Search PubMed⌕ Search

Biomedical subjects

T Harada

Publications and source records attributed to T Harada.

At least 1,225 records · Page 68Linked to original sources
PubMed1976

A clottable protein (coagulogen) from amoebocyte lysate of Japanese horseshoe crab (Tachypleus tridentatus). Its isolation and biochemical properties.

A clottable protein, named coagulogen, was highly purified from the amoebocyte lysate of Japanese horseshoe crab (Tachypleus tridentatus) by a method similar to that used for the lysate of Limulus polyphemus amoebocytes. The isolated material gave a single protein band on analytical gel electrophoresis at pH 3.2, gel electrofocusing, and sodium dodecyl sulfate (SDS) gel electrophoresis with or without 2-mercaptoethanol. It was 90 percent coagulable, and the total yield from 10 ml of the amoebocyte lysate was about 40 mg. The sedimentation coefficient of purified coagulogen was 2.6 S and its molecular weight was estimated to be about 15,300 by sedimentation equilibrium analysis. The molecular weight estimated by SDS-gel electrophoretic analysis was 19,500 +/- 1,000. This discrepancy was apparently due to abnormal mobility arising from the basic nature of this protein on electrophoresis. The protein had a high isoelectric point of pH 10.0 +/- 0.2, as measured by the isoelectric focusing technique. It consisted of a total of 132 to 135 amino acid residues and contained high levels of basic amino acids, which accounted for more than 16 per cent of the total amino acid residues. No methionine was detected. High contents of valine, half-cystine, glutamic acid (glutamine), and phenylalanine were found. The N-terminal sequence of the first three residues of the coagulogen was Ala-Asx-Thr, and its C-terminal residues was identified as phenylalanine, indicating that it consists of a single polypeptide chain. It is of interest that the first three N-terminal residues are homologous with those of the Aalpha-chain of non-human primate fibrinogen.

Amino Acids↗
PubMed1976

Immune response against hamster erythrocytes in the low-responder mouse strains. XI. Strain difference in the effects of various microbial adjuvants.

Enhancing and suppressing effects of microbial adjuvants were studied in female mice of the C3H/He, AKR and SL strains. Propionibacterium acnes, Bordetella pertussis, BCG and yeast cell wall (YCW) were chosen as adjuvants. As antigens, we chose hamster erythrocytes (HRBC) which proved to be a weak antigen for mice. Adjuvants were given on day --7, day 0 or day 3, and HRBC were injected on day 0. The results were as follows. 1) P. acnes facilitated IgM and IgG antibody production in AKR mice and suppressed IgM antibody production in SL mice, when given on day --7. When P. acnes was given on day 0, they suppressed IgM antibody production in all of the strains used. 2) When B. pertussis was given on day 0, it exhibited enhancing effects on IgG antibody production in all of the strains and a suppressing effect on IgM antibody production in SL mice. 3) BCG suppressed IgM antibody production in all strains when given on day 0. 4) YCW showed no influence on antibody production in any combination used in this work. 5) SL mice were very sensitive to suppressing effects by adjuvants. Strain differences in the expression of enhancing and suppressing effects by adjuvants appear to be under some control independent of antigen-specific immune response genes.

Adjuvants, Immunologic↗
PubMed1976

Regulation of tyramine oxidase synthesis in Klebsiella aerogenes.

Tyramine oxidase in Klebsiella aerogenes is highly specific for tyramine, dopamine, octopamine, and norepinephrine, and its synthesis is induced specifically by these compounds. The enzyme is present in a membrane-bound form. The Km value for tyramine is 9 X 10(-4) M. Tyramine oxidase synthesis was subjected to catabolite repression by glucose in the presence of ammonium salts. Addition of cyclic adenosine 3',5'-monophosphate (cAMP) overcame the catabolite repression. A mutant strain, K711, which can produce a high level of beta-galactosidase in the presence of glucose and ammonium chloride, can also synthesize tyramine oxidase and histidase in the presence of inducer in glucose ammonium medium. Catabolite repression of tyramine oxidase synthesis was relieved when the cells were grown under conditions of nitrogen limitation, whereas beta-galactosidase was strongly repressed under these conditions. A cAMP-requiring mutant, MK54, synthesized tyramine oxidase rapidly when tyramine was used as the sole source of nitrogen in the absence of cAMP. However, a glutamine synthetase-constitutive mutant, MK94, failed to synthesize tyramine oxidase in the presence of glucose and ammonium chloride, although it synthesized histidase rapidly under these conditions. These results suggest that catabolite repression of tyramine oxidase synthesis in K. aerogenes is regulated by the intracellular level of cAMP and an unknown cytoplasmic factor that acts independently of cAMP and is formed under conditions of nitrogen limitation.

Amino Acid Oxidoreductases↗
PubMed1976

Some properties of p-coumarate decarboxylase from Cladosporium phlei.

The optimal pH and temperature of p-coumarate decarboxylase were 6.0 and 23 degrees C respectively. The enzyme activity was reduced to three quarters by heat treatment at 35 degrees C for 5 min and by half at 25 degrees C in 24 h, but kept almost unchanged at -20 degrees C at least for 10 days. The activity was not inhibited by potassium cyanide, sodium diethyldithiocarbamate, ethylenediaminetetraacetic acid disodium salt, or sodium citrate at 10 mM concentration, but was inhibited by p-chloromercuribenzoate or iodoacetate at 0.1 mM, the inhibition by the former being prevented to a great extent by the presence of reduced glutathione or dithiothreitol. The activity was inhibited by maleic acid cinnamic acid, or p-methoxycinnamic acid, but not by fumaric acid, acrylic acid, p-hydroxystyrene, furcatin p-hydroxyphenylacetic acid, or phloretic acid. An unsubstituted p-hydroxy group on the benzene ring and an acrylic acid side chain were required for the enzyme activity. Km value for trans-p-coumaric acid was about 6.5 X 10(-4) M.

Carbon Dioxide↗
PubMed1976

Atigenic similarity between Ceratocystis species and Sporothrix schenckii as observed by immunofluorescence.

Antigenic properties of Sporothrix schenckiii and 2 species of Ceratocystis (C. stenoceras and C. ulmi) were compared by indirect immunofluorescent staining technique. Both species of Ceratocystis and 2 strains of S. schenckii reacted equally well with the unabsorbed antisera against 2 strains of S. schenckii, indicating that these three species share common antigen. The absorption experiments showed that only S. schencki human strain demonstrated a unique antigen. These results support the hypothesis of Ceratocystis-Sporothrix complex in the point that both species have one major common antigen.

Antigens, Fungal↗
PubMed1975

A Pseudomonas intracellular amylase with high activity on maltodextrins and cyclodextrins.

An intracellular amylase from Pseudomonas MSl was purified 95-fold in a 14% yield by fractionation with (NH4) 2SO4, followed by chromatographies on CM-cellulose, hydroxylapatite and Sephadex G-200. On polyacrylamide gel electrophoresis at pH 8.3 it gave a single band and its molecular weight was determined to be 96 000 from its mobility on sodium dodecylsulfate gel electrophoresis. Its activity was maximal at pH 5.5 and 50 degrees C. This enzyme hydrolyzed maltotriose and maltotetraose faster than amylose, but did not hydrolyze maltose. It also rapidly hydrolyzed a series of cyclomaltodextrins. Amylopectin and glycogen, which have branched structures, were attacked much slower than amylose. The enzyme cleaved the substrates in an endo-wise fashion and produced almost equimolar amounts of glucose and maltose as the final products from various substrates. The enzyme mechanism is discussed on the basis of quantitative autoradiographic data. The K-m values for maltotriose, maltotetraose, cyclomaltohexaose, corn amylose and waxycorn amylopectin were 1.0, 1.4, 3.5, 3.3 and 13 - 10-minus 3 g/ml, respectively. The products of the enzyme had an alpha-configuration. Thus, this enzyme is a specific alpha-amylase.

Amylases↗
PubMed1975

Purification and properties of a beta-1,6-clucosidase from Flavobacterium.

An intracellular beta-1,6-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) was produced semiconstitutively by Flavobacterium M64. This enzyme was purified 180-fold by fractionation with ammonium sulfate followed by chromatographies on carboxymethylcellulose, hydroxyapatite and Sephadex G-100. The final preparation appeared homogeneous on disc electrophoresis on polyacrylamide gel. The molecular weight of the enzyme was determined to be ca. 59 000 by Sephadex G-100 gel filtration and sodium dodecylsulfate-polyacrylamide gel electrophoresis. The optimum pH of the enzyme was 5.8 and the optimum temperature was 40 degrees C. The enzyme readily hydrolyzed oligomers with beta-a,6-glucosidic linkages, converting them to glucose. The Km values for gentio-biose, -triose, -tetraose and -pentaose were 2.8, 3.0, 4.2 and 4.6 times 10- minus 4 M, respectively. The rates of their hydrolyses decreased with increase in their chain lengths. The enzyme was concluded to be a beta-1,6-glucosidase from its substrate specificity, production of glucose, transferring ability and inhibition by glucono-delta-lactone. The enzyme activity was inhibited by Hg-2+, Cu-2+, Ag-+, Fe-3+, p-chloromercuribenzoate, N-ethylmaleimide, glucose and trishydroxyaminomethane (Tris) but not by ethylenediaminetetraacetic acid.

Chromatography↗
PubMed1975

Acute gangrenous colitis proximal to obstructive cancer of the sigmoid colon.

Two cases of massive gangrenous inflammation of the colon proximal to obstructive carcinomatous lesions, the so-called obstructive colitis, are reported. Because of the rarity of this condition, the etiological factors responsible for this entity are not yet clear. The detailed pathological and microbiological studies at the time of operation are essential to their further clarification.

Acute Disease↗
PubMed1975

Studies on biliary bile acid metabolism in hepato-biliary diseases.

Biliary bile acid have been analyzed in patients with various hepato-biliary diseases by thin-layer chromatography, and divided into 4 types of glycine- and taurine-conjugates. The composition of biliary bile acid was different according to the hepatic impairement, and the ratio of glycine-conjugate to taurine-conjugate was decreased in chronic liver diseases. The G/T ratio was 1.49 +/- 0.36 in the control group, but was 0.96 +/- 0.18 in severe liver cirrhosis, and 1.38 +/- 0.44 in chronic active hepatitis. In acute hepatitis, the G/T ratio was low on the initial stage of the diseases, and returned to a normal range upon recovery. There was also a dicrease in the ratio of dihydroxycholic to cholic acid of biliary bile acid in patients with chronic liver diseases. In conclusion, the measurement of bile acid in bile has a diagnostic value for chronic hepatic impairement.

Bile Acids and Salts↗