m6A modification of lncRNA in middle ear cholesteatoma. / 中耳胆脂瘤中lncRNA的m6A修饰.

OBJECTIVES: Middle ear cholesteatoma is a non-tumorous condition that typically leads to hearing loss, bone destruction, and other severe complications. Despite surgery being the primary treatment, the recurrence rate remains high. Therefore, exploring the molecular mechanisms underlying cholesteatoma is crucial for discovering new therapeutic approaches. This study aims to explore the involvement of N6-methyladenosine (m6A) methylation in long non-coding RNAs (lncRNAs) in the biological functions and related pathways of middle ear cholesteatoma. METHODS: The m6A modification patterns of lncRNA in middle ear cholesteatoma tissues (n=5) and normal post-auricular skin tissues (n=5) were analyzed using an lncRNA m6A transcriptome microarray. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to identify potential biological functions and signaling pathways involved in the pathogenesis of middle ear cholesteatoma. Methylated RNA immunoprecipitation (MeRIP)-PCR was used to validate the m6A modifications in cholesteatoma and normal skin tissues. RESULTS: Compared with normal skin tissues, 1 525 lncRNAs were differentially methylated in middle ear cholesteatoma tissues, with 1 048 showing hypermethylation and 477 showing hypomethylation [fold change (FC)≥3 or <1/3, P<0.05]. GO enrichment analysis indicated that hypermethylated lncRNAs were involved in protein phosphatase inhibitor activity, neuron-neuron synapse, and regulation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor activity. Hypomethylated lncRNAs were associated with mRNA methyltransferase activity, secretory granule membrane, and mRNA methylation. KEGG analysis revealed that hypermethylated lncRNAs were mainly associated with 5 pathways: the Hedgehog signaling pathway, viral protein interaction with cytokines and cytokine receptors, mitogen-activated protein kinase (MAPK) signaling pathway, cytokine-cytokine receptor interaction, and adrenergic signaling in cardiomyocytes. Hypomethylated lncRNAs were mainly involved in 4 pathways: Renal cell carcinoma, tumor necrosis factor signaling pathway, transcriptional misregulation in cancer, and cytokine-cytokine receptor interaction. Additionally, MeRIP-PCR confirmed the changes in m6A methylation levels in NR_033339, NR_122111, NR_130744, and NR_026800, consistent with microarray analysis. Real-time PCR also confirmed the significant upregulation of MAPK1 and NF-κB, key genes in the MAPK signaling pathway. CONCLUSIONS: This study reveals the m6A modification patterns of lncRNAs in middle ear cholesteatoma, suggests a direction for further research into the role of lncRNA m6A modification in the etiology of cholesteatoma. The findings provide potential therapeutic targets for the treatment of middle ear cholesteatoma.

PTHrP participates in the bone destruction of middle ear cholesteatoma via promoting macrophage differentiation into osteoclasts induced by RANKL. / PTHrP促进RANKLè¯±å¯¼å·¨å™¬ç»†èƒžåˆ†åŒ–ä¸ºç ´éª¨ç»†èƒžå‚ä¸Žä¸­è€³èƒ†è„‚ç˜¤éª¨ç ´å.

OBJECTIVES: Progressive bone resorption and destruction is one of the most critical clinical features of middle ear cholesteatoma, potentially leading to various intracranial and extracranial complications. However, the mechanisms underlying bone destruction in middle ear cholesteatoma remain unclear. This study aims to explore the role of parathyroid hormone-related protein (PTHrP) in bone destruction associated with middle ear cholesteatoma. METHODS: A total of 25 cholesteatoma specimens and 13 normal external auditory canal skin specimens were collected from patients with acquired middle ear cholesteatoma. Immunohistochemical staining was used to detect the expressions of PTHrP, receptor activator for nuclear factor-kappa B ligand (RANKL), and osteoprotegerin (OPG) in cholesteatoma and normal tissues. Tartrate-resistant acid phosphatase (TRAP) staining was used to detect the presence of TRAP positive multi-nucleated macrophages in cholesteatoma and normal tissues. Mono-nuclear macrophage RAW264.7 cells were subjected to interventions, divided into a RANKL intervention group and a PTHrP+ RANKL co-intervention group. TRAP staining was used to detect osteoclast formation in the 2 groups. The mRNA expression levels of osteoclast-related genes, including TRAP, cathepsin K (CTSK), and nuclear factor of activated T cell cytoplasmic 1 (NFATc1), were measured using real-time polymerase chain reaction (real-time PCR) after the interventions. Bone resorption function of osteoclasts was assessed using a bone resorption pit analysis. RESULTS: Immunohistochemical staining showed significantly increased expression of PTHrP and RANKL and decreased expression of OPG in cholesteatoma tissues (all P<0.05). PTHrP expression was significantly positively correlated with RANKL, the RANKL/OPG ratio, and negatively correlated with OPG expression (r=0.385, r=0.417, r=-0.316, all P<0.05). Additionally, the expression levels of PTHrP and RANKL were significantly positively correlated with the degree of bone destruction in cholesteatoma (r=0.413, r=0.505, both P<0.05). TRAP staining revealed a large number of TRAP-positive cells, including multi-nucleated osteoclasts with three or more nuclei, in the stroma surrounding the cholesteatoma epithelium. After 5 days of RANKL or PTHrP+RANKL co-intervention, the number of osteoclasts was significantly greater in the PTHrP+RANKL co-intervention group than that in the RANKL group (P<0.05), with increased mRNA expression levels of TRAP, CTSK, and NFATc1 (all P<0.05). Scanning electron microscopy of bone resorption pits showed that the number (P<0.05) and size of bone resorption pits on bone slices were significantly greater in the PTHrP+RANKL co-intervention group compared with the RANKL group. CONCLUSIONS: PTHrP may promote the differentiation of macrophages in the surrounding stroma of cholesteatoma into osteoclasts through RANKL induction, contributing to bone destruction in middle ear cholesteatoma.

Bacterial diversity of middle ear cholesteatoma by 16S rRNA gene sequencing in China.

In this study, the bacterial diversity of acquired middle ear cholesteatoma (MEC) was evaluated to reveal its pathogenesis and provides a guide for the use of antibiotics. Twenty-nine cases of acquired MEC and eight cases of healthy middle ears undergoing cochlear implantation (CI) were evaluated. Full-length 16S rRNA gene sequencing was performed to profile the bacterial communities in lesions and healthy tissues of the middle ear. ACE (P = 0.043) and Chao1 (P = 0.039) indices showed significant differences in alpha diversity (P < 0.05). Analysis of PERMANOVA/Anosim using the Bray-Curtis distance matrix results suggested that the between-group differences were greater than the within-group differences (R = 0.238, P < 0.05, R2 = 0.066, P < 0.05). Bacterial community analysis revealed that Alphaproteobacteria at the class level and Caulobacterales and Sphingomonadales at the order level were significantly different (P < 0.05). In the LefSe (Linear discriminant analysis effect size) analysis, Porphyromonas bennonis was elevated, and Bryum argenteum and unclassified Cyanobacteriales were reduced at the species level in MEC (P < 0.05). Fifteen metabolic pathways were found to be significantly different between the two groups by analysing the abundance of metabolic pathways in level 2 of the Kyoto Encyclopaedia of Genes and Genomes (KEGG). Seven and eight metabolic pathways were significantly elevated in the MEC and control groups, respectively (P < 0.05). The role of bacteria in the pathogenesis of acquired MEC was further refined through analysis of metabolic pathways. These findings indicate that the acquired MEC and healthy middle ear contain more diverse microbial communities than previously thought.

Comparison of the EAONO/JOS, STAMCO and ChOLE cholesteatoma staging systems in the prognostic evaluation of acquired middle ear cholesteatoma in children.

OBJECTIVE: To compare the performance of the EAONO/JOS, STAMCO, and ChOLE Cholesteatoma Staging Systems in prognostic evaluation of children acquired middle ear cholesteatoma after primary surgery and identify the other factors that could predict cholesteatoma recidivism. And the correlation between the staging and the recidivism of cholesteatoma after grouping according to operation was evaluated. METHODS: A total of 123 ears of 118 patients that underwent surgery for primary cholesteatoma from November 2008 to May 2020 were included in this retrospective study, and then classified and staged according to the EAONO/JOS, STAMCO, and ChOLE cholesteatoma staging system, respectively. Each indicator involved in the system above was analyzed separately to evaluate its prognostic value for cholesteatoma recidivism. RESULTS: The type of surgical procedure performed (P = 0.020) was shown to be associated with cholesteatoma recidivism. Cholesteatoma location the supratubal recess (S1) (P = 0.026, HR = 3.614, 95% CI 1.137, 7.945), and the sinus tympani (S2) (P = 0.004, HR = 4.208, 95% CI 1.574, 11.250) were shown to be significantly associated with disease recidivism. When focusing on the CWU operation group, ossicular chain status in STAMCO stage (P = 0.043) and in the ChOLE stage (P = 0.018) were significantly associated with cholesteatoma recidivism. The results had shown no association between the three stages and cholesteatoma recidivism in the CWD and endoscopic surgery groups. CONCLUSIONS: Based on our study, the EAONO/JOS, STAMCO, and ChOLE Classifications have limited value in predicting cholesteatoma recidivism, in acquired middle ear cholesteatoma in children. Adding the pathological status of the ossicular chain may be useful for predicting the recidivism of cholesteatoma. Additional validation studies are entailed to definitively assess the clinical utility of these classifications.

Application of high resolution computed tomography image assisted classification model of middle ear diseases based on 3D-convolutional neural network. / 基于3Då·ç§¯ç¥žç»ç½‘ç»œçš„ä¸­è€³ç–¾ç— é«˜åˆ†è¾¨çŽ‡CTå›¾åƒè¾ åŠ©åˆ†ç±»è¯Šæ–­æ¨¡åž‹çš„åº”ç”¨.

OBJECTIVES: Chronic suppurative otitis media (CSOM) and middle ear cholesteatoma (MEC) are the 2 most common chronic middle ear diseases. In the process of diagnosis and treatment, the 2 diseases are prone to misdiagnosis and missed diagnosis due to their similar clinical manifestations. High resolution computed tomography (HRCT) can clearly display the fine anatomical structure of the temporal bone, accurately reflect the middle ear lesions and the extent of the lesions, and has advantages in the differential diagnosis of chronic middle ear diseases. This study aims to develop a deep learning model for automatic information extraction and classification diagnosis of chronic middle ear diseases based on temporal bone HRCT image data to improve the classification and diagnosis efficiency of chronic middle ear diseases in clinical practice and reduce the occurrence of missed diagnosis and misdiagnosis. METHODS: The clinical records and temporal bone HRCT imaging data for patients with chronic middle ear diseases hospitalized in the Department of Otorhinolaryngology, Xiangya Hospital from January 2018 to October 2020 were retrospectively collected. The patient's medical records were independently reviewed by 2 experienced otorhinolaryngologist and the final diagnosis was reached a consensus. A total of 499 patients (998 ears) were enrolled in this study. The 998 ears were divided into 3 groups: an MEC group (108 ears), a CSOM group (622 ears), and a normal group (268 ears). The Gaussian noise with different variances was used to amplify the samples of the dataset to offset the imbalance in the number of samples between groups. The sample size of the amplified experimental dataset was 1 806 ears. In the study, 75% (1 355) samples were randomly selected for training, 10% (180) samples for validation, and the remaining 15% (271) samples for testing and evaluating the model performance. The overall design for the model was a serial structure, and the deep learning model with 3 different functions was set up. The first model was the regional recommendation network algorithm, which searched the middle ear image from the whole HRCT image, and then cut and saved the image. The second model was image contrast convolutional neural network (CNN) based on twin network structure, which searched the images matching the key layers of HRCT images from the cut images, and constructed 3D data blocks. The third model was based on 3D-CNN operation, which was used for the final classification and diagnosis of the 3D data block construction, and gave the final prediction probability. RESULTS: The special level search network based on twin network structure showed an average AUC of 0.939 on 10 special levels. The overall accuracy of the classification network based on 3D-CNN was 96.5%, the overall recall rate was 96.4%, and the average AUC under the 3 classifications was 0.983. The recall rates of CSOM cases and MEC cases were 93.7% and 97.4%, respectively. In the subsequent comparison experiments, the average accuracy of some classical CNN was 79.3%, and the average recall rate was 87.6%. The precision rate and the recall rate of the deep learning network constructed in this study were about 17.2% and 8.8% higher than those of the common CNN. CONCLUSIONS: The deep learning network model proposed in this study can automatically extract 3D data blocks containing middle ear features from the HRCT image data of patients' temporal bone, which can reduce the overall size of the data while preserve the relationship between corresponding images, and further use 3D-CNN for classification and diagnosis of CSOM and MEC. The design of this model is well fitting to the continuous characteristics of HRCT data, and the experimental results show high precision and adaptability, which is better than the current common CNN methods.

TFIIB-related factor 2 regulates glucose-regulated protein 78 expression in acquired middle ear cholesteatoma.

Acquired middle ear cholesteatoma leads to hearing loss, ear discharge, ear pain, and more serious intracranial complications. However, there is still no effective treatment other than surgery. TFIIB-related factor 2 (BRF2) acted as a redox sensor overexpressing in oxidative stress which linked endoplasmic reticulum (ER) stress, while glucose-regulated protein 78 (GRP78) was a biomarker of ER stress in cancer, atherosclerosis and inflammation. In our study, we investigated the roles of BRF2 and GRP78 in acquired middle ear cholesteatoma. Our results revealed that the expression of BRF2 was significant increased in acquired middle ear cholesteatoma, and which was positively correlated with the expression of GRP78. In addition, BRF2 and GRP78 showed colocalization in epithelium of acquired middle ear cholesteatomas and HaCaT cells. Prolongation of LPS stimulation in HaCaT cells escalated the expression of BRF2 and GRP78. To confirm the role of BRF2 and GRP78, we transfected si-BRF2 into HaCaT cells. All results indicated that BRF2 expression positively regulates the expression of GRP78 and may participate in the pathogenesis of acquire middle ear cholesteatoma.

Keratinocytes-derived exosomal miRNA regulates osteoclast differentiation in middle ear cholesteatoma.

The occurrence and development of osteoclasts can directly affect the severity of bone destruction in middle ear cholesteatoma. At the same time, cell communication between keratinocytes and fibroblasts can stimulate osteoclast differentiation. However, the molecular mechanism of osteoclast differentiation in cholesteatoma is still poorly understood. In this study, we try to isolate the exosomes of keratinocytes from patients with middle ear cholesteatoma, and explore the effects of keratinocyte-derived exosomes (Ker-Exo) on osteoclast differentiation by co-culturing Ker-Exo with fibroblasts and osteoclast precursor cells. As a result, we confirmed that Ker-Exo primed fibroblasts can up-regulate the expression of RANKL and promote osteoclast differentiation. We revealed that the effect of Ker-Exo depened on its miRNA-17 conponent. Analysis confirmed that miRNA-17 was down-regulated in Ker-Exo, and they can increase RANKL level in fibroblasts, thus promoting the differentiation of osteoclasts. In conclusions, we provide evidence that exosomes miRNA-17 secreted by keratinocytes in patients with middle ear cholesteatoma can up-regulate the expression of RANKL in fibroblasts and induce osteoclast differentiation.

[Age aspects of the clinical course of the middle ear cholesteatoma in children]. / Vozrastnye aspekty klinicheskogo techeniia kholesteatomy srednego ukha u detei.

MATERIAL AND METHODS: The study included 125 patients with middle ear cholesteatoma, from 1 year to 17 years (131 cases - 6 patients had bilateral cholesteatoma). All patients were operated in the ENT department of St. Petersburg State Medical University from 2000 to 2017. A comparative analysis of the clinical course and results of surgical treatment of the middle ear cholesteatoma in two age groups was performed: 1 group (1-6 years) - 34 patients (37 cases); 2 group (7-17 years) - 91 patients (94 cases). RESULTS AND DISCUSSION: The average duration of the period from diagnosis to surgery was 7.1±6,4 months in the 1 group and 27.3±23.1 months in the 2 group. This is due to a brighter and more aggressive manifestation of cholesteatoma in children under 7 years old. Due to extensive bone destruction and cholesteatoma, 30% of children of the 1st group underwent radical surgery on the middle ear, in the 2nd group - only 15%. The postoperative period in children under 7 years was more unfavorably: large radical cavities, their late epithelization, growth of granulation tissue. The percentage of cholesteatoma recurrence after hearing-saving operations in the 1st group was 50%, in the 2nd group - 25%. CONCLUSION: The tendency to a more unfavorable course of the disease in young children has been identified. This must be taken into account in choosing the type of operation and predicting the course of the disease.

Utility of diffusion-weighted magnetic resonance imaging in the diagnosis of cholesteatoma and the influence of the learning curve.

OBJECTIVE: The aim of this study is to assess the usefulness and reliability of this technique in our center, correlating the radiological and surgical findings and to study the influence of the learning curve by comparing the initial results with a radiological analysis performed 3 years after. STUDY DESIGN: Retrospective cohort study. METHODS: 67 patients with clinical cholesteatoma suspicion were included in the study, 24 with previously not operated cholesteatoma and 43 with suspicion of recurrent or residual cholesteatoma. All of them underwent diffusion-weighted magnetic resonance imaging, comparing these results with the histological confirmation after surgery. At 3 years, a blind radiological review of these cases was performed and the results were compared with those obtained after the first assessment to objectify the influence of the learning curve. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of the total sample were 93.9, 77.8, 92 and 82.4. The overall results after the blind review of the cases were 95.9, 94.4, 97.9 and 89.5, respectively. CONCLUSION: The diffusion-weighted magnetic resonance imaging is a very useful technique during the diagnostic process of doubtful cases of cholesteatoma, especially in cases of follow-up. As for the influence of the learning curve, we observed a clear improvement in the specificity of the test.

Osteoclasts are not activated in middle ear cholesteatoma.

It is unclear whether osteoclasts are present and activated in cholesteatomas. We explored the expression of messenger RNA (mRNA) for osteoclast biomarkers and regulating factors in middle ear cholesteatomas to elucidate the level of osteoclast activity in this disease. Bone powder was collected from 14 patients with cholesteatomatous and noncholesteatomatous chronic otitis media during tympanomastoidectomy, separately from cortical bone of the mastoid (clean bone powder), from bone neighboring cholesteatoma (cholesteatomatous bone powder), and from bone of the air cells and antrum of noncholesteatomatous chronic otitis media patients (noncholesteatomatous bone powder). The samples collected were soaked in TRIzol reagent, and total RNA was extracted and purified by the acid guanidinium thiocyanate-phenol-chloroform method, followed by the use of magnetic bead technology. The sample was then subjected to quantitative reverse transcription polymerase chain reaction for receptor activator of nuclear factor κB (RANK), tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK), osteoclast-associated receptor (OSCAR), calcitonin receptor (CALCR), matrix metalloproteinase 9 (MMP9), receptor activator of nuclear factor κB ligand (RANKL), and osteoprotegerin (OPG). There was no significant difference in the expression of TRAP, CTSK, OSCAR, CALCR, MMP9, or OPG among the clean, cholesteatomatous, and noncholesteatomatous bone powder. On the other hand, the expression of RANK and RANKL was significantly lower in the cholesteatomatous bone powder than in the noncholesteatomatous bone powder (P = 0.003 and P = 0.028, respectively). The RANKL mRNA/OPG mRNA ratio did not differ among the three samples. These results indicate that osteoclasts are unlikely to be activated in cholesteatomas. Bone resorption mechanisms not mediated by osteoclasts may need to be reappraised in cholesteatoma research in future studies.

[Endoscopic ear surgery - complement to microscopic ear surgery]. / Endoskopische Ohrchirurgie ­ eine Weiterentwicklung der modernen Ohrchirurgie.

Wullstein, the founder of modern microscopic ear surgery, already used an oto-endoscope intraoperatively. However, it is only after the recent development of modern video-endoscopy with high definition, 4­k, and 3­dimensional imaging that endoscopically guided surgery of the middle ear is gaining some importance. Key ventilation routes like the isthmus tympani and the epitympanic diaphragma can be visualized far better by using an endoscope rather than a microscope. Going through the external meatus surgery of middle ear pathologies is possible without external incision. This type of primary endoscopic ear surgery has to be distinguished from secondary endoscopic ear surgery, where standard microscopic ear surgery is supplemented by endoscopic surgery. Having to hold the endoscope in one hand, surgery has to be performed single-handed, which is awkward. In case of extensive bone removal or excessive bleeding the view through the endoscope lense is obscured, the endoscope therefore cannot fully substitute the use of the microscope. It is however an interesting adjunct to microscopic ear surgery.

Osteopontin-driven partial epithelial-mesenchymal transition governs the development of middle ear cholesteatoma.

Cholesteatoma is a common disease of the middle ear. Currently, surgical removal is the only treatment option and patients face a high risk of relapse. The molecular basis of cholesteatoma remains largely unknown. Here, we show that Osteopontin (OPN), a predominantly secreted protein, plays a crucial role in the development of middle ear cholesteatoma. Global transcriptome analysis revealed the loss of epithelial features and an enhanced immune response in human cholesteatoma tissues. Quantitative RT-PCR and immunohistochemical staining of middle ear cholesteatoma validated the reduced expression of epithelial markers, as well as the elevated expression of mesenchymal markers including Vimentin and Fibronectin, but not N-Cadherin, α-smooth muscle actin (α-SMA) or ferroptosis suppressor protein 1 (FSP1), indicating a partial epithelial-mesenchymal transition (EMT) state. Besides, the expression of OPN was significantly elevated in human cholesteatoma tissues. Treatment with OPN promoted cell proliferation, survival and migration and led to a partial EMT in immortalized human keratinocyte cells. Importantly, blockade of OPN signaling could remarkably improve the cholesteatoma-like symptoms in SD rats. Our mechanistic study demonstrated that the AKT-zinc finger E-box binding homeobox 2 (ZEB2) axis mediated the effects of OPN. Overall, these findings suggest that targeting the OPN signaling represents a promising strategy for the treatment of middle ear cholesteatoma.

Risk factors for middle ear cholesteatoma surgery based on Korean population data.

BACKGROUND: Studies of risk factors for middle ear cholesteatoma surgery using population-based data are lacking. OBJECTIVES: To investigate the risk factors for cholesteatoma surgery in adults based on population data from Korea. MATERIALS AND METHODS: For this retrospective study, we used Korean National Health Insurance Service National Sample Cohort data. Patients who were 20 years or older and underwent mastoidectomy from 2006 through 2015 under the diagnostic codes of cholesteatoma were defined as patients with middle ear cholesteatoma surgery. The control group was comprised of the remaining database sample in 2006. Sociodemographic factors in 2006 and histories of medical diseases, allergic diseases, and chronic sinusitis from 2003 through 2005 were compared between cholesteatoma surgery and control groups. RESULTS: A total of 459 patients underwent cholesteatoma surgery. In multivariate Cox regression analysis, age 40-59 years and residence in metropolitan cities and small- and medium-sized cities and counties were significant risk factors for cholesteatoma surgery whereas allergic rhinitis, asthma, atopic dermatitis, and chronic sinusitis were not significant risk factors for middle ear cholesteatoma surgery. CONCLUSIONS AND SIGNIFICANCE: The present study found no evidence of associations between allergic diseases or chronic sinusitis and cholesteatoma surgery in adults.

[The effect of different degrees of Eustachian tube dysfunction on hearing threshold in patients with acquired primary middle ear cholesteatoma after balloon eustachian tuboplasty].

Objective:To investigate the changes in hearing threshold of the acquired primary cholesteatoma of the middle ear with different degrees of eustachian tube dysfunction after balloon eustachian tuboplasty. Methods:This retrospective study included forty cases with middle ear cholesteatoma and eustachian tube dysfunction who underwent open mastoidectomy + tympanoplasty + balloon eustachian tuboplasty were enrolled. All patients were admitted from November 2020 to April 2022. The preoperative eustachian tube score of 0-2 were defined as the lower group, and the scores of 3-5 were defined as the higher group. Pure tone audiometry was measured preoperatively and 1, 3, 6 and 12 months postoperatively. The average value of bone conduction threshold and air conduction threshold of 250-4 000 Hz were calculated, and the air-bone gap was calculated simultaneously. SPSS 25.0 was used for statistical analysis. P<0.05 was considered statistically significant. Results:In the lower group, the air conduction threshold and air-bone gap at 3 months postoperatively were significantly decreased in comparison with those preoperatively（P<0.05），as was the air-bone gap at 6 months postoperatively（P<0.05）. In the higher group, the air conduction threshold and air-bone gap were significantly decreased at 3, 6 and 12 months postoperatively（P<0.05）. Conclusion:The air conduction threshold and air-bone gap of patients with the acquired primary cholesteatoma of the middle ear and eustachian tube dysfunction were significantly decreased after eustachian tube balloon dilatation. Hearing improvement lasted longer in patients with slight eustachian tube dysfunction.

N6-methyladenosine methylation analysis of circRNAs in acquired middle ear cholesteatoma.

Introduction: Middle ear cholesteatoma is a chronic middle ear disease characterized by severe hearing loss and adjacent bone erosion, resulting in numerous complications. This study sought to identify pathways involved in N6-methyladenosine (m6A) modification of circRNA in middle ear cholesteatoma. Methods: A m6A circRNA epitranscriptomic microarray analysis was performed in middle ear cholesteatoma tissues (n = 5) and normal post-auricular skin samples (n = 5). Bioinformatics analyses subsequently explored the biological functions (Gene Ontology, GO) and signaling pathways (Kyoto Encyclopedia of Genes and Genomes, KEGG) underlying middle ear cholesteatoma pathogenesis. Methylated RNA immunoprecipitation qPCR (MeRIP-qPCR) was performed to verify the presence of circRNAs with m6A modifications in middle ear cholesteatoma and normal skin samples. Results: Microarray analysis identified 3,755 circRNAs as significantly differentially modified by m6A methylation in middle ear cholesteatoma compared with the normal post-auricular skin. Among these, 3,742 were hypermethylated (FC ≥ 2, FDR < 0.05) and 13 were hypomethylated (FC ≤ 1/2, FDR < 0.05). GO analysis terms with the highest enrichment score were localization, cytoplasm, and ATP-dependent activity for biological processes, cellular components, and molecular functions respectively. Of the eight hypermethylated circRNA pathways, RNA degradation pathway has the highest enrichment score. Peroxisome Proliferator-Activated Receptor (PPAR) signaling pathway was hypomethylated. To validate the microarray analysis, we conducted MeRIP-qPCR to assess the methylation levels of five specific m6A-modified circRNAs: hsa_circRNA_061554, hsa_circRNA_001454, hsa_circRNA_031526, hsa_circRNA_100833, and hsa_circRNA_022382. The validation was highly consistent with the findings from the microarray analysis. Conclusion: Our study firstly presents m6A modification patterns of circRNAs in middle ear cholesteatoma. This finding suggests a direction for circRNA m6A modification research in the etiology of cholesteatoma and provides potential therapeutic targets for the treatment of middle ear cholesteatoma.

Development of Air Cell System Following Canal Wall Up Mastoidectomy for Pediatric Cholesteatoma.

Background: The development of temporal bone pneumatization is related to the postnatal middle ear environment, where the development of air cells is suppressed with otitis media in early childhood. However, whether air cell formation restarts when mastoidectomy is performed during temporal bone pneumatization remains unclear. Herein, we evaluated temporal bone pneumatization after canal wall up (CWU) tympanomastoidectomy for middle ear cholesteatoma in children. Methods: In total, 63 patients, including 29 patients with congenital cholesteatoma (CC) and 34 patients with acquired cholesteatoma (AC), were assessed using a set of pre- and postoperative computed tomography images. The air cells of the temporal bone were divided into five areas: periantral (anterior), periantral (posterior), periantral (medial), peritubal, and petrous apex. The number of areas with air cells before and after surgery was compared to evaluate temporal bone pneumatization after surgery. Results: A total of 63 patients, comprising 29 with CC and 34 with AC (pars flaccida; 23, pars tensa; 7, unclassified; 4), were evaluated. The median age of patients (18 males and 11 females) with CC was 5.0 (range, 2-15 years), while that of the AC group (23 males and 11 females) was 8 (range, 2-15 years). A significant difference in air cell presence was identified in the CC and AC groups after surgery (Mann-Whitney U, p < 0.001 and p = 0.003, respectively). Between the two groups, considerably better postoperative pneumatization was observed in the CC group. A correlation between age at surgery and gain of postoperative air cell area development was identified in the CC group (Spearman's rank-order correlation coefficient, r = -0.584, p < 0.001). In comparison with the postoperative pneumatization rate of each classified area, the petrous apex area was the lowest in the CC and AC groups. Conclusions: Newly developed air cells were identified in the temporal bones after CWU mastoidectomy for pediatric cholesteatoma. These findings may justify CWU tympanomastoidectomy, at least for younger children and CC patients, who may subsequently develop air cell systems after surgery.

Cholesterol Granuloma From a Developmental Odontogenic Cyst: A Report of a Rare Case and a Literature Review.

Dentigerous cysts are the second most common developmental odontogenic cysts that develop around the crown of unerrupted teeth with the maxillary canine region being one of the common sites of occurrence. The cystic lining of this lesion has been shown to develop into ameloblastoma, Muco epidermoid carcinoma, and squamous cell carcinomas. However, the development of cholesterol granuloma (CG) in the cystic lining of a dentigerous cyst is extremely rare. CG is a histological observation distinguished by the presence of a conglomeration of connective tissue and granulation tissue. The condition is predominantly seen in the field of otolaryngology, with very few cases reported in the maxillofacial region, most of which are associated with the maxillary sinus. This article presents the findings of a CG in a 39-year-old male patient that developed within the dentigerous cyst and discusses the possible etiopathogenesis, surgical management, and histological presentation.

Clinical analysis, diagnosis, and treatment strategies for otogenic brain abscesses.

Objective: To explore the clinical features, diagnosis, and treatment strategies for otogenic brain abscesses (OBA). Methods: Clinical data from 10 patients with OBA were analyzed retrospectively. Clinical characteristics, diagnosis, and treatment experiences were summarized. Results: Two were first diagnosed in the Department of Otorhinolaryngology, 5 in Neurosurgery, and 3 in other departments. There were 6 cases of temporal lobe abscess and 4 cases of cerebellar abscesses. Five cases were accompanied by 1 or more intracranial complications. Headache is a common presentation in all cases. The main pathogenic bacteria were anaerobic bacteria. All patients had no previous ear or brain surgery history, and no history of traumatic brain injury, 7 received surgical treatment in the neurosurgery and/or otolaryngology department. Two patients died, the other 8 fully recovered and so were discharged. Conclusions: Diagnosis and treatment of OBA must involve multiple departments. Multidisciplinary consultation (MDT) is crucial to the success of the first OBA diagnosis. The diagnosis and treatment team develops personalized treatment plans by integrating MDT treatment opinions and combining the actual condition of patients, thereby making the diagnosis and treatment of OBA accurate and timely.

Fusion computed tomography-magnetic resonance imaging scans for pre-operative staging of congenital middle-ear cholesteatoma.

OBJECTIVE: To evaluate if fusion computed tomography-diffusion-weighted magnetic resonance imaging may have a role in the pre-operative assessment of congenital middle-ear cholesteatoma. METHODS: A retrospective chart review of surgically treated congenital middle-ear cholesteatoma patients over a 2-year timespan was conducted. Pre-operative staging was performed on computed tomography and fusion computed tomography-diffusion-weighted magnetic resonance imaging based on extension of the disease according to the ChOLE classification system and the Potsic classification system. Intra-operative staging was compared to imaging findings to evaluate accuracy of the two imaging modalities in predicting congenital middle-ear cholesteatoma extent. RESULTS: Computed tomography was able to correctly predict congenital middle-ear cholesteatoma extent in three out of six cases according to the ChOLE classification system, all of which were staged as Ch1a and Ch1b on pre-operative computed tomography. Cases in which computed tomography was not able correctly to determine congenital middle-ear cholesteatoma extent were staged as Ch3 on pre-operative computed tomography. Fusion scans correctly determined congenital middle-ear cholesteatoma extent in all cases according to the ChOLE classification. CONCLUSIONS: Fusion computed tomography-diffusion-weighted magnetic resonance imaging may be helpful in cases of congenital middle-ear cholesteatoma where pre-operative computed tomography shows mastoid and antrum opacification, in which computed tomography alone may overestimate cholesteatoma extension beyond the level of the lateral semi-circular canal.

Analysis of mRNA m6A modification and mRNA expression profiles in middle ear cholesteatoma.

Introduction: Middle ear cholesteatoma is characterized by the hyperproliferation of keratinocytes. In recent decades, N6-methyladenosine (m6A) modification has been shown to play an essential role in the pathogenesis of many proliferative diseases. However, neither the m6A modification profile nor its potential role in the pathogenesis of middle ear cholesteatoma has currently been investigated. Therefore, this study aimed to explore m6A modification patterns in middle ear cholesteatoma. Materials and methods: An m6A mRNA epitranscriptomic microarray analysis was performed to analyze m6A modification patterns in middle ear cholesteatoma tissue (n = 5) and normal post-auricular skin samples (n = 5). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the potential biological functions and signaling pathways underlying the pathogenesis of middle ear cholesteatoma. Subsequently, m6A modification levels were verified by methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) in middle ear cholesteatoma tissue and normal skin samples, respectively. Results: A total of 6,865 distinctive m6A-modified mRNAs were identified, including 4,620 hypermethylated and 2,245 hypomethylated mRNAs, as well as 9,162 differentially expressed mRNAs, including 4,891 upregulated and 4,271 downregulated mRNAs, in the middle ear cholesteatoma group relative to the normal skin group. An association analysis between methylation and gene expression demonstrated that expression of 1,926 hypermethylated mRNAs was upregulated, while expression of 2,187 hypomethylated mRNAs and 38 hypermethylated mRNAs was downregulated. Moreover, GO analysis suggested that differentially methylated mRNAs might influence cellular processes and biological behaviors, such as cell differentiation, biosynthetic processes, regulation of molecular functions, and keratinization. KEGG pathway analysis demonstrated that the hypermethylated transcripts were involved in 26 pathways, including the Hippo signaling pathway, the p53 signaling pathway, and the inflammatory mediator regulation of transient receptor potential (TRP) channels, while the hypomethylated transcripts were involved in 13 pathways, including bacterial invasion of epithelial cells, steroid biosynthesis, and the Hippo signaling pathway. Conclusion: Our study presents m6A modification patterns in middle ear cholesteatoma, which may exert regulatory roles in middle ear cholesteatoma. The present study provides directions for mRNA m6A modification-based research on the epigenetic etiology and pathogenesis of middle ear cholesteatoma.