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Biomedical subjects

Kaoru Ogawa

Publications and source records attributed to Kaoru Ogawa.

At least 19 recordsLinked to original sources
PubMed2006

Pulse-oximetery is useful in determining the indications for adeno-tonsillectomy in pediatric sleep-disordered breathing.

OBJECTIVE: Although first line therapy of sleep-disordered breathing (SDB) in children is adeno-tonsillectomy, the indications for this operation have not yet been clearly established. We investigated whether pulse-oximetry is useful for determining the optional treatment modality for pediatric SDB. METHOD: Two hundred and thirty-two children presenting with snoring and gasping had their oxygen saturation levels examined during sleep. Among them, 86 underwent on adeno-tonsillectomy and were evaluated pre- and post-surgery. We also examined 25 healthy children as controls. RESULTS: Little desaturation was observed in healthy children. The difference in oxygen saturation levels of the patients between pre- and post-surgery was closely correlated with the pre-surgery levels. We examined the reaction operation characteristics and concluded that children with an oxygen desaturation index of 4% or more (ODI4) of more than 1.5 and/or ODI3 of more than 3.5 should undergo surgery. CONCLUSION: Pulse-oximetry is useful in determining the indications for adeno-tonsillectomy.

Adenoidectomy↗
PubMed2006

Cholesterol granuloma surrounding the endolymphatic sac.

We report a unique case of cholesterol granuloma (CG) surrounding the endolymphatic sac (ES). A 49-year-old man presented with the left side of sensorineural hearing loss, tinnitus, and vertigo. Magnetic resonance and computed tomography imaging revealed a CG surrounding the left ES. The patient initially underwent left transmastoid surgical resection of the tumor. At the time of surgery, brown fluid was aspirated from the tumor, but no other tumors were found. Histopathological examination revealed that the tumor contained cholesterol crystals, confirming the diagnosis of CG. At his 12-month postoperative follow-up, there was no evidence of recurrence. We discuss the radiology, pathology, and surgical removal of CGs surrounding ES.

Audiometry, Pure-Tone↗
PubMed2006

Laryngeal carcinoma presenting as a large anterior neck abscess.

Laryngeal carcinoma presenting as a cervical abscess is rare, so that its diagnosis is not easy. We described a case of laryngeal squamous cell carcinoma presenting as a prelaryngeal large abscess. Markedly swollen false vocal fold inhibited fiberscopic examination of the vocal folds. CT scan indicated destruction of the thyroid cartilage. Although biopsies from the abscess did not reveal malignancy, laryngeal squamous cell carcinoma was confirmed by laryngomicrosurgery with laryngeal vestibulectomy. The patient was treated by total laryngectomy with neck dissection followed by radiotherapy. The abscess was thought to be formed not by direct extension and necrosis of the tumor, but by the leakage of air and mucus through the fistula on the destroyed thyroid cartilage. Precise observation and biopsy under directscopic vestibulectomy played an important role in diagnosis of malignancy inherent in severe inflammatory tissues.

Abscess↗
PubMed2006

Resorption of auditory ossicles and hearing loss in mice lacking osteoprotegerin.

Bones conduct sound in the middle ear. The three ossicles-the malleus, incus, and stapes-form a chain that transmits vibrations from the tympanic membrane to the oval window of the inner ear. Little is known about bone remodeling events in these ossicles and about potential effects of osteoporosis on hearing loss. Osteoclastic bone resorption is enhanced in Opg(-/-) mice lacking osteoprotegerin, which is a soluble decoy receptor for the osteoclastogenic cytokine RANKL. We asked whether auditory ossicles are resorbed in Opg(-/-) mice, and whether these mice suffer from impaired auditory function. All three ossicles in Opg(-/-) mice showed thinning, especially at the malleal manubrium and incus body. Most notably, unlike in the case in wild-type mice, the junction between the stapes and the otic capsule was fixed in Opg(-/-) mice, and the stapedial footplate was thinner and broader. Radiological analyses revealed that malleal cortical thickness was positively correlated with tibial bone mineral density in Opg(-/-) and control littermate mice. Furthermore, progressive hearing loss was detected in Opg(-/-) mice starting at 6 to 15 weeks of age. These data suggest that osteoprotegerin plays a crucial role in hearing by protecting the auditory ossicles and otic capsule from osteoclastic bone resorption.

Acoustic Stimulation↗
PubMed2006

Adenoviral gene transfer of BDNF and GDNF synergistically prevent motoneuron loss in the nucleus ambiguus.

We have previously shown that neuroprotective effects of an adenoviral glial cell line-derived neurotrophic factor (GDNF) gene transfer on the lesioned adult rat motoneurons in the nucleus ambiguus. In the present study, we examined neuroprotective effects of adenoviral gene transfer of brain-derived neurotrophic factor (BDNF) or/and GDNF to motoneurons in nucleus ambiguus using an adult rat vagal nerve avulsion model. The animals avulsed and inoculated with adenoviral vectors encoding BDNF (AxCAmBDNFME) or/and GDNF (AxCAhGDNF) showed immunolabeling for BDNF or/and GDNF in the nucleus ambiguus on the treated side, respectively, and expression of virus-induced BDNF or/and GDNF mRNA transcripts in the brainstem tissue that contained the nucleus ambiguus of the treated side. The treatment with AxCAhGDNF or AxCAmBDNFME significantly prevented the loss of vagal motoneurons in comparison to the control; the protective effect of AxCAmBDNFME was greater than that of AxCAhGDNF. The combined treatment with AxCAmBDNFME and AxCAhGDNF acted synergistically and significantly larger number of vagal motoneurons was preserved as compared to either AxCAmBDNFME treatment or AxCAhGDNF treatment. The treatment with AxCAmBDNFME or/and AxCAhGDNF after avulsion also suppressed the activity of nitric oxide synthase in lesioned motoneurons in the nucleus ambiguus. These results indicate that adenovirus-mediated BDNF and GDNF gene transfer may prevent the degeneration of motoneurons in humans after either vagal nerve injury or recurrent laryngeal nerve injury.

Adenoviridae↗
PubMed2006

Suitability of calcium phosphate cement for injection laryngoplasty in rabbits.

Calcium phosphate cement (CPC) consists of powder and liquid, which become an injectable paste after mixing, self-hardening and recrystallizing to calcium hydroxylapatite (CaHA) after injection into a living body. In this study, we investigated the suitability of CPC as an injectable material for injection laryngoplasty using rabbits. All rabbits underwent left recurrent laryngeal nerve section and injection laryngoplasty with CPC. At 7 days, scanning electron microscopic findings revealed that complete recrystallization from CPC to CaHA was achieved in the larynx. At 1, 3, and 6 months, injected CPC stayed in the paraglottic space and did not migrate, and the average remaining CPC volume percentage was 91.7%. Focal foreign body reaction to injected CPC was almost the same as that of autologous fat for all time periods observed. These results indicated that CPC appears to be biocompatible, nonabsorbable, nonmigratory, and suitable for injection laryngoplasty.

Animals↗
PubMed2006

Proinflammatory cytokines expression in noise-induced damaged cochlea.

Recent studies have showed that inflammatory responses occur in inner ear under various damaging conditions including noise-overstimulation. We evaluated the time-dependent expression of proinflammatory cytokines in noise-exposed rat cochlea. Among several detected cytokines, real-time RT-PCR showed that interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) were significantly induced 3 hr after noise exposure, and quickly downregulated to the basal level. Tumor necrosis factor-alpha (TNF-alpha) was also slightly upregulated immediately after noise exposure. Immunohistochemical analysis showed that IL-6 expression was distinctively induced within the lateral side of the spiral ligament. Sequential expression analysis showed that IL-6 immunoreactivity was initially found in the cytoplasm of lateral wall cells, including Type IV and III fibrocytes, and expanded broader throughout the lateral wall, finally to the stria vascularis. Because of the negative Iba-1 staining, IL-6 expression in the early-phase was not due to macrophage or microglia activation. IL-6 was also detected in spiral ganglion neurons at 12 and 24 hr after noise exposure. Our data demonstrates the production of proinflammatory cytokines, including TNF-alpha, IL-1beta, and IL-6, in early phase of noise overstimulated cochlea. IL-6 expression was observed in the spiral ligament, stria vascularis, and spiral ganglion neurons. These cytokines, produced by the cochlear structure itself in response to noise exposure, may initiate an inflammatory response and have some role in the mechanism of noise-induced cochlear damage.

Animals↗
PubMed2006

[Clinical experience with silicon pharyngeal tube for pharyngocutaneous fistula and cervical esophagus stenosis].

Total laryngectomy or laryngopharyngectomy are commonly performed for the treatment of laryngeal cancer or hypopharyngeal cancer. However pharyngocutaneous fistula and cervical esophageal stenosis have been reported as postoperative complications of these procedures. We used a silicon pharyngeal tube in cases that developed pharyngocutaneous fistula and cervical esophageal stenosis. The pharyngeal tube was useful for controlling aspiration pneumonia and for starting oral feeding in a case of pharyngocutaneous fistula after a total laryngectomy. It was also helpful for starting oral feeding in a case with cervical esophageal stenosis after total laryngopharyngectomy and free jejunum interposition. This patient was able to maintain a good quality of life until re-operation. Adverse effects from the insertion of the tube included a foreign body sensation and pharyngeal pain that was tolerable with the use of NSAIDs for a short time. Silicon pharyngeal tubes are useful for the treatment of pharyngocutaneous fistula and cervical esophageal stenosis.

Aged↗
PubMed2006

[Surgical management of parapharyngeal space tumors].

Despite its rarity, information on the diagnosis of parapharyngeal space tumors such as through imaging and aspiration biopsy cytology, is slowly accumulating. Little detailed examination has been conducted, however, on surgical approach, complications, and sequelae. We report the results of a retrospective review of 27 patients with primary parapharyngeal space tumors-25 with benign disease and 2 with malignant lesions-treated surgically. Surgical approach, postoperative complications, sequelae, and operative indications of parapharyngeal space tumors were examined in 28 operations on the 27 patients. Tumors found in the prestyloid region in CT or MRI are treated as salivary gland or malignant tumors. Those found in the poststyloid region are treated as shwannoma or paraganglioma. The transcervical approach is often used in patients with shwannoma, while a variety of approaches are selected for patients with salivary gland tumors. Complications occur in 50% of patients, however, bias based on pathological diagnosis has not been examined to the degree needed. Sequelae in our series occurred in 46.4% of our patients. Sequela in the patients with shwannoma, however, is 81.8%, compared to 9.1% in patients with salivary gland tumors. Prestyloid parapharyngeal space tumors seem to be "automatically" indicated for surgery, because the surgical risk is lower than the risk of inaction. In poststyloid parapharyngeal space tumors, however, it appears necessary to judge indication for surgery more carefully while considering the social background, age, and occupation of prospective surgical candidates.

Adult↗
PubMed2005

Nuclear factor-kappa B nuclear translocation in the cochlea of mice following acoustic overstimulation.

There is increasing evidence to suggest that the expression of many molecules in the lateral wall of the cochlea plays an important role in noise-induced stress responses. In this study, activation of the nuclear transcription factor nuclear factor-kappa B (NF-kappaB) was investigated in the cochlea of mice treated with intense noise exposure (4 kHz, octave band, 124 dB, for 2 h). The present noise exposure led to remarkable auditory brainstem response threshold shifts and cochlear damage on surface preparations. To assess the effects of noise exposure on NF-kappaB/DNA binding activity in the cochlea, we prepared nuclear extracts from the cochlea at different time points after noise exposure and carried out an electrophoretic mobility shift assay using a probe specific to NF-kappaB. NF-kappaB/DNA binding was significantly enhanced in the cochlea 2-6 h after noise exposure and returned to basal levels after 12 h. Supershift analysis using antibodies against p65 and p50 proteins, which are components of NF-kappaB, demonstrated that enhancement of NF-kappaB/DNA binding was at least in part due to nuclear translocation of p65. An immunohistochemical study also showed that nuclear translocation of both p65 and p50 was observed in the lateral wall after noise exposure and that there may be a possible close association between p65 and enhanced inducible nitric oxide synthase expression. These results suggest that NF-kappaB may have a detrimental role in the response to acoustic overstimulation in the cochlea of mice.

Acoustic Stimulation↗
PubMed2005

Intercalated duct cell is starting point in development of pancreatic ductal carcinoma?

BACKGROUND: Although it is well known that the pancreatic ductal carcinoma may develop having a relationship to the mucous gland hyperplasia (MGH) with atypia (PanIN-1B by PanIN system), the starting point of this atypical MGH is unclear. To know it, we examined the pancreas tissue using many methods described below. METHODS: 1. Twenty-seven surgically resected pancreas tissue specimens, including pancreatic ductal carcinomas (PDC), chronic pancreatitis and normal pancreas, were investigated using immunohistochemical stainings for MUC1, MUC6, 45M1, Ki67 and p53. 2. DNA extraction and analysis of K-ras mutation at codon 12 using microdissection method: The paraffin blocks with 16 regions including the intercalated duct cell (IC) adjacent to the atypical MGH were prepared for DNA extraction. Mutation of K-ras codon 12 was analyzed and compared in enriched polymerase chain reaction-enzyme-linked mini sequence assay (PCR-ELMA). RESULTS: 1. In the normal pancreas, although no positive cell was seen in 45M1, p53, Ki67, the cytoplasm of IC were always positive for MUC1 and sometimes positive for MUC6. In the pancreas with fibrosis or inflammation, MGH was positive for MUC6 and 45M1. And atypical MGH was positive for MUC1, MUC6 and 45M1. Some IC adjacent to the atypical MGH was positive for Ki67 as well as atypical MGH. The carcinoma cells in all cases of PDC were diffusely positive for MUC1, 45M1, p53 and Ki67, and focally positive for MUC6. 2. In K-ras mutation, we examined the regions including IC adjacent to the atypical MGH, because the immunohistochemical apomucin stainings of these regions resembled those of PDC as described above. And K-ras mutation was confirmed in 12 of 16 regions (75%). All mutations were a single mutation, in 6 regions GTT was detected, in 4 regions GAT was detected and in 2 region AGT was detected. CONCLUSION: Some intercalated duct cell may be the starting point of the pancreatic ductal carcinoma, because the exhibitions of mucin expressions, Ki67, p53 and K-ras mutation in some intercalated duct cell resembled those of mucous gland hyperplasia or pancreatic ductal carcinoma.

Journal Article↗
PubMed2005

Infantile congenital petrosal cholesteatoma: a case report and literature review.

Congenital cholesteatoma of the middle ear is frequently seen in younger children including infant. By contrast, that of the petrous bone is rarely seen in younger children. We report an exceptional case occurring in 23-month-old infant who presented with unilateral facial nerve paralysis at about 18-month-old. Computed tomography and magnetic resonance imaging revealed congenital cholesteatoma measuring approximately 2 cm in the area of the right geniculate ganglion. The mass was completely eradicated via the middle fossa approach, which allowed for preservation of hearing. The facial nerve maintained intact during surgery and paralysis showed partial recovery after the operation. To our knowledge, the present case seems to be the youngest case of congenital petrosal cholesteatoma reported, and also demonstrates congenital petrosal cholesteatoma could exhibit facial nerve paralysis in early childhood.

Audiometry, Evoked Response↗
PubMed2005

Permanent threshold shift caused by acute cochlear mitochondrial dysfunction is primarily mediated by degeneration of the lateral wall of the cochlea.

Mitochondrial dysfunction in the cochlea is thought to be an important cause of sensorineural hearing loss. Recently, we have established a novel rat model with acute hearing impairment caused by exposure to the mitochondrial toxin 3-nitropropionic acid (3-NP) to analyze the mechanism of cochlear mitochondrial dysfunction. Both permanent and temporary threshold shifts were observed in this model depending on the amount of 3-NP used to induce hearing impairment. In this study, we demonstrate cochlear morphological changes in the permanent threshold shift model. Marked degeneration was detected in type 2 fibrocytes in the spiral prominence, type 4 fibrocytes in the spiral ligament, marginal cells and intermediate cells in the stria vascularis 3 h after 3-NP administration; these changes were progressive for at least 14 days. Less prominent degeneration was detected in type 1 and type 3 fibrocytes in the spiral ligament. These results indicate that permanent threshold shift caused by acute cochlear mitochondrial dysfunction is primarily mediated by cellular degeneration in the lateral wall of the cochlea, and suggest that therapy of cochlear hearing loss due to acute energy failure may be achieved through protection and regeneration of the cochlear lateral wall.

Acute Disease↗
PubMed2005

Tenascin-C is upregulated in the skin lesions of patients with atopic dermatitis.

BACKGROUND: Tenascin-C is a large, hexameric extracellular matrix glycoprotein that is expressed during embryogenesis, carcinogenesis and wound healing. In normal adult human skin the expression level of tenascin-C is low, but levels are elevated in skin tumors and rise significantly in the dermal compartment during wound healing. Although the expression of tenascin-C could be upregulated by inflammatory cytokines, the role of tenascin-C in atopic dermatitis (AD) is still unclear. OBJECTIVE: To identify genes that plays a role in AD. METHODS: We screened for differentially expressed genes in lesional and non-lesional skin of AD patients using DNA microarray. Then we monitored with quantitative PCR the expression of the novel disease related genes in human keratinocytes or pinnae from NC/Nga mice. RESULTS: We found that tenascin-C gene expression was expressed at higher levels in lesional skin compared to non-lesional skin of the patients, whereas it was not upregulated in the skin of psoriatic patients or healthy controls. In human cultured keratinocytes, tenascin-C was markedly upregulated by IL-4 and IL-13, and moderately upregulated by IFN-gamma. Tenascin-C expression was also upregulated in the AD-like skin lesions induced in NC/Nga mice ears by intradermal injection of mite antigen, and this upregulation was inhibited by prednisolone. CONCLUSION: These results suggest that upregulation of the tenascin-C expression is specific to AD lesions, and that tenascin-C may therefore play a critical role in regulating the underlining inflammatory processes, which are involved in the pathology of AD.

Animals↗
PubMed2005

Brl1p -- a novel nuclear envelope protein required for nuclear transport.

In this article, we identify a cold-sensitive mutant of Xpo1p designated as xop1-2 (but will be referred to from here on as xpo1-ok) that is synthetically lethal with srm1-1, a Saccharomyces cerevisiae RCC1 homolog. xpo1-ok was a novel mutated allele with a single point mutation, T283P. Suppressors of xpo1-ok were isolated, and one of them was found to encode a novel nuclear envelope integral membrane protein designated as Brl1p (Brr6 like protein no. 1). Brl1p is homologous with Brr6p at the C-terminal domain, which is well conserved in the Brr6/Brl1 family. To characterize the function of Brl1p, a series of temperature-sensitive mutants of Brl1p were isolated. All of brl1 mutations were localized to the conserved C-terminal domain that is essential for a function of Brl1p. Some brl1 alleles showed defects in nuclear export of either mRNA or protein, and nuclear pore clustering, similar to brr6-1. The cellular localization of Brl1p is also similar to that of Brr6p. The genetic analysis suggested that Brl1p functionally interacts with Brr6p. An interaction of Brl1p with Brr6p was shown by the two-hybrid method. We hypothesize that Brl1p functions for nuclear export as a complex with Brr6p.

Active Transport, Cell Nucleus↗
PubMed2005

[Evaluation of the quality of life in sudden deafness patients by HHIA (hearing Hatidicap Inventory) and questionnaire].

After treatments, several patients with sudden deafness (SD) continued to have symptoms, including hearing loss, tinnitus and dizziness. These unresolved symptoms and their effect on the quality of life (QOL) in SD patients have not been studied. We evaluated QOL using the Hearing handicap inventory (HHIA) and an original questionnaire in SD patients who had been treated more than 6 months prior to the study. Compared to results in bilateral sensorineural hearing were significantly lower in SD patients (p<0.01). In bil SNHL, this score peaked two to 10 years after onset of disease and decreased thereafter. The score peaked more than 10 years after onset of disease in patients with SD. While hearing and test scores were correlated in bil-SNHL, this was not observed in SD. About half of patients were embarrassed by hearing loss and tinnitus after treatment. Among patients who scored more than 44 points on HHIA, all reported hearing loss and tinnitus. When asked about subjective changes in hearing after treatment, 27% believed their hearing had improved, 60% believed there was no change, and 13% believed their hearing had deteriorated. Cases believing deterioration in hearing also had high scores on HHIA. Sequelae of SD may worsen QOL, driving embarrassed patients to visit other medical facilities in to improve their QOL. Even though hearing may not improve after initial treatment in ears affected by SD, informed consent about the clinical course and audiological follow-up should be done.

Adult↗