114 research outputs found

    Suppressive activity of tiotropium bromide on matrix metalloproteinase production from lung fibroblasts in vitro

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    Kazuhito Asano1, Yusuke Shikama2, Yasuhiro Shibuya2, Hiroaki Nakajima2, Ken-ichi Kanai3, Naohiro Yamada3, Harumi Suzaki31Division of Physiology, School of Nursing and Rehabilitation Sciences; 2Respiratory Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan; 3Department of Otolaryngology, School of Medicine, Showa University, Tokyo, JapanBackground: Chronic obstructive pulmonary disease (COPD) is characterized by airway remodeling with an accumulation of inflammatory cells. There is also increasing evidence that metalloproteinases (MMPs) may contribute to the pathogenesis of COPD, but the influence of agents that used for the treatment of COPD is not well understood.Objective: We evaluated whether tiotropium bromide hydrate (TBH), a M3 muscarinic receptor antagonist, could inhibit MMP production from lung fibroblasts (LFs) in response to tumor necrosis factor (TNF)-α stimulation.Methods: LFs were established from normal lung tissues taken from patients with lung tumors. LFs (5 × 105 cells/ml) were stimulated with TNF-α in the presence of various concentrations of TBH. After 24 h, culture supernatants were obtained and assayed for the levels of MMPs and tissue inhibitor of metalloproteinases (TIMPs) by ELISA. The influence of TBH on mRNA expression of MMPs and TIMPs in 4 h-cultured cells was also examined by real-time RT-PCR. Furthermore, nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) in LFs treated with TBH for 4 h was examined by ELISA.Results: TBH at more than 15 pg/ml inhibited the production of MMP-2 from LFs after TNF-α stimulation, whereas TIMP-1 and TIMP-2 production was scarcely affected by TBH through the suppression of both mRNA expression and transcription factor, NF-κB, activation in LFs induced by TNF-α stimulation.Conclusion: These results suggest that the attenuating effect of TBH on MMP-2 production from LFs induced by inflammatory stimulation may be additional beneficial therapeutic effects not directly relating to its bronchodilatory effects.Keywords: tiotropium, lung fibroblasts, matrix metalloproteinases, suppression, in vitr

    Multicascade-linked synthetic wavelength digital holography using an optical-comb-referenced frequency synthesizer

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    Digital holography (DH) is a promising method for non-contact surface topography because the reconstructed phase image can visualize the nanometer unevenness in a sample. However, the axial range of this method is limited to the range of the optical wavelength due to the phase wrapping ambiguity. Although the use of two different wavelengths of light and the resulting synthetic wavelength, i.e., synthetic wavelength DH, can expand the axial range up to a few tens of microns, this method is still insufficient for practical applications. In this article, a tunable external cavity laser diode phase-locked to an optical frequency comb, namely, an optical-comb-referenced frequency synthesizer, is effectively used for multiple synthetic wavelengths within the range of 32 um to 1.20 m. A multiple cascade link of the phase images among an optical wavelength (= 1.520 um) and 5 different synthetic wavelengths (= 32.39 um, 99.98 um, 400.0 um, 1003 um, and 4021 um) enables the shape measurement of a reflective millimeter-sized stepped surface with the axial resolution of 34 nm. The axial dynamic range, defined as the ratio of the maximum axial range (= 0.60 m) to the axial resolution (= 34 nm), achieves 1.7*10^8, which is much larger than that of previous synthetic wavelength DH. Such a wide axial dynamic range capability will further expand the application field of DH for large objects with meter dimensions.Comment: 19 pages, 7 figure

    A Ly-alpha Emitter with an Extremely Large Rest-frame Equivalent Width of ~900A at z=6.5: A Candidate of Population III-dominated Galaxy?

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    We have identified a very interesting Ly-alpha emitter, whose Ly-alpha emission line has an extremely large observed equivalent width of EW_0=436^{+422}_{-149}A, which corresponds to an extraordinarily large intrinsic rest-frame equivalent width of EW_0^{int}=872^{+844}_{-298}A after the average intergalactic absorption correction. The object was spectroscopically confirmed to be a real Ly-alpha emitter by its apparent asymmetric Ly-alpha line profile detected at z=6.538. The continuum emission of the object was definitely detected in our deep z'-band image; thus, its EW_0 was reliably determined. Follow-up deep near-infrared spectroscopy revealed emission lines of neither He II lambda1640 as an apparent signature of Population III, nor C IV lambda1549 as a proof of active nucleus. No detection of short-lived He II lambda1640 line is not necessarily inconsistent with the interpretation that the underlying stellar population of the object is dominated by Population III. We found that the observed extremely large EW_0 of the Ly-alpha emission and the upper limit on the EW_0 of the He II lambda1640 emission can be explained by population synthesis models favoring a very young age less than 2-4Myr and massive metal-poor (Z<10^{-5}) or even metal-free stars. The observed large EW_0 of Ly-alpha is hardly explained by Population I/II synthesis models with Z>10^{-3}. However, we cannot conclusively rule out the possibility that this object is composed of a normal stellar population with a clumpy dust distribution, which could enhance the Ly-alpha EW_0, though its significance is still unclear.Comment: 10 pages, 5 figures. Accepted for publication in Ap

    Dual-optical-comb spectroscopic ellipsometry

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    Spectroscopic ellipsometry is a means to investigate optical and dielectric material responses. Conventional spectroscopic ellipsometry has trade-offs between spectral accuracy, resolution, and measurement time. Polarization modulation has afforded poor performance due to its sensitivity to mechanical vibrational noise, thermal instability, and polarization wavelength dependency. We equip a spectroscopic ellipsometer with dual-optical-comb spectroscopy, viz. dual-optical-comb spectroscopic ellipsometry (DCSE). The DCSE directly and simultaneously obtains amplitude and phase information with ultra-high spectral precision that is beyond the conventional limit. This precision is due to the automatic time-sweeping acquisition of the interferogram using Fourier transform spectroscopy and optical combs with well-defined frequency. Ellipsometric evaluation without polarization modulation also enhances the stability and robustness of the system. In this study, we evaluate the DCSE of birefringent materials and thin films, which showed improved spectral accuracy and a resolution of up to 1.2x10-5 nm across a 5-10 THz spectral bandwidth without any mechanical movement.Comment: 30 pages, 4 figure

    Dual-comb spectroscopic ellipsometry

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    Spectroscopic ellipsometry is a means of investigating optical and dielectric material responses. Conventional spectroscopic ellipsometry is subject to trade-offs between spectral accuracy, resolution, and measurement time. Polarization modulation has afforded poor performance because of its sensitivity to mechanical vibrational noise, thermal instability, and polarization-wavelength dependency. We combine spectroscopic ellipsometry with dual-comb spectroscopy, namely, dual-comb spectroscopic ellipsometry. Dual-comb spectroscopic ellipsometry (DCSE). DCSE directly and simultaneously obtains the ellipsometric parameters of the amplitude ratio and phase difference between s-polarized and p-polarized light signals with ultra-high spectral resolution and no polarization modulation, beyond the conventional limit. Ellipsometric evaluation without polarization modulation also enhances the stability and robustness of the system. In this study, we construct a polarization-modulation-free DCSE system with a spectral resolution of up to 1.2 × 10−5 nm throughout the spectral range of 1514–1595 nm and achieved an accuracy of 38.4 nm and a precision of 3.3 nm in the measurement of thin-film samples
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