Showing papers by "University of Tokyo published in 1986"
••
TL;DR: Its sequence shows that the c-erb-B-2 gene encodes a possible receptor protein and allows an analysis of the similarity of the protein to the EGF receptor and the neu product.
Abstract: A novel v-erb-B-related gene, c-erb-B-2, which has been identified in the human genome, maps to human chromosome 17 at q21 (ref. 40), and seems to encode a polypeptide with a kinase domain that is highly homologous with, but distinct from, that of the epidermal growth factor (EGF) receptor. The c-erb-B-2 gene is conserved in vertebrates and it has been suggested that the neu gene, detected in a series of rat neuro/glioblastomas, is, in fact, the rat c-erb-B-2 gene. Amplification of the c-erb-B-2 gene in a salivary adenocarcinoma and a gastric cancer cell line MKN-7 suggests that its over-expression is sometimes involved in the neoplastic process. To determine the nature of the c-erb-B-2 protein, we have now molecularly cloned complementary DNA for c-erb-B-2 messenger RNA prepared from MKN-7 cells. Its sequence shows that the c-erb-B-2 gene encodes a possible receptor protein and allows an analysis of the similarity of the protein to the EGF receptor and the neu product. As a consequence of chromosomal aberration in MKN-7 cells, a 4.6-kilobase (kb) normal transcript and a truncated 2.3-kb transcript of c-erb-B-2 are synthesized at elevated levels. The latter transcript presumably encodes only the extracellular domain of the putative receptor.
1,259 citations
••
TL;DR: Southern hybridization analysis of DNA from normal leukocytes and CHU-2 cells suggests that the human genome contains only one gene for G-CSF and that some rearrangement has occurred within one of the alleles of the G- CSF gene in CHU -2 cells.
Abstract: Granulocyte colony-stimulating factor (G-CSF) is a member of the CSF family of hormone-like glycoproteins that regulate haematopoietic cell proliferation and differentiation1,2, and G-CSF almost exclusively stimulates the colony formation of granulocytes from committed precursor cells in semi-solid agar culture2. Recently, Nomura et al.3 have established a human squamous carcinoma cell line (designated CHU-2) from a human oral cavity tumour which produces large quantities of CSF constitutively, and the CSF produced by CHU-2 cells has been purified to homogeneity from the conditioned medium. We have now determined the partial amino-acid sequence of the purified G-CSF protein, and by using oligonucleotides as probes, have isolated several clones containing G-CSF complementary DNA from the cDNA library prepared with messenger RNA from CHU-2 cells. The complete nucleotide sequences of two of these cDNAs were determined and the expression of the cDNA in monkey COS cells gave rise to a protein showing authentic G-CSF activity. Furthermore, Southern hybridization analysis of DNA from normal leukocytes and CHU-2 cells suggests that the human genome contains only one gene for G-CSF and that some rearrangement has occurred within one of the alleles of the G-CSF gene in CHU-2 cells.
851 citations
••
TL;DR: Although the c-erbB-2 protein was predicted to encode a protein very similar to epidermal growth factor (EGF) receptor, EGF did not stimulate this kinase activity either in vivo or in vitro.
Abstract: Antibodies were raised against a synthetic peptide corresponding to 14 amino acid residues at the COOH-terminus of a protein deduced from the human c-erbB-2 nucleotide sequence. These antibodies immunoprecipitated a 185-kilodalton glycoprotein from MKN-7 adenocarcinoma cells. Incubation of the immunoprecipitates with (gamma-32P)ATP resulted in the phosphorylation of this protein on tyrosine residues. These results indicate that the human c-erbB-2 gene product is the 185-kilodalton glycoprotein that is associated with tyrosine kinase activity. Although the c-erbB-2 protein was predicted to encode a protein very similar to epidermal growth factor (EGF) receptor, EGF did not stimulate this kinase activity either in vivo or in vitro.
809 citations
••
TL;DR: In this paper, the authors studied the settling and growth of dust particles in the subsequent laminar phase of the solar nebula in detail, treating a dust layer as a two-component fluid composed of the dust and the gas, and obtained analytic expressions for the settling path, the growing size, and the settling time.
628 citations
••
TL;DR: Results strongly suggest that a major antigenic determinant of PHF is phosphorylated tau itself.
Abstract: Antisera to paired helical filaments (PHF) were found to contain a significant amount of tau antibodies specific for a phosphorylated form, but only a negligible amount of those specific for a non-phosphorylated form. Also, the phosphorylated tau-specific antibodies, but not the non-phosphorylated tau-specific ones, labeled neurofibrillary tangles isolated in the presence of sodium dodecyl sulfate (SDS) and stained both tangles and senile plaque neuritis in fixed tissue sections in a very similar way to as the whole antiserum did. Taken together, these results strongly suggest that a major antigenic determinant of PHF is phosphorylated tau itself.
513 citations
••
TL;DR: Optical emission, soft X-ray, and hard X-rays have been observed simultaneously from the black hole candidate GX 3339-4 in a typical high state as mentioned in this paper, and each of these components is interpreted as arising from a characteristic region of the accretion disk.
Abstract: Optical emission, soft X-rays, and hard X-rays have been observed simultaneously from the black hole candidate GX 3339-4 in a typical high state. Each of these components is interpreted as arising from a characteristic region of the accretion disk. Considered as a black hole, GX 339-4 lacks the variable 2 keV blackbody component that would be emitted from the 'solid' surface of a neutron star in the low-mass neutron star binaries. The X-ray emission in the high state is therefore extremely soft and stable in time. The intermediate disk region is optically thick and geometrically thin. The observed soft X-ray component with a 'disk blackbody' spectrum comes from this region. The innermost disk region is dynamically unstable due to the effect of general relativity and possibly due to radiation pressure. This region is responsible for the generation of the hard X-ray tail through Comptonization.
497 citations
••
TL;DR: It was concluded that Ado and m-ACh receptors link with the same population of K+ channels via GTP-binding proteins Ni and/or No in the atrial cell membrane.
Abstract: The molecular mechanisms underlying activation of a K+ channel by adenosine (Ado) and acetylcholine (ACh) were examined in single atrial cells of guinea-pig. Whole cell clamp and patch clamp techniques were used to characterize the K+ channel. In the whole cell clamp conditions, Ado and ACh increased the K+ channel current in a dose-dependent manner. The maximum responses and the apparent dissociation constants were different for Ado and ACh activations of the current. Theophylline blocked activation of the K+ current by Ado, while atropine blocked ACh-activation, indicating that two different membrane receptors were involved. Measurements of the conductance and kinetic properties of both whole cell and single channel currents indicate that Ado and ACh regulate the same K+ channels. In “inside-out” patch conditions, GTP was required in the intracellular side of the membrane for activation of the K+ channel by agonists (present in the patch electrode). The A protomer of pertussis toxin inhibited the channel activation only when NAD was also present. Furthermore, GTP-γS, a non-hydrolyzable GTP analogue, gradually caused activation of the K+ channel in the absence of agonists. Therefore, it was concluded that Ado and m-ACh receptors link with the same population of K+ channels via GTP-binding proteins Ni and/or No in the atrial cell membrane.
456 citations
••
TL;DR: HIV-1 RNA load testing is sometimes requested to resolve equivocal serologic findings or to facilitate the diagnosis of HIV-1 infection during the acute phase or in a pediatric setting.
Abstract: The human immunodeficiency virus (HIV) is the etiologic agent of AIDS. HIVs are enveloped plus-stranded RNA viruses. The HIV genome is organized similarly to other retroviruses. It contains the gag, pol, and env genes which encode structural proteins, viral enzymes, and envelope glycoproteins, respectively. The major structural proteins which are encoded by the gag gene include p17, p24, p7, and p9. Replication begins with the attachment of virus to the target cell via the interaction of gp120 and the cellular receptor CD4. Both HIV-1 and HIV-2 have the same modes of transmission. The most common mode of HIV infection is sexual transmission at the genital mucosa through direct contact with infected blood fluids, including blood, semen, and vaginal secretions. Serological testing for HIV antibody is used for various purposes, including primary diagnosis, screening of blood products, management of untested persons in labor and delivery, evaluation of occupational exposures to blood/body fluid, and epidemiological surveillance. The first generation of HIV antibody assays relied on the detection of antibody to HIV viral protein lysates. A test using a sandwich-capture format and significantly more blood than other methods was more sensitive in early seroconversion. HIV-1 RNA load testing is sometimes requested to resolve equivocal serologic findings or to facilitate the diagnosis of HIV-1 infection during the acute phase or in a pediatric setting.
445 citations
01 Jan 1986
431 citations
••
TL;DR: This paper showed that the amplified c-erbB-2 gene may have a role in the evolution of adenocarcinomas, as does the EGF receptor in some squamous-cell carcinomas.
411 citations
••
TL;DR: The results do indicate that the adjuvant activity of DEP can not be excluded as a possible cause of the associated change in the number of diesel cars and allergic rhinitis caused by pollen in Japan.
Abstract: The prevalence rate of allergic rhinitis caused by pollen has strikingly increased in Japan in the last three decades. The number of diesel cars in use has also rapidly increased in the country. This fact urged us to study the effects of particulates emitted from diesel cars on the production of IgE antibody. The primary IgE antibody responses in mice immunized with intraperitoneal injection of ovalbumin (OA) mixed with diesel-exhaust particulates (DEP) were higher than those in the animals immunized with OA alone. This effect of DEP on the production of IgE antibody in mice was also demonstrated when mice were immunized with repeated injections of dinitrophenylated-OA. In addition, persistent IgE-antibody response to major allergen of Japanese cedar pollen (JCPA), a most common pollen causing allergic rhinitis in Japan, was observed in mice immunized with JCPA mixed with DEP but not in the animals immunized with JCPA alone. The results do indicate that the adjuvant activity of DEP can not be excluded as a possible cause of the associated change in the number of diesel cars and allergic rhinitis caused by pollen in Japan.
••
TL;DR: The structure of NiO-SrTiO/sub 3/ powder has been studied by spectroscopic methods such as SEM, TEM, EXAFS, XANES, and XPS as mentioned in this paper.
Abstract: The structure of NiO-SrTiO/sub 3/ powder, which is a photocatalyst for the decomposition of water into H/sub 2/ and O/sub 2/, has been studied by spectroscopic methods such as SEM, TEM, EXAFS, XANES, and XPS. It has been clearly shown that the active catalyst has a peculiar structure; that is, nickel metal exists at the interface of NiO and SrTiO/sub 3/. The surface of NiO changes further into Ni(OH)/sub 2/ during the photocatalytic reaction in water. 31 references, 7 figures, 2 tables.
••
TL;DR: It is reported that antibodies against purified PHF recognize tau protein, a brain-specific microtubule-associated protein, suggesting that a portion of PHF is tauprotein.
Abstract: Paired helical filaments (PHF) are unusual neuronal fibers which accumulate progressively in the brain in Alzheimer's disease (AD). The insolubility of PHF in various kinds of solvents enabled us to obtain highly purified PHF, but prevented the application of conventional analytical methods to identify their components. Here we report that antibodies against purified PHF recognize tau protein, a brain-specific microtubule-associated protein, suggesting that a portion of PHF is tau protein.
••
TL;DR: It is concluded that CA facilitates the diffusion of DIC from outside the cells to the site(s) of the carboxylation reaction and the concentration of Dic is achieved via an active transporter, indicating the existence of CO2-concentrating mechanisms in these cells.
Abstract: Among the microbial phototrophs, those belonging to the cyanobacteria utilize CO2 and HCO−3 for photosynthesis. Some Chlorophyceae mainly take up CO2 in photosynthesis, and others, which have carbonic anhydrase (CA) on their cell surface can utilize HCO−3 as well as CO2. Kinetic studies revealed that most of the HCO−3 is utilized after this ion is converted to CO2 via CA located on the cell surface. Therefore, the actual molecular species which crosses the plasmalemma is mostly free CO2. There is apparent variation in the mode of utilization of dissolved inorganic carbon (DIC) for photosynthesis in microalgae in other classes. The apparent Km(CO2) values for photosynthesis in most microalgae grown in ordinary air (low-CO2 cells) are as low as in terrestrial C4 plants, although the algal cells fix CO2 via the C3 pathway. In contrast, the apparent Km(CO2) values in cells grown on CO2-enriched air (high-CO2 cells) are as high as those in the terrestrial C3 plants. Most low-CO2 cells show low photorespiration; a low CO2 compensation point, low rates of glycolate excretion and no or low O2 inhibition of photosynthesis. These results indicate that the efficiency of DIC utilization for photosynthesis in low-CO2 cells is very high. The activity of CA in low-CO2 cells is higher than that in high-CO2 cells, while no difference has been confirmed in the activities of other photosynthetic enzymes between low- and high-CO2 cells. In addition, low-CO2 cells can accumulate large amounts of DIC internally, indicating the existence of CO2-concentrating mechanisms in these cells. When CA activity or CO2 concentrating ability is reduced by inhibitors or by mutation, the apparent Km(CO2) values for photosynthesis and the rate of photorespiration increased notably. These results indicate that the high efficiency of DIC utilization in low-CO2 cells depends on both CA and a CO2-concentrating mechanism. It is concluded that CA facilitates the diffusion of DIC from outside the cells to the site(s) of the carboxylation reaction and the concentration of DIC is achieved via an active transporter.
••
TL;DR: Cloned cDNAs encoding alpha subunits of the guanine nucleotide-binding proteins Gs, Gi, and Go were cloned and their nucleotide sequences were determined; they contain 394 and 355 amino acid residues, respectively.
Abstract: We have cloned cDNAs encoding alpha subunits of the guanine nucleotide-binding proteins Gs, Gi, and Go and determined their nucleotide sequences Purified preparations of Gi and Go alpha subunits (Gi alpha and Go alpha) from rat brain were completely digested with trypsin, and peptides were subjected to amino acid sequence analysis By screening of a cDNA library from rat C6 glioma cells with a synthetic probe corresponding to a 17 amino acid sequence, a clone encoding the sequence of Go alpha was obtained Then, the library was rescreened with a Go alpha cDNA probe to isolate several strongly or weakly hybridizing clones cDNAs encoding the complete sequences of Gi alpha and Gs alpha were thus obtained From nucleotide sequence analysis, the amino acid sequences of Gs alpha and Gi alpha were deduced; they contain 394 and 355 amino acid residues (including the initiator methionine), respectively The calculated molecular weights for Gs alpha and Gi alpha were 45,663 and 40,499, respectively The Go alpha clone encoded a sequence of 310 amino acid residues that lacked the NH2 terminus The homology of the alpha subunits of Gs, Gi, Go, transducin, and ras-encoded protein is discussed
••
TL;DR: A region (virG) on the 230 kb virulence plasmid of S. flexneri that is required for cell-to-cell spread of the bacterium is identified and Sequences hybridizing to this region were found in all intact virulent plasmids of Shigellae and enteroinvasive E. coli.
••
TL;DR: In this article, a series of drained plane strain compression tests was performed on saturated samples of fine angular to subangular sand at confining pressures from 0.05 kgf/cm2 (4.9 kN/m2) up to 4.
••
TL;DR: A series of periodic increases in intracellular free calcium concentration ([Ca2+]i) occurred upon fertilization in golden hamster eggs, and the spatial distribution of the Ca2+ transients was investigated in single zona-free, aequorin-injected eggs, inseminated by single sperm.
••
TL;DR: In this article, the authors compared 2nd-order QCD calculations with 3-and 4-jet models in the energy range of 14.0-46.7 GeV and showed that the observed excess of spherical events can partially be explained by the production of multi-parton events expected from higher order QCD contributions.
Abstract: Hadronic jet production bye+e−-annihilation has been studied in the energy range of 14.0–46.7 GeV. The data have been analysed in terms of a cluster algorithm and other topological quantities. The results are compared with 2nd order QCD calculations which incorporate models for the fragmentation of quarks and gluons into hadrons. At the higher energies we observe more spherical and 4-jet like events than predicted by these calculations. We cannot achieve a simultaneous description of the observed 3- and 4-jet production by adjusting the strong coupling constant αs or the fragmentation parameters of the 2nd order QCD models. The observed excess of spherical events can partially be explained by the production of multi-parton events expected from higher order QCD contributions. Consequences of the presented results for the value of αs, determined in previous analyses, are discussed. QCD parton shower models, including soft gluon interference, are able to describe the observed number of spherical events.
••
TL;DR: The observed dependence of \ensuremath{\mu} on ${N}_{s}$ at low temperatures is shown to be in excellent agreement with the theory of ionized-impurity scattering, whereas the high-temperature data disagree with the existing theory of polar-optical phonon scattering.
Abstract: We describe our systematic study of the two-dimensional electron mobilities \ensuremath{\mu} of n-type ${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As/GaAs heterojunctions, in particular their dependence on the electron concentration ${N}_{s}$ and the temperatures T, in a variety of field-effect transistors in which the impurity locations are precisely controlled to vary \ensuremath{\mu} over the wide range of 5\ifmmode\times\else\texttimes\fi{}${10}^{3}$ to 1.5\ifmmode\times\else\texttimes\fi{}${10}^{6}$ ${\mathrm{cm}}^{2}$/V s. It is found that \ensuremath{\mu} increases with increasing ${N}_{s}$ in the temperature range of 10 to 300 K. The measured mobilities are compared with theoretical calculations. The observed dependence of \ensuremath{\mu} on ${N}_{s}$ at low temperatures is shown to be in excellent agreement with the theory of ionized-impurity scattering, whereas the high-temperature data disagree with the existing theory of polar-optical phonon scattering. A quantitative study has been successfully made on the effect of an undoped ${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As spacer layer, which enhances not only \ensuremath{\mu} itself but also the slope in log\ensuremath{\mu}-log${N}_{s}$ characteristics. The presence of both positive and negative temperature dependences of \ensuremath{\mu} at low temperatures (T40 K) is noted, and its connection with the effects of nondegeneracy and lattice scattering is also discussed.
••
TL;DR: Gabber and Kato as discussed by the authors used the basic Rudakov-Shafarevich result on existence and smoothness of moduli for K3 surfaces in characteristic p to study the moduli space when p = 2.
Abstract: What follows is a report on joint work with O. Gabber and K. Kato.* A manuscript with complete proofs exists and is currently being revised. For compelling physical reasons (viz. time, space, and distance) however, I will give here only statements of results; and my coauthors have not had the opportunity to correct any stupidities which may have slipped in. The conjectures in §3 are my own. I like to think that this research has been strongly influenced by the work of Shafarevich, both by his work on algebraic geometry in characteristic p and by his work on arithmetical algebraic geometry. In fact, recently Ogus has used these results to apply the basic Rudakov-Shafarevich result on existence and smoothness of moduli for K3 surfaces in characteristic p to the study of the moduli space when p = 2.
••
TL;DR: The paper provides an overview of basic concepts underlying random field theory, describes specific analytical tools to convey first- and second-order information about homogeneous random fields, and surveys available information on the space-time variation of random loads and material properties encountered in structural engineering.
••
TL;DR: In this paper, an energy transfer from the parent wave to two daughter Alfven-like waves and a sound-like wave is observed (a stimulated Brillouin scattering process), and the observed growth rates and propagation characteristics of these daughter waves agree with the analytical results.
Abstract: By means of a numerical simulation, nonlinear evolution of large amplitude dispersive Alfven waves is studied. An energy transfer from the parent wave to two daughter Alfven-like waves and a soundlike wave is observed (a stimulated Brillouin scattering process). The observed growth rates and propagation characteristics of these daughter waves agree with the analytical results, which we obtain by extending the previous treatments by Goldstein, Derby, Sakai, and Sonnerup. Ions are first trapped by the electrostatic potential of the daughter soundlike waves. Along with the eventual decay (ion Landau damping) of the soundlike waves, ions are phase-mixed and left heated in the parallel direction. The increased parallel energy of ions is transferred to the perpendicular thermal energy through the nonresonant scattering process in the colliding Alfven waves (parent and daughter waves). We further observe that the daughter Alfven waves, which still have a large amplitude, are also unstable for further decay, and that the wave energy is continuously transferred to the longer wavelength regime (inverse cascading process).
••
TL;DR: Results showed the production of TTX and anhydroTTX in the Vibrio sp.
Abstract: Vibrio sp. isolated from a xanthid crab, Atergatis floridus, was cultured, and tetrodotoxin (TTX) and anhydroTTX were indicated to be present in several fractions of the cell extract and the culture medium by reverse phase HPLC. The presence of the C9-base in alkaline hydrolyzates of these fractions was confirmed by GC-MS and UV spectrometry. These results showed the production of TTX and anhydroTTX in the Vibrio sp., thus indicating one of the origins of TTX in nature.
••
TL;DR: Evidence is provided that CPP injected into a ligated loop of rat small intestine enhanced absorption of calcium from the loop and augmented the deposition of calcium in the femur, suggesting that this peptide enhances calcium absorption from the small intestinal lumen by increasing the concentration of soluble calcium.
Abstract: A casein phosphopeptide (CPP) was prepared from beta-casein of cow's milk and the effect of this peptide on the absorption of calcium from a ligated segment of rat small intestine was investigated. CPP injected into a ligated loop of rat small intestine enhanced absorption of calcium from the loop and augmented the deposition of calcium in the femur. Furthermore, CPP inhibited the precipitation of calcium phosphate in vitro, suggesting that this peptide enhances calcium absorption from the small intestinal lumen by increasing the concentration of soluble calcium. This new evidence confirms our previous hypothesis that CPP is an important factor in raising the availability of calcium in milk.
••
TL;DR: In this article, a generalized coordinate system is used so that a sufficient number of grid points are distributed in the boundary layer and the wake, and a numerical scheme which suppresses non-linear instability for calculations of high Reynolds number flows is developed.
••
TL;DR: Mise en evidence, par diffusion de neutrons, de l'apparition a frequence finie des excitations les plus basses dans l'antiferromagnetique a spin 1 CsNiCl 3 , dans sa phase a une dimension.
Abstract: Neutron scattering has shown that the lowest spin excitations in the spin-1 antiferromagnet ${\mathrm{CsNiCl}}_{3}$ in its one-dimensional phase occur at finite frequency. After allowance for the known weak interchain coupling the gap is found to be in good agreement with recent numerical calculations. The results support the Haldane conjecture that in integral-spin chains with isotropic interactions a gap separates the ground state from the excitations.
••
TL;DR: Low-tension glaucoma eyes seem to consist of two different groups; one which develops recurrent DH and one which is very unlikely to bleed through its entire course.
••
TL;DR: The function of the only ras homolog in S. pombe detectable by Southern blotting is analyzed and ras1 appears to have no effect on adenylate cyclase activity, suggesting that the target enzymes presumably modulated by ras proteins in signal transduction are not the same for all organisms.