An Unusual Location of Ossified Intramuscular Lipoma: A Case Report

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Mehdi Ramezan Shirazi

2011-09-01

Full Text Available "nLipoma is the most common soft tissue tumor but the presence of osseous component within the tumor is quite rare. Some studies show that less than 1% of lipomas were ossified. We describe the histological, radiological and diagnostic features of an ossified intramuscular lipoma. To the best of the authors' knowledge, a symptomatic ossified intramuscular lipoma without any cortical erosion and hyperostosis has not been previously reported in the literature.

Central Cemento-Ossifying Fibroma: Primary Odontogenic or Osseous Neoplasm?

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Woo, Sook-Bin

2015-12-01

Currently, central cemento-ossifying fibroma is classified by the World Health Organization as a primary bone-forming tumor of the jaws. However, histopathologically, it is often indistinguishable from cemento-osseous dysplasias in that it forms osteoid and cementicles (cementum droplets) in varying proportions. It is believed that pluripotent cells within the periodontal membrane can be stimulated to produce either osteoid or woven bone and cementicles when stimulated. If this is true, cemento-ossifying fibroma would be better classified as a primary odontogenic neoplasm arising from the periodontal ligament. Cemento-ossifying fibromas also do not occur in the long bones. The present report compares several entities that fall within the diagnostic realm of benign fibro-osseous lesions and reviews the evidence for reclassifying central cemento-ossifying fibroma as a primary odontogenic neoplasm. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Cemento-ossifying Fibroma Of Paranasal Sinus Presenting Acutely As Orbital Cellulitis.

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Khanna, Maneesh; Buddhavarapu, Shanker Rao; Hussain, Sheik Akbar; Amir, Emran

2009-01-01

Fibro-osseous lesions of the face and paranasal sinuses are relatively uncommon. These lesions have overlapping clinical, radiologic and pathologic features causing difficulty in diagnosis. Neoplastic fibro-osseous paranasal sinus lesions can be benign or malignant. The benign fibro-osseous lesions described are: ossifying fibroma (and its histologic variants) and fibrous dysplasia. The variants of ossifying fibroma differ in the nature of calcified material (i.e. cementum versus bone), in the location of the lesion (oral versus paranasal sinus or orbital), other morphologic variations (presence of psammomatoid concretions) and biologic behavior (aggressive versus stable). Presence of cementum or bone classifies the lesion as cementifying fibroma or ossifying fibroma respectively while lesions with mixture of both cementum and bone are called cemento-ossifying fibroma. We describe a case of a young adult male with cemento-ossifying fibroma of paranasal sinus presenting acutely as left orbital cellulitis with proptosis.

On the stability and compressive nonlinearity of a physiologically based model of the cochlea

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Nankali, Amir [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan (United States); Grosh, Karl [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

2015-12-31

Hearing relies on a series of coupled electrical, acoustical (fluidic) and mechanical interactions inside the cochlea that enable sound processing. A positive feedback mechanism within the cochlea, called the cochlear amplifier, provides amplitude and frequency selectivity in the mammalian auditory system. The cochlear amplifier and stability are studied using a nonlinear, micromechanical model of the Organ of Corti (OoC) coupled to the electrical potentials in the cochlear ducts. It is observed that the mechano-electrical transduction (MET) sensitivity and somatic motility of the outer hair cell (OHC), control the cochlear stability. Increasing MET sensitivity beyond a critical value, while electromechanical coupling coefficient is within a specific range, causes instability. We show that instability in this model is generated through a supercritical Hopf bifurcation. A reduced order model of the system is approximated and it is shown that the tectorial membrane (TM) transverse mode effect on the dynamics is significant while the radial mode can be simplified from the equations. The cochlear amplifier in this model exhibits good agreement with the experimental data. A comprehensive 3-dimensional model based on the cross sectional model is simulated and the results are compared. It is indicated that the global model qualitatively inherits some characteristics of the local model, but the longitudinal coupling along the cochlea shifts the stability boundary (i.e., Hopf bifurcation point) and enhances stability.

Influence of Young's moduli in 3D fluid-structure coupled models of the human cochlea

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Böhnke, Frank; Semmelbauer, Sebastian; Marquardt, Torsten

2015-12-01

The acoustic wave propagation in the human cochlea was studied using a tapered box-model with linear assumptions respective to all mechanical parameters. The discretisation and evaluation is conducted by a commercial finite element package (ANSYS). The main difference to former models of the cochlea was the representation of the basilar membrane by a 3D elastic solid. The Young's moduli of this solid were modified to study their influence on the travelling wave. The lymph in the scala vestibuli and scala tympani was represented by a viscous and nearly incompressible fluid finite element approach. Our results show the maximum displacement for f = 2kHz at half of the length of the cochlea in accordance with former experiments. For low frequencies f <200 Hz nearly zero phase shifts were found, whereas for f =1 kHz it reaches values up to -12 cycles depending on the degree of orthotropy.

Ossifying fibroma in the sinonasal tract: a rare case report.

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Charavarty, Shekhar; Datta, Debashish; Boro, Esha; Dutta, Bijita

2014-08-01

Ossifying fibroma involving the sinonasal tract is an extremely rare occurrence. We are reporting a case of ossifying fibroma in the left maxillary sinus in a 19-year-old female who presented with a mass in the left cheek and nasal obstruction. On examination, the swelling in the left cheek seemed to originate from the left maxilla and was smooth and bony hard. Patient underwent detailed radiological and image guided cytopathological investigations. Depending on the results of these tests complete surgical excision of the mass was done. Histopathological evaluation of the excised mass revealed it to be an Ossifying Fibroma.

Low-grade osteosarcoma arising from cemento-ossifying fibroma: a case report.

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Lee, Yong Bin; Kim, Nam-Kyoo; Kim, Jae-Young; Kim, Hyung Jun

2015-02-01

Cemento-ossifying fibromas are benign tumors, and, although cases of an aggressive type have been reported, no cases of cemento-ossifying fibroma transforming into osteosarcoma have been documented previously. Low-grade osteosarcoma is a rare type of primary bone tumor, representing 1%-2% of all osteosarcomas. A 45-year-old female patient was diagnosed with cemento-ossifying fibroma, treated with mass excision several times over a period of two years and eight months, and followed up. After biopsy gathered because of signs of recurrence, she was diagnosed with low-grade osteosarcoma. The patient underwent wide excision, segmental mandibulectomy, and reconstruction with fibula free flap. The aim of this report is to raise awareness of the possibility that cemento-ossifying fibroma can transform into osteosarcoma and of the consequent necessity for careful diagnosis and treatment planning.

The Coda of the Transient Response in a Sensitive Cochlea: A Computational Modeling Study.

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Yizeng Li

2016-07-01

Full Text Available In a sensitive cochlea, the basilar membrane response to transient excitation of any kind-normal acoustic or artificial intracochlear excitation-consists of not only a primary impulse but also a coda of delayed secondary responses with varying amplitudes but similar spectral content around the characteristic frequency of the measurement location. The coda, sometimes referred to as echoes or ringing, has been described as a form of local, short term memory which may influence the ability of the auditory system to detect gaps in an acoustic stimulus such as speech. Depending on the individual cochlea, the temporal gap between the primary impulse and the following coda ranges from once to thrice the group delay of the primary impulse (the group delay of the primary impulse is on the order of a few hundred microseconds. The coda is physiologically vulnerable, disappearing when the cochlea is compromised even slightly. The multicomponent sensitive response is not yet completely understood. We use a physiologically-based, mathematical model to investigate (i the generation of the primary impulse response and the dependence of the group delay on the various stimulation methods, (ii the effect of spatial perturbations in the properties of mechanically sensitive ion channels on the generation and separation of delayed secondary responses. The model suggests that the presence of the secondary responses depends on the wavenumber content of a perturbation and the activity level of the cochlea. In addition, the model shows that the varying temporal gaps between adjacent coda seen in experiments depend on the individual profiles of perturbations. Implications for non-invasive cochlear diagnosis are also discussed.

ACIR: automatic cochlea image registration

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Al-Dhamari, Ibraheem; Bauer, Sabine; Paulus, Dietrich; Lissek, Friedrich; Jacob, Roland

2017-02-01

Efficient Cochlear Implant (CI) surgery requires prior knowledge of the cochlea's size and its characteristics. This information helps to select suitable implants for different patients. To get these measurements, a segmentation method of cochlea medical images is needed. An important pre-processing step for good cochlea segmentation involves efficient image registration. The cochlea's small size and complex structure, in addition to the different resolutions and head positions during imaging, reveals a big challenge for the automated registration of the different image modalities. In this paper, an Automatic Cochlea Image Registration (ACIR) method for multi- modal human cochlea images is proposed. This method is based on using small areas that have clear structures from both input images instead of registering the complete image. It uses the Adaptive Stochastic Gradient Descent Optimizer (ASGD) and Mattes's Mutual Information metric (MMI) to estimate 3D rigid transform parameters. The use of state of the art medical image registration optimizers published over the last two years are studied and compared quantitatively using the standard Dice Similarity Coefficient (DSC). ACIR requires only 4.86 seconds on average to align cochlea images automatically and to put all the modalities in the same spatial locations without human interference. The source code is based on the tool elastix and is provided for free as a 3D Slicer plugin. Another contribution of this work is a proposed public cochlea standard dataset which can be downloaded for free from a public XNAT server.

Cemento-ossifying fibroma of maxillary antrum in a young female patient.

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Singhal, A; Ram, R; Singhal, P; Bhatnagar, S; Das, U M

2011-12-01

The cemento-ossifying fibroma is classified as a fibro-osseous lesion of the jaws. It commonly presents as a progressively growing lesion that can attain an enormous size with resultant deformity if left untreated. The cemento-ossifying fibroma is a central neoplasm of bone as well as periodontium which has caused considerable controversy because of controversy regarding terminology and the criteria for its diagnosis. This case report describes a female patient with cemento-ossifying fibroma involving maxillary antrum. The clinical, radiographic and histological features as well as the surgical findings are presented.

Giant cemento-ossifying fibroma of the mandible.

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Naik, Raghavendra Mahadev; Guruprasad, Yadavalli; Sujatha, D; Gurudath, Shubha; Pai, Anuradha; Suresh, Kv

2014-01-01

Cemento-ossifying fibroma (COF) is classified as a fibro-osseous neoplasm and included among the non-odontogenic tumors derived from the mesenchymal blast cells of the periodontal ligament, with a potential for forming fibrous tissue, cementum and bone, or a combination of such elements. These are slow-growing lesions, and are more frequent in women between the third and fourth decades of life. Case reports of massive expansile COF, measuring more than 10 cm are rarely reported in the literature. We report a case of giant cemento-ossifying fibroma of the mandible in a 34 year old female patient.

Potassium recycling pathways in the human cochlea.

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Weber, P C; Cunningham, C D; Schulte, B A

2001-07-01

Potential pathways for recycling potassium (K+) used in the maintenance of inner ear electrochemical gradients have been elucidated in animal models. However, little is known about K+ transport in the human cochlea. This study was designed to characterize putative K+ recycling pathways in the human ear and to determine whether observations from animal models can be extrapolated to humans. A prospective laboratory study using an immunohistochemical approach to analyze the distribution of key ion transport mediators in the human cochlea. Human temporal bones were fixed in situ within 1 to 6 hours of death and subsequently harvested at autopsy. Decalcification was accomplished with the aid of microwaving. Immunohistochemical staining was then performed to define the presence and cell type-specific distribution of Na,K-ATPase, sodium-potassium-chloride cotransporter (NKCC), and carbonic anhydrase (CA) in the inner ear. Staining patterns visualized in the human cochlea closely paralleled those seen in other species. Anti-Na,K-ATPase stained strongly the basolateral plasma membrane of strial marginal cells and nerve endings underlying hair cells. This antibody also localized Na,K-ATPase to type II, type IV, and type V fibrocytes in the spiral ligament and in limbal fibrocytes. NKCC was present in the basolateral membrane of strial marginal cells as well as in type II, type V, and limbal fibrocytes. Immunoreactive carbonic anhydrase was present in type I and type III fibrocytes and in epithelial cells lining Reissner's membrane and the spiral prominence. The distribution of several major ion transport proteins in the human cochlea is similar but not identical to that described in various rodent models. These results support the presence of a complex system for recycling and regulating K+ homeostasis in the human cochlea, similar to that described in other mammalian species.

Ossifying chondrolipoma of the tongue

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Tasić Desanka

2012-01-01

Full Text Available Introduction. Chondrolipomas and osteolipomas are uncommon variants of lipomatous tumors. Case report. We presented a 60-year-old woman with ossifying chondrolipoma of the tongue. Clinical examination revealed a firm nodular mass, located in the midline of the posterior region on the dorsal surface of the tongue. Histologically, the lesion was well-delimited showing areas of mature adipocytes arranged in lobules and separated by fibrous connective tissue septa, islands of mature cartilaginous tissue and osseous metaplasia. Trabeculae of lamellar bone within a fibro-fatty background were visible throughout the tumor. The cartilaginous areas merging centrally with bone formation and fatty marrow tissue were present, as well as the hematopoietic elements in the fatty marrow. The bone forming was found to be through both membranous and enchondral mechanisms. Conclusion. Ossifying chrondrolipoma with hematopoietic elements is extremely unusual lesion. This interesting entity should be kept in mind in the differential diagnosis of lingual lesions.

An FPGA-Based Electronic Cochlea

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M. P. Leong

2003-06-01

Full Text Available A module generator which can produce an FPGA-based implementation of an electronic cochlea filter with arbitrary precision is presented. Although hardware implementations of electronic cochlea models have traditionally used analog VLSI as the implementation medium due to their small area, high speed, and low power consumption, FPGA-based implementations offer shorter design times, improved dynamic range, higher accuracy, and a simpler computer interface. The tool presented takes filter coefficients as input and produces a synthesizable VHDL description of an application-optimized design as output. Furthermore, the tool can use simulation test vectors in order to determine the appropriate scaling of the fixed point precision parameters for each filter. The resulting model can be used as an accelerator for research in audition or as the front-end for embedded auditory signal processing systems. The application of this module generator to a real-time cochleagram display is also presented.

Peripheral ossifying fibroma

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Ameet Mani

2010-01-01

Full Text Available The peripheral ossifying fibroma (POF is an exophytic gingival mass of fibrous connective tissue covered with a surface epithelium associated with the formation of randomly dispersed foci of a mineralized product consisting of bone, cementum-like tissue, or dystrophic calcifications having a recurrent rate of nearly 20%. It is one of the most common reactive gingival lesions, which have often been called by the generic term "epulis." This case report describes the clinical and histopathological findings of POF, its differential diagnosis, and treatment.

Juvenile Ossifying Fibroma of the Mandible: a Case Report

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Bahar Keles

2010-04-01

Full Text Available Background: Fibro-osseous lesions of the jaws, including juvenile ossifying fibroma, pose diagnostic and therapeutic difficulties due to their clinical, radiological and histological variability. The aim of this study was to report the outcome of a 9 years old girl with diagnosed juvenile ossifying fibroma treatment.Methods: A 9 years old girl presented with a 6 x 8 cm sized hard fixed tumour on right ramus and corpus of the mandible. On the radiological examination tumour showed an irregular but well bordered, unilocular and expansive lesion on the right corpus and ramus of the mandible. There was no teeth displacement or teeth root resorbtion. Microscopically, the tumour had trabeculae, fibrillary osteoid and woven bone. After the clinical, radiological (panoramic radiography, computed tomography and magnetic resonance imaging and histologic analysis it was diagnosed juvenile ossifying fibroma. In the history of the patient there has been an acute lymphocytic leukaemia in the remission for 3 years.Results: Because of large size of mandibular tumour, resultant expansion and destruction of mandibular cortex, the patient underwent right hemimandibulectomy using transmandibular approach. There was no recurrence or complications for two years follow-up.Conclusions: Although juvenile ossifying fibroma is an uncommon clinical entity, its aggressive local behaviour and high recurrence rate means that it is important to make an early diagnosis, apply the appropriate treatment and, especially, follow-up the patient over the long-term.

Fibrous Dysplasia versus Juvenile Ossifying Fibroma: A Dilemma

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Sreelakshmi N. Nair

2016-01-01

Full Text Available Fibrous dysplasia (FD is a condition characterized by excessive proliferation of bone forming mesenchymal cells which can affect one bone (monostotic type or multiple bones (polyostotic type. It is predominantly noticed in adolescents and young adults. Fibrous dysplasia affecting the jaws is an uncommon condition. The most commonly affected facial bone is the maxilla, with facial asymmetry being the chief complaint. The lesion in many instances is confused with ossifying fibroma (OF. Diagnosis of these two lesions has to be done based on clinical, radiographic, and microscopic findings. Here, we present a case of fibrous dysplasia of maxilla in a nine-year-old boy mimicking juvenile ossifying fibroma.

Cemento-ossifying fibroma of the mandible. A clinicopathological report.

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Bala, Tapas K; Soni, Sarmeshta; Dayal, Prakriti; Ghosh, Indrajeet

2017-05-01

Cemento-ossifying fibromas are rare fibro-osseous benign neoplasms that affect the jaws. They are included in the group of mesodermal odontogenic tumors and commonly present as a progressively growing lesion that might attain enormous size with resultant deformity, if left untreated. A confusion prevails on the terminology, which can only be confirmed by histopathologic evaluation. A case of cemento-ossifying fibroma involving the right mandible is described in a 30 year-old female patient. The clinical, radiographic, histologic features are presented and the various differential diagnosis are discussed.

A case report of cemento-ossifying fibroma presenting as a mass of the ethmoid sinus.

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Hekmatnia, Ali; Ghazavi, Amirhossein; Saboori, Masih; Mahzouni, Parvin; Tayari, Nazila; Hekmatnia, Farzaneh

2011-02-01

Cemento-ossifying fibroma is a lesion containing both fibrous and osseous components. Such lesions include fibrous dysplasia, ossifying fibroma, cemento-ossifying fibroma and cementifying fibroma. Periodontal membrane is the origin of fibro-osseous lesions other than fibrous dysplasia.Here a clinical case of a young woman referred for evaluation of a mass in the right side of face between eye and nose is presented. The first time she noticed the mass was 2 years ago and was growing larger inwards. She was treated with surgical resection.In this case of a cemento-ossifying fibroma, histological interpretation was critical, and was the basis of correct treatment.

Central cemento-ossifying fibroma of posterior maxilla

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Uday Shankar Yaga

2015-01-01

Full Text Available Cemento-ossifying fibromas (COFs are relatively rare, benign lesions affecting the jaws and other craniofacial bones and are included in the group of mesodermal odontogenic tumors by Gorlin. They have a predilection for females between the third and fourth decades of life, and about 60% of the lesions are seen most often in the mandibular arch, predominantly occurring in the premolar/molar region of the mandible. This report describes a case of central COF in a 49-year-old male involving the maxillary posterior region. The current case is reported because of the rarity of such lesions and the paucity of information concerning them in the dental literature. We believe that this case illustrates many of the clinical, radiographic, and histologic features associated with cemento-ossifying tumors.

Conservative Management of Central Cemento-Ossifying Fibroma.

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Gomes-Ferreira, Pedro Henrique Silva; Carrasco, Leandro Carlos; de Oliveira, Danila; Pereira, Járede Carvalho; Alcalde, Luis Fernando Azambuja; Faverani, Leonardo Perez

2017-01-01

Central cemento-ossifying fibroma is characterized by the combined production of osteoid and cementoid tissue. Radiographically, this lesion is presented as an outlined cortical and variable radiopaque spots, also can be present complete radiolucent or different degrees of radiopacity. The recommended treatment is curettage or enucleation, and the recurrence rate is less than 5%. Considering that surgical treatment is invasive, mainly in large lesions, this study aims to report a patient in whom conservative treatment was carried out by involving the preservation of teeth, with a long-term follow-up. A 48-year-old black female patient, diagnosed with central cemento-ossifying fibroma in mandible, treated conservatively and a 2 years of follow-up. It was concluded that the conservative treatment with a long term of follow-up for maintaining teeth was satisfactory.

The clinical and radiologic consideration of cementifying and ossifying fibroma of the jaws

International Nuclear Information System (INIS)

Jo, Eun Young; Kim, Kee Deog; Park, Chang Seo

1997-01-01

The purpose of this study was to know the proper diagnosis and to establish the treatment plan of cementifying and ossifying fibroma in the jaws through the clinical, radiological, and histopathologic considerations. The authors compared and analyzed the clinicoradiologic features of the thirteen cases of cementifying and ossifying fibroma, diagnosed at the Dental college hospital in Yonsei university, Seoul, Korea, during the period from 1980 to 1995. The obtained results were as follows : 1. Cementifying and ossifying fibroma occurred in the mean age, 44 years, ranged from 29 to 65 years and the male to female ratio was approximately 1:5. 2. Swelling was the most common frequent presenting complaints. Other reported symptoms included pain, tooth mobility and symptom. 3. The frequency of the lesions was twelve cases in the mandible and one case in the maxilla. And eleven of thirteen cases were distributed on the premolar and molar region. 4. Radiologically, eight of thirteen cases were well defined lesions, five cases were relatively well defined lesions. And nine of thirteen cases were mixed lesions, three cases were radiopaque lesions, and only one case was purely radiolucent lesion. 5. Histologically, seven of thirteen cases were classified ossifying fibroma, four cases were cemento-ossifying fibroma, and two cases were cementifying fibroma.

Peripheral ossifying fibroma. A case report

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Karen Nair Vallejos Duarte

2016-12-01

Full Text Available Introduction: Peripheral ossifying fibroma, a pseudotumoral injury, considered within simple reactive hyperplasia, which in general has a definite cause and is often reversible. Objective: To present a case of an injury to a patient, which manifested as a radiolucent and asymptomatic injury lesion. Its differential diagnosis, which is based on clinical manifestations and conventional radiographic study, is controversial. Case Description: A case is presented in a male patient with 51-year-old with a lesion in the maxillary incisor-canine area, aspects of which were suggestive of granuloma telangiectasico. Previous clinical and radiographic evaluation, the patient underwent surgical resection of the lesion and was sent for histopathological examination, showing compact osteoid material revealing the peripheral final diagnosis, ossifying fibroma. Conclusion: The professional dentist must have knowledge and ability to clinical management of oral pathologies, to make a correct diagnosis and treatment, for it is essential to perform a biopsy, to avoid possible disputes between the clinical and histological diagnosis.

Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

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Cheng, Xiao-Bing; Li, Yun-Peng; Lei, De-Lin; Li, Xiao-Dong; Tian, Lei

2011-03-01

Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

Pathological fracture in non-ossifying fibroma with histological features simulating aneurysmal bone cyst

International Nuclear Information System (INIS)

Hoeffel, C.; Mainard, L.; Hoeffel, J.C.; Panuel, M.; Plenat, F.

1999-01-01

A 12-year-old-girl presented with a fracture of an osteolytic lesion of the distal radius. A 7-year-old girl presented with a fracture of an osteolytic lesion of the femoral shaft. In both cases it was a non-ossifying fibroma with fracture misdiagnosed at pathology as aneurysmal bone cyst. Fractures through non-ossifying fibromas may alter the histological pattern of the initial lesion in two ways: firstly, by the presence of blood pigments due to the fracture, and secondly, by formation of new bone. Radiological-pathological correlation is essential to avoid histological errors after pathological fracture in a non-ossifying fibroma. (orig.)

Peripheral ossifying fibroma of oral cavity: histopathologic differential diagnoses.

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Shamim, Thorakkal

2012-01-01

Peripheral ossifying fibroma is a benign neoplasm that usuallydevelops from gingiva, presenting as an exophytic smooth surfaced pink or red nodular mass that is sessile or is less frequently seen on a pedicle. From the Indian perspective, it is usually noticed in 5th-6th decades of life with female predilection. Microscopically, the tumour shows stratified squamous epithelium and highly cellular fibrous stroma, sparse endothelial proliferation with fibroblasts and dystrophic calcifications. It has to be differentiated histopathologically from pyogenic granuloma, fibroma, peripheral giant cell granuloma, peripheral odontogenic fibroma and fibrous hyperplasia. A case of peripheral ossifying fibroma of maxillary gingiva in a 55-year-old Indian woman is reported.

A huge cemento-ossifying fibroma of paranasal sinus: a case report.

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Erdim, Ibrahim; Yazici, Zahide Mine; Yilmazer, Rasim; Sever, Nurten; Kayhan, Fatma Tulin

2012-01-01

Cemento-ossifying fibroma is a well-bordered, slow-growing, benign fibro-osseous disease. Although its localization is generally in the mandible, it can be seen in any area of the craniofacial region. Radiology and histopathology help to diagnose the condition. Treatment is based on close observation and/or surgical excision. In this case, we report the case of a 62-year-old male patient who had a large radiological appearance, cemento-ossifying fibroma in the paranasal sinuses.

PSAMMOMATOID OSSIFYING FIBROMA OF THE PARANASAL SINUSES - AN EXTRAGNATHIC VARIANT OF CEMENTO-OSSIFYING FIBROMA - REPORT OF 3 CASES

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SLOOTWEG, PJ; PANDERS, AK; NIKKELS, PGJ

1993-01-01

Psammomatoid ossifying fibroma (POF) is a diagnostic designation for a sinonasal or orbital fibroosseous lesion characterized by numerous small round mineralized spherules lying in a fibroblastic stroma. We report 3 cases. One occurred in the frontal sinus of an 18-years-old male; 1 in the frontal

Characterizing and modeling dynamic processes in the cochlea using otoacoustic emissions

DEFF Research Database (Denmark)

Verhulst, Sarah

2010-01-01

mechanism is essential for our hearing and degrades when hearing impairment develops. A comprehensive understanding of the gain involved in the intact human cochlea is crucial, as hearing instruments try to compensate for the loss in cochlear gain caused by hearing damage. This thesis investigates dynamic......An important characteristic of human hearing is that it amplifies weak sounds while attenuating louder ones. This gain transformation takes place in the inner ear (i.e., cochlea), and is responsible for a compressive relation between the level of the presented and perceived sound. The cochlear gain...... constant in cochlear compression may be of interest for the future development of signal processing in hearing instruments....

MRI of fibrous cortical defect and non-ossifying fibroma

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Mishima, Yoshiko; Aoki, Takatoshi; Watanabe, Hideyuki; Nakata, Hajime; Hashimoto, Hiroshi; Nakamura, Toshitaka [Univ. of Occupational and Environmental Health, Kitakyushu, Fukuoka (Japan). School of Medicine

1999-02-01

Fibrous cortical defect and non-ossifying fibroma are the benign fibrous lesions of bone commonly involving children. Their diagnosis is usually done with radiography, and MR examinations are rarely performed. We evaluated MRI findings of 11 lesions in 10 cases of fibrous cortical defect and non-ossifying fibroma. Signal intensity of the lesions was varied and large lesions (2 cm<) tended to show heterogeneous signal intensity on both T1-weighted and T2-weighted images corresponding to a mixture of components including fibrous tissue, hemosiderin and foam cells. MRI helps to delineate the extent of the involved bone and to assess the various histological components of the lesions. However, their diagnosis is basically made on the radiographic findings and the role of MRI is limited. (author)

Cemento-ossifying fibroma of the maxilla.

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Al-Shaham, A A; Samher, A A

2010-12-01

Despite the fact that cemento-ossifying fibromas of the maxilla may be quite large and locally aggressive, en-bloc excision is achieved by gentle blunt dissection, with the whole tumour mass peeled out from the adjacent structures. Until recently different fibro-osseous tumours that contained cementum were classified together as "cementomas". In 1992 The World Health Organization adopted a new classification that included these fibromas as benign osseous tumours. While such tumours of the mandible are common, those of the maxilla are rare. They are growth products of periodontal membrane remnant. The triggering mechanism in the formation of cementum outside the periodontal membrane remains unclear. We present a 35-year-old woman who had a giant expanding lobular mass in the right maxilla of 5 years duration. She had visual disturbances and nasal obstruction, and was treated successfully by surgical en-bloc resection of the tumour through an infraorbital transverse incision. The differential diagnosis included fibrous dysplasia, osteoid osteoma, osteoblastoma, chronic sclerosing osteomyelitis, ameloblastoma, squamous cell carcinoma of the maxillary sinus, calcifying epithelial odontogenic tumour (Pindborg tumour) and calcifying odontogenic cyst (Gorlin cyst). Histopathological examination confirmed a cemento-ossifying fibroma.

Unpartitioned versus incompletely partitioned cochleae: radiologic differentiation.

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Sennaroglu, Levent; Saatci, Isil

2004-07-01

In the process of evaluating our patients, we realized that the term "Mondini deformity" was being used to describe two different types of incomplete partition of the cochlea. THE First one consisted of an unpartitioned, completely empty cochlea where the interscalar septum and entire modiolus were absent, giving the cochlea a cystic appearance; a grossly dilated vestibule accompanied this lesion. The second pathology fitted the classic description of Mondini deformity, consisting of a normal basal turn and cystic apex (where the middle and apical turns form a cystic cavity), dilated vestibule, and enlarged vestibular aqueduct. This study was planned to investigate the differences between the two types of incomplete partition for inner ear malformations based on radiologic features. We conducted a retrospective review of temporal bone computed tomography (CT) findings. The subjects were 18 patients with profound bilateral sensorineural hearing loss who had high-resolution CT with contiguous 1-mm thick images obtained through the petrous bone in axial sections. The CT results were reviewed as incomplete partition type I (IP-I) and type II (IP-II). Incomplete partition type I (unpartitioned cochlea, cystic cochleovestibular malformation) is defined as a malformation in which the cochlea lacks the entire modiolus and interscalar septa, resulting in a cystic appearance and there is an accompanying grossly dilated vestibule. In incomplete partition type II (incompletely partitioned cochlea, the Mondini deformity), there is a cochlea comprised of a normal basal turn and cystic apex accompanied by a minimally dilated vestibule and enlarged vestibular aqueduct (VA). Measurements involving the cochlea, vestibule, vestibular aqueduct, and internal auditory canal (IAC) were done to determine the characteristic features of these pathologies. : Thirteen ears had IP-I and 18 ears had IP-II anomaly. The size of the cochleae in both anomalies showed no significant difference from

Cemento-ossifying fibroma in a patient with end-stage renal disease.

Science.gov (United States)

Gopinath, Divya; Beena, V T; Sugirtharaj, G; Vidhyadharan, K; Salmanul Faris, K; Kumar, Sajai J

2013-01-01

The presence of chronic renal disease (CRD) is a predisposing factor for the occurrence of soft and hard tissue lesions in the oral cavity. The cemento-ossifying fibroma (COF) is an uncommon benign fibroosseous lesion composed of fibrocellular component and calcified materials like cementum and woven bone. A 37-year-old female patient undergoing chronic haemodialysis reported to our institution with a complaint of slow growing, nontender swelling of mandible of 6-month duration. Computed tomography disclosed an ill-defined lesion showing thinning and expansion of buccal as well as lingual cortical plate with flecks of radiopacity in centre. Incision biopsy revealed histological characteristics consistent with cemento-ossifying fibroma. The lesion was excised under local anesthesia. The histopathological examination revealed irregularly shaped bone and cementum-like hard tissue calcifications contained within hypercellular fibrous tissue stroma, leading to a confirmation of the diagnosis of cemento-ossifying fibroma. This paper aims to provide light to the fact that the soft and hard tissues of the oral region may become susceptible to the development of pathological growths in case of some particular systemic conditions.

Morphological and radiological study of ossified superior transverse scapular ligament as potential risk factor of suprascapular nerve entrapment.

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Polguj, Michał; Sibiński, Marcin; Grzegorzewski, Andrzej; Waszczykowski, Michał; Majos, Agata; Topol, Mirosław

2014-01-01

The suprascapular notch is covered superiorly by the superior transverse scapular ligament. This region is the most common place of suprascapular nerve entrapment formation. The study was performed on 812 specimens: 86 dry scapulae, 104 formalin-fixed cadaveric shoulders, and 622 computer topography scans of scapulae. In the cases with completely ossified superior transverse scapular ligament, the following measurements were performed: proximal and distal width of the bony bridge, middle transverse and vertical diameter of the suprascapular foramen, and area of the suprascapular foramen. An ossified superior transverse scapular ligament was observed more often in men and in the right scapula. The mean age of the subjects with a completely ossified superior transverse scapular ligament was found to be similar than in those without ossification. The ossified band-shaped type of superior transverse scapular ligament was more common than the fan-shaped type and reduced the space below the ligament to a significantly greater degree. The ossified band-shaped type should be taken into consideration as a potential risk factor in the formation of suprascapular nerve entrapment. It could explain the comparable frequency of neuropathy in various populations throughout the world despite the significant differences between them in occurrence of ossified superior transverse scapular ligament.

Cochlea and other spiral forms in nature and art.

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Marinković, Slobodan; Stanković, Predrag; Štrbac, Mile; Tomić, Irina; Ćetković, Mila

2012-01-01

The original appearance of the cochlea and the specific shape of a spiral are interesting for both the scientists and artists. Yet, a correlation between the cochlea and the spiral forms in nature and art has been very rarely mentioned. The aim of this study was to investigate the possible correlation between the cochlea and the other spiral objects in nature, as well as the artistic presentation of the spiral forms. We explored data related to many natural objects and examined 13,625 artworks created by 2049 artists. We also dissected 2 human cochleas and prepared histologic slices of a rat cochlea. The cochlea is a spiral, cone-shaped osseous structure that resembles certain other spiral forms in nature. It was noticed that parts of some plants are arranged in a spiral manner, often according to Fibonacci numbers. Certain animals, their parts, or their products also represent various types of spirals. Many of them, including the cochlea, belong to the logarithmic type. Nature created spiral forms in the living world to pack a larger number of structures in a limited space and also to improve their function. Because the cochlea and other spiral forms have a certain aesthetic value, many artists presented them in their works of art. There is a mathematical and geometric correlation between the cochlea and natural spiral objects, and the same functional reason for their formation. The artists' imagery added a new aspect to those domains. Obviously, the creativity of nature and Homo sapiens has no limits--like the infinite distal part of the spiral. Copyright © 2012 Elsevier Inc. All rights reserved.

A contrastive analysis of laser heating between the human and guinea pig cochlea by numerical simulations.

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Zhang, Kaiyin; Zhang, Yulong; Li, Ji; Wang, Qiuling

2016-05-23

The photo-thermal effect has been hypothesised to be one of the most possible biophysical mechanisms for laser-cochlea stimulation. However, there is a lack of studies to date for direct assessing laser heating in humans due to the large body of evidence required to demonstrate safety and efficacy. Instead, the majority focus on animals like the guinea pig, from which a number of valuable results have been gained. However, in light of the increasing need to improve laser safety, it has became necessary to find out whether studies on animals can shed light on safe laser parameters in the human cochlea. Hence, we conducted this contrastive analysis of laser heating between the human and guinea pig cochlea with the aim of assisting further investigations in this field. In this work, a 3D symmetrical model was adopted to simplify the spiraled cochlea. With attention focused on the effect of heat conduction, the time-dependent heat equation was solved using finite element method with the COMSOL Script. In the simulations, cochleae with different sizes and various boundary thermal conditions were utilized. Laser heating in both cochleae has a similar trend. In the first stage, or at the beginning of the laser heating, both cochleae increased their temperatures rapidly. In the second stage in which the laser heating reached a quasi-steady stage, the peak temperatures began to rise slowly as more laser pulses were applied. However, three differences of the laser heating were observed. The first is regarding the temperature rise. The results show that laser heating in guinea pig is higher than that in human under the same laser parameters. The second difference is the fluctuation of temperature rise at the center of the modiolus. There is a larger fluctuation of temperature rise in the guinea pig cochlea, compared with that in the human cochlea. The third one is the time for reaching a steady thermal state. The results show that the guinea pig cochlea takes longer time to

The mechanisms underlying multiple lobes in SOAE suppression tuning curves in a transmission line model of the cochlea

DEFF Research Database (Denmark)

Epp, Bastian; Manley, Geoff; van Dijk, Pim

2018-01-01

]. In the present study, a nonlinear and active transmission line model of the cochlea is used to investigate this hypothesis. The model is able to produce SOAEs with plausible characteristics and further shows the suggested standing wave pattern. This approach hence makes it possible to disentangle contributions...

Response to a pure tone in a nonlinear mechanical-electrical-acoustical model of the cochlea.

Science.gov (United States)

Meaud, Julien; Grosh, Karl

2012-03-21

In this article, a nonlinear mathematical model is developed based on the physiology of the cochlea of the guinea pig. The three-dimensional intracochlear fluid dynamics are coupled to a micromechanical model of the organ of Corti and to electrical potentials in the cochlear ducts and outer hair cells (OHC). OHC somatic electromotility is modeled by linearized piezoelectric relations whereas the OHC hair-bundle mechanoelectrical transduction current is modeled as a nonlinear function of the hair-bundle deflection. The steady-state response of the cochlea to a single tone is simulated in the frequency domain using an alternating frequency time scheme. Compressive nonlinearity, harmonic distortion, and DC shift on the basilar membrane (BM), tectorial membrane (TM), and OHC potentials are predicted using a single set of parameters. The predictions of the model are verified by comparing simulations to available in vivo experimental data for basal cochlear mechanics. In particular, the model predicts more amplification on the reticular lamina (RL) side of the cochlear partition than on the BM, which replicates recent measurements. Moreover, small harmonic distortion and DC shifts are predicted on the BM, whereas more significant harmonic distortion and DC shifts are predicted in the RL and TM displacements and in the OHC potentials. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The shortened cochlea: its classification and histopathologic features.

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Zheng, Yiqing; Schachern, Patricia A; Cureoglu, Sebahattin; Mutlu, Cemil; Dijalilian, Hamid; Paparella, Michael M

2002-03-15

The term 'Mondini dysplasia' has been used to describe virtually any congenital abnormality of the osseous labyrinth resulting in confusion and seemingly contradictory observations and conclusions about this type of deformity. The purpose of this study is to histopathologically classify and describe temporal bones whose cochleas have less than 2.5 turns. Of the 1800 temporal bones in our collection, 21 from 12 cases were found to have cochleas with less than 2.5 cochlear turns. Ages ranged from stillborn to 50 years. Temporal bones were harvested at autopsy, processed and embedded in celloidin. Sections were cut at a thickness of 20 microm and every 10th section stained with hematoxylin-eosin and examined using light microscopy. The number of turns, length of cochlea, integrity of cochlear base, length of modiolus, abnormalities of the semicircular canals and vestibule, enlargement of the vestibular aqueduct and middle ears were documented. Twenty-one temporal bones from age-matched patients without cochlear deformities were used as controls for modiolar length measurements. Malformation of the shortened cochlea was histopathologically classified into three groups as follows: (1) Common cavity, cochlear dysplasia (one ear)--severe dysplasia of the cochlea without a complete basal turn; (2) Mondini dysplasia (11 ears)--1.5 cochlear turns, a complete basal turn, an incomplete or absent interscalar septum and a complete bone at the base of the modiolus; and (3) Mondini-like dysplasia type A (five ears)--2 turns to the cochlea including a complete basal turn and complete bone at the base of the modiolus; and type B (four ears)--1.5-2 turns to the cochlea, hypoplasia of or a missing bone at the base of the modiolus (either with or without a communication between the internal auditory canal and the cochlea) and a complete basal turn. The range of congenital malformations in short cochlea is highly variable. Fundamental to the accurate evaluation of a labyrinthine anomaly

Cemento-Ossifying Fibroma in a Patient with End-Stage Renal Disease

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Divya Gopinath

2013-01-01

Full Text Available The presence of chronic renal disease (CRD is a predisposing factor for the occurrence of soft and hard tissue lesions in the oral cavity. The cemento-ossifying fibroma (COF is an uncommon benign fibroosseous lesion composed of fibrocellular component and calcified materials like cementum and woven bone. A 37-year-old female patient undergoing chronic haemodialysis reported to our institution with a complaint of slow growing, nontender swelling of mandible of 6-month duration. Computed tomography disclosed an ill-defined lesion showing thinning and expansion of buccal as well as lingual cortical plate with flecks of radiopacity in centre. Incision biopsy revealed histological characteristics consistent with cemento-ossifying fibroma. The lesion was excised under local anesthesia. The histopathological examination revealed irregularly shaped bone and cementum-like hard tissue calcifications contained within hypercellular fibrous tissue stroma, leading to a confirmation of the diagnosis of cemento-ossifying fibroma. This paper aims to provide light to the fact that the soft and hard tissues of the oral region may become susceptible to the development of pathological growths in case of some particular systemic conditions.

Cemento-ossifying fibroma of the maxilla: a case report.

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Verma, Piyush; Rathore, Praveen K; Mrig, Sumit; Pal, Manisha; Sial, Ankush

2011-07-01

We report a case of very large ossifying fibroma of the maxilla in a 22-year-old male. It is a bony tumour of the maxilla of possibly odontogenic origin with aggressive behavior and high tendency for recurrence.

Giant cemento-ossifying fibroma of the mandible: a rare case.

Science.gov (United States)

Sujatha, D; Shubha, Gurudath; Anuradha, Pai; Ragavendra, Mahadev Naik

2013-01-01

The World Health Organization classifies cemento-ossifying fibroma (COF) as a fibro-osseous neoplasm included among the nonodontogenic tumors derived from the mesenchymal blast cells of the periodontal ligament, with a potential for forming fibrous tissue, cementum and bone, or a combination of such elements. These are slow-growing lesions, and are more frequent in women, between the third and fourth decades of life. Case reports of massive expansile COFs (measuring more than 10 cm) are rarely reported in the literature. This article aims to describe a case of giant cemento-ossifying fibroma with radiographic and 3D CT features in a 34 year old female patient, who came with the complaint of progressive swelling of the face which had started 6 years earlier.

A Novel Treatment of Aggressive Psammomatoid Juvenile Ossifying Fibroma: A Case Report

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Badri

2014-08-01

Full Text Available Introduction Juvenile ossifying fibroma is a benign, bone-forming neoplasm with aggressive local growth that is distinguished from other fibro-osseous lesions primarily by its age of onset, clinical presentation and aggressive behavior. Although a benign entity, juvenile ossifying fibroma is known to be locally aggressive and has a high tendency to recur. Two distinctive microscopic patterns have been described: a trabecular variant and a psammomatoid variant. This latter variant is predominantly a craniofacial lesion and occurs rarely in the jaws. Treatment plans include a range of enucleation to total resection. Case Presentation Reported here is a case of a huge psammomatoid juvenile ossifying fibroma of the maxilla in a 19-year-old man. Right maxillectomy was done while brain exposure in sphenoid and ethmoidal region was covered with fat and bone graft. After 1 year follow up, an endosseous dental implant was inserted in right lateral pterygoid plate. Conclusions Six months later an obturator was made over that osseointegrated implant to reconstruct the anatomic defect, achieving functional rehabilitation and satisfactory facial appearance.

Recurrent peripheral cemento-ossifying fibroma.

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Pereira, Treville; Shetty, Subraj; Shetty, Arvind; Pereira, Svylvy

2015-01-01

Peripheral cement-ossifying fibroma (PCOF) is a rare osteogenic neoplasm that ordinarily presents as an epulis-like growth. It frequently occurs in maxillary anterior region in teenagers and young adults. We report a case of PCOF in a 42-year-old male, which was previously surgically excised and recurred after a period of 2 years. PCOF should be considered in the differential diagnosis of reactive hyperplastic lesions originating from gingiva. Hence, early diagnosis with proper surgical excision and aggressive curettage of the adjacent tissues is essential for prevention of recurrence.

Juvenile ossifying fibroma: Psammamatoid variant

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Shivani Aggarwal

2012-01-01

Full Text Available Juvenile ossifying fibroma is a rare fibro-osseous lesion containing variable amount of calcified masses, which resembles bone or cementum within a fibrocellular connective tissue stroma. It has variable clinical behavior, highly aggressive in nature including invasion and destruction of adjacent anatomic structures with a strong tendency to recur. We reported a 28-year-old female patient with a growth in the upper left vestibule region extending from canine to molar region with clinical, histopathological, and radiological features are presented. Surgical management was done, and regular follow-up was advised.

Facial reconstruction using polypropylene mesh after resection of maxillary ossifying fibroma

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R. Soesanto

2012-09-01

Full Text Available Background: Ossifying fibroma is a variant of fibrous dysplasia and catagorized as osteofibrosis lesion. It commonly affects long bones but occasionally involves jaws. Mandible affected more common than maxilla. The treatment of ossifying fibroma include excision and resection. Excision of lesion and resection of maxilla could cause facial defect which cannot be reconstructed with bone graft. Purpose: The aim of this case report is to report the potential use of polypropylene mesh in facial reconstruction after hemimaxillectomy in patients diagnosed with ossifying fibroma of the maxilla. Case: A 17-years-old female patient came to Oral and Maxillofacial Surgery clinic, Dental Hospital, Faculty of Dentistry, Airlangga University, with chief complaint of swelling in the upper left cheek of 2 years duration which was not related to any history of toothache. Patient also complained of the itchiness and pain on the swelling area occasionally as well as salty discharge from the mass. The FNA was done and the citology result indicated a benign mesenchimal tumor. Incisonal biopsy was subsequently performed and the histopathology report confirmed the diagnosis of cementifying fibroma. Case management: Left hemimaxillectomy was done, and post surgical defect in the facial and buccal aspect was immediately reconstructed using three layers of polypropylene mesh. On follow-up, eleven months post-operatively, the patient was well and there was no facial deformity or asymmetry. Conclusion: Polypropylene mesh is a potential material for facial reconstruction as it can reduce the risk of facial deformity after hemimaxillectomy of patients with tumor of the maxilla.Latar belakang: Ossifying fibroma merupakan varian dari fibrous dysplasia dan termasuk di dalam kategori lesi osteofibrosis. Umumnya mengenai tulang panjang tetapi dapat juga mengenai rahang dan lebih banyak menyerang tulang mandibula dibanding maksila. Perawatan ossifying fibroma dilakukan dengan

Cochlea Segmentation using Iterated Random Walks with Shape Prior

DEFF Research Database (Denmark)

Ruiz Pujadas, Esmeralda; Kjer, Hans Martin; Vera, Sergio

2016-01-01

Cochlear implants can restore hearing to deaf or partially deaf patients. In order to plan the intervention, a model from high resolution μCT images is to be built from accurate cochlea segmentations and then, adapted to a patient-specific model. Thus, a precise segmentation is required to build...

The mechanical consequence of failure of ossified union in attempted posterior spinal fusion. A canine model.

Science.gov (United States)

Stonecipher, T K; Vanderby, R; Sciammarella, C A; Lei, S S; Fisk, J R

1983-01-01

The mechanical behavior of pseudarthrosis in posterior spinal fusion was investigated. A canine model was developed in which an incompletely ossified posterior fusion mass was consistently produced. The spines were excised, and the motion segments were mechanically tested using a specially developed loading apparatus. Tests were performed to evaluate stiffness of the segments to loading with compression, torsion, and anterioposterior and lateral bending shear stiffness. Changes in other modes of loading were less consistent. The motion characteristics of the pseudarthrosis could not be predicted from the extent of the osseous defect noted on roentgenograms. These findings correlate clinically with the progression of curvature seen with pseudarthrosis in scoliosis surgery and the unpredictable results of pseudarthrosis in posterior fusion performed in treatment of degenerative disc disease.

A case of ossified yellow ligaments (ossified ligamenta flava) in thoraco-lumbar region and magnetic resonance imaging

International Nuclear Information System (INIS)

Yatsuzuka, Hitoshi; Kitajima, Tomohide; Taguchi, Yoshio; Sakai, Haruo; Nakamura, Norio

1986-01-01

A Case of ossified yellow ligaments in thoracolumbar region is reported. A 47-year-old-male complained of low back pain with suddenness in August, 1984. One month later, he noticed dysesthesia on his right lower extremity and gait disturbance. These symptoms progressed slowly. In June, 1985, he admitted to The Jikei University Hospital. On neurological examinations, he was noticed an intermittent claudication, spastic paraparesis and stocking type sensory loss in his lower extremities. Plain lumbar X-ray films showed ossified yellow ligaments (OYL) in the posterior half of the spinal canal from the level of 10th thoracic to second lumbar vertebrae. Magnetic resonance imaging disclosed marked indentations of the spinal cord at the same level. The wide laminectomy was carried out and OYL were removed totally in gentle manner. Postoperative course was uneventful. His sensory disorders improved remarkably and he gaind good muscle strength in his lower extremities, but a considerable spasticity remained still. OYL is closely related to the developmental canal stenosis, the spondylosis and the other degenerative disorders such as ossification of posterior longitudinal ligaments. This allows more complicated neurological signs and symptoms in the case of OYL. When OYL is suggested, it is recommended to performed whole spinal radiological survey. The surgical consideration should be done. From this point of view, MRI would be a most useful weapon. (author)

Hearing and the cochlea

Science.gov (United States)

... like structure that contains the receptor organ for hearing. The cochlea contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate ...

Reconstruction of Cochlea Based on Micro-CT and Histological Images of the Human Inner Ear

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Christos Bellos

2014-01-01

Full Text Available The study of the normal function and pathology of the inner ear has unique difficulties as it is inaccessible during life and, so, conventional techniques of pathologic studies such as biopsy and surgical excision are not feasible, without further impairing function. Mathematical modelling is therefore particularly attractive as a tool in researching the cochlea and its pathology. The first step towards efficient mathematical modelling is the reconstruction of an accurate three dimensional (3D model of the cochlea that will be presented in this paper. The high quality of the histological images is being exploited in order to extract several sections of the cochlea that are not visible on the micro-CT (mCT images (i.e., scala media, spiral ligament, and organ of Corti as well as other important sections (i.e., basilar membrane, Reissner membrane, scala vestibule, and scala tympani. The reconstructed model is being projected in the centerline of the coiled cochlea, extracted from mCT images, and represented in the 3D space. The reconstruction activities are part of the SIFEM project, which will result in the delivery of an infrastructure, semantically interlinking various tools and libraries (i.e., segmentation, reconstruction, and visualization tools with the clinical knowledge, which is represented by existing data, towards the delivery of a robust multiscale model of the inner ear.

Cemento-ossifying fibroma

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Chandramani More

2011-01-01

Full Text Available Cemento-ossifying fibromas (COFs are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adult females between the third and fourth decade of life, predominantly occurring in the premolar/molar region of the mandible. Most of the lesions typically show slow and often expansile growth, centrally within the jaw and characteristically behave in a benign form, but occasionally they may present as an aggressive gigantiform lesion. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumor may grow quite extensively; thus, the term "aggressive" is sometimes applied. Surgical resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. Clinical, radiographic and histopathologic features of COF and other fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis and treatment.

Giant atypical ossifying fibromyxoid tumour of the calf

International Nuclear Information System (INIS)

Harish, Srinivasan; Polson, Alexander; Griffiths, Meryl; Morris, Paul; Malata, Charles; Bearcroft, Philip W.P.

2006-01-01

We present a case of giant atypical ossifying fibromyxoid tumour (OFMT) of soft tissue, occurring in the calf, in a 77-year-old woman. The patient presented with a history of bleeding ulcer over a calf lump that had been present for over 4 years. Clinical presentation, radiological features and histopathologic findings are described, and the relevant literature is reviewed. (orig.)

CT examination of the temporal bones for cochlear implantation; Badanie CT kosci skroniowych u osob przygotowanych do operacji wszczepu slimakowego

Energy Technology Data Exchange (ETDEWEB)

Szyfter, W.; Szymiec, E.; Pruszewicz, A.; Szmeja, Z.; Paprzycki, W.; Sekula, A.; Przybylska, J. [Klinika Otolaryngologii, Akademia Medyczna, Poznan (Poland)

1995-12-31

CT examinations of temporal bones were performed in 31 deaf patients from qualify diagnostic stage prepared for cochlear implants. Essential for surgical treatment anatomic details were estimated, especially canalis spiralis cochleae was paid to attention. In our group, 8 patients had some CT changes (abnormal findings) which corresponded to different stages of obliteration the cochlea. The majority of patients lost the hearing because of meningitis. In 6 implanted patients CT scan was compared with surgical findings. During the operation 1 patient with patent cochlea on CT scan had partially ossified basal turn. (author) 16 refs, 4 figs, 2 tabs

Spontaneous regeneration after juvenile ossifying fibroma resection: a case report.

Science.gov (United States)

Espinosa, Sebastián A; Villanueva, Julio; Hampel, Hans; Reyes, Daniel

2006-11-01

A case of unusual bone regeneration after resection of a juvenile ossifying fibroma (JOF) is presented. Secondary mandibular reconstruction with autogenous grafts was delayed due to the rapid bone formation. To the best of our knowledge there are no reports of this unusual response following JOF resection.

En bloc resection of huge cemento-ossifying fibroma of mandible: avoiding lower lip split incision.

Science.gov (United States)

Ayub, Tahera; Katpar, Shahjahan; Shafique, Salman; Mirza, Talat

2011-05-01

Cemento-ossifying Fibroma (COF) is an osteogenic benign neoplasm affecting the jaws and other craniofacial bones. It commonly presents as a progressively slow growing pathology, which can sometimes attain an enormous size, causing facial deformity. A case of a huge cemento-ossifying fibroma, appearing as a mandibular dumbell tumour in a male patient is documented, which caused massive bone destruction and deformity. It was surgically removed by performing en bloc resection of mandible avoiding the splitting of lower lip incision technique, thereby maintaining his normal facial appearance.

A Protocol for Decellularizing Mouse Cochleae for Inner Ear Tissue Engineering.

Science.gov (United States)

Neal, Christopher A; Nelson-Brantley, Jennifer G; Detamore, Michael S; Staecker, Hinrich; Mellott, Adam J

2018-01-01

In mammals, mechanosensory hair cells that facilitate hearing lack the ability to regenerate, which has limited treatments for hearing loss. Current regenerative medicine strategies have focused on transplanting stem cells or genetic manipulation of surrounding support cells in the inner ear to encourage replacement of damaged stem cells to correct hearing loss. Yet, the extracellular matrix (ECM) may play a vital role in inducing and maintaining function of hair cells, and has not been well investigated. Using the cochlear ECM as a scaffold to grow adult stem cells may provide unique insights into how the composition and architecture of the extracellular environment aids cells in sustaining hearing function. Here we present a method for isolating and decellularizing cochleae from mice to use as scaffolds accepting perfused adult stem cells. In the current protocol, cochleae are isolated from euthanized mice, decellularized, and decalcified. Afterward, human Wharton's jelly cells (hWJCs) that were isolated from the umbilical cord were carefully perfused into each cochlea. The cochleae were used as bioreactors, and cells were cultured for 30 days before undergoing processing for analysis. Decellularized cochleae retained identifiable extracellular structures, but did not reveal the presence of cells or noticeable fragments of DNA. Cells perfused into the cochlea invaded most of the interior and exterior of the cochlea and grew without incident over a duration of 30 days. Thus, the current method can be used to study how cochlear ECM affects cell development and behavior.

Scanning laser optical tomography for in toto imaging of the murine cochlea.

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Lena Nolte

Full Text Available The mammalian cochlea is a complex macroscopic structure due to its helical shape and the microscopic arrangements of the individual layers of cells. To improve the outcomes of hearing restoration in deaf patients, it is important to understand the anatomic structure and composition of the cochlea ex vivo. Hitherto, only one histological technique based on confocal laser scanning microscopy and optical clearing has been developed for in toto optical imaging of the murine cochlea. However, with a growing size of the specimen, e.g., human cochlea, this technique reaches its limitations. Here, we demonstrate scanning laser optical tomography (SLOT as a valuable imaging technique to visualize the murine cochlea in toto without any physical slicing. This technique can also be applied in larger specimens up to cm3 such as the human cochlea. Furthermore, immunolabeling allows visualization of inner hair cells (otoferlin or spiral ganglion cells (neurofilament within the whole cochlea. After image reconstruction, the 3D dataset was used for digital segmentation of the labeled region. As a result, quantitative analysis of position, length and curvature of the labeled region was possible. This is of high interest in order to understand the interaction of cochlear implants (CI and cells in more detail.

Ossified skeletal muscle hemangioma: Radiologic and pathologic features

Energy Technology Data Exchange (ETDEWEB)

Engelstad, B L; Gilula, L A [Mallinckrodt Inst. of Radiology, St. Louis, MO (USA); Kynakos, M [Washington Univ., St. Louis, MO (USA). Dept. of Surgical Pathology

1980-01-01

Skeletal muscle hemangiomas are relatively uncommon tumors in children and young adults. Although the operative management of these lesions may be affected by their vascularity, the correct preoperative diagnosis is often not made. Ossification of these lesions is rare. Two patients are described whose skeletal muscle hemangiomas contained abundant osseous tissue. This was radiologically reflected by the 'swiss cheese' appearance of the tumors. Such an appearance in an ossified soft tissue mass may allow the correct preoperative diagnosis of this condition.

Normal tissue complication probability modeling for cochlea constraints to avoid causing tinnitus after head-and-neck intensity-modulated radiation therapy

International Nuclear Information System (INIS)

Lee, Tsair-Fwu; Yeh, Shyh-An; Chao, Pei-Ju; Chang, Liyun; Chiu, Chien-Liang; Ting, Hui-Min; Wang, Hung-Yu; Huang, Yu-Jie

2015-01-01

Radiation-induced tinnitus is a side effect of radiotherapy in the inner ear for cancers of the head and neck. Effective dose constraints for protecting the cochlea are under-reported. The aim of this study is to determine the cochlea dose limitation to avoid causing tinnitus after head-and-neck cancer (HNC) intensity-modulated radiation therapy (IMRT). In total 211 patients with HNC were included; the side effects of radiotherapy were investigated for 422 inner ears in the cohort. Forty-nine of the four hundred and twenty-two samples (11.6 %) developed grade 2+ tinnitus symptoms after IMRT, as diagnosed by a clinician. The Late Effects of Normal Tissues–Subjective, Objective, Management, Analytic (LENT-SOMA) criteria were used for tinnitus evaluation. The logistic and Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) models were used for the analyses. The NTCP-fitted parameters were TD 50 = 46.31 Gy (95 % CI, 41.46–52.50), γ 50 = 1.27 (95 % CI, 1.02–1.55), and TD 50 = 46.52 Gy (95 % CI, 41.91–53.43), m = 0.35 (95 % CI, 0.30–0.42) for the logistic and LKB models, respectively. The suggested guideline TD 20 for the tolerance dose to produce a 20 % complication rate within a specific period of time was TD 20 = 33.62 Gy (95 % CI, 30.15–38.27) (logistic) and TD 20 = 32.82 Gy (95 % CI, 29.58–37.69) (LKB). To maintain the incidence of grade 2+ tinnitus toxicity <20 % in IMRT, we suggest that the mean dose to the cochlea should be <32 Gy. However, models should not be extrapolated to other patient populations without further verification and should first be confirmed before clinical implementation

A case report of ossifying fibroma of the mandible

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoo Dong [College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1973-11-15

The author has observed a case of ossifying fibroma occurred in the left mandibular body area of 19 year old woman. In the serial roentgenograms, the author has drawn following conclusions: 1. The lesion is circumscribed and demarcated from the surrounding bone tissues. 2. The cortical bone of the involved area was expanded and thinned markedly on the site. 3. The radiopacity was increased with more or less mottled appearance on the site.

Implanting straight into cochlea risks the facial nerve: a Cartesian coordinate study.

Science.gov (United States)

Deshpande, Anita S; Wendell Todd, N

2016-12-01

To describe the straight-into-cochlea line that affords the best access for an electrode array to enter via the round window, and how this line relates to the facial nerve, the incus, and mastoid size. The straight-into-cochlea line is important to minimize the cochlear trauma and maximize the likelihood of placement into the scala tympani. High-resolution CT scans were obtained for ten craniums with the extremes of large (N = 5) and small (N = 5) mastoid pneumatization; the specimens were from a series of 41 ear normal craniums. Using FIJI, a publicly available software program, the straight-into-cochlea insertion line was determined by defining the x-y-z coordinates of the middle of the round window and a point 6.0 mm into the cochlea on its centrifugal wall. Then, from the extended straight-into-cochlea insertion line, we determined the shortest perpendicular distance to the middle of the fallopian canal, and from that "fallopian point" to the apex of the posterior process of the incus. We found good repeatability of measurements. We found the extended straight-into-cochlea insertion lines routinely close to or in the midst of the fallopian canal (50 % ≤ 1.0 mm). We found the lines 4.7-7.8 mm from the apex of the posterior process of the incus. Line positions relative to "fallopian point" and incus showed no relation to mastoid pneumatization. For the distance "fallopian point" to incus, bilateral symmetry was suggested. Using landmarks registered in an x-y-z coordinate system, straight-into-cochlea insertion via the round window puts the facial nerve at risk.

[Effects of electroacupuncture on cochlea morphology and expression of aquaporins in guinea pigs with endolymphatic hydrops].

Science.gov (United States)

Jiang, Liyuan; Wang, Canjun; Ni, Fangying; Chen, Huade

2015-06-01

To observe the effects of electroacupuncture (EA) on cochlea morphology and expression of aquaporin 1 (AQP1) in guinea pigs with endolymphatic hydrops, so as to explore the possible mechanism of EA on endolymphatic hydrops. Forty guinea pigs were randomly divided into a blank group, a model group, a medication group and an EA group, 10 guinea pigs in each one. Model of endolymphatic hydrops was established by using intraperitoneal injection of aldosterone. Guinea pigs in the blank group and model group were treated with identical immobilization as EA group but no treatment was given; guinea pigs in the medication group were treated with intragastric administration of hydrochlorothiazide at a dose of 5 mg/kg, once a day for consecutive 10 days; guinea pigs in the EA group were treated with' EA at "Baihui" (GV 20) and "Tinggong"(SI 19), once a day for consecutive 10 days. The serum ionic concentration in each group was tested by turbidimetric method; hematoxylin-eosin staining was used to measure the severity of cochlea hydrops; immunohistochemical method was used to observe the expression of AQP1 in the cochlea. (1) There was no endolymphatic hydrops in the blank group, moderate-severe endolymphatic hydrops in the model group and slight endolymphatic hydrops in the EA group and medication group. (2) The concentration of K+ and Ca2+ in the EA group was higher than that in the model group and medication group (all P0. 05). (3) The ratio of expression area of AQP1 in the model group was lower than that in the blank group (P0. 05). EA could relieve the endolymphatic hydrops in guinea pigs; the mechanism is likely to be related with up-regulating the expression of AQP1 in cochlea and ion concentration might be an important factor involved.

Cystic Shape Cemento-Ossifying Fibroma of Ethmoid Sinus.

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Shejbal, Dražen; Vonsović, Gabrijela; Baudoin, Tomislav; Vagic, Davor

2015-06-01

Cemento-ossifying fibromas are a group of rarely occurring benign tumours, developing from the periodontal membrane and varying considerably in appearance and in the progress of the disease. Their common feature is higher or lower production of cemental tissue. In most cases the tumours are small because their cementoma mature quickly and become inactive, which causes the tumour to stop growing. They develop most frequently in the mandible and also in the maxilla. Other sites, such as paranasal cavities, soft tissues and bones of the head, are extremely rare. The case of a cemento-fibrosing tumour with psammoma infiltrations, developing from the ethmoid sinus in a nine-year-old girl is reported. Due to frontal headaches and sight defects as well as impaired vision on the right side, NMR was done, which showed a mucocele of the front and rear ethmoid with destruction of the orbital wall and a breakthrough into the orbit. The right maxillary sinus showed a visible retention and a thickened mucous membrane. A rhinoscopy revealed a ball-shaped spherical mass in the medial nasal meatus, which was defined as concha bullosa. An endoscopic examination showed that the tumour protruded in front of the medium nasal concha into the right nasal cavity, softened the ethmoid roof, penetrated toward the base of the skull, adhered and pushed the orbit. It was removed by FESS technique, and PHD revealed subsequently that it was not a mucocele but a cemento-ossifying fibroma.

CT and Magnetic Resonance Imaging Findings of Psammomatoid Juvenile Ossifying Fibroma of the Middle Turbinate: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Kwon; Choe, Mi Sun [Dongsan Medical Center, Keimyung University School of Medicine, Daegu (Korea, Republic of)

2013-06-15

Ossifying fibroma of the middle turbinate is extremely rare. We report a case of psammomatoid juvenile ossifying fibroma (PsJOF) of the middle turbinate in an 18-year-old adolescent female along with its CT, MRI and pathologic features. PsJOF of the middle turbinate may present a well-demarcated, expansile, solidly enhancing mass with focal bony destruction, which may mimic various benign and malignant neoplasms of the sinonasal area. A combination of clinical, imaging and pathologic findings is prerequisite for establishing an accurate diagnosis.

Effects of 60Co γ-ray radiation on cochlea in guinea pigs

International Nuclear Information System (INIS)

Fan Jingping; Lu Shuchang; Hu Zhengyan; Shi Xiufeng

1992-01-01

The effects of different doses of γ-ray on cochlea are reported. Significant hearing loss and severe cochlea hair cells injury were found while radiation dose was more than 80 Gy. With 40 Gy to 60 Gy, slight hearing loss, but cochlea hair cells and support cells impairment were observed. With 20 Gy, no hearing loss and no hair cell damage were found. The results indicated that the damage increases with a dose of radiation and there is a delay effect of radiation on cochles

A clinico‑pathologic review of 56 cases of ossifying fibroma of the ...

African Journals Online (AJOL)

2014-01-07

Jan 7, 2014 ... Objective: This study aims at contributing to the definitive diagnosis of ossifying fibroma (OF) based on ... Most of the lesions (70.3%) occurred in the mandible, involving ... or cellular woven bone or osteoid were found, in 36 (64.3%) cases. ... procedures before looking into the clinical and radiographic.

A clinico-pathologic review of 56 cases of ossifying fibroma of the ...

African Journals Online (AJOL)

Materials and Methods: A total of 80 patients who were diagnosed either as cementifying fibroma CF, OF and cemento.ossifying fibroma (COF) of the jaws from the files of the Oral Pathology Department of the University of the Witwatersrand Dental School were retrieved and the histology slides of each case were reviewed ...

Fractures of the distal phalanx and associated soft tissue and osseous abnormalities in 22 horses with ossified sclerotic ungual cartilages diagnosed with magnetic resonance imaging.

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Selberg, Kurt; Werpy, Natasha

2011-01-01

Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments. © 2011 Veterinary Radiology & Ultrasound.

Dose verification to cochlea during gamma knife radiosurgery of acoustic schwannoma using MOSFET dosimeter.

Science.gov (United States)

Sharma, Sunil D; Kumar, Rajesh; Akhilesh, Philomina; Pendse, Anil M; Deshpande, Sudesh; Misra, Basant K

2012-01-01

Dose verification to cochlea using metal oxide semiconductor field effect transistor (MOSFET) dosimeter using a specially designed multi slice head and neck phantom during the treatment of acoustic schwannoma by Gamma Knife radiosurgery unit. A multi slice polystyrene head phantom was designed and fabricated for measurement of dose to cochlea during the treatment of the acoustic schwannoma. The phantom has provision to position the MOSFET dosimeters at the desired location precisely. MOSFET dosimeters of 0.2 mm x 0.2 mm x 0.5 μm were used to measure the dose to the cochlea. CT scans of the phantom with MOSFETs in situ were taken along with Leksell frame. The treatment plans of five patients treated earlier for acoustic schwannoma were transferred to the phantom. Dose and coordinates of maximum dose point inside the cochlea were derived. The phantom along with the MOSFET dosimeters was irradiated to deliver the planned treatment and dose received by cochlea were measured. The treatment planning system (TPS) estimated and measured dose to the cochlea were in the range of 7.4 - 8.4 Gy and 7.1 - 8 Gy, respectively. The maximum variation between TPS calculated and measured dose to cochlea was 5%. The measured dose values were found in good agreement with the dose values calculated using the TPS. The MOSFET dosimeter can be a suitable choice for routine dose verification in the Gamma Knife radiosurgery.

Swept source optical coherence tomography for in vivo imaging and vibrometry in the apex of the mouse cochlea

Energy Technology Data Exchange (ETDEWEB)

Lee, Hee Yoon [E.L. Ginzton Laboratory and Department of Electrical Engineering, Stanford University, Stanford, California (United States); Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California (United States); Raphael, Patrick D.; Oghalai, John S. [Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California (United States); Ellerbee, Audrey K. [E.L. Ginzton Laboratory and Department of Electrical Engineering, Stanford University, Stanford, California (United States); Applegate, Brian E. [Department of Biomedical Engineering, Texas A& M University, College Station, Texas (United States)

2015-12-31

Cochlear amplification has been most commonly investigated by measuring the vibrations of the basilar membrane in animal models. Several different techniques have been used for measuring these vibrations such as laser Doppler vibrometry, miniature pressure sensors, low coherence interferometry, and spectral-domain optical coherence tomography (SD-OCT). We have built a swept-source OCT (SS-OCT) system, which is similar to SD-OCT in that it is capable of performing both imaging and vibration measurements within the mouse cochlea in vivo without having to open the bone. In vivo 3D images of a mouse cochlea were obtained, and the basilar membrane, tectorial membrane, Reissner’s membrane, tunnel of Corti, and reticular lamina could all be resolved. We measured vibrations of multiple structures within the mouse cochlea to sound stimuli. As well, we measured the radial deflections of the reticular lamina and tectorial membrane to estimate the displacement of the outer hair cell stereocilia. These measurements have the potential to more clearly define the mechanisms underlying the linear and non-linear processes within the mammalian cochlea.

Calcifying/ossifying synovial sarcoma: A clinicopathologic and molecular study of 5 cases

Directory of Open Access Journals (Sweden)

Nasir Ud Din

2015-01-01

Full Text Available Background: Synovial sarcoma (SS is a soft tissue sarcoma with a generally aggressive behavior. Calcifying/ossifying SS is a rare variant associated with a favorable prognosis. Aim: The aim was to report clinicopathological features and molecular analysis of 5 cases of calcifying/ossifying SS. Materials and Methods: Record of 370 cases of SS reported in the section of Histopathology, of a tertiary care Hospital, between 2002 and 2011 were retrieved. Five cases exhibiting extensive calcification and ossification were identified. Immunohistochemistry was performed using Flex technique. Molecular analysis of these 5 cases was performed later at the collaborative Hospital abroad, by reverse transcription polymerase chain reaction. Results and Conclusions: The ages of the patients ranged from 13 to 44 years (mean age 27 years; female to male ratio 1.6:1. The duration of symptoms ranged from 5 months to 5 years. Histologically, 4 were monophasic, and 1 was biphasic. Three cases exhibited extensive calcification and two extensive ossification. Immunohistochemical stain (epithelial membrane antigen was positive in all 5 cases, CKAE1/AE3 (3/4, Bcl2 (4/4, S100 (4/4, CK7 (2/2, CD99 (1/3 and vimentin (2/2. Intact RNA was obtained from 3 cases, all of which were positive for the SYT/SSX fusion transcript. Follow-up was available in 4 cases and ranged from 19 months to 85 months (mean 50 months. Local recurrence was seen in 2 cases. In conclusions, we report clinicopathologic features of 5 cases of calcifying/ossifying SS. The duration of symptoms and mean age of patients is similar to the literature. A slight female predominance was seen in contrast to a male predominance described in the literature. The clinical course of our cases validates the favorable prognosis of this rare type of SS.

Peripheral cemento-ossifying fibroma: Report of a recurrence case.

Science.gov (United States)

Sah, Kunal; Kale, Alka D; Hallikerimath, Seema; Chandra, Sunira

2012-04-01

Peripheral cemento-ossifying fibroma [PCOF] is a reactive gingival overgrowth occurring frequently in the maxillary anterior region in teenagers and young adults. Here, we report a case of POCF in a 13-year-old male, which was previously surgically excised and had recurred after a period of 9 months. PCOF should be considered in differential diagnosis of such reactive hyperplastic lesions originating from the gingiva. Hence, early diagnosis with proper surgical excision and aggressive curettage of the adjacent tissues are essential for prevention of recurrence.

JUVENILE OSSIFYING FIBROMA - AN ANALYSIS OF 33 CASES WITH EMPHASIS ON HISTOPATHOLOGICAL ASPECTS

NARCIS (Netherlands)

SLOOTWEG, PJ; PANDERS, AK; KOOPMANS, R; NIKKELS, PGJ

1994-01-01

Juvenile ossifying fibroma (JOF) is a maxillofacial fibro-osseous lesion that may show cell-rich osteoid strands or psammoma-like ossicles. Whether both types are variants of a single entity or different lesions under the same diagnostic label is a subject of debate. This problem was investigated by

Juvenile aggressive cemento-ossifying fibroma of the sphenoid sinus with proptosis: a surgical dilemma.

Science.gov (United States)

Singh, Rohit; Ramaswamy, Balakrishnan; Hazarika, Manali

2013-11-27

The term fibro-osseous lesion has currently grown in popularity as an overall designation for a number of rare, histologically benign head and neck lesions that are made up of bone, fibrous tissue and cementum. Cemento-ossifying fibroma is a variant of cementifying fibroma and is a fibro-osseous disease. They are usually small innocuous lesions which follow a slow benign course and are commonly seen in the skull bone rather than the sphenoid. It is rare for these tumours to attain large size, behave aggressively, destroy bone and require a radical surgery. One such rapidly growing juvenile cemento-ossifying lesion of sphenoid in our 10-year-old young patient causing proptosis and impaired vision is reported here because of its uncommon nature and its surgical dilemma. Selection of surgical approach to resect this tumour becomes difficult because it is deeply seated and needs a multidisciplinary approach.

Pericoronal occurrence of cemento-ossifying fibroma: an unexemplified and unusual case report with review of literature.

Science.gov (United States)

K L, Kumaraswamy; R S, Arvind Babu; P, Sheshadri; Kumaran, Santhosh

2014-03-01

The Cemento-ossifying fibroma (COF) is an odontogenic neoplasm that is predominantly considered as a fibro osseous lesion of the jaw bone. The histogenetic origin of COF was thought to be derived from the periodontal cells, which have the ability to form fibrous, cementum and osseous tissue. Due to the periodontal cellular origin, the lesion often occurs in the radicular portion of the bicuspid and molar tooth region of the lower jaw. We present a case of Cemento-ossifying fibroma in a 43-year-old female in the pericoronal aspect of an impacted third molar mimicking an odontogenic lesion. The occurrence of COF in pericoronal region is an unusual site. This article also discusses about the various hamartomatous lesions occurring in the pericoronal region of the teeth.

The Use of Lexical Neighborhood Test (LNT) in the Assessment of Speech Recognition Performance of Cochlear Implantees with Normal and Malformed Cochlea.

Science.gov (United States)

Kant, Anjali R; Banik, Arun A

2017-09-01

The present study aims to use the model-based test Lexical Neighborhood Test (LNT), to assess speech recognition performance in early and late implanted hearing impaired children with normal and malformed cochlea. The LNT was administered to 46 children with congenital (prelingual) bilateral severe-profound sensorineural hearing loss, using Nucleus 24 cochlear implant. The children were grouped into Group 1-(early implantees with normal cochlea-EI); n = 15, 31/2-61/2 years of age; mean age at implantation-3½ years. Group 2-(late implantees with normal cochlea-LI); n = 15, 6-12 years of age; mean age at implantation-5 years. Group 3-(early implantees with malformed cochlea-EIMC); n = 9; 4.9-10.6 years of age; mean age at implantation-3.10 years. Group 4-(late implantees with malformed cochlea-LIMC); n = 7; 7-12.6 years of age; mean age at implantation-6.3 years. The following were the malformations: dysplastic cochlea, common cavity, Mondini's, incomplete partition-1 and 2 (IP-1 and 2), enlarged IAC. The children were instructed to repeat the words on hearing them. Means of the word and phoneme scores were computed. The LNT can also be used to assess speech recognition performance of hearing impaired children with malformed cochlea. When both easy and hard lists of LNT are considered, although, late implantees (with or without normal cochlea), have achieved higher word scores than early implantees, the differences are not statistically significant. Using LNT for assessing speech recognition enables a quantitative as well as descriptive report of phonological processes used by the children.

The innervation of the bat cochlea

NARCIS (Netherlands)

Firbas, Wilhelm

1970-01-01

For different species of bats, fixed in 5 % formaldehyd, an estimation of the number of neurons in the spiral ganglion was made. The cochleae were decalcified in EDTA and embedded in paraffin. The complete series of sections were stained with hematoxylin. On the sections through the ganglion, the

Multiple complex odontomas and subsequent occurrence of an ossifying fibroma at the same site as the removed odontoma

Directory of Open Access Journals (Sweden)

Kou Matsuo

2013-06-01

Full Text Available We report a rare case of multiple complex odontomas and the subsequent occurrence of an ossifying fibroma at the same site as one of the removed odontomas. A 3-year-old Japanese boy presented three complex odontomas at the unerupted deciduous first and second molars and permanent first molar on the left side of the mandible. The two odontomas at the deciduous teeth were immediately extirpated, and, after 2 years of follow-up, the odontoma at the unerupted permanent first molar was removed. At the age of 7 years, a small odontoma surrounding the deciduous second molar emerged as a recurrence. When the patient was 9 years old, an ossifying fibroma occurred near the apex of the first premolar, i.e., the site where one of the original odontomas existed. Furthermore, a small radiopaque mass over the crown of the unerupted permanent second molar was observed at the age of 10 years; this mass was probably an additional fourth complex odontoma. This is not only a rare case report of ossifying fibroma associated with multiple complex odontomas but also a valuable time course observation of the development of such odontogenic tumors.

Vibration induced hearing loss in guinea pig cochlea: expression of TNF-alpha and VEGF.

Science.gov (United States)

Zou, Jing; Pyykkö, Ilmari; Sutinen, Päivi; Toppila, Esko

2005-04-01

Transcranial vibration was applied for seven animals at a frequency of 250 Hz for 15 min, and five animals were used as normal controls to investigate cellular and molecular mechanism linked to vibration-induced hearing loss in animal model. Compound action potential (CAP) thresholds were measured by round window niche electrode. The expression of tumour necrosis factor alpha (TNF-alpha) and its receptors (TNF R1, TNF R2), vascular endothelium growth factor (VEGF) and its receptors (VEGF R1, VEGF R2) were analysed by immunohistochemistry. Transcranial vibration caused expression of TNF-alpha, TNF R1 and TNF R2 in the cochlea and the expression of TNF R2 was stronger than that of TNF R1. Vibration also induced VEGF and VEGF R2 expression in the cochlea. The average immediate hearing loss was 62 dB and after three days still 48 dB. It is concluded that transcranial vibration as during temporal bone drilling produces cochlear shear stress that is connected with up-regulation of TNF-alpha and its receptors. Also VEGF and VEGF R2 are up-regulated. These responses may be linked to both the damage and repair process of the cochlea.

Basilar membrane and reticular lamina motion in a multi-scale finite element model of the mouse cochlea

Science.gov (United States)

Soons, Joris; Dirckx, Joris; Steele, Charles; Puria, Sunil

2015-12-01

A multi-scale finite element (FE) model of the mouse cochlea, based on its anatomy and material properties is presented. The important feature in the model is a lattice of 400 Y-shaped structures in the longitudinal direction, each formed by Deiters cells, phalangeal processes and outer hair cells (OHC). OHC somatic motility is modeled by an expansion force proportional to the shear on the stereocilia, which in turn is proportional to the pressure difference between the scala vestibule and scala tympani. Basilar membrane (BM) and reticular lamina (RL) velocity compare qualitatively very well with recent in vivo measurements in guinea pig [2]. Compared to the BM, the RL is shown to have higher amplification and a shift to higher frequencies. This comes naturally from the realistic Y-shaped cell organization without tectorial membrane tuning.

A large parosteal ossifying lipoma of lower limb encircling the femur

Science.gov (United States)

2014-01-01

Introduction Lipoma is a benign soft tissue neoplasm that may contain mesenchymal elements, as a result of metaplastic process. Ossification in benign and malignant soft tissue tumors can also manifest due to metaplastic process. Case presentation A 45 year old woman presented with a large thigh mass. The mass was developed one and a half year ago which insidiously increased in size and was associated with movement restriction. Radiological findings revealed soft tissue neoplasm on antero-medial aspect of thigh encircling the femur and displacing adjacent muscles. Fine trabeculations were seen in neoplasm suggestive of ossification. Excision of the mass was performed and histopathology revealed adipocytes with mature bony trabeculae possessing prominent osteoblastic rimming suggestive of ossifying lipoma. Conclusion It is important to recognize this variant of lipoma as it is associated with a better clinical outcome in contrast to most of the deep seated soft tissue neoplasms. Secondly it should also be differentiated from myositis ossificans and heterologous differentiation in other soft tissue neoplasms. We suggest an algorithmic approach to the diagnosis of ossifying soft tissue neoplasms histopathologically. Mature bony trabeculae with prominent osteoblastic rimming in a soft tissue lesion are due to a metaplastic process and should not be confused with osteosarcoma. PMID:24433545

Generation of induced neurons by direct reprogramming in the mammalian cochlea.

Science.gov (United States)

Nishimura, K; Weichert, R M; Liu, W; Davis, R L; Dabdoub, A

2014-09-05

Primary auditory neurons (ANs) in the mammalian cochlea play a critical role in hearing as they transmit auditory information in the form of electrical signals from mechanosensory cochlear hair cells in the inner ear to the brainstem. Their progressive degeneration is associated with disease conditions, excessive noise exposure and aging. Replacement of ANs, which lack the ability to regenerate spontaneously, would have a significant impact on research and advancement in cochlear implants in addition to the amelioration of hearing impairment. The aim of this study was to induce a neuronal phenotype in endogenous non-neural cells in the cochlea, which is the essential organ of hearing. Overexpression of a neurogenic basic helix-loop-helix transcription factor, Ascl1, in the cochlear non-sensory epithelial cells induced neurons at high efficiency at embryonic, postnatal and juvenile stages. Moreover, induced neurons showed typical properties of neuron morphology, gene expression and electrophysiology. Our data indicate that Ascl1 alone or Ascl1 and NeuroD1 is sufficient to reprogram cochlear non-sensory epithelial cells into functional neurons. Generation of neurons from non-neural cells in the cochlea is an important step for the regeneration of ANs in the mature mammalian cochlea. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Giant cemento-ossifying fibroma of the maxilla.

Science.gov (United States)

Unal, Adnan; Yurtsever Kum, Nurcan; Kum, Rauf Oguzhan; Erdogan, Aysun; Ciliz, Deniz Sozmen; Guresci, Servet; Ozcan, Muge

2015-11-14

Fibro-osseous lesions of the skull and facial bones are benign tumors, but they can be mistaken for malignant tumors due to their clinically aggressive behavior. Cemento-ossifying fibroma (COF) is a benign fibro-osseous lesion characterized by slow growth and fibrous and calcified tissue content. COFs are locally destructive lesions causing deformities in the bones. The recurrence risk is high if they are not completely removed. In this case report we describe a giant COF mimicking chondrosarcoma in the oral cavity of a 55-year-old woman causing significant facial deformity and feeding problems. Giant COF occurs rarely in the jaws and given that this lesion has similar imaging and clinical features to several other tumors, the diagnosis is always a challenge for clinicians, radiologists and pathologists.

Effects on auditory-nerve fibers of opening the otic capsule at the apex of the chinchilla cochlea

Science.gov (United States)

Recio-Spinoso, Alberto; Temchin, Andrei N.; Ruggero, Mario A.

2015-12-01

Vibration responses to clicks measured at the apex of chinchilla cochleae with open otic capsules have onsets much shorter than those of responses of auditory-nerve fibers (ANFs) corrected for synaptic and neural delays. Apical vibration responses to tones in open cochleae also differ in other respects from the responses to tones of ANFs with low characteristic frequency (CF) in normal chinchilla cochleae. To further specify the origin(s) of these differences, we recorded from chinchilla ANFs after delicately opening a small hole in the otic capsule overlying scala vestibuli in the cochlear apex. In those cochleae, the earliest ANF responses to clicks are often evoked by condensation (rather than rarefaction) clicks and responses to tones often exhibit level-dependent phase changes different from those in normal cochleae. These findings are largely consistent with, and seem to account for, apical vibration responses of cochleae with open otic capsules. An unexpected finding is that the tuning curves of ANFs with moderately high CF and normal CF thresholds often had hypersensitive tails.

Optical path of infrared neural stimulation in the guinea pig and cat cochlea

Science.gov (United States)

Rajguru, Suhrud M.; Hwang, Margaret; Moreno, Laura E.; Matic, Agnella I.; Stock, Stuart R.; Richter, Claus-Peter

2011-03-01

It has been demonstrated previously that infrared neural stimulation (INS) can be used to stimulate spiral ganglion cells in the cochlea. With INS, neural stimulation can be achieved without direct contact of the radiation source and the tissue and is spatially well resolved. The presence of fluids or bone between the target structure and the radiation source may lead to absorption or scattering of the radiation and limit the efficacy of INS. To develop INS based cochlear implants, it is critical to determine the beam path of the radiation in the cochlea. In the present study, we utilized noninvasive X-ray microtomography (microCT) to visualize the orientation and location of the optical fiber within the guinea pig and cat cochlea. Overall, the results indicated that the optical fiber was directed towards the spiral ganglion cells in the cochlea and not the nerve fibers in the center of the modiolus. The fiber was approximately 300 μm away from the target structures. In future studies, results from the microCT will be correlated with physiology obtained from recordings in the midbrain.

Fibrous metaphyseal defect (fibrous cortical defect, non-ossifying fibroma). Pt. 2

International Nuclear Information System (INIS)

Freyschmidt, J.; Ostertag, H.; Saure, D.

1981-01-01

FMD, whether in the stage of a fibrous cortical defect or a non-ossifying fibroma, possesses very characteristic radiological appearances which rarely make it necessary to resort to biopsy. In order to avoid mistakes, it is necessary to observe strictly the known radiological features: metaphyseal position, clearcut relationship to the cortex, well defined margins, maximal size 6 to 7 cm., presence during growth, rarely observed in the upper extremity. The differential diagnosis, which needs to be considered only rarely, is discussed. (orig.) [de

Optical coherence tomography of the rat cochlea

NARCIS (Netherlands)

Wong, B. J. F.; de Boer, JF; Park, B.H.; Chen, ZP; Nelson, JS

2000-01-01

Optical coherence tomography (OCT) was used to image the internal structure of a rat cochlea (ex vivo). Immediately following sacrifice, the temporal bone of a Sprague-Dawley rat was harvested. Axial OCT cross sectional images lover regions of interest, 1x1 mm-2x8 mm) were obtained with a spatial

Simple landmark for preservation of the cochlea during maximum drilling of the petrous apex through the anterior transpetrosal approach

International Nuclear Information System (INIS)

Seo, Yoshinobu; Sasaki, Takehiko; Nakamura, Hirohiko

2010-01-01

The cochlea is one of the most important organs to preserve during skull base surgery. However, no definite landmark for the cochlea has been identified during maximum drilling of the petrous apex such as anterior transpetrosal approach. The relationship between the cochlea and the petrous portion of the internal carotid artery (ICA) was assessed with computed tomography (CT) in 70 petrous bones of 35 patients, 16 males and 19 females aged 12-85 years (mean 48.6 years). After accumulation of volume data with multidetector CT, axial bone window images of 1-mm thickness were obtained to identify the cochlea and the horizontal petrous portion of the ICA. The distance was measured between the extended line of the posteromedial side of the horizontal petrous portion of the ICA and the basal turn of the cochlea. If the cochlea was located posteromedial to the ICA, the distance was expressed as a positive number, but if anterolateral, as a negative number. The mean distance was 0.6 mm (range -4.9 to 3.9 mm) and had no significant correlation with sex or age. The cochlea varies in location compared with the horizontal petrous portion of the ICA. Measurement of the depth and distance between the extended line of the posteromedial side of the horizontal intrapetrous ICA and the cochlea before surgery will save time, increase safety, and maximize bone evacuation during drilling of the petrous apex. (author)

Simulation of mechano-electrical transduction in the cochlea considering basilar membrane vibration and the ionic current of the inner hair cells

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Lee, Sinyoung; Koike, Takuji

2018-05-01

The inner hair cells (IHCs) in the cochlea transduce mechanical vibration of the basilar membrane (BM), caused by sound pressure, to electrical signals that are transported along the acoustic nerve to the brain. The mechanical vibration of the BM and the ionic behaviors of the IHCs have been investigated. However, consideration of the ionic behavior of the IHCs related to mechanical vibration is necessary to investigate the mechano-electrical transduction of the cochlea. In this study, a finite-element model of the BM, which takes into account the non-linear activities of the outer hair cells (OHCs), and an ionic current model of IHC were combined. The amplitudes and phases of the vibration at several points on the BM were obtained from the finite-element model by applying sound pressure. These values were fed into the ionic current model, and changes in membrane potential and calcium ion concentration of the IHCs were calculated. The membrane potential of the IHC at the maximum amplitude point (CF point) was higher than that at the non-CF points. The calcium ion concentration at the CF point was also higher than that at the non-CF points. These results suggest that the cochlea achieves its good frequency discrimination ability through mechano-electrical transduction.

Comparison of doses received in the mandibular condyle, cochlea, and parotid gland in neuroaxial treatment

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Fernanda L.; Lima, Fabiana F. de; Vilela, Eudice, E-mail: fluoliveira@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fo, Joao Antonio, E-mail: jaf@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

2015-07-01

Sensorineural hearing loss is a common side effect in patients who undergo radiotherapy for the treatment of cancer tumors in the head and neck. In fractioned doses of radiotherapy, in the majority of intracranial tumors, the cochlea is the most affected organ. In addition to the cochlea, the mandible and the parotid glands are also exposed to radiation, which commonly leads to Osteoradionecrosis of the mandible and Xerostomia. In the head and neck regions, this can be complicated by the semi-independence of the positioning in this region, as regards the rigid cranium, connected to the semi-rigid mandible, and successive levels of the upper cervical spine and thoracic spine, which can lead to uncertainty in rotation as well as in head-neck movements, both up and down and side to side. The present study performed an intercomparison of the doses applied through four radiotherapy planning techniques for the neuro axial regions of the cochlea, mandible, and parotid glands, considering the changes carried out in each planning technique, including the protective shield, the angulations gantry and the field size. The results obtained by applying the half beam and angled field techniques varied in the cochlea by an average of 113.8% from the prescribed dose, whereas when applying the angled field technique with and without the mobile gap, the results varied in 104.5%. In the mandible, the half beam and angled field techniques showed that the dose varied an average of 16.5%, while in the techniques with and without the mobile gap, the variation showed an average of 116.4%. These values were also received by the parotid glands, which overlap the mandible. It can therefore be concluded that the protection shields of the first two techniques were less efficient in protecting the mandible due to its modeling. (author)

The difference in endolymphatic hydrostatic pressure elevation induced by isoproterenol between the ampulla and the cochlea.

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Inamoto, Ryuhei; Miyashita, Takenori; Matsubara, Ai; Hoshikawa, Hiroshi; Mori, Nozomu

2017-06-01

The purpose of the study was to investigate the difference in the responses of endolymphatic hydrostatic pressure to isoproterenol, β-adrenergic receptor agonist, between pars superior and pars inferior. The hydrostatic pressure of endolymph and perilymph and endolymphatic potential in the ampulla and the cochlea during the intravenous administration of isoproterenol were recorded using a servo-null system in guinea pigs. The hydrostatic pressure of endolymph and perilymph in the ampulla and cochlea was similar in magnitude. Isoproterenol significantly increased hydrostatic pressure of ampullar and cochlear endolymph and perilymph with no change in the ampullar endolymphatic potential and endocochlear potential, respectively. The isoproterenol-induced maximum change of endolymphatic hydrostatic pressure in ampulla was significantly (phydrostatic pressure in the ampulla disappeared like that in the cochlea. Isoproterenol elevates endolymphatic hydrostatic pressure in different manner between the vestibule and the cochlea. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Schwannoma in the vestibule and cochlea

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Susilawati, S. [Fatmawati Hospital, Jakarta (Indonesia). Department of Ear, Nose and Throat; Adler, J. [Sutherland Imaging Centre, Sydney, NSW (Australia); Fagan, P. [St Vincents Hospital, Darlinghurst, NSW (Australia)

1997-05-01

Schwannoma of the vestibule or the cochlea is an unusual lesion. In the past, most examples have been found at autopsy or as unsuspected findings at surgery for vertigo. The symptoms of isolated labyrinthine schwannoma may be indistinguishable from advanced Meniere`s disease. Magnetic resonance imaging has led to pre-operative diagnosis in some cases. Two cases of schwannoma within the labyrinth from a series of 339 symptomatic acoustic tumours, are presented and the imaging findings are discussed. 8 refs., 2 figs.

Central ossifying fibroma, periapical cemento-osseous dysplasia and complex odontoma occurring in the same jaw

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Farzaneh Agha Hosseini

2011-05-01

Full Text Available Central ossifying fibroma is a rare, benign fibro-osseous lesion that arises from the periodontal ligament. Periapical cemento-osseous dysplasia is another variant of fibro-osseous lesion which occurs in the anterior region of the mandible of females. Odontoma is a benign odontogenic tumor that contains enamel, dentine cement and pulp tissue. A 46-year-old woman was referred to the Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, with two nonpainful swellings on both sides of the mandible, which had been slowly growing over a period of one year. Our differential diagnosis was florid cemento-osseous dysplasia, focal cemento-osseous dysplasia for the right side, complex odontoma for the left side and periapical cement-osseous dysplasia for the anterior side. The historical feature revealed ossifying fibroma, complex odontoma and periapical cemento-osseous dysplasia. The occurrence of these three lesions in the same jaw has been rarely reported in the literature. The relationship between the occurrence of these three lesions is not obvious it could be coincidental. It seems that more case reports are needed to establish the relationship between them.

Mechanisms of Sensorineural Cell Damage, Death and Survival in the Cochlea

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Allen Frederic Ryan

2015-04-01

Full Text Available The majority of acquired hearing loss, including presbycusis, is caused by irreversible damage to the sensorineural tissues of the cochlea. This article reviews the intracellular mechanisms that contribute to sensorineural damage in the cochlea, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. These data have primarily been generated in hearing loss not directly related to age. However, there is evidence that similar mechanisms operate in presbycusis. Moreover, accumulation of damage from other causes can contribute to age-related hearing loss. Potential therapeutic interventions to balance opposing but interconnected cell damage and survival pathways, such as antioxidants, anti-apoptotics, and pro-inflammatory cytokine inhibitors, are also discussed.

Effect of erythropoietin on acoustically traumatized rat cochlea: an immunohistochemical study.

Science.gov (United States)

Gürgen, Oğuzhan; Gürgen, Seren Gülşen; Kirkim, Günay; Kolatan, Efsun; Gürkan, Selhan; Güvenç, Yeşim; Eskiizmir, Görkem

2014-08-01

To investigate the audiological and histopathological effects of erythropoietin on acoustic overstimulation in rats. Twenty-two male Wistar albino rats were divided into 3 groups: sham group (n = 7), erythropoietin injection group (n = 8), and saline injection group (n = 7). Both erythropoietin and saline injection groups were exposed to white noise (100 decibel [dB] sound pressure level [SPL]) for 3 hours. Auditory brainstem responses were measured before, immediately after, and on the 7th day of noise exposure. All animals were sacrificed on the 7th day and temporal bones were collected. The serial sections of the cochleae were stained by caspase-3 and caspase-9 immunostaining and by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method in order to detect apoptotic cells. In the saline group statistically significant differences were detected between the baseline and immediate postacoustic overstimulation thresholds of click and 6 kHz stimuli. However, when the baseline and immediate postacoustic overstimulation thresholds of click and 6 kHz stimuli were compared in the erythropoietin injection group, no statistically significant difference was determined. Histopathologic evaluations demonstrated that erythropoietin decreased the amount of apoptotic cells in the cochlea. Erythropoietin is likely to prevent the acute threshold changes and decrease the amount of apoptosis in cochlea after acoustic overstimulation in rats.

Combination tones along the basilar membrane in a 3D finite element model of the cochlea with acoustic boundary layer attenuation

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Böhnke, Frank; Scheunemann, Christian; Semmelbauer, Sebastian

2018-05-01

The propagation of traveling waves along the basilar membrane is studied in a 3D finite element model of the cochlea using single and two-tone stimulation. The advantage over former approaches is the consideration of viscous-thermal boundary layer damping which makes the usual but physically unjustified assumption of Rayleigh damping obsolete. The energy loss by viscous boundary layer damping is 70 dB lower than the actually assumed power generation by outer hair cells. The space-time course with two-tone stimulation shows the traveling waves and the periodicity of the beat frequency f2 - f1.

Dose-dependent effects of ouabain on spiral ganglion neurons and Schwann cells in mouse cochlea.

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Zhang, Zhi-Jian; Guan, Hong-Xia; Yang, Kun; Xiao, Bo-Kui; Liao, Hua; Jiang, Yang; Zhou, Tao; Hua, Qing-Quan

2017-10-01

This study aimed in fully investigating the toxicities of ouabain to mouse cochlea and the related cellular environment, and providing an optimal animal model system for cell transplantation in the treatment of auditory neuropathy (AN) and sensorineural hearing loss (SNHL). Different dosages of ouabain were applied to mouse round window. The auditory brainstem responses and distortion product otoacoustic emissions were used to evaluate the cochlear function. The immunohistochemical staining and cochlea surface preparation were performed to detect the spiral ganglion neurons (SGNs), Schwann cells and hair cells. Ouabain at the dosages of 0.5 mM, 1 mM and 3 mM selectively and permanently destroyed SGNs and their functions, while leaving the hair cells relatively intact. Ouabain at 3 mM resulted in the most severe SGNs loss and induced significant loss of Schwann cells started as early as 7 days and with further damages at 14 and 30 days after ouabain exposure. The application of ouabain to mouse round window induces damages of SGNs and Schwann cells in a dose- and time-dependent manner, this study established a reliable and accurate animal model system of AN and SNHL.

Juvenile psammomatoid ossifying fibroma of the neurocranium. Report of four cases.

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Hasselblatt, Martin; Jundt, Gernot; Greiner, Christoph; Rama, Burckhard; Schmäl, Frank; Iglesias-Rozas, José R; van de Nes, Johannes A P; Paulus, Werner

2005-06-01

Juvenile psammomatoid ossifying fibroma (JPOF) is a benign fibroosseous lesion predominantly arising within the paranasal sinuses in children and young adults. Neurocranial occurrence is exceedingly rare and a location within the neurocranial portion of the temporal bone has not been described. The authors report on one case of sinonasal JPOF secondarily extending into the cranial cavity and three cases primarily affecting the neurocranial bones to increase clinical awareness of this uncommon tumor, which may be easily mistaken for meningioma. Moreover, the absence of activating missense mutations of the GNAS1 gene in two cases strongly argues against a relationship between JPOF and fibrous dysplasia.

“Pseudo-thyroid lobe”: A diagnostic conundrum caused by ossified anterior longitudinal ligament on bone scan

International Nuclear Information System (INIS)

Zaman, Maseeh Uz; Fatima, Nosheen; Sajjad, Zafar; Zaman, Unaiza; Zaman, Areeba; Tahseen, Rabia

2015-01-01

Radionuclide bone imaging is one of the most commonly performed nuclear medicine procedure around the world and characterized by its high sensitivity and relatively low specificity. False positive findings on a bone scan are very common; however, dense uptake over unilateral ossified anterior longitudinal ligament appearing as single thyroid lobe on a bone scan has not been described in the literature

Noise stimulation decreases the concentration of norepinephrine in the rat cochlea.

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Vicente-Torres, M A; Gil-Loyzaga, P

1999-05-14

The present study was designed to analyze, by using high performance liquid chromatography (HPLC), the effect of acoustic stimulation on the cochlear concentration of norepinephrine (NE). Independently of the rat strain (Long-Evans or Wistar strains), NE concentration decreased about 18% when animals were exposed to white noise (90 dB SPL for 1 h). The same decrease was observed in animals perfused by aortic pathway to remove the blood, indicating that this decrease corresponds exclusively to a neurophysiological process. In fact, these findings could indicate that noise stimulation is involved in the NE release from sympathetic fibers innervating the cochlea. This likely release of NE supports that sympathetic fibers play a functional role in cochleae exposed to noisy situations.

Fractalkine Signaling Regulates Macrophage Recruitment into the Cochlea and Promotes the Survival of Spiral Ganglion Neurons after Selective Hair Cell Lesion.

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Kaur, Tejbeer; Zamani, Darius; Tong, Ling; Rubel, Edwin W; Ohlemiller, Kevin K; Hirose, Keiko; Warchol, Mark E

2015-11-11

Macrophages are recruited into the cochlea in response to injury caused by acoustic trauma or ototoxicity, but the nature of the interaction between macrophages and the sensory structures of the inner ear remains unclear. The present study examined the role of fractalkine signaling in regulating the injury-evoked behavior of macrophages following the selective ablation of cochlear hair cells. We used a novel transgenic mouse model in which the human diphtheria toxin receptor (huDTR) is selectively expressed under the control of Pou4f3, a hair cell-specific transcription factor. Administration of diphtheria toxin (DT) to these mice resulted in nearly complete ablation of cochlear hair cells, with no evident pathology among supporting cells, spiral ganglion neurons, or cells of the cochlear lateral wall. Hair cell death led to an increase in macrophages associated with the sensory epithelium of the cochlea. Their numbers peaked at 14 days after DT and then declined at later survival times. Increased macrophages were also observed within the spiral ganglion, but their numbers remained elevated for (at least) 56 d after DT. To investigate the role of fractalkine signaling in macrophage recruitment, we crossed huDTR mice to a mouse line that lacks expression of the fractalkine receptor (CX3CR1). Disruption of fractalkine signaling reduced macrophage recruitment into both the sensory epithelium and spiral ganglion and also resulted in diminished survival of spiral ganglion neurons after hair cell death. Our results suggest a fractalkine-mediated interaction between macrophages and the neurons of the cochlea. It is known that damage to the inner ear leads to recruitment of inflammatory cells (macrophages), but the chemical signals that initiate this recruitment and the functions of macrophages in the damaged ear are unclear. Here we show that fractalkine signaling regulates macrophage recruitment into the cochlea and also promotes the survival of cochlear afferents after

α-Synuclein deficiency and efferent nerve degeneration in the mouse cochlea: a possible cause of early-onset presbycusis.

Science.gov (United States)

Park, S N; Back, S A; Choung, Y H; Kim, H L; Akil, O; Lustig, L R; Park, K H; Yeo, S W

2011-11-01

Efferent nerves under the outer hair cells (OHCs) play a role in the protection of these cells from loud stimuli. Previously, we showed that cochlear α-synuclein expression is localized to efferent auditory synapses at the base of the OHCs. To prove our hypothesis that α-synuclein deficiency and efferent auditory deficit might be a cause of hearing loss, we compared the morphology of efferent nerve endings and α-synuclein expression within the cochleae of two mouse models of presbycusis. Comparative animal study of presbycusis. The C57BL/6J(C57) mouse strain, a well-known model of early-onset hearing loss, and the CBA mouse strain, a model of relatively late-onset hearing loss, were examined. Auditory brainstem responses and distortion product otoacoustic emissions were recorded, and cochlear morphology with efferent nerve ending was compared. Western blotting was used to examine α-synuclein expression in the cochlea. Compared with CBA mice, C57 mice showed earlier onset high-frequency hearing loss and decreased function in OHCs, especially within high-frequency regions. C57 mice demonstrated more severe pathologic changes within the cochlea, particularly within the basal turn, than CBA mice of the same age. Weaker α-synuclein and synaptophysin expression in the efferent nerve endings and cochlear homogenates in C57 mice was observed. Our results support the hypothesis that efferent nerve degeneration, possibly due to differential α-synuclein expression, is a potential cause of early-onset presbycusis. Further studies at the cellular level are necessary to verify our results. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Central ossifying fibroma, periapical cemento-osseous dysplasia and complex odon-toma occurring in the same jaw.

Science.gov (United States)

Hosseini, Farzaneh Agha; Moslemi, Elham

2011-05-16

Central ossifying fibroma is a rare, benign fibro-osseous lesion that arises from the periodontal ligament. Periapical cemento-osseous dysplasia is another variant of fibro-osseous lesion which occurs in the anterior region of the mandible of females. Odontoma is a benign odontogenic tumor that contains enamel, dentine cement and pulp tissue. A 46-year-old woman was referred to the Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, with two non-painful swellings on both sides of the mandible, which had been slowly growing over a period of one year. Our differential diagnosis was florid cemento-osseous dysplasia, focal cemento-osseous dysplasia for the right side, complex odontoma for the left side and periapical cement-osseous dysplasia for the anterior side. The historical feature revealed ossifying fibroma, complex odontoma and periapical cemento-osseous dysplasia. The occurrence of these three lesions in the same jaw has been rarely reported in the literature. The relationship between the occurrence of these three lesions is not obvious it could be coincidental. It seems that more case reports are needed to establish the relationship between them.

LGR4 and LGR5 regulate hair cell differentiation in the sensory epithelium of the developing mouse cochlea

NARCIS (Netherlands)

Zak, Magdalena; Van Oort, Thijs; Hendriksen, Ferry G.; Garcia, Marie Isabelle; Vassart, Gilbert; Grolman, Wilko

2016-01-01

In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. Not much, however, is known about the regulation of Wnt/β-catenin activity in the cochlea. In multiple tissues, the

Application of 810-nm diode laser in the management of peripheral ossifying fibroma

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Beela Ram Anuradha

2015-01-01

Full Text Available Peripheral ossifying fibroma (POF is a reactive gingival growth, which accounts for 9.6% of gingival lesions. It exhibits a peak incidence between the second and third decades of life with a female predilection. Treatment includes surgical excision down to the periosteum and periodontal ligament with thorough root planning. Another option available in place of conventional surgical excision is the excision using lasers. Here is a case of POF affecting anterior maxillary gingiva in 19-year-old male patient successfully managed using an 810-nm diode laser.

Gap junction mediated intercellular metabolite transfer in the cochlea is compromised in connexin30 null mice.

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Qing Chang

Full Text Available Connexin26 (Cx26 and connexin30 (Cx30 are two major protein subunits that co-assemble to form gap junctions (GJs in the cochlea. Mutations in either one of them are the major cause of non-syndromic prelingual deafness in humans. Because the mechanisms of cochlear pathogenesis caused by Cx mutations are unclear, we investigated effects of Cx30 null mutation on GJ-mediated ionic and metabolic coupling in the cochlea of mice. A novel flattened cochlear preparation was used to directly assess intercellular coupling in the sensory epithelium of the cochlea. Double-electrode patch clamp recordings revealed that the absence of Cx30 did not significantly change GJ conductance among the cochlear supporting cells. The preserved electrical coupling is consistent with immunolabeling data showing extensive Cx26 GJs in the cochlea of the mutant mice. In contrast, dye diffusion assays showed that the rate and extent of intercellular transfer of multiple fluorescent dyes (including a non-metabolizable D-glucose analogue, 2-NBDG among cochlear supporting cells were severely reduced in Cx30 null mice. Since the sensory epithelium in the cochlea is an avascular organ, GJ-facilitated intercellular transfer of nutrient and signaling molecules may play essential roles in cellular homeostasis. To test this possibility, NBDG was used as a tracer to study the contribution of GJs in transporting glucose into the cochlear sensory epithelium when delivered systemically. NBDG uptake in cochlear supporting cells was significantly reduced in Cx30 null mice. The decrease was also observed with GJ blockers or glucose competition, supporting the specificity of our tests. These data indicate that GJs facilitate efficient uptake of glucose in the supporting cells. This study provides the first direct experimental evidence showing that the transfer of metabolically-important molecules in cochlear supporting cells is dependent on the normal function of GJs, thereby suggesting a

Adeno-associated virus transformation into the normal miniature pig and the normal guinea pigs cochlea via scala tympani.

Science.gov (United States)

Shi, Xunbei; Wu, Nan; Zhang, Yue; Guo, Weiwei; Lin, Chang; Yang, Shiming

2017-09-01

To investigate the expression of the miniature pig cochlea after AAV1 transfect into the cochlea via round window membrane (RWM). Twenty miniature pigs are equally divided into four experimental groups. Twelve miniature pigs are equally divided into four control groups. Each pig was transfected with the AAV1 in the experimental group via RWM and each pig was transduced with the artificial perilymph in the control group. The expression of green fluorescent protein (GFP) was observed at 2 weeks, 3 weeks and 4 weeks, respectively. Likewise, AAV1 was delivered into the guinea pigs cochleas using the same method, and the results were compared with that of the miniature pigs. The expression was mainly in the inner hair cells of the miniature pig. The expression of GFP began to appear at 2 weeks, reached the peak at 3 weeks. It also expressed in Hensen's cells, inner pillar cells, outer pillar cells, spiral limbus, and spiral ligament. In the meanwhile, AAV1 was delivered into guinea pig cochlea via the same method, and AAV1 was also expressed in the inner hair cells. But the expression peaked at 2 weeks, and the efficiency of the inner hair cell transfection was higher than that of the pig. AAV1 can be transformed into miniature pig cochlea via scala tympani by the RWM method efficiently.

Modelling Cochlear Mechanics

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Guangjian Ni

2014-01-01

Full Text Available The cochlea plays a crucial role in mammal hearing. The basic function of the cochlea is to map sounds of different frequencies onto corresponding characteristic positions on the basilar membrane (BM. Sounds enter the fluid-filled cochlea and cause deflection of the BM due to pressure differences between the cochlear fluid chambers. These deflections travel along the cochlea, increasing in amplitude, until a frequency-dependent characteristic position and then decay away rapidly. The hair cells can detect these deflections and encode them as neural signals. Modelling the mechanics of the cochlea is of help in interpreting experimental observations and also can provide predictions of the results of experiments that cannot currently be performed due to technical limitations. This paper focuses on reviewing the numerical modelling of the mechanical and electrical processes in the cochlea, which include fluid coupling, micromechanics, the cochlear amplifier, nonlinearity, and electrical coupling.

Cemento-ossifying fibroma of mandible mimicking complex composite odontome.

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Dewan, Hitesh Sudarshan; Dewan, Sudarshan Kumar; Bahl, Sumit; Tushar Parekh, Parth

2016-10-19

Cemento-ossifying fibroma (COF) is a fibro-osseous lesion or non-odontogenic tumour that affects craniofacial bones. These lesions are included in the spectrum of fibro-osseous lesions arising from periodontal ligament cells, which can deposit combination of cementum and bone surrounded by fibrous tissue. It clinically, macroscopically and radiologically resembles complex composite odontome and can be differentiated only on the basis of histopathology. They usually occur solitarily as a painless and expansile spherical or ovoid jawbone mass that may displace the roots of adjacent teeth. They predominantly occur in females in third and fourth decades of life. We present a case report of a 20-year-old man, with a mildly painful swelling in the mandible which was successfully treated with enucleation and diagnosed as COF. Its resemblance to complex composite odontome and unique surgical approach are highlighted in this paper. 2016 BMJ Publishing Group Ltd.

Diode laser for excisional biopsy of peripheral ossifying fibroma

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Kirti Chawla

2014-01-01

Full Text Available Peripheral Ossifying Fibroma is one of the commonest occurring reactive lesions on gingiva. It is associated with local irritational factors and often interferes with speech, mastication and maintenance of oral hygiene, in addition to being aesthetically unpleasant. It is usually treated with surgical excision using scalpel and removal of irritational factors, often resulting in mucogingival defect. Other modalities such as radiosurgery and electrocautery have also been used for its management, but they cause changes in microarchitecture of biopsy specimen, altering the histologic picture for true diagnosis. We are presenting a case of excisional biopsy of this lesion in an adult female using a diode laser with excellent post-operative results, without affecting microarchitecture of biopsy specimen. The patient is being followed for last 1 year and no sign of recurrence has been found. A diode laser may offer a good alternative modality for management of such cases.

Reconstruction of maxillary cemento-ossifying fibroma defect with buccal pad of fat.

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Sivaraj, Subramonian; Jeevadhas, Pratheep

2013-07-01

A cemento-ossifying fibroma (COF) is a rare benign neoplasm of maxilla when compared with mandible (World Health Organization, 1992). COF of maxilla may be quite large and locally very aggressive lesion. These tumor mass was peeled out by en-bloc excision using gentle blunt dissection. This paper presents 35-year-old male patient who had a gradually expanding lobular mass in the left maxillary posterior region for past 1 year. He has been treated successfully by surgical en-bloc resection. Various techniques were used to reconstruction the defect. Buccal pad of fat is a simple technique having advantages like good vascularity, adaptability, good closure of the defect with favorable prognosis.

Relationship of glucocorticoid receptor expression in peripheral blood mononuclear cells and the cochlea of guinea pigs and effects of dexamethasone administration.

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Ling Lu

Full Text Available BACKGROUND: Glucocorticoids (GCs are widely used to treat sudden sensorineural hearing loss (SSNHL and significantly improve hearing. However, GC insensitivity has been observed in some patients of SSNHL. OBJECTIVE: To study the correlation between GR expression in peripheral blood mononuclear cells (PBMCs and in the cochlea of guinea pigs at mRNA and protein levels. METHODS: One group of guinea pigs received dexamethasone (10 mg/kg/day intraperitoneally for 7 consecutive days (dexamethasone group, and another group of guinea pigs received normal saline (control group. Real time PCR and Western blotting were used to detect the expression of GR mRNA and GR protein in PBMCs and the cochleae. RESULTS: The GR mRNA and GR protein were detected in both PBMCs and the cochlear tissue of guinea pigs. GR mRNA and GR protein levels in PBMCs were positively correlated with those in the cochlea. The expression of GR mRNA and GR protein was significantly increased in the dexamethasone group compared to the control group. CONCLUSIONS: Levels of GR mRNA and GR protein in the PBMCs were positively correlated with those in the cochlea of guinea pigs. Systemic dexamethasone treatment can significantly up-regulate GR expression in PBMCs and in the cochlea. Measurement of the GR level in PBMCs could be used as an indicator of GR level in the cochlea.

Noise-induced nitrotyrosine increase and outer hair cell death in guinea pig cochlea.

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Han, Wei-ju; Shi, Xiao-rui; Nuttall, Alfred

2013-01-01

Modern research has provided new insights into the biological mechanisms of noise-induced hearing loss, and a number of studies showed the appearance of increased reactive oxygen species (ROS) and reactive nitrogen species (RNS) during and after noise exposure. This study was designed to investigate the noise exposure induced nitrotyrosine change and the mechanism of outer hair cells death in guinea pig cochlea. Thirty guinea pigs were used in this study. The experimental animals were either exposed for 4 hours per day to broadband noise at 122 dB SPL (A-weighted) for 2 consecutive days or perfused cochleae with 5 mg/ml of the SIN1 solutions, an exogenous NO and superoxide donor, for 30 minutes. Then the cochleae of the animals were dissected. Propidium iodide (PI), a DNA intercalating fluorescent probe, was used to trace morphological changes in OHC nuclei. The distribution of nitrotyrosine (NT) in the organ of Corti and the cochlear lateral wall tissue from the guinea pigs were examined using fluorescence immunohistochemistry method. Whole mounts of organ of Corti were prepared. Morphological and fluorescent changes were examined under a confocal microscope. Either after noise exposure or after SIN1 perfusion, outer hair cells (OHCs) death with characteristics of both apoptotic and necrotic degradation appeared. Nitrotyrosine immunolabeling could be observed in the OHCs from the control animals. After noise exposure, NT immunostaining became much greater than the control animals in OHCs. The apoptotic OHC has significant increase of nitrotyrosine in and around the nucleus following noise exposure. In the normal later wall of cochleae, relatively weak nitrotyrosine immunolabeling could be observed. After noise exposure, nitrotyrosine immunoactivity became stronger in stria vascularis. Noise exposure induced increase of nitrotyrosine production is associated with OHCs death suggesting reactive nitrogen species participation in the cochlear pathophysiology of noise

Aspectos radiográficos de periostite ossificante em metatarso de vaca Holandesa Radiografic aspects of ossifying periostitis in metatarsus of Holstein cow

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Rodrigo Melo Meneses

2010-05-01

Full Text Available Periostite ossificante é uma neoformação óssea inflamatória extensa, frequentemente oriunda de infecção de tecidos moles adjacentes ao osso afetado, sendo mais proeminente nos bovinos, especialmente em animais jovens. Neste trabalho, é descrito um caso de periostite ossificante no osso metatársico III direito de uma vaca Holandesa após trauma. O diagnóstico foi realizado com base nos achados clínicos e radiográficos e confirmado cirurgicamente.Ossifying periostitis is an extensive inflamatory new bone formation frequently extensive from soft tissue infection next to these bones. It is more observed in young bovines. A case of pos traumatic ossifying periostitis in the right metatarsus of a Holstein cow is described. The diagnosis was made based on clinical and radiographic findings and confirmed cirurgically.

Ethanol extract of Piper longum L. attenuates gentamicin-induced hair cell loss in neonatal cochlea cultures.

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Du, Xiao Fei; Song, Jae-Jun; Hong, Seungug; Kim, Jihye

2012-06-01

Piper longum L. (PL), also as known as long pepper, a well-known spice and traditional medicine in Asia and Pacific islands, has been reported to exhibit wide spectrum activity including antioxidant activity. However, little information is available on its protective effect on gentamicin (GM) induced ototoxicity which is commonly regarded as being mediated by reactive oxygen species and reactive nitrogen species. This study was undertaken to investigate the protective effect of PL ethanol extract on gentamicin-induced hair cell loss in neonatal cochlea cultures. Cochlea cultures from postnatal day 2-3 mice were used for analysis of the protective effects of PL against gentamicin-induced hair cell loss by phalloidin staining. E. coil cultures were used to determine whether PL interferes with the antibiotic activity of GM. Nitric oxide (NO)-scavenging activity of PL was also measured in vitro. GM induced significant dose-dependent hair cell loss in cochlea cultures. However, without interfering with the antibiotic activity of GM, PL showed a significant and concentration-dependent protective effect against GM-induced hair cell loss, and hair cells retained their stereocilia well. In addition, PL expressed direct scavenging activity toward NO radical liberated within solution of sodium nitroprusside. These findings demonstrate the protective effect of PL on GM-induced hair cell loss in neonatal cochlea cultures, and suggest that it might be of therapeutic benefit for treatment of GM-induced ototoxicity.

Three-dimensional hard and soft tissue imaging of the human cochlea by scanning laser optical tomography (SLOT.

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Nadine Tinne

Full Text Available The present study focuses on the application of scanning laser optical tomography (SLOT for visualization of anatomical structures inside the human cochlea ex vivo. SLOT is a laser-based highly efficient microscopy technique which allows for tomographic imaging of the internal structure of transparent specimens. Thus, in the field of otology this technique is best convenient for an ex vivo study of the inner ear anatomy. For this purpose, the preparation before imaging comprises decalcification, dehydration as well as optical clearing of the cochlea samples in toto. Here, we demonstrate results of SLOT imaging visualizing hard and soft tissue structures with an optical resolution of down to 15 μm using extinction and autofluorescence as contrast mechanisms. Furthermore, the internal structure can be analyzed nondestructively and quantitatively in detail by sectioning of the three-dimensional datasets. The method of X-ray Micro Computed Tomography (μCT has been previously applied to explanted cochlea and is solely based on absorption contrast. An advantage of SLOT is that it uses visible light for image formation and thus provides a variety of contrast mechanisms known from other light microscopy techniques, such as fluorescence or scattering. We show that SLOT data is consistent with μCT anatomical data and provides additional information by using fluorescence. We demonstrate that SLOT is applicable for cochlea with metallic cochlear implants (CI that would lead to significant artifacts in μCT imaging. In conclusion, the present study demonstrates the capability of SLOT for resolution visualization of cleared human cochleae ex vivo using multiple contrast mechanisms and lays the foundation for a broad variety of additional studies.

Imaging vibration of the cochlear partition of an excised guinea pig cochlea using phase-sensitive Fourier domain optical coherence tomography

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Choudhury, Niloy; Zeng, Yaguang; Fridberger, Anders; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.; Wang, Ruikang K.

2011-03-01

Studying the sound stimulated vibrations of various membranes that form the complex structure of the organ of Corti in the cochlea of the inner ear is essential for understanding how the travelling sound wave of the basilar membrane couples its energy to the organ structures. In this paper we report the feasibility of using phase-sensitive Fourier domain optical coherence tomography (FD-OCT) to image the vibration of various micro-structures of the cochlea at the same time. An excised cochlea of a guinea pig was stimulated using sounds at various frequencies and vibration image was obtained. When measuring the apex area, vibration signal from different turns, which have different best response frequencies are obtained in the same image. The method has the potential to measure the response from a much wider region of the cochlea than any other currently used method. The noise floor for vibration image for the system at 200 Hz was ~0.3nm.

Cases report of ossifying fibroma showing various radiographic appearances in posterior mandible

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Lee, Byung Do; Oh, Seung Hwan; Son, Hyun Jin

2010-01-01

Common radiographic appearances of ossifying fibroma (OF) are well demarcated margin, radiolucent or mixed lesion. Lesions for the radiographic differential diagnosis with OF include fibrous dysplasia, focal cemento-osseous dysplasia. Other confusing lesions might be the mixed lesions such as calcifying odontogenic cyst, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, and benign cementoblastoma. We reported three cases of OF in posterior mandible. These cases showed a little distinguished radiographic features of OF and diagnosed from a combination of clinical, radiographic, and histopathologic information. We need to further refine radiographic and histopathological features of OF and other confusing lesions with literatures review because some cases of these lesions are not easily differentiated radiographically and histopathologically.

Cases report of ossifying fibroma showing various radiographic appearances in posterior mandible

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Lee, Byung Do; Oh, Seung Hwan [School of Dentistry, Wonkwang University, Seoul (Korea, Republic of); Son, Hyun Jin [Department of Pathology, School of Medicine, Eulji University, Daejeon (Korea, Republic of)

2010-06-15

Common radiographic appearances of ossifying fibroma (OF) are well demarcated margin, radiolucent or mixed lesion. Lesions for the radiographic differential diagnosis with OF include fibrous dysplasia, focal cemento-osseous dysplasia. Other confusing lesions might be the mixed lesions such as calcifying odontogenic cyst, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, and benign cementoblastoma. We reported three cases of OF in posterior mandible. These cases showed a little distinguished radiographic features of OF and diagnosed from a combination of clinical, radiographic, and histopathologic information. We need to further refine radiographic and histopathological features of OF and other confusing lesions with literatures review because some cases of these lesions are not easily differentiated radiographically and histopathologically.

Measuring uncertainty in dose delivered to the cochlea due to setup error during external beam treatment of patients with cancer of the head and neck

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Yan, M.; Lovelock, D.; Hunt, M.; Mechalakos, J.; Hu, Y.; Pham, H.; Jackson, A., E-mail: jacksona@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10065 (United States)

2013-12-15

Purpose: To use Cone Beam CT scans obtained just prior to treatments of head and neck cancer patients to measure the setup error and cumulative dose uncertainty of the cochlea. Methods: Data from 10 head and neck patients with 10 planning CTs and 52 Cone Beam CTs taken at time of treatment were used in this study. Patients were treated with conventional fractionation using an IMRT dose painting technique, most with 33 fractions. Weekly radiographic imaging was used to correct the patient setup. The authors used rigid registration of the planning CT and Cone Beam CT scans to find the translational and rotational setup errors, and the spatial setup errors of the cochlea. The planning CT was rotated and translated such that the cochlea positions match those seen in the cone beam scans, cochlea doses were recalculated and fractional doses accumulated. Uncertainties in the positions and cumulative doses of the cochlea were calculated with and without setup adjustments from radiographic imaging. Results: The mean setup error of the cochlea was 0.04 ± 0.33 or 0.06 ± 0.43 cm for RL, 0.09 ± 0.27 or 0.07 ± 0.48 cm for AP, and 0.00 ± 0.21 or −0.24 ± 0.45 cm for SI with and without radiographic imaging, respectively. Setup with radiographic imaging reduced the standard deviation of the setup error by roughly 1–2 mm. The uncertainty of the cochlea dose depends on the treatment plan and the relative positions of the cochlea and target volumes. Combining results for the left and right cochlea, the authors found the accumulated uncertainty of the cochlea dose per fraction was 4.82 (0.39–16.8) cGy, or 10.1 (0.8–32.4) cGy, with and without radiographic imaging, respectively; the percentage uncertainties relative to the planned doses were 4.32% (0.28%–9.06%) and 10.2% (0.7%–63.6%), respectively. Conclusions: Patient setup error introduces uncertainty in the position of the cochlea during radiation treatment. With the assistance of radiographic imaging during setup

SIMULATION OF A COCHLEA OF AN INTERIOR EAR OF THE HUMAN

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S. A. Naida

2012-12-01

Full Text Available There was conducted the simulations of a cochlea of an interior ear of the human by means of a long line. The following regularities of operation of a cochlea were determined: without the count of flexibilities Reissner's and basilar membranes swing pressure on walls of a cochlear course does not exceed 3,6 % from pressure in the field of an oval window; allocation of a differential of sound pressure fluctuates in a time with frequency; taking into account the slenderness of a membrane and dependence of a standing of resonances from f are spotted by non-uniformity of a basilar membrane; the differential travelling wave exists only near to a resonance on each  frequency where the amplitude buildup of oscillations to a maximum happens for many continuances of resonance frequency. Small relative meaning of range of pressure of travelling wave could become the parent of that Peterson's and Bogert's work has not had the further evolution.

Cemento-ossifying fibroma of mandible: An unusual case report and review of literature.

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Mohapatra, Mounabati; Banushree, C S; Nagarajan, K; Pati, Debashish

2015-01-01

The term ossifying fibroma (OF) has recently been included under fibro-osseous lesions. Cemento-OF (COF) is a benign neoplasm that arises from the periodontal membrane which contains multipotential cells that are capable of forming cementum, lamellar bone and fibrous tissue. These tumors occur in the third and fourth decades of life with a predilection for women. The mandible is more commonly involved than the maxilla. This lesion has caused considerable controversy regarding the use of terminology, origin and diagnostic criteria. This article describes an unusual case of COF presenting as unilocular lytic lesion of mandible in a 38-year-old male patient with review of literature.

Spiral Form of the Human Cochlea Results from Spatial Constraints.

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Pietsch, M; Aguirre Dávila, L; Erfurt, P; Avci, E; Lenarz, T; Kral, A

2017-08-08

The human inner ear has an intricate spiral shape often compared to shells of mollusks, particularly to the nautilus shell. It has inspired many functional hearing theories. The reasons for this complex geometry remain unresolved. We digitized 138 human cochleae at microscopic resolution and observed an astonishing interindividual variability in the shape. A 3D analytical cochlear model was developed that fits the analyzed data with high precision. The cochlear geometry neither matched a proposed function, namely sound focusing similar to a whispering gallery, nor did it have the form of a nautilus. Instead, the innate cochlear blueprint and its actual ontogenetic variants were determined by spatial constraints and resulted from an efficient packing of the cochlear duct within the petrous bone. The analytical model predicts well the individual 3D cochlear geometry from few clinical measures and represents a clinical tool for an individualized approach to neurosensory restoration with cochlear implants.

Effects of obesity on protein kinase C, brain creatine kinase, transcription, and autophagy in cochlea.

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Hwang, Juen-Haur

2017-06-01

Diet-induced obesity (DIO) has been shown to exacerbate hearing degeneration via increased hypoxia, inflammatory responses, and cell loss via both caspase-dependent and caspase-independent apoptosis signaling pathways. This study aimed to investigate the effects of DIO on the mRNA expressions of protein kinase c-β (PKC-β), brain creatine kinase (CKB), transcription modification genes, and autophagy-related genes in the cochlea of CD/1 mice. Sixteen 4-week-old male CD/1 mice were randomly divided into 2 groups. For 16 weeks, the DIO group was fed a high fat diet (60% kcal fat) and the controls were fed a standard diet. Morphometry, biochemistry, auditory brainstem response thresholds, omental fat, and histopathology of the cochlea were compared. Results showed that body weight, body length, body-mass index, omental fat, plasma triglyceride, and auditory brainstem response thresholds were significantly elevated in the DIO group compared with those of the control group. The ratio of vessel wall thickness to radius in the stria vascularis was significantly higher in the DIO group. The cell densities in the spiral ganglion, but not in the spiral prominence, of the cochlea were significantly lower in the DIO group. The expression of histone deacetylation gene 1 (HDAC1) was significantly higher in the DIO group than the control group. However, the expressions of PKC-β, CKB, HDAC3, histone acetyltransferase gene (P300), lysosome-associated membrane protein 2 (Lamp2), and light chain 3 (Lc3) genes were not significantly different between two groups. These results suggest that DIO might exacerbate hearing degeneration possibly via increased HDAC1 gene expression in the cochlea of CD/1 mice.

Peripheral cemento-ossifying fibroma: A case report with review of literature.

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Mishra, Amit Kumar; Maru, Rahul; Dhodapkar, Shrikant Vishnuprasad; Jaiswal, Gagan; Kumar, Rajesh; Punjabi, Heena

2013-06-16

Peripheral cemento-ossifying fibroma (PCOF) is a rare osteogenic neoplasm that ordinarily presents as an epulis-like growth. This is of a reactive rather than neoplastic nature and its pathogenesis is uncertain. PCOF predominantly affects adolescent and young adults with greatest prevalence around 28 years. We report here a rare clinical case of PCOF of the mandible, 1 cm mesiodistally and 1.5 cm occluso-gingivally in diameter, which caused difficulty in eating and speech, in a 42-year-old female patient. She was asymptomatic for 1 year and on follow-up for 6 mo post surgically showed gingival health and normal radioopacity of bone without any recurrence. Clinical, radiographic and histological characteristics are discussed and recommendations regarding differential diagnosis, treatment and follow up are provided. The controversial varied nomenclature and possible etiopathogenesis of PCOF are emphasized.

Age-related hearing loss: Aquaporin 4 gene expression changes in the mouse cochlea and auditory midbrain

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Christensen, Nathan; D'Souza, Mary; Zhu, Xiaoxia; Frisina, Robert D.

2009-01-01

Presbycusis – age-related hearing loss, is the number one communication disorder, and one of the top three chronic medical conditions of our aged population. Aquaporins, particularly aquaporin 4 (Aqp4), are membrane proteins with important roles in water and ion flux across cell membranes, including cells of the inner ear and pathways of the brain used for hearing. To more fully understand the biological bases of presbycusis, 39 CBA mice, a well-studied animal model of presbycusis, underwent non-invasive hearing testing as a function of sound frequency (auditory brainstem response – ABR thresholds, and distortion-product otoacoustic emission – DPOAE magnitudes), and were clustered into four groups based on age and hearing ability. Aqp4 gene expression, as determined by genechip microarray analysis and quantitative real-time PCR, was compared to the young adult control group in the three older groups: middle aged with good hearing, old age with mild presbycusis, and old age with severe presbycusis. Linear regression and ANOVA showed statistically significant changes in Aqp4 gene expression and ABR and DPOAE hearing status in the cochlea and auditory midbrain – inferior colliculus. Down-regulation in the cochlea was seen, and an initial down-, then up-regulation was discovered for the inferior colliculus Aqp4 expression. It is theorized that these changes in Aqp4 gene expression represent an age-related disruption of ion flux in the fluids of the cochlea that are responsible for ionic gradients underlying sound transduction in cochlear hair cells necessary for hearing. In regard to central auditory processing at the level of the auditory midbrain, aquaporin gene expression changes may affect neurotransmitter cycling involving supporting cells, thus impairing complex sound neural processing with age. PMID:19070604

Morphometric study of suprascapular notch in Indian dry scapulae with specific reference to the incidence of completely ossified superior transverse scapular ligament.

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Kannan, Usha; Kannan, N S; Anbalagan, J; Rao, Sudha

2014-03-01

The suprascapular notch, a depression on the lateral part of the superior border of the scapula, medial to the coracoid process, is bridged by the superior transverse scapular ligament, which is sometimes ossified and the foramen which is thus completed, transmits the suprascapular nerve to the supraspinatus fossa. Variations in the morphology of suprascapular notch have been identified as one of the causes of suprascapular nerve entrapment. Rengachary et al. classified this notch into six types, based on its shape. To study morphological variations of suprascapular notch in Indian dry scapulae and to analyze the incidence of completely ossified superior transverse scapular ligament with other ethnic populations which have been cited earlier. A total of 400 human dry scapulae which were obtained from the Department of Anatomy of selected eight medical colleges were analyzed. The type of suprascapular notch was noted and it was recorded as per the description given by Rengachary et al. The results of the present study were compared with the results of previous authors in different populations. In our study, out of 400 scapulae, 40 (10%), were identified to have completely ossified superior transverse scapular ligaments. The frequencies of various types of suprascapular notches were: Type I -20%, Type II -10%, Type III -52%, Type IV -4%, Type V -4%, Type VI -10%. Since the suprascapular nerve entrapment syndrome might be caused by complete ossification of superior transverse scapular ligament with formation of suprascapular foramen and other morphometric variations of suprascapular notch, the knowledge on such variations is essential for clinicians, for making a proper diagnosis and for planning the most suitable surgical intervention.

Cortical fibrous defects and non-ossifying fibromas in children and young adults: The analysis of radiological features in 28 cases and a review of literature

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Błaż, Marcin; Palczewski, Piotr; Świątkowski, Jan; Gołębiowski, Marek

2011-01-01

To assess and describe the variability of radiological presentations of fibrous cortical defects and non-ossifying fibromas in children and young adults. Medical records of 28 patients (15 males, 13 females, mean age of 17 years) with a radiological diagnosis of cortical fibrous defect or non-ossifying fibroma were reviewed retrospectively. The presentation of the lesion, its location and morphology according to Ritschl’s classification, as well as the number and types of imaging studies performed in the study group were assessed. Almost all lesions constituted an incidental finding discovered on plain films performed due to trauma. One lesion presented with a pathological fracture. There were 4 patients (mean age of 11 years) with stage A lesion, 9 patients (mean age of 16 years) with stage B lesion, 10 patients (mean age of 18 years) with stage C lesion, and 5 patients (mean age of 23 years) with stage D lesion. The lesions were located mostly in bones around the knee joint. In more than a half of the patients, further imaging was performed apart from plain films. Four lesions were biopsied (1 of stage B and 3 of stage C). A considerable morphological variability of cortical fibrous defects and non-ossifying fibromas, especially of stage C, seems to be the main cause of unnecessary additional imaging and invasive diagnostic procedures in patients with this benign pathology. The knowledge of their age-related evolution and typical skeletal distribution should help in making a correct diagnosis

Expression of tumor necrosis factor-α and interleukin-1β genes in the cochlea and inferior colliculus in salicylate-induced tinnitus

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Chen Jin-Cherng

2011-04-01

Full Text Available Abstract Background Changes in the gene expressions for tumor necrosis factor-α (TNF-α and/or interleukin-1β (IL-1β during tinnitus have not been previously reported. We evaluated tinnitus and mRNA expression levels of TNF-α, IL-1β, and N-methyl D-aspartate receptor subunit 2B (NR2B genes in cochlea and inferior colliculus (IC of mice after intraperitoneal injections of salicylate. Methods Forty-eight 3-month-old male SAMP8 mice were randomly and equally divided into two groups: salicylate-treated and saline-treated. All mice were trained to perform an active avoidance task for 5 days. Once conditioned, an active avoidance task was performed 2 hours after daily intraperitoneal injections of saline, either alone or containing 300 mg/kg sodium salicylate. Total numbers of times (tinnitus score the mice climbed during the inter-trial silent period for 10 trials were recorded daily for 4 days (days 7 to 10, and then mice were euthanized for determination of mRNA expression levels of TNF-α, IL-1β, and NR2B genes in cochlea and IC at day 10. Results Tinnitus scores increased in response to daily salicylate treatments. The mRNA expression levels of TNF-α increased significantly for the salicylate-treated group compared to the control group in both cochlea (1.89 ± 0.22 vs. 0.87 ± 0.07, P p = 0.0040. mRNA expression levels for the IL-1β gene also increased significantly in the salicylate group compared to the control group in both cochlea (3.50 ± 1.05 vs. 2.80 ± 0.28, p versus 1.24 ± 0.52, p = 0.0013. Linear regression analysis revealed a significant positive association between tinnitus scores and expression levels of TNF-α, IL-1β, and NR2B genes in cochlea and IC. In addition, expression levels of the TNF-α gene were positively correlated with those of the NR2Bgene in both cochlea and IC; whereas, the expression levels of the IL-1β gene was positively correlated with that of the NR2B gene in IC, but not in cochlea. Conclusion We

Depletion of resident macrophages does not alter sensory regeneration in the avian cochlea.

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Mark E Warchol

Full Text Available Macrophages are the primary effector cells of the innate immune system and are also activated in response to tissue injury. The avian cochlea contains a population of resident macrophages, but the precise function of those cells is not known. The present study characterized the behavior of cochlear macrophages after aminoglycoside ototoxicity and also examined the possible role of macrophages in sensory regeneration. We found that the undamaged chick cochlea contains a large resting population of macrophages that reside in the hyaline cell region, immediately outside the abneural (inferior border of the sensory epithelium. Following ototoxic injury, macrophages appear to migrate out of the hyaline cell region and towards the basilar membrane, congregating immediately below the lesioned sensory epithelium. In order to determine whether recruited macrophages contribute to the regeneration of sensory receptors, we quantified supporting cell proliferation and hair cell recovery after the elimination of most resident macrophages via application of liposomally-encapsulated clodronate. Examination of macrophage-depleted specimens at two days following ototoxic injury revealed no deficits in hair cell clearance, when compared to normal controls. In addition, we found that elimination of macrophages did not affect either regenerative proliferation of supporting cells or the production of replacement hair cells. However, we did find that macrophage-depleted cochleae contained reduced numbers of proliferative mesothelial cells below the basilar membrane. Our data suggest that macrophages are not required for normal debris clearance and regeneration, but that they may play a role in the maintenance of the basilar membrane.

Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae

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Wen-wei Luo

2018-02-01

Full Text Available Notch inhibition is known to generate supernumerary hair cells (HCs at the expense of supporting cells (SCs in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0 with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.

Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae.

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Luo, Wen-Wei; Wang, Xin-Wei; Ma, Rui; Chi, Fang-Lu; Chen, Ping; Cong, Ning; Gu, Yu-Yan; Ren, Dong-Dong; Yang, Juan-Mei

2018-01-01

Notch inhibition is known to generate supernumerary hair cells (HCs) at the expense of supporting cells (SCs) in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0) with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.

Radiosurgery for Para-IAC Meningiomas: The Effect of Radiation Dose to the Cochlea on Hearing Outcome

International Nuclear Information System (INIS)

Kim, Young-Hoon; Kim, Dong Gyu; Han, Jung Ho; Chung, Hyun-Tai; Kim, In Kyung; Song, Sang Woo; Park, Jeong-Hoon; Kim, Jin Wook; Kim, Yong Hwy; Park, Chul-Kee; Kim, Chae-Yong; Paek, Sun Ha; Jung, Hee-Won

2012-01-01

Purpose: This study was performed to assess the radiosurgical results of meningiomas extending into the internal acoustic canal (para-IAC meningiomas), with a particular focus on the effect of radiation dose to the cochlea on hearing outcome. Methods and Materials: A total of 50 patients who underwent radiosurgery for para-IAC meningiomas between 1998 and 2009, which were followed for 2 years, were enrolled. The mean age was 55.8 years (range, 15–75). The mean tumor volume was 6.1 cm 3 (range, 1.0–19.0), the mean tumor length in the IAC was 6.9 mm (range, 1.3–13.3), and the mean prescribed marginal dose was 13.1 Gy (range, 10–15) at an isodose line of 50%. The mean follow-up duration was 46 months (range, 24–122). Results: Eight (16.0%) patients had nonserviceable hearing at the time of surgery. At the last follow-up, the tumor control rate was 94%; unchanged in 17 patients, decreased in 30 patients, and increased in 3 patients. Among 42 patients with serviceable hearing at the time of radiosurgery, it was preserved in 41 (97.6%) patients at the last follow-up. The maximal and mean radiation doses to the cochleae of these 41 patients were 5.8 Gy ± 0.3 (range, 3.1–11.5) and 4.3 Gy ± 0.2 (range, 2.2–7.5), respectively. The maximal dose to the cochlea of the patient who lost hearing after radiosurgery was 4.7 Gy. Conclusions: The radiation dose to the cochlea may have the minimal toxic effect on the hearing outcome in patients who undergo radiosurgery for para-IAC meningiomas.

Cemento-ossifying fibroma occurring in an elderly patient. A case report and a review of literature.

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Dalghous, Abdulbaset; Alkhabuli, Juma O

2007-06-01

Cemento-ossifying fibromas (COF) are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adults between the third and fourth decade of life. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses, commonly in the premolar/molar region of the mandible. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumour may grow quite extensively, thus the term aggressive is some times applied. Their clinical, radiographical and histopathological features and those of fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis, and treatment. The histopathology is composed of fibrous tissues with calcified structures resembling bone or cementum. Surgical enucleation or resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. This case report presents a case of COF in 70 years old female patient that was asymptomatic. Clinically, there was an expansion of the buccal plate but not the lingual plate of the right mandible. The covering mucosa was normal and there was no tenderness or paraesthesia. Radiographically, the lesion extends superio-inferiory from the alveolar ridge to the area of inferior dental canal and mesiodistally from the premolar region to the retro-molar area. The lesion was of mixed radiolucent densities. The patient was followed up periodically for 5 years without any treatment. The patient continued to be asymptomatic with minimum changes. Occurrence of cemento-ossifying fibroma in patients over 60 years of age is unusual and had not been reported. The clinical, radiographic, histopathology and literature review are discussed.

Cemento-ossifying fibroma occurring in an elderly patient: A case report and a review of literature

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Juma O. Alkhabuli

2007-01-01

Full Text Available Cemento-ossifying fibromas (COF are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adults between the third and fourth decade of life. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses, commonly in the premolar/molar region of the mandible. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumour may grow quite extensively, thus the term aggressive is some times applied. Their clinical, radiographical and histopathological features and those of fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis, and treatment.The histopathology is composed of fibrous tissues with calcified structures resembling bone or cementum. Surgical enucleation or resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. This case report presents a case of COF in 70 years old female patient that was asymptomatic.Clinically, there was an expansion of the buccal plate but not the lingual plate of the right mandible. The covering mucosa was normal and there was no tenderness or paraesthesia. Radiographically, the lesion extends superio-inferiory from the alveolar ridge to the area of inferior dental canal and mesiodistally from the premolar region to the retro-molar area. The lesion was of mixed radiolucent densities. The patient was followed up periodically for 5 years without any treatment. The patient continued to be asymptomatic with minimum changes. Occurrence of cemento-ossifying fibroma in patients over 60 years of age is unusual and had not been reported. The clinical, radiographic, histopathology and literature review are discussed.

A second, low-frequency mode of vibration in the intact mammalian cochlea.

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Lukashkin, Andrei N; Russell, Ian J

2003-03-01

The mammalian cochlea is a structure comprising a number of components connected by elastic elements. A mechanical system of this kind is expected to have multiple normal modes of oscillation and associated resonances. The guinea pig cochlear mechanics was probed using distortion components generated in the cochlea close to the place of overlap between two tones presented simultaneously. Otoacoustic emissions at frequencies of the distortion components were recorded in the ear canal. The phase behavior of the emissions reveals the presence of a nonlinear resonance at a frequency about a half octave below that of the high-frequency primary tone. The location of the resonance is level dependent and the resonance shifts to lower frequencies with increasing stimulus intensity. This resonance is thought to be associated with the tectorial membrane. The resonance tends to minimize input to the cochlear receptor cells at frequencies below the high-frequency primary and increases the dynamic load to the stereocilia of the receptor cells at the primary frequency when the tectorial membrane and reticular lamina move in counterphase.

The cochlea of the enigmatic pygmy right whale Caperea marginata informs mysticete phylogeny.

Science.gov (United States)

Park, Travis; Marx, Felix G; Fitzgerald, Erich M G; Evans, Alistair R

2017-06-01

The pygmy right whale, Caperea marginata, is the least understood extant baleen whale (Cetacea, Mysticeti). Knowledge on its basic anatomy, ecology, and fossil record is limited, even though its singular position outside both balaenids (right whales) and balaenopteroids (rorquals + grey whales) gives Caperea a pivotal role in mysticete evolution. Recent investigations of the cetacean cochlea have provided new insights into sensory capabilities and phylogeny. Here, we extend this advance to Caperea by describing, for the first time, the inner ear of this enigmatic species. The cochlea is large and appears to be sensitive to low-frequency sounds, but its hearing limit is relatively high. The presence of a well-developed tympanal recess links Caperea with cetotheriids and balaenopteroids, rather than balaenids, contrary to the traditional morphological view of a close Caperea-balaenid relationship. Nevertheless, a broader sample of the cetotheriid Herpetocetus demonstrates that the presence of a tympanal recess can be variable at the specific and possibly even the intraspecific level. © 2017 Wiley Periodicals, Inc.

Survival of partially differentiated mouse embryonic stem cells in the scala media of the guinea pig cochlea.

Science.gov (United States)

Hildebrand, Michael S; Dahl, Hans-Henrik M; Hardman, Jennifer; Coleman, Bryony; Shepherd, Robert K; de Silva, Michelle G

2005-12-01

The low regenerative capacity of the hair cells of the mammalian inner ear is a major obstacle for functional recovery following sensorineural hearing loss. A potential treatment is to replace damaged tissue by transplantation of stem cells. To test this approach, undifferentiated and partially differentiated mouse embryonic stem (ES) cells were delivered into the scala media of the deafened guinea pig cochlea. Transplanted cells survived in the scala media for a postoperative period of at least nine weeks, evidenced by histochemical and direct fluorescent detection of enhanced green fluorescent protein (EGFP). Transplanted cells were discovered near the spiral ligament and stria vascularis in the endolymph fluid of the scala media. In some cases, cells were observed close to the damaged organ of Corti structure. There was no evidence of significant immunological rejection of the implanted ES cells despite the absence of immunosuppression. Our surgical approach allowed efficient delivery of ES cells to the scala media while preserving the delicate structures of the cochlea. This is the first report of the survival of partially differentiated ES cells in the scala media of the mammalian cochlea, and it provides support for the potential of cell-based therapies for sensorineural hearing impairment.

Anatomic variations of the cochlea and relations to other temporal bone structures

Energy Technology Data Exchange (ETDEWEB)

Dimopoulos, P.; Muren, C. (Akademiska Sjukhuset, Uppsala (Sweden). Dept. of Diagnostic Radiology Sabbatsberg' s Sjukhus, Stockholm (Sweden). Dept. of Diagnostic Radiology)

1990-09-01

The size and shape of the human cochlea and the normal ranges of variation of its dimensions were evaluated in 95 plastic casts, prepared from temporal bone specimens. The normal range of variation is fairly small, and is not age-dependent. Obvious digression from this range, associated with pertinent clinical symptoms, indicates an abnormality. (orig./MG).

Localization of (/sup 3/H). gamma. -aminobutyric acid in the cochlea. Light and electron microscopic autoradiography

Energy Technology Data Exchange (ETDEWEB)

Richrath, W; Kraus, H; Fromme, H G [Muenster Univ. (F.R. Germany). Hals-, Nasen- und Ohrenklinik; Muenster Univ. (F.R. Germany). Inst. fuer Medizinische Physik)

1974-01-01

In guinea pigs, 1 h after intraarterial and local administration of /sup 3/H-GABA, autoradiographs of the cochlea and the brain were performed. As a parameter of distribution of this substance, silver grain density was examined by means of light and electron microscopy. Intraarterial injection was not followed by any activity neither in brain nor in the cochlea, an observation suggesting the existence of a blood-perilymph barrier additional to the blood-brain barrier. Perfusion of the cochlea produced a marked activity in the spiral ganglion. Different from other tritium labelled amino acids, /sup 3/H-GABA activity could be found only in glia cells but not in nerve cell bodies or axons. The significance of this finding is open to question. In the organ of Corti a selective labelling of efferent nerve fibres could be found by means of light microscopy, additionally, using electron microscopy, only efferent synapses proved to be labelled. Most of silver grains were attached to vesicles and mitochondria, some grains to the synaptie deft. Afferent synapses remained unlabelled. Comparing with publications concerning GABA localization and concentration in the brain, we conclude that the efferent system of the Organ of Corti contains a high concentration of GABA. As present electrophysiological results are contradictory the GABA distribution alone gives no convincing evidence that this substance may serve as a transmitter.

Expression of tumor necrosis factor-α and interleukin-1β genes in the cochlea and inferior colliculus in salicylate-induced tinnitus.

Science.gov (United States)

Hwang, Juen-Haur; Chen, Jin-Cherng; Yang, Shan-Ying; Wang, Ming-Fu; Chan, Yin-Ching

2011-04-09

Changes in the gene expressions for tumor necrosis factor-α (TNF-α) and/or interleukin-1β (IL-1β) during tinnitus have not been previously reported. We evaluated tinnitus and mRNA expression levels of TNF-α, IL-1β, and N-methyl D-aspartate receptor subunit 2B (NR2B) genes in cochlea and inferior colliculus (IC) of mice after intraperitoneal injections of salicylate. Forty-eight 3-month-old male SAMP8 mice were randomly and equally divided into two groups: salicylate-treated and saline-treated. All mice were trained to perform an active avoidance task for 5 days. Once conditioned, an active avoidance task was performed 2 hours after daily intraperitoneal injections of saline, either alone or containing 300 mg/kg sodium salicylate. Total numbers of times (tinnitus score) the mice climbed during the inter-trial silent period for 10 trials were recorded daily for 4 days (days 7 to 10), and then mice were euthanized for determination of mRNA expression levels of TNF-α, IL-1β, and NR2B genes in cochlea and IC at day 10. Tinnitus scores increased in response to daily salicylate treatments. The mRNA expression levels of TNF-α increased significantly for the salicylate-treated group compared to the control group in both cochlea (1.89 ± 0.22 vs. 0.87 ± 0.07, P salicylate group compared to the control group in both cochlea (3.50 ± 1.05 vs. 2.80 ± 0.28, p salicylate treatment resulting in tinnitus augments expression of the TNF-α and IL-1β genes in cochlea and IC of mice, and we suggest that these proinflammatory cytokines might lead to tinnitus directly or via modulating the NMDA receptor.

Maxillo-Mandibular Cemento-ossifying Fibroma: A Rare Case Report.

Science.gov (United States)

Peravali, Ranjit Kumar; Bhat, H Hari Kishore; Reddy, Sreenatha

2015-03-01

Cemento-ossifying fibroma (COF) is a benign fibro osseous lesion of the jaws which has been described as a demarcated or rarely encapsulated neoplasm consisting of fibrous tissue and varying amounts of mineralized material resembling bone and/or cementum (Dinkar et al. in IJDA 2(4):45-47, 2010). Majority of lesions occur in the mandible and only few cases of COFs of the maxillary sinus and bilateral COFs of the mandible have been reported in literature (Dinkar et al. in IJDA 2(4):45-47, 2010; Tamiolakis et al. in Acta Stomatol Croat 39(3):319-321, 2005; Hamner et al. in Oral Surg Oral Med Oral Pathol 26(4):579-587, 1968; Gunaseelan et al. in Oral Med Oral Pathol Oral Radiol Endod 104:e21-e25, 2007). These lesions have a very low recurrence rate (Ertug et al. in Quintessence Int 35(10):808-810, 2004) and are generally treated by enucleation. In this paper we present a rare case of COF occurring in both the maxilla and mandible of the same patient. Only one such case (Takeda and Fujioka in Int J Oral Maxillofac Surg 16(3):368-371, 1987) has been reported in literature so far.

Adenosine A1 Receptor Protects Against Cisplatin Ototoxicity by Suppressing the NOX3/STAT1 Inflammatory Pathway in the Cochlea

Science.gov (United States)

Kaur, Tejbeer; Borse, Vikrant; Sheth, Sandeep; Sheehan, Kelly; Ghosh, Sumana; Tupal, Srinivasan; Jajoo, Sarvesh; Mukherjea, Debashree; Rybak, Leonard P.

2016-01-01

Cisplatin is a commonly used antineoplastic agent that produces ototoxicity that is mediated in part by increasing levels of reactive oxygen species (ROS) via the NOX3 NADPH oxidase pathway in the cochlea. Recent studies implicate ROS generation in mediating inflammatory and apoptotic processes and hearing loss by activating signal transducer and activator of transcription (STAT1). In this study, we show that the adenosine A1 receptor (A1AR) protects against cisplatin ototoxicity by suppressing an inflammatory response initiated by ROS generation via NOX3 NADPH oxidase, leading to inhibition of STAT1. Trans-tympanic administration of the A1AR agonist R-phenylisopropyladenosine (R-PIA) inhibited cisplatin-induced ototoxicity, as measured by auditory brainstem responses and scanning electron microscopy in male Wistar rats. This was associated with reduced NOX3 expression, STAT1 activation, tumor necrosis factor-α (TNF-α) levels, and apoptosis in the cochlea. In vitro studies in UB/OC-1 cells, an organ of Corti immortalized cell line, showed that R-PIA reduced cisplatin-induced phosphorylation of STAT1 Ser727 (but not Tyr701) and STAT1 luciferase activity by suppressing the ERK1/2, p38, and JNK mitogen-activated protein kinase (MAPK) pathways. R-PIA also decreased the expression of STAT1 target genes, such as TNF-α, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and reduced cisplatin-mediated apoptosis. These data suggest that the A1AR provides otoprotection by suppressing NOX3 and inflammation in the cochlea and could serve as an ideal target for otoprotective drug therapy. SIGNIFICANCE STATEMENT Cisplatin is a widely used chemotherapeutic agent for the treatment of solid tumors. Its use results in significant and permanent hearing loss, for which no US Food and Drug Administration-approved treatment is currently available. In this study, we targeted the cochlear adenosine A1 receptor (A1AR) by trans-tympanic injections of the agonist R

Dead regions in the cochlea: Implications for speech recognition and applicability of articulation index theory

DEFF Research Database (Denmark)

Vestergaard, Martin David

2003-01-01

Dead regions in the cochlea have been suggested to be responsible for failure by hearing aid users to benefit front apparently increased audibility in terms of speech intelligibility. As an alternative to the more cumbersome psychoacoustic tuning curve measurement, threshold-equalizing noise (TEN...

Usefulness of Intravital Multiphoton Microscopy in Visualizing Study of Mouse Cochlea and Volume Changes in the Scala Media.

Science.gov (United States)

Ju, Hyun Mi; Lee, Sun Hee; Kong, Tae Hoon; Kwon, Seung-Hae; Choi, Jin Sil; Seo, Young Joon

2017-01-01

Conventional microscopy has limitations in viewing the cochlear microstructures due to three-dimensional spiral structure and the overlying bone. But these issues can be overcome by imaging the cochlea in vitro with intravital multiphoton microscopy (MPM). By using near-infrared lasers for multiphoton excitation, intravital MPM can detect endogenous fluorescence and second harmonic generation of tissues. In this study, we used intravital MPM to visualize various cochlear microstructures without any staining and non-invasively analyze the volume changes of the scala media (SM) without removing the overlying cochlear bone. The intravital MPM images revealed various tissue types, ranging from thin membranes to dense bone, as well as the spiral ganglion beneath the cochlear bone. The two-dimensional, cross-sectional, and serial z-stack intravital MPM images also revealed the spatial dilation of the SM in the temporal bone of pendrin-deficient mice. These findings suggest that intravital MPM might serve as a new method for obtaining microanatomical information regarding the cochlea, similar to standard histopathological analyses in the animal study for the cochlea. Given the capability of intravital MPM for detecting an increase in the volume of the SM in pendrin-deficient mice, it might be a promising new tool for assessing the pathophysiology of hearing loss in the future.

Usefulness of Intravital Multiphoton Microscopy in Visualizing Study of Mouse Cochlea and Volume Changes in the Scala Media

Directory of Open Access Journals (Sweden)

Hyun Mi Ju

2017-07-01

Full Text Available Conventional microscopy has limitations in viewing the cochlear microstructures due to three-dimensional spiral structure and the overlying bone. But these issues can be overcome by imaging the cochlea in vitro with intravital multiphoton microscopy (MPM. By using near-infrared lasers for multiphoton excitation, intravital MPM can detect endogenous fluorescence and second harmonic generation of tissues. In this study, we used intravital MPM to visualize various cochlear microstructures without any staining and non-invasively analyze the volume changes of the scala media (SM without removing the overlying cochlear bone. The intravital MPM images revealed various tissue types, ranging from thin membranes to dense bone, as well as the spiral ganglion beneath the cochlear bone. The two-dimensional, cross-sectional, and serial z-stack intravital MPM images also revealed the spatial dilation of the SM in the temporal bone of pendrin-deficient mice. These findings suggest that intravital MPM might serve as a new method for obtaining microanatomical information regarding the cochlea, similar to standard histopathological analyses in the animal study for the cochlea. Given the capability of intravital MPM for detecting an increase in the volume of the SM in pendrin-deficient mice, it might be a promising new tool for assessing the pathophysiology of hearing loss in the future.

Computed tomography measurements of the normal and the pathologic cochlea in children

International Nuclear Information System (INIS)

Teissier, Natacha; Abbeele, Thierry van den; Sebag, Guy; Elmaleh-Berges, Monique

2010-01-01

Radiological investigation is frequently undertaken to assess the aetiology of sensorineural hearing loss (SNHL). To establish the CT measurements of the normal cochlea in children and to determine radiological criteria correlated with SNHL. A retrospective study of temporal bone CT performed in 159 children, age range from 3 days to 16 years between February 1999 and July 2004. A control group (n = 88) comprised children without SNHL; the SNHL group comprised 71 children. The width of the second turn of the cochlea (CW), the cochlear height (CH), and the width of the bony canal for the cochlear nerve (WCN) were measured on a reference plane containing the modiolus, the posterior semicircular canal, the footplate, and the stapes arch. Width of the canal measurements ≤1.7 mm or ≥2.5 mm supported the diagnosis of SNHL with a specificity of 97% and 91%, respectively. Cochlear width was found to be significantly smaller in the SNHL group (5.61 ± 0.51 mm) than in the control group (5.75 ± 0.31 mm, P < 0.02), a size <5.4 mm being highly suggestive of SNHL with a specificity of 90%. No significant variations of all measurements were found with age. Appropriate measurements of WCN and CW are highly correlated with SNHL. (orig.)

Adenosine A1 Receptor Protects Against Cisplatin Ototoxicity by Suppressing the NOX3/STAT1 Inflammatory Pathway in the Cochlea.

Science.gov (United States)

Kaur, Tejbeer; Borse, Vikrant; Sheth, Sandeep; Sheehan, Kelly; Ghosh, Sumana; Tupal, Srinivasan; Jajoo, Sarvesh; Mukherjea, Debashree; Rybak, Leonard P; Ramkumar, Vickram

2016-04-06

Cisplatin is a commonly used antineoplastic agent that produces ototoxicity that is mediated in part by increasing levels of reactive oxygen species (ROS) via the NOX3 NADPH oxidase pathway in the cochlea. Recent studies implicate ROS generation in mediating inflammatory and apoptotic processes and hearing loss by activating signal transducer and activator of transcription (STAT1). In this study, we show that the adenosine A1 receptor (A1AR) protects against cisplatin ototoxicity by suppressing an inflammatory response initiated by ROS generation via NOX3 NADPH oxidase, leading to inhibition of STAT1. Trans-tympanic administration of the A1AR agonist R-phenylisopropyladenosine (R-PIA) inhibited cisplatin-induced ototoxicity, as measured by auditory brainstem responses and scanning electron microscopy in male Wistar rats. This was associated with reduced NOX3 expression, STAT1 activation, tumor necrosis factor-α (TNF-α) levels, and apoptosis in the cochlea. In vitro studies in UB/OC-1 cells, an organ of Corti immortalized cell line, showed that R-PIA reduced cisplatin-induced phosphorylation of STAT1 Ser(727) (but not Tyr(701)) and STAT1 luciferase activity by suppressing the ERK1/2, p38, and JNK mitogen-activated protein kinase (MAPK) pathways.R-PIA also decreased the expression of STAT1 target genes, such as TNF-α, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and reduced cisplatin-mediated apoptosis. These data suggest that the A1AR provides otoprotection by suppressing NOX3 and inflammation in the cochlea and could serve as an ideal target for otoprotective drug therapy. Cisplatin is a widely used chemotherapeutic agent for the treatment of solid tumors. Its use results in significant and permanent hearing loss, for which no US Food and Drug Administration-approved treatment is currently available. In this study, we targeted the cochlear adenosine A1 receptor (A1AR) by trans-tympanic injections of the agonist R

Protein transduction therapy into cochleae via the round window niche in guinea pigs

Directory of Open Access Journals (Sweden)

Hiroki Takeda

2016-01-01

Full Text Available Cell-penetrating peptides (CPPs are short sequences of amino acids that facilitate the penetration of conjugated cargoes across mammalian cell membranes, and as such, they may provide a safe and effective method for drug delivery to the inner ear. Simple polyarginine peptides have been shown to induce significantly higher cell penetration rates among CPPs. Herein, we show that a peptide consisting of nine arginines (“9R” effectively delivered enhanced green fluorescent protein (EGFP into guinea pig cochleae via the round window niche without causing any deterioration in auditory function. A second application, 24 hours after the first, prolonged the presence of EGFP. To assess the feasibility of protein transduction using 9R-CPPs via the round window, we used “X-linked inhibitor of apoptosis protein” (XIAP bonded to a 9R peptide (XIAP-9R. XIAP-9R treatment prior to acoustic trauma significantly reduced putative hearing loss and the number of apoptotic hair cells loss in the cochleae. Thus, the topical application of molecules fused to 9R-CPPs may be a simple and promising strategy for treating inner ear diseases.

Expanding the Molecular Signature of Ossifying Fibromyxoid Tumors with 2 Novel Gene Fusions: CREBBP-BCORL1 and KDM2A-WWTR1

OpenAIRE

Kao, Yu-Chien; Sung, Yun-Shao; Zhang, Lei; Chen, Chun-Liang; Huang, Shih-Chiang; Antonescu, Cristina R.

2016-01-01

Ossifying fibromyxoid tumor (OFMT) is an uncommon mesenchymal neoplasm of uncertain differentiation and intermediate malignant potential. Recurrent gene fusions involving either PHF1 or BCOR have been found in 85% of OFMT, including typical and malignant examples. As a subset of OFMT still lack known genetic abnormalities, we identified two OFMTs negative for PHF1 and BCOR rearrangements, which were subjected to transcriptome analysis for fusion discovery. The RNA sequencing found a novel CRE...

Analysis of Salient Feature Jitter in the Cochlea for Objective Prediction of Temporally Localized Distortion in Synthesized Speech

Directory of Open Access Journals (Sweden)

Wenliang Lu

2009-01-01

Full Text Available Temporally localized distortions account for the highest variance in subjective evaluation of coded speech signals (Sen (2001 and Hall (2001. The ability to discern and decompose perceptually relevant temporally localized coding noise from other types of distortions is both of theoretical importance as well as a valuable tool for deploying and designing speech synthesis systems. The work described within uses a physiologically motivated cochlear model to provide a tractable analysis of salient feature trajectories as processed by the cochlea. Subsequent statistical analysis shows simple relationships between the jitter of these trajectories and temporal attributes of the Diagnostic Acceptability Measure (DAM.

Miositis osificante de los aductores de la cadera Ossifying myositis of hip adductors

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Feliberto Blanco Trujillo

2011-08-01

Full Text Available Se presenta el caso clínico de un paciente de 24 años de edad, asistido en la Escuela de Trabajadores Sociales de Santiago de Cuba por aumento de volumen en la cadera izquierda y limitación funcional total, no dolorosa, de esa parte del cuerpo. Se comprobó clínica y radiográficamente que se trataba de una miositis osificante de los aductores de la cadera, pero no pudo ser operado en esta provincia porque regresó a su país natal.The clinical case of a 24-year-old patient attended at Social Workers School in Santiago de Cuba due to increased left hip size and total functional limitation without pain of that body area was presented. It was clinically and radiographically documented that the diagnosis was ossifying myositis of hip adductors. However, surgery could not be done in that province because the patient travelled back to his country.

Clinical characteristics of peripheral ossifying fibroma: A series of 20 cases

Directory of Open Access Journals (Sweden)

Mohammad Reza Zarei

2014-10-01

Full Text Available BACKGROUND AND AIM: Peripheral ossifying fibroma (POF is a reactive chronic localized hyperplastic gingival lesion. The present case-series was undertaken to determine the clinical variations in a series of different cases of oral POF. METHODS: Demographic and clinical data including age, gender, location, color, clinical diagnosis, size, consistency and radiographic view of the lesions were studied among clinical records at Kerman Dental School from 1998 to 2012. RESULTS: A total of 20 POF cases was subjected to clinical analyses, in equal numbers of men and women. The total frequency of POF was 2.5%, and 11 cases (55% had occurred in the maxilla. POF showed a greater frequency of pink color (60%, anterior location (55%, firm consistency (85% and a size of 1-1.5 cm (60%. Bone resorption and calcification were found in 35% and 25% of cases, respectively. CONCLUSION: In comparison with previous studies, despite investigation of similar clinical features of POF in the present study, findings also showed that characteristics such as age, gender and location cannot help in the differential diagnosis of POF from pyogenic granuloma.

Ossifying tendinitis of the rotator cuff after arthroscopic excision of calcium deposits: report of two cases and literature review.

Science.gov (United States)

Merolla, Giovanni; Dave, Arpit C; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe

2015-03-01

Ossifying tendinitis (OT) is a type of heterotopic ossification, characterized by deposition of hydroxyapatite crystals in a histologic pattern of mature lamellar bone. It is usually associated with surgical intervention or trauma and is more commonly seen in Achilles or distal biceps tendons, and also in the gluteus maximus tendon. To our knowledge, there is no description of OT as a complication of calcifying tendinitis of the rotator cuff. In this report, we describe two cases in which the patients developed an OT of the supraspinatus after arthroscopic removal of calcium deposits. The related literature is reviewed.

Cellular development of the human cochlea and the regenerative potential of hair follicle bulge stem cells

NARCIS (Netherlands)

Locher, heiko

2015-01-01

The embryonic development of the human cochlea (the organ of hearing) has been investigated for over one hundred years. However, little is still known about the development on a cellular and protein level, which is important to better understand etiologies and pathologies of various types of

Caloric restriction suppresses apoptotic cell death in the mammalian cochlea and leads to prevention of presbycusis.

Science.gov (United States)

Someya, Shinichi; Yamasoba, Tatsuya; Weindruch, Richard; Prolla, Tomas A; Tanokura, Masaru

2007-10-01

Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Calorie restricted (CR) mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed a significant reduction in the number of TUNEL-positive cells and cleaved caspase-3-positive cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 24 apoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR can retard this process by suppressing apoptosis in the inner ear tissue.

The rat cochlea in the absence of circulating adrenal hormones: an electrophysiological and morphological study.

Science.gov (United States)

Lohuis, P J; Börjesson, P K; Klis, S F; Smoorenburg, G F

2000-05-01

Circulating adrenal hormones affect strial function. Removal of endogenous levels of adrenal steroids by bilateral adrenalectomy (ADX) in rats causes a decrease of Na(+)/K(+)-ATPase activity in the cochlear lateral wall [Rarey et al., 1989. Arch. Otolaryngol. Head Neck Surg. 115, 817-821] and a decrease of the volume of the marginal cells in the stria vascularis [Lohuis et al., 1990. Acta Otolaryngol. (Stockh.) 110, 348-356]. To study further the effect of absence of circulating adrenocorticosteroids on cochlear function, 18 male Long Evans rats underwent either an ADX or a SHAM operation. Electrocochleography was performed 1 week after surgery for tone bursts in a frequency range of 1-16 kHz. Thereafter, the cochleas were harvested and examined histologically. No significant changes in the amplitude growth curves of the summating potential (SP), the compound action potential (CAP) and the cochlear microphonics (CM) were detected after ADX. However, visually, there appeared to be a decrease of endolymphatic volume (tentatively called imdrops). Reissner's membrane (RM) extended less into scala vestibuli in ADX animals than in SHAM-operated animals. The ratio between the length of RM and the straight distance between the medial and lateral attachment points of RM were used as an objective measure to quantify this effect in each sub-apical half turn of the cochlea. The decrease in length of RM was statistically significant. Thus, circulating adrenal hormones appear to be necessary for normal cochlear fluid homeostasis. Absence of one or more of these hormones leads to shrinkage of the scala media (imdrops). However, the absence of adrenal hormones does not affect the gross cochlear potentials. Apparently, the cochlea is capable of compensating for the absence of circulating adrenal hormones to sustain the conditions necessary for proper cochlear transduction.

Random walks with shape prior for cochlea segmentation in ex vivo μCT

DEFF Research Database (Denmark)

Ruiz Pujadas, Esmeralda; Kjer, Hans Martin; Piella, Gemma

2016-01-01

Purpose Cochlear implantation is a safe and effective surgical procedure to restore hearing in deaf patients. However, the level of restoration achieved may vary due to differences in anatomy, implant type and surgical access. In order to reduce the variability of the surgical outcomes, we...... propose a new framework for cochlea segmentation in ex vivo μCT images using random walks where a distance-based shape prior is combined with a region term estimated by a Gaussian mixture model. The prior is also weighted by a confidence map to adjust its influence according to the strength of the image...... contour. Random walks is performed iteratively, and the prior mask is aligned in every iteration. Results We tested the proposed approach in ten μCT data sets and compared it with other random walks-based segmentation techniques such as guided random walks (Eslami et al. in Med Image Anal 17...

Effect of 60Co gamma irradiation on cochlea function and structure in guinea pigs

International Nuclear Information System (INIS)

Wang Zhonghe; Cai Yilin; Hu Haisen

1994-01-01

In the experiment inner ears of guinea pigs were irradiated with 60 Co gamma rays using the method of simulated clinical routine irradiation in order to find the effects of ionizing radiation on the cochlea function and structure and to explore the mechanism and protective measure that lead to hearing impairment following radiotherapy to the head and neck of cancer patients. Ten weeks after irradiation it was found that ABR threshold increased with increasing dose of radiation. The mean values of ABR thresholds in 70 Gy and 90 Gy groups were 10 dB and 28 dB respectively. The number of inner and outer hair cell and pillar cell loss was counted under microscope. The number of lost cells increased with increasing dose of radiation. The severity of damage in morphology of inner, outer hair cells and pillar cells reduced progressively. The groups of 70 Gy and 90 Gy lost significantly more than groups of control and 50 Gy(P<0.05). It is concluded that the damage of hair cells of cochlea is the direct result of gamma ray irradiation of the inner ear and is the main cause of hearing impairment following irradiation

Blood circulation of the inner ear under the influence of medications. Radiotracer experiments using guinea pig cochlea

International Nuclear Information System (INIS)

Neumeier, A.

1987-01-01

The dependence of the blood circulation in the inner ear on various medications is discussed. By means of a radiotracer clearance technique the cochlear clearance curves for the guinea pig cochlea after the administration of various circulation stimulants were determined. (MBC) [de

Minimally invasive drug delivery to the cochlea through application of nanoparticles to the round window membrane

Czech Academy of Sciences Publication Activity Database

Buckiová, Daniela; Ranjan, S.; Newman, T. A.; Johnston, A. H.; Sood, R.; Kinnunen, P. K. J.; Popelář, Jiří; Chumak, Tetyana; Syka, Josef

2012-01-01

Roč. 7, č. 9 (2012), s. 1339-1354 ISSN 1743-5889 R&D Projects: GA ČR GA309/07/1336; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50390512 Keywords : nanoparticles * cochlea * drug delivery Subject RIV: FH - Neurology Impact factor: 5.260, year: 2012

[The expression and significance of VIP and its receptor in the cochlea of different degrees of chronic alcoholism rats].

Science.gov (United States)

Feng, Jing; Liu, Haibing

2015-07-01

To determine whether chronic alcoholism alters the expression levels of Vasoactive intestinal polypeptide (VIP) and its receptor (VIPR1) in the cochlea of chronic alcoholism rats. We measured their expression levels in 30 SD rats, in which we created models of different degrees of chronic alcoholism. We investigated the presence of the mRNA of VIP in the cochlea of chronic alcoholism rats and controls by reverse transcription-polymerase chain reaction (RT-PCR) method. We investigated the presence of proteins of VIPR1 in poisoned rats and controls by western blot. We also evaluated the local distribution of VIP cells by immunohistochemistry. We found that the levels of VIP and VIPR1 were downregulated in the chronic alcoholism groups compared to the controls group. The differences in some expression levels were significant different between chronic alcoholism rats and control rats. Moreover, at different degrees of alcohol poisoning in rats, the contents of VIP and VIPR1 differed. Decreased levels of VIP and VIPR1 were detected in the deep chronic alcoholism group compared to the group with low-degree poisoning (P 0.05). These results suggest that VIP and VIPR1 play an important role in the auditory function in rats with chronic alcoholism. Chronic alcoholism may cause a peptide hormone secretion imbalance in the auditory system, eventually leading to hearing loss.

Deletion of Menin in craniofacial osteogenic cells in mice elicits development of mandibular ossifying fibroma.

Science.gov (United States)

Lee, S; Liu, P; Teinturier, R; Jakob, J; Tschaffon, M; Tasdogan, A; Wittig, R; Hoeller, S; Baumhoer, D; Frappart, L; Vettorazzi, S; Bertolino, P; Zhang, C; Tuckermann, J

2018-02-01

Ossifying fibroma (OF) is a rare benign tumor of the craniofacial bones that can reach considerable and disfiguring dimensions if left untreated. Although the clinicopathological characteristics of OF are well established, the underlying etiology has remained largely unknown. Our work indicates that Men1-a tumor suppressor gene responsible of Multiple endocrine neoplasia type 1-is critical for OF formation and shows that mice with targeted disruption of Men1 in osteoblasts (Men1 Runx2Cre ) develop multifocal OF in the mandible with a 100% penetrance. Using lineage-tracing analysis, we demonstrate that loss of Men1 arrests stromal osteoprogenitors in OF at the osterix-positive pre-osteoblastic differentiation stage. Analysis of Men1-lacking stromal spindle cells isolated from OF (OF-derived MSCs (OFMSCs)) revealed a downregulation of the cyclin-dependent kinase (CDK) inhibitor Cdkn1a, consistent with an increased proliferation rate. Intriguingly, the re-expression of Men1 in Men1-deficient OFMSCs restored Cdkn1a expression and abrogated cellular proliferation supporting the tumor-suppressive role of Men1 in OF. Although our work presents the first evidence of Men1 in OF development, it further provides the first genetic mouse model of OF that can be used to better understand the molecular pathogenesis of these benign tumors and to potentially develop novel treatment strategies.

Case Presentation of Concomitant and Contiguous Adenomatoid Odontogenic Tumor and Focal Cemento-Ossifying Dysplasia.

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Rezvani, Gita; Donoghue, Mandana; Reichart, Peter A; Pazuhi, Neda

2015-01-01

A 24 year-old male was presented for the diagnosis of an asymptomatic bony expansion in relation to the right maxillary canine and first premolar. The unilocular radiolucent lesion with central foci of calcification had caused divergence of canine and first premolar roots without any resorption. This case report details a diagnosis of two distinct disease processes of different cellular origin namely, focal cemento-ossifying dysplasia and adenomatoid odontogenic tumor in a previously unreported concomitant and contiguous relationship. The diagnosis was determined by a combination of clinical, radiographic, histopathological and surgical evidence. This case highlights two points, first the need to examine all mixed radiolucent-radiopaque lesions with advanced imaging techniques to assess the number and extent of the lesions prior to treatment planning. Second a likely role of periodontal ligament as the tissue source for odontogenic epithelial cells and mesenchymal stem cells required for the development of odontogenic tumors and cemento-osseous dysplasias.

Communication analysis for feedback control of civil infrastructure using cochlea-inspired sensing nodes

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Peckens, Courtney A.; Cook, Ireana; Lynch, Jerome P.

2016-04-01

Wireless sensor networks (WSNs) have emerged as a reliable, low-cost alternative to the traditional wired sensing paradigm. While such networks have made significant progress in the field of structural monitoring, significantly less development has occurred for feedback control applications. Previous work in WSNs for feedback control has highlighted many of the challenges of using this technology including latency in the wireless communication channel and computational inundation at the individual sensing nodes. This work seeks to overcome some of those challenges by drawing inspiration from the real-time sensing and control techniques employed by the biological central nervous system and in particular the mammalian cochlea. A novel bio-inspired wireless sensor node was developed that employs analog filtering techniques to perform time-frequency decomposition of a sensor signal, thus encompassing the functionality of the cochlea. The node then utilizes asynchronous sampling of the filtered signal to compress the signal prior to communication. This bio-inspired sensing architecture is extended to a feedback control application in order to overcome the traditional challenges currently faced by wireless control. In doing this, however, the network experiences high bandwidths of low-significance information exchange between nodes, resulting in some lost data. This study considers the impact of this lost data on the control capabilities of the bio-inspired control architecture and finds that it does not significantly impact the effectiveness of control.

Involvement of p53 and Bcl-2 in sensory cell degeneration in aging rat cochleae.

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Xu, Yang; Yang, Wei Ping; Hu, Bo Hua; Yang, Shiming; Henderson, Donald

2017-06-01

p53 and Bcl-2 (B-cell lymphoma 2) are involved in the process of sensory cell degeneration in aging cochleae. To determine molecular players in age-related hair cell degeneration, this study examined the changes in p53 and Bcl-2 expression at different stages of apoptotic and necrotic death of hair cells in aging rat cochleae. Young (3-4 months) and aging (23-24 months) Fisher 344/NHsd rats were used. The thresholds of the auditory brainstem response (ABR) were measured to determine the auditory function. Immunolabeling was performed to determine the expression of p53 and Bcl-2 proteins in the sensory epithelium. Propidium iodide staining was performed to determine the morphologic changes in hair cell nuclei. Aging rats exhibited a significant elevation in ABR thresholds at all tested frequencies (p aging hair cells showing the early signs of apoptotic changes in their nuclei. The Bcl-2 expression increase was also observed in hair cells displaying early signs of necrosis. As the hair cell degenerative process advanced, p53 and Bcl-2 immunoreactivity became reduced or absent. In the areas where no detectable nuclear staining was present, p53 and Bcl-2 immunoreactivity was absent.

Curcumin protects against acoustic trauma in the rat cochlea.

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Soyalıç, Harun; Gevrek, Fikret; Karaman, Serhat

2017-08-01

In this study we evaluated the therapeutic utility of curcumin in a rodent model of acoustic trauma using histopathology, immunohistochemical, and distortion product otoacoustic emission (DPOAEs) measurements. 28 Wistar albino rats were included in the study and randomly assigned to 4 treatment groups. The first group (group 1) served as the control and was exposed to acoustic trauma alone. Group 2 was the curcumin group. Group 3 was the curcumin plus acoustic trauma group. Group 4 was the saline plus acoustic trauma group. Otoacoustic emission measurements were collected at the end of the experiment and all animals were sacrificed. Cochlea were collected and prepared for TUNEL (TdT-mediated deoxyuridinetriphosphate nick end-labelling) staining assay. Group 3 maintained baseline DPOAEs values at 3000 Hz, 4000 Hz and 8000 Hz on the 3rd and 5th day of the experiment. DPOAEs results were correlated with the immunohistochemical and histopathological findings in all groups. In comparison to the histopathologic control group, Group 1 exhibited a statistically significant increase in apoptotic indices in the organ of Corti, inner hair cell, and outer hair cell areas (p curcumin may protect the cochlear tissues from acoustic trauma in rats. Curcumin injection prior to or after an acoustic trauma reduces cochlear hair cell damage and may protect against hearing loss. Copyright © 2017 Elsevier B.V. All rights reserved.

Segmental analysis of cochlea on three-dimensional MR imaging and high-resolution CT. Application to pre-operative assessment of cochlear implant candidates

International Nuclear Information System (INIS)

Akiba, Hidenari; Himi, Tetsuo; Hareyama, Masato

2002-01-01

High-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) have recently become standard pre-operative examinations for cochlear implant candidates. HRCT can demonstrate ossification and narrowing of the cochlea, but subtle calcification or soft tissue obstruction may not be detected by this method alone, and so conventional T2 weighted image (T2WI) on MRI has been recommended to disclose them. In this study, segmental analyses of the cochlea were made on three-dimensional MRI (3DMRI) and HRCT in order to predict cochlear implant difficulties. The study involved 59 consecutive patients with bilateral profound sensorineural hearing loss who underwent MRI and HRCT from November 1992 to February 1998. Etiologies of deafness were meningogenic labyrinthitis (n=9), tympanogenic labyrinthitis (n=12), and others (n=38). Pulse sequence of heavy T2WI was steady state free precession and 3DMRI was reconstructed by maximum intensity projection method. HRCT was reconstructed by bone algorithm focusing on the temporal bone. For alternative segmental analysis, cochleas were anatomically divided into five parts and each of them was classified by three ranks of score depending on 3DMRI or HRCT findings. There was a close correlation by ranks between the total score of the five parts on 3DMRI and HRCT (rs=0.86, P<0.001), and a statistically significant difference was identified between causes of deafness in the total score on 3DMRI or HRCT (P<0.001, respectively). There was a significant difference in the score among the five parts on each examination (P<0.001, respectively), and abnormal findings were more frequent in the inferior horizontal part (IHP) of the basal turn. Of the 35 patients who underwent cochlear implantation, no one had ossification in the IHP on HRCT and only one patient had an obstacle to implantation. When no signal void in the IHP on 3DMRI and no ossification in the IHP on HRCT were assumed to be the criteria for candidacy for cochlear

Energy flow in passive and active 3D cochlear model

International Nuclear Information System (INIS)

Wang, Yanli; Steele, Charles; Puria, Sunil

2015-01-01

Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations

Energy flow in passive and active 3D cochlear model

Energy Technology Data Exchange (ETDEWEB)

Wang, Yanli; Steele, Charles [Department of Mechanical Engineering, Stanford University, Stanford, California (United States); Puria, Sunil [Department of Mechanical Engineering, Stanford University, Stanford, California (United States); Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California (United States)

2015-12-31

Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.

Sox10 expressing cells in the lateral wall of the aged mouse and human cochlea.

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Xinping Hao

Full Text Available Age-related hearing loss (presbycusis is a common human disorder, affecting one in three Americans aged 60 and over. Previous studies have shown that presbyacusis is associated with a loss of non-sensory cells in the cochlear lateral wall. Sox10 is a transcription factor crucial to the development and maintenance of neural crest-derived cells including some non-sensory cell types in the cochlea. Mutations of the Sox10 gene are known to cause various combinations of hearing loss and pigmentation defects in humans. This study investigated the potential relationship between Sox10 gene expression and pathological changes in the cochlear lateral wall of aged CBA/CaJ mice and human temporal bones from older donors. Cochlear tissues prepared from young adult (1-3 month-old and aged (2-2.5 year-old mice, and human temporal bone donors were examined using quantitative immunohistochemical analysis and transmission electron microscopy. Cells expressing Sox10 were present in the stria vascularis, outer sulcus and spiral prominence in mouse and human cochleas. The Sox10(+ cell types included marginal and intermediate cells and outer sulcus cells, including those that border the scala media and those extending into root processes (root cells in the spiral ligament. Quantitative analysis of immunostaining revealed a significant decrease in the number of Sox10(+ marginal cells and outer sulcus cells in aged mice. Electron microscopic evaluation revealed degenerative alterations in the surviving Sox10(+ cells in aged mice. Strial marginal cells in human cochleas from donors aged 87 and older showed only weak immunostaining for Sox10. Decreases in Sox10 expression levels and a loss of Sox10(+ cells in both mouse and human aged ears suggests an important role of Sox10 in the maintenance of structural and functional integrity of the lateral wall. A loss of Sox10(+ cells may also be associated with a decline in the repair capabilities of non-sensory cells in the

Artificial Dermis Graft on the Mandible Lacking Periosteum After Excision of an Ossifying Fibroma: A Case Report

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Chun-Ming Chen

2007-07-01

Full Text Available Collagen-based grafts have often been used as artificial tissue substitutes for the repair of tissue and organ defects. It is common surgical knowledge that autogenous or artificial skin grafts take well on the intact periosteum of bone. However, many experienced surgeons indicate that auto-genous or artificial skin grafts subsist poorly on the bone surface without periosteum. Therefore, primary closure is usually recommended in the wound healing of exposed bone. Vestibuloplasty might be needed to create enough depth of vestibule in the future. In this case report, we describe a peripheral ossifying fibroma surgically excised leaving a bony defect, which was covered by a piece of artificial dermis. Satisfactory result of the repaired surgical defect showed no need of vestibuloplasty after 6 years of follow-up.

Structural Dynamic Response Compressing Technique in Bridges using a Cochlea-inspired Artificial Filter Bank (CAFB)

International Nuclear Information System (INIS)

Heo, G; Jeon, J; Son, B; Kim, C; Jeon, S; Lee, C

2016-01-01

In this study, a cochlea-inspired artificial filter bank (CAFB) was developed to efficiently obtain dynamic response of a structure, and a dynamic response measurement of a cable-stayed bridge model was also carried out to evaluate the performance of the developed CAFB. The developed CAFB used a band-pass filter optimizing algorithm (BOA) and peakpicking algorithm (PPA) to select and compress dynamic response signal containing the modal information which was significant enough. The CAFB was then optimized about the El-Centro earthquake wave which was often used in the construction research, and the software implementation of CAFB was finally embedded in the unified structural management system (USMS). For the evaluation of the developed CAFB, a real time dynamic response experiment was performed on a cable-stayed bridge model, and the response of the cable-stayed bridge model was measured using both the traditional wired system and the developed CAFB-based USMS. The experiment results showed that the compressed dynamic response acquired by the CAFB-based USMS matched significantly with that of the traditional wired system while still carrying sufficient modal information of the cable-stayed bridge. (paper)

The Wnt/β-catenin pathway is deregulated in cemento-ossifying fibromas.

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Pereira, Thaís Dos Santos Fontes; Diniz, Marina Gonçalves; França, Josiane Alves; Moreira, Rennan Garcias; Menezes, Grazielle Helena Ferreira de; Sousa, Sílvia Ferreira de; Castro, Wagner Henriques de; Gomes, Carolina Cavaliéri; Gomez, Ricardo Santiago

2018-02-01

The molecular pathogenesis of cemento ossifying fibroma (COF) is unclear. The purpose of this study was to investigate mutations in 50 oncogenes and tumor suppressor genes, including APC and CTNNB1, in which mutations in COF have been previously reported. In addition, we assessed the transcriptional levels of the Wnt/β-catenin pathway genes in COF. We used a quantitative polymerase chain reaction array to evaluate the transcriptional levels of 44 Wnt/β-catenin pathway genes in 6 COF samples, in comparison with 6 samples of healthy jaws. By using next-generation sequencing (NGS) in 7 COF samples, we investigated approximately 2800 mutations in 50 genes. The expression assay revealed 12 differentially expressed Wnt/β-catenin pathway genes in COF, including the upregulation of CTNNB1, TCF7, NKD1, and WNT5 A, and downregulation of CTNNBIP1, FRZB, FZD6, RHOU, SFRP4, WNT10 A, WNT3 A, and WNT4, suggesting activation of the Wnt/β-catenin signaling pathway. NGS revealed 5 single nucleotide variants: TP53 (rs1042522), PIK3 CA (rs2230461), MET (rs33917957), KIT (rs3822214), and APC (rs33974176), but none of them was pathogenic. Although NGS detected no oncogenic mutation, deregulation of key Wnt/β-catenin signaling pathway genes appears to be relevant to the molecular pathogenesis of COF. Copyright © 2017 Elsevier Inc. All rights reserved.

Hedgehog Signaling Promotes the Proliferation and Subsequent Hair Cell Formation of Progenitor Cells in the Neonatal Mouse Cochlea

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Chen, Yan; Lu, Xiaoling; Guo, Luo; Ni, Wenli; Zhang, Yanping; Zhao, Liping; Wu, Lingjie; Sun, Shan; Zhang, Shasha; Tang, Mingliang; Li, Wenyan; Chai, Renjie; Li, Huawei

2017-01-01

Hair cell (HC) loss is the major cause of permanent sensorineural hearing loss in mammals. Unlike lower vertebrates, mammalian cochlear HCs cannot regenerate spontaneously after damage, although the vestibular system does maintain limited HC regeneration capacity. Thus HC regeneration from the damaged sensory epithelium has been one of the main areas of research in the field of hearing restoration. Hedgehog signaling plays important roles during the embryonic development of the inner ear, and it is involved in progenitor cell proliferation and differentiation as well as the cell fate decision. In this study, we show that recombinant Sonic Hedgehog (Shh) protein effectively promotes sphere formation, proliferation, and differentiation of Lgr5+ progenitor cells isolated from the neonatal mouse cochlea. To further explore this, we determined the effect of Hedgehog signaling on cell proliferation and HC regeneration in cultured cochlear explant from transgenic R26-SmoM2 mice that constitutively activate Hedgehog signaling in the supporting cells of the cochlea. Without neomycin treatment, up-regulation of Hedgehog signaling did not significantly promote cell proliferation or new HC formation. However, after injury to the sensory epithelium by neomycin treatment, the over-activation of Hedgehog signaling led to significant supporting cell proliferation and HC regeneration in the cochlear epithelium explants. RNA sequencing and real-time PCR were used to compare the transcripts of the cochleae from control mice and R26-SmoM2 mice, and multiple genes involved in the proliferation and differentiation processes were identified. This study has important implications for the treatment of sensorineural hearing loss by manipulating the Hedgehog signaling pathway. PMID:29311816

Hedgehog Signaling Promotes the Proliferation and Subsequent Hair Cell Formation of Progenitor Cells in the Neonatal Mouse Cochlea

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Yan Chen

2017-12-01

Full Text Available Hair cell (HC loss is the major cause of permanent sensorineural hearing loss in mammals. Unlike lower vertebrates, mammalian cochlear HCs cannot regenerate spontaneously after damage, although the vestibular system does maintain limited HC regeneration capacity. Thus HC regeneration from the damaged sensory epithelium has been one of the main areas of research in the field of hearing restoration. Hedgehog signaling plays important roles during the embryonic development of the inner ear, and it is involved in progenitor cell proliferation and differentiation as well as the cell fate decision. In this study, we show that recombinant Sonic Hedgehog (Shh protein effectively promotes sphere formation, proliferation, and differentiation of Lgr5+ progenitor cells isolated from the neonatal mouse cochlea. To further explore this, we determined the effect of Hedgehog signaling on cell proliferation and HC regeneration in cultured cochlear explant from transgenic R26-SmoM2 mice that constitutively activate Hedgehog signaling in the supporting cells of the cochlea. Without neomycin treatment, up-regulation of Hedgehog signaling did not significantly promote cell proliferation or new HC formation. However, after injury to the sensory epithelium by neomycin treatment, the over-activation of Hedgehog signaling led to significant supporting cell proliferation and HC regeneration in the cochlear epithelium explants. RNA sequencing and real-time PCR were used to compare the transcripts of the cochleae from control mice and R26-SmoM2 mice, and multiple genes involved in the proliferation and differentiation processes were identified. This study has important implications for the treatment of sensorineural hearing loss by manipulating the Hedgehog signaling pathway.

Absolute measurement of subnanometer scale vibration of cochlear partition of an excised guinea pig cochlea using spectral-domain phase-sensitive optical coherence tomography

Science.gov (United States)

Subhash, Hrebesh M.; Choudhury, Niloy; Jacques, Steven L.; Wang, Ruikang K.; Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L.

2012-01-01

Direct measurement of absolute vibration parameters from different locations within the mammalian organ of Corti is crucial for understanding the hearing mechanics such as how sound propagates through the cochlea and how sound stimulates the vibration of various structures of the cochlea, namely, basilar membrane (BM), recticular lamina, outer hair cells and tectorial membrane (TM). In this study we demonstrate the feasibility a modified phase-sensitive spectral domain optical coherence tomography system to provide subnanometer scale vibration information from multiple angles within the imaging beam. The system has the potential to provide depth resolved absolute vibration measurement of tissue microstructures from each of the delay-encoded vibration images with a noise floor of ~0.3nm at 200Hz.

Ossifying fibroma of the maxilla: An uncommon tumor presenting diagnostic and management dilemma for the clinician: A rare case report

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Shahanavaj I Khaji

2014-01-01

In the present case, we hereby report a 35-year-old male patient who presented with painless swelling over middle one third of face - left side since 8 months. Patient had no significant medical history in the previous past (history of trauma 6 years earlier. Panoramic radiography revealed rounded mixed type of image over left side of posterior maxilla in relation to 23, 24, 25, 26 region, respectively. An incisional biopsy was carried out which yielded a definitive diagnosis of ossifying fibroma of the maxilla. Management of the lesion was carried out by taking into account the benign nature, growth pattern, and behavior of the lesion clinically and radio graphically with regular and periodic follow-up postoperatively.

Volumetric label-free imaging and 3D reconstruction of mammalian cochlea based on two-photon excitation fluorescence microscopy

International Nuclear Information System (INIS)

Zhang, Xianzeng; Zhan, Zhenlin; Xie, Shusen; Geng, Yang; Ye, Qing

2013-01-01

The visualization of the delicate structure and spatial relationship of intracochlear sensory cells has relied on the laborious procedures of tissue excision, fixation, sectioning and staining for light and electron microscopy. Confocal microscopy is advantageous for its high resolution and deep penetration depth, yet disadvantageous due to the necessity of exogenous labeling. In this study, we present the volumetric imaging of rat cochlea without exogenous dyes using a near-infrared femtosecond laser as the excitation mechanism and endogenous two-photon excitation fluorescence (TPEF) as the contrast mechanism. We find that TPEF exhibits strong contrast, allowing cellular and even subcellular resolution imaging of the cochlea, differentiating cell types, visualizing delicate structures and the radial nerve fiber. Our results further demonstrate that 3D reconstruction rendered with z-stacks of optical sections enables better revealment of fine structures and spatial relationships, and easily performed morphometric analysis. The TPEF-based optical biopsy technique provides great potential for new and sensitive diagnostic tools for hearing loss or hearing disorders, especially when combined with fiber-based microendoscopy. (paper)

Reciprocal synapses between outer hair cells and their afferent terminals: evidence for a local neural network in the mammalian cochlea.

Science.gov (United States)

Thiers, Fabio A; Nadol, Joseph B; Liberman, M Charles

2008-12-01

Cochlear outer hair cells (OHCs) serve both as sensory receptors and biological motors. Their sensory function is poorly understood because their afferent innervation, the type-II spiral ganglion cell, has small unmyelinated axons and constitutes only 5% of the cochlear nerve. Reciprocal synapses between OHCs and their type-II terminals, consisting of paired afferent and efferent specialization, have been described in the primate cochlea. Here, we use serial and semi-serial-section transmission electron microscopy to quantify the nature and number of synaptic interactions in the OHC area of adult cats. Reciprocal synapses were found in all OHC rows and all cochlear frequency regions. They were more common among third-row OHCs and in the apical half of the cochlea, where 86% of synapses were reciprocal. The relative frequency of reciprocal synapses was unchanged following surgical transection of the olivocochlear bundle in one cat, confirming that reciprocal synapses were not formed by efferent fibers. In the normal ear, axo-dendritic synapses between olivocochlear terminals and type-II terminals and/or dendrites were as common as synapses between olivocochlear terminals and OHCs, especially in the first row, where, on average, almost 30 such synapses were seen in the region under a single OHC. The results suggest that a complex local neuronal circuitry in the OHC area, formed by the dendrites of type-II neurons and modulated by the olivocochlear system, may be a fundamental property of the mammalian cochlea, rather than a curiosity of the primate ear. This network may mediate local feedback control of, and bidirectional communication among, OHCs throughout the cochlear spiral.

Case presentation of florid cemento-osseous dysplasia with concomitant cemento-ossifying fibroma discovered during implant explantation.

Science.gov (United States)

Gerlach, Robert C; Dixon, Douglas R; Goksel, Tamer; Castle, James T; Henry, Walter A

2013-03-01

A 39-year-old African American woman presented for treatment of a symptomatic mandibular right first molar with a large, periapical radiolucency. After initial attempts at endodontic therapy, this tooth was ultimately extracted owing to unabated symptoms. The extraction site underwent ridge preservation grafting, implant placement, and restoration. After 26 months of implant function, the patient returned with clinical symptoms of pain, buccal swelling, and the sensation of a "loose" implant. This case report details a diagnosis of 2 distinct disease entities associated with the implant site, a cemento-ossifying fibroma and florid cemento-osseous dysplasia of the mandible. This diagnosis was determined from clinical, surgical, radiographic, and histopathologic evidence after biopsy and removal of the previously osseointegrated implant following postinsertion failure by fibrous encapsulation. Before implant therapy, it is essential to conduct a thorough radiographic evaluation of any dental arch with suspected bony lesions to prevent implant failure. Published by Mosby, Inc.

The structure and material composition of ossified aortic valves identified using a set of scientific methods

Science.gov (United States)

Zeman, Antonín; Šmíd, Michal; Havelcová, Martina; Coufalová, Lucie; Kučková, Štěpánka; Velčovská, Martina; Hynek, Radovan

2013-11-01

Degenerative aortic stenosis has become a common and dangerous disease in recent decades. This disease leads to the mineralization of aortic valves, their gradual thickening and loss of functionality. We studied the detailed assessment of the proportion and composition of inorganic and organic components in the ossified aortic valve, using a set of analytical methods applied in science: polarized light microscopy, scanning electron microscopy, X-ray fluorescence, X-ray diffraction, gas chromatography/mass spectrometry and liquid chromatography-tandem mass spectrometry. The sample valves showed the occurrence of phosphorus and calcium in the form of phosphate and calcium carbonate, hydroxyapatite, fluorapatite and hydroxy-fluorapatite, with varying content of inorganic components from 65 to 90 wt%, and with phased development of degenerative disability. The outer layers of the plaque contained an organic component with peptide bonds, fatty acids, proteins and cholesterol. The results show a correlation between the formation of fluorapatite in aortic valves and in other parts of the human bodies, associated with the formation of bones.

Inner ear injury caused by air intrusion to the scala vestibuli of the cochlea.

Science.gov (United States)

Kobayashi, T; Sakurada, T; Ohyama, K; Takasaka, M

1993-11-01

In a previous communication, we demonstrated that the introduction of air into the scala tympani of the cochlea causes a decrease of cochlear potentials; however, the change in endocochlear dc potential (EP) was mild and the decreased cochlear microphonics (CM) and compound action potentials (CAP) were, at least partially, reversible. In contrast, we have now found that air perfusion (3-60 microliters/min) in the scala vestibuli decreased cochlear potentials more drastically than that in the scala tympani. The change in the EP after air perfusion in the scala vestibuli was characterized by a decrease of the negative EP in response to anoxia. The CM drastically decreased upon the initiation of air perfusion and no recovery was observed after refilling of the perilymph. Histological examination showed collapse of Reissner's membrane in 12 out of 17 cochleas examined. The extent and frequency of the collapse increased with an increase in the amount of air perfused in the scala vestibuli. As the minimal amount of air needed to cause inner ear damage by air perfusion in the scala vestibuli is as small as 3 microliters, it is possible that the prognosis is worse in cases with fistula of the oval window compared to that of the round window area, if the pneumolabyrinth is involved in the pathophysiology of perilymphatic fistula. It is also indicated that air inflation of the middle ear is dangerous in cases with fistula in the oval window.

A Bio-Realistic Analog CMOS Cochlea Filter With High Tunability and Ultra-Steep Roll-Off.

Science.gov (United States)

Wang, Shiwei; Koickal, Thomas Jacob; Hamilton, Alister; Cheung, Rebecca; Smith, Leslie S

2015-06-01

This paper presents the design and experimental results of a cochlea filter in analog very large scale integration (VLSI) which highly resembles physiologically measured response of the mammalian cochlea. The filter consists of three specialized sub-filter stages which respectively provide passive response in low frequencies, actively tunable response in mid-band frequencies and ultra-steep roll-off at transition frequencies from pass-band to stop-band. The sub-filters are implemented in balanced ladder topology using floating active inductors. Measured results from the fabricated chip show that wide range of mid-band tuning including gain tuning of over 20 dB, Q factor tuning from 2 to 19 as well as the bio-realistic center frequency shift are achieved by adjusting only one circuit parameter. Besides, the filter has an ultra-steep roll-off reaching over 300 dB/dec. By changing biasing currents, the filter can be configured to operate with center frequencies from 31 Hz to 8 kHz. The filter is 9th order, consumes 59.5 ∼ 90.0 μW power and occupies 0.9 mm2 chip area. A parallel bank of the proposed filter can be used as the front-end in hearing prosthesis devices, speech processors as well as other bio-inspired auditory systems owing to its bio-realistic behavior, low power consumption and small size.

Wnt activation followed by Notch inhibition promotes mitotic hair cell regeneration in the postnatal mouse cochlea

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Li, Wenyan; Chen, Yan; Zhang, Shasha; Tang, Mingliang; Sun, Shan; Chai, Renjie; Li, Huawei

2016-01-01

Hair cell (HC) loss is the main cause of permanent hearing loss in mammals. Previous studies have reported that in neonatal mice cochleae, Wnt activation promotes supporting cell (SC) proliferation and Notch inhibition promotes the trans-differentiation of SCs into HCs. However, Wnt activation alone fails to regenerate significant amounts of new HCs, Notch inhibition alone regenerates the HCs at the cost of exhausting the SC population, which leads to the death of the newly regenerated HCs. Mitotic HC regeneration might preserve the SC number while regenerating the HCs, which could be a better approach for long-term HC regeneration. We present a two-step gene manipulation, Wnt activation followed by Notch inhibition, to accomplish mitotic regeneration of HCs while partially preserving the SC number. We show that Wnt activation followed by Notch inhibition strongly promotes the mitotic regeneration of new HCs in both normal and neomycin-damaged cochleae while partially preserving the SC number. Lineage tracing shows that the majority of the mitotically regenerated HCs are derived specifically from the Lgr5+ progenitors with or without HC damage. Our findings suggest that the co-regulation of Wnt and Notch signaling might provide a better approach to mitotically regenerate HCs from Lgr5+ progenitor cells. PMID:27564256

Effect of low-level laser treatment on cochlea hair-cell recovery after ototoxic hearing loss

Science.gov (United States)

Rhee, Chung-Ku; He, Peijie; Jung, Jae Yun; Ahn, Jin-Chul; Chung, Phil-Sang; Lee, Min Young; Suh, Myung-Whan

2013-12-01

The primary cause of hearing loss includes damage to cochlear hair cells. Low-level laser therapy (LLLT) has become a popular treatment for damaged nervous systems. Based on the idea that cochlea hair cells and neural cells are from same developmental origin, the effect of LLLT on hearing loss in animal models is evaluated. Hearing loss animal models were established, and the animals were irradiated by 830-nm diode laser once a day for 10 days. Power density of the laser treatment was 900 mW/cm2, and the fluence was 162 to 194 J. The tympanic membrane was evaluated after LLLT. Thresholds of auditory brainstem responses were evaluated before treatment, after gentamicin, and after 10 days of LLLT. Quantitative scanning electron microscopic (SEM) observations were done by counting remaining hair cells. Tympanic membranes were intact at the end of the experiment. No adverse tissue reaction was found. On SEM images, LLLT significantly increased the number of hair cells in middle and basal turns. Hearing was significantly improved by laser irradiation. After LLLT treatment, both the hearing threshold and hair-cell count significantly improved.

Direct administration of 2-Hydroxypropyl-Beta-Cyclodextrin into guinea pig cochleae: Effects on physiological and histological measurements.

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J T Lichtenhan

Full Text Available 2-Hydroxypropyl-Beta-Cyclodextrin (HPβCD can be used to treat Niemann-Pick type C disease, Alzheimer's disease, and atherosclerosis. But, a consequence is that HPβCD can cause hearing loss. HPβCD was recently found to be toxic to outer hair cells (OHCs in the organ of Corti. Previous studies on the chronic effects of in vivo HPβCD toxicity did not know the intra-cochlear concentration of HPβCD and attributed variable effects on OHCs to indirect drug delivery to the cochlea. We studied the acute effects of known HPβCD concentrations administered directly into intact guinea pig cochleae. Our novel approach injected solutions through pipette sealed into scala tympani in the cochlear apex. Solutions were driven along the length of the cochlear spiral toward the cochlear aqueduct in the base. This method ensured that therapeutic levels were achieved throughout the cochlea, including those regions tuned to mid to low frequencies and code speech vowels and background noise. A wide variety of measurements were made. Results were compared to measurements from ears treated with the HPβCD analog methyl-β-cyclodextrin (MβCD, salicylate that is well known to attenuate the gain of the cochlear amplifier, and injection of artificial perilymph alone (controls. Histological data showed that OHCs appeared normal after treatment with a low dose of HPβCD, and physiological data was consistent with attenuation of cochlear amplifier gain and disruption of non-linearity associated with transferring acoustic sound into neural excitation, an origin of distortion products that are commonly used to objectively assess hearing and hearing loss. A high dose of HPβCD caused sporadic OHC losses and markedly affected all physiologic measurements. MβCD caused virulent destruction of OHCs and physiologic responses. Toxicity of HPβCD to OHC along the cochlear length is variable even when a known intra-cochlear concentration is administered, at least for the duration

Increased signal intensity of the cochlea on pre- and post-contrast enhanced 3D-FLAIR in patients with vestibular schwannoma

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Yamazaki, Masahiro; Naganawa, Shinji; Kawai, Hisashi; Nihashi, Takashi [Nagoya University, Department of Radiology, Graduate School of Medicine, Nagoya (Japan); Fukatsu, Hiroshi [Aichi Medical University Hospital, Department of Medical Informatics, Nagakute (Japan); Nakashima, Tsutomu [Nagoya University, Department of Otorhinolaryngology, Graduate School of Medicine, Nagoya (Japan)

2009-12-15

In the vestibular schwannoma patients, the pathophysiologic mechanism of inner ear involvement is still unclear. We investigated the status of the cochleae in patients with vestibular schwannoma by evaluating the signal intensity of cochlear fluid on pre- and post-contrast enhanced thin section three-dimensional fluid-attenuated inversion recovery (3D-FLAIR). Twenty-eight patients were retrospectively analyzed. Post-contrast images were obtained in 18 patients, and 20 patients had the records of their pure-tone audiometry. Regions of interest of both cochleae (C) and of the medulla oblongata (M) were determined on 3D-FLAIR images by referring to 3D heavily T2-weighted images on a workstation. The signal intensity ratio between C and M on the 3D-FLAIR images (CM ratio) was then evaluated. In addition, correlation between the CM ratio and the hearing level was also evaluated. The CM ratio of the affected side was significantly higher than that of the unaffected side (p < 0.001). In the affected side, post-contrast signal elevation was observed (p < 0.005). In 13 patients (26 cochleae) who underwent both gadolinium injection and the pure-tone audiometry, the post-contrast CM ratio correlated with hearing level (p < 0.05). The results of the present study suggest that alteration of cochlear fluid composition and increased permeability of the blood-labyrinthine barrier exist in the affected side in patients with vestibular schwannoma. Furthermore, although weak, positive correlation between post-contrast cochlear signal intensity on 3D-FLAIR and hearing level warrants further study to clarify the relationship between 3D-FLAIR findings and prognosis of hearing preservation surgery. (orig.)

Increased signal intensity of the cochlea on pre- and post-contrast enhanced 3D-FLAIR in patients with vestibular schwannoma

International Nuclear Information System (INIS)

Yamazaki, Masahiro; Naganawa, Shinji; Kawai, Hisashi; Nihashi, Takashi; Fukatsu, Hiroshi; Nakashima, Tsutomu

2009-01-01

In the vestibular schwannoma patients, the pathophysiologic mechanism of inner ear involvement is still unclear. We investigated the status of the cochleae in patients with vestibular schwannoma by evaluating the signal intensity of cochlear fluid on pre- and post-contrast enhanced thin section three-dimensional fluid-attenuated inversion recovery (3D-FLAIR). Twenty-eight patients were retrospectively analyzed. Post-contrast images were obtained in 18 patients, and 20 patients had the records of their pure-tone audiometry. Regions of interest of both cochleae (C) and of the medulla oblongata (M) were determined on 3D-FLAIR images by referring to 3D heavily T2-weighted images on a workstation. The signal intensity ratio between C and M on the 3D-FLAIR images (CM ratio) was then evaluated. In addition, correlation between the CM ratio and the hearing level was also evaluated. The CM ratio of the affected side was significantly higher than that of the unaffected side (p < 0.001). In the affected side, post-contrast signal elevation was observed (p < 0.005). In 13 patients (26 cochleae) who underwent both gadolinium injection and the pure-tone audiometry, the post-contrast CM ratio correlated with hearing level (p < 0.05). The results of the present study suggest that alteration of cochlear fluid composition and increased permeability of the blood-labyrinthine barrier exist in the affected side in patients with vestibular schwannoma. Furthermore, although weak, positive correlation between post-contrast cochlear signal intensity on 3D-FLAIR and hearing level warrants further study to clarify the relationship between 3D-FLAIR findings and prognosis of hearing preservation surgery. (orig.)

Modeling microstructure of incudostapedial joint and the effect on cochlear input

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Gan, Rong Z.; Wang, Xuelin

2015-12-01

The incudostapedial joint (ISJ) connects the incus to stapes in human ear and plays an important role for sound transmission from the tympanic membrane (TM) to cochlea. ISJ is a synovial joint composed of articular cartilage on the lenticular process and stapes head with the synovial fluid between them. However, there is no study on how the synovial ISJ affects the middle ear and cochlear functions. Recently, we have developed a 3-dimensinal finite element (FE) model of synovial ISJ and connected the model to our comprehensive FE model of the human ear. The motions of TM, stapes footplate, and basilar membrane and the pressures in scala vestibule and scala tympani were derived over frequencies and compared with experimental measurements. Results show that the synovial ISJ affects sound transmission into cochlea and the frequency-dependent viscoelastic behavior of ISJ provides protection for cochlea from high intensity sound.

Modeling and segmentation of intra-cochlear anatomy in conventional CT

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Noble, Jack H.; Rutherford, Robert B.; Labadie, Robert F.; Majdani, Omid; Dawant, Benoit M.

2010-03-01

Cochlear implant surgery is a procedure performed to treat profound hearing loss. Since the cochlea is not visible in surgery, the physician uses anatomical landmarks to estimate the pose of the cochlea. Research has indicated that implanting the electrode in a particular cavity of the cochlea, the scala tympani, results in better hearing restoration. The success of the scala tympani implantation is largely dependent on the point of entry and angle of electrode insertion. Errors can occur due to the imprecise nature of landmark-based, manual navigation as well as inter-patient variations between scala tympani and the anatomical landmarks. In this work, we use point distribution models of the intra-cochlear anatomy to study the inter-patient variations between the cochlea and the typical anatomic landmarks, and we implement an active shape model technique to automatically localize intra-cochlear anatomy in conventional CT images, where intra-cochlear structures are not visible. This fully automatic segmentation could aid the surgeon to choose the point of entry and angle of approach to maximize the likelihood of scala tympani insertion, resulting in more substantial hearing restoration.

Peripheral osteoma, compound odontoma, focal cemento-osseous dysplasia, and cemento-ossifying fibroma in the same hemimandible: CBCT findings of an unusual case.

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Borghesi, Andrea; Tonni, Ingrid; Pezzotti, Stefania; Maroldi, Roberto

2017-12-01

Peripheral osteoma is the most common subtype of osteoma that arises most frequently in the craniofacial bones. It may occur at any age with a male-to-female ratio of 2:1. Peripheral osteoma may affect the mandible, particularly the ramus and the condyle. Compound odontoma is a subtype of odontoma that occurs in young subjects without gender predilection. It affects the maxilla more frequently than the mandible. Focal cemento-osseous dysplasia and cemento-ossifying fibroma are 2 benign fibro-osseous lesions with a female predominance that occur most commonly in the posterior region of the mandible. We report the first case involving the simultaneous occurrence of these 4 benign lesions in the same hemimandible diagnosed by CBCT.

Measurement of electric intensity distribution inside a human cadaver cochlea for multichannel cochlear implants; Multichannel jinko naiji no tame no hito no tekishutsu kagyunai ni okeru denkai kyodo bunpu no sokutei

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Miyoshi, S.; Ifukube, T.; Matsushima, J. [Hokkaido University, Sapporo (Japan)

1998-03-01

We have proposed a Tripolar Electrode Stimulation Method (TESM) which may succeed in narrowing the stimulation region and continuously moving the stimulation site for cochlear implants. The TESM stimulates the auditory nerve array through lymph liquid using the 3 adjacent electrodes which are selected among the electrodes of an electrode array. The currents from the two electrodes on both sides are emitted and a central electrode receives them. The current received by the central electrode is made equal to the sum of the currents emitted from the electrodes on both sides. In this paper, the electric intensity profiles produced by the TESM and the monopolar stimulation were measured in a human cadaver cochlea and in a saline solution. As a result, in the TESM, the electric intensity profile produced in the human cadaver cochlea was about the same as that in the saline solution In monopolar stimulation, the electric intensity profile was broader than that of TESM in a human cadaver cochlea. 9 refs., 14 figs.

Grafting and early expression of growth factors from adipose-derived stem cells transplanted into the cochlea, in a guinea pig model of acoustic trauma

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Anna Rita Fetoni

2014-10-01

Full Text Available Noise exposure causes damage of multiple cochlear cell types producing permanent hearing loss with important social consequences. In mammals, no regeneration of either damaged hair cells or auditory neurons has been observed and no successful treatment is available to achieve a functional recovery. Several evidences indicate adipose-derived stem cells (ASCs as promising tools in diversified regenerative medicine applications, due to the high degree of plasticity and trophic features.This study was aimed at identifying the path of in vivo cell migration and expression of trophic growth factors, upon ASC transplantation into the cochlea, following noise-induced injury. ASCs were isolated in primary culture from the adipose tissue of a guinea pig, transduced using a viral vector to express the green fluorescent protein, and implanted into the scala tympani of deafened animals. Auditory function was assessed 3 and 7 days after surgery. The expression of trophic growth factors was comparatively analyzed using real time PCR in control and noise-injured cochlear tissues. Immunofluorescence was used to assess the in vivo localization and expression of trophic growth factors in ASCs and cochleae, 3 and 7 days following homologous implantation. ASC implantation did not modify auditory function. ASCs migrated from the perilymphatic to the endolymphatic compartment, during the analyzed time course. Upon noise exposure, the expression of chemokine ligands and receptors related to the PDGF, VEGF and TGFbeta pathways, increased in the cochlear tissues, possibly guiding in vivo cell migration. Immunofluorescence confirmed the increased expression, which appeared to be further strengthened by ASC implantation.These results indicate that ASCs are able to migrate at the site of tissue damage and express trophic factors, upon intracochlear implantantion, providing an original proof of principle, which could pave the way for further developments of ASC

Laser-capture micro dissection combined with next-generation sequencing analysis of cell type-specific deafness gene expression in the mouse cochlea.

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Nishio, Shin-Ya; Takumi, Yutaka; Usami, Shin-Ichi

2017-05-01

Cochlear implantation (CI), which directly stimulates the cochlear nerves, is the most effective and widely used medical intervention for patients with severe to profound sensorineural hearing loss. The etiology of the hearing loss is speculated to have a major influence of CI outcomes, particularly in cases resulting from mutations in genes preferentially expressed in the spiral ganglion region. To elucidate precise gene expression levels in each part of the cochlea, we performed laser-capture micro dissection in combination with next-generation sequencing analysis and determined the expression levels of all known deafness-associated genes in the organ of Corti, spiral ganglion, lateral wall, and spiral limbs. The results were generally consistent with previous reports based on immunocytochemistry or in situ hybridization. As a notable result, the genes associated with many kinds of syndromic hearing loss (such as Clpp, Hars2, Hsd17b4, Lars2 for Perrault syndrome, Polr1c and Polr1d for Treacher Collins syndrome, Ndp for Norrie Disease, Kal for Kallmann syndrome, Edn3 and Snai2 for Waardenburg Syndrome, Col4a3 for Alport syndrome, Sema3e for CHARGE syndrome, Col9a1 for Sticker syndrome, Cdh23, Cib2, Clrn1, Pcdh15, Ush1c, Ush2a, Whrn for Usher syndrome and Wfs1 for Wolfram syndrome) showed higher levels of expression in the spiral ganglion than in other parts of the cochlea. This dataset will provide a base for more detailed analysis in order to clarify gene functions in the cochlea as well as predict CI outcomes based on gene expression data. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

The structural and functional differentiation of hair cells in a lizard's basilar papilla suggests an operational principle of amniote cochleas.

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Chiappe, M Eugenia; Kozlov, Andrei S; Hudspeth, A J

2007-10-31

The hair cells in the mammalian cochlea are of two distinct types. Inner hair cells are responsible for transducing mechanical stimuli into electrical responses, which they forward to the brain through a copious afferent innervation. Outer hair cells, which are thought to mediate the active process that sensitizes and tunes the cochlea, possess a negligible afferent innervation. For every inner hair cell, there are approximately three outer hair cells, so only one-quarter of the hair cells directly deliver information to the CNS. Although this is a surprising feature for a sensory system, the occurrence of a similar innervation pattern in birds and crocodilians suggests that the arrangement has an adaptive value. Using a lizard with highly developed hearing, the tokay gecko, we demonstrate in the present study that the same principle operates in a third major group of terrestrial animals. We propose that the differentiation of hair cells into signaling and amplifying classes reflects incompatible strategies for the optimization of mechanoelectrical transduction and of an active process based on active hair-bundle motility.

Role of Neuropilin-1/Semaphorin-3A signaling in the functional and morphological integrity of the cochlea.

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Pezhman Salehi

2017-10-01

Full Text Available Neuropilin-1 (Nrp1 encodes the transmembrane cellular receptor neuropilin-1, which is associated with cardiovascular and neuronal development and was within the peak SNP interval on chromosome 8 in our prior GWAS study on age-related hearing loss (ARHL in mice. In this study, we generated and characterized an inner ear-specific Nrp1 conditional knockout (CKO mouse line because Nrp1 constitutive knockouts are embryonic lethal. In situ hybridization demonstrated weak Nrp1 mRNA expression late in embryonic cochlear development, but increased expression in early postnatal stages when cochlear hair cell innervation patterns have been shown to mature. At postnatal day 5, Nrp1 CKO mice showed disorganized outer spiral bundles and enlarged microvessels of the stria vascularis (SV but normal spiral ganglion cell (SGN density and presynaptic ribbon body counts; however, we observed enlarged SV microvessels, reduced SGN density, and a reduction of presynaptic ribbons in the outer hair cell region of 4-month-old Nrp1 CKO mice. In addition, we demonstrated elevated hearing thresholds of the 2-month-old and 4-month-old Nrp1 CKO mice at frequencies ranging from 4 to 32kHz when compared to 2-month-old mice. These data suggest that conditional loss of Nrp1 in the inner ear leads to progressive hearing loss in mice. We also demonstrated that mice with a truncated variant of Nrp1 show cochlear axon guidance defects and that exogenous semaphorin-3A, a known neuropilin-1 receptor agonist, repels SGN axons in vitro. These data suggest that Neuropilin-1/Semaphorin-3A signaling may also serve a role in neuronal pathfinding in the developing cochlea. In summary, our results here support a model whereby Neuropilin-1/Semaphorin-3A signaling is critical for the functional and morphological integrity of the cochlea and that Nrp1 may play a role in ARHL.

Thyroid hormone is required for the pruning of afferent type II spiral ganglion neurons in the mouse cochlea

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Sundaresan, Srividya; Balasubbu, Suganthalakshmi; Mustapha, Mirna

2015-01-01

Afferent connections to the sensory inner and outer hair cells in the cochlea refine and functionally mature during the thyroid hormone (TH)- critical period of inner ear development that occurs perinatally in rodents. In this study, we investigated the effects of hypothyroidism on afferent type II innervation to outer hair cells (OHCs) using the Snell dwarf mouse (Pit1dw). Using a transgenic approach to specifically label type II spiral ganglion neurons, we found that a lack of TH causes persistence of excess type II SGN connections to the OHCs, as well as continued expression of the hair cell functional marker, otoferlin, in the OHCs beyond the maturation period. We also observed a concurrent delay in efferent attachment to the OHCs. Supplementing with TH during the early postnatal period from postnatal day (P) 3 to P4 reversed the defect in type II SGN pruning but did not alter otoferlin expression. Our results show that hypothyroidism causes a defect in the large-scale pruning of afferent type II spiral ganglion neurons in the cochlea, and a delay in efferent attachment and the maturation of otoferlin expression. Our data suggest that the state of maturation of hair cells, as determined by otoferlin expression, may not regulate the pruning of their afferent innervation. PMID:26592716

Expression pattern of wolframin, the WFS1 (Wolfram syndrome-1 gene) product, in common marmoset (Callithrix jacchus) cochlea.

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Suzuki, Noriomi; Hosoya, Makoto; Oishi, Naoki; Okano, Hideyuki; Fujioka, Masato; Ogawa, Kaoru

2016-08-03

Wolfram syndrome is an autosomal recessive disorder of the neuroendocrine system, known as DIDMOAD (Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy and Deafness) syndrome, and considered an endoplasmic reticulum disease. Patients show mutations in WFS1, which encodes the 890 amino acid protein wolframin. Although Wfs1 knockout mice develop diabetes, their hearing level is completely normal. In this study, we examined the expression of wolframin in the cochlea of a nonhuman primate common marmoset (Callithrix jacchus) to elucidate the discrepancy in the phenotype between species and the pathophysiology of Wolfram syndrome-associated deafness. The marmoset cochlea showed wolframin immunoreactivity not only in the spiral ligament type I fibrocytes, spiral ganglion neurons, outer hair cells, and supporting cells, but in the stria vascularis basal cells, where wolframin expression was not observed in the previous mouse study. Considering the absence of the deafness phenotype in Wfs1 knockout mice, the expression of wolframin in the basal cells of primates may play an essential role in the maintenance of hearing. Elucidating the function of wolframin protein in the basal cells of primates would be essential for understanding the pathogenesis of hearing loss in patients with Wolfram syndrome, which may lead to the discovery of new therapeutics.

Peripheral osteoma, compound odontoma, focal cemento-osseous dysplasia, and cemento-ossifying fibroma in the same hemimandible: CBCT findings of an unusual case

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Andrea Borghesi, MD

2017-12-01

Full Text Available Peripheral osteoma is the most common subtype of osteoma that arises most frequently in the craniofacial bones. It may occur at any age with a male-to-female ratio of 2:1. Peripheral osteoma may affect the mandible, particularly the ramus and the condyle. Compound odontoma is a subtype of odontoma that occurs in young subjects without gender predilection. It affects the maxilla more frequently than the mandible. Focal cemento-osseous dysplasia and cemento-ossifying fibroma are 2 benign fibro-osseous lesions with a female predominance that occur most commonly in the posterior region of the mandible. We report the first case involving the simultaneous occurrence of these 4 benign lesions in the same hemimandible diagnosed by CBCT.

The structural and functional differentiation of hair cells in a lizard’s basilar papilla suggests an operational principle of amniote cochleas

Science.gov (United States)

Chiappe, M. Eugenia; Kozlov, Andrei S.; Hudspeth, A. J.

2007-01-01

The hair cells in the mammalian cochlea are of two distinct types. Inner hair cells are responsible for transducing mechanical stimuli into electrical responses, which they forward to the brain through a copious afferent innervation. Outer hair cells, which are thought to mediate the active process that sensitizes and tunes the cochlea, possess a negligible afferent innervation. For every inner hair cell there are approximately three outer hair cells, so only a quarter of the hair cells directly deliver information to the central nervous system. Although this is a surprising feature for a sensory system, the occurrence of a similar innervation pattern in birds and crocodilians suggests that the arrangement has an adaptive value. Using a lizard with highly developed hearing, the tokay gecko, we demonstrate in the present study that the same principle operates in a third major group of terrestrial animals. We propose that the differentiation of hair cells into signaling and amplifying classes reflects incompatible strategies for the optimization of mechanoelectrical transduction and of an active process based on active hair-bundle motility. PMID:17978038

SU-F-T-392: Superior Brainstem and Cochlea Sparing with VMAT for Glioblastoma Multiforme

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Briere, TM; McAleer, MF; Levy, LB; Yang, JN; Anderson, MD [Cancer Ctr., Houston, TX (United States)

2016-06-15

Purpose: Volumetric arc therapy (VMAT) can provide similar target coverage and normal tissue sparing as IMRT but with shorter treatment times. At our institution VMAT was adopted for the treatment glioblastoma multiforme (GBM) after a small number of test plans demonstrated its non-inferiority. In this study, we compare actual clinical treatment plans for a larger cohort of patients treated with either VMAT or IMRT. Methods: 90 GBM patients were included in this study, 45 treated with IMRT and 45 with VMAT. All planning target volumes (PTVs) were prescribed a dose of 50 Gy, with a simultaneous integrated boost to 60 Gy. Most IMRT plans used 5 non-coplanar beams, while most VMAT plans used 2 coplanar beams. Statistical analysis was performed using Fisher’s exact test or the Wilcoxon-Mann-Whitney rank sum test. Included in the analysis were patient and treatment characteristics as well as the doses to the target volumes and organs at risk. Results: Treatment times for the VMAT plans were reduced by 5 minutes compared with IMRT. The PTV coverage was similar, with at least 95% covered for all plans, while the median boost PTV dose differed by 0.1 Gy between the IMRT and VMAT cohorts. The doses to the brain, optic chiasm, optic nerves and eyes were not significantly different. The mean dose to the brainstem, however, was 9.4 Gy less with VMAT (p<0.001). The dose to the ipsilateral and contralateral cochleae were respectively 19.7 and 9.5 Gy less (p<0.001). Conclusion: Comparison of clinical treatment plans for separate IMRT and VMAT cohorts demonstrates that VMAT can save substantial treatment time while providing similar target coverage and superior sparing of the brainstem and cochleae. To our knowledge this is the first study to demonstrate this benefit of VMAT in the management of GBM.

Leakage detection on CT myelography for targeted epidural blood patch in spontaneous cerebrospinal fluid leaks: calcified or ossified spinal lesions ventral to the thecal sac.

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Yoshida, Hiroki; Takai, Keisuke; Taniguchi, Makoto

2014-09-01

The purpose of this study was to describe significant CT myelography findings for determination of the leak site and outcome of targeted epidural blood patch (EBP) in patients with spontaneous CSF leaks. During 2005-2013, spontaneous CSF leaks were diagnosed for 12 patients with orthostatic headaches. The patients received targeted EBP on the basis of CT myelography assessments. Computed tomography myelograms revealed ventral extradural collection of contrast medium distributed over multiple spinal levels (average 16 levels). Intraforaminal contrast medium extravasations were observed at multiple spinal levels (average 8.2 levels). For 8 (67%) of 12 patients, spinal lesions were noted around the thecal sac and included calcified discs with osteophytes, an ossified posterior longitudinal ligament, and an ossified yellow ligament; lesions were mostly located ventral to the thecal sac and were in close contact with the dura mater. The levels of these spinal lesions were considered potential leak sites and were targeted for EBP. For the remaining 4 patients who did not have definite spinal lesions around the thecal sac, leak site determination was based primarily on the contrast gradient hypothesis. The authors hypothesized that the concentration of extradural contrast medium would be the greatest and the same as that of intradural contrast medium at the leak site but that it would decrease with increased distance from the leak site according to the contrast gradient. Epidural blood patch was placed at the level of spinal lesions and/or of the greatest and same concentration of contrast medium between the intradural and extradural spaces. For 10 of the 12 patients, the orthostatic headaches decreased significantly within a week of EBP and disappeared within a month. For the remaining 2 patients, headaches persisted and medical treatment was required for several months. For 3 patients, thick chronic subdural hematomas caused severe headaches and/or disturbed

The origins of the cochlea and impedance matching hearing in synapsids

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Michael Laass

2016-06-01

Full Text Available The origin of tympanic hearing in early synapsids is still controversial, because little is known about their inner ear and the function of their sound conducting apparatus. Here I describe the earliest known tympanic ear in the synapsid lineage, the ear of Pristerodon (Therapsida, Anomodontia from the Late Permian of South Africa, which was virtually reconstructed from neutron tomographic data. Although Pristerodon is not a direct ancestor of mammals, its inner ear with distinctive cochlear cavity represents a connecting link between the primitive therapsid inner ear and the mammalian inner ear. The anatomy of the sound conducting apparatus of Pristerodon and the increased sound pressure transformer ratio points to a sensitivity to airborne sound. Furthermore, the origins of the cochlea and impedance matching hearing in synapsids coincided with the loss of contact between head and substrate, which already took place at least in Late Permian therapsids even before the postdentary bones became detached from the mandible.

Automatic Model Generation Framework for Computational Simulation of Cochlear Implantation

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Mangado Lopez, Nerea; Ceresa, Mario; Duchateau, Nicolas

2016-01-01

. To address such a challenge, we propose an automatic framework for the generation of patient-specific meshes for finite element modeling of the implanted cochlea. First, a statistical shape model is constructed from high-resolution anatomical μCT images. Then, by fitting the statistical model to a patient......'s CT image, an accurate model of the patient-specific cochlea anatomy is obtained. An algorithm based on the parallel transport frame is employed to perform the virtual insertion of the cochlear implant. Our automatic framework also incorporates the surrounding bone and nerve fibers and assigns......Recent developments in computational modeling of cochlear implantation are promising to study in silico the performance of the implant before surgery. However, creating a complete computational model of the patient's anatomy while including an external device geometry remains challenging...

Expression of EFR3A in the mouse cochlea during degeneration of spiral ganglion following hair cell loss.

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Chen Nie

Full Text Available Retrograde degeneration of spiral ganglion cells in the cochlea following hair cell loss is similar to dying back in pathology. The EFR3A gene has recently been discovered to be involved in the pathogenesis of dying back. The relationship of EFR3A and spiral ganglion degeneration, however, was rarely investigated. In this study, we destroyed the hair cells of the mouse cochlea by co-administration of kanamycin and furosemide and then investigated the EFR3A expression during the induced spiral ganglion cell degeneration. Our results revealed that co-administration of kanamycin and furosemide quickly induced hair cell loss in the C57BL/6J mice and then resulted in progressive degeneration of the spiral ganglion beginning at day 5 following drug administration. The number of the spiral ganglion cells began to decrease at day 15. The expression of EFR3A increased remarkably in the spiral ganglion at day 5 and then decreased to near normal level within the next 10 days. Our study suggested that the change of EFR3A expression in the spiral ganglion was coincident with the time of the spiral ganglion degeneration, which implied that high expression of EFR3A may be important to prompt initiation of spiral ganglion degeneration following hair cell loss.

Selective retrograde labeling of lateral olivocochlear neurons in the brainstem based on preferential uptake of 3H-D-aspartic acid in the cochlea

International Nuclear Information System (INIS)

Ryan, A.F.; Schwartz, I.R.; Helfert, R.H.; Keithley, E.; Wang, Z.X.

1987-01-01

We have previously shown that perfusion of the gerbil cochlea with probe concentrations of 3 H-D-aspartic acid (D-ASP) results in immediate, selective labeling of 50-60% of the efferent terminals under the inner hair cells, presumably by high-affinity uptake. The present study was undertaken to determine the origin of these endings. Twenty-four hours after cochlear perfusion with D-ASP, labeled neurons were observed in the ipsilateral, and to a much lesser extent in the contralateral, lateral superior olivary nucleus (LSO). The cells were small, primarily fusiform, and showed fewer synaptic contacts than other LSO cells. Combined transport of D-ASP and horseradish peroxidase indicated that all olivocochlear neurons within the LSO that projected to the injected cochlea were labeled by D-ASP. Labeled fibers coursed dorsally from the LSO, joined contralateral fibers that had passed under the floor of the fourth ventricle, and entered the VIIIth nerve root at its ventromedial edge. Adjacent to the ventral cochlear nucleus (VCN), densely labeled collateral fibers crossed the nerve root to enter the VCN. Labeled fibers and terminals were prominent in the central VCN. Neither retrograde transport of D-ASP by medial olivocochlear and vestibular efferents nor anterograde transport by VIIIth nerve afferents was observed. The D-ASP-labeled cells and fibers are clearly lateral olivocochlear efferents. Retrograde transport of D-ASP thus allows the cells, axons, and collaterals of the lateral olivocochlear system to be studied, morphologically, in isolation from other cells that project to the cochlea. Since the olivocochlear neurons are almost certainly cholinergic, retrograde amino acid transport does not necessarily identify the primary neurotransmitter of a neuron. Rather, it indicates the presence of selective uptake by the processes of that neuron at the site of amino acid injection

Differences between mechanical and neural tuning at the apex of the intact guinea pig cochlea

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Recio-Spinoso, Alberto; Oghalai, John S.

2018-05-01

While most of human speech information is contained within frequencies guinea pig cochlea using volumetric optical coherence tomography vibrometry (VOCTV). We found that vibrations within apical cochlear regions, with neural tuning below 2 kHz, demonstrate low-pass filter characteristics. There was evidence of a low-level of broad-band cochlear amplification that did not sharpen frequency selectivity. We compared the vibratory responses we measured to previously-measured single-unit auditory nerve tuning curves in the same frequency range, and found that mechanical responses do not match neural responses. These data suggest that, for low frequency cochlear regions, inner hair cells not only transduce vibrations of the organ of Corti but also sharpen frequency tuning.

Effect of c-myc on the ultrastructural structure of cochleae in guinea pigs with noise induced hearing loss

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Han, Yu; Zhong, Cuiping [Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China); Hong, Liu [First Division of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China); Wang, Ye; Qiao, Li [Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China); Qiu, Jianhua, E-mail: qiujh@fmmu.edu.cn [Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China)

2009-12-18

Noise over-stimulation may induce hair cells loss and hearing deficit. The c-myc oncogene is a major regulator for cell proliferation, growth, and apoptosis. However, the role of this gene in the mammalian cochlea is still unclear. The study was designed to firstly investigate its function under noise condition, from the aspect of cochlear ultrastructural changes. We had established the adenoviral vector of c-myc gene and delivered the adenovirus suspension into the scala tympani of guinea pigs 4 days before noise exposure. The empty adenoviral vectors were injected as control. Then, all subjects were exposed to 4-kHz octave-band noise at 110 dB SPL for 8 h/day, 3 days consecutively. Auditory thresholds were assessed by auditory brainstem response, prior to and 7 days following noise exposure. On the seventh days after noise exposure, the cochlear sensory epithelia surface was observed microscopically and the cochleae were taken to study the ultrastructural changes. The results indicated that auditory threshold shift after noise exposure was higher in the ears treated with Ad.EGFP than that treated with Ad.c-myc-EGFP. Stereocilia loss and the disarrangement of outer hair cells were observed, with greater changes found in the Ad.EGFP group. Also, the ultrastructure changes were severe in the Ad.EGFP group, but not obvious in the Ad.c-myc-EGFP group. Therefore, c-myc gene might play an unexpected role in hearing functional and morphological protection from acoustic trauma.

Effect of c-myc on the ultrastructural structure of cochleae in guinea pigs with noise induced hearing loss

International Nuclear Information System (INIS)

Han, Yu; Zhong, Cuiping; Hong, Liu; Wang, Ye; Qiao, Li; Qiu, Jianhua

2009-01-01

Noise over-stimulation may induce hair cells loss and hearing deficit. The c-myc oncogene is a major regulator for cell proliferation, growth, and apoptosis. However, the role of this gene in the mammalian cochlea is still unclear. The study was designed to firstly investigate its function under noise condition, from the aspect of cochlear ultrastructural changes. We had established the adenoviral vector of c-myc gene and delivered the adenovirus suspension into the scala tympani of guinea pigs 4 days before noise exposure. The empty adenoviral vectors were injected as control. Then, all subjects were exposed to 4-kHz octave-band noise at 110 dB SPL for 8 h/day, 3 days consecutively. Auditory thresholds were assessed by auditory brainstem response, prior to and 7 days following noise exposure. On the seventh days after noise exposure, the cochlear sensory epithelia surface was observed microscopically and the cochleae were taken to study the ultrastructural changes. The results indicated that auditory threshold shift after noise exposure was higher in the ears treated with Ad.EGFP than that treated with Ad.c-myc-EGFP. Stereocilia loss and the disarrangement of outer hair cells were observed, with greater changes found in the Ad.EGFP group. Also, the ultrastructure changes were severe in the Ad.EGFP group, but not obvious in the Ad.c-myc-EGFP group. Therefore, c-myc gene might play an unexpected role in hearing functional and morphological protection from acoustic trauma.

Gender differences in myogenic regulation along the vascular tree of the gerbil cochlea.

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Katrin Reimann

Full Text Available Regulation of cochlear blood flow is critical for hearing due to its exquisite sensitivity to ischemia and oxidative stress. Many forms of hearing loss such as sensorineural hearing loss and presbyacusis may involve or be aggravated by blood flow disorders. Animal experiments and clinical outcomes further suggest that there is a gender preference in hearing loss, with males being more susceptible. Autoregulation of cochlear blood flow has been demonstrated in some animal models in vivo, suggesting that similar to the brain, blood vessels supplying the cochlea have the ability to control flow within normal limits, despite variations in systemic blood pressure. Here, we investigated myogenic regulation in the cochlear blood supply of the Mongolian gerbil, a widely used animal model in hearing research. The cochlear blood supply originates at the basilar artery, followed by the anterior inferior cerebellar artery, and inside the inner ear, by the spiral modiolar artery and the radiating arterioles that supply the capillary beds of the spiral ligament and stria vascularis. Arteries from male and female gerbils were isolated and pressurized using a concentric pipette system. Diameter changes in response to increasing luminal pressures were recorded by laser scanning microscopy. Our results show that cochlear vessels from male and female gerbils exhibit myogenic regulation but with important differences. Whereas in male gerbils, both spiral modiolar arteries and radiating arterioles exhibited pressure-dependent tone, in females, only radiating arterioles had this property. Male spiral modiolar arteries responded more to L-NNA than female spiral modiolar arteries, suggesting that NO-dependent mechanisms play a bigger role in the myogenic regulation of male than female gerbil cochlear vessels.

The consequences of neural degeneration regarding optimal cochlear implant position in scala tympani: a model approach.

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Briaire, Jeroen J; Frijns, Johan H M

2006-04-01

Cochlear implant research endeavors to optimize the spatial selectivity, threshold and dynamic range with the objective of improving the speech perception performance of the implant user. One of the ways to achieve some of these goals is by electrode design. New cochlear implant electrode designs strive to bring the electrode contacts into close proximity to the nerve fibers in the modiolus: this is done by placing the contacts on the medial side of the array and positioning the implant against the medial wall of scala tympani. The question remains whether this is the optimal position for a cochlea with intact neural fibers and, if so, whether it is also true for a cochlea with degenerated neural fibers. In this study a computational model of the implanted human cochlea is used to investigate the optimal position of the array with respect to threshold, dynamic range and spatial selectivity for a cochlea with intact nerve fibers and for degenerated nerve fibers. In addition, the model is used to evaluate the predictive value of eCAP measurements for obtaining peri-operative information on the neural status. The model predicts improved threshold, dynamic range and spatial selectivity for the peri-modiolar position at the basal end of the cochlea, with minimal influence of neural degeneration. At the apical end of the array (1.5 cochlear turns), the dynamic range and the spatial selectivity are limited due to the occurrence of cross-turn stimulation, with the exception of the condition without neural degeneration and with the electrode array along the lateral wall of scala tympani. The eCAP simulations indicate that a large P(0) peak occurs before the N(1)P(1) complex when the fibers are not degenerated. The absence of this peak might be used as an indicator for neural degeneration.

The impact of round window vs cochleostomy surgical approaches on interscalar excursions in the cochlea: Preliminary results from a flat-panel computed tomography study

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Nicole T. Jiam

2016-09-01

Full Text Available Objective: To evaluate incidence of interscalar excursions between round window (RW and cochleostomy approaches for cochlear implant (CI insertion. Methods: This was a retrospective case-comparison. Flat-panel CT (FPCT scans for 8 CI users with Med-El standard length electrode arrays were collected. Surgical technique was identified by a combination of operative notes and FPCT imaging. Four cochleae underwent round window insertion and 4 cochleae underwent cochleostomy approaches anterior and inferior to the round window. Results: In our pilot study, cochleostomy approaches were associated with a higher likelihood of interscalar excursion. Within the cochleostomy group, we found 29% of electrode contacts (14 of 48 electrodes to be outside the scala tympani. On the other hand, 8.5% of the electrode contacts (4 of 47 electrodes in the round window insertion group were extra-scalar to the scala tympani. These displacements occurred at a mean angle of occurrence of 364° ± 133°, near the apex of the cochlea. Round window electrode displacements tend to localize at angle of occurrences of 400° or greater. Cochleostomy electrodes occurred at an angle of occurrence of 19°–490°. Conclusions: Currently, the optimal surgical approach for standard CI electrode insertion is highly debated, to a certain extent due to a lack of post-operative assessment of intracochlear electrode contact. Based on our preliminary findings, cochleostomy approach is associated with an increased likelihood of interscalar excursions, and these findings should be further evaluated with future prospective studies. Keywords: Cochlear implantation, Round window insertion, Cochleostomy, Interscalar excursion, Electrode position, Flat-panel computed tomography, Surgical approach

Fatigue-type stress fractures of the lower limb associated with fibrous cortical defects/non-ossifying fibromas in the skeletally immature

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Shimal, A.; Davies, A.M. [Department of Radiology, Royal Orthopaedic Hospital, Birmingham B31 2AP (United Kingdom); James, S.L.J., E-mail: steven.james@roh.nhs.u [Department of Radiology, Royal Orthopaedic Hospital, Birmingham B31 2AP (United Kingdom); Grimer, R.J. [Department of Orthopaedic Oncology, Royal Orthopaedic Hospital, Birmingham B31 2AP (United Kingdom)

2010-05-15

Aim: To investigate the association of a fatigue-type stress fracture and a fibrous cortical defect/non-ossifying fibroma (FCD/NOF) of the lower limb long bones in skeletally immature patients. Materials and methods: The patient database of a specialist orthopaedic oncology centre was searched to determine the number of skeletally immature patients (<=16 years of age) over an 18 year period with a lower limb long bone lesion ultimately shown to be a fatigue-type stress fracture. The diagnosis was established by a combination of typical imaging findings of a fatigue-type stress fracture, the absence of aggressive features suggestive of a sarcoma (e.g., interrupted periosteal reaction, cortical breach, and a soft-tissue mass) together with evidence of consolidation or healing on follow-up radiographs and resolution of symptoms over the subsequent weeks. The database was also used to determine the number of skeletally immature cases (<=16 years of age) referred in the same period in which the principal lesion was shown to be a fibrous cortical defect (FCD) or non-ossifying fibroma (NOF) of the lower limb long bones. The clinical and imaging features of those cases common to both groups (i.e., with both a fatigue-type stress fracture and a FCD or NOF) were reviewed. Results: Six percent of patients (five cases) referred to an orthopaedic oncology unit, who were subsequently shown to have a stress fracture of the lower limb long bones, were found to have a related FCD/NOF. All had been referred with a suggested diagnosis of a bone sarcoma and/or osteomyelitis. The possibility of a stress fracture had been raised in only one case. Four cases involved the proximal tibia and one the distal femur. Radiographs revealed that both lesions arose in the posteromedial cortex in all but one of the cases. The radiographs and magnetic resonance imaging (MRI) features were considered typical of the overlapping pathological features of the lesions. Conclusions: A sarcoma could be

Fatigue-type stress fractures of the lower limb associated with fibrous cortical defects/non-ossifying fibromas in the skeletally immature

International Nuclear Information System (INIS)

Shimal, A.; Davies, A.M.; James, S.L.J.; Grimer, R.J.

2010-01-01

Aim: To investigate the association of a fatigue-type stress fracture and a fibrous cortical defect/non-ossifying fibroma (FCD/NOF) of the lower limb long bones in skeletally immature patients. Materials and methods: The patient database of a specialist orthopaedic oncology centre was searched to determine the number of skeletally immature patients (≤16 years of age) over an 18 year period with a lower limb long bone lesion ultimately shown to be a fatigue-type stress fracture. The diagnosis was established by a combination of typical imaging findings of a fatigue-type stress fracture, the absence of aggressive features suggestive of a sarcoma (e.g., interrupted periosteal reaction, cortical breach, and a soft-tissue mass) together with evidence of consolidation or healing on follow-up radiographs and resolution of symptoms over the subsequent weeks. The database was also used to determine the number of skeletally immature cases (≤16 years of age) referred in the same period in which the principal lesion was shown to be a fibrous cortical defect (FCD) or non-ossifying fibroma (NOF) of the lower limb long bones. The clinical and imaging features of those cases common to both groups (i.e., with both a fatigue-type stress fracture and a FCD or NOF) were reviewed. Results: Six percent of patients (five cases) referred to an orthopaedic oncology unit, who were subsequently shown to have a stress fracture of the lower limb long bones, were found to have a related FCD/NOF. All had been referred with a suggested diagnosis of a bone sarcoma and/or osteomyelitis. The possibility of a stress fracture had been raised in only one case. Four cases involved the proximal tibia and one the distal femur. Radiographs revealed that both lesions arose in the posteromedial cortex in all but one of the cases. The radiographs and magnetic resonance imaging (MRI) features were considered typical of the overlapping pathological features of the lesions. Conclusions: A sarcoma could be

Direct measurement of cerebrospinal fluid pressure through the cochlea in a congenitally deaf child with Mondini dysplasia undergoing cochlear implantation.

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Graham, J M; Ashcroft, P

1999-03-01

Perilymph/cerebrospinal fluid (CSF) "gushers" may occur at cochleostomy during cochlear implant surgery, particularly in patients with congenital cochlear duct malformation in which CSF in the internal auditory meatus is in direct communication with the perilymphatic space in the cochlea. The object of the study was to measure the pressure and flow of a CSF gusher at cochleostomy. The design was a preoperative pressure measurement. The setting was a multidisciplinary cochlear implant program. A 4-year-old girl with bilateral Mondini deformity undergoing cochlear implantation was studied. A size 23 FG intravenous cannula was inserted into the cochlea and connected to a pediatric drip set to form an improvised manometer. Intracochlear fluid pressure was measured at 14 cm H2O, equivalent to the normal CSF pressure that would be recorded in a child of this age at lumbar puncture. An indirect measurement of the likely size of the CSF/perilymph defect was made. This technique may allow better assessment of the risk of postoperative CSF leakage and meningitis. This simple technique of measuring the pressure in a perilymph gusher can be used to assess the need for careful sealing of the cochleostomy, to measure the reduction in pressure produced by head elevation or a spinal drain, and to assess the probable size of a defect in the lamina cribrosa.

The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

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Anna Kirjavainen

2015-03-01

Full Text Available Hair cells of the organ of Corti (OC of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubule cytoskeletons. The Rho GTPase Cdc42 regulates cytoskeletal dynamics and polarization of various cell types, and, thus, serves as a candidate regulator of hair cell polarity. We have here induced Cdc42 inactivation in the late-embryonic OC. We show the role of Cdc42 in the establishment of planar polarity of hair cells and in cellular patterning. Abnormal planar polarity was displayed as disturbances in hair bundle orientation and morphology and in kinocilium/basal body positioning. These defects were accompanied by a disorganized cell-surface microtubule network. Atypical protein kinase C (aPKC, a putative Cdc42 effector, colocalized with Cdc42 at the hair cell apex, and aPKC expression was altered upon Cdc42 depletion. Our data suggest that Cdc42 together with aPKC is part of the machinery establishing hair cell planar polarity and that Cdc42 acts on polarity through the cell-surface microtubule network. The data also suggest that defects in apical polarization are influenced by disturbed cellular patterning in the OC. In addition, our data demonstrates that Cdc42 is required for stereociliogenesis in the immature cochlea.

Morphometrical and Topographical Anatomy of Position of Nutrient Foramen on Fully Ossified Left Femur

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Tanvir Hossain Parash

2013-05-01

Full Text Available Background: The femur is the typical long bone of lower limb which extends from the pelvis to the knee. It forms the skeleton of the thigh, bears body weight, supports movement of legs; provide attachment to muscles, form blood cells and acts as a store house for calcium and phosphate. The nutrient foramina are cavities that conduct the nutrient arteries and the peripheral nerves. The majority blood supply for femur originates from the nutrient arteries, mainly during the growing period and during the early phase of ossification. In bone grafts the nutrient blood supply is crucial and it should be preserved in order to promote the fracture healing.Objective: The anatomy of nutrient foramen of femur is very essential for orthopedic & vascular surgeons as well as to radiologists for planning of treatment.Materials and method: This cross sectional study was carried out in the department of Anatomy, Sir Salimullah Medical College, Dhaka, Bangladesh from July 2011 to June 2012. The study comprised 199 fully ossified left sided dry femur of both sex (n=89 male, n=110 female. Sampling technique was purposive. Morphometric and topographic study was carried out on all samples by direct physical and photographic methods.Results: The most common position of nutrient foramen on the shaft of femur was found on the middle 1/5th in both male and female femur (50.78% in male and 56.86% in female respectively.Conclusion: The anatomical knowledge about this study might be useful in certain surgical procedures as well as micro vascular bone transfer to preserve the circulation.

Tetramethylammonium for in vivo marking of the cross-sectional area of the scala media in the guinea pig cochlea.

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Salt, A N; DeMott, J

1992-01-01

A physiologic technique was developed to measure endolymphatic cross-sectional area in vivo using tetramethylammonium (TMA) as a volume marker. The technique was evaluated in guinea pigs as an animal model. In the method, the cochlea was exposed surgically and TMA was injected into endolymph of the second turn at a constant rate by iontophoresis. The concentration of TMA was monitored during and after the injection using ion-selective electrodes. Cross-section estimates derived from the TMA concentration measurements were compared in normal animals and animals in which endolymphatic hydrops had been induced by ablation of the endolymphatic duct and sac 8 weeks earlier. The method demonstrated a mean increase in cross-sectional area of 258% in the hydropic group. Individually measured area values were compared with action potential threshold shifts and the magnitude of the endocochlear potential (EP). Hydropic animals typically showed an increase in threshold to 2 kHz stimuli and a decrease in EP. However, the degree of threshold shift or EP decrease did not correlate well with the degree of hydrops present.

Cell-cell junctions: a target of acoustic overstimulation in the sensory epithelium of the cochlea

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Zheng Guiliang

2012-06-01

Full Text Available Abstract Background Exposure to intense noise causes the excessive movement of the organ of Corti, stretching the organ and compromising sensory cell functions. We recently revealed changes in the transcriptional expression of multiple adhesion-related genes during the acute phases of cochlear damage, suggesting that the disruption of cell-cell junctions is an early event in the process of cochlear pathogenesis. However, the functional state of cell junctions in the sensory epithelium is not clear. Here, we employed graded dextran-FITC, a macromolecule tracer that is impermeable to the organ of Corti under physiological conditions, to evaluate the barrier function of cell junctions in normal and noise-traumatized cochlear sensory epithelia. Results Exposure to an impulse noise of 155 dB (peak sound pressure level caused a site-specific disruption in the intercellular junctions within the sensory epithelium of the chinchilla cochlea. The most vulnerable sites were the junctions among the Hensen cells and between the Hensen and Deiters cells within the outer zone of the sensory epithelium. The junction clefts that formed in the reticular lamina were permeable to 40 and 500 but not 2,000 kDa dextran-FITC macromolecules. Moreover, this study showed that the interruption of junction integrity occurred in the reticular lamina and also in the basilar membrane, a site that had been considered to be resistant to acoustic injury. Finally, our study revealed a general spatial correlation between the site of sensory cell damage and the site of junction disruption. However, the two events lacked a strict one-to-one correlation, suggesting that the disruption of cell-cell junctions is a contributing, but not the sole, factor for initiating acute sensory cell death. Conclusions Impulse noise causes the functional disruption of intercellular junctions in the sensory epithelium of the chinchilla cochlea. This disruption occurs at an early phase of cochlear

The efficacy of N-acetylcysteine to protect the human cochlea from subclinical hearing loss caused by impulse noise: A controlled trial

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Ann-Cathrine Lindblad

2011-01-01

Full Text Available In military outdoor shooting training, with safety measures enforced, the risk of a permanent, noise-induced hearing loss is very small. But urban warfare training performed indoors, with reflections from walls, might increase the risk. A question is whether antioxidants can reduce the negative effects of noise on human hearing as it does on research animals. Hearing tests were performed on a control group of 23 military officers before and after a shooting session in a bunker-like room. The experiments were repeated on another group of 11 officers with peroral adminstration of N-acetyl-cysteine (NAC, directly after the shooting. The measurements performed were tone thresholds; transient-evoked otoacoustic emissions, with and without contralateral noise; and psycho-acoustical modulation transfer function (PMTF, thresholds for brief tones in modulated noise. Effects from shooting on hearing thresholds were small, but threshold behavior supports use of NAC treatment. On the PMTF, shooting without NAC gave strong effects. Those effects were like those from continuous noise, which means that strict safety measures should be enforced. The most striking finding was that the non-linearity of the cochlea, that was strongly reduced in the group without NAC, as manifested by the PMTF-results, was practically unchanged in the NAC-group throughout the study. NAC treatment directly after shooting in a bunkerlike room seems to give some protection of the cochlea.

Piribedil affects dopamine turnover in cochleas stimulated by white noise.

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Gil-Loyzaga, P; Vicente-Torres, M A; Fernández-Mateos, P; Arce, A; Esquifino, A

1994-09-01

The presence of dopamine (DA) within the cochlea has been previously reported, indicating that its turnover increases under noise stimulation. In the present report, piribedil, a dopaminergic D2 agonist, was used in order to provide evidence of the activity of D2 receptors in the turnover of DA under noise stimulation. Long-Evans rats were intraperitoneally injected with distilled water or with a solution of piribedil one hour previously to either noise or silence exposure. Noise stimulation was performed in an anechoic chamber at 70, 90 or 110 dB SPL for one hour. The animals were then sacrificed and the cochlear contents of DA and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were quantified by HPLC with electrochemical detection. The administration of piribedil to animals kept in silence did not modify the cochlear DA, DOPAC and HVA content. Noise stimulation resulted in a decrease of the cochlear DA content and an increase of the cochlear DOPAC and HVA contents in vehicle treated animals. The administration of piribedil resulted in a blockade of this noise induced cochlear DA turnover. These results suggest that piribedil stimulates cochlear D2 receptors controlling the cochlear DA release. Piribedil action on D2 receptors could explain the improvement observed in some cochleo-vestibular diseases signs after piribedil treatment.

Macrophage-Mediated Glial Cell Elimination in the Postnatal Mouse Cochlea

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LaShardai N. Brown

2017-12-01

Full Text Available Hearing relies on the transmission of auditory information from sensory hair cells (HCs to the brain through the auditory nerve. This relay of information requires HCs to be innervated by spiral ganglion neurons (SGNs in an exclusive manner and SGNs to be ensheathed by myelinating and non-myelinating glial cells. In the developing auditory nerve, mistargeted SGN axons are retracted or pruned and excessive cells are cleared in a process referred to as nerve refinement. Whether auditory glial cells are eliminated during auditory nerve refinement is unknown. Using early postnatal mice of either sex, we show that glial cell numbers decrease after the first postnatal week, corresponding temporally with nerve refinement in the developing auditory nerve. Additionally, expression of immune-related genes was upregulated and macrophage numbers increase in a manner coinciding with the reduction of glial cell numbers. Transient depletion of macrophages during early auditory nerve development, using transgenic CD11bDTR/EGFP mice, resulted in the appearance of excessive glial cells. Macrophage depletion caused abnormalities in myelin formation and transient edema of the stria vascularis. Macrophage-depleted mice also showed auditory function impairment that partially recovered in adulthood. These findings demonstrate that macrophages contribute to the regulation of glial cell number during postnatal development of the cochlea and that glial cells play a critical role in hearing onset and auditory nerve maturation.

Self-resolving focal non-ossifying myositis: a poorly known clinical and imaging entity diagnosed with MRI

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Perlepe, Vasiliki; Dallaudière, Benjamin; Omoumi, Patrick; Hristova, Lora; Rezzazadeh, Afshin; Vande Berg, Bruno; Malghem, Jacques; Lecouvet, Frederic

2015-01-01

Focal myositis is a rare benign inflammatory pseudotumor, presenting as a painful nodular mass within a muscle, and characterized by spontaneous resolution within weeks. To assess the clinical and imaging findings of focal nodular myositis simulating a neoplasm at clinical examination, with no history of trauma. This study describes the locations and appearance at ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) of this condition in a series of five patients. MRI and US displayed a solid intramuscular “tumor” and suggested a continuum between the proximal and distal muscle fibers that appeared thickened within the nodular lesion, a sign that has been reported in myositis ossificans. MRI showed edema in adjacent muscles and soft tissues, as well as intense enhancement of the mass. Intense vascular flows were seen at Doppler analysis. CT did not reveal the appearance of peripheral ossifications, ruling out the diagnosis of myositis ossificans. In some patients, the diagnosis of sarcoma had been suggested as possible by the radiologist. Imaging follow-up with MRI showed complete resolution of the masses over several weeks, thus avoiding a biopsy; no recurrence was observed at long-term follow-up (more than 24 months). This paper highlights MRI and US findings in focal non-ossifying myositis, and emphasizes the role of MRI in suggesting this diagnosis, leading to the careful follow-up of the lesion until its resolution, and ruling out more aggressive lesions

Accumulation of potassium in scala vestibuli perilymph of the mammalian cochlea.

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Salt, A N; Ohyama, K

1993-01-01

Movements of potassium (K+) were monitored during perfusion of either the scala tympani (ST) or the scala vestibuli (SV) of the guinea pig cochlea with a solution containing 15 mmol/LK+. A highly asymmetric clearance of K+ was observed, with K+ rapidly being taken up from the ST and allowed to accumulate in the SV. Under some conditions the SV K+ concentration could exceed that in the perfused ST. These observations are believed to result from the distortion of passive K+ diffusion by the high circulating current of K+ that is part of the transduction process. Calculations are presented to demonstrate that circulating fluxes are of sufficient magnitude to generate the results observed. The high rate of circulating K+ current is probably also responsible for the difference in physiologic K+ concentration between the ST and SV, in which the ST perilymph K+ concentration is typically found to be half that of the SV. A clearance of K+ from the ST and its eventual accumulation in the SV could play a role in how the ear responds to abnormal ion concentrations, such as may occur in Meniere's disease. It is proposed that an accumulation of K+ in the SV would result in vestibular dysfunction that might contribute to the vestibular symptoms of the disease.

Inflammatory and immune responses in the cochlea: potential therapeutic targets for sensorineural hearing loss

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Masato eFujioka

2014-12-01

Full Text Available The inner ear was previously assumed to be an immune-privileged organ due to the existence of its tight junction-based blood-labyrinth barrier. However, studies performed during the past decade revealed that the mesenchymal region of the cochlea, including its lateral wall, is a common site of inflammation. Neutrophils do not enter this region, which is consistent with the old dogma; however, bone marrow-derived resident macrophages are always present in the spiral ligament of the lateral wall and are activated in response to various types of insults, including noise exposure, ischemia, mitochondrial damage and surgical stress. Recent studies have also revealed another type of immune cell, called perivascular melanocyte-like macrophages (PVM/Ms, in the stria vascularis. These dedicated antigen-presenting cells also control vascular contraction and permeability. This review discusses a series of reports regarding inflammatory/immune cells in the cochlear lateral wall, the pathways involved in cochlear damage and their potential as therapeutic targets.

Vascular defects and sensorineural deafness in a mouse model of Norrie disease.

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Rehm, Heidi L; Zhang, Duan-Sun; Brown, M Christian; Burgess, Barbara; Halpin, Chris; Berger, Wolfgang; Morton, Cynthia C; Corey, David P; Chen, Zheng-Yi

2002-06-01

Norrie disease is an X-linked recessive syndrome of blindness, deafness, and mental retardation. A knock-out mouse model with an Ndp gene disruption was studied. We examined the hearing phenotype, including audiological, histological, and vascular evaluations. As is seen in humans, the mice had progressive hearing loss leading to profound deafness. The primary lesion was localized to the stria vascularis, which houses the main vasculature of the cochlea. Fluorescent dyes showed an abnormal vasculature in this region and eventual loss of two-thirds of the vessels. We propose that one of the principal functions of norrin in the ear is to regulate the interaction of the cochlea with its vasculature.

Cognitive task demands modulate the sensitivity of the human cochlea

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David W Smith

2012-02-01

Full Text Available Recent studies lead to the conclusion that focused attention, through the activity of corticofugal and medial olivocochlear efferent pathways, modulates activity at the most peripheral aspects of the auditory system within the cochlea. In two experiments we investigated the effects of different intermodal attention manipulations on the response of outer hair cells (OHCs, and the control exerted by the medial olivocochlear (MOC efferent system. The effect of the MOCs on OHC activity was characterized by measuring the amplitude and rapid adaptation time course of distortion product otoacoustic emissions (DPOAEs. In the first, DPOAE recordings were compared while participants were reading a book and counting the occurrence of the letter a (auditory ignoring and while counting the either short- or long-duration eliciting tones (auditory attending. In the second, DPOAEs were recorded while subjects watched muted movies with subtitles (auditory ignoring/visual distraction and were compared with DPOAEs recorded while subjects counted the same tones (auditory attending as in experiment 1. In both experiments 1 and 2, the absolute level of the averaged DPOAEs recorded during the auditory-ignoring condition was statistically higher than that recorded in the auditory-attending condition. Efferent-induced rapid adaptation was evident in all DPOAE contours, under all attention conditions, suggesting that two medial efferent processes act independently to determine rapid adaptation, which is unaffected by attention, and the overall DPOAE level, which is significantly affected by changes in the focus of attention.

Genetic Architecture of the Variation in Male-Specific Ossified Processes on the Anal Fins of Japanese Medaka.

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Kawajiri, Maiko; Fujimoto, Shingo; Yoshida, Kohta; Yamahira, Kazunori; Kitano, Jun

2015-10-28

Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTL with previously identified QTL controlling anal fin length. First, we found that only a few QTL were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays often were controlled by different QTL. Finally, we produced another independent cross and found that some QTL were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTL that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTL and have the potential for independent evolution. Copyright © 2015 Kawajiri et al.

Cochlear spike synchronization and neuron coincidence detection model

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Bader, Rolf

2018-02-01

Coincidence detection of a spike pattern fed from the cochlea into a single neuron is investigated using a physical Finite-Difference model of the cochlea and a physiologically motivated neuron model. Previous studies have shown experimental evidence of increased spike synchronization in the nucleus cochlearis and the trapezoid body [Joris et al., J. Neurophysiol. 71(3), 1022-1036 and 1037-1051 (1994)] and models show tone partial phase synchronization at the transition from mechanical waves on the basilar membrane into spike patterns [Ch. F. Babbs, J. Biophys. 2011, 435135]. Still the traveling speed of waves on the basilar membrane cause a frequency-dependent time delay of simultaneously incoming sound wavefronts up to 10 ms. The present model shows nearly perfect synchronization of multiple spike inputs as neuron outputs with interspike intervals (ISI) at the periodicity of the incoming sound for frequencies from about 30 to 300 Hz for two different amounts of afferent nerve fiber neuron inputs. Coincidence detection serves here as a fusion of multiple inputs into one single event enhancing pitch periodicity detection for low frequencies, impulse detection, or increased sound or speech intelligibility due to dereverberation.

Disrupted bone remodeling leads to cochlear overgrowth and hearing loss in a mouse model of fibrous dysplasia.

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Omar Akil

Full Text Available Normal hearing requires exquisite cooperation between bony and sensorineural structures within the cochlea. For example, the inner ear secretes proteins such as osteoprotegrin (OPG that can prevent cochlear bone remodeling. Accordingly, diseases that affect bone regulation can also result in hearing loss. Patients with fibrous dysplasia develop trabecular bone overgrowth resulting in hearing loss if the lesions affect the temporal bones. Unfortunately, the mechanisms responsible for this hearing loss, which could be sensorineural and/or conductive, remain unclear. In this study, we used a unique transgenic mouse model of increased Gs G-protein coupled receptor (GPCR signaling induced by expression of an engineered receptor, Rs1, in osteoblastic cells. These ColI(2.3+/Rs1+ mice showed dramatic bone lesions that histologically and radiologically resembled fibrous dysplasia. We found that ColI(2.3+/Rs1+ mice showed progressive and severe conductive hearing loss. Ossicular chain impingement increased with the size and number of dysplastic lesions. While sensorineural structures were unaffected, ColI(2.3+/Rs1+ cochleae had abnormally high osteoclast activity, together with elevated tartrate resistant acid phosphatase (TRAP activity and receptor activator of nuclear factor kappa-B ligand (Rankl mRNA expression. ColI(2.3+/Rs1+ cochleae also showed decreased expression of Sclerostin (Sost, an antagonist of the Wnt signaling pathway that normally increases bone formation. The osteocyte canalicular networks of ColI(2.3+/Rs1+ cochleae were disrupted and showed abnormal osteocyte morphology. The osteocytes in the ColI(2.3+/Rs1+ cochleae showed increased expression of matrix metalloproteinase 13 (MMP-13 and TRAP, both of which can support osteocyte-mediated peri-lacunar remodeling. Thus, while the ossicular chain impingement is sufficient to account for the progressive hearing loss in fibrous dysplasia, the deregulation of bone remodeling extends to the

Automatic Model Generation Framework for Computational Simulation of Cochlear Implantation.

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Mangado, Nerea; Ceresa, Mario; Duchateau, Nicolas; Kjer, Hans Martin; Vera, Sergio; Dejea Velardo, Hector; Mistrik, Pavel; Paulsen, Rasmus R; Fagertun, Jens; Noailly, Jérôme; Piella, Gemma; González Ballester, Miguel Ángel

2016-08-01

Recent developments in computational modeling of cochlear implantation are promising to study in silico the performance of the implant before surgery. However, creating a complete computational model of the patient's anatomy while including an external device geometry remains challenging. To address such a challenge, we propose an automatic framework for the generation of patient-specific meshes for finite element modeling of the implanted cochlea. First, a statistical shape model is constructed from high-resolution anatomical μCT images. Then, by fitting the statistical model to a patient's CT image, an accurate model of the patient-specific cochlea anatomy is obtained. An algorithm based on the parallel transport frame is employed to perform the virtual insertion of the cochlear implant. Our automatic framework also incorporates the surrounding bone and nerve fibers and assigns constitutive parameters to all components of the finite element model. This model can then be used to study in silico the effects of the electrical stimulation of the cochlear implant. Results are shown on a total of 25 models of patients. In all cases, a final mesh suitable for finite element simulations was obtained, in an average time of 94 s. The framework has proven to be fast and robust, and is promising for a detailed prognosis of the cochlear implantation surgery.

Characterization of neuronal cell death in the spiral ganglia of a mouse model of endolymphatic hydrops.

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Semaan, Maroun T; Zheng, Qing Y; Han, Fengchan; Zheng, Yuxi; Yu, Heping; Heaphy, John C; Megerian, Cliff A

2013-04-01

Spiral ganglion neurons (SGN) in the Phex male mouse, a murine model of postnatal endolymphatic hydrops (ELH) undergo progressive deterioration reminiscent of human and other animal models of ELH with features suggesting apoptosis as an important mechanism. Histologic analysis of the mutant's cochlea demonstrates ELH by postnatal Day (P) 21 and SGN loss by P90. The SGN loss seems to occur in a consistent topographic pattern beginning at the cochlear apex. SGN were counted at P60, P90, and P120. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative PCR, and immunohistochemical analyses of activated caspase-3, caspase-8, and caspase-9 were performed on cochlear sections obtained from mutants and controls. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay (TUNEL) was carried out on 2 mutants and 2 controls. Corrected SGN counts in control mice were greater in the apical turn of the cochleae at P90 and P120, respectively (p < 0.01). Increased expression of activated caspase-3, caspase-8, and caspase-9 was seen in the mutant. At later time points, activated caspase expression gradually declined in the apical turns and increased in basal turns of the cochlea. Quantitative and semiquantitative PCR analysis confirmed increased expression of caspase-3, caspase-8, and caspase-9 at P21 and P40. TUNEL staining demonstrated apoptosis at P90 in the apical and basal turns of the mutant cochleae. SGN degeneration in the Phex /Y mouse seems to mimic patterns observed in other animals with ELH. Apoptosis plays an important role in the degeneration of the SGN in the Phex male mouse.

Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea.

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Chen, Qianqian; Quan, Yizhou; Wang, Naitao; Xie, Chengying; Ji, Zhongzhong; He, Hao; Chai, Renjie; Li, Huawei; Yin, Shankai; Chin, Y Eugene; Wei, Xunbin; Gao, Wei-Qiang

2017-07-11

Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment. Copyright © 2017 International Society for Stem Cell Research. Published by Elsevier Inc. All rights reserved.

Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea

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Qianqian Chen

2017-07-01

Full Text Available Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment.

The vibrating reed frequency meter : digital investigation of an early cochlear model

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Bell, Andrew; Wit, Hero P.

2015-01-01

The vibrating reed frequency meter, originally employed by Bekesy and later by Wilson as a cochlear model, uses a set of tuned reeds to represent the cochlea's graded bank of resonant elements and an elastic band threaded between them to provide nearest-neighbour coupling. Here the system,

Modelling three-dimensional cochlear micromechanics within the guinea pig organ of Corti

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Ni, Guangjian; Elliott, Stephen J.

2018-05-01

The active amplification process in the mammalian cochlea depends on a complex interaction between cells within the organ of Corti. A three-dimensional (3D) model was developed using the finite element method based on anatomy for the apical end in the guinea pig cochlea, which is comprised of 3D discrete hair cells, 3D continuous membranes and fluid. The basilar membrane, tectorial membrane and the reticular lamina are modelled with orthotropic materials. The Y-shape structures formed by the outer hair cell (OHC), the Deiters' cell and Deiters' cell phalangeal process are also included to account for the structural longitudinal coupling. The motion within the organ of Corti was first simulated in response to a pressure difference loading on the basilar membrane, in order to calculate the passive vibration pattern. Then, the outer hair cells somatic electromotility was implemented by applying a voltage across the OHC walls to investigate its contribution to membranes motion.

Evaluation of the usefulness of three-dimensional optical coherence tomography in a guinea pig model of endolymphatic hydrops induced by surgical obliteration of the endolymphatic duct

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Cho, Nam Hyun; Lee, Jang Woo; Cho, Jin-ho; Kim, Jeehyun; Jang, Jeong Hun; Jung, Woonggyu

2015-03-01

Optical coherence tomography (OCT) has advanced significantly over the past two decades and is currently used extensively to monitor the internal structures of organs, particularly in ophthalmology and dermatology. We used ethylenediamine tetra-acetic acid (EDTA) to decalcify the bony walls of the cochlea and investigated the inner structures by deep penetration of light into the cochlear tissue using OCT on a guinea pig model of endolymphatic hydrops (EH), induced by surgical obliteration of the endolymphatic duct. The structural and functional changes associated with EH were identified using OCT and auditory brainstem response tests, respectively. We also evaluated structural alterations in the cochlea using three-dimensional reconstruction of the OCT images, which clearly showed physical changes in the cochlear structures. Furthermore, we found significant anatomical variations in the EH model and conducted graphical analysis by strial atrophy for comparison. The physical changes included damage to and flattening of the organ of Corti-evidence of Reissner's membrane distention-and thinning of the lateral wall. These results indicate that observation of EDTA-decalcified cochlea using OCT is significant in examination of gradual changes in the cochlear structures that are otherwise not depicted by hematoxylin and eosin staining.

Topics in Modeling of Cochlear Dynamics: Computation, Response and Stability Analysis

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Filo, Maurice G.

This thesis touches upon several topics in cochlear modeling. Throughout the literature, mathematical models of the cochlea vary according to the degree of biological realism to be incorporated. This thesis casts the cochlear model as a continuous space-time dynamical system using operator language. This framework encompasses a wider class of cochlear models and makes the dynamics more transparent and easier to analyze before applying any numerical method to discretize space. In fact, several numerical methods are investigated to study the computational efficiency of the finite dimensional realizations in space. Furthermore, we study the effects of the active gain perturbations on the stability of the linearized dynamics. The stability analysis is used to explain possible mechanisms underlying spontaneous otoacoustic emissions and tinnitus. Dynamic Mode Decomposition (DMD) is introduced as a useful tool to analyze the response of nonlinear cochlear models. Cochlear response features are illustrated using DMD which has the advantage of explicitly revealing the spatial modes of vibrations occurring in the Basilar Membrane (BM). Finally, we address the dynamic estimation problem of BM vibrations using Extended Kalman Filters (EKF). Due to the limitations of noninvasive sensing schemes, such algorithms are inevitable to estimate the dynamic behavior of a living cochlea.

Differential physiologic effects of perfusion of scala tympani versus scala vestibuli in the ischemic cochlea.

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Kobayashi, T; Rokugo, M; Takasaka, T; Thalmann, R

1993-07-01

The effectiveness of perilymphatic perfusion with oxygenated artificial media upon the endocochlear potential (EP) was measured during systemic ischemia in the guinea pig. Differences in the effects of perfusion of the two perilymphatic scalae were determined. Perfusion of scala vestibuli with oxygenated artificial perilymph at a high flow rate resulted in complete recovery of the EP to the pre-ischemic level, whereas perfusion of scala tympani with the same medium was unable to effect complete recovery. The recovery obtained by perfusion of scala tympani was about half that obtained of scala vestibuli. The pO2 in scala media was measured during perfusion by means of oxygen-sensitive microelectrodes. perfusion of scala vestibuli led to an approximately two-fold higher pO2 in scala media than perfusion of scala tympani. During perfusion, the pO2 in scala media varied dependent upon depth of electrode insertion, with a gradient decreasing toward the stria vascularis, a direction opposite to that seen under normal metabolic conditions. These findings suggest that, in the ischemic cochlea, oxygen enters scala media more easily from scala vestibuli across Reissner's membrane than from scala tympani via the basilar membrane/organ of Corti complex.

Involvement of Ubiquitin-Editing Protein A20 in Modulating Inflammation in Rat Cochlea Associated with Silver Nanoparticle-Induced CD68 Upregulation and TLR4 Activation

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Feng, Hao; Pyykkö, Ilmari; Zou, Jing

2016-05-01

Silver nanoparticles (AgNPs) were shown to temporarily impair the biological barriers in the skin of the external ear canal, mucosa of the middle ear, and inner ear, causing partially reversible hearing loss after delivery into the middle ear. The current study aimed to elucidate the molecular mechanism, emphasizing the TLR signaling pathways in association with the potential recruitment of macrophages in the cochlea and the modulation of inflammation by ubiquitin-editing protein A20. Molecules potentially involved in these signaling pathways were thoroughly analysed using immunohistochemistry in the rat cochlea exposed to AgNPs at various concentrations through intratympanic injection. The results showed that 0.4 % AgNPs but not 0.02 % AgNPs upregulated the expressions of CD68, TLR4, MCP1, A20, and RNF11 in the strial basal cells, spiral ligament fibrocytes, and non-sensory supporting cells of Corti's organ. 0.4 % AgNPs had no effect on CD44, TLR2, MCP2, Rac1, myosin light chain, VCAM1, Erk1/2, JNK, p38, IL-1β, TNF-α, TNFR1, TNFR2, IL-10, or TGF-β. This study suggested that AgNPs might confer macrophage-like functions on the strial basal cells and spiral ligament fibrocytes and enhance the immune activities of non-sensory supporting cells of Corti's organ through the upregulation of CD68, which might be involved in TLR4 activation. A20 and RNF11 played roles in maintaining cochlear homeostasis via negative regulation of the expressions of inflammatory cytokines.

Zonas mortas na cóclea em freqüências altas: implicações no processo de adaptação de prótese auditivas Dead regions in the cochlea at high frequencies: implications for the adaptation to hearing aids

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Angela Gordo

2007-06-01

Full Text Available Em perdas auditivas de grau moderado a severo nas freqüências altas, a lesão coclear pode estar relacionada a "zonas mortas", regiões onde as células ciliadas internas e/ou neurônios adjacentes não são funcionais. OBJETIVO: Avaliar o reconhecimento de fala em pacientes com e sem zonas mortas na cóclea em freqüências altas. MATERIAL e MÉTODO: Estudo clínico e experimental de 30 indivíduos adultos, distribuídos em dois grupos: grupo 1 - 15 indivíduos sem zonas mortas, e grupo 2 - 15 com zonas mortas na cóclea. Os pacientes foram submetidos à pesquisa do índice de reconhecimento de fala, limiar de reconhecimento de sentenças, sem e com ruído competitivo. Os testes de fala foram realizados sem prótese, com próteses auditivas amplificando a faixa de freqüências de 100 a 8000 Hz (programa 1 e com amplificação restrita, 100 a 2560 Hz (programa 2. RESULTADOS: O grupo 1 apresentou melhor desempenho utilizando as próteses auditivas no programa 1. Já o grupo 2 obteve melhor desempenho com o programa 2. CONCLUSÕES: Pacientes sem zonas mortas na cóclea obtêm maior benefício com a amplificação em freqüências altas. Na presença de zonas mortas em freqüências altas, o melhor desempenho é obtido com a amplificação restrita nestas freqüências.In patients with moderate to severe high-frequency hearing loss, cochlear damage may include "dead regions" where there are no functional inner hair cells and/or associated neurons. AIM: This study examines speech recognition in sensorineural impaired hearing patients with and without cochlear dead regions at high frequencies. METHODS: a clinical and experimental study was made of thirty patients with sensorineural hearing loss that were classified into two groups: group 1 - included 15 subjects with hearing loss and no dead regions; and group 2 - included 15 subjects with dead regions in the cochlea at high frequencies. Patients undertook word recognition score and speech

Implante coclear via fossa craniana média: uma nova técnica para acesso ao giro basal da cóclea Cochlear implantation through the middle cranial fossa: a novel approach to access the basal turn of the cochlea

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Aline Gomes Bittencourt

2013-04-01

Full Text Available A técnica clássica para o implante coclear é realizada através de mastoidectomia e timpanotomia posterior. A abordagem pela fossa craniana média provou ser uma alternativa valiosa, embora venha sendo usada para o implante coclear apenas esporadicamente e sem normatização. OBJETIVO: Descrever uma nova abordagem para expor o giro basal da cóclea para o implante coclear através da fossa craniana média. MÉTODO: Cinquenta ossos temporais foram dissecados. A cocleostomia foi realizada através de uma abordagem via fossa craniana média, na parte mais superficial do giro basal da cóclea, usando o plano meatal e seio petroso superior como pontos de reparo. A parede lateral do meato acústico interno foi dissecada após o broqueamento e esqueletização do ápice petroso. A parede dissecada do meato acústico interno foi acompanhada longitudinalmente até a cocleostomia. Design: Estudo anatômico de osso temporal. RESULTADOS: Em todos os ossos temporais, apenas a parte superficial do giro basal da cóclea foi aberta. A exposição do giro basal da cóclea permitiu que as escalas timpânica e vestibular fossem visualizadas. Assim, não houve dificuldade na inserção do feixe de eletrodos através da escala timpânica. CONCLUSÃO: A técnica proposta é simples e permite exposição suficiente do giro basal da cóclea.The classic approach for cochlear implant surgery includes mastoidectomy and posterior tympanotomy. The middle cranial fossa approach is a proven alternative, but it has been used only sporadically and inconsistently in cochlear implantation. OBJECTIVE: To describe a new approach to expose the basal turn of the cochlea in cochlear implant surgery through the middle cranial fossa. METHOD: Fifty temporal bones were dissected in this anatomic study of the temporal bone. Cochleostomies were performed through the middle cranial fossa approach in the most superficial portion of the basal turn of the cochlea, using the meatal plane and

A mouse model for degeneration of the spiral ligament.

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Kada, Shinpei; Nakagawa, Takayuki; Ito, Juichi

2009-06-01

Previous studies have indicated the importance of the spiral ligament (SL) in the pathogenesis of sensorineural hearing loss. The aim of this study was to establish a mouse model for SL degeneration as the basis for the development of new strategies for SL regeneration. We injected 3-nitropropionic acid (3-NP), an inhibitor of succinate dehydrogenase, at various concentrations into the posterior semicircular canal of adult C57BL/6 mice. Saline-injected animals were used as controls. Auditory function was monitored by measurements of auditory brain stem responses (ABRs). On postoperative day 14, cochlear specimens were obtained after the measurement of the endocochlear potential (EP). Animals that were injected with 5 or 10 mM 3-NP showed a massive elevation of ABR thresholds along with extensive degeneration of the cochleae. Cochleae injected with 1 mM 3-NP exhibited selective degeneration of the SL fibrocytes but alterations in EP levels and ABR thresholds were not of sufficient magnitude to allow for testing functional recovery after therapeutic interventions. Animals injected with 3 mM 3-NP showed a reduction of around 50% in the EP along with a significant loss of SL fibrocytes, although degeneration of spiral ganglion neurons and hair cells was still present in certain regions. These findings indicate that cochleae injected with 3 mM 3-NP may be useful in investigations designed to test the feasibility of new therapeutic manipulations for functional SL regeneration.

Plexiform neurofibroma causing an ossifying subperiosteal haematoma: a rare case in the tibia of an 11-year-old girl

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Lavell, Anton [Fiona Stanley Hospital, Department of Radiology, Murdoch, WA (Australia); Jones, Christopher W. [Perth Orthopaedic Institute, Nedlands, WA (Australia); Sir Charles Gairdner Hospital, Department of Orthopaedic Surgery, Nedlands, WA (Australia); Princess Margaret Hospital, Subiaco, WA (Australia); Wong, Daniel [PathWest, QEII Medical Centre, Anatomical Pathology, Nedlands, WA (Australia); Counsel, Peter [Princess Margaret Hospital, Department of Radiology, Subiaco, WA (Australia); Perth Radiological Clinic, Mirrabooka, WA (Australia); Carey-Smith, Richard [Sir Charles Gairdner Hospital, Department of Orthopaedic Surgery, Nedlands, WA (Australia); Princess Margaret Hospital, Subiaco, WA (Australia)

2017-10-15

Ossifying subperiosteal haematoma is an exceedingly rare manifestation of Neurofibromatosis type 1 (NF-1). We report an interesting case of plexiform neurofibroma causing a rapidly growing tibial mass as a result of subperiosteal haemorrhage, in an 11-year-old girl with previously undiagnosed NF-1. This reflects a precursor of the more mature periosteal ossification seen in cases traditionally termed ''subperiosteal cysts''. A previously well young girl was referred by her general practitioner with an increasingly large, mildly tender, soft lump on the anterior aspect of her right tibia. Plain radiographs demonstrated soft tissue thickening overlying the anterior tibia, without appreciable periosteal ossification. Magnetic resonance imaging (MRI) illustrated a single central fluid-fluid level and periosteal elevation with saucerisation of the anterior tibial cortex and mild surrounding oedema. Histopathology revealed a large plexiform neurofibroma. Interestingly, this was associated with haemorrhagic change and a peripheral rim of florid reactive new bone formation. This unusual presentation was discussed at a multidisciplinary bone and soft tissue tumour meeting, where in combination with the clinical history of cafe au lait spots and positive family history, a consensus diagnosis of NF-1 was made. To date, there have only been limited case reports of this rare pathological process. In summary, this case report accounts an acute presentation of this rare osseous manifestation of NF-1, being the first to clearly demonstrate a timeline of subperiosteal haematoma with subsequent subperiosteal bone proliferation. The clinical reasoning and radiological features for such a presentation are also described. (orig.)

Plexiform neurofibroma causing an ossifying subperiosteal haematoma: a rare case in the tibia of an 11-year-old girl

International Nuclear Information System (INIS)

Lavell, Anton; Jones, Christopher W.; Wong, Daniel; Counsel, Peter; Carey-Smith, Richard

2017-01-01

Ossifying subperiosteal haematoma is an exceedingly rare manifestation of Neurofibromatosis type 1 (NF-1). We report an interesting case of plexiform neurofibroma causing a rapidly growing tibial mass as a result of subperiosteal haemorrhage, in an 11-year-old girl with previously undiagnosed NF-1. This reflects a precursor of the more mature periosteal ossification seen in cases traditionally termed ''subperiosteal cysts''. A previously well young girl was referred by her general practitioner with an increasingly large, mildly tender, soft lump on the anterior aspect of her right tibia. Plain radiographs demonstrated soft tissue thickening overlying the anterior tibia, without appreciable periosteal ossification. Magnetic resonance imaging (MRI) illustrated a single central fluid-fluid level and periosteal elevation with saucerisation of the anterior tibial cortex and mild surrounding oedema. Histopathology revealed a large plexiform neurofibroma. Interestingly, this was associated with haemorrhagic change and a peripheral rim of florid reactive new bone formation. This unusual presentation was discussed at a multidisciplinary bone and soft tissue tumour meeting, where in combination with the clinical history of cafe au lait spots and positive family history, a consensus diagnosis of NF-1 was made. To date, there have only been limited case reports of this rare pathological process. In summary, this case report accounts an acute presentation of this rare osseous manifestation of NF-1, being the first to clearly demonstrate a timeline of subperiosteal haematoma with subsequent subperiosteal bone proliferation. The clinical reasoning and radiological features for such a presentation are also described. (orig.)

Mammalian Auditory Hair Cell Bundle Stiffness Affects Frequency Tuning by Increasing Coupling along the Length of the Cochlea.

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Dewey, James B; Xia, Anping; Müller, Ulrich; Belyantseva, Inna A; Applegate, Brian E; Oghalai, John S

2018-06-05

The stereociliary bundles of cochlear hair cells convert mechanical vibrations into the electrical signals required for auditory sensation. While the stiffness of the bundles strongly influences mechanotransduction, its influence on the vibratory response of the cochlear partition is unclear. To assess this, we measured cochlear vibrations in mutant mice with reduced bundle stiffness or with a tectorial membrane (TM) that is detached from the sensory epithelium. We found that reducing bundle stiffness decreased the high-frequency extent and sharpened the tuning of vibratory responses obtained postmortem. Detaching the TM further reduced the high-frequency extent of the vibrations but also lowered the partition's resonant frequency. Together, these results demonstrate that the bundle's stiffness and attachment to the TM contribute to passive longitudinal coupling in the cochlea. We conclude that the stereociliary bundles and TM interact to facilitate passive-wave propagation to more apical locations, possibly enhancing active-wave amplification in vivo. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Comparative Impacts of Scala Vestibuli Versus Scala Tympani Cochlear Implantation on Auditory Performances and Programming Parameters in Partially Ossified Cochleae.

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Trudel, Mathieu; Côté, Mathieu; Philippon, Daniel; Simonyan, David; Villemure-Poliquin, Noémie; Bussières, Richard

2018-07-01

To compare scala vestibuli versus scala tympani cochlear implantation in terms of postoperative auditory performances and programming parameters in patients with severe scala tympani ossification. Retrospective case-control study. Tertiary referral center. One hundred three pediatric and adult patients who underwent cochlear implant surgery between 2000 and 2016. Three groups were formed: a scala vestibuli group, a scala tympani with ossification group, and a scala tympani without ossification group. Patients were matched based on their age, sex, duration of deafness, and side of implantation (ratio of 1:2:2). Postoperative evaluation of auditory performances and programming parameters following intensive functional rehabilitation program completion. Multimedia adaptive test (MAT), hearing in noise test (HINT SNR +10 dB, HINT SNR +5 dB, and HINT SNR +0 dB), impedances, neural response telemetry thresholds (NRT), neural response imaging thresholds (NRI), comfortable levels (C-levels), and threshold levels (T-levels) were compared between groups. Twenty-one patients underwent scala vestibuli cochlear implantation: 19 adults and two children. Auditory performances were similar between groups, although sentence recognition in a noisy environment was slightly higher in the scala vestibuli group. Impedance values were also higher in the scala vestibuli group, but all other programming parameters were similar between groups. We present the largest series of patients with scala vestibuli cochlear implantation. This approach provides at least comparable auditory performances without having any deleterious effects on programming parameters. This viable and useful insertion route might be the primary surgical alternative when facing partial cochlear ossification.

Release of ATP from Marginal Cells in the Cochlea of Neonatal Rats Can Be Induced by Changes in Extracellular and Intracellular Ion Concentrations

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Peng, Yating; Chen, Jie; He, Shan; Yang, Jun; Wu, Hao

2012-01-01

Background Adenosine triphosphate (ATP) plays an important role in the cochlea. However, the source of ATP and the mechanism by which it is released remain unclear. This study investigates the presence and release mechanism of ATP in vitro cultured marginal cells isolated from the stria vascularis of the cochlea in neonatal rats. Methods Sprague-Dawley rats aged 1–3 days old were used for isolation, in vitro culture, and purification of marginal cells. Cultured marginal cells were verified by flow cytometry. Vesicles containing ATP in these cells were identified by fluorescence staining. The bioluminescence assay was used for determination of ATP concentration in the extracellular fluid released by marginal cells. Assays for ATP concentration were performed when the ATP metabolism of cells was influenced, and ionic concentrations in intracellular and extracellular fluid were found to change. Results Evaluation of cultured marginal cells with flow cytometry revealed the percentage of fluorescently-labeled cells as 92.9% and 81.9%, for cytokeratin and vimentin, respectively. Quinacrine staining under fluorescence microscopy revealed numerous green, star-like spots in the cytoplasm of these cells. The release of ATP from marginal cells was influenced by changes in the concentration of intracellular and extracellular ions, namely extracellular K+ and intra- and extracellular Ca2+. Furthermore, changes in the concentration of intracellular Ca2+ induced by the inhibition of the phospholipase signaling pathway also influence the release of ATP from marginal cells. Conclusion We confirmed the presence and release of ATP from marginal cells of the stria vascularis. This is the first study to demonstrate that the release of ATP from such cells is associated with the state of the calcium pump, K+ channel, and activity of enzymes related to the phosphoinositide signaling pathway, such as adenylate cyclase, phospholipase C, and phospholipase A2. PMID:23071731

Nonlinear time-domain cochlear model for transient stimulation and human otoacoustic emission

DEFF Research Database (Denmark)

Verhulst, Sarah; Dau, Torsten; Shera, Christopher A.

2012-01-01

This paper describes the implementation and performance of a nonlinear time-domain model of the cochlea for transient stimulation and human otoacoustic emission generation. The nonlinearity simulates compressive growth of measured basilar-membrane impulse responses. The model accounts...... for reflection and distortion-source otoacoustic emissions (OAEs) and simulates spontaneous OAEs through manipulation of the middle-ear reflectance. The model was calibrated using human psychoacoustical and otoacoustic tuning parameters. It can be used to investigate time-dependent properties of cochlear...

Energy Flux in the Cochlea: Evidence Against Power Amplification of the Traveling Wave.

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van der Heijden, Marcel; Versteegh, Corstiaen P C

2015-10-01

Traveling waves in the inner ear exhibit an amplitude peak that shifts with frequency. The peaking is commonly believed to rely on motile processes that amplify the wave by inserting energy. We recorded the vibrations at adjacent positions on the basilar membrane in sensitive gerbil cochleae and tested the putative power amplification in two ways. First, we determined the energy flux of the traveling wave at its peak and compared it to the acoustic power entering the ear, thereby obtaining the net cochlear power gain. For soft sounds, the energy flux at the peak was 1 ± 0.6 dB less than the middle ear input power. For more intense sounds, increasingly smaller fractions of the acoustic power actually reached the peak region. Thus, we found no net power amplification of soft sounds and a strong net attenuation of intense sounds. Second, we analyzed local wave propagation on the basilar membrane. We found that the waves slowed down abruptly when approaching their peak, causing an energy densification that quantitatively matched the amplitude peaking, similar to the growth of sea waves approaching the beach. Thus, we found no local power amplification of soft sounds and strong local attenuation of intense sounds. The most parsimonious interpretation of these findings is that cochlear sensitivity is not realized by amplifying acoustic energy, but by spatially focusing it, and that dynamic compression is realized by adjusting the amount of dissipation to sound intensity.

Characterization of a knock-in mouse model of the homozygous p.V37I variant in Gjb2.

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Chen, Ying; Hu, Lingxiang; Wang, Xueling; Sun, Changling; Lin, Xin; Li, Lei; Mei, Ling; Huang, Zhiwu; Yang, Tao; Wu, Hao

2016-09-13

The homozygous p.V37I variant in GJB2 is prevalent in East and Southeast Asians and may lead to mild-to-moderate hearing loss with reduced penetrance. To investigate the pathogenic mechanism underlying this variant, we generated a knock-in mouse model of homozygous p.V37I by an embryonic stem cell gene targeting method. Auditory brainstem response test showed that the knock-in mice developed progressive, mild-to-moderate hearing loss over the first 4-9 months. Overall no significant developmental and morphological abnormality was observed in the knock-in mouse cochlea, while confocal immunostaining and electron microscopic scanning revealed minor loss of the outer hair cells. Gene expression microarray analysis identified 105 up-regulated and 43 down-regulated genes in P5 knock-in mouse cochleae (P knock-in mouse modeled the hearing phenotype of the human patients and can serve as a useful animal model for further studies. The differentially expressed genes identified in this study may shed new insights into the understanding of the pathogenic mechanism and the phenotypic modification of homozygous p.V37I.

17β-Estradiol reduces nitric oxide production in the Guinea pig cochlea.

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Heinrich, U-R; Brieger, J; Striedter, C; Fischer, I; Schmidtmann, I; Li, H; Mann, W J; Helling, K

2013-11-01

Intense noise exposure and the application of ototoxic substances result in increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO). In order to reduce the free NO concentration in the inner ear under pathological conditions, the use of natural cytoprotective substances such as 17β-estradiol is a promising therapeutic concept. In male guinea pigs the organ of Corti and the lateral wall were isolated from the cochlea and afterwards incubated for 6 h in cell-culture medium. 17β-Estradiol was adjusted in 2 concentrations to organ cultures of the right ears (12 animals per concentration). The left ears were used as controls. The NO production was quantified in the supernatant by chemiluminescence after incubation. Depending on the concentration, 17β-estradiol reduced NO in the organ of Corti by 43% (p=0.015) and 46% (p=0.026), respectively. In the lateral wall, the NO concentration was reduced by 24%, but without statistical significance (p=0.86). However, when analyzing the association between the 2 cochlear regions for each animal separately, the NO concentrations were lower in nearly all 17β-estradiol-treated ears compared to controls. In order to demonstrate the flexibility of the organ culture system, the NO donor DETA NONOate and the nitric oxide synthase inhibitors L-NAME and L-NMMA were applied. The electron microscopic analysis revealed a well-preserved cochlear cell morphology after incubation. The ability of 17β-estradiol to influence the NO production preferentially in the organ of Corti might offer new therapeutic perspectives for inner ear protection. © Georg Thieme Verlag KG Stuttgart · New York.

GSR is not essential for the maintenance of antioxidant defenses in mouse cochlea: Possible role of the thioredoxin system as a functional backup for GSR.

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Chul Han

Full Text Available Glutathione reductase (GSR, a key member of the glutathione antioxidant defense system, converts oxidized glutathione (GSSG to reduced glutathione (GSH and maintains the intracellular glutathione redox state to protect the cells from oxidative damage. Previous reports have shown that Gsr deficiency results in defects in host defense against bacterial infection, while diquat induces renal injury in Gsr hypomorphic mice. In flies, overexpression of GSR extended lifespan under hyperoxia. In the current study, we investigated the roles of GSR in cochlear antioxidant defense using Gsr homozygous knockout mice that were backcrossed onto the CBA/CaJ mouse strain, a normal-hearing strain that does not carry a specific Cdh23 mutation that causes progressive hair cell degeneration and early onset of hearing loss. Gsr-/- mice displayed a significant decrease in GSR activity and GSH/GSSG ratios in the cytosol of the inner ears. However, Gsr deficiency did not affect ABR (auditory brainstem response hearing thresholds, wave I amplitudes or wave I latencies in young mice. No histological abnormalities were observed in the cochlea of Gsr-/- mice. Furthermore, there were no differences in the activities of cytosolic glutathione-related enzymes, including glutathione peroxidase and glutamate-cysteine ligase, or the levels of oxidative damage markers in the inner ears between WT and Gsr-/- mice. In contrast, Gsr deficiency resulted in increased activities of cytosolic thioredoxin and thioredoxin reductase in the inner ears. Therefore, under normal physiological conditions, GSR is not essential for the maintenance of antioxidant defenses in mouse cochlea. Given that the thioredoxin system is known to reduce GSSG to GSH in multiple species, our findings suggest that the thioredoxin system can support GSSG reduction in the mouse peripheral auditory system.

Dynamic expression of Lgr6 in the developing and mature mouse cochlea

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Zhang, Yanping; Chen, Yan; Ni, Wenli; Guo, Luo; Lu, Xiaoling; Liu, Liman; Li, Wen; Sun, Shan; Wang, Lei; Li, Huawei

2015-01-01

The Wnt/β-catenin signaling pathway plays important roles in mammalian inner ear development. Lgr5, one of the downstream target genes of the Wnt/β-catenin signaling pathway, has been reported to be a marker for inner ear hair cell progenitors. Lgr6 shares approximately 50% sequence homology with Lgr5 and has been identified as a stem cell marker in several organs. However, the detailed expression profiles of Lgr6 have not yet been investigated in the mouse inner ear. Here, we first used Lgr6-EGFP-Ires-CreERT2 mice to examine the spatiotemporal expression of Lgr6 protein in the cochlear duct during embryonic and postnatal development. Lgr6-EGFP was first observed in one row of prosensory cells in the middle and basal turn at embryonic day 15.5 (E15.5). From E18.5 to postnatal day 3 (P3), the expression of Lgr6-EGFP was restricted to the inner pillar cells (IPCs). From P7 to P15, the Lgr6-EGFP expression level gradually decreased in the IPCs and gradually increased in the inner border cells (IBCs). At P20, Lgr6-EGFP was only expressed in the IBCs, and by P30 Lgr6-EGFP expression had completely disappeared. Next, we demonstrated that Wnt/β-catenin signaling is required to maintain the Lgr6-EGFP expression in vitro. Finally, we demonstrated that the Lgr6-EGFP-positive cells isolated by flow cytometry could differentiate into myosin 7a-positive hair cells after 10 days in-culture, and this suggests that the Lgr6-positive cells might serve as the hair cell progenitor cells in the cochlea. PMID:26029045

Dynamic Expression of Lgr6 in the Developing and Mature Mouse Cochlea

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Yanping eZhang

2015-05-01

Full Text Available The Wnt/β-catenin signaling pathway plays important roles in mammalian inner ear development. Lgr5, one of the downstream target genes of the Wnt/β-catenin signaling pathway, has been reported to be a marker for inner ear hair cell progenitors. Lgr6 shares approximately 50% sequence homology with Lgr5 and has been identified as a stem cell marker in several organs. However, the detailed expression profiles of Lgr6 have not yet been investigated in the mouse inner ear. Here, we first used Lgr6-EGFP-Ires-CreERT2 mice to examine the spatiotemporal expression of Lgr6 protein in the cochlear duct during embryonic and postnatal development. Lgr6-EGFP was first observed in one row of prosensory cells in the middle and basal turn at embryonic day 15.5 (E15.5. From E18.5 to postnatal day 3 (P3, the expression of Lgr6-EGFP was restricted to the inner pillar cells (IPCs. From P7 to P15, the Lgr6-EGFP expression level gradually decreased in the IPCs and gradually increased in the inner border cells (IBCs. At P20, Lgr6-EGFP was only expressed in the IBCs, and by P30 Lgr6-EGFP expression had completely disappeared. Next, we demonstrated that Wnt/β-catenin signaling is required to maintain the Lgr6-EGFP expression in vitro. Finally, we demonstrated that the Lgr6-EGFP-positive cells isolated by flow cytometry could differentiate into myosin 7a-positive hair cells after 10 days in-culture, and this suggests that the Lgr6-positive cells might serve as the hair cell progenitor cells in the cochlea.

Defining the cellular environment in the organ of Corti following extensive hair cell loss: a basis for future sensory cell replacement in the Cochlea.

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Ruth R Taylor

Full Text Available BACKGROUND: Following the loss of hair cells from the mammalian cochlea, the sensory epithelium repairs to close the lesions but no new hair cells arise and hearing impairment ensues. For any cell replacement strategy to be successful, the cellular environment of the injured tissue has to be able to nurture new hair cells. This study defines characteristics of the auditory sensory epithelium after hair cell loss. METHODOLOGY/PRINCIPAL FINDINGS: Studies were conducted in C57BL/6 and CBA/Ca mice. Treatment with an aminoglycoside-diuretic combination produced loss of all outer hair cells within 48 hours in both strains. The subsequent progressive tissue re-organisation was examined using immunohistochemistry and electron microscopy. There was no evidence of significant de-differentiation of the specialised columnar supporting cells. Kir4.1 was down regulated but KCC4, GLAST, microtubule bundles, connexin expression patterns and pathways of intercellular communication were retained. The columnar supporting cells became covered with non-specialised cells migrating from the outermost region of the organ of Corti. Eventually non-specialised, flat cells replaced the columnar epithelium. Flat epithelium developed in distributed patches interrupting regions of columnar epithelium formed of differentiated supporting cells. Formation of the flat epithelium was initiated within a few weeks post-treatment in C57BL/6 mice but not for several months in CBA/Ca's, suggesting genetic background influences the rate of re-organisation. CONCLUSIONS/SIGNIFICANCE: The lack of dedifferentiation amongst supporting cells and their replacement by cells from the outer side of the organ of Corti are factors that may need to be considered in any attempt to promote endogenous hair cell regeneration. The variability of the cellular environment along an individual cochlea arising from patch-like generation of flat epithelium, and the possible variability between individuals

Optical stimulation of the hearing and deaf cochlea under thermal and stress confinement condition

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Schultz, M.; Baumhoff, P.; Kallweit, N.; Sato, M.; Krüger, A.; Ripken, T.; Lenarz, T.; Kral, A.

2014-03-01

There is a controversy, to which extend cochlear stimulation with near infrared laser pulses at a wavelength of 1860 nm is based on optoacoustic stimulation of intact hair cells or -in contrast- is based on direct stimulation of the nerve cells in absence of functional hair cells. Thermal and stress confinement conditions apply, because of the pulse duration range (5 ns, 10 μs-20 ms) of the two lasers used. The dependency of the signal characteristics on pulse peak power and pulse duration was investigated in this study. The compound action potential (CAP) was measured during stimulation of the cochlea of four anaesthetized guinea pigs, which were hearing at first and afterwards acutely deafened using intracochlear neomycin-rinsing. For comparison hydrophone measurements in a water tank were performed to investigate the optoacoustic signals at different laser interaction regimes. With rising pulse peak power CAPs of the hearing animals showed first a threshold, then a positively correlated and finally a saturating dependency. CAPs also showed distinct responses at laser onset and offset separated with the pulse duration. At pulse durations shorter than physiological response times the signals merged. Basically the same signal characteristics were observed in the optoacoustic hydrophone measurements, scaled with the sensitivity and response time of the hydrophone. Taking together the qualitative correspondence in the signal response and the absence of any CAPs in deafened animals our results speak in favor of an optoacoustic stimulation of intact hair cells rather than a direct stimulation of nerve cells.

The Effect of Erythropoietin on S100 Protein Expression in Cochlea After Acoustic Overstimulation: An Experimental Study

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Gulsen Gurgen

2014-03-01

Full Text Available Aim: To investigate the effect of Erythropoietin on acoustically overstimulated rat spiral ganglion neurons (SGNs using S100 protein immunostaining.Material and Method: Twenty-two Wistar albino rats were divided into three groups: healthy control group (n=7, Saline solution (n=7 and Erythropoietin injection groups (n=8. Saline solution and Erythropoietin injection groups received white noise (100 dB SPL for 3 hours. Cochlear sections were stained by silver staining technique and immunostained by S100 antibody. Results: Histochemical analysis of silver staining sections revealed normal structure and a weak staining in SGNs of healthy control group. However, dark-black cytoplasmic staining, cellular shrinkage and degeneration were detected in saline injection group. On the other hand, a few weakly stained neurons were observed in erythropoietin injection group. S100 staining demonstrated strong reaction in Schwann cells and myelin sheaths of SGNs in healthy control group (p<0.05. In saline solution injection group, Schwann cells showed moderate S100 reaction and other regions of SGNs showed weak reaction (p<0.05. In erythropoietin injection group, strong S100 expression almost similar to the healthy control group was determined, although there was an occasional decrease. Discussion: Erythropoetin may prevent noise induced SGN degeneration via protecting the Schwann cells in rat cochlea.

The cochlear nerve canal and internal auditory canal in children with normal cochlea but cochlear nerve deficiency

International Nuclear Information System (INIS)

Yan, Fei; Li, Jianhong; Xian, Junfang; Wang, Zhenchang; Mo, Lingyan

2013-01-01

Background: There is an increasing frequency of requests for cochlear implantation (CI) in deaf children and more detailed image information is necessary for selecting appropriate candidates. Cochlear nerve deficiency (CND) is a contraindication to CI. Magnetic resonance imaging (MRI) has been used to evaluate the integrity of the cochlear nerve. The abnormalities of the cochlear nerve canal (CNC) and internal auditory canal (IAC) have been reported to be associated with CND. Purpose: To correlate CNC manifestation, size, and IAC diameter on high-resolution CT (HRCT) with CND diagnosed by MRI in children. Material and Methods: HRCT images from 35 sensorineurally deaf children who had normal cochlea but bilateral or unilateral CND diagnosed by MRI were studied retrospectively. The CNC and IAC manifestation and size were assessed and correlated with CND. Results: CND was diagnosed by MRI in 54/70 ears (77.1%). Thirty-two ears had an absent cochlear nerve (59.3%), while 22 ears had a small cochlear nerve (40.7%). The CNC diameter was 2.0 mm in 11 ears (20.4%). The IAC diameter was 3.0 mm in 29 ears (53.7%). Conclusion: The hypoplastic CNC might be more highly indicative of CND than that of a narrow IAC

Hyposmotic stimulation-induced nitric oxide production in outer hair cells of the guinea pig cochlea.

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Takeda-Nakazawa, Hiroko; Harada, Narinobu; Shen, Jing; Kubo, Nobuo; Zenner, Hans-Peter; Yamashita, Toshio

2007-08-01

Nitric oxide (NO) production during hyposmotic stimulation in outer hair cells (OHCs) of the guinea pig cochlea was investigated using the NO sensitive dye DAF-2. Simultaneous measurement of the cell length and NO production showed rapid hyposmotic-induced cell swelling to precede NO production in OHCs. Hyposmotic stimulation failed to induce NO production in the Ca2+-free solution. L-NG-nitroarginine methyl ester (L-NAME), a non-specific NO synthase inhibitor and gadolinium, a stretch-activated channel blocker inhibited the hyposmotic stimulation-induced NO production whereas suramin, a P2 receptor antagonist did not. S-nitroso-N-acetylpenicillamine (SNAP), a NO donor inhibited the hyposmotic stimulation-induced increase in the intracellular Ca2+ concentrations ([Ca2+]i) while L-NAME enhanced it. 1H-[1,2,4]oxadiazole[4,3a]quinoxalin-1-one, an inhibitor of guanylate cyclase and KT5823, an inhibitor of cGMP-dependent protein kinase (PKG) mimicked effects of L-NAME on the Ca2+ response. Transient receptor potential vanilloid 4 (TRPV4), an osmo- and mechanosensitive channel was expressed in the OHCs by means of immunohistochemistry. 4alpha-phorbol 12,13-didecanoate, a TRPV4 synthetic activator, induced NO production in OHCs. These results suggest that hyposmotic stimulation can induce NO production by the [Ca2+]i increase, which is presumably mediated by the activation of TRPV4 in OHCs. NO conversely inhibits the Ca2+ response via the NO-cGMP-PKG pathway by a feedback mechanism.

Sheep as a large animal ear model: Middle-ear ossicular velocities and intracochlear sound pressure.

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Péus, Dominik; Dobrev, Ivo; Prochazka, Lukas; Thoele, Konrad; Dalbert, Adrian; Boss, Andreas; Newcomb, Nicolas; Probst, Rudolf; Röösli, Christof; Sim, Jae Hoon; Huber, Alexander; Pfiffner, Flurin

2017-08-01

Animals are frequently used for the development and testing of new hearing devices. Dimensions of the middle ear and cochlea differ significantly between humans and commonly used animals, such as rodents or cats. The sheep cochlea is anatomically more like the human cochlea in size and number of turns. This study investigated the middle-ear ossicular velocities and intracochlear sound pressure (ICSP) in sheep temporal bones, with the aim of characterizing the sheep as an experimental model for implantable hearing devices. Measurements were made on fresh sheep temporal bones. Velocity responses of the middle ear ossicles at the umbo, long process of the incus and stapes footplate were measured in the frequency range of 0.25-8 kHz using a laser Doppler vibrometer system. Results were normalized by the corresponding sound pressure level in the external ear canal (P EC ). Sequentially, ICSPs at the scala vestibuli and tympani were then recorded with custom MEMS-based hydrophones, while presenting identical acoustic stimuli. The sheep middle ear transmitted most effectively around 4.8 kHz, with a maximum stapes velocity of 0.2 mm/s/Pa. At the same frequency, the ICSP measurements in the scala vestibuli and tympani showed the maximum gain relative to the P EC (24 dB and 5 dB, respectively). The greatest pressure difference across the cochlear partition occurred between 4 and 6 kHz. A comparison between the results of this study and human reference data showed middle-ear resonance and best cochlear sensitivity at higher frequencies in sheep. In summary, sheep can be an appropriate large animal model for research and development of implantable hearing devices. Copyright © 2017 Elsevier B.V. All rights reserved.

Fluid coupling in a discrete model of cochlear mechanics.

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Elliott, Stephen J; Lineton, Ben; Ni, Guangjian

2011-09-01

A discrete model of cochlear mechanics is introduced that includes a full, three-dimensional, description of fluid coupling. This formulation allows the fluid coupling and basilar membrane dynamics to be analyzed separately and then coupled together with a simple piece of linear algebra. The fluid coupling is initially analyzed using a wavenumber formulation and is separated into one component due to one-dimensional fluid coupling and one comprising all the other contributions. Using the theory of acoustic waves in a duct, however, these two components of the pressure can also be associated with a far field, due to the plane wave, and a near field, due to the evanescent, higher order, modes. The near field components are then seen as one of a number of sources of additional longitudinal coupling in the cochlea. The effects of non-uniformity and asymmetry in the fluid chamber areas can also be taken into account, to predict both the pressure difference between the chambers and the mean pressure. This allows the calculation, for example, of the effect of a short cochlear implant on the coupled response of the cochlea. © 2011 Acoustical Society of America

Bisphosphonate-Linked TrkB Agonist: Cochlea-Targeted Delivery of a Neurotrophic Agent as a Strategy for the Treatment of Hearing Loss.

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Kempfle, Judith S; Nguyen, Kim; Hamadani, Christine; Koen, Nicholas; Edge, Albert S; Kashemirov, Boris A; Jung, David H; McKenna, Charles E

2018-04-18

Hearing loss affects more than two-thirds of the elderly population, and more than 17% of all adults in the U.S. Sensorineural hearing loss related to noise exposure or aging is associated with loss of inner ear sensory hair cells (HCs), cochlear spiral ganglion neurons (SGNs), and ribbon synapses between HCs and SGNs, stimulating intense interest in therapies to regenerate synaptic function. 7,8-Dihydroxyflavone (DHF) is a selective and potent agonist of tropomyosin receptor kinase B (TrkB) and protects the neuron from apoptosis. Despite evidence that TrkB agonists can promote survival of SGNs, local delivery of drugs such as DHF to the inner ear remains a challenge. We previously demonstrated in an animal model that a fluorescently labeled bisphosphonate, 6-FAM-Zol, administered to the round window membrane penetrated the membrane and diffused throughout the cochlea. Given their affinity for bone mineral, including cochlear bone, bisphosphonates offer an intriguing modality for targeted delivery of neurotrophic agents to the SGNs to promote survival, neurite outgrowth, and, potentially, regeneration of synapses between HCs and SGNs. The design and synthesis of a bisphosphonate conjugate of DHF (Ris-DHF) is presented, with a preliminary evaluation of its neurotrophic activity. Ris-DHF increases neurite outgrowth in vitro, maintains this ability after binding to hydroxyapatite, and regenerates synapses in kainic acid-damaged cochlear organ of Corti explants dissected in vitro with attached SGNs. The results suggest that bisphosphonate-TrkB agonist conjugates have promise as a novel approach to targeted delivery of drugs to treat sensorineural hearing loss.

MicroRNA profiling reveals dysregulated microRNAs and their target gene regulatory networks in cemento-ossifying fibroma.

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Pereira, Thaís Dos Santos Fontes; Brito, João Artur Ricieri; Guimarães, André Luiz Sena; Gomes, Carolina Cavaliéri; de Lacerda, Júlio Cesar Tanos; de Castro, Wagner Henriques; Coimbra, Roney Santos; Diniz, Marina Gonçalves; Gomez, Ricardo Santiago

2018-01-01

Cemento-ossifying fibroma (COF) is a benign fibro-osseous neoplasm of uncertain pathogenesis, and its treatment results in morbidity. MicroRNAs (miRNA) are small non-coding RNAs that regulate gene expression and may represent therapeutic targets. The purpose of the study was to generate a comprehensive miRNA profile of COF compared to normal bone. Additionally, the most relevant pathways and target genes of differentially expressed miRNA were investigated by in silico analysis. Nine COF and ten normal bone samples were included in the study. miRNA profiling was carried out by using TaqMan® OpenArray® Human microRNA panel containing 754 validated human miRNAs. We identified the most relevant miRNAs target genes through the leader gene approach, using STRING and Cytoscape software. Pathways enrichment analysis was performed using DIANA-miRPath. Eleven miRNAs were downregulated (hsa-miR-95-3p, hsa-miR-141-3p, hsa-miR-205-5p, hsa-miR-223-3p, hsa-miR-31-5p, hsa-miR-944, hsa-miR-200b-3p, hsa-miR-135b-5p, hsa-miR-31-3p, hsa-miR-223-5p and hsa-miR-200c-3p), and five were upregulated (hsa-miR-181a-5p, hsa-miR-181c-5p, hsa-miR-149-5p, hsa-miR-138-5p and hsa-miR-199a-3p) in COF compared to normal bone. Eighteen common target genes were predicted, and the leader genes approach identified the following genes involved in human COF: EZH2, XIAP, MET and TGFBR1. According to the biology of bone and COF, the most relevant KEGG pathways revealed by enrichment analysis were proteoglycans in cancer, miRNAs in cancer, pathways in cancer, p53-, PI3K-Akt-, FoxO- and TGF-beta signalling pathways, which were previously found to be differentially regulated in bone neoplasms, odontogenic tumours and osteogenesis. miRNA dysregulation occurs in COF, and EZH2, XIAP, MET and TGFBR1 are potential targets for functional analysis validation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Re-Emergent Inhibition of Cochlear Inner Hair Cells in a Mouse Model of Hearing Loss.

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Zachary, Stephen Paul; Fuchs, Paul Albert

2015-07-01

Hearing loss among the elderly correlates with diminished social, mental, and physical health. Age-related cochlear cell death does occur, but growing anatomical evidence suggests that synaptic rearrangements on sensory hair cells also contribute to auditory functional decline. Here we present voltage-clamp recordings from inner hair cells of the C57BL/6J mouse model of age-related hearing loss, which reveal that cholinergic synaptic inputs re-emerge during aging. These efferents are functionally inhibitory, using the same ionic mechanisms as do efferent contacts present transiently before the developmental onset of hearing. The strength of efferent inhibition of inner hair cells increases with hearing threshold elevation. These data indicate that the aged cochlea regains features of the developing cochlea and that efferent inhibition of the primary receptors of the auditory system re-emerges with hearing impairment. Synaptic changes in the auditory periphery are increasingly recognized as important factors in hearing loss. To date, anatomical work has described the loss of afferent contacts from cochlear hair cells. However, relatively little is known about the efferent innervation of the cochlea during hearing loss. We performed intracellular recordings from mouse inner hair cells across the lifespan and show that efferent innervation of inner hair cells arises in parallel with the loss of afferent contacts and elevated hearing threshold during aging. These efferent neurons inhibit inner hair cells, raising the possibility that they play a role in the progression of age-related hearing loss. Copyright © 2015 the authors 0270-6474/15/359701-06$15.00/0.

Expanding the Molecular Signature of Ossifying Fibromyxoid Tumors with 2 Novel Gene Fusions: CREBBP-BCORL1 and KDM2A-WWTR1

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Kao, Yu-Chien; Sung, Yun-Shao; Zhang, Lei; Chen, Chun-Liang; Huang, Shih-Chiang; Antonescu, Cristina R.

2017-01-01

Ossifying fibromyxoid tumor (OFMT) is an uncommon mesenchymal neoplasm of uncertain differentiation and intermediate malignant potential. Recurrent gene fusions involving either PHF1 or BCOR have been found in 85% of OFMT, including typical and malignant examples. As a subset of OFMT still lack known genetic abnormalities, we identified two OFMTs negative for PHF1 and BCOR rearrangements, which were subjected to transcriptome analysis for fusion discovery. The RNA sequencing found a novel CREBBP-BCORL1 fusion candidate in an axillary mass of a 51 year-old male and a KDM2A-WWTR1 in a thigh mass of a 36 year-old male. The gene fusions were validated by RT-PCR and FISH in the index cases and then screened by FISH on 4 additional OFMTs lacking known fusions. An identical CREBBP-BCORL1 fusion was found in an elbow tumor from a 30 year-old male. Both OFMTs with CREBBP-BCORL1 fusions had areas of typical OFMT morphology, exhibiting uniform round to epithelioid cells arranged in cords or nesting pattern in a fibromyxoid stroma. The OFMT with KDM2A-WWTR1 fusion involved dermis and superficial subcutis, being composed of ovoid cells in a fibromyxoid background with hyalinized giant rosettes. The S100 immunoreactivity ranged from very focal to absent. Similar to other known fusion genes in OFMT, BCORL1, CREBBP and KDM2A are also involved in histone modification. In summary, we expand the spectrum of molecular abnormalities in OFMT with 2 novel fusions, CREBBP-BCORL1 and KDM2A-WWTR1, further implicating the epigenetic deregulation as the leading pathogenetic mechanism in OFMT. PMID:27537276

Bone Marrow Blood Vessel Ossification and “Microvascular Dead Space” in Rat and Human Long Bone

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Prisby, Rhonda D.

2014-01-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4–6 mon; n=8) and old (22–24 mon; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner’s Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via µCT to quantify microvascular ossification. Bone marrow blood vessels from rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and “normal” vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p necrosis. The progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. PMID:24680721

Fibro-osseous lesions of the face and jaws

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MacDonald-Jankowski, D.S.

2004-01-01

Maxillofacial fibro-osseous lesions (FOL) consists of lesions that differ, with the exception of fibrous dysplasia, to those found in the rest of the skeleton. FOLs of the face and jaws are cemento-ossifying dysplasia, fibrous dysplasia and cemento-ossifying fibroma. Radiology is central to their diagnosis because the pathology for all FOLs is similar, although they range widely in behaviour, from dysplasia, hamartoma to benign neoplasia with occasional recurrence. Furthermore, once diagnosed the management of each is different. For cemento-ossifying dysplasia, this may mean doing nothing, simply because no treatment is generally appropriate. Almost all cemento-ossifying fibromas should be treated surgically, whereas cases of fibrous dysplasia are treated according to their clinical presentation, ranging from review and follow-up to surgery necessary to save the patient's sight or reduce deformity. The most important and frequent features of the FOLs differential diagnosis is discussed with assistance of a flow-chart

Fibro-osseous lesions of the face and jaws

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MacDonald-Jankowski, D.S

2004-01-01

Maxillofacial fibro-osseous lesions (FOL) consists of lesions that differ, with the exception of fibrous dysplasia, to those found in the rest of the skeleton. FOLs of the face and jaws are cemento-ossifying dysplasia, fibrous dysplasia and cemento-ossifying fibroma. Radiology is central to their diagnosis because the pathology for all FOLs is similar, although they range widely in behaviour, from dysplasia, hamartoma to benign neoplasia with occasional recurrence. Furthermore, once diagnosed the management of each is different. For cemento-ossifying dysplasia, this may mean doing nothing, simply because no treatment is generally appropriate. Almost all cemento-ossifying fibromas should be treated surgically, whereas cases of fibrous dysplasia are treated according to their clinical presentation, ranging from review and follow-up to surgery necessary to save the patient's sight or reduce deformity. The most important and frequent features of the FOLs differential diagnosis is discussed with assistance of a flow-chart.

Modeling of Auditory Neuron Response Thresholds with Cochlear Implants

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Frederic Venail

2015-01-01

Full Text Available The quality of the prosthetic-neural interface is a critical point for cochlear implant efficiency. It depends not only on technical and anatomical factors such as electrode position into the cochlea (depth and scalar placement, electrode impedance, and distance between the electrode and the stimulated auditory neurons, but also on the number of functional auditory neurons. The efficiency of electrical stimulation can be assessed by the measurement of e-CAP in cochlear implant users. In the present study, we modeled the activation of auditory neurons in cochlear implant recipients (nucleus device. The electrical response, measured using auto-NRT (neural responses telemetry algorithm, has been analyzed using multivariate regression with cubic splines in order to take into account the variations of insertion depth of electrodes amongst subjects as well as the other technical and anatomical factors listed above. NRT thresholds depend on the electrode squared impedance (β = −0.11 ± 0.02, P<0.01, the scalar placement of the electrodes (β = −8.50 ± 1.97, P<0.01, and the depth of insertion calculated as the characteristic frequency of auditory neurons (CNF. Distribution of NRT residues according to CNF could provide a proxy of auditory neurons functioning in implanted cochleas.

Transparent model of temporal bone and vestibulocochlear organ made by 3D printing.

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Suzuki, Ryoji; Taniguchi, Naoto; Uchida, Fujio; Ishizawa, Akimitsu; Kanatsu, Yoshinori; Zhou, Ming; Funakoshi, Kodai; Akashi, Hideo; Abe, Hiroshi

2018-01-01

The vestibulocochlear organ is composed of tiny complex structures embedded in the petrous part of the temporal bone. Landmarks on the temporal bone surface provide the only orientation guide for dissection, but these need to be removed during the course of dissection, making it difficult to grasp the underlying three-dimensional structures, especially for beginners during gross anatomy classes. We report herein an attempt to produce a transparent three-dimensional-printed model of the human ear. En bloc samples of the temporal bone from donated cadavers were subjected to computed tomography (CT) scanning, and on the basis of the data, the surface temporal bone was reconstructed with transparent resin and the vestibulocochlear organ with white resin to create a 1:1.5 scale model. The carotid canal was stuffed with red cotton, and the sigmoid sinus and internal jugular vein were filled with blue clay. In the inner ear, the internal acoustic meatus, cochlea, and semicircular canals were well reconstructed in detail with white resin. The three-dimensional relationships of the semicircular canals, spiral turns of the cochlea, and internal acoustic meatus were well recognizable from every direction through the transparent surface resin. The anterior semicircular canal was obvious immediately beneath the arcuate eminence, and the topographical relationships of the vestibulocochlear organ and adjacent great vessels were easily discernible. We consider that this transparent temporal bone model will be a very useful aid for better understanding of the gross anatomy of the vestibulocochlear organ.

Enhanced bioavailability of nerve growth factor with phytantriol lipid-based crystalline nanoparticles in cochlea

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Bu M

2015-11-01

Full Text Available Meng Bu,1,2 Jingling Tang,3 Yinghui Wei,4 Yanhui Sun,1 Xinyu Wang,1 Linhua Wu,2 Hongzhuo Liu1 1School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, People’s Republic of China; 2Department of Pharmacy, the Second Affiliated Hospital, 3School of Pharmacy, Harbin Medical University, Harbin, People’s Republic of China; 4College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China Purpose: Supplementation of exogenous nerve growth factor (NGF into the cochlea of deafened animals rescues spiral ganglion cells from degeneration. However, a safe and potent delivery of therapeutic proteins, such as NGF, to spiral ganglion cells remains one of the greatest challenges. This study presents the development of self-assembled cubic lipid-based crystalline nanoparticles to enhance inner ear bioavailability of bioactive NGF via a round window membrane route.Methods: A novel nanocarrier-entrapped NGF was developed based on phytantriol by a liquid precursor dilution, with Pluronic® F127 and propylene glycol as the surfactant and solubilizer, respectively. Upon dilution of the liquid lipid precursors, monodispersed submicron-sized particles with a slight negative charge formed spontaneously.Results: Biological activity of entrapped NGF was assessed using pheochromocytoma cells with NGF-loaded reservoirs to induce significant neuronal outgrowth, similar to that seen in free NGF-treated controls. Finally, a 3.28-fold increase in inner ear bioavailability was observed after administration of phytantriol lipid-based crystalline nanoparticles as compared to free drug, contributing to an enhanced drug permeability of the round window membrane. Conclusion: Data presented here demonstrate the potential of lipid-based crystalline nanoparticles to improve the outcomes of patients bearing cochlear implants. Keywords: nerve growth factor, lipid-based crystalline nanoparticles, PC12 cells, inner ear drug

Characterization of Lgr6+ Cells as an Enriched Population of Hair Cell Progenitors Compared to Lgr5+ Cells for Hair Cell Generation in the Neonatal Mouse Cochlea

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Yanping Zhang

2018-05-01

Full Text Available Hair cell (HC loss is irreversible because only very limited HC regeneration has been observed in the adult mammalian cochlea. Wnt/β-catenin signaling regulates prosensory cell proliferation and differentiation during cochlear development, and Wnt activation promotes the proliferation of Lgr5+ cochlear HC progenitors in newborn mice. Similar to Lgr5, Lgr6 is also a Wnt downstream target gene. Lgr6 is reported to be present in adult stem cells in the skin, nail, tongue, lung, and mammary gland, and this protein is very important for adult stem cell maintenance in rapidly proliferating organs. Our previous studies showed that Lgr6+ cells are a subpopulation of Lgr5+ progenitor cells and that both Lgr6+ and Lgr5+ progenitors can generate Myosin7a+ HCs in vitro. Thus we hypothesized that Lgr6+ cells are an enriched population of cochlear progenitor cells. However, the detailed distinctions between the Lgr5+ and Lgr6+ progenitors are unclear. Here, we systematically compared the proliferation, HC differentiation, and detailed transcriptome expression profiles of these two progenitor populations. We found that the same number of isolated Lgr6+ progenitors generated significantly more Myosin7a+ HCs compared to Lgr5+ progenitors; however, Lgr5+ progenitors formed more epithelial colonies and more spheres than Lgr6+ progenitors in vitro. Using RNA-Seq, we compared the transcriptome differences between Lgr5+ and Lgr6+ progenitors and identified a list of significantly differential expressed genes that might regulate the proliferation and differentiation of these HC progenitors, including 4 cell cycle genes, 9 cell signaling pathway genes, and 54 transcription factors. In conclusion, we demonstrate that Lgr6+ progenitors are an enriched population of inner ear progenitors that generate more HCs compared to Lgr5+ progenitors in the newborn mouse cochlea, and the our research provides a series of genes that might regulate the proliferation of progenitors

HPN-07, a free radical spin trapping agent, protects against functional, cellular and electrophysiological changes in the cochlea induced by acute acoustic trauma

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Hu, Ning; Du, Xiaoping; Li, Wei; West, Matthew B.; Choi, Chul-Hee; Floyd, Robert; Kopke, Richard D.

2017-01-01

Oxidative stress is considered a major cause of the structural and functional changes associated with auditory pathologies induced by exposure to acute acoustic trauma AAT). In the present study, we examined the otoprotective effects of 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07), a nitrone-based free radical trap, on the physiological and cellular changes in the auditory system of chinchilla following a six-hour exposure to 4 kHz octave band noise at 105 dB SPL. HPN-07 has been shown to suppress oxidative stress in biological models of a variety of disorders. Our results show that administration of HPN-07 beginning four hours after acoustic trauma accelerated and enhanced auditory/cochlear functional recovery, as measured by auditory brainstem responses (ABR), distortion product otoacoustic emissions (DPOAE), compound action potentials (CAP), and cochlear microphonics (CM). The normally tight correlation between the endocochlear potential (EP) and evoked potentials of CAP and CM were persistently disrupted after noise trauma in untreated animals but returned to homeostatic conditions in HPN-07 treated animals. Histological analyses revealed several therapeutic advantages associated with HPN-07 treatment following AAT, including reductions in inner and outer hair cell loss; reductions in AAT-induced loss of calretinin-positive afferent nerve fibers in the spiral lamina; and reductions in fibrocyte loss within the spiral ligament. These findings support the conclusion that early intervention with HPN-07 following an AAT efficiently blocks the propagative ototoxic effects of oxidative stress, thereby preserving the homeostatic and functional integrity of the cochlea. PMID:28832600

Expanding the molecular signature of ossifying fibromyxoid tumors with two novel gene fusions: CREBBP-BCORL1 and KDM2A-WWTR1.

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Kao, Yu-Chien; Sung, Yun-Shao; Zhang, Lei; Chen, Chun-Liang; Huang, Shih-Chiang; Antonescu, Cristina R

2017-01-01

Ossifying fibromyxoid tumor (OFMT) is an uncommon mesenchymal neoplasm of uncertain differentiation and intermediate malignant potential. Recurrent gene fusions involving either PHF1 or BCOR have been found in 85% of OFMT, including typical and malignant examples. As a subset of OFMT still lack known genetic abnormalities, we identified two OFMTs negative for PHF1 and BCOR rearrangements, which were subjected to transcriptome analysis for fusion discovery. The RNA sequencing found a novel CREBBP-BCORL1 fusion candidate in an axillary mass of a 51 year-old male and a KDM2A-WWTR1 in a thigh mass of a 36 year-old male. The gene fusions were validated by RT-PCR and FISH in the index cases and then screened by FISH on 4 additional OFMTs lacking known fusions. An identical CREBBP-BCORL1 fusion was found in an elbow tumor from a 30 year-old male. Both OFMTs with CREBBP-BCORL1 fusions had areas of typical OFMT morphology, exhibiting uniform round to epithelioid cells arranged in cords or nesting pattern in a fibromyxoid stroma. The OFMT with KDM2A-WWTR1 fusion involved dermis and superficial subcutis, being composed of ovoid cells in a fibromyxoid background with hyalinized giant rosettes. The S100 immunoreactivity ranged from very focal to absent. Similar to other known fusion genes in OFMT, BCORL1, CREBBP and KDM2A are also involved in histone modification. In summary, we expand the spectrum of molecular abnormalities in OFMT with 2 novel fusions, CREBBP-BCORL1 and KDM2A-WWTR1, further implicating the epigenetic deregulation as the leading pathogenetic mechanism in OFMT. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

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Prisby, Rhonda D

2014-07-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (pnecrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. Copyright © 2014 Elsevier Inc. All rights reserved.

The cochlear nerve canal and internal auditory canal in children with normal cochlea but cochlear nerve deficiency

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Yan, Fei; Li, Jianhong; Xian, Junfang; Wang, Zhenchang [Dept. of Radiology, Beijing Tongren Hospital, Capital Medical Univ., Beijing (China)], e-mail: cjr.wzhch@vip.163.com; Mo, Lingyan [Dept. of Otorhinolaryngology, Beijing Tongren Hospital, Capital Medical Univ., Beijing (China)

2013-04-15

Background: There is an increasing frequency of requests for cochlear implantation (CI) in deaf children and more detailed image information is necessary for selecting appropriate candidates. Cochlear nerve deficiency (CND) is a contraindication to CI. Magnetic resonance imaging (MRI) has been used to evaluate the integrity of the cochlear nerve. The abnormalities of the cochlear nerve canal (CNC) and internal auditory canal (IAC) have been reported to be associated with CND. Purpose: To correlate CNC manifestation, size, and IAC diameter on high-resolution CT (HRCT) with CND diagnosed by MRI in children. Material and Methods: HRCT images from 35 sensorineurally deaf children who had normal cochlea but bilateral or unilateral CND diagnosed by MRI were studied retrospectively. The CNC and IAC manifestation and size were assessed and correlated with CND. Results: CND was diagnosed by MRI in 54/70 ears (77.1%). Thirty-two ears had an absent cochlear nerve (59.3%), while 22 ears had a small cochlear nerve (40.7%). The CNC diameter was <1.5 mm in 36 ears (66.7%). The CNC diameter ranged between 1.5 and 2.0 mm in seven ears (13.0%) and was >2.0 mm in 11 ears (20.4%). The IAC diameter was <3.0 mm in 25 ears (46.3%) and >3.0 mm in 29 ears (53.7%). Conclusion: The hypoplastic CNC might be more highly indicative of CND than that of a narrow IAC.

Cochlear implant-related three-dimensional characteristics determined by micro-computed tomography reconstruction.

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Ni, Yusu; Dai, Peidong; Dai, Chunfu; Li, Huawei

2017-01-01

To explore the structural characteristics of the cochlea in three-dimensional (3D) detail using 3D micro-computed tomography (mCT) image reconstruction of the osseous labyrinth, with the aim of improving the structural design of electrodes, the selection of stimulation sites, and the effectiveness of cochlear implantation. Three temporal bones were selected from among adult donors' temporal bone specimens. A micro-CT apparatus (GE eXplore) was used to scan three specimens with a voxel resolution of 45 μm. We obtained about 460 slices/specimen, which produced abundant data. The osseous labyrinth images of three specimens were reconstructed from mCT. The cochlea and its spiral characteristics were measured precisely using Able Software 3D-DOCTOR. The 3D images of the osseous labyrinth, including the cochlea, vestibule, and semicircular canals, were reconstructed. The 3D models of the cochlea showed the spatial relationships and surface structural characteristics. Quantitative data concerning the cochlea and its spiral structural characteristics were analyzed with regard to cochlear implantation. The 3D reconstruction of mCT images clearly displayed the detailed spiral structural characteristics of the osseous labyrinth. Quantitative data regarding the cochlea and its spiral structural characteristics could help to improve electrode structural design, signal processing, and the effectiveness of cochlear implantation. Clin. Anat. 30:39-43, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Calcified epidural hematoma in pediatric age group: A report of two cases

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A Trivedi

2010-01-01

Full Text Available The authors present a rare case of calcified (ossified chronic epidural hematoma developed in a six-and-a-half-year-old female patient who was operated for cerebellar astrocytoma 6 months earlier. There was no history of trauma. Ossified epidural hematoma was seen as an incidental finding in the follow-up in computed tomography scan after 6 months of primary glioma surgery. Ossified chronic epidural hematoma with thick collagenous wall and newly formed bone on dura was excised. The development of calcified chronic subdural hematoma after decompressive intracranial surgery is a well-known occurrence, but the fact that a calcified epidural hematoma, which is rare and which can also develop after decompressive surgery, and the occurrence of calcified (ossified epidural hematoma after postfossa a glioma surgery is not yet reported. The second case is a 9-year-old male anemic child with a history of fall while playing 5 months earlier who presented with headache of 3 months duration. He had bifrontal calcified epidural hematoma operated by craniotomy and excision of calcified dural edge.

Biomedical Simulation Models of Human Auditory Processes

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Bicak, Mehmet M. A.

2012-01-01

Detailed acoustic engineering models that explore noise propagation mechanisms associated with noise attenuation and transmission paths created when using hearing protectors such as earplugs and headsets in high noise environments. Biomedical finite element (FE) models are developed based on volume Computed Tomography scan data which provides explicit external ear, ear canal, middle ear ossicular bones and cochlea geometry. Results from these studies have enabled a greater understanding of hearing protector to flesh dynamics as well as prioritizing noise propagation mechanisms. Prioritization of noise mechanisms can form an essential framework for exploration of new design principles and methods in both earplug and earcup applications. These models are currently being used in development of a novel hearing protection evaluation system that can provide experimentally correlated psychoacoustic noise attenuation. Moreover, these FE models can be used to simulate the effects of blast related impulse noise on human auditory mechanisms and brain tissue.

Gene expression changes for antioxidants pathways in the mouse cochlea: relations to age-related hearing deficits.

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Sherif F Tadros

Full Text Available Age-related hearing loss - presbycusis - is the number one neurodegenerative disorder and top communication deficit of our aged population. Like many aging disorders of the nervous system, damage from free radicals linked to production of reactive oxygen and/or nitrogen species (ROS and RNS, respectively may play key roles in disease progression. The efficacy of the antioxidant systems, e.g., glutathione and thioredoxin, is an important factor in pathophysiology of the aging nervous system. In this investigation, relations between the expression of antioxidant-related genes in the auditory portion of the inner ear - cochlea, and age-related hearing loss was explored for CBA/CaJ mice. Forty mice were classified into four groups according to age and degree of hearing loss. Cochlear mRNA samples were collected and cDNA generated. Using Affymetrix® GeneChip, the expressions of 56 antioxidant-related gene probes were analyzed to estimate the differences in gene expression between the four subject groups. The expression of Glutathione peroxidase 6, Gpx6; Thioredoxin reductase 1, Txnrd1; Isocitrate dehydrogenase 1, Idh1; and Heat shock protein 1, Hspb1; were significantly different, or showed large fold-change differences between subject groups. The Gpx6, Txnrd1 and Hspb1 gene expression changes were validated using qPCR. The Gpx6 gene was upregulated while the Txnrd1 gene was downregulated with age/hearing loss. The Hspb1 gene was found to be downregulated in middle-aged animals as well as those with mild presbycusis, whereas it was upregulated in those with severe presbycusis. These results facilitate development of future interventions to predict, prevent or slow down the progression of presbycusis.

Laser ablation in temporomandibular joint disorders and a case report involving an ossifying fibroma: how optics could potentially advance treatments in oral and maxillofacial surgery

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Tandon, Rahul; Stevens, Timothy W.; Stringer, Dale E.; Dean, Jeff S.; Herford, Alan S.

2013-03-01

Introduction: In the field of oral and maxillofacial surgery, there are many applications for lasers and optics. The first part of this manuscript is to discuss laser therapy and garner suggestions on how it can be improved. The second part is to present a case in which complications of a bone graft delayed healing and a return to normalcy for the patient. It is the goal of this paper to utilize the new advancements in optics so that patient care can be improved. Laser Therapy: Laser ablation and low-level laser therapy have been used in a variety of joint adhesion cases, including arthritis of the hand and foot. In the field of oral and maxillofacial surgery, this method has been used to treat pain and mobility dysfunction in patients with temporomandibular joint disease. While the outcomes have been promising, lack of familiarity with the device or doubt about its effects have reduced its use. This reduction in use has left the actual process of laser therapy relatively unchanged. Case Presentation: A 28 year-old female presented for a mandibular resection due to an ossifying fibroma. In the next several months her reconstructed area displayed significant signs of infection, as well as graft failure. X-rays, unfortunately, did not display the actual metabolic activity. Although the patient was reconstructed successfully thereafter, with more advanced technology available the patient could have endured a more comfortable treatment. Conclusion: While there are many more areas of oral and maxillofacial surgery that could potentially benefit from advances in optical technology, we have chosen to highlight these two areas due to their prevalence within our community.

Hyperparathyroidism-jaw Tumor Syndrome: An Overlooked Cause of Severe Hypercalcemia.

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Mathews, Joseph Wolfgang; Winchester, Rhonda; Alsaygh, Nebras; Bartlett, Anne M; Luttrell, Louis

2016-09-01

Ossifying fibromas of the maxillofacial bones are an uncommon form of benign neoplasm usually treated by surgical excision. Up to 30% of patients with hyperparathyroidism-jaw tumor syndrome, a rare form of multiple endocrine neoplasia resulting from autosomal dominant inactivating mutation of the Hrpt2 tumor suppressor gene, initially present with ossifying fibromas. Coincident hypercalcemia because of the presence of parathyroid adenoma is common in these patients, of whom 15% may have or may develop parathyroid carcinoma. The authors present a case of severe postsurgical hypercalcemia after removal of a large maxillary ossifying fibroma in a patient with previously unrecognized hyperparathyroidism-jaw tumor AU3 syndrome. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Estimation of gadolinium-induced T1-shortening with measurement of simple signal intensity ratio between the cochlea and brain parenchyma on 3D-FLAIR. Correlation with T1 measurement by TI scout sequence

International Nuclear Information System (INIS)

Naganawa, Shinji; Ishihara, Shunichi; Iwano, Shingo; Kawai, Hisashi; Sone, Michihiko; Nakashima, Tsutomu

2010-01-01

The purpose of this study was to T 1 -shortening of labyrinthine fluid on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) has been reported in many inner ear disorders. Although semi-quantitative assessment by simple signal intensity ratio between cochlear fluid and brain tissue has been tried, its feasibility using a multi-channel phased-array head coil with an inherently inhomogenous sensitivity distribution has not been fully evaluated. We evaluated the feasibility of measuring simple signal intensity ratio by correlating rapid T 1 measurements using an inversion time (TI) scout sequence. We evaluated 10 patients with Meniere's disease and 4 patients with sudden deafness. Nine of the patients with Meniere's disease received a unilateral intratympanic injection of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA); the tenth patient received bilateral injections. The 4 patients with sudden deafness received a double-dose intravenous injection. Magnetic resonance (MR) images were obtained 24 hours after intratympanic injections and 4 hours after intravenous injections at 3 tesla using a 32-channel head coil. We measured the ratio (CM ratio) between the signal intensity of the perilymph in the cochlea (C) and that of the medulla oblongata (M) and correlated it with the null-point inversion time (TI null ) obtained with the TI scout sequence. The TI scout consisted of 85 images obtained with TI values between 132.5 and 3087.5 ms at increments of 37.5 ms. The correlation coefficient between TI null and the natural logarithm of the CM ratio was -0.88 (P<0.01). There was significant negative linear correlation. Measurement of the simple signal intensity ratio between the cochlea and the medulla can be used for semi-quantitative analysis of 3D-FLAIR. The results of this study may facilitate clinical research of inner-ear disease using 3D-FLAIR. (author)

The vibrating reed frequency meter: digital investigation of an early cochlear model

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Andrew Bell

2015-10-01

Full Text Available The vibrating reed frequency meter, originally employed by Békésy and later by Wilson as a cochlear model, uses a set of tuned reeds to represent the cochlea’s graded bank of resonant elements and an elastic band threaded between them to provide nearest-neighbour coupling. Here the system, constructed of 21 reeds progressively tuned from 45 to 55 Hz, is simulated numerically as an elastically coupled bank of passive harmonic oscillators driven simultaneously by an external sinusoidal force. To uncover more detail, simulations were extended to 201 oscillators covering the range 1–2 kHz. Calculations mirror the results reported by Wilson and show expected characteristics such as traveling waves, phase plateaus, and a response with a broad peak at a forcing frequency just above the natural frequency. The system also displays additional fine-grain features that resemble those which have only recently been recognised in the cochlea. Thus, detailed analysis brings to light a secondary peak beyond the main peak, a set of closely spaced low-amplitude ripples, rapid rotation of phase as the driving frequency is swept, frequency plateaus, clustering, and waxing and waning of impulse responses. Further investigation shows that each reed’s vibrations are strongly localised, with small energy flow along the chain. The distinctive set of equally spaced ripples is an inherent feature which is found to be largely independent of boundary conditions. Although the vibrating reed model is functionally different to the standard transmission line, its cochlea-like properties make it an intriguing local oscillator model whose relevance to cochlear mechanics needs further investigation.

Fatigue-type stress fractures of the lower limb associated with fibrous cortical defects/non-ossifying fibromas in the skeletally immature.

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Shimal, A; Davies, A M; James, S L J; Grimer, R J

2010-05-01

To investigate the association of a fatigue-type stress fracture and a fibrous cortical defect/non-ossifying fibroma (FCD/NOF) of the lower limb long bones in skeletally immature patients. The patient database of a specialist orthopaedic oncology centre was searched to determine the number of skeletally immature patients (lower limb long bone lesion ultimately shown to be a fatigue-type stress fracture. The diagnosis was established by a combination of typical imaging findings of a fatigue-type stress fracture, the absence of aggressive features suggestive of a sarcoma (e.g., interrupted periosteal reaction, cortical breach, and a soft-tissue mass) together with evidence of consolidation or healing on follow-up radiographs and resolution of symptoms over the subsequent weeks. The database was also used to determine the number of skeletally immature cases (lower limb long bones. The clinical and imaging features of those cases common to both groups (i.e., with both a fatigue-type stress fracture and a FCD or NOF) were reviewed. Six percent of patients (five cases) referred to an orthopaedic oncology unit, who were subsequently shown to have a stress fracture of the lower limb long bones, were found to have a related FCD/NOF. All had been referred with a suggested diagnosis of a bone sarcoma and/or osteomyelitis. The possibility of a stress fracture had been raised in only one case. Four cases involved the proximal tibia and one the distal femur. Radiographs revealed that both lesions arose in the posteromedial cortex in all but one of the cases. The radiographs and magnetic resonance imaging (MRI) features were considered typical of the overlapping pathological features of the lesions. A sarcoma could be effectively excluded in the absence of true cortical destruction and soft-tissue extension. Both fatigue-type stress fractures and FCD/NOFs occur at similar sites in the long bones. It is postulated that the existence of the latter may cause localized weakening of

Modeling auditory evoked potentials to complex stimuli

DEFF Research Database (Denmark)

Rønne, Filip Munch

. Sensorineural hearing impairments is commonly associated with a loss of outer hair-cell functionality, and a measurable consequence is the decreased amount of cochlear compression at frequencies corresponding to the damaged locations in the cochlea. In clinical diagnostics, a fast and objective measure of local...

Characterization of the Transcriptomes of Lgr5+ Hair Cell Progenitors and Lgr5- Supporting Cells in the Mouse Cochlea.

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Cheng, Cheng; Guo, Luo; Lu, Ling; Xu, Xiaochen; Zhang, ShaSha; Gao, Junyan; Waqas, Muhammad; Zhu, Chengwen; Chen, Yan; Zhang, Xiaoli; Xuan, Chuanying; Gao, Xia; Tang, Mingliang; Chen, Fangyi; Shi, Haibo; Li, Huawei; Chai, Renjie

2017-01-01

Cochlear supporting cells (SCs) have been shown to be a promising resource for hair cell (HC) regeneration in the neonatal mouse cochlea. Previous studies have reported that Lgr5+ SCs can regenerate HCs both in vitro and in vivo and thus are considered to be inner ear progenitor cells. Lgr5+ progenitors are able to regenerate more HCs than Lgr5- SCs, and it is important to understand the mechanism behind the proliferation and HC regeneration of these progenitors. Here, we isolated Lgr5+ progenitors and Lgr5- SCs from Lgr5-EGFP-CreERT2/Sox2-CreERT2/Rosa26-tdTomato mice via flow cytometry. As expected, we found that Lgr5+ progenitors had significantly higher proliferation and HC regeneration ability than Lgr5- SCs. Next, we performed RNA-Seq to determine the gene expression profiles of Lgr5+ progenitors and Lgr5- SCs. We analyzed the genes that were enriched and differentially expressed in Lgr5+ progenitors and Lgr5- SCs, and we found 8 cell cycle genes, 9 transcription factors, and 24 cell signaling pathway genes that were uniquely expressed in one population but not the other. Last, we made a protein-protein interaction network to further analyze the role of these differentially expressed genes. In conclusion, we present a set of genes that might regulate the proliferation and HC regeneration ability of Lgr5+ progenitors, and these might serve as potential new therapeutic targets for HC regeneration.

Characterization of the Transcriptomes of Lgr5+ Hair Cell Progenitors and Lgr5- Supporting Cells in the Mouse Cochlea

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Haibo Shi

2017-04-01

Full Text Available Cochlear supporting cells (SCs have been shown to be a promising resource for hair cell (HC regeneration in the neonatal mouse cochlea. Previous studies have reported that Lgr5+ SCs can regenerate HCs both in vitro and in vivo and thus are considered to be inner ear progenitor cells. Lgr5+ progenitors are able to regenerate more HCs than Lgr5- SCs, and it is important to understand the mechanism behind the proliferation and HC regeneration of these progenitors. Here, we isolated Lgr5+ progenitors and Lgr5- SCs from Lgr5-EGFP-CreERT2/Sox2-CreERT2/Rosa26-tdTomato mice via flow cytometry. As expected, we found that Lgr5+ progenitors had significantly higher proliferation and HC regeneration ability than Lgr5- SCs. Next, we performed RNA-Seq to determine the gene expression profiles of Lgr5+ progenitors and Lgr5- SCs. We analyzed the genes that were enriched and differentially expressed in Lgr5+ progenitors and Lgr5- SCs, and we found 8 cell cycle genes, 9 transcription factors, and 24 cell signaling pathway genes that were uniquely expressed in one population but not the other. Last, we made a protein–protein interaction network to further analyze the role of these differentially expressed genes. In conclusion, we present a set of genes that might regulate the proliferation and HC regeneration ability of Lgr5+ progenitors, and these might serve as potential new therapeutic targets for HC regeneration.

Characterization of the Transcriptomes of Lgr5+ Hair Cell Progenitors and Lgr5- Supporting Cells in the Mouse Cochlea

Science.gov (United States)

Cheng, Cheng; Guo, Luo; Lu, Ling; Xu, Xiaochen; Zhang, ShaSha; Gao, Junyan; Waqas, Muhammad; Zhu, Chengwen; Chen, Yan; Zhang, Xiaoli; Xuan, Chuanying; Gao, Xia; Tang, Mingliang; Chen, Fangyi; Shi, Haibo; Li, Huawei; Chai, Renjie

2017-01-01

Cochlear supporting cells (SCs) have been shown to be a promising resource for hair cell (HC) regeneration in the neonatal mouse cochlea. Previous studies have reported that Lgr5+ SCs can regenerate HCs both in vitro and in vivo and thus are considered to be inner ear progenitor cells. Lgr5+ progenitors are able to regenerate more HCs than Lgr5- SCs, and it is important to understand the mechanism behind the proliferation and HC regeneration of these progenitors. Here, we isolated Lgr5+ progenitors and Lgr5- SCs from Lgr5-EGFP-CreERT2/Sox2-CreERT2/Rosa26-tdTomato mice via flow cytometry. As expected, we found that Lgr5+ progenitors had significantly higher proliferation and HC regeneration ability than Lgr5- SCs. Next, we performed RNA-Seq to determine the gene expression profiles of Lgr5+ progenitors and Lgr5- SCs. We analyzed the genes that were enriched and differentially expressed in Lgr5+ progenitors and Lgr5- SCs, and we found 8 cell cycle genes, 9 transcription factors, and 24 cell signaling pathway genes that were uniquely expressed in one population but not the other. Last, we made a protein–protein interaction network to further analyze the role of these differentially expressed genes. In conclusion, we present a set of genes that might regulate the proliferation and HC regeneration ability of Lgr5+ progenitors, and these might serve as potential new therapeutic targets for HC regeneration. PMID:28491023

Osteogenic differentiation in dedifferentiated liposarcoma: a study of 36 cases in comparison to the cases without ossification.

Science.gov (United States)

Yamashita, Kyoko; Kohashi, Kenichi; Yamada, Yuichi; Ishii, Takeaki; Nishida, Yoshihiro; Urakawa, Hiroshi; Ito, Ichiro; Takahashi, Mitsuru; Inoue, Takeshi; Ito, Masafumi; Ohara, Yuuki; Oda, Yoshinao; Toyokuni, Shinya

2018-04-01

Ossification is found occasionally in dedifferentiated liposarcoma (DDLPS). The aims of this study were to elucidate whether the formed bone tissue is usually produced by tumour cells or by reactive non-neoplastic cells, and to reveal the clinicopathological characteristics of DDLPS with ossification. We examined 36 cases of ossified DDLPS by comparing them to 31 cases of non-ossified DDLPS. MDM2 amplification was confirmed in osteocytes and/or osteoblastic cells in all but one ossified DDLPS cases (27 of 28) using fluorescence in-situ hybridisation, although the morphological impression of ossification appeared to be mainly metaplastic (27 of 36) or high-grade osteosarcoma-like (six of 36). The bone tissue was often formed predominantly at the periphery of the DDLPS area near the well-differentiated liposarcoma component (18 of 36), and an organised structure such as bone marrow-like differentiation was not uncommon (12 of 36). According to a modified French Fédération Nationale des Centers de Lutte Contre le Cancer (FNCLCC) grading system, ossified DDLPS tended to be lower grade than non-ossified DDLPS (mean grade: 1.88 and 2.15, respectively). Ossification in DDLPS was associated significantly with shorter local recurrence-free survival by multivariate analysis (P = 0.02347), but metaplastic-appearing ossification tended to be associated with longer overall survival (P = 0.1400). The bone tissue formed in DDLPS was mainly neoplastic regardless of its morphology and maturity, which highlighted the osteogenic differentiation of the tumour cells. DDLPS patients with osteogenic differentiation tended to suffer from earlier local recurrences, which did not necessarily lead to poor life outcomes. © 2017 John Wiley & Sons Ltd.

The stylohyoid chain: CT imaging

Energy Technology Data Exchange (ETDEWEB)

Uysal Ramadan, Selma, E-mail: uysalselma@yahoo.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Goekharman, Dilek, E-mail: gokharman@ttnet.net.t [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kosar, Pinar, E-mail: pkosar@hotmail.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kacar, Mahmut, E-mail: mkacar1961@gamil.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kosar, Ugur, E-mail: ugurkosar@hotmail.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey)

2010-09-15

We aimed in this report to discuss the embryology, anatomy, theories of ossification and symptoms, clinical presentation, and diagnosis of the stylohyoid chain (SHC) variations, together with the role of radiographs, computed tomography (CT) and three-dimensional (3D)-CT in showing these variations. Because CT/3D-CT additionally facilitates visualization of the entire SHC with different axes, it is the most valuable method for establishing the relationship between the SHC and the surrounding tissue. SHC variation can be discovered during CT performed for indications other than ossified SHC. It is important to diagnose whether or not the SHC is ossified, since one of the treatment procedures in ossified SHC is total excision. If the clinician and radiologist are aware of these variations observed in the SHC, patients with vague symptoms may be spared unnecessary investigations and may be properly diagnosed earlier.

Reduced sensory stimulation alters the molecular make-up of glutamatergic hair cell synapses in the developing cochlea.

Science.gov (United States)

Barclay, M; Constable, R; James, N R; Thorne, P R; Montgomery, J M

2016-06-14

Neural activity during early development is known to alter innervation pathways in the central and peripheral nervous systems. We sought to examine how reduced sound-induced sensory activity in the cochlea affected the consolidation of glutamatergic synapses between inner hair cells (IHC) and the primary auditory neurons as these synapses play a primary role in transmitting sound information to the brain. A unilateral conductive hearing loss was induced prior to the onset of sound-mediated stimulation of the sensory hair cells, by rupturing the tympanic membrane and dislocating the auditory ossicles in the left ear of P11 mice. Auditory brainstem responses at P15 and P21 showed a 40-50-dB increase in thresholds for frequencies 8-32kHz in the dislocated ear relative to the control ear. Immunohistochemistry and confocal microscopy were subsequently used to examine the effect of this attenuation of sound stimulation on the expression of RIBEYE, which comprises the presynaptic ribbons, Shank-1, a postsynaptic scaffolding protein, and the GluA2/3 and 4 subunits of postsynaptic AMPA receptors. Our results show that dislocation did not alter the number of pre- or postsynaptic protein puncta. However, dislocation did increase the size of RIBEYE, GluA4, GluA2/3 and Shank-1 puncta, with postsynaptic changes preceding presynaptic changes. Our data suggest that a reduction in sound stimulation during auditory development induces plasticity in the molecular make-up of IHC glutamatergic synapses, but does not affect the number of these synapses. Up-regulation of synaptic proteins with sound attenuation may facilitate a compensatory increase in synaptic transmission due to the reduced sensory stimulation of the IHC. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Microanatomy of the cochlear hook

Science.gov (United States)

Kwan, Changyow Claire; Tan, Xiaodong; Stock, Stuart R.; Soriano, Carmen; Xiao, Xianghui; Richter, Claus-Peter

2017-09-01

Communication among humans occurs through coding and decoding of acoustic information. The inner ear or cochlea acts as a frequency analyzer and divides the acoustic signal into small frequency bands, which are processed at different sites along the cochlea. The mechano-electrical conversion is accomplished by the soft tissue structures in the cochlea. While the anatomy for most of the cochlea has been well described, a detailed description of the very high frequency and vulnerable cochlear hook region is missing. To study the cochlear hook, mice cochleae were imaged with synchrotron radiation and high-resolution reconstructions have been made from the tomographic scans. This is the first detailed description of the bony and soft tissues of the hook region of the mammalian cochlea.

Wnt1 from cochlear schwann cells enhances neuronal differentiation of transplanted neural stem cells in a rat spiral ganglion neuron degeneration model.

Science.gov (United States)

He, Ya; Zhang, Peng-Zhi; Sun, Dong; Mi, Wen-Juan; Zhang, Xin-Yi; Cui, Yong; Jiang, Xing-Wang; Mao, Xiao-Bo; Qiu, Jian-Hua

2014-04-01

Although neural stem cell (NSC) transplantation is widely expected to become a therapy for nervous system degenerative diseases and injuries, the low neuronal differentiation rate of NSCs transplanted into the inner ear is a major obstacle for the successful treatment of spiral ganglion neuron (SGN) degeneration. In this study, we validated whether the local microenvironment influences the neuronal differentiation of transplanted NSCs in the inner ear. Using a rat SGN degeneration model, we demonstrated that transplanted NSCs were more likely to differentiate into microtubule-associated protein 2 (MAP2)-positive neurons in SGN-degenerated cochleae than in control cochleae. Using real-time quantitative PCR and an immunofluorescence assay, we also proved that the expression of Wnt1 (a ligand of Wnt signaling) increases significantly in Schwann cells in the SGN-degenerated cochlea. We further verified that NSC cultures express receptors and signaling components for Wnts. Based on these expression patterns, we hypothesized that Schwann cell-derived Wnt1 and Wnt signaling might be involved in the regulation of the neuronal differentiation of transplanted NSCs. We verified our hypothesis in vitro using a coculture system. We transduced a lentiviral vector expressing Wnt1 into cochlear Schwann cell cultures and cocultured them with NSC cultures. The coculture with Wnt1-expressing Schwann cells resulted in a significant increase in the percentage of NSCs that differentiated into MAP2-positive neurons, whereas this differentiation-enhancing effect was prevented by Dkk1 (an inhibitor of the Wnt signaling pathway). These results suggested that Wnt1 derived from cochlear Schwann cells enhanced the neuronal differentiation of transplanted NSCs through Wnt signaling pathway activation. Alterations of the microenvironment deserve detailed investigation because they may help us to conceive effective strategies to overcome the barrier of the low differentiation rate of transplanted

Developing an active artificial hair cell using nonlinear feedback control

Science.gov (United States)

Joyce, Bryan S.; Tarazaga, Pablo A.

2015-09-01

The hair cells in the mammalian cochlea convert sound-induced vibrations into electrical signals. These cells have inspired a variety of artificial hair cells (AHCs) to serve as biologically inspired sound, fluid flow, and acceleration sensors and could one day replace damaged hair cells in humans. Most of these AHCs rely on passive transduction of stimulus while it is known that the biological cochlea employs active processes to amplify sound-induced vibrations and improve sound detection. In this work, an active AHC mimics the active, nonlinear behavior of the cochlea. The AHC consists of a piezoelectric bimorph beam subjected to a base excitation. A feedback control law is used to reduce the linear damping of the beam and introduce a cubic damping term which gives the AHC the desired nonlinear behavior. Model and experimental results show the AHC amplifies the response due to small base accelerations, has a higher frequency sensitivity than the passive system, and exhibits a compressive nonlinearity like that of the mammalian cochlea. This bio-inspired accelerometer could lead to new sensors with lower thresholds of detection, improved frequency sensitivities, and wider dynamic ranges.

Tinnitus. I: Auditory mechanisms: a model for tinnitus and hearing impairment.

Science.gov (United States)

Hazell, J W; Jastreboff, P J

1990-02-01

A model is proposed for tinnitus and sensorineural hearing loss involving cochlear pathology. As tinnitus is defined as a cortical perception of sound in the absence of an appropriate external stimulus it must result from a generator in the auditory system which undergoes extensive auditory processing before it is perceived. The concept of spatial nonlinearity in the cochlea is presented as a cause of tinnitus generation controlled by the efferents. Various clinical presentations of tinnitus and the way in which they respond to changes in the environment are discussed with respect to this control mechanism. The concept of auditory retraining as part of the habituation process, and interaction with the prefrontal cortex and limbic system is presented as a central model which emphasizes the importance of the emotional significance and meaning of tinnitus.

Deep soft tissue leiomyoma of the thigh

International Nuclear Information System (INIS)

Watson, G.M.T.; Saifuddin, A.; Sandison, A.

1999-01-01

A case of ossified leiomyoma of the deep soft tissues of the left thigh is presented. The radiographic appearance suggested a low-grade chondrosarcoma. MRI of the lesion showed signal characteristics similar to muscle on both T1- and T2-weighted spin echo sequences with linear areas of high signal intensity on T1-weighted images consistent with medullary fat in metaplastic bone. Histopathological examination of the resected specimen revealed a benign ossified soft tissue leiomyoma. (orig.)

Modeling of light absorption in tissue during infrared neural stimulation

Science.gov (United States)

Thompson, Alexander C.; Wade, Scott A.; Brown, William G. A.; Stoddart, Paul R.

2012-07-01

A Monte Carlo model has been developed to simulate light transport and absorption in neural tissue during infrared neural stimulation (INS). A range of fiber core sizes and numerical apertures are compared illustrating the advantages of using simulations when designing a light delivery system. A range of wavelengths, commonly used for INS, are also compared for stimulation of nerves in the cochlea, in terms of both the energy absorbed and the change in temperature due to a laser pulse. Modeling suggests that a fiber with core diameter of 200 μm and NA=0.22 is optimal for optical stimulation in the geometry used and that temperature rises in the spiral ganglion neurons are as low as 0.1°C. The results show a need for more careful experimentation to allow different proposed mechanisms of INS to be distinguished.

3DCRT for posterior fossa: Sparing of surrounding organs at risk

African Journals Online (AJOL)

Azza Helal

2013-06-25

Jun 25, 2013 ... including non-posterior fossa brain, pituitary, cochlea, eyes, optic nerves, optic chiasm, ... grams; Rt.C, right cochlea; Lt. C, left cochlea; Non P.F, non posterior ... child's cognitive function and quality of life.6 Although the.

Reduced acoustic startle response and peripheral hearing loss in the 5xFAD mouse model of Alzheimer's disease.

Science.gov (United States)

O'Leary, T P; Shin, S; Fertan, E; Dingle, R N; Almuklass, A; Gunn, R K; Yu, Z; Wang, J; Brown, R E

2017-06-01

Hearing dysfunction has been associated with Alzheimer's disease (AD) in humans, but there is little data on the auditory function of mouse models of AD. Furthermore, characterization of hearing ability in mouse models is needed to ensure that tests of cognition that use auditory stimuli are not confounded by hearing dysfunction. Therefore, we assessed acoustic startle response and pre-pulse inhibition in the double transgenic 5xFAD mouse model of AD from 3-4 to 16 months of age. The 5xFAD mice showed an age-related decline in acoustic startle as early as 3-4 months of age. We subsequently tested auditory brainstem response (ABR) thresholds at 4 and 13-14 months of age using tone bursts at frequencies of 2-32 kHz. The 5xFAD mice showed increased ABR thresholds for tone bursts between 8 and 32 kHz at 13-14 months of age. Finally, cochleae were extracted and basilar membranes were dissected to count hair cell loss across the cochlea. The 5xFAD mice showed significantly greater loss of both inner and outer hair cells at the apical and basal ends of the basilar membrane than wild-type mice at 15-16 months of age. These results indicate that the 5xFAD mouse model of AD shows age-related decreases in acoustic startle responses, which are at least partially due to age-related peripheral hearing loss. Therefore, we caution against the use of cognitive tests that rely on audition in 5xFAD mice over 3-4 months of age, without first confirming that performance is not confounded by hearing dysfunction. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Deep soft tissue leiomyoma of the thigh

Energy Technology Data Exchange (ETDEWEB)

Watson, G.M.T.; Saifuddin, A. [Department of Radiology, The Royal National Orthopaedic Hospital Trust, Brockley Hill (United Kingdom); Sandison, A. [Department of Pathology, The Royal National Orthopaedic Hospital Trust, Stanmore, Middlesex (United Kingdom)

1999-07-01

A case of ossified leiomyoma of the deep soft tissues of the left thigh is presented. The radiographic appearance suggested a low-grade chondrosarcoma. MRI of the lesion showed signal characteristics similar to muscle on both T1- and T2-weighted spin echo sequences with linear areas of high signal intensity on T1-weighted images consistent with medullary fat in metaplastic bone. Histopathological examination of the resected specimen revealed a benign ossified soft tissue leiomyoma. (orig.) With 3 figs., 13 refs.

Design, construction and mechanical optimisation process of electrode with radial current flow in the scala tympani.

Science.gov (United States)

Deman, P R; Kaiser, T M; Dirckx, J J; Offeciers, F E; Peeters, S A

2003-09-30

A 48 contact cochlear implant electrode has been constructed for electrical stimulation of the auditory nerve. The stimulating contacts of this electrode are organised in two layers: 31 contacts on the upper surface directed towards the habenula perforata and 17 contacts connected together as one longitudinal contact on the underside. The design of the electrode carrier aims to make radial current flow possible in the cochlea. The mechanical structure of the newly designed electrode was optimised to obtain maximal insertion depth. Electrode insertion tests were performed in a transparent acrylic model of the human cochlea.

Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

International Nuclear Information System (INIS)

Joyce, Bryan S; Tarazaga, Pablo A

2014-01-01

The mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea’s nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity. (papers)

Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

Science.gov (United States)

Joyce, Bryan S.; Tarazaga, Pablo A.

2014-07-01

The mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea’s nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

An assessment of a conical horn waveguide to represent the human eardrum

Science.gov (United States)

Fields, Taylor N.; Schnetzer, Lucia; Brister, Eileen; Yates, Charles W.; Withnell, Robert H.

2018-05-01

This study examined a model of the acoustic input impedance of the ear that includes a waveguide model of the eardrum. The eardrum was modeled as a lossless conical-horn with rigid walls. The ear canal was modeled as a one-dimensional lossy transmission line. The output impedance of the eardrum, the middle ear, and the cochlea, was modeled as a circuit analog. The model was fit to acoustic input impedance data from human ears using a nonlinear least-squares fit. The impact of a conical-horn shape for the eardrum was quantified by comparison with the eardrum modeled as a near-flat surface. The model provided a good match to the data over the frequency range examined. A conical-horn model of the human eardrum provided gain at high frequencies, most notably above 1–2 kHz, with a broader middle-ear frequency response. This finding may suggest that eardrum shape plays an important role in sound transmission to the cochlea.

A surgical approach appropriate for targeted cochlear gene therapy in the mouse.

Science.gov (United States)

Jero, J; Tseng, C J; Mhatre, A N; Lalwani, A K

2001-01-01

Therapeutic manipulations of the mammalian cochlea, including cochlear gene transfer, have been predominantly studied using the guinea pig as the experimental model. With the significant developments in mouse genomics and the availability of mutant strains of mice with well-characterized hearing loss, the mouse justifiably will be the preferred animal model for therapeutic manipulations. However, the potential advantages of the mouse model have not been fully realized due to the surgical difficulty of accessing its small cochlea. This study describes a ventral approach, instead of the routinely used postauricular approach in other rodents, for accessing the mouse middle and inner ear, and its application in cochlear gene transfer. This ventral approach enabled rapid and direct delivery of liposome-transgene complex to the mouse inner ear while avoiding blood loss, facial nerve morbidity, and mortality. Transgene expression at 3 days was detected in Reissner's membrane, spiral limbus, spiral ligament, and spiral ganglion cells, in a pattern similar to that previously described in the guinea pig. The successful access and delivery of material to the mouse cochlea and the replication of gene expression seen in the guinea pig demonstrated in this study should promote the use of the mouse in future studies investigating targeted cochlear therapy.

Partial corrosion casting to assess cochlear vasculature in mouse models of presbycusis and CMV infection.

Science.gov (United States)

Carraro, Mattia; Park, Albert H; Harrison, Robert V

2016-02-01

Some forms of sensorineural hearing loss involve damage or degenerative changes to the stria vascularis and/or other vascular structures in the cochlea. In animal models, many methods for anatomical assessment of cochlear vasculature exist, each with advantages and limitations. One methodology, corrosion casting, has proved useful in some species, however in the mouse model this technique is difficult to achieve because digestion of non vascular tissue results in collapse of the delicate cast specimen. We have developed a partial corrosion cast method that allows visualization of vasculature along much of the cochlear length but maintains some structural integrity of the specimen. We provide a detailed step-by-step description of this novel technique. We give some illustrative examples of the use of the method in mouse models of presbycusis and cytomegalovirus (CMV) infection. Copyright © 2015 Elsevier B.V. All rights reserved.

A Mid-scala Cochlear Implant Electrode Design Achieves a Stable Post-surgical Position in the Cochlea of Patients Over Time-A Prospective Observational Study.

Science.gov (United States)

Dees, Guido; Smits, Jeroen Jules; Janssen, A Miranda L; Hof, Janny R; Gazibegovic, Dzemal; Hoof, Marc van; Stokroos, Robert J

2018-04-01

Cochlear implant (CI) electrode design impacts the clinical performance of patients. Stability and the occurrence of electrode array migration, which is the postoperative movement of the electrode array, were investigated using a mid-scalar electrode array and postoperative image analysis. A prospective observational study was conducted. A mid-scalar electrode was surgically placed using a mastoidectomy, followed by a posterior tympanotomy and an extended round-window or cochleostomy insertion. A few days after surgery and 3 months later Cone Beam Computed Tomography (CBCT) was performed. The two different CBCT's were fused, and the differences between the electrode positions in three dimensions were calculated (the migration). A migration greater than 0.5 mm was deemed clinically relevant. Fourteen subjects participated. The mid-scalar electrode migrated in one patient (7%). This did not lead to the extrusion of an electrode contact. The mean migration of every individual electrode contact in all patients was 0.36 mm (95% confidence interval 0.22-0.50 mm), which approximates to the estimated measurement error of the CBCT technique. A mid-scalar electrode array achieves a stable position in the cochlea in a small but representative group of patients. The methods applied in this work can be used for providing postoperative feedback for surgeons and for benchmarking electrode designs.

Myositis Ossificans.

Science.gov (United States)

Walczak, Brian E; Johnson, Christopher N; Howe, B Matthew

2015-10-01

Myositis ossificans is a self-limiting, benign ossifying lesion that can affect any type of soft tissue, including subcutaneous fat, tendons, and nerves. It is most commonly found in muscle as a solitary lesion. Ossifying soft-tissue lesions historically have been inconsistently classified. Fundamentally, myositis ossificans can be categorized into nonhereditary and hereditary types, with the latter being a distinct entity with a separate pathophysiology and treatment approach. The etiology of myositis ossificans is variable; however, clinical presentation generally is characterized by an ossifying soft-tissue mass. Advanced cross-sectional imaging alone can be nonspecific and may appear to be similar to more sinister etiologies. Therefore, the evaluation of a suspicious soft-tissue mass often necessitates multiple imaging modalities for accurate diagnosis. When imaging is indeterminate, biopsy may be required for a histologic diagnosis. However, histopathology varies based on stage of evolution. The treatment of myositis ossificans is complex and is often made in a multidisciplinary fashion because accurate diagnosis is fundamental to a successful outcome. Copyright 2015 by the American Academy of Orthopaedic Surgeons.

Spectrogram inversion and potential applications for hearing research

DEFF Research Database (Denmark)

Decorsière, Remi Julien Blaise

are a reasonable model of the signal processing performed by the human cochlea. The robustness of the reconstruction from such spectrograms with regards to the properties of the cochlear model showed that, for previously documented IHC models as well as for more restrictive conditions, the TFS-related information...

Pathogenesis of presbycusis in animal models: a review.

Science.gov (United States)

Fetoni, Anna R; Picciotti, Pasqualina M; Paludetti, Gaetano; Troiani, Diana

2011-06-01

Presbycusis is the most common cause of hearing loss in aged subjects, reducing individual's communicative skills. Age related hearing loss can be defined as a progressive, bilateral, symmetrical hearing loss due to age related degeneration and it can be considered a multifactorial complex disorder, with both environmental and genetic factors contributing to the aetiology of the disease. The decline in hearing sensitivity caused by ageing is related to the damage at different levels of the auditory system (central and peripheral). Histologically, the aged cochlea shows degeneration of the stria vascularis, the sensorineural epithelium, and neurons of the central auditory pathways. The mechanisms responsible for age-associated hearing loss are still incompletely characterized. This work aims to give a broad overview of the scientific findings related to presbycusis, focusing mainly on experimental studies in animal models. Copyright © 2011 Elsevier Inc. All rights reserved.

MR imaging of capitellar ossification: a study in children of different ages

International Nuclear Information System (INIS)

Fader, Lauren M.; Laor, Tal; Eismann, Emily A.; Cornwall, Roger; Little, Kevin J.

2014-01-01

The capitellar ossification center is used routinely to evaluate elbow alignment on radiography. However, whether capitellar ossification is central and concentric to support this practice is unknown. To define the pattern of capitellar ossification at different ages of childhood. This HIPAA-compliant study was IRB approved. MR imaging examinations from 81 children (ages 1-13 years, at least 3 boys and 3 girls in each age group) were included. We determined the center points of the ossified capitellum and the cartilaginous capitellum on the sagittal and coronal sequences that best showed differentiation between cartilage and bone. Percentage offset of the center of the ossified capitellum from the center of the cartilaginous capitellum was calculated in anterior-posterior, proximal-distal and medial-lateral dimensions, and compared across age groups and between genders. Linear regressions were used to ascertain the effect of age on percentage offset for all patients and for each gender. Capitellar ossification begins eccentrically with sagittal anterior proximal offset and coronal medial offset. With age, ossification proceeds posteriorly, distally and laterally. Percentage offset gradually diminishes with age. The ossified capitellum centralizes in the sagittal plane by 12-13 years. In the coronal plane, the capitellum ossifies medially beyond the proximal radioulnar joint and remains eccentric at 12-13 years. Centralization in boys lags in the anterior-posterior dimension. Capitellar ossification is an eccentric process, with lag in anterior-posterior centralization in boys. Medial offset persists at 12-13 years. Recognition of this eccentric ossification may allow for more accurate assessment of elbow alignment on radiographs, especially in younger children. (orig.)

MR imaging of capitellar ossification: a study in children of different ages

Energy Technology Data Exchange (ETDEWEB)

Fader, Lauren M. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Laor, Tal [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Eismann, Emily A.; Cornwall, Roger; Little, Kevin J. [Cincinnati Children' s Hospital Medical Center, Division of Orthopaedic Surgery, Cincinnati, OH (United States)

2014-08-15

The capitellar ossification center is used routinely to evaluate elbow alignment on radiography. However, whether capitellar ossification is central and concentric to support this practice is unknown. To define the pattern of capitellar ossification at different ages of childhood. This HIPAA-compliant study was IRB approved. MR imaging examinations from 81 children (ages 1-13 years, at least 3 boys and 3 girls in each age group) were included. We determined the center points of the ossified capitellum and the cartilaginous capitellum on the sagittal and coronal sequences that best showed differentiation between cartilage and bone. Percentage offset of the center of the ossified capitellum from the center of the cartilaginous capitellum was calculated in anterior-posterior, proximal-distal and medial-lateral dimensions, and compared across age groups and between genders. Linear regressions were used to ascertain the effect of age on percentage offset for all patients and for each gender. Capitellar ossification begins eccentrically with sagittal anterior proximal offset and coronal medial offset. With age, ossification proceeds posteriorly, distally and laterally. Percentage offset gradually diminishes with age. The ossified capitellum centralizes in the sagittal plane by 12-13 years. In the coronal plane, the capitellum ossifies medially beyond the proximal radioulnar joint and remains eccentric at 12-13 years. Centralization in boys lags in the anterior-posterior dimension. Capitellar ossification is an eccentric process, with lag in anterior-posterior centralization in boys. Medial offset persists at 12-13 years. Recognition of this eccentric ossification may allow for more accurate assessment of elbow alignment on radiographs, especially in younger children. (orig.)

Interactions between hair cells shape spontaneous otoacoustic emissions in a model of the tokay gecko's cochlea.

Directory of Open Access Journals (Sweden)

Michael Gelfand

2010-06-01

Full Text Available The hearing of tetrapods including humans is enhanced by an active process that amplifies the mechanical inputs associated with sound, sharpens frequency selectivity, and compresses the range of responsiveness. The most striking manifestation of the active process is spontaneous otoacoustic emission, the unprovoked emergence of sound from an ear. Hair cells, the sensory receptors of the inner ear, are known to provide the energy for such emissions; it is unclear, though, how ensembles of such cells collude to power observable emissions.We have measured and modeled spontaneous otoacoustic emissions from the ear of the tokay gecko, a convenient experimental subject that produces robust emissions. Using a van der Pol formulation to represent each cluster of hair cells within a tonotopic array, we have examined the factors that influence the cooperative interaction between oscillators.A model that includes viscous interactions between adjacent hair cells fails to produce emissions similar to those observed experimentally. In contrast, elastic coupling yields realistic results, especially if the oscillators near the ends of the array are weakened so as to minimize boundary effects. Introducing stochastic irregularity in the strength of oscillators stabilizes peaks in the spectrum of modeled emissions, further increasing the similarity to the responses of actual ears. Finally, and again in agreement with experimental findings, the inclusion of a pure-tone external stimulus repels the spectral peaks of spontaneous emissions. Our results suggest that elastic coupling between oscillators of slightly differing strength explains several properties of the spontaneous otoacoustic emissions in the gecko.

Interactions between hair cells shape spontaneous otoacoustic emissions in a model of the tokay gecko's cochlea.

Science.gov (United States)

Gelfand, Michael; Piro, Oreste; Magnasco, Marcelo O; Hudspeth, A J

2010-06-15

The hearing of tetrapods including humans is enhanced by an active process that amplifies the mechanical inputs associated with sound, sharpens frequency selectivity, and compresses the range of responsiveness. The most striking manifestation of the active process is spontaneous otoacoustic emission, the unprovoked emergence of sound from an ear. Hair cells, the sensory receptors of the inner ear, are known to provide the energy for such emissions; it is unclear, though, how ensembles of such cells collude to power observable emissions. We have measured and modeled spontaneous otoacoustic emissions from the ear of the tokay gecko, a convenient experimental subject that produces robust emissions. Using a van der Pol formulation to represent each cluster of hair cells within a tonotopic array, we have examined the factors that influence the cooperative interaction between oscillators. A model that includes viscous interactions between adjacent hair cells fails to produce emissions similar to those observed experimentally. In contrast, elastic coupling yields realistic results, especially if the oscillators near the ends of the array are weakened so as to minimize boundary effects. Introducing stochastic irregularity in the strength of oscillators stabilizes peaks in the spectrum of modeled emissions, further increasing the similarity to the responses of actual ears. Finally, and again in agreement with experimental findings, the inclusion of a pure-tone external stimulus repels the spectral peaks of spontaneous emissions. Our results suggest that elastic coupling between oscillators of slightly differing strength explains several properties of the spontaneous otoacoustic emissions in the gecko.

Case report 359: Gigantic benign fibrous histiocytoma (nonossifying fibroma)

International Nuclear Information System (INIS)

Remagen, W.; Nidecker, A.; Prein, J.

1986-01-01

In summary, a fascinating case is presented of an enormous 'blow-out' lesion in the left half of the mandible in a 17-year-old boy. The histological diagnosis was benign fibrous histiocytoma or non-ossifying fibroma. An extensive differential diagnosis was presented by the authors and although benign fibrous histiocytoma was their final diagnosis, they could not exclude an example of the rarely encountered entity called the Jaffe-Campanacci syndrome. This syndrome consists of multiple non-ossifying fibromas of the mandible, cafe-au-lait spots, various endocrine disorders, mental retardation, occular anomalies and cardiovascular malformations. (orig./SHA)

An animal model of tinnitus: a decade of development.

Science.gov (United States)

Jastreboff, P J; Sasaki, C T

1994-01-01

Although tinnitus affects approximately 9 million people in the United States, a cure remains elusive and the mechanisms of its origin are speculative. The crucial obstacle in tinnitus research has been the lack of an animal model. Over the last decade we have been creating such a model by combining a variety of methodologies, including a behavioral component, to allow for the detection of tinnitus perception. Initially, 2-deoxyglucose had been used to map changes in the metabolic activity after unilateral destruction of the cochlea. It has been found that the initial decrease of the metabolic rate in the auditory nuclei recovered to preoperative values, which could be attributable to the development of tinnitus. The spontaneous activity of single units recorded from the inferior colliculus before and after salicylate administration revealed an increase of discharges, which might reflect the presence of salicylate-induced tinnitus. Recent data have confirmed, and further elaborated this observation, including the discovery of abnormal, epileptic-like, neuronal activity. Finally, the authors have developed a behavioral model of tinnitus, tested it extensively, and used it to measure tinnitus pitch and loudness. The model is presently used for investigating the hypotheses for the mechanisms of tinnitus.

A New Method for Rating Hazard from Intense Sounds: Implications for Hearing Protection, Speech Intelligibility, and Situation Awareness

National Research Council Canada - National Science Library

Price, G. R

2005-01-01

.... The AHAAH model operates in a PC-level computer and analyzes hazard in the time domain. In addition to reproducing the conductive path from air to the cochlea accurately, it includes a nonlinear stapes...

Limits on normal cochlear 'third' windows provided by previous investigations of additional sound paths into and out of the cat inner ear.

Science.gov (United States)

Rosowski, John J; Bowers, Peter; Nakajima, Hideko H

2018-03-01

While most models of cochlear function assume the presence of only two windows into the mammalian cochlea (the oval and round windows), a position that is generally supported by several lines of data, there is evidence for additional sound paths into and out of the inner ear in normal mammals. In this report we review the existing evidence for and against the 'two-window' hypothesis. We then determine how existing data and inner-ear anatomy restrict transmission of sound through these additional sound pathways in cat by utilizing a well-tested model of the cat inner ear, together with anatomical descriptions of the cat cochlear and vestibular aqueducts (potential additional windows to the cochlea). We conclude: (1) The existing data place limits on the size of the cochlear and vestibular aqueducts in cat and are consistent with small volume-velocities through these ducts during ossicular stimulation of the cochlea, (2) the predicted volume velocities produced by aqueducts with diameters half the size of the bony diameters match the functional data within ±10 dB, and (3) these additional volume velocity paths contribute to the inner ear's response to non-acoustic stimulation and conductive pathology. Copyright © 2017 Elsevier B.V. All rights reserved.

Inner ear test battery in guinea pig models - a review.

Science.gov (United States)

Young, Yi-Ho

2018-06-01

This study reviewed the development of the inner ear test battery comprising auditory brainstem response (ABR), and caloric, ocular vestibular-evoked myogenic potential (oVEMP), and cervical vestibular-evoked myogenic potential (cVEMP) tests in guinea pig models at our laboratory over the last 20 years. Detailed description of the methodology for testing the small animals is also included. Inner ear disorders, i.e. ototoxicity, noise exposure, or perilymph fistula were established in guinea pig models first. One to four weeks after operation, each animal underwent ABR, oVEMP, cVEMP, and caloric tests. Then, animals were sacrificed for morphological study in the temporal bones. Inner ear endorgans can be comprehensively evaluated in guinea pig models via an inner ear test battery, which provides thorough information on the cochlea, saccule, utricle, and semicircular canal function of guinea pigs. Coupled with morphological study in the temporal bones of the animals may help elucidate the mechanism of inner ear disorders in humans. The inner ear test battery in guinea pig models may encourage young researchers to perform basic study in animals and stimulate the progress of experimental otology which is in evolution.

Histological evidence for a supraspinous ligament in sauropod dinosaurs.

Science.gov (United States)

Cerda, Ignacio A; Casal, Gabriel A; Martinez, Rubén D; Ibiricu, Lucio M

2015-10-01

Supraspinous ossified rods have been reported in the sacra of some derived sauropod dinosaurs. Although different hypotheses have been proposed to explain the origin of this structure, histological evidence has never been provided to support or reject any of them. In order to establish its origin, we analyse and characterize the microstructure of the supraspinous rod of two sauropod dinosaurs from the Upper Cretaceous of Argentina. The supraspinous ossified rod is almost entirely formed by dense Haversian bone. Remains of primary bone consist entirely of an avascular tissue composed of two types of fibre-like structures, which are coarse and longitudinally (parallel to the main axis of the element) oriented. These structures are differentiated on the basis of their optical properties under polarized light. Very thin fibrous strands are also observed in some regions. These small fibres are all oriented parallel to one another but perpendicular to the element main axis. Histological features of the primary bone tissue indicate that the sacral supraspinous rod corresponds to an ossified supraspinous ligament. The formation of this structure appears to have been a non-pathological metaplastic ossification, possibly induced by the continuous tensile forces applied to the element.

Practical Gammatone-Like Filters for Auditory Processing

Directory of Open Access Journals (Sweden)

R. F. Lyon

2007-12-01

Full Text Available This paper deals with continuous-time filter transfer functions that resemble tuning curves at particular set of places on the basilar membrane of the biological cochlea and that are suitable for practical VLSI implementations. The resulting filters can be used in a filterbank architecture to realize cochlea implants or auditory processors of increased biorealism. To put the reader into context, the paper starts with a short review on the gammatone filter and then exposes two of its variants, namely, the differentiated all-pole gammatone filter (DAPGF and one-zero gammatone filter (OZGF, filter responses that provide a robust foundation for modeling cochlea transfer functions. The DAPGF and OZGF responses are attractive because they exhibit certain characteristics suitable for modeling a variety of auditory data: level-dependent gain, linear tail for frequencies well below the center frequency, asymmetry, and so forth. In addition, their form suggests their implementation by means of cascades of N identical two-pole systems which render them as excellent candidates for efficient analog or digital VLSI realizations. We provide results that shed light on their characteristics and attributes and which can also serve as “design curves” for fitting these responses to frequency-domain physiological data. The DAPGF and OZGF responses are essentially a “missing link” between physiological, electrical, and mechanical models for auditory filtering.

Automatic Fontanel Extraction from Newborns' CT Images Using Variational Level Set

Science.gov (United States)

Kazemi, Kamran; Ghadimi, Sona; Lyaghat, Alireza; Tarighati, Alla; Golshaeyan, Narjes; Abrishami-Moghaddam, Hamid; Grebe, Reinhard; Gondary-Jouet, Catherine; Wallois, Fabrice

A realistic head model is needed for source localization methods used for the study of epilepsy in neonates applying Electroencephalographic (EEG) measurements from the scalp. The earliest models consider the head as a series of concentric spheres, each layer corresponding to a different tissue whose conductivity is assumed to be homogeneous. The results of the source reconstruction depend highly on the electric conductivities of the tissues forming the head.The most used model is constituted of three layers (scalp, skull, and intracranial). Most of the major bones of the neonates’ skull are ossified at birth but can slightly move relative to each other. This is due to the sutures, fibrous membranes that at this stage of development connect the already ossified flat bones of the neurocranium. These weak parts of the neurocranium are called fontanels. Thus it is important to enter the exact geometry of fontaneles and flat bone in a source reconstruction because they show pronounced in conductivity. Computer Tomography (CT) imaging provides an excellent tool for non-invasive investigation of the skull which expresses itself in high contrast to all other tissues while the fontanels only can be identified as absence of bone, gaps in the skull formed by flat bone. Therefore, the aim of this paper is to extract the fontanels from CT images applying a variational level set method. We applied the proposed method to CT-images of five different subjects. The automatically extracted fontanels show good agreement with the manually extracted ones.

Middle ear influence on otoacoustic emissions. I : Noninvasive investigation of the human transmission apparatus and comparison with model results

NARCIS (Netherlands)

Avan, P; Buki, B; Maat, B; Dordain, M; Wit, HP

Evoked otoacoustic emissions (EOAEs) are generated within the cochlea in response to external sounds, and they can be acoustically detected in the external auditory meatus after backward propagation through the middle ear. In addition to being used to probe the cochlear mechanisms, they are expected

Murine dishevelled 3 functions in redundant pathways with dishevelled 1 and 2 in normal cardiac outflow tract, cochlea, and neural tube development.

Science.gov (United States)

Etheridge, S Leah; Ray, Saugata; Li, Shuangding; Hamblet, Natasha S; Lijam, Nardos; Tsang, Michael; Greer, Joy; Kardos, Natalie; Wang, Jianbo; Sussman, Daniel J; Chen, Ping; Wynshaw-Boris, Anthony

2008-11-01

Dishevelled (Dvl) proteins are important signaling components of both the canonical beta-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3(-/-) mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3(-/-) and LtapLp/+ mutants, Dvl3(+/-);LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant.

Murine dishevelled 3 functions in redundant pathways with dishevelled 1 and 2 in normal cardiac outflow tract, cochlea, and neural tube development.

Directory of Open Access Journals (Sweden)

S Leah Etheridge

2008-11-01

Full Text Available Dishevelled (Dvl proteins are important signaling components of both the canonical beta-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3(-/- mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+. Although neurulation appeared normal in both Dvl3(-/- and LtapLp/+ mutants, Dvl3(+/-;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant.

Separated centers of ossification caudal to the wing of the pedal bone in horses - a help [to] rule out fractures of the wings and ossification in the accessory cartilages

International Nuclear Information System (INIS)

Hertsch, B.; Neuberth, M.

1991-01-01

Radiographic evaluation of a lat-med. x-ray of the digits of 278 normal three year old standard bred stallions (group I) and of 300 mares and geldings over the age of six years (group II) was made in view of frequency and clinical relevance of a separated center of ossification caudal to each wing of the pedal bone. The material served both age associated judgement and localisation dependant morphological description of these separated ossified bone piece. Through comparative measurements of the angle of the dorsal hoof wall in the two groups of horses, a possible etiological aspect especially concerning the hoof form is discussed, to true nature of this small separated ossified bone piece

Can components in distortion-product otoacoustic emissions be separated?

DEFF Research Database (Denmark)

Christensen, Anders Tornvig; W. Purcell, David; Christensen, Flemming

2012-01-01

Otoacoustic emissions are signals emitted from the cochlea, either spontaneously or evoked by stimuli. Measured with an acoustic probe sealed in the ear-canal, they reveal information about a part of the mechanism of hearing that is otherwise inaccessible. Outer hair cells in the cochlea work...... to improve hearing sensitivity by means of nonlinear amplification, which produces distortion. In the measurement of otoacoustic emissions, two tones can be delivered to the cochlea to invoke this nonlinearity and elicit the distortion-product otoacoustic emission (DPOAE). DPOAEs arise mainly from two...... spatially separated generation mechanisms, thus making interpretation of DPOAE measurements complicated. In this study, we test whether or not source separation by group delays is equivalent to separation by time delays – either result is equally interesting to understand given the complexity of the cochlea...

Scar formation in mice deafened with kanamycin and furosemide

NARCIS (Netherlands)

Zak, Magdalena; van der Linden, Cynthia A; Bezdjian, Aren; Hendriksen, Ferry G; Klis, Sjaak F L; Grolman, Wilko

In mammals, hair cell loss is irreversible and leads to hearing loss. To develop and test the functioning of different strategies aiming at hair cell regeneration, animal models of sensorineural hearing loss are essential. Although cochleae of these animals should lack hair cells, supporting cells

Localization of the cochlear amplifier in living sensitive ears.

Directory of Open Access Journals (Sweden)

Tianying Ren

Full Text Available BACKGROUND: To detect soft sounds, the mammalian cochlea increases its sensitivity by amplifying incoming sounds up to one thousand times. Although the cochlear amplifier is thought to be a local cellular process at an area basal to the response peak on the spiral basilar membrane, its location has not been demonstrated experimentally. METHODOLOGY AND PRINCIPAL FINDINGS: Using a sensitive laser interferometer to measure sub-nanometer vibrations at two locations along the basilar membrane in sensitive gerbil cochleae, here we show that the cochlea can boost soft sound-induced vibrations as much as 50 dB/mm at an area proximal to the response peak on the basilar membrane. The observed amplification works maximally at low sound levels and at frequencies immediately below the peak-response frequency of the measured apical location. The amplification decreases more than 65 dB/mm as sound levels increases. CONCLUSIONS AND SIGNIFICANCE: We conclude that the cochlea amplifier resides at a small longitudinal region basal to the response peak in the sensitive cochlea. These data provides critical information for advancing our knowledge on cochlear mechanisms responsible for the remarkable hearing sensitivity, frequency selectivity and dynamic range.

Evaluation of focused multipolar stimulation for cochlear implants: a preclinical safety study

Science.gov (United States)

Shepherd, Robert K.; Wise, Andrew K.; Enke, Ya Lang; Carter, Paul M.; Fallon, James B.

2017-08-01

Objective. Cochlear implants (CIs) have a limited number of independent stimulation channels due to the highly conductive nature of the fluid-filled cochlea. Attempts to develop highly focused stimulation to improve speech perception in CI users includes the use of simultaneous stimulation via multiple current sources. Focused multipolar (FMP) stimulation is an example of this approach and has been shown to reduce interaction between stimulating channels. However, compared with conventional biphasic current pulses generated from a single current source, FMP is a complex stimulus that includes extended periods of stimulation before charge recovery is achieved, raising questions on whether chronic stimulation with this strategy is safe. The present study evaluated the long-term safety of intracochlear stimulation using FMP in a preclinical animal model of profound deafness. Approach. Six cats were bilaterally implanted with scala tympani electrode arrays two months after deafening, and received continuous unilateral FMP stimulation at levels that evoked a behavioural response for periods of up to 182 d. Electrode impedance, electrically-evoked compound action potentials (ECAPs) and auditory brainstem responses (EABRs) were monitored periodically over the course of the stimulation program from both the stimulated and contralateral control cochleae. On completion of the stimulation program cochleae were examined histologically and the electrode arrays were evaluated for evidence of platinum (Pt) corrosion. Main results. There was no significant difference in electrode impedance between control and chronically stimulated electrodes following long-term FMP stimulation. Moreover, there was no significant difference between ECAP and EABR thresholds evoked from control or stimulated cochleae at either the onset of stimulation or at completion of the stimulation program. Chronic FMP stimulation had no effect on spiral ganglion neuron (SGN) survival when compared with

A Nonlinear Transmission Line Model of the Cochlea With Temporal Integration Accounts for Duration Effects in Threshold Fine Structure

DEFF Research Database (Denmark)

Verhey, Jesko L.; Mauermann, Manfred; Epp, Bastian

2017-01-01

For normal-hearing listeners, auditory pure-tone thresholds in quiet often show quasi periodic fluctuations when measured with a high frequency resolution, referred to as threshold fine structure. Threshold fine structure is dependent on the stimulus duration, with smaller fluctuations for short...... than for long signals. The present study demonstrates how this effect can be captured by a nonlinear and active model of the cochlear in combination with a temporal integration stage. Since this cochlear model also accounts for fine structure and connected level dependent effects, it is superior...

Low power adder based auditory filter architecture.

Science.gov (United States)

Rahiman, P F Khaleelur; Jayanthi, V S

2014-01-01

Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

Low Power Adder Based Auditory Filter Architecture

Directory of Open Access Journals (Sweden)

P. F. Khaleelur Rahiman

2014-01-01

Full Text Available Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

Effect of excitation direction on cochlear macro-mechanics during bone conduction stimulation

Science.gov (United States)

Kamieniecki, Konrad; Tudruj, Sylwester; Piechna, Janusz; Borkowski, Paweł

2018-05-01

In many instances of hearing loss, audiological improvement can be made via direct excitation of a temporal bone (i.e., bone conduction). In order to design better and more efficient devices, the macro-mechanics of the bone conduction hearing pathway must be better understood. Based on previous empirical work, numerical models are useful. In this work, we present results of a time-domain Fluid Structure Interaction model that describes stimulation of the bone conduction pathway. The cochlea was modelled as uncoiled and consisted of an oval window, a round window, a basilar membrane and a helicotrema. In order to monitor pressure waves in the perilymph, the fluid was considered compressible. The excitation, in form of sinusoidal velocity, was applied to the cochlea bony walls. The system was excited in three perpendicular directions: along the basilar membrane, perpendicularly to the membrane and transversely to the membrane. The numerical simulation examined which stimulation direction maximally excited the basilar membrane, the pressure distributions for each excitation direction, and the associated mechanics.

Cochlear Outer-Hair-Cell Power Generation and Viscous Fluid Loss

Science.gov (United States)

Wang, Yanli; Steele, Charles R.; Puria, Sunil

2016-01-01

Since the discovery of otoacoustic emissions and outer hair cell (OHC) motility, the fundamental question of whether the cochlea produces mechanical power remains controversial. In the present work, direct calculations are performed on power loss due to fluid viscosity and power generated by the OHCs. A three-dimensional box model of the mouse cochlea is used with a feed-forward/feed-backward approximation representing the organ of Corti cytoarchitecture. The model is fit to in vivo basilar membrane motion with one free parameter for the OHCs. The calculations predict that the total power output from the three rows of OHCs can be over three orders of magnitude greater than the acoustic input power at 10 dB sound pressure level (SPL). While previous work shows that the power gain, or the negative damping, diminishes with intensity, we show explicitly based on our model that OHC power output increases and saturates with SPL. The total OHC power output is about 2 pW at 80 dB SPL, with a maximum of about 10 fW per OHC.

Deriving cochlear delays in humans using otoacoustic emissions and auditory evoked potentials

DEFF Research Database (Denmark)

Pigasse, Gilles

A great deal of the processing of incoming sounds to the auditory system occurs within the cochlear. The organ of Corti within the cochlea has differing mechanical properties along its length that broadly gives rise to frequency selectivity. Its stiffness is at maximum at the base and decreases...... relation between frequency and travel time in the cochlea defines the cochlear delay. This delay is directly associated with the signal analysis occurring in the inner ear and is therefore of primary interest to get a better knowledge of this organ. It is possible to estimate the cochlear delay by direct...... and invasive techniques, but these disrupt the normal functioning of the cochlea and are usually conducted in animals. In order to obtain an estimate of the cochlear delay that is closer to the normally functioning human cochlea, the present project investigates non-invasive methods in normal hearing adults...

Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling

Directory of Open Access Journals (Sweden)

Shanguo Yang

2016-01-01

Full Text Available Round window (RW stimulation is a new type of middle ear implant’s application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation’s ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation’s ESP severely at higher frequencies.

Follow-up of cochlear implant use in patients who developed bacterial meningitis following cochlear implantation.

Science.gov (United States)

Mancini, Patrizia; D'Elia, Chiara; Bosco, Ersilia; De Seta, Elio; Panebianco, Valeria; Vergari, Valeria; Filipo, Roberto

2008-08-01

The present study is a long-term follow-up of speech perception outcomes and cochlear implant use in three cases of meningitis that occurred after cochlear implantation. Case series study. Study was performed on three children implanted with different models of Clarion devices, two of them with positioner. Recognition and comprehension were assessed via the Italian adaptation of GASP (TAP) test, and phonetically balanced bi-syllabic words in open-set. High resolution computed tomography scan acquisition was performed to obtain axial coronal and oblique multiplanar reconstructions of the cochlea. Two patients were affected by enlarged cochlear acqueduct and Mondini malformation the first carrying positioner. One patient had a normal cochlea, and the positioner could have been the main cause of bacterial spread. As a consequence of meningitis the child with normal cochlea and the other with enlarged vestibular acqueduct developed cochlear ossification, increased M-level and worsening of hearing outcomes. The child with Mondini malformation developed facial nerve stimulation. Contralateral implantation was performed in the first two patients. Bacterial meningitis occurring after cochlear implantation may induce cochlear ossification, facial nerve stimulation, and permanent or temporary loss of implant use. Planned follow-up with high resolution computed tomography and evaluation of M-levels could be useful prognostic tools in the management of these patients.

Modiolus-Hugging Intracochlear Electrode Array with Shape Memory Alloy

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Kyou Sik Min

2013-01-01

Full Text Available In the cochlear implant system, the distance between spiral ganglia and the electrodes within the volume of the scala tympani cavity significantly affects the efficiency of the electrical stimulation in terms of the threshold current level and spatial selectivity. Because the spiral ganglia are situated inside the modiolus, the central axis of the cochlea, it is desirable that the electrode array hugs the modiolus to minimize the distance between the electrodes and the ganglia. In the present study, we propose a shape-memory-alloy-(SMA- embedded intracochlear electrode which gives a straight electrode a curved modiolus-hugging shape using the restoration force of the SMA as triggered by resistive heating after insertion into the cochlea. An eight-channel ball-type electrode array is fabricated with an embedded titanium-nickel SMA backbone wire. It is demonstrated that the electrode array changes its shape in a transparent plastic human cochlear model. To verify the safe insertion of the electrode array into the human cochlea, the contact pressures during insertion at the electrode tip and the contact pressures over the electrode length after insertion were calculated using a 3D finite element analysis. The results indicate that the SMA-embedded electrode is functionally and mechanically feasible for clinical applications.

Effects of Tumor Necrosis Factor Blocker on Salicylate-Induced Tinnitus in Mice.

Science.gov (United States)

Hwang, Juen-Haur; Huang, David Chang-Wei; Lu, Yin-Chang; Yang, Wei-Shiung; Liu, Tien-Chen

2017-06-01

Neuroinflammation is considered a novel mechanism for acute tinnitus. Here, we investigated the effects of a tumor necrosis factor (TNF) blocker on the gene expression of inflammatory-cytokine in the cochlea in a tinnitus animal model. Enbrel® (30 mg/kg, intraperitoneally (i.p.)) were administrated to the mice with the salicylate induced tinnitus for 3 days. Tinnitus score and mRNA expression levels of TNFR1, TNFR2, and N-methyl-d-aspartate receptor subunit 2B (NR2B) and its downstream regulatory element antagonist modulator (DREAM) in the cochlea of mice were measured and compared to the control. The tinnitus score significantly decreased in the Enbrel® treated group. The mRNA levels of both TNFR1 and TNFR2 were significantly lower in the treatment than in the control group. The mRNA levels of NR2B and DREAM followed a similar trend. we found that treatment with 30 mg/ kg Enbrel® decreased salicylate-induced behavior associated with tinnitus and reduced the mRNA expression levels of TNFR1/R2, NR2B, and DREAM in the cochlea of mice. These findings supported the hypothesis that neuroinflammation might be a novel mechanism for salicylate-induced tinnitus.

Expression and function of scleraxis in the developing auditory system.

Directory of Open Access Journals (Sweden)

Zoe F Mann

Full Text Available A study of genes expressed in the developing inner ear identified the bHLH transcription factor Scleraxis (Scx in the developing cochlea. Previous work has demonstrated an essential role for Scx in the differentiation and development of tendons, ligaments and cells of chondrogenic lineage. Expression in the cochlea has been shown previously, however the functional role for Scx in the cochlea is unknown. Using a Scx-GFP reporter mouse line we examined the spatial and temporal patterns of Scx expression in the developing cochlea between embryonic day 13.5 and postnatal day 25. Embryonically, Scx is expressed broadly throughout the cochlear duct and surrounding mesenchyme and at postnatal ages becomes restricted to the inner hair cells and the interdental cells of the spiral limbus. Deletion of Scx results in hearing impairment indicated by elevated auditory brainstem response (ABR thresholds and diminished distortion product otoacoustic emission (DPOAE amplitudes, across a range of frequencies. No changes in either gross cochlear morphology or expression of the Scx target genes Col2A, Bmp4 or Sox9 were observed in Scx(-/- mutants, suggesting that the auditory defects observed in these animals may be a result of unidentified Scx-dependent processes within the cochlea.

Osteological development of wild-captured larvae and a juvenile Sebastes koreanus (Pisces, Scorpaenoidei from the Yellow Sea

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Hyo Jae Yu

2016-06-01

Full Text Available Abstract The osteological development in Sebastes koreanus is described and illustrated on the basis of 32 larvae [6.11–11.10 mm body length (BL] and a single juvenile (18.60 mm BL collected from the Yellow Sea. The first-ossified skeletal elements, which are related to feeding, swimming, and respiration, appear in larvae of 6.27 mm BL; these include the jaw bones, palatine, opercular, hyoid arch, and pectoral girdle. All skeletal elements are fully ossified in the juvenile observed in the study. Ossification of the neurocranium started in the frontal, pterotic, and parietal regions at 6.27 mm BL, and then in the parasphenoid and basioccipital regions at 8.17 mm BL. The vertebrae had started to ossify at ~7.17 mm BL, and their ossification was nearly complete at 11.10 mm BL. In the juvenile, although ossification of the pectoral girdle was fully complete, the fusion of the scapula and uppermost radial had not yet occurred. Thus, the scapula and uppermost radial fuse during or after the juvenile stage. The five hypurals in the caudal skeleton were also fused to form three hypural elements. The osteological results are discussed from a functional viewpoint and in terms of the comparative osteological development in related species.

Mouse Models for Pendrin-Associated Loss of Cochlear and Vestibular Function

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Philine Wangemann

2013-12-01

Full Text Available The human gene SLC26A4 and the mouse ortholog Slc26a4 code for the protein pendrin, which is an anion exchanger expressed in apical membranes of selected epithelia. In the inner ear, pendrin is expressed in the cochlea, the vestibular labyrinth and the endolymphatic sac. Loss-of-function and hypo-functional mutations cause an enlargement of the vestibular aqueduct (EVA and sensorineural hearing loss. The relatively high prevalence of SLC26A4 mutations provides a strong imperative to develop rational interventions that delay, ameliorate or prevent pendrin-associated loss of cochlear and vestibular function. This review summarizes recent studies in mouse models that have been developed to delineate the role of pendrin in the physiology of hearing and balance and that have brought forward the concept that a temporally and spatially limited therapy may be sufficient to secure a life-time of normal hearing in children bearing mutations of SLC26A4.

Nanosecond laser pulse stimulation of spiral ganglion neurons and model cells.

Science.gov (United States)

Rettenmaier, Alexander; Lenarz, Thomas; Reuter, Günter

2014-04-01

Optical stimulation of the inner ear has recently attracted attention, suggesting a higher frequency resolution compared to electrical cochlear implants due to its high spatial stimulation selectivity. Although the feasibility of the effect is shown in multiple in vivo experiments, the stimulation mechanism remains open to discussion. Here we investigate in single-cell measurements the reaction of spiral ganglion neurons and model cells to irradiation with a nanosecond-pulsed laser beam over a broad wavelength range from 420 nm up to 1950 nm using the patch clamp technique. Cell reactions were wavelength- and pulse-energy-dependent but too small to elicit action potentials in the investigated spiral ganglion neurons. As the applied radiant exposure was much higher than the reported threshold for in vivo experiments in the same laser regime, we conclude that in a stimulation paradigm with nanosecond-pulses, direct neuronal stimulation is not the main cause of optical cochlea stimulation.

Virtualized cognitive network architecture for 5G cellular networks

KAUST Repository

Elsawy, Hesham; Dahrouj, Hayssam; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

2015-01-01

, tactile Internet, online gaming, multimedia). Such an ossified architecture imposes several hurdles against achieving the ambitious metrics of next generation cellular systems. This article first highlights the features and drawbacks of such architectural

X-ray and neutron tomography on the bony inner ear of baleen whales; Roentgen- und Neutronentomographie am knoechernen Innenohr der Bartenwale

Energy Technology Data Exchange (ETDEWEB)

Arlt, Tobias [Technische Univ. Berlin (Germany); Wieder, Frank [Bundesanstalt fuer Materialforschung und -pruefung BAM, Berlin (Germany). Fachgruppe 8.3 ' ' Radiologische Verfahren' ' ; Hilger, Andre; Kardjilov, Nikolay [Helmholtz-Zentrum Berlin HZB, Berlin (Germany); Hampe, Oliver [Museum fuer Naturkunde, Berlin (Germany); Manke, Ingo [Helmholtz-Zentrum Berlin (HZB) fuer Materialien und Energie, Berlin (Germany). Fachgruppe ' ' Bildgebende Verfahren' ' ; Ritsche, Indira; Fahlke, Julia M.

2018-04-01

During their evolution whales and dolphins developed a highly specialized hearing organ for orientation in their deep sea territory covering a broad acoustic spectrum. The internal anatomy of the periotic bone, especially the morphology of the cochlea, has a significant influence on the hearing capability of mammals. The bony and fossilized cochleae of several fossil representatives of extinct baleen whales (e.g., Cetotheriidae) and modern rorquals (Balaenopteridae) and right whales, as well as cochleae of an archaeocete and some land mammals are investigated by X-ray and neutron tomography in order to record morphological changes that may be responsible for the development of low frequency hearing. Differences in the cochlear morphology have been determined by means of morphometric parameters, such as the number of turns, the length of the cochlea, and the curvature of the cochlear canal. In particular, X-ray tomography enables a high resolution display of the bony inner ear.

X-ray and neutron tomography on the bony inner ear of baleen whales

International Nuclear Information System (INIS)

Arlt, Tobias; Wieder, Frank; Hampe, Oliver; Manke, Ingo; Ritsche, Indira; Fahlke, Julia M.

2018-01-01

During their evolution whales and dolphins developed a highly specialized hearing organ for orientation in their deep sea territory covering a broad acoustic spectrum. The internal anatomy of the periotic bone, especially the morphology of the cochlea, has a significant influence on the hearing capability of mammals. The bony and fossilized cochleae of several fossil representatives of extinct baleen whales (e.g., Cetotheriidae) and modern rorquals (Balaenopteridae) and right whales, as well as cochleae of an archaeocete and some land mammals are investigated by X-ray and neutron tomography in order to record morphological changes that may be responsible for the development of low frequency hearing. Differences in the cochlear morphology have been determined by means of morphometric parameters, such as the number of turns, the length of the cochlea, and the curvature of the cochlear canal. In particular, X-ray tomography enables a high resolution display of the bony inner ear.

Medline Plus

Full Text Available ... cochlea, which is a fluid-filled snail-like structure that contains the receptor organ for hearing. The cochlea contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate the fluid vibration of sounds from ...

Concomitant occurrence of cochleosaccular dysplasia and Down's syndrome.

Science.gov (United States)

Walby, A P; Schuknecht, H F

1984-07-01

Inherited cochleosaccular dysplasia occurred in a woman coincidentally with Down's syndrome. Study of the right temporal bone revealed abnormalities of the cochlea and saccule consistent with Scheibe 's original description. There was also a short cochlea and small lateral semicircular canal consistent with previous descriptions of Down's syndrome.

The Role of Thiamine Pyrophosphate in Prevention of Cisplatin Ototoxicity in an Animal Model

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Ozan Kuduban

2013-01-01

Full Text Available Objective. The aim of this study was to evaluate the effectiveness of thiamine pyrophosphate against cisplatin-induced ototoxicity in guinea pigs. Materials and Methods. Healthy guinea pigs (n=18 were randomly divided into three groups. Group 1 (n=6 received an intraperitoneal injection of saline solution and cisplatin for 7 days, group 2 (n=6 received an intraperitoneal injection of thiamine pyrophosphate and cisplatin for 7 days, and group 3 (n=6 received only intraperitoneal injection of saline for 7 days. The animals in all groups were sacrificed under anesthesia, and their cochleas were harvested for morphological and biochemical observations. Results. In group 1, receiving only cisplatin, cochlear glutathione concentrations, superoxide dismutase, and glutathione peroxidase activities significantly decreased (P<0.05 and malondialdehyde concentrations significantly increased (P<0.05 compared to the control group. In group 2, receiving thiamine pyrophosphate and cisplatin, the concentrations of enzymes were near those of the control group. Microscopic examination showed that outer hair cells, spiral ganglion cells, and stria vascularis were preserved in group 2. Conclusion. Systemic administration of thiamine pyrophosphate yielded statistically significant protection to the cochlea of guinea pigs from cisplatin toxicity. Further experimental animal studies are essential to determine the appropriate indications of thiamine pyrophosphate before clinical use.

ISSN 2073-9990 East Cent. Afr. J. 0 East Cent. Afr. J. 0 East Cent ...

African Journals Online (AJOL)

dell

2014-04-01

Apr 1, 2014 ... literature exhibit the rare existence of this lesion in the nasal bone, orbit, ethmoid sinus, sphenoid ... diagnosis of ossifying fibroma (OF) was made. ... Radiographic examination revealed a giant expansile lesion involving the.

Cochlear pathology following reimplantation of a multichannel scala tympani electrode array in the macaque.

Science.gov (United States)

Shepherd, R K; Clark, G M; Xu, S A; Pyman, B C

1995-03-01

The histopathologic consequence of removing and reimplanting intracochlear electrode arrays on residual auditory nerve fibers is an important issue when evaluating the safety of cochlear prostheses. The authors have examined this issue by implanting multichannel intracochlear electrodes in macaque monkeys. Macaques were selected because of the similarity of the surgical technique used to insert electrodes into the cochlea compared to that in humans, in particular the ability to insert the arrays into the upper basal turn. Five macaques were bilaterally implanted with the Melbourne/Cochlear banded electrode array. Following a minimum implant period of 5 months, the electrode array on one side of each animal was removed and another immediately implanted. The animals were sacrificed a minimum of 5 months following the reinsertion procedure, and the cochleas prepared for histopathologic analysis. Long-term implantation of the electrode resulted in a relatively mild tissue response within the cochlea. Results also showed that inner and outer hair cell survival, although significantly reduced adjacent to the array, was normal in 8 of the 10 cochleas apicalward. Moreover, the electrode reinsertion procedure did not appear to adversely affect this apical hair cell population. Significant new bone formation was frequently observed in both control and reimplanted cochleas close to the electrode fenestration site and was associated with trauma to the endosteum and/or the introduction of bone chips into the cochlea at the time of surgery. Electrode insertion trauma, involving the osseous spiral lamina or basilar membrane, was more commonly observed in reimplanted cochleas. This damage was usually restricted to the lower basal turn and resulted in a more extensive ganglion cell loss. Finally, in a number of cochleas part of the electrode array was located within the scala media or scala vestibuli. These electrodes did not appear to evoke a more extensive tissue response or

Fine Tuning of CaV1.3 Ca2+ channel properties in adult inner hair cells positioned in the most sensitive region of the Gerbil Cochlea.

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Valeria Zampini

Full Text Available Hearing relies on faithful signal transmission by cochlear inner hair cells (IHCs onto auditory fibres over a wide frequency and intensity range. Exocytosis at IHC ribbon synapses is triggered by Ca(2+ inflow through Ca(V1.3 (L-type Ca(2+ channels. We investigated the macroscopic (whole-cell and elementary (cell-attached properties of Ca(2+ currents in IHCs positioned at the middle turn (frequency ∼ 2 kHz of the adult gerbil cochlea, which is their most sensitive hearing region. Using near physiological recordings conditions (body temperature and a Na(+ based extracellular solution, we found that the macroscopic Ca(2+ current activates and deactivates very rapidly (time constant below 1 ms and inactivates slowly and only partially. Single-channel recordings showed an elementary conductance of 15 pS, a sub-ms latency to first opening, and a very low steady-state open probability (Po: 0.024 in response to 500-ms depolarizing steps at ∼-18 mV. The value of Po was significantly larger (0.06 in the first 40 ms of membrane depolarization, which corresponds to the time when most Ca(2+ channel openings occurred clustered in bursts (mean burst duration: 19 ms. Both the Po and the mean burst duration were smaller than those previously reported in high-frequency basal IHCs. Finally, we found that middle turn IHCs are likely to express about 4 times more Ca(2+ channels per ribbon than basal cells. We propose that middle-turn IHCs finely-tune Ca(V1.3 Ca(2+ channel gating in order to provide reliable information upon timing and intensity of lower-frequency sounds.

Fine Tuning of CaV1.3 Ca2+ channel properties in adult inner hair cells positioned in the most sensitive region of the Gerbil Cochlea.

Science.gov (United States)

Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Knipper, Marlies; Holley, Matthew C; Magistretti, Jacopo; Russo, Giancarlo; Marcotti, Walter; Masetto, Sergio

2014-01-01

Hearing relies on faithful signal transmission by cochlear inner hair cells (IHCs) onto auditory fibres over a wide frequency and intensity range. Exocytosis at IHC ribbon synapses is triggered by Ca(2+) inflow through Ca(V)1.3 (L-type) Ca(2+) channels. We investigated the macroscopic (whole-cell) and elementary (cell-attached) properties of Ca(2+) currents in IHCs positioned at the middle turn (frequency ∼ 2 kHz) of the adult gerbil cochlea, which is their most sensitive hearing region. Using near physiological recordings conditions (body temperature and a Na(+) based extracellular solution), we found that the macroscopic Ca(2+) current activates and deactivates very rapidly (time constant below 1 ms) and inactivates slowly and only partially. Single-channel recordings showed an elementary conductance of 15 pS, a sub-ms latency to first opening, and a very low steady-state open probability (Po: 0.024 in response to 500-ms depolarizing steps at ∼-18 mV). The value of Po was significantly larger (0.06) in the first 40 ms of membrane depolarization, which corresponds to the time when most Ca(2+) channel openings occurred clustered in bursts (mean burst duration: 19 ms). Both the Po and the mean burst duration were smaller than those previously reported in high-frequency basal IHCs. Finally, we found that middle turn IHCs are likely to express about 4 times more Ca(2+) channels per ribbon than basal cells. We propose that middle-turn IHCs finely-tune Ca(V)1.3 Ca(2+) channel gating in order to provide reliable information upon timing and intensity of lower-frequency sounds.

A zebrafish model for Waardenburg syndrome type IV reveals diverse roles for Sox10 in the otic vesicle.

Science.gov (United States)

Dutton, Kirsten; Abbas, Leila; Spencer, Joanne; Brannon, Claire; Mowbray, Catriona; Nikaido, Masataka; Kelsh, Robert N; Whitfield, Tanya T

2009-01-01

In humans, mutations in the SOX10 gene are a cause of the auditory-pigmentary disorder Waardenburg syndrome type IV (WS4) and related variants. SOX10 encodes an Sry-related HMG box protein essential for the development of the neural crest; deafness in WS4 and other Waardenburg syndromes is usually attributed to loss of neural-crest-derived melanocytes in the stria vascularis of the cochlea. However, SOX10 is strongly expressed in the developing otic vesicle and so direct roles for SOX10 in the otic epithelium might also be important. Here, we examine the otic phenotype of zebrafish sox10 mutants, a model for WS4. As a cochlea is not present in the fish ear, the severe otic phenotype in these mutants cannot be attributed to effects on this tissue. In zebrafish sox10 mutants, we see abnormalities in all otic placodal derivatives. Gene expression studies indicate deregulated expression of several otic genes, including fgf8, in sox10 mutants. Using a combination of mutant and morphant data, we show that the three sox genes belonging to group E (sox9a, sox9b and sox10) provide a link between otic induction pathways and subsequent otic patterning: they act redundantly to maintain sox10 expression throughout otic tissue and to restrict fgf8 expression to anterior macula regions. Single-cell labelling experiments indicate a small and transient neural crest contribution to the zebrafish ear during normal development, but this is unlikely to account for the strong defects seen in the sox10 mutant. We discuss the implication that the deafness in WS4 patients with SOX10 mutations might reflect a haploinsufficiency for SOX10 in the otic epithelium, resulting in patterning and functional abnormalities in the inner ear.

Epithelial cell stretching and luminal acidification lead to a retarded development of stria vascularis and deafness in mice lacking pendrin.

Directory of Open Access Journals (Sweden)

Hyoung-Mi Kim

2011-03-01

Full Text Available Loss-of-function mutations of SLC26A4/pendrin are among the most prevalent causes of deafness. Deafness and vestibular dysfunction in the corresponding mouse model, Slc26a4(-/-, are associated with an enlargement and acidification of the membranous labyrinth. Here we relate the onset of expression of the HCO(3 (- transporter pendrin to the luminal pH and to enlargement-associated epithelial cell stretching. We determined expression with immunocytochemistry, cell stretching by digital morphometry and pH with double-barreled ion-selective electrodes. Pendrin was first expressed in the endolymphatic sac at embryonic day (E 11.5, in the cochlear hook-region at E13.5, in the utricle and saccule at E14.5, in ampullae at E16.5, and in the upper turn of the cochlea at E17.5. Epithelial cell stretching in Slc26a4(-/- mice began at E14.5. pH changes occurred first in the cochlea at E15.5 and in the endolymphatic sac at E17.5. At postnatal day 2, stria vascularis, outer sulcus and Reissner's membrane epithelial cells, and utricular and saccular transitional cells were stretched, whereas sensory cells in the cochlea, utricle and saccule did not differ between Slc26a4(+/- and Slc26a4(-/- mice. Structural development of stria vascularis, including vascularization, was retarded in Slc26a4(-/- mice. In conclusion, the data demonstrate that the enlargement and stretching of non-sensory epithelial cells precedes luminal acidification in the cochlea and the endolymphatic sac. Stretching and luminal acidification may alter cell-to-cell communication and lead to the observed retarded development of stria vascularis, which may be an important step on the path to deafness in Slc26a4(-/- mice, and possibly in humans, lacking functional pendrin expression.

MR imaging of proximal femur: age-related changes

International Nuclear Information System (INIS)

Kim, Ju Heon; Jeon, Woo Jin; Sohn, Cheol Ho; Park, Mi Ok; Lee, Seong Mun; Joo, Yang Gu; Suh, Soo Jhi; Pyun, Young Sik

1995-01-01

The purpose of this study is to illustrate MR patterns of signal intensity of proximal femur in normal subjects according to the age distribution. T1-weighted MR images of the proximal femur in 125 subjects, aged 13 days to 25 years, were retrospectively analyzed. Age distribution was classified to 4 groups; below 4 months, 5 months to 4 years, 5 years to 14 years, and 15 years to 25 years. By the age of 4 months, the non-ossified femoral epiphysis was seen as intermediate-signal-intensity cartilage. At 5 months-4 years, the ossified femoral capital epiphysis was seen within intermediate-signal-intensity cartilage and appeared as decreased or increased signal-intensity red or yellow marrow surrounded by a rim of low-signal-intensity cortical bone. At 5-14 years, the ossified femoral capital and greater trochanteric epiphysis were seen within the intermediate-signal-intensity cartilage and appeared as decreased or increased signal-intensity red or yellow marrow. At 15-25 years, the proximal metaphyseal marrow showed increased signal intensity. Four patterns of the metaphyseal marrow were recognized by Ricci et al. The frequency of pattern 1 a progressively decreased with age. Pattern 2 and 3 were visible in the 15-25 years age group. An understanding of the spectrum of normal age-related change of the proximal femoral cartilage and marrow patterns serves as the foundation for interpretation of proximal femur pathologies

Anomalous facial nerve canal with cochlear malformations.

Science.gov (United States)

Romo, L V; Curtin, H D

2001-05-01

Anteromedial "migration" of the first segment of the facial nerve canal has been previously identified in a patient with a non-Mondini-type cochlear malformation. In this study, several patients with the same facial nerve canal anomaly were reviewed to assess for the association and type of cochlear malformation. CT scans of the temporal bone of 15 patients with anteromedial migration of the first segment of the facial nerve canal were collected from routine departmental examinations. In seven patients, the anomalous course was bilateral, for a total of 22 cases. The migration was graded relative to normal as either mild/moderate or pronounced. The cochlea in each of these cases was examined for the presence and size of the basilar, second, and apical turns. The turns were either absent, small, normal, or enlarged. The CT scans of five patients with eight Mondini malformations were examined for comparison. The degree of the facial nerve migration was pronounced in nine cases and mild/moderate in 13. All 22 of these cases had associated cochlear abnormalities of the non-Mondini variety. These included common cavity anomalies with lack of definition between the cochlea and vestibule (five cases), cochleae with enlarged basilar turns and absent second or third turns (five cases), and cochleae with small or normal basilar turns with small or absent second or third turns (12 cases). None of the patients with Mondini-type cochlear malformations had anteromedial migration of the facial nerve canal. Anteromedial migration of the facial nerve canal occurs in association with some cochlear malformations. It did not occur in association with the Mondini malformations. A cochlea with a Mondini malformation, being similar in size to a normal cochlea, may physically prohibit such a deviation in course.

Four variations of the Mondini inner ear malformations as seen in microdissections.

Science.gov (United States)

Johnsson, L G; Hawkins, J E; Rouse, R C; Kingsley, T C

1984-01-01

Four variations and degrees of severity of the Mondini malformation were found in the temporal bones from two neonates, one with congenital heart disease and the other with trisomy D, and from one teenager with leukemia: 1) short cochlea and normal vestibular organs; 2) short cochlea and persistent horizontal canal anlage; 3) markedly shortened cochlea with no modiolus, wide internal auditory meatus, and persistent horizontal canal anlage; 4) same as variation 3, but with persistent anlagen in all semicircular canals. Variations 3 and 4 were from the case of trisomy D, in which the left cochlea had a normal hair cell population but few nerve fibers, and the intraganglionic spiral bundle was displaced from Rosenthal's canal to the osseous spiral lamina. The right ear had no cochlear nerve fibers; the organ of Corti was present, but hair cells were unusually small. In the case of trisomy D, both ears showed subtotal loss of vestibular nerve fibers. Although the rudimentary cristae of the right ear had numerous hair cells, the macular hair cells were fewer and malformed. No hydrops was present.

Collagen-based mechanical anisotropy of the tectorial membrane: implications for inter-row coupling of outer hair cell bundles.

Directory of Open Access Journals (Sweden)

Núria Gavara

Full Text Available The tectorial membrane (TM in the mammalian cochlea displays anisotropy, where mechanical or structural properties differ along varying directions. The anisotropy arises from the presence of collagen fibrils organized in fibers of approximately 1 microm diameter that run radially across the TM. Mechanical coupling between the TM and the sensory epithelia is required for normal hearing. However, the lack of a suitable technique to measure mechanical anisotropy at the microscale level has hindered understanding of the TM's precise role.Here we report values of the three elastic moduli that characterize the anisotropic mechanical properties of the TM. Our novel technique combined Atomic Force Microscopy (AFM, modeling, and optical tracking of microspheres to determine the elastic moduli. We found that the TM's large mechanical anisotropy results in a marked transmission of deformations along the direction that maximizes sensory cell excitation, whereas in the perpendicular direction the transmission is greatly reduced.Computational results, based on our values of elastic moduli, suggest that the TM facilitates the directional cooperativity of sensory cells in the cochlea, and that mechanical properties of the TM are tuned to guarantee that the magnitude of sound-induced tip-link stretching remains similar along the length of the cochlea. Furthermore, we anticipate our assay to be a starting point for other studies of biological tissues that require directional functionality.

Eagle's syndrome: report of two cases using computed tomography

International Nuclear Information System (INIS)

Lee, Sul Mi; Kwon, Hyuk Rok; Choi, Hang Moon; Park, In Woo

2002-01-01

Two cases of Eagle's syndrome are reported. The first case involved a 31-year-old man who complained of pain in his throat and pain at preauricular area on turning his head. Panoramic and computed tomography (CT) views showed bilateral stylohyoid ligament ossification. The symptoms were relieved after surgical removal. The second case involved a 56-year-old female whose chief complaints were a continuous dull pain and occasional 'shooting' pain on lower left molar area. During the physical examination, an ossified stylohyoid ligament was palpated at the left submandibular area. Panoramic and CT images showed prominent bilateral stylohyoid ligament ossification. CT scans also showed hypertrophy of left medial and lateral pterygoid muscles. The symptoms were relieved after medication. CT is a useful tool for the examination of ossified stylohyoid ligaments and studying the relationship between Eagle's syndrome and adjacent soft tissue.

Radiation Therapy and Hearing Loss

International Nuclear Information System (INIS)

Bhandare, Niranjan; Jackson, Andrew; Eisbruch, Avraham; Pan, Charlie C.; Flickinger, John C.; Antonelli, Patrick; Mendenhall, William M.

2010-01-01

A review of literature on the development of sensorineural hearing loss after high-dose radiation therapy for head-and-neck tumors and stereotactic radiosurgery or fractionated stereotactic radiotherapy for the treatment of vestibular schwannoma is presented. Because of the small volume of the cochlea a dose-volume analysis is not feasible. Instead, the current literature on the effect of the mean dose received by the cochlea and other treatment- and patient-related factors on outcome are evaluated. Based on the data, a specific threshold dose to cochlea for sensorineural hearing loss cannot be determined; therefore, dose-prescription limits are suggested. A standard for evaluating radiation therapy-associated ototoxicity as well as a detailed approach for scoring toxicity is presented.

Effects of aspirin on distortion product fine structure: interpreted by the two-source model for distortion product otoacoustic emissions generation.

Science.gov (United States)

Rao, Aparna; Long, Glenis R

2011-02-01

Distortion product otoacoustic emission (DPOAE) fine structure is due to the interaction of two major components coming from different places in the cochlea. One component is generated from the region of maximal overlap of the traveling waves generated by the two primaries and is attributed to nonlinear distortion (nonlinear component). The other component arises predominantly from the tonotopic region of the distortion product and is attributed to linear coherent reflection (reflection component). Aspirin (salicylate) ototoxicity can cause reversible hearing loss and reduces otoacoustic emission generation in the cochlea. The two components are expected to be affected differentially by cochlear health. Changes in DPOAE fine structure were recorded longitudinally in three subjects before, during, and after aspirin consumption. Full data sets were analyzed for two subjects, but only partial data could be analyzed from the third subject. Resulting changes in the two components of DPOAE fine structure revealed variability among subjects and differential effects on the two components. For low-intensity primaries, both components were reduced with the reflection component being more vulnerable. For high-intensity primaries, the nonlinear component showed little or no change, but the reflection component was always reduced.

Tracheobroncopathia osteochondroplastica: Three case reports with ...

African Journals Online (AJOL)

Besides, final diagnosis can be established by viewing ossified nodules in trachea and bronchus through the fiberoptic bronchoscopy. Amyloidosis, tuberculosis, sarcoidosis, bronchial carcinoma, and tracheobronchial calcinosis must be remembered in differential diagnosis. Also ossifications in submucosa and proof of ...

Cochlear pathology: CT and MRI findings

International Nuclear Information System (INIS)

Martinez, Manuel; Bruno, Claudio; Martin, Eduardo; Canale, Nancy; De Luca, Laura; Spina, Juan C. h

2002-01-01

The authors present a retrospective analysis of 50 patients with perceptive hearing loss. The neuro physiological work-up (evoked potentials, audiometric tests and otoemissions) identified the cochlea as the site of origin of the hearing loss. The imaging studies (high resolution CT and MR, including 3D volumes) showed petrous bone trauma (n=5) infections (bacterial or viral origin) (n=12) otosclerosis (n=8), Paget disease (n=3), and labyrinthine neurinomas (n=2). The other 20 cases showed development-linked disorders (Mitchel's, Mondini, Scheibe, Alexander, and hypoplasia of the cochlear canal). Imaging with CT and MR can identify in detail the structural abnormality affecting the cochlea and occasionally the immediate peri-cochlear region (otic capsule); the affected portion of the cochlea may thus be determined. (author)

Reactive lesion of the gingiva - Report of a case Ambika c., Soheyl S ...

African Journals Online (AJOL)

Department of Oral Medicine and Radiology, Maharishi Markandeshwer College of Dental Sciences and. Research, Mullana 133203, Haryana. ABSTRACT. Objective: Peripheral ossifying .... origin from cells of the periodontal ligament has been suggested 1,2. The reasons for considering a periodontal ligament origin for ...

An echo-poor spine at 13 weeks

DEFF Research Database (Denmark)

Hove, H D; Hermann, N V; Jørgensen, C

2008-01-01

of the vertebral spine. The clavicles were barely seen and the calvarial bones were significantly less ossified than expected for gestational age. The fetus had otherwise normal anatomy and biometry. Serial ultrasound examinations during pregnancy confirmed the diagnosis, but the manifestations became less...

Diffuse idiopathic skeletal hyperostosis in ancient clergymen.

NARCIS (Netherlands)

Verlaan, J.J.; Oner, F.C.; Maat, G.J.

2007-01-01

Diffuse idiopathic skeletal hyperostosis (DISH) is a common but often unrecognized systemic disorder observed mainly in the elderly. DISH is diagnosed when the anterior longitudinal ligament of the spine is ossified on at least four contiguous spinal levels or when multiple peripheral enthesopathies

Diffuse idiopathic skeletal hyperostosis in ancient clergymen

NARCIS (Netherlands)

Verlaan, J.J.; Oner, F.C.; Maat, G.R.J.

2007-01-01

Diffuse idiopathic skeletal hyperostosis (DISH) is a common but often unrecognized systemic disorder observed mainly in the elderly. DISH is diagnosed when the anterior longitudinal ligament of the spine is ossified on at least four contiguous spinal levels or when multiple peripheral

Computerized tomography diagnosis of cartilage destruction in carcinoma of the larynx

International Nuclear Information System (INIS)

Kawashima, Osamu; Tomizawa, Yoshio; Yasuoka, Yoshihito; Kamei, Tamio

1991-01-01

In 20 cases of laryngeal carcinoma, the pre-operative computerized tomography (CT) films were correlated with the macroscopic appearance of specimens obtained at the time of surgery. A correct diagnosis of cartilage destruction was made by pre-operative CT in 75% of cases in which the thyroid cartilage was involved and in about 79% of those with either arytenoid or cricoid cartilage involvement. A comparison between the pathological findings and the pre-operative CT findings in 9 cases of laryngeal carcinoma with destruction of the thyroid cartilage revealed several pathological changes which may lead to an incorrect CT diagnosis. These changes include microscopic infiltration; destruction of cartilage at the anterior commisure; tumor advance to sites of ossification, especially infiltration into ossifying cartilage located between two areas of non-ossifying cartilage; and infiltration of the tumor within the cartilage with preservation of the perichondrium. (author)

An articulated predictive model for fluid-free artificial basilar membrane as broadband frequency sensor

Science.gov (United States)

Ahmed, Riaz; Banerjee, Sourav

2018-02-01

In this article, an extremely versatile predictive model for a newly developed Basilar meta-Membrane (BM2) sensors is reported with variable engineering parameters that contribute to it's frequency selection capabilities. The predictive model reported herein is for advancement over existing method by incorporating versatile and nonhomogeneous (e.g. functionally graded) model parameters that could not only exploit the possibilities of creating complex combinations of broadband frequency sensors but also explain the unique unexplained physical phenomenon that prevails in BM2, e.g. tailgating waves. In recent years, few notable attempts were made to fabricate the artificial basilar membrane, mimicking the mechanics of the human cochlea within a very short range of frequencies. To explain the operation of these sensors a few models were proposed. But, we fundamentally argue the "fabrication to explanation" approach and proposed the model driven predictive design process for the design any (BM2) as broadband sensors. Inspired by the physics of basilar membrane, frequency domain predictive model is proposed where both the material and geometrical parameters can be arbitrarily varied. Broadband frequency is applicable in many fields of science, engineering and technology, such as, sensors for chemical, biological and acoustic applications. With the proposed model, which is three times faster than its FEM counterpart, it is possible to alter the attributes of the selected length of the designed sensor using complex combinations of model parameters, based on target frequency applications. Finally, the tailgating wave peaks in the artificial basilar membranes that prevails in the previously reported experimental studies are also explained using the proposed model.

Dynamic properties of human incudostapedial joint-Experimental measurement and finite element modeling.

Science.gov (United States)

Jiang, Shangyuan; Gan, Rong Z

2018-04-01

The incudostapedial joint (ISJ) is a synovial joint connecting the incus and stapes in the middle ear. Mechanical properties of the ISJ directly affect sound transmission from the tympanic membrane to the cochlea. However, how ISJ properties change with frequency has not been investigated. In this paper, we report the dynamic properties of the human ISJ measured in eight samples using a dynamic mechanical analyzer (DMA) for frequencies from 1 to 80 Hz at three temperatures of 5, 25 and 37 °C. The frequency-temperature superposition (FTS) principle was used to extrapolate the results to 8 kHz. The complex modulus of ISJ was measured with a mean storage modulus of 1.14 MPa at 1 Hz that increased to 3.01 MPa at 8 kHz, and a loss modulus that increased from 0.07 to 0.47 MPa. A 3-dimensional finite element (FE) model consisting of the articular cartilage, joint capsule and synovial fluid was then constructed to derive mechanical properties of ISJ components by matching the model results to experimental data. Modeling results showed that mechanical properties of the joint capsule and synovial fluid affected the dynamic behavior of the joint. This study contributes to a better understanding of the structure-function relationship of the ISJ for sound transmission. Copyright © 2018. Published by Elsevier Ltd.

CDC73-Related Disorders: Clinical Manifestations and Case Detection in Primary Hyperparathyroidism

NARCIS (Netherlands)

van der Tuin, Karin; Tops, Carli M. J.; Adank, Muriel A.; Cobben, Jan-Maarten; Hamdy, Neveen A. T.; Jongmans, Marjolijn C.; Menko, Fred H.; van Nesselrooij, Bernadette P. M.; Netea-Maier, Romana T.; Oosterwijk, Jan C.; Valk, Gerlof D.; Wolffenbuttel, Bruce H. R.; Hes, Frederik J.; Morreau, Hans

2017-01-01

Context: Heterozygous pathogenic germline variants in CDC73 predispose to the development of primary hyperparathyroidism (pHPT) and, less frequently, ossifying fibroma of the jaw and renal and uterine tumors. Clinical information on CDC73-related disorders has so far been limited to small case

Tonotopically Ordered Traveling Waves in the Hearing Organs of Bushcrickets in-vivo

Science.gov (United States)

Udayashankar, Arun Palghat; Kössl, Manfred; Nowotny, Manuela

2011-11-01

Experimental investigation of auditory mechanics in the mammalian cochlea has been difficult to address in-vivo due to its secure housing inside the temporal bone. Here we studied the easily accessible hearing organ of bushcrickets, located in their forelegs, known as the crista acustica. A characteristic feature of the organ is that it is lined with an array of auditory receptors in a tonotopic fashion with lower frequencies processed at the proximal part and higher frequencies at the distal part of the foreleg. Each receptor cell is associated with so called cap cells. The cap cells, graded in size, are directly involved in the mechanics of transduction along with the part of the acoustic trachea that supports the cap cells. Functional similarities between the crista acustica and the vertebrate cochlea such as frequency selectivity and distortion product otoacoustic emissions have been well documented. In this study we used laser Doppler vibrometry to study the mechanics of the organ and observed sound induced traveling waves (TW) along it's length. Frequency representation was tonotopic with TW propagating from the high frequency to the low frequency region of the organ similar to the situation in the cochlea. Traveling wave velocity increased monotonically from 4 to 12 m/s for a frequency range of 6 to 60 kHz, reflecting a smaller topographic spread (organ length: 1 mm) compared to the guinea pig cochlea (organ length: 18 mm). The wavelength of the traveling wave decreased monotonically from 0.67 mm to 0.27 mm for the same frequency range. Vibration velocity of the organ reached noise threshold levels (10 μm/s) at 30 dB SPL for a frequency of 21 kHz. A small non-linear compression (73 dB increase in velocity for an 80 dB increase in SPL) was also observed at the 21 kHz. Our results indicate that bushcrickets can be a good model system for exploration of auditory mechanics in-vivo.

Impact of morphometry, myelinization and synaptic current strength on spike conduction in human and cat spiral ganglion neurons.

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Frank Rattay

Full Text Available Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction.Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA synaptic stimuli.Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat cochlea.

Impact of Morphometry, Myelinization and Synaptic Current Strength on Spike Conduction in Human and Cat Spiral Ganglion Neurons

Science.gov (United States)

Rattay, Frank; Potrusil, Thomas; Wenger, Cornelia; Wise, Andrew K.; Glueckert, Rudolf; Schrott-Fischer, Anneliese

2013-01-01

Background Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction. Methodology/Principal Findings Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs) along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA) synaptic stimuli. Conclusions/Significance Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat

Consequences of Location-Dependent Organ of Corti Micro-Mechanics.

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Yanju Liu

Full Text Available The cochlea performs frequency analysis and amplification of sounds. The graded stiffness of the basilar membrane along the cochlear length underlies the frequency-location relationship of the mammalian cochlea. The somatic motility of outer hair cell is central for cochlear amplification. Despite two to three orders of magnitude change in the basilar membrane stiffness, the force capacity of the outer hair cell's somatic motility, is nearly invariant over the cochlear length. It is puzzling how actuators with a constant force capacity can operate under such a wide stiffness range. We hypothesize that the organ of Corti sets the mechanical conditions so that the outer hair cell's somatic motility effectively interacts with the media of traveling waves-the basilar membrane and the tectorial membrane. To test this hypothesis, a computational model of the gerbil cochlea was developed that incorporates organ of Corti structural mechanics, cochlear fluid dynamics, and hair cell electro-physiology. The model simulations showed that the micro-mechanical responses of the organ of Corti are different along the cochlear length. For example, the top surface of the organ of Corti vibrated more than the bottom surface at the basal (high frequency location, but the amplitude ratio was reversed at the apical (low frequency location. Unlike the basilar membrane stiffness varying by a factor of 1700 along the cochlear length, the stiffness of the organ of Corti complex felt by the outer hair cell remained between 1.5 and 0.4 times the outer hair cell stiffness. The Y-shaped structure in the organ of Corti formed by outer hair cell, Deiters cell and its phalange was the primary determinant of the elastic reactance imposed on the outer hair cells. The stiffness and geometry of the Deiters cell and its phalange affected cochlear amplification differently depending on the location.

Clinico-radiological study of fibro-osseous lesions of the jaw

International Nuclear Information System (INIS)

Nah, Kyung Sik; Park, Tae Won

1982-01-01

Since the fibro-osseous lesion is not a specific diagnostic term, the author studied clinically and radiologically 44 cases which had been diagnosed as fibro-osseous lesion in SNUDH (1972-1981.12). The obtained results were as follows. 1. Clinico-radiologically, the cases of fibro-osseous lesions were divided into two groups. 2. The first group was fibrous dysplasia(21 cases). 3. The second group was tumors of periodontal ligament origin, including ossifying fibroma, cementifying fibroma and cemento-ossifying fibroma (23 cases). 4. In most cases the chief complaint was painless swelling of the jaw and the mean age of the fibrous dysplasia (24.6 yrs) was a little younger than that of the periodontal ligament origin lesions (29.2 yrs). 5. In fibrous dysplasia, maxilla was often involved and showed ground-glass of smoke pattern radiologically. 6. The tumors of periodontal ligament origin occurred more in female, mandible and radiologically showed varying amounts of radiopaque foci in well-circumscribed osteolytic lesion.

Insertion characteristics and placement of the Mid-Scala electrode array in human temporal bones using detailed cone beam computed tomography.

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Dietz, Aarno; Gazibegovic, Dzemal; Tervaniemi, Jyrki; Vartiainen, Veli-Matti; Löppönen, Heikki

2016-12-01

The aim of this study was to evaluate the insertion results and placement of the new Advanced Bionics HiFocus Mid-Scala (HFms) electrode array, inserted through the round window membrane, in eight fresh human temporal bones using cone beam computed tomography (CBCT). Pre- and post-insertion CBCT scans were registered to create a 3D reconstruction of the cochlea with the array inserted. With an image fusion technique both the bony edges of the cochlea and the electrode array in situ could accurately be determined, thus enabling to identify the exact position of the electrode array within the scala tympani. Vertical and horizontal scalar location was measured at four points along the cochlea base at an angular insertion depth of 90°, 180° and 270° and at electrode 16, the most basal electrode. Smooth insertion through the round window membrane was possible in all temporal bones. The imaging results showed that there were no dislocations from the scala tympani into the scala vestibule. The HFms electrode was positioned in the middle of the scala along the whole electrode array in three out of the eight bones and in 62 % of the individual locations measured along the base of the cochlea. In only one cochlea a close proximity of the electrode with the basilar membrane was observed, indicating possible contact with the basilar membrane. The results and assessments presented in this study appear to be highly accurate. Although a further validation including histopathology is needed, the image fusion technique described in this study represents currently the most accurate method for intracochlear electrode assessment obtainable with CBCT.

Molecular characterization and expression of maternally expressed gene 3 (Meg3/Gtl2) RNA in the mouse inner ear

DEFF Research Database (Denmark)

Manji, S.S.; Sørensen, Brita Singers; Klockars, T.

2006-01-01

The pathways responsible for sound perception in the cochlea involve the coordinated and regulated expression of hundreds of genes. By using microarray analysis, we identified several transcripts enriched in the inner ear, including the maternally expressed gene 3 (Meg3/Gtl2), an imprinted...... noncoding RNA. Real-time PCR analysis demonstrated that Meg3/Gtl2 was highly expressed in the cochlea, brain, and eye. Molecular studies revealed the presence of several Meg3/Gtl2 RNA splice variants in the mouse cochlea, brain, and eye. In situ hybridizations showed intense Meg3/Gtl2 RNA staining...... otocyst and localized to the spiral ganglion, stria vascularis, Reissner's membrane, and greater epithelial ridge (GER) in the cochlear duct. RT-PCR analysis performed on cell lines derived from the organ of Corti, representing neural, supporting, and hair cells, showed significantly elevated levels...

Recent advances in the study of age-related hearing loss - A Mini-Review

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Kidd, Ambrose R; Bao, Jianxin

2013-01-01

Hearing loss is a common age-associated affliction that can result from the loss of hair cells and spiral ganglion neurons (SGNs) in the cochlea. Although hair cells and SGNs are typically lost in the same cochlea, recent analysis suggests that they can occur independently, via unique mechanisms. Research has identified both environmental and genetic factors that contribute to degeneration of cochlear cells. Additionally, molecular analysis has identified multiple cell signaling mechanisms that likely contribute to pathological changes that result in hearing deficiencies. These analyses should serve as useful primers for future work, including genomic and proteomic analysis, to elucidate the mechanisms driving cell loss in the aging cochlea. Significant progress in this field has occurred in the past decade. As our understanding of aging-induced cochlear changes continues to improve, our ability to offer medical intervention will surely benefit the growing elderly population. PMID:22710288

Listening to the ear

Science.gov (United States)

Shera, Christopher A.

Otoacoustic emissions demonstrate that the ear creates sound while listening to sound, offering a promising acoustic window on the mechanics of hearing in awake, listening human beings. That window is clouded, however, by an incomplete knowledge of wave reflection and transmission, both forth and back within the cochlea and through the middle ear. This thesis "does windows," addressing wave propagation and scattering on both sides of the middle ear. A summary of highlights follows. Measurements of the cochlear input impedance in cat are used to identify a new symmetry in cochlear mechanics-termed "tapering symmetry" after its geometric interpretation in simple models-that guarantees that the wavelength of the traveling wave changes slowly with position near the stapes. Waves therefore propagate without reflection through the basal turns of the cochlea. Analytic methods for solving the cochlear wave equations using a perturbative scattering series are given and used to demonstrate that, contrary to common belief, conventional cochlear models exhibit negligible internal reflection whether or not they accurately represent the tapering symmetries of the inner ear. Frameworks for the systematic "deconstruction" of eardrum and middle-ear transduction characteristics are developed and applied to the analysis of noninvasive measurements of middle-ear and cochlear mechanics. A simple phenomenological model of inner-ear compressibility that correctly predicts hearing thresholds in patients with missing or disarticulated middle-ear ossicles is developed and used to establish an upper bound on cochlear compressibility several orders of magnitude smaller than that provided by direct measurements. Accurate measurements of stimulus frequency evoked otoacoustic emissions are performed and used to determine the form and frequency variation of the cochlear traveling-wave ratio noninvasively. Those measurements are inverted to obtain the spatial distribution of mechanical

Case report 525: Benign fibrous histiocytoma (BFH) of thumb

International Nuclear Information System (INIS)

Statz, E.M.; Philipps, E.; Pochebit, S.M.; Cooper, A.; Leslie, B.M.

1989-01-01

A case was presented of benign fibrous histiocytoma (BFH) involving the distal phalanx of the thumb, a location heretofore not described in the literature. The distinction between BFH and other lesions (e.g. non-ossifying fibroma) was considered in depth. The distinction between benign and malignant fibrous histiocytoma was also described. (orig.)

SALICYLATE INCREASES THE GAIN OF THE CENTRAL AUDITORY SYSTEM

Science.gov (United States)

Sun, W.; Lu, J.; Stolzberg, D.; Gray, L.; Deng, A.; Lobarinas, E.; Salvi, R. J.

2009-01-01

High doses of salicylate, the anti-inflammatory component of aspirin, induce transient tinnitus and hearing loss. Systemic injection of 250 mg/kg of salicylate, a dose that reliably induces tinnitus in rats, significantly reduced the sound evoked output of the rat cochlea. Paradoxically, salicylate significantly increased the amplitude of the sound-evoked field potential from the auditory cortex (AC) of conscious rats, but not the inferior colliculus (IC). When rats were anesthetized with isoflurane, which increases GABA-mediated inhibition, the salicylate-induced AC amplitude enhancement was abolished, whereas ketamine, which blocks N-methyl-d-aspartate receptors, further increased the salicylate-induced AC amplitude enhancement. Direct application of salicylate to the cochlea, however, reduced the response amplitude of the cochlea, IC and AC, suggesting the AC amplitude enhancement induced by systemic injection of salicylate does not originate from the cochlea. To identify a behavioral correlate of the salicylate-induced AC enhancement, the acoustic startle response was measured before and after salicylate treatment. Salicylate significantly increased the amplitude of the startle response. Collectively, these results suggest that high doses of salicylate increase the gain of the central auditory system, presumably by down-regulating GABA-mediated inhibition, leading to an exaggerated acoustic startle response. The enhanced startle response may be the behavioral correlate of hyperacusis that often accompanies tinnitus and hearing loss. Published by Elsevier Ltd on behalf of IBRO. PMID:19154777

Theoretical study on onset of cubic distortion product otoacoustic emissions

Science.gov (United States)

Vencovský, Václav; Vetešník, Aleš

2018-05-01

The distortion product otoacoustic emissions (DPOAEs) are generated when the cochlea is stimulated by two pure tones with different frequencies f1 and f2. Onset of the DPOAE amplitude may have a nonmonotonic complex shape when the f2 is pulsed during a stationary f1 input. Observed complexities have been explained as (1) due to the secondary source of the DPOAE at the distortion product (DP) characteristic site, and (2) due to the spatial distribution of DP sources with different phases. There is also a third possibility that the complexities are due to the suppression of the f1 basilar membrane (BM) response during the f2 onset. In this study, a hydrodynamic cochlea model is used to examine influence of f1 suppression on the time course of DPOAE onset. In particular, a set of simulations was performed for frequency ratio f2/f1 = 1.26 and various levels of the primary tones (L1 and L2=30-70 dB SPL) to determine the relationship between time dependencies of the DPOAE onset and the suppression of the f1 BM response. The model predicts that suppression of the f1 BM response can cause suppression of DPOAE amplitude during the onset period.

Quantifying Spiral Ganglion Neurite and Schwann Behavior on Micropatterned Polymer Substrates.

Science.gov (United States)

Cheng, Elise L; Leigh, Braden; Guymon, C Allan; Hansen, Marlan R

2016-01-01

The first successful in vitro experiments on the cochlea were conducted in 1928 by Honor Fell (Fell, Arch Exp Zellforsch 7(1):69-81, 1928). Since then, techniques for culture of this tissue have been refined, and dissociated primary culture of the spiral ganglion has become a widely accepted in vitro model for studying nerve damage and regeneration in the cochlea. Additionally, patterned substrates have been developed that facilitate and direct neural outgrowth. A number of automated and semi-automated methods for quantifying this neurite outgrowth have been utilized in recent years (Zhang et al., J Neurosci Methods 160(1):149-162, 2007; Tapias et al., Neurobiol Dis 54:158-168, 2013). Here, we describe a method to study the effect of topographical cues on spiral ganglion neurite and Schwann cell alignment. We discuss our microfabrication process, characterization of pattern features, cell culture techniques for both spiral ganglion neurons and spiral ganglion Schwann cells. In addition, we describe protocols for reducing fibroblast count, immunocytochemistry, and methods for quantifying neurite and Schwann cell alignment.

Fibroma osificante periférico: caso clínico

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Zoila Beatriz Carbonell Muñoz

2013-10-01

Full Text Available ResumenEl fibroma osificante periférico es una lesión reactiva, se considera que se origina de las células del ligamento periodontal; son lesiones benignas de tejido conectivo con focos de calcificación generalmente asintomáticas. En este artículo se presenta un caso de fibroma osificante periférico, permitiendo destacar la importancia clínica de este tipo de patología poco frecuente y con una actualizada revisión de literatura se busca afianzar conocimientos que conlleven a un correcto diagnóstico y adecuado manejo terapéutico para la resolución de la patología. El caso clínico trata de una paciente de 30 años de edad que acude a consulta por presentar lesión tumoral a nivel del cuerpo mandibular izquierdo. Previa valoración clínica y radiográfica, se sometió a la paciente al retiro quirúrgico de la lesión, el examen histopatológico reportó el diagnóstico de fibroma osificante periférico. (DUAZARY 2010, 223 - 227AbstractThe peripheral ossifying fibroma (POF is a reactive lesion who originates in the cells of the periodontal ligament. They are benign tumors of connective tissue usually asymptomatic and they are located in both jaws with greater predilection in the upper jaw, in the region of the interdental papilla and adjacent teeth. It´s presented a case of a 30 years old patient who was attended for an injury tumor located at the left of the mandibular body. After clinical assessment the patient was submitted to surgical removal of the lesion, the review reported histopathologic diagnosis of peripheral ossifying fibroma.Keywords: peripheral ossifying fibroma; Fibroma with Calcification; Calcifying Fibroblastic Granuloma.

Indian hedgehog signaling promotes chondrocyte differentiation in enchondral ossification in human cervical ossification of the posterior longitudinal ligament.

Science.gov (United States)

Sugita, Daisuke; Yayama, Takafumi; Uchida, Kenzo; Kokubo, Yasuo; Nakajima, Hideaki; Yamagishi, Atsushi; Takeura, Naoto; Baba, Hisatoshi

2013-10-15

Histological, immunohistochemical, and immunoblot analyses of the expression of Indian hedgehog (Ihh) signaling in human cervical ossification of the posterior longitudinal ligament (OPLL). To examine the hypothesis that Ihh signaling in correlation with Sox9 and parathyroid-related peptide hormone (PTHrP) facilitates chondrocyte differentiation in enchondral ossification process in human cervical OPLL. In enchondral ossification, certain transcriptional factors regulate cell differentiation. OPLL is characterized by overexpression of these factors and disturbance of the normal cell differentiation process. Ihh signaling is essential for enchondral ossification, especially in chondrocyte hypertrophy. Samples of ossified ligaments were harvested from 45 patients who underwent anterior cervical decompressive surgery for symptomatic OPLL, and 6 control samples from patients with cervical spondylotic myelopathy/radiculopathy without OPLL. The harvested sections were stained with hematoxylin-eosin and toluidine blue, examined by transmission electron microscopy, and immunohistochemically stained for Ihh, PTHrP, Sox9, type X, XI collagen, and alkaline phosphatase. Immunoblot analysis was performed in cultured cells derived from the posterior longitudinal ligaments in the vicinity of the ossified plaque and examined for the expression of these factors. The ossification front in OPLL contained chondrocytes at various differentiation stages, including proliferating chondrocytes in fibrocartilaginous area, hypertrophic chondrocytes around the calcification front, and apoptotic chondrocytes near the ossified area. Immunoreactivity for Ihh and Sox9 was evident in proliferating chondrocytes and was strongly positive for PTHrP in hypertrophic chondrocytes. Mesenchymal cells with blood vessel formation were positive for Ihh, PTHrP, and Sox9. Cultured cells from OPLL tissues expressed significantly higher levels of Ihh, PTHrP, and Sox9 than those in non-OPLL cells. Our results

Patrones de osificación en Tupinambis merianae y Tupinambis rufescens (Squamata: Teiidae y patrones generales en Squamata

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Arias, Federico

2006-06-01

Full Text Available Se describe la variación ontogenética del esqueleto de 13 embriones de Tupinambis merianae y 11 de Tupinambis rufescens, detectándose heterocronías entre ambas especies. Los resultados muestran que los elementos dermales (tanto del cráneo como de la cintura pectoral osifican antes que los elementos condrales, siendo los elementos que forman la mandíbula inferior, el paladar (especialmente los palatinos y los pterigoides y la clavícula los primeros en osificarse, mientras que los elementos del dermatocráneo más tardíos en osificarse son los del arco temporal superior (lacrimal, postorbital, postfrontal. Las principales diferencias en los tiempos de aparición y osificación se producen en algunos huesos del cráneo y en el autopodio (carpo/tarso, pero estas heterocronías no alteran la arquitectura final del esqueleto. Los resultados encontrados son comparados y discutidos con el conocimiento existente sobre otros linajes de Squamata. We describe the ontogenetic variation of skeleton of 13 Tupinambis meriane embryos and 11 Tupinambis rufescens embryos. Furthermore heterochronies in ossification sequence between both species are recorded. Results show that dermal elements (belonging to the skull and the pectoral girdle ossify before the chondral elements, being the elements that constitute the lower jaw, the palate (especially the palatine and the pterygoid, and the clavicle the first ones to ossify. The elements belonging to the dermatocranium which ossify later are the ones of the upper temporal arch (lacrimal, postorbital and postfrontal. The main differences present in timing of onset and ossification are produced in some bones of the skull and of the autopodium (carpus / tarsus; though, these heterochronies do not alter the final structure of the skeleton. Results achieved are compared and discussed with the available knowledge of other squamate lineages.

Traditional open surgery for advanced benign nasal tumours in an ...

African Journals Online (AJOL)

The indications were simple nasal polyps 17(45%), mucocoele 10(26%), inverted paplloma 8(21%), invasive fungal sinusitis 2(5%) and ossifying fibroma 1(2%). Postoperatively, recurrence was 1/17(6%) caldwel-Luc surgery and 1/9 (11%) lateral rhinotomy for inverted papilloma. Facial scar was seen in 21/38(55%) but the ...

At the Garden Gate: Community Building through Food--Revisiting the Critique of "Food, Folk and Fun" in Multicultural Education

Science.gov (United States)

Richardson, Troy A.

2011-01-01

This essay takes up a re-evaluation of the ossified view of food events that have circulated in the canonical texts of multicultural education. While agreeing with the critique by progressive multiculturalists against a "touristic" approach to diversity, the author argues that such a conception of food-centered events in schools has obscured how…

Tinnitus: from cortex to cochlea

NARCIS (Netherlands)

Geven, Leontien

2014-01-01

Het medische woord voor oorsuizen is tinnitus. Tinnitus is het waarnemen van geluid, waar geen bron voor is. Het kan dus alleen worden waargenomen door de persoon zelf en niet door anderen. De meeste volwassenen hebben wel eens last gehad van tijdelijke tinnitus. Tinnitus kan echter ook blijvend

[Clinical development of acute noise-induced acoustic trauma. An evaluation of a study of 250 cases].

Science.gov (United States)

Suc, B; Poulet, M; Asperge, A; Vix, J; Barberot, J P; Doucet, F

1994-01-01

Traumatic damage on Cochlea (250 cases) induced by assault gun (F.A.M.A.S.) consists in tinitus and hearing impairement on 6000 Hz. Noise's effects are specific to one Cochlea. Dissociated developments of both tinitus and hearing loss show that their anatomical sites are different. Acoustic injury entails definitive haire cells lesions, cellular biochemical and vascular changes. The treatment that reestablishes or raises cochlear blood flow entails recovery in 80% of cases provided that it is given within 48 hours after the trauma.

Hyperparathyroidism-jaw tumour syndrome detected by aggressive generalized osteitis fibrosa cystica.

Science.gov (United States)

Guerrouani, Alae; Rzin, Abdelkader; El Khatib, Karim

2013-01-01

Severe hyperparathyroidism can affect bone metabolism and be in the origine of multiple brown tumours (generalized osteitis fibrosa cystica). When associated with fibro-ossifying tumours of the jaw, it realizes a rare genetic syndrome referred as Hyperparathyroidism-jaw tumour HPT-JT. We report the case of a patient we treated for HPT-JT, and literature review.

Intracochlear pressure measurements in scala media inform models of cochlear mechanics

Science.gov (United States)

Kale, Sushrut; Olson, Elizabeth S.

2015-12-01

In the classic view of cochlear mechanics, the cochlea is comprised of two identical fluid chambers separated by the cochlear partition (CP). In this view the traveling wave pressures in the two chambers mirror each other; they are equal in magnitude and opposite in phase. A fast pressure mode adds approximately uniformly. More recent models of cochlear mechanics take into account the structural complexity of the CP and the resulting additional mechanical modes would lead to distinct (non-symmetric) patterns of pressure and motion on the two sides of the CP. However, there was little to no physiological data that explored these predictions. To this aim, we measured intracochlear fluid pressure in scala media (SM), including measurements close to the sensory tissue, using miniaturized pressure sensors (˜ 80 μm outer diameter). Measurements were made in-vivo from the basal cochlear turn in gerbils. SM pressure was measured at two longitudinal locations in different preparations. In a subset of the experiments SM and ST (scala tympani) pressures were measured at the same longitudinal location. Traveling wave pressures were observed in both SM and ST, and showed the relative phase predicted by the classical theory. In addition, SM pressure showed spatial variations that had not been observed in ST, which points to a relatively complex CP motion on the SM side. These data both underscore the first-order validity of the classic cochlear traveling wave model, and open a new view to CP mechanics.

A partial hearing animal model for chronic electro-acoustic stimulation

Science.gov (United States)

Irving, S.; Wise, A. K.; Millard, R. E.; Shepherd, R. K.; Fallon, J. B.

2014-08-01

Objective. Cochlear implants (CIs) have provided some auditory function to hundreds of thousands of people around the world. Although traditionally carried out only in profoundly deaf patients, the eligibility criteria for implantation have recently been relaxed to include many partially-deaf patients with useful levels of hearing. These patients receive both electrical stimulation from their implant and acoustic stimulation via their residual hearing (electro-acoustic stimulation; EAS) and perform very well. It is unclear how EAS improves speech perception over electrical stimulation alone, and little evidence exists about the nature of the interactions between electric and acoustic stimuli. Furthermore, clinical results suggest that some patients that undergo cochlear implantation lose some, if not all, of their residual hearing, reducing the advantages of EAS over electrical stimulation alone. A reliable animal model with clinically-relevant partial deafness combined with clinical CIs is important to enable these issues to be studied. This paper outlines such a model that has been successfully used in our laboratory. Approach. This paper outlines a battery of techniques used in our laboratory to generate, validate and examine an animal model of partial deafness and chronic CI use. Main results. Ototoxic deafening produced bilaterally symmetrical hearing thresholds in neonatal and adult animals. Electrical activation of the auditory system was confirmed, and all animals were chronically stimulated via adapted clinical CIs. Acoustic compound action potentials (CAPs) were obtained from partially-hearing cochleae, using the CI amplifier. Immunohistochemical analysis allows the effects of deafness and electrical stimulation on cell survival to be studied. Significance. This animal model has applications in EAS research, including investigating the functional interactions between electric and acoustic stimulation, and the development of techniques to maintain residual

Investigation of biological microstructures by using diffraction-enhanced imaging computed tomography

International Nuclear Information System (INIS)

Shu Hang; Liu Bo; Zhu, Peiping; Gao Xin; Yin Hongxia; Yuan Qingxi; Wang Junyue; Huang Wanxia; Gao Xiulai; Luo Shuqian; Wu Ziyu; Fang Shouxian

2006-01-01

Diffraction-enhanced imaging computer tomography (DEI-CT) is a new method to provide the object's inner information. Previous reports demonstrated its applicability in soft and hard tissue imaging. Here, we provide further evidence for the improved overall image quality and for the option to distinguish the inner microstructures of the guinea pig's cochlea. Data has shown the details of the cochlea's inner microstructure such as vestibular membrane which only have 6 μm. A better knowledge of these microstructures may be relevant to achieve progress in the otology of clinical anatomization

Selective Vulnerability of the Cochlear Basal Turn to Acrylonitrile and Noise

International Nuclear Information System (INIS)

Pouyatos, B.; Gearhart, C.A.; Miller, A.N.; Fulton, S.; Fechter, L.D.; Pouyatos, B.

2009-01-01

Exposure to acrylonitrile, a high-production industrial chemical, can promote noise-induced hearing loss (NIHL) in the rat even though this agent does not itself produce permanent hearing loss. The mechanism by which acrylonitrile promotes NIHL includes oxidative stress as antioxidant drugs can partially protect the cochlea from acrylonitrile + noise. Acrylonitrile depletes glutathione levels while noise can increase the formation of reactive oxygen species. It was previously noted that the high-frequency or basal turn of the cochlea was particularly vulnerable to the combined effects of acrylonitrile and noise when the octave band noise (OBN) was centered at 8 k Hz. Normally, such a noise would be expected to yield damage at a more apical region of the cochlea. The present study was designed to determine whether the basal cochlea is selectively sensitive to acrylonitrile or whether, by adjusting the frequency of the noise band, it would be possible to control the region of the auditory impairment. Rats were exposed to one of three different OBNs centered at different frequencies (4 k Hz, 110 dB and 8 or 16 k Hz at 97 dB) for 5 days, with and without administration of acrylonitrile (50 mg/kg/day). The noise was set to cause limited NIHL by itself. Auditory function was monitored by recording distortion products, by compound action potentials, and by performing cochlear histology. While the ACN-only and noise-only exposures induced no or little permanent auditory loss, the three exposures to acrylonitrile + noise produced similar auditory and cochlear impairments above 16 k Hz, despite the fact that the noise exposures covered 2 octaves. These observations show that the basal cochlea is much more sensitive to acrylonitrile + noise than the apical partition. They provide an initial basis for distinguishing the pattern of cochlear injury that results from noise exposure from that which occurs due to the combined effects of noise and a chemical contaminant.

Gentamicin concentration gradients in scala tympani perilymph following systemic applications.

Science.gov (United States)

Hahn, Hartmut; Salt, Alec N; Schumacher, Ulrike; Plontke, Stefan K

2013-01-01

It has been shown in prior studies that round window membrane (RWM) application of gentamicin produced a robust basal-apical concentration gradient in the perilymph of scala tympani (ST) with peak concentrations in the basal turn of ST. These gradients potentially contribute to the clinical efficacy and safety of intratympanic gentamicin applications for the treatment of Ménière's disease. The present study aimed to establish the distribution of gentamicin along ST perilymph after systemic applications. Gentamicin sulfate was applied intravenously in the amounts of 100, 300 and 600 mg/kg body weight (BW) over a period of 3 h or as a 300 mg/kg BW subcutaneous bolus injection. At 3 and 5 h after the start of the application perilymph of ST was aspirated from the cochlea apex of the right and left cochlea, respectively, and 10 sequential 1-µl perilymph samples from the apex of each cochlea were quantitatively analyzed using a fluorescence polarization immunoassay. In contrast to local RWM delivery, systemic application of gentamicin resulted in the highest perilymph levels in the apex of the cochlea with decreasing concentrations towards the basal regions of ST. The absolute gentamicin concentrations increased with the amount of drug applied and time before sampling. While it is likely that the basal-apical gradient measured after local drug applications to the round window niche is the result of the direct uptake of drugs into the perilymph of the ST, distribution by diffusion and a very low perilymph flow towards the cochlear apex, computer simulations suggested that the apical-basal gradient observed with these systemic applications can be explained by higher entry rates of gentamicin in the apex compared to the basal turns of the cochlea. It is also possible that gentamicin enters perilymph indirectly from the blood via the endolymph. In this case the faster kinetics in apical turns could be due to the smaller cross-sectional area of ST relative to endolymph in

Site of cochlear stimulation and its effect on electrically evoked compound action potentials using the MED-EL standard electrode array

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Helbig Silke

2009-12-01

Full Text Available Abstract Background The standard electrode array for the MED-EL MAESTRO cochlear implant system is 31 mm in length which allows an insertion angle of approximately 720°. When fully inserted, this long electrode array is capable of stimulating the most apical region of the cochlea. No investigation has explored Electrically Evoked Compound Action Potential (ECAP recordings in this region with a large number of subjects using a commercially available cochlear implant system. The aim of this study is to determine if certain properties of ECAP recordings vary, depending on the stimulation site in the cochlea. Methods Recordings of auditory nerve responses were conducted in 67 subjects to demonstrate the feasibility of ECAP recordings using the Auditory Nerve Response Telemetry (ART™ feature of the MED-EL MAESTRO system software. These recordings were then analyzed based on the site of cochlear stimulation defined as basal, middle and apical to determine if the amplitude, threshold and slope of the amplitude growth function and the refractory time differs depending on the region of stimulation. Results Findings show significant differences in the ECAP recordings depending on the stimulation site. Comparing the apical with the basal region, on average higher amplitudes, lower thresholds and steeper slopes of the amplitude growth function have been observed. The refractory time shows an overall dependence on cochlear region; however post-hoc tests showed no significant effect between individual regions. Conclusions Obtaining ECAP recordings is also possible in the most apical region of the cochlea. However, differences can be observed depending on the region of the cochlea stimulated. Specifically, significant higher ECAP amplitude, lower thresholds and steeper amplitude growth function slopes have been observed in the apical region. These differences could be explained by the location of the stimulating electrode with respect to the neural tissue

Sex Genotyping of Archival Fixed and Immunolabeled Guinea Pig Cochleas.

Science.gov (United States)

Depreux, Frédéric F; Czech, Lyubov; Whitlon, Donna S

2018-03-26

For decades, outbred guinea pigs (GP) have been used as research models. Various past research studies using guinea pigs used measures that, unknown at the time, may be sex-dependent, but from which today, archival tissues may be all that remain. We aimed to provide a protocol for sex-typing archival guinea pig tissue, whereby past experiments could be re-evaluated for sex effects. No PCR sex-genotyping protocols existed for GP. We found that published sequence of the GP Sry gene differed from that in two separate GP stocks. We used sequences from other species to deduce PCR primers for Sry. After developing a genomic DNA extraction for archival, fixed, decalcified, immunolabeled, guinea pig cochlear half-turns, we used a multiplex assay (Y-specific Sry; X-specific Dystrophin) to assign sex to tissue as old as 3 years. This procedure should allow reevaluation of prior guinea pig studies in various research areas for the effects of sex on experimental outcomes.

Mice deleted for cell division cycle 73 gene develop parathyroid and uterine tumours: model for the hyperparathyroidism-jaw tumour syndrome.

Science.gov (United States)

Walls, G V; Stevenson, M; Lines, K E; Newey, P J; Reed, A A C; Bowl, M R; Jeyabalan, J; Harding, B; Bradley, K J; Manek, S; Chen, J; Wang, P; Williams, B O; Teh, B T; Thakker, R V

2017-07-13

The hyperparathyroidism-jaw tumour (HPT-JT) syndrome is an autosomal dominant disorder characterized by occurrence of parathyroid tumours, often atypical adenomas and carcinomas, ossifying jaw fibromas, renal tumours and uterine benign and malignant neoplasms. HPT-JT is caused by mutations of the cell division cycle 73 (CDC73) gene, located on chromosome 1q31.2 and encodes a 531 amino acid protein, parafibromin. To facilitate in vivo studies of Cdc73 in tumourigenesis we generated conventional (Cdc73 +/- ) and conditional parathyroid-specific (Cdc73 +/L /PTH-Cre and Cdc73 L/L /PTH-Cre) mouse models. Mice were aged to 18-21 months and studied for survival, tumour development and proliferation, and serum biochemistry, and compared to age-matched wild-type (Cdc73 +/+ and Cdc73 +/+ /PTH-Cre) littermates. Survival of Cdc73 +/- mice, when compared to Cdc73 +/+ mice was reduced (Cdc73 +/- =80%; Cdc73 +/+ =90% at 18 months of age, Pfourfold higher than that in parathyroid glands of wild-type littermates (P<0.0001). Cdc73 +/- , Cdc73 +/L /PTH-Cre and Cdc73 L/L /PTH-Cre mice had higher mean serum calcium concentrations than wild-type littermates, and Cdc73 +/- mice also had increased mean serum parathyroid hormone (PTH) concentrations. Parathyroid tumour development, and elevations in serum calcium and PTH, were similar in males and females. Cdc73 +/- mice did not develop bone or renal tumours but female Cdc73 +/- mice, at 18 months of age, had uterine neoplasms comprising squamous metaplasia, adenofibroma and adenomyoma. Uterine neoplasms, myometria and jaw bones of Cdc73 +/- mice had increased proliferation rates that were 2-fold higher than in Cdc73 +/+ mice (P<0.05). Thus, our studies, which have established mouse models for parathyroid tumours and uterine neoplasms that develop in the HPT-JT syndrome, provide in vivo models for future studies of these tumours.

Heterotopic ossifications in a mouse model of albright hereditary osteodystrophy.

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David L Huso

Full Text Available Albright hereditary osteodystrophy (AHO is characterized by short stature, brachydactyly, and often heterotopic ossifications that are typically subcutaneous. Subcutaneous ossifications (SCO cause considerable morbidity in AHO with no effective treatment. AHO is caused by heterozygous inactivating mutations in those GNAS exons encoding the α-subunit of the stimulatory G protein (Gα(s. When inherited maternally, these mutations are associated with obesity, cognitive impairment, and resistance to certain hormones that mediate their actions through G protein-coupled receptors, a condition termed pseudohypoparathyroidism type 1a (PHP1a. When inherited paternally, GNAS mutations cause only AHO but not hormonal resistance, termed pseudopseudohypoparathyroidism (PPHP. Mice with targeted disruption of exon 1 of Gnas (Gnas(E1-/+ replicate human PHP1a or PPHP phenotypically and hormonally. However, SCO have not yet been reported in Gnas(E1+/- mice, at least not those that had been analyzed by us up to 3 months of age. Here we now show that Gnas(E1-/+ animals develop SCO over time. The ossified lesions increase in number and size and are uniformly detected in adult mice by one year of age. They are located in both the dermis, often in perifollicular areas, and the subcutis. These lesions are particularly prominent in skin prone to injury or pressure. The SCO comprise mature bone with evidence of mineral deposition and bone marrow elements. Superficial localization was confirmed by radiographic and computerized tomographic imaging. In situ hybridization of SCO lesions were positive for both osteonectin and osteopontin. Notably, the ossifications were much more extensive in males than females. Because Gnas(E1-/+ mice develop SCO features that are similar to those observed in AHO patients, these animals provide a model system suitable for investigating pathogenic mechanisms involved in SCO formation and for developing novel therapeutics for heterotopic bone

Liposarcoma of the thigh with mixed calcification and ossification

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Jeremy R. Child, MD

2016-09-01

Full Text Available Liposarcoma is one of the most common soft-tissue sarcomas. Calcification and ossification can occur in liposarcoma; however, the presence of both ossification and calcification is a very rare entity. We present a case of a partially calcified and ossified dedifferentiated liposarcoma of the thigh in a 76-year-old woman, which contained heterologous elements of chondrosarcoma and rhabdomyosarcoma.

The technology of binaural listening

CERN Document Server

2013-01-01

This book reports on the application of advanced models of the human binaural hearing system in modern technology, among others, in the following areas:  binaural analysis of aural scenes, binaural de-reverberation, binaural quality assessment of audio channels, loudspeakers and performance spaces, binaural perceptual coding, binaural processing in hearing aids and cochlea implants, binaural systems in robots, binaural/tactile human-machine interfaces, speech-intelligibility prediction in rooms and/or multi-speaker scenarios. An introduction to binaural modeling and an outlook to the future are provided. Further, the book features a MATLAB toolbox to enable readers to construct their own dedicated binaural models on demand.

Gene transfection mediated by polyethyleneimine-polyethylene glycol nanocarrier prevents cisplatin-induced spiral ganglion cell damage

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Guan-gui Chen

2015-01-01

Full Text Available Polyethyleneimine-polyethylene glycol (PEI-PEG, a novel nanocarrier, has been used for transfection and gene therapy in a variety of cells. In our previous study, we successfully carried out PEI-PEG-mediated gene transfer in spiral ganglion cells. It remains unclear whether PEI-PEG could be used for gene therapy with X-linked inhibitor of apoptosis protein (XIAP in the inner ear. In the present study, we performed PEI-PEG-mediated XIAP gene transfection in the cochlea of Sprague-Dawley rats, via scala tympani fenestration, before daily cisplatin injections. Auditory brainstem reflex tests demonstrated the protective effects of XIAP gene therapy on auditory function. Immunohistochemical staining revealed XIAP protein expression in the cytoplasm of cells in the spiral ganglion, the organ of Corti and the stria vascularis. Reverse transcription-PCR detected high levels of XIAP mRNA expression in the cochlea. The present findings suggest that PEI-PEG nanocarrier-mediated XIAP gene transfection results in XIAP expression in the cochlea, prevents damage to cochlear spiral ganglion cells, and protects hearing.

Effects of C-phycocyanin and Spirulina on Salicylate-Induced Tinnitus, Expression of NMDA Receptor and Inflammatory Genes

Science.gov (United States)

Hwang, Juen-Haur; Chen, Jin-Cherng; Chan, Yin-Ching

2013-01-01

Effects of C-phycocyanin (C-PC), the active component of Spirulina platensis water extract on the expressions of N-methyl D-aspartate receptor subunit 2B (NR2B), tumor necrosis factor–α (TNF-α), interleukin-1β (IL-1β), and cyclooxygenase type 2 (COX-2) genes in the cochlea and inferior colliculus (IC) of mice were evaluated after tinnitus was induced by intraperitoneal injection of salicylate. The results showed that 4-day salicylate treatment (unlike 4-day saline treatment) caused a significant increase in NR2B, TNF-α, and IL-1β mRNAs expression in the cochlea and IC. On the other hand, dietary supplementation with C-PC or Spirulina platensis water extract significantly reduced the salicylate-induced tinnitus and down-regulated the mRNAs expression of NR2B, TNF-α, IL-1β mRNAs, and COX-2 genes in the cochlea and IC of mice. The changes of protein expression levels were generally correlated with those of mRNAs expression levels in the IC for above genes. PMID:23533584

Effects of C-phycocyanin and Spirulina on salicylate-induced tinnitus, expression of NMDA receptor and inflammatory genes.

Directory of Open Access Journals (Sweden)

Juen-Haur Hwang

Full Text Available Effects of C-phycocyanin (C-PC, the active component of Spirulina platensis water extract on the expressions of N-methyl D-aspartate receptor subunit 2B (NR2B, tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β, and cyclooxygenase type 2 (COX-2 genes in the cochlea and inferior colliculus (IC of mice were evaluated after tinnitus was induced by intraperitoneal injection of salicylate. The results showed that 4-day salicylate treatment (unlike 4-day saline treatment caused a significant increase in NR2B, TNF-α, and IL-1β mRNAs expression in the cochlea and IC. On the other hand, dietary supplementation with C-PC or Spirulina platensis water extract significantly reduced the salicylate-induced tinnitus and down-regulated the mRNAs expression of NR2B, TNF-α, IL-1β mRNAs, and COX-2 genes in the cochlea and IC of mice. The changes of protein expression levels were generally correlated with those of mRNAs expression levels in the IC for above genes.

Role of neuronal activity in regulating the structure and function of auditory neurons

International Nuclear Information System (INIS)

Born, D.E.

1986-01-01

The role of afferent activity in maintaining neuronal structure and function was investigated in second order auditory neurons in nucleus magnocellularis (NM) of the chicken. The cochlea provides the major excitatory input to NM neurons via the eighth nerve. Removal of the cochlea causes dramatic changes in NM neurons. To determine if the elimination of neuronal activity is responsible for the changes in NM seen after cochlea removal, tetrodotoxin was used block action potentials in the cochlear ganglion cells. Tetrodotoxin injections into the perilymph reliably blocked neuronal activity in the cochlear nerve and NM. Far field recordings of sound-evoked potentials revealed that responses returned within 6 hours. Changes in amino acid incorporation in NM neurons were measured by giving intracardiac injections of 3 H-leucine and preparing tissue for autoradiographic demonstration of incorporated amino acid. Grain counts over individual neurons revealed that a single injection of tetrodotoxin produced a 40% decrease in grain density in ipsilateral NM neurons. It is concluded that neuronal activity plays an important contribution to the maintenance of the normal properties of NM neurons

Patient-specific estimation of detailed cochlear shape from clinical CT images

DEFF Research Database (Denmark)

Kjer, H Martin; Fagertun, Jens; Wimmer, Wilhelm

2018-01-01

of the detailed patient-specific cochlear shape from CT images. From a collection of temporal bone [Formula: see text]CT images, we build a cochlear statistical deformation model (SDM), which is a description of how a human cochlea deforms to represent the observed anatomical variability. The model is used...... for regularization of a non-rigid image registration procedure between a patient CT scan and a [Formula: see text]CT image, allowing us to estimate the detailed patient-specific cochlear shape. We test the accuracy and precision of the predicted cochlear shape using both [Formula: see text]CT and CT images...

Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, Rune, E-mail: rune333@gmail.com [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Claesson, Magnus [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Stangerup, Sven-Eric [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Roed, Henrik [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Christensen, Ib Jarle [Finsen Laboratory, Rigshospitalet, Copenhagen (Denmark); Caye-Thomasen, Per [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Juhler, Marianne [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark)

2012-08-01

Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a 'wait-and-scan' group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

International Nuclear Information System (INIS)

Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric; Roed, Henrik; Christensen, Ib Jarle; Cayé-Thomasen, Per; Juhler, Marianne

2012-01-01

Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a “wait-and-scan” group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

Magnetic stem cell targeting to the inner ear

Science.gov (United States)

Le, T. N.; Straatman, L.; Yanai, A.; Rahmanian, R.; Garnis, C.; Häfeli, U. O.; Poblete, T.; Westerberg, B. D.; Gregory-Evans, K.

2017-12-01

Severe sensorineural deafness is often accompanied by a loss of auditory neurons in addition to injury of the cochlear epithelium and hair cell loss. Cochlear implant function however depends on a healthy complement of neurons and their preservation is vital in achieving optimal results. We have developed a technique to target mesenchymal stem cells (MSCs) to a deafened rat cochlea. We then assessed the neuroprotective effect of systematically delivered MSCs on the survival and function of spiral ganglion neurons (SGNs). MSCs were labeled with superparamagnetic nanoparticles, injected via the systemic circulation, and targeted using a magnetized cochlea implant and external magnet. Neurotrophic factor concentrations, survival of SGNs, and auditory function were assessed at 1 week and 4 weeks after treatments and compared against multiple control groups. Significant numbers of magnetically targeted MSCs (>30 MSCs/section) were present in the cochlea with accompanied elevation of brain-derived neurotrophic factor and glial cell-derived neurotrophic factor levels (p < 0.001). In addition we saw improved survival of SGNs (approximately 80% survival at 4 weeks). Hearing threshold levels in magnetically targeted rats were found to be significantly better than those of control rats (p < 0.05). These results indicate that magnetic targeting of MSCs to the cochlea can be accomplished with a magnetized cochlear permalloy implant and an external magnet. The targeted stem cells release neurotrophic factors which results in improved SGN survival and hearing recovery. Combining magnetic cell-based therapy and cochlear implantation may improve cochlear implant function in treating deafness.

Investigation of biological microstructures by using diffraction-enhanced imaging computed tomography

Energy Technology Data Exchange (ETDEWEB)

Shu Hang [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Graudate School of the Chinese Academy of Sciences, 100864 Beijing (China); Liu Bo [Capital University of Medical Sciences (China); Zhu, Peiping [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China)]. E-mail: zhupp@ihep.ac.cn; Gao Xin [Capital University of Medical Sciences (China); Yin Hongxia [Capital University of Medical Sciences (China); Yuan Qingxi [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Wang Junyue [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Graudate School of the Chinese Academy of Sciences, 100864 Beijing (China); Huang Wanxia [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Gao Xiulai [Capital University of Medical Sciences (China); Luo Shuqian [Capital University of Medical Sciences (China); Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China) and National Center for NanoScience and Technology (China)]. E-mail: wuzy@mail.ihep.ac.cn; Fang Shouxian [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China)

2006-11-15

Diffraction-enhanced imaging computer tomography (DEI-CT) is a new method to provide the object's inner information. Previous reports demonstrated its applicability in soft and hard tissue imaging. Here, we provide further evidence for the improved overall image quality and for the option to distinguish the inner microstructures of the guinea pig's cochlea. Data has shown the details of the cochlea's inner microstructure such as vestibular membrane which only have 6 {mu}m. A better knowledge of these microstructures may be relevant to achieve progress in the otology of clinical anatomization.

Establishment of a model of cochlear lesions in rats to study potential gene therapy for sensorineural hearing loss.

Science.gov (United States)

Wang, Ye; Qiao, Li; Chen, Yang; Wen, Liting; Yue, Bo; Qiu, Jianhua; Wu, Shengxi

2015-12-01

Sensorineural hearing loss seriously influences a patient's daily life, and no effective treatments exist to date. Gene therapy is a potential treatment for regenerating hair cells to restore hearing. In this study, we established a cochlear lesions model to study hair cell regeneration by co-administration of kanamycin and furosemide. After the injections, we assessed the survival of outer hair cells (OHC), inner hair cells (IHC), supporting cells (SC), spiral ganglion neurons (SGN) and peripheral axons. Moreover, we used two viral vectors to detect the transgene distribution. Our results showed at 12h post-treatment, numerous OHC were missing in the basal turn. At 24h post-treatment, all OHCs in basal half of the cochlea were lost, and by 48h, OHC loss had spread to the apical coil. Four days after the injections, all OHCs were absent. At 1mo post-treatment, the organ of Corti had collapsed. In contrast, most of the SC remained 4d after the injections. The loss of SGN and peripheral axons was consistent with this time course post-treatment. The results of transgene distribution suggested the correlative gene can be transferred into the organ of Corti using adenoviruses (AdV) vectors and lentiviruses (LV) vectors in our cochlear lesion model. We assessed the details of HC death at more time point and chosen the time point for gene transfer in this model. We conclude that this cochlear lesion model would be suitable for the study of hair cell regeneration. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Visualization of normal and abnormal inner ear with volume rendering technique using multislice spiral CT

International Nuclear Information System (INIS)

Ma Hui; Han Ping; Liang Bo; Lei Ziqiao; Liu Fang; Tian Zhiliang

2006-01-01

Objective: To evaluate the ability of the volume rendering technique to display the normal and abnormal inner ear structures. Methods: Forty normal earand 61 abnormal inner ears (40 congenital inner ear malformations, 7 labyrinthitis ossificans, and 14 inner ear erosion caused by cholesteatomas) were examined with a MSCT scanner. Axial imaging were performed using the following parameters: 120 kV, 100 mAs, 0.75 mm slice thickness, a pitch factor of 1. The axial images of interested ears were reconstructed with 0.1 mm reconstruction increment and a FOV of 50 mm. The 3D reconstructions were done with volume rendering technique on the workstation. Results: In the subjects without ear disorders a high quality 3D visualization of the inner ear could be achieved. In the patients with inner ear' disorders all inner ear malformations could be clearly displayed on 3D images as follows: (1) Michel deformity (one ear): There was complete absence of all cochlear and vestibular structures. (2) common cavity deformity (3 ears): The cochlea and vestibule were represented by a cystic cavity and couldn't be differentiated from each other. (3)incomplete partition type I (3 ears): The cochlea lacked the entire modiolus and cribriform area, resulting in a cystic appearance. (4) incomplete partition type II (Mondini deformity) (5 ears): The cochlea consisted of 1.5 turns, in which the middle and apical turns coalesced to form a cystic apex. (5) vestibular and semicircular canal malformations (14 ears): Cochlea was normal, vestibule dilated, semicircular canals were absent, hypoplastic or enlarged. (6) dilated vestibular aqueduct (14 ears): The vestibular aqueduct was bell-mouthed. In 7 patients with labyrinthifis ossificans, 3D images failed to clearly show the completeinner ears in 4 ears because of too high ossifications in the membranous labyrinth. In the other 3 ears volume rendering could display the thin cochlea basal turn and the intermittent semicircular canals. In the patients

[Investigation of neural stem cell-derived donor contribution in the inner ear following blastocyst injection].

Science.gov (United States)

Volkenstein, S; Brors, D; Hansen, S; Mlynski, R; Dinger, T C; Müller, A M; Dazert, S

2008-03-01

Utilising the enormous proliferation and multi-lineage differentiation potentials of somatic stem cells represents a possible therapeutical strategy for diseases of non-regenerative tissues like the inner ear. In the current study, the possibility of murine neural stem cells to contribute to the developing inner ear following blastocyst injection was investigated. Fetal brain-derived neural stem cells from the embryonic day 14 cortex of male mice were isolated and expanded for four weeks in neurobasal media supplemented with bFGF and EGF. Neural stem cells of male animals were harvested, injected into blastocysts and the blastocysts were transferred into pseudo-pregnant foster animals. Each blastocyst was injected with 5-15 microspheres growing from single cell suspension from neurospheres dissociated the day before. The resulting mice were investigated six months POST PARTUM for the presence of donor cells. Brainstem evoked response audiometry (BERA) was performed in six animals. To visualize donor cells Lac-Z staining was performed on sliced cochleas of two animals. In addition, the cochleas of four female animals were isolated and genomic DNA of the entire cochlea was analyzed for donor contribution by Y-chromosome-specific PCR. All animals had normal thresholds in brainstem evoked response audiometry. The male-specific PCR product indicating the presence of male donor cells were detected in the cochleas of three of the four female animals investigated. In two animals, male donor cells were detected unilateral, in one animal bilateral. The results suggest that descendants of neural stem cells are detectable in the inner ear after injection into blastocysts and possess the ability to integrate into the developing inner ear without obvious loss in hearing function.

Low-frequency sound affects active micromechanics in the human inner ear

Science.gov (United States)

Kugler, Kathrin; Wiegrebe, Lutz; Grothe, Benedikt; Kössl, Manfred; Gürkov, Robert; Krause, Eike; Drexl, Markus

2014-01-01

Noise-induced hearing loss is one of the most common auditory pathologies, resulting from overstimulation of the human cochlea, an exquisitely sensitive micromechanical device. At very low frequencies (less than 250 Hz), however, the sensitivity of human hearing, and therefore the perceived loudness is poor. The perceived loudness is mediated by the inner hair cells of the cochlea which are driven very inadequately at low frequencies. To assess the impact of low-frequency (LF) sound, we exploited a by-product of the active amplification of sound outer hair cells (OHCs) perform, so-called spontaneous otoacoustic emissions. These are faint sounds produced by the inner ear that can be used to detect changes of cochlear physiology. We show that a short exposure to perceptually unobtrusive, LF sounds significantly affects OHCs: a 90 s, 80 dB(A) LF sound induced slow, concordant and positively correlated frequency and level oscillations of spontaneous otoacoustic emissions that lasted for about 2 min after LF sound offset. LF sounds, contrary to their unobtrusive perception, strongly stimulate the human cochlea and affect amplification processes in the most sensitive and important frequency range of human hearing. PMID:26064536

Binaural frequency selectivity in humans.

Science.gov (United States)

Verhey, Jesko L; van de Par, Steven

2018-01-23

Several behavioural studies in humans have shown that listening to sounds with two ears that is binaural hearing, provides the human auditory system with extra information on the sound source that is not available when sounds are only perceived through one ear that is monaurally. Binaural processing involves the analysis of phase and level differences between the two ear signals. As monaural cochlea processing (in each ear) precedes the neural stages responsible for binaural processing properties it is reasonable to assume that properties of the cochlea may also be observed in binaural processing. A main characteristic of cochlea processing is its frequency selectivity. In psychoacoustics, there is an ongoing discussion on the frequency selectivity of the binaural auditory system. While some psychoacoustic experiments seem to indicate poorer frequency selectivity of the binaural system than that of the monaural processing others seem to indicate the same frequency selectivity for monaural and binaural processing. This study provides an overview of these seemingly controversial results and the different explanations that were provided to account for the different results. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Anatomy, Physiology and Function of the Auditory System

Science.gov (United States)

Kollmeier, Birger

The human ear consists of the outer ear (pinna or concha, outer ear canal, tympanic membrane), the middle ear (middle ear cavity with the three ossicles malleus, incus and stapes) and the inner ear (cochlea which is connected to the three semicircular canals by the vestibule, which provides the sense of balance). The cochlea is connected to the brain stem via the eighth brain nerve, i.e. the vestibular cochlear nerve or nervus statoacusticus. Subsequently, the acoustical information is processed by the brain at various levels of the auditory system. An overview about the anatomy of the auditory system is provided by Figure 1.

Diffuse arachnoid ossification and multiple arachnoid cysts presenting with progressive thoracic myelopathy

Energy Technology Data Exchange (ETDEWEB)

Sakai, Toshinori; Sairyo, Koichi; Kashima, Masahiro; Kosaka, Hirofumi; Katoh, Shinsuke; Yasui, Natsuo [The University of Tokushima Graduate School, Department of Orthopedics, Institute of Health Biosciences, Tokushima (Japan)

2010-03-15

An ossified arachnoid membrane combined with cystic formation is rarely reported as a cause of spinal cord compression. We report the case of a 60-year-old man who presented with diffuse ossification of the arachnoid membrane (arachnoid ossification) and multiple cystic changes (arachnoid cyst) at the thoracic and lumbar spine. The lesions were surgically removed and progressive deterioration was prevented, although no marked improvement of neurological symptoms was attained. (orig.)

IHC-TM connect-disconnect in relation to sensitization and masking of a HF-tone burst by a LF tone. IV.

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Crane, H D

1982-05-01

Evidence continues to accumulate that although the outer hair cells (OHCs) of the cochlea are firmly bonded to the tectorial membrane (TM), the inner hair cells (IHCS) are not. This is the fourth in a series of papers that explores how the idea of a set of disconnected hair cells that "impact" the TM is consistent with psychophysical data. The paper extends the exploration to the masking of high-frequency (HF) tone bursts by low-frequency (LF) tones and shows that the model can explain the important features of these complex data.

Murine model for congenital CMV infection and hearing impairment

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Tao Liu

2011-02-01

Full Text Available Abstract Background Congenital cytomegalovirus (CMV infection is the leading cause of sensorineural hearing loss (SNHL, and SNHL is the most frequent sequela of congenital CMV infection. But the pathogenic mechanism remains unknown, and there is no ideal CMV intrauterine infection animal model to study the mechanisms by which SNHL develops. Methods We established the congenital murine cytomegalovirus (MCMV infection model by directly injecting the virus into the placenta on day 12.5 of gestation. Then, we observed the development and the MCMV congenital infection rate of the fetuses on the day they were born. Furthermore, we detected the auditory functions, the conditions of the MCMV infection, and the histological change of the inner ears of 28-day-old and 70-day-old offspring. Results Both the fetal loss rate and the teratism rate of offspring whose placentas were inoculated with MCMV increased, and their body length, head circumference, and weight decreased. The hearing level of offspring both decreased at both 28- and 70-days post birth; the 70-day-old mice developed lower hearing levels than did the 28-day old mice. No significant inflammatory changes in the cochleae of the mice were observed. MCMV DNA signals were mainly detected in the spiral ganglion neurons and the endolymph area, but not in the perilymph area. The number of neurons decreased, and their ultrastructures changed. Moreover, with age, the number of neurons dramatically decreased, and the ultrastructural lesions of neurons became much more severe. Conclusions The results suggest that the direct injection of MCMV into the placenta may efficiently cause fetal infection and disturb the intrauterine development of the fetus, and placental inoculation itself has no obvious adverse effects on offspring. The reduction in the number of spiral ganglion neurons and the ultrastructural lesions of the neurons may be the major cause of congenital CMV infection-induced progressive SNHL.

Arctigenin protects against neuronal hearing loss by promoting neural stem cell survival and differentiation.

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Huang, Xinghua; Chen, Mo; Ding, Yan; Wang, Qin

2017-03-01

Neuronal hearing loss has become a prevalent health problem. This study focused on the function of arctigenin (ARC) in promoting survival and neuronal differentiation of mouse cochlear neural stem cells (NSCs), and its protection against gentamicin (GMC) induced neuronal hearing loss. Mouse cochlea was used to isolate NSCs, which were subsequently cultured in vitro. The effects of ARC on NSC survival, neurosphere formation, differentiation of NSCs, neurite outgrowth, and neural excitability in neuronal network in vitro were examined. Mechanotransduction ability demonstrated by intact cochlea, auditory brainstem response (ABR), and distortion product optoacoustic emissions (DPOAE) amplitude in mice were measured to evaluate effects of ARC on GMC-induced neuronal hearing loss. ARC increased survival, neurosphere formation, neuron differentiation of NSCs in mouse cochlear in vitro. ARC also promoted the outgrowth of neurites, as well as neural excitability of the NSC-differentiated neuron culture. Additionally, ARC rescued mechanotransduction capacity, restored the threshold shifts of ABR and DPOAE in our GMC ototoxicity murine model. This study supports the potential therapeutic role of ARC in promoting both NSCs proliferation and differentiation in vitro to functional neurons, thus supporting its protective function in the therapeutic treatment of neuropathic hearing loss in vivo. © 2017 Wiley Periodicals, Inc.

Age-related auditory pathology in the CBA/J mouse

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Sha, Su-Hua; Kanicki, Ariane; Dootz, Gary; Talaska, Andra E.; Halsey, Karin; Dolan, David; Altschuler, Richard; Schacht, Jochen

2008-01-01

Commercially obtained aged male CBA/J mice presented a complex pattern of hearing loss and morphological changes. A significant threshold shift in auditory brainstem responses (ABR) occurred at 3 months of age at 4 kHz without apparent loss of hair cells, rising slowly at later ages accompanied by loss of apical hair cells. A delayed high-frequency deficit started at 24 kHz around the age of 12 months. At 20 to 26 months, threshold shifts at 12 and 24 kHz and the accompanying hair cell loss at the base of the cochlea were highly variable with some animals appearing almost normal and others showing large deficits. Spiral ganglion cells degenerated by 18 months in all regions of the cochlea, with cell density reduced by approximately 25%. There was no degeneration of the stria vascularis and the endocochlear potential remained stable from 3 to 25 months of age regardless of whether the animals had normal or highly elevated ABR thresholds. The slow high frequency hearing loss combined with a modest reduction of ganglion cell density and an unchanged endocochlear potential suggest sensorineural presbycusis. The superimposed early hearing loss at low frequencies, which is not seen in animals bred in-house, may complicate the use of these animals as a presbycusis model. PMID:18573325

Treatment of peripheral vestibular dysfunction using photobiomodulation

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Lee, Min Young; Hyun, Jai-Hwan; Suh, Myung-Whan; Ahn, Jin-Chul; Chung, Phil-Sang; Jung, Jae Yun; Rhee, Chung Ku

2017-08-01

Gentamicin, which is still used in modern medicine, is a known vestibular toxic agent, and various degrees of balance problems have been observed after exposure to this pharmacologic agent. Photobiomodulation is a candidate therapy for vertigo due to its ability to reach deep inner ear organs such as the cochlea. Previous reports have suggested that photobiomodulation can improve hearing and cochlea function. However, few studies have examined the effect of photobiomodulation on balance dysfunction. We used a rat model to mimic human vestibulopathy resulting from gentamicin treatment and evaluated the effect of photobiomodulation on vestibular toxicity. Slow harmonic acceleration (SHA) rotating platform testing was used for functional evaluation and both qualitative and quantitative epifluorescence analyses of cupula histopathology were performed. Animals were divided into gentamicin only and gentamicin plus laser treatment groups. Laser treatment was applied to one ear, and function and histopathology were evaluated in both ears. Decreased function was observed in both ears after gentamicin treatment, demonstrated by low gain and no SHA asymmetry. Laser treatment minimized the damage resulting from gentamicin treatment as shown by SHA asymmetry and recovered gain in the treated ear. Histology results reflected the functional results, showing increased hair cell density and epifluorescence intensity in laser-treated cupulae.

The effect of the inner-hair-cell mediated transduction on the shape of neural tuning curves

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Altoè, Alessandro; Pulkki, Ville; Verhulst, Sarah

2018-05-01

The inner hair cells of the mammalian cochlea transform the vibrations of their stereocilia into releases of neurotransmitter at the ribbon synapses, thereby controlling the activity of the afferent auditory fibers. The mechanical-to-neural transduction is a highly nonlinear process and it introduces differences between the frequency-tuning of the stereocilia and that of the afferent fibers. Using a computational model of the inner hair cell that is based on in vitro data, we estimated that smaller vibrations of the stereocilia are necessary to drive the afferent fibers above threshold at low (≤0.5 kHz) than at high (≥4 kHz) driving frequencies. In the base of the cochlea, the transduction process affects the low-frequency tails of neural tuning curves. In particular, it introduces differences between the frequency-tuning of the stereocilia and that of the auditory fibers resembling those between basilar membrane velocity and auditory fibers tuning curves in the chinchilla base. For units with a characteristic frequency between 1 and 4 kHz, the transduction process yields shallower neural than stereocilia tuning curves as the characteristic frequency decreases. This study proposes that transduction contributes to the progressive broadening of neural tuning curves from the base to the apex.

Development of forelimb bones in indigenous sheep fetuses

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N. S. Ahmed

2008-01-01

Full Text Available The study included detection of the sites of ossification centers and their sequence of appearance in the forelimb bones of indigenous sheep fetuses by using double staining method with younger specimens and radiography or maceration methods with old specimens, as well as, histological study with some ages. The results showed that the primary ossification centers of the forelimb in indigenous sheep fetuses appeared firstly in the diaphyses of radius and ulna, humerus, scapula, metacarpus, phalanges and lastly in the carpal bone at an estimated age of 43, 45, 46, 47, 49 - 56 and 90-118 days old respectively. The results of statistical analysis of the total lengths of scapula, humerus, radius, ulna and metacarpus with the lengths of their ossified parts through the 7th – 15th weeks of fetus age, showed presence of significant differences in the average of these measurements among most of studied weeks. Also there was a significant differences in the average of relative increase in the total length and length of ossified part of diaphysis of studied bones during the 7th week in comparison to the same average in the other studied weeks (8th-15th week of indigenous sheep fetuses age.

Fibroblastic and myofibroblastic tumors of the head and neck: Comprehensive imaging-based review with pathologic correlation

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Hourani, Roula, E-mail: rh64@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Taslakian, Bedros, E-mail: bt05@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Shabb, Nina S., E-mail: ns04@aub.edu.lb [Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut (Lebanon); Nassar, Lara, E-mail: ln07@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Hourani, Mukbil H., E-mail: mh17@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Moukarbel, Roger, E-mail: rm17@aub.edu.lb [Department of Otolaryngology – Head and Neck Surgery, American University of Beirut Medical Center, Beirut (Lebanon); Sabri, Alain, E-mail: as71@aub.edu.lb [Department of Otolaryngology – Head and Neck Surgery, American University of Beirut Medical Center, Beirut (Lebanon); Rizk, Toni, E-mail: tonirisk@hotmail.com [Department of Neurosurgery, Hôtel-Dieu de France, Saint-Joseph University, Beirut (Lebanon)

2015-02-15

Highlights: • Almost all fibroblastic tumors are evaluated with non-invasive imaging. • Radiologists should be familiar with the imaging appearance of fibroblastic tumors. • Most appropriate initial examination when fibromatosis coli suspected is ultrasound. • Most common location of ossifying fibromas is the tooth-bearing regions. - Abstract: Fibroblastic and myofibroblastic tumors of the head and neck are a heterogeneous group of disorders characterized by the proliferation of fibroblasts, myofibroblasts, or both. These tumors may be further subclassified on the basis of their behavior as benign, intermediate with malignant potential, or malignant. There are different types of fibroblastic and myofibroblastic tumors that can involve the head and neck including desmoid-type fibromatosis, solitary fibrous tumor, myofibroma/myofibromatosis, nodular fasciitis, nasopharyngeal angiofibroma, fibrosarcoma, dermatofibrosarcoma protuberans, fibromatosis coli, inflammatory myofibroblastic tumor, ossifying fibroma, fibrous histiocytoma, nodular fasciitis, fibromyxoma, hyaline fibromatosis and fibrous hamartoma. Although the imaging characteristics of fibroblastic and myofibroblastic tumors of the head and neck are nonspecific, imaging plays a pivotal role in the noninvasive diagnosis and characterization of these tumors, providing information about the constitution of tumors, their extension and invasion of adjacent structures. Correlation with the clinical history may help limit the differential diagnosis and radiologists should be familiar with the imaging appearance of these tumors to reach an accurate diagnosis.

An operated case with post-traumatic epilepsy following atomic bombing injury

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Morioka, Takato; Nishio Shunji; Muraishi; Mitsuteru; Hisada, Kei; Takase, Keiichirou; Matsukado, Koichiro; Sasaki, Masayuki; Fukui, Masashi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medicine; Ohta, Michiya

1999-12-01

The case was 54-years-old man who was bombed at 4-years old 1.5 km apart from the center of explosion in Hiroshima, and had intractable epilepsy after 10 years or more. He suffered from systemic convulsion from 18 years old and took anti-convulsant drugs from 23 years old. The frequency of seizure increased from once a half year to thrice 2 months for these 3-4 years. The attack mainly occurred at night, and it was generalized tonicoclonic convulsion accompanied with unconsciousness and urinary incontience. Valproate (1,800 mg) and clonazepam (1 mg) failed to control the attack, and then he was referred to author's hospital. By CT scanning, MRI and HMPAO-SPECT, the area around the ossified lesion in the right frontal lobe was considered the focus of the epilepsy, and the focus was removed on June 4, 1998. No neurodegeneration and convulsive seizure occurred after surgery. The ossified lesion was confirmed to be bone tissue containing osteoblasts from histological findings and was accompanied by severe gliosis to the brain surface. A large number of active astrocytes were found around the nerve cells in the cortex showing spine-like wave focus, but there were no significant changes in blood vessels in the brain. (K.H.)

Fibroblastic and myofibroblastic tumors of the head and neck: Comprehensive imaging-based review with pathologic correlation

International Nuclear Information System (INIS)

Hourani, Roula; Taslakian, Bedros; Shabb, Nina S.; Nassar, Lara; Hourani, Mukbil H.; Moukarbel, Roger; Sabri, Alain; Rizk, Toni

2015-01-01

Highlights: • Almost all fibroblastic tumors are evaluated with non-invasive imaging. • Radiologists should be familiar with the imaging appearance of fibroblastic tumors. • Most appropriate initial examination when fibromatosis coli suspected is ultrasound. • Most common location of ossifying fibromas is the tooth-bearing regions. - Abstract: Fibroblastic and myofibroblastic tumors of the head and neck are a heterogeneous group of disorders characterized by the proliferation of fibroblasts, myofibroblasts, or both. These tumors may be further subclassified on the basis of their behavior as benign, intermediate with malignant potential, or malignant. There are different types of fibroblastic and myofibroblastic tumors that can involve the head and neck including desmoid-type fibromatosis, solitary fibrous tumor, myofibroma/myofibromatosis, nodular fasciitis, nasopharyngeal angiofibroma, fibrosarcoma, dermatofibrosarcoma protuberans, fibromatosis coli, inflammatory myofibroblastic tumor, ossifying fibroma, fibrous histiocytoma, nodular fasciitis, fibromyxoma, hyaline fibromatosis and fibrous hamartoma. Although the imaging characteristics of fibroblastic and myofibroblastic tumors of the head and neck are nonspecific, imaging plays a pivotal role in the noninvasive diagnosis and characterization of these tumors, providing information about the constitution of tumors, their extension and invasion of adjacent structures. Correlation with the clinical history may help limit the differential diagnosis and radiologists should be familiar with the imaging appearance of these tumors to reach an accurate diagnosis

Type I vs type II spiral ganglion neurons exhibit differential survival and neuritogenesis during cochlear development

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Housley Gary D

2011-10-01

Full Text Available Abstract Background The mechanisms that consolidate neural circuitry are a major focus of neuroscience. In the mammalian cochlea, the refinement of spiral ganglion neuron (SGN innervation to the inner hair cells (by type I SGNs and the outer hair cells (by type II SGNs is accompanied by a 25% loss of SGNs. Results We investigated the segregation of neuronal loss in the mouse cochlea using β-tubulin and peripherin antisera to immunolabel all SGNs and selectively type II SGNs, respectively, and discovered that it is the type II SGN population that is predominately lost within the first postnatal week. Developmental neuronal loss has been attributed to the decline in neurotrophin expression by the target hair cells during this period, so we next examined survival of SGN sub-populations using tissue culture of the mid apex-mid turn region of neonatal mouse cochleae. In organotypic culture for 48 hours from postnatal day 1, endogenous trophic support from the organ of Corti proved sufficient to maintain all type II SGNs; however, a large proportion of type I SGNs were lost. Culture of the spiral ganglion as an explant, with removal of the organ of Corti, led to loss of the majority of both SGN sub-types. Brain-derived neurotrophic factor (BDNF added as a supplement to the media rescued a significant proportion of the SGNs, particularly the type II SGNs, which also showed increased neuritogenesis. The known decline in BDNF production by the rodent sensory epithelium after birth is therefore a likely mediator of type II neuron apoptosis. Conclusion Our study thus indicates that BDNF supply from the organ of Corti supports consolidation of type II innervation in the neonatal mouse cochlea. In contrast, type I SGNs likely rely on additional sources for trophic support.

Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla

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Cristian eAedo

2015-03-01

Full Text Available There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP and cochlear microphonics (CM were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the

Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla.

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Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H; Robles, Luis

2015-01-01

There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla cochlea.

Hybrid pregnant reference phantom series based on adult female ICRP reference phantom

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Rafat-Motavalli, Laleh; Miri-Hakimabad, Hashem; Hoseinian-Azghadi, Elie

2018-03-01

This paper presents boundary representation (BREP) models of pregnant female and her fetus at the end of each trimester. The International Commission on Radiological Protection (ICRP) female reference voxel phantom was used as a base template in development process of the pregnant hybrid phantom series. The differences in shape and location of the displaced maternal organs caused by enlarging uterus were also taken into account. The CT and MR images of fetus specimens and pregnant patients of various ages were used to replace the maternal abdominal pelvic organs of template phantom and insert the fetus inside the gravid uterus. Each fetal model contains 21 different organs and tissues. The skeletal model of the fetus also includes age-dependent cartilaginous and ossified skeletal components. The replaced maternal organ models were converted to NURBS surfaces and then modified to conform to reference values of ICRP Publication 89. The particular feature of current series compared to the previously developed pregnant phantoms is being constructed upon the basis of ICRP reference phantom. The maternal replaced organ models are NURBS surfaces. With this great potential, they might have the feasibility of being converted to high quality polygon mesh phantoms.

Transient Abnormalities in Masking Tuning Curve in Early Progressive Hearing Loss Mouse Model

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Marion Souchal

2018-01-01

Full Text Available Damage to cochlear outer hair cells (OHCs usually affects frequency selectivity in proportion to hearing threshold increase. However, the current clinical heuristics that attributes poor hearing performance despite near-normal auditory sensitivity to auditory neuropathy or “hidden” synaptopathy overlooks possible underlying OHC impairment. Here, we document the part played by OHCs in influencing suprathreshold auditory performance in the presence of noise in a mouse model of progressive hair cell degeneration, the CD1 strain, at postnatal day 18–30 stages when high-frequency auditory thresholds remained near-normal. Nonetheless, total loss of high-frequency distortion product otoacoustic emissions pointed to nonfunctioning basal OHCs. This “discordant profile” came with a huge low-frequency shift of masking tuning curves that plot the level of interfering sound necessary to mask the response to a probe tone, against interfering frequency. Histology revealed intense OHC hair bundle abnormalities in the basal cochlea uncharacteristically associated with OHC survival and preserved coupling with the tectorial membrane. This pattern dismisses the superficial diagnosis of “hidden” neuropathy while underpinning a disorganization of cochlear frequency mapping with optimistic high-frequency auditory thresholds perhaps because responses to high frequencies are apically shifted. The audiometric advantage of frequency transposition is offset by enhanced masking by low-frequency sounds, a finding essential for guiding rehabilitation.

A Rare Case Of Non Traumatic Myositis Ossificans Circumscripta

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Mahale, Yashwant J.; Vyawahare, Chaitanya S.; Dravid, Nandkishore V.; Upase, Aditya; Rathi, Romil

2015-01-01

Introduction: Myositis ossificans circumscripta is a benign non neoplastic ossifying tumor presenting with bone like osteoid tissue extraskelletaly amidst the muscle planes. This condition when not associated with trauma is very trivial and considering the way it mimics certain characteristics, it may be misunderstood as a malignant neoplasm, abscess or antibioma. The aetiology of this atraumatic condition is still indistinct and remains a question unsolved. We would like to report such a cas...

Synchronized Progression of Prestin Expression and Auditory Brainstem Response during Postnatal Development in Rats

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Jianfeng Hang

2016-01-01

Full Text Available Prestin is the motor protein expressed in the cochlear outer hair cells (OHCs of mammalian inner ear. The electromotility of OHCs driven by prestin is responsible for the cochlear amplification which is required for normal hearing in adult animals. Postnatal expression of prestin and activity of OHCs may contribute to the maturation of hearing in rodents. However, the temporal and spatial expression of prestin in cochlea during the development is not well characterized. In the present study, we examined the expression and function of prestin from the OHCs in apical, middle, and basal turns of the cochleae of postnatal rats. Prestin first appeared at postnatal day 6 (P6 for basal turn, P7 in middle turn, and P9 for apical turn of cochlea. The expression level increased progressively over the next few days and by P14 reached the mature level for all three segments. By comparison with the time course of the development of auditory brainstem response for different frequencies, our data reveal that prestin expression synchronized with the hearing development. The present study suggests that the onset time of hearing may require the expression of prestin and is determined by the mature function of OHCs.

Progression of changes in the sensorial elements of the cochlear and peripheral vestibular systems: The otitis media continuum.

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Monsanto, Rafael da Costa; Schachern, Patricia; Paparella, Michael M; Cureoglu, Sebahattin; Penido, Norma de Oliveira

2017-08-01

Our study aimed to evaluate pathologic changes in the cochlear (inner and outer hair cells and stria vascularis) and vestibular (vestibular hair cells, dark, and transitional cells) sensorial elements in temporal bones from donors who had otitis media. We studied 40 temporal bones from such donors, which were categorized in serous otitis media (SOM), serous-purulent otitis media (SPOM), mucoid/mucoid-purulent otitis media (MOM/MPOM), and chronic otitis media (COM); control group comprised 10 nondiseased temporal bones. We found significant loss of inner and outer cochlear hair cells in the basal turn of the SPOM, MOM/MPOM and COM groups; significant loss of vestibular hair cells was observed in the MOM/MPOM and COM groups. All otitis media groups had smaller mean area of the stria vascularis in the basal turn of the cochlea when compared to controls. In conclusion, our study demonstrated more severe pathologic changes in the later stages of the continuum of otitis media (MOM/MPOM and COM). Those changes seem to progress from the basal turn of the cochlea (stria vascularis, then inner and outer hair cells) to the middle turn of the cochlea and to the saccule and utricle in the MOM/MPOM and COM stages. Copyright © 2017 Elsevier B.V. All rights reserved.

Mondini dysplasia and congenital cytomegalovirus infection.

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Bauman, N M; Kirby-Keyser, L J; Dolan, K D; Wexler, D; Gantz, B J; McCabe, B F; Bale, J F

1994-01-01

We report a case of bilateral temporal bone anomalies in a child with symptomatic congenital cytomegalovirus infection and severe, bilateral sensorineural hearing loss identified at 3 months of age. High-resolution temporal bone computed tomography (HRCT) revealed bilateral findings of a short, malformed cochlea lacking an interscalar septum, a short and wide internal auditory canal, and an enlarged vestibular aqueduct, features diagnostic of bilateral Mondini dysplasia. To determine the importance of this observation, we completed HRCT in five additional children between 7 months and 9 years of age who had evidence of symptomatic congenital cytomegalovirus infection. One child with profound sensorineural hearing loss had severe bilateral temporal bone dysplasia with a small cochlea lacking an interscalar septum, an abnormal vestibule, and a large cochlear aqueduct. Of the remaining four children, hearing thresholds ranged from normal to profoundly decreased, but their HRCT scans were normal to visual inspection. When inner ear dimensions of these temporal bones were compared with norms established by Pappas and coworkers, however, seven of the eight ears had short cochleas and narrow lateral semicircular canals, and three ears had short or narrow vestibules. These results indicate that congenital cytomegalovirus infection may cause anomalies or growth disturbances of the temporal bone.

Round window administration of gentamicin: a new method for the study of ototoxicity of cochlear hair cells.

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Husmann, K R; Morgan, A S; Girod, D A; Durham, D

1998-11-01

Damage to inner ear sensory hair cells after systemic administration of ototoxic drugs has been documented in humans and animals. Birds have the ability to regenerate new hair cells to replace those damaged by drugs or noise. Unfortunately, the systemic administration of gentamicin damages both ears in a variable fashion with potentially confounding systemic drug effects. We developed a method of direct application of gentamicin to one cochlea of hatchling chickens, allowing the other ear to serve as a within-animal control. We tested variables including the vehicle for application, location of application, dosage, and duration of gentamicin exposure. After 5 or 28 days survival, the percent length damage to the cochlea and regeneration of hair cells was evaluated using scanning electron microscopy. Controls consisted of the opposite unexposed cochlea and additional animals which received saline instead of gentamicin. Excellent damage was achieved using gentamicin-soaked Gelfoam pledgets applied to the round window membrane. The percent length damage could be varied from 15 to 100% by changing the dosage of gentamicin, with exposures as short as 30 min. No damage was observed in control animals. Regeneration of hair cells was observed in both the base and apex by 28 days survival.

Mosaic evolution of the mammalian auditory periphery.

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Manley, Geoffrey A

2013-01-01

The classical mammalian auditory periphery, i.e., the type of middle ear and coiled cochlea seen in modern therian mammals, did not arise as one unit and did not arise in all mammals. It is also not the only kind of auditory periphery seen in modern mammals. This short review discusses the fact that the constituents of modern mammalian auditory peripheries arose at different times over an extremely long period of evolution (230 million years; Ma). It also attempts to answer questions as to the selective pressures that led to three-ossicle middle ears and the coiled cochlea. Mammalian middle ears arose de novo, without an intermediate, single-ossicle stage. This event was the result of changes in eating habits of ancestral animals, habits that were unrelated to hearing. The coiled cochlea arose only after 60 Ma of mammalian evolution, driven at least partly by a change in cochlear bone structure that improved impedance matching with the middle ear of that time. This change only occurred in the ancestors of therian mammals and not in other mammalian lineages. There is no single constellation of structural features of the auditory periphery that characterizes all mammals and not even all modern mammals.

The Effects of Urethane on Rat Outer Hair Cells

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Mingyu Fu

2016-01-01

Full Text Available The cochlea converts sound vibration into electrical impulses and amplifies the low-level sound signal. Urethane, a widely used anesthetic in animal research, has been shown to reduce the neural responses to auditory stimuli. However, the effects of urethane on cochlea, especially on the function of outer hair cells, remain largely unknown. In the present study, we compared the cochlear microphonic responses between awake and urethane-anesthetized rats. The results revealed that the amplitude of the cochlear microphonic was decreased by urethane, resulting in an increase in the threshold at all of the sound frequencies examined. To deduce the possible mechanism underlying the urethane-induced decrease in cochlear sensitivity, we examined the electrical response properties of isolated outer hair cells using whole-cell patch-clamp recording. We found that urethane hyperpolarizes the outer hair cell membrane potential in a dose-dependent manner and elicits larger outward current. This urethane-induced outward current was blocked by strychnine, an antagonist of the α9 subunit of the nicotinic acetylcholine receptor. Meanwhile, the function of the outer hair cell motor protein, prestin, was not affected. These results suggest that urethane anesthesia is expected to decrease the responses of outer hair cells, whereas the frequency selectivity of cochlea remains unchanged.

Expression of the Norrie disease gene (Ndp) in developing and adult mouse eye, ear, and brain.

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Ye, Xin; Smallwood, Philip; Nathans, Jeremy

2011-01-01

The Norrie disease gene (Ndp) codes for a secreted protein, Norrin, that activates canonical Wnt signaling by binding to its receptor, Frizzled-4. This signaling system is required for normal vascular development in the retina and for vascular survival in the cochlea. In mammals, the pattern of Ndp expression beyond the retina is poorly defined due to the low abundance of Norrin mRNA and protein. Here, we characterize Ndp expression during mouse development by studying a knock-in mouse that carries the coding sequence of human placental alkaline phosphatase (AP) inserted at the Ndp locus (Ndp(AP)). In the CNS, Ndp(AP) expression is apparent by E10.5 and is dynamic and complex. The anatomically delimited regions of Ndp(AP) expression observed prenatally in the CNS are replaced postnatally by widespread expression in astrocytes in the forebrain and midbrain, Bergman glia in the cerebellum, and Müller glia in the retina. In the developing and adult cochlea, Ndp(AP) expression is closely associated with two densely vascularized regions, the stria vascularis and a capillary plexus between the organ of Corti and the spiral ganglion. These observations suggest the possibility that Norrin may have developmental and/or homeostatic functions beyond the retina and cochlea. Copyright © 2010 Elsevier B.V. All rights reserved.

Fibrous metaphyseal defect (fibrous cortical defect, non-ossifying fibroma)

International Nuclear Information System (INIS)

Freyschmidt, J.; Saure, D.; Dammenhain, S.

1981-01-01

Fibrous cortical defect and nonossifying fibromas can be classified together as fibrous metaphyseal defects (FMD) since they have the same pahtological substrate, with a tendency to the same localisation around the knee, and occuring at the same age. They have a tendency to spontaneous healing, are clinically silent and are usually discovered accidentally during radiological examination. A radiological survey fo 5.674 metaphyseal regions in the upper and lower extremities of 2.065 unselected patients aged one to 20 years revealed an incidence of 1.8%; exlcusive examination of the distal femur showed an incidence of 2.7%. 96% of all lesions were in the lower extremities and only 4% in the upper. The marked discrepancy in the incidence rate between American and German publications is discussed. (orig.) [de

Radiographically ossified ganglion cyst of finger in a swimmer

Energy Technology Data Exchange (ETDEWEB)

Tehranzadeh, J.; Anavim, A. [Department of Radiological Sciences, University of California, Orange (United States); Lin, F. [Department of Pathology, University of California, Irvine Medical Center, Orange (Canada)

1998-12-01

Ganglion cysts are fibrous-walled cystic lesions closely associated with joint or tendon sheaths and contain gelatinous mucinous fluid. The radiographic appearance is usually normal. Calcification or ossification in these cysts is extremely unusual. We report on an unusual appearing ganglion cyst of the little finger in a swimmer with ossification resembling myositis ossificans. (orig.) With 3 figs., 8 refs.

Molecular mechanisms involved in cochlear implantation trauma and the protection of hearing and auditory sensory cells by inhibition of c-Jun-N-terminal kinase signaling.

Science.gov (United States)

Eshraghi, Adrien A; Gupta, Chhavi; Van De Water, Thomas R; Bohorquez, Jorge E; Garnham, Carolyn; Bas, Esperanza; Talamo, Victoria Maria

2013-03-01

To investigate the molecular mechanisms involved in electrode insertion trauma (EIT) and to test the otoprotective effect of locally delivered AM-111. An animal model of cochlear implantation. Guinea pigs' hearing thresholds were measured by auditory brainstem response (ABR) before and after cochlear implantation in four groups: EIT; pretreated with hyaluronate gel 30 minutes before EIT (EIT+Gel); pretreated with hyaluronate gel/AM-111 30 minutes before EIT (EIT+AM-111); and unoperated contralateral ears as controls. Neurofilament, synapsin, and fluorescein isothiocyanate (FITC)-phalloidin staining for hair cell counts were performed at 90 days post-EIT. Immunostaining for 4-hydroxy-2-nonenal (HNE), activated caspase-3, CellROX, and phospho-c-Jun were performed at 24 hours post-EIT. ABR thresholds increased post-EIT in the cochleae of EIT only and EIT+Gel treated animals. There was no significant increase in hearing thresholds in cochleae from either EIT+AM-111 treated or unoperated control ears. AM-111 protection of organ of Corti sensory elements (i.e., hair cells [HCs], supporting cells [SCs], nerve fibers, and synapses) was documented at 3 months post-EIT. Immunostaining of 24-hour post-EIT specimens demonstrated increased levels of HNE in HCs and SCs; increased levels of CellROX and activation of caspase-3 was observed only in SCs, and phosphorylation of c-Jun occurred only in HCs of the EIT-only and EIT+Gel specimens. There was no immunostaining for either HNE, CellROX, caspase-3, or phospho-c-Jun in the organ of Corti specimens from AM-111 treated cochleae. Molecular mechanisms involved in programmed cell death of HCs are different than the ones involved in programmed cell death of SCs. Local delivery of AM-111 provided a significant level of protection against EIT-induced hearing losses, HC losses, and damage to neural elements. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Congenital aplasia of the semicircular canals.

Science.gov (United States)

Satar, Bulent; Mukherji, Suresh K; Telian, Steven A

2003-05-01

To describe the underrecognized inner ear malformation characterized by complete aplasia of the labyrinthine semicircular canals associated with a relatively well-formed cochlea, to investigate its relationship with known syndromic forms of hearing loss, and to hypothesize regarding the potential embryopathogenesis of this anomaly. A retrospective case review consisting of cases of sensorineural hearing loss with radiographic evidence demonstrating agenesis of the semicircular canals associated with a cochlea that was either morphologically normal or sufficiently well developed to accommodate the full insertion of a cochlear implant electrode. Cases were identified by computerized tomography findings that identified the anomaly under study. Departments of otolaryngology and radiology in a tertiary referral center, with a large cochlear implant program serving over 800 patients, more than half of whom are children. Fifteen patients with the anomaly under study were identified. Each patient underwent a complete otologic examination, audiometric studies, and high resolution computerized tomography of the temporal bone in axial and coronal planes. The bony morphology of the cochlea, round and oval windows, vestibule, semicircular canals, and vestibular aqueduct, and the course of the facial nerve were examined. Auditory findings and otologic treatment are presented. Of the 15 identified patients, 4 were nonsyndromic, 9 had CHARGE association (Coloboma of the eye, congenital Heart defects, choanal Atresia, mental and/or growth Retardation, Genital hypoplasia, and Ear anomalies and/or deafness), 1 met criteria for Noonan's syndrome, and one had features of both these syndromes. Although the cochlea was present in all cases, the cochlear morphology was usually abnormal in the CHARGE association patients. Of the 20 ears in the CHARGE subjects, only 3 ears (15%) were seen to have completely normal development of the cochlea in both the basal and upper turns. The others

Gracile bone dysplasias

International Nuclear Information System (INIS)

Kozlowski, Kazimierz; Masel, John; Sillence, David O.; Arbuckle, Susan; Juttnerova, Vera

2002-01-01

Gracile bone dysplasias constitute a group of disorders characterised by extremely slender bones with or without fractures. We report four newborns, two of whom showed multiple fractures. Two babies had osteocraniostenosis and one had features of oligohydramnios sequence. The diagnosis in the fourth newborn, which showed thin long bones and clavicles and extremely thin, poorly ossified ribs, is uncertain. Exact diagnosis of a gracile bone dysplasia is important for genetic counselling and medico-legal reasons. (orig.)

Myositis Ossificans of Psoas Muscle: Magnetic Resonance Imaging Findings

Energy Technology Data Exchange (ETDEWEB)

Sirvanci, M.; Ganiyusufoglu, A.K.; Karaman, K.; Tezer, M.; Hamzaoglu, A. [Univ. of Kadir Has, Istanbul (Turkey). Dept. of Radiology

2004-08-01

Myositis ossificans is a benign, localized, self-limiting ossifying soft tissue mass with unknown pathogenesis. It may be confused with a malignant tumor of bone or soft tissues, especially in the early stages of the disease. In this report, we present a case of myositis ossificans affecting unilateral psoas muscle, which to our knowledge is a very uncommon location. There was no history of trauma. We describe the imaging findings and clues to early diagnosis of myositis ossificans.

Myositis Ossificans of Psoas Muscle: Magnetic Resonance Imaging Findings

International Nuclear Information System (INIS)

Sirvanci, M.; Ganiyusufoglu, A.K.; Karaman, K.; Tezer, M.; Hamzaoglu, A.

2004-01-01

Myositis ossificans is a benign, localized, self-limiting ossifying soft tissue mass with unknown pathogenesis. It may be confused with a malignant tumor of bone or soft tissues, especially in the early stages of the disease. In this report, we present a case of myositis ossificans affecting unilateral psoas muscle, which to our knowledge is a very uncommon location. There was no history of trauma. We describe the imaging findings and clues to early diagnosis of myositis ossificans

Gracile bone dysplasias

Energy Technology Data Exchange (ETDEWEB)

Kozlowski, Kazimierz [Department of Medical Imaging, The Children' s Hospital at Westmead, Locked Bag 4001, Westmead 2145, NSW (Australia); Masel, John [Department of Radiology, Royal Children' s Hospital, Brisbane (Australia); Sillence, David O. [Department of Paediatrics and Child Health, The University of Sydney (Australia); Arbuckle, Susan [Department of Anatomical Pathology, The Children' s Hospital at Westmead, NSW (Australia); Juttnerova, Vera [Oddeleni Lekarske Genetiky, Hradec Kralove (Czech Republic)

2002-09-01

Gracile bone dysplasias constitute a group of disorders characterised by extremely slender bones with or without fractures. We report four newborns, two of whom showed multiple fractures. Two babies had osteocraniostenosis and one had features of oligohydramnios sequence. The diagnosis in the fourth newborn, which showed thin long bones and clavicles and extremely thin, poorly ossified ribs, is uncertain. Exact diagnosis of a gracile bone dysplasia is important for genetic counselling and medico-legal reasons. (orig.)

Protective role of hydrogen sulfide against noise-induced cochlear damage: a chronic intracochlear infusion model.

Directory of Open Access Journals (Sweden)

Xu Li

Full Text Available BACKGROUND: A reduction in cochlear blood flow plays an essential role in noise-induced hearing loss (NIHL. The timely regulation of cochlear perfusion determines the progression and prognosis of NIHL. Hydrogen sulfide (H(2S has attracted increasing interest as a vasodilator in cardiovascular systems. This study identified the role of H(2S in cochlear blood flow regulation and noise protection. METHODOLOGY/PRINCIPAL FINDINGS: The gene and protein expression of the H(2S synthetase cystathionine-γ-lyase (CSE in the rat cochlea was examined using immunofluorescence and real-time PCR. Cochlear CSE mRNA levels varied according to the duration of noise exposure. A chronic intracochlear infusion model was built and artificial perilymph (AP, NaHS or DL-propargylglycine (PPG were locally administered. Local sodium hydrosulfide (NaHS significantly increased cochlear perfusion post-noise exposure. Cochlear morphological damage and hearing loss were alleviated in the NaHS group as measured by conventional auditory brainstem response (ABR, cochlear scanning electron microscope (SEM and outer hair cell (OHC count. The highest percentage of OHC loss occurred in the PPG group. CONCLUSIONS/SIGNIFICANCE: Our results suggest that H(2S plays an important role in the regulation of cochlear blood flow and the protection against noise. Further studies may identify a new preventive and therapeutic perspective on NIHL and other blood supply-related inner ear diseases.

Importance of cochlear health for implant function.

Science.gov (United States)

Pfingst, Bryan E; Zhou, Ning; Colesa, Deborah J; Watts, Melissa M; Strahl, Stefan B; Garadat, Soha N; Schvartz-Leyzac, Kara C; Budenz, Cameron L; Raphael, Yehoash; Zwolan, Teresa A

2015-04-01

Amazing progress has been made in providing useful hearing to hearing-impaired individuals using cochlear implants, but challenges remain. One such challenge is understanding the effects of partial degeneration of the auditory nerve, the target of cochlear implant stimulation. Here we review studies from our human and animal laboratories aimed at characterizing the health of the implanted cochlea and the auditory nerve. We use the data on cochlear and neural health to guide rehabilitation strategies. The data also motivate the development of tissue-engineering procedures to preserve or build a healthy cochlea and improve performance obtained by cochlear implant recipients or eventually replace the need for a cochlear implant. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of embedded dexamethasone in cochlear implant array on insertion forces in an artificial model of scala tympani.

Science.gov (United States)

Nguyen, Yann; Bernardeschi, Daniele; Kazmitcheff, Guillaume; Miroir, Mathieu; Vauchel, Thomas; Ferrary, Evelyne; Sterkers, Olivier

2015-02-01

Loading otoprotective drug into cochlear implant might change its mechanical properties, thus compromising atraumatic insertion. This study evaluated the effect of incorporation of dexamethasone (DXM) in the silicone of cochlear implant arrays on insertion forces. Local administration of DXM with embedded array can potentially reduce inflammation and fibrosis after cochlear implantation procedure to improve hearing preservation and reduce long-term impedances. Four models of arrays have been tested: 0.5-mm distal diameter array (n = 5) used as a control, drug-free 0.4-mm distal diameter array (n = 5), 0.4-mm distal diameter array with 1% eluded DXM silicone (n = 5), and 0.4-mm distal diameter array with 10% eluded DXM silicone (n = 5). Via a motorized insertion bench, each array has been inserted into an artificial scala tympani model. The forces were recorded by a 6-axis force sensor. Each array was tested seven times for a total number of 140 insertions. During the first 10-mm insertion, no difference between the four models was observed. From 10- to 24-mm insertion, the 0.5-mm distal diameter array presented higher insertion forces than the drug-free 0.4-mm distal diameter arrays, with or without DXM. Friction forces for drug-free 0.4-mm distal diameter array and 0.4-mm distal diameter DXM eluded arrays were similar on all insertion lengths. Incorporation of DXM in silicone for cochlear implant design does not change electrode array insertion forces. It does not raise the risk of trauma during array insertion, making it suitable for long-term in situ administration to the cochlea.

Interactions between Hair Cells Shape Spontaneous Otoacoustic Emissions in a Model of the Tokay Gecko's Cochlea

OpenAIRE

Gelfand, Michael; Piro, Oreste; Magnasco, Marcelo O.; Hudspeth, A. J.

2010-01-01

Background The hearing of tetrapods including humans is enhanced by an active process that amplifies the mechanical inputs associated with sound, sharpens frequency selectivity, and compresses the range of responsiveness. The most striking manifestation of the active process is spontaneous otoacoustic emission, the unprovoked emergence of sound from an ear. Hair cells, the sensory receptors of the inner ear, are known to provide the energy for such emissions; it is unclear, though, how ens...

Comparative studies on the ossification in several experimental animals

International Nuclear Information System (INIS)

Matsuoka, Osamu; Fukuda, Shun

1978-01-01

For estimating the risk of the bone seeking radionuclides in man, it is necessary to extrapolate the data of experimental animals to those of man. Detailed information on the biological stages of development, especially on bone growth of several experimental animals and of man is required for better extrapolation. Multi-species comparison of bone growth and ossification was carried out in several mammalian species such as mouse, rat, dog and monkey. The appearance, ossifying process and fusion of the secondary ossification centers in extremities were selected as indicators of the biological stage of bone. The observation of the secondary ossification centers was made by radiography. The maturity process of the secondary ossification centers in each animal was illustrated. The ossifying process of the secondary ossification center could be divided into the following three categories; (1) the acute ossification observed in mouse, rat, dog and monkey (2) the delayed ossification observed in mouse, rat, dog and monkey, (3) the incomplete ossification without complete fusion which is specific in mouse and rat, appeared and continued up to at least 27 weeks in mouse and up to 134 weeks in rat. The results of the study suggested that a mouse 17 weeks old, a rat 17 - 21 weeks old, a dog (beagle) 14 months old and a monkey about 6 years old may correspond to a man about 20 years old. (author)

Characterization of ossification of the posterior rim of acetabulum in the developing hip and its impact on the assessment of femoroacetabular impingement.

Science.gov (United States)

Morris, William Z; Chen, Jason Y; Cooperman, Daniel R; Liu, Raymond W

2015-02-04

Many radiographic indices that are used to assess adolescents for femoroacetabular impingement rely on an ossified posterior acetabular wall. A recent study identified a secondary ossification center in the posterior rim of the acetabulum, the ossification of which may affect perceived acetabular coverage. The purpose of this study was to characterize ossification of the posterior rim of the acetabulum with use of a longitudinal radiographic study and quantify its impact on the radiographic assessment of femoroacetabular impingement. In this study, we utilized a historical collection of annual radiographs made in a population of healthy adolescents. Six hundred and twelve anteroposterior radiographs of the left hip of ninety-eight patients were reviewed to identify the appearance, duration, and fusion of the secondary ossification center in the posterior rim of the acetabulum. The center-edge angle was then measured before appearance and after fusion of the secondary ossification center in a subset of ten patients who had 40°), the use of radiographs in adolescents with incompletely ossified hips may lead to misinterpretation of acetabular coverage. In patients with open triradiate cartilage, magnetic resonance imaging may be considered for the assessment of femoroacetabular impingement. The posterior rim ossification sign is a normal finding in adolescent hip development and has important implications for the proper evaluation of femoroacetabular impingement. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Studies on diagnostic value of CT images for hypopharyngeal cancer by comparing with sliced specimens

International Nuclear Information System (INIS)

Fujimura, Akiko

1988-01-01

The findings of preoperative CT were compared with extirpated specimens in 11 patients to evaluate the value of CT in diagnosing the extent of hypopharyngeal cancer. CT was capable of detecting tumor extent to the submucosal fibrofatty tissue, except for the case of tumor extent to the laryngeal ventricle that contains many mucous glands and is usually depicted as a dense shadow. When the margin of ossified cortex of the thyroid cartilage was irregular and surrounded by tumor shadow, or when the margin of the cricoid cartilage was irregular and accompanied by increased medullary concentration, the invasion of the tumor into these cartilages was histopathologically demonstrated. Tumor extension next to these ossified cartilages did not indicate histopathological invasion of the tumor whenever their margins were smooth and regular. The intrinsic laryngeal muscle and the inferior pharyngeal constrictor muscle were identified on CT. Tumor extent to these muscles was well correlated to histologically demonstrated tumor invasion. When vocal cord fixation was present, CT showed tumor extent either to the paralaryngeal space only or to the paralaryngeal space and thyroarytenoid muscle or posterior cricoarytenoid muscle. Extraluminal spread through the thyrohyoid membrane was depicted on CT as a distinctive shadow in the visceral space that surrounds the hypopharyngeal cavity. Computed tomography overestimated tumor invation into the submucosal layer, muscles, or laryngeal cartilages. (Namekawa, K.)

Lower Cretaceous fossils from China shed light on the ancestral body plan of crown softshell turtles (Trionychidae, Cryptodira).

Science.gov (United States)

Brinkman, Donald; Rabi, Márton; Zhao, Lijun

2017-07-27

Pan-trionychids or softshell turtles are a highly specialized and widespread extant group of aquatic taxa with an evolutionary history that goes back to the Early Cretaceous. The earliest pan-trionychids had already fully developed the "classic" softshell turtle morphology and it has been impossible to resolve whether they are stem members of the family or are within the crown. This has hindered our understanding of the evolution of the two basic body plans of crown-trionychids. Thus it remains unclear whether the more heavily ossified shell of the cyclanorbines or the highly reduced trionychine morphotype is the ancestral condition for softshell turtles. A new pan-trionychid from the Early Cretaceous of Zhejiang, China, Perochelys hengshanensis sp. nov., allows a revision of softshell-turtle phylogeny. Equal character weighting resulted in a topology that is fundamentally inconsistent with molecular divergence date estimates of deeply nested extant species. In contrast, implied weighting retrieved Lower Cretaceous Perochelys spp. and Petrochelys kyrgyzensis as stem trionychids, which is fully consistent with their basal stratigraphic occurrence and an Aptian-Santonian molecular age estimate for crown-trionychids. These results indicate that the primitive morphology for soft-shell turtles is a poorly ossified shell like that of crown-trionychines and that shell re-ossification in cyclanorbines (including re-acquisition of peripheral elements) is secondary.

Adipose-derived stromal cells enhance auditory neuron survival in an animal model of sensory hearing loss.

Science.gov (United States)

Schendzielorz, Philipp; Vollmer, Maike; Rak, Kristen; Wiegner, Armin; Nada, Nashwa; Radeloff, Katrin; Hagen, Rudolf; Radeloff, Andreas

2017-10-01

A cochlear implant (CI) is an electronic prosthesis that can partially restore speech perception capabilities. Optimum information transfer from the cochlea to the central auditory system requires a proper functioning auditory nerve (AN) that is electrically stimulated by the device. In deafness, the lack of neurotrophic support, normally provided by the sensory cells of the inner ear, however, leads to gradual degeneration of auditory neurons with undesirable consequences for CI performance. We evaluated the potential of adipose-derived stromal cells (ASCs) that are known to produce neurotrophic factors to prevent neural degeneration in sensory hearing loss. For this, co-cultures of ASCs with auditory neurons have been studied, and autologous ASC transplantation has been performed in a guinea pig model of gentamicin-induced sensory hearing loss. In vitro ASCs were neuroprotective and considerably increased the neuritogenesis of auditory neurons. In vivo transplantation of ASCs into the scala tympani resulted in an enhanced survival of auditory neurons. Specifically, peripheral AN processes that are assumed to be the optimal activation site for CI stimulation and that are particularly vulnerable to hair cell loss showed a significantly higher survival rate in ASC-treated ears. ASC transplantation into the inner ear may restore neurotrophic support in sensory hearing loss and may help to improve CI performance by enhanced AN survival. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

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Kao Ming-Ching

2011-02-01

Full Text Available Abstract Background Hyperbaric oxygen therapy (HBOT is a known adjuvant for treating ischemia-related inner ear diseases. Controversies still exist in the role of HBOT in cochlear diseases. Few studies to date have investigated the cellular changes that occur in inner ears after HBOT. Nitric oxide, which is synthesized by nitric oxide synthase (NOS, is an important signaling molecule in cochlear physiology and pathology. Here we investigated the effects of hyperbaric oxygen on eardrum morphology, cochlear function and expression of NOS isoforms in cochlear substructures after repetitive HBOT in guinea pigs. Results Minor changes in the eardrum were observed after repetitive HBOT, which did not result in a significant hearing threshold shift by tone burst auditory brainstem responses. A differential effect of HBOT on the expression of NOS isoforms was identified. Upregulation of constitutive NOS (nNOS and eNOS was found in the substructures of the cochlea after HBOT, but inducible NOS was not found in normal or HBOT animals, as shown by immunohistochemistry. There was no obvious DNA fragmentation present in this HBOT animal model. Conclusions The present evidence indicates that the customary HBOT protocol may increase constitutive NOS expression but such upregulation did not cause cell death in the treated cochlea. The cochlear morphology and auditory function are consequently not changed through the protocol.

Auditory hair cell centrioles undergo confined Brownian motion throughout the developmental migration of the kinocilium.

Science.gov (United States)

Lepelletier, Léa; de Monvel, Jacques Boutet; Buisson, Johanna; Desdouets, Chantal; Petit, Christine

2013-07-02

Planar polarization of the forming hair bundle, the mechanosensory antenna of auditory hair cells, depends on the poorly characterized center-to-edge displacement of a primary cilium, the kinocilium, at their apical surface. Taking advantage of the gradient of hair cell differentiation along the cochlea, we reconstituted a map of the kinocilia displacements in the mouse embryonic cochlea. We then developed a cochlear organotypic culture and video-microscopy approach to monitor the movements of the kinocilium basal body (mother centriole) and its daughter centriole, which we analyzed using particle tracking and modeling. We found that both hair cell centrioles undergo confined Brownian movements around their equilibrium positions, under the apparent constraint of a radial restoring force of ∼0.1 pN. This magnitude depended little on centriole position, suggesting nonlinear interactions with constraining, presumably cytoskeletal elements. The only dynamic change observed during the period of kinocilium migration was a doubling of the centrioles' confinement area taking place early in the process. It emerges from these static and dynamic observations that kinocilia migrate gradually in parallel with the organization of hair cells into rows during cochlear neuroepithelium extension. Analysis of the confined motion of hair cell centrioles under normal and pathological conditions should help determine which structures contribute to the restoring force exerting on them. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Mechanical frequency selectivity of an artificial basilar membrane using a beam array with narrow supports

International Nuclear Information System (INIS)

Kim, Sangwon; Jang, Jongmoon; Choi, Hongsoo; Song, Won Joon; Jang, Jeong Hun

2013-01-01

The study presented in this paper assessed the frequency selectivity of an artificial basilar membrane (ABM) constructed using a piezoelectric beam array with narrow supports. Three ABM samples were constructed. Each ABM contained 16 beams with various lengths in a one-dimensional array. To experimentally assess the frequency selectivity of the ABM, mechanical vibration induced either by an electrical or an acoustic stimulus was measured with a scanning laser-Doppler vibrometer. The electro-mechanical and acousto-mechanical transfer functions were defined for the same purpose. The tonotopy of each beam array was visualized by post-processing the experimental results. Finite element analyses were conducted to numerically compute the resonance frequencies, identify the associated vibrational modes, and evaluate the harmonic responses of the beams. The influence of the residual stresses existing in the beams was reflected in the geometric models by introducing three different levels of arc-shaped lateral deformations in the beams. The harmonic analyses revealed that each beam of the ABM samples presented independent band-pass characteristics. The experiments and simulations commonly showed a frequency selectivity of the fabricated ABMs in the range of 2–20 kHz. Therefore, the device is suitable for development of a totally implantable artificial cochlea, implementing a mechanical frequency analyzer. This work is part of research to develop a prototype of a totally implantable artificial cochlea. (paper)

A histological study of scala communis with radiological implications.

Science.gov (United States)

Makary, Chadi; Shin, Jennifer; Caruso, Paul; Curtin, Hugh; Merchant, Saumil

2010-01-01

Scala communis or interscalar septum (IS) defect is a developmental abnormality of the inner ear characterized by a dehiscence in the partition separating the turns of the cochlea. The goals of the present study were to (1) study this anomaly and describe its characteristics compared to control ears using a histological analysis of temporal bones, (2) discuss radiological implications regarding its diagnosis, and (3) describe its embryological derivation. Out of 1775 temporal bones assessed, 22 specimens were found to have scala communis in cochleae containing all 3 turns (basal, middle and apical). These 22 ears were studied in detail by qualitative and quantitative methods using light microscopy. Scala communis occurred as an isolated inner ear anomaly, or in association with other congenital cochlear and/or vestibular anomalies. The defect occurred most often between the middle and apical turns of the cochlea. Compared to control ears, scala communis ears were found to have a smaller modiolar area (p Scala communis was compatible with normal hearing. Flattening of the interscalar ridge has the potential to improve the diagnosis of scala communis in patients using CT scanning. The anomaly may result from a mesodermal defect such as excessive resorption of mesenchyme during the formation of the scalae, an error in the formation of bone, or both. Copyright © 2010 S. Karger AG, Basel.

A lack of immune system genes causes loss in high frequency hearing but does not disrupt cochlear synapse maturation in mice.

Science.gov (United States)

Calton, Melissa A; Lee, Dasom; Sundaresan, Srividya; Mendus, Diana; Leu, Rose; Wangsawihardja, Felix; Johnson, Kenneth R; Mustapha, Mirna

2014-01-01

Early cochlear development is marked by an exuberant outgrowth of neurites that innervate multiple targets. The establishment of mature cochlear neural circuits is, however, dependent on the pruning of inappropriate axons and synaptic connections. Such refinement also occurs in the central nervous system (CNS), and recently, genes ordinarily associated with immune and inflammatory processes have been shown to play roles in synaptic pruning in the brain. These molecules include the major histocompatibility complex class I (MHCI) genes, H2-K(b) and H2-D(b), and the complement cascade gene, C1qa. Since the mechanisms involved in synaptic refinement in the cochlea are not well understood, we investigated whether these immune system genes may be involved in this process and whether they are required for normal hearing function. Here we report that these genes are not necessary for normal synapse formation and refinement in the mouse cochlea. We further demonstrate that C1qa expression is not necessary for normal hearing in mice but the lack of expression of H2-K(b) and H2-D(b) causes hearing impairment. These data underscore the importance of the highly polymorphic family of MHCI genes in hearing in mice and also suggest that factors and mechanisms regulating synaptic refinement in the cochlea may be distinct from those in the CNS.

Localization and expression of clarin-1, the Clrn1 gene product, in auditory hair cells and photoreceptors

Science.gov (United States)

Zallocchi, Marisa; Meehan, Daniel T.; Delimont, Duane; Askew, Charles; Garrige, Suneetha; Gratton, Michael Anne; Rothermund-Franklin, Christie A.; Cosgrove, Dominic

2009-01-01

The Usher syndrome 3A (CLRN1) gene encodes clarin-1, which is a member of the tetraspanin family of transmembrane proteins. Although identified more than 6 years ago, little is known about its localization or function in the eye and ear. We developed a polyclonal antibody that react with all clarin-1 isoforms and used it to characterize protein expression in cochlea and retina. In the cochlea, we observe clarin-1expression in the stereocilia of P0 mice, and in synaptic terminals present at the base of the auditory hair cells from E18 to P6. In the retina, clarin-1 localizes to the connecting cilia, inner segment of photoreceptors and to the ribbon synapses. RT-PCR from P0 cochlea and P28 retina show mRNAs encoding only isoforms 2 and 3. Western-blots show that only isoform 2 is present in protein extracts from these same tissues. We examined clarin-1 expression in the immortomouse-derived hair cell line UB/OC-1. Only isoform 2 is expressed in UB/OC-1 at both mRNA and protein levels, suggesting this isoform is biologically relevant to hair cell function. The protein co-localizes with microtubules and post-transgolgi vesicles. The sub-cellular localization of clarin-1 in hair cells and photoreceptors suggests it functions at both the basal and apical poles of neurosensoriepithelia. PMID:19539019

In vitro calcification and in vivo biocompatibility of the cross-linked polypentapeptide of elastin

International Nuclear Information System (INIS)

Wood, S.A.; Lemons, J.E.; Prasad, K.U.; Urry, D.W.

1986-01-01

The in vitro calcifiability and molecular weight dependence of calcification of the polypentapeptide, (L X Val1-L X Pro2-Gly3-L X Val4-Gly5)n, which had been gamma-irradiation cross-linked have been determined when exposed to dialyzates of normal, nonaugmented fetal bovine serum. The material was found to calcify: calcifiability was found to be highly molecular weight dependent and to be most favored when the highest molecular weight polymers (n approximately equal to 240) had been used for cross-linking. The in vivo biocompatibility, biodegradability, and calcifiability of the gamma-irradiation cross-linked polypentapeptide were examined in rabbits in both soft and hard tissue sites. The material was found to be biocompatible irrespective of its physical form and to be biodegradable but with n of 200 or less it was not shown to calcify or ossify in the rabbit tibial nonunion model

In vivo analysis of the role of metabotropic glutamate receptors in the afferent regulation of chick cochlear nucleus neurons.

Science.gov (United States)

Carzoli, Kathryn L; Hyson, Richard L

2011-02-01

Cochlea removal results in the death of approximately 20-30% of neurons in the chick nucleus magnocellularis (NM). One early event in NM neuronal degradation is the disruption of their ribosomes. This can be visualized in the first few hours following cochlea removal using Y10B, an antibody that recognizes ribosomal RNA. Previous studies using a brain slice preparation suggest that maintenance of ribosomal integrity in NM neurons requires metabotropic glutamate receptor (mGluR) activation. Isolating the brain slice in vitro, however, may eliminate other potential sources of trophic support and only allows for evaluation of the early changes that occur in NM neurons following deafferentation. Consequently, it is not known if mGluR activation is truly required for the maintenance of NM neurons in the intact system. The current experiments evaluated the importance of mGluRs in vivo. The effects of short-term receptor blockade were assessed through Y10B labeling and the effects of long-term blockade were assessed through stereological counting of NM neurons in Nissl-stained tissue. mGluR antagonists or vehicle were administered intracerebroventricularly following unilateral cochlea removal. Vehicle-treated subjects replicated the previously reported effects of cochlea removal, showing lighter Y10B labeling and fewer Nissl-stained NM neurons on the deafened side of the brain. Blockade of mGluRs prevented the rapid activity-dependent difference in Y10B labeling, and in some cases, had the reverse effect, yielding lighter labeling of NM neurons on the intact side of the brain. Similarly, mGluR blockade over longer survival periods resulted in a reduction in number of cells on both intact and deafferented sides of the brain, and in some cases, yielded a reverse effect of fewer neurons on the intact side versus deafened side. These data are consistent with in vitro findings and suggest that mGluR activation plays a vital role in the afferent maintenance of NM neurons

Acoustic input and efferent activity regulate the expression of molecules involved in cochlear micromechanics

Science.gov (United States)

Lamas, Veronica; Arévalo, Juan C.; Juiz, José M.; Merchán, Miguel A.

2015-01-01

Electromotile activity in auditory outer hair cells (OHCs) is essential for sound amplification. It relies on the highly specialized membrane motor protein prestin, and its interactions with the cytoskeleton. It is believed that the expression of prestin and related molecules involved in OHC electromotility may be dynamically regulated by signals from the acoustic environment. However little is known about the nature of such signals and how they affect the expression of molecules involved in electromotility in OHCs. We show evidence that prestin oligomerization is regulated, both at short and relatively long term, by acoustic input and descending efferent activity originating in the cortex, likely acting in concert. Unilateral removal of the middle ear ossicular chain reduces levels of trimeric prestin, particularly in the cochlea from the side of the lesion, whereas monomeric and dimeric forms are maintained or even increased in particular in the contralateral side, as shown in Western blots. Unilateral removal of the auditory cortex (AC), which likely causes an imbalance in descending efferent activity on the cochlea, also reduces levels of trimeric and tetrameric forms of prestin in the side ipsilateral to the lesion, whereas in the contralateral side prestin remains unaffected, or even increased in the case of trimeric and tetrameric forms. As far as efferent inputs are concerned, unilateral ablation of the AC up-regulates the expression of α10 nicotinic Ach receptor (nAChR) transcripts in the cochlea, as shown by RT-Quantitative real-time PCR (qPCR). This suggests that homeostatic synaptic scaling mechanisms may be involved in dynamically regulating OHC electromotility by medial olivocochlear efferents. Limited, unbalanced efferent activity after unilateral AC removal, also affects prestin and β-actin mRNA levels. These findings support that the concerted action of acoustic and efferent inputs to the cochlea is needed to regulate the expression of major

Giant oral tumor in a child with malnutrition and sickle cell trait: Anesthetic challenges

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Preet Mohinder Singh

2013-01-01

Full Text Available Pediatric oral tumors have always been challenging for the even most skilled anesthesiologists. The conventional method of awake intubation is not realistic in this age group. The management is to chart out a plan to intubate the child post induction. We describe successful management of a case of giant of ossifying fibroma in a child with sickle cell trait where non-conventional innovate approach helped us to secure the airway pre-operatively and avoid possible medical complications.

Three dimensional conformal postoperative radiotherapy for ...

African Journals Online (AJOL)

Azza Helal

2013-06-17

Jun 17, 2013 ... during postoperative 3DCRT treatment of parotid gland cancer patients. ... contralateral parotid, oral cavity, cochlea, spinal cord, brain stem, eyes, lenses and ... xerostomia, dry ear, ear infections, hearing deficits and ipsilat-.

Treatment of Noise-Induced Hearing Loss

National Research Council Canada - National Science Library

d'Aldin, Gervais

1999-01-01

.... Guinea pigs are subjected to an acoustic trauma. The recovery of the noise-induced hearing loss is followed up to 14 days post exposure by electrocochleography and morphologic examination of the cochlea is performed...

Optical coherence tomography (OCT) leading to more insight into cochlear mechanics

Energy Technology Data Exchange (ETDEWEB)

Boer, Egbert de [Academic Medical Centre, University of Amsterdam, Amsterdam (Netherlands); Oregon Health & Science University, Portland, Oregon (United States); Chen, Fangyi; Zha, Dingjun; Nuttall, Alfred L. [Oregon Health & Science University, Portland, Oregon (United States)

2015-12-31

Optical Coherence Tomography (OCT) was used to measure vibrations of the basilar membrane (BM) and the Reticular Lamina (RL) in the cochlea of the guinea pig, at frequencies up to 25 kHz. Because of the difficulty of the experiments the data have limited sets of parameters and are subject to high noise levels. In a viable guinea-pig cochlea, the RL moves in the region of maximum response with a larger amplitude than the BM. We cannot rule out that some of that difference is due to a geometrical factor. We also found a consistent increase of this amplitude difference with frequency, which points to a low-pass filtering process. That process might be linked to the mass of the fluid contained in the Organ of Corti channel (OoC channel)

Pre-, intra- and post-operative imaging of cochlear implants

Energy Technology Data Exchange (ETDEWEB)

Vogl, T.J.; Naguib, N.N.N.; Burck, I. [University Hospital Frankfurt (Germany). Inst. of Diagnostic and Interventional Radiology; Tawfik, A. [Mansoura Univ. (Egypt). Dept. of Diagnostic and Interventional Radiology; Emam, A. [University Hospital Alexandria (Egypt). Dept. of Diagnostic and Interventional Radiology; Nour-Eldin, A. [University Hospital Cairo (Egypt). Dept. of Radiology; Stoever, T. [University Hospital of Frankfurt (Germany). Dept. of Otolaryngology

2015-11-15

The purpose of this review is to present essential imaging aspects in patients who are candidates for a possible cochlear implant as well as in postsurgical follow-up. Imaging plays a major role in providing information on preinterventional topography, variations and possible infections. Preoperative imaging using DVT, CT, MRI or CT and MRI together is essential for candidate selection, planning of surgical approach and exclusion of contraindications like the complete absence of the cochlea or cochlear nerve, or infection. Relative contraindications are variations of the cochlea and vestibulum. Intraoperative imaging can be performed by fluoroscopy, mobile radiography or DVT. Postoperative imaging is regularly performed by conventional X-ray, DVT, or CT. In summary, radiological imaging has its essential role in the pre- and post-interventional period for patients who are candidates for cochlear implants.

Medline Plus

Full Text Available ... like structure that contains the receptor organ for hearing. The cochlea contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate ...