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Biomedical subjects

T Okazaki

Publications and source records attributed to T Okazaki.

At least 451 records · Page 25Linked to original sources
PubMed1981

Phosphatidylinositol-specific phospholipase C in fetal membranes and uterine decidua.

An assay procedure was developed in which phosphatidyl[2-(3)H]inositol was employed as substrate for the measurement of phosphatidylinositol-specific phospholipase C activity. Employing this assay, phosphatidylinositol-specific phospholipase C activity in human fetal membranes and uterine decidua was identified and characterized. The specific activity of this enzyme in amnion (4.4 mumol x mg(-1) protein x h(-1)) was three times that in uterine decidua and more than five times that in chorion laeve. No difference was found between the specific activity of phosphatidylinositol-specific phospholipase C in placental amnion and that in reflected amnion. The products of phosphatidylinositol hydrolysis in short-term incubations were stoichiometric amounts of diacylglycerol and inositol-1,2-cyclic-phosphate plus inositol-1-phosphate. After longer periods of incubation, monoacylglycerol also was detected. Diacylglycerol lipase activity also was demonstrated in these tissues. More than 90% of phosphatidylinositol-specific phospholipase C activity of amnion tissue was recovered in the 105,000-g supernatant fraction, and optimal enzymatic activity in vitro was observed at pH 6.5-7.5 in the presence of Ca(2+) (8 mM) and mercaptoethanol (4 mM). Phosphatidylinositol-specific phospholipase C activity was stimulated by fatty acids in low concentrations, but was inhibited by lysophosphatidylcholine and a variety of detergents. No effect of labor on the specific activity of phosphatidylinositol-specific phospholipase C in either fetal membranes or uterine decidua could be detected. The finding of an active phosphatidylinositol-specific phospholipase C activity in human fetal membranes and uterine decidua is complementary to our previous finding of a selective loss of arachidonic acid from phosphatidylinositol of human fetal membranes during labor. The action of phosphatidylinositol-specific phospholipase C, coupled to diacylglycerol lipase action, could provide a mechanism for the release of arachidonic acid for prostaglandin biosynthesis during parturition.

Arachidonic Acids↗
PubMed1981

Candiplanecin, a new antibiotic from Ampullariella regularis subsp. mannitophila subsp. nov. I. Taxonomy of producing organism and fermentation.

A soil isolate of actinomycete, strain No. 43871 produced a new antifungal antibiotic, candiplanecin. Pale brownish to yellow orange color of colonies on agar media, the formation of bottle-shaped, cylindrical sporangia bearing motile spores and the presence of meso-DAP and glycine in the cell wall ascribed this strain to genus Ampullariella. From its morphological characteristics together with the cultural and physiological features, this strain was determined to be a new subspecies of Ampullariella regularis and designated as Ampullariella regularis subsp. mannitophila subsp. nov. (FERM-P No. 5646). Production of candiplanecin was carried out by conventional submerged culture, in which 2 micrograms/ml as the highest antibiotic titer was obtained.

Actinomycetales↗
PubMed1981

Computer assisted medical record retrieval system.

A medical record retrieval system for access to patients' records has been developed as the first step toward constructing a medical record data base. Since retrieval is a logical process, a logical system was used to describe the retrieval conditions. For access to a patient set having a number of medical data of interest, the patients concerned are taken as one set for each data item. and a logical computation is carried out between several selected sets to obtain the required set. The retrieval conditions can be designated in two categories, admission and history, thus enabling quite flexible retrieval condition to be described. Since retrieval is one-line, the major file key was introduced to reduce response time and file access frequency.

Computers↗
PubMed1980

Distribution of the phosphatidate phosphohydrolase activity in the lamellar body and lysosomal fractions of lung tissue.

Phosphatidate phosphohydrolase (PAPase) activity was measured in lamellar bodies purified from porcine lung tissue. After repeated freeze-thawing, only a negligible amount of PAPase activity was released into the soluble fractions, whereas there was release of 2 lysosomal marker enzyme activities, glucosaminidase and beta-galactosidase into the soluble fraction. In addition, a lysosomal-enriched fraction was prepared from adult rat lung tissue by prior treatment of the rats with Triton WR 1339. Treatment with Triton WR 1339 resulted in the significant shift of the activities of the lysosomal marker enzymes, glucosaminidase and beta-galactosidase, to less dense subcellular fractions. The highest specific activity of PAPase was found in a subcellular fraction which had a density that was intermediate between that of the mitochondrial and microsomal fractions and the distribution of PAPase activity was not affected by the prior treatment of the rats with Triton WR 1339.

Animals↗
PubMed1979

RNA-linked nascent DNA pieces in phage T7-infected Escherchia coli. II. Primary structure of the RNA portion.

Short DNA chains were purified from phage T7 infected E. coli cells and 5' ends were labeled with 32P. By an alkali-treatment, pNp's rich in pAp and pCp were liberated from the T7 short DNA chains. After digestion of the [5'-32P] short DNA with the 3' to 5' exonuclease of T4 DNA polymerase, [5'-32P] mono- to pentaribonucleotides tipped with a deoxyribonucleotide residue at their 3' ends were isolated. 5' terminal ribonucleotides were; exclusively AMP in the penta- and the tetraribonucleotides, mostly CMP in the triribonucleotide and mainly CMP and AMP in di- and monoribonucleotides. The 5' terminal dinucleotide of the penta- and the tetraribonucleotides was pApC. The nucleotide sequence of the tetraribonucleotide was mainly pApCpCpN and some pApCpApN, where N was mainly A and C. These results indicate that oligoribonucleotides shorter than trinucleotide may result from in vivo degradation of the tetra- and pentaribonucleotides. A possibility that the tetra- and pentaribonucleotides with a 5' triphosphate terminus are the intact primers for the discontinuous T7 DNA replication is discussed.

Base Sequence↗
PubMed1979

RNA-linked nascent DNA pieces in phage T7-infected Escherichia coli. III. Detection of intact primer RNA.

RNA-linked DNA fragments of T7-infected Escherichiacoli were labeled with [(32)P]orthophosphate invivo. The RNA segments of the labeled fragments were isolated by degrading the DNA portion with the 3'--> 5' exonuclease intrinsic to bacteriophage T4 DNA polymerase and fractionated according to net charge by a DEAE-Sephadex A-25 column chromatography in the presence of 7 M urea. Tri-, tetra- and pentanucleotides were obtained which have ATP residues at their 5' ends. Most of the pentanucleotides had a single deoxynucleotide at the 3' end but a minor portion was totally an oligoribonucleotide. In the light of prior results, the former is a cooligomer of an intact tetraribonucleotide primer and a monodeoxynucleotide and the latter is an intact pentaribonucleotide primer. Tri- and tetraribonucleotides with ATP at the 5' ends had no deoxynucleotide at the 3' ends, therefore it is not clear if intact triribonucleotide primers are present. The 5'-terminal dinucleotides of the tetra- and pentanucleotides were mostly pppApC and a trace amount of pppApA was present.Images

Base Sequence↗
PubMed1979

Liver ribonucleases from the bullfrog, Rana catesbeiana. Purification, properties and changes in activity during metamorphosis.

A major and three minor RNAases exhibiting activity at neutral pH were found in bullfrog liver homogenates. These RNAases were purified to electrophoretic homogeneity. Total purification was 1100 to 1600-fold, and the average recovery was 35%. The molecular weight estimated by gel filtration and SDS-urea-polyacrylamide gel electrophoresis was 12,000 for all the components. An antibody against the major RNAase (component B) reacted with the major RNAase to form a single precipitin line on double immunodiffusion and inhibited the activity of the major RNAase but did not cross-react with the other three components and bovine pancreatic RNAase A. Amino acid analyses revealed that the major RNAase differed markedly from the other three RNAase components in the contents of ten amino acid residues, whereas the minor RNAases were similar to each other. The major RNAase was contained in both frog and tadpole liver and its activity in the liver markedly increased at the metamorphic climax.

Amino Acids↗