研究者詳細 - 小川　郁

論文 - 小川　郁

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G-proteins coupled to phosphoinositide hydrolysis in the cochlear and vestibular sensory epithelia of the rat are insensitive to cholera and pertussis toxins

Ogawa Kaoru, Schacht Jochen

Hearing Research 74 （ 1-2 ） 197 - 203 1994年

ISSN 0378-5955

In the cochlear (CSE) and vestibular sensory epithelia (VSE), phosphoinositides are hydrolyzed in response to stimulation of phospholipase C (PLC) by cholinergic muscarinic and purinergic P_2y agonists. Such receptor-mediated activation of PLC is expected to be coupled through guanine nucleotide-binding proteins (G-proteins). Although several classes of G-proteins have been identified in the inner ear, nothing is known about the type of G-proteins associated with the phosphoinositide second messenger system in CSE and VSE. Phosphoinositide hydrolysis was determined by the release of radiolabeled inositol phosphates (InsPs). Ten mM NaF plus 10 μM AlCl₃ increased basal InsPs accumulation 2-fold in both CSE and VSE of the rat. Release of InsPs was also enhanced by guanosine 5'-O-(3-thiotriphosphate) (GTP-γ-S) in saponin-permeabilized tissues. Furthermore, release of InsPs stimulated by both carbamylcholine (CCh) and adenosine 5'-O-[3-thiotriphosphate](ATP-γ-S) was significantly inhibited by 100 μM guanosine 5'-O-[2-thiodiphosphate](GDP-β-S). These results strongly suggest the involvement of G-proteins in the receptor-PLC coupling in CSE and VSE. ADP-ribosylation in membrane fractions of CSE and VSE in the presence of cholera toxin (CTX) or pertussis toxin (PTX) indicated the existence of G_s- and G_i-type G-proteins. However, neither CTX nor PTX affected basal or agonist-stimulated release of InsPs. These observations suggest that muscarinic and P_2y purinergic receptors are coupled to PLC via CTX- and PTX-insensitive G-proteins in CSE and VSE.

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Receptor-mediated release of inositol phosphates in the cochlear and vestibular sensory epithelia of the rat

Ogawa Kaoru, Schacht Jochen

Hearing Research 69 （ 1-2 ） 207 - 214 1993年

ISSN 0378-5955

Various neurotransmitters, hormones and other modulators involved in intercellular communication exert their biological action at receptors coupled to phospholipase C (PLC). This enzyme catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdInsP₂) to inositol 1,4,5-trisphosphate (InsP₃) and 1,2-diacylglycerol (DG) which act as second messengers. In the organ of Corti of the guinea pig, the InsP₃ second messenger system is linked to muscarinic cholinergic and P₂y purinergic receptors. However, nothing is known about the the InsP₃ second messenger system in the vestibule. In this study, the receptor-mediated release of inositol phosphates (InsPs) in the vestibular sensory epithelia was compared to that in the cochlear sensory epithelia of Fischer-344 rats. After preincubation of the isolated intact tissues with myo-[³H] in-ositol, stimulation with the cholinergic agonist carbamylcholine or the P₂ purinergic agonist ATP-γ-S resulted in a concentration-dependent increase in the formation of [³H]InsPs in both epithelia. Similarly, the muscarinic cholinergic agonist muscarine enhanced InsPs release in both organs, while the nicotinic cholinergic agonist dimethylphenylpiperadinium (DMPP) was ineffective. The muscarinic cholinergic antagonist atropine completely suppressed the InsPs release induced by carbamylcholine, while the nicotinic cholinergic antagonist mecamylamine was ineffective. Potassium depolarization did not alter unstimulated or carbamylcholine-stimulated release of InsPs in either organ. In both tissues, the P₂ purinergic agonist α,β-methylene ATP also increased InsPs release, but the P₁ purinergic agonist adenosine did not. These results extend our previous observations in the organ of Corti of the guinea pig to the rat and suggest a similar control of the InsP₃ second messenger system in the vestibular sensory epithelia. In contrast to the cochlear sensory epithelia, atropine also significantly suppressed unstimulated InsPs release in the vestibular sensory epithelia. This suggests that the physiological mechanisms of the efferent nervous systems involving InsP₃ second messenger system might be different in vestibular versus cochlear sensory epithelia.

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Light and electron microscopic study of vestibular sensory epithelia in 17 cases with acoustic neurinoma

Matsunaga T., Kanzaki J., Shatari T., Ogawa K., O-Uchi T., Hosoda Y.

Auris Nasus Larynx 19 （ 4 ） 199 - 208 1992年

ISSN 0385-8146

Vestibular sensory epithelia were studied histologically and ultrastructurally in 17 cases with acoustic neurinoma (AN). The superior vestibular nerve (SVN) near the fundus was also histologically studied in 5 of these 17 cases. Histologically, severe fibrotic change of the vestibular sensory epithelia was found in 1 case, and severe fibrotic change of the SVN was also found in this case. Intra-epithelial cysts were found at the edge of the utricular sensory epithelia in 2 cases. The cysts consisted of the transitional epithelium and were filled with the darkly stained substances. Ultrastructurally, abnormal accumulation of darkly stained masses within the nerve ending and abnormal accumulation of the fibrillar material below the normal basal lamina were frequently observed. These morphological changes described above were regarded as the pathological changes due to AN. In addition, the relationship among the histologic changes, ultrastructural changes and clinical data were fully investigated, and some histologic and ultrastructural changes were regarded as artifacts or age-related changes.

A case of possible MS with the onset of vertigo and hemifacial palsy

Matsunaga T., Ogawa S., Ogawa K., Takahashi M., Kanzaki J.

Equilibrium Research 50 （ 2 ） 215 - 220 1991年

ISSN 0385-5716

Sudden deafness and vascular loop in the internal auditory canal

Ogawa K.

Otolaryngology - Head and Neck Surgery (Tokyo) 63 （ 9 ） 681 - 686 1991年

ISSN 0914-3491

Acoustic neuromas with normal hearing

Ogawa Kaoru, Kanzaki Jin, Ogawa Shigeo, Tsuchihashi Nobuaki, Yamamoto Minako

Acta Oto-Laryngologica 111 （ S487 ） 144 - 149 1991年

ISSN 0001-6489

We report on 10 patients with surgically proven acoustic neuroma (AN) who have normal hearing, and their clinical features have been investigated. The results obtained in this study were as follows: The clinical features of AN patients with normal hearing involved 1) predominance in younger adults, 2) predominance in small tumors with short duration after onset, 3) subjective hearing loss accompanied with tinnitus was the most common symptom, and 4) vertigo or dizziness without any cochlear symptoms was also a frequently seen symptom. We conclude that in order not to overlook AN among patients with normal hearing, transorbital X-ray and ABR tests should be performed on these patients for the screening purpose.

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Progression of hearing loss in acoustic neuromas

Ogawa Kaoru, Kanzaki Jin, Ogawa Shigeo, Tsuchihashi Nobuaki, Ikeda Shunya

Acta Oto-Laryngologica 111 （ S487 ） 133 - 137 1991年

ISSN 0001-6489

The progression of hearing loss and the factors influencing it are not well understood in patients with acoustic neuroma (AN). We investigated the relationships between the progression of hearing loss and the clinical findings in 42 patients with unilateral AN whose hearing could be examined for a period of 6 months or more. There was a tendency for hearing to deteriorate progressively in the patients with retrocochlear hearing loss, or with a small tumor. Based on these results, we conclude that an operation for hearing preservation should be performed as early as possible in these patients.

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Changes in clinical features of acoustic neuroma

Kanzaki Jin, Ogawa Kaoru, Ikeda Shunya

Acta Oto-Laryngologica 111 （ S487 ） 120 - 124 1991年

ISSN 0001-6489

During a 14-year period from 1976 to 1989, the authors experienced 160 cases of acoustic neuroma (AN). The clinical features were investigated in 132 of these cases (excluding those cases of recurrence and neurofibromatosis 2). The cases were divided into three periods for study. There were no significant differences in the patients' age, sex, or affected side among the three periods. The number of intracanalicular tumors have increased in recent years. The proportion of medium-sized and large tumors, however, has not changed, comprising about 70% of the total number of cases. Tumors of 20 mm or smaller in diameter were found in 24% of the cases in the early period, but increased to 58% in the most recent period. There was no difference among the periods in the length of time elapsed from the onset of symptoms to the first examination. A higher proportion of cases were diagnosed in otolaryngology departments in the middle and most recent periods than in the early period. Fewer cases in the most recent period presented initially with disequilibrium or trigeminal nerve symptoms. This was believed to be due to the increase in early stage cases. Patients are increasingly presenting with early stage AN. We feel that in order to support this favorable tendency, more emphasis needs to be placed on early diagnosis.

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The growth rate of acoustic neuromas

Ogawa Kaoru, Kanzaki Jin, Ogawa Shigeo, Yamamoto Minako, Ikeda Shunya, Shiobara Ryuzo

Acta Oto-Laryngologica 111 （ S487 ） 157 - 163 1991年

ISSN 0001-6489

Growth rate of acoustic neuromas (AN) was studied in 43 patients. The growth rate was analyzed using tumor increasing size (IS) and tumor volume doubling time (VDT). The growth rate of unilateral AN was lower than that of bilateral AN associated with neuroflbromatosis2 (NF2). The growth rate of recurrent tumors was higher than that of non-operative tumors. The relationships between growth rate and age and tumor size were also analyzed. The younger the patient or the greater the tumor size, the higher the growth rate. Several factors, i.e. age and sex of patients, tumor pathology and tumor size, should be considered together for predicting the growth rate on AN.

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Acoustic neuromas presenting as sudden hearing loss

Ogawa Kaoru, Kanzaki Jin, Ogawa Shigeo, Tsuchihashi Nobuaki, Inoue Yasuhiro

Acta Oto-Laryngologica 111 （ S487 ） 138 - 143 1991年

ISSN 0001-6489

Progressive hearing loss is well known as a usually existing complaint in patients with acoustic neuromas. However, sudden hearing loss is also a relatively frequent condition in acoustic neuroma patients. In our review of 132 patients with surgically proven unilateral acoustic neuromas, 29 (22.0% presented a history of sudden hearing loss. We investigated the clinical and audiological characteristics of these patients, and discuss the etiology of sudden hearing loss in patients with acoustic neuromas. The characteristics of patients with AN presenting sudden hearing loss were as follows: 1) a small tumor, 2) short duration after onset, 3) low incidences of vertigo, dizziness, facial and trigeminal nerve symptoms, 4) the trough type in the audiogram configuration, 5) normal caloric response. Based on the analysis of these results, we conclude that a conduction block of the cochlear nerve is likely to be the etiology of sudden hearing loss.

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Diagnostic procedure for acoustic neuroma

Kanzaki Jin, Ogawa Kaoru, Tsuchihashi Nobuaki, Yamamoto Minako, Ogawa Shigeo, O-uchi Toshiaki

Acta Oto-Laryngologica 111 （ S487 ） 114 - 119 1991年

ISSN 0001-6489

The authors' diagnostic procedure for unilateral acoustic neuroma and the reasoning behind it are explained. The actual methods involved will change with advances in methodology. At the present time, however, pure tone audiometry and simple radiographic imaging of the internal auditory canal (transorbital and Stenvers View) are first carried out. Then, if the hearing level (average hearing at 4 kHz and 8 kHz) is 70 dB or lower, auditory brain stem response audiometry is carried out. If it is 71 dB or higher, the patient is examined by MRI or CT. Contrast-enhanced CT is carried out when MRI is not available. Air CT is not necessary if MRI is available, but, in cases where hearing preservation is indicated, it may provide valuable information for identifying the tumor site within the internal auditory canal.

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Preoperative findings and hearing preservation in acoustic neuroma surgery

Ogawa Kaoru, Kanzaki Jin, O-uchi Toshiaki, Inoue Yasuhiro, Ikeda Shunya

Acta Oto-Laryngologica 111 （ S487 ） 30 - 35 1991年

ISSN 0001-6489

For the purpose of clarifying whether or not the possibility of hearing preservation can be predicted preoperatively, we compared clinical characteristics and preoperative test results between hearing preserved and hearing unpreserved patients. Based on an analysis of this study, we conclude that duration of symptoms, ABR findings and caloric test results, in addition to hearing level, speech discrimination score and tumor size should be considered as prognostic signs of hearing preservation. Although all factors do not suggest a definite possibility of hearing preservation, candidates for hearing preservation surgery should be selected according to these prognositc factors.

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Results of acoustic neuroma surgery by the extended middle cranial fossa approach

Kanzaki Jin, Ogawa Kaoru, Yamamoto Minako, Ikeda Toshiya, Shiobara Ryuzo, Toya Shigeo

Acta Oto-Laryngologica 111 （ S487 ） 17 - 21 1991年

ISSN 0001-6489

The results of surgery in 160 cases of AN are reported. Surgery was carried out by the extended middle cranial fossa (EMCF) approach in 138 cases and by the middle cranial fossa (MCF) approach in 22 cases. The tumor extended an average of 28.9 mm into the posterior cranial fossa; 42% of the tumors extended 31 mm or more. Mortality was 1.9% Of the 3 cases of death, two had large tumors of 45 mm and 52 mm each, and one was a case of recurrence. Total tumor removal was achieved in an average of 78.8% of the cases. When the cases were classified by date of operation, the total tumor removal rate in the 60 most recent cases was 93.3% The rate of facial nerve preservation was 82.4% on average and 93% in the recent cases. Hypoglossal-facial nerve anastomosis was performed in 33% of the cases in which facial nerve function failed to recover for an extended period of time. Among recent cases, however, anastomosis has been carried out in 22% of the cases. Hearing was preserved in 20 cases. Useful hearing was preserved in 8 (38% of 22 cases. Recurrence was confirmed through surgery in 3 cases. Recurrence was suspected but was unconfirmed in 3 cases.

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Surgical anatomy for the extended middle cranial fossa approach

Ogawa Kaoru, Inoue Yasuhiro, Yamamoto Minako, Ikeda Shunya, Kanzaki Jin

Acta Oto-Laryngologica 111 （ S487 ） 41 - 47 1991年

ISSN 0001-6489

The surgical anatomy of the temporal bone and the cerebellopontine angle was studied in cadavers, by performing simulated surgery via the extended middle cranial fossa approach. This approach is classified into 3 types according to extension of the drilling area of the temporal bone. In this paper, the surgical anatomy visualized by the EMCF type II and type III is described. In the EMCF type II, mastoidectomy and labyrinthectomy are performed completely through the middle cranial fossa, and in the EMCF type III permitting hearing preservation surgery, sections of the middle cranial fossa dura and the cerebellar tentorium are added to House's middle cranial fossa approach. The comprehension of these anatomical structures is essential for surgeons in performing acoustic neuroma surgery. We believe that this study will serve to expand our knowledge of surgical anatomy, and that as a result the EMCF approach for acoustic neuroma surgery will become more popular.

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Hearing preservation in acoustic neuroma surgery by the extended middle cranial fossa method

Kanzaki Jin, Ogawa Kaoru, O-uchi Toshiaki, Shiobara Ryuzo, Toya Shigeo

Acta Oto-Laryngologica 111 （ S487 ） 22 - 29 1991年

ISSN 0001-6489

The results of attempted hearing preservation were investigated in 160 cases of acoustic neuroma surgery carried out by a team of otologists and neurosurgeons at Keio University Hospital during a 14-year period from 1976 to 1989. Surgery was carried out by the middle cranial fossa (MCF) approach in the earlier cases and by the extended middle cranial fossa (EMCF) approach in the more recent cases. Measurable postoperative hearing was preserved in 20 of the 160 cases. Preoperatively, 22 cases had tumors of 20 mm or smaller in diameter, hearing levels (HL) of 50 dB or lower, and speech discrimination scores (SDS) of 50% or higher; 8 (36% met these conditions postoperatively. Among those cases with hearing preserved postoperatively, hearing was unchanged from the preoperative level in 9 cases and changed in 11 cases. Total tumor removal was achieved in 19 cases. In one case, part of the tumor was left in order to preserve hearing, but MRI and CT have revealed no change in hearing or tumor enlargement to date, at 4 12 years after surgery. Hearing was preserved but progressively deteriorated postoperatively in one case in which the tumor was believed to have been totally removed but there was recurrence and in another case of total resection of neurofibromatosis II. Postoperatively, there were increased incidences of absence of the stapedius reflex, Type V by Bekesy audiometry, and prolongation of the IT5, disappearance of Wave V, and no response in measurements of the ABR.

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Postoperative complications in acoustic neuroma surgery by the extended middle cranial fossa approach

Kanzaki Jin, Ogawa Kaoru, Tsuchihashi Nobuaki, Inoue Yasuhiro, Yamamoto Minako, Ikeda Shunya

Acta Oto-Laryngologica 111 （ S487 ） 75 - 79 1991年

ISSN 0001-6489

The complications of acoustic neuroma (AN) surgery by the extended middle cranial fossa approach were studied in 160 cases. Death during surgery occurred in 3 cases (1.9%; 2 of these involved large tumors and the third was a case of recurrence. Transient temporal lobe symptoms were seen in 24 cases (15.3%; the average tumor diameter in these cases was 36.0 mm. Beside symptoms of 7th and 8th nerve disturbance, hemiparesis was seen 7.6%; 3rd, 4th, and 6th cranial nerve symptoms in 7.0%; and cerebellar symptoms in 7.6% of the patients. The incidence of these disturbances increased with tumor size. Cerebrospinal fluid (CSF) leakage occurred in 20.4% of the cases and this necessitated surgical treatment in 5% of the cases.

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Audiological findings in acoustic neuroma

Kanzaki Jin, Ogawa Kaoru, Ogawa Shigeo, Yamamoto Minako, Ikeda Shunya, O-uchi Toshiaki

Acta Oto-Laryngologica 111 （ S487 ） 125 - 132 1991年

ISSN 0001-6489

Audiological examinations are vital in the diagnosis of acoustic neuroma. In interpreting their results, however, it is necessary to consider the patient's hearing level. The most sensitive audiological examination is auditory brain stem response (ABR) audiometry. Its most useful parameter is the IT5. A U-shaped audiometric configuration suggests AN, since it is seen in 10% of patients with small tumors. Psychological audiometric tests can be excluded from the battery of screening tests since they have low rates of positive diagnosis. The stapedius reflex (SR) test also has a low positive diagnostic rate in cases of small tumors. Even with the parameters of absence of reflex, elevated threshold, and decay combined, the overall SR test has a lower positive diagnostic rate than ABR audiometry. Nevertheless, the SR test can be employed as a screening device in cases in which the hearing level at 2 kHz and lower is 70 dB or lower, even if it is 71 dB or higher at 4 kHz and 8 kHz. At present, ABR audiometry is applicable in only about half of AN cases. Therefore, the need for early diagnosis must be further emphasized.

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Intracranial reconstruction of the facial nerve clinical observation

Kanzaki Jin, Kunihiro Takanobu, O-uchi Toshiaki, Ogawa Kaoru, Shiobara Ryuzo, Toya Shigeo

Acta Oto-Laryngologica 111 （ S487 ） 85 - 90 1991年

ISSN 0001-6489

Nine cases of intracranial facial nerve reconstruction are reviewed in this paper. All patients underwent this procedure for severe injury or disruption of the facial nerve during surgery for acoustic neruroma through the modified extended middle cranial fossa approach (1). Satisfactory recovery of facial function was obtained in 4 patients. Three patients underwent hypoglossal-facial nerve anastomosis 1.3-1.5 years later for no or poor recovery of the facial function. One patient refused any further surgical treatment despite unsatisfactory recovery. The remaining 1 patient, during a telephone interview, stated that facial function had not returned at all 1 year and 5 months postoperatively. Although some degree of associated movement or mass movement was unavoidable, facial movement and mimetic facial expression were better in the patients with satisfactory recovery, as compared with those after hypoglossal-facial nerve anastomosis (2). Fibrin glue, which we used in the latest 3 cases instead of suture, seemed to possibly solve the technical difficulty in placing a suture. Facial function after intracranial reconstruction with fibrin glue was as good or better than that after repair by suturing.

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Psychological aspects of psychogenic deafness in children

Yamamoto Minako, Kanzaki Jin, Ogawa Kaoru, Asano Kyoko

International Journal of Pediatric Otorhinolaryngology 21 （ 2 ） 113 - 120 1991年

ISSN 0165-5876

Twenty-nine children with psychogenic deafness were investigated from audiological and psychological aspects. ABR and Békésy audiometry were useful for diagnosing psychogenic deafness. The elapsed time from the start of treatment to audiometric recovery was significantly shorter in patients receiving psychological treatment, indicating that treatment by a team of otologists and counselors was able to hasten recovery in children with psychogenic deafness. The pattern of hearing recovery in the treated group was classified into 3 types and in the control group into 4 types. Counseling seemed to have a positive effect on patients with fluctuating improvement. In the patients in the treated group, the elapsed time to audiometric recovery from the beginning of psychological treatment was 7.5 months; however, in the control group recovery it took 17.1 months. Psychological treatment revealed that the clinical course of psychogenic deafness in children seemed to have some relation to the patient's personality and psychological stresses.

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Further investigation on loudness balance test for tinnitus

O-Uchi T., Fujii M., Kunihiro T., Okada Y., Satoh A., Ogawa K., Kanzaki J.

Audiology Japan 33 （ 1 ） 76 - 83 1990年

ISSN 0303-8106

We conducted the loudness balance test at 3 frequencies with the center at the pitch of tinnitus. The subjects were 68 tinnitus ears without hearing loss or associated with cochlear deafness, and their tinnitus pitch was simulated by pure tones. Results obtained were as follows; (1) There were no statistically significant differences among the values of loudness estimated at 3 test frequencies. (2) The values of loudness estimated at 3 test frequencies coincided in about 30% of the subjects. (3) The values of loudness estimated at neighboring 2 test frequencies coincided in about 50% of the subjects. (4) There was a slight negative correlation between the value of loudness and the hearing level at the pitch of tinnitus. (5) There was no clear correlation between the subjective scoring for loudness and the hearing level at the pitch of tinnitus. (6) There were positive correlations among the values of loudness estimated at 3 test frequencies. (7) Correlation coefficients were less than 0.260 between the subjective scoring for loudness and the values of loudness estimated at 3 test frequencies. (8) The optimal evaluating method of subjective scoring for loudness should be re-investigated.

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小川 郁

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小川　郁

論文 - 小川　郁