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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 1,207 records · Page 67Linked to original sources
PubMed1979

Effect of an amino acid imbalance on intestinal sucrase and leucine aminopeptidase activities in rats.

In order to investigate the relationship between dietary amino acids and protein, as well as the activities of intestinal sucrase and leucine aminopeptidase in rats, the effects of an amino acid imbalance on these enzyme activities were studied. The amino acid imbalance was created by adding 8% of an indispensable amino acid mixture lacking threonine to a 6% casein diet supplemented with 0.3% methionine. The food intake and growth of rats fed the imbalanced diet ad libitum were depressed, and the segmental weights of the small intestine and its sucrase activity were clearly lower than those of rats fed the basal diet. The effect of the imbalanced diet under pair-feeding condition on the sucrase activity was similar to that under an ad libitum feeding condition. The food intake and segmental sucrase activity, that is, sucrase activity per length of the small intestine, of rats injected with cortisol (1 mg/day) and fed the imbalanced diet were not depressed, although administration of insulin (1.5 U/day) had no effect on the food intake or segmental sucrase activity. Force-feeding stimulated growth of rats receiving the imbalanced diet, as well as increasing their segmental sucrase activities. The effects of these different conditions on the leucine aminopeptidase activity of rats receiving the imbalanced diet were obscure. These results suggest that changes in segmental sucrase activity might be mediated by stimulating factors in food intake affected by the composition of ingested amino acids and protein together with sucrose in the gastrointestinal lumen.

Animals↗
PubMed1979

An alpha 1-antitrypsin variant, Pi B Alhambra (Lys to Asp, Glu to Asp), with rapid anodal electrophoretic mobility.

A variant of human alpha 1-antitrypsin (alpha 1 AT) was found by acid starch gel electrophoresis and by thin-layer electrofocusing. The variant has an anodal migration velocity almost identical to PiB. It is designated as Pi B Alhambra. Pi B Alhambra was purified to homogeneity from a heterozygous PiM1/PiB Alhambra subject. Specific trypsin inhibitory activity and composition of amino acids and carbohydrates were similar to those of normal PiM1. The structural difference between the normal and the variant inhibitors was elucidated by peptide mapping of their tryptic digests. Two amino acid substitutions, Lys to Asp and Glu to Asp, were found. The amino acid substitution, Gly to Asp, has been found in a common PiM2 variant [1]. The Pi B Alhambra variant presumably originated by two steps of mutation: generation of PiM2 from wild type PiM1 by the substitution Gly to Asp, and subsequent generation of Pi B Alhambra from PiM2 by another substitution, Lys to Asp.

Amino Acid Sequence↗
PubMed1979

Structural difference between the normal PiM1 and the common PiM2 variant of human alpha 1-antitrypsin.

The common PiM2 variant of human alpha 1-antitrypsin (alpha 1-AT) which can be distinguished from the wild type PiM1 by isoelectric focusing (IEF) in a narrow pH gradient, was purified to homogeneity from plasma of a homozygous PiM2/PiM2 subject. The specific trypsin inhibitory activity and the amino acid and carbohydrate composition of the normal PiM1 and the variant PiM2 are very similar. The structural difference between the normal and the variant inhibitors was elucidated by peptide mapping of their tryptic digests. An amino acid substitution of glutamic acid in the normal inhibitor by aspartic acid in the variant inhibitor was found. The same amino acid substitution was found in PiMN, which was presumed to be identical to PiM2 based on their IEF patterns.

Amino Acid Sequence↗
PubMed1978

Follow up study of sudden deafness.

It is significant to follow up patients with sudden deafness, because the change of hearing level after a long-term period and a differential diagnosis from Meniére's disease must be studied. We reported the follow-up study of 27 patients with sudden deafness who were admitted to the Department of Otolaryngology of the Second Tokyo National Hospital. The duration of follow-up ranged from 6-58 months, with a mean duration of 23.7 months. In the Complete Recovery Group there was little change of mean hearing loss during the follow-up period. We coud demonstrate that the once recovered hearing level rarely deteriorated afterwards, but the not recovered hearing level would sometimes deteriorate.

Adult↗
PubMed1978

A variant glucose-6-phosphate dehydrogenase Gd(-) Chiapas associated with moderate enzyme deficiency and occasional hemolytic anemia.

Erythrocyte glucose-6-phosphate deficiency is an X-chromosomal-linked hereditary trait often associated with hemolytic anemia. This report defines a new variant designated as Gd(-) Chiapas, which was found in a subject with occasional hemolytic jaundice. The red cell enzyme activity of the subject is about 15% of normal. The variant enzyme is thermolabile in vitro and has faster-than-normal anodal electrophoretic mobility and stronger-than-normal substrate affinity. The patient's hemolytic problem might be correlated with instability of the variant enzyme under physiologic stress.

Adult↗
PubMed1978

Human blood group glycosyltransferases. I. Purification of n-acetylgalactosaminyltransferase.

An N-acetylgalactosaminyltransferase, which converts blood group O red blood cells to A cells, was purified to homogeneity from plasma of blood group A1 subjects. The enzyme was adsorbed on Sepharose 4B, and after washing out the impurities, the enzyme was eluted with UDP. This procedure resulted in a 70,000- to 100,000-fold increase in specific activity with recovery of about 80%. Further purification of the enzyme was achieved by Bio-Gel P treatment. The final enzyme preparation showed a single protein band, which coincided with enzyme activity, on acrylamide gel electrophoresis, and revealed a single protein band on sodium dodecyl sulfate-gel electrophoresis. Judging from the molecular weight (90,000 to 100,000), which was estimated by Sephadex gel filtration, and the subunit size estimated by sodium dodecyl sulfate-gel electrophoresis, the enzyme is presumably in a dimeric form. The enzyme required Mn2+ and had optimum activity at pH 6.5 to 7.0.

ABO Blood-Group System↗
PubMed1978

Human blood group glycosyltransferase. II. Purification of galactosyltransferase.

A galactosyltransferase, which converts blood group O red bloodcells to B-cells, was purfied to homogeneity from plasma of blood group B subjects. The stepwise purification procedures include: (a) column chromatography with CM-Sephadex, followed by ammonium sulfate fractionation; (b) Sephadex G-200 gel filtration; (c) column chromatogr,phy with DEAE-Sephadex; and (d) column chromatography with hydroxylapatite. The procedures provided about a 400,000-fold increase of specific activity with a 40 to 50% yield. Further purification of the enzyme was performed by small scale preparative acrylamide gel electrophoresis at pH 4.3. The final enzyme preparation showed a single protein band which coincided with enzyme activity, in acrylamide gel electrophoresis, and revealed a single protein band in sodium dodecyl sulfate-gel electrophoresis. Judging from the molecular weight, which was estimated by Sephadex gel filtration, and subunit size estimated by sodium dodecyl sulfate-gel electrophoresis, the enzyme is presumably in a dimeric form. The enzyme required Mn2+ for its activity and had a pH optimum at 7.0 to 7.5.

ABO Blood-Group System↗
PubMed1978

Origin of the multiple components of human alpha1-antitrypsin.

Multiple components of human alpha1-antitrypsin were separated by preparative starch gel electrophoresis, and the sialic acid contents of these components were determined. The acidic components contained more sialic acid per molecule than the basic components. The molecular sizes of these components were identical, excluding the possibility of polymerization of the inhibitor in the formation of the multiple components. Consequently, the multiple components of the inhibitor are primarily due to differences in the sialic acid content of each component. Three major components contain eight, seven, and six sialic acid residues per molecule, respectively.

Electrophoresis, Starch Gel↗
PubMed1978

Long-term effectiveness of dietary iron and ascorbic acid in the prevention and cure of cadmium toxicity in rats.

The protective and curative effects of dietary iron and ascorbic acid on chronic (180 days) cadmium toxicity in rats were examined. Growth retardation and anemia were observed in rats fed a diet containing 50 ppm of cadmium for 180 days; during this period the contents of iron in the liver, kidney, spleen, testis, intestine, and tibia decreased and the zinc contents of the liver and kidney increased, but the calcium content of bone did not change. Addition of 400 ppm of iron and 1% of ascorbic acid to the cadmium-containing diet overcame the growth retardation and anemia due to cadmium toxicity and reduced the tissue levels of cadmium; however, it did not restore the zinc contents in the liver, kidney, and bone to normal. Similar effects were observed when these compounds were added to cadmium containing diet for 90 days after feeding the cadmium diet alone for 90 days. The glutamic-pyruvic transminase and glutamic-oxaloacetic transminase activities in the plasma of rats fed the cadmium diet increased significantly and these increases were prevented by supplementing the diet with iron and ascorbic acid. Glucose, urea, and alkaline phosphatase in the plasma and glycogen in the liver were not changed by feeding the cadmium diet for 180 days. These results indicate the long-term effectiveness of supplementing the diet with iron and ascorbic-acid for preventing and curing dietary cadmium toxicity in rats.

Animals↗
PubMed1978

Effect of dietary amino acids on jejunal sucrase and leucineaminopeptidase activities in rats.

The effect of dietary amino acids on jejunal sucrase (EC 3.2.1.26) and leucineaminopeptidase (EC 3.4.11.1, LAPase) activities in rats was studied. Rats were force-fed a 10% complete amino acid diet or valine-free diet. The sucrase and LAPase activities in rats force-fed the valine-free diet for 2 days were significantly lower than those in rats force-fed the complete amino acid diet, although the specific activities of these enzymes in the isolated brush border fragment were 10 times higher than those in the mucosa, and most of the activities of these enzymes in the mucosa were localized in the isolated brush border fragment. Results of experiments undertaken to investigate the effects of dietary amino acids during the initial period after the dietary alteration on the sucrase and LAPase activities showed that decreases in the activities of these enzymes in rats force-fed the valine-free diet appeared by 26 hours after the first feed administration; whereas, incorporation of dietary 14C-amino acids administered in the first feed administration into the mucosal protein was significantly lower in rats receiving the valine-free diet than in rats receiving the complete amino acid diet by 7 hours following the first feed administration. These results suggest that decreases in availability of dietary amino acids in the valine-free diet for protein formation in the small intestinal mucosa during the initial period caused the decreases in the sucrase and LAPase activities localized in the brush border membrane.

Amino Acids↗