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Biomedical subjects

Y Okano

Publications and source records attributed to Y Okano.

351 records · Page 20Linked to original sources
PubMedDate not supplied

Microfissure between the round window niche and posterior canal ampulla.

The microfissure between the round window niche and the posterior canal ampulla was examined in fetal, child, and adult human temporal bones. The communication which was filled with mesenchymal tissue and blood vessels extending from the middle ear, was observed between the round window niche and the posterior canal ampulla in 10 to 15-week human fetuses. The mesenchymal tissue in the communication was replaced by cartilage with advancing age of the fetus. No communication was observed at birth. From newborn to 12 months of age, no microfissure was observed. After one year of age, the microfissure was first observed and the frequency of the observation increased with increasing age of the patient. After six years of age, the microfissure was observed bilaterally in 100% of cases studied. The microfissure has its origin from the communication between the round window niche and the posterior canal ampulla in fetal life, and is a normal developmental and anatomical structure, and not a pathological finding.

Adolescent↗
PubMedDate not supplied

Crista neglecta in man.

The prevalence, location, and size of the crista neglecta in man were investigated by examining the histological sections of 223 human temporal bones (137 cases). The relationship between the crista neglecta and the singular nerve was also described. The crista neglecta was observed in 17 cases, ranging in age from 15-week fetal life to 76 years. This structure was located on the wall of the anterolateral quadrant of the posterior canal ampulla, close to the cribriform area of the singular nerve in the area between the utriculoampullar duct and the intermediate portion of the posterior canal crista. The average width, length, and height of the crista neglecta were described. The crista neglecta had a mound-like shape and contained nerve fibers, transitional epithelium, sensory hair cells, and a cupula. The nerve fibers from the crista neglecta were joined to a small branch of the singular nerve at the cribriform area in 5 of 17 crista neglecta cases, and to the main trunk of the singular nerve in the remaining 12 cases.

Aged↗
PubMedDate not supplied

Branch of the singular nerve (posterior ampullary nerve) in the otic capsule.

The frequency of occurrence, location and course of the branch of the singular nerve in the otic capsule in man was investigated by examining the histological sections of 223 human temporal bones. In the proximal portion near the internal auditory meatus the branch of the singular nerve was observed in 194 bones (87%), and was seen to join the main trunk of the singular nerve in 181 of those bones. In the distal portion near the posterior semicircular canal ampulla in 58 bones (26%) and in 45 of those bones it was seen to arise directly from the main trunk of the singular nerve. In 13 bones the branch was seen taking its course in the otic capsule independently from the main trunk all the way to the posterior canal crista. The accessory portion of the branch of the singular nerve reached the dura mater of the posterior cranial fossa near the internal auditory meatus in 11 of 223 bones.

Adolescent↗
PubMedDate not supplied

Temporal bone histopathology of necrotizing external otitis. A case report.

Histopathological examination of the temporal bone of an individual with necrotizing external otitis revealed severe inflammation with necrosis in the subcutaneous granulation tissue in the external auditory canal. Erosion of the bony walls of the canal had created a defect in the anterior wall, through which infection spread to the preauricular region. The lateral part of the middle ear cavity was also filled with granulation tissue and purulent exudate. A dehiscence of the horizontal portion of the facial canal had apparently allowed spread of an inflammatory round cell infiltrate along the facial nerve up to the fundus of the internal auditory canal. The only evidence of inner ear pathology was the presence of eosinophilic fluid material in the perilymphatic spaces of the labyrinth. A review of other reports of cases of necrotizing external otitis seems to show that this is the only instance of this disease in which infection spread from the external canal through the tympanic membrane to the middle ear and thence to the internal auditory canal.

Aged↗
PubMedDate not supplied

Sonodynamically induced cell damage with 4'-O-tetrahydropyranyladriamycin, THP.

BACKGROUND: 4'-O-tetrahydropyranyladriamycin (THP) is a novel anthracycline derivative with cardiotoxicity significantly lower than ADM. In this study, the ultrasonically induced in vitro cell damaging effect of THP was investigated. MATERIALS AND METHODS: Sarcoma 180 cells suspended in air-saturated PBS were exposed to ultrasound for up to 60 s in the presence and absence of THP. The viability of the isolated cells was determined by staining of the cells with Trypan Blue dye. RESULTS: The rate of inducing cell damage with ultrasound was doubled with 80 microM THP, while no cell damage was observed with THP alone. CONCLUSION: The enhancement of ultrasonically induced in vitro cell damage was demonstrated with THP. This enhancement was significantly inhibited by histidine, which may suggest a sonochemical mechanism.

Animals↗
PubMedDate not supplied

Effect of N-acetylneuraminic acid on respiratory tract secretion and inflammation in the bronchitic rabbit.

Long-term exposure of rabbits to SO2 gas caused the following changes in the respiratory tract system: decreases in the respiratory rate and pO2 blood level; an increase in the viscosity of sputum associated with increases in protein, unsaturated phosphatidylethanolamine and sphingomyelin; subacute rhinitis, tracheitis and multiple bronchopneumonia. Pretreatment with repeated administrations (inhalations) of N-acetylneuraminic acid remarkably prevented these inflammatory changes. The significance of this finding is discussed.

Animals↗
PubMedDate not supplied

The effect of N-acetylneuraminic acid on the mucociliary transport impaired by cigarette smoke.

Cigarette smoke exposure impaired the mucociliary transport on the tracheal mucosa of pigeons. N-acetylneuraminic acid (NANA), but not lactose, dose-dependently protected against the impairment of the mucociliary transport. The results suggest that NANA, a representative sialic acid existing on the airway epithelium, may participate the defence mechanism in the respiratory tract against irritant gases.

Animals↗