759 research outputs found

    The University of California, Irvine is INFAMOUS (Irvine\u27s New Financial Aid Management On-line University System)

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    Acute inflammatory response to contrast agent aspiration and its mechanisms in the rat lung.

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    Objectives/hypothesisContrast agent (CA) aspiration is an established complication of upper gastrointestinal and videofluoroscopic swallow studies. The underlying molecular biological mechanisms of acute response to CA aspiration in the respiratory organs remain unclear. The aims of this study were to elucidate the histological and biological influences of three kinds of CAs on the lung and to clarify the differences in acute responses.Study designAnimal model.MethodsEight-week-old male Sprague Dawley rats were divided into five groups (n = 6 in each group). Three groups underwent tracheal instillation of one of three different CAs: barium (Ba) sulfate, nonionic contrast agents (NICAs), and ionic contrast agents (ICAs). A control group was instilled with saline and a sham group was instilled with air. All animals were euthanized on day 2 after treatment and histological and gene analysis was performed.ResultsNo animal died after CA or control/sham aspiration. Ba caused severe histopathologic changes and more prominent inflammatory cell infiltration in the lungs compared with the two other iodinated contrast agents. Increases in expressions of inflammatory cytokines (tumor necrosis factor [Tnf], interleukin-1β [Il1b], and interferon-γ [Ifng]) were observed in Ba aspiration rats, and upregulation of Il1b was seen in ICA aspiration rats. NICA did not cause obvious histologic changes or expressions of inflammatory cytokines and fibrosis-related genes in the lungs.ConclusionsBa caused significantly more acute lung inflammation in a rodent model than did ioinic and nonionic iodinated CAs. Nonionic contrast did not cause any discernible inflammatory response in the lungs, suggesting that it may be the safest contrast for videofluoroscopic swallow studies.Level of evidenceNA Laryngoscope, 129:1533-1538, 2019

    Dose-Dependent Effects of Insulin-Like Growth Factor 1 in the Aged Olfactory Epithelium

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    Background: Olfaction is known to be impaired by aging. We hypothesized that insulin-like growth factor-1 (IGF-1) administered at an appropriate dose could prevent age-induced negative effects on olfactory receptor neurons (ORNs). We explored the effects of low- and high-dose administration of IGF-1 on the ORN cell system in aged mice and investigated the involvement of the cellular mechanisms of IGF-1 in the regeneration of ORNs in aged mice.Methods: We subcutaneously administered recombinant human IGF-1 (rhIGF-1) to 16-month-old male mice over 56 days, and then examined the histological effects of rhGF-1 on cellular composition, cell proliferation, and cell death in the aged olfactory epithelium (OE), by comparing among saline-treated and low- and high-dose rhIGF-1-treated mice.Results: Low-dose rhIGF-1 administration increased the numbers of olfactory progenitors, immature ORNs, and mature ORNs in the OE, despite an increase in Cas3+ apoptotic cells. Notably, high-dose rhIGF-1 administration increased the numbers of only immature ORNs, not olfactory progenitors and mature ORNs, with a concurrent increase in apoptotic cells.Conclusion: Our data suggest that in aged mice, IGF-1 administered at an appropriate dose could increase the number of mature ORNs and further human studies may contribute to the development of treatments for aging-related olfactory impairment

    A Single-Element Tuning Fork Piezoelectric Linear Actuator

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    This paper describes the design of a piezoelectric tuning-fork, dual-mode motor. The motor uses a single multilayer piezoelectric element in combination with tuning fork and shearing motion to form an actuator using a single drive signal. Finite-element analysis was used in the design of the motor, and the process is described along with the selection of the device\u27s materials and its performance. Swaging was used to mount the multilayer piezoelectric element within the stator. Prototypes of the 25-mm long bidirectional actuator achieved a maximum linear no-load speed of 16.5 cm/s, a maximum linear force of 1.86 N, and maximum efficiency of 18.9%

    タバコ煙と加齢が嗅神経上皮の恒常性維持に及ぼす影響に関する実験的研究

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    学位の種別: 論文博士審査委員会委員 : (主査)東京大学教授 高戸 毅, 東京大学准教授 中冨 浩文, 東京大学講師 狩野 章太郎, 東京大学講師 平田 陽一郎, 東京大学講師 槇野 陽介University of Tokyo(東京大学

    Reduced tubulin tyrosination as an early marker of mercury toxicity in differentiating N2a cells

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    The aims of this work were to compare the effects of methyl mercury chloride and Thimerosal on neurite/process outgrowth and microtubule proteins in differentiating mouse N2a neuroblastoma and rat C6 glioma cells. Exposure for 4 h to sublethal concentrations of both compounds inhibited neurite outgrowth to a similar extent in both cells lines compared to controls. In the case of N2a cells, this inhibitory effect by both compounds was associated with a fall in the reactivity of western blots of cell extracts with monoclonal antibody T1A2, which recognises C-terminally tyrosinated α-tubulin. By contrast, reactivity with monoclonal antibody B512 (which recognises total α-tubulin) was unaffected at the same time point. These findings suggest that decreased tubulin tyrosination represents a neuron-specific early marker of mercury toxicity associated with impaired neurite outgrowth

    冷凍保存骨芽細胞シートの骨形成能評価

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    Cryopreservation of tissue engineered bone (TEB), whilst maintaining its osteogenic ability, is imperative for large-scale clinical application. We previously reported a novel cell transplantation method, in which bone-marrow-derived mesenchymal stem cells (BMSCs) were cultured to confluence and differentiated down the osteogenic lineage to form osteogenic matrix cell sheets (OMCS). OMCS have high alkaline phosphatase (ALP) activity and osteocalcin (OC) contents and can be easily used for producing TEB. The aim of the present study was to investigate whether TEB produced by cryopreserved OMCS maintains sufficient osteogenic potential in vivo. OMCS were prepared and divided into three groups according to storage period of cryopreservation (fresh (no cryopreservation), 4 week and 12 week cryopreservation groups). OMCS were cryopreserved by storage in freezing medium (Cell Banker 1®) at -80 °C. Cryopreserved OMCSs were rapidly thawed at room temperature and wrapped around Hydroxyapatite (HA) scaffolds prior to implantation into subcutaneous sites in rats, to determine their in vivo bone-forming capability. The constructs were harvested 4 weeks after transplantation and examined histologically and biochemically. Histological analysis of the constructs showed extensive bone formation in the HA pores with high ALP activity and OC content detected in the cryopreservation groups. The present study clearly indicates that cryopreserved/thawed OMCS are still capable of producing mineralized matrix on scaffolds, resulting in bone formation. This cryopreservation technique could be applied for hard tissue reconstruction to ease the cell preparation method prior to time of use.博士(医学)・甲第607号・平成25年11月27

    骨欠損再建における培養細胞シートを併用した培養人工骨移植の有用性

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    AIM: To determine the effects of transplanting osteogenic matrix cell sheets and beta-tricalcium phosphate (TCP) constructs on bone formation in bone defects. METHODS: Osteogenic matrix cell sheets were prepared from bone marrow stromal cells (BMSCs), and a porous TCP ceramic was used as a scaffold. Three experimental groups were prepared, comprised of TCP scaffolds (1) seeded with BMSCs; (2) wrapped with osteogenic matrix cell sheets; or (3) both. Constructs were implanted into a femoral defect model in rats and bone growth was evaluated by radiography, histology, biochemistry, and mechanical testing after 8 wk. RESULTS: In bone defects, constructs implanted with cell sheets showed callus formation with segmental or continuous bone formation at 8 wk, in contrast to TCP seeded with BMSCs, which resulted in bone non-union. Wrapping TCP constructs with osteogenic matrix cell sheets increased their osteogenic potential and resulting bone formation, compared with conventional bone tissue engineering TCP scaffolds seeded with BMSCs. The compressive stiffness (mean ± SD) values were 225.0 ± 95.7, 30.0 ± 11.5, and 26.3 ± 10.6 MPa for BMSC/TCP/Sheet constructs with continuous bone formation, BMSC/TCP/Sheet constructs with segmental bone formation, and BMSC/TCP constructs, respectively. The compressive stiffness of BMSC/TCP/Sheet constructs with continuous bone formation was significantly higher than those with segmental bone formation and BMSC/TCP constructs. CONCLUSION: This technique is an improvement over current methods, such as TCP substitution, and is useful for hard tissue reconstruction and inducing earlier bone union in defects.博士(医学)・乙第1366号・平成27年11月27日Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved. This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license,which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/ licenses/by-nc/4.0
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