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Dive into the research topics where Rumiko Murayama is active.

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Featured researches published by Rumiko Murayama.


Noise & Health | 2006

Salivary chromogranin A as a measure of stress response to noise.

Masamitsu Miyakawa; Toshihito Matsui; Hiroki Kishikawa; Rumiko Murayama; Iwao Uchiyama; Toshihiro Itoh; Takahiko Yoshida

Effects of noise on the secretion of salivary chromogranin A (CgA), which is considered to be a substitute measure of catecholamines, were investigated in a laboratory experiment. This study included 20 male subjects with normal hearing; their ages ranged from 21 to 24 years. Prior to the experiment, the subjects were asked to answer a questionnaire containing the 28-item General Health Questionnaire (GHQ-28) and Weinsteins noise sensitivity scale. White noise at 90 dB was presented to the subjects for 15 min with 15-minute-rest periods before and after noise exposure. It was shown that salivary CgA levels increased significantly during noise exposure and decreased immediately after it (Friedmans test, p = 0.001, two tailed). This result suggests that salivary CgA can be used to measure the stress response to noise. Furthermore, individual differences in the change in salivary CgA levels were discussed in relation to the subjective responses of the participants to the questionnaire. Some subjects showed prolonged elevation in the salivary CgA levels and the others showed immediate recovery or no effects. These individual differences correlated with the score on the somatic symptoms in GHQ-28; this implies that the score on the somatic symptoms in GHQ-28 could be a measure of physiological sensitivity to noise.


Journal of Applied Toxicology | 2014

Effects of Asian sand dust particles on the respiratory and immune system.

Akiko Honda; Yugo Matsuda; Rumiko Murayama; Kenshi Tsuji; Masataka Nishikawa; Eiko Koike; Seiichi Yoshida; Takamichi Ichinose; Hirohisa Takano

Epidemiologic studies have reported that Asian sand dust (ASD) particles can affect respiratory health; however, the mechanisms remain unclear. We investigated the effects of ASD on airway epithelial cells and immune cells, and their contributing factors to the effects. Human airway epithelial cells were exposed to ASD collected on 1–3 May (ASD1) and on 12–14 May (ASD2) 2011 in Japan and heat‐treated ASD1 for excluding heat‐sensitive substances (H‐ASD) at a concentration of 0, 3, 30 or 90 µg ml–1 for 4 or 24 h. Furthermore, bone marrow‐derived dendritic cells (BMDC) from atopic prone mice were differentiated by culture with granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) then these BMDC were exposed to the ASD for 24 h. Also splenocytes as mixture of immune cells were exposed to the ASD for 72 h. All ASD dose dependently reduced viability of airway epithelial cells. Non‐heated ASD showed a dose‐dependent increase in the protein release of interleukin (IL)‐6 and IL‐8. The raises induced by ASD1 were higher than those by ASD2. ASD1 and ASD2 also elevated ICAM‐1 at the levels of mRNA, cell surface protein and soluble protein in culture medium. In contrast, H‐ASD did not change most of these biomarkers. Non‐heated ASD showed enhancement in the protein expression of DEC205 on BMDC and in the proliferation of splenocytes, whereas H‐ASD did not. These results suggest that ASD affect airway epithelial cells and immune cells such as BMDC and splenocytes. Moreover, the difference in ASD events and components adhered to ASD can contribute to the health effects. Copyright


International Journal of Toxicology | 2015

Effects of Air Pollution-Related Heavy Metals on the Viability and Inflammatory Responses of Human Airway Epithelial Cells

Akiko Honda; Kenshi Tsuji; Yugo Matsuda; Tomohiro Hayashi; Wataru Fukushima; Takahiro Sawahara; Hitomi Kudo; Rumiko Murayama; Hirohisa Takano

Various metals produced from human activity are ubiquitously detected in ambient air. The metals may lead to induction and/or exacerbation of respiratory diseases, but the significant metals and factors contributing to such diseases have not been identified. To compare the effects of each metal and different oxidation states of metals on human airway, we examined the viability and production of interleukin (IL)-6 and IL-8 using BEAS-2B cell line, derived from human airway epithelial cells. Airway epithelial cells were exposed to Mn2+, V4+, V5+, Cr3+, Cr6+, Zn2+, Ni2+, and Pb2+ at a concentration of 0.5, 5, 50, or 500 μmol/L for 24 hours. Mn and V decreased the cell viability in a concentration-dependent manner, and V5+ tended to have a greater effect than V4+. The Cr decreased the cell viability, and (Cr+6) at concentrations of 50 and 500 μmol/L was more toxic than (Cr+3). Zn at a concentration of 500 μmol/L greatly decreased the cell viability, whereas Ni at the same concentration increased it. Pb produced fewer changes. Mn and Ni at a concentration of 500 μmol/L induced the significant production of IL-6 and IL-8. However, most of the metals including (V+4, V+5), (Cr+3, Cr+6), Zn, and Pb inhibited the production of both IL-6 and IL-8. The present results indicate that various heavy metals have different effects on toxicity and the proinflammatory responses of airway epithelial cells, and those influences also depend on the oxidation states of the metals.


Toxicology Mechanisms and Methods | 2014

Effects of hydrogen peroxide on mucociliary transport in human airway epithelial cells.

Akiko Honda; Rumiko Murayama; Yugo Matsuda; Kenshi Tsuji; Takahiro Sawahara; Wataru Fukushima; Tomohiro Hayashi; Akinori Shimada; Hirohisa Takano

Abstract The effects of environmental pollutants on airway clearance have not been well elucidated. This study examined mucociliary transport using different sized-fluorescent particles on polarized human airway epithelial cells which were maintained in an air–liquid interface (ALI) culture system. The effects of hydrogen peroxide (H2O2) exposure on mucociliary transport were also investigated. The movement of fluorescent particles with diameters of 10–14 and 2.5–4.5 µm was observed by fluorescent microscopy as an index of the mucociliary transport. The mixture of the particles with two different sizes was propelled concentrically on the apical surface by the interaction of ciliary activity and mucus in the control condition, whereas H2O2 exposure for 24 h significantly inhibited the movement of the particles. The particle sizes did not affect their movement after the control or H2O2 exposure. These results suggest that particle tracking on polarized human airway epithelial cells is a useful experimental tool for the evaluation of the effect of environmental pollutants on mucociliary transport. In addition, reactive oxygen species may impair mucociliary transport, leading to the airway damage and exacerbation of respiratory diseases.


Allergologia Et Immunopathologia | 2015

Effects of cedar pollen extract on the immune system in vitro.

Wataru Fukushima; Akiko Honda; Rumiko Murayama; Yugo Matsuda; Kenshi Tsuji; Tomohiro Hayashi; Takahiro Sawahara; S. Ozawa; Yoshio Okamoto; Hirohisa Takano

1. Orange JS, Ochs HD, Cunningham-Rundles C. Prioritization of evidence-based indications for intravenous immunoglobulin. J Clin Immunol. 2013;33:1033--6. 2. Fernández-Cruz E, Sánchez-Ramón S, García R, Gil J, Carbone J, Durán E, et al. Guía de las indicaciones del uso terapéutico de las inmunoglobulinas intravenosas. In: Fernández-Cruz E, editor. Avances en inmunomodulación de las patologías inmunológicas. Letramédica SCP; 2011. p. 79--111. 3. Kaveri SV, Maddur MS, Hegde P, Lacroix-Desmazes S, Bayry J. Intravenous immunoglobulins in immunodeficiencies: more than mere replacement therapy. Clin Exp Immunol. 2011;164 Suppl. 2:2--5. 4. Carbone J. Adverse reactions and pathogen safety of intravenous immunoglobulin. Curr Drug Saf. 2007;2:9--18.


Experimental Biology and Medicine | 2013

Streamer discharge reduces pollen-induced inflammatory responses and injury in human airway epithelial cells:

Akiko Honda; Rumiko Murayama; Kenshi Tsuji; Yugo Matsuda; Eiko Koike; Yoshio Okamoto; Nobuyuki Shirasawa; Hirohisa Takano

Although epidemiological studies have demonstrated that cedar pollen influences respiratory health, effective method for inactivating cedar pollen has not been established. Streamer discharge is a type of plasma discharge in which high-speed electrons collide with oxygen and nitrogen molecules. It reportedly has the ability to eliminate bacteria, mould, chemical substances and allergens. The present study investigated the influence of pollen on BEAS-2B cell line, derived from human airway epithelial cells, as well as the efficiency of streamer discharge on pollen-induced health effects. Airway epithelial cells were exposed to non-treated pollen and streamer-discharged pollen at doses of 100 and 1000 μg/mL for 6 or 24 h. Non-treated pollen at a dose of 1000 μg/mL significantly decreased cell viability and induced both mRNA and protein expression of interleukin-6, whereas streamer-discharged pollen showed the attenuated changes as compared with non-treated pollen. Further, scanning electron micrographs showed that streamer discharge caused the fine structural changes of pollen. These results provide the first experimental evidence that pollen at a high dose affects cell viability and inflammatory responses, and streamer discharge technology attenuates their influences by decomposing pollen.


Journal of Environmental Chemistry | 1997

Mutagenicity and PAH Contents of the Heavy Oil that Drifted Ashore on the Coast from the Tanker Nakhodka

Sumio Goto; Shigeru Mineki; Kazutoshi Sugita; Osamu Endo; Rumiko Murayama; Iwao Uchiyama; Motohiro Tanaka; Kazuichi Hayakawa


The journal of the INCE of Japan | 2004

Residents' Opinions on the Environmental Quality Standards for Indoor Noise

Masamitsu Miyakawa; Toshihito Matsui; Satoru Uenoyama; Rumiko Murayama; Iwao Uchiyama


Japanese Journal of Risk Analysis | 2010

Necessity of Risk Communication on Contaminated Site

Aiichiro Fujinaga; Rumiko Murayama; Iwao Uchiyama; Hiroki Kishikawa; Nahoko Nakaune


Journal of UOEH | 2006

Measurements of exposure concentrations of benzene, toluene and xylene, and amounts of respiratory uptake.

Rumiko Murayama; Sumio Goto; Daisuke Nakajima; Hidekazu Fujimaki; Ikuo Watanabe; Keiichi Arashidani; Iwao Uchiyama

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Masamitsu Miyakawa

Kibi International University

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