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Y Takada

Publications and source records attributed to Y Takada.

At least 739 records · Page 41Linked to original sources
PubMed1978

Characteristics of hepatic alanine-glyoxylate aminotransferase in different mammalian species.

Mitochondrial extracts of dog, cat, rat and mouse liver contain two forms of alanine-glyoxylate aminotransferase (EC 2.6.1.44): one, designated isoenzyme 1, has mol.wt. approx. 80 000 and predominates in dog and cat liver; the other, designated isoenzyme 2, has mol.wt. approx. 175 000 and predominates in rat and mouse liver. In rat and mouse liver, isoenzyme 1 activity was increased by the injection in vivo of glucagon, but not isoenzyme 2 activity. Isoenzyme 1 was purified and characterized from liver mitochondrial extracts of the four species. Both rat and mouse enzyme preparations catalysed transamination between a number of L-amino acids and glyoxylate, and with L-alanine as amino donor the effective amino acceptors were glyoxylate, phenylpyruvate and hydroxypyruvate. In contrast, both dog and cat enzyme preparations were specific for L-alanine and L-serine with glyoxylate, and used glyoxylate and hydroxypyruvate as effective amino acceptors with L-alanine. Evidence that isoenzyme 1 is identical with serine-pyruvate aminotransferase (EC 2.6.1.51) was obtained. Isoenzyme 2 was partially purified from mitochondrial extracts of rat and mouse liver. Both enzyme preparations were specific for L-alanine and glyoxylate. On the basis of physical properties and substrate specificity, it was concluded that isoenzyme 2 is a separate enzyme. Some other properties of isoenzymes 1 and 2 are described.

Alanine Transaminase↗
PubMed1978

Inhibition of the classical and alternative pathways by amino acids and their derivatives.

Effects of various aminoacids and their derivatives on the classical pathway and alternative pathway of the complement were studied. Leupeptin, acetyl-leucyl-leucyl-arginal, inhibited CH50 and Cl-esterase, but did not inhibit the alternative pathway. When aminoacids of carbon chains of the order of seven were used, arginine and lysine had stronger effects than trans-aminomethyl cyclohexane carboxylic acid (t-AMCHA), cis-aminomethyl cyclohexane carboxylic acid (cis-AMCHA) and epsilon aminocaproic acid (EACA). SH-compounds, cysteine, homocysteine and glutathione, had the strongest inhibitory effects among these aminoacids on both classical and alternative pathways. When effects on Cl esterase were compared, arginine, lysine, t-AMCHA, cis-AMCHA and EACA had weak inhibition while SH-compounds showed strong inhibition. Poly-L-lysine, which had extremely strong inhibition of CH50, had no inhibition of Cl esterase. The inhibitory effects of antifibrinolytic agents, EACA and t-AMCHA, were weak but when effects on early parts of the classical pathway, C(1,4,2)H50 were tested, some inhibitory activities were recognized. Thus inhibitory effects of these agents were due to their activities on the early parts of the classical pathway.

Amino Acids↗
PubMed1977

Characteristics of hepatic serine-pyruvate aminotransferase in different mammalian species.

1. Serine-pyruvate aminotransferase was purified from mouse, rat, dog and cat liver. Each enzyme preparation was homogeneous as judged by polyacrylamide-disc-gel electrophoresis in the presence of sodium dodecyl sulphate. However, isoelectric focusing resulted in the detection of two or more active forms from enzyme preparations from dog, cat and mouse. A single active form was obtained with the rat enzyme. All four enzyme preparations had similar pH optima and molecular weights. 2. Both mouse and rat preparations catalysed transamination between a number of L-amino acids (serine, leucine, asparagine, methionine, glutamine, ornithine, histidine, phenylalanine or tyrosine) and pyruvate. Effective amino acceptors were pyruvate, phenylpyruvate and glyoxylate with serine as amino donor. The reverse transamination activity, with hydroxypyruvate and alanine as subtrates, was lower than with serine and pyruvate for both species. Serine-pyruvate aminotransferase activities were inhibited by isonicotinic acid hydrazide. 3. In contrast, both dog and cat enzyme preparations were highly specific for serine as amino donor with pyruvate, and utilized pyruvate and glyoxylate as effective amino acceptors. A little activity was detected with phenylpyruvate. The reverse activity was higher than with serine and pyruvate for both species. Serine-pyruvate amino-transferase activities were not inhibited by isonicotinic acid hydrazide.

Amino Acids↗
PubMed1977

Heliotherapy of pityriasis lichenoides chronica.

Fifteen patients with pityriasis lichenoides chronica (parapsoriasis guttata) were treated with sunlight irradiation during the summer months at seaside resorts under the supervision of the authors. Complete clearing occurred in 1 of the patients, almost complete clearing in 8, definte improvement in 4, temporary clearing in 2. All patients responded beneficially and no worsening was noted in these 15 cases. In an additional six cases who were instructed to expose themselves to sunlight similar results were obtained.

Adolescent↗
PubMed1977

Glutamate-glyoxylate aminotransferase in rat liver cytosol. Purification, properties and identity with alanine-2-oxoglutarate aminotransferase.

After cortisone injection, virtually identical increases in rat liver cytosol alanine-2-oxoglutarate aminotransferase and glutamate-glyoxylate aminotransferase activities were observed. The two activities were co-purified to homogeneity from rat liver cytosol. The purified enzyme was specific for L-alanine with 2-oxoglutarate as amino acceptor. With glyoxylate, however, the enzyme utilized various L-amino acids as amino donors in the following order of activity: glutamate greater than alanine greater than glutamine greater than methionine. The ratio of alanine-2-oxoglutarate aminotransferase activity to glutamate-glyoxylate aminotransferase activity remained constant during purification and was unchanged by a variety of treatments of the purified enzyme. These results suggest that glutamate-glyoxylate aminotransferase is identical with alanine-2-oxoglutarate aminotransferase. Evidence was obtained that the two enzyme activities in the cytosol of dog, cat and human liver are also properties of the same protein.

Alanine Transaminase↗
PubMed1977

[Trypsin inhibitors in human urine (author's transl)].

By using ammonium sulfate, Arg-Sepharose and gel filtration, an urinary trypsin inhibitor (UTI) with molecular weight of 67,000 (UTI7) was isolated from normal human urine. The yield of UTI7 was about 3,200 U per liter of urine. When urine was acidified, an uropepsin-like substance was activated which caused molecular weight change of UTI7. New UTIs had molecular weight of 45,000 and 22,000 (UTI4-5 and UTI-2-2), respectively. These inhibitors showed a strong effect on trypsin, alpha--chymotrypsin and lesser extent on plasmin and elastase, but had no effect on esterolytic activity on thrombin and the first components of complement Cls an Clr.

Electrophoresis, Polyacrylamide Gel↗
PubMed1976

Membrane characteristics of established human T- and B-cell lines. Cross-reactivity of human T-antigenic determinants with peripheral lymphocytes of non-human primates and the presence of MLC antigens on cultured T-cell lines.

Human T-cell lines (MOLT-4 and SOMMER-T) were injected into rabbits and monkeys (stumptail and squirrel monkeys). Rabbit anti-MOLT serum was absorbed with human liver and cultured B cells. Absorbed anti-MOLT serum was cytotoxic to lymphocytes of baboons and stumptail monkeys. Rabbit anti-MOLT and SOMMER-T sera after absorption with liver and B cell showed florescent ring formation in baboon and stumptail lymphocytes by using immunoflurescence techniques. On the other hand, antisera against MOLT and SOMMER-T cells in stumptail and squirrel monkeys were not only cytotoxic to MOLT and SOMMER-T cells, but also to other T-cell lines, CCRF-CEM and CCRF-HSB-2 cells. Cultured B-cell lines stimulated allogeneic and xenogeneic (rabbit and monkeys) lymphocytes far better than cultured T-cells lines did. T-cell lines, CCRF-HSB-2 and SOMMER-T (number 8402), gave small but significant stimulation to allogenic lymphocytes especially in the presence of foetal calf serum. MOLT-4B failed to stimulatie allogeneic lymphocytes. When lymphocytes of non-human primates and rabbit were cultured with human B- and T-cell lines in the presence of foetal calf serum, CCRF-HSB-2 and SOMMER-T cells stimulated xenogeneic lymphocytes of rabbit, squirrel monkey and stumptail monkey. MOLT-4 cells stimulated lymphocytes of baboon to some extent. These results indicate that although cultured B-cell lines had more mixed lyphocyte reaction (MLR) stimulating structure than T-cell lines, the latter still maintained some stimulating structure on the membrances.

Animals↗
PubMed1976

Lymphokine-like factors produced by human lymphoid cell lines with B or T cell surface markers.

In the present series of experiments we examined the ability of eight continuous cell lines derived from human lymphocytes to release lymphokines into their culture media. We have demonstrated that all could produce a macrophage migration inhibitory factor and a neutrophil chemotactic factor. This ability was independent of the B or T cell origin of the cell lines. As a further extension of previous reports, we report that the migration inhibitory effect does not seem to be due to cytotoxic effects as judged by trypan blue exclusion studies, and more important by the demonstration that the inhibition is reversible. The demonstration that neutrophil chemotactic activity is removable by treatment with a previously described and characterized anti-lymphokine antiserum suggests that this factor may be chemically similar to some of the lymphokines (migration inhibitory factor or chemotactic factor for macrophages) produced by antigen-activated guinea pig lymphocyte cultures. The failure to effect similar removal or inactivation of the macrophage migration inhibitory factor may simply reflect greater interspecies heterogeneity in this factor, or more interestingly, that this does not correspond to "classic" MIF. These results extend previous observations by defining further the capacity of lymphoid cell lines in continuous culture to produce mediators and by characterizing their relationship to conventional lymphokines produced by antigen or mitogen-activated lymphocytes.

B-Lymphocytes↗