203 research outputs found

    Involvement of both protein kinase C and G proteins in superoxide production after IgE triggering in guinea pig eosinophils

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    ABSTRACTTo study the function and mechanism of eosinophils via the low affinity IgE receptor (FceRII), we examined the production of 02 metabolites by measuring the luminol-dependent chemiluminescence (LDCL) response and the generation of cysteinyl leukotrienes. Eosinophils obtained from guinea pig peritoneal fluid sensitized with horse serum were purified. Luminol-dependent chemiluminescence was induced by stimulation with monoclonal anti-CD23 antibody, but not by mouse serum (controls). The mean (±SEM) value of LDCL was 20.6±1.3X103 c.p.m. This reaction consisted of an initial rapid phase and a propagation phase and ended within lOmin. Guinea pig eosinophils were histochemically stained with monoclonal anti-CD23 antibody. The major product generated in the LDCL response was superoxide, as determined by the measurement of superoxide by cytochrome c reduction and the complete inhibitory effect of superoxide dismutase on the LDCL response. Pretreatment with either pertussis toxin or cholera toxin inhibited the LDCL reaction. Depletion of bivalent ions by EDTA inhibited this response and the protein kinase C inhibitor D-sphingosin inhibited both 1-oleoyl-2-acetyl-glycerol-induced and FcϵRII-mediated LDCL. These findings suggest that the NADPH-protein kinase C pathway may be involved in the FceRII-mediated LDCL response in guinea pig eosinophils

    Effects of phosphodiesterase inhibitors on secretions of human monokines

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    ABSTRACTThe purpose of this study was to evaluate the effect of newly developed selective phosphodiesterase (PDE) inhibitors, KF19514 (type l/IV) and cilostazol (type III), and theophylline on the secretions of tumor necrosis factor a (TNFα) and interleukin-1β (IL-1 β) from human peripheral monocytes stimulated by lipopolysaccha- ride (LPS). Human blood monocytes were incubated with LPS in the absence or presence of KF19514, cilostazol or theophylline. TNFα and IL-1in the cell- free supernatants were measured with enzyme-linked immunosorbent assay. KF19514 showed significant inhibition on the release of TNFα (% inhibition ± SEM was 82.8 ± 7.4% at 1 nmol/L) and IL-1 β (34.4 ± 7.5% at 10 (μmol/L). In addition, KF19514 inhibited the expression of TNFa mRNA. Cilostazol inhibited the release of TNFa significantly (60.2 ± 8.9% at 30 μmol/L) but not IL-1 β. Theophylline inhibited slightly but significantly the release of TNFa at a therapeutic concentration (1 7.4 ± 5.1% at 100 μmol/L). These results suggest that theophylline may not only have a bronchodilating action but also an anti-inflammatory property in the treatment of bronchial asthma, and that KF19514 may have an anti-inflammatory action on at least the transcriptional level

    μ-opioid Receptor-Mediated Alterations of Allergen-Induced Immune Responses of Bronchial Lymph Node Cells in a Murine Model of Stress Asthma

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    ABSTRACTBackgroundPsychological stress has a recognized association with asthma symptoms. Using a murine model of allergic asthma, we recently demonstrated the involvement of μ-opioid receptors (MORs) in the central nervous system in the stress-induced exacerbation of airway inflammation. However, the involvement of MORs on neurons and immunological alterations in the stress asthma model remain unclear.MethodsMOR-knockout (MORKO) mice that express MORs only on noradrenergic and adrenergic neurons (MORKO/Tg mice) were produced and characterized for stress responses. Sensitized mice inhaled antigen and were then subjected to restraint stress. After a second antigen inhalation, bronchoalveolar lavage cells were counted. Before the second inhalation, bronchial lymph node (BLN) cells and splenocytes from stressed and non-stressed mice were cultured with antigen, and cytokine levels and the proportions of T cell subsets were measured.ResultsStress-induced worsening of allergic airway inflammation was observed in wild-type and MORKO/Tg mice but not MORKO mice. In wild-type stressed mice, IFN-γ/IL-4 ratios in cell culture supernatants and the proportion of regulatory T cells in BLN cell populations were significantly lower than those in non-stressed mice. These differences in BLN cells were not observed between the stressed and non-stressed MORKO mice. Restraint stress had no effect on cytokine production or T cell subsets in splenocytes.ConclusionsRestraint stress aggravated allergic airway inflammation in association with alterations in local immunity characterized by greater Th2-associated cytokine production and a reduced development of regulatory T cells, mediated by MORs

    Two-Layer Pop-Up Origami Deployable Membrance Reflectarray Antenna Stowed in 1U CubeSat

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    The present paper shows the innovative deployable reflectarray antenna concept that enables to stow a 1m-by-1m square antenna into 1U CubeSat volume. The antenna is composed of two-layer membranes to obtain an air gap. A one-layer deployable membrane structure was demonstrated by the 3U CubeSat OrigamiSat-1 in 2019. The authors are currently developing two technologies to realize the reflectarray antenna. First, the deployable two-layer membrane structure is to be achieved by using pop-up picture book’s mechanism. Second, reflection elements for the reflectarray antenna that do not cross folding lines are proposed to avoid gain degradation

    Percolative phase separation induced by nonuniformly distributed excess oxygens

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    The zero-field 139^{139}La and 55^{55}Mn nuclear magnetic resonances were studied in La0.8Ca0.2MnO3+δ\rm La_{0.8}Ca_{0.2}MnO_{3+\delta} with different oxygen stoichiometry δ\delta. The signal intensity, peak frequency and line broadening of the 139^{139}La NMR spectrum show that excess oxygens have a tendency to concentrate and establish local ferromagnetic ordering around themselves. These connect the previously existed ferromagnetic clusters embedded in the antiferromagnetic host, resulting in percolative conduction paths. This phase separation is not a charge segregation type, but a electroneutral type. The magnetoresistance peak at the temperature where percolative paths start to form provides a direct evidence that phase separation is one source of colossal magnetoresistance effect.Comment: 4 pages, 5 figure

    Blood‑patch pleurodesis for pneumothorax in lung fibrosis due to progressive systemic sclerosis: A case report

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    Pneumothorax in patients with progressive systemic sclerosis (PSS) often presents as a difficult‑to‑treat disease. Autologous blood‑patch pleurodesis has previously been used for the treatment of pneumothorax. Blood outside its own environment is an irritant; therefore, chest physicians must watch closely for an allergic reaction. The injection is simple, painless, causes no side effects, is an inexpensive treatment for pneumothorax and is available not only in patients with persistent air leak but also in those with residual air space. A case is reported here of blood‑patch pleurodesis for pneumothorax in lung fibrosis due to PSS. As an alternative therapy for difficult‑to‑treat pneumothorax in patients with PSS with persistent air leak and residual air space, autologous blood‑patch pleurodesis would be one of the treatment options

    Phase separation of an actin nucleator by junctional microtubules regulates epithelial function

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    Liquid-liquid phase separation (LLPS) is involved in various dynamic biological phenomena. In epithelial cells, dynamic regulation of junctional actin filaments tethered to the apical junctional complex (AJC) is critical for maintaining internal homeostasis against external perturbations; however, the role of LLPS in this process remains unknown. Here, after identifying a multifunctional actin nucleator, cordon bleu (Cobl), as an AJC-enriched microtubule-associated protein, we conducted comprehensive in vitro and in vivo analyses. We found that apical microtubules promoted LLPS of Cobl at the AJC, and Cobl actin assembly activity increased upon LLPS. Thus, microtubules spatiotemporally regulated junctional actin assembly for epithelial morphogenesis and paracellular barriers. Collectively, these findings established that LLPS of the actin nucleator Cobl mediated dynamic microtubule-actin cross-talk in junctions, which fine-tuned the epithelial barrier

    Superficial‑type endobronchial metastases from colon cancer : A case report

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    Certain internal malignancies, including colon cancer, can develop endobronchial metastasis. The present study reports a case of colon cancer with superficial‑type endobronchial metastases in a 76‑year‑old male. Chest computed tomography revealed small masses and infiltrates in each lung, with bilateral hilar lymph node swelling. Superficial endobronchial tumors in each of the bronchi were unexpectedly found by bronchoscopic examination. A biopsy specimen obtained from the endobronchial tumor was diagnosed as colon cancer. Superficial‑type endobronchial metastasis from colon cancer is extremely rare, however, such metastasis should be considered for patients who have a history of colon cancer. There should be no hesitation in performing a bronchoscopic biopsy as an additional examination

    Space Demonstration of Two-Layer Pop-Up Origami Deployable Membrane Reflectarray Antenna by 3U CubeSat OrigamiSat-2

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    3U CubeSat OrigamiSat-2 demonstrates a 50-cm × 50-cm two-layer pop-up Origami deployable membrane reflectarray antenna in space. The membrane has small stowage volume and high gain even though it has low flatness because of a large enough antenna area to cover its un-flatness. C-band transmitter is equipped in the CubeSat and offers 20-Mbps amateur satellite communication. In 3U size, a 1-m length deployable gravity gradient mast and magnetic torquer are equipped to stabilize and control its attitude. A camera is attached to the satellite to measure the shape of the membrane antenna. OrigamiSat-2 was selected as the Innovative Satellite Technology Demonstration-4 by Japan Aerospace Exploration Agency (JAXA) and is going to be launched in 2024 by Epsilon Launch Vehicle

    A comprehensive study on impurity behavior in LHD long pulse discharges

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    Impurity behavior is studied in a variety of LHD (Large Helical Device) long pulse discharges, i.e. standard hydrogen plasmas, super dense core plasmas, helium plasmas with ICH (Ion Cyclotron Frequency Heating), multi-species plasmas mixed with H and He. Density scan experiments show a specific density range of impurity accumulation for only hydrogen discharges. Strong suppression of impurity accumulative behavior is observed in high temperature plasmas with high power heating. The main contributions to impurity transport are extracted by a comprehensive study on impurity behavior, i.e. investigating the critical conditions for impurity accumulation and the parameter dependences. It is found that the impurity behavior is determined by three dominant contributions, i.e. neoclassical transport mainly depending on radial electric field, turbulent transport increasing with heating power and impurity screening at high edge collisionality in the ergodic layer. The mapping of impurity behavior on n-T (electron density and temperature) space at the plasma edge shows a clear indication of the domain without impurity accumulation and provides operation scenarios to build up fusion-relevant plasmas
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