T. Ohta

Publication List Details

Period

1977 - 2009

Number

207

Co-Authors

Quantum Transport in Ladder-Type Networks: Role of nonlinearity, topology and spin (2009)

Nakamura, K., Matrasulov, D., Milibaeva, G., Yusupov, J., Salomov, U., Ohta, T., ...

We investigate quantum transport of electrons, phase solitons, etc. through mesoscopic networks of zero-dimensional quantum dots. Straight and circular ladders are chosen as networks with each...

Groundwater dating by estimation of groundwater flow velocity and dissolved 4He accumulation rate calibrated by 36Cl in the Great Artesian Basin, Australia (2009)

Mahara, Yasunori, Habermehl, M.A., Hasegawa, T., Nakata, K., Ransley, T.R, Hatano, T., ...

We tested two methods for dating groundwaters that cannot be reliably measured by 36Cl dating alone, one based on groundwater flow velocity plus distance along a flow path and the other based on 4He...

Tension Dynamics and Linear Viscoelastic Behavior of a Single Semiflexible Polymer Chain (2009)

Hiraiwa, T., Ohta, T.

We study the dynamical response of a single semiflexible polymer chain based on the theory developed by Hallatschek et al. for the wormlike-chain model. The linear viscoelastic response under...

High resolution angle resolved photoemission studies on quasi-particle dynamics in graphite (2009)

Leem, C. S., Kim, B. J., Kim, Chul, Park, S. R., Kim, Min-Kook, Johnston, S., ...

We obtained the spectral function of the graphite H point using high resolution angle resolved photoelectron spectroscopy (ARPES). The extracted width of the spectral function (inverse of the...

Simulating carbon and water cycles of larch forests in East Asia by the BIOME-BGC model with AsiaFlux data (2009)

M. Ueyama, K. Ichii, R. Hirata, K. Takagi, J. Asanuma, T. Machimura, ...

Larch forests are widely distributed across many cool-temperate and boreal regions, and they are expected to play an important role in global carbon and water cycles. Model parameterizations for...

Impact of meteorological anomalies in the 2003 summer on gross primary productivity in East Asia (2009)

N. Saigusa, K. Ichii, H. Murakami, R. Hirata, J. Asanuma, H. Den, ...

Northern Eurasia experienced anomalous weather conditions in the 2003 summer. We examined how forest ecosystems responded to the meteorological anomalies during the period using the dataset collected...

Origins of large critical temperature variations in single layer cuprates (2008)

Palczewski, A. D., Kondo, T., Khasanov, R., Kolesnikov, N. N., Timonina, A. V., Rotenberg, E., ...

We study the electronic structures of two single layer superconducting cuprates, Tl$_2$Ba$_2$CuO$_{6+\delta}$ (Tl2201) and (Bi$_{1.35}$Pb$_{0.85}$)(Sr$_{1.47}$La$_{0.38}$)CuO$_{6+\delta}$ (Bi2201)...

Symmetry Breaking in Few Layer Graphene Films (2008)

Bostwick, A., Ohta, T., McChesney, J.L., Emtsev, K., Seyller, Th., Horn, K., ...

Recently, it was demonstrated that the quasiparticle dynamics, the layer-dependent charge and potential, and the c-axis screening coefficient could be extracted from measurements of the spectral...

Spectroscopy of 24Al and extraction of Gamow-Teller strengths with the 24Mg(3He,t) reaction at 420 MeV (2008)

Zegers, R. G. T., Meharchand, R., Adachi, T., Austin, Sam M., Brown, B. A., Fujita, Y., ...

The 24Mg(3He,t)24Al reaction has been studied at E(3He)=420 MeV. An energy resolution of 35 keV was achieved. Gamow-Teller strengths to discrete levels in 24Al are extracted by using a recently...

Coupled Pb Chains on Si(557): Origin of One-Dimensional Conductance (2008)

Tegenkamp, T., Ohta, T, McChesney, J. L., Dil, Hugo, Rotenberg, E., Pfnür, H., ...

The Pb/Si(557) system exhibits a strong anisotropy in conductance below 78 K, with the evolution of a characteristic chain structure. Here we show, using angle-resolved photoemission, that chain...

Leucettamol A: A new inhibitor of Ubc13-Uev1A interaction isolated from a marine sponge, Leucetta aff. microrhaphis (2008)

Tsukamoto, S., Takeuchi, T., Rotinsulu, H., Mangindaan, R.E.P., Ukai, K., ...

A compound that inhibits the formation of a complex composed of the ubiquitin E2 enzyme Ubc13 and Uev1A was isolated from the marine sponge Leucetta aff. microrhaphis. The compound was identified as...

Interannual variation of water balance and summer evapotranspiration in an eastern Siberian larch forest over a 7-year period (1998-2006) (2008)

Ohta, T., Maximov, T.C., Dolman, A.J., Nakai, T., Kononov, A.V., ...

Water vapor, energy fluxes, and environmental conditions were measured in an eastern Siberian larch forest for 7 water years, from 1998 to 2006, to understand the water-balance characteristics and...

Effect of linear density of states on the quasi-particle dynamics and small electron-phonon coupling in graphite (2007)

Leem, C. S., Kim, B. J., Kim, Chul, Park, S. R., Ohta, T., Bostwick, A., ...

We obtained the spectral function of very high quality natural graphite single crystals using angle resolved photoelectron spectroscopy (ARPES). A clear separation of non-bonding and bonding bands...

On the extraction of weak transition strengths via the (3He,t) reaction at 420 MeV (2007)

Zegers, R. G. T, Adachi, T., Akimune, H., Austin, Sam M., Brown, B. A., ...

Differential cross sections for transitions of known weak strength were measured with the (3He,t) reaction at 420 MeV on targets of 12C, 13C, 18O, 26Mg, 58Ni, 60Ni, 90Zr, 118Sn, 120Sn and 208Pb....

Journal of Synchrotron Radiation (2007)

D. M. Mills, T. Ohta

electronic reprint Application of glancing-emergent-angle fluorescence for polarized XAFS studies of single crystals

Dual character of the electronic structure in YBa2Cu4O8: conduction bands of CuO2 planes and CuO chains (2006)

Kondo, T., Khasanov, R., Karpinski, J., Kazakov, S. M., Zhigadlo, N. D., Ohta, T., ...

We use microprobe Angle-Resolved Photoemission Spectroscopy (muARPES) to separately investigate the electronic properties of CuO2 planes and CuO chains in the high temperature superconductor,...

A simple model of reactor cores for reactor neutrino flux calculations for the KamLAND experiment (2006)

Nakajima, K., Inoue, K., Owada, K., Suekane, F., Suzuki, A., Hirano, G., ...

KamLAND is a reactor neutrino oscillation experiment with a very long baseline. This experiment successfully measured oscillation phenomena of reactor antineutrinos coming mainly from 53 reactors in...

Zinc modulates primary afferent fiber-evoked responses of ventral roots in neonatal rat spinal cord in vitro (2006)

Otsuguro, K., Ohta, T., Ito, S., 乙黒, 兼一

Zinc ions (Zn2+) are known to modulate the functions of a variety of channels, receptors and transporters. We examined the effects of Zn2+ on the reflex potentials evoked by electrical stimulation...

Zinc modulates primary afferent fiber-evoked responses of ventral roots in neonatal rat spinal cord in vitro (2006)

Otsuguro, K., Ohta, T., Ito, S.

Zinc ions (Zn2+) are known to modulate the functions of a variety of channels, receptors and transporters. We examined the effects of Zn2+ on the reflex potentials evoked by electrical stimulation...

Zinc modulates primary afferent fiber-evoked responses of ventral roots in neonatal rat spinal cord in vitro (2006)

Otsuguro, K., Ohta, T., Ito, S.

Zinc ions (Zn2+) are known to modulate the functions of a variety of channels, receptors and transporters. We examined the effects of Zn2+ on the reflex potentials evoked by electrical stimulation...

An observational study of the factors that influence interception loss in boreal and temperate forests (2005)

Toba, T., Ohta, T.

This study used same methods to observe interception loss in two boreal forest sites in Siberia and five temperate forest sites in Japan; interception characteristics of the two climate regions were...

Parameters of carbon and water cycles in the forest ecosystems of the cryolithozone (2005)

Maximov, T.C., Dolman, A.J., Moors, E.J., Ohta, T., Sugimoto, A., Ivanov, B.I.

Instrumental data from meteorological and geocryological stations of the former USSR indicate that there is a clear tendency of climate warming by 2-3.5°C in most regions of Yakutia over the last...

Journal of (2004)

Synchrotron Radiation Issn, D. M. Mills, T. Ohta, Alastair A. Macdowell, Rich S. Celestre, Malcolm Howells, ...

this paper may load this reprint on their own web site provided that this cover page is retained. Republication of this article or its storage in electronic databases or the like is not permitted...

Chaos in an Exact Relativistic 3-body Self-Gravitating System (2003)

Burnell, F. J., Malecki, J. J., Mann, R. B., Ohta, T.

We consider the problem of three body motion for a relativistic one-dimensional self-gravitating system. After describing the canonical decomposition of the action, we find an exact expression for...

Identification of four highly conserved genes between breakpoint hotspots BP1 and BP2 of the Prader-Willi/Angelman syndromes deletion region that have undergone evolutionary transposition mediated by flanking duplicons. (2003)

Chai, J-H., Locke, D. P., Greally, J. M., Knoll, J. H. M., Ohta, T., Dunai, J., ...

Prader-Willi and Angelman syndromes (PWS and AS) typically result from an approximately 4-Mb deletion of human chromosome 15q11-q13, with clustered breakpoints (BP) at either of two proximal sites...

GENIA corpus--a semantically annotated corpus for bio-textmining (2003)

Ohta, T., Tateisi, Y., Tsujii, J.

Motivation: Natural language processing (NLP) methods are regarded as being useful to raise the potential of text mining from biological literature. The lack of an extensively annotated corpus of...

Neurons but not glial cells show reciprocal imprinting of sense and antisense transcripts of Ube3a (2003)

Yamasaki, K., Joh, K., Ohta, T., Masuzaki, H., Ishimaru, T., Mukai, T., ...

The human UBE3A gene shows brain-specific partial imprinting, and lack of a maternally inherited allele causes Angelman syndrome (AS), which is characterized by neurobehavioral anomalies. In several...

Chaos in a Relativistic 3-body Self-Gravitating System (2002)

Burnell, F. J., Mann, R. B., Ohta, T.

We consider the 3-body problem in relativistic lineal gravity and obtain an exact expression for its Hamiltonian and equations of motion. While general-relativistic effects yield more tightly-bound...

Exact Charged 2-Body Motion and the Static Balance Condition in Lineal Gravity (2001)

Mann, R. B., Ohta, T.

We find an exact solution to the charged 2-body problem in $(1+1)$ dimensional lineal gravity which provides the first example of a relativistic system that generalizes the Majumdar-Papapetrou...

In/Si(111): Self-assembled one and two-dimensional electron gases (2001)

Rotenberg, Eli, Yeom, H.W., Takeda, S., Matsuda, I., Horikoshi, K., Schaefer, J., ...

We present angle-resolved photoemission measurements for ultrathin In films on Si(111). Depending on the coverage, this system self-organizes into a metallic monolayer with either 4x1 or sqrt7 x...

The declarative language STR (state transition rule (2001)

T. Yoneda, T. Ohta

Abstract. The declarative language STR (State Transition Rule) is proposed to describe service specifications and programs. Given that telecommunication service specifications can be represented in...

Structural Phase Transition Accompanied by Metal - Insulator Transition in PrRu4P12 (2000)

Lee, C. H., Matsuhata, H., Yamamoto, A., Ohta, T., Takazawa, H., Ueno, K., ...

A structural phase transition has been found using electron diffraction technique in PrRu4P12 accompanied by a metal - insulator (M - I) transition (TMI = 60K). Weak superlattice spots appeared at...

Exact Solutions to the Motion of Two Charged Particles in Lineal Gravity (2000)

Mann, R. B., Robbins, D., Ohta, T., Trott, M. R.

We extend the canonical formalism for the motion of $N$-particles in lineal gravity to include charges. Under suitable coordinate conditions and boundary conditions the determining equation of the...

Exact Solutions of Relativistic Two-Body Motion in Lineal Gravity (1999)

Mann, R. B., Robbins, D., Ohta, T.

We develop the canonical formalism for a system of $N$ bodies in lineal gravity and obtain exact solutions to the equations of motion for N=2. The determining equation of the Hamiltonian is derived...

A transgene insertion creating a heritable chromosome deletion mouse model of Prader-Willi and angelman syndromes. (1999)

Gabriel, J. M., Merchant, M., Ohta, T., Ji, Y., Caldwell, R. G., Ramsey, M. J., ...

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) result from the loss of function of imprinted genes in human chromosome 15q11-q13. The central part of mouse chromosome 7 is homologous to human...

Imprinting-mutation mechanisms in Prader-Willi syndrome. (1999)

Ohta, T, Gray, T A, Rogan, P K, Buiting, K, Gabriel, J M, Saitoh, S, ...

Microdeletions of a region termed the "imprinting center" (IC) in chromosome 15q11-q13 have been identified in several families with Prader-Willi syndrome (PWS) or Angelman syndrome who show...

Molecular mechanism of angelman syndrome in two large families involves an imprinting mutation. (1999)

Ohta, T, Buiting, K, Kokkonen, H, McCandless, S, Heeger, S, Leisti, H, ...

Patients with Angelman syndrome (AS) and Prader-Willi syndrome with mutations in the imprinting process have biparental inheritance but uniparental DNA methylation and gene expression throughout band...

Serum leucine aminopeptidase as an activity indicator in systemic lupus erythematosus: a study of 46 consecutive cases (1999)

Inokuma, S., Setoguchi, K., Ohta, T., Matsuzaki, Y., Yoshida, A.

Objective. To determine whether elevations in serum leucine aminopeptidase (LAP) levels reflected the underlying evolution of active disease in systemic lupus erythematosus (SLE). Methods. We studied...

Exact Relativistic Two-Body Motion in Lineal Gravity (1998)

Mann, R. B., Robbins, D., Ohta, T.

We consider the N-body problem in (1+1) dimensional lineal gravity. For 2 point masses (N=2) we obtain an exact solution for the relativistic motion. In the equal mass case we obtain an explicit...

Adsorption and Surface Reaction of SO2 on Cu(100) Studied by S K-Edge XAFS and STM (1997)

Nakahashi, T., Hamamatsu, H., Terada, S., Sakano, M., Matsui, F., Yokoyama, T., ...

Adsorption and reaction of SO2 on Cu(100) at room temperature has been studied by means of S K-edge XAFS, AES, LEED, XPS and STM. It has been revealed that there are atomic S and SO3 with the...

Adsorption of SO2 on Pd(100) Studied by S K-Edge XAFS (1997)

Terada, S., Sakano, M., Kitajima, Y., Yokoyama, T., Ohta, T.

Surface structure and an electronic property of SO2 adsorbed on Pd(100) were studied by S K-edge NEXAFS, SEXAFS and S1s XPS. The molecule was found by the polar-angle dependent NEXAFS to adsorb with...

Structure of CH3SH on Cu(100) Studied by S-K SEXAFS and NEXAFS (1997)

Imanishi, A., Takenaka, S., Yokoyama, T., Kitajima, Y., Ohta, T.

A surface structure of submonolayer methanethiol CH3SH molecularly adsorbed on Cu(100) has been investigated by means of S K-edge SEXAFS and NEXAFS. From the analysis of these spectra, it was...

Adsorption and Surface Reaction of SO2 on Cu(100) Studied by S K-Edge XAFS and STM (1997)

Nakahashi, T., Hamamatsu, H., Terada, S., Sakano, M., Matsui, F., Yokoyama, T., ...

Adsorption and reaction of SO2 on Cu(100) at room temperature has been studied by means of S K-edge XAFS, AES, LEED, XPS and STM. It has been revealed that there are atomic S and SO3 with the...

Adsorption of SO2 on Pd(100) Studied by S K-Edge XAFS (1997)

Terada, S., Sakano, M., Kitajima, Y., Yokoyama, T., Ohta, T.

Surface structure and an electronic property of SO2 adsorbed on Pd(100) were studied by S K-edge NEXAFS, SEXAFS and S1s XPS. The molecule was found by the polar-angle dependent NEXAFS to adsorb with...

Structure of CH3SH on Cu(100) Studied by S-K SEXAFS and NEXAFS (1997)

Imanishi, A., Takenaka, S., Yokoyama, T., Kitajima, Y., Ohta, T.

A surface structure of submonolayer methanethiol CH3SH molecularly adsorbed on Cu(100) has been investigated by means of S K-edge SEXAFS and NEXAFS. From the analysis of these spectra, it was...

Adsorption and Surface Reaction of SO2 on Cu(100) Studied by S K-Edge XAFS and STM (1997)

Nakahashi, T., Hamamatsu, H., Terada, S., Sakano, M., Matsui, F., Yokoyama, T., ...

Adsorption and reaction of SO2 on Cu(100) at room temperature has been studied by means of S K-edge XAFS, AES, LEED, XPS and STM. It has been revealed that there are atomic S and SO3 with the...

Adsorption of SO2 on Pd(100) Studied by S K-Edge XAFS (1997)

Terada, S., Sakano, M., Kitajima, Y., Yokoyama, T., Ohta, T.

Surface structure and an electronic property of SO2 adsorbed on Pd(100) were studied by S K-edge NEXAFS, SEXAFS and S1s XPS. The molecule was found by the polar-angle dependent NEXAFS to adsorb with...

Structure of CH3SH on Cu(100) Studied by S-K SEXAFS and NEXAFS (1997)

Imanishi, A., Takenaka, S., Yokoyama, T., Kitajima, Y., Ohta, T.

A surface structure of submonolayer methanethiol CH3SH molecularly adsorbed on Cu(100) has been investigated by means of S K-edge SEXAFS and NEXAFS. From the analysis of these spectra, it was...

Exact Solution for the Metric and the Motion of Two Bodies in (1+1) Dimensional Gravity (1996)

Mann, R. B., Ohta, T.

We present the exact solution of two-body motion in (1+1) dimensional dilaton gravity by solving the constraint equations in the canonical formalism. The determining equation of the Hamiltonian is...

Exact Solution for Relativistic Two-Body Motion in Dilaton Gravity (1996)

Mann, R. B., Ohta, T.

We present an exact solution to the problem of the relativistic motion of 2 point masses in $(1+1)$ dimensional dilaton gravity. The motion of the bodies is governed entirely by their mutual...

Canonical reduction of two-dimensional gravity for Particle Dynamics (1996)

Ohta, T., Mann, R. B.

We develop the formalism for canonical reduction of $(1+1)$--dimensional gravity coupled with a set of point particles by eliminating constraints and imposing coordinate conditions. The formalism...

SURFACE EXAFS AND XANES STUDIES OF S/Ni (110) AND S/Ni (111) (1986)

Ohta, T., Kitajima, Y., Stefan, P., Shek Stefan, M., Kosugi, N., Kuroda, H.

S K-edge SEXAFS were measured on c(2x2)S/Ni(110) and S/Ni(111) by monitoring the S KLL Auger intensity as a function of photon energy and polarization direction. Analysis of the data from...

SURFACE EXAFS AND XANES STUDIES OF S/Ni (110) AND S/Ni (111) (1986)

Ohta, T., Kitajima, Y., Stefan, P., Shek Stefan, M., Kosugi, N., Kuroda, H.

S K-edge SEXAFS were measured on c(2x2)S/Ni(110) and S/Ni(111) by monitoring the S KLL Auger intensity as a function of photon energy and polarization direction. Analysis of the data from...

SURFACE EXAFS AND XANES STUDIES OF S/Ni (110) AND S/Ni (111) (1986)

Ohta, T., Kitajima, Y., Stefan, P., Shek Stefan, M., Kosugi, N., Kuroda, H.

S K-edge SEXAFS were measured on c(2x2)S/Ni(110) and S/Ni(111) by monitoring the S KLL Auger intensity as a function of photon energy and polarization direction. Analysis of the data from...

NEW APPLICATIONS OF NARROW-LINEWIDTH POLYCRYSTALLINE CaVG's TO MS-MODE ANALOGUE DELAY LINE, MS-MODE-SUPPRESSED FERRI-MAGNETIC RESONATOR, AND NEAR INFRARED FARADAY ROTATOR (1977)

Ogasawara, N., Sawado, E., Ohta, T., Inui, T.

Device-oriented researches under way in author's laboratory are outline which are devoted to the applications of the narrow-linewidth polycrystalline CaVG's as a class of replacements of the familiar...

NEW APPLICATIONS OF NARROW-LINEWIDTH POLYCRYSTALLINE CaVG's TO MS-MODE ANALOGUE DELAY LINE, MS-MODE-SUPPRESSED FERRI-MAGNETIC RESONATOR, AND NEAR INFRARED FARADAY ROTATOR (1977)

Ogasawara, N., Sawado, E., Ohta, T., Inui, T.

Device-oriented researches under way in author's laboratory are outline which are devoted to the applications of the narrow-linewidth polycrystalline CaVG's as a class of replacements of the familiar...

NEW APPLICATIONS OF NARROW-LINEWIDTH POLYCRYSTALLINE CaVG's TO MS-MODE ANALOGUE DELAY LINE, MS-MODE-SUPPRESSED FERRI-MAGNETIC RESONATOR, AND NEAR INFRARED FARADAY ROTATOR (1977)

Ogasawara, N., Sawado, E., Ohta, T., Inui, T.

Device-oriented researches under way in author's laboratory are outline which are devoted to the applications of the narrow-linewidth polycrystalline CaVG's as a class of replacements of the familiar...

A transgene insertion creating a heritable chromosome deletion mouse model of Prader-Willi and Angelman syndromes

Gabriel, J. M., Merchant, M., Ohta, T., Ji, Y., Caldwell, R. G., Ramsey, M. J., ...

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) result from the loss of function of imprinted genes in human chromosome 15q11–q13. The central part of mouse chromosome 7 is homologous to...

Evolutionary conservation of human TATA-binding-polypeptide-associated factors TAFII31 and TAFII80 and interactions of TAFII80 with other TAFs and with general transcription factors.

Hisatake, K, Ohta, T, Takada, R, Guermah, M, Horikoshi, M, Nakatani, Y, ...

Human transcription initiation factor TFIID is composed of the TATA-binding polypeptide (TBP) and at least 13 TBP-associated factors (TAFs) that collectively or individually are involved in...

Differentiation-dependent expression of the Na+/glucose cotransporter (SGLT1) in LLC-PK1 cells: role of protein kinase C activation and ongoing transcription.

Shioda, T, Ohta, T, Isselbacher, K J, Rhoads, D B

We examined changes in the mRNA level of SGLT1, a Na+/glucose cotransporter, by the differentiation status of LLC-PK1 renal epithelial cells. Proliferating (undifferentiated) cells revealed no...

Amino acid substitution at the Adh locus of Drosophila is facilitated by small population size.

Ohta, T

The number of amino acid replacement substitutions and that of synonymous substitutions are examined by using DNA sequences of the Adh locus of Drosophila. The ratio of replacement to synonymous...

An examination of the generation-time effect on molecular evolution.

Ohta, T

By using DNA sequences of 17 mammalian genes, the generation-time effect is estimated separately for synonymous substitutions and nonsynonymous substitutions. Star phylogenies composed of rodentia,...

Negative supercoiling of DNA facilitates an interaction between transcription factor IID and the fibroin gene promoter.

Mizutani, M, Ohta, T, Watanabe, H, Handa, H, Hirose, S

Transcription of the fibroin gene can be reconstituted with partially purified components from HeLa cells. Transcription factors IIB, IID, and IIE and RNA polymerase II are required for accurate...

Role of diversifying selection and gene conversion in evolution of major histocompatibility complex loci.

Ohta, T

Genes at the major histocompatibility complex (MHC) in mammals are known to have exceptionally high polymorphism and linkage disequilibrium. In addition, these genes form highly complicated gene...

Purification of a DNA supercoiling factor from the posterior silk gland of Bombyx mori.

Ohta, T, Hirose, S

A protein factor with an estimated molecular mass of 50 kDa has been purified to homogeneity from the silk gland of Bombyx mori. In the presence of a molar excess of this factor and eukaryotic DNA...

Dominant negative umuD mutations decreasing RecA-mediated cleavage suggest roles for intact UmuD in modulation of SOS mutagenesis.

Battista, J R, Ohta, T, Nohmi, T, Sun, W, Walker, G C

The products of the SOS-regulated umuDC operon are required for most UV and chemical mutagenesis in Escherichia coli. The UmuD protein shares homology with a family of proteins that includes LexA and...

Acetylpolyamine amidohydrolase from Mycoplana ramosa: gene cloning and characterization of the metal-substituted enzyme.

Sakurada, K, Ohta, T, Fujishiro, K, Hasegawa, M, Aisaka, K

We have cloned a gene (aphA) encoding acetylpolyamine amidohydrolase from Mycoplana ramosa ATCC 49678, (previously named Mycoplana bullata). A genomic library of M. ramosa was screened with an...

Molecular cloning of two new heat shock genes related to the hsp70 genes in Staphylococcus aureus.

Ohta, T, Saito, K, Kuroda, M, Honda, K, Hirata, H, Hayashi, H

We have identified two new heat shock protein genes, orf37 and orf35, in Staphylococcus aureus, located upstream and downstream of grpE(hsp20), dnaK(hsp70), and dnaJ(hsp40) homologous genes in the...

A monocysteine approach for probing the structure and interactions of the UmuD protein.

Lee, M H, Ohta, T, Walker, G C

UmuD participates in a variety of protein-protein interactions that appear to be essential for its role in UV mutagenesis. To learn about these interactions, we have initiated an approach based on...

Design of temperature-sensitive penicillinase repressors by replacement of Pro in predicted beta-turn structures.

Imanaka, T, Nakae, M, Ohta, T, Takagi, M

Pro residues in predicted beta-turn structures were substituted with other amino acids to obtain temperature-sensitive penicillinase repressors (PenI). A mutant repressor (P70L; Pro-70 is substituted...

Cloning, expression, and characterization of the Micromonospora viridifaciens neuraminidase gene in Streptomyces lividans.

Sakurada, K, Ohta, T, Hasegawa, M

We have cloned the Micromonospora viridifaciens neuraminidase (EC 3.2.1.18) gene (nedA) in Streptomyces lividans. This was accomplished by using the vector pIJ702 and BglII-BclI libraries of M....

A novel, highly efficient gene-cloning system for Micromonospora strains.

Hasegawa, M, Dairi, T, Ohta, T, Hashimoto, E

A highly efficient gene-cloning system for Micromonospora olivasterospora, a producer of the antibiotic fortimicin A (astromicin), suited to shotgun cloning has been developed. The system is...

Nucleotide sequence of the rodA gene, responsible for the rod shape of Escherichia coli: rodA and the pbpA gene, encoding penicillin-binding protein 2, constitute the rodA operon.

Matsuzawa, H, Asoh, S, Kunai, K, Muraiso, K, Takasuga, A, Ohta, T

The rodA gene, which is responsible for the rod shape of Escherichia coli, was located 5 nucleotides downstream of another rod-shape-determining gene, pbpA, encoding penicillin-binding protein 2. The...

Molecular structure and immunity specificity of colicin E6, an evolutionary intermediate between E-group colicins and cloacin DF13.

Akutsu, A, Masaki, H, Ohta, T

The primary structure of a 3.1-kilobase E6 or E3 segment carrying colicin and related genes was determined. Plasmid ColE6-CT14 showed striking homology to ColE3-CA38 throughout this segment,...

The balance between different peptidoglycan precursors determines whether Escherichia coli cells will elongate or divide.

Begg, K J, Takasuga, A, Edwards, D H, Dewar, S J, Spratt, B G, Adachi, H, ...

The rodA(Sui) mutation allows cell division to take place at 42 degrees C in ftsI23 mutant cells, which produce a thermolabile penicillin-binding protein 3 (PBP3, the septation-specific peptidoglycan...

Colicin E8, a DNase which indicates an evolutionary relationship between colicins E2 and E3.

Toba, M, Masaki, H, Ohta, T

Colicin E8-J and its immunity protein were characterized with regard to their activities and gene structures. Colicin E8 is a complex of proteins A and B; protein A (the naked E8) exhibits an...

Genes encoding two lipoproteins in the leuS-dacA region of the Escherichia coli chromosome.

Takase, I, Ishino, F, Wachi, M, Kamata, H, Doi, M, Asoh, S, ...

The coding of two rare lipoproteins by two genes, rlpA and rlpB, located in the leuS-dacA region (15 min) on the Escherichia coli chromosome was demonstrated by expression of subcloned genes in a...

Escherichia coli K-12 tolZ mutants tolerant to colicins E2, E3, D, Ia, and Ib: defect in generation of the electrochemical proton gradient.

Matsuzawa, H, Ushiyama, S, Koyama, Y, Ohta, T

Spontaneous Escherichia coli K-12 mutants tolerant to colicin E3 were isolated, and on the basis of their tolerance patterns to 19 kinds of colicins, a new phenotypic class of tolZ mutants was found....

Molecular cloning and characterization of the genes (pbpA and rodA) responsible for the rod shape of Escherichia coli K-12: analysis of gene expression with transposon Tn5 mutagenesis and protein synthesis directed by constructed plasmids.

Asoh, S, Matsuzawa, H, Matsuhashi, M, Ohta, T

Two cell shape-determining genes of Escherichia coli K-12, pbpA, the structural gene for penicillin-binding protein 2, and rodA, whose protein is unknown, were subcloned into plasmid vectors from the...

Time for acquiring a new gene by duplication.

Ohta, T

In view of the widespread occurrence of gene families in eukaryotic genomes that suggests the importance of gene duplication in evolution, a population genetic model incorporating unequal...

Immunohistochemical localization of apolipoprotein E in human glial neoplasms.

Murakami, M, Ushio, Y, Morino, Y, Ohta, T, Matsukado, Y

Immunocytochemical analyses revealed the presence and distribution of apolipoprotein E (apo E) in normal human brain tissue as well as in 77 human intracranial neoplasms. In normal brain tissues, the...

Some calculations on the amount of selfish DNA.

Ohta, T, Kimura, M

A population genetical theory is developed to treat the amount of selfish DNA in a genome. We assume that the selfish DNA consists of replicating units and that it evolves by multiplication within a...

The active site structure of Na+/K+-transporting ATPase: location of the 5'-(p-fluorosulfonyl)benzoyladenosine binding site and soluble peptides released by trypsin.

Ohta, T, Nagano, K, Yoshida, M

When the dog kidney Na+/K+-transporting ATPase (EC 3.6.1.37, formerly EC 3.6.1.3) was labeled with an ATP analogue, 5'-(p-fluorosulfonyl)benzoyladenosine (FSBA), there was a concomitant loss of...

Molecular cloning and sequence analysis of human Na,K-ATPase beta-subunit.

Kawakami, K, Nojima, H, Ohta, T, Nagano, K

We have isolated a cDNA clone for the beta-subunit of HeLa cell Na,K-ATPase, containing a 2208-base-pair cDNA insert covering the whole coding region of the beta-subunit. Nucleotide sequence analysis...

Structure and expression of the ColE2-P9 immunity gene.

Masaki, H, Toba, M, Ohta, T

The primary structure and expression of the ColE2-P9 immunity gene (imm) were investigated. The imm gene is located behind the colicin gene (col) in the same orientation with an intergenic space of...

Allelic and nonallelic homology of a supergene family.

Ohta, T

A model to explain the high degree of polymorphism at the major histocompatibility complex (MHC) is described. The model incorporates domain transfer between the different loci in a supergene family...

Regulation of glucose transporters in LLC-PK1 cells: effects of D-glucose and monosaccharides.

Ohta, T, Isselbacher, K J, Rhoads, D B

Regulation of D-glucose transport in the porcine kidney epithelial cell line LLC-PK1 was examined. To identify the sodium-coupled glucose transporter (SGLT), we cloned and sequenced several partial...

Population genetics of multigene family with special reference to decrease of genetic correlation with distance between gene members on a chromosome.

Kimura, M, Ohta, T

A mathematical method is developed which enables us to treat exactly the process of coincidental evolution under mutation, unequal intrachromosomal crossing-over as well as ordinary crossing-over...

Stepwise mutation model and distribution of allelic frequencies in a finite population.

Kimura, M, Ohta, T

A mathematical theory is developed that enables us to derive a formula for the equilibrium distribution of allelic frequencies in a finite population when selectively neutral alleles are produced in...

Population genetics of multigene families that are dispersed into two or more chromosomes.

Ohta, T, Dover, G A

The evolution of multigene families whose members are dispersed into two or more nonhomologous chromosomes is studied from the standpoint of population genetics. By using a simple model of gene...

Variances and covariances of identity coefficients of a multigene family.

Ohta, T

By using a model of gene conversion for treating concerted evolution of multigene families, a theory for calculating the variances and covariances of identity coefficients has been developed. Six...

Studies on the in vivo and in vitro distribution of apolipoprotein A-IV in human plasma and lymph.

Ohta, T, Fidge, N H, Nestel, P J

To investigate the unique distribution in plasma of apolipoprotein A-IV (apo A-IV) we have determined, in a series of in vitro and in vivo studies, the redistribution among lipoproteins of 125I-apo...

Kinetic alteration of a human dihydrodiol/3alpha-hydroxysteroid dehydrogenase isoenzyme, AKR1C4, by replacement of histidine-216 with tyrosine or phenylalanine.

Ohta, T, Ishikura, S, Shintani, S, Usami, N, Hara, A

Human dihydrodiol dehydrogenase with 3alpha-hydroxysteroid dehydrogenase activity exists in four forms (AKR1C1-1C4) that belong to the aldo-keto reductase (AKR) family. Recent crystallographic...

Molecular mechanism of angelman syndrome in two large families involves an imprinting mutation.

Ohta, T, Buiting, K, Kokkonen, H, McCandless, S, Heeger, S, Leisti, H, ...

Patients with Angelman syndrome (AS) and Prader-Willi syndrome with mutations in the imprinting process have biparental inheritance but uniparental DNA methylation and gene expression throughout band...

Imprinting-mutation mechanisms in Prader-Willi syndrome.

Ohta, T, Gray, T A, Rogan, P K, Buiting, K, Gabriel, J M, Saitoh, S, ...

Microdeletions of a region termed the "imprinting center" (IC) in chromosome 15q11-q13 have been identified in several families with Prader-Willi syndrome (PWS) or Angelman syndrome who show...

Role of nodal involvement and the periductal soft-tissue margin in middle and distal bile duct cancer.

Kayahara, M, Nagakawa, T, Ohta, T, Kitagawa, H, Tajima, H, Miwa, K

OBJECTIVE: To determine the pattern of middle (Bm) and distal (Bi) bile duct cancers in an attempt to optimize surgical treatment. SUMMARY BACKGROUND DATA: Lymph node involvement and neural plexus...

Inward current activated by carbachol in rat intestinal smooth muscle cells.

Ito, S, Ohta, T, Nakazato, Y

1. Carbachol (0.1 mM or 10 microM)-evoked inward currents were studied with standard and perforated whole-cell patch clamp techniques in smooth muscle cells isolated from rat small intestine. The...

Chloride currents activated by caffeine in rat intestinal smooth muscle cells.

Ohta, T, Ito, S, Nakazato, Y

1. Current responses to caffeine in single smooth muscle cells isolated from rat intestine were studied with the whole-cell patch clamp technique. Intracellular calcium concentration, [Ca2+]i, was...

The inhibitory action of cyclic AMP on responses to carbachol dependent on calcium stores in rat gastric smooth muscle.

Ohta, T, Ito, S, Noto, T, Tachibana, R, Nakazato, Y, Ohga, A

1. The effects of cyclic AMP on contraction and Ca(2+)-activated K+ currents induced by carbachol (CCh), caffeine and inositol 1,4,5-trisphosphate (InsP3) were examined in intact and skinned smooth...

Mechanical, electrical and cyclic nucleotide responses to peptide VIP and inhibitory nerve stimulation in rat stomach.

Ito, S, Kurokawa, A, Ohga, A, Ohta, T, Sawabe, K

1. Effects of apamin on electrical and mechanical activities and cyclic nucleotide accumulation in response to vasoactive intestinal peptide (VIP) and intramural nerve stimulation were investigated...

Gastric vasodilatation and vasoactive intestinal peptide output in response to vagal stimulation in the dog.

Ito, S, Ohga, A, Ohta, T

1. Gastric vasodilatation, relaxation, and vasoactive intestinal peptide (VIP) output in response to vagal stimulation were studied in anaesthetized dogs. 2. Stimulation of the peripheral end of the...

Gastric relaxation and vasoactive intestinal peptide output in response to reflex vagal stimulation in the dog.

Ito, S, Ohga, A, Ohta, T

1. Gastric relaxation, vasodilatation and vasoactive intestinal peptide (VIP) output from the stomach in response to stimulation of the central end of the cut vagus nerve were studied in...

Evolution by Gene Duplication and Compensatory Advantageous Mutations

Ohta, T.

Relaxation of selective constraint is thought to play an important role for evolution by gene duplication, in connection with compensatory advantageous mutant substitutions. Models were investigated...

Time for Spreading of Compensatory Mutations under Gene Duplication

Ohta, T.

Evolution by compensatory mutations is accelerated by gene duplication because selective constraint is relaxed by gene redundancy. A mutation is called compensatory if it corrects the effect of an...

Theoretical Study of near Neutrality. I. Heterozygosity and Rate of Mutant Substitution

Ohta, T., Tachida, H.

In order to clarify the nature of ``near neutrality'' in molecular evolution and polymorphism, extensive simulation studies were performed. Selection coefficients of new mutations are assumed to be...

Theoretical Study of near Neutrality. II. Effect of Subdivided Population Structure with Local Extinction and Recolonization

Ohta, T.

There are several unsolved problems concerning the model of nearly neutral mutations. One is the interaction of subdivided population structure and weak selection that spatially fluctuates. The model...

Simulation Study of a Multigene Family, with Special Reference to the Evolution of Compensatory Advantageous Mutations

Basten, C. J., Ohta, T.

We investigate the evolution of a multigene family incorporating the forces of drift, mutation, gene conversion, unequal crossing over and selection. The use of simulation studies is required due to...

Pattern of Nucleotide Substitutions in Growth Hormone-Prolactin Gene Family: A Paradigm for Evolution by Gene Duplication

Ohta, T.

The growth hormone-prolactin gene family in mammals is an interesting example of evolution by gene duplication. Divergence among members of duplicated gene families and among species was examined by...

Further Examples of Evolution by Gene Duplication Revealed through DNA Sequence Comparisons

Ohta, T.

To test the theory that evolution by gene duplication occurs as a result of positive Darwinian selection that accompanies the acceleration of mutant substitutions, DNA sequences of recent duplication...

A transgene insertion creating a heritable chromosome deletion mouse model of Prader-Willi and Angelman syndromes

Gabriel, J. M., Merchant, M., Ohta, T., Ji, Y., Caldwell, R. G., Ramsey, M. J., ...

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) result from the loss of function of imprinted genes in human chromosome 15q11–q13. The central part of mouse chromosome 7 is homologous to...

Evolutionary conservation of human TATA-binding-polypeptide-associated factors TAFII31 and TAFII80 and interactions of TAFII80 with other TAFs and with general transcription factors.

Hisatake, K, Ohta, T, Takada, R, Guermah, M, Horikoshi, M, Nakatani, Y, ...

Human transcription initiation factor TFIID is composed of the TATA-binding polypeptide (TBP) and at least 13 TBP-associated factors (TAFs) that collectively or individually are involved in...

Differentiation-dependent expression of the Na+/glucose cotransporter (SGLT1) in LLC-PK1 cells: role of protein kinase C activation and ongoing transcription.

Shioda, T, Ohta, T, Isselbacher, K J, Rhoads, D B

We examined changes in the mRNA level of SGLT1, a Na+/glucose cotransporter, by the differentiation status of LLC-PK1 renal epithelial cells. Proliferating (undifferentiated) cells revealed no...

Amino acid substitution at the Adh locus of Drosophila is facilitated by small population size.

Ohta, T

The number of amino acid replacement substitutions and that of synonymous substitutions are examined by using DNA sequences of the Adh locus of Drosophila. The ratio of replacement to synonymous...

An examination of the generation-time effect on molecular evolution.

Ohta, T

By using DNA sequences of 17 mammalian genes, the generation-time effect is estimated separately for synonymous substitutions and nonsynonymous substitutions. Star phylogenies composed of rodentia,...

Negative supercoiling of DNA facilitates an interaction between transcription factor IID and the fibroin gene promoter.

Mizutani, M, Ohta, T, Watanabe, H, Handa, H, Hirose, S

Transcription of the fibroin gene can be reconstituted with partially purified components from HeLa cells. Transcription factors IIB, IID, and IIE and RNA polymerase II are required for accurate...

Role of diversifying selection and gene conversion in evolution of major histocompatibility complex loci.

Ohta, T

Genes at the major histocompatibility complex (MHC) in mammals are known to have exceptionally high polymorphism and linkage disequilibrium. In addition, these genes form highly complicated gene...

Purification of a DNA supercoiling factor from the posterior silk gland of Bombyx mori.

Ohta, T, Hirose, S

A protein factor with an estimated molecular mass of 50 kDa has been purified to homogeneity from the silk gland of Bombyx mori. In the presence of a molar excess of this factor and eukaryotic DNA...

Dominant negative umuD mutations decreasing RecA-mediated cleavage suggest roles for intact UmuD in modulation of SOS mutagenesis.

Battista, J R, Ohta, T, Nohmi, T, Sun, W, Walker, G C

The products of the SOS-regulated umuDC operon are required for most UV and chemical mutagenesis in Escherichia coli. The UmuD protein shares homology with a family of proteins that includes LexA and...

Acetylpolyamine amidohydrolase from Mycoplana ramosa: gene cloning and characterization of the metal-substituted enzyme.

Sakurada, K, Ohta, T, Fujishiro, K, Hasegawa, M, Aisaka, K

We have cloned a gene (aphA) encoding acetylpolyamine amidohydrolase from Mycoplana ramosa ATCC 49678, (previously named Mycoplana bullata). A genomic library of M. ramosa was screened with an...

Molecular cloning of two new heat shock genes related to the hsp70 genes in Staphylococcus aureus.

Ohta, T, Saito, K, Kuroda, M, Honda, K, Hirata, H, Hayashi, H

We have identified two new heat shock protein genes, orf37 and orf35, in Staphylococcus aureus, located upstream and downstream of grpE(hsp20), dnaK(hsp70), and dnaJ(hsp40) homologous genes in the...

A monocysteine approach for probing the structure and interactions of the UmuD protein.

Lee, M H, Ohta, T, Walker, G C

UmuD participates in a variety of protein-protein interactions that appear to be essential for its role in UV mutagenesis. To learn about these interactions, we have initiated an approach based on...

Design of temperature-sensitive penicillinase repressors by replacement of Pro in predicted beta-turn structures.

Imanaka, T, Nakae, M, Ohta, T, Takagi, M

Pro residues in predicted beta-turn structures were substituted with other amino acids to obtain temperature-sensitive penicillinase repressors (PenI). A mutant repressor (P70L; Pro-70 is substituted...

Cloning, expression, and characterization of the Micromonospora viridifaciens neuraminidase gene in Streptomyces lividans.

Sakurada, K, Ohta, T, Hasegawa, M

We have cloned the Micromonospora viridifaciens neuraminidase (EC 3.2.1.18) gene (nedA) in Streptomyces lividans. This was accomplished by using the vector pIJ702 and BglII-BclI libraries of M....

A novel, highly efficient gene-cloning system for Micromonospora strains.

Hasegawa, M, Dairi, T, Ohta, T, Hashimoto, E

A highly efficient gene-cloning system for Micromonospora olivasterospora, a producer of the antibiotic fortimicin A (astromicin), suited to shotgun cloning has been developed. The system is...

Nucleotide sequence of the rodA gene, responsible for the rod shape of Escherichia coli: rodA and the pbpA gene, encoding penicillin-binding protein 2, constitute the rodA operon.

Matsuzawa, H, Asoh, S, Kunai, K, Muraiso, K, Takasuga, A, Ohta, T

The rodA gene, which is responsible for the rod shape of Escherichia coli, was located 5 nucleotides downstream of another rod-shape-determining gene, pbpA, encoding penicillin-binding protein 2. The...

Molecular structure and immunity specificity of colicin E6, an evolutionary intermediate between E-group colicins and cloacin DF13.

Akutsu, A, Masaki, H, Ohta, T

The primary structure of a 3.1-kilobase E6 or E3 segment carrying colicin and related genes was determined. Plasmid ColE6-CT14 showed striking homology to ColE3-CA38 throughout this segment,...

The balance between different peptidoglycan precursors determines whether Escherichia coli cells will elongate or divide.

Begg, K J, Takasuga, A, Edwards, D H, Dewar, S J, Spratt, B G, Adachi, H, ...

The rodA(Sui) mutation allows cell division to take place at 42 degrees C in ftsI23 mutant cells, which produce a thermolabile penicillin-binding protein 3 (PBP3, the septation-specific peptidoglycan...

Colicin E8, a DNase which indicates an evolutionary relationship between colicins E2 and E3.

Toba, M, Masaki, H, Ohta, T

Colicin E8-J and its immunity protein were characterized with regard to their activities and gene structures. Colicin E8 is a complex of proteins A and B; protein A (the naked E8) exhibits an...

Genes encoding two lipoproteins in the leuS-dacA region of the Escherichia coli chromosome.

Takase, I, Ishino, F, Wachi, M, Kamata, H, Doi, M, Asoh, S, ...

The coding of two rare lipoproteins by two genes, rlpA and rlpB, located in the leuS-dacA region (15 min) on the Escherichia coli chromosome was demonstrated by expression of subcloned genes in a...

Escherichia coli K-12 tolZ mutants tolerant to colicins E2, E3, D, Ia, and Ib: defect in generation of the electrochemical proton gradient.

Matsuzawa, H, Ushiyama, S, Koyama, Y, Ohta, T

Spontaneous Escherichia coli K-12 mutants tolerant to colicin E3 were isolated, and on the basis of their tolerance patterns to 19 kinds of colicins, a new phenotypic class of tolZ mutants was found....

Molecular cloning and characterization of the genes (pbpA and rodA) responsible for the rod shape of Escherichia coli K-12: analysis of gene expression with transposon Tn5 mutagenesis and protein synthesis directed by constructed plasmids.

Asoh, S, Matsuzawa, H, Matsuhashi, M, Ohta, T

Two cell shape-determining genes of Escherichia coli K-12, pbpA, the structural gene for penicillin-binding protein 2, and rodA, whose protein is unknown, were subcloned into plasmid vectors from the...

Time for acquiring a new gene by duplication.

Ohta, T

In view of the widespread occurrence of gene families in eukaryotic genomes that suggests the importance of gene duplication in evolution, a population genetic model incorporating unequal...

Immunohistochemical localization of apolipoprotein E in human glial neoplasms.

Murakami, M, Ushio, Y, Morino, Y, Ohta, T, Matsukado, Y

Immunocytochemical analyses revealed the presence and distribution of apolipoprotein E (apo E) in normal human brain tissue as well as in 77 human intracranial neoplasms. In normal brain tissues, the...

Some calculations on the amount of selfish DNA.

Ohta, T, Kimura, M

A population genetical theory is developed to treat the amount of selfish DNA in a genome. We assume that the selfish DNA consists of replicating units and that it evolves by multiplication within a...

The active site structure of Na+/K+-transporting ATPase: location of the 5'-(p-fluorosulfonyl)benzoyladenosine binding site and soluble peptides released by trypsin.

Ohta, T, Nagano, K, Yoshida, M

When the dog kidney Na+/K+-transporting ATPase (EC 3.6.1.37, formerly EC 3.6.1.3) was labeled with an ATP analogue, 5'-(p-fluorosulfonyl)benzoyladenosine (FSBA), there was a concomitant loss of...

Molecular cloning and sequence analysis of human Na,K-ATPase beta-subunit.

Kawakami, K, Nojima, H, Ohta, T, Nagano, K

We have isolated a cDNA clone for the beta-subunit of HeLa cell Na,K-ATPase, containing a 2208-base-pair cDNA insert covering the whole coding region of the beta-subunit. Nucleotide sequence analysis...

Structure and expression of the ColE2-P9 immunity gene.

Masaki, H, Toba, M, Ohta, T

The primary structure and expression of the ColE2-P9 immunity gene (imm) were investigated. The imm gene is located behind the colicin gene (col) in the same orientation with an intergenic space of...

Allelic and nonallelic homology of a supergene family.

Ohta, T

A model to explain the high degree of polymorphism at the major histocompatibility complex (MHC) is described. The model incorporates domain transfer between the different loci in a supergene family...

Regulation of glucose transporters in LLC-PK1 cells: effects of D-glucose and monosaccharides.

Ohta, T, Isselbacher, K J, Rhoads, D B

Regulation of D-glucose transport in the porcine kidney epithelial cell line LLC-PK1 was examined. To identify the sodium-coupled glucose transporter (SGLT), we cloned and sequenced several partial...

Population genetics of multigene family with special reference to decrease of genetic correlation with distance between gene members on a chromosome.

Kimura, M, Ohta, T

A mathematical method is developed which enables us to treat exactly the process of coincidental evolution under mutation, unequal intrachromosomal crossing-over as well as ordinary crossing-over...

Stepwise mutation model and distribution of allelic frequencies in a finite population.

Kimura, M, Ohta, T

A mathematical theory is developed that enables us to derive a formula for the equilibrium distribution of allelic frequencies in a finite population when selectively neutral alleles are produced in...

Population genetics of multigene families that are dispersed into two or more chromosomes.

Ohta, T, Dover, G A

The evolution of multigene families whose members are dispersed into two or more nonhomologous chromosomes is studied from the standpoint of population genetics. By using a simple model of gene...

Variances and covariances of identity coefficients of a multigene family.

Ohta, T

By using a model of gene conversion for treating concerted evolution of multigene families, a theory for calculating the variances and covariances of identity coefficients has been developed. Six...

Studies on the in vivo and in vitro distribution of apolipoprotein A-IV in human plasma and lymph.

Ohta, T, Fidge, N H, Nestel, P J

To investigate the unique distribution in plasma of apolipoprotein A-IV (apo A-IV) we have determined, in a series of in vitro and in vivo studies, the redistribution among lipoproteins of 125I-apo...

Inward current activated by carbachol in rat intestinal smooth muscle cells.

Ito, S, Ohta, T, Nakazato, Y

1. Carbachol (0.1 mM or 10 microM)-evoked inward currents were studied with standard and perforated whole-cell patch clamp techniques in smooth muscle cells isolated from rat small intestine. The...

Chloride currents activated by caffeine in rat intestinal smooth muscle cells.

Ohta, T, Ito, S, Nakazato, Y

1. Current responses to caffeine in single smooth muscle cells isolated from rat intestine were studied with the whole-cell patch clamp technique. Intracellular calcium concentration, [Ca2+]i, was...

The inhibitory action of cyclic AMP on responses to carbachol dependent on calcium stores in rat gastric smooth muscle.

Ohta, T, Ito, S, Noto, T, Tachibana, R, Nakazato, Y, Ohga, A

1. The effects of cyclic AMP on contraction and Ca(2+)-activated K+ currents induced by carbachol (CCh), caffeine and inositol 1,4,5-trisphosphate (InsP3) were examined in intact and skinned smooth...

Identification of Four Highly Conserved Genes between Breakpoint Hotspots BP1 and BP2 of the Prader-Willi/Angelman Syndromes Deletion Region That Have Undergone Evolutionary Transposition Mediated by Flanking Duplicons

Chai, J-H., Locke, D. P., Greally, J. M., Knoll, J. H. M., Ohta, T., Dunai, J., ...

Prader-Willi and Angelman syndromes (PWS and AS) typically result from an ∼4-Mb deletion of human chromosome 15q11-q13, with clustered breakpoints (BP) at either of two proximal sites (BP1 and BP2)...

Mechanical, electrical and cyclic nucleotide responses to peptide VIP and inhibitory nerve stimulation in rat stomach.

Ito, S, Kurokawa, A, Ohga, A, Ohta, T, Sawabe, K

1. Effects of apamin on electrical and mechanical activities and cyclic nucleotide accumulation in response to vasoactive intestinal peptide (VIP) and intramural nerve stimulation were investigated...

Gastric vasodilatation and vasoactive intestinal peptide output in response to vagal stimulation in the dog.

Ito, S, Ohga, A, Ohta, T

1. Gastric vasodilatation, relaxation, and vasoactive intestinal peptide (VIP) output in response to vagal stimulation were studied in anaesthetized dogs. 2. Stimulation of the peripheral end of the...

Gastric relaxation and vasoactive intestinal peptide output in response to reflex vagal stimulation in the dog.

Ito, S, Ohga, A, Ohta, T

1. Gastric relaxation, vasodilatation and vasoactive intestinal peptide (VIP) output from the stomach in response to stimulation of the central end of the cut vagus nerve were studied in...

Role of nodal involvement and the periductal soft-tissue margin in middle and distal bile duct cancer.

Kayahara, M, Nagakawa, T, Ohta, T, Kitagawa, H, Tajima, H, Miwa, K

OBJECTIVE: To determine the pattern of middle (Bm) and distal (Bi) bile duct cancers in an attempt to optimize surgical treatment. SUMMARY BACKGROUND DATA: Lymph node involvement and neural plexus...

Evolution by Gene Duplication and Compensatory Advantageous Mutations

Ohta, T.

Relaxation of selective constraint is thought to play an important role for evolution by gene duplication, in connection with compensatory advantageous mutant substitutions. Models were investigated...

Time for Spreading of Compensatory Mutations under Gene Duplication

Ohta, T.

Evolution by compensatory mutations is accelerated by gene duplication because selective constraint is relaxed by gene redundancy. A mutation is called compensatory if it corrects the effect of an...

Theoretical Study of near Neutrality. I. Heterozygosity and Rate of Mutant Substitution

Ohta, T., Tachida, H.

In order to clarify the nature of ``near neutrality'' in molecular evolution and polymorphism, extensive simulation studies were performed. Selection coefficients of new mutations are assumed to be...

Theoretical Study of near Neutrality. II. Effect of Subdivided Population Structure with Local Extinction and Recolonization

Ohta, T.

There are several unsolved problems concerning the model of nearly neutral mutations. One is the interaction of subdivided population structure and weak selection that spatially fluctuates. The model...

Simulation Study of a Multigene Family, with Special Reference to the Evolution of Compensatory Advantageous Mutations

Basten, C. J., Ohta, T.

We investigate the evolution of a multigene family incorporating the forces of drift, mutation, gene conversion, unequal crossing over and selection. The use of simulation studies is required due to...

Pattern of Nucleotide Substitutions in Growth Hormone-Prolactin Gene Family: A Paradigm for Evolution by Gene Duplication

Ohta, T.

The growth hormone-prolactin gene family in mammals is an interesting example of evolution by gene duplication. Divergence among members of duplicated gene families and among species was examined by...

Further Examples of Evolution by Gene Duplication Revealed through DNA Sequence Comparisons

Ohta, T.

To test the theory that evolution by gene duplication occurs as a result of positive Darwinian selection that accompanies the acceleration of mutant substitutions, DNA sequences of recent duplication...

Kinetic alteration of a human dihydrodiol/3alpha-hydroxysteroid dehydrogenase isoenzyme, AKR1C4, by replacement of histidine-216 with tyrosine or phenylalanine.

Ohta, T, Ishikura, S, Shintani, S, Usami, N, Hara, A

Human dihydrodiol dehydrogenase with 3alpha-hydroxysteroid dehydrogenase activity exists in four forms (AKR1C1-1C4) that belong to the aldo-keto reductase (AKR) family. Recent crystallographic...

Molecular mechanism of angelman syndrome in two large families involves an imprinting mutation.

Ohta, T, Buiting, K, Kokkonen, H, McCandless, S, Heeger, S, Leisti, H, ...

Patients with Angelman syndrome (AS) and Prader-Willi syndrome with mutations in the imprinting process have biparental inheritance but uniparental DNA methylation and gene expression throughout band...

Imprinting-mutation mechanisms in Prader-Willi syndrome.

Ohta, T, Gray, T A, Rogan, P K, Buiting, K, Gabriel, J M, Saitoh, S, ...

Microdeletions of a region termed the "imprinting center" (IC) in chromosome 15q11-q13 have been identified in several families with Prader-Willi syndrome (PWS) or Angelman syndrome who show...

Mechanisms of molecular evolution.

Ohta, T

Both drift and selection are important for nucleotide substitutions in evolution. The nearly neutral theory was developed to clarify the effects of these processes. In this article, the nearly...

Mosaic pattern of ornithine transcarbamylase expression in spfash mouse liver.

Shiojiri, N., Imai, H., Goto, S., Ohta, T., Ogawa, K., Mori, M.

Mosaicism of ornithine transcarbamylase expression was immunohistochemically examined in hepatocytes of spfash heterozygous female mouse livers. An immunohistochemical method using polyclonal...

Confocal microscopy in cornea guttata and Fuchs' endothelial dystrophy

Chiou, A., Kaufman, S., Beuerman, R., Ohta, T., Soliman, H., Kaufman, H.

AIMS—To report the appearances of cornea guttata and Fuchs' endothelial dystrophy from white light confocal microscopy.
METHODS—Seven eyes of four consecutive patients with cornea guttata were...

Confocal microscopy in the iridocorneal endothelial syndrome

Chiou, A., Kaufman, S., Beuerman, R., Ohta, T., Yaylali, V., Kaufman, H.

AIMS—To report the appearances of iridocorneal endothelial (ICE) syndrome from real time, white light confocal microscopy.
METHODS—Three consecutive patients, each with ICE syndrome, were...

Isolation of a cosmid clone corresponding to an inv(21) breakpoint of a patient with transient abnormal myelopoiesis.

Ohta, T., Nakano, M., Tsujita, T., Abe, K., Osoegawa, K., Yamagata, T., ...

Transient abnormal myelopoiesis (TAM) is a leukemoid reaction occurring occasionally on Down syndrome (DS) newborn infants. It has been hypothesized that "disomic homozygosity" in 21-trisomic cells...

Ca2+ entry activated by emptying of intracellular Ca2+ stores in ileal smooth muscle of the rat.

Ohta, T, Kawai, K, Ito, S, Nakazato, Y

1. The effects of depletion of intracellular Ca2+ stores on muscle tension and the intracellular Ca2+ concentration ([Ca2+])i were studied in fura-2 loaded longitudinal smooth muscle cells of the rat...

Inhibitory effects of caffeine on secretagogue-induced catecholamine secretion from adrenal chromaffin cells of the guinea-pig.

Nakazato, Y., Tani, Y., Teraoka, H., Sugawara, T., Asano, T., Ohta, T., ...

1. The inhibitory action of caffeine on catecholamine secretion induced by secretagogues was investigated in perfused adrenal glands and dispersed chromaffin cells of the guinea-pig. 2. Caffeine (10...

All-or-nothing responses to carbachol in single intestinal smooth muscle cells of rat.

Ohta, T., Ito, S., Nakazato, Y.

1. Concentration-response relationships for carbachol (CCh)-induced increases in the cytosolic calcium concentration ([Ca2+]i) and membrane currents were studied by use of fura-2 microfluorimetry and...

Co-release of PHI and VIP in dog stomach by peripheral and central vagal stimulation.

Ohta, T., Ito, S., Ohga, A.

1. The purpose of this investigation was to examine the outputs of peptide histidine isoleucine (PHI) and vasoactive intestinal peptide (VIP) from the gastric corpus in response to stimulation of the...

Effects of vasoactive intestinal peptide (VIP) on contractile responses of smooth muscle in rat stomach.

Ohta, T., Ito, S., Ohga, A.

1. The effects of vasoactive intestinal peptide (VIP) on contractile responses to carbachol (CCh), KCl and caffeine of the circular smooth muscle in rat stomach were examined by the isometric tension...

Pancreatic trypsinogen and cathepsin B in human pancreatic carcinomas and associated metastatic lesions.

Ohta, T., Terada, T., Nagakawa, T., Tajima, H., Itoh, H., Fonseca, L., ...

Expression of pancreatic trypsinogen and cathepsin B in 23 surgically resected pancreatic ductal adenocarcinomas was evaluated immunohistochemically, using a monoclonal antibody against human...

Expression of basic fibroblast growth factor and its receptor in human pancreatic carcinomas.

Ohta, T., Yamamoto, M., Numata, M., Iseki, S., Tsukioka, Y., Miyashita, T., ...

We examined the expression of basic fibroblast growth factor (FGF) and FGF receptor by immunohistochemistry in 32 human pancreatic ductal adenocarcinomas. Mild to marked basic FGF immunoreactivity...

Expression of 16 kDa proteolipid of vacuolar-type H(+)-ATPase in human pancreatic cancer.

Ohta, T., Numata, M., Yagishita, H., Futagami, F., Tsukioka, Y., Kitagawa, H., ...

Recent studies have shown that bafilomycin A1-sensitive vacuolar-type H(+)-ATPase (V-ATPase) plays important roles in cell growth and differentiation. However, there is no published study that has...