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Biomedical subjects

S Inouye

Publications and source records attributed to S Inouye.

At least 361 records · Page 20Linked to original sources
PubMed1988

[Antibacterial activity of cefminox in human urine].

The antibacterial activity of cefminox (CMNX) was compared to those of cefotaxime (CTX) and latamoxef (LMOX) in human urine using 11 clinical isolates from complicated urinary tract infections. When the inoculum size was increased from 10(4) (or 10(3)) to 10(8) (or 10(7)) CFU/ml, MIC values increased in general, but the increment of average MICs of CMNX was the smallest of the 3 drugs: 4 approximately 8 fold with CMNX, 32 approximately 64 fold with CTX and 8 approximately 32 fold with LMOX. MICs also increased when the urinary pH was altered from 8.5 to 5.5, but again the increment of MICs of CMNX was the smallest. Using 5 clinical isolates of Gram-negative bacteria as test organisms, the bactericidal activity of CMNX was compared to those of CTX and LMOX. In spite of the inferior activity of CMNX as determined by the MIC values, CMNX showed killing activity equal to or better than CTX and LMOX, particularly at low concentrations (2 approximately 20 micrograms/ml). The bacteriolytic activity of CMNX was also equal or superior to those of CTX and LMOX against 6 test organisms. These results suggest the usefulness of CMNX in the treatment of urinary tract infections, particularly when dense bacterial populations are present.

Bacteria↗
PubMed1987

Structure of msDNA from Myxococcus xanthus: evidence for a long, self-annealing RNA precursor for the covalently linked, branched RNA.

The branched RNA (msdRNA) of M. xanthus consists of 77 bases. The 20th rG residue is linked to the 5' end of msDNA, consisting of 162 bases, by a 2', 5' phosphodiester linkage. The msdRNA coding region is located on the chromosome in the opposite orientation to the msDNA coding region, with the 3' ends overlapping by eight bases. S1 nuclease mapping experiments indicate that the primary product of msdRNA is much longer at both the 5' and 3' ends (approximately 375 bases). Because of homologous sequences upstream of the msdRNA and msDNA coding regions, the precursor RNA molecule is considered to form an extremely stable stem-and-loop structure (delta G = -210 kcal). We propose a novel mechanism of DNA synthesis in which the stem-and-loop structure serves as a primer as well as a template to form the branched RNA-linked msDNA.

Base Sequence↗
PubMed1987

Identification of a vegetative promoter in Myxococcus xanthus. A protein that has homology to histones.

A physical map of 330 x 10(3) base-pairs near the replication origin of Myxococcus xanthus chromosome has been established already. Using DNA fragments from this region, Northern blot hybridization analysis was carried out in order to identify the genes expressed during vegetative growth. One of the genes, tentatively designated as vegA, was cloned and its entire DNA sequence was determined. The amino acid sequence of the gene product deduced from the DNA sequence reveals that the VegA protein is a very basic protein with a molecular weight of 18,700. The gene was expressed in Escherichia coli using an expression vector, and its gene product was identified using SDS/polyacrylamide gel electrophoresis. From the results of S1 nuclease mapping, the vegA promoter was found to contain the sequence TAGACA at the -35 region and the sequence AAGGGT at the -10 region. These two regions are separated by 18 nucleotides. Genetic analysis suggests that the vegA gene may be essential for the growth of M. xanthus. From a computer-aided search for homologies to know protein structures, it was found that the VegA protein has homologies to histone H4 of Tetrahymena thermophila and histone H2B of sea urchin.

Amino Acid Sequence↗
PubMed1987

Branched RNA covalently linked to the 5' end of a single-stranded DNA in Stigmatella aurantiaca: structure of msDNA.

Stigmatella aurantiaca is a gliding, gram-negative bacterium that shows a spectacular fruiting body formation upon starvation of nutrient. This bacterium was found to contain approximately 500 copies per cell of a short single-stranded linear DNA (multicopy single-stranded DNA: msDNA). The primary structure of msDNA was determined and found to consist of 162 or 163 deoxyribonucleotides. Its unique chromosomal gene was cloned and sequenced. The msDNA was found to be attached to a branched RNA by its 5' end. Structural analysis of the branched RNA revealed that it consists of a triribonucleotide, 5'A-G-(C or U)3', and that msDNA is branched out from the 2' position of the rG residue forming a 2', 5' phosphodiester linkage with the dC residue at the 5' end of msDNA.

Base Sequence↗
PubMed1987

Biosynthesis and structure of stable branched RNA covalently linked to the 5' end of multicopy single-stranded DNA of Stigmatella aurantiaca.

Stigmatella aurantiaca, a gram-negative bacterium, contains approximately 500 copies per cell of a short single-stranded linear DNA (multicopy single-stranded DNA: msDNA). This DNA is attached to a branched RNA (msdRNA) by its 5' end. The entire sequence of msdRNA was determined and found to consist of 76 bases. The msDNA is linked at the 19th G residue of msdRNA by a 2', 5' phosphodiester linkage. The coding region for msdRNA (msr) is located downstream of the coding region for msDNA (msd). These coding regions exist in opposite orientation with respect to each other and overlap by 8 bases at their 3' ends. Biosynthesis of RNA-linked msDNA was characterized and mechanisms of synthesis are proposed.

Base Sequence↗
PubMed1987

Cold-adaptation of human rotavirus.

A human rotavirus strain was cold-adapted for possible future use as a live vaccine. The original strain was isolated in 1980 in primary cynomolgus monkey kidney cells and has a serotype I and subgroup II antigenicity. The virus was serially passaged in African green monkey kidney cells; it was cultivated at 37 degrees C at the first stage of passages, and the cultivation temperature was then shifted down stepwise by 3 degrees C per each 10 passages. Finally the virus was passaged 10 times at 25 degrees C (total passage number of 55). The virus formed small-size plaques with irregular shaped borders at 31 degrees C. Growth at 25 degrees C of the cold-adapted virus was higher than that of the original virus. There was no difference between the migration patterns of 11 dsRNA segments in polyacrylamide gel electrophoresis of the original and the cold-adapted viruses.

Adaptation, Physiological↗
PubMed1987

Synthesis and quantitative structure-activity relationship analysis of N-triiodoallyl- and N-iodopropargylazoles. New antifungal agents.

New series of N-(2,3,3-triiodoallyl) and N-(3-iodopropargyl) azole derivatives (100 compounds) involving pyrrole, pyrazole, imidazole, triazole, and tetrazole nuclei were synthesized successively with the aid of quantitative structure-activity relationship (QSAR) analysis to obtain potent antifungal agents. Starting from the derivatives of nitropyrrole-containing antibiotics, the QSAR analysis of the pyrrole derivatives against Candida albicans and Trichophyton mentagrophytes strains indicated the positive contribution of the nitro group and negative effect of the size of molecule. Further application of the QSAR analysis on the multi-azole derivatives revealed the importance of hydrophobicity and electronegativity as well as steric effect to the activities and led to the synthesis of one of the most potent iodo compounds, 2-(2,3,3-triiodoallyl)tetrazole (67, ME1401).

Allyl Compounds↗
PubMed1987

Expression of the regulatory gene xylS on the TOL plasmid is positively controlled by the xylR gene product.

The regulatory gene xylS on the TOL plasmid of Pseudomonas putida activates the transcription of the xylDLEGF operon for the m-toluate-degrading pathway in the presence of m-toluate. The gene also activates the transcription of the same operon in the presence of m-xylene or m-methylbenzyl alcohol, but for this activation another regulatory gene, xylR, is required. In this study we examined the xylS expression by determining the mRNA by reverse transcriptase mapping and by monitoring the enzyme activity of the xylE gene product, which was expressed under the control of the xylS promoter. The results of the above experiments provide evidence that xylR positively controls the transcription of xylS in the presence of m-xylene or m-methylbenzyl alcohol. The xylS product thus amplified may in turn activate the xylDLEGF operon. The nucleotide sequence of the xylS promoter resembles that of the promoter of the xylCAB operon for the m-xylene-degrading pathway, which is also activated by xylR in the presence of m-xylene or m-methylbenzyl alcohol. In addition, we have demonstrated that the expression of xylR is negatively controlled by its own product. On the basis of these findings, we propose a revised model for the regulation of expression of xyl genes on the TOL plasmid.

Base Sequence↗
PubMed1987

Fluorometric enzyme-linked immunosorbent assay for the measurement of IgE antibody to mite Dermatophagoides farinae.

We have developed a fluorometric enzyme-linked immunosorbent assay for measuring IgE antibody to Dermatophagoides farinae. Polystyrene microplates were coated with proteins extracted from the mites. The IgE antibody which attached to the solid-phase antigen was detected by anti-IgE antibody conjugated with beta-galactosidase. Four-methylumbelliferyl-beta-D-galactoside was used as the enzyme substrate and the fluorescence intensity of the reaction product was measured. The antibody levels determined by this method well correlated with those determined by the radioallergosorbent test (RAST). This method is simpler and less expensive to carry out than the RAST when dealing with a large number of serum specimens for seroepidemiological studies of asthma and nasal allergy.

Adolescent↗
PubMed1987

Overproduction of the xylS gene product and activation of the xylDLEGF operon on the TOL plasmid.

The effect of high-level expression of the regulatory gene xylS of the Pseudomonas putida TOL plasmid on the activation of the xylDLEGF operon was investigated in Escherichia coli. The xylS gene was placed downstream from the tac promoter, and the resultant fusion was cloned in cis to the xylDLEGF operon. The expression of the operon was monitored by the level of catechol 2,3-dioxygenase, whose structural gene xylE was placed directly after the operator-promoter region of xylDLEGF. xylS transcription was also determined by reverse transcriptase mapping of mRNA. Overproduction of the xylS gene product elicited constitutive high expression of the xylDLEGF operon even in the absence of the inducer for the operon. The results were consistent with a cascade model for the positive control of the xylDLEGF operon by the xylR and xylS genes (S. Inouye, A. Nakazawa, and T. Nakazawa, Proc. Natl. Acad. Sci. USA, in press): m-xylene, a substrate of the degradative pathway, binds to the xylR gene product; the m-xylene-xylR product complex activates the xylS gene; and the xylS product thus synthesized de novo activates the xylDLEGF operon.

Bacterial Proteins↗
PubMed1987

Dactimicin, a new, less toxic aminoglycoside antibiotic active against resistant bacteria.

Dactimicin is a new member of the pseudodisaccharide group of antibiotics. It possesses an unusual N-formimidoyl group which differentiates it from astromicin. Dactimicin is active against wide variety of bacteria, including resistant strains with aminoglycoside-modifying enzymes. However, AAC(3)-I enzyme slowly acetylates dactimicin. Animal toxicity studies show that the ototoxicity and nephrotoxicity of dactimicin are lower than those of amikacin and gentamicin. No notable abnormal findings have been found in pharmacological and toxicological studies.

Amikacin↗
PubMed1986

Structural requirement at the cleavage site for efficient processing of the lipoprotein secretory precursor of Escherichia coli.

A phenotypically silent mutation in the signal peptide of the Escherichia coli outer membrane prolipoprotein was combined with other mutations in the mature lipoprotein structure. Under conditions where the individual mutations permit normal lipoprotein secretion, the prolipoprotein with both mutations was unable to be normally modified or processed. These results demonstrate that a given signal peptide is fully functional only if it is structurally compatible with the protein to be secreted. This structural compatibility between the signal peptide and the secretory protein is considered to be dependent on the secondary structure formed at or near the signal peptide cleavage site.

Amino Acid Sequence↗
PubMed1986

Nucleotide sequence characterization of a Drosophila retrotransposon, 412.

The nucleotide sequence of the internal region of a Drosophila retrotransposon. 412, was determined. The genome of 412 was found to consist of two long open-reading frames (ORFs 1 and 2), an unusually long putative leader region and long terminal repeats (LTRs). As with 17.6, 297 and gypsy, ORFs 1 and 2 slightly overlap each other and are out of phase by +2. ORF2 includes the nucleotide sequences coding for the putative protease, reverse transcriptase and integrase, and is similar in entire organization to the pol gene of Moloney murine leukaemia virus. In spite of the difference in insertion specificity, integrase, an enzyme presumably responsible for insertion, was found to be similar in amino acid sequence to the counterparts of 17.6, 297 and gypsy. There is no ORF in 412 which corresponds to retroviral env or ORF3s of 17.6 and 297. Analysis of 412 transcripts suggested that 412 LTR is composed of U3, R and U5. The gene for a potential primer tRNA for putative reverse transcription of 412 was also surveyed and the 3'-terminal 15 nucleotides of a putative arginine tRNA were found to be exactly complementary to the putative primer-binding site of 412.

Amino Acid Sequence↗
PubMed1986

Structural variations in the Drosophila retrotransposon, 17.6.

More than 21 members of 17.6, a Drosophila retrotransposon, were isolated and their possible structural changes were examined by restriction mapping, blot hybridization, heteroduplex analysis and nucleotide sequence determination of long terminal repeats (LTRs). At least 7 members were found to suffer with terminal or internal long deletions. No pair of LTRs having an identical nucleotide sequence was found either within an element or between elements. Although an initiation site for the presumable genome-sized transcript of 17.6, a potential substrate for reverse transcription on translocation, was identified within the left-hand LTR, our results as a whole support the notion that the majority of 17.6s have continued to reside for a long period of time at their present chromosomal loci and hence the rate of translocation of 17.6 is very low.

Animals↗
PubMed1986

Identification of genes for reverse transcriptase-like enzymes in two Drosophila retrotransposons, 412 and gypsy; a rapid detection method of reverse transcriptase genes using YXDD box probes.

Using synthetic oligonucleotides corresponding to the amino acid sequences best conserved among retroviral reverse transcriptases, we developed a rapid method to detect cloned DNA fragments with the genes for reverse transcriptases. By this technique followed by nucleotide sequence determination, nucleotide sequences coding for reverse transcriptase-like enzymes were identified in two Drosophila retrotransposons, gypsy and 412. Our sequence analysis suggested that there are at least two major groups of retrotransposons in Drosophila with respect to putative reverse transcriptases and both gypsy and 412 belong to a category of retrotransposons which have putative reverse transcriptases very similar in amino acid sequence to the counterpart of Moloney murine leukaemia virus, a typical mammalian retrovirus.

Amino Acid Sequence↗