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Biomedical subjects

K Ogata

Publications and source records attributed to K Ogata.

At least 415 records · Page 23Linked to original sources

Inherited deficiency of protein S in a Japanese family with recurrent venous thrombosis: a study of three generations.

We found a new thrombophilic tendency in a family with protein S deficiency. The propositus, a 38-year-old Japanese man, is an offspring of consanguineous marriage and suffered from recurrent episodes of thromboembolism. Hemostatic studies, including platelet counts, platelet aggregation, assays of coagulation factors, and plasminogen activity were all within normal limits. The levels of antithrombin III, alpha 2-macroglobulin, protein C, and protein C inhibitor were also normal. However, functional protein S activity in plasma was markedly decreased (9%) in the propositus. The family study revealed that the reduced levels of functional protein S, less than 5% to 29% of normal (normal range: mean +/- 2 SD of 15 normal adults were 44 to 180%), were found in 11 members of this family over three generations. Six of 11 members had severe protein S deficiency (less than 5%), whereas five had partial deficiency. Four of eight adults with protein S deficiency had recurrent episodes of thrombosis. Immunologic levels of protein S antigen were variable in this family and did not correlate closely with the functional levels. These results suggest that the recurrent thrombotic disease in this family appears to be associated with an inherited deficiency of functional protein S.

Blood Coagulation Factors↗

Experimental study on thermal burns caused by plaster bandage.

Plaster bandage is frequently used in the field of orthopaedic surgery. Little is known however of thermal burns caused by plaster bandage. Experience has shown that heat producing levels differ depending on application conditions, i.e., water temperature into which plaster of Paris is dipped, thickness of the plaster cast, kind of plaster, etc. We made a series of experiments to find out what factors are related to elevation of the skin temperature in a plaster splint applied to a human forearm. The highest skin temperature of 47.7 degrees C was obtained upon application of a plaster bandage made of 30 layers of plaster with short setting time, dipped in water at 42 degrees C. In this condition the examinee had a first degree burn on the skin surface. Thus, care must be taken in applying a plaster bandage to assure that it does not cause a serious burn to the skin.

Burns↗

Coupled transcription and processing of mouse ribosomal RNA in a cell-free system.

An in vitro processing system of mouse rRNA was achieved using an RNA polymerase I-specific transcription system, (S100) and recombinant plasmids consisting of mouse rRNA gene (rDNA) segments containing the transcription initiation and 5'-terminal region of 18S (or 41S) rRNA. Pulse-chase experiments showed that a specific processing occurred with transcripts of the plasmid DNAs when the direction of transcription was the correct orientation relative to the 18S rRNA coding sequence, but not with transcripts of the DNA templates in which this coding sequence was in the opposite orientation. From the S1 nuclease protection analyses, we concluded that there are several steps of endonucleolytic cleavage including one 105 nucleotides upstream from the 5' end of 18S rRNA. Intermediates cleaved at this site were identified in in vivo processing of rRNA. This result indicates that endonucleolytic cleavage takes place 105 nucleotides upstream from the 5' terminus of 18S rRNA prior to the formation of mature 18S rRNA. Trimming or cleavage of the 105 nucleotides may be involved in the formation of the 5' terminus of mature 18S rRNA.

Animals↗

Attachment of the 5'-terminal portion of globin mRNAs to 5S-RNA X L5-protein in the 80S initiation complex.

An 80S initiation complex was formed by incubating a heterologous cell-free system with 125I-labeled globin mRNAs in the presence of sparsomycin. The 80S initiation complex was then digested with micrococcal nuclease. The ribosomal 5S-RNA X L5-protein (5S RNP) fraction, released by EDTA treatment, contained 125I-labeled mRNA fragments. The attachment of labeled mRNA fragments to 5S RNP was shown by (a) CsCl isopycnic centrifugation, (b) recentrifugation through a sucrose density gradient and (c) acrylamide gel electrophoresis of 5S RNP purified by (b). Labeled fragments were released from 5S RNP by treatment with sodium dodecyl sulfate or pronase, indicating the participation of protein L5 in the attachment. The attached mRNA fragments were 23-25 nucleotides in length. Hybridization experiments, using restriction fragments of cDNA for rabbit beta globin mRNA, showed that the attached mRNA fragments were derived from the 5' portion of globin mRNAs. The attachment of 125I-labeled mRNA fragments to 5S RNP was also observed in the 80S initiation complex formed by incubation of reticulocyte lysate with 125I-labeled globin mRNA, but not in labeled polysomal fractions. These findings may indicate that 5S RNP interacted with the 5' portion of globin mRNA, containing the translation initiation codon of globin mRNA in the 80S initiation complex. The biochemical significance of these results is discussed.

Animals↗

Nucleotide sequence of cloned cDNA specific for rat ribosomal protein S11.

A cDNA clone specific for rat ribosomal protein S11 was isolated by hybrid-selected translation from the cDNA library made for 8-9 S poly(A) RNA from regenerating rat liver. Since this cDNA had not enough length, another clone was selected by colony hybridization using a fragment of isolated cDNA as a probe. The nucleotide sequence of the cDNA was determined. The sequence contains 2 base pairs from the 5' noncoding region, the entire coding region of 477 base pairs, and the 3' noncoding region of 55 base pairs besides the poly(A) tail. The primary structure of the protein S11 was deduced from the nucleotide sequence. It consists of 157 amino acids. Its molecular weight is 18,299. The calculated amino acid composition is consistent with the reported composition of S11 determined on the protein hydrolysate. The amino acid sequence showed a marked homology with that of S16 of Halobacterium cutirubrum and an appreciable homology with that of S17 of Escherichia coli.

Amino Acid Sequence↗

Neighboring proteins in rat liver 60 S ribosomal subunits disulfide-linked by hydrogen peroxide oxidation or cross-linked with dithiobis(succinimidyl propionate).

Neighboring proteins in rat liver 60 S ribosomal subunits were investigated by two kinds of cross-linking techniques: treatment of 60 S subunits with 1) hydrogen peroxide, which promotes the formation of protein-protein disulfide linkages and 2) a disulfide-bridged bifunctional reagent dithiobis(succinimidyl propionate). The cross-linked protein complexes formed were separated by two-dimensional polyacrylamide gel electrophoresis in a basic-sodium dodecyl sulfate gel system under nonreducing conditions. Each complex in the gel was labeled with 125I and extracted under reducing conditions. The protein components of the complex were analyzed by two kinds of two-dimensional polyacrylamide gel electrophoresis, followed by autoradiography. Closely neighboring pairs disulfide-linked by hydrogen peroxide were identified as L4-L6, L4-L29, L6-L29, L18a-L29, and L29-L32; more distant pairs cross-linked with dithiobis(succinimidyl propionate) were identified as L3-L5, L3-L24, L3-L37a, L4-L14, L4-L18a, L5-L10, L5-L11, L7/L7a-L27, L7/L7a-L36, L13-L35, and L13a-L14.

Animals↗

Cross-linking study on protein topography of rat liver 60 S ribosomal subunits with 2-iminothiolane.

Rat liver 60 S ribosomal subunits were modified with 2-iminothiolane. After treatment with hydrogen peroxide, the cross-linked proteins were extracted and then separated into 24 fractions by chromatography on carboxymethylcellulose. Each protein fraction was then analyzed by diagonal polyacrylamide-sodium dodecyl sulfate gel electrophoresis (Sommer, A., and Traut, R.R. (1974) Proc. Natl. Acad. Sci. U. S. A. 71, 3946-3950). The pieces of gel containing cross-linked protein spots that were shifted from the diagonal line were labeled with 125I. The labeled protein was extracted from the gel and identified by three kinds of two-dimensional gel electrophoresis, followed by autoradiography. Fifty-three cross-linked protein pairs involving 35 protein species containing two acidic proteins were identified. From these and previous results, a preliminary model of the protein topography of the 60 S ribosomal subunit was constructed and discussed in relation to other functional data on 60 S ribosomal proteins.

Animals↗

Estrogen-mediated induction of a vitellogenin-specific nonhistone chromatin protein in the male chicken liver.

Non-histone chromatin proteins prepared from the livers of estrogen-treated and nontreated male chickens were compared by reverse-phase high performance liquid chromatography (RP-HPLC), followed by sodium dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results revealed that the hormone-treated male liver chromatin contained a specific protein corresponding to the vitellogenin-specific protein previously purified from the liver of egg-laying hens (Nakayama 1985). The chicken protein, purified further by gel-filtration high performance liquid chromatography (GF-HPLC), showed specific binding activity to DNA fragments carrying a part of the vitellogenin gene. On the basis of similarities in the elution patterns from GF-HPLC and RP-HPLC as well as in the mobility on SDS-PAGE, we concluded that this hormone-induced protein in the male chicken liver was identical to the vitellogenin-specific protein identified in the hen liver, and assumed it to be a specific regulatory protein for the vitellogenin gene expression. The amino acid composition of this chicken protein has been determined.

Amino Acids↗

Molecular cloning and nucleotide sequences of cDNAs specific for rat liver ribosomal proteins S17 and L30.

cDNA clones coding for rat liver ribosomal proteins S17 and L30 have been isolated by positive hybridization-translation assay from a cDNA library prepared from 8-9S poly(A)+RNA from free polysomes of regenerating rat liver. The cDNA clone specific for S17 protein (pRS17-2) has a 466-bp insert with the poly(A) tail. The complete amino acid (aa) sequence of S17 protein was deduced from the nucleotide sequence of the cDNA. S17 protein consists of 134 aa residues with an Mr of 15 377. The N-terminal aa sequence of S17 protein determined by automatic Edman degradation is consistent with the sequence data. The aa sequence of S17 shows strong homology (76.9%) to that of yeast ribosomal protein 51 [Teem and Rosbash, Proc. Natl. Acad. Sci. USA 80 (1983) 4403-4407] in the two-thirds N-terminal region. The cDNA clone specific for L30 protein (pRL30) has a 394-bp insert. The aa sequence of L30 protein was deduced from the nucleotide sequence of the cDNA. The protein consists of 114 aa residues with an Mr of 12 652. When compared with the N-terminal aa sequence of rat liver L30 protein [Wool, Annu. Rev. Biochem. 48 (1979) 719-754], pRL30 was found not to contain the initiation codon and 5'-noncoding region. The cDNA showed twelve silent changes in the coding region, one point mutation and one base deletion in the 3'-noncoding region, compared with mouse genomic DNA for L30 protein [Wiedemann and Perry, Mol. Cell Biol. 4 (1984) 2518-2528].

Amino Acid Sequence↗

Pharmacology of ephedroxanes.

On the central nervous system, ephedrine showed intense stimulatory activities but pseudoephedrine mediated weaker influences, while ephedroxane and pseudoephedroxane exerted inhibitory actions. The effects of ephedroxane were generally intense as compared with those of pseudoephedroxane. On the autonomic nervous system, the ephedrines contracted vas deferens and potentiated the effect of norepinephrine, while the ephedroxanes elicited no contraction of vas deferens but potentiation of the action of norepinephrine in the catecholaminergic nervous system. In antihistamine and antibarium activity, the ephedrines elicited remarkable actions but the effects of the ephedroxanes were weak.

Analgesics↗

Nutrient pathways to extensor tendons of primates.

The nutrient pathways to the extensor tendon beneath the extensor retinaculum of young adult monkeys was investigated using hydrogen as tracer material. The results indicate that diffusion from the synovium is a more significant nutrient pathway than vascular perfusion from either the mesotendon or the longitudinal intratendinous vascular network.

Animals↗

Molecular cloning and nucleotide sequence of DNA complementary to rat ribosomal protein S26 messenger RNA.

A cDNA clone specific for rat ribosomal protein S26 was isolated by a positive hybridization translation assay from a cDNA library made for 8-9S poly(A)mRNA from regenerating rat liver. The nucleotide sequence of the cDNA was determined. The sequence contains 23 base pairs in the 5' noncoding region, 345 base pairs in the protein coding region and 67 base pairs in the 3' noncoding region besides the poly(A) tail. The primary structure of the protein S26 was deduced from the nucleotide sequence. It consists of 115 amino acids. Its molecular weight is 13,015 and its pI is about 11.1. The calculated amino acid composition is consistent with the reported composition of S26. From the results of Southern blot analysis, the protein S26 appears to have multiple genes.

Amino Acid Sequence↗

Evidence for the exchangeability of acidic ribosomal proteins on cytoplasmic ribosomes in regenerating rat liver.

We purified acidic ribosomal proteins (P1 and P2) in good yield from rat liver ribosomes by precipitation of ribosomes with MgCl2 prior to ethanol extraction and chromatography of the extract on a column of CM-cellulose at pH 4.8. The newly-synthesized acidic ribosomal proteins in regenerating rat liver, labeled in vivo with [3H]leucine, were rapidly incorporated into cytoplasmic ribosomes without any detectable time lag and, after reaching a maximum at 30 min, they gradually disappeared from the ribosomes, suggesting a short metabolic-life. However, it was found later that they were re-incorporated slowly when newly-labeled proteins were "chased" by an injection of a large amount of cold leucine intraperitoneally at 15 min after the injection of [3H]leucine. Furthermore, in a long-term experiment, acidic ribosomal proteins were found to disappear with a half-life of 100 h from the ribosomes. Thus, these results suggest that acidic ribosomal proteins have a long metabolic life and are exchangeable on cytoplasmic ribosomes in regenerating rat liver.

Animals↗

Hepatocellular carcinoma and metastatic cancer detected by iodized oil.

An oily contrast medium was injected into the hepatic artery in rabbits with implanted VX2 carcinoma in the liver. The contrast medium was initially detected in all of the branches of the injected artery, but 3 and 7 days after injection it was found only in the tumor tissue on plain radiographs. Taking advantage of this phenomenon, an oily contrast medium was injected into the hepatic artery in 5 patients with liver tumors. A plain radiograph of the abdomen after the injection presented a clearer picture of the tumor and detected smaller tumors, compared with a conventional selective celiac angiogram in 5 patients. It is concluded that an injection of oily contrast medium into a hepatic artery is a useful technique to detect liver tumor.

Adenocarcinoma↗