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Volume 45 (2002)
- Issue 6 Pages 671-
- Issue 5 Pages 313-
- Issue 4 Pages 271-
- Issue 3 Pages 203-
- Issue 2 Pages 131-
- Issue 1 Pages 1-
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Volume 45, Issue 4
Displaying 1-6 of 6 articles from this issue
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Shunji Takeuchi2002 Volume 45 Issue 4 Pages 271-277
Published: August 31, 2002
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe stria vascularis produces the K+-rich endolymph and the positive endocochlear potential. Recent cell-physiological and molecularbiological studies revealed mechanisms underlying the production of the endolymph and the endocochlear potential. In this report, ionic mechanisms in the stria vascularis and structures related to the function were reviewed.View full abstractDownload PDF (2771K) -
Kunihiro Fukushima2002 Volume 45 Issue 4 Pages 278-282
Published: August 31, 2002
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSRecent progress in molecular genetics for hearing impairment makes it possible to apply the genetic research to clinical medicine as medical intervention. Future applications of molecular genetics to hereditary hearing impairment may include 1) prevention for the occurrence/progression of hearing impairment, 2) diagnosis of prognostic factors for educational intervention, and 3) therapeutic intervention. Before the application of the medical intervention, however, solutions are required for many practical problems including 1) needs for industrialization of the technologies that would be protected by patents, 2) needs for a nation-wide genetic counseling system, and 3) technological establishment of the simultaneous diagnosis of variable genetic alterations. It is desired that new scheme for the treatment based upon the knowledge from molecular biology should be established in near future.View full abstractDownload PDF (684K) -
Ken Kitamura2002 Volume 45 Issue 4 Pages 283-288
Published: August 31, 2002
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSFor prelingual hearing loss, epidemiological data show that 1 neonate in 1, 000 is born with severe to profound hearing loss and in half that number the loss is inherited. Hereditary hearing loss is classified into syndromic (30%) and non-syndromic (70%) deafness. Nonsyndromic deafness is further classified by mode of inheritance (DFNA, dominant (30%); DFNB, recessive (66%); DFN, X-linked (4%)), with the loci being numbered in the order of discovery by Human Genome Organization. Deafness caused by maternal inheritance by mitochondrial DNA has been also demonstrated. To date, 41 autosomal dominant, 30 autosomal recessive, and 8 X-linked nonsyndromic sensorineural hearing impairment loci have been mapped and 27 genes have been cloned (Hereditary Hearing Loss Homepage, http://dnalab-www.uia.ac.be/dnalab/hhh/). The common deafness genes as well as deafness genes which can cause variable phenotype, such as syndromic or nonsyndromic deafness, or dominant or recessive inheritance, are reviewed. And mutant mice with inner ear disorders, which represent the most likely candidates for homology with syndromic and non-syndromic losses of hearing in humans are briefly discussed.View full abstractDownload PDF (767K) -
The finite-element analysisTakuji Koike, Hiroshi Wada, Toshimitsu Kobayashi2002 Volume 45 Issue 4 Pages 289-297
Published: August 31, 2002
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA guinea pig is usually used for a study of auditory mechanics. However, the dynamic characteristics of guinea pig middle ear have not been fully understood. In this study, a finite-element model of the middle ear of a guinea pig was established, and the sound-transfer mechanism of the middle ear was analyzed. Unknown mechanical properties of middle-ear parts were determined so that the tympanic membrane vibration obtained from the FEM resembled that obtained by using the electronic speckle pattern interferometry. The validity of this model was confirmed by comparing the ossicular vibration and the middle-ear sound transmission obtained by this model with those by measurements.
The guinea pig's middle ear was found to keep a flat sound transfer function in the frequency range from 1kHz to 5kHz by changing its vibration mode gradually.View full abstractDownload PDF (1575K) -
Keiko Takada, Toshimasa Matsuhira, Koichi Yamashita, Koichi Tomoda2002 Volume 45 Issue 4 Pages 298-305
Published: August 31, 2002
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSBy examining pure-tone and speech audiometric test results of 183 ears with sensorineural hearing loss, we investigated a simple procedure for selecting test speech levels to obtain the maximum recognition score efficiently in speech recognition test.
1. Maximum speech recognition score (within 10%) was obtained at the speech level estimated from the mean hearing threshold level (HTL) of the ear in 87.4% (160 ears) of the subjects.
2. From the analysis of speech recognition curves of the subjects, rules of selecting subsequent speech levels to be tested were determined for each of the 3 groups classified by mean HTL.
3. It was assumed that the maximum speech recognition scores is obtained in all the subjects by testing 4 speech levels at maximum if the above rules were adopted.View full abstractDownload PDF (973K) -
Toshiyuki Fujisaki, Tadashi Wada, Masayuki Kabeya, Hitoshi Sato, Sugat ...2002 Volume 45 Issue 4 Pages 306-311
Published: August 31, 2002
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA 58-year-old woman with idiopathic hypertrophic cranial pachymeningitis presented with right progressive sensorineural hearing loss and tinnitus. Transient mild dysphagia and several attacks of rotatory vertigo were also observed. Gadolinium-enhanced MRI revealed diffuse linear enhancement of posterior f ossa dura. Cerebrospinal fluid analysis showed mild elevation of monocytes. Dural thickening was normalized after corticosteroid administration on MRI and tinnitus was improved but hearing loss was not improve. No recurrence of the disease was observed after tapering of corticosteroid. ABR at early stage of the disease showed elongation of I-III inter-wave latency, that suggested the cochlear nerve encasement by hypertrophic dura. Additionally, the positive SISI test and type II of Bekesy audiometry suggested cochlear impairment caused by vascular insufficiency. Down beat positional nystagmus suggested some damage in the posterior fossa.View full abstractDownload PDF (2398K)
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