Gene Screening for Non-Syndromic Deafness in Hainanese Patients.

BACKGROUND: Hainan Province is the southernmost island in China, far from the mainland, and the resident population changes little. In order to understand the mutation spectrum in Hainan and provide effective genetic counseling for deaf people, we carried out genetic analysis on the non-comprehensive hearing impairment in this population. Therefore, in this study, 183 children with moderate sensorineural deafness in the northeast of Hainan were analyzed with susceptibility gene carrying and gene mutation, providing some reference for hainan to guide the prevention and treatment of deafness. METHODS: Complete clinical evaluations were performed on 183 unrelated patients with a non-syndromic hearing impairment from Hainan Province. Each subject was screened for common mutations using the matrix-assisted laser desorption ionization-time of flight mass spectrometry, including GJB2 c.35delG,c.235delC,c.299_300del AT,c.176_191del16,c.167delT; GJB3 c.538 C>T,c.547G >A;SLC26A4 IVS7-2 A>G,c.2168 A>G,c.1174A>T,c.1229 C>T,c.1226G>A,c.1975G>C,c.2027T>A,c.2162C>T,c.281C>T,c.589G>A,IVS15+5G>A; and mtRNA 1494 C>T,1555 A>G. RESULTS: Genetic analysis showed that GJB2, SLC26A4, and mitochondrial M. 1555A > G mutations accounted for 7.10%, 8.74%, and 0.55% of the etiology of non-syndromic hearing impairment, respectively. Common mutations include GJB2 C. 235delC, SLC26A4 c.I vs7-2a →G, C. 2168A→G, and mitochondrial M. 1555A > G. The total mutation rate in Hainan was 16.39%. CONCLUSION: Our study is the first one to carry out genetic analysis on non-syndromic hearing impairment in Hainan. The results show that in the cases of non-syndromic hearing impairment in these areas, there is a clear genetic cause accounted for 16.39%, and the mutation hot spots are mainly GJB2 and SLC26A4, and SLC26A4 is the most common mutation site. This study provides useful and targeted information for genetic counseling of deafness in people with non-syndromic hearing impairment in Hainan.

A dominant variant in apoptosis-related gene XKR8 is relevant to hereditary auditory neuropathy.

BACKGROUND: Auditory neuropathy is an unusual type of hearing loss. At least 40% of patients with this disease have underlying genetic causes. However, in many hereditary auditory neuropathy cases, etiology remains undetermined. METHODS: We collected data and blood samples from a four-generation Chinese family. After excluding relevant variants in known deafness-related genes, exome sequencing was conducted. Candidate genes were verified by pedigree segregation, transcript/protein expression in the mouse cochlea, and plasmid expression studies in HEK 293T cells. Moreover, a mutant mouse model was generated and underwent hearing evaluations; protein localization in the inner ear was also assessed. RESULTS: The clinical features of the family were diagnosed as auditory neuropathy. A novel variant c.710G > A (p.W237X) in apoptosis-related gene XKR8 was identified. Genotyping of 16 family members confirmed the segregation of this variant with the deafness phenotype. Both XKR8 mRNA and XKR8 protein were expressed in the mouse inner ear, predominantly in regions of spiral ganglion neurons; Moreover, this nonsense variant impaired the surface localization of XKR8 in cells. Transgenic mutant mice exhibited late-onset auditory neuropathy, and their altered XKR8 protein localization in the inner ear confirmed the damaging effects of this variant. CONCLUSIONS: We identified a variant in the XKR8 gene that is relevant to auditory neuropathy. The essential role of XKR8 in inner ear development and neural homeostasis should be explored.

Clinical Profiles and Prognoses of Adult Patients with Full-Frequency Sudden Sensorineural Hearing Loss in Combination Therapy.

We aimed to characterize the clinical profiles and short-term outcomes of adult patients with full-frequency idiopathic sudden sensorineural hearing loss (ISSNHL) treated uniformly with combination therapy, and to determine the prognostic predictors for the combination therapy. A total of 131 eligible cases hospitalized in our department from January 2018 to June 2021 were retrospectively reviewed. All enrolled cases received a standardized combination therapy employing intravenous methylprednisolone, batroxobin, and Ginkgo biloba extract during the 12 days of hospitalization. The clinical and audiometric profiles were compared between recovered patients and their unrecovered counterparts. The overall recovery rate was 57.3% in the study. Accompanying vertigo (odds ratio = 0.360, p = 0.006) and body mass index (BMI, odds ratio = 1.158, p = 0.016) were two independent predictors of hearing outcomes of the therapy. The male gender and cigarette-smoking history were marginally associated with good hearing prognosis (p = 0.051 and 0.070, respectively). Patients with BMI ≥ 22.4 kg/m2 had a better chance of hearing recovery (p = 0.02). Conclusions: Accompanying vertigo and low BMI (<22.4 kg/m2) were independently associated with poor prognosis for full-frequency ISSNHL in combination therapy. Male gender and cigarette-smoking history might be considered positive effects on hearing prognosis.

[Correlation of temporal bone HRCT, SLC26A4 gene and hearing loss in enlarged vestibular aqueduct].

Objective:To explore the correlation between high-resolution computed tomography（HRCT） of temporal bones, SLC26A4 gene mutation and hearing loss in patients with enlarged vestibular aqueduct（EVA）. Methods:The medical records of 257 subjects hospitalized for moderate to severe sensorineural hearing loss in the Department of Otolaryngology Head and Neck Surgery, Hainan General Hospital between May 2018 to 2021 were retrospectively reviewed. All included cases received audiological examination, HRCT scanning of temporal bones and SLC26A4 gene sequencing. According to the Valvassori standard, cases with the diameter from the common peduncle of the semicircular canal to the midpoint of the outer orifice of the vestibular aqueduct（MP） over 1.5 mm, or the diameter of the outer orifice of the vestibular aqueduct（OP） more than 2.0 mm were diagnosed as EVA. There were 22 cases（44 ears） of EVA in the study, aged between 6 months to 17 years old. Based on the hearing changes at birth and during growth, 18 ears of which were classified into the stable hearing group, while the other 26 ears in the unstable group. Moreover, all involved cases were grouped by MP（1.5 to <3.0 mm and ≥3.0 mm） and OP（2.0 to <4.0 mm and ≥4.0 mm）. SPSS 25.0 software was applied in the study. The correlation between hearing loss and MP and OP was analyzed. The results of HRCT of temporal bones and SLC26A4 gene sequencing were compared as well. Results:Though the size of MP and OP was not statistically different between the stable and hearing groups in EVA ears（P>0.05）, it was significantly correlated with the severity of hearing loss（P<0.05）. Of the 22 EVA patients diagnosed by HRCT, 21 were positive for SLC26A4 gene mutation. The positive rate of EVA by SLC26A4 gene sequencing was highly consistent with HRCT（Kappa=0.975）. Conclusion:The size of MP and OP in EVA patients was related to the degree of hearing loss, but not to the stable nature of hearing loss. Temporal bone HRCT scanning and SLC26A4 gene sequencing are highly consistent in the diagnosis of EVA. The latter has no radiation and can be combined with hearing screening for early diagnosis of EVA.

Inhibition of Histone Methyltransferase G9a Attenuates Noise-Induced Cochlear Synaptopathy and Hearing Loss.

Posttranslational modification of histones alters their interaction with DNA and nuclear proteins, influencing gene expression and cell fate. In this study, we investigated the effect of G9a (KMT1C, EHMT2), a major histone lysine methyltransferase encoded by the human EHMT2 gene and responsible for histone H3 lysine 9 dimethylation (H3K9me2) on noise-induced permanent hearing loss (NIHL) in adult CBA/J mice. The conditions of noise exposure used in this study led to losses of cochlear synapses and outer hair cells (OHCs) and permanent auditory threshold shifts. Inhibition of G9a with its specific inhibitor BIX 01294 or with siRNA significantly attenuated these pathological features. Treatment with BIX 01294 also prevented the noise-induced decrease of KCNQ4 immunolabeling in OHCs. Additionally, G9a was increased in cochlear cells, including both outer and inner sensory hair cells, some spiral ganglion neurons (SGNs), and marginal cells, 1 h after the completion of the noise exposure. Also subsequent to noise exposure, immunoreactivity for H3K9me2 appeared in some nuclei of OHCs following a high-to-low frequency gradient with more labeled OHCs in the 45-kHz than the 32-kHz region, as well as in the marginal cells and in some SGNs of the basal turn. These findings suggest that epigenetic modifications of H3K9me2 are involved in NIHL and that pharmacological targeting of G9a may offer a strategy for protection against cochlear synaptopathy and NIHL.

Mitochondrial Calcium Transporters Mediate Sensitivity to Noise-Induced Losses of Hair Cells and Cochlear Synapses.

Mitochondria modulate cellular calcium homeostasis by the combined action of the mitochondrial calcium uniporter (MCU), a selective calcium entry channel, and the sodium calcium exchanger (NCLX), which extrudes calcium from mitochondria. In this study, we investigated MCU and NCLX in noise-induced hearing loss (NIHL) using adult CBA/J mice and noise-induced alterations of inner hair cell (IHC) synapses in MCU knockout mice. Following noise exposure, immunoreactivity of MCU increased in cochlear sensory hair cells of the basal turn, while immunoreactivity of NCLX decreased in a time- and exposure-dependent manner. Inhibition of MCU activity via MCU siRNA pretreatment or the specific pharmacological inhibitor Ru360 attenuated noise-induced loss of sensory hair cells and synaptic ribbons, wave I amplitudes, and NIHL in CBA/J mice. This protection was afforded, at least in part, through reduced cleavage of caspase 9 (CC9). Furthermore, MCU knockout mice on a hybrid genetic CD1 and C57/B6 background showed resistance to noise-induced seizures compared to wild-type littermates. Owing to the CD1 background, MCU knockouts and littermates suffer genetic high frequency hearing loss, but their IHCs remain intact. Noise-induced loss of IHC synaptic connections and reduction of auditory brainstem response (ABR) wave I amplitude were recovered in MCU knockout mice. These results suggest that cellular calcium influx during noise exposure leads to mitochondrial calcium overload via MCU and NCLX. Mitochondrial calcium overload, in turn, initiates cell death pathways and subsequent loss of hair cells and synaptic connections, resulting in NIHL.

Efficient parallel implementation of active appearance model fitting algorithm on GPU.

The active appearance model (AAM) is one of the most powerful model-based object detecting and tracking methods which has been widely used in various situations. However, the high-dimensional texture representation causes very time-consuming computations, which makes the AAM difficult to apply to real-time systems. The emergence of modern graphics processing units (GPUs) that feature a many-core, fine-grained parallel architecture provides new and promising solutions to overcome the computational challenge. In this paper, we propose an efficient parallel implementation of the AAM fitting algorithm on GPUs. Our design idea is fine grain parallelism in which we distribute the texture data of the AAM, in pixels, to thousands of parallel GPU threads for processing, which makes the algorithm fit better into the GPU architecture. We implement our algorithm using the compute unified device architecture (CUDA) on the Nvidia's GTX 650 GPU, which has the latest Kepler architecture. To compare the performance of our algorithm with different data sizes, we built sixteen face AAM models of different dimensional textures. The experiment results show that our parallel AAM fitting algorithm can achieve real-time performance for videos even on very high-dimensional textures.

Magnetic resonance imaging-detected inner ear hemorrhage as a potential cause of sudden sensorineural hearing loss.

PURPOSE: The aim of this study is to assess the value of magnetic resonance imaging in identifying the etiology of sudden sensorineural hearing loss, and to correlate the high signals in the labyrinth with clinical features to identify if inner ear hemorrhage could be implicated. MATERIALS AND METHODS: In this retrospective study, inner ear magnetic resonance imaging was given to 112 patients with sudden sensorineural hearing loss in the First Affiliated Hospital of Sun Yat-sen University from 2011 to 2012. The clinical features of patients with high signals in the labyrinth on magnetic resonance imaging were analyzed. RESULTS: Abnormal magnetic resonance images were identified in 13 (11.6%) patients. Retrocochlear pathology was found in six patients, including two cases of lacunar infarction, one case of multiple ischemias in the brainstem and bilateral centrum semiovale, two cases of acoustic neuroma, and one case of inner ear hemangioma. There were seven cases showing high signals in the labyrinth on unenhanced T1-weighted and fluid-attenuated inversion recovery images. Clinical features of these seven patients were characterized by irreversible profound hearing impairment and vestibular dysfunction. These findings were consistent with the hypothesis that their symptoms were caused by an inner ear hemorrhage. CONCLUSION: The results indicate the importance of magnetic resonance imaging in sudden sensorineural hearing loss in patients. Moreover, patients with vestibular dysfunction and sudden profound hearing loss may have an inner ear hemorrhage evident by interpreting clinical and magnetic resonance imaging results.

Modified laryngotracheal separation for intractable aspiration pneumonia in patients with nasopharyngeal carcinoma treated by radiotherapy.

OBJECTIVES: Intractable aspiration pneumonia in patients with post-radiotherapeutic nasopharyngeal carcinoma (PNC) is a formidable complication, but has not attracted enough attention in clinical practice. Modified laryngotracheal separation (MLTS) was applied for these patients in our hospital, the surgical effects of which were assessed. PATIENTS AND METHODS: Retrospective analysis of 9 PNC cases complicated by intractable aspiration pneumonia in our hospital was carried out. All cases were diagnosed as lower cranial nerve palsy. Their aspiration pneumonia was not effectively prevented or controlled after a series of previous treatments, including active anti-infectives, neurotrophy, acupuncture, nutrition support, nasogastric feeding and tracheotomy. Ultimately all of them received modified laryngotracheal separation (MLTS) surgery. Efficacy of the operation was assessed. RESULTS: In all patients, aspiration pneumonia was effectively controlled after the operation, body weights increased more than 6kg six months later, and nutrition status, swallowing function and quality of life were all improved. CONCLUSIONS: Intractable post-radiotherapeutic aspiration pneumonia in patients with nasopharyngeal carcinoma was possibly caused by lower cranial nerve palsy, which might be related to radiation fields overlapped. Modified laryngotracheal separation is effective in eliminating intractable aspiration in PNC. Suitable patients should be carefully selected although the procedure is potentially reversible.

Combination of taxanes, cisplatin and fluorouracil as induction chemotherapy for locally advanced head and neck cancer: a meta-analysis.

BACKGROUND: Some investigations have suggested that induction chemotherapy with a combination of taxanes, cisplatin and fluorouracil (TPF) is effective in locally advanced head and neck cancer. However, other trials have indicated that TPF does not improve outcomes. The objective of this study was to compare the efficacy and safety of TPF with a cisplatin and fluorouracil (PF) regimen through a meta-analysis. METHODS: Four randomized clinical trials were identified, which included 1,552 patients with locally advanced head and neck cancer who underwent induction chemotherapy with either a TPF or PF protocol. The outcomes included the 3-year survival rate, overall response rate and different types of adverse events. Risk ratios (RRs) and their 95% confidence intervals (CIs) were pooled using RevMan 5.1 software. RESULTS: The 3-year survival rate (51.0% vs. 42.4%; p = 0.002), 3-year progression-free survival rate (35.9% vs. 27.2%; p = 0.007) and overall response to chemotherapy (72.9% vs. 62.1%; p<0.00001) of the patients in the TPF group was statistically superior to those in the PF group. In terms of toxicities, the incidence of febrile neutropenia (7.0% vs. 3.2%; p = 0.001) and alopecia (10.8% vs. 1.1%; p<0.00001) was higher in the TPF group. CONCLUSION: The TPF induction chemotherapy regimen leads to a significant survival advantage with acceptable toxicity rates for patients with locally advanced head and neck cancer compared with the PF regimen.