Search

The influence on human equilibrium of positive and negative middle ear pressure was studied with a strain gauge platform and head position sensor system. The data obtained were digitalized and analysed by a microcomputer, Deviation of head and body sway center followed by eye closure was adopted as the parameter for the analysis. Three groups of people were examined; 1) patients with unilateral otitis media with effusion (OME), 2) normal volunteers, 3) patients with middle ear ventilation tubes on one side. Patients in group 1 were examined before and after the treatment of OME. Those in groups 2 and 3 were examined with positive or negative pressure applied on the ear randomly chosen (group 2), or on the ear with a ventilation tube inserted (group 3). The OME patients' head deviation to the affected side turned to the opposite side right after treatment. Head deviation similar to that of the untreated OME patients was observed when positive external earcanal pressure (group 2) or negative middle ear pressure was applied. The shift of the stapes' foot plate might be one of the causes of these head deviations. More studies are needed to clarify the mechanisms of disequilibrium produced by unusual middle ear pressure.

Varying survival rates have been reported for differentiated carcinoma of the thyroid gland. The rate, however, does progressively decrease over a longer period of time than the usually reported five-year survival rates. Significant local invasion outside the thyroid capsule and of blood vessels yields a poorer prognosis, and mortality is largely attributed to distant metastasis. To improve the long-term survival rate, 1) sharp dissection with ample safety margin including resection of the neighboring organs, 2) reconstruction of the sacrificed organs, if possible, and 3) postoperative prophylactic radioiodine therapy, were adopted for invasive well-differentiated carcinoma for a period of 10 years. Of the 191 well-differentiated carcinomas operated on, in a series of 486 consecutive thyroid operations, 33 patients underwent this prophylactic radioactive iodine therapy (dose amount up to 300 mCi) following ablative surgery including, in several patients, mediastinal dissection. Periodical whole body survey by sodium iodide 131I showing no signs of recurrence up to five years except in three patients indicating two suspected lung metastasis and one death from bone metastasis, demonstrated that this is a promising method for the treatment of invasive well-differentiated carcinoma of the thyroid gland, although further long-term analysis is required.

Middle ear cholesteatomas developed in dizygotic twins. In three of the four ears cholesteatomas developed as a result of longstanding otitis media with effusion. In the remaining ear, no cholesteatoma has been formed so far, in spite of severe eardrum retraction. The differences in the clinical course showed that not only Eustachian tube dysfunction but also blockade of the ventilation pathway between the mesotympanum and the epitympanum may play an important role in the development of cholesteatoma. High resolution CT is very useful in the diagnosis of this blockade. More dizygotic and monozygotic twins with cholesteatoma should be studied to decide whether hereditary factors have any significant influence on the occurrence of this disease.

段階的鼓室形成術での保存軟骨板の使用経験を報告した. 第一段階手術では, 鼓室腔形成材料としてシリコン板の代りに軟骨板を使用して, 含気性鼓室腔の確保が充分可能なことがわかった. 第二段階手術では, 鼓膜の術後陥凹防止とコルメラ保持の目的で軟骨板を使用するのが良い.

Ultra-thin oxides (5-12 nm) were nitrided by lamp-heated rapid thermal annealing in an ammonia ambient at 900-1150°C for 5-300 s. Interface states and fixed charges in the nitrided oxides have been studied, and, for a given temperature, both are found to vary in a similar manner as nitridation time increases: at first both increase, reach respective maxima at a certain nitridation time, and then decrease gradually showing turnarounds. Interface state densities and fixed charge densities at the initial and the final nitridation stages are in the low 1010- cm-2/eV range and the low 1011-cm-2range, respectively, and are comparable with those of thermally grown oxides.

The influence of middle ear pressure changes on the otolith organs was investigated in cats. The activits of both the primary and secondary vestibular neurons were influenced by middle ear pressure changes. More otolith neurons were influenced by middle ear pressures than semicircular canal neurons. Among the otolith neurons, those which were activated by lateral tilt were more sensitive to middle ear pressure than those which were activated by the nose up or the nose down position.

Ion implantation (i/i) technology is employed for silicon trench sidewall doping. The aspect ratio of trenches for high Mbit DRAM is very large (depth/width≥10), so that very small glancing‐angle i/i to sidewalls is necessary. In this case, reflected ions are large in number and are implanted to the opposite sidewall. It is very important to know the elemental depth profile in the opposite sidewall to understand the implantation mechanism. For the first time, we measured the depth profiles at several positions of the opposite trench sidewall by secondary‐ion mass spectroscopy for arsenic and boron ion implantations. It is found that reflected ions are distributed near the facing region of the directly implanted region with smaller energies than the primary energy. These findings are compared with the simulations based on the marlowe program.

The effect of oxygenation through the round window membrane was estimated using polarographic technique and the combined action potential of the inner ear. The calculated amount of oxygen permeable through the round window membrane (14% in room air and 80% in pure oxygen) revealed to have very limited effect in maintaining the inner ear potential. Carbogen inflation in maintaining the Nl potential during asphyxia was significantly effective only at 8 kHz. Oxygen supply by this route, however, may enable the inner ear tissue alive even in misery perfusion and recover the high tone potential as a therapy of otitis media with effusion.

We determined a complete nucleotide sequence of an activated form of the c-H-ras-1 proto-oncogene cloned from the human cell line (QG56), using the DNA transfection technique and NIH3T3 cells as recipients. This cell line was established from a squamous-cell lung carcinoma of a Japanese patient, and the activated gene had 2 nucleotide substitutions. One substitution of a thymidine for an adenosine was found at position 1069 of the 2898 nucleotide sequence in a restriction endonuclease (Sacl) fragment, which corresponds to the second base of the 61 st codon of the gene encoding P 21 protein. This nucleotide replacement was assumed to be responsible for the transforming activity. Another substitution of a guanosine for an adenosine which was detected at position 746 in the first intron was thought to be a genetic polymorphism unassociated with the transforming activity. Comparison of the various lengths of restricted fragments suggested that the activity was markedly influenced by certain sequences flanking the c-H-ras-1 gene.

Hemoglobin G Waimanalo, in which an asparagine residue is substituted for an aspartic acid at position 64 (E13) of the a-chains, was found in a Japanese family. The propositus was a 40-year-old man with normal hematological parameters. Electro-phoresis of the hemolysates on a cellulose acetate sheet detected a hemoglobin variant that migrated slower than Hb A. The relative mobility was -4.88 at pH 8.6 (1). The variant, Hb A2, and Hb F comprised 24.1%, 2.0%, and 1% of the total hemoglobins, respectively (2).

• Magnetic resonance (MR) imaging of the eustachian tube (auditory tube) was performed in normal subjects and in a patient with nasopharyngeal carcinoma. The MR images obtained in an anteriorly tilted transaxial plane parallel to the eustachian tubes were compared with serial slices of a cadaver specimen. The eustachian tube cartilage, mucous lining of the eustachian tube, the lateral pharyngeal recess, the tensor veli palatini muscle, and the levator veli palatini muscle were identified in MR images using anatomical relationships. A patient with nasopharyngeal carcinoma is described to demonstrate an example of topographical morbid changes appearing around the eustachian tube. ( Arch Otolaryngol Head Neck Surg 1987;113:1281-1284)

Magnetic resonance imaging (MRI) of the eustachian tube, the nasopharynx, and the middle ear was performed in normal subjects and patients with ear diseases. In normal subjects, the high soft tissue contrast resolution of MRI gave a clearer view of nasopharyngeal structures compared to roentogenologic examinations including computed tomography (CT). Severar cases of nasopharyngeal pathology are also presented. Nasopharyngeal carcinoma was excelmently depicted, and its margin was clearly visualized. Tumor involvement of the eustachian tube and accompanying otitis media with effusion were clearly visualized. In a patient with submucous cleft palate, abnormal arrangement of levator veli palatini muscles and possible deformity of the eustachian tube cartilage were found. Magnetic resonance imaging is expected to become a valuable tool for the diagnosis of nasopharyngeal and middle ear diseases.

The origin of the hyperintense signal (HIS) of the pituitary gland posterior lobe (PL) on T1-weighted magnetic resonance (MR) images was investigated. Six rabbits were imaged on a 1.5 T device before and after 2 weeks' feeding of hypertonic saline solution (phase I). Two were killed soon after the second imaging; the pituitary gland was examined histochemically for neurosecretory granules containing antidiuretic hormone (ADH). The other four rabbits were given regular water for another 2 weeks (phase II) and then were again imaged. The plasma ADH level was monitored at each imaging session. In all subjects, the signal intensity of the PL decreased at the end of phase I, and the HIS reappeared at the end of phase II. The neurosecretory granules in the PL significantly diminished in number in phase I. Plasma ADH levels significantly increased in phase I and returned to their normal range in phase II. These clear correlations between MR findings and hormonal and histochemical results strongly suggest that the source of the HIS of the PL is the neurosecretory granules containing ADH.

Images of the eustachian tube from various directions were obtained using computer graphics. Serial cross sections of a human temporal bone specimen including the eustachian tube were digitized for reconstruction. Wire-frame models of the structures such as the eustachian tube lumen, the tubal cartilage, the tensor vell palatini muscle, and the levator veli palatini muscle were drawn. Through observation of the eustachian tube from various directions with the tubal muscles attached or detached, the physiology of the eustachian tube system could be understood more clearly.

In a Japanese family several members in three generations had, on hemoglobin analysis, typical findings of heterozygous beta-thalassemia. However, hemoglobin concentrations, red cell morphology, splenic size and clinical histories indicated that the disorder was more severe than in the usual beta-thalassemia trait. From the previous and the present studies folic acid supplements appeared to be beneficial in ameliorating the anemia. The findings may provide an apparent pathophysiologic and genetic explanations for the more severe anemia and red-cell abnormalities present in a small proportion of families with beta-thalassemia trait.

To reveal the interaction between the motor speech areas and the auditory areas during vocalization, brain activity during reading tasks was examined using Positron Emission Tomography (PET). The regional cerebral blood flow (rcBF) of six normal subjects was measured at rest, while reading everyday sentences silently, and while reading aloud. Regions of interest (ROIs) were set on the primary auditory area, the auditory association area, Broca's area, the motor area, the supplementary motor area (SMA) and the cerebellum. We subtracted rcBF data in ROIs during resting from those during each reading task, and evaluated the areas in which rcBF increased during each task. During silent reading, Broca's area, the SMA, and the cerebellum were activated bilaterally. During reading aloud, the primary auditory area, Broca's area, the motor area, the SMA, and the cerebellum were activated bilaterally, but the auditory association areas were not activated, even though the subjects heard their own voice. These results suggest that the activity of the auditory association area is suppressed when vocalizing everyday sentences. They also show a reasonable interaction between the motor speech areas and the auditory areas during vocalization.

The electromigration resistance of ultra-large scale integration (ULSI) Cu interconnects can be improved by inserting an adhesion promoter between Cu and the diffusion barrier. A metallurgical survey was accomplished to select the element having a good Cu adhesion property. For adoption as an interconnect material, it should have a low resistivity and should not react with Cu to avoid increasing the resistance of Cu interconnects. Ru, Os, Mo, W, and Ta satisfied the above conditions. The Cu adhesion property of these elements was estimated by the lattice misfit concept. The Cu adhesion property was experimentally examined and compared hcp elements (Ru and Os), which have a good matching interface with fcc Cu, with the bcc elements (Mo and Ta). Ru and Os, which had lower lattice misfit values, showed a better adhesion property than the bcc elements having higher lattice misfit values. Among these elements, Ru had the best Cu adhesion property and thus it can be an optimum glue layer element for Cu interconnects.

To elucidate cortical correlates of vestibulo-ocular reflex (VOR) modulation, we observed cortical activation during fixation suppression and habituation of caloric vestibular nystagmus in 12 normal subjects, using PET. Significant positive correlation between regional cerebral blood flow (rCBF) and slow phase eye velocity of caloric nystagmus was observed in the middle and posterior insula, inferior parietal lobule, temporal pole, right fusiform gyrus, lingual gyrus, and cerebellar vermis and hemisphere. The rCBF increase in the insular region and the inferior parietal lobule was lateralized depending on the direction of the nystagmus. Caloric nystagmus was suppressed as a result of visual fixation, during which time the area around the right frontal eye field, temporal pole, inferior temporal gyrus, a broad area in the visual cortex, including fusiform and lingual gyrus, cerebellar uvula/nodulus and flocculus, exhibited positive correlation with fixation suppression of caloric nystagmus, while vestibular cortices exhibited negative correlation. The caloric nystagmus habituated with repetition of stimulation. With habituation, we observed activation in the right anterior cingulate gyrus, left superior parietal lobule and right cuneus, and deactivation in the anterior insula, cingulate gyrus, inferior parietal lobule and occipito-temporal visual cortex. The region that showed significant co-activation with fixation suppression and habituation of caloric nystagmus was the right cuneus, and significant co-deactivation was observed in the anterior insula, cingulate gyrus, inferior parietal lobule and middle temporal visual cortex. The present results support previous observations that the parieto-insular cortex and inferior parietal lobule are involved in processing of vestibular information, and, in addition, suggest that activation may depend on the direction of nystagmus. Deactivation of vestibular cortices during visual fixation supports the concept of inhibitory visual-vestibular interaction in the cortex. Significant activation of the cingulate, superior parietal and visual cortices, and cerebellar vermis accompanying reduction of caloric response with repeated stimuli suggests possible involvement of these regions in vestibular habituation. Common activation of the cuneus in visual cortex and deactivation of vestibular and visuo-spatial association cortices by both visual suppression and habituation of VOR suggests that these two mechanisms are not completely independent but may share some cortical and subcortical regions.

To elucidate cortical processing during vocalization, we used positron emission tomography to measure regional cerebral blood flow during vocalization in six Japanese subjects. During reading Japanese sentences used daily or short syllables aloud, the visual cortices, the left Heschl's gyrus, Broca's area, the primary motor area of the articulatory organs, the supplementary motor area and the cerebellum were significantly activated, compared with resting conditions. The superior temporal gyri were rarely activated. Significant activation of the cerebellum was observed by comparing cortical activity during reading sentences used daily with that during reading meaningless short syllables. These results suggest that vocalization of familiar materials is taken over by the cerebellum, rather than cortical speech areas, and without engagement of the superior temporal gyri.

A new resonator method for measuring the ultrasonic absorption in liquids at low frequency range below 1 MHz is proposed. The resonator is composed of a quartz transducer and a concave reflector with a very slight curvature, which successfully reduces the diffraction effect at low frequencies. The standing wave in the resonator filled with the test liquid is optically detected and the resonance spectrum yields the ultrasonic absorption. The usefulness of this apparatus is demonstrated by measuring absorption in water and benzene over the frequency range 300 kHz–10 MHz.

Very thin oxides in nm range were nitrided by lamp heated rapid thermal annealing in an ammonia ambient. The nitrided oxides were studied using Auger electron spectroscopy, angular resolved x‐ray photoelectron spectroscopy, secondary ion mass spectroscopy, and electrical metal–insulator–semiconductor (MIS) characterization. It is found by Auger depth profiling that the thickness of the oxide film does not increase by nitridation. The hydrogen concentration increases monotonically as nitridation proceeds. In the early stages of nitridation, nitrogen piles up at SiOxNy/Si interface and in the final stages it distributes uniformly throughout the film. Fixed charge and interface state densities increase with nitrogen concentration at the interface up to a critical nitrogen concentration (about 9%). Beyond this value, they decrease as nitridation proceeds. Nitrided oxides of the same nitrogen distribution, that were obtained at different nitridation temperatures, show the same electrical MIS characteristics. T...