Search Results - (Author, Cooperation:K. Okumura)

2011-07-09

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

1525-1314

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

This paper presents the results of numerical modelling to investigate the regional occurrence of prehnite-bearing metamorphic rocks at shallow levels in subduction zones. The modelling assumes a simple geometrical configuration in which the thermal structure in a prism is controlled by boundary conditions at the top and base of the prism. It is expected that the predominant metamorphic facies in a prism will change with decreasing age of the descending slab. The results of thermal modelling show that the facies boundary between pumpellyite–actinolite and prehnite–actinolite facies (including prehnite–pumpellyite facies) overlaps with an array of P–T conditions in the prism when the age of a descending slab is younger than 10 Myr. This implies that the change of the predominant metamorphic facies from pumpellyite–actinolite to prehnite–actinolite facies will switch drastically. The critical age of the switch depends on subduction parameters. In particular, the critical age of the descending slab is 〈5 Myr in the case of no shear heating, with a subduction rate of v=75–200 mm y−1 and subduction angle of θ=5–15°. For shear heating (constant shear stress=30 MPa) with a subduction rate of v=75 mm y−1 and subduction angle of θ=10° the critical age is 7 Myr. To test this switching behaviour in the development of prehnite–actinolite facies in the prism, petrologic data from the Cretaceous Shimanto Accretionary Complex (CSAC) in Kyushu, Japan were compiled. The regional occurrence and mineral assemblages of prehnite-bearing metamorphic rocks suggest that the most of CSAC was metamorphosed under prehnite–actinolite facies. This conclusion is consistent with subduction of a young, hot slab, as has been proposed based on other geological observations. This suggests that the regional extent of the prehnite–actinolite facies metamorphic rocks may be a unique evidence for the subduction of a young, hot slab.

Electronic Resource

1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Recently, we reported the functional expression of CD86 on cultured human Langerhans cells derived from normal epidermis. In the present study, we investigated the expression and function of co-stimulatory molecules in the pathogenesis of atopic dermatitis. In immunohistochemical analysis, CD80 and/or CD86 were detected on dendritic-shaped cells not only in the epidermis but also in the dermis in the inflammatory lesions of atopic dermatitis (n = 12). CD80 was expressed in only five cases (42%), while CD86 was expressed in all cases (100%). These molecules were not detected in normal control subjects (n = 8). In non-lesional skin of atopic dermatitis (n = 4). CD86 but not CD80 was detected in one case. CD86 was preferentially induced on dendritic-shaped cells in positive patch test sites to Dermatophagoides pteronyssinus or house dust allergen in atopic dermatitis (n = 4). The CD80- or CD86-positive cells were confirmed as Langerhans cells by double immunostaining using anti-CD1a monoclonal antibody. Neither CD86 over that CD80 was detected n keratinocytes. Similar results of the stronger expression of CD86 over that of CD80 were obtained from psoriasis vulgaris (n = 11) and from contact dermatitis (n=7), although CD86 was expressed only in 57% of the contact dermatitis cases. The percentage of Langerhans cells positive for CD86 was higher than for CD80, i.e. 48% compared with 9%, respectively, in the epidermis of lesional skin of atopic dermatitis (n=8). The expression rate of these molecules on Langerhans cells increased in the dermis. To investigate the function of co-stimulatory molecules on Langerhans cells in atopic dermatitis, we conducted an inhibition test with antibodies. Anti-CD86 monoclonal antibody almost completely nhibited T-cell proliferation stimulated with crude extract of D. pteronyssinus in the presence of epidermal cells as antigen-presenting cells, whereas anti-CD80 monoclonal antibody produced less of an inhibitory effect. These data indicate that CD86 expressed on Langerhans cells may play an important part in the pathogenesis of atopic dermatitis.for Investigative Dermatology. Washington, DC (1–5 May 1996).

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1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

CD80 (B7-1) and CD86 (B7-2/B70) have recently been identified in cultured human Langerhans cells (LCs), although their role and regulatory properties remain unclear. We present our comparison of the expression of the molecules, mRNAs and the function between CD80 and CD86 in human LCs treated by interferon γ (IFN-γ). We examined the regulatory properties of CD80 and CD86 expression in human LCs pretreated with IFN-γ. Flow cytometric analysis indicated that the mean fluorescence intensity of CD86 but not CD80 was enhanced. However, the percentage modulation of both CD80 and CD86 positive cells were significantly up-regulated in a dose-dependent manner, after 48-h culturing with IFN-γ. The regulatory properties of CD80 and CD86 mRNA expressions in human LC were studied using polymerase chain reaction methods. We found that both CD80 and CD86 mRNA of enriched LCs following IFN-γ pretreatment for 12 h were higher than those without pretreatment.We have demonstrated that the primary allogeneic mixed epidermal cell-lymphocyte reaction induced by human LCs treated by IFN-γ increased in a dose-dependent manner. There was a 61.5% inhibition by anti-CD86 monoclonal antibody and a 32.5% inhibition by anti-CD80 monoclonal antibody. These data indicate that the CD80 and CD86 expression of human LCs may be differently regulated by IFN-γ.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Detailed studies of infrared absorption in nominally undoped and boron-doped, free-standing diamond thin films are reported. Difference measurements reveal absorption at 1300 cm−1 (0.16 eV) due to boron-induced single phonon, vibronic excitations. A relatively sharp peak at about 2420 cm−1 (0.30 eV), a stronger, broader band centered at 3060 cm−1 (0.38 eV), and a weak, broad peak at 4200 cm−1 (0.52 eV), are identified as electronic transitions, with or without phonon assistance, of the boron acceptor. These results provide important confirmation of the hitherto presumed substitutional nature of boron doping and recent suggestions concerning electronic transport mechanisms in diamond thin films.

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1077-3118

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Physics

Photosensitization of diamond thin films, prepared by the hot-filament technique, has been achieved with thin overcoatings of hydrogenated amorphous silicon. It is observed that injection of electrons, photogenerated in the amorphous silicon, proceeds with efficiencies approaching unity. To reconcile this with the reported electron energy structures of these two materials, the presence of localized, acceptor-like states 2 eV above the valence band of diamond must be invoked. In addition their density must be sufficiently high to account for the inferred lower limit of 10−8 cm2 /V for the electron range.

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1077-3118

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Physics

The electrical conductivity of diamond thin films produced by the hot-filament technique is found to increase when diborane is incorporated in the precursor gas mixture. The combination of well-defined bulk conductivity measurements with quantitative secondary-ion mass spectrometry and Raman spectroscopy shows that the conductivity increase is associated with atomic boron doping and rules out any significant role for a graphitic-type component.

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1077-3118

AIP Digital Archive

Physics

Diamond films have been in-diffused with lithium in an effort to produce n-type diamond by interstitial doping. Although lithium incorporation was established, only small changes in electrical conductivity and no thermionic emission from donor levels, which should lie only a few tenths of an electron volt below the vacuum level, were observed. To account for these observations, studies of the spectral dependence of external photoemission of lithium-doped and undoped films were undertaken. These indicate that the lithium donors are compensated by high densities of acceptor states distributed over several electron volts. This first, direct observation of band-gap states in diamond films accounts for a number of reported properties including their relatively high electrical conductivity and small field effect.

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1077-3118

AIP Digital Archive

Physics

Space-charge-limited hole currents in nominally undoped diamond thin films have been studied using thin, highly boron-doped (p+) diamond layers as injecting contacts. The results obtained from these p+-p-Si structures have been analyzed to determine, for the first time, the bulk distribution of localized states N(E) in polycrystalline diamond thin films. The values of N(E), covering an energy range of about 0.8–0.6 eV above the valence band, indicate that the density of states at 0.8 eV is about 1015 cm−3 eV−1 but rises rapidly, within the 0.2 eV, to about 1018 cm−3 eV−1.

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1077-3118

AIP Digital Archive

Physics

Diamond thin films have been doped with nitrogen during growth by the hot-filament technique. For nitrogen concentrations in the films, determined by quantitative secondary ion-mass spectroscopy (SIMS) exceeding about 3×1018 atoms/cc, a decrease of several orders of magnitude is observed in the electrical conductivity for temperatures at or above room temperature. Qualitatively, this decrease is as expected, assuming compensation of existing acceptor states in nominally undoped diamond thin films by substitutional nitrogen which is known to introduce a deep-lying donor level.

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1077-3118

AIP Digital Archive

Physics

The C49-to-C54 transition in TiSi2 was investigated using samples having submicron line width film, by an x-ray diffraction technique. Arrhenius plots of the transition rate show that the C49-to-C54 transition of polycrystalline TiSi2 films with arsenic impurities have an activation energy barrier strongly dependent on the arsenic concentration. The energy increases as a function of arsenic impurity concentration, from 3.5 eV for TiSi2 formed on Si substrate ion implanted with the dose of 2×1015 cm−2, to 7.8 eV with the dose of 5×1015 cm−2. The annealing time dependence of the x-ray intensity on (004) orientation indicates that TiSi2 formed on Si substrate with the arsenic dose of 2×1015 cm−2 shows a diffusion-limited process and that with the dose of 5×1015 cm−2 shows an interface-limited process. The arsenic precipitates act to pin the C49 phase in the C49-to-C54 transition.

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1077-3118

AIP Digital Archive

Physics

We have deposited a silicon oxide (SiOx) film with a high optical transmittance in the DUV region by a focused ion beam induced deposition technique using a gallium ion beam and a mixture of oxygen and TMCTS(1,3,5,7-tetramethylcyclotetrasiloxane) as a source gas. The optical transmittance of a 0.3 μm thick film is higher than 90% at the wavelength of 250 nm. The transmittance of the deposited SiOx film depends on both the source gas and ion beam irradiation conditions. A scaling to explain the transmittance along with the ion beam conditions is proposed. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

We obtain a closed expression for the response function for damped anharmonic vibrational modes using the Feynman rule obtained through the nonequilibrium generating functional derived in our previous paper [Phys. Rev. E 53, 214 (1996)]. The linear absorption spectra are explicitly calculated through the Feynman diagrams for molecules with anharmonic potential in solution. The dependence of the spectra both on the temperature and on the solvent nature can be taken into account in our theory. The result is examined numerically for various dampings, anharmonicities, and temperatures. © 1996 American Institute of Physics.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

To clarify the activation of peripheral blood T cells in Kawasaki disease (KD) patients, we investigated whether expression of lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18) and/or intercellular adhesion molecule-1 (ICAM-1, CDS4) on peripheral blood T cells increases during the acute stage. Expression of cellular adhesion molecules was measured using flow cytometry. There was a decrease in the percentage of CD3+ T cells in the bright LFA-1α and LFA-1β population and a concomitant increase in the dim population of LFA-1α and LFA-1β during the acute stage, in comparison with those of the convalescent stage. In addition, we observed no significant differences in ICAM-1 expression during the acute stage compared with that of the convalescent stage. In our view the present data, in conjunction with previous reports on T-cell function during acute KD, suggest that activated T cells are temporarily withdrawn from peripheral circulation during acute KD.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The rosetting of sheep erythrocytes (SRBC) coated with non-haemagglutinating monoclonal antibodies rather than conventional haemagglutinating antisera revealed readily detectable FcR on most splenic natural killer (NK) cells since 76% of splenic lymphocytes forming conjugates with YAC also resetted with SRBC coated with high concentrations of monoclonal anti-SRBC antibody of the IgG2b subclass and since Ficoll depletion or enrichment of splenic lymphocytes rosetting with IgG2b-coated SRBC resulted in a corresponding 4-fold decrease or increase in conjugate-forming cells and a 10-fold decrease or increase in NK cytolytic acttvity. NK cells bound much less readily to monoclonal IgG2a and not at all to monoclonal IgGI or IgM, but the degree of binding was directly proportional to the amount of antibody on the erythrocytes and was not isotype-restricted. In addition, immunofluorescent studies revealed that YAC-1-conjugated lymphocytes were Lyt-1-, Lyt-2-, partially Thy-1+ (60%), asiato-GMI + (80%), Qa-4+ (77%), Qa-5+ (79%), and Ly-5+ (94%). In comparison, a proportion (39%) of alloimmune peritoneal exudate cells which conjugated with P815–2 also siained by immunofluorescence with anti-asialo GM1 antisera. Most (〉90%) P815- conjugated cells were Thy-1+, Lyt-2+. and a subpopulation of Lyt-l+2+ conjugates was observed (25 %). Qa-5 and Ly-5 were also expressed on most (two-thirds) cytolytic T lymphocytes (CTL) conjugates, whereas Qa-4 and FcR for IgG2b were not detected. The best phenotypic distinctions between NK cells and CTL were therefore based on the presence or absence of Lyt-2, Qa-4, and FcR for IgG2b on most effector cells. Anti-asialo-GMl or monoclonal anti-Qa-4 and complement treatment greatly diminished both the frequency of NK conjugates and the percentage of conjugates with detectable IgG2b FcR or asialo-GM1. These results confirm that NK cells co-express asialo-GMI and Fc receptors, at the single-celt level, and provide a simple method for greatly enriching NK populations at least 10-fold.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The passage of spleen cells through a tightly packed nylon wool column partially separated two populations of cells required for the antigen-induced secondary proliferative response of T cells. The proliferating T cells were in the nylon wool column-passed cell population, but the addition of a small number of nylon-wool-adherent cells was required for their maximal proliferative response. Such adherent cells were non-T, non-B, Ia antigen-positive cells serving as antigen-presenting cells. Ia determinants on this cell type are encoded in two separate I subregions, I-A and I-E/C, and they are expressed simultaneously on the same cells. Antisera specific for I-J subregion gene products having as a known activity the killing of antigen-specific suppressor and helper T cells were unable to kill antigen-presenting adherent cells. The results indicated that at least I-J subregion gene products expressed on suppressor and helper T cells are not present on antigen-presenting accessory cells. The Ia specificities detected on accessory cells follow the cross-reactive pattern found in Ia molecules of B cells, and thus antigen-presenting cells carry Ia antigen identical to those of B cells, and not those of T cells.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Assuming that the polarizability is a linear function of the nuclear coordinate, i.e., α(q)=α0+α1q, we obtain analytical expressions of the (2n+1)th-order signals and show that the leading order of the signals (n〉1) is proportional to gn+1, where gn+1 is the coefficient of the anharmonic potential V(q)=g3q3/3!+g4q4/4!+⋅⋅⋅. In other words, detection of the (2n+1)th-order signal implies the direct observation of the (n+1)th-order anharmonicity within the approximation. Based on this fact we discuss a possibility to detect the (n+1)th-order anharmonicity directly from the (2n+1)th-order experiment. Calculations are made by using novel Feynman rules for the nonequilibrium multitime correlation functions relevant to the higher-order off-resonant spectroscopy. The rules have been developed by the authors and are presented compactly in this paper. With the help of a conventional double-sided Feynman diagram, we draw physical pictures of higher-order off-resonant optical processes. Representative calculations for CHCl3 of the fifth-, seventh-, and ninth-order optical processes are presented and discussed. © 1997 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

We have developed a theory of the fifth-order off-resonant spectroscopy to study the effect of anharmonicity of molecular vibrational modes. The anharmonicity, as well as nonlinear dependence of polarizability on nuclear coordinates, can be the origin of the fifth-order Raman signal. A profile of the signal varies depending on the relative importance of the two effects—the anharmonicity and the nonlinearity. The anharmonicity of a potential can be distinguished from the other effects such as the nonlinearity or the inhomogeneity of vibrational modes. In order to carry out calculations analytically, we employ the multimode Brownian oscillator model and treat anharmonicity as perturbation to the harmonic vibrational modes. A simple analytical expression for the fifth-order polarization is obtained through a diagrammatic technique, called Feynman rule on the unified time path. Physical pictures for the analytical expression are given for a single mode system through numerical calculations and through double-sided Feynman diagrams. Applications to CHCl3 and CS2 are made where the third-order experiments are used to extract parameters. In the CS2 case, the theoretical fifth-order signals are compared with recent experiment, which suggests some sign of anharmonicity. © 1997 American Institute of Physics.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Complement-dependent cytotoxicity (CDC) mediated by a chimeric anti-Lewis Y monoclonal antibody (cH18A; human IgGl) was investigated in this study. Human lung adenocarcinoma cell lines (PC7, PC9, and PC 14) were used as the target cells. PC7 and PC9 cells, expressed Lewis Y antigen and were lysed by cH18A as effectively as by the parent mouse anti-Lewis Y antibodies (mH18A) in a concentration-dependent manner. PC14 cells did not express Lewis Y antigen and were not lysed by either cH18A or mH18A. cH18A mediated CDC activity against PC7 and PC9 cells was enhanced by the combined use of monoclonal antibodies directed against CD46(MCP), CD55(DAF), and CD59. These molecules are complement-regulatory proteins which protect host cells from CDC. PC7 and PC9 cells, showed high levels of surface expression of these proteins, PC7 cells were more susceptible to cH ISA-mediated CDC than PC9 cells. Use of multiple blocking antibodies to the complement-regulatory proteins produced more enhancement of cH18A-mediated CDC than a single antibody. Moreover, expression of CD55 and CD59 by PC7 and PC9 cells was decreased after treatment with Pl-PLC, resulting in increased susceptibility to cHISA-mediated CDC. Although the reason is unknown, PC7 cells became more susceptible to CDC than PC9 cells after PI-PLC treatment even in the absence of cH18A. These data suggest that chimeric monoclonal antibodies can be used to induce CDC against lung adenocarcinoma, and that such CDC is potentiated by a variety of antibodies blocking compliment-regulatory proteins on the tumour cell surface.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Atopic dermatitis is a chronic, relapsing inflammatory disorder characterized by pruritic and eczematous skin lesions. Transforming growth factor (TGF)-β1 has been implicated in the suppression of inflammatory responses.〈section xml:id="abs1-2"〉〈title type="main"〉ObjectiveThe purpose of this study is to determine whether TGF-β1 suppresses skin lesions in a mouse model of atopic dermatitis.〈section xml:id="abs1-3"〉〈title type="main"〉MethodsWe used the NC/Nga strain of mice as an in vivo model of atopic dermatitis. The effects of exogenous TGF-β1 on atopic dermatitis-like skin lesions in NC/Nga mice were evaluated clinically, histologically and immunologically.〈section xml:id="abs1-4"〉〈title type="main"〉ResultsSubcutaneous injection of recombinant TGF-β1 macroscopically suppressed eczematous skin lesions in NC/Nga mice associated with reduced serum immunoglobulin E (IgE) levels. Histological analysis showed that TGF-β1 significantly inhibited the infiltration of inflammatory cells such as mast cells and eosinophils into the skin of NC/Nga mice. Spontaneous interferon (IFN)-γ production from splenocytes of NC/Nga mice was down-regulated by the treatment with TGF-β1 and neutralizing antibody against IFN-γ inhibited skin lesions in NC/Nga mice. The inhibitory effect of TGF-β1 on the skin lesions lasted at least 1 week after cessation of the treatment.〈section xml:id="abs1-5"〉〈title type="main"〉ConclusionThese findings indicate that TGF-β1 suppressed atopic dermatitis-like skin lesions in NC/Nga mice at least in part through down-regulation of IFN-γ. These results suggest that TGF-β1 may have a therapeutic potential for atopic dermatitis.

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