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Biomedical subjects

M Kuwabara

Publications and source records attributed to M Kuwabara.

At least 217 records · Page 12Linked to original sources
PubMed1987

Continuous measurement of coronary sinus oxygen saturation after cardiac surgery.

To estimate the balance of myocardial oxygen supply and demand after cardiac surgery, we used fiberoptic reflection oximetry to measure continuously the coronary sinus oxygen saturation (ScsO2) in six patients. ScsO2 decreased with massive bleeding, atrial fibrillation, after DC countershock, and continuous iv infusion of hydralazine, phentolamine, and dibutyryl cyclic-AMP. ScsO2 increased with iv infusion of nicardipine or nitroglycerin, suggesting an improved oxygen metabolism in the myocardium. Continuous ScsO2 measurement provides such on-line information on myocardial oxygenation in postoperative patients.

Adult↗
PubMed1987

OH-induced free radicals in 3'-UMP and poly(U): spin-trapping and radical chromatography.

Characterization of OH-induced free radicals using 3'-UMP and poly(U) was performed by a method combining spin-trapping and radical chromatography. A N2O-saturated aqueous solution containing 3'-UMP and 2-methyl-2-nitrosopropane as a spin-trap was X-irradiated. The spin adducts generated by the reactions of OH radicals with 3'-UMP were separated by paired-ion HPLC and the separated spin adducts were identified by ESR spectroscopy. In the case of poly(U), the spin adducts were digested to oligonucleotides with RNase A and then separated and identified in the same manner as 3'-UMP. The free radicals observed for poly(U) were identical to those for 3'-UMP. The 5-yl radical and the 6-yl radical were identified as precursors of various oxidized products of the base moiety, and the 4'-yl radical and 5'-yl radical, formed by H-abstraction at the C-4' and C-5' positions of the sugar moieties, respectively, were identified as precursors of strand breaks. The 1'-yl radical, produced by H-abstraction at the C-1' position of the sugar moiety, was also identified. From the similarity of the free radicals of 3'-UMP and poly(U), it is suggested that the reactivities of OH radicals with nucleotides are identical to those in polynucleotides.

Chromatography, High Pressure Liquid↗
PubMed1987

[The role of tumor markers in lung cancer management].

A variety of substances, including enzymes, hormones, antigens and proteins are called tumor markers. In this report, tumor marker of lung cancer refers to substances in serum of patients with lung cancer. In order to evaluate usefulness of tumor markers in lung cancer management, contributory tumor markers to diagnosis of lung cancer were selected by the incidence of elevation. Consequently CEA, SCC, SSEA-1, CA15-3 and NSE were considered to be possibly useful for diagnosis and also classification of histological types of lung cancer. Then the following areas were examined for these markers: (1) usefulness for making a decision of therapeutic strategy, (2) predictability for drug and radiosensitivity, (3) judgment of therapeutic effect; and (4) value in monitoring clinical course. From these analyses some positive data for tumor markers to be useful in lung cancer management were obtained as follows. Since serum values exceeding 10 ng/ml for NSE were observed mostly in advanced stage of small cell lung cancer, intensive chemotherapy should be carried out in such cases. But inoperability of non-small cell lung cancer could hardly be predicted by elevation of tumor markers. No correlation was proved between expression of any tumor markers to be available in today's clinical practice and therapeutic sensitivity. Response to treatments could be evaluated by serial measurements of serum level although definite criteria for judgment have not been determined. Periodic surveys of tumor markers expressed in lung cancer were predictable for relapse prior to imaging detection. Tumor markers of lung cancer take an important role in lung cancer management.

Antigens, Neoplasm↗
PubMed1986

Nuclease activity of 1,10-phenanthroline-copper ion: reaction with CGCGAATTCGCG and its complexes with netropsin and EcoRI.

The self-complementing dodecamer 5'-CGCGAATTCGCG-3' and its complexes with the antibiotic netropsin and the restriction endonuclease EcoRI provide substrates of known three-dimensional structure to study the stereochemistry and mechanism of the artificial nuclease of 1,10-phenanthroline-copper ion [(OP)2Cu+]. Analysis of the reaction products with the 5'-32P dodecamer on 20% sequencing gels has demonstrated the presence of 3'-phosphoglycolate ends in addition to 3'-phosphomonoester ends expected from previous studies. A reaction intermediate, which is a precursor to 3'-phosphomonoester termini, has been trapped; in contrast, no comparable species for the 5'-phosphomonoester termini can be detected when 3'-labeled DNAs are utilized as substrates. The reactive oxidative species formed by the coreactants (OP)2Cu+ and hydrogen peroxide is distinguishable in its chemistry from the hydroxyl radicals produced by cobalt-60 gamma-irradiation. The freely diffusible hydroxyl radicals generated by cobalt-60 irradiation produce equivalent amounts of 3'-phosphomonoester and 3'-phosphoglycolate termini whereas the 3'-phosphomonoesters are the preferred product of (OP)2Cu+ and H2O2. On the basis of the structures of the products obtained, the principal site of attack of the coordination complex is on the C-1 of the deoxyribose within the minor groove. This conclusion is supported by the footprinting of netropsin binding to the dodecamer. Crystallographic results have demonstrated that netropsin binds to the minor groove at the central AATT residue. A clear protection of attack by the coordination complex at the deoxyriboses associated with A-5, T-6, T-7, and C-9 is fully consistent with attack from the minor groove without intercalation during the course of the cleavage reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1986

Spin-labeling of influenza virus hemagglutinin permits analysis of the conformational change at low pH and its inhibition by antibody.

To study the conformational changes in the hemagglutinin (HA) molecule of A/seal/Mass/1/80 (H7N7) (Seal) influenza virus at low pH, a spin-labeling method was used. This method also permits study of antibody interaction with the HA. A synthetic nitroxide compound was used for spin-labeling of tyrosine residues of the isolated HA molecule. Electron spin resonance (ESR) spectra of the spin-labeled HA at various pH values indicated that a conformational transition occurred under acidic conditions, and around pH 5.8 the HA molecule has maximal flexibility. Since virus-induced hemolysis occurs optimally at pH 5.8-5.9, the HA molecule in the maximally flexible conformation is considered to mediate membrane fusion. The ESR spectra of the antibody-bound HA at various pH values revealed that monoclonal antibodies to different regions on the molecule may inhibit the conformational change by different modes. One antibody inhibited the changes in the HA that resulted in flexibility, while the other did not. These results support the assumption that monoclonal antibodies, which failed to inhibit hemagglutination of the virus yet neutralized viral infectivity, inhibited the fusion step in the viral replication process by interfering with a low pH-induced conformational change in the HA molecule (Kida, H., Webster, R.G. and Yanagawa, R. (1983) Arch. Virol. 76, 91-99).

Animals↗
PubMed1986

Influence of dissolved gases on chemical and biological effects of ultrasound.

The influence of dissolved gases (O2, Ar, N2O, and CO2) on the chemical and biological effects of 1.2 MHz continuous wave ultrasound was investigated. Spin-trapping of OH and H radicals with 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) and observation of iodine liberation from a potassium iodide-starch solution were employed for monitoring the chemical effects, while lysing of mouse L5178Y cells was employed for monitoring the biological effects. The effectiveness of the dissolved gases in producing OH-DMPO adducts and H-DMPO adducts was O2 greater than Ar greater than N2O = CO2 approximately equal to O and Ar greater than O2 = N2O = CO2 approximately equal to O, respectively. A result similar to the yield of OH-DMPO was obtained from the liberation of iodine induced by ultrasound. In addition, the effectiveness of the dissolved gases in lysing mouse L5178Y cells by ultrasound was O2 = Ar greater than N2O = CO2 approximately equal to O. These results suggest that both dissolved N2O and CO2 gases in solution suppressed not only the chemical effect but also the biological effect.

Animals↗
PubMed1986

Reaction of the hydrated electron with histone H1 and related compounds studied by e.s.r. and spin-trapping.

The reactions of the hydrated electron with histone H1, protamine and related compounds (poly-L-lysine, poly-L-arginine and poly-D,L-alanine) were investigated by the spin-trapping technique. In order to identify the radical structure of the spin-adducts originating from macromolecules, the usual spin-trapping technique was developed as follows: N2-saturated aqueous solutions of proteins containing sodium formate were X-irradiated (4.5 kGy) in the presence of 2-methyl-2-nitrosopropane (MNP) as a spin-trap. The side-products due to the self trapping of MNP radicals were then removed from the spin-adducts of the proteins by a Sephadex G-25 column. Finally the spin-adducts were enzymatically digested to transform the broad e.s.r. signals due to slow tumbling of nitroxyl radicals to identifiable ones. The e.s.r. spectra obtained for all samples showed that the deaminated radical, R--CH--CO--NH--(R:amino acid side chain), was produced. Furthermore, polyacrylamide gel electrophoresis of the irradiated protamine and histone H1 indicated reduction of molecular size. These results confirm that hydrated electrons react with proteins and induce the deamination reaction which leads to main-chain scission.

Electron Spin Resonance Spectroscopy↗
PubMed1986

OH-induced free radicals in purine nucleosides and their homopolymers: e.s.r. and spin-trapping with 2-methyl-2-nitrosopropane.

Free radicals produced by X-irradiation of N2O-saturated aqueous solutions of purine nucleosides (2'-deoxyadenosine, adenosine, 2'-deoxyguanosine, 3'-deoxyadenosine, guanosine and inosine) and the corresponding homopolymers (poly A and poly I) have been investigated by the technique of spin-trapping and e.s.r. spectroscopy. 2-Methyl-2-nitrosopropane was used as a spin-trap. For 2'-deoxyadenosine and 2'-deoxyguanosine, the resulting spin-adducts were separated by Bio-Gel P-2 column chromatography and analysed by e.s.r. spectroscopy. For homopolymers, e.s.r. spectra were recorded at 50 degrees C after enzymatic digestion to obtain signals with narrower line width. The e.s.r. signal consisting of only a primary triplet without further splittings, which is consistent with assignment to the trapping of an H-abstraction radical at the C4' position of the sugar moiety, was observed in all cases. For 2'-deoxyguanosine an e.s.r. signal consisting of a secondary triplet was observed. Examinations using other spin-trapping reagents such as PBN, 4-PyOBN and DMPO provided no positive evidence supporting the proposal that this was due to an alpha-nitrogen. The e.s.r. signal consisting of a secondary doublet which further splits into a doublet was observed for 2'-deoxyadenosine, adenosine, 3'-deoxyguanosine, 2'-deoxyguanosine, and inosine, and tentatively associated with a radical centered in the sugar moiety.

Adenosine↗
PubMed1986

Bile alcohol profiles in bile, urine, and feces of a patient with cerebrotendinous xanthomatosis.

Bile alcohols in bile, urine, and feces of a patient with cerebrotendinous xanthomatosis have been analyzed by a combination of capillary gas-liquid chromatography and mass spectrometry after fractionation into groups according to mode of conjugation. The presence of at least 18 bile alcohols, which were excreted mainly as glucurono-conjugates in bile and urine, and as unconjugated forms in feces, was demonstrated. The following bile alcohols were identified with certainty by direct comparison with reference compounds: 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol; (23R)-5 beta-cholestane-3 alpha,7 alpha,12 alpha,23-tetrol; 5 alpha- and 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24-tetrols; 5 alpha- and 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrols; 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentol; (22R)-5 beta-cholestane-3 alpha,7 alpha,12 alpha,22,25-pentol; (23R)- and (23S)-5 beta-cholestane-3 alpha,7 alpha, 12 alpha,23,25-pentols; 3 alpha,12 alpha,25-trihydroxy-5 beta-cholestane-7-one; (24R)- and (24S)-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentols; 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25,26-pentol. Although the bile alcohol profile in urine was quite different from those in bile and feces, the determination of urinary bile alcohols as well as of biliary and fecal bile alcohols could be used for diagnosis of cerebrotendinous xanthomatosis.

Adult↗
PubMed1986

Biological and clinical implication of neuron-specific enolase and creatine kinase BB in small cell lung cancer.

The specificity of neuron-specific enolase (NSE) and creatine kinase BB (CK-BB) for small cell lung cancer (SCLC) was determined by biological and immunohistochemical procedures in lung cancer tissues and cultured cell lines. Average values of extractable NSE and CK-BB of SCLC tissues were significantly higher than those of non-SCLC and normal lung tissues. A large amount of NSE and CK-BB was demonstrated in SCLC cell lines. Immunohistochemical examination showed positive staining for NSE and CK-BB in most cases of SCLC and in a few cases of non-SCLC. From these data NSE and CK-BB should be considered to be highly specific for SCLC. In a clinical study serum values exceeding 10 ng/ml for NSE and 1.5 ng/ml for CK-BB were set as positive for the enzymes. Positive rates in SCLC were 71.4% for NSE and 65.3% for CK-BB, which were significantly higher than those in non-SCLC. All positive cases were in an advanced stage. Consecutive daily NSE determinations during induction chemotherapy showed transient elevation immediately after the initiation of drug administration (tumor lysis syndrome), followed by a decline to normal range in responders. This phenomenon seems to indicate tumor sensitivity to cytotoxic drugs. NSE positive non-SCLC was as sensitive to cytotoxic drugs as SCLC. These findings indicate that lung cancer with elevated serum NSE and CK-BB levels at diagnosis should be strongly suspected of being SCLC in the advanced stage.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

OH-induced free radicals in uridine studied by a method combining ESR, spin-trapping, and liquid chromatography.

Free radicals produced by the reactions of OH radicals with uridine were investigated by a method combining ESR, spin-trapping, and liquid chromatography. A N2O-saturated aqueous solution of uridine, containing 2-methyl-2-nitrosopropane as a spin-trap, was X-irradiated and the resulting spin-adducts were separated by gel permeation chromatography and reverse-phase HPLC. ESR and uv-absorbance spectra obtained from the separated spin-adducts show that 5-yl and 6-yl radicals are produced by OH addition to the 5,6 double bond of the base moiety. It is also shown that radicals due to H abstraction from the sugar moiety at the C-4' and C-5' positions are produced.

Chromatography, Gel↗