Nobukazu Yamamoto

Measurement of the Mechanical Properties of the Tympanic Membrane with a Microtension Tester

The mechanical properties of guinea pig and human tympanic membranes were measured by a microtension tester newly developed by us. Guinea pig tympanic membranes were tested under various conditions. When the tensile rate was 4.17 x 10(-4) m.sec-1 fresh specimens were 8.8 times stronger for a tension applied parallel to the radial fibres than for that applied at a right angle to them. No difference in tensile strength was seen when the tension was applied at a right angle to the radial fibres. When the tensile direction was parallel to the radial fibres, the posterior part was stronger than the anterior part. Two human tympanic membranes were measured under formalin fixation. The measured values were calculated into those of the fresh specimens based on the results of the guinea pig material. The adjusted values for fresh human specimens were 2.56 kgf.mm-2 at a right angle to the radial fibres and 3.28 kgf.mm-2 parallel to them. Applying the thin cylinder and shell theory, the breakage pressure of the human tympanic membrane was calculated to be 1.02-22.4 atmospheric pressure.

The Physical Strength of the Membranous Labyrinth and Its Relation to Endolymphatic Hydrops

Pathological findings of Meniere’s disease were first reported by Hallpike and Cairns [1]. The main finding was an enlarged endolymphatic space of the cochlear duct and saccule which was called “endolymphatic hydrops.” Subsequent histopathological studies on temporal bones with Meniere’s disease have confirmed the presence of endolymphatic hydrops in the cochlea and saccule, although some investigators reported enlargement of the utricle or deformity of the semicircular canal [2, 3].

Mechanical Properties of Membranous Labyrinths Measured with a Microtension Tester

Mechanical properties of the semicircular canals of guinea pigs, frogs and water fishes, and of human membranous labyrinths were tested. Tensile strength of the semicircular canals of guinea pig, frog and water fish was greater in the order of guinea pig, frog and fish. In the human membranous labyrinth, the saccular membrane was the weakest, followed by Reissners membrane, the utricular membrane and the semicircular canal. These values were converted from tensile strength to breakage pressure. The breakage pressure of the saccular membrane was 64.0 mmHg.

Investigation of Treatment Results of Iaryngeal Carcinoma at Our Departments

1981年から1988年の8年間に当科で一次治療を行った喉頭癌104症例の治療成績を検討した。男女別では男性97人, 女性7人で, 圧倒的に男性に多かった。発生部位別では声門上癌は28例で, これは比較的進行例が多かった。声門癌は76例で, 反対に比較的早期例が多かった。治療成績は声門上癌で5年生存率51.8%, 喉頭保存率46.4%であった。声門癌では同様に5生率は85.1%, 喉保率は77.6%であった。死因は声門上癌は原病死が多く, 声門癌は他因死, 特に重複癌が多かった。したがって, 今回の検討では声門上癌の治療の徹底と重複癌監視のための計画的経過観察が必要であると思われた。