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Biomedical subjects

K Yoda

Publications and source records attributed to K Yoda.

At least 145 records · Page 8Linked to original sources
PubMed1980

A study of profound hypothermia by surface cooling.

Profound hypothermia below 20 degrees C achieved by surface cooling using simple ice water bath equipment and deep ether anaesthesia is used with the aid of autonomic nerve blocking agents to obtain cardiac arrest for periods of over one hour for open-heart surgery. Blood levels of ether were between 40.6 mg/dl and 285.7 mg/dl during anaesthesia. No arrhythmia occurred and vital signs were quite stable. Hypocarbia throughout the procedure, severe base deficit after circulatory arrest, spontaneous recovery of metabolic acidosis, and a nearly normal cH+ (pH) were observed. Catecholamine increased moderately after circulatory arrest, but was far below shock levels. Plasma renin activity was markedly elevated but angiotensin II stayed at non-significant levels throughout the procedure. Excess lactate showed no significant change. Hyperglycaemia was noted. The mortality rate was 7.7 per cent and neurological disorders occurred in less than 5.8 per cent of the recent 52 cases.

Acid-Base Equilibrium↗
PubMed1978

Modification of rat liver chromatin by N-methyl-N'-nitro-N-nitrosoguanidine or N-ethyl-N'-nitro-N-nitrosoguanidine and template activity for RNA synthesis by Escherichia coli RNA polymerase after reconstitution.

Rat liver chromatin was fractionated into DNA, histones and non-histone chromosomal proteins and each component was modified with N-methyl-l-N'-nitro-N-nitrosoguanidine of N-ethyl-N'-nitrosoguanidine. The radioactivity of 14C-labeled alkyl or guanidino moieties of both compounds bound significantly to both histones and non-histone chromosomal proteins and the binding of N-methyl-N'-nitro-N-nitrosoguanidine was higher than N-ethyl-N'-nitro-N-nitrosoguanidine. However the binding of both compounds to DNA was very low and its significance was hard to evaluate. All of the three components, one of which was modified, were reconstituted into chromatin, then, [3H]UMP incorporation into acid insoluble material using Escherichia coli RNA polymerase (EC 2.7.7.6) was measured. Only with the reconstituted chromatin containing histones modified either by N-methyl-N'-nitro-N-nitrosoguanidine or N-ethyl-N'-nitro-N-nitrosoguanidine, the template activity increased drastically; i.e., about 10 or 5 times higher than that with the unmodified reconstituted chromatin, respectively. However, any remarkable alteration in the electrophoretic pattern of protein fraction of the reconstituted chromatin could not be found. The results obtained in this study are discussed in the context that the modified histones could give rise to change in the mutual interaction of chromosomal components during the reconstitution of chromatin accompanied with the increase of chromatine template activity.

Animals↗
PubMed1977

Alkaline serine proteinases D and E of Streptomyces griseus K-1.

Two DFP-sensitive alkaline proteinases with strong esterase activity toward Ac-(Ala)3-OMe, designated as alkaline serine proteinases D and E, were purified pronase, a protease mixture from St. griseus K-1. Each was shown to be homogeneous by acrylamide disc gel electrophoresis. The molecular weights of these enzymes were estimated to be about 27,000 be gel filtration. Studies on their actions on acyl-tl-amino acid methyl or ethyl esters indicated that proteinases D and E both exhibited a broad substrate specificity and hydrolyzed the ester bonds of esters containing Trp, Tyr, Phe, Leu, and Ala. The esterase activities of both enzymes toward Ac-(Ala)3-OMe were the highest among proteinases so far isolated from various sources. Proteinases D and E also lacked cystine residues in their molecules, being entirely different from alkaline serine proteinases A, B, and C in pronase. Some differences were , however, observed between them as regards pH stability, behavior on CM-cellulose, mobility on polyacrylamide electrophoresis, and amidase activity toward Suc-(Ala)3-pNA.

Hydrogen-Ion Concentration↗
PubMed1977

[Whole body autoradiography with 201Tl and clinical results].

Thallium-201 has been suggested as a useful diagnostic agent for myocardial scanning. We report herewith the clinical usefulness of Tl-201 as a result of our animal studies with rats as well as clinical trial for human being. After intravenous injection, we killed rats at regular intervals, then measured the activity in each anatomized organ by gamma-well counter and observed the internal distribution and examined autoradiograms with the naked eye. As a result, the accumulation of Tl=201 in the myocardium observed in 5 min after injection, reaching the maximum level in 30 min and gradually decreased hereafter. We performed 22 myocardial clinical scans. In adults we could clearly detect the lesion of myocardial infarction, but in children found it difficult to obtain full sufficient information due to small heart size and high pulse rate. Judging from the foregoing we think it possible to obtain much clearer images by using a data analyzer.

Adolescent↗
PubMed1977

Properties of proteins produced after damage to deoxyribonucleic acid of Escherichia coli.

Large amounts of extra proteins, X (in the envelope fraction) and X' (in the cytoplasmic fraction) were detected by SDS-polyacrylamide gel electrophoresis when DNA of Escherichia coli was damaged. These two proteins had the same apparent molecular weight (appproximately 40,000) and were produced under identical conditions, including requirement for the recA" and lexA+ genotype. Sucrose density gradient centrifugation revealed that protein X' consisted of relatively large and heterogeneous aggregates in the cytoplasmic fraction; the distribution of protein X in the envelope was not determined. As proteins X and X' were shown to be equivalent, it is suggested that they are identical. Co-precipitation of the aggregates of protein X' with the envelope led to the appearance of protein X in the envelope fraction.

Bacterial Proteins↗
PubMed1977

Purification and specificity of carboxypeptidase from Streptomyces griseus K-1.

A carboxypeptidase of St. griseus K-1 (CPase S) was found to possess the specificities of both mammalian pancreatic CPase A and B. Three adsorbents for affinity chromatography were prepared by coupling l-Leu, d-Leu, and d-Arg with CH-Sepharose 4B. d-Arg-CH-Sepharose and l-Leu-CH-Sepharose retained the purified CPase S but d-Leu-CH-Sepharose did not. The activities of CPase S toward CGL and BGA were eluted in the same position. CPase S migrated as a single band on polyacrylamide gel electrophoresis and the two activities were both extracted from this band on the gel.

Carboxypeptidases↗
PubMed1976

Alkaline proteinase E of Streptomyces griseus K-1.

A fifth and new DFP-sensitive alkaline proteinase E, with strong esterase activity toward Ac-(Ala)3-OMe was found in pronase, a protease mixture from St. griseus K-1. Proteinase E was shown to be different from the elastase [EC 3.4.21.11]-like enzyme or subtilisin [EC 3.4.21.14]like enzyme, and alkaline proteinase A, B, and C in pronase. Proteinase E was purified to a state appearing homogeneous on polyacrylamide gel electrophoresis. Its molecular weight was estimated as 26,600 by gel filtration. It was unstable below pH 5.6. Studies on its actions on acyl-amino acid esters showed that it hydrolyzed the ester bonds of esters of tryptophan, tyrosine, phenylalanine, leucine, and alanine in decreasing order of ease.

Drug Stability↗