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Biomedical subjects

H Wada

Publications and source records attributed to H Wada.

At least 1,099 records · Page 61Linked to original sources
PubMed1981

Automated analysis for plasma epinephrine and norepinephrine by liquid chromatography, including a sample cleanup procedure.

We describe a fully automated method of analysis for plasma epinephrine and norepinephrine by use of a two-column system of "high-performance" liquid chromatography. Catecholamines in deproteinized plasma are purified on the first (preparation) column, then transferred automatically to the second (analytical) column in which epinephrine and norepinephrine are resolved. These compounds are then determined fluorometrically with a continuous-flow reaction system by the trihydroxyindole method. The minimum sensitivity of the method is 0.02 and 0.04 pmol for epinephrine and norepinephrine, respectively. One assay can be completed in 30 min, and greater than 1 mL of plasma is required for the procedure. The within-run CV in the chromatographic determination of pooled plasma was greater than 3%, and the analytical overall recovery of the two compounds was 95%. The concentrations in plasma of medical students at rest were 0.32 (SE 0.06) nmol/L for epinephrine and 0.98 (SE 0.08) nmol/L for norepinephrine.

Autoanalysis↗
PubMed1981

Immunological studies on modified enzymes. I. soluble L-asparaginase/mouse albumin copolymer with enzyme activity and substantial loss of immunogenicity.

For the successful administration of exogenous proteins and enzymes for therapeutic purposes, abrogation or modifications of antigenicity and immunogenicity of the protein must be achieved without substantial loss of the biological activity necessary for therapeutic purposes. In order to try this, a model experiment was carried out in the present study. Escherichia coli L-asparaginase, whose chemical properties have been well defined and which is used for the treatment of acute lymphocytic leukemia and malignant lymphomas, was modified by copolymerization with isologous albumin, and alterations of its immunogenicity were examined in mice. The results demonstrated that the immunogenicity of the modified L-asparaginase was remarkably reduced and satisfactory enzyme activity was preserved.

Albumins↗
PubMed1980

A new acidic protein in porcine brain.

An extremely acidic protein has been isolated in a purified form from porcine rain extract, by (NH4)2SO4 fractionation followed by column chromatography on DEAE-Sephadex A-50 and on Sephadex G-75. The purified protein was tentatively named as glutamic acid-rich protein because it was characterized by its remarkably high content of glutamic acid which accounted for 49% of the total amino acid composition. The protein appeared to be a single polypeptide chain with a molecular weight of 56 000-58 000, and had an isoelectric point of 4.6. The N-terminal amino acid sequence was Asp-Glu-Pro-Pro-Ser-Glu-Gly. The immunochemical analysis using rabbit antiserum prepared to the porcine protein has suggested that it is present in the brain of human, cow, cat, dog and goat as well as in various goat organs including liver, kidney, heart, small intestine and spleen.

Amino Acids↗
PubMed1980

Complete amino acid sequence of mitochondrial aspartate aminotransferase from pig heart muscle. Tryptic peptides.

The amino acid sequences of 39 tryptic peptides from carboxymethylated mitochondrial aspartate aminotransferase from pig heart muscle were analyzed. The peptides were purified by gel filtration, ion exchange column chromatography, paper chromatography, and high voltage paper electrophoresis, and their sequences were examined by manual Edman degradation, carboxypeptidase digestion, and fragmentation with thermolysin or chymotrypsin. These peptides accounted for 318 of the total 401 amino acid residues in the protein subunit.

Amino Acid Sequence↗
PubMed1980

Complete amino acid sequence of mitochondrial aspartate aminotransferase from pig heart muscle. Cyanogen bromide peptides.

Twelve cyanogen bromide peptides were isolated from S-carboxymethylated mitochondrial aspartate aminotransferase and their amino acid sequences were determined. These peptides were purified first by gel filtration on a Sephadex G-75 column, and then by gel filtration on Bio-Gel, or by ion exchange chromatography on a phosphocellulose column in the presence of 8 M urea, or by both methods. Small peptides were purified by paper chromatography. The cyanogen bromide peptides accounted for 367 of the 401 amino acid residues in the subunit of the enzyme. No peptide accounting for the other 34 residues was obtained in a homogeneous state, but peptide mixtures containing this particular peptide were analyzed by various procedures including Edman degradation and digestion with Staphylococcus aureus protease. The results accounted for all 401 amino acid residues.

Amino Acid Sequence↗
PubMed1980

The effects of protease inhibitors on histidine decarboxylase activities and assay of enzyme in various rat tissues.

Histidine decarboxylase (L-histidine carboxy-lyase, EC 4.1.1.22) of an extract of rat stomach was inactivated by a pancreatic extract. This inactivation was prevented by the protease inhibitors leupeptin, antipan, chymostatin, pepstatin, Trasylol and phenylmethanesulfonyl fluoride. Leupeptin, antipain, chymostatin and pepstatin together and phenylmethanesulfonyl fluoride alone prevented complete inactivation of the enzyme, while Trasylol had a weak protective effect. The inactivation and protection of histidine decarboxylase purified from whole fetal rats were similar to those of the stomach enzyme: both enzymes were strongly inactivated by trypsin and chymotrypsin, but not by elatase or carboxypeptidase Y. The histidine decarboxylase activities of various rat tissues were assayed in the presence of protease inhibitors: activity was highest in mast cells followed by the whole bodies of fetal rats and the stomach, while the activities were lower in decreasing order in the brain, spleen, lung and liver. Heart and kidney had no activity.

Animals↗
PubMed1980

Effects of dietary amino acids on brain amino acids and transmitter amines in rats with a portacaval shunt.

The etiologic relationship between disturbances in metabolism of amino acids and amines and hepatic coma was investigated by examining the effects of diets containing various mixtures of amino acids on brain amine metabolism in rats with a portacaval shunt, using a method for simultaneous analysis of amino acids and amines. Rats with a portacaval shunt were fed on four different amino acid compositions with increased amounts of various amino acids suspected to be etiologically related to hepatic coma, such as methionine, phenylalanine, tyrosine, and tryptophan. The animals were killed 4 weeks after operation. During the experimental period, these animals did not become comatose, but exhibited various behavioral abnormalities. Marked increase in the plasma and brain levels of the augmented amino acids, especially methionine and tyrosine, were observed in rats with a portacaval shunt. Brain noradrenaline, dopamine, and serotonin levels were significantly decreased when the brain tyrosine level was increased. These results indicate that in rats with a portacaval shunt the dietary levels of amino acids greatly influence the brain levels of both amino acids and transmitter amines.

Amino Acids↗