Metabolic associated fatty liver disease (MAFLD) is closely linked to metabolic disorders and lack of effective therapeutic options. Schisandrin A (SA), derived from the traditional Chinese medicinal herb Schisandra, has shown liver-protective properties. SA may counteract MAFLD by modulating endoplasmic reticulum stress (ERS) and inhibiting apoptosis. This study aimed to investigate the protective effects of SA on high-fat diet-induced MAFLD in C57BL/6 mice. The study also sought to elucidate the underlying mechanisms, focusing on the ERS signaling pathway and apoptosis. A MAFLD mouse model was established by feeding mice a high-fat diet. The mice were then randomly divided into the following groups: control, model, SA intervention (various dosages), atorvastatin-treated positive control, and ERS inhibitor combined with SA intervention. serum lipid profiles, liver enzymes, and liver histopathology were assessed. Western blot, immunofluorescence (IF), and TUNEL assay were used to evaluate ERS and apoptosis-related protein expression. SA intervention markedly enhanced serum lipid profiles and reduced liver enzyme levels. The histopathological alterations observed in the model group were significantly mitigated by SA treatment. Western blot analysis revealed that SA effectively modulated the expression levels of proteins associated with ERS and apoptosis. Furthermore, IF and TUNEL assay results substantiated SA’s regulatory influence on ERS and apoptotic pathways. SA effectively improved dyslipidemia and hepatic lipid metabolism abnormalities. It reduced hepatic lipid deposition and pathological damage in MAFLD mice induced by a high-fat diet. The mechanism of action may involve the regulation of the ERS signaling pathway, thereby protecting cells from apoptosis.

For cochlear implant (CI) users, differences in peripheral input patterns across ears may disrupt binaural fusion, thereby limiting binaural perception. The present study investigated factors affecting binaural fusion for speech segregation. Speech recognition thresholds (SRTs) were adaptively measured in 11 simultaneously implanted (SIM) and 10 sequentially implanted (SEQ) bilateral CI (BiCI) users, as well as in 16 CI users with substantial acoustic hearing (AH) in the non-implanted ear (acoustic-electric hearing; “AEH”). Target sentences, spoken by a male talker, were presented alongside two competing sentences spoken by two different male talkers (same-sex maskers) or female talkers (different-sex maskers). The target speech was delivered to one ear, while masker speech was presented either to the same ear as the target (monaural) or to both ears simultaneously (bilateral). The difference in SRTs between bilateral and monaural listening (bilateral-monaural difference; “BMD”) was used to indirectly estimate binaural fusion. Results showed higher (poorer) SRTs with bilateral than with monaural listening in SEQ-BiCI, but not in SIM-BiCI users. Across BiCI users, the BMD was negatively correlated with the inter-implant interval. Across AEH CI users, SRTs were statistically significantly better with bilateral than with monaural listening when the target speech was presented to the AH ear, but statistically significantly poorer when the target speech was presented to the CI ear. The impact of binaural fusion on speech segregation was highly asymmetric in SEQ-BiCI and AEH CI users, with a relative advantage when the target speech is presented to the first-implanted ear or the AH ear, respectively.

Middle ear adenoma, also known as middle ear adenomatous neuroendocrine tumors (MEANTs), is a rare neoplasm, accounting for < 2% of all middle ear tumors. It is characterized by slow growth, non-invasive behavior, and nonspecific symptoms, which often complicate preoperative diagnosis. This review summarizes our clinical experience in the diagnosis and treatment of 11 cases of MEANT. In this cohort, four cases were preoperatively diagnosed as cholesterol granuloma, five as cholesteatoma, and two as middle ear tumors. The median age at diagnosis was 36.7 years, with all patients (100%) experienced progressive conductive or mixed hearing loss. Additional symptoms included tonal tinnitus (9/11, 81.8%), aural fullness (6/11, 54.5%), otalgia (4/11, 36.4%), pulsatile tinnitus (2/11, 18.2%), otorrhea (2/11, 18.2%), and facial nerve paresis (1/11, 9%). None of the patients exhibited carcinoid syndrome or bloody otorrhea. All patients underwent surgical treatment, and postoperative histopathology confirmed the diagnosis of MEANTs. Immunohistochemical analysis showed positivity for CK and SYN in all cases, S-100 was positive in 91% (10/11) of patients. All patients were followed up for 1.5 to 10 years postoperatively. These findings highlight the nonspecific presentation of middle ear adenoma, which may lead to misdiagnosis as chronic inflammatory disease or other middle ear neoplasms. For differential diagnosis of MEANTs, high-resolution computed tomography (HRCT) of the ear or MRI with non-echo-planar diffusion-weighted imaging (non-EPI DWI) are valuable. Complete surgical resection remains the mainstay of treatment, and ossicular chain reconstruction should be considered when appropriate.

The benefit of binaural summation (“summation”) is often measured in co-located steady-state noise; summation for competing speech is less understood. The goal of the present study was to evaluate how the target-masker acoustic properties and binaural listening mode affect summation for speech-in-speech recognition. Recognition of target speech in two-talker speech maskers was measured with each ear alone and with both ears in bilateral CI users (BiCI), CI users with asymmetric hearing loss (AHL), CI users who were single-sided deaf (SSD), and normal-hearing listeners (NH). Target and masker speech was co-located; the talker sex of the maskers was either the same as or different from the target. With same-sex maskers, significant binaural summation was observed only in the BiCI group. In contrast, with different-sex maskers, significant summation was observed only in the SSD and NH groups, where binaural summation was significantly greater with different-sex than with same-sex maskers. A significant but weak correlation between interaural performance asymmetry and binaural summation was observed in some within-group comparisons, but not in across-group comparisons. For the BiCI group, summation was significantly correlated with SRTs from the better-performing CI ear, but not with performance asymmetry. The findings can be partly accounted for by psychometric-function slope and performance asymmetry within a probability-summation model. However, the probability-summation model generally overestimated the observed summation, suggesting that the assumption of independent processing across ears may not hold for CI users, possibly due to the variability in binaural fusion across individuals.

PURPOSE:The goal of the present study was to investigate how monaural performance, interaural asymmetry, and the timing of bilateral implantation (simultaneous, sequential) contribute to binaural spectral ripple discrimination and binaural summation in bilateral cochlear implant (BiCI) users. METHOD:Twenty Mandarin-speaking adult BiCI users participated in the study. Of the 20 participants, 10 underwent sequential bilateral cochlear implantation, and 10 underwent simultaneous bilateral cochlear implantation. Spectral resolution was assessed using the Spectral-temporally Modulated Ripple Test (SMRT) under both monaural and binaural listening conditions. Binaural summation benefit was quantified as the difference between binaural SMRT scores and monaural SMRT scores in the better performing ear. Interaural performance asymmetry was quantified as the difference in monaural SMRT scores between each cochlear implant (CI) ear tested individually. Binaural and monaural spectral resolutions were compared in terms of SMRT scores, with binaural summation further examined as a function of interaural performance asymmetry. RESULTS:There was no significant difference in binaural or monaural SMRT scores between the simultaneously implanted BiCI (SIM-BiCI) and sequentially implanted BiCI (SEQ-BiCI) groups. Greater interaural performance asymmetry was strongly associated with reduced binaural summation in the SIM-BiCI group (r = -.91, p < .001) and the SEQ-BiCI group (r = -.89, p < .001). SMRT scores with both CIs were significantly correlated with SMRT scores with the poorer performing CI (r = .70, p < .001). Binaural SMRT scores were significantly predicted by a linear combination of SMRT scores with the poorer ear (p < .001) and the laterality of the poorer ear (right or left ear; p = .022). CONCLUSIONS:While there was no significant difference in binaural summation between SIM-BiCI and SEQ-BiCI users, binaural summation was strongly and negatively associated with interaural performance asymmetry. This suggests that the binaural benefit for spectral resolution is primarily limited by interaural differences in spectral resolution. Binaural SMRT performance was largely dependent on the spectral resolution of the poorer performing CI, with additional improvement associated with better spectral resolution in the right CI.

Currently, HIV-associated neurocognitive disorders (HAND) remains one of the major challenges faced by people living with HIV (PLWH). HAND involves the vulnerability of neural circuits caused by synaptic degeneration and abnormal synaptic pruning. In recent years, connectomics has been gradually applied to HAND research as a cutting-edge method for describing the structural and functional connectivity patterns of the brain, to further elucidate the specific mechanisms underlying these neural circuit vulnerabilities. Using multimodal neuroimaging techniques such as diffusion tensor imaging (DTI), structural magnetic resonance imaging (sMRI), and resting-state functional magnetic resonance imaging (rs-fMRI), researchers can detail the connectome network changes in the brains of PLWH. These technologies offer potential biomarkers for the early diagnosis, prognosis, and treatment monitoring of HAND, while also providing new avenues for personalized prediction of cognitive status. Here, we start with the pathogenesis and risk factors of HAND, providing a comprehensive review of the basic concepts of unimodal and multimodal macro connectomics and related graph theory methods, and we review the latest progress in HAND connectomics research. We emphasize the use of connectomics to identify specific disease patterns of HIV-associated neurodegeneration and discuss the potential research directions and challenges in understanding these diseases from a connectomics perspective.

BACKGROUND:Head trauma often leads to bilateral sensorineural hearing loss (SNHL), and determining the optimal side for cochlear implantation (CI) remains a critical issue that requires further investigation. Objective: To evaluate the role of preoperative aided threshold (AT) testing in selecting the optimal CI side for patients with bilateral SNHL caused by head trauma. METHODS:This study included 9 patients with bilateral SNHL resulting from head trauma. Preoperative audiological and radiological evaluations were performed. The correlation between preoperative AT, duration of deafness (DoD), radiological findings, and Nijmegen Cochlear Implant Questionnaire (NCIQ) scores was analyzed. RESULTS:Preoperative AT showed a tendency for a negative correlation with advanced sound perception scores (r = -0.740, p = 0.057), while DoD exhibited a significant negative correlation with auditory self-confidence (r = -0.803, p = 0.029). Imaging combined with AT provides a foundational framework for selecting the implantation side; however, the limited sample size restricts the generalizability of the findings. CONCLUSION:Lower preoperative AT and shorter DoD may predict better auditory rehabilitation outcomes following CI. It is recommended to integrate imaging and audiological evaluations for individualized decision-making. Future studies with larger sample sizes are necessary to validate these findings and explore the clinical implications of early CI.

Objective:To evaluate the effects of cochlear implantation in patients with single-sided deafness（SSD） and asymmetrical hearing loss（AHL）. Methods:Seventeen Mandarin-speaking CI patients diagnosed as SSD/AHL were recruited in our study. The Tinnitus Handicap Inventory（THI） and the Visual Analogue Scale（VAS） were used to assess changes in tinnitus distress and tinnitus loudness in SSD patients at each time point（pre-operation and post-operation）. Results:The THI score and all 3 dimensions were significant decreased with CI-on than pre-operation（P<0.05）. Tinnitus VAS scores were also decreased, and VAS scores were lower with CI-on than with CI-off, and were both significantly different at each time point after CI switch-on（P<0.05）. Conclusion:CI could help SSD/AHL patients to suppress tinnitus and reduce the loudness of tinnitus. However, CI should not be a treatment of tinnitus.

Non-alcoholic fatty liver disease (NAFLD) affects approximately 25 % of the global population, presenting a significant threat to human health and imposing a substantial economic burden on society. Cytokeratin 18 (CK18) has emerged as a promising non-invasive biomarker for early detection of NAFLD. However, current diagnostic methods face challenges in accurately identifying NAFLD in its early stages. To address this issue, our study aimed to generate new CK18 antibodies and utilize a highly sensitive single -molecule immunodetection system customized for NAFLD. We embarked on a process involving the production of novel CK18 monoclonal antibodies, which were subsequently engineered into recombinant forms. In comparison to commercial antibodies, our antibodies exhibited superior affinity. Grounded in the SMCxPRO platform, our assay underwent rigorous assessment, adhering to well-defined biomarker assay criteria. The assay demonstrated specificity to CK18 and achieved a lower limit of quantification of 1 pg/ml. Importantly, elevated serum CK18 levels were observed among NAFLD patients compared to healthy individuals. The single -molecule detection system, utilizing our novel antibodies, holds significant promise for the early -stage diagnosis, dynamic disease monitoring, and prognostic evaluation of NAFLD patients.

As a member of the p53-binding protein family, apoptosis-stimulating protein p53 2 (ASPP2) is closely related to autophagy and apoptosis. However, the mechanistic role of ASPP2 in the development of metabolic dysfunction-associated steatohepatitis (MASH) remains elusive. Therefore, we investigated the role and underlying mechanisms of ASPP2 in MASH progression in a mouse model of MASH and a cellular model of metabolic dysfunction-associated fatty liver disease. ASPP2 deficiency significantly promoted the inflammatory response, steatosis, and MASH progression in mice. Through transcriptomic analysis, increased ACSL4 expression was identified as a potential key factor. Further elucidation of the underlying mechanisms demonstrated that ASPP2 deficiency increased lipid accumulation and inhibited mitochondrial respiration capacity in HepG2 cells induced by oleic acid. However, silencing of ACSL4 reversed these effects. Thus, our study indicates that ASPP2 is an important regulator of MASH progression through ACSL4 upregulation, highlighting its potential as an alternative approach to MASH treatment.

OBJECTIVE:The objectives of this study are twofold: first, to visualize the structure of malformed cochleae through image reconstruction; and second, to develop a predictive model for postoperative outcomes of cochlear implantation (CI) in patients diagnosed with cochlear hypoplasia (CH) and incomplete partition (IP) malformation. METHODS:The clinical data from patients diagnosed with cochlear hypoplasia (CH) and incomplete partition (IP) malformation who underwent cochlear implantation (CI) at Beijing Tongren Hospital between January 2016 and August 2020 were collected. Radiological features were analyzed through 3D segmentation of the cochlea. Postoperative auditory speech rehabilitation outcomes were evaluated using the Categories of Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR). This study aimed to investigate the relationship between cochlear parameters and postoperative outcomes. Additionally, a predictive model for postoperative outcomes was developed using the K-nearest neighbors (KNN) algorithm. RESULTS:In our study, we conducted feature selection by using patients' imaging and audiological attributes. This process involved methods such as the removal of missing values, correlation analysis, and chi-square tests. The findings indicated that two specific features, cochlear volume (V) and cochlear canal length (CDL), significantly contributed to predicting the outcomes of hearing and speech rehabilitation for patients with inner ear malformations. In terms of hearing rehabilitation, the KNN classification achieved an accuracy of 93.3%. Likewise, for speech rehabilitation, the KNN classification demonstrated an accuracy of 86.7%. CONCLUSION:The measurements obtained from the 3D reconstruction model hold significant clinical relevance. Despite the considerable variability in cochlear morphology across individuals, radiological features remain effective in predicting cochlear implantation (CI) prognosis for patients with inner ear malformations. The utilization of 3D segmentation techniques and the developed predictive model can assist surgeons in conducting preoperative cochlear structural measurements for patients with inner ear malformations. This, in turn, can offer a more informed perspective on the anticipated outcomes of cochlear implantation.

English-speaking bimodal and bilateral cochlear implant (CI) users can segregate competing speech using talker sex cues but not spatial cues. While tonal language experience allows for greater utilization of talker sex cues for listeners with normal hearing, tonal language benefits remain unclear for CI users. The present study assessed the ability of Mandarin-speaking bilateral and bimodal CI users to recognize target sentences amidst speech maskers that varied in terms of spatial cues and/or talker sex cues, relative to the target. Different from English-speaking CI users, Mandarin-speaking CI users exhibited greater utilization of spatial cues, particularly in bimodal listening.

BackgroundRadiofrequency ablation (RFA) is the primary curative treatment for hepatocellular carcinoma (HCC) patients who are not eligible for surgery. However, the effects of RFA on the global tumor immune response remain unclear.MethodIn this study, we examined the phenotypic and functional changes in peripheral blood mononuclear cells (PBMCs) from recurrent HCC patients who had undergone two RFA treatments using mass cytometry and high-throughput mRNA assays. ResultsWe observed significant increase in monocytes and decrease in T cell subpopulations three days after the first RFA treatment and three days after the second RFA treatment. The down-regulation of GZMB, GZMH, GZMK, and CD8A, which are involved in the cytotoxic function of T cells, was observed following RFA. Furthermore, the population of CD8 effector and memory T cells (CD8 Teff and CD8 Tem) significantly decreased after RFA. The expression of CD5 and CD161 in various T cell subpopulations also showed significant reductions. Additionally, elevated secretion of VEGF was observed in monocytes, B cells, regulatory T cells (Tregs), and CD4 naive T cells. ConclusionIn recurrent HCC patients, serum components derived from radiofrequency therapy can enhance the antigen-presenting capacity of monocytes. However, they also inhibit the anti-cancer immune response by reducing the population of CD8 effector and memory T cells and suppressing the activation of T cells, as well as down-regulating the expression of CD161 and CD5 in various T cell subpopulations. These tumor-derived components also contribute to an immunosuppressive microenvironment by promoting the secretion of VEGF in monocytes, Tregs, B cells, and CD4 naive T cells.

BACKGROUND:Kenny-Caffey Syndrome type 2 (KCS2) is a genetic disease affecting bone metabolism. However, cochlear implantation (CI) results have yet to be published in detail. OBJECTIVE:This study presents the gene, clinical characteristics, surgical outcomes, and literature review of 2 patients with sensorineural hearing loss related to KCS2. To enhance diagnostic detection and accuracy, we also compare the differential diagnosis between KCS2, otosclerosis, and Cogan's syndrome (CS). METHODS:Prior to CI, patients with KCS2 and CS underwent comprehensive audiological and radiological evaluations. Postoperative auditory speech outcomes and impedance values were recorded and analyzed statistically. A systematic search of the literature was conducted to summarize clinical characteristics. RESULTS:Patients diagnosed with KCS2 exhibit more pronounced changes in the inner ear. The impedance values in the KCS2 cohort were considerably higher (Mean = 12.13 kΩ) than those with CS (Mean = 8.8 kΩ) one year post-activation. The literature review exhibits the clinical manifestations associated with KCS2. CONCLUSION:CI is an effective treatment for KCS2 to restore hearing loss. More frequent programming and accurate adjustment of stimulation is of great necessity. A thorough examination, including temporal bone HRCT, 3D-MRI, audiological evaluations, and whole-exome sequencing, is essential for the diagnosis and treatment of KCS2.

目的 构建靶向RelA(p65)基因的短发夹RNA(short hairpin RNA,shRNA)慢病毒载体,并对其功能进行验证.方法 设计3 对针对RelA基因的RNA干扰序列,并合成相应的shRNA序列.shRNA退火形成双链oligo序列后应用基因重组技术构建重组质粒,经菌落聚合酶链式反应(PCR)及测序鉴定,将重组正确的质粒进行慢病毒包装和滴度测定,通过Western blot实验筛选出对HepG2 细胞株中RelA基因干扰效果最好的慢病毒,并通过CCK-8 检测Lenti-shRelA对细胞增殖活性的影响.结果 测序结果显示重组慢病毒载体与设计参考序列一致,提示重组慢病毒载体构建成功.重组慢病毒Y4056、Y21318、Y21319、Y21320 的滴度分别为3.13×108 TU/ml、2.97×108 TU/ml、2.51×108 TU/ml、3.40×108 TU/ml.用慢病毒Lenti-shRelA(Y21318、Y21319、Y21320、Y4056)感染HepG2 细胞,Western blot实验结果显示Y21320 对HepG2 细胞株中RelA基因的干扰效果最好.CCK-8 实验结果显示RelA的敲降可显著抑制细胞增殖活力.结论 该研究成功构建了靶向RelA基因shRNA慢病毒载体,其能有效下调HepG2 细胞RelA的表达并抑制细胞增殖,为进一步研究RelA在肝癌发生、发展中的机制奠定了基础.

Different from normal-hearing (NH) listeners, speech recognition thresholds (SRTs) in cochlear implant (CI) users are typically poorer with dynamic maskers than with speech-spectrum noise (SSN). The effectiveness of different masker types may depend on their acoustic and linguistic characteristics. The goal of the present study was to evaluate the effectiveness of different masker types with varying acoustic and linguistic properties in CI and NH listeners. SRTs were measured with nine maskers, including SSN, dynamic nonspeech maskers, and speech maskers with or without lexical content. Results showed that CI users performed significantly poorer than NH listeners with all maskers. NH listeners were much more sensitive to masker type than were CI users. Relative to SSN, NH listeners experienced significant masking release for most maskers, which could be well explained by the glimpse proportion, especially for maskers containing similar cues related to fundamental frequency or lexical content. In contrast, CI users generally experienced negative masking release. There was significant intercorrelation among the maskers for CI users' SRTs but much less so for NH listeners' SRTs. Principal component analysis showed that one factor explained 72% of the variance in CI users' SRTs but only 55% in NH listeners' SRTs across all maskers. Taken together, the results suggest that SRTs in SSN largely accounted for the variability in CI users' SRTs with dynamic maskers. Different from NH listeners, CI users appear to be more susceptible to energetic masking and do not experience a release from masking with dynamic envelopes or speech maskers.

Objective The present paper aimed to inhibit the expression of tumor suppressor p53-binding protein 2（TP53BP2） in liver cancer by short hairpin RNAs（shRNAs） with lentiviral vector. Methods Two pairs of RNA interference sequences targeting to TP53BP52 gene were designed, and their corresponding shRNA sequences were synthesized. After annealing of shRNA to form double-stranded oligo sequences, the recombinant plasmid was constructed by gene recombination technique. The correct recombinant plasmid was used after PCR and sequencing identification of the colony for lentivirus packaging and titer determination. The interference effect of lentivirus lenti-shTP53BP2 on TP53BP2 gene in HepG2 cells was observed by Western Blot, qRT-PCR and laser confocal technique. Results The sequencing alignment results showed that each recombinant lentiviral vector was consistent with the designed reference sequence, indicating that each recombinant lentiviral vector was successfully constructed; the titers of pHS-ASR-LW429, pHS-ASR-LW512 and pHS-ASR-LW513 were 9.7×10~8 TU/mL, 6.1×10~8 TU/mL and 6.4×10~8 TU/mL, respectively; the HepG2 cells were infected with lentivirus lenti-shTP53BP2（pHS-ASR-LW512 and pHS-ASR-LW513）, and the results of Western blot, qRT-PCR and laser confocal technique showed that the two lenti-shTP53BP2 significantly down-regulated the TP53BP2 RNA level and its protein expression in HepG2 cells as compared with the control lentivirus（PHS-ASR-LW429）. Conclusion In this study, we successfully construct the shRNA lentiviral vector targeting to TP53BP2 gene with the capacity of effectively down-regulation of TP53BP2 expression in HepG2 cells, which might lay a foundation for further research on the mechanism of TP53BP2 in the hepatocarcinogenesis.

To the Editor: Acoustic neuroma is the most common tumor in the cerebellopontine angle (CPA) area. The surgical approaches used for acoustic neuroma include the labyrinth, middle cranial fossa, posterior sigmoid sinus, and posterior labyrinth routes. However, regardless of the approach used to expose the tumor in the internal auditory canal (IAC), the bone around the IAC must be abraded, which inevitably exposes the surrounding air cells to damage and increases the risk of cerebrospinal fluid (CSF) leak after surgery. CSF leak is the most common postoperative complication after the removal of a tumor from the CPA area and has a reported incidence of 2% to 10% after acoustic neuroma surgery.[1-3] Clinical treatment of CSF leak is challenging; and continuous lumbar puncture and drainage or reoperation are sometimes required to avoid meningitis. Therefore, prevention of postoperative CSF leak is a key issue to consider when surgery is performed to remove a tumor in the CPA area. Risk factors for CSF leak after tumor removal in the CPA area include a high body mass index, cranial hypertension, hyper pneumatization of the air chambers in the temporal bone, and a long operating time.[4-6] Although several studies have shown that CSF leak is related to the air chamber in the temporal bone, their conclusions are mostly based on the air chamber in the mastoid portion.[7-9] Moreover, some researchers have proposed that hyper pneumatization of the petrous apex is an independent risk factor for CSF leak,[4] but have not provided quantitative assessment data. Therefore, a comprehensive assessment of pneumatization of the air cells in the petrous apex is needed before surgery to prevent postoperative CSF leak. Air cells in the petrous apex around the IAC reach from the superior margin to the inferior margin of the petrous bone and from the labyrinth to the IAC. There is a positive relationship between the volume of the air chamber around the IAC and the actual surgical cavity that needs to be treated, that is, the larger the volume of the air chamber around the IAC, the larger the cavity that needs to be treated during surgery. However, there have been no reports on the three-dimensional distribution or volume of air cells around the IAC. Therefore, the aims of this study were to (1) perform a multi-planar reconstruction and analysis of the air chambers around the IAC using standardized temporal high-resolution computed tomography (HRCT) data and (2) observe the distribution of air chambers in the different quadrants centered on the IAC and calculate their volumes to provide an anatomic foundation for predicting potential sites of postoperative CSF leak before surgery. This study was approved by the Institutional Review Board in Beijing Tongren Hospital, Capital Medical University (No. HXP201611ST). All the patients signed an informed written consent form. A total of 110 temporal HRCT scans obtained for 73 patients with acquired sensorineural hearing loss (35 males, 38 females) of mean age 41 ± 16 (range, 18–76) years at Beijing Tongren Hospital between January 2019 and December 2019 were retrospectively analyzed. The inclusion criteria were that the structures of temporal bones were normal on HRCT. The exclusion criteria were as follows: (1) patients with external, middle, and inner ear malformation or inflammation; (2) patients with a history of ear trauma; (3) patients with a history of ear surgery; and (4) patients with a high jugular bulb or an anterior sigmoid sinus. The HRCT images were obtained using a SOMATOM Definition Flash scanner (Siemens, Erlangen, Germany) in a spiral mode. All scans were obtained with the patient in the supine position, and the scanning range was from the superior margin of the petrous bone to the inferior margin of the external auditory meatus. The scanning parameters were as follows: voltage, 140 kV; effective tube current, 150 mAs/slice; collimator width, 64 mm × 0.6 mm; pitch, 0.5; tube rotation time, 1 s per revolution; field of view, 180.00 mm; matrix, 512 × 512; slice thickness 0.5 mm; and inter-slice gap, 0.25 mm. All source images were reconstructed using the bone algorithm. The window width was kept at 4000 HU and the window level at 700 HU. The source HRCT images were sent to an image post-processing workstation (Extended Brilliance Workspace 2, Phillips Medical Systems, Best, The Netherlands) and then standardized for multi-planar reconstruction. The reformatted baseline of the oblique plane was parallel to the long axis of the superior semicircular canal. To standardize the volume, the following temporal bone structures were marked: the middle cranial fossa meninges (superior margin of the petrous bone), inferior margin of the petrous bone, lateral semicircular canal, posterior semicircular canal, common crus, the bottom of the IAC, and porus of the IAC. Axial images were used to completely expose the horizontal semicircular canal and show the posterior semicircular canal simultaneously. A straight line was drawn along the middle line of the longitudinal axis of the IAC, after which a vertical line was drawn through the common crus and used as the starting point to cut the IAC into several 1-mm thick slices. The boundaries of the air chamber around the IAC were defined as follows: superior boundary, the middle cranial fossa meninges (superior margin of the petrous bone); inferior boundary, the inferior margin of the petrous bone; anterior boundary, the bottom of the IAC, and posterior boundary, the porus of the IAC. On an axial view, the air chamber around the IAC was divided into four quadrants, labeled counterclockwise as I (anterior–superior), II (posterior–superior), III (posterior–inferior), and IV (anterior–inferior). We calculated the area of the air chambers in the petrous bone in four quadrants for each layer. Next, the volume of each layer was obtained by multiplying the area of the air chamber in each layer by 1 mm. Finally, the total volume of the air chamber around the IAC was calculated. In this study, we found that the volume of each quadrant around the IAC and the total volume of the four quadrants varied widely from patient to patient. The average volumes of quadrants I, II, III, and IV were 66.87 ± 132.16 mm3, 67.99 ± 111.47 mm3, 236.45 ± 372.47 mm3, and 302.37 ± 560.17 mm3, respectively. And the average total air chamber volume was 673.68 ± 737.47 mm3, which is consistent with the range of 0.93–3.56 cm3 previously reported for the anterior portion of the petrous apex.[10] This wide range of values means that the relevant anatomic variables in the air chambers around the IAC should be assessed in each individual patient before surgery. In quadrant I, the air chamber was not developed (air volume, 0) in 37 temporal bones, accounting for 33.6% of the entire study cohort; for quadrants II, III, and IV, 56, 2, and 9 temporal bones were not developed, accounting for 50.9%, 1.8%, and 8.2%, respectively. Furthermore, the air chambers were not developed in quadrants I and II in 30 cases, which represented 27.3% of the total study cohort. Analysis of variance and Tamhane's T2 multiple comparisons test revealed a statistically significant difference in air chamber volume between quadrants I, II, III, and IV (P < 0.05) but no significant difference between quadrants I and II or between quadrants III and IV (both P > 0.05) [Figure 1]. The air volumes were significantly greater in quadrants III and IV than in quadrants I and II (P < 0.05). This finding indicates that the volumes of the air chambers in the posterior–inferior and anterior–inferior quadrants should be investigated carefully while planning CPA surgery.Figure 1: (A–C) The axial view of the IAC and the four quadrants. (D) Comparison of mean volume of four quadrants. Green line: middle line of a longitudinal axis of the IAC on HRCT; blue line: the vertical line perpendicular to the middle line through the common crus; red line: middle line of the IAC perpendicular to the green line in the axial view of the IAC on HRCT. ∗ P > 0.05. HRCT: High-resolution computed tomography; IAC: Internal auditory canal.This cohort contained HRCT data for 52 male ears and 58 female ears. There was no significant sex-related difference in air volume for quadrants I, II, and III (P > 0.05, Wilcoxon rank-sum test). However, there was a significant difference between the air volume in quadrant IV and total air volume (P < 0.05). The air volume was significantly greater in men than in women [Supplementary Table 1, https://links.lww.com/CM9/B331]. In this study, we found no significant correlation between patient age and the volume of the air chambers around the IAC (P > 0.05). The patients in this cohort were all at least 18 years of age, indicating that the air chambers around the IAC do not change with age. Our findings in this regard are consistent with a previous suggestion that the development of the mastoid air chambers is independent of age in persons over the age of 20 years.[11] The Wilcoxon rank-sum test revealed a significant difference in air volume in quadrants III and IV (P < 0.05) but not in quadrants I and II (P > 0.05) between the left and right ears. There was no significant difference in total air volume between the two sides (P > 0.05) [Supplementary Table 2, https://links.lww.com/CM9/B331]. This study investigated the three-dimensional distribution and volume of the air chambers around the IAC. Its findings provide a new perspective on these chambers. Unlike in previous studies of the air chambers at the petrous apex, the present study shows that the distribution and volume of these air chambers is an important consideration while predicting the risk of postoperative CSF leak before surgery and during surgical planning. Moreover, its findings show that standardized post-processing of HRCT images is useful for determining the distribution and volume of the air chambers around the IAC. Acoustic neuroma is one of the most common tumors found in the posterior cranial fossa. Complete removal of a tumor in the IAC requires the removal of an extensive amount of bone around the IAC. During surgery, the air chambers around the IAC may be opened, leading to exposure of the subarachnoid space and a risk of CSF leak in the temporal bone area or directly into the nasopharynx via the Eustachian tube. CSF leak occurs nearly twice as often in patients with a well-pneumatized petrous apex compared with those in whom the petrous apex is poorly pneumatized. Furthermore, larger acoustic neuromas have less risk of CSF leak, possibly because they extend into and obstruct the air chambers in the petrous apex surrounding the IAC, which decreases the communication channels for CSF.[12] Therefore, accurate evaluation of the distribution and volume of air chambers around the IAC is one of the key issues while planning surgery to remove a CPA tumor. Our finding indicates that the volumes of the air chambers in the posterior–inferior and anterior–inferior quadrants may play an important role. Taken together, we found that the distribution and volume of the air chambers in the different quadrants around the IAC may help to prevent CSF leak after surgery in the CPA area. Acknowledgments The authors thank the patients, as well as the global network of investigators, nurses, study coordinators, and operations staff. Funding None. Conflicts of interest None.

Objectives: Talker sex and spatial cues can facilitate segregation of competing speech. However, the spectrotemporal degradation associated with cochlear implants (CIs) can limit the benefit of talker sex and spatial cues. Acoustic hearing in the nonimplanted ear can improve access to talker sex cues in CI users. However, it’s unclear whether the CI can improve segregation of competing speech when maskers are symmetrically placed around the target (i.e., when spatial cues are available), compared with acoustic hearing alone. The aim of this study was to investigate whether a CI can improve segregation of competing speech by individuals with unilateral hearing loss. Design: Speech recognition thresholds (SRTs) for competing speech were measured in 16 normal-hearing (NH) adults and 16 unilaterally deaf CI users. All participants were native speakers of Mandarin Chinese. CI users were divided into two groups according to thresholds in the nonimplanted ear: (1) single-sided deaf (SSD); pure-tone thresholds <25 dB HL at all audiometric frequencies, and (2) Asymmetric hearing loss (AHL; one or more thresholds > 25 dB HL). SRTs were measured for target sentences produced by a male talker in the presence of two masker talkers (different male or female talkers). The target sentence was always presented via loudspeaker directly in front of the listener (0°), and the maskers were either colocated with the target (0°) or spatially separated from the target at ±90°. Three segregation cue conditions were tested to measure masking release (MR) relative to the baseline condition: (1) Talker sex, (2) Spatial, and (3) Talker sex + Spatial. For CI users, SRTs were measured with the CI on or off. Results: Binaural MR was significantly better for the NH group than for the AHL or SSD groups (P < 0.001 in all cases). For the NH group, mean MR was largest with the Talker sex + spatial cues (18.8 dB) and smallest for the Talker sex cues (10.7 dB). In contrast, mean MR for the SSD group was largest with the Talker sex + spatial cues (14.7 dB), and smallest with the Spatial cues (4.8 dB). For the AHL group, mean MR was largest with the Talker sex + spatial cues (7.8 dB) and smallest with the Talker sex (4.8 dB) and the Spatial cues (4.8 dB). MR was significantly better with the CI on than off for both the AHL (P = 0.014) and SSD groups (P < 0.001). Across all unilaterally deaf CI users, monaural (acoustic ear alone) and binaural MR were significantly correlated with unaided pure-tone average thresholds in the nonimplanted ear for the Talker sex and Talker sex + spatial conditions (P < 0.001 in both cases) but not for the Spatial condition. Conclusion: Although the CI benefitted unilaterally deaf listeners’ segregation of competing speech, MR was much poorer than that observed in NH listeners. Different from previous findings with steady noise maskers, the CI benefit for segregation of competing speech from a different talker sex was greater in the SSD group than in the AHL group.