Variational Monte Carlo study of generalized flux phases in the t-J model.
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Journal Article↗
Biomedical subjects
M Ogata
Publications and source records attributed to M Ogata.
Acatalasemia.
The abnormalities in acatalasemia at the gene level as well as properties of the residual catalase in Japanese acatalasemia are historically reviewed. The replacement of the fifth nucleic acid, guanine, in the fourth intron by adenine in the acatalasemic gene causes a splicing mutation and hence a deficiency of mRNA. The guanine-to-adenine substitution was detected in two Japanese acatalasemic cases from different families. The properties of the residual catalase are similar to those of normal catalase; the exons are identical. The properties of the residual catalase and the molecular defect in the catalase gene are compared among Japanese, Swiss, and mouse acatalasemias. The physiological role of catalase, as judged from human acatalasemic blood and acatalasemic mice, is also described.
Animals↗
Quantitation of urinary chlorobenzene metabolites by HPLC: concentrations of 4-chlorocatechol and chlorophenols in urine and of chlorobenzene in biological specimens of subjects exposed to chlorobenzene.
A simple method for the determination of 4-chlorocatechol (ClCh, 4-chloro-1,2-benzenediol) and chlorophenols (ClPh), metabolites of monochlorobenzene (ClBz), in urine by high performance liquid chromatography (HPLC) is described. Enzymatic hydrolysates of urine were applied to a stainless-steel column packed with octadecyl-silanized silica gel, and a mixed solution of 20 mM potassium phosphate monobasic: acetonitryl (75:25, v/v) was used as a mobile phase. The procedures for ether extraction and evaporation of extract could be omitted. The accuracy and precision of the present HPLC method were satisfactory. The excretion kinetics of ClCh and p-ClPh were investigated over 35 h after cessation of ClBz inhalation. Proportional relationships between concentrations of ClBz in air and of its metabolites in urine were observed. The slopes of regression lines predicting the levels of ClCh, p-ClPh and total ClPh in urine taken during the last 2 h of exposure to ClBz in air were 6.56, 1.13 and 2.83 mg/g creatinine for 1 ppm ClBz, respectively. ClBz in the blood and the end exhaled air of subjects at the end of exposure were identified by gas chromatography (GC) and mass spectrometry. A proportional relationship was observed between the concentration of ClBz in air and that in blood. The validity of the threshold limit value (TLV) for ClBz as evaluated from the subjective and objective symptoms is discussed.
Adult↗
Urinary 2,5-hexanedione assay involving its conversion to 2,5-dimethylpyrrole.
High-performance liquid chromatography (HPLC), gas chromatography (GC) and spectrophotometry were used to examine 2,5-dimethylpyrrole, derived from 2,5-hexanedione in the acid-hydrolyzed urine of subjects exposed to n-hexane. The urine of a subject exposed to n-hexane was hydrolyzed with hydrochloric acid and then neutralized. Thereafter, 2,5-hexanedione in the hydrolysate was heated with ammonium carbonate to yield 2,5-dimethylpyrrole. A methanol extract of the 2,5-dimethylpyrrole formed was subjected to HPLC and an ethylacetate extract of it was subjected to GC, with a flame thermoionic detector (FTD). For spectrophotometry, the ethylacetate extract was allowed to react with Ehrlich's reagent and then the absorbance of the colored compound formed was read at 525 nm. Pyrrole condensation with ammonia is specific to 1,4-diketones and these three assay methods can be used for determination of 2,5-hexanedione in the urine of workers exposed to n-hexane. The hydrolytic conditions for urine of subjects exposed to n-hexane for analysis of 2,5-hexanedione were discussed.
Benzaldehydes↗
1H NMR studies on ferricytochrome c3 from Desulfovibrio vulgaris Miyazaki F and its interaction with ferredoxin I.
The 1H NMR signals of the heme methyl, propionate and related chemical groups of cytochrome c3 from Desulfovibrio vulgaris Miyazaki F (D.v. MF) were site-specifically assigned by means of 1D NOE, 2D DQFCOSY and 2D TOCSY spectra. They were consistent with the site-specific assignments of the hemes with the highest and second-lowest redox potentials reported by Fan et al. (Biochemistry, 29 (1990) 2257-2263). The site-specific heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val18. All the results contradicted the heme assignments for D.v. MF cytochrome c3 made on the basis of electron spin resonance (Gayda et al. (1987) FEBS Lett., 217 57-61). Based on these assignments, the interaction of cytochrome c3 with D.v. MF ferredoxin I was investigated by NMR. The major interaction site of cytochrome c3 was identified as the heme with the highest redox potential, which is surrounded by the highest density of positive charges. The stoichiometry and association constant were two cytochrome c3 molecules per monomer of ferredoxin I and 10(8) M-2 (at 53 mM ionic strength and 25 degrees C), respectively.
Binding Sites↗
Effects of chlordane on parameters of liver and muscle toxicity in man and experimental animals.
An attempt was made to compare the toxic effects of the organochlorine insecticide 'chlordane' in man and rats. Analysis of blood for chlordane metabolites showed their presence in the descending order of trans-nonachlor, oxychlordane, heptachlorepoxide and cis-nonachlor. The total range of chlordane and its metabolites in the sera of workers was 9.84 +/- 4.47 ng/g. Serum levels of triglycerides (TG), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activities were also found to be higher in pest-control operators. In a simultaneous study, rats were administered 100 mg/kg body wt. of chlordane by stomach tube once a day for 4 days, whereas 50 mg/kg body wt. of chlordane was injected intraperitoneally once a day for 4 days. The data show that total cholesterol and serum TG as well as CPK and LDH activities are increased after chlordane treatment. The isoenzyme patterns suggest that an increase in CPK and LDH is related to skeletal muscle. Furthermore, the hepatotoxicity of chlordane was also studied in rats only. A significant increase in liver weight, its water content, total lipids, triglycerides and phospholipids was recorded. Chlordane induced lipid peroxidation in the liver, exhibiting a dose-response relationship. Although no appreciable effect on mitochondrial function and latent ATPase activity was observed, 2,4-dinitrophenol-stimulated ATPase activity was inhibited. Histological examination of the liver confirmed fatty infiltration induced by chlordane in rats.
Adolescent↗
New "leap-frog" technique for autologous blood donation.
In order to obtain a sufficient volume of autologous blood for elective surgery, we used a Sterile Connection Device (SCD, DuPont, Mass. U.S.A.) and a liquid storage method that is called the leap-frog. From 300 to 2800 mL (mean 1158 mL) of blood were collected from 126 patients during an average of six donations over 14-125 days (mean 33 days). 101 patients (80%) required no homologous blood during their surgery. No bacterial contamination was observed in the connected tubes. We submit that it is possible to obtain an adequate volume of blood with a simple technique using this method.
Adolescent↗
Analysis of Pseudomonas exotoxin activation and conformational changes by using monoclonal antibodies as probes.
Pseudomonas exotoxin (PE) is a protein toxin composed of three structural domains. In its native form, the toxin is a 66,000-Mr proenzyme that must be activated to express full ADP-ribosylating activity. To study the process of activation and accompanying conformational changes, we have isolated 10 monoclonal antibodies to a 40,000-Mr fragment of the toxin (PE40) that exhibits full enzyme activity but lacks the toxin's cell-binding domain and contains amino acids 253 to 613 (comprising domains II, Ib, and III). By using mutant PE molecules in which all of domain I and portions of domains II, Ib, and III were deleted, the locations of the epitopes for each of the antibodies were determined. Eight of these monoclonal antibodies were further characterized. Of these eight, all reacted with soluble PE40 and an interleukin-2-PE40 conjugate, but only two reacted strongly with native soluble PE. However, all eight reacted with PE after it had been immobilized on nitrocellulose or after it had been activated to express full ADP-ribosylating activity. Antibodies were also assessed for their ability to neutralize the cytotoxic activity of either PE or interleukin-2-PE40. These antibodies should be useful as probes for monitoring the activation and processing of PE that occur during endocytosis and in determining the location of epitopes that are important for toxin activity.
ADP Ribose Transferases↗
Enhancement of lipopolysaccharide-induced tumor necrosis factor production in mice by carrageenan pretreatment.
Tumor necrosis factor (TNF) is a cytokine which mediates endotoxin shock and causes multiple organ damage. It is thought that macrophage (MP) activation is necessary to increase lipopolysaccharide (LPS)-induced TNF production and lethality. Carrageenan (CAR) is sulfated polygalactose which destroys MP; it is used as a MP blocker. We found that CAR pretreatment can increase both endotoxin-induced TNF production and the mortality rate in mice. The ddY mice (7 to 8 weeks old) were injected intraperitoneally with CAR (5-mg dose) and challenged intravenously with LPS 24 h later. Without CAR pretreatment, LPS doses of less than 10 micrograms did not induce TNF in sera. After pretreatment, however, about 3 x 10(3) to 4 x 10(4) U of TNF per ml was produced after LPS injection at doses of 0.1 to 10 micrograms, respectively. TNF production was significantly increased by CAR pretreatment at LPS doses of more than 10 micrograms. CAR pretreatment rendered the mice more sensitive to the lethal effect of LPS; 50% lethal doses of LPS in CAR-pretreated mice and nonpretreated mice were 26.9 and 227 micrograms, respectively. The mortality of the two groups was significantly different at doses of 50, 100, and 200 micrograms of LPS. CAR increased LPS-induced TNF production and mortality within 2 h, much earlier than MP activators, which needed at least 4 days. Our results made clear that TNF production is enhanced not only by a MP activator but also by a MP blocker.
Animals↗
[Analysis of maximal expiratory flow-volume curves--visual evaluation and quantitative evaluation].
Maximal expiratory flow-volume (MEFV) curves have been utilized in the diagnosis of chronic obstructive lung diseases, in the survey of air pollution, and in studies of respiratory functions in school children. Indices for the lower lung volumes of MEFV curves have been used in statistical analysis or individual evaluation because of their effort independence, while indices for higher lung volumes of MEFV curves, which were considered to be effort-dependent, have not been used. A few reports using indices for higher and lower lung volumes have been described because the indices for higher lung volumes are as reproducible to the maximal expiration as those for lower lung volumes. Recently, MEFV-type analysis has been studied and this analysis has been useful in assessing the effects of smoking on MEFV curves, or in assessing subjects with nasal allergies or those with prior nasal allergies. From the aspects of hygiene, this review mainly describes MEFV-type analysis and the quantitative analysis of discriminant analysis.
Adult↗
Survey of infectious coryza of chickens in Indonesia.
A survey of infectious coryza of chickens was performed in West Jawa of Indonesia between 1987 to 1988 by the detection of hemagglutination-inhibition (HI) antibody against Haemophilus paragallinarum (Hpg) in non-vaccinated healthy laying (12 farms, 196 chickens) and native (8 farms, 197 chickens) chickens. HI antibodies against Hpg were detected not only in the native chickens but also in the laying chickens, regardless of the district, and were observed in 70% (14/20) of farms and 19% (73/393) of chickens. HI antibodies against serotype A were detected from 11 farms (55%) and 11% (45/393) in chickens. Those against serotype C were detected from 5 farms (25%) and 8% (30/393) in chickens. Three Hpg strains were isolated from different chickens affected with infectious coryza. Two of them were identified as type A and the other as type C by the rapid plate agglutination test. These results demonstrated that the outbreaks of infectious coryza caused by serotype A and C strains had occurred in Indonesia.
Animals↗
The three dimensional distribution of chromium and nickel alloy welding fumes.
In the present study, the fumes generated from manual metal arc (MMA) and submerged metal arc (SMA) welding of low temperature service steel, and the chromium and nickel percentages in these fumes, were measured at various horizontal distances and vertical heights from the arc in order to obtain a three dimensional distribution. The MMA welding fume concentrations were significantly higher than the SMA welding fume concentrations. The highest fume concentration on the horizontal was shown in the fumes collected directly above the arc. The fume concentration vertically was highest at 50 cm height and reduced by half at 150 cm height. The fume concentration at 250 cm height was scarcely different from that at 150 cm height. The distribution of the chromium concentration vertically was analogous to the fume concentration, and a statistically significant difference in the chromium percentages was not found at the different heights. The nickel concentrations were not statistically significant within the welding processes, but the nickel percentages in the SMA welding fumes were statistically higher than in the MMA welding fumes. The highest nickel concentration on the horizontal was found in the fumes collected directly above the arc. The highest nickel concentration vertically showed in the fume samples collected at 50 cm height, but the greater the height the larger the nickel percentage in the fumes.
Air Pollutants, Occupational↗
Methemoglobin formation by potassium ferrocyanide in the hemolysate of acatalasemic mice.
Increased methemoglobin (metHb) formation is harmful to the normal oxygen transport. There are some mechanisms to reduce metHb formation in the erythrocyte. In the present study, effect of catalase (EC 1.11.1.6) on metHb formation by potassium ferrocyanide was examined spectrophotometrically in the hemolysates of acatalasemic, homozygous hypocatalasemic and normal mice. MetHb formation in the hemolysate of acatalasemic mice was significantly higher than that of normal mice. The addition of catalase reduced the metHb level, while superoxide dismutase (SOD) had little effect on it. A negative intimate correlation was observed between the logarithm of catalase activity (PU/gHb) and the metHb level (%) in the hemolysate. 3-Amino-1,2,4-triazole (AT), a specific catalase inhibitor, significantly increased the formation of metHb. These results indicate that hydrogen peroxide is generated in the process of metHb formation by potassium ferrocyanide and that catalase inhibits the metHb formation by destroying the H2O2 produced.
Acatalasia↗
Effect of a protease inhibitor on the stability of catalase in liver and blood from acatalasemic and normal mice.
Effects of Gabexate mesilate (GM) (([ethyl-4-(6-guanidino hexanoyloxy) benzoate] methane sulfonate)), a protease inhibitor, on the activities of catalase in liver, erythrocytes and reticulocytes from acatalasemic mice were examined. Preincubation without GM at 37 degrees C for 160 min lowered the catalase activities of liver, erythrocytes and reticulocytes from acatalasemic mice, to 24%, 40% and 10% of the initial levels, respectively. But, preincubation with GM at 37 degrees C for 160 min delayed the rapid decrease in activities of residual catalases in the liver, erythrocytes and reticulocytes of acatalasemic mice to 65%, 93% and 85% of the initial values, respectively. At 20 degrees C or below, no reduction in catalase activity of reticulocytes from acatalasemic mice occurred with or even without GM. At pH 5.0, the decrease in catalase activity of acatalasemic mice was small both in the presence and the absence of GM. In the alkaline range, the reduction in the enzyme activity of the mutant mice without GM was enhanced with increase in pH values up to 8.5. But the presence of GM during preincubation at pH 7.5, retained the catalase activity of acatalasemic mice, to 64% of the activity at pH 6.5. These data suggest that some factors affected by GM, might be responsible for the low stability and activity of catalase in the acatalasemic mice.
Acatalasia↗
The role of catalase in protecting erythrocytes against methemoglobin formation.
Some mechanisms to reduce methemoglobin (metHb) formation for the maintenance of normal oxygen transport have been proposed. To study the role of catalase (EC 1.11.1.6), metHb formation in the hemolysate of normal and Japanese acatalasemic human subjects were examined spectrophotometrically. Significantly increased level of metHb was induced by potassium ferrocyanide in the hemolysate of acatalasemic subject. The addition of catalase reduced the metHb formation, while 3-amino-1,2,4-triazole (AT), a specific inhibitor of catalase-H2O2 compound I, increased it. These results obtained from human subjects were well consistent with those from mice and suggested that catalase plays a role in protecting erythrocytes against metHb formation.
Amitrole↗
Maximal expiratory flow-volume types in young subjects with past history of nasal allergy and bronchial asthma.
Pulmonary function tests were performed on 252 healthy young subjects free from respiratory and allergic symptoms, and 80 young subjects with past history of nasal allergy (PNA) and 10 subjects with past history of bronchial asthma (PBA). All the subjects were non-smokers. Maximal expiratory flow-volume (MEFV) curves were visually classified into five types (A-E). The percent distribution of type A in healthy subjects was significantly higher than in the PNA group, while the total sum of percentage of types B, C, and D in the PNA group was significantly higher than in the healthy subjects. The percent distribution of type E in the PNA group was similar to that in the healthy subjects. The percent distribution of MEFV types were significantly different between healthy males and healthy females. The percent distribution of types A, B and E were the highest in healthy subjects, PNA and PBA groups, respectively. Conclusively, the difference in the percent distributions of MEFV types was recognized among healthy subjects, PNA and PBA groups.
Adult↗
Glycoconjugates in the otolithic organ of the developing chick embryo.
The presence of glycoconjugates in the otolithic organ of developing chick embryos was investigated histochemically using lectins. On the 6-day-old chick embryo, intense labelling with lectins was observed in the sensory epithelium, on the surface of the epithelium and on the immature otoconia. The otoconia were intensely labelled with lectins at every stage of the chick embryos, while the labelling with lectins in the sensory epithelium became weaker with the maturing of the otoconia. In TEM observation, the secretory granules of the supporting cells of the sensory epithelium were labelled with lectin. The reaction of lectin was more intense in the electronic dense zone of the otoconium than in the electronic lucent zone at every stage of the chick embryos. These findings indicate that the precursors of the otoconia are secreted by the supporting cells of the sensory epithelium and that glycoconjugates play an important role in otoconial formation.
Animals↗
GABA distribution in the central vestibular system after retroauricular galvanic stimulation. An immunohistochemical study.
The changes of the neurotransmitter (GABA) distribution in the brain stem of rats by retroauricular galvanic stimulation were investigated using the immunohistochemical method. In the lateral vestibular nucleus GABA-like immunoreactivity was more intensive on the side ipsilateral to the anodal stimulation than on the other side. It is concluded that retroauricular galvanic stimulation causes some changes in the inhibitory activity of the lateral vestibulo-spinal tract and of the spinal motor neuron.
Animals↗