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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 811 records · Page 45Linked to original sources

Oxygen uptake and blood flow of the lower limb in maximal treadmill and bicycle exercise.

The present study was undertaken to compare the effects of maximal treadmill and bicycle exercise on maximum oxygen uptake and blood flow in the lower extremity. Mean maximum oxygen uptake in maximal treadmill exercise was higher than that in bicycle exercise (p less than 0.001). Mean values and standard errors of blood flow measured immediately after maximal treadmill and bicycle exercise in the thigh were 39.1 +/- 4.0 and 44.2 +/- 2.8 ml/100 ml . min, the difference not being significant. However, a significant difference in blood flow in the calf measured immediately after both types of exercise was observed (p less than 0.001). Blood flow in the thigh immediately after bicycle exercise was significantly higher than that in the calf (p less than 0.001), whereas the difference between thigh and calf in treadmill exercise was small and statistically not significant. Leg blood flow, the average value of blood flow of the thigh and calf added together, was used as an index of blood flow in the lower extremity. It was found that the leg blood flow was significantly higher on the treadmill than with bicycle exercise (p less than 0.05). From these results, it is suggested that the lower maximum oxygen uptake observed during bicycle exercise as compared with treadmill exercise seems to be due to a lower blood flow in the lower limb.

Adult↗

High-performance liquid chromatographic determination of hippuric acid in human urine.

A method is described for the determination of urinary hippuric acid by high-performance liquid chromatography. The method used ethyl acetate extraction for partial clean up of the urine. The separation was carried out on a reversed-phase column using 20% methanol in 0.01 M aqueous potassium phosphate containing 0.5% acetic acid as a mobile phase. The column effluent was monitored with a UV detector at 254 nm. Hippuric acid was separated from other normal urine constituents in less than 10 min. Metabolites of xylene and styrene did not interfere with the assay. Analytical recoveries from urine were excellent and peak height and concentration were linearly related.

Chromatography, High Pressure Liquid↗

Aerobic power as related to body growth and training in Japanese boys: a longitudinal study.

Maximal aerobic power was measured for 5-6 successive years in 50 Japanese schoolboys starting from the age of 9 or 13 yr. and for 2-3 yr in 6 superior junior runners from the age of 14 yr. A large increase in aerobic power was observed during the adolescent growth spurt for 7 schoolboys who trained between the ages of 9 and 14 yr. Aerobic power for 43 average schoolboys increased from 45.0 to 52.2 ml/kg.min between the ages of 13 and 17 yr. The aerobic power of 6 superior junior runners increased from 63.4 to 73.4 ml/kg.min between the ages of 14 and 17 yr. A remarkable increase in aerobic power was not observed in trained boys before the age of peak height growth velocity (PHV). Beginning approximately 1 yr prior to the age of PHV and thereafter, training effectively increased aerobic power above the normal increase attributable to age and growth. The highly developed aerobic power found in superior junior runners may have been derived from strenuous training and partially by genetically superior endowment.

Adolescent↗

Effects of diltiazem hydrochloride (CRD-401) on hepatic, superior mesenteric and femoral hemodynamics.

The effects of d-3-acetoxy-cis-2,3-dihydro-5-[2-(dimethylamino)ethyll-2-(p-methoxyphenyl)-1,5-benzothiazepine-4(5H)-one hydrochloride (diltiazem hydrochloride; CRD-401) on the hepatic, superior mesenteric and femoral arteries were investigated in dogs. The results obtained were as follows: 1. At an i.v. dose of 100 microgram/kg, CRD-401 lowered the mean aortic blood pressure (-5%). It also decreased the diastolic aortic blood pressure (-11%) but did not affect the systolic aortic blood pressure. 2. The mean aortic blood pressure decreased after injection of CRD-401, but the blood flows in the hepatic, superior mesneteric and femoral arteries increased to 33%, 31% and 17%, respectively, more than did the control values and the vascular resistances of these arteries decreased by 25%, 27% and 17%, respectively. The present study obviously demonstrates that CRD-401 has vasodilating action on the hepatic, superior mesenteric and femoral arteries.

Animals↗

Effects of diltiazem Hydrochloride (CRD-401) on renal hemodynamics of dogs.

The effect of d-3-acetoxy-cis-2,3-dihydro-5-[2-(dimethylamino)ethyl]-2-(p-methoxyphenyl)-1,5-benzothiazepine-4(5H)one hydrochloride (ditiazem hydrochloride, CRD-401) on renal hemodynamics was investigated in 18 mongrel adult dogs, and the following results were obtained. 1. Renal blood flow (RBF) was significantly increased following i.v. injection of 100 microgram/kg of CRD-401, in spite of decreased ao-tic blood pressure. Moreover the same dose of the drug elicited greater increase in RBF while the renal arteries were perfused at a constant pressure in order to prevent the decrease in systemic blood pressure from affecting RBF. These results suggest that CRD-401 has a vasodilatory action on the renal arteries. 2. The increasing rate of RBF and decreasing rate of renal vascular resistance (RVR) after injection of the drug into the renal artery at the dose level of 3 microgram/kg were found to diminish by pretreatment with hexamethonium (C6) before CRD-401. The vasodilating effect of CRD-401 on the renal arteries was therefore assumed to be more prominent in a state of renal arterial constriction. 3. RBF and RVR were increased and decreased, respectively, in proportion to the doses of CRD-401 ranging from 3 to 100 microgram/kg, the vasodilating action of CRD-401 on the renal arteries increased dose-dependently.

Animals↗

Purification and characteristics of (Na+, K+)-ATPase from canine kidney by zonal centrifugation in sucrose density gradient.

Microsomes were prepared from the outer medulla of canine kidney. Partially purified preparation of (Na+, K+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) was obtained by solubilization of microsomes with sodium deoxycholate, and by precipitation with dilution. The deoxycholate-enzyme thus obtained was further purified by incubation with sodium dodecyl sulphate in the presence of ATP followed by a single zonal centrifugation in a sucrose density gradient by the method of Jørgensen [(1974) Biochim. Biophys. Acta 356, 36-52]. The (Na+, K+)-ATPase was purified to a specific activity of 1600--1800 micronmol Pi - h-1 - mg-1 protein. The yield was 20 mg per single centrifugation with a zonal rotor. Electron microscopy showed that the sectioned pellet of the purified enzyme contained exclusively membranous fragments in contrast with membranous vesicles of starting microsomes. Sodium dodecyl sulphate polyacrylamide gel electrophoresis showed that almost all proteins were accounted for by two polypeptides with molecular weights of 105 000 and 58 000, and that the mass ratio of the large to the small polypeptide was 82 : 18.

Adenosine Triphosphatases↗

Mutation of an inosine-producing strain of Bacillus subtilis to DL-methionine sulfoxide resistance for guanosine production.

An inosine-producing strain of Bacillus subtilis was mutated to resistance against the antagonist of glutamine, DL-methionine sulfoxide. Among the mutants derived, guanosine producers were observed frequently. The best strain, 14119, produced 9.6 g of guanosine per liter at a weight yield of 12% from consumed sugar. Inosine production decreased concomitantly. When resistance was increased further by exposure to higher doses of DL-methionine sulfoxide, another strain, AG169, was obtained that did not excrete inosine but produced increased amounts of xanthosine. In these strains, the specific activity of 5'-nucleotidase was lower and that of inosine 5'-monophosphate (IMP) dehydrogenase was higher than the parent strain. It is speculated that the metabolic flow from IMP to xanthosine 5'-monophosphate proceeds more smoothly than that from IMP to inosine and yields more xanthosine and guanosine.

Bacillus subtilis↗

Quantitative determination of hippuric and m-methylhippuric acids in urine by high-speed liquid chromatography.

High-speed liquid chromatography employing an ultraviolet photometric detector has been applied to the simultaneous determination of hippuric and m-methylhippuric acids in urine. Reversed-phase partition chromatography is carried out on a muBondapak C18 column with methanol-water as the eluent system. This method obviates the necessity for isolation or reaction of these acids before assay. The only pretreatment necessary is extraction of sample with ethyl acetate. A linear relationship is obtained between the peak heights and the hippuric or m-methylhippuric acid concentrations. Mean recovery of hippuric and m-methylhippuric acids in urine is 99.8% and 99.3% respectively. The determination of hippuric acid by this method gives lower concentrations in normal urine than does the colorimetric method of Umberger and Fiorese (1963).

Chromatography, High Pressure Liquid↗

[Aspects of enzymatic toxicology of metals. A review (author's transl)].

The adverse and beneficial effects of metals have occupied a great concern in many branches of biology for centuries, but their biochemical roles have been studied systematically only in the last four decades. Almost all the metals, especially those of high toxicity, bind readily to mercapto groups, and these are frequently important in enzyme systems. Furthermore, a large number of in vitro and in vivo studies have shown that toxic metals can replace essential metals in many of their metalloenzymes, with resultant changes in activity. Metals also bind to protein, phospholipid and nucleic acid, and have been shown to effect a change in the conformation of enzymes required for normal function, or to uncouple oxidative phosphorylation. This review, of necessity brief, will focus on the biochemical and enzymatic effects of metals, emphasizing meanings available to occupational medicine. The present knowledge on enzymatic toxicology of metals can provide for access to three main problems. These include an exposure evaluation, a health injury evaluation and a pathogenic understanding of workers exposed to metals. In this article, these problems are discussed in general, and the recent developments made in the enzymatic toxicology of cadmium and lead are presented with pertinent literatures.

Alanine Transaminase↗

Use of freeze-dried sensitized erythrocytes in indirect hemagglutination test for serodiagnosis of leptospirosis.

The indirect hemagglutination (HA) test using freeze-dried tanned formalinized sheep erythrocytes sensitized with deoxycholate-extracted leptospiral antigen was investigated for its applicability to serodiagnosis of leptospirosis. The sensitized erythrocytes suspension containing an adequate concentration of glycine was lyophilized and used for the HA test. The lyophilized sensitized cells are rehydrated after at least 10 months storage without any loss of HA titer. The sensitivity of such cell suspension tested on sera from cases of leptospirosis equals that of the suspension before freeze-drying.

Animals↗