnitude of dependency was affected by the size of inter- and intraindividual variances. With a smaller value of interindividual variance, the dependency on sampling time was less apparent. Effects of sampling time were further examined using clinical data obtained from 20 patients taking theophylline, and the results were in good agreement with the theoretical consideration. The present general equations are useful to investigate the sampling strategy as well as structural and variance modeling on the predictive performance of the Bayesian method.

Adult↗
PubMed1993

Stimulation and inhibition of polymorphonuclear leukocytes phagocytosis by lipoamino acids isolated from Serratia marcescens.

The role of the lipoamino acids (serratamolide and ornithine lipid), membrane lipid components of Serratia marcescens, was examined in phagocytosis and phagosome-lysosome fusion of human peripheral polymorphonuclear leukocytes. A mutant strain of Serratia marcescens (NS 38-09) lacking serratamolide was actively phagocytosed by human PMN, while the wild-type strain (NS 38) producing serratamolide was more resistant to phagocytosis by human PMN. Phagocytosis of killed Staphylococcus aureus coated with lipoamino acid (serratamolide), showed that they were more resistant to phagocytosis by PMN, while the cells coated with ornithine lipid or serratamic acid were phagocytosed more actively. Staphylococci coated with phosphatidylethanolamine or phosphatidylglycerol had no significant effect on phagocytosis by PMN. Phagosome-lysosome fusion by PMN labelled with acridine orange was examined by fluorescence microscopy. The fusion indices of lipoamino acid-coated staphylococci were the same as that of controls. Further, ornithine lipid-coated staphylococci stimulated the release of superoxide anion from PMN slightly, but serratamolide did not. These results suggested that serratamolide may contribute to the virulence of S. marcescens in vitro.

Depsipeptides↗
PubMed1993

Survival of Pseudomonas pseudomallei strains at 5 degrees C.

The ability of 15 Pseudomonas pseudomallei strains of different origin to survive at 5 degrees C was tested, in comparison with the type strains of Pseudomonas aeruginosa and Pseudomonas cepacia. Viable cells of each strain were suspended in tryptic soy broth (diluted 1:10) at a concentration of about 10(6) CFU/ml. The suspensions were kept at 5 degrees C, and the number of viable cells was determined by counting colonies every 10 days. Four strains of P. pseudomallei, including the type strain for the species, died within 90-100 days at 5 degrees C. Ten other P. pseudomallei strains together with the type strain of P. cepacia survived 160 days or more, although viable counts of these strains decreased to 10(1-2) CFU/ml. The Oklahoma strain of P. pseudomallei and the type strain of P. aeruginosa maintained 10(5) CFU/ml after 170-190 days. It was concluded that resistance of P. pseudomallei to low temperature differs from strain to strain. From the results of our experiments and those reported in the literature of nation-wide soil contamination by P. pseudomallei in France, prejudice regarding the organism as a tropical inhabitant must be corrected.

Burkholderia cepacia↗
PubMed1993

Population pharmacokinetics of theophylline. II: Intravenous infusion to patients with stable chronic airway obstruction.

The population pharmacokinetics of theophylline were studied in 55 patients with stable chronic airway obstruction. Two hundred and seventy six theophylline serum concentrations after intravenous short infusion were analyzed using a nonlinear mixed-effect model. The influence of hepatic dysfunction, smoking habit, age and the measurement of arterial blood gases (oxygen tension: PaO2, carbon dioxide tension: PaCO2, blood pH) and clinical laboratory tests (serum albumin concentration, haematocrit) on the pharmacokinetic parameters of theophylline was examined by the likelihood ratio test. Assessment of each factor was made by a forward selection method. In the final regression model, the total body clearance (CL, l/h/kg) was related to the value of PaCO2 as well as to the presence of hepatic dysfunction, and the volume of distribution (Vd, l/kg) was related with the PaCO2 value as expressed in the following equations: CL = exp(-3.78 - 0.525.HF + 0.0233.PaCO2) and Vd = exp(-1.12 + 0.00934.PaCO2), where HF is a categorical variable with a value of unity if a patient has hepatic dysfunction otherwise zero. The interactions among blood gas measurements were observed and the CL and Vd of theophylline would be inversely correlated with PaO2 or pH, if we selected PaO2 or blood pH to be a more important factor than PaCO2. The inter-individual variabilities in CL and Vd were 38.5% and 12.5%, respectively, and the residual variability in theophylline serum concentrations was 10.6% as a coefficient of variation. This final model and the population parameters of theophylline will be useful for individualization of a drug dosage regimen by means of the Bayesian method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Population pharmacokinetics of theophylline. I: Intravenous infusion to children in the acute episode of asthma.

The population pharmacokinetics of theophylline during constant-rate intravenous infusion has been studied in 66 children (8.7 +/- 4.7 year of age; 26.0 +/- 12.8 kg, mean +/- S.D.) with an episode of acute asthma. One hundred and twelve theophylline serum concentrations (13.9 +/- 4.8 micrograms/ml) collected retrospectively were analyzed using a nonlinear mixed-effect model. The influence of hepatic dysfunction, age, gender, days after admission, blood gas measurements (PaO2, PaCO2, blood pH) and clinical analyses data (total serum protein, albumin concentration, haemoglobin concentration, haematocrit) on theophylline clearance was examined by the likelihood ratio test. A final estimate of population mean clearance was 58.6 ml/kg/h, which was decreased by 36% in patients with hepatic dysfunction. Other factors tested displayed no statistically significant effect on theophylline clearance. The inter-individual variability in clearance was 26% while the intra-individual variability in theophylline concentrations was 2.6 micrograms/ml as a standard deviation, which was almost double that observed for stable patients. Taking into account that the therapeutic window of this drug is 10-20 micrograms/ml, this value indicates a relatively large intra-individual variability and suggests that frequent (daily) monitoring of serum concentrations is necessary for patients with an episode of acute asthma.

Acute Disease↗
PubMed1993

Effect of okadaic acid on leukocyte movement.

The effect of Okadaic acid (OA), a potent inhibitor of intracellular phosphatases, on neutrophil movement was studied. 1) Random movement was suppressed by OA at a concentration of 200 ng/ml. 2) Chemotaxis was suppressed by OA at concentrations between 50 and 100 ng/ml and completely suppressed at concentrations above 200 ng/ml. 3) Phagocytosis (latex particles) was suppressed by OA at concentrations more than 100 ng/ml.

Adolescent↗
PubMed1992

Hemolysis of phosphatidylcholine-containing erythrocytes by serratamic acid from Serratia marcescens.

1. The hemolysis by serratamic acid, "N-(D-3-hydroxydecanoyl)-L-serine and N-(D-3-hydroxydodecanoyl)-L-serine", was investigated with human and animal erythrocytes using serratamic acid-containing liposomes. 2. The hemolytic activity was found to depend on the incubation temperature and the concentration of the liposomes. 3. The concentration of serratamic acid for 50% hemolysis was 0.17 mM at 37 degrees C for 0.2% human erythrocyte suspension in the liposomes which composed of phosphatidylserine, cholesteryl nervonate and serratamic acid (1:0.50:0.37 by mol). 4. The hemolysis was shown specifically in human, horse and rabbit erythrocytes containing phosphatidylcholine, but not in sheep or bovine erythrocytes lacking phosphatidylcholine. 5. The hemolytic activity was strongly inhibited by the exogenous addition of phosphatidylcholine. It was suggested that the hemolysis by serratamic acid-containing liposomes was specific for phosphatidylcholine-containing erythrocyte membranes.

Animals↗
PubMed1992

Necrobiotic xanthogranuloma in a human T-lymphotropic virus type 1 carrier.

A 67-year-old man who had necrobiotic xanthogranuloma associated with paraproteinemia is described. He was a human T-lymphotropic virus type 1 (HTLV-1) carrier who had a high titer of circulating anti-HTLV-1 antibodies and neurologic abnormalities that suggested HTLV-1-associated myelopathy. The patient's necrobiotic xanthogranuloma and neurologic symptoms improved after he received four 5-day courses of melphalan, 2 mg/day, and prednisolone, 20 mg/day, at 4-week intervals.

Aged↗
PubMed1992

Identification of Oklahoma isolate as a strain of Pseudomonas pseudomallei.

Based on the morphological, physiological, biochemical and nutritional characteristics, cellular fatty acid and lipid composition, ubiquinone-8 as the major respiratory quinone, guanine-plus-cytosine content of DNA, DNA-DNA homology value, and sequence alignment of 16S rRNA nucleotides, Oklahoma isolate was reidentified as a strain of Pseudomonas pseudomallei.

Anti-Bacterial Agents↗
PubMed1992

Proposal of Burkholderia gen. nov. and transfer of seven species of the genus Pseudomonas homology group II to the new genus, with the type species Burkholderia cepacia (Palleroni and Holmes 1981) comb. nov.

Based on the 16S rRNA sequences, DNA-DNA homology values, cellular lipid and fatty acid composition, and phenotypic characteristics, a new genus Burkholderia is proposed for the RNA homology group II of genus Pseudomonas. Seven species in this group were transferred to the new genus. Thus seven new combinations, Burkholderia cepacia (Palleroni and Holmes 1981), Burkholderia mallei (Zopf 1885), Burkholderia pseudomallei (Whitmore 1913), Burkholderia caryophylli (Burkholder 1942), Burkholderia gladioli (Severini 1913), Burkholderia pickettii (Ralston et al 1973) and Burkholderia solanacearum (Smith 1896) were proposed.

Amino Acids↗
PubMed1992

A novel extracellular cyclic lipopeptide which promotes flagellum-dependent and -independent spreading growth of Serratia marcescens.

Serrawettin W2, a surface-active exolipid produced by nonpigmented Serratia marcescens NS 25, was examined for its chemical structure and physiological functions. The chemical structure was determined by degradation analyses, infrared spectroscopy, mass spectrometry, and proton magnetic resonance spectroscopy. Serrawettin W2 was shown to be a novel cyclodepsipeptide containing a fatty acid (3-hydroxydecanoic acid) and five amino acids. The peptide was proposed to be D-leucine (N-bonded to the carboxylate of the fatty acid)-L-serine-L-threonine-D-phenylalanine-L-isoleucine (bonded to the 3-hydroxyl group). By examining the effects of isolated serrawettin W2 on serrawettinless mutants, this lipopeptide was shown to be active in the promotion of flagellum-independent spreading growth of the bacteria on a hard agar surface. The parent strain NS 25 formed a giant colony with a self-similar characteristic after incubation for a relatively long time (1 to 2 weeks), similar to other fractal colony-producing strains of S. marcescens (producers of the different serrawettins W1 and W3). On a semisolid medium that permitted flagellum-dependent spreading growth, an external supply of serrawettin W2 accelerated surface translocation of a serrawettinless mutant during a short period (12 h) of observation. In contrast, bacterial translocation in the subsurface space of the semisolid agar was not enhanced by serrawettins. Thus, the extracellular lipids seem to contribute specifically to the surface translocation of the bacteria by exhibiting surfactant activity.

Amino Acid Sequence↗
PubMed1992

Effect of leukotriene C4 on theophylline disposition in guinea pigs.

The pharmacokinetics of theophylline in acutely ill patients show wide intraindividual variability associated with the severity of clinical status. To investigate the mechanism of this variability, we studied the effects of leukotriene C4 (LTC4)-induced pathophysiologic changes on the disposition of theophylline. The plasma concentration-time profiles were measured after simultaneous intravenous bolus injection of theophylline and antipyrine in guinea pigs. The animals received 5 micrograms/kg of LTC4 intravenously 60 min later. The plasma theophylline concentration 30 min after LTC4 treatment was significantly lower (p less than 0.05) than that of nontreated control animals, whereas the plasma antipyrine concentration at that time was not affected. In addition, the treated animals showed significantly slower declines in plasma concentrations of both drugs (0.0805 +/- 0.0199 and 0.291 +/- 0.020 h-1 for theophylline and antipyrine, respectively, mean +/- SEM) than did controls (0.197 +/- 0.010 and 0.439 +/- 0.028 h-1). Leukotriene C4 treatment also induced moderate bronchoconstriction and metabolic acidosis, increased blood hemoglobin concentration and hematocrit, and decreased concentration of serum proteins. In connection with these changes, the plasma unbound fraction of theophylline increased significantly (p less than 0.001, 94.4 +/- 3.3% in treatment versus 58.2 +/- 4.4% in control), but that of antipyrine was unchanged (94.9 +/- 3.0% in treatment versus 92.1 +/- 0.9% in control). These findings indicated that an increase in the volume of distribution was responsible for the abrupt change in plasma theophylline concentration following LTC4 treatment, and the apparent change in the volume of distribution was estimated as 26.1 +/- 5.6%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminophylline↗
PubMed1992

[Benign familial neonatal convulsions in a family with one member with infantile spasms].

A pedigree of benign familial neonatal convulsions (BFNC) was reported. Seven members of two generations experienced convulsions in the neonatal period and/or in early infancy. All of these members except one had a good prognosis. One member who had infantile spasms was uneventfully delivered at 37 weeks of gestation, with a birth weight of 2,562 g and, without trouble during pregnancy. At the age of 20 days, she began to have adversive seizures. Later, she developed complex partial seizures and infantile spasms at 1 month and 10 days of age. Interictal EEG showed hypsarrhythmia. Biochemical investigations and MRI of the head revealed no abnormality. Treatment with sodium valproate and carbamazepine succeeded in stopping the seizures and she had no seizures after 3 months. But her psychomotor development was moderately delayed at 8 months. No case with severe epilepsy such as infantile spasms has been reported in the previous literature on BFNC. From our experience, early treatment and careful follow-up are considered to be important for BFNC.

Child↗
PubMed1991

Mycolic acid-containing glycolipid as a possible virulence factor of Rhodococcus equi for mice.

By the use of various Rhodococcus equi strains differing in the length of carbon chains of glycolipid, we examined whether the glycolipid, glucose monomycolate, was contributing to the virulence of R. equi for mice. R. equi strains with longer carbon chain mycolic acid showed a higher virulence as determined by lethality and granuloma formation in mice than those with shorter ones. When purified glycolipid was injected into mice, granuloma formation and liver damage were most prominent with the glycolipid having longer carbon chain mycolic acid. Only a representative strain with longer carbon chain mycolic acid persisted in the spleen of mice after intravenous injection, while a strain with shorter carbon chain mycolic acid was readily eliminated. These results suggested that glycolipid was at least one of the virulence factors of R. equi and that the carbon chain length of mycolic acid might be critical in the expression of virulence.

Actinomycetales Infections↗
PubMed1991

Rapid serodiagnosis of human mycobacteriosis by ELISA using cord factor (trehalose-6,6'-dimycolate) purified from Mycobacterium tuberculosis as antigen.

IgG antibodies against purified cord factor (trehalose-6,6'-dimycolate, TDM) in sera of 99 patients infected with mycobacteria (42 patients with tuberculosis excreting tubercle bacilli in the sputum, 11 patients with non-tuberculous mycobacteriosis excreting acid-fast bacilli in the sputum, and 46 patients without bacilli in the sputum but diagnosed as having pulmonary tuberculosis by chest X-ray films and physical examination), five patients with lung cancer, and 100 healthy controls which included subjects positive and negative for the tuberculin test were tested by the ELISA with TDM purified from Mycobacterium tuberculosis H37Rv as the antigen. Of the 99 cases of mycobacteriosis, 83 patients (83.8%) had positive results (48 samples from 53 patients, or 90.5%, with bacilli in the sputum, and 35 samples from 46 patients (76%) with tuberculosis diagnosed clinically). The sera of the five patients with lung cancer and the 100 controls all gave negative results. Thus, the sensitivity and specificity were 83.8% and 100%, respectively. ELISA with TDM as the antigen is simple, reproducible, and useful for the rapid serodiagnosis of general mycobacterial infections including tuberculosis, because it does not involve the cultivation of bacteria.

Adult↗