Search Results - (Author, Cooperation:H. Inomata)

2011-02-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Bone Morphogenetic Protein 4/deficiency/genetics/metabolism ; Cadherins/metabolism ; *Cell Differentiation ; Cell Lineage ; Cells, Cultured ; Embryo, Mammalian/cytology/embryology/metabolism ; Embryonic Stem Cells/*cytology/metabolism ; Gene Expression Regulation, Developmental/genetics ; Germ Layers/cytology/embryology/metabolism ; HEK293 Cells ; Humans ; Mice ; Models, Biological ; Neural Plate/cytology/embryology/metabolism ; Neural Stem Cells/*cytology/metabolism ; Oligonucleotide Array Sequence Analysis ; SOXB1 Transcription Factors/metabolism ; Transcription Factors/deficiency/genetics/*metabolism ; Transcriptional Activation ; Xenopus ; p300-CBP Transcription Factors/metabolism

1089-7550

AIP Digital Archive

Physics

A rapid optical absorption change is observed in a GaAs/AlAs short-period superlattice having Wannier–Stark localization. This phenomenon is clearly explained by a rapid collapse of Wannier–Stark localization due to electric field screening by photogenerated space charges. The screening causes a positive feedback loop between restoration of the blue-shifted wavelength of the absorption band-edge towards the red and an increase in optical absorption, which causes an additional field screening. The experimental bias voltage dependence of the intensity of photoluminescence and photocurrent under high optical excitation, agree well with a model applying Fowler–Nordheim tunneling at the heterointerface cladding layer. It is concluded that the space charges are stopped near the cladding layer and that the superlattice region is almost fully screened to near the flat-band bias condition. © 1996 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Unstrained InGaAs (4.5 nm)/InAlAs (1.0 nm) short-period superlattices grown on a (100) GaAs substrate were studied. To achieve this growth, an In-composition-graded buffer layer and a thick InGaAs buffer layer were adopted. Structural properties were investigated by x-ray diffraction, atomic force microscopy, and a compositional analysis by the thickness fringe method. X-ray diffraction patterns showed clear periodicity in the superlattices and atomic force spectroscopy images showed cross-hatch morphology for the main ridge along the (011¯) direction. Clear thickness fringes in the bright-field electron microscope images for the superlattice region and ambiguous fringes for the graded buffer layer indicate that misfit dislocation due to lattice mismatch concentrates in the graded buffer and a high-quality superlattice is successfully grown in spite of the large lattice mismatch between the superlattice and the substrate. Optical characteristics measured by photocurrent spectroscopy reveal a clear Wannier–Stark localization effect at room temperature. The experimental absorption energies agree well with calculated values by a transfer matrix method using parameters for bulk InGaAs and InAlAs. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Ab initio self-consistent-field (SCF) and electron correlation calculations have been carried out for the dihedral angle dependence of the vicinal proton–proton coupling constants, 3JHH, in ethane molecule. The four contributions to 3JHH, (JFC, JSD, JOP, and JOD) have been computed with the three different basis sets, [5s2p1d/2s1p], [5s3p1d/3s1p], and [7s4p2d/5s2p]. The Fermi contact (FC) contribution was largest and the spin–dipole (SD) contribution was smallest. The FC and orbital paramagnetic (OP) contributions showed large basis set dependence, but the SD and orbital diamagnetic (OD) contributions presented little basis set dependence. The calculated total SCF contribution to 3JHH was higher than the experimental coupling. Using the Møller–Plesset perturbation theory we have introduced electron correlation effects on the FC and OP terms. The correlation effects on the OP term was shown to be negligible. The second-order correlation in the FC term was very large and amounted to half of its SCF value in magnitude with opposite sign. However, the third-order correlation in the FC contribution was small. Unfortunately, the calculated 3JHH value including correlation corrections through third order was too small compared to the experimental one. The poor agreement between calculation and experiment is claimed to be due to higher than third-order correlations in the FC term. © 1995 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The lowest order relativistic effect theory for nuclear magnetic shieldings was derived from a two-component positive energy Hamiltonian. It was shown that the previous relativistic shielding theory based on the two-component Hamiltonian is not gauge invariant and the new terms have to be added to make a result gauge invariant. The presented theory is gauge invariant to the order of (Z/137)4 where Z is the atomic number of the heaviest atom in the molecule. One of the new contributions to the relativistic magnetic shieldings is a second-order perturbation term due to the combination of the spin-orbit interaction and the Fermi-contact interaction. A numerical estimation for this term was performed for the four hydrogen halides, HF, HCl, HBr, and HI. The computational results showed that the contribution of this term to the hydrogen shieldings is negligibly small, but the contribution to the halogen atoms is considerable. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Nuclear magnetic shieldings in first- and second-row hydrides were calculated with electron correlation taken into account through third order. The calculation was performed using London's gauge-invariant atomic orbitals (GIAOs) and finite-field Møller–Plesset perturbation theory (FF-MPPT). Furthermore, the vibrational motion corrections to the magnetic shieldings were evaluated. It was shown that the calculated isotropic shielding constants at the experimental geometries are higher than the experimental values, but that vibrational corrections are generally negative and improve the calculated shielding constants. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Electronic Resource

0375-9601

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0039-6028

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0030-4018

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0896-8446

VLE ; aromatic compounds ; supercritical fluid

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Process Engineering, Biotechnology, Nutrition Technology

Electronic Resource

0896-8446

Beer-Lambert ; CO"2 ; molar absorption coefficient ; naphthalene ; supercritical fluid

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Process Engineering, Biotechnology, Nutrition Technology

Electronic Resource

0896-8446

Fermi resonance ; infrared spectra ; supercritical CO"2

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Process Engineering, Biotechnology, Nutrition Technology

Electronic Resource

1435-702X

Springer Online Journal Archives 1860-2000

Medicine

Abstract Retinal sheathed vessels from five patients with various vascular diseases were examined by light and electron microscopy. All of these vessels were characterized by a marked increase and disarrangement of collagen fibrils in the media and adventitia. Cytoplasmic processes of glial cells had invaded the adventitia in sheathed vessels and even in unsheathed ones. Thickening and multilamination of the basal laminae were observed in both the sheathed and unsheathed vessels. The lumens of most sheathed vessels were still patent, and the blood cells and endothelial cells of these vessels appeared to be intact. We found no essential differences in the ultrastructure of these vessels in the five patients with various vascular diseases. It is concluded that the increase and disarrangement of collagen fibrils may be mainly related to the ophthalmoscopic appearance of the sheathing and that other factors seem to be of lesser significance.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary The effects of tetraethylammonium (TEA) on the action potential in cultured chick embryonic heart muscle cells were investigated. The onset of prolongation of the action potential occurred within 10 min following intracellular iontophoretic application of TEA, but after more than 50 min following extracellular application. These facts suggest that the major site of action of TEA is on the inner surface of the membrane in these cells.

Electronic Resource

1432-2307

Vascular endothelial growth factor ; Retinal glial cells ; Hypoxia ; Angiogenesis ; Retinal capillary endothelial cells

Springer Online Journal Archives 1860-2000

Medicine

Abstract To determine whether retinal glial cells (RGCs) participate in the paracrine regulation of retinal neovascularization, we investigated whether cultured RGCs synthesize and release vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) under normoxic or hypoxic conditions. Northern blot analysis demonstrated that cultured RGCs transcribed both VEGF mRNA with two molecular bands approximately 3.9 and 4.3 kilobases (kb), and bFGF mRNA with approximately 3.7 and 6.0 kb. The expression of VEGF mRNA was greatly enhanced by hypoxic cultivation (2% oxygen) when compared with normoxic cultivation (20% oxygen), while the expression of bFGF mRNA by RGCs was not significantly affected by hypoxia. The effects of RGCs-conditioned media (CM) on tritiated-thymidine incorporation and in vitro angiogenesis by retinal capillary endothelial cells (RECs) in producing the formation of capillary-like tubes in type I collagen gels, were evident in the observation that RGCs-CM harvested after hypoxic cultivation significantly enhanced tritiated-thymidine incorporation (1.9 times, P〈0.01) and in vitro angiogenesis (2.4 times, P〈0.01) compared with the normoxic RGCs-CM. These enhancing effects of RGCs-CM at hypoxia were suppressed by anti-VEGF neutralizing antibody. Furthermore, RECs were shown to express mRNA encoding the VEGF receptor flt-1 by northern blot analysis. These results suggest that VEGF expressed by RGCs under hypoxic conditions plays an integral role in the initiation and progression of retinal neovascularization in a paracrine manner.

Electronic Resource

1432-0428

Keywords Advanced glycation end products ; blood retinal barrier ; diabetic retinopathy ; Ne-(carboxymethyl)lysine ; vascular endothelial growth factor.

Springer Online Journal Archives 1860-2000

Medicine

Summary Both advanced glycation end products and vascular endothelial growth factor are believed to play a role in the pathogenesis of diabetic retinopathy. It is known that vascular endothelial growth factor causes retinal neovascularization and a breakdown of the blood-retinal barrier; how advanced glycation end products affect the retina, however, remains largely unclear. The substance Ne-(carboxymethyl)lysine is a major immunologic epitope, i. e. a dominant advanced glycation end products antigen. We generated an anti-Ne-(carboxymethyl)lysine antibody to investigate the relationship between the localization of advanced glycation end products and that of vascular endothelial growth factor in 27 human diabetic retinas by immunohistochemistry. Nine control retinas were also examined. In all 27 diabetic retinas, Ne-(carboxymethyl)lysine was located in the thickened vascular wall. In 19 of the 27 retinas, strand-shaped Ne-(carboxymethyl)lysine immunoreactivity was also observed around the vessels. In all 27 diabetic retinas, vascular endothelial growth factor revealed a distribution pattern similar to that of Ne-(carboxymethyl)lysine. Vascular endothelial growth factor was also located in the vascular wall and in the perivascular area. Neither Ne-(carboxymethyl)lysine nor vascular endothelial growth factor immunoreactivity was detected in the 9 control retinas. Vessels with positive immunoreactivity for Ne-(carboxymethyl)lysine and/or vascular endothelial growth factor were counted. A general association was noted between accumulation of Ne-(carboxymethyl)lysine and expression of vascular endothelial growth factor in the eyes with non-proliferative diabetic retinopathy (p 〈 0.01) and proliferative diabetic retinopathy (p 〈 0.05). [Diabetologia (1997) 40: 764–769]

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Herpes simplex virus can cause acute retinal necrosis, a blinding retinal disease in man. A unilateral intracameral inoculation of herpes simplex virus type 1 (HSV-1) in mice induces retinal necrosis primarily in the contralateral eye and provides an experimental model for the disease. Previous studies suggested that a major envelope glycoprotein of HSV-1, glycoprotein C (gC), is required for retinal necrosis. We studied HSV-1 strain TN-1, a gC-deficient clinical isolate from a lesion of herpetic keratitis, for its pathogenicity in mice with an intracameral inoculation of the virus and found that TN-1 could induce severe necrotizing retinitis in both inoculated and uninoculated eyes of BALB/c mice. Inoculation with a lower dose of TN-1 resulted in a unilateral necrotizing retinitis in the uninoculated eyes. Tissue virus titration of infected mice killed at various times after inoculation detected an infectious virus in various organs including the eyeballs, trigeminal ganglia, brain and adrenal glands. Anterior chamber-associated immune deviation (ACAID) was observed in TN-1-inoculated mice as well as in mice inoculated with gC-positive laboratory strain KOS 7 days postinoculation. Our findings suggested that gC of HSV-1 is not necessary for either the induction of retinal necrosis, neural spread of the virus, or ACAID.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary BALB/c mice developed contralateral necrotizing retinitis following intracameral inoculation with herpes simplex virus type 1 (HSV-1). The animals showed a positive delayed-type hypersensitivity (DTH) response at 10 days postinoculation, indicating that the anterior chamber-associated immune deviation was transient after HSV-1 inoculation. Since glycoprotein C (gC) of HSV-1 is a major immunogen, we examined DTH and the antibody response induced by a gC-deficient strain TN-1 and compared them with those induced by the recombinant gC-positive mutants. We found that gC was not required for DTH reaction, and that gC was neither necessary for nor protective against the contralateral retinal necrosis. Serial lymphocyte subset analyses of the draining lymph nodes revealed an absolute increase of B cells, CD 4-positive T cells, and CD 8-positive T cells. CD 4-positive T cells but not CD 8-positive T cells increased in the contralateral eyes during the inflammation and necrosis. The coincident emergence of the positive DTH and contralateral retinal necrosis of HSV-1-inoculated mice, together with the presence of CD 4-positive cells in the retina, indicated that CD 4-positive T cells responsible for DTH induction may participate in the retinal necrosis.

Electronic Resource

1432-2013

guinea-pig vas deferens ; adenosine triphosphate ; depolarization ; membrane conductance ; ATP reversal potential

Springer Online Journal Archives 1860-2000

Medicine

Abstract The effects of exogenously applied adenosine triphosphate (ATP) on the smooth muscle of guinea-pig vas deferens were studied with the double sucrose-gap method. ATP evoked a membrane depolarization which was associated with a decrease in the size of electrotonic potentials. Conditioning hyperpolarization induced by current application caused an increase in the magnitude of the ATP-induced depolarization; the larger the conditioning hyperpolarization, the greater the ATP-induced depolarization. These results are discussed with respect to the ionic mechanism of the electrical event in response to ATP in this tissue.

Electronic Resource