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Koji Kamimura, Yoshito Honma, Satoshi Iwasaki, Yoshihito Sueki, Kazuo ...
1992 Volume 1992 Issue Supplement60 Pages
1-8
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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Mondini dysplasia was found by high resolution CT scanning of the temporal bones in 13 patients with congenital hearing loss. High resolution CT scanning of the temporal bone has made it possible to diagnose Mondini dysplasia much easier than before. However diagnosis of slight hypoplasia of the inner ear is still difficult. Assessment of hyperplasia of the interscalar septum in front of the stapes is a significant sign in the diagnosis of slight hypoplasia of cochlea. This finding may indicate dysplasia of the modiolus.
The axial section of CT scanning is most useful in demonstrating the inner ear and slice thickness of less than 2 mm is optimum thickness that can effectively demonstrate the inner ear changes.
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1992 Volume 1992 Issue Supplement60 Pages
e1-
Published: 1992
Released on J-STAGE: December 14, 2012
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-Analysis of Prognostic Factors-
Tetsufumi Ogino, Masayoshi Onodera, Toshiya Fujimori, Michihiko Nozue
1992 Volume 1992 Issue Supplement60 Pages
9-15
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We statistically analyzed 71 patients with sudden deafness between April,1989 and March,1992.
There was no sex difference, and the hearing type on initial examination was most frequently the horizontal type.
The hearing level on initial examination averaged 55.5 dB. The prognosis tended to be good in patients less than 40 years of age, with low t o ne deafness, early treatment, and without complication. On the other hand, the prognosis tended to be poor in elderly patients, with severe deafness delayed treatment, and with complications.
Adrenal corticosteroid hormone and prostaglandin E1 treatments had no significant effects. Also, no difference was observed between outpatients and inpatients or between the patients with and without dizziness.
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Shiro Iwabuchi, Kazuo Matsui, Michihiko Nozue
1992 Volume 1992 Issue Supplement60 Pages
16-22
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We studied 41 patients with acute low-tone sensorineural hearing loss who visited our department between 1982 and 1988. Also we sent them questionnaires by mail.
Two of them were excluded from this study because their diagnosis was later confirmed to be Meniere's disease. Nineteen of the other 39 (49%) returned their answers. Most of them recovered in a short period but, some patients had fluctuation of hearing disturbance.
Several entities such as cochlear hydrops, or endolymphatic hydrops without vertigo, or cochlear Meniere's disease, might contribute to the similar clinical picture.
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-The Improvement of Hearing Aids-
Kazumoto Suzuki
1992 Volume 1992 Issue Supplement60 Pages
23-28
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A new algorithm for signal processing to improve the hearing ability of hearing aid users under noisy circumstances is proposed.
In the auditory system, the sound directions are detected precisely by analyzing two kinds of information; 1) the interaural time difference and 2) the interaural sound pressure difference. Using a personal computer, acoustic signals were analyzed according to an algorithm similar to that of the auditory system. The sound coming from the optional direction could be readily detected. If this algorithm is applied to the electric circuits of hearing aids, the user's hearing ability under noisy circumstances could be improved greatly.
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-Wavelength Theory-
Kazumoto Suzuki
1992 Volume 1992 Issue Supplement60 Pages
29-37
Published: December 25, 1992
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A new theory of sound analysis in the auditory system is proposed. The main function of the inner ear is not frequency analysis but transformation of acoustic information into impulses in the auditory neurons. An impulse evoked by sound stimulations in the inner ear has only two kinds of information, that is,1) “when” and 2) “in which neuron” it was evoked. The accuracy of the information is guaranteed by hair cells having the function of “phase locked” response to traveling waves and being aligned on the basement membrane.
These two kinds of information can be analyzed as precisely as is needed by the convergences and the divergences of neurons in the central auditory system. The nature of “tonality” in the auditory system is the inevitable attribute of the theory of sound analysis I propose, which is called “Wavelength Theory”. The resonate nature of the basement membrane functions to transform the sound intensity into the total number of impulses evoked in the inner ear. There is a conflict in “Place Theory” with respect to the insufficient transformation of the sound intensity.
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Hisayoshi Ishizaki, Koji Iwasaki, Satoshi Iwasaki, Hiroyuki Mineta, Iz ...
1992 Volume 1992 Issue Supplement60 Pages
38-44
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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Meniere's disease is difficult to treat because its etiology is still unknown and pathophysiology is not fully understood. Clinical laboratory studies indicate that the inner ear changes in Meniere's disease may be caused by a dysfunction of the endolymphatic sac. Surgery was performed on the patients with intractable Meniere's disease, who had progressive sensorineural hearing loss, vertigo and unsteadiness against oral medication. Postural stability after operation was evaluated chronologically with a force platform is to measure the change of the center point of foot pressure on the platform surface. The signal from the force platform fed into a signal processor (San-eisokki 7T-17) was analyzed with an 8-directional vectrogram after sampling and eliminating the noise.
Thirty six patients were compared with 31 controls. The vectrogram was useful for observing the 8-directional sway. Postural stability was abnormal in 25 out of 36 cases (69%) before the operation,13 of 22 cases (59%) at 1-3 months, in 4 out of 16 cases (25%) at 4-6 months and in 1 out of 10 cases (10%) at 7-12 months after endolymphatic sac operation.
From our obervation, postural control was well compensated in 75% of the operated patients 4-6 months following operation. The results of postural stability after operation were in agreement with the results of the general questionnaire.
The 8-directional vectrogram proved useful for evaluating the postural stability in postoperative patients with Meniere's disease.
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Hisayoshi Ishizaki, Michihiko Nozue, Ilmari Pyykkö
1992 Volume 1992 Issue Supplement60 Pages
45-50
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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Postural stability in children was investigated from the point of postural strategy (visual, vestibular, somatosensory) in response to the change of position, velocity and acceleration on the foot pressure of the soul and distension of the muscle spindles, and head position. In order to clarify this study, we investigated the degree of contribution o f the input from each receptor in maintaining postural control and the kind of receptor synergy in children and adults. Postural stability was analyzed by the change of displacement of the foot pressure on the force platform. The subjects were applied vibration stimulations to the calf muscles to deprive informationfrom proprioceptive organs or give misleading information to the central nervous system. The analysis was performed with variability of the cumulative distribution in position, velocity and accerelation data. The variability of velocity in children was high in vibration. The variability acceleration was highly significant for both vibration and non-vibration.
In conclusion, postural stability in children was attributed to prematurity of the central nervous and musculoskeletal systems and unbalanced body mass.
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Yoshihiro Asai, Kazuo Umemura, Michihiko Nozue, Akio Yasuhara, Atsuro ...
1992 Volume 1992 Issue Supplement60 Pages
51-56
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We investigated the subjective disability in actions of daily life by a self-registering questionnaire study on 102 patients (50 males and 52 females, mean age 67.7 years old), who visited our institutions without any vertiginous diseases. Multiple regression analysis demonstrated that subjective disability in daily actions depended on age, joint problems and employment, with age being the most significant factor among them. Age-dependent actions were walking in the dark, going up and down stairs, standing with the area of soles or the head position changed, sitting and standing up, standing upright in a moving vehicle. Going up and down stairs, sitting and standing up, standing upright in a moving vehicle were significantly influenced not only by age but also joint problems. We thought that subjective disability in the age-dependent actions were caused mainly by the deterioration of balance function. Discriminant functions showed that the borderline age for subjective disability in daily actions was around 70 years old. We suggest that the border of age can be applied to the subjective disability due to aging of balance function and also the subjective disability due to joint problems.
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Hiroyuki Mineta, Keisuke Araki, Mika Suganuma, Akio Yasuhara, Takeo Sa ...
1992 Volume 1992 Issue Supplement60 Pages
57-63
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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Various recently developed reconstructive procedures have made it possible to surgically treat advanced head and neck cancers that were previously considered inoperable. From 1979 through March,1992, we extensively removed cancers followed by reconstruction from 120 patients (153 cases), the results of which are presented herein. For reconstruction, we used the myocutaneous or cutaneous flaps in 111, alimentary tract in 38, and rib or iliac bone graft in four cases. In the first reconstruction,16 of the 121 cases (13.2%) were unsuccessful. Among them free flaps were utilized in nine cases. It is important to improve the surgical techniques, and also to prevent postoperative bleeding and infection.
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Koji Iwasaki, Hisayoshi Ishizaki, Hiroyuki Mineta, Michihiko Nozue
1992 Volume 1992 Issue Supplement60 Pages
64-71
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We studied 118 cases of major salivary gland tumors. The tumors arose in the parotid gland in 93 patients (malignant tumor: 22 cases), the submandibular gland in 24 patients (malignant tumor: 8 cases), and the sublingual gland in one patient.
For parotid benign tumor, extracapsular removal with preservation of the facial nerve was the principal method and the results were satisfactory without any recurrence. On the other hand, total parotidectomy, with or without preservation of the facial nerve, were performed for malignant parotid tumors and radical neck dissections were done in 11 cases. Tumors of the submandibular and sublingual gland were removed totally with those glands. The 5-and 10-year survival rates of the malignant tumors of the major salivary glands were 54% and 45% respectively.
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Takeo Sakai, Hiroyuki Mukohdaka, Osamu Nozawa, Hiroyuki Mineta, Michih ...
1992 Volume 1992 Issue Supplement60 Pages
72-76
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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The postoperative treatment of paranasal sinus cancers is often very painful. We tried to palliate such pain by the application of MS-Contin®. MS-Contie® tablets were prescribed to two patients (a maxillary cancer patient and an ethmoid cancer patient) who complained of serious pain with the postoperative treatment. Subjectively their pain was mitigated from ten to three-four by the application of MS-Contin®. Two patients did not show abstinence syndromes or psychic dependence. We concluded that MS-Contin® was an effective and safe drug for the relief of the pain accompanying the postoperative treatment.
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Mikino Kikura, Akio Yasuhara, Hiroyuki Mineta, Michihiko Nozue
1992 Volume 1992 Issue Supplement60 Pages
77-82
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We experienced 679 cases of head and neck cancers between 1978 and 1991. Among them,10 cases were triple primary cancers. We studied these 10 triple cancer cases with regard to the incidence, primary organs, intervals, risk factors, and prognosis. The incidence of triple primary cancers was 1.47%, and 9 were in males and one in a female. The mean age at the time of the first primary cancer occurred was 63.2 years old. The oral cavity and esophagus were the most frequently involved (70%) as a prim a ry region. With regard to the intervals, the average between first and second cancer, and between second and third cancer were 2 years and 8 months respectively. As risk factors of multiple primary cancers, Brink man Index and Sake Index were 651and 80, respectively. The prognosis of triple primary cancers was very poor and the average of the periods from the third primary cancer to death was 7 months. In this investigation, we emphasized the im portance of early diagnosis and treatment for the multiple cancers.
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Shuji Ocho, Yasuo Mori, Shinri Kinaga
1992 Volume 1992 Issue Supplement60 Pages
83-88
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We had performed total laryngectomy or narrow-field laryngectomy on a total of ten patients, who had been disabled by severe dysphagia causing repeated aspiration pneumonia since their cerebro-vascular accidents. We reported herein three recent cases, in which food could be taken orally without aspiration and general condition improved after narrowfield laryngectomy. We believe that the laryngectomy had improved the quality of life of these patients.
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Shinri Kinaga, Yasuo Mori, Shuji Ocho
1992 Volume 1992 Issue Supplement60 Pages
89-92
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A case of self-inflicted laryngeal injury in a suicide attempt was reported. A 36-yearold male with atypical psychosis cut his own throat. Although the thyroid cartilage was cut horizontally, the esophagus and vessels were intact. An intubation through the open wound to trachea was performed. After the inferior tracheotomy, wire suture of thyroid cartilage without stent was done to preserve his larynx. As a result, he had slight hoarseness and psychological signs, so medical and psychological management was not avoidable.
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Kazuo Matsui, Yoshihiro Asai, Mikino Kikura, Michihiko Nozue, Shiro Iw ...
1992 Volume 1992 Issue Supplement60 Pages
93-98
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We encountered two patients with Kimura's disease (Eosinophilic granuloma of the soft tissue) in the same family. One was in a 22-year-old male and the other was in a 44year-old female, who was his mother. The former patient visited our institution in 1991, complaining of tumescences in the left parotid and auricular region, right post auricular region and bilateral cubital region. The mass was pathologically confirmed to be eosinophilic granuloma of the soft tissue. The serum IgE level rose up to 13700 IU/ml and the complete blood count showed granulocytosis up to 10400/mm
3 with eosinophilia accounting for 57% of the total granulocytes. On the other hand, the mother complained of tumescences in the left parotid and post-auricular region. Her serum IgE level also increased to the same degree as her son's and the count of eosinophilic leukocytes showed an abnormal increase.
Previously, the etiology of Kimura's disease has been considerd to be type I allergy to Candida albicans. Although we checked 10 kinds of RAST on both patients, the increase of specific IgE level for Candida albicans was not detected. The result of RAST examination failed to prove that this disease was caused by type I allergy to Candida albicans.
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Takayuki Katoh, Tomoyuki Hoshino
1992 Volume 1992 Issue Supplement60 Pages
99-102
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A 46-year-old man with a schwannoma in the nasal cavity and in the nasopharynx was presented. He complained of right nasal obstruction for about 5 years. Axial CT demonstrated a large mass occluding the right nasal cavity and a part of the epipharynx and the antrum. Pre-operative biopsy made by postrhinoscopy revealed the schwannoma. The lesion was excised through the transpalatine and transantral approach via a Caldwell-Luc incision with a Denker extension. A softmass at the olfactory groove caused total occlusion and expansion of the right nasal cavity with protrusion into the choana. Final histological diagnosis was a schwannoma. In the head and neck area, benign peripheral nerve sheath tumors include both schwannoma and neurofibroma. Because of distinct prognostic implication, a correct histological diagnosis is important.
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Hiroshi Miyashita, Yasuhiro Ohkawa, Takamasa Maruchi
1992 Volume 1992 Issue Supplement60 Pages
103-109
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We report a case of rhinogenic epidural empyema. The patient was a 39-year-old male, who was admitted because of headache and forehead swelling. CT scan revealed that he had an epidural empyema and a subcutaneous empyema, which developed from acute frontal sinusitis. Close monitoring with serial CT scans offered us important intracranial and sinus information for the management of this disease. We successfully treated the case by administration of antibiotcs. We emphasized the usefulness of the serial CT scans and briefly discuss the treatment of rhinogenic intracranial complications.
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Yasuhiro Ohkawa, Kazuo Umemura, Yumiko Matsuura, Shinji Matsunaga, Hir ...
1992 Volume 1992 Issue Supplement60 Pages
110-114
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A 56-year-old male with a CSF-producing tumor of the thyroid gland is reported. Although the histological diagnosis of the tumor was undifferentiated carcinoma, the patient showed marked leukocytosis up to 81000/μ 1,98% of which consisted of matured neutrophils. Because there was no evidence of infection or leukemia, this tumor was considered to be CSF producing. Finally the diagnosis was confirmed by the result of the in vitro colony assay, showing extremely higher level of CSF activity in the conditioned medium of this tumor cells.
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Masahiko Adachi, Atsuro Seki, Yo Ueda, Yoshifumi Kinoshita, Yasuhiro H ...
1992 Volume 1992 Issue Supplement60 Pages
115-119
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We report a 45-year-old male with swelling of a neck lymph node as the main complaint. He was histopathologically diagnosed to have malignant melanoma with its origin at the oral hard palate. DAV chemotherapy was instituted but with no success. Then he was given immunotherapy with LAK combined with IL-2 and INF-β followed by surgical resection of tumor and lymph nodes. After the operation, histiopathological examination of neck lymph nodes revealed no evidence of melanoma cells but a marked deposition of melanin pigment and infiltration of lymphocytes and macrophages. We conclude that the immunotherapeutic approach led to successful tumor regression in this patient.
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Atsuro Seki, Masahiko Adachi, Yo Ueda, Yoshito Honma, Kazuo Matsui
1992 Volume 1992 Issue Supplement60 Pages
120-123
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A 34-year-old woman presented with swelling of the left cheek and obstruction of nasal breathing. A plain skull x-ray and a computed tomographic scan showed a mass lesion and bone destruction in the left maxilla. The patient had under-gone bilateral sinusotomy 12years previously, and the tentative diagnosis was postoperative maxillary cyst. At surgery, total excision proved impossible because of excessive bleeding. The histological diagnosis was giant cell tumor. Because the tumor was locally aggressive, radiation therapy was administered. At present,39 months after irradiation, there is no sign of local tumor activity or distant metastasis.
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Yumiko Matsuura, Yasuhiro Hayashi, Kazuo Matsui, Jin Nakajima, Naoto I ...
1992 Volume 1992 Issue Supplement60 Pages
124-129
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A case of malignant fibrous histiocytoma (MFH) in the right maxillary sinus of a 73year-old female is reported.
Thirty five years previously, the patient had been treated with surgery and irradiation for right maxillary sinus cancer. The tumor was noticed in maxillary sinus and orbit by MRI. The pathological diagnosis was malignant fibrous histiocytoma.
The feeder artery of the tumor was radiollogically com f irmed and selectively embolized, followed by systemic chemotherapy but the growth of the tumor was not successfully controlled. The clinical course suggested that this case might be a radiation induced MFH. We emphasized that surgical total removal is the best treatment for MFH.
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Yo Ueda, Masahiko Adachi, Atsuro Seki
1992 Volume 1992 Issue Supplement60 Pages
130-134
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We experienced a 75-year-old female with jugular venous aneurysm along the right side of her neck. She was older than any patient reported previously. She visited our institution complaining of an asymptomatic right-sided neck mass which could be enlarged by Valsalva maneuver. The venous aneurysm was finally diagnosed by venography and surgically removed without any complications. We considered that the Valsalva maneuver, ultrasonography and enhanced CT scan were non-invasive and useful for the diagnosis before the surgery.
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Yasuhiro Hayashi, Kazuo Matsui, Naohito Ishid, Ikuko Suzuki, Yumiko Ma ...
1992 Volume 1992 Issue Supplement60 Pages
136-140
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A 70-year-old male was referred to us because of a constant sensation of a foreign body in the throat. He had undergone a tonsillectomy in another hospital. CT scan and MRI showed a giant and somewhat homogeneous soft tissue mass with fixation to the right sternocleidomastoid muscle. The tumor was removed together with the vagus nerve, and the fresh specimen measured 150 × 50 × 30 mm and 80 g. A diagnosis of schwannoma derived from the vagus nerve was made on the basis of anatomic location of this huge tumor and pathological study. His constant sensation in the throat had completely disappeared postoperatively and no symptom was observed except for the persistent hoarseness. Six months later following the tumor extirpation, the patient underwent vocal fold augmentation by intracordal injection of atelocollagen, and his phonatory function improved.
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Naohito Ishida, Kazuo Matsui, Yasuhiro Hayashi, Yumiko Matsuura, Ikuko ...
1992 Volume 1992 Issue Supplement60 Pages
141-145
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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A case of surgically confirmed perilymphatic fistula is reported. A 50-year-old woman visited us on the 26th day of having hearing loss, tinnitus, ear fullness, dizziness and the sensation of water-flow in the right ear, which began just after blowing the nose. The pure tone audiogram showed sensory hearing loss of 74 dB. An exploratory tympanotomy on the 110th day revealed a fracture of the stapedial footplate and perilymphatic leakage from the fracture. The fistula was sealed with a piece of connective tissue and Gelform, with resultant control of dizziness.
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Ikuko Suzuki, Kazuo Matsui, Hiroyuki Mineta, [in Japanese], Hisayoshi ...
1992 Volume 1992 Issue Supplement60 Pages
146-150
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We report a 9-month-old girl infant and a 50-year old female with a teratoma of the nasopharynx.
Teratoid tumors of nasopharynx are divided into 1) dermoids (hairy polyps),2)teratoid tumors,3) teratomas and 4) epignathi. Both cases were classified into dermoids which contained two germ cells. The latter case was very rare case considering her age be cause most nasopharyngeal teratomas present with upper respiratory obstruction within a year of birth.
Computed tomography and magnetic resonance imaging (MRI) were used to evaluate the most useful for the character of the lesions.
We concluded that MRI is the most useful for diagnosis of nasopharyngeal teratomas.
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Kazuo Umemura, Yoshihiro Asai, Kunihiro Mizuta, Mitsuyoshi Nakashima, ...
1992 Volume 1992 Issue Supplement60 Pages
151-154
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We produced a new model of hearing disturbance in rats due to photochemically induced thrombosis in inner ear microcirculation. Under sodium pentobarbital anesthesia, green light (540 nm) was irradiated on the lateral bony wall, which was exposed by a ventrolateral approch, while rose bengal (RB,20 mg/kg, i. v. ) was injected. The disintegration of hair cells and stria vascularis was observed 24 hours after the completion of the illumination with RB in light microscopy and platelets and fibrin nets, which entrapped the red blood cells, filled in the arteriole of the inner ear in scanning electron microscopy. The compound action potential of the cochlear nerve (AP) was measured every minute after the injection of RB. The AP disappeared about 4 minutes after the administration of RB. The time required to completely suppress the AP was significantly prolonged in animals treated with aspirin (30 mg/kg), which was injected 5 minutes before the administration of RB, as compared with controls. In conclusion, our method causes a photochemically induced occlusion in inner ear's microcirculation and is potentially usefull for evaluating the various effects of drugs on inner ear's microcirculation disorders.
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Yoshihiro Asai, Kazuo Umemura, Mitsuyoshi Nakashima, Michihiko Nozue
1992 Volume 1992 Issue Supplement60 Pages
155-159
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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We established a new model of hearing disturbance caused by photochemically induced thrombosis in the rat anterior inferior cerebellar artery (AICA). Under pentobarbital anesthesia, the left tympanic bulla and the ipsilateral AICA were ventrally approched. Rose bengal (20 mg/kg) solution was injected intravenously under selective irradiation on the AICA with the focused green light while measuring both compound action potentials (CAP) with the electrocochleogram and cochlear blood flow with laser Doppler flowmetry. The time required to completely occlude the AICA was significantly prolonged by the aspirin pretreatment. And the t-PA successfully reopened the thrombotic occlusion of the AICA followed by complete recovery of the lost CAP. We concluded that this model w as potentially useful for the research on the pathophysiology and the pharmacological therapeutics of the sensorineural hearing disorders due to thrombotic ischemia of the inner ear.
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Satoshi Iwasaki, Hisako Ito, Kunihiro Mizuta, Michihiko Nozue
1992 Volume 1992 Issue Supplement60 Pages
160-163
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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Evoked otoacoustic emissions (e-OAE) are nearly always observed in normal human ears. Testing the validity of animal models is useful to explain the human auditory system.
Evoked otoacoustic emissions at 2 kHz tone-burst have been measured in 34 cat ears. The responses of e-OAE were detectable in 27 ears (77.6%). In most cats (23 out of 27 ears)nonlinear behavior could be identified. The amplitudes of e-OAE were saturated as the stimulus level increased (above 15 to 20 dBnHL). The responses had very short latencies (to their peak pressures) of 5,53 ms to 7,28 ms.
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Hisako Ito, Mitsuyasu Itoh
1992 Volume 1992 Issue Supplement60 Pages
164-167
Published: December 25, 1992
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Among the non-pathologic determinants of auditory brainstem response (ABR), the body temperature is known to act centrally; a decrease in the body temperature causes a greater delay in the later waves and a prolonged central conduction time. We measured the ABR in acute streptozotocin-diabetic mice to determine the interaction of the body temperature and the metabolic disturbance. The degree of prolongation of the central conduction time was smaller in the diabetic mice when the body temperature was lowered, but the mechanism of this apparent resistance to a change in temperature remains unclear. Thus, caution should be paid to the body temperature in discussing ABR latencies, especially in metabolic disturbances such as diabetes mellitus.
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Kunihiro Mizuta, Hirofumi Morita, Osamu Nozawa, Takeo Sakai, Tomoyuki ...
1992 Volume 1992 Issue Supplement60 Pages
168-173
Published: December 25, 1992
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The basilar fiber inside the organ of Corti was studied using the scanning electron microscope (SEM) in the cat. The basilar fiber, afferent in nature, emerged between the inner pillar cells in the medial angle of the Corti's tunnel under the efferent tunnel radial fibers. They ran across the tunnel floor obliquely toward the basal end of the cochlea and entered the Nuel's space between the outer pillars' feet. They turned spirally in the outer spiral bundle and slowly climbed the lateral wall of the Nuel's space toward the outer hair cells. In the adult cat, the basilar fibers were embedded in the cytoplasma of the pillar cells in the tunnel floor, but were clearly seen in young cats. Using the SEM, the number of these fibers at the feet of the outer pillars could be counted. We obtained a ration of 1.3nerve fibers per pillar cell dividing 402 basilar fibers by 313 outer pillars.
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Hirofumi Morita, Tomoyuki Hoshino, Kunihiro Mizuta
1992 Volume 1992 Issue Supplement60 Pages
174-180
Published: December 25, 1992
Released on J-STAGE: November 27, 2012
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The Nuel's space in the guinea pig cochlea was studied. Thick sections were cut from celloidin-embedded cochlea and observed by SEM. Four types of nerve endings were observed at the outer hair cells; ball-shaped nerve endings, high nerve endings, en passant, and the large irregular-shaped cluster of nerve endings. The outer spiral fibers were partly covered by Deiters'cells and showed a complicated network. At the hook portion, the tunnel basilar fibers took a spiral course attached to the bottom of the Nuel's space. At the upper portion of the cochlea, they ran radially and freely above the bottom.
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