Publications by authors named "Risa Tona"

Article Synopsis
  • Mutations in the TBC1D24 gene are linked to various conditions like deafness, epilepsy, and DOORS syndrome, but how these mutations lead to different health issues is still unclear.
  • Researchers conducted a study to identify new protein partners of TBC1D24 and discovered that it interacts with KIBRA, a scaffold protein involved in cognitive functions and the Hippo signaling pathway.
  • Specific mutations in the TLDc domain of TBC1D24 can disrupt its interaction with KIBRA, revealing a potential link between TBC1D24 and epilepsy, suggesting that this interaction is crucial for reducing epilepsy risk.
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Hearing depends on intricate morphologies and mechanical properties of diverse inner ear cell types. The individual contributions of various inner ear cell types into mechanical properties of the organ of Corti and the mechanisms of their integration are yet largely unknown. Using sub-100-nm spatial resolution atomic force microscopy (AFM), we mapped the Young's modulus (stiffness) of the apical surface of the different cells of the freshly dissected P5-P6 cochlear epithelium from wild-type and mice lacking either Trio and F-actin binding protein (TRIOBP) isoforms 4 and 5 or isoform 5 only.

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Although variant alleles of hundreds of genes are associated with sensorineural deafness in children, the genes and alleles involved remain largely unknown in the Sub-Saharan regions of Africa. We ascertained 56 small families mainly of Yoruba ethno-lingual ancestry in or near Ibadan, Nigeria, that had at least one individual with nonsyndromic, severe-to-profound, prelingual-onset, bilateral hearing loss not attributed to nongenetic factors. We performed a combination of exome and Sanger sequencing analyses to evaluate both nuclear and mitochondrial genomes.

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Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype-phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype-phenotype correlation.

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Hereditary deafness is clinically and genetically heterogeneous. We investigated deafness segregating as a recessive trait in two families. Audiological examinations revealed an asymmetric mild to profound hearing loss with childhood or adolescent onset.

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Human pathogenic variants of are associated with clinically heterogeneous phenotypes, including recessive nonsyndromic deafness DFNB86, dominant nonsyndromic deafness DFNA65, seizure accompanied by deafness, a variety of isolated seizure phenotypes and DOORS syndrome, characterized by deafness, onychodystrophy, osteodystrophy, intellectual disability and seizures. Thirty-five pathogenic variants of human associated with deafness have been reported. However, functions of TBC1D24 in the inner ear and the pathophysiology of TBC1D24-related deafness are unknown.

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Hepatocyte growth factor (HGF) is a multifunctional protein that signals through the MET receptor. HGF stimulates cell proliferation, cell dispersion, neuronal survival, and wound healing. In the inner ear, levels of HGF must be fine-tuned for normal hearing.

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TRIOBP remodels the cytoskeleton by forming unusually dense F-actin bundles and is implicated in human cancer, schizophrenia, and deafness. Mutations ablating human and mouse TRIOBP-4 and TRIOBP-5 isoforms are associated with profound deafness, as inner ear mechanosensory hair cells degenerate after stereocilia rootlets fail to develop. However, the mechanisms regulating formation of stereocilia rootlets by each TRIOBP isoform remain unknown.

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Article Synopsis
  • Epilepsy, deafness, and other disorders linked to TBC1D24 mutations are not fully understood, prompting researchers to create a mouse model with a specific mutant gene variant associated with early infantile epileptic encephalopathy (EIEE).
  • The engineered mice exhibit normal hearing but develop spontaneous seizures around postnatal day 15, mimicking the human condition, which corresponds with a change in how the TBC1D24 protein is made during development.
  • The study highlights the important role of TBC1D24 in neuronal function and opens the door for testing new medications to treat seizure disorders linked to TBC1D24 mutations.
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KCNE1 encodes a regulatory subunit of the KCNQ1 potassium channel-complex. Both KCNE1 and KCNQ1 are necessary for normal hearing and cardiac ventricular repolarization. Recessive variants in these genes are associated with Jervell and Lange-Nielson syndrome (JLNS1 and JLNS2), a cardio-auditory syndrome characterized by congenital profound sensorineural deafness and a prolonged QT interval that can cause ventricular arrhythmias and sudden cardiac death.

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Objectives: An effect of audio-visual (AV) integration is observed when the auditory and visual stimuli are incongruent (the McGurk effect). In general, AV integration is helpful especially in subjects wearing hearing aids or cochlear implants (CIs). However, the influence of AV integration on spoken word recognition in individuals with bilateral CIs (Bi-CIs) has not been fully investigated so far.

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Objective: The objective of this study was to evaluate safety and efficacy of regenerative treatment using gelatin sponge with basic fibroblast growth factor (bFGF) in patients with tympanic membrane perforation (TMP).

Methods: The current study was a prospective, multicenter, open-label, single-arm, and exploratory clinical trial to evaluate the safety and efficacy of the TM regeneration procedure (TMRP). Myringotomy was used to mechanically disrupt the edge of the TMP, and a gelatin sponge immersed in bFGF was then placed over the perforation.

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Objective: To investigate the McGurk effect in profoundly deafened Japanese children with cochlear implants (CI) and in normal-hearing children. This was done to identify how children with profound deafness using CI established audiovisual integration during the speech acquisition period.

Methods: Twenty-four prelingually deafened children with CI and 12 age-matched normal-hearing children participated in this study.

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The solitary fibrous tumor (SFT) is a rare spindle cell neoplasm derived from mesenchymal cells. It sometimes recurs clinically, and is categorized as an 'intermediate malignancy' tumor under the WHO (World Health Organization) classification of soft tissue tumors. Several studies have reported on intraorbital SFTs, but none of them has pointed out the utility of preoperative arterial embolization in the case of an intraorbital SFT.

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Background: The efficacy of posttreatment surveillance (18) F-fluorodeoxyglucose positron emission tomography ((18) F-FDG PET)/CT was evaluated in patients with head and neck squamous cell carcinoma (HNSCC).

Methods: The subjects were 158 patients with HNSCC who underwent PET/CT after definitive treatment. PET/CT detection of subclinical recurrence or a second primary cancer and the effect of timing of PET/CT scans on survival were analyzed.

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Primary angiosarcoma is a rare disease with a poor prognosis. It most commonly arises in the head and neck region; localization in the deep soft tissue of the neck is extremely rare. We herein present a case of angiosarcoma derived from the right internal jugular vein.

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Objective: Kawasaki disease (KD) is an acute multisystemic vasculitis of unknown etiology that occurs in infants and children. Retropharyngeal cellulitis has been reported as a rare manifestation of KD. This study investigated the frequency and characteristics of patients with KD manifesting as retropharyngeal soft-tissue swelling.

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Background: The purpose of this study was to determine whether pretreatment 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET/CT) volume-based parameters, such as metabolic tumor volume and total lesion glycolysis, add more prognostic information in patients with oropharyngeal squamous cell carcinoma (SCC).

Methods: The subjects were 47 patients with oropharyngeal SCC who underwent 18F-FDG PET/CT before any treatment and followed by definitive therapy. PET parameters (metabolic tumor volume and total lesion glycolysis) and tumor p16/p53 status were evaluated retrospectively.

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Backgrounds: A p16 protein is known to be overexpressed in human papillomavirus-positive head and neck squamous cell carcinoma specimens. p53 is a tumor suppressor protein detectable by immunohistochemistry in carcinogen-associated head and neck squamous cell carcinoma as a result of gene mutations. The purpose of this study is to investigate the prognostic impact of p16 and p53 expression in oropharyngeal squamous cell carcinomas.

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We report two cases of elderly diabetic men with skull base osteomyelitis (SBO) originating from malignant external otitis (MEO). In both, a devastating infection and neural paralysis deteriorated after conventional therapy, including long-term intravenous administration of culture-directed antibiotics with strict control of blood sugar levels and surgical debridement of infectious granulation tissue. Since poor perfusion of antibiotics in the lesion may be associated with serious nature of MEO/SBO, we administered antibiotics intra-arterially via a retrograde catheter with the tip set at the proximal point of the external carotid artery to increase the tissue drug concentration in the maxillary artery (MA) and ascending pharyngeal artery (APA) supply areas, in which intense inflammation was observed.

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Conclusion: The extent of middle ear aeration before second-stage canal wall-down (CWD) tympanoplasty was correlated with postoperative middle ear stability.

Objective: To evaluate middle ear aeration before second-stage CWD tympanoplasty as a predictor of postoperative re-aeration potential and external auditory canal (EAC) stability in staged CWD tympanoplasty with soft-wall reconstruction (SWR).

Methods: Middle ear aeration was evaluated before and at 1 year after the second-stage operation in patients who underwent staged CWD tympanoplasty with SWR for middle ear cholesteatoma.

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Conclusion: Rapidly progressive bilateral sensorineural hearing loss (SNHL) often develops as a symptom of intracranial diseases or systemic vasculitis. For early diagnosis and treatment of these potentially fatal diseases, a history of hearing deterioration within 2 months and associated symptoms may be important.

Objectives: To reveal clinical features and causative diseases for rapidly progressive bilateral SNHL.

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