Ken Kitamura

Tsuchiura Kyodo General Hospital, Tsukuba, Ibaraki, Japan

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Publications (167)178.39 Total impact

  • Yurika Kimura · Nao Makino · Hitome Kobayashi · Ken Kitamura ·

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    ABSTRACT: Objective: To characterize the long-term outcomes of meatoplasty using our new technique, inferiorly based retroauricular island pedicle flap for external auditory canal (EAC) stenosis. Methods: A long-term clinical analysis of meatoplasty for nine patients (mean age, 33 years; age range, 8-64 years) with stenotic EAC was performed. The follow-up period after meatoplasty ranged from 5 years to 14 years, with a mean duration of 8.4 years. We compared preoperative and postoperative otoscopic findings, high-resolution computed tomographic (CT) images of the EAC, and hearing levels. Results: Otoscopic examinations demonstrated widened EAC in eight of the nine patients. There was a significant increase in the size of the EAC on postoperative CT examinations when compared with the preoperative state. The hearing outcome in all patients was variable. The postoperative air-bone gap (ABG) was closed to 10dB or less in two cases, while the other seven cases showed ABG ranging from 15.0dB to 57.5dB. Conclusions: We performed meatoplasty using inferiorly based retroauricular island pedicle flap for nine patients with EAC stenosis and eight of the nine patients demonstrated satisfactory patent EAC during a mean follow-up of 8.4 years.
    Auris, nasus, larynx 10/2015; DOI:10.1016/j.anl.2015.09.002 · 1.14 Impact Factor
  • Yurika Kimura · Nao Makino · Motoji Sawabe · Ken Kitamura ·

    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 07/2015; DOI:10.1097/MAO.0000000000000819 · 1.79 Impact Factor
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    01/2015; 58(3):189-197. DOI:10.4295/audiology.58.189

  • Practica Otologica, Supplement 01/2015; 141:80-81. DOI:10.5631/jibirinsuppl.141.80
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    ABSTRACT: Croup is an acute respiratory tract inflammation characterized by swelling of the subglottic tissue caused by an infection with respiratory viruses such as parainfluenza virus, influenza virus, adenovirus and respiratory syncytial virus. Its symptoms include fever, barking cough, stridor and hoarseness. It is a relatively common condition in childhood, especially at younger than three years of age. Since it rarely occurs in adulthood, the clinical features of adult croup are mostly unknown. We report herein on three cases of adult croup and review another 17 cases of adult croup described in the literatures written in English or Japanese. The clinical features of adult croup were compared to that of croup in children. The patients with adult croup present with symptoms such as sore throat and dysphagia in addition to the symptoms that are common for croup in children. A coronal neck X-ray revealed a characteristic narrowing of the subglottic trachea, the steeple sign, in all cases. Although flexible laryngoscopy also has a high diagnostic value, it is necessary to pay careful attention to the clinical findings of possible airway obstruction. Two of our three cases and eight of 17 reported cases required airway management, indicating a much more severe condition in adults compared to that in children. Another clinical characteristics of adult cases include that only very severe cases have been diagnosed as croup. A rise of antigen titer against parainfluenza virus type 3 was detected in one case, while influenza virus antigen was detected in the other two cases.
    Practica Otologica, Supplement 01/2015; 141(10):82-83. DOI:10.5631/jibirinsuppl.141.82
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    ABSTRACT: Drawing illustrates the distribution of kainate receptor subunits, GluK1,2,4,5, and the AMPA receptor subunit, GluA2, at synapses on inner (IHC) and outer (OHC) hair cells in the adult rat, as described in this study. At IHC afferent (a) synapses, GluA2, GluK2 and GluK5 are postsynaptic and GluK2 is presynaptic. OHC afferent synapses bearing ribbons (usually one or two; colored green in drawing) have GluK2 and GluK5, while those lacking ribbons have small amounts of GluK5 only; efferent (e) synapses have GluK1, GluK2, and GluK5.
    Hearing Research 08/2014; 314. DOI:10.1016/j.heares.2014.05.001 · 2.97 Impact Factor
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    ABSTRACT: Conclusion: Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) is considered to be a distinct entity in Japan. The combination of both HPV-DNA sequencing analysis and immunohistochemistry (IHC) for p16(INK4A) is useful to discriminate the OPSCC patients with a better prognosis from other cases, especially in the advanced stage. Surgical treatment is recommended for HPV-negative advanced cancer. Objective: The number of HPV-related OPSCCs has been increasing worldwide. However, the incidence and prognostic significance of this cancer in Japan have not yet been fully elucidated. Methods: Seventy-seven Japanese patients with OPSCC were enrolled in this study. The prevalence of HPV-DNA was assessed by PCR and sequencing. The expression of p16(INK4A) and p53 was examined by IHC. The clinicopathological parameters and disease-specific survival were analyzed for HPV-positive and -negative patients. Results: HPV-DNA was detected in 32 patients. Thirty-four patients were p16(INK4A)-positive by IHC. The patients who were positive for HPV infection were significantly younger. Furthermore, in the stage III or IV cases, the 3-year disease-specific survival of the HPV infection-positive group was significantly better than that of the HPV-negative group. Surgical treatment was demonstrated to lead to a good prognosis for the patients with HPV-negative advanced cancer.
    Acta Oto-Laryngologica 07/2014; 134(12). DOI:10.3109/00016489.2014.944272 · 1.10 Impact Factor
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    Ayako Maruyama · Takao Tokumaru · Ken Kitamura ·
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    ABSTRACT: Introduction Pleomorphic adenoma accounts for 65 percent of all salivary gland tumors. It has been identified in several anatomical regions, but pleomorphic adenoma arising in the ear canal, first described in 1951, is extremely rare. Case presentation A 40-year-old Japanese man’s left ear canal was obstructed by a pleomorphic adenoma that caused mild conductive hearing loss. The tumor was resected and he remains disease-free two years after surgery. Conclusions Pleomorphic adenoma usually arises from a major and minor salivary gland, but pleomorphic adenoma of the ear canal is derived from the ceruminous gland. We discuss the present case and 37 other case reports in our effort to clarify the clinical features and the course of pleomorphic adenoma in the ear canal.
    Journal of Medical Case Reports 06/2014; 8(1):178. DOI:10.1186/1752-1947-8-178
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    ABSTRACT: Hypothesis: Micro-computed tomography (micro-CT) is useful for assessing the 3-dimensional (3D) morphology and age-related changes of the otoconial layer. Background: Wriggle mouse Sagami (WMS) is a mutant of the plasma membrane Ca2+ ATPase type2 gene (Atp2b2) with deficits in the saccular otoconia. We examined the effectiveness of micro-CT in evaluating the otoconial layer of WMS and C57BL/6J mice. Methods: Otic capsules of C57BL/6J mice at different fixation time were examined using micro-CT to evaluate the effects of the fixation time on the otoconial layer. Otic capsules of Atp2b2wri/wri, Atp2b2wri/+, and Atp2b2+/+ mice at P14, P21, and the age of 3 months were used to analyze age-related changes in the otoconial layer. A series of cross-section and 3D reconstructed images of the otoconial layer were obtained. The micro-CT findings were compared with the otic capsule findings cleared in methyl salicylate using stereomicroscopy. Results: Micro-CT produced high-resolution images of the otoconial layer, thereby providing information regarding the spatial configuration and 3D curvature. There were no changes between the different fixation times. In the Atp2b2wri/+ and Atp2b2+/+ mice, the saccular and utricular otoconial layers were normal among all age groups. In the Atp2b2wri/wri mice, the saccular otoconial layer decreased on P14 and was absent on P21, whereas the utricular otoconial layer disappeared at 3 months of age. Conclusion: We obtained precise information regarding the mouse otoconial layer with minimum artifacts. This method is expected to improve our understanding of the physiologic function and age-related changes in otolith organs.
    Ontology & Neurotology 06/2014; 36(2). DOI:10.1097/MAO.0000000000000376 · 1.79 Impact Factor
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    ABSTRACT: Conclusion: The long-term follow-up study revealed a good audiovestibular prognosis in our patients with Vogt-Koyanagi-Harada disease (VKH) after adequate treatment. Objectives: To evaluate the audiovestibular findings and long-term prognosis of patients with VKH. Methods: A total of 82 ears in 41 patients (9 males and 32 females, aged 18-78 years) with VKH were examined in the audiovestibular study. Of the 41 patients, 16 patients with follow-up periods of more than 12 months (13-158 months) were included in the long-term follow-up study. Audiovestibular examinations included pure-tone audiometry; positional, positioning, and spontaneous nystagmus tests; and a caloric test. Results: Among the 41 patients, 28 (68%) complained of auditory symptoms at the initial visit and 28 (68%) showed sensorineural hearing loss (SNHL). Of the 24 patients who underwent nystagmus tests, only 3 (13%) presented with vestibular symptoms whereas 11 (46%) had nystagmus. Among 32 ears in 16 patients enrolled in the long-term follow-up study, 19 ears showed SNHL at the initial visit. The SNHL returned to normal in 14 ears (74%) and remained minimal in severity in the other 5 ears (26%) at the last visit. None of the patients showed persistent or repetitive vestibular symptoms.
    Acta oto-laryngologica 04/2014; 134(4):339-44. DOI:10.3109/00016489.2013.868604 · 1.10 Impact Factor
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    ABSTRACT: Mutations in DFNA5 lead to autosomal dominant nonsyndromic hereditary hearing loss (NSHHL). To date, four different mutations in DFNA5 have been reported to cause hearing loss. A 3 bp deletion mutation (c.991-15_991-13del) was identified in Chinese and Korean families with autosomal dominant NSHHL, which suggested that the 3 bp deletion mutation was derived from a single origin. In the present study, we performed genetic screening of mutations in the interval between intron 6 and exon 9 of DFNA5 in 65 Japanese patients with autosomal dominant NSHHL and identified the c.991-15_991-13del mutation in two patients. Furthermore, we compared the DFNA5-linked haplotypes consisting of intragenic SNPs between the reported Chinese and Korean families and found that the Japanese patients showed a shared region spanning 41,874 bp. This is the first report of DFNA5 mutations in Japanese patients with autosomal dominant NSHHL, supporting the suggestion that the 3 bp deletion mutation occurred in their ancestors.
    Annals of Human Genetics 02/2014; 78(2). DOI:10.1111/ahg.12053 · 2.21 Impact Factor

  • 01/2014; 57(1):63-70. DOI:10.4295/audiology.57.63
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    ABSTRACT: Objective: Molecular analysis using archival human inner ear specimens is challenging because of the anatomical complexity, long-term fixation, and decalcification. However, this method may provide great benefit for elucidation of otological diseases. Here, we extracted mRNA for RT-PCR from tissues dissected from archival FFPE human inner ears by laser microdissection. Methods: Three human temporal bones obtained at autopsy were fixed in formalin, decalcified by EDTA, and embedded in paraffin. The samples were isolated into spiral ligaments, outer hair cells, spiral ganglion cells, and stria vascularis by laser microdissection. RNA was extracted and heat-treated in 10 mM citrate buffer to remove the formalin-derived modification. To identify the sites where COCH and SLC26A5 mRNA were expressed, semi-nested RT-PCR was performed. We also examined how long COCH mRNA could be amplified by semi-nested RT-PCR in archival temporal bone. Results: COCH was expressed in the spiral ligament and stria vascularis. However, SLC26A5 was expressed only in outer hair cells. The maximum base length of COCH mRNA amplified by RT-PCR was 98 bp in 1 case and 123 bp in 2 cases. Conclusion: We detected COCH and SLC26A5 mRNA in specific structures and cells of the inner ear from archival human temporal bone. Our innovative method using laser microdissection and semi-nested RT-PCR should advance future RNA study of human inner ear diseases.
    Hearing research 05/2013; 302. DOI:10.1016/j.heares.2013.04.008 · 2.97 Impact Factor
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    ABSTRACT: Hearing loss (HL) is the most common sensory disorder in humans. Many patients with mitochondrial diseases have sensorineural HL (SNHL). The HL of these patients manifests as a consequence of either syndromic or nonsyndromic mitochondrial diseases. Furthermore, the phenotypes vary among patients even if they are carrying the same mutation. Therefore, these features make it necessary to analyze every presumed mutation in patients with hereditary HL, but the extensive analysis of various mutations is laborious. We analyzed 373 patients with suspected hereditary HL by using an extended suspension-array screening system for major mitochondrial DNA (mtDNA) mutations, which can detect 32 other mtDNA mutations in addition to the previously analyzed 29 mutations. In the present study, we detected 2 different mtDNA mutations among these 373 patients; m.7444G>A in the MT-CO1 gene and m.7472insC in the MT-TS1 gene in 1 patient (0.3%) for each. As these two patients had no clinical features other than HL, they had not been suspected of having mtDNA mutations. This extended screening system together with the previous one is useful for the genetic diagnosis and epidemiological study of both syndromic and nonsyndromic HL.Journal of Human Genetics advance online publication, 13 September 2012; doi:10.1038/jhg.2012.109.
    Journal of Human Genetics 09/2012; 57(12). DOI:10.1038/jhg.2012.109 · 2.46 Impact Factor
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    ABSTRACT: When we assess anatomical problems and the safety and effectiveness for performing a difficult surgical procedure or planning novel surgical approaches, preoperative human dissections are very helpful. However, embalming with the conventional formaldehyde method makes the soft tissue of the cadaver harder than that of a living body. Therefore, the cadaver embalmed with conventional formaldehyde is not appropriate for dissections when assess surgical approaches. Thiel's method is a novel embalming technique, first reported by W. Theil in 1992. This method can preserve color and softness of the cadaver without risk of infections. We have used cadavers embalmed with Thiel's method for preoperative assessments and have confirmed the usefulness of this method especially for the prevention of complications or in assessing surgical approaches. The cadaver embalmed with this method has several advantages over other embalming methods and it might be also useful for the developments of new surgical devices or evaluation of a surgeon's skill.
    Nippon Jibiinkoka Gakkai Kaiho 08/2012; 115(8):791-4. DOI:10.3950/jibiinkoka.115.791
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    ABSTRACT: Conclusion: Haplogroup D4b, especially subhaplogroup D4b2, may be one of the modifiers associated with the phenotypic expression of hereditary hearing loss (HL). Objectives: The present study investigated the association between suspected hereditary HL and 12 major mtDNA haplogroups in a Japanese population. Besides the mutations of mitochondrial DNA, many modifiers including environmental factors and genetic polymorphisms are involved in HL. Methods: The subjects comprised 373 unrelated Japanese patients with suspected hereditary HL and 480 controls. Twenty of the 373 patients were excluded from the study because the m.1555A>G or the m.3243A>G mutation had been detected in them. The mitochondrial haplotypes were classified into 12 major Japanese haplogroups (i.e. F, B, A, N9a, N9b, M7a, M7b, G1, G2, D4a, D4b, and D5). The frequency of each haplogroup in patients with HL was compared with that of the controls using the chi-squared test. Results: The frequency of the HL patients carrying the mitochondrial haplogroup D4b was significantly higher than that of the controls (37/353 [10.5%] vs 31/480 [6.5%]; OR 1.70 [95% CI 1.03-2.79, p = 0.036]) and evidence for enhancement was found in subhaplogroup D4b2 (32/353 [9.1%] vs 24/480 [5%], OR 1.89 [95% CI 1.09-3.28, p = 0.021]).
    Acta oto-laryngologica 07/2012; 132(11):1178-82. DOI:10.3109/00016489.2012.693624 · 1.10 Impact Factor
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    ABSTRACT: We report on the case of a 51-year-old woman who presented with refractory pharyngitis caused by toxigenic Corynebacteriumn ulcerans (C. ulcerans). Thick pseudomembrane formations and yellowish pus were observed in her nasopharynx. Based on her clinical course and history of breeding cats, we considered C. ulcerans infection as the possible diagnosis. She was treated with macrolide administration and her symptoms immediately improved. C. ulcerans was identified in pus from the patient's pharynx as well as in discharge material from her cat's eyes, and C. ulcerans was thought to have caused her pharyngitis. C. ulcerans is one of the infecting bacteria which can cause a zoonotic infection. In Japan, some cases with C. ulcerans infection from cats have been reported. It is important that we should consider C. ulcerans infection as a differential diagnosis of refractory pharyngitis.
    Nippon Jibiinkoka Gakkai Kaiho 07/2012; 115(7):682-6. DOI:10.3950/jibiinkoka.115.682
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    ABSTRACT: Intralabyrinthine schwannomas (ILSs) are rare benign neoplasms arising from distal branches of the cochlear, superior vestibular, or inferior vestibular nerves. We report on a case of ILS with extensions to the round window niche and internal auditory canal (IAC) in a 47-year-old male. The patient noticed sudden hearing loss and tinnitus in his left ear at the age of 36, received steroid therapies, but was left with complete deafness. He had suffered from repetitive vertigo attacks for 6 months at 41. At 46 when he presented with deterioration of his left tinnitus, he was finally diagnosed as having ILS on enhanced MRI and constructive interference in steady-state analysis. The tumor was located in all turns of cochlea, vestibule, and the fundus of the IAC. Because follow-up MRI suggested growth of the IAC tumor, we performed total removal of the tumor via the translabyrinthine and transcanal approaches. The tumor had invaded only the cochlear nerve in the IAC and appeared in the round window niche in the middle ear. Pathological examination showed an Antoni A type schwannoma with fibrous changes of the semicircular canals. We should remember this inner
    Nippon Jibiinkoka Gakkai Kaiho 07/2012; 115(7):687-92. DOI:10.3950/jibiinkoka.115.687
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    ABSTRACT: Drug-resistant S. pneumoniae and H. influenzae, which have been major causes for otolaryngological infections are now being more frequently detected in recent years. In contrast, Cefditoren Pivoxil (CDTRPI) still preserves high antibacterial activity against both PRSP and BLNAR which are common drugresistant bacteria, and high-dose medication with this drug is recommended at the time of acute sinusitis or acute aggravation of chronic sinusitis. However, there have been few reports on the clinical efficacy of high-dose administration of CDTR-PI in the treatment of adult sinusitis. Here we examined the clinical efficacy of the treatment of CDTR-PI 200 mg 3 times daily in the treatment of these diseases. CDTR-PI 200 mg was prescribed 3 times daily for 7 to 14 days (8.2±2.2 days) in 61 patients who came for consultation during the period from June, 2009 to December, 2010. The clinical efficacy rate of the doctor's judgment was 89.8% (53/61). Based on the scoring judgment, marked improvement was demonstrated in 20 patients, and moderate improvement was found in 30 cases, which meant that 50 of 61 (82.0%) patients exhibited remarkable improvement. S. pneumoniae was detected in 7 patients, eradicated in 3 patients, and decreased in 1 patient. H. influenzae was detected in 8 patients, eradicated in 4 patients, and decreased in 2 patients. Adverse events were observed in 8 patients with diarrhea but it was not serious. In conclusion, the treatment with CDTR-PI 200 mg 3 times daily was found effective for acute sinusitis or acute aggravation of chronic sinusitis in adults.
    Practica Otologica 01/2012; 105(10):999-1009. DOI:10.5631/jibirin.105.999

Publication Stats

2k Citations
178.39 Total Impact Points


  • 2015
    • Tsuchiura Kyodo General Hospital
      Tsukuba, Ibaraki, Japan
  • 1999-2014
    • Tokyo Medical and Dental University
      • • Tokyo Medical and Dental University Hospital
      • • Department of Otolaryngology
      • • Department of Otorhinolaryngology
      • • Department of Head and Neck Surgery
      • • Department of Medicine
      Edo, Tōkyō, Japan
  • 2004
    • Teikyo University
      • Department of Medicine
      Edo, Tōkyō, Japan
  • 1990-2004
    • The University of Tokyo
      Tōkyō, Japan
  • 2003
    • Tokyo Dental College
      Edo, Tōkyō, Japan
  • 1992-2002
    • Jichi Medical University
      • Department of Otolaryngology
      Totigi, Tochigi, Japan
  • 2000
    • Harvard Medical School
      • Department of Radiology
      Boston, Massachusetts, United States
    • Iwate Medical University
      • Department of Otorhinolaryngology
      Morioka, Iwate, Japan