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K Kanamori

Publications and source records attributed to K Kanamori.

At least 19 recordsLinked to original sources
PubMed1992

Real-time study of the urea cycle using 15N n.m.r. in the isolated perfused rat liver.

1. Isolated rat liver was perfused with 10 mM-15NH4Cl, 5 mM-lactate and 1 mM-ornithine, or with 3 mM-[15N]alanine and 1 mM-ornithine, in haemoglobin-free medium. The liver was physiologically stable for over 3 h and synthesized urea at the rate of 1.15 mumol.min-1.g of liver-1 (15NH4(+)-perfused) or 0.41 mumol.min-1.g-1 ([15N]alanine-perfused). 2. The perfused liver was continuously monitored by 15N n.m.r. spectroscopy at 20.27 MHz for 15N. Well-resolved 15N resonances of precursors and intermediates of the urea cycle, present at tissue concentrations of 0.2-3.0 mumol/g, were observed from the intact liver in 5-40 min of acquisition. Key metabolites in liver extract and the final perfusion medium were analysed by n.m.r. and by biochemical assays to determine fractional 15N enrichment and the total 15N recovery. 3. In 15NH4(+)-perfused liver (n = 6), 15N incorporation into glutamate and alanine (1.0-1.3 mumol/g), as well as progressive formation of [15N2]urea, was observed during the first 2 h of perfusion. In the second and third hour, hepatic concentrations of [omega-15N]citrulline and [omega,omega'-15N]argininosuccinate increased to n.m.r.-detectable levels (0.3-0.9 mumol/g). The [15N]aspartate pool was large in the absence of added ornithine, but on its addition was rapidly incorporated into argininosuccinate (n = 3). 4. In [15N]alanine-perfused liver, major metabolites were [15N]glutamate, [gamma-15N]glutamine and [15N]urea. Urea-cycle intermediates were undetectable. 5. The results suggest that, in intact liver provided with excess ammonia, low concentrations of cytosolic argininosuccinate synthetase and argininosuccinate lyase limited the rate of metabolite flux in the urea cycle. By contrast, in alanine-perfused liver at a physiological rate of urea synthesis, mitochondrial carbamoylphosphate synthetase was rate-limiting. 6. The potential utility of 15N n.m.r. for study of metabolite channelling through urea-cycle enzymes in intact liver is discussed.

Alanine↗
PubMed1992

[Theophylline toxicity in a patient with status asthmaticus].

A 70-year-old woman was hospitalized for status asthmaticus. The level of CRP was high and chest roentgenogram showed infiltrative shadows in the left middle lung field. Artificial respiration and continuous infusion of methylprednisolone and aminophylline 750 mg/24 hr were performed. Eight hours after admission, seizures suddenly occurred. At this time, brain CT showed no abnormal findings. The seizures were thought to be induced by theophylline toxicity, since serum theophylline concentration was high at 69.9 micrograms/ml. Because theophylline clearance of the patient in a clinically stable condition was normal, it was speculated that theophylline clearance was reduced during status asthmaticus. It is thought that this rare case of theophylline toxicity occurred due to reduction of theophylline clearance during status asthmaticus associated with pneumonia.

Aged↗
PubMed1991

A 15N-NMR study of isolated brain in portacaval-shunted rats after acute hyperammonemia.

Acute hyperammonemia was induced by 15NH4+ infusion in portacaval-shunted (PCS) and control rats to investigate its effects on cerebral metabolism of glutamine, glutamate and gamma-aminobutyrate. Cerebral 15N-metabolites were observed by 15N-NMR spectroscopy in the ex vivo brain, removed in toto at the end of infusion. Key 15N-metabolites in the brain and liver were quantitated and their specific activities measured by NMR and biochemical assays in perchloric acid extracts of the freeze-clamped organs. In the ex vivo brain, [gamma-15N]glutamine, present at tissue concentrations of 3-5 mumol/g with 15N enrichment of 36-48%, was observable within 6-13 min of data acquisition. [alpha-15N]glutamine/glutamate, each present at 0.5-1 mumol/g (approx. 10% enrichment), were observed in 27 min. The results demonstrate the feasibility of observing these cerebral metabolites by 15N-NMR within a physiological time scale. In a rat pretreated with glutamine synthetase inhibitor, L-methionine DL-sulfoximine, cerebral [15N]gamma-aminobutyrate was observed after 910 min. In PCS rats, decreased 15NH4+ removal in the liver was accompanied by formation of approx. 2-fold higher concentration of cerebral [gamma-15N]glutamine relative to that in weight-matched controls. The result suggests that increased diffusion of blood-borne 15NH3 into the brain led to increased [gamma-15N]glutamine synthesis in astrocytes as well as ammonia-mediated inhibition of glutaminase.

Ammonia↗
PubMed1991

[Development and clinical evaluation of a new urinary protein test paper (URINE-TP)].

Because standard urinary protein test paper reacts more strongly to albumin than to globulin, we attempted to develop a test paper sensitive to globulin by applying chromatic analysis principles used in quantitative analysis of urinary protein. We developed a new urinary protein test paper (URINE-TP) containing a reagent of ACID VIOLET 17. It was found that URINE-TP reacts with the same strength to gamma-globulin as to albumin. This new test paper therefore allows accurate detection of Bence Jones protein, which was formerly detectable with standard test paper. There was a correlation between values for urinary protein obtained with URINE-TP and those obtained by quantitative analysis. As with standard test paper, URINE-TP indicates urinary protein values in the normal range by a lack of reaction, but on URINE-TP positive and negative results are more clearly distinguishable than on standard test paper. From these results, we conclude that URINE-TP enables detection of both gamma-globulin and albumin in the urine, and that is as sensitive as the analytical method in the screening of urinary proteins.

Bence Jones Protein↗
PubMed1990

A 15N-n.m.r. study of cerebral, hepatic and renal nitrogen metabolism in hyperammonaemic rats.

1. Rats were infused with 15NH4+ or L-[15N]alanine to induce hyperammonaemia, a potential cause of hepatic encephalopathy. HClO4 extracts of freeze-clamped brain, liver and kidney were analysed by 15N-n.m.r. spectroscopy in combination with biochemical assays to investigate the effects of hyperammonaemia on tissue concentrations of ammonia, glutamine, glutamate and urea. 2. 15NH4+ infusion resulted in a 36-fold increase in the concentration of blood ammonia. Cerebral glutamine concentration increased, with 15NH4+ incorporated predominantly into the gamma-nitrogen atom of glutamine. Incorporation into glutamate was very low. Cerebral ammonia concentration increased 5-10-fold. The results suggest that the capacity of glutamine synthetase for ammonia detoxification was saturated. 3. Pretreatment with the glutamine synthetase inhibitor L-methionine DL-sulphoximine resulted in 84% inhibition of [gamma-15N]glutamine synthesis, but incorporation of 15N into other metabolites was not observed. The result suggests that no major alternative pathway for ammonia detoxification, other than glutamine synthetase, exists in rat brain. 4. In the liver 15NH4+ was incorporated into urea, glutamine, glutamate and alanine. The specific activity of 15N was higher in the gamma-nitrogen atom of glutamine than in urea. A similar pattern was observed when [15N]alanine was infused. The results are discussed in terms of the near-equilibrium states of the reactions involved in glutamate and alanine formation, heterogeneous distribution in the liver lobules of the enzymes involved in ammonia removal and their different affinities for ammonia. 5. Synthesis of glutamine, glutamate and hippurate de novo was observed in kidney. Hippurate, as well as 15NH4+, was contributed by co-extracted urine. 6. The potential utility and limitations of 15N n.m.r. for studies of mammalian metabolism in vivo are discussed.

Adenosine Triphosphate↗
PubMed1990

Congenital bronchobiliary fistula in adults.

Congenital bronchobiliary fistula is a rare malformation. We have presented a case that was diagnosed and treated successfully in an adult. The diagnosis was made by bronchoscopy and bronchography. After excision of the fistula the patient recovered completely. For each patient in whom this anomaly is suspected, bronchoscopy and bronchography are useful for diagnosis.

Adult↗
PubMed1990

Efficiency factors and ATP/ADP ratios in nitrogen-fixing Bacillus polymyxa and Bacillus azotofixans.

The efficiency factor, the number of moles of ATP generated per mole of glucose fermented, was determined in anaerobic, non-carbon-limited N2-fixing cultures of Bacillus polymyxa, Bacillus macerans, Bacillus azotofixans, and Clostridium butyricum through identification and quantitation of the fermentation products by 13C nuclear magnetic resonance spectroscopy and measurement of acetate kinase activities. All three Bacillus species had acetate kinase activities and produced acetate and ethanol as the major fermentation products. The maximum amounts of ATP generated per mole of glucose fermented were 2.70, 2.64, and 2.88 mol in B. polymyxa, B. macerans, and B. azotofixans, respectively, compared with 3.25 mol in C. butyricum. Thus, in the N2-fixing Bacillus species, the efficiency factors are lower than that in C. butyricum. Steady-state ATP/ADP concentration ratios were measured in non-carbon-limited N2-fixing cultures of B. polymyxa and B. azotofixans through separation and quantitation of the adenylates in cell extracts by ion-pair reversed-phase high-performance liquid chromatography. The observed ATP/ADP ratios were 4.5 and 3.8, and estimated energy charges were 0.81 to 0.86 and 0.81 to 0.83, respectively, for B. polymyxa and B. azotofixans. The results suggest that under these growth conditions, the rate of ATP regeneration is adequate to meet the energy requirement for N2 fixation in the Bacillus species, in contrast to N2-fixing Clostridium pasteurianum and Klebsiella pneumoniae, for which substantially lower steady-state ATP/ADP ratios and energy charges have been reported. Implications of the results are discussed in relation to possible differences between Bacillus and Clostridium species in energy requirements for N2 fixation and concomitant ammonia assimilation.

Acetate Kinase↗
PubMed1990

In vivo viscoelastic behavior in the human aorta.

To characterize the viscoelastic properties of the human aorta in vivo, the pressure-diameter relation was determined in the abdominal aorta in 15 subjects. Diameter was measured noninvasively with a highly sensitive ultrasonic displacement meter, while intra-aortic pressure was measured with a catheter tip micromanometer inserted from the femoral artery. The frequency-dependent changes in the pressure-strain modulus (Ep) of the aorta and the phase lag of diameter to pressure were calculated by frequency analysis of these wave forms at the mean blood pressure of 109 mm Hg. The Ep and the phase lag at the fundamental frequency component (1.2 +/- 0.3 Hz, mean +/- SD) were (1.52 +/- 0.57) x 10(6) dyne/cm2 and -6.7 degrees +/- 2.1 degrees, respectively. Although the phase lag at the fundamental frequency was in good agreement with the published in vitro data, the calculated phase lags above the second harmonic were inconsistent, which was probably due to the nonlinearity in the pressure-diameter relation. To separate the effect of this nonlinearity, analysis was conducted with a model consisting of a static nonlinear component representing the elasticity and a dynamic linear component representing the viscosity. This method of analysis revealed that the phase lag due to the viscous component provided relatively flat frequency response to the 10th harmonic. It was confirmed that the aortic wall viscosity showed no apparent difference between the in vivo and the in vitro experimental conditions.

Adult↗
PubMed1990

The effect of various treatments on composite materials in bonding with resin cements.

The present study investigated the influence of surface treatments of composite materials using 6% hydrofluoric acid or 2% acidulated phosphate fluoride, the influence of the application of a bonding agent to the surface, and the influence of incremental curing of composite materials on the shear bonding strength between composite materials and resin cements. These results were studied statistically by analyzing variances in three-way classification and by their contributory ratios. The effects of hydrofluoric acids or acidulated phosphate fluorides on the treated surfaces of composite materials, and also the interfaces between composite materials and resin cements were further examined by mean of scanning electron microscopy (SEM). Unlike the controls, surfaces of all specimens treated with hydrofluoric acid or fluoride revealed micro-porous surfaces, but the effect of the surface treatment on the bonding strength was not equal for all the composite materials tested. The application of a bonding agent influenced some composite material, but the incremental curing of composite materials had no influence on bonding with resin cements.

Acidulated Phosphate Fluoride↗
PubMed1990

[Study on porcelain veneer restorations. 2. Influence of hydrofluoric acid on bonding strength at the porcelain-resin interface].

Recently, porcelain veneer restoratives have been introduced to the general practice, and their clinical performances have been confirmed through many longterm clinical investigations. It is expected that porcelain veneer restorations will perform successfully in esthetic, conservative and abhesive dentistry. It is an well known fact that the micro-mechanical bonding strength at the porcelain-resin interface which is achieved through the application of hydrofluoric acid to the porcelain surface is quite a strong bonding mechanism. However, there are very few studies reporting on the acid treatment of porcelain surfaces. The authors have been studying the influence of hydrofluoric acid on porcelain surfaces, and in our previous report we reported, the degrees of corroded porcelain treated with different concentrations of hydrofluoric acid for different durations of application. In the present study, shear bonding strength was measured between resin cements and porcelain surfaces treated with different concentrations (4, 6, 8%) of hydrofluoric acid and for different durations (1 to 24 min.), and the appropriate treatment of porcelain surfaces with regard to the bonding strength was determined. The results obtained were as follows. 1. As the treating time increased with any concentration (4, 6, 8%) of hydrofluoric acid, corrosion of the porcelain surface became more intense. Hardly any evidence of corrosion was observed on any porcelain surface treated for one minute, so it seems that the treatment of porcelain surfaces using 4 to 8% hydrofluoric acids should be continued for over three minutes. 2. Observation of the surface profile by SEM showed no significant differences between the surfaces treated for 3, 6, 12 and 24 minutes. 3. It was not clear as to how the differences of hydrofluoric acid concentrations (4, 6, 8%) plus the differences in the kinds of porcelain (Super Porcelain AAA, NORITAKE Co. Ltd., VMK 68, Vita Zahnfabrik Gmbh & Co., Cosmotech Porcelain, G-C Co. Ltd.) had affected the differences in the amount of corrosion. 4. Regarding to the shear bonding strength at the porcelain-resin cement interface, in comparison with control specimens which were only sandblasted, about all two to three times higher bonding strength were obtained in specimens treated with any concentration (4, 6, 8%) of hydrofluoric acids and for any duration between 3 to 24 minutes. Specimens treated for one minute were an exception.

Composite Resins↗
PubMed1990

[Study on the porcelain veneer restoration. 3. Effect of various treatments of porcelain surface on the bonding strength at porcelain-resin interface].

In a previous report, observations were made on the apporopriate concentrations of hydrofluoric acid and durations of application in treating porcelain surfaces to improve the bonding strength at the porcelain-resin interface. Particular concentrations and durations were found, such as 4%, 6 min. for Supper Porcelain AAA, 8%, 6 min. for VMK 68, and 6%, 3 min. for Cosmotech Porcelain, and it was clearly shown that hydrofluoric acid treatment was the most effective treatment for porcelain-resin micro-mechanical bonding. However, because of its strong corrosive action, the use of hydrofluoric acid is very dangerous, and it must be handled with extreme care even in the laboratory. Accordingly, there is a need to find a safer and more effective way of treating porcelain surfaces, particularly in the field of interoral repairs to fractured porcelain restoratives by means of porcelain-resin micro-mechanical bonding. In the present study, 2% acidulated phosphate fluoride (APF), which corrodes the surface of porcelain restoratives, PorceLock (PL), which is a 2.5% buffered hydrofluoric acid made by DenMat Co. and a 6% hydrofluoric acid (HF) preparations were applied to the surface of porcelain specimens and the resulting effects on treated porcelain surfaces were examined by means of SEM observations and shear bonding strength tests. The following results were obtained: 1. In comparison with control specimens which were not treated with any acids or fluoride, a much higher bonding strength at the porcelain-resin interface was obtained in the specimens treated with 2% APF, PL and 6% HF. 2. Regarding to SEM observations, both of the specimens treated 6% HF or PL showed extremely micro-porous surfaces.2+ surfaces of the

Acidulated Phosphate Fluoride↗
PubMed1979

Influence of running pace upon performance: effects upon oxygen intake, blood lactate, and rating of perceived exertion.

Three different techniques of middle distance running (fast/slow, slow/fast, and steady pace) have been compared in terms of oxygen intake, blood lactate and ratings of perceived exertion (RPE). The subjects (10 middle distance and long distance male runners) carried out the three patterns of running on the laboratory threadmill according to a randomly ordered sequence, on each occasion covering 1400 m in 4 min. The fast/slow protocol resulted in a rapid and sustained on-transient of oxygen intake, less lactate accumulation, and a lower rating of perceived exertion during the final 2 min of th4 min run. Physiological data thus support coaching impressions of the superiority of the fast/slow protocol.

Adult↗
PubMed1978

[Effect of furosemide on ouabain toxicity in guinea pigs (author's transl)].

An attempt was made to study the effect of furosemide on the toxic and lethal dose (LD) of ouabain. Ouabain was infused continuously in guinea pigs anesthetized with urethane. The toxic dose of ouabain was determined by the minimal dose which produced ventricular arrhythmias. The LD of ouabain was 300.8 +/- 13.8 microgram/kg (mean +/- SE) in control guinea pigs. When furosemide was administered in a dose of 2 mg/kg i.v. prior to ouabain, this was significantly decreased to 225.2 +/- 14.1 microgram/kg (P less than 0.01). Furosemide-treated guinea pigs also showed a marked decrease in toxic dose of ouabain. In another series of experiment, the ouabain uptake by the heart and its subcellular fraction were determined by the infusion of 3H-ouabain at a constant rate under the same experimental conditions aforementioned. Approximately 30% decrease in the LD of 3H-ouabain was also observed in the furosemide pretreated guinea pigs. 3H-ouabain concentration in blood, cardiac muscles and microsomal fraction were lower than control group. These findings suggest that potentiation of ouabain toxicity produced by furosemide is not associated with increased cardiac ouabain uptake, but with increased sensitivity at the site of action.

Animals↗