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Biomedical subjects

T Shiba

Publications and source records attributed to T Shiba.

At least 181 records · Page 10Linked to original sources
PubMed1988

Nucleotide sequence of dengue type 3 virus genomic RNA encoding viral structural proteins.

Complementary DNAs to the 5' proximal region of the dengue virus type 3 RNA were cloned into bacterial plasmids and the nucleotide sequence of 3,000 bases from the 5' terminus of the genome were determined by DNA and RNA sequencing methods using dideoxy chain-termination reactions. Comparison of the nucleotide sequence thus obtained with those of other flavivirus genomes revealed significant homology existing in nucleotide sequence of the flavivirus genomes. When we compared amino acid sequence deduced from the nucleotide sequence with those of other flaviviruses, this genome region was found to include sequences encoding three viral structural proteins C, M, and E and a part of the viral nonstructural protein NS1 in this order in addition to the 5'-noncoding sequence. The characteristics and functions of these proteins were discussed based on the deduced amino acid sequences and their hydrophobic profiles. The genetic relationship of flaviviruses was also discussed based on the genetic variation observed in their genomes.

Amino Acid Sequence↗
PubMed1988

Low molecular weight RNA of Drosophila cells which is induced by heat shock--II. Structural properties.

Heat shock-induced small cytoplasmic RNA (HSI scRNA) from Drosophila culture cell was larger in size after dimethylchloroacetal treatment than in 7 M urea. Judging from its thermal denaturation profile and the nuclease S1 digestion experiment it was supposed that HSI scRNA is double-stranded. Nucleotide sequence analysis of the scRNA also suggested that it is double-stranded RNA with the blunt-ends.

Animals↗
PubMed1988

Structural requirements of endotoxic lipopolysaccharides and bacterial cell walls in induction of interleukin-1.

A variety of compounds, synthetic, semisynthetic or bacterial, which corresponds to structural components of endotoxic lipopolysaccharides (LPS) and bacterial cell wall peptidoglycans were studied for their activity to enhance interleukin-1 (IL-1) production of murine peritoneal macrophages and the ability to activate the complement cascade in fresh adult human serum. Not only bacterial LPS and cell walls or peptidoglycans but also their structural components with appropriate size and structure induced IL-1 production by macrophages and activated the human complement cascade, which may lead to the IL-1 production by monocytes/macrophages.

Animals↗
PubMed1987

Endotoxic properties of synthetic pentaacyl lipid A precursor Ib and a structural isomer.

A pentaacyl precursor of lipid A biosynthesis, termed precursor Ib, and a structural isomer have been chemically synthesized. These compounds were, in comparison to synthetic Escherichia-coli type lipid A or lipopolysaccharide, analyzed for their activity in typical endotoxin test systems. It was found that both precursor Ib and the isomer exhibited similar or only slightly lower pyrogenic, lethal and Shwartzman-phenomenon-inducing activity than lipid A. All preparations were comparable in their B-lymphocyte mitogenicity, macrophage-activating capacity and immunoreactivity towards lipid A antisera. The proton nuclear magnetic resonance spectra of the 1-dephospho derivative of synthetic and bacterial precursor Ib were indistinguishable proving that the previously proposed structure for precursor Ib is correct.

Animals↗
PubMed1987

Production of virus-like particles by the transposable genetic element, copia, of Drosophila melanogaster.

Using the calcium-phosphate procedure the plasmid cDm2055, which carries the copia transposable element of Drosophila melanogaster, was co-transfected with the Neor-carrying plasmid pSVCneo-1 into the D. hydei cell line KUN-DH-33 which was free of copia. The Neor transfectants stably carried both plasmids as tandem oligomers integrated in the chromosome and virus-like particles (VLP) were produced specifically in the transfectants that received the copia plasmid. The particles were quite similar in various aspects such as size, morphology, density, RNA content and molecular weight of the major protein component, to retrovirus-like particles (RVLP) that spontaneously appear in cultured cells of D. melanogaster: the reverse transcriptase activity however seemed to be low compared to that of the D. melanogaster RVLP. This finding demonstrates that the retrovirus-like particles (RVLP) in Drosophila cultured cells are produced by the transposable genetic element copia resident in the host chromosomes.

Animals↗
PubMed1987

A positive regulatory sequence of the Saccharomyces cerevisiae ENO1 gene.

ENO1-'lacZ fusions with various lengths of the ENO1 5'-flanking region were constructed on various types of yeast plasmid vectors. The fully expressed level of beta Gal directed by ENO1-'lacZ fusions differed depending on the type of vector, but on any type of vector, beta Gal activity was not greatly influenced by the carbon source in the medium. The 86-bp DNA region of ENO1 at position -487 to -402 upstream of the initiation codon, in which we had previously delimited the positive regulatory region of ENO1 (Uemura, H., Shiba, T., Paterson, M., Jigami, Y., & Tanaka, H. (1986) Gene 45, 67-75), exerted its function without requiring precise location with respect to the TATA box. The action of the positive regulatory region was not affected by its orientation. In addition, the substitution of the UASs of PHO5, encoding repressible acid phosphatase, with the regulatory region of ENO1 changed the expression of PHO5-'lacZ gene to constitutive, irrespective of the concentration of inorganic phosphate in the medium. Furthermore, the GCR1 gene cloned in a multicopy plasmid increased the expression of the ENO1-'lacZ fused genes.

Escherichia coli↗
PubMed1987

One-stage abdominal wall reconstruction with oblique abdominal fasciocutaneous flaps.

The coverage of large soft-tissue defects of the abdominal wall resulting from ablative surgery continues to be a challenging problem. Numerous flaps have been used, but flaps have their limitations in size and as well as arc of rotation, and often require skin grafting of the secondary donor site. Thus, a combination of flaps may be required to close some of the larger defects without resorting to the use of skin grafts. This article reports a patient with an ulcerated abdominal wall tumor defect reconstructed with oblique abdominal fasciocutaneous flaps. Two flaps based on superior and inferior epigastric perforators were contoured to fit the massive defect in one stage without using a skin graft. After surgery the flap healed uneventfully and the patient was discharged from the hospital. She is now undergoing irradiation therapy in an outpatient clinic.

Abdominal Muscles↗
PubMed1987

Activation of the human complement cascade by bacterial cell walls, peptidoglycans, water-soluble peptidoglycan components, and synthetic muramylpeptides--studies on active components and structural requirements.

Cell walls isolated from 29 strains of 24 gram-positive bacterial species, whose peptidoglycans belong to the group A type of Schleifer and Kandler's classification, with one exception (Arthrobacter sp.), were shown to activate the complement cascade in pooled fresh human serum mainly through the alternative pathway and partly through the classical one. The complement-activating effect of cell walls (5 species) possessing group B type peptidoglycan, except those of Corynebacterium insidiosum, was weaker than that of the walls with group A type peptidoglycan. Preparations of peptidoglycan isolated from cell walls of Staphylococcus aureus, Streptococcus pyogenes, and Lactobacillus plantarum also activated the alternative pathway of the complement cascade, but less effectively than the respective parent cell walls. A water-soluble "polymer" of peptidoglycan subunits (SEPS), which was prepared from Staphylococcus epidermidis peptidoglycans by treatment with a cross-bridge degrading endopeptidase, retained most of the complement-activating ability of the parent cell walls. A peptidoglycan "monomer," SEPS-M, which was obtained by hydrolysis of the glycan chain of SEPS with endo-N-acetylmuramidase to disaccharide units did not activate complement. In conformity with this finding, neither synthetic N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) nor MDP-L-Lys-D-Ala activated the complement cascade. Among several lipophilic derivatives of MDP, 6-O-(3-hydroxy-3-docosylhexacosanoyl)-MDP-L-Lys-D-Ala (BH48-MDP-L-Lys-D-Ala) and 6-O-(2-tetradecylhexadecanoyl)-MDP (B30-MDP) were shown to activate complement through the alternative as well as the classical pathway and exclusively through the classical pathway, respectively. The finding that a D-isoasparagine analog of B30-MDP caused the same effect as the parent molecule strongly suggests that the activation of complement by B30-MDP is different from that caused by cell wall peptidoglycans and a water-soluble "polymer" of peptidoglycan subunits.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Requirement of a properly acylated beta(1-6)-D-glucosamine disaccharide bisphosphate structure for efficient manifestation of full endotoxic and associated bioactivities of lipid A.

Several synthetic acylated glucosamine monophosphates, with structures corresponding to the nonreducing or reducing moiety of the lipid A of the Escherichia coli or Salmonella minnesota type, and a synthetic compound corresponding to a biosynthetic disaccharide lipid A precursor (designated Ia or IVA) were examined for their endotoxic and related bioactivities in comparison with those of the synthetic and bacterial parent molecules, i.e., acylated beta(1-6)-D-glucosamine disaccharide bisphosphates. Some of the test monosaccharide compounds were definitely active in most of the in vitro assays. Their activities, except for complement activation, however, were weaker than those of the reference compounds, synthetic and bacterial acylated disaccharide bisphosphates. The differences between the test monosaccharide and disaccharide compounds were much more apparent in in vivo assays, in which the test acylated glucosamine monophosphates were scarcely active, though some test compounds exhibited weak lethal toxicity in galactosamine-loaded mice and were weakly active in pyrogenicity, immunoadjuvant activity, and possible tumor necrosis factor and alpha and beta interferon-inducing ability in Mycobacterium bovis BCG- and Propionibacterium acnes-primed mice, respectively. Mixture at an equimolar ratio of acyl glucosamine monophosphates, each of which has the structure of the reducing or nonreducing moiety of the reference disaccharide compound, did not restore the endotoxic or associated bioactivities of the corresponding parent molecules. No essential differences in bioactivity were noted between synthetic and bacterial monosaccharide compounds, i.e., lipid X, whose structure corresponds to the reducing moiety of E. coli-type lipid A.

Acylation↗
PubMed1987

Structural requirements of muramylpeptides for induction of necrosis at sites primed with Mycobacterium tuberculosis in guinea pigs.

Intracutaneous injection of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) in guinea pigs caused an extensive necrotic reaction in footpads prepared by injection of heat-killed Mycobacterium tuberculosis in water-in-mineral-oil emulsion. We examined a variety of analogs and derivatives of muramylpeptides for their ability to provoke this reaction. A maximum and a minimum structure responsible for the necrotic reaction were found to be N-acetylglycosaminyl-beta(1-4)-N-acetylmuramyl-tripeptide (GlcNAc-MurNAc-L-Ala-D-isoGln-meso-A2pm) and MDP, respectively. An unexpected finding was that GlcNAc-MurNAc-tetrapeptides having L-amino acids at their C termini, unlike comparable compounds having C-terminal D-amino acids, exhibited definite necrosis-inducing activity, probably due to their tendency to undergo in vivo degradation to GlcNAc-MurNAc-tripeptide. Introduction of some acyl groups, especially the stearoyl group, to the 6-O position of the muramic acid or the peptide moiety of muramylpeptides increased the necrosis-inducing activity of the parent molecules. However, this was not observed with 1-thio-muramic acid analogs of MDP. Modification of the alpha- or gamma-carboxyl groups of the glutamic acid residues of muramylpeptides tended to decrease their necrosis-inducing ability. Analogs and derivatives of muramylpeptides which are capable of inducing necrosis at a primed site, with few exceptions, exhibited powerful adjuvanticity against ovalbumin in guinea pigs. However, the reverse was not necessarily true.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1986

Biological activity of synthetic heptaacyl lipid A representing a component of Salmonella minnesota R595 lipid A.

A synthetic lipid A (preparation 516), containing seven acyl groups and representing one component of natural free lipid A of Salmonella minnesota R595, has been investigated for biological activity in a number of endotoxin test systems. It was found that the synthetic preparation was, in typical in vivo endotoxin tests (lethality, pyrogenicity, Shwartzman reactivity) as well as in its antigenicity and macrophage activation capacity, significantly less active than natural Salmonella lipid A. However, in other in vitro assay systems (B-cell mitogenicity, complement activation, Limulus amoebocyte lysate gelation) it expressed similar activity as Salmonella lipid A.

Animals↗
PubMed1986

Purified tyrosine kinases, the EGF receptor kinase and the src kinase, can catalyze the phosphorylation of the band 3 protein from human erythrocytes.

The band 3 glycoprotein from human erythrocytes was found to be phosphorylated on tyrosine residues by the purified EGF receptor kinase and the purified src kinase in vitro. Kinetic analysis revealed that Km of the band 3 protein phosphorylation by the EGF receptor kinase was 0.17 microM and 0.65 microM in the absence and presence of EGF (3 X 10(-7)M), respectively, and that in the case of the src kinase it was 0.4 microM. From these data the band 3 protein can be regarded as one of the best substrates common for the EGF receptor kinase and the src kinase in vitro.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1986

Analysis of thromboxane B3 converted from eicosapentaenoic acid in human platelet rich plasma by gas chromatography/mass spectrometry.

Gas chromatographic mass spectrometric determination of thromboxane B3 (TXB3) synthesized from platelet is described. Eicosapentaenoic acid (EPA) was added to human platelet rich plasma and after the reaction the exstraction was carried out. Plasma thromboxanes were run through an Amberlite XAD-2 and SEP-PAK silica cartridge, and then chromatographed using silicagel thin layer plate to remove interfering materials, such as 6-keto-prostaglandin F1 alpha. Extracted thromboxanes were converted into the methoxime-dimethylisopropylsilylmethyl ester derivatives and they were measured by gas chromatography/ammonia chemical ionization mass spectrometry. Three peaks were obtained on the gas chromatogram which were presumed to be 3-series metabolite product TXB3 and their related substances. Results indicates the human platelet may easily convert EPA to TXB3 by adding EPA to PRP without adding arachidonic acid.

Ammonia↗