[Stereotaxic radiosurgery (gamma-knife)].
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Brain Neoplasms↗
Biomedical subjects
Y Oda
Publications and source records attributed to Y Oda.
NMR studies for identification of dI:dG mismatch base-pairing structure in DNA.
One- and two-dimensional NMR experiments have been undertaken to investigate deoxyinosine:deoxyguanosine (dI:dG) base pairing in a self-complementary dodecadeoxyribonucleotide, d(C1-G2-C3-I4-A5-A6-T7-T8-G9-G10-G11-G12) (designated IG-12), duplex. The NMR data indicate formation of a dI(syn):dG(anti) base pair in a B-DNA helix. This unusual base pairing results in altered NOE patterns between the base protons (H8 and H2) of the I4 residue and the sugar protons of its own and the 5'-flanking C3 residues. The dI(syn):dG(anti) base pair is accommodated in the B-DNA duplex with only a subtle distortion of the local conformation. Identification of the dI:dG base pairing in this study confirms that a hypoxanthine base can form hydrogen-bonded base pairs with all of the four normal bases, C, A, T, and G, in DNA.
Base Composition↗
The plasma cell membrane glycoprotein, PC-1, is a threonine-specific protein kinase stimulated by acidic fibroblast growth factor.
A 32P-labeled protein that co-purified with acidic fibroblast growth factor (aFGF) receptor from bovine liver proved to be a distinct membrane protein, which itself has kinase activity that is stimulated by aFGF. The protein was designated MAFP for major aFGF-stimulated phosphoprotein. MAFP was purified from bovine liver using immunoaffinity chromatography with monoclonal antibody to MAFP following Triton X-100 extraction of plasma membranes and wheat germ lectin-Sepharose 4B column chromatography. The purified MAFP showed molecular masses of 130 kDa and 260 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing and nonreducing conditions, respectively. Purified MAFP elicited aFGF-stimulated Thr-specific autophosphorylation activity and phosphorylation activity toward protein substrates (myelin basic protein and histone). Amino acid sequence analyses of 16 peptide fragments of MAFP, produced by endoproteinase Lys-C digestion followed by reduction and S-pyridylethylation, showed approximately 80-100% homology with the cDNA-deduced amino acid sequences of human and mouse plasma cell membrane glycoprotein, PC-1 (Buckley, M. F., Loveland, K. A., McKinstry, W. J., Garson, O. M., and Goding, J. W. (1990) J. Biol. Chem. 265, 17506-17511), suggesting that MAFP is the bovine version of PC-1. The amino acid sequences of bovine MAFP, human and mouse PC-1 reveal a putative ATP binding site in their extracellular domains. These results suggest that MAFP(PC-1) is an ectoprotein kinase. In addition to the kinase activity, MAFP(PC-1) was also found to possess alkaline nucleotide phosphodiesterase activity. It is now clear that several of the unique properties previously attributed to the aFGF receptor kinase are actually properties of this novel Thr-specific ectoprotein kinase, which co-purifies with the aFGF receptor and is responsive to stimulation by aFGF.
Amino Acid Sequence↗
Inhibition of cell growth and tumorigenesis of human glioblastoma cells by a neutralizing antibody against human basic fibroblast growth factor.
We report here that a neutralizing mouse monoclonal antibody against basic FGF inhibited both anchorage-dependent and anchorage-independent growth of U-87MG and T98G human glioblastoma cells and HeLa cells, all of which express both the basic FGF and the FGF receptor genes. In addition, the subcutaneous administration of this antibody significantly suppressed the tumor development of these tumor cells in nude mice. Therefore, basic FGF plays an important role in neoplastic growth of these cells. The neutralization of basic FGF will be effective in controlling the growth of tumors, such as glioblastoma and other cancer cells which bear basic FGF and FGF receptors.
Animals↗
Gene expression of fibroblast growth factor receptors in the tissues of human gliomas and meningiomas.
Northern blot analysis showed transcripts of two types of the fibroblast growth factor (FGF) receptor genes, flg and bek, in almost all the tissues samples of 18 human gliomas and 22 human meningiomas, which produced abundant basic and/or acidic FGF. From immunohistochemistry, FGF receptors were expressed in the tumor cells of a glioma and a meningioma. RNA expression of these FGF receptors was also detectable in normal human brains and normal bovine meninges. The expression level of either FGF receptor gene was not significantly different between tumor tissues and normal tissues.
Blotting, Northern↗
High-performance affinity chromatography of a chick lectin on an adsorbent based on hydrophilic polymer gel.
A mouse monoclonal antibody (SIA4-5) which reacts with a chick 14K lectin (C14K) was covalently attached to a new support for high-performance affinity chromatography, TSKgel Tresyl-5PW, which is a preactivated, polymer-based particle. The immobilized antibody (SIA4-5-5PW) thus prepared proved to be useful in measuring not only the molecular properties of C14K but also specific interactions of C14K with SIA4-5 and hapten sugars. The C14K preparation was fractionated according to the oligomeric structure and with slight differences in affinity to SIA4-5 although the former was homogeneous in sodium dodecyl sulphate polyacrylamide gel electrophoresis. Application of the method for quantitative analytical purposes was successful.
Adsorption↗
NMR studies of a DNA containing 8-hydroxydeoxyguanosine.
The effects of hydroxylation at the C8 of a deoxyguanosine residue in DNA were studied by NMR analysis of a self-complementary dodecanucleotide, d(C1-G2-C3-oh8G4-A5-A6-T7-T8-C9-G10-C11-G12), which has an 8-hydroxy-2'-deoxyguanosine (oh8dG) residue at the 4th position. NMR data indicate that the 8-hydroxyguanine (oh8G) base takes a 6,8-diketo tautomeric form and is base-paired to C with Watson-Crick type hydrogen bonds in a B-form structure. The thermal stability of the duplex is reduced, but the overall structure is much the same as that of the unmodified d(CGCGAATTCGCG) duplex. The structural changes caused by 8-hydroxylation of the deoxyguanosine, if any, are localized near the modification site.
8-Hydroxy-2'-Deoxyguanosine↗
Human breast carcinoma cDNA encoding a galactoside-binding lectin homologous to mouse Mac-2 antigen.
A galactoside-binding lectin (Mr 29,000) has previously been identified in rat, mouse and human tissues. It is an abundant cell-surface component of inflammatory macrophages and their major non-integrin laminin-binding protein. It has also been found in the nucleus of other cell types. Here, we report the cloning and sequencing of a cDNA encoding the human galactoside-binding lectin from a breast carcinoma. The clone encodes a protein of 250 amino acids (aa) that is over 80% identical to its mouse and rat counterparts. The aa sequence has an N-terminal and a C-terminal, 'carbohydrate-binding', domain. The N-terminal domain consists of two parts. The first 41 aa are homologous to a transcription factor, i.e., the serum response factor. The adjacent part (aa 42-106) contains an unusual repeating element, that occurs seven times in human protein compared to nine times in rat and mouse. The C-terminal 'carbohydrate-binding' domain (aa 115-250) shows homology to L-14, another galactoside-binding lectin.
Amino Acid Sequence↗
Microfilamentous type VI collagen in the hyalinized stroma of the hypertrophied ligamentum flavum.
Thickened ligamenta flava obtained from 14 patients with spinal canal stenosis were examined with special reference to type VI collagen. The characteristic histological finding in the thickened area was rupture or normal elastic fibre meshwork with resultant fibrosis which usually appeared hyaline. Using an immunohistological method, collagen types VI, I and III were found to be present in the hyaline matrix. Ultrastructural study revealed many microfilamentous structures of type VI collagen admixed in loosely packed, banded collagen fibres. With differential salt precipitation of pepsin-extracted collagen the existence of type VI collagen was confirmed by SDS-polyacrylamide gel electrophoresis analysis and Western blotting analysis using anti-type VI collagen antibody. Quantification of type VI collagen in pepsin-extracted crude collagen samples by an inhibition enzyme-linked immunosorbent assay showed an increasing amount of type VI collagen in the thickened ligamenta flava compared to the normal ligaments. Thus, increase of type VI collagen is the main contribution to the thickening of the ligamentum flavum. This may represent an adaptational and reparative process associated with disruption of elastic fibres.
Collagen↗
Binding of metal ions to E. coli RNase HI observed by 1H-15N heteronuclear 2D NMR.
The divalent metal ion binding site and binding constant of ribonuclease HI from Escherichia coli were investigated by observing chemical shift changes using 1H-15N heteronuclear NMR. Chemical shift changes were monitored during the titration of the enzyme with salts of the divalent cations. The enzyme was uniformly labeled by 15N, which facilitated the monitoring of the chemical shift change of each cross peak between the backbone amide proton and the amide 15N. The chemical shifts of several amide groups were affected upon the addition of a divalent metal ion: Mg2+, Ca2+, or Ba2+. These amide groups resided close to the active site, consistent with the previous X-ray crystallographic studies. From the titration analysis, a single divalent ion binding site was observed with a weak binding constant (KD = 2-4 mM for the current divalent ions).
Amino Acid Sequence↗
Alpha 1-adrenergic regulation of thyrotropin-stimulated release of 3, 5, 3' -triiodothyronine and thyroxine from perifused mouse thyroid.
The effect of methoxamine, a specific alpha 1-adrenergic agonist, on the release of T3, T4 and cAMP from perifused mouse thyroid was studied to clarify the role of the alpha 1-adrenergic receptor in the regulation of thyroid hormone secretion. TSH-stimulated T3 and T4 release was inhibited significantly by methoxamine. With regard to cAMP release, methoxamine inhibited TSH-stimulated cAMP release in the presence of 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone but did not inhibit TSH-stimulated cAMP release in the presence of 3-isobutyl-1-methylxanthine. Methoxamine did significantly suppress TSH-stimulated release of T3 and T4 in the presence of each phosphodiesterase inhibitor. Depletion of Ca2+ in the perifusion buffer abolished completely the inhibitory effect of methoxamine on TSH-stimulated T3 and T4 release. The present study suggests that activation of the alpha 1-adrenergic receptor inhibits TSH-stimulated T3 and T4 secretion through a Ca(2+)-dependent mechanism in the mouse thyroid gland.
1-Methyl-3-isobutylxanthine↗
Stimulation of pulmonary surfactant secretion by activating neutrophils in rat type II pneumocytes culture.
The influence of activating neutrophils on the secretion of phosphatidylcholine (PC), the predominant component of pulmonary surfactant, was examined using primary culture of rat type II pneumocytes. Simultaneous addition of neutrophils and opsonized zymosan, but not neutrophils or opsonized zymosan alone, to type II pneumocytes caused a significant increase in PC secretion without affecting the release of lactate dehydrogenase, a marker of cytotoxicity. The increase in PC secretion was dependent on the number of activating neutrophils. In addition, pretreatment of culture with the combination of superoxide dismutase and catalase inhibited the increase in PC secretion. These findings indicate that activating neutrophils stimulate the secretion of pulmonary surfactant and that the stimulation is mediated by oxygen radicals.
Animals↗
Construction of a sucrose-fermenting bakers' yeast incapable of hydrolysing fructooligosaccharides.
Fructooligosaccharides stimulate the growth of intestinal bifidobacteria which are related to the favorable health and nutrition of humans and other animals. Since the efficient amount of fructooligosaccharide for an adult human is relatively large (about 5 g per day), its addition to daily foods like bakery goods might be beneficial. However, commercial Bakers' yeast hydrolyses fructooligosaccharides by the action of invertase encoded in SUC genes and ferments the resulting monosaccharides. According to the findings that strains carrying the MAL-constitutive gene and lacking the SUC gene fermented sucrose and not fructooligosaccharide, we constructed a sucrose-fermenting strain, YOY920, incapable of hydrolysing fructooligosaccharide, by cross-breeding a baking strain and a laboratory strain. In a molasses medium, the cell yield of YOY920 was comparable to that of a baking strain FSC6001, and much higher than that of the non-sucrose-fermenting strains. Although fructooligosaccharide inhibited the dough leavening ability of YOY920, white bread containing fructooligosaccharide could be produced in the defined dough formula using the new strain.
Animals↗
A microplate version of the SOS/umu-test for rapid detection of genotoxins and genotoxic potentials of environmental samples.
The umu-microtest is a miniaturized automated short-term test version proposed for screening of umuC-dependent mutagenic potentials of chemicals relevant to environmental pollution, river water and industrial waste water. The test is based on the SOS/umu-test and has been modified in order to allow extensive testing of environmental samples. Genetically engineered Salmonella typhimurium (TA1535/pSK1002) are incubated on a microplate rotor in a sloping position for 2 h with the test samples, followed by addition of fresh culture medium to reach a 10-fold dilution of the incubation medium. 2 h later, the activity of the beta-galactosidase, which reflects umuC induction, is determined colorimetrically. The incubation of the bacteria in the presence of the test compounds as well as the assessment of beta-galactosidase activity takes place in 96-well microplates, thus enabling simultaneous screening of large numbers of samples. Data of the genotoxic potentials are available within 8 h. Computer-controlled automation is possible by using a laboratory workstation.
Azides↗
Effect of saikosaponin on the immune responses in mice.
The in vivo effects of saikosaponin, isolated from Bupleurum radix, on the immune responses are still poorly understood. We have already shown that saikosaponin-d increases phagocytic activities of murine peritoneal macrophages such as spreading activity, phagocytosis, lysosomal enzyme activity and intracellular killing activity of living yeast. This work extends these observations by showing that treatment with saikosaponin also increased the antibody response in plaque-forming cell numbers after in vivo immunization with sheep red blood cells (SRBC) and an augmentation of spleen cell proliferation responses to stimulation with T- or B-cell mitogens both before and after immunization. Furthermore, after SRBC immunization, the macrophages from mice treated with saikosaponin-d revealed significant increases in spreading activity and lysosomal enzyme activity. The chemiluminescences of the macrophages from mice treated with saikosaponin-d stimulated by opsonized zymosan and PMA were enhanced and interleukin-1 production by the cells was increased in a dose-dependent manner. These results demonstrate that saikosaponin-d may stimulate in vivo immunological lymphocyte functions, partly by activating some macrophage functions.
Animals↗
Column-switching high-performance liquid chromatography for on-line simultaneous determination and resolution of enantiomers of verapamil and its metabolites.
An on-line simultaneous assay for the enantiomers of verapamil (VA) and its three metabolites in plasma was developed with column-switching HPLC. This system consists of an ovomucoid protein chiral stationary phase coupled to an achiral reversed-phase column via a dilution tube and a trapping column. The reversed-phase column was used to separate and quantitate VA, its metabolites, and internal standard, without interference from plasma components. Then each of the eluates containing VA and its metabolites was selectively switched into a sampling loop, and the samples were transferred successively to the trapping column after dilution with a new mobile phase. After concentration on the trapping column, each sample was passed to the ovomucoid column, where the enantiomers were resolved and quantitated. The mobile phases for both HPLC columns were independently optimized and the diffusion of the sample during column switching was minimized. This method was shown to be efficient and reliable.
Chromatography, High Pressure Liquid↗
Water and electrolyte balance in the vascular space during graded exercise in humans.
We analyzed the changes in water content and electrolyte concentrations in the vascular space during graded exercise of short duration. Six male volunteers exercised on a cycle ergometer at 20 degrees C (relative humidity = 30%) as exercise intensity was increased stepwise until voluntary exhaustion. Blood samples were collected at exercise intensities of 29, 56, 70, and 95% of maximum aerobic power (VO2max). A curvilinear relationship between exercise intensity and Na+ concentration in plasma ([Na+]p) was observed. [Na+]p significantly increased at 70% VO2max and at 95% VO2max was approximately 8 meq/kgH2O higher than control. The change in lactate concentration in plasma ([Lac-]p) was closely correlated with the change in [Na+]p (delta[Na+]p = 0.687 delta[Lac-]p + 1.79, r = 0.99). The change in [Lac-]p was also inversely correlated with the change in HCO3- concentration in plasma (delta[HCO3-]p = -0.761 delta[Lac-]p + 0.22, r = -1.00). At an exercise intensity of 95% VO2max, 60% of the increase in plasma osmolality (Posmol) was accounted for by an increase in [Na+]p. These results suggest that lactic acid released into the vascular space from active skeletal muscles reacts with [HCO3-]p to produce CO2 gas and Lac-. The data raise the intriguing notion that increase in [Na+]p during exercise may be caused by elevated Lac-.
Adult↗
Mitogenic activity of Tulipa gesneriana lectins on mouse and human lymphocytes.
Tulipa gesneriana lectin-erythrocyte (TGL-E) which agglutinates mouse erythrocytes showed a potent mitogenic activity on mouse spleen cells and human peripheral blood lymphocytes, however, TGL-E had only slight mitogenic activity on mouse thymus cells. Its subunit alpha with a molecular weight (MW) of about 26,000 showed a potent mitogenic activity as did that of native lectin, but subunit beta with a MW of about 14,000 showed no activity, indicating that the mitogenic activity of TGL-E originates from subunit alpha. TGL-E stimulated T cell enriched spleen cells which passed through a nylon column, but not spleen cells from a nude mouse or spleen cells treated with anti-Thy 1.2 antibody and complement. Thus, TGL-E stimulates only mouse T cells but not B cells. The other lectin in tulip bulbs, Tulipa gesneriana lectin-yeast showed no mitogenic activity on mouse spleen, thymus cells or human paripheral blood lymphocytes.
Animals↗