Hiroshi Ikeoka

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The recovery process of pathological changes in the respiratory mucosa following exposure to styrene were experimentally studied to improve the understanding of the respiratory toxicity of styrene. Thirty male SD rats were exposed to 150 ppm or 1000 ppm of styrene for 4 h a day over 3 weeks (5 days a week). They were killed for examination at 1 day or 12(More)
The toxicity of isopropyl alcohol (IPA) on the nasal mucosa in the guinea pig was experimentally studied, with special reference to the recovery process of the organ. The results showed that 400 ppm of IPA has an acute effect on the nasal mucosa and the recovery from such degeneration can occur in 2 weeks. When functional and morphological damages were(More)
Our previous investigation using normal guinea pigs disclosed that, like respiratory mucosa, the middle ear lining has ciliary activity, and that this ciliary activity becomes more active as the location becomes more distal to the eustachian tube. In this experimental study, the effects of Staphylococcus aureus on the middle ear lining was examined from(More)
Since the middle ear lining is an extension and a modification of the respiratory mucosa, it is conceivable that it has a mucociliary system and it plays an important role in clearance of the tympanic cavity. It was already noted in morphological studies that the middle ear lining had ciliated cells. To our knowledge, however, ciliary activity has never(More)
The ciliary activity in some pathological middle ear lining was discussed with special reference to the morphology of the epithelial cells in this paper. The changes in ciliary activity due to in vitro Staphylococcus aureus injection did not practically show any differences between the sites. On the other hand, the time-course changes in ciliary activity(More)
We studied the mucosal pathology present in the eustachian tubes of guinea pigs following exposure to sulfur dioxide. Secretory sthenia but with slight deterioration of ciliary activity was observed in the mucosal samples examined. Our data have shown that 24-h exposure to 300 ppm sulfur dioxide does not cause otitis media with effusion in the guinea pig(More)
Ten guinea pigs were irradiated with 30 Gy of x-radiation. Five were killed on the eighth day after irradiation, and the remainder were killed at the sixteenth day after irradiation. At the time of death, examination was made of the ciliary activity and the fine structure of the middle ear mucosa. Serous effusion was found in each tympanic cavity of all(More)
Radiation-induced changes in the ciliary activity of the eustachian tube and middle ear mucosa were investigated in a laboratory model. Twenty-four guinea pigs were sacrificed, and a mucosa at the bony portion of each eustachian tube and from the middle ear proximal and distal to the tube were sampled. The mucosal samples were irradiated with 200 kV hard(More)
Guinea pigs were exposed to 400 ppm or 5500 ppm of isopropyl alcohol (IPA) for 24 successive hours, and then middle ear mucosal samples in both proximal and distal sites to the eustachian tube were obtained for functional and morphological examinations. The ciliary activity was examined according to the photoelectric method of Ohashi and Nakai. The(More)
Single field, fixed irradiation of bilateral tympanic cavities using 200-kV x-rays was administered to five guinea pigs. The irradiation dose was 30 Gy. They were killed immediately after irradiation, and bilateral middle ear mucosa was examined for ciliary activity and epithelial structure. Significant deterioration of the ciliary activity in the middle(More)