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Biomedical subjects

M Ogata

Publications and source records attributed to M Ogata.

At least 505 records · Page 28Linked to original sources
PubMed1982

In vitro susceptibility of varicella-zoster virus to E-5-(2-bromovinyl)-2'-deoxyuridine and related compounds.

The in vitro susceptibility of eight strains of varicella-zoster virus (VZV) to E-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) was examined in human embryonic fibroblasts by the following techniques: inhibition of focus formation by either cell-free VZV (4-day assay) or cell-associated VZV (2-day assay), inhibition of viral antigen formation (2-day assay), and inhibition of viral cytopathogenicity (15-day assay). The 50% inhibitory dose (ID50) of BVDU ranged from 0.001 microgram/ml (2-day assay) to 0.01 microgram/ml (15-day assay). BVDU appeared highly selective in its anti-VZV activity since even at concentrations as high as 100 micrograms/ml, BVDU did not markedly affect the viability of the host cells. The ID50 of BVDU for VZV was comparable to that of IVDU (E-5-(2-iodovinyl)-2'-deoxyuridine). Both drugs inhibited the replication of VZV at a much lower concentration than did other antiviral compounds such as iododeoxyuridine, ethyldeoxyuridine, arabinosylcytosine, arabinosyladenine, phosphonoacetic acid, iododeoxycytidine, and acycloguanosine. BVDU and IVDU were virtually inactive against a thymidine kinase-deficient VZV mutant, suggesting that phosphorylation by the viral enzyme is responsible, at least in part, for the selective anti-VZV activity of the compounds.

Antiviral Agents↗
PubMed1982

[Effects of physical loads on the urinary excretion of metabolites from organic solvents. Part I. Change in the urinary excretion of glycine conjugate, hippuric acids, and glycine after a physical burden].

Effects of physical loads on the excretion of urinary glycine conjugates, which are commonly used as an index of organic solvent intake, were examined. After physical exertion by Kendo exercise university students for about 2 hours, urinary protein excretion changed from the levels of (-) or (+) before the exercise to (+) to (formula: see text) after the exercise revealed by the test-tape semi-quantitative indication, and the levels of urinary creatinine increased to approximately 1.9 time and initial level. Under the present experimental conditions, the following results were obtained. 1) Statistically no significant change was observed in the levels of urinary hippuric acid, but an increasing trend was recognized. 2) The glycine levels in the urine decreased and the significance was stressed when the values were adjusted with reference to the specific gravity of urine or to the levels of urinary creatinine. 3) The ratio of hippuric acid to the glycine in the urine increased almost twice as high as the initial ratio and the physical load seemed to promote the glycine conjugation. 4) As to the adjusted levels of urinary metabolites, especially due to several organic solvents, values adjusted with reference to the specific gravity of urine and those to the levels of urinary creatinine correlated well in the samples collected before the exertion. But a poor correlation was observed in the samples collected after the exertion. Therefore, a notice should be given when the adjustment of the values with reference to the levels of urinary creatinine, which is widely used in the health administration practice for organic solvent workers to assess the levels of exposure, since the adjusted values were lowered unnecessarily by excess excretion of creatinine after the physical exertion and the tendency would be exaggerated especially under the low level exposure to organic solvent vapours in the work yard.

Glycine↗
PubMed1982

Discriminant analysis of pulmonary function parameters. Healthy adults versus mild asthmatics and moderate asthmatics.

Volume-time (V-T) and flow-volume (F-V) curves were measured in all the subjects of nonsmoking young males (mean value 26.3 yrs. of age), healthy and asthmatics. Eleven parameters of pulmonary function tests composed of two V-T, six F-V, and three mean time constant (MTC) parameters, were calculated from the curves. These parameters were used in the two analyses through the all possible selection procedure (APSP) discriminating between healthy adults and mild asthmatics and also between healthy and moderate. Flow rate at 75% of FVC (V75) proved to be the most useful parameter and V50 the next best in both analyses. The probability of misclassification using all eleven parameters was 19.64% in the analysis of healthy adults and mild asthmatics, and 4.29% in the analysis of healthy adults and moderate asthmatics. There was a little difference in the parameters selected at every step. The discriminant analysis proved that the flow-volume patterns were different according to the severity of bronchial asthma. Thus flow-volume recognition was considered to be important in analyzing the severity of bronchial asthma.

Adult↗
PubMed1982

Methemoglobin formation by paraquat.

Paraquat is a broad spectrum herbicide known to be highly lethal to man and animals. Its toxicity is characterized by acute lung injury. Paraquat produces such toxic effects through the generation of the superoxide anion according to one proposed mechanism. The present experiment, methemoglobin formation was demonstrated after incubation of oxyhemoglobin with paraquat. The generation of the superoxide anion through the interaction of oxyhemoglobin with paraquat was suggested by chemiluminescence of luminol. Superoxide dismutase (SOD) and catalare inhibited methemoglobin formation. The generation of the superoxide anion is discussed in regard to methemoglobin formation by paraquat.

Chromatography, Ion Exchange↗
PubMed1982

Differences in urinary monochlorobenzene metabolites between rats and humans.

Differences in urinary excretion of monochlorobenzene between rats and humans were studied. Monochlorobenzene was administered to rats and humans intraperitoneally, orally or by inhalation. Urinary p-chlorophenylmercapturic acid and 4-chlorocatechol, after hydrolysis of its conjugate, were measured. The excretion of p-chlorophenylmercapturic acid was somewhat more than that of 4-chlorocatechol in rats which were administered monochlorobenzene orally or intraperitoneally. The excretion of p-chlorophenylmercapturic acid was markedly less than that of 4-chlorocatechol in humans who received monochlorobenzene orally or by inhalation. The results indicate that the 4-chlorocatechol conjugate is a suitable index of metabolites in the urine of workers exposed to monochlorobenzene.

Animals↗
PubMed1982

Discriminant analysis of volume-time and flow-volume parameters between healthy adults and asthmatic patients.

Volume-time (V-T) and flow-volume (F-V) curves were measured in all the subjects of nonsmoking young males (mean value 26.3 yrs.), healthy and asthmatic. Eleven parameters of pulmonary function tests, which were composed of two V-T, six F-V, and three mean time constants (MTC) parameters, were calculated from the curves. These were used in the discriminant analysis through all possible selection procedures (APSP) to make clear the importance of the F-V recognition. In using only one parameter, V75, which was one of the F-V parameters, showed the lowest probability of misclassification, 18.78%, and was the most useful parameter to discriminate the two groups. The probability of misclassification of the eleven parameters showed 15.46%, and that of the six F-V ones showed 17.45%. Though the probability of the six F-V ones was higher than that of the eleven ones, it was lower than that of the twoV-T or of the three MTC ones. Therefore the six F-V parameters including V75 was sufficient to discriminate the two groups of subjects. Thus it was made clear that the flow-volume recognition was important by the discriminant analysis.

Adult↗
PubMed1982

Immunological properties of erythrocyte catalase in Japanese type acatalasemia.

The reaction between acatalasemia hemolysate and anti-normal erythrocyte catalase IgG gave a precipitin line which was interrupted by a normal precipitin line, in the double immunodiffusion method. Hypocatalasemia hemolysate revealed two precipitin lines, one completely, the other partially, fused with a normal precipitin line. No immunological reactions between fresh hemolysates of acatalasemia, hypocatalasemia and normal erythrocytes and antihuman C-reactive protein serum were observed, but the lysates stored for 4 weeks in an ice cold water bath reacted slightly with this antiserum.

Catalase↗
PubMed1982

Properties of catalase subfractions separated by chromatofocusing of acatalasemia hemolysates.

Erythrocyte catalase in normal and Japanese type acatalasemia hemolysates was separated by chromatofocusing into several fractions in the pH range of 6.1 to 5.7. Normal hemolysate gave a major peak of catalase activity with a pH of 6.1 to 5.5, while acatalasemia hemolysate gave several small peaks in this pH range and a main peak with a pH of 6.6 to 6.2. The main protein band in catalase active fractions separated from normal erythrocytes had a molecular weight of 60,000 by SDS polyacrylamide gel electrophoresis. A similar faint protein band having a molecular weight of 60,000 was also found in acatalasemia hemolysate in addition to a fairly intense band with a molecular weight of about 30,000. Catalase active fractions from normal erythrocytes reacted with antihuman erythrocyte catalase rabbit serum by double immunodiffusion.

Acatalasia↗
PubMed1982

The effects of echinatin and its related compounds on the mitochondrial energy transfer reaction.

To investigate the mechanism by which various biological action of licorice root are brought about, the effects of echinatin as a small constituent of Glycyrrhiza echinata and several related compounds on mitochondrial energy transfer reactions were examined. The results obtained were as follows: 1) Echinatin, 4'-hydroxychalcone, chalcone and 3,4'-dihydroxychalcone at a low concentration cause deterioration of respiratory control and oxidative phosphorylation of isolated rat liver mitochondria. 2) Chalcone and 4'-hydroxychalcone stimulate both latent and DNP-ATPase activity of mitochondria. Echinatin inhibits DNP-ATPase activity while stimulating range latent ATPase activity in the low concentration. 3) Chalcone and 4'-hydroxychalcone induce a rapid potassium release from mitochondrial vesicles, while echinatin and 3,4'-dihydroxychalcone have lesser effect than the former two substances. From these results, it can be concluded that echinatin and several related compounds disturb the mitochondrial energy transfer reactions and membrane permeability.

Adenosine Triphosphatases↗