Long-Term Hearing Stability at Different Frequencies after Lower Intact Bridge Tympanomastoidectomy and Possible Theoretical Basis.

Objective: We aimed to review the long-term hearing outcomes of intact bridge tympanomastoidectomy (IBM) to discuss hearing preservation and combine the theory of "modified miniature lung," middle ear ventilation, and gas pressure balance theory to explore the possible reasons for long-term stable hearing. Study Design: We designed a collection of patients with chronic suppurative otitis media (CSOM) who underwent IBM and divided them into 2 groups to compare long-term and short-term hearing level. Setting: From April 2007 to July 2017, 102 patients received IBM for CSOM treatment in Eye & ENT Hospital of Fudan University. Methods: We divided the patients into 2 groups according to whether the follow-up period was longer than 6 months. We used the numerical value of the air-bone gap difference as an index to evaluate the degree of hearing recovery. Results: We found that 99/102 (97.1%) of the hearings were improved to more than 3 frequencies. There was no significant difference between long-term hearing level and short-term hearing level, which means IBM could get long-term hearing stability. Conclusion: Intact bridge tympanomastoidectomy could provide significant hearing recovery and long-term hearing stability.

Comparison of Different Slice Thicknesses in Computed Tomography for Labyrinthine Fistula Evaluation.

OBJECTIVES: The aim of the present study is to assess the impact of different slice thicknesses in computed tomography for labyrinthine fistula evaluation and to determine the appropriate slice thickness. METHODS: A total of 258 patients who underwent mastoidectomy and tympanoplasty for chronic otitis media with cholesteatoma from 2010 to 2014 were reviewed. The radiological diagnoses were compared with intraoperative findings. Sensitivity and specificity of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick computed tomographic (CT) images for the evaluation of labyrinthine fistulae were calculated. Cohen's κ coefficient was also calculated. RESULTS: The sensitivities of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images for the evaluation of labyrinthine fistulae were 76.9, 86.5, 90.4, and 93.3% (observer 1) and 67.3, 76.0, 79.8, and 87.5% (observer 2), respectively. The specificities of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images for labyrinthine fistula evaluation were 96.1, 94.8, 95.5, and 95.5% (observer 1) and 99.4, 97.4, 95.5, and 94.8% (observer 2), respectively. Cohen's κ coefficients were 0.790, 0.788, 0.876, and 0.911 in 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images, respectively. CONCLUSIONS: The sensitivity of CT for labyrinthine fistula evaluation increases with decreasing slice thickness, while the specificity does not improve.

Chondrocytes cultured in silk-based biomaterials maintain function and cell morphology.

OBJECTIVE:: To characterize the morphology of chondrocytes and the expression and secretion of active collagen II by these cells cultured within a regenerated silk fibroin film. Silk fibroin film cytocompatibility and the effect of silk fibroin on chondrocytes in vitro were also evaluated. METHODS:: Chondrocytes were transfected with a lentivirus containing a green fluorescent protein marker and cultured within a regenerated silk fibroin film. Effects on chondrocyte adhesion, growth, and expression of functional collagen II were assessed in vitro by analysis with immunofluorescent histochemistry and laser scanning confocal microscopy. RESULTS:: The results of this study showed that the regenerated silk fibroin film had no cytotoxic effect on chondrocytes. The regenerated silk fibroin film facilitated the adhesion of chondrocytes with typical morphology. Chondrocytes cultured within silk fibroin films exhibited the expression of collagen II in vitro. CONCLUSION:: Regenerated silk fibroin film was found to be an excellent biomaterial with good cytocompatibility for chondrocytes, because these cells remained functional and maintained normal cell morphology when cultured in silk-based biomaterials. These results suggest that silk-based chondrocyte biomaterial complexes may provide a feasible and functional biomaterial for repairing clinical cartilage defects.

Extension of the Clinical Significance of the "Cog".

OBJECTIVE: To study the clinical anatomy of the epitympanum, the attic, and its medial wall, to try to discover a new clinical operation-related anatomical landmark, and to investigate the adjacent anatomical relationship with this landmark. MATERIALS AND METHODS: Eight donor temporal bone specimens were dissected endoscopically. For 29 healthy persons (17 males and 12 females), CT images of the temporal bone (57 ears) were taken, 3-dimensional (3-D) reconstruction and multidimensional plane reconstruction were performed, and identification and assessment of 3-D spatial relationships between any 2 of these complex structures were done. RESULTS: 3-D images of the temporal bone structures including the facial nerve, the cochlea, the semicircular canal, and the brain plate were reconstructed and shown in detail. We discovered a new clinical surgery-related anatomical landmark (the "cog" tangent and the trailing edge of the cog). Based on the tangent and the trailing edge of the cog, we quantified the anatomical relationship between it and its neighboring important structures. CONCLUSION: Based on endoscopic anatomy and the temporal bone spiral CT 3-D structure reconstruction of the epitympanum, the attic, and the adjacent structures, we found an extension of the clinical significance the cog. Quantification of the adjacent anatomical relationship of this landmark is very important for otology microsurgical operation.

FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength.

The ceramic-metal interface is present in various material structures and devices that are vulnerable to failures, like cracking, which are typically due to their incompatible properties, e.g., thermal expansion mismatch. In failure of these multilayer systems, interfacial shear strength is a good measure of the robustness of interfaces, especially for planar films. There is a widely-used shear lag model and method by Agrawal and Raj to analyse and measure the interfacial shear strength of thin brittle film on ductile substrates. The use of this classical model for a type of polymer derived ceramic coatings (thickness ~18 µm) on steel substrate leads to high values of interfacial shear strength. Here, we present finite element simulations for such a coating system when it is subjected to in-plane tension. Results show that the in-plane stresses in the coating are non-uniform, i.e., varying across the thickness of the film. Therefore, they do not meet one of the basic assumptions of the classical model: uniform in-plane stress. Furthermore, effects of three significant parameters, film thickness, crack spacing, and Young's modulus, on the in-plane stress distribution have also been investigated. 'Thickness-averaged In-plane Stress' (TIS), a new failure criterion, is proposed for estimating the interfacial shear strength, which leads to a more realistic estimation of the tensile strength and interfacial shear strength of thick brittle films/coatings on ductile substrates.

Quantitative Assessment of Surgical Anatomy and Three-Dimensional Relationships in the Supralabyrinthine Space.

OBJECTIVE: To explore and quantify the surgically relevant anatomic relationships and three-dimensional (3D) morphology of the supralabyrinthine space, and enable a deeper, clearer understanding of its regional anatomy. MATERIALS AND METHODS: 3D-DOCTOR software was used to create a 3D reconstruction of the axial CT images and multiplanar reformatting of 55 slices of temporal bone in 29 patients (17 males and 12 females), whose average age was 38.69 ± 17.81 years. The 3D relationships between the mutual complex structures were displayed graphically and measured. RESULTS: The important structures within the temporal bone were displayed in detail. 3D relationships between the structures in the temporal bone, such as the ossicles, facial nerves, labyrinth, and skull base, were quantified. CONCLUSION: Quantification of surgically relevant anatomic relationships and the morphology of the supralabyrinthine space in three dimensions are very helpful in surgical dissection.

Characterization of the relationship between APOBEC3B deletion and ACE Alu insertion.

The insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE), commonly associated with many diseases, is believed to have affected human adaptation to environmental changes during the out-of-Africa expansion. APOBEC3B (A3B), a member of the cytidine deaminase family APOBEC3s, also exhibits a variable gene insertion/deletion polymorphism across world populations. Using data available from published reports, we examined the global geographic distribution of ACE and A3B genotypes. In tracking the modern human dispersal routes of these two genes, we found that the variation trends of the two I/D polymorphisms were directly correlated. We observed that the frequencies of ACE insertion and A3B deletion rose in parallel along the expansion route. To investigate the presence of a correlation between the two polymorphisms and the effect of their interaction on human health, we analyzed 1199 unrelated Chinese adults to determine their genotypes and other important clinical characteristics. We discovered a significant difference between the ACE genotype/allele distribution in the A3B DD and A3B II/ID groups (P = 0.045 and 0.015, respectively), indicating that the ACE Alu I allele frequency in the former group was higher than in the latter group. No specific clinical phenotype could be associated with the interaction between the ACE and A3B I/D polymorphisms. A3B has been identified as a powerful inhibitor of Alu retrotransposition, and primate A3 genes have undergone strong positive selection (and expansion) for restricting the mobility of endogenous retrotransposons during evolution. Based on these findings, we suggest that the ACE Alu insertion was enabled (facilitated) by the A3B deletion and that functional loss of A3B provided an opportunity for enhanced human adaptability and survival in response to the environmental and climate challenges arising during the migration from Africa.

Control of surface energy of silicon oxynitride films.

Microstructure and chemical composition determine the wetting property of solid surfaces. To achieve hydrophobicity or hydrophilicity, recent efforts have mostly focused on designed patterns and sophisticated surface modification. Here we show the fabrication of a dense amorphous silicon oxynitride (SiON) film by simple annealing of perhydropolysilazane (PHPS), which experiences significant and abrupt transition in surface energy as a function of temperature. The polar component of surface energy, derived from contact angle measurements, exhibits an increase of 20-40 times in an annealing temperature window of ~100 °C, which leads to a 5-fold increase of its total surface energy. On the basis of the chemical analyses, we propose a compositional gradient in the film. Due to this gradient, the hydrophilic SiON film, for instance, can be used as the bond coat material in a double-layer environmental barrier coating system with outstanding oxidation resistant properties.

[The clinical analysis of cervical lymph node metastases from squamous cell carcinoma of the larynx and hypopharynx treated with total laryngectomy].

OBJECTIVE: To detect the distribution and characteristics of lymph nodes metastasis in patients of laryngeal and hypopharyngeal cancer. METHOD: A retrospective review of 129 patients who had radical neck dissection, including first recurrence in cervical lymph nodes after laryngectomy, was performed to analyze the cervical lymph node metastases of different types of laryngeal and hypopharyngeal cancer treated by total laryngectomy. RESULT: The patients of the hypopharyngeal and supraglottic cancer had a tendency of cervical lymph nodes metastasis in their early stage. The rate of the fusional lymph nodes was high in hypopharyngeal cancer, and so as to the rate of the positive lymph nodes in their level IV. In our study the percentage of the poor-differentiated squamous cell carcinoma was relatively high in hypopharyngeal and supraglottic cancer than in glottic cancer. And there was no statistical difference in stages of the primary tumour between groups of neck dissection with laryngectomy simultaneously and of first recurrence in lymph nodes after laryngectomy. CONCLUSION: The latent lymph nodes metastasis and preventive neck dissection should be considered in patients of hypopharyngeal and supraglottic cancer in or above stages of T2, especially in patients with poor-differentiated squamous cell carcinoma, though the sign of positive lymph nodes was not evident.