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Search Results: 1 - 10 of 11140 matches for " Angela On Kei Choi "
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Activation of Eosinophils Interacting with Dermal Fibroblasts by Pruritogenic Cytokine IL-31 and Alarmin IL-33: Implications in Atopic Dermatitis
Chun-Kwok Wong, Karen Ming-Lam Leung, Huai-Na Qiu, Joyce Yin-Sau Chow, Angela On Kei Choi, Christopher Wai-Kei Lam
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0029815
Abstract: Background IL-31 is a pruritogenic cytokine, and IL-33 is an alarmin for damaging inflammation. They together relate to the pathogenesis of atopic dermatitis (AD). Eosinophil infiltration into the inner dermal compartment is a predominant pathological feature of AD. We herein investigated the in vitro inflammatory effects of IL-31 and IL-33 on the activation of human eosinophils and dermal fibroblasts. Methodology/Principal Findings Receptors, adhesion molecules and signaling molecules were assessed by Western blot or flow cytometry. Chemokines and cytokine were quantitated by multiplex assay. Functional IL-31 receptor component IL-31RA, OSMR-β and IL-33 receptor component ST2 were constitutively expressed on the surface of eosinophils. Co-culture of eosinophils and fibroblasts significantly induced pro-inflammatory cytokine IL-6 and AD-related chemokines CXCL1, CXCL10, CCL2 and CCL5. Such inductions were further enhanced with IL-31 and IL-33 stimulation. IL-31 and IL-33 could significantly provoke the release of CXCL8 from eosinophils and fibroblasts, respectively, which was further enhanced upon co-culture. In co-culture, eosinophils and fibroblasts were the main source for the release of CCL5, and IL-6, CXCL1, CXCL8, CXCL10 and CCL2, respectively. Direct interaction between eosinophils and fibroblasts was required for CXCL1, CXCL10, CXCL8 and CCL5 release. Cell surface expression of intercellular adhesion molecule-1 on eosinophils and fibroblasts was up-regulated in co-culture upon IL-31 and IL-33 stimulation. The interaction between eosinophils and fibroblasts under IL-31 and IL-33 stimulation differentially activated extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, nuclear factor-κB and phosphatidylinositol 3-kinase–Akt pathways. Using specific signaling molecule inhibitors, the differential induction of IL-31 and IL-33-mediated release of cytokines and chemokines such as IL-6 and CXCL8 from co-culture should be related to their distinct activation profile of intracellular signaling pathways. Conclusions/Significance The above findings suggest a crucial immunopathological role of IL-31 and IL-33 in AD through the activation of eosinophils-fibroblasts interaction via differential intracellular signaling mechanisms.
Numerical Study on Nonlinear Sound Propagation for Parametric Array  [PDF]
Kei Fujisawa
Journal of Flow Control, Measurement & Visualization (JFCMV) , 2014, DOI: 10.4236/jfcmv.2014.23014
Abstract: This paper presents the numerical study on the nonlinear sound propagation for the parametric array using the compressible form of Navier-Stokes equations combined with the mass and energy conservation equations and the state equation. These governing equations are solved by finite difference time domain (FDTD) based method. The numerical result is shown for the parametric sound propagation in the near field of the sound source in cylindrical coordinate. The result indicates the generation of low-frequency unsteady beat by the interaction of two frequency sound waves in the near field, which grows to a difference frequency sound in the far field.
Determinants of Health Expenditures: Stylized Facts and a New Signal  [PDF]
Kei Hosoya
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.513109
Abstract: This article further investigates the determinants of health expenditures by using aggregate data. Specifically, a panel data analysis of 25 OECD countries reveals that under several model specifications, the proxy for population ageing has no effect on health costs in accordance with recent findings. In contrast to this well-known result, an additional estimation conducted to check robustness revealed that the ageing variable becomes positive and significant. The significant effect may provide a new signal for a determinant of health expenditures. This result suggests that ageing is an important factor that cannot be ignored when considering variations in health expenditures.
Seeking a Better Recovery Process from Major Natural Disasters: A Lesson from Several Growth Models with Multiple Equilibria  [PDF]
Kei Hosoya
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.75103
Abstract: Based on several existing growth models with multiple steady states, this paper examines economic conditions that enable recovery from major natural disasters. We focus on recovery from the 2011 Great East Japan Earthquake and Tsunami. More concretely, we survey three recently released studies, which indicate that the sense of direction for expectation formation has the potential to play an important role in recovering from large natural disasters. We also find an inference that the big-push development scenarios that traditionally appear in developing economies have a low affinity with disaster reconstruction in developed countries. After a discussion of these equilibrium selections, this paper makes further reference to economic environments needed for a sustainable recovery path toward a superior long-run, steady-state equilibrium. This equilibrium allows interpreting the terminal of a series of recovery programs in our context.
Is Consumption in the United States and Japan Too Much or Too Little?  [PDF]
Yutaka Kurihara, Kei Tomimura
iBusiness (IB) , 2012, DOI: 10.4236/ib.2012.43029
Abstract: This article reports on the results of an empirical examination of whether consumption in the United States and Japan is too much or too little relative to productivity in these countries (1993-2011). Findings reveal some clear and common characteristics of both countries for the sample period. The most typical one occurred during financial crises around 2008, which is often called the Lehman shock. In both countries, consumers had considerably reduced consumption around that period. The IT boom collapse at the beginning of the 2000s also diminished consumption in the United States. This paper examines impulse responses to trace the effect of a productivity shock to one of the innovations on the current and future value of consumption. Findings indicate that the effect of the shock of productivity on consumption is long both countries
Nonlinear Acoustic Shadow Method to Reduce Reverberation Artifact  [PDF]
Kei Fujisawa, Akira Asada
Journal of Flow Control, Measurement & Visualization (JFCMV) , 2016, DOI: 10.4236/jfcmv.2016.42005
Abstract: A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this technique, the conventional acoustic shadow method is modified by using the secondary wave generated by nonlinear interaction of two primary sound waves emitted from parametric array. Either conventional or nonlinear acoustic shadow imaging is carried out for aluminum square cylinder and the size of the shadow is compared. The result shows that the nonlinear acoustic shadow method reduces reverberation artifact inside the square cylinder and has better accuracy in the size measurement than conventional acoustic shadow method.
Identification and Functional Analysis of Epigenetically Silenced MicroRNAs in Colorectal Cancer Cells
Hongli Yan,Ae-jin Choi,Byron H. Lee,Angela H. Ting
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0020628
Abstract: Abnormal microRNA (miRNA) expression has been linked to the development and progression of several human cancers, and such dysregulation can result from aberrant DNA methylation. While a small number of miRNAs is known to be regulated by DNA methylation, we postulated that such epigenetic regulation is more prevalent. By combining MBD-isolated Genome Sequencing (MiGS) to evaluate genome-wide DNA methylation patterns and microarray analysis to determine miRNA expression levels, we systematically searched for candidate miRNAs regulated by DNA methylation in colorectal cancer cell lines. We found 64 miRNAs to be robustly methylated in HCT116 cells; eighteen of them were located in imprinting regions or already reported to be regulated by DNA methylation. For the remaining 46 miRNAs, expression levels of 18 were consistent with their DNA methylation status. Finally, 8 miRNAs were up-regulated by 5-aza-2′-deoxycytidine treatment and identified to be novel miRNAs regulated by DNA methylation. Moreover, we demonstrated the functional relevance of these epigenetically silenced miRNAs by ectopically expressing select candidates, which resulted in inhibition of growth and migration of cancer cells. In addition to reporting these findings, our study also provides a reliable, systematic strategy to identify DNA methylation-regulated miRNAs by combining DNA methylation profiles and expression data.
Spurious and functional correlates of the isotopic composition of a generalist across a tropical rainforest landscape
Terrence P McGlynn, Hee K Choi, Stefanie T Mattingly, Angela Upshaw, Evan K Poirson, Justin Betzelberger
BMC Ecology , 2009, DOI: 10.1186/1472-6785-9-23
Abstract: We found that 75% of the variance in the fraction of 15N in the tissue of A. araneoides was accounted by one environmental parameter, the concentration of soil phosphorus. After taking into account landscape-scale variation in baseline resources, the most parsimonious model indicated that colony growth and leaf litter biomass accounted for nearly all of the variance in the δ15N discrimination factor, whereas the δ13C discrimination factor was most parsimoniously associated with colony size and the rate of leaf litter decomposition. There was no indication that competitor density or diversity accounted for spatial differences in the isotopic composition of gypsy ants.Across a 500 ha. landscape, soil phosphorus accounted for spatial variation in baseline nitrogen isotope ratios. The δ15N discrimination factor of a higher order consumer in this food web was structured by bottom-up influences - the quantity and decomposition rate of leaf litter. Stable isotope studies on the trophic biology of consumers may benefit from explicit spatial design to account for edaphic properties that alter the baseline at fine spatial grains.It is generally thought that stable isotope ratios vary across terrestrial landscapes. The extent of this spatial variation is enigmatic, and not explicitly built into the design of experiments wherein stable isotopes of carbon and nitrogen are employed to infer the trophic biology of consumers [1]. Typically, a landscape may be sampled broadly, with samples pooled together based on the assumption that baseline isotopic ratios will not vary appreciably within one kilometer (e.g., [2,3]). Nevertheless, to our knowledge there has been no study to test whether baseline stable isotope ratios are consistent across short distances. Moreover, no study has heretofore elucidated the contribution of spatial variation in isotope ratios to the isotopic variation in the tissue of consumers, relative to the effects of biotic factors shaping spatial patterns in isot
Quantum dot-induced cell death involves Fas upregulation and lipid peroxidation in human neuroblastoma cells
Angela O Choi, Sung Ju Cho, Julie Desbarats, Jasmina Lovri?, Dusica Maysinger
Journal of Nanobiotechnology , 2007, DOI: 10.1186/1477-3155-5-1
Abstract: We show here that QD surface modifications with N-acetylcysteine (NAC) alter QD physical and biological properties. In human neuroblastoma (SH-SY5Y) cells, NAC modified QDs were internalized to a lesser extent and were less cytotoxic than unmodified QDs. Cytotoxicity was correlated with Fas upregulation on the surface of treated cells. Alongside the increased expression of Fas, QD treated cells had increased membrane lipid peroxidation, as measured by the fluorescent BODIPY-C11 dye. Moreover, peroxidized lipids were detected at the mitochondrial level, contributing to the impairment of mitochondrial functions as shown by the MTT reduction assay and imaged with confocal microscopy using the fluorescent JC-1 dye.QD core and surface compositions, as well as QD stability, all influence nanoparticle internalization and the consequent cytotoxicity. Cadmium telluride QD-induced toxicity involves the upregulation of the Fas receptor and lipid peroxidation, leading to impaired neuroblastoma cell functions. Further improvements of nanoparticles and our understanding of the underlying mechanisms of QD-toxicity are critical for the development of new nanotherapeutics or diagnostics in nano-oncology.Neuroblastoma is the most frequently occurring extracranial solid tumour in children, accounting for 9% of all childhood cancers, with poor prognosis [1]. This malignant tumour arises from neuroepithelial cells of the sympathetic nervous system early in development, and is typically found in the adrenal medulla, abdomen, chest or neck [2]. Neuroblastoma, however, remains a therapeutic challenge as current surgical and chemical treatments are insufficient to prevent tumour recurrence, metastasis and progression [3]. Accurate disease staging is critical for appropriate therapeutic intervention, but existing imaging tools are still lacking in early and accurate diagnosis [4].The introduction of nanoparticles in the field of cancer research has recently improved diagnosis, targeting and
Women entrepreneurship in Romania
Angela ON
Revista Romana de Economie , 2011,
Abstract: Considering entrepreneurship the domain with the greatest potential for creativity and innovation, any investigation on this field is recommended, in order to reveal new aspects that can influence the small enterprises development. From this point of view, female entrepreneurship represents an important source of innovation, only partially exploited or even forgotten.
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