Effect of trans-retinoic acid in the inhibition of cholesteatoma in guinea pigs.

UNLABELLED: Middle ear cholesteatoma affected more than 5 million people until the 80;s. Many animal models were used, unsuccessfully, to study an alternative therapy to cholesteatoma. AIM: observe the effect of the trans-retinoic acid in the inhibition of middle ear cholesteatomas induced by propylene glycol. STUDY DESIGN: Clinical and Experimental. METHODS: 25 guinea pigs were submitted to the application of a 100% propylene glycol solution in their bulla bilaterally and a solution of trans-retinoic acid was applied locally in the external right ear, while in the left ear saline solution was applied (control ear). The guinea pigs were slaughtered and their temporal bones were prepared for macroscopic and histological analysis. RESULTS: The macroscopic findings had evidenced the presence of cholesteatoma in 25% of the right ears and 85% of the left ears (P=0.0003 *). The histological study had evidenced the presence of cholesteatoma in 30% of right ears and 75% of the left ears (P=0.0104*). CONCLUSION: The local use of the trans-retinoic acid is effective in inhibiting the induced formation of cholesteatomas in guinea pigs.

Influence of cyclic AMP on facial nerve regeneration in rats.

UNLABELLED: Promoting facial nerve regeneration is a significant challenge. AIM: To evaluate the possible neurotrophic influence of cyclic AMP on facial nerve regeneration of Wistar rats. METHOD: The right facial nerve of thirty-two animals were completely transected and immediately sutured, followed by exposure or not to topical cyclic AMP. Behavioral and histometric analyses were done at 14 and 28 days. RESULTS: Statistical differences (p<0.05) were found in the behavioral and histometric analyses on the 14th day, suggesting an early regenerative response of the facial nerve to cAMP exposure. CONCLUSION: This study demonstrates a possible neurotrophic effect of cAMP on facial nerve regeneration in rats.

Selective attention: psi performance in children with learning disabilities.

UNLABELLED: Selective attention is essential for learning how to write and read. AIM: The objective of this study was to examine the process of selective auditory attention in children with learning disabilities. MATERIAL AND METHOD: Group I included forty subjects aged between 9 years and six months and 10 years and eleven months, who had a low risk of altered hearing, language and learning development. Group II included 20 subjects aged between 9 years and five months and 11 years and ten months, who presented learning disabilities. A prospective study was done using the Pediatric Speech Intelligibility Test (PSI). RESULT: Right ear PSI with an ipsilateral competing message at speech/noise ratios of 0 and -10 was sufficient to differentiate Group I and Group II. Special attention should be given to the performance of Group II on the first tested ear, which may substantiate important signs of improvements in performance and rehabilitation. CONCLUSION: The PSI - MCI of the right ear at speech/noise ratios of 0 and -10 was appropriate to differentiate Groups I and II. There was an association with the group that presented learning disabilities: this group showed problems in selective attention.

Matrix metalloproteinase 2: an important genetic marker for cholesteatomas.

AIM: This study is to determine the MMP2s presence in cholesteatomas and whether complicating cholesteatomas show a higher immunohistochemical expression of matrix metalloproteinase 2. Cholesteatoma produces enzymes that cause bone erosion like matrix metalloproteinase 2 (MMP2). MATERIAL AND METHODS: We analyzed the expression of MMP2 in invasive (causing complications) compared to latent cholesteatomas (not causing complications). A cross-sectional study with nineteen slides and paraffin blocks of cholesteatomas derived from mastoidectomies were located and processed, including 8 invasive and 11 latent cholesteatomas. Immunohistochemical technique was empregated to MMP2. RESULTS: The results are expressed as 0, + (to low), ++ and +++(high) according to the quantity and color of the immunohistochemical staining of MMP2. Higher expression of MMP2 was observed in 7 (87.5%) of the 8 invasive cholesteatomas. With respect to latent cholesteatomas, higher expression of MMP2 was observed in 27.3% (3 cases), with Fishers exact test indicating a significant difference (p=0.015). CONCLUSIONS: Cholesteatoamas express MMP2 and Invasive cholesteatomas had high MMP2 compared to latent cholesteatomas.

Intracranial complications of otitis media: 15 years of experience in 33 patients.

OBJECTIVES: Complications in the central nervous system (CNS) from acute otitis media (AOM) and chronic otitis media (COM) are becoming fewer, although they still represent a challenge for early recognition, adequate treatment, and satisfactory results. This retrospective study analyzed clinical data and therapeutic options in 33 patients with intracranial involvement resulting from otitis media. Important clinical features of intracranial complications and the sequence of the most efficient therapeutic maneuvers are discussed. METHODS: Charts of six patients with AOM and 27 patients with COM associated with CNS complications were analyzed for clinical presentation, imaging, and therapeutic approach. RESULTS: Ages ranged from 6 months to 79 years, with no gender predilection. Persistent fever, headache, and purulent otorrhea were the main symptoms. Proteus mirabilis , Enterococcus , and Pseudomonas aeruginosa were the most common microorganisms in COM, and Pneumococcus and Haemophilus were the most common microorganisms in AOM. Nineteen patients (58%) presented with more than 1 CNS complication, resulting in a total of 56 complications, including 26 cases of otogenic brain abscess, 21 cases of meningitis, 5 cases of lateral sinus thromboses, two cases of subdural empyemas, 1 case of epidural empyema, and 1 case of meningocele. Surgical interventions included craniotomy and drainage of the abscess (n = 17), open mastoidectomy with abscess drained through the mastoid (n = 10), open mastoidectomy alone (n = 8), and closed mastoidectomy (n = 2). Twelve patients who underwent craniotomy had subsequent mastoidectomy for recurrent abscess. At the 6-month, 66% of patients presented without sequelae, 24% presented with sequelae, and 9% died. CONCLUSION: Early identification and prompt clinical and surgical intervention with mandatory drainage of the middle ear (primary disease), was essential for better outcome.

Growth of cholesteatoma by implantation of epithelial tissue along the femoral bone of rats.

UNLABELLED: Cholesteatoma is a well-known infection resembling a pearl. Its histological aspect is of an epidermal cyst formation characterized by epidermal-keratinized tissue in the middle ear and mastoid that can migrate and erode to adjacent structures. AIM: To verify epidermal cyst (cholesteatoma) growth through implantation of auricular skin of a mouse next to its femoral bone. STUDY DESIGN: Experimental. MATERIAL AND METHOD: Ten healthy rats between two and five months of age and of both sexes underwent implantation of auricular skin on the femoral bone during a three-month period. Paraffin-embedded sections were obtained from the sample and stained with hematoxylin and eosin for pathology investigation. RESULTS: Macroscopic view: round soft yellowish granulation tissue. Microscopic view: keratinizing stratified squamous epithelium cystic formation. The cyst presented innermost corneal layer, resulted from keratinized skin, followed by granulated and squamous layers, and outermost basal layer. CONCLUSIONS: Growth of epidermal cyst (cholesteatoma) may start from a transplanted epithelial tissue next to the femoral bone of rats.

Microscopic anatomy of the carotid canal and its relations with cochlea and middle ear.

UNLABELLED: The knowledge of the relations between the noble and vital structures of temporal bone is still a great challenge for the otologic surgeon. The microscopic anatomic studies of the temporal bone are one of the greatest help to prevent lesions during surgical intervention. AIM: To study the anatomic correlations between the carotid canal and the cochlea, and the occurrence of dehiscence of the carotid canal in the middle ear tympanic cavity. MATERIAL AND METHODS: Microscopic study of 122 human temporal bones. RESULTS: The average distance between the carotid canal and the cochlea were: the shortest distance, 1.05 mm; basal turn, 2.04 mm; middle turn, 2.32 mm; and apical turn, 5.70 mm. The occurrence of dehiscence of the carotid canal inside the tympanic cavity was 35.2%. CONCLUSION: The small distances between the cochlea and carotid canal, and the high incidence of dehiscence in the tympanic cavity remind us that anatomical knowledge of the temporal bone is required for the best qualification of otologists.

Distortion product otoacoustic emissions in tinnitus patients.

Tinnitus is a symptom that affects a great number of patients. Its diagnosis, treatment, and follow-up are difficult, owing to its subjectivity. The authors propose the use of distortion product otoacoustic emissions (DPOAEs) in tinnitus evaluation. They studied three groups: controls, having no complaint of tinnitus and normal hearing; group 1, presenting tinnitus and normal audiometry; and group 2, presenting tinnitus and sensorineural hearing loss. The results showed 3.6% of DPOAE alterations in the control group, 18.8% in group 1, and 61.3% in group 2. This study shows a correlation between DPOAE alterations and tinnitus complaint, but many patients with tinnitus do not present with DPOAE alterations. The authors conclude that DPOAEs constitute a useful audiological method for evaluating patients complaining of tinnitus.

Audiological evaluation of twenty patients receiving pentoxifylline and prednisone after sudden deafness: prospective study.

Idiopathic sudden deafness is defined as sudden sensorineural hearing loss of undetermined etiology. As a consequence, various treatments have been developed for this disorder. Our study evaluated the effectiveness of pentoxifylline and prednisone in such treatment. We analyzed this treatment's results in our patients through conventional audiograms, and speech audiometry was performed in the acute stage and during the treatment. We diagnosed idiopathic sudden hearing loss in 20 patients (8 female and 12 male). The left ear was involved in 9 patients and the right in 11. All patients had been examined by us within 15 days from the onset of hearing loss. We compared the hearing threshold results in the different periods in this prospective study.

Relation of hyperacusis in sensorineural tinnitus patients with normal audiological assessment.

Hyperacusis is mainly a consequence of the noise level in the twenty-first century, owing to dramatic changes in people's lifestyles. Of every 100 people with otological complaints (e.g., tinnitus and hyperacusis), 20 are affected by hyperacusis. Because of its high incidence, this symptom has long been the subject of investigation. Nine patients (eight female, one male) with sensorineural tinnitus voluntarily participated in this study. Among the evaluated patients, three were between 25 and 40 years of age and six were between 41 and 60 years. The patients did not report a history of acoustic trauma, use of drugs, or otological diseases. The duration of complaints at the time the study began varied from 3 months to 8 years. The patients answered a questionnaire, submitted to an ear, nose, and throat examination, and were evaluated by pure-tone and speech audiometry and otoacoustic emissions and laboratory tests. In all patients, ear, nose, and throat assessments and audiological tests were within the normal ranges. Of the nine subjects in our study, 100% had tinnitus, and 89% (n = 8) had hyperacusis as an associated symptom. Six subjects (67%) had severe tinnitus; among them, four had moderate hyperacusis, one had severe hyperacusis, and one was not affected by hyperacusis. In two subjects (22%) with moderate tinnitus, one had moderate hyperacusis and the other referred severe symptoms. Another patient (11%) reported mild tinnitus and mild hyperacusis. No patient classified his or her tinnitus as disabling. The findings of the present study led us to conclude that the most affected age range of patients with tinnitus and hyperacusis was 41-60 years and that women are affected significantly more often than men. Tinnitus preceded hyperacusis as a complaint in 78% of the subjects. Hyperacusis was present in eight (89%) of the patients. There was no direct correlation between the severity of tinnitus and of hyperacusis, although we noticed that the discomfort of tinnitus was generally perceived as equal to or worse than that of hyperacusis.

Perilymphatic fistula in guinea pigs: natural evolution versus surgical treatment.

UNLABELLED: Perilymphatic fistulas still represent a major treatment challenge. In some cases, its surgical closure can reduce auditory and vestibular sequelae. AIM: To compare the behavior of cochlear window perilymphatic fistulas in guinea pigs as to their natural evolution and immediate surgical closure. MATERIALS AND METHODS: Experimental study. Forty guinea pigs were submitted to cochlear window membrane lesion and randomly broken down into two groups: open fistula (OF) and surgically closed fistula (SCF). We found the summation potential (SP) and action potential (AP) latencies and amplitudes and the SP/AP ratio at three times: pre-fistula (PRE), immediate post-fistula (IPF) and late post-fistula (LPF). RESULTS: There was a significant drop in amplitudes and raise in SP and AP latencies among the times studied. As to the SP/AP ratios, there was a reduction between PRE and IPF, both were significant. There was no behavior difference between the OF and SCF. CONCLUSIONS: Within the time frame considered, guinea pigs submitted to cochlear window membrane lesions evolved with a worsening in potentials and latencies. Despite the partial improvement in electrophysiological parameters, surgical closure did not prove statistically more effective than natural evolution.

The action of topical basic fibroblast growth factor in facial nerve regeneration.

OBJECTIVE: To analyze the influence of the topical use of basic fibroblast growth factor (bFGF) in the regeneration of the facial nerve in rats. STUDY DESIGN: Experimental study. MATERIALS AND METHODS: Twenty-eight Wistar adult male rats underwent complete section of the facial nerve trunk, followed by end-to-end anastomosis with epineural sutures. An osmotic minipump equipped with a delivery catheter was implanted subcutaneously near the neural anastomosis. During the subsequent 14 days, 14 animals received a solution containing 25 microg/ml of bFGF, 250 UI/ml of sodium heparin, and 1,000 microg/ml of human albumin diluted in Ringer lactate, and 14 animals received a control solution of the same components without bFGF. To evaluate facial nerve regeneration, the number of myelinated fibers evident on histologic sections was counted on the 14th (7 experimental and 8 control animals) and the 28th days (7 experimental and 6 control animals) after surgery, and the facial movements of vibrissae and the blink reflex were evaluated on alternate days until the 28th day. RESULTS: On histologic evaluation, the number of myelinated fibers was similar between groups on the 14th day and greater in the group that received bFGF on the 28th day. Behavioral evaluation showed that the animals of the bFGF group presented better functional results between the 6th and 16th days for the blink test and the 14th to the 16th days for vibrissae movements. CONCLUSION: This study showed that the regeneration of the facial nerve occurred earlier and resulted in significantly more myelinated nerve fibers in the animals that received topical bFGF.

Fístula perilinfática em cobaias: comparação entre evolução natural e correção cirúrgica / Perilymphatic fistula in guinea pigs: natural evolution versus surgical treatment

As fístulas perilinfáticas ainda constituem um grande desafio quanto ao seu tratamento. Em alguns casos, seu fechamento cirúrgico pode reduzir as sequelas auditivas e vestibulares. OBJETIVO: Comparar o comportamento de fístulas perilinfáticas de janela coclear em cobaias quanto à evolução natural e fechamento cirúrgico imediato. MATERIAL E MÉTODOS: Estudo experimental. Quarenta cobaias foram submetidas à lesão da membrana da janela coclear e divididas em dois grupos aleatoriamente: fístula aberta (FA) e fístula fechada cirurgicamente (FF). Foram determinadas as amplitudes e latências do potencial de somação (PS) e do potencial de ação (PA) e da relação PS/PA em três momentos: pré-fístula (PRÉ), pós-fístula imediato (PFI) e pós-fístula tardio (PFT). RESULTADOS: Observou-se significativa queda das amplitudes e aumento das latências do PS e PA entre os momentos considerados. Quanto à relação PS/PA, houve diminuição entre PRÉ e PFI mas aumento entre PFI e PFT, ambos significantes. Não houve diferença de comportamento entre os grupos FA e FF. CONCLUSÕES: No período considerado, cobaias submetidas a lesões da membrana da janela coclear evoluíram com piora dos potenciais e latências. Apesar da melhora parcial dos parâmetros eletrofisiológicos o fechamento cirúrgico não se mostrou estatisticamente mais efetivo que a evolução natural das mesmas.

Perilymphatic fistulas still represent a major treatment challenge. In some cases, its surgical closure can reduce auditory and vestibular sequelae. AIM: to compare the behavior of cochlear window perilymphatic fistulas in guinea pigs as to their natural evolution and immediate surgical closure. MATERIALS AND METHODS: Experimental study. Forty guinea pigs were submitted to cochlear window membrane lesion and randomly broken down into two groups: open fistula (OF) and surgically closed fistula (SCF). We found the summation potential (SP) and action potential (AP) latencies and amplitudes and the SP/AP ratio at three times: pre-fistula (PRE), immediate post-fistula (IPF) and late post-fistula (LPF). RESULTS: There was a significant drop in amplitudes and raise in SP and AP latencies among the times studied. As to the SP/AP ratios, there was a reduction between PRE and IPF, both were significant. There was no behavior difference between the OF and SCF. CONCLUSIONS: Within the time frame considered, guinea pigs submitted to cochlear window membrane lesions evolved with a worsening in potentials and latencies. Despite the partial improvement in electrophysiological parameters, surgical closure did not prove statistically more effective than natural evolution.

Internal auditory canal: pre- and postnatal growth.

OBJECTIVE: The purpose of this study was to describe the size and shape of the internal auditory canal (IAC) during development. STUDY DESIGN: The study was conducted in 98 dried temporal bones from 7-month-old fetuses to adults. Silicone mould casts of the IAC were used. METHODS: The length of the IAC was measured on the moulds corresponding four walls as the diameter on the fundus, middle portion, and porus. RESULTS: Although size and shape vary considerably among individuals, the data showed no significant differences between the right and left sides of the same individual. The values of the wall length and porus diameter increase as a function of age, especially for the upper wall and horizontal diameter. Both middle portion diameters suffer variations at different ages, increasing and decreasing until reaching the final shape. The diameter of the fundus, near the inner ear, remains stable. CONCLUSIONS: Our results showed that during development, the shape of the IAC adapts to cranial growth, with those of adults and fetuses having a similar shape but different dimensions, which was quite evident near the porus.

Efeito do ácido trans-retinóico na inibição de colesteatoma em cobaias / Effect of trans-retinoic acid in the inhibition of cholesteatoma in guinea pigs

O colesteatoma de orelha média atingia mais de 5 milhões de pessoas até a década de 80. Vários modelos animais já foram utilizados para alternativas de tratamento do colesteatoma sem sucesso. OBJETIVO: Estudar os efeitos do ácido trans-retinóico, uso tópico na orelha externa em cobaias, na inibição da formação do colesteatoma de orelha média induzido pelo propilenoglicol. Estudo experimental prospectivo. MATERIAL E MÉTODOS: 25 cobaias foram submetidas à aplicação de propilenoglicol a 100 por cento na bula timpânica bilateralmente e uma solução de ácido trans-retinóico foi aplicada topicamente (total de 5 aplicações) na orelha externa, região justa-timpânica, na orelha direita, enquanto na orelha esquerda aplicou-se solução fisiológica (orelha controle). As cobaias foram sacrificadas após 6 semanas do procedimento inicial e os ossos temporais foram separados, fixados e descalcificados, para análise macroscópica e histológica. RESULTADOS: Os achados macroscópicos evidenciaram a presença e suspeita de colesteatoma em 25 por cento das orelhas direitas e 85 por cento das orelhas esquerdas (P=0,0003*). Os achados histológicos dos 40 ossos temporais evidenciaram a presença de colesteatoma em 30 por cento das orelhas direitas e 75 por cento das orelhas esquerdas (P=0,0104*). CONCLUSÃO: O uso tópico do ácido trans-retinóico é efetivo na inibição da formação de colesteatoma induzido pelo propilenoglicol em cobaias.

Middle ear cholesteatoma affected more than 5 million people until the 80`s. Many animal models were used, unsuccessfully, to study an alternative therapy to cholesteatoma. AIM: observe the effect of the trans-retinoic acid in the inhibition of middle ear cholesteatomas induced by propylene glycol. STUDY DESIGN: Clinical and Experimental. METHODS: 25 guinea pigs were submitted to the application of a 100 percent propylene glycol solution in their bulla bilaterally and a solution of trans-retinoic acid was applied locally in the external right ear, while in the left ear saline solution was applied (control ear). The guinea pigs were slaughtered and their temporal bones were prepared for macroscopic and histological analysis. RESULTS: The macroscopic findings had evidenced the presence of cholesteatoma in 25 percent of the right ears and 85 percent of the left ears (P=0.0003 *). The histological study had evidenced the presence of cholesteatoma in 30 percent of right ears and 75 percent of the left ears (P=0.0104*). CONCLUSION: The local use of the trans-retinoic acid is effective in inhibiting the induced formation of cholesteatomas in guinea pigs.

Influência do AMP cíclico na regeneração do nervo facial em ratos / Influence of cyclic AMP on facial nerve regeneration in rats

Estimular a regeneração do nervo facial é ainda hoje um desafio. OBJETIVO: Estudar a possível influência neurotrófica do nucleotídeo cíclico adenosina monofosfato (AMPc) na regeneração do nervo facial de ratos Wistar. MÉTODO: Trinta e dois animais foram submetidos à transecção completa com sutura imediata do nervo facial direito, sendo divididos em expostos ou não expostos à aplicação tópica de AMPc, com análises comportamentais (movimentação de vibrissas e fechamento da rima palpebral) e histométrica (contagem de fibras mielinizadas) em dois períodos, 14 e 28 dias após a lesão. RESULTADO: Encontramos diferenças estatísticas (p<0,05) nas análises comportamental e histométrica no 14º dia, sugerindo uma precocidade na regeneração do nervo facial exposto ao AMPc. CONCLUSÃO: Nosso estudo constatou uma possível ação neurotrófica do AMPc na regeneração do nervo facial em ratos.

Promoting facial nerve regeneration is a significant challenge. AIM: To evaluate the possible neurotrophic influence of cyclic AMP on facial nerve regeneration of Wistar rats. METHOD: The right facial nerve of thirty-two animals were completely transected and immediately sutured, followed by exposure or not to topical cyclic AMP. Behavioral and histometric analyses were done at 14 and 28 days. RESULTS: Statistical differences (p<0.05) were found in the behavioral and histometric analyses on the 14th day, suggesting an early regenerative response of the facial nerve to cAMP exposure. CONCLUSION: This study demonstrates a possible neurotrophic effect of cAMP on facial nerve regeneration in rats.

Atenção seletiva: PSI em crianças com distúrbio de aprendizagem / Selective attention: psi performance in children with learning disabilities

A atenção seletiva é importante para o aprendizado da leitura e escrita. OBJETIVO: Estudar os processos de atenção seletiva de crianças com e sem distúrbio de aprendizagem. MATERIAL E MÉTODO: O Grupo I foi constituído de quarenta indivíduos com idades entre nove anos e seis meses a dez anos e 11 meses, que apresentavam baixo risco para alteração no desenvolvimento das habilidades auditivas, linguagem e aprendizagem. O Grupo II foi constituído de 20 indivíduos com idades entre nove anos e cinco meses a 11 anos e dez meses, diagnosticados como portadores de distúrbio de aprendizagem. Foi realizado estudo prospectivo através do Teste Pediátrico de Inteligibilidade de Fala (PSI). RESULTADO: O teste PSI com mensagem competitiva ipsilateral, à orelha direita, na relação fala/ruído 0 e -10 foi apropriado para diferenciar o Grupo I e o Grupo II de forma estatisticamente significante. Atenção ao desempenho do Grupo II na performance da primeira orelha testada deve ser dada, por subsidiar características importantes de desempenho e reabilitação. CONCLUSÃO: O PSI foi adequado para diferenciar os grupos, havendo uma associação com o grupo com distúrbio de aprendizagem, que revelou alteração nos processos de atenção seletiva.

Selective attention is essential for learning how to write and read. AIM: The objective of this study was to examine the process of selective auditory attention in children with learning disabilities. MATERIAL AND METHOD: Group I included forty subjects aged between 9 years and six months and 10 years and eleven months, who had a low risk of altered hearing, language and learning development. Group II included 20 subjects aged between 9 years and five months and 11 years and ten months, who presented learning disabilities. A prospective study was done using the Pediatric Speech Intelligibility Test (PSI). RESULT: Right ear PSI with an ipsilateral competing message at speech/noise ratios of 0 and -10 was sufficient to differentiate Group I and Group II. Special attention should be given to the performance of Group II on the first tested ear, which may substantiate important signs of improvements in performance and rehabilitation. CONCLUSION: The PSI - MCI of the right ear at speech/noise ratios of 0 and -10 was appropriate to differentiate Groups I and II. There was an association with the group that presented learning disabilities: this group showed problems in selective attention.

Matriz Metaloproteinase 2: um importante marcador genético para colesteatomas / Matrix Metalloproteinase 2: an important genetic marker for cholesteatomas

Este estudo foi desenvolvido para determinar a presença de MMP2 em colesteatomas humanos e observar se colesteatomas que complicam (invasivos) apresentam uma maior expressão imunohistoquímica de Matriz Metaloproteinase 2 (MMP2). Colesteatomas produzem enzimas que causam erosão óssea, como a MMP2. MATERIAL E MÉTODO: Analisamos a expressão imunohistoquímica de MMP2 em colesteatomas invasivos, comparando-os aos latentes. Um estudo de corte transversal com dezenove lâminas e blocos parafinados de colesteatoma, derivados de mastoidectomias, foram desparafinados e submetidos à técnica imunohistoquímica com anticorpos anti-MMP2. RESULTADOS: Os resultados foram expressos em 0 (tênue), + (leve), ++ (moderado) e +++ (intenso), de acordo com a intensidade da expressão de MMP2. As expressões 0 e + foram denominadas Fraca e as expressões ++ e +++, Forte. Dos 8 colesteatomas invasivos, 7 apresentaram Forte expressão de MMP2 (87,5 por cento). Com relação aos colesteatomas latentes (11), apenas 3 apresentaram Forte expressão de MMP2 (27,3 por cento), com um teste exato de Fisher significante (p= 0,015). CONCLUSÃO: Colesteatomas expressam MMP2 e colesteatomas invasivos expressam MMP2 com maior intensidade, em relação aos latentes.

AIM: This study is to determine the MMP2Æs presence in cholesteatomas and whether complicating cholesteatomas show a higher immunohistochemical expression of matrix metalloproteinase 2. Cholesteatoma produces enzymesthat cause bone erosion like Matrixmetalloproteinase 2 (MMP2). MATERIAL AND METHODS: We analyzed the expression of MMP2 in invasive (causing complications) compared to latent cholesteatomas (not causing complications). A crosssectional study with nineteen slides and paraffin blocks of cholesteatomas derived from mastoidectomies were located and processed, including 8 invasive and 11 latent cholesteatomas. Immunohistochemical thecnique was empregated to MMP2. RESULTS: The results are expressed as 0, + (to low), ++ and +++(high) according to the quantity and color of the immunohistochemical staining of MMP2. Higher expression of MMP2 was observed in 7 (87.5 percent) of the 8 invasive cholesteatomas. With respect to latent cholesteatomas, higher expression of MMP2 was observed in 27.3 percent (3 cases), with FisherÆs exact test indicating a significant difference (p=0.015). CONCLUSIONS: Cholesteatoamas express MMP2 and Invasive cholesteatomas had high MMP2 compared to latent cholesteatomas.

Anatomia microscópica do canal carótico e suas relações com a cóclea e a cavidade timpânica / Microscopic anatomy of the carotid canal and its relations with cochlea and middle ear

As relações entre as diversas estruturas nobres e vitais que se apresentam na intimidade do osso temporal constituem ainda hoje um grande desafio para o cirurgião otológico. Os estudos micro-anatômicos do mesmo se encontram entre as grandes armas na busca deste entendimento. OBJETIVO: Estudar as correlações anatômicas entre o canal carótico e a cóclea, e a ocorrência de deiscências do mesmo junto à cavidade timpânica. MATERIAL E MÉTODO: Estudo microscópico de 122 ossos temporais humanos. RESULTADOS As distâncias médias entre o canal carótico e os giros cocleares foram: no local de menor distância 1,05mm; no giro basal, 2,04mm; no giro médio, 2,32mm; e no giro apical, 5,7mm. A ocorrência de deiscências do canal carótico na cavidade timpânica foi de 35,2 por cento. CONCLUSÃO: A pequena distância entre estruturas cocleares e o canal carótico, e a alta prevalência de deiscências do mesmo na cavidade timpânica nos relembram o desafio com o qual o cirurgião otológico se depara ao atuar sobre o osso temporal.

Formacão de cisto epidermóide (colesteatoma) com implantacão de tecido epitelial junto ao osso femural de ratos / Growth of cholesteatoma by implantation of epithelial tissue along the femoral bone of rats

O colesteatoma é um cisto epidermóide, caracterizado por tecido epidérmico queratinizado, com capacidade de migracão e erosão de estruturas adjacentes. OBJETIVO: Verificar o crescimento do cisto epidermóide (colesteatoma) quando se implanta fragmento de pele do pavilhão auricular junto ao osso femoral de ratos. FORMAL DE ESTUDO: experimental. MATERIAL E MÉTODO: Foram selecionados 10 ratos, os quais foram submetidos à implantacão de fragmento de pele do pavilhão auricular na coxa e mantidos por 3 meses, seguido de remocão do tecido implantado após este período. Cada fragmento ressecado dos animais foi incluso em parafina, corado em hematoxilina-eoxina e preparado em lâminas para efetivacão de estudo anatomopatológico. RESULTADO: Aspecto macroscópico: aspecto granulomatoso, de coloracão amarelada, de forma arredondada e amolecida. Aspecto microscópico: estrutura cística com revestimento constituído por epitélio escamoso estratificado. O cisto apresenta camada mais interna córnea, com descamacão de queratina, seguida da camada granulosa e camadas escamosa e basal mais externamente. CONCLUSAO: O cisto epidermóide (colesteatoma) pode se desenvolver a partir de tecido epitelial transplantado junto ao osso femoral de ratos.