Publications by authors named "Rumiko Murayama"

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 Weinstein's noise sensitivity scale.

View Article and Find Full Text PDF

With respect to benzene, toluene, and o-, m- and p-xylene contained in indoor air, this study determined the amounts of their uptake through the human respiratory system using the difference between concentrations in inhalation and exhalation, and examined their relationship to concentrations in blood and urine measured before and after exposure. At relatively high concentrations, respiratory absorption of these compounds tended to increase rapidly in the early stage of exposure but decrease after several hours. It was also confirmed that concentrations of these compounds in both blood and urine increased during the first 3 hours of exposure.

View Article and Find Full Text PDF

We investigated the relationships between neutrophil functions and lifestyle factors in the elderly. The subjects (84 males, 73.9+/-5.

View Article and Find Full Text PDF