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Biomedical subjects

Y Ueno

Publications and source records attributed to Y Ueno.

At least 19 recordsLinked to original sources
PubMed1992

A novel Arg-Gly-Asp containing peptide specific for platelet aggregation and its effect on tumor metastasis: a possible mechanism of RGD peptide-mediated inhibition of tumor metastasis.

A novel cyclic tetrapeptide containing L-arginine-glycine-L-aspartic acid-L-phenylglycine (cyclo-RGDPhg) was synthesized and found to be a potent inhibitor of platelet aggregation induced by highly metastatic murine squamous cell carcinoma (SCCVII) cells (IC50 = 3.3 microM) as well as ADP (1.5 microM). This cyclic peptide, however, showed similar or less inhibitory activities on adhesion of SCCVII cells to fibronectin, vitronectin and type IV collagen as compared with those of parent linear tetrapeptide, RGDS. These results show that cyclo-RGDPhg peptide is a highly specific antagonist for gpIIb/IIIa on platelets. Moreover, this peptide failed to suppress pulmonary metastasis of SCCVII cells in an experimental metastasis model. These results indicate that RGD peptide-mediated inhibition of tumor metastasis is attributed to the suppression of cell adhesion but not platelet aggregation. These also suggest that platelet aggregation is not an essential step during blood circulation of tumor cells for the completion of metastasis.

Animals↗
PubMed1992

A 1H-NMR study of the solution conformation of cyclo(GRGDSPA): conformational effects on the physiological activity.

Solution conformations of cyclo(GRGDSPA) have been analyzed by the use of two-dimensional proton nuclear magnetic resonance spectroscopy and the dynamical simulated annealing calculation. It has been shown that the RGDS segment in cyclo(GRGDSPA) takes a beta-turn conformation. We have concluded that this beta-turn conformation is essential for the physiological activity of cyclo(GRGDSPA).

Amino Acid Sequence↗
PubMed1992

Genotoxicity of fungi evaluated by SOS microplate assay.

By an introduction of sodium dodecylsulfate for cell lysis and immunomicroplate for mass assay, the modified SOS microplate assay method was established and applied for the evaluation of genotoxicity of mycotoxins and fungal cultures. Among 20 mycotoxins, the carcinogenic dihydrobisfuranoids such as aflatoxin B1, sterigmatocystin, and versicolorin A were positive in the presence of the activation system. While, the carcinogenic anthraquinones and lactones such as luteoskyrin, rugulosin, ochratoxin A, patulin, and citrinin were negative. The survey on genotoxic fungi revealed that, among 15 fungal isolates Aspergillus versicolor, Emericella acristata, and others were positive. Additional survey on 265 fungal isolates have revealed that various Aspergillus genera such as A. flavus, A. parasiticus, A. ustus, A. nidulans, and others were positive for SOS induction, along with several isolates of Fusarium moniliforme. The chemical analysis revealed that the dihydrobisfuranoids such as aflatoxin B1, and sterigmatocystin were the major genotoxic metabolites of several Aspergillus species. The SOS microplate assay system is a simple and rapid procedure for the mass screening of genotoxic fungi, particularly of the dihydrobisfuranoids-producing strains.

Animals↗
PubMed1992

Identification of epitopes associated with different biological activities on the glycoprotein of vesicular stomatitis virus by use of monoclonal antibodies.

Thirteen monoclonal antibodies (MAbs) to the glycoprotein (G) of vesicular stomatitis virus (VSV) serotype Indiana were prepared and examined for their effects on various biological activities of VSV, including in vitro infection, hemagglutination, adsorption to cells, and mediation of cell fusion. Competitive binding assays with these MAbs revealed the presence of at least seven distinct antigenic determinants (epitopes) on the G protein. In some cases, overlappings among epitopes to various degrees were observed as partial inhibition or binding enhancement. The MAbs to all the epitopes but one (epitopes 1-6) reacted with the denatured G protein in a Western immunoblot analysis. Four of the epitopes (epitopes 2, 4, 5, and 7) were involved in neutralization and two (epitopes 1 and 2) in hemagglutination inhibition. None of the MAbs inhibited the adsorption of radiolabeled VSV to BHK-21 cells; the MAbs to epitope 2 slightly enhanced the virus adsorption. All neutralization epitopes except epitope 2 (epitopes 4, 5, and 7) were associated with inhibition of VSV-mediated cell fusion. These results show a direct spatial relationship between the epitopes recognized by the MAbs and functional sites on G protein and further insights into the structure and function of G protein.

Adsorption↗
PubMed1992

Radical-mediated modification of deoxyguanine and deoxyribose by luteoskyrin and related anthraquinones.

When cultured Reuber hepatoma H4-II-E and fibroblast Balb/3T3 cells were exposed to various concentrations of 5 derivatives of anthraquinones, luteoskyrin, a bis-anthraquinoid hepatocarcinogenic mycotoxin, exhibited the highest cytotoxicity to these cell lines. The content of 8-hydroxydeoxyguanine residues in the DNA of H4-II-E cells was dose- and time-dependently increased by luteoskyrin. The tumorigenic anthraquinones such as rugulosin and danthron also slightly elevated the level of this modified DNA base, while no such modification was observed with chrysophanol and emodin. Detailed experiments with luteoskyrin have demonstrated the formation of 8-hydroxydeoxyguanine and the degradation of deoxyribose into thiobarbituric acid-reactive products in the presence of ascorbic acid. These findings suggest the possible involvement of anthraquinone-derived hydroxy radicals for the modification of DNA base and deoxyribose.

3T3 Cells↗
PubMed1992

Growth of a giant aneurysm following complete thrombosis by detachable balloon occlusion.

A giant basilar artery aneurysm demonstrating growth and causing neurological deterioration even after complete detachable balloon occlusion is reported. Autopsy revealed total thrombosis of the aneurysm and a hemiconcentric, onion skin-like, laminated structure. Numerous vascular channels and multiple fresh intramural hemorrhages were noted within the outer margin of the aneurysmal wall. Repeated intramural hemorrhages appeared to have been responsible for the aneurysmal laminated structure and contributed to progressive aneurysmal growth. This case demonstrates that the growth of some giant aneurysms is not dependent upon the continuity with the parent artery, and progressive enlargement cannot always be prevented by balloon occlusion.

Basilar Artery↗
PubMed1992

Hepatic accumulation and hepatotoxicity of luteoskyrin in mice.

HPLC analysis revealed that luteoskyrin administered orally to male mice accumulated selectively in the liver, with minor distribution to the serum and kidneys. Elevation of serum GOT and GPT values was maximal 3 days after administration. In mice administered this mycotoxin intravenously, selective accumulation was also observed in the liver, and the half-life of hepatic luteoskyrin in males was significantly longer than that in females. Increment of serum transaminases was also marked in males with maximum accumulation at 24 h after administration. Histopathologically, cellular membrane damage was an early effect of luteoskyrin on cell necrosis, and these morphological changes were also marked in males. Luteoskyrin also elevated hepatic lipid peroxides, the maximum elevation being 8 h after injection; this increase was suppressed by alpha-tocopherol and Bi(NO3)3. HPLC-ECD analysis indicated that the level of 8-hydroxy-deoxyguanosine, one of the markers of hydroxy-radical-mediated modification of DNA guanine residues, was increased in hepatic DNA. These findings indicate that luteoskyrin has a high affinity for the liver, resulting in induction of lipid peroxidation, hepatocellular membrane damage, and elevation of serum transaminase activities. It is suggested that the hydroxy radicals derived from this anthraquinone contribute to these toxicological changes.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1992

Enhancement of GST-P-positive liver cell foci development by nivalenol, a trichothecene mycotoxin.

In order to elucidate whether T-2 toxin (T-2) and nivalenol (NIV), the naturally occurring trichothecene mycotoxins in food and feed, are carcinogenic or possess an ability to modulate aflatoxin B1 (AFB1)-induced hepatocarcinogenicity, a medium-term liver bioassay was carried out. F344 male rats were given a single i.p. injection of diethylnitrosamine (DEN, 200 mg/kg), and then fed the test trichothecenes in diet (2 and 5 p.p.m. T-2 or 6 p.p.m. NIV) for 6 weeks beginning 2 weeks after the injection. Some control groups received DEN alone. For synergism between AFB1 and the trichothecenes, DEN-initiated rats as above were given a single i.p. injection of AFB1 (0.5 mg/kg) 2 weeks later and were fed a NIV-containing diet (6 p.p.m.) for 6 weeks. The other control group received the vehicle alone. Control rats not initiated with DEN were also treated with AFB1, NIV or T-2 alone as above. All rats were subjected to a two-thirds partial hepatectomy (PH) at week 3 and killed at week 8, and liver sections were analyzed by glutathione S-transferase placental form (GST-P) expression. In rats that did not receive DEN, AFB1 alone enhanced both the numbers and areas of GST-P-positive foci as reported earlier, while NIV or T-2 alone induced no marked changes. In rats initiated with DEN, AFB1 caused a marked expression of GST-P, and thus the hepatocarcinogenicity of AFB1 was reconfirmed. The expression of GST-P foci in rats fed T-2 or NIV was found to be at background level, indicating that the hepatocarcinogenicity was not predicted for the trichothecene mycotoxins such as T-2 and NIV by this medium-term bioassay system. In the group initiated by DEN followed by AFB1, on the other hand, an elevation of both the numbers and areas of GST-P-positive foci was observed by the subsequent feeding of rats with NIV, and this elevation was statistically significant from the sum totals of individual data of AFB1 or NIV alone. From this evidence, it is predicted that NIV causes an enhancing effect on AFB1-induced hepatocarcinogenesis.

Animals↗
PubMed1992

T-cell-dependent production of IgG by human cord blood B cells in reconstituted SCID mice.

Reconstitution of severe combined immunodeficient (SCID) mice with human lymphocytes has recently allowed the elucidation of abnormalities of immune responses in various immunological disorders. In the present study, mononuclear cells (MNC) from neonatal cord blood and adult peripheral blood were intraperitoneally injected into SCID mice to examine induction of human Ig in respective mice recipients. Human IgG was consistently detected in the serum of SCID transferred with adult MNC, but only a few SCID recipients of cord blood MNC showed detectable but low levels of IgG in the serum. The combination experiments of isolated B and T cells disclosed that some interactions between B and T cells might be necessary for IgG production in transferred SCID mice. Notably, transfer of cord blood B cells with adult but not cord blood T cells resulted in efficient induction of IgG, associated with a change in subclass distribution. The results suggest that inability of neonatal B cells to produce IgG can be overcome by transfer with adult mature T cells into SCID mice.

Animals↗
PubMed1992

Antibacterial activity of the new quinolone CI-960 (PD 127391) against clinical isolates at a major tertiary care center in Saudi Arabia.

The antibacterial activity of the new fluoroquinolone CI-960 (PD 127391) was evaluated against 1,162 clinical isolates and compared with other quinolones and various commonly used antibiotics. CI-960 was highly effective against members of Enterobacteriaceae inhibiting 626 of the 629 isolates at a less than or equal to 0.03 to 0.12 microgram/ml concentration. All the 305 isolates of Pseudomonas aeruginosa, Xanthomona maltophilia, and Acinetobacter were susceptible to CI-960. It was the only effective drug against 10 multi-resistant isolates of pseudomonads and Acinetobacter. All staphylococci, including methicillin-resistant Staphylococcus aureus, were inhibited by less than or equal to 0.03-0.5 microgram/ml of CI-960. Like other drugs of its class, it had little activity against enterococci.

Anti-Infective Agents↗
PubMed1992

In vitro activity of sparfloxacin (CI-978), a new broad-spectrum fluoroquinolone.

The in vitro activity of sparfloxacin (CI-978, AT-4140), a new fluoroquinolone, was compared with ciprofloxacin, norfloxacin and other commonly used antimicrobial agents against 650 strains of Enterobacteriaceae, 237 isolates of other gram-negative bacilli and 318 strains of gram-positive cocci. The MICs of sparfloxacin against 90% of the members of Enterobacteriaceae were between 0.12 and 0.5 microgram/ml. All the 48 isolates of notoriously drug-resistant Serratia marcescens were inhibited by less than 0.03-4.0 micrograms/ml of sparfloxacin. All the 90 isolates of Acinetobacter, 80 of the 88 strains of Pseudomonas aeruginosa and all the 28 isolates of Xanthomonas maltophilia were susceptible to sparfloxacin. The MIC90 for all the cocci tested ranged between 0.5 and 4.0 micrograms/ml of sparfloxacin. It inhibited 92% of enterococci as compared with 27% for ciprofloxacin and 22% for norfloxacin. It was better or comparable in activity to other fluoroquinolones and superior to penicillins, cephalosporins and aminoglycosides tested. There was cross-resistance between ciprofloxacin, norfloxacin and sparfloxacin.

Anti-Infective Agents↗
PubMed1992

Antibacterial activity of citreamicin-alpha (LL-E 19085 alpha) against gram-positive cocci.

In vitro antibacterial activity of 429 clinical isolates of gram-positive cocci was tested against citreamicin-alpha (LL-E 19085-alpha) by the agar dilution method. The microorganisms consisted of 313 isolates of staphylococci and 116 strains of streptococci. In vitro activity of citreamicin-alpha was compared with ampicillin, augmentin, cephalothin, erythromycin and vancomycin. MICs of citreamicin-alpha for staphylococci ranged between 0.12-4.0 micrograms/ml and 0.03-0.12 micrograms/ml for Streptococcus pyogenes. Enterococci, however, were relatively more resistant, requiring 2.0 micrograms/ml of this drug to inhibit 64% of the 62 isolates tested. In vitro activity of this antibacterial agent was far superior to that of ampicillin, augmentin, cephalothin and erythromycin, but equal to or slightly inferior to that of vancomycin.

Anti-Bacterial Agents↗
PubMed1992

[Perception of odor quality by Free Image-Association Test].

A method was devised for evaluating odor quality. Subjects were requested to freely describe the images elicited by smelling odors. This test was named the "Free Image-Association Test (FIT)". The test was applied for 20 flavors of various foods, five odors from the standards of T&T olfactometer (Japanese standard olfactory test), butter of yak milk, and incense from Lamaism temples. The words for expressing imagery were analyzed by multidimensional scaling and cluster analysis. Seven clusters of odors were obtained. The feature of these clusters were quite similar to that of primary odors which have been suggested by previous studies. However, the clustering of odors can not be explained on the basis of the primary-odor theory, but the information processing theory originally proposed by Miller (1956). These results support the usefulness of the Free Image-Association Test for investigating odor perception based on the images associated with odors.

Adult↗
PubMed1992

Susceptibility of recent clinical isolates to temafloxacin (A-63004) and other antimicrobial agents.

In vitro susceptibility of 1008 strains of recent clinical isolates was determined against the new aryl fluoroquinolone temafloxacin (T-167, A-63004) ciprofloxacin, norfloxacin, ampicillin, piperacillin, cephalothin, cefoxitin, ceftazidime, gentamicin, amikacin, oxacillin and vancomycin. The minimum inhibitory concentrations (MICs) of temafloxacin in micrograms/ml required for > or = 90% isolates were 0.13-0.5 for enterobacter, 0.03-0.25 for Escherichia coli, 0.12-0.5 for Klebsiella, 0.5-1.0 for Proteus mirabilis, 0.12-0.5 for Morganella morganii, 0.03-0.12 for Salmonella, 0.25-1.0 for Serratia marcescens, 0.03-0.12 for Shigella, 0.06-4.0 for Pseudomonas aeruginosa, 0.06-0.12 for Aeromonas hydrophila, 0.12-0.5 for Staphylococcus aureus, 0.12-1.0 for coagulase negative staphylococci and 4.0-8.0 for enterococci. The antibacterial activity of temafloxacin was comparable or superior to other drugs tested against most organisms. However, Xanthomonas malthophilia was relatively more susceptible to ciprofloxacin and norfloxacin, and temafloxacin had significantly high antibacterial activity against enterococci as compared to other fluoroquinolones.

Anti-Infective Agents↗