Granulomatous Mucormycosis of the Temporal Bone extending Into Temporomandibular Joint and Infratemporal Fossa: A Case Report.

Mucormycosis of temporal bone is extremely rare. They are usually associated with host immunodeficiency, are difficult to diagnose, and many cases are fatal. We performed a literature review and found only 10 reported cases of temporal bone mucormycosis. We present a case of temporal bone mucormycosis involving the temporomandibular joint and infratemporal fossa in a 53-year-old woman with diabetes mellitus who presented with unbearable otalgia. Computed tomography and magnetic resonance imaging demonstrate inhomogeneous density mass in the parapharyngeal and retropharyngeal space accompanied with lytic bone destruction on the temporomandibular joint. After undergoing a biopsy of the left infratemporal fossa, the patient's pathology exhibited fungal hyphae consistent with mucormycosis. To our knowledge, this is the first report of temporal bone mucormycosis with extensive involvement of temporomandibular joint and its adjacent structures, which exhibited no otologic or rhinologic signs. A definitive diagnosis is made by biopsy.

Expression of Ki-67 and P16 are related with HPV in squamous cell carcinoma of the external auditory canal.

BACKGROUND: Squamous cell carcinoma of the external auditory canal (EACSCC) is an uncommon tumor and responsible for no more than 0.2% of all the head and neck malignancies. Although there is remarkable research evidence exhibiting that high-risk human papillomavirus (HPV) accounts for considerable head and neck malignancies, its role in the pathogenesis of EACSCC is yet to be determined. METHODS: We evaluated 16 patients with EACSCC treated at our department. We employed PCR to assay for high-risk subtypes of HPV. Two pathologists reviewed the histopathological staining via hematoxylin and eosin along with immunohistochemical staining of p16INK4a and Ki­67. RESULTS: Detection of HPV DNA was done via PCR in 3 (18.75%) patients, and 8 (50%) positive (+) cases were determined via p16INK4a immunostaining. Besides, 3 (37.5%) individuals were HPV positive as per p16INK4a PCR results. In addition, all of the p16INK4a-positive specimens were diagnosed as moderately differentiated carcinomas. CONCLUSIONS: Expression of Ki-67 was related to HPV status. This is the first report implicating high-risk HPV in squamous cell carcinoma of the external auditory canal. However, p16INK4a immunostaining is a suspectable approach for diagnosing HPV for EACSCC. In addition, HPV might enhance an elevated proliferation rate in EACSCC, illustrated via expression of Ki-67.

Microfluidic Preparation of Gelatin Methacryloyl Microgels as Local Drug Delivery Vehicles for Hearing Loss Therapy.

Local drug delivery has become an effective method for disease therapy in fine organs including ears, eyes, and noses. However, the multiple anatomical and physiological barriers, unique clearance pathways, and sensitive perceptions characterizing these organs have led to suboptimal drug delivery efficiency. Here, we developed dexamethasone sodium phosphate-encapsulated gelatin methacryloyl (Dexsp@GelMA) microgel particles, with finely tunable size through well-designed microfluidics, as otic drug delivery vehicles for hearing loss therapy. The release kinetics, encapsulation efficiency, drug loading efficiency, and cytotoxicity of the GelMA microgels with different degrees of methacryloyl substitution were comprehensively studied to optimize the microgel formulation. Compared to bulk hydrogels, Dexsp@GelMA microgels of certain sizes hardly cause air-conducted hearing loss in vivo. Besides, strong adhesion of the microgels on the round window membrane was demonstrated. Moreover, the Dexsp@GelMA microgels, via intratympanic administration, could ameliorate acoustic noise-induced hearing loss and attenuate hair cell loss and synaptic ribbons damage more effectively than Dexsp alone. Our results strongly support the adhesive and intricate microfluidic-derived GelMA microgels as ideal intratympanic delivery vehicles for inner ear disease therapies, which provides new inspiration for microfluidics in drug delivery to the fine organs.

CoCl2 -simulated hypoxia potentiates the osteogenic differentiation of fibroblasts derived from tympanosclerosis by upregulating the expression of BMP-2.

Tympanosclerosis (TS) is a result of long-standing middle ear inflammation characterized by fibroblasts ossification. Fibrosis is the last revertible stage in the progress of middle ear inflammation to TS. It was hypothesized that chronic hypoxia could be modulating fibrosis, which in turn additionally further aggravated hypoxia via decreasing oxygen diffusion. However, the effects of hypoxia on osteoinductive activity of fibroblasts have not been explored. Herein, we purposed to explore the role of hypoxia in osteogenic differentiation of fibroblasts derived from TS. The expression of bone morphogenetic protein-2 (BMP-2), hypoxia-inducible factor-1α (HIF-1α), and Vimentin in the human surgical specimens of tympansclerosis was investigated by immunofluorescent staining. Furthermore, cultured fibroblasts were stratified into the following study groups: control, 25, 50, and 100 µM cobaltous chloride (CoCl2 ) group. BMP-2, as well as HIF-1α levels of expression were detected via western blotting and immunofluorescence analysis. We found that the expression of BMP-2 and HIF-1α was significantly upregulated in TS tissues and these fibroblasts, which was vimentin positive surrounding sclerotic plaques, were also expressing HIF-1α positive. The results also demonstrated that CoCl2 treatment increased nuclear HIF-1α protein level in the fibroblast. Furthermore, treatment with CoCl2 significantly increased BMP-2 expression and remarkably elevated alkaline phosphatse activity and the mineralized nodules area. These data illustrate that hypoxia may play an osteogenic role in TS fibroblasts via the elevated expression of a possible osteogenic factor, BMP-2.

Cobalt chloride-stimulated hypoxia promotes the proliferation of cholesteatoma keratinocytes via the PI3K/Akt signaling pathway.

Herein, we purposed to explore whether hypoxia triggers proliferation of cholesteatoma keratinocytes via the PI3K-Akt signaling cascade. Cells were inoculated with different concentration of CoCl2. The proliferation and cellular HIF-1α, p-PDK1 and p­Akt expression levels of cholesteatoma keratinocytes were assessed in vitro. Hypoxia escalated cell proliferation via upregulating p-PDK1 and p­Akt expressions. Specific inhibitor of the PI3K-Akt signaling cascade, LY294002 markedly inhibited the expression of p­Akt and significantly reduces the hypoxia­induced proliferation of cholesteatoma keratinocytes. Our data provides research evidence confirming that hypoxia participates in the onset and progress of cholesteatoma.

Cytokine secretion and pyroptosis of cholesteatoma keratinocytes mediated by AIM2 inflammasomes in response to cytoplasmic DNA.

Cholesteatoma constitutes an acquired benign epidermal non­permanent bone lesion that is locally destructive and patients often relapse. Inflammasomes, which mediate the maturation and production of IL­18 and IL­1ß, resulting in pyroptosis, have been documented to serve a core function in multiple inflammatory conditions. Absent in melanoma 2 (AIM2) is an inflammasome that identifies cytoplasmic DNA and has previously been reported as a pivotal modulator of inflammatory responses. Therefore, the present study aimed to determine the expression levels of AIM2 in human cholesteatoma tissues, and elucidate its function in modulating cytokine production. The expression levels of IL­18, apoptosis­associated speck­like protein containing a CARD (ASC), IL­1ß, AIM2 and caspase­1 were markedly elevated in cholesteatoma tissues. Protein expression levels of AIM2, caspase­1 and ASC were localized in the cellular cytoplasm, primarily in the granular and prickle­cell layers in the cholesteatoma epithelium. Induction using IFN­Î³, as well as cytoplasmic DNA markedly activated the AIM2 inflammasome and elevated the release of IL­18 and IL­1ß in human cholesteatoma keratinocytes. IFN­Î³ was found to enhance poly(dA:dT)­induced pyroptosis of cells and cytokine production. The results of the present study revealed that AIM2 expressed in human cholesteatoma serves a vital function in the inflammatory response by initiating the inflammasome signaling cascade in cholesteatoma.

Ligand-Activated Peroxisome Proliferator-Activated Receptor ß/δ Facilitates Cell Proliferation in Human Cholesteatoma Keratinocytes.

Cholesteatoma is characterized by both the overgrowth of hyperkeratinized squamous epithelium and bone erosion. However, the exact mechanism underlying the hyperproliferative ability of cholesteatoma remains unknown. In this study, we investigated PPAR ß/δ expression in human surgical specimens of cholesteatoma and analyzed its functional role as a regulator of epithelial keratinocyte hyperproliferation. We found that the expression of PPAR ß/δ was significantly upregulated in cholesteatoma and ligand-activated PPAR ß/δ markedly promoted the proliferation of cholesteatoma keratinocytes. Furthermore, we showed that PPAR ß/δ activation increased PDK1 expression and decreased PTEN generation, which led to increased phosphorylation of AKT and GSK3ß and increased the expression level of Cyclin D1. Overall, our data suggested that the proliferating effect of PPAR ß/δ on the cholesteatoma keratinocytes was mediated by the positive regulation of the PDK1/PTEN/AKT/GSK3ß/Cyclin D1 pathway. These findings warranted further investigation of PPAR ß/δ as a therapeutic target for recurrent or residual cholesteatoma.

Deep Learning in Automated Region Proposal and Diagnosis of Chronic Otitis Media Based on Computed Tomography.

OBJECTIVES: The purpose of this study was to develop a deep-learning framework for the diagnosis of chronic otitis media (COM) based on temporal bone computed tomography (CT) scans. DESIGN: A total of 562 COM patients with 672 temporal bone CT scans of both ears were included. The final dataset consisted of 1147 ears, and each of them was assigned with a ground truth label from one of the 3 conditions: normal, chronic suppurative otitis media, and cholesteatoma. A random selection of 85% dataset (n = 975) was used for training and validation. The framework contained two deep-learning networks with distinct functions: a region proposal network for extracting regions of interest from 2-dimensional CT slices; and a classification network for diagnosis of COM based on the extracted regions. The performance of this framework was evaluated on the remaining 15% dataset (n = 172) and compared with that of 6 clinical experts who read the same CT images only. The panel included 2 otologists, 3 otolaryngologists, and 1 radiologist. RESULTS: The area under the receiver operating characteristic curve of the artificial intelligence model in classifying COM versus normal was 0.92, with sensitivity (83.3%) and specificity (91.4%) exceeding the averages of clinical experts (81.1% and 88.8%, respectively). In a 3-class classification task, this network had higher overall accuracy (76.7% versus 73.8%), higher recall rates in identifying chronic suppurative otitis media (75% versus 70%) and cholesteatoma (76% versus 53%) cases, and superior consistency in duplicated cases (100% versus 81%) compared with clinical experts. CONCLUSIONS: This article presented a deep-learning framework that automatically extracted the region of interest from two-dimensional temporal bone CT slices and made diagnosis of COM. The performance of this model was comparable and, in some cases, superior to that of clinical experts. These results implied a promising prospect for clinical application of artificial intelligence in the diagnosis of COM based on CT images.

Induction of cytokine production in cholesteatoma keratinocytes by extracellular high-mobility group box chromosomal protein 1 combined with DNA released by apoptotic cholesteatoma keratinocytes.

High-mobility group box chromosomal protein 1 (HMGB-1), a nuclear DNA binding protein, was recently rediscovered as a new proinflammatory cytokine. The purpose of this study was to determine HMGB-1 expression in vivo and to identify the effect of extracellular HMGB-1 in inflammatory process associated with bone destruction in cholesteatoma. We investigated the expression and location of HMGB-1 in the cholesteatoma and healthy skin using an immunofluorescence assay. We also detected apoptosis and DNA fragments in the cholesteatoma by TUNEL staining. HMGB-1 concentration in apoptotic supernatants from UV light-treated cells, culture supernatants and its translocation in cholesteatoma keratinocytes stimulated by supernatants from UV light-treated cells were measured by immunoblot analysis and immunofluorescence assay. Cultures of human cholesteatoma keratinocytes were exposed to CpG-DNA, HMGB-1, or CpG-DNA complexed to HMGB-1 for 24 h. Cytokines in the culture supernatant were measured by ELISA. In addition, levels of proinflammatory cytokines released by cholesteatoma keratinocytes stimulated by supernatants from UV light-treated cells with or without anti-HMGB-1 antibodies and supernatants from UV light-treated cells with DNase 1 were measured by enzyme-linked immunosorbent assay. The expression of HMGB-1 in cholesteatoma increased and it translocated both to the cytoplasm and extracellular space. Furthermore, the HMGB-1 concentration in supernatants increased significantly after addition of supernatants from UV light-treated cells. TNF-α and IL-1ß can be induced by purified HMGB-1 combined with CpG-DNA in the cholesteatoma keratinocytes. In addition, supernatants of apoptotic cells containing HMGB-1-DNA were effective in inducing TNF-α and IL-1ß secretion. This study suggested that persistent expression of extracellular HMGB-1 and DNA fragments in cholesteatoma leads to TNF-α and IL-1ß production, causing bone resorption and destruction. Thus, we have implicated that HMGB-1-DNA complexes might act as a key molecule involved in bone resorption associated with cholesteatoma.

[Morphological changes associated with low-tone hearing loss in guinea pig models of early endolymphatic hydrops].

The present study was to explore the functional and morphological changes in cochleas of guinea pig models of early endolymphatic hydrops. Thirty albino guinea pigs were randomly divided into three groups: control, 4-week model and 8-week model groups. For each group, n = 10. Model groups were operated on the right ears to result in endolymphatic hydrops with the method of slight destruction of endolymphatic sac and duct from extradural posterior cranial fossa approach, and the animals in control group were sham operated. Electrocochleogram recorded by trans-tympanic approach and auditory brainstem response (ABR) were tested in preoperative model groups, control group, 4-week model group and 8-week model group to assess the hearing changes. Histologic morphometry was used to quantify hydrops by testing scala media area (SMA) ratio. Scanning electron microscope was used to assess the changes of cochlea hair cells. The results showed that the summating potential/compound action potential (SP/AP) ratio of electrocochleogram in 4-week model group (0.33 ± 0.14) and 8-week model group (0.43 ± 0.14) increased significantly, compared with that in control group (0.07 ± 0.06). The maximum SMA ratio in 4-week model group (2.64 ± 0.10) and 8-week model group (3.54 ± 0.13) increased significantly, compared with that in control group (1.06 ± 0.08). The results of maximum SMA ratio correlated with SP/AP ratio of electrocochleogram (r = 0.86). The results of hearing threshold of ABR revealed that the operated ears of model groups were higher than the preoperative results at frequencies of 2 kHz and 4 kHz. And the damage of cochlea hair cells in operated ears occurred in apical and subapical turns. These results suggest the increased SP/AP ratio of electrocochleogram can indicate early endolymphatic hydrops. There is low-tone hearing loss in guinea pig models of early endolymphatic hydrops, and it may be associated with the abnormalities of the stereocilia among the outer hair cells in operated ears which occurs in apical and subapical turns.

[Analysis of correlation between congenital auricular deformities and middle ear malformations].

OBJECTIVE: To explore the potential value of knowing the relationship between congenital auricular deformities and middle ear malformations. METHODS: A total of 86 patients with congenital auricular deformities and middle ear malformations, including 51 males and 35 females, were admitted from January 2008 to December 2009 to the Eye Ear Nose and Throat Hospital of Fudan University. Fifty-eight patients had unilateral deformities (R:L = 34:24), while 28 were bilateral. One hundred and fourteen ears with congenital auricular deformities were included. High-resolution CT (HRCT) data was obtained from each patient. The auricular deformities were classified into three grades using the Marx H classification system. The modified Jahrsdoerfer grading system was used to score the malformations using HRCT data. The correlation between the grades of auricular deformities and scores of middle ear malformations was analyzed using Spearman rank correlation analysis. RESULTS: The Marx H grades of congenital auricular deformities were 12 patients with grade I, 25 patients with grade II and 77 patients with grade III, while their corresponding Jahrsdoerfer scores were 7.8 ± 2.4, 6.8 ± 2.6 and 6.0 ± 2.8, respectively. The statistical analysis suggested a trend of negative correlation between the Marx H grades of auricular deformities and the Jahrsdoerfer scores of middle ear malformations (r = -0.2386, P = 0.0106). CONCLUSION: There was a trend to a negative correlation between congenital auricular deformities and middle ear malformations.