Ototoxicity of boric acid powder in a rat animal model / Ototoxicidade de ácido bórico em pó em um modelo animal de rato

Abstract Introduction: Boric acid, which has antiseptic and acidic properties, is used to treat external and middle ear infections. However, we have not found any literature about the effect of boric acid powder on middle ear mucosa and inner ear. Objective: The purpose of this study is to investigate possible ototoxic effects of boric acid powder on cochlear outer hair cell function and histological changes in middle ear mucosa in a rat animal model. Methods: Twenty healthy, mature Wistar albino rats were used in this study. The rats were divided into two groups, Group A and Group B, each of which consisted of 10 rats. Initially, the animals in each group underwent distortion product otoacoustic emissions testing of their right and left ears. After the first distortion product otoacoustic emissions test, a surgical microscope was used to make a small perforation in both ears of the rats in each group, and a second distortion product otoacoustic emissions test was used to measure both ears in all of the rats. Boric acid powder was applied to the right middle ear of the rats using tympanic membrane perforation, and the distortion product otoacoustic emissions were measured immediately after the boric acid powder application. The histological changes and distortion product otoacoustic emissions were evaluated three days later in Group A and 40 days later in Group B. Results: No significant differences were found at all of the distortion product otoacoustic emissions frequencies. In Group A, mild inflammation of the middle ear mucosa was found on the third day after boric acid powder application. In Group B, boric acid powder caused mild inflammatory changes on the 40th day, which declined over time. Those changes did not lead to significant fibrosis within the mucosa. Conclusion: In rats, boric acid powder causes mild inflammation in middle ear mucosa and it has no ototoxic effects on cochlear outer hair cell function in the inner ear of rats.

Resumo Introdução: O ácido bórico, que tem propriedades antissépticas e ácidas, é usado para tratar infecções de orelha externa e média. No entanto, não encontramos literatura sobre o efeito do ácido bórico em pó sobre a mucosa da orelha interna e da orelha média. Objetivo: Investigar possíveis efeitos ototóxicos do ácido bórico em pó sobre a função das células ciliadas externas cocleares e alterações histológicas na mucosa da orelha média em um modelo animal de rato. Método: Vinte ratos Wistar albinos maduros e saudáveis foram usados neste estudo. Os ratos foram divididos em dois grupos, Grupo A e Grupo B, cada um dos quais com 10 ratos. Inicialmente, os animais de cada grupo foram submetidos a testes de emissões otoacústicas - produto de distorção, nas orelhas direita e esquerda. Após o primeiro teste de emissões otoacústicas - produto de distorção, utilizou-se um microscópio cirúrgico para fazer uma pequena perfuração em ambas as orelhas dos ratos em cada grupo, e um segundo teste de emissões otoacústicas - produto de distorção foi utilizado para medir e avaliar as orelhas em todos os ratos. O ácido bórico em pó foi aplicado na orelha média direita dos ratos utilizando perfuração da membrana timpânica e as emissões otoacústicas - produto de distorção foram medidas imediatamente após a aplicação de ácido bórico em pó. As alterações histológicas e emissões otoacústicas - produto de distorção foram avaliadas três dias depois no Grupo A e 40 dias depois no Grupo B. Resultados: Não foram encontradas diferenças significativas em todas as frequências da emissões otoacústicas - produto de distorção. No Grupo A, foi observada uma ligeira inflamação da mucosa da orelha média no terceiro dia após a aplicação de ácido bórico em pó. No Grupo B, o ácido bórico em pó causou leves alterações inflamatórias após 40 dias, que diminuíram ao longo do tempo. Essas alterações não levaram à fibrose significativa da mucosa. Conclusão: Em ratos, o ácido bórico em pó causa inflamação leve na mucosa da orelha média e não tem efeitos ototóxicos na função das células ciliadas externas da cóclea na orelha interna.

A regional fight against Chagas disease: lessons learned from a successful collaborative partnership / Lucha regional contra la enfermedad de Chagas: lecciones aprendidas de una alianza colaborativa exitosa

Objective. To identify the intangible elements that characterize the successful effort to fight Chagas disease in the Americas, determine how they contributed to the overall success of the partnership, and learn lessons from the experience that could be applied to other programs. Methods. This study was based on the Partnership Assessment Tool (PAT) developed by the Nuffield Institute for Health ("the Institute") at the University of Leeds (London). The PAT draws heavily on scientific literature and the extensive experience of sociologists and health experts working for the Institute. The Pan American Health Organization (PAHO) modified the tool slightly to adapt it to its needs and provide a general structure for the study. The six key principles of the PAT framework were applied in the design of the research questionnaires. Results. The findings show that a successful collaboration requires a clear objective; a good-quality pool of data; and comprehensive qualitative and quantitative knowledge of the problem, its dimensions, and its impact. The collaboration was elaborated from a common idea and a shared, quantified plan based on data gathered by independent scientists plus a strategy with explicit milestones. The clarity of purpose allowed for an improved synergy of efforts and made it possible to resolve differences in opinions and approaches. Conclusions. PAHO's experience with effective collaborations such as the joint initiative to fight Chagas disease provides a rich knowledge base for analysis of the advantages, limitations, and paradigms of community involvement, collaborative practices, and partnerships.

Objetivo. Establecer los elementos intangibles que caracterizan la exitosa iniciativa para combatir la enfermedad de Chagas en la Región de las Américas, determinar cómo contribuyeron al éxito general de la alianza y extraer enseñanzas de la experiencia que podrían ser aplicadas a otros programas. Métodos. Este estudio se basó en la Herramienta de Evaluación de Alianzas (PAT, por sus siglas en inglés: Partnership Assessment Tool) creada por el Nuffield Institute for Health ("el Instituto") de la Universidad de Leeds (Londres). La PAT utiliza en gran medida la bibliografía científica y la vasta experiencia de los sociólogos y expertos en salud que trabajan para el Instituto. La Organización Panamericana de la Salud (OPS) modificó ligeramente la herramienta para adaptarla a sus necesidades y proporcionar una estructura general para el estudio. En el diseño de los cuestionarios de investigación, se aplicaron los seis principios clave del marco de la PAT. Resultados. Los resultados indican que una colaboración exitosa requiere un objetivo claro; una base de datos de buena calidad; y un conocimiento exhaustivo cualitativo y cuantitativo del problema, sus dimensiones y su repercusión. La colaboración se elaboró a partir de una idea común y un plan compartido y cuantificado basado en datos recopilados por científicos independientes, junto a una estrategia con hitos explícitos. La claridad de los objetivos permitió una mejor sinergia de las iniciativas e hizo posible la resolución de las diferencias de opiniones y enfoques. Conclusiones. La experiencia de la OPS en materia de colaboraciones eficaces, como la iniciativa conjunta para combatir la enfermedad de Chagas, proporciona una rica base de conocimientos para analizar las ventajas, las limitaciones y los paradigmas de la participación comunitaria, las prácticas colaborativas y las alianzas.

Dehiscencia del canal semicircular superior, un nuevo diagnóstico en pacientes con vértigo / Superior semicircular canal dehiscence, a new diagnosis in patients with vertigo

Introduction: The superior semicircular canal dehiscence syndrome (SSCD) is a pathology described in 1998, which presents several symptoms including sound induced vertigo, hearing loss and autophony due to bone dehiscence of this semicircular canal. Material and Methods: A retrospective and descriptive study was carried out, reviewing the medical records of patients with computed tomography suggestive of SSCD between 2006 and 2010 from the Radiology department of the Clinical Hospital of the University of Chile. Results: We obtained six cases of SSCD (4 female) with a mean age of 52.7 years. SSCD was observed in four cases bilaterally and in two cases on the left ear. We confirmed a clinical syndrome in two patients, based on the presence of hearing loss and sound induced vertigo. Conclusions: The diagnosis of SSCD syndrome should be supported on both clinical and imaging studies. We should maintain a high level of suspicion, particularly in cases of sound induced vertigo and of conductive hearing loss with normal otoscopy.

inner ear neuroepithelium is a vulnerable target for impact during cisplatin chemotherapy a histological study in albino rabbits

Cisplatin is a widely used chemotherapeutic agent with potential toxicity to normal tissues including the inner ear. Cochlear damage has been always recognized as its primary ototoxic side effect with negligence to the vestibular involvement. The present study aimed to provide a histological assessment for the vulnerability of the inner car cochlear and vestibular tissues in albino rabbits to the impact by cisplatin administration. Ten adult male albino rabbits were divided among a control group and another experimented group. The latter received 8 therapeutic - equivalent doses of cisplatin [2mg/kg body weight/ dose; intraperitoneal injection every other day]. Two days after the last injection, animals were subjected to intravital perfusion by 5% gluteraldehyd under light ether anaesthesia then sacrificed by decapitation. The petrous temporal bones were dissected out, fixed, properly decalcified, and further processed for examination by the light microscope using routine hematoxylin and eosin stain and by the scanning electron microscope. Light microsopic findings showed histological degenerative changes involving the outer and inner hair cells of the organ of Corti, the supporting cells, the spiral ganglion cells and the epithelium of the stria vascularis. It also revealed degeneration of the epithelium of the crista ampullaris. The scanning electron microscopic examination explored the architectural damages affecting the cochlear hair cells and the vestibular otoconia. Cisplatin can affect both the cochlear as well as the vestibular epithelium of the inner ear in albino rabbits. Emesis in patients receiving cisplatin therapy should not mask the possibility for a vestibular impact. Accordingly, an ongoing counseling of an otolaryngeologist is mandatory for the follow up assessment of the auditory-vestibular functions during the cisplatin chemotherapy. On the other hand, multidisciplinary research studies should be expanded, particularly on the molecular level, to came out with new generations of platinum drugs that could be selectively targeted to cancer cells and escape the damage to the normal tissues

Lipomas en conducto auditivo interno: experiencia clínica y revisión del tema / Internal auditory canal lipomas: clinical experience and literature review

Se presentan dos casos clínicos del Departamento de Otorrinolaringología de la Pontificia Universidad Católica de Chile, con diagnóstico de lipoma del conducto auditivo interno (CAí). Los lipomas del CAí son neoplasias benignas poco frecuentes, con una frecuencia de 0,15 por ciento de los tumores del CAL Se presentan principalmente entre la tercera y quinta década de la vida, en su mayoría hombres caucásicos. Clínica y audiológicamente son indistinguibles de otros tumores de la misma zona, siendo el neurinoma del acústico (schwanoma vestibular) el tumor más frecuente en el CAí (90 por ciento). Las Imágenes de resonancia magnética permiten realizar el diagnóstico específico de lipoma. El tratamiento quirúrgico ha sido desplazado por el manejo conservador, dado que los lipomas tienen crecimiento lento, sin trasformación maligna, en general, junto con difícil técnica quirúrgica por infiltración a estructuras adyacentes. Sólo estaría indicada la cirugía en casos que exista crecimiento tumoral durante el seguimiento o en pacientes con síntomas intensos y progresivos.

Two case reports with diagnosis of internal auditory canal lipomas are presented. Lipomas of the internal auditory canal are benign neoplasms, making up 0.15 percent of all tumors in this area. They occur more frequently in the third to fifth decade of life predominantly in Caucasian males. The are clinically and audiologically indistinguishable from other tumors in this region, with eighth cranial nerve schwannomas (vestibular schwannomas) being the most common I AC tumor (90 percent). MRI findings allow for specific diagnosis of a lipoma. Regarding treatment, surgery has been displaced by a conservative treatment of this rare lesion. Lipomas are slow growth lesions, without malignant transformation, and with inherent difficulties to their removal because of the adipose tissue infiltrating the nerve, as well as only partial resolution of symptoms in most cases. Surgery could only be indicated when relevant and disabling symptoms are present.

Implante cocclear / Cochlear implant

Atualmente, a cirurgia de implante coclear é o único tratamento eficaz em casos de surdez profunda bilateral em crianças e adultos. É importante fazer o diagnóstico da surdez sensorioneural através de uma bateria de exames especializados. Nesta avaliação há participação de uma equipe multidisciplinar. Com a avaliação realizada e os resultados obtidos e levando-se em conta os critérios de indicação para o implante, o paciente é selecionado para ser submetido à cirurgia de implantação. Nesta revisão a intenção foi focalizar o estado atual do tratamento da surdez profunda sensorioneural bilateral pela cirurgia de implante coclear.

Meningioma of the internal auditory canal: a case report.

Meningioma of the internal auditory canal is very rare. There are only 15 previous reports of intracanalicular meningioma. The authors add a case report of a patient with meningioma of the internal auditory canal. A 31-year-old woman presented with a one-year history of headache, dizziness, hearing loss and left facial paralysis. An MRI of the temporal bone demonstrated a tiny isointense intracanalicular tumor with inhomogeneous enhancement. In the operative field carried out by translabyrinthine approach, the tumor was found in the IAC without intracranial involvement. Pathology revealed a meningioma. The patient was followed up for 2 years without recurrence.

Ressonância magnética em surdez súbita / Magnetic resonance imaging in sudden deafness

A surdez súbita é um sintoma cuja etiologia nem sempre é elucidada mesmo dispondo-se de toda propedêutica atual. Neste estudo avaliaremos as alterações encontradas em ressonância magnética de pacientes portadores de surdez súbita. FORMA DE ESTUDO: coorte transversal. MATERIAL E MÉTODO: Estudo prospectivo com realização de RM em 49 dos 61 pacientes com surdez súbita atendidos no pronto socorro de Otorrinolaringologia do Hospital São Paulo, no período de abril de 2001 a maio de 2003. Doze pacientes abandonaram ou não foram submetidos à ressonância magnética por outros motivos. RESULTADOS: 23 (46,9 por cento) pacientes apresentaram alterações à ressonância magnética. Foram encontrados dois tumores sugestivos de meningioma e três schwannomas do oitavo par craniano. Lesões subcorticais e periventriculares esparsas e hiperintensas em FLAIR foram encontradas em 13 pacientes. Cinco (21,7 por cento) pacientes apresentaram alterações periféricas. CONCLUSÃO: A surdez súbita deve ser abordada como um sintoma comum a diferentes doenças. A presença de tumores do ângulo pontocerebelar em 10,2 por cento dos nossos casos, entre outras causas tratáveis, justifica o uso da ressonância magnética com contraste tanto para o estudo do sistema auditivo periférico quanto para o estudo das vias auditivas centrais, incluindo o cérebro.

Angioma cavernoso do meato acústico interno envolvendo o complexo VII e VIII nervos cranianos: relato de caso / Cavernous hemangioma of the internal auditory canal encasing the VII and VIII cranial nerve complex: case report

Relata-se o caso de homem de 21 anos, leucoderma, portador de angioma cavernoso do meato acústico interno direito envolvendo o complexo VII e VIII nervos cranianos tratado cirurgicamente. Apenas 18 casos de angiomas cavernosos dessa localização foram relatados na literatura. São comentados os aspectos clínicos, o diagnóstico diferencial e o tratamento.

Kogan syndrome report of a case

Cogan syndrome is a rare autoimmune disease that is characterized by acute with Audiovestibular dysfunction. Bilateral and progressive profound sensorineural hearing loss is the most important sign of the disease. Delay diagnosis leads to deafness or death and atypical form has not complete response to therapy. The purpose of this case report is presenting the sign and symptom of syndrome and advancing knowledge for early diagnosis and reporting an exceptional case. The patients was a 51-y male with chief complaints of eye redness and then hearing loss and typical vertigo. Clinical and Para clinical data rule out is the main differential diagnosis of syndrome [sarcoidosis, syphilis] and finally the Cogan syndrome was the diagnosis. Treatment with early high dose corticosteroid was used and fortunately good response was observed. The diagnosis of Cogan syndrome is based on classic finding and rule out of differential. The main differential diagnosis of Cogan syndrome includes syphilis, sarcoidosis, [PAN] all causes of peripheral vertigo. Clinical and Para clinical findings lead to diagnosis of Cogan syndrome. Exceptional items in this case: 1- Cogan syndrome is the disease of young adults, but this case was 51 year old 2- Atypical from of Cogan has not good response to drugs. But our patient completely recovered by using high dose prednisolone. At end we have to say that complete knowledge about the symptom of inner ear autoimmune disease and early treatment led to better response even in the case of atypical form

effects of electromagnetic fields on some neuroepithelial structures in the inner ear of rats

This work was dedicated to study the effects of long term exposure to time varying extremely low frequency electromagnetic fields on some neuroepithelial structures in the inner ear of rats. This work was conducted on 15 male adult albino rats, 5 rats were sham exposed and served as normal controls and 10 rats were exposed to time varying electromagnetic field of extremely low frequency [50 Hz] and 10-mT flux density for one hour daily, for 30 days. By the end of the experiment animals were anesthetized, perfused with the proper fixative then decapitated. The inner ears were reperfused and the temporal bones obtained. The specimens were put in a decalcifying agent for about 5 days. The specimens were prepared for either histological or scanning electron microscopical study. The present study revealed histological changes in all experimental specimens examined. The cochlea showed variable degrees of affection ranging from of cytoplasmic vacuolation of some supporting cells, to complete destruction of the organ of Corti. Stria vascularis showed atrophied lining cells. Spiral ganglionic cells appeared swollen with karyolitic nuclei. Vestibular neuroepithelial structures revealed milder response in the form of cytoplasmic vacuolation of both hair cells and supporting cells. From the previous results it could be concluded that long-term exposure to 10-mT extremely low frequency time varying electromagnetic field caused degenerative changes in the neuroepithelial structures of rat's inner ear

Manifestaciones vestibulares en las enfermedades metabolicas / Vestibular manifestations in metabolic diseases

Se sugiere un estudio minucioso en todos los pacientes con sintomatología vestibular vertiginosa haciendo, notar la importancia de la evaluación otoneurologíca en relación a los pacientes con alteraciones metabólicas mas comunes como las disglicemias, hiperuricemia, hipercolesterolemia.

Intra-uterine ototoxicity of gentamycin in guinea pigs

Twenty five female pregnant guinea pigs were used to study the effect of administration of gentamycin to the pregnant animal on the hearing apparatus of the developing embryo. Various concentrations of the drug were administered daily over a variable duration in both early and late stages of gestation. The inner ear, spiral ganglion, cochlear nerve and cochlear nuclei of the newly born animals were histologically examined. The extent of damage was largely dependant on the overall total dose of gentamycin received rather than on the daily dose. The sensory elements of the inner ear were more susceptible than the neural and nuclear elements. The various pathological changes are described and important clinical implications are stated

Intra-uterine ototoxicity of kanamycin: an experimental histopathological study

Kanamycin, in various concentrations was administered to25 adult female pregnant guinea pigs, over a variable duration in both early and late stages of gestation. The inner ear spiral ganglion, cochlear nerve and cochlear nuclei of the offspring born to the animals under test were histologically examined. The sensory cells of the inner ear were the elements to be primarily damaged, while the retrocochlear structures were invariably saved. The damage was largely dependent on the total dose of kanamycin, and was more pronounced when given in late pregnancy than in its early stages. The various pathological changes are described and important clinical implications are stated