Internal acoustic opening: different osseous landmarks and their clinical implications / Poro acústico interno: diferentes hitos óseos y sus implicaciones clínicas

SUMMARY: Internal acoustic opening is a space that opens to facies posterior of the petrous piece of temporal bone that goes inside facial nerve, vestibulocochlear nerve, intermedial nevre and labyrinthine artery. The purpose of this study is the assessment of internal acoustic opening from a morphometric perspective, determination of the shape of the hole and determination of the distance to some important anatomic formations. This study is conducted on 166 temporal bones with unknown sex formation which are part of the skull collection in NEU and KTO Karatay University, Anatomy Department. In this study, the vertical and diameter of internal acoustic meatus, its distance to the bottom and top sides of posterior surface of the petrous part, its distance to groove for superior sagittal sinus and its distance to apex were measured. Moreover, in this study internal acoustic opening spaces are categorized into six groups as round, oval, U-shaped, fissure, irregular and V shape. Digital caliper was used for internal acoustic meatus measurements. While the vertical horizontal diameters and distance to groove for superior sagittal sinus of internal acoustic opening on the right side are 4.12 mm, 6.83 mm and 19.64mm respectively, they are 4.56 mm, 7.10 mm and 21.06 mm on the left side respectively. We have observed in this study, 37.3 % of the internal acoustic opening as round, 34.3 % as oval, 6.6 % as U-shaped, 6.6 % as fissure, 12.7 % as irregular and 2.4 % as V-shaped. We believe that these measurements can provide guidance and help in surgical procedures.

RESUMEN: El poro acústico interno es un espacio que se abre en la cara posterior de la parte petrosa del hueso temporal, donde entran los nervios facial, intermedio y vestibulococlear, además de la arteria laberíntica. El propósito de este estudio fue la evaluación del poro acústico interno desde una perspectiva morfométrica, determinación de la forma del foramen y de la distancia a algunas formaciones anatómicas importantes. Este estudio se realizó en 166 huesos temporales de individuos de sexo desconocido que forman parte de la colección de cráneos del Departamento de Anatomía en NEU y KTO, Universidad de Karatay, Se midió la altura vertical y el diámetro del poro acústico interno, su distancia a los lados inferior y superior de la superficie posterior de la parte petrosa, su distancia al surco del seno sagital superior y su distancia al vértice. Además, el poro acústico interno se clasificó en seis grupos: redondos, ovalados, en forma de U, de fisura, irregulares y en forma de V. Se utilizó un calibrador digital para las mediciones del meato acústico interno. Mientras que los diámetros horizontales, verticales y la distancia al surco para el seno sagital superior del poro acústico interno en el lado derecho fue de 4,12 mm, 6,83 mm y 19,64 mm respectivamente, en el lado izquiedo fue de 4,56 mm, 7,10 mm y 21,06 mm, respectivamente. Hemos observado que en el 37,3 % de los casos el poro acústico interno era redondo, el 34,3 % ovalado, el 6,6 % en forma de U, el 6,6 % de fisura, el 12,7 % irregular y el 2,4 % en forma de V. Estas medidas pueden servir de guía y ayuda en los procedimientos quirúrgicos.

Histology and immunocytochemical localization of glial fibrillary acidic protein in the inner ear of Scincella tsinlingensis / Histología y localización inmunocitoquímica de la proteína ácida fibrilar glial en el oído interno de Scincella tsinlingensis

SUMMARY: The microstructure of inner ear in Scincella tsinlingensis was observed by light microscopy and the expression of glial fibrillary acidic protein (GFAP) in membranous labyrinth among the juvenile age group, subadult age group and adult age group were also detected by methods of immunohistochemistry. The inner ear in S. tsinlingensis resembled those in other Scincid lizards in their anatomy and histology. Large and elongate cochlear duct was slightly bowed or arched laterally. There was no hint of limbic modifications and the limbic lip was absent in cochlear recess. The basilar papilla elongated anteroventrally possessed specialized tectorial sallets. GFAP staining was significantly distributed in supporting cells of the sensory epithelia of cochlear duct, while the utricular macula and canal ampullae showed immunopositive for the GFAP antibody, with weaker staining in the saccular macula. The membranous inner ear of three different age groups revealed the similar pattern of GFAP expression, which suggested that the distribution of supporting cells were independent of age in S. tsinlingensis.

RESUMEN: La microestructura del oído interno en Scincella tsinlingensis fue analizada mediante microscopía óptica y por otra parte, fue cuantificada la expresión de la proteína ácida fibrilar glial (GFAP) en el laberinto membranoso, entre los grupos de edad juvenil, subadulto y adulto, utilizándose métodos inmunohistoquímicos. El oído interno de S. tsinlingensis se asemejaba al de otros lagartos Scincid tanto en su anatomía como en su histología. El conducto coclear mayor estaba ligeramente arqueado o arqueado lateralmente. No había indicios de modificaciones límbicas y no se evidenció el labio en el receso coclear. La papila basilar alargada anteroventralmente poseía sallets tectoriales especializados. La tinción de GFAP se distribuyó significativamente en las células del epitelio sensorial del conducto coclear, mientras que la mácula utricular y la ampolla del canal mostraron inmunopositividad para el anticuerpo GFAP, con una tinción más débil en la mácula sacular. El oído interno membranoso de los tres grupos de edad diferentes reveló un patrón similar de expresión de GFAP, lo que sugiere que la distribución de las células de soporte son independiente de la edad en S. tsinlingensis.

Práctica experimental de disección y modelación 3D de oído medio e Interno para la construcción significativa de conocimiento en el área de anatomía humana / Experimental practice of dissection and 3D modeling of the middle and inner ear for the development of increased knowledge of human anatomy

La comprensión de la anatomía humana y especialmente de algunos órganos muy pequeños como es el oído medio e interno, resulta desafiante debido a su compleja estructura tridimensional. Construir conocimiento en la comprensión de la Anatomía del oído medio e interno humano, a partir del experimento de disección y modelación 3D. Con imágenes DICOM de una tomografía axial computarizada del oído humano convertidas a un modelo 3D (Mimics) y disecciones cadavéricas del hueso temporal, se diseñaron las estructuras óseas y blandas del oído externo, medio e interno mediante la implementación de software de modelado orgánico. Creación de un protocolo operativo estándar, modelado 3D de oído medio e interno e impresión 3D de las estructuras, diferenciando por color cada una de ellas. La experimentación, en este caso, la disección y modelación de las piezas anatómicas fue fundamental en la enseñanza y aprendizaje de esta área de las ciencias, permitiendo que se construya conocimiento a partir de la búsqueda de información, observación, análisis y reflexión. Los estudiantes manifestaron fascinación y aprendizaje profundo en la práctica realizada. La construcción de modelos explicativos en torno a la experimentación cualitativa permite comprender a profundidad los diferentes fenómenos. La actividad experimental, supera la demostración y facilita la confrontación de pensamiento, los estudiantes a través de esta actividad comprendieron a profundidad la anatomía del oído medio e interno, han adquirido destrezas quirúrgicas, han propuesto y analizado proyectos que les ha permitido participar eventos académicos, adquiriendo competencias como el uso comprensivo del conocimiento científico.

Understanding human anatomy, and especially some very small organs such as the middle and inner ear, is challenging due to their complex three-dimensional structure. To build knowledge in understanding of anatomy, of the human inner and middle ear, from the 3D modeling and dissection experiment. Using DICOM images from a computerized axial tomography of the human ear converted to a 3D model (Mimics) and cadaveric dissections of the temporal bone, the bony and soft structures of the external, middle, and internal ear were designed, using organic modeling software. A standard operating protocol, 3D modeling of the middle and inner ear and 3D printing of the structures was created, differentiating each one by color. In this case, the dissection and modeling of the anatomical pieces was fundamental in the teaching and learning of this area of science, allowing expanded knowledge from the search for information, observation, analysis and reflection. The students showed fascination and deep learning in the practice carried out. The construction of explanatory models around qualitative experimentation allows an in-depth understanding of the different phenomena. The experimental activity overcomes the demonstration and facilitates thought process. The students achieve and in depth understanding of the middle and inner ear anatomy, acquired surgical skills, proposed and analyzed projects that allowed them to participate in academic event. They have also acquired additional skills, such as the comprehensive use of scientific knowledge.

Mejorar el acceso mundial a las nuevas vacunas: propiedad intelectual, transferencia de tecnología y vías de reglamentación / Improving global access to new vaccines: intellectual property, technology transfer, and regulatory pathways

En el Plan de acción mundial sobre vacunas, aprobado por la Asamblea Mundial de la Salud en el 2012, se hizo un llamamiento en pro del acceso mundial a las nuevas vacunas en un plazo de 5 años desde que se otorga la licencia. Sin embargo, los métodos actuales han resultado insuficientes para lograr fijar precios sostenibles para las vacunas en dicho plazo. En paralelo con la estrategia exitosa de la competencia de los genéricos para reducir el precio de los medicamentos, está surgiendo un consenso claro sobre el hecho de que la entrada en el mercado de múltiples proveedores es un factor fundamental para reducir rápidamente el precio de las nuevas vacunas. En este contexto, los principales objetivos para mejorar el acceso a las nuevas vacunas incluyen superar los obstáculos de la propiedad intelectual, simplificar las vías de reglamentación de las vacunas biosimilares y reducir los plazos de entrada en el mercado de los fabricantes de vacunas de los países en desarrollo mediante la transferencia de tecnología y conocimientos prácticos. En este artículo propongo crear un banco de propiedad intelectual, tecnología y conocimientos prácticos como un nuevo enfoque a fin de facilitar el acceso generalizado a las nuevas vacunas en los países de ingresos medianos y bajos mediante la transferencia eficaz de las técnicas de producción de vacunas patentadas a múltiples fabricantes de vacunas en los países en desarrollo.

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers.

Micro-endoscopic ear anatomy of guinea pig applied to experimental surgery

PURPOSE: To describe topographic and endoscopic anatomy of guinea pig ear for development of surgical approaches in experimental studies. METHODS: Experimental study. Eight adult guinea pigs (Cavia porcellus) were used in this study. Four animals were described through endoscopic view and four animals were used to describe topographic anatomy. RESULTS: The main structures of middle ear were well identified through endoscopy view: oval and round window, ossicles and vascular structures. Temporal bone position, landmarks and its relations to skull are perceived with topographic description. CONCLUSION: Topographic anatomic description allowed exposition of temporal bone relations for external surgical approaches. Alternatively, grooves and middle ear structures were identified and may be used to transcanal accesses. .

Conhecimento da anatomia da orelha de cobaias e ratos e sua aplicação na pesquisa otológica básica / Understanding the anatomy of ears from guinea pigs and rats and its use in basic otologic research

O uso de mostras animais é importante na pesquisa otológica e o conhecimento da anatomia de sua orelha permite sua utilização adequada. OBJETIVO: Estudar a anatomia da orelha da cobaia e do rato por microscopia óptica de luz (MOL) e microscopia eletrônica de varredura (MEV) e suas vantagens anatômicas na pesquisa otológica básica. MATERIAL E MÉTODO: Os ossos temporais, as bulas timpânicas e cócleas de três cobaias e ratos albinos foram fotografados e analisados ao MOL e MEV. RESULTADOS: O rato não é tão simples de manipular como a cobaia, e freqüentemente apresenta otite média. O rato apresenta uma junção frágil da bula timpânica, duas e meia espiras na cóclea e a membrana timpânica não veda todo o conduto auditivo externo. A cobaia possui uma bula inteiriça, martelo e bigorna fundidos e três e meia espiras na cóclea. Pela MEV a cobaia e o rato possuem Membrana Tectória, Membrana de Raissner e o Órgão de Corti. As Células de Hensen estão presentes somente na cobaia. CONCLUSÃO: A cobaia foi considerada de fácil manipulação para a microdissecção, pelo tamanho e rigidez do osso temporal, e para experimentos cirúrgicos envolvendo o estribo, janela oval e a membrana timpânica. Pela MEV nota-se semelhança entre cobaia e rato, podendo ambos serem utilizados em estudos da orelha interna.

The use of animal samples is important in otologic research and understanding the anatomy of their ears help make proper use of them in research projects. AIM: to study guinea pig's and rat's ears under light microscopy(LM) and scanning electron microscopy(SEM) and understand their anatomical advantages in basic otologic research. MATERIALS AND METHODS: The temporal bones, tympanic bullas and cochleas from three albino guinea pigs and rats were photographed and analyzed under LM and SEM. RESULTS: Rats aren't as simple to handle as guinea pigs, and often present with otitis media. Rats have a fragile junction of the tympanic bulla, two and half turns in the cochlea, and their tympanic membranes do not seal off the entire external auditory canal. Guinea pigs have full bullas, their incus and malleus are fused and they have three and half cochlear turns. Under SEM, guinea pigs and rats have Tectori Membrane, Raissner's Membrane and the Organ of Corti. Only guinea pigs have Hensen's Cells. CONCLUSION: Guinea pigs were considered easy to handle for microdissection purposes because of the size and robustness of their temporal bones, and for surgical experiments involving the stapes, the oval window and the tympanic membrane. Under SEM there are similarities guinea pigs and rats, and both can be used in inner ear studies.

Estudio morfológico del oído medio e interno de la Chinchilla laniger / Morphological study of the middle and internal ear of Chinchilla laniger

Introducción: La Chinchilla laniger, roedor originario de la Cordillera de Los Andes, ha sido utilizada como modelo de investigación otológica por más de 40 años. Sin embargo, no existe un estudio anatómico e histológico detallado del oído de este animal. La mayoría de las investigaciones se han desarrollado en neurofisiología de la audición. Objetivos: Describir macroscópica y microscópicamente el oído medio e interno de la Chinchilla laniger. Material y método: Estudio realizado en cinco chinchillas adultas (previa aprobación del Comité de Bioética sobre la Investigación en Animales). Macroscopía: Se realizó una cirugía vía conducto auditivo externo y se estudió también con una tomografía computada de oído s. Microscopía: Disección, fijación e inclusión en parafina. Tinción con hematoxilina-eosina. Resultados: Vía conducto auditivo externo se realiza un colgajo timpanomeatal similar al de estapedectomía. Se accede a la caja timpánica por el cuadrante posterosuperior Se observa que el martillo presenta un delgado mango unido verticalmente al tímpano. Presenta una cabeza con un gran proceso anterior en vez de ligamento timpanomaleolar anterior. Su cabeza se une al yunque, fusionándose. El proceso lenticular del yunque se une a un delgado estribo, en el cual se observa el vestigio de la arteria estapedial, entre las cruras. El promontorio es visible fácilmente dado su tamaño y prominencia. La ventana oval se encuentra levemente más superoanterior que la ventana redonda. La cóclea da 3 y media vueltas sobre el modiolo. El órgano de Corti, sáculo, utrículo y crista ampularis se identificaron en los cortes histológicos. Conclusiones: El estudio morfológico detallado de un modelo de investigación como la chinchilla es imprescindible para el desarrollo de nuevos estudios en audición.

Introduction: Chinchilla laniger is a rodent that has been used as a model of ear research for more than 40 years; nevertheless, a macroscopic and microscopic detailed study of the ear in this animal is lacking. Purposes: Jo describe the anatomy and histology of the middle and inner ear of Chinchilla laniger. Materials and methods: Five adult chinchillas were used in this study. The macroscopic study was made with a computed tomography of the ear and then dissection under a microscope. For the microscopic study ears were dissected, fixed, decalcified, included in paraffin and then sectioned and stained with hematoxylin-eosin. Results: A tympanomeatal flap was made via the external acoustic meatus, similar to a stapedectomy The tympanic cavity was accessed through the posterosuperior quadrant to examine the malleus. A thin manubrium attached vertically to the eardrum could be observed. The malleus head is characterized by a large anterior process, instead of the anterior tympanomallear ligament, and it was fused to the incus. The lenticular process of the latter joined a thin stapedius, in which the vestige of the stapedial artery was observed (between the cruras). The promontory was visible easily because of its size and prominence. The oval window was located more superoanterior than the round window. The cochlea gave 31/2 turns around the modiolus. The organ of Corti, saccule, utricle and ampullary crest were identified in the histological sections. Conclusions: The ear of Chinchilla laniger is similar to the human ear supporting its use as a model in ear research. The study of the ear specially the cochlea, is difficult and needs great dedication in order to obtain good results.

MR Imaging of the Internal Auditory Canal and Inner Ear at 3T: Comparison between 3D Driven Equilibrium and 3D Balanced Fast Field Echo Sequences

OBJECTIVE: To compare the use of 3D driven equilibrium (DRIVE) imaging with 3D balanced fast field echo (bFFE) imaging in the assessment of the anatomic structures of the internal auditory canal (IAC) and inner ear at 3 Tesla (T). MATERIALS AND METHODS: Thirty ears of 15 subjects (7 men and 8 women; age range, 22-71 years; average age, 50 years) without evidence of ear problems were examined on a whole-body 3T MR scanner with both 3D DRIVE and 3D bFFE sequences by using an 8-channel sensitivity encoding (SENSE) head coil. Two neuroradiologists reviewed both MR images with particular attention to the visibility of the anatomic structures, including four branches of the cranial nerves within the IAC, anatomic structures of the cochlea, vestibule, and three semicircular canals. RESULTS: Although both techniques provided images of relatively good quality, the 3D DRIVE sequence was somewhat superior to the 3D bFFE sequence. The discrepancies were more prominent for the basal turn of the cochlea, vestibule, and all semicircular canals, and were thought to be attributed to the presence of greater magnetic susceptibility artifacts inherent to gradient-echo techniques such as bFFE. CONCLUSION: Because of higher image quality and less susceptibility artifacts, we highly recommend the employment of 3D DRIVE imaging as the MR imaging choice for the IAC and inner ear.

Anthropometry of Internal Acoustic Meatus / Antropometría del Meato Acústico Interno

Knowledge of the normal dimensions and local anatomy of the internal acoustic canal (IAM) is necessary during evaluation of temporal bone trauma, congenital anomalies, affecting the individual nerves, and some neuro-otologic surgeries. The purpose of this study was therefore to characterize the anthropometry of the IAM. We made the following measurements in 14 normal temporal bones of Iranian male skulls from individuals 35 to 60 years of age (average of 50): Height and width of the middle portion of the IAM (mean 4.04 and 3.69mm), Height and width of the fundus of the IAM (mean 2.86 and 2.43mm), inferior and superior length of the IAM (mean 8.39 and 10.75mm).This study provides baseline information that maybe used to evaluate the congenital anomalies of the IAM. These data may also be helpful in the presurgical evaluations of the patients undergoing surgeries involving the IAM.

El conocimiento de las dimensiones normales y de la anatomía local del meato acústico interno (MAI) es necesario durante la evaluación del trauma del hueso temporal, anomalías congénitas que afectan a nervios individuales y algunas cirugías neurootológicas. El objetivo del trabajo fue caracterizar la antropometría del MAL Las siguientes mediciones las realizamos en 14 huesos temporales normales de individuos iraníes masculinos, de 35 a 60 años de edad (promedio 50 años): altura y ancho de la porción media del MAI (4,04 y 3,69mm), altura y ancho del fondo del MAI (2,86 y 2,43mm), largo inferior y largo superior del MAI (promedio 8,39 y 10,75mm). Este estudio entrega información básica que puede ser usada para evaluar anomalías congénitas del MAL Estos datos también pueden ayudar en evaluaciones prequirúrgicas de pacientes que serán sometidos a cirugías que involucren el MAL.

Comparação morfométrica da orelha interna entre ovinos e humanos através da tomografia computadorizada / CT-Scan sheep and human inner ear morphometric comparison

INTRODUÇÃO: trabalhos sobre o uso de ovelhas em cirurgias experimentais e treinamento em cirurgia otológica são raros. Este estudo pretende contribuir para ampliar o conhecimento nessa área. OBJETIVO: Estudar a orelha interna da ovelha por meio de tomografia computadorizada e cortes sucessivos com o intuito de apresentar dados morfométricos mais precisos relacionados à comparação entre a orelha de ovelhas e a de humanos. MATERIAL E MÉTODO: Foi realizado um estudo descritivo sem seguimento no qual foram comparadas as estruturas da orelha interna da ovelha com as dos humanos. As medidas foram obtidas através de tomografias computadorizadas e avaliadas por meio de um programa de análise de imagens médicas (Osíris 4.16). RESULTADOS: O estudo morfológico da orelha da ovelha, em média, e da orelha humana, em média, revelaram grande similaridade de anatomia. A maior parte das estruturas (10 de 15) preservou a relação proposta de 2/3 da dimensão humana em relação à dimensão ovina. CONCLUSÃO: Os achados contribuem para uso da orelha da ovelha como modelo em cirurgia experimental e treinamento em cirurgia otológica.

INTRODUCTION: Studies about the use of sheep in surgical training and experimental otologic surgery are rare. This study intends to contribute to the knowledge on this field. AIM: To study sheep inner ear structures using computerized tomography and serial cross-sections to collect more accurate morphometric data to compare sheep and human ears. MATERIAL AND METHODS: This descriptive study compared the inner structures of sheep and human ears. Measurements were made using computerized tomography, and they were stored in a DICOM compact disc for later analysis and manipulation, with a program used for medical image analysis (Osíris 4.16). RESULTS: Mean measures for sheep and human ears were found to be similar in this morphological study. Most structures (10 out of 15) maintained the 2/3 ratio of sheep to human ear. CONCLUSION: The results of this morphometric study of sheep ear are an important contribution to the development of an animal model to be used for surgical training and experimental otologic surgeries.

Stress in hearing and balance in Meniere's disease.

Stress is an unavoidable every-day phenomenon. Physiological coping with stress depends on the appropriate release of stress hormones as well as their alleviation at the termination of the stress. Despite quite a body of research indicating that stress affects inner ear function, this concept has found little application in otolaryngology. Today's evidence clearly indicates that the inner ear is equipped to detect stress hormones and some of these hormones have been shown to affect the inner ear function. Major stress control pathways shown to affect the inner ear include several third order axes, the hypothalamus-pituitary-adrenal axis, the hypothalamus-pituitary-thyroid axis and the hypothalamus-pituitary-gonadal axis whose functioning are interactive and inter-dependent. Less well-studied are the second order hypothalamus-pituitary control axis and its interaction with other hormones. To explore these we carried out a retrospective study on a series of Ménière's patients who had undergone a neurotomy of the vestibular nerve in the dept of ORL at the Hopital Nord, Marseille. Ménière's patients were particularly appropriate for this study since stress has long been recognised as a factor associated with the triggering of the symptoms of this pathology. Patients with acoustic neuroma and facial spasm were taken as a control population. We investigated the level of a battery of stress hormones including prolactin beta-endorphin and growth hormone. The blood sample was taken on the morning before surgery. The most striking observation was the presence of hyperprolactinemia in 30% of the Ménière patients (more than 20 microg/l) with confirmation of prolactinoma in 6 patients. The level of beta-endorphin could also be elevated. Horner, K.C., Guieu, R., Magnan, J., Chays, A. and Cazal, Y. Neuropysychopharmacology, (2001) 26:135-138. These observations suggest that neuroendocrinological feedback pathways controlling stress can be disturbed in Ménière's patients and depression of hypothalamic dopaminergic inhibition of prolactin secretion might be implicated. A further study on non-operated Ménière's patients presenting hyperprolactinemia and on dopamine agonist treatment, is needed in order to assess the role of stress in Ménière's patients. Progress in this domain could open the door towards integration of the stress concept into clinical management of various inner ear disorders.

Enfoque multidisciplinario sobre la respiración bucal. Parte 4: clasificación personal de las papadas / A multidisciplinary approach on mouth breathing. 4th part: personal classification of the chins

Continuando con la cadena kinésica de Talmant con aportes independientes, entre ellos de varios autores y nacionalidades, realizados antes y después de su concepción original, los autores los interrelacionamos y sumamos los propios a ella un 8vo. eslabón, -sobre la clasificación de las papadas- que finaliza esta serie de publicaciones. Consideramos que aún podremos ampliarla si nuestras actuales investigaciones confirman mediante pruebas clínicas la influencia en el síndrome sobre la posición ortostática y la orientación individual de los laberintos del oído interno (sic).

El cobayo como modelo de estudios audiológicos / the guinea pig as a model for audiological research

Se menciona la utilidad del cobayo en la investigación audiológica, describiendo dos acceso quirúrgicos tanto al oído medio como al interno, utilizando estas técnicas para la producción de hipoacusia experimentales. También se discute sobre registros electrofisiológicos obtenidos en animales recién nacidos y adultos, con la finalidad de proponer al cobayo como modelo ideal de estudios audiológicos

Estudo da abertura externa do aqueduto vestibular como referência na preservaçäo do labirinto pelo acesso suboccipital retrossigmóideo transmeatal / Study of external aperture of vestibular aqueduct as a landmark in the preservation of the labyrinth by the suboccipital retrosigmoid transmeatal approach

A abertura externa do aqueduto vestibular foi avaliada como uma referência para ajudar na preservaçäo do labirinto por meio do acesso suboccipital retrossigmóideo transmeatal. Foram estudados ossos temporais, segmentos cefálicos, pacientes portadores de neurinomas do acústico e exames por tomografia computadorizada dos ossos temporais. As correlaçöes existentes entre a abertura externa do aqueduto vestibular, poro acústico interno e crista transversa foram observadas, e realizadas medidas entre essas estruturas. Dissecaçöes foram efetuadas nas partes anatômicas para a exposiçäo da abertura externa do aqueduto vestibular junto à saída do saco endolinfático. A parede posterior do meato acústico interno foi aberta, sem atingir, porém, a abertura externa do aqueduto vestibular , que foi usada como referência para o limite lateral da brocagem. Finalmente, o aqueduto vestibular, a crus commune e o canal semicircular posterior foram abertos para certificar-se de que eles näo haviam sido lesados anteriormente, e para comprovar que ainda existia um limite ósseo entre a extremidade lateral do meato acústico interno e o labirinto. A mesma referência foi utilizada em 24 pacientes portadores de neurinomas do acústico, com o propósito de preservar as partes óssea e membranosa do labirinto, e foi estudada por tomografia computadorizada dos ossos temporais. Existia sempre uma correlaçäo entre a abertura externa do aqueduto vestibular, a extremidade lateral do meato e o labirinto. A distância entre o poro acústico interno e a abertura externa do aqueduto vestibular nunca foi menor que a distância entre esse mesmo poro e a crista transversa. A aberrtura externa do aqueduto vestibular estava, em geral, lateral à projeçäo perpendicular da extremidade meatal lateral na superfície petrosa superior, e, quando sob linha direta da visäo, fornecia um ângulo apropriado para que pudessem ser evitadas lesöes na porçäo mais póstero-medial do labirinto. Se a parede posterior do meato näo fosse brocada até a abertura externa do aqueduto vestibular, o labirinto poderia ser preservado. Os resultados dos casos cirúrgicos mostraram que o labirinto pôde ser mantido intacto em todos os pacientes, e que os tumores foram completamente removidos...

Ototoxicidade: diagnóstico, prevençäo e tratamento / Ototoxicity: diagnosis, prevention and treatment

O uso de medicamentos ototóxicos produziu inúmeros deficientes auditivos. Os efeitos colaterais atingem o ouvido interno além de outros órgäos, principalmente o rim säo antibióticos, diuréticos e substâncias usadas como armas no combate a várias doenças. Os otorrinolaringologistas devema alertar seus colegas médicos sobre os riscos da ototoxicidade. Deveriam ainda estar aptos a avaliar e acompanhar os pacientes que tiveram comcprometimento do ouvido interno durante ou após a terapia. O presente trabalho apresenta uma sumária revisäo sobre o tema, seus aspectos clínicos, patologia e tratamento. Tem como objetivo salientar importantes aspectos de interesse do especialista e do médico generalista. Destaca, à luz dos recentes avanços da farmacologia e à partir da melhor compreensäo da histofisiologia do ouvido interno, com o advento da microscopia eletrônica, as alteraçöes histopatológicas presentes no fenômeno da ototoxicidade

Some gross anatomical studies on the ear of rabbits part II tympanic cavity and internal ear

The gross anatomy of the tympanic cavity and internal ear has been conducted on 30 heads collected from rabbits of different ages. A detailed description for the epitympanic recess, tympanic cavity proper, bulla tympanica and the intra-tympanic muscles has been offered in the text. Moreover, the osseous labyrinth and the arrangement of the different parts of the membranous labyrinth have been carefully studied