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Biomedical subjects

K Ogata

Publications and source records attributed to K Ogata.

At least 433 records · Page 24Linked to original sources
PubMed1985

Purification and N-terminal amino acid sequence of proliferating cell nuclear antigen (PCNA)/cyclin and development of ELISA for anti-PCNA antibodies.

Proliferating cell nuclear antigen (PCNA), also called cyclin, was purified from PBS extract of rabbit thymus by using a combination of ammonium sulfate fractionation, DEAE-Sephacel, HPLC ion exchange, and HPLC gel filtration column chromatography. PCNA was purified more than 600 times and was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. SDS-PAGE showed that a 36 kD protein was selectively isolated in this purification process, and this protein was identified as PCNA by immunoblotting. Other previously identified nuclear antigens, Sm, nRNP, SS-A/Ro, SS-B/La, histone, and DNA, were not detected in this preparation by counterimmunoelectrophoresis and enzyme-linked immunosorbent assay (ELISA). Purified PCNA was used as an antigen to develop ELISA for rapid and specific detection of anti-PCNA in human sera. For further purification, the 36 kD band was electrophoretically eluted from SDS gel slices. The amino acid composition and the first 25 residues from the N-terminus of the protein were determined by using electroeluted PCNA. This amino acid sequence was found to be unique and showed little sequence homology with existent proteins in the protein identification resources databank.

Amino Acid Sequence↗
PubMed1985

The effect of surgical dissection on regional blood flow to the ulnar nerve in the cubital tunnel.

Regional blood flow to the ulnar nerve within the cubital tunnel of nonhuman primates was determined before and after surgical dissection by use of the hydrogen washout technique. The results indicate that anterior transposition is associated with a significant decrease in regional blood flow to the ulnar nerve for a period of at least three days. This relative ischemia was not noted following arcuate ligament incision or after medial humeral epicondylectomy. Vascular injection studies showed an abundant extrinsic arterial supply to the ulnar nerve, especially just distal to the groove that was apparently compromised during the anterior transposition.

Animals↗
PubMed1984

Effects of cell sap, ATP, and RNA synthesis on the transfer of ribosomal proteins into nuclei and nucleoli in a rat liver cell-free system.

To investigate the mechanism for the transfer of ribosomal proteins from cytoplasm into nuclei and nucleoli, the uptake of 3H-labelled ribosomal proteins by the isolated rat liver nuclei was investigated in the system containing ATP, GTP, CTP, UTP, and an energy-regenerating system. In the presences of cell sap, the transfer became temperature-dependent. The concentration of ribosomal proteins was also very important for their specific transfer and 10-15 micrograms of ribosomal proteins/ml were suitable in the presence of 10(7) nuclei. Removal of one of the four nucleoside triphosphates from the complete system containing cell sap, especially that of CTP or UTP, resulted in a marked decrease of the uptake. A low concentration of actinomycin D inhibited significantly the transfer of ribosomal proteins, while alpha-amanitin to a less extent. The results indicate that the uptake of ribosomal proteins by liver nuclei is largely dependent on RNA synthesis especially rRNA synthesis. The transfer was enhanced to some extent by ATP alone. Other nucleoside triphosphates were less effective. Non-hydrolyzable ATP analogues, adenosine 5'-[beta, gamma-methylene]triphosphate and adenosine 5'-[alpha, beta-methylene]-triphosphate were only slightly stimulative. Although ATP enhanced the transfer into the extranucleolar fraction to some extent, the maximal transfer not only into nucleoli but also into the extranucleolar fraction was dependent on the rRNA synthesis. Sedimentation analyses of the nucleolar fraction of rat liver nuclei incubated with [3H]GTP or 3H-labelled ribosomal proteins, showed that small but distinct amounts of the both labelled compounds were incorporated into 60S preribosomal particles although most of them were found in ribonucleoprotein particles below 30S which were previously shown to be degraded products containing larger rRNA precursors [Tsurugi, K., Morita, T., and Ogata, K. (1972) Eur. J. Biochem. 25, 117-128].

Adenosine Triphosphate↗
PubMed1984

Purification and properties of a thiol protease from rat liver nuclei.

A thiol protease was purified about 800-fold from the chromatin fraction of rat liver by employing Sepharose 6B gel filtration, chromatofocusing and Sephadex G-100 gel filtration. It was nearly homogeneous on sodium dodecyl sulfate/polyacrylamide gel electrophoresis and its molecular weight was about 29000. The isoelectric point of the enzyme was 7.1. The pH optimum for degradation of 3H-labelled ribosomal proteins was 4.5. It is noticeable that the maximal activity was shifted to pH 5.5 by DNA, and that 30-40% of the maximal activity was observed at neutral pH in the presence of DNA. The activity was increased about twice by 2-4 mM dithiothreitol. The protease may be specific for the nuclei because it is different from all lysosomal thiol proteases ever known.

Animals↗
PubMed1984

Hepatic hematoma after blunt trauma--a case of nonoperative management to prevent liver abscess formation.

In an eighteen-year-old boy with a high fever, an intra-hepatic infectious hematoma following blunt hepatic trauma was treated twice with intrahepatic arterial injection chemotherapy in an attempt to prevent conversion of the hematoma to an abscess. A decrease in body temperature occurred after the arterial injections, and the hematoma was gradually diminished in size. In selected patients with blunt hepatic trauma, intrahepatic arterial injection chemotherapy seems to be an effective treatment for prevention of liver abscess formation.

Adolescent↗
PubMed1984

Ophthalmic and norophthalmic acid in lens, liver, and brain of higher animals.

A sensitive high-performance liquid chromatographic method for the determination of nanomole levels of ophthalmic and norophthalmic acid has been described. The procedure is based upon the conversion of amino group to 2,4-dinitrophenyl derivatives and the detection at 420 nm. This method was applied to the determination of the peptides in lens, liver, and brain of several animals. Mean recoveries were 93.6% for ophthalmic acid and 92.3% for norophthalmic acid added to cattle lens homogenate.

Animals↗
PubMed1984

The permeability of the blood-brain barrier to protein in the post-hypoxic cerebral edema of the rat.

The permeability of the blood-brain barrier to protein was studied in the post-hypoxic cerebral edema of rats, using horseradish peroxidase (HRP) as a tracer protein. Under halothane anesthesia, HRP was injected intravenously. Then the animals were exposed to hypoxic-ischemia by inhalation of 5% oxygen in nitrogen and temporary occlusion of the left common carotid artery for 10-30 min. Twenty-four, 48 or 72 h after the hypoxic experiments, the animals were anesthetized with sodium pentobarbital and their body tissues were fixed by perfusion with a mixture of glutaraldehyde and p-formaldehyde before the autopsy. No brain edema was observed in the animals exposed to hypoxia for 10 min, but the animals exposed to hypoxia for 20-30 min revealed a left hemispheric brain edema. The brain was immediately immersed in the same fixatives, and then sectioned with a cryostat. The sections were stained histochemically according to the method of Graham and Karnovsky (1966) to identify the distribution of the HRP. HRP was not found even in the edematous hemisphere. In this type of brain edema, it is suggested that there was no acceleration of permeability of blood-brain barrier to serum proteins whose molecular weights were larger than HRP, and therefore it would have no causative relationship with the production of brain edema.

Animals↗
PubMed1984

Vertically growing ectopic nail. Nature's experiment on nail growth direction.

The cul-de-sac in which the nail is formed determines that it should grow outward instead of upward according to Kligman. This view was questioned by Baran based on clinical observations and review of the literature. A case of vertically growing ectopic nail of congenital origin indicated that the cul-de-sac was directed to the skin surface and the nail was growing vertically to the skin. The anatomy of the cul-de-sac, which may be influenced by local factors, appears to determine the direction of the nail.

Choristoma↗
PubMed1984

Molecular cloning and nucleotide sequence of DNA complementary to human decidual prolactin mRNA.

Three human decidual prolactin (PRL) cDNA clones (pdPL-1:349 base pairs, pdPL-2:584 base pairs, pdPL-3:807 base pairs without poly(A) tract) were prepared and sequenced. The insert DNA of the largest clone pdPL-3 contained the coding region corresponding to 217 amino acid residues including 18 amino acid residues of the signal peptide, and 157 nucleotides of the 3'-untranslated region. A comparison of the pdPL-3 cDNA sequence with that of human pituitary PRL cDNA revealed 4 silent nucleotide differences. Two of the base changes occurred in the third position of the amino acid codons, and the other two occurred in the 3'-untranslated region. Therefore, the amino acid sequence of decidual PRL deduced from the nucleotide sequence of pdPL-3 was identical with that of pituitary PRL. Minor changes were also observed among the three PRL mRNAs: a silent change in the third codon in the translated region, and another change in the 3'-untranslated region. Southern blot hybridization of human cellular DNA with the pdPL-3 probe indicates that PRL gene may occur once per haploid genome. Therefore, these minor changes may reflect microheterogeneity of PRL gene. The existence of multiple poly(A)-adjacent sequences was shown in the three species of human decidual PRL mRNA and in human pituitary PRL mRNA. This variation may be due to heterogeneity in the processing at the 3' terminus of mRNA or the termination sites of the transcription.

Amino Acid Sequence↗
PubMed1984

Immunoenzymatic detection of three kinds of 43,000-molecular-weight antigens by monoclonal antibodies in the insoluble fraction of Toxoplasma gondii.

Monoclonal antibodies (TpM 3, TpM 6, and TpM 19) against Toxoplasma gondii insoluble antigens were produced by the hybridization of NS-1, a mouse myeloma cell line, with spleen cells from mice immunized with T. gondii insoluble antigens. TpM 3, TpM 6, and TpM 19 were characterized by the dye test, the latex agglutination test, two types of enzyme-linked immunosorbent assays, using either T. gondii supernatant antigens or T. gondii insoluble antigens, and immunoperoxidase staining. TpM 3, TpM 6, and TpM 19 antigens were analyzed by the immunoblotting method, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretic transfer of the antigens to nitrocellulose sheets. TpM 3, TpM 6, and TpM 19 were all negative by the dye test, the latex agglutination test, and the enzyme-linked immunosorbent assay, using T. gondii supernatant antigens but positive by the enzyme-linked immunosorbent assay, using T. gondii insoluble antigens. Each antibody gave unique spot patterns in the cytoplasm of tachyzoites, and each detected antigens of ca. 43,000 molecular weight with different electrophoretic patterns. Purified TpM 3 antigen bound only to TpM 3 but not to TpM 6 or TpM 19. Comparable results were obtained with TpM 6 and TpM 19 antigens. Rabbit anti-T. gondii sera reacted with both TpM 3 and TpM 19 antigens. However, human anti-T. gondii sera reacted only with TpM 3 antigen. These results indicate that T. gondii insoluble antigens contained at least three types of 43,000-molecular-weight antigens that have been revealed for the first time in this paper.

Animals↗