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1.
HNO ; 2024 May 30.
Artigo em Alemão | MEDLINE | ID: mdl-38829524

RESUMO

BACKGROUND: With targeted inhibition of type 2 inflammation, biologics represent the standard add-on therapy for inadequately controlled severe forms of chronic rhinosinusitis with nasal polyps (CRSwNP). Despite standardization with paper-based checklists, the documentation of medical history and current findings pertinent to indication criteria are a significant challenge for physicians. Through development of an application based on structured reporting, the current study aimed to improve documentation quality and simplify the decision-making process. Previously available paper checklists served as a comparison. METHODS: For this study, a digital incremental tool was programmed to record current findings and check for fulfilment of indication criteria. The tool was compared with other checklists in terms of completeness, time required, and readability. RESULTS: A total of 20 findings were collected for each of the three documentation options and included in the analysis. Documentation with the two paper-based checklists had comparable information content: 17.5 ± 5.1/21.7 ± 7.6 points out of a maximum of 43 points; p > 0.05. Documentation using the digital application led to a significant increase in information content compared to all paper-based documentation. The average score was 38.25 ± 3.7 (88.9% of maximum; p < 0.001). On average, user satisfaction was high (9.6/10). Use of the digital application was initially more time consuming, but as more cases were documented, the time taken improved significantly. CONCLUSION: In the future, structured reporting using apps could replace paper-based reporting for the indication of biologic therapy in CRSwNP patients and offer additional benefits in terms of data quality and traceability of results. The increasing volume of documentation in the future, the progress of digitalization, and the possibility of networking between individual centers make introduction of the app in the near future both likely and economical.

2.
Clin Case Rep ; 12(1): e8292, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38223514

RESUMO

Key Clinical Message: Color changes of the tympanic membranes without an inflammatory component or perforation are rarely described. They may result from hemorrhage after barotrauma or spontaneously. Other explanatory models include discoloration due to otomycosis. Abstract: This is a case of a 61-year-old patient with an unexplained incidental of black dots located almost symmetrically on the antero-inferior quadrant of both tympanic membranes. This harmless anatomical rarity has not been published before. Underlying pathologies should be excluded in the case of discoloration of the tympanic membranes.

3.
Nitric Oxide ; 27(2): 106-16, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22659013

RESUMO

Nitric oxide (NO) is a signaling molecule which can generally be formed by three nitric oxide synthases (NOS). Two of them, the endothelial nitric oxide synthase (eNOS) and the neural nitric oxide synthase (nNOS), are calcium/calmodulin-dependent and constitutively expressed in many cell types. Both isoforms are found in the vertebrate cochlea. The inducible nitric oxide synthase (iNOS) is independent of calcium and normally not detectable in the un-stimulated cochlea. In the inner ear, as in other tissues, NO was identified as a multitask molecule involved in various processes such as neurotransmission and neuromodulation. In addition, increasing evidence demonstrates that the NO-dependent processes of cell protection or, alternatively, cell destruction seem to depend, among other things, on changes in the local cochlear NO-concentration. These alterations can occur at the cellular level or within a distinct cell population both leading to an NO-imbalance within the hearing organ. This dysfunction can result in hearing loss or even in deafness. In cases of cochlear malfunction, regulatory systems such as the gap junction system, the blood vessels or the synaptic region might be affected temporarily or permanently by an altered NO-level. This review discusses potential cellular mechanisms how NO might contribute to different forms of hearing disorders. Approaches of NO-reduction are evaluated and the transfer of results obtained from experimental animal models to human medication is discussed.


Assuntos
Cóclea/metabolismo , Transtornos da Audição/metabolismo , Óxido Nítrico/metabolismo , Animais , Antioxidantes/metabolismo , Ácido Ascórbico/farmacologia , Cóclea/efeitos dos fármacos , Junções Comunicantes/metabolismo , Gentamicinas/efeitos adversos , Humanos , Camundongos
4.
Mol Cell Neurosci ; 45(3): 297-305, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20627126

RESUMO

Hearing impairment is a worldwide health problem. Employing semi-quantitative immunological detection methods, we found that the apoptosis inhibitor protein Birc5 is expressed in cell types critical for hearing perception. In the guinea pig model, moderate noise exposure causing only a temporary mean hearing impairment of 33dB significantly enhanced Birc5 expression in the spiral ligament, nerve fibers and the organ of Corti. In contrast, intratympanic gentamicin injection inducing permanent cell damage and mean hearing loss of 24dB correlated with a significant Birc5 downregulation in the ligament, nerve fibers and the organ of Corti. The cytoprotective activity of the guinea pig and human Birc5 protein was confirmed by cloning of the gene and by subsequent ectopic expression and challenging studies against the ototoxin gentamicin in epithelial and auditory cell models. As the mammalian cochlea is unable to regenerate upon damage, these data suggest that modulation of Birc5 expression may represent a novel physiological mechanism to protect the inner ear against stress-induced cell damage. Hence, the targeted modulation of Birc5 levels may lead to novel otoprotective therapeutic strategies.


Assuntos
Citoproteção , Orelha Interna/fisiologia , Perda Auditiva Provocada por Ruído/fisiopatologia , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Células Cultivadas , Orelha Interna/anatomia & histologia , Feminino , Gentamicinas/toxicidade , Cobaias , Células HeLa , Perda Auditiva/induzido quimicamente , Humanos , Proteínas Inibidoras de Apoptose , Masculino , Camundongos , Camundongos Nus , Proteínas Associadas aos Microtúbulos/genética , Ruído/efeitos adversos , Inibidores da Síntese de Proteínas/toxicidade , Survivina
6.
Laryngoscope ; 118(5): 837-42, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18197132

RESUMO

OBJECTIVES: Noise-induced hearing loss can be caused, among other causes, by increased nitric oxide (NO) production in the inner ear leading to nitroactive stress and cell destruction. Some studies in the literature suggest that the degree of hearing loss (HL) could be reduced in an animal model through ascorbic acid supplementation. To identify the effect of ascorbic acid on tissue-dependent NO content in the inner ear of the guinea pig, we determined the local NO production in the organ of Corti and the lateral wall separately 6 hours after noise exposure. STUDY DESIGN: Prospective animal study in guinea pigs. METHODS: Over a period of 7 days, male guinea pigs were supplied with minimum (25 mg/kg body weight/day) and maximum (525 mg/kg body weight/day) ascorbic acid doses, and afterwards exposed to noise (90 dB sound pressure level for 1 hour). The acoustic-evoked potentials were recorded before and after noise exposure. The organ of Corti and the lateral wall were incubated differently for 6 hours in culture medium, and the degree of NO production was determined by chemiluminescence. RESULTS: Ascorbic acid treatment reduced the hearing threshold shift after noise exposure depending on concentration. When the maximum ascorbic acid dose was substituted, NO production was significantly reduced in the lateral wall after noise exposure and slightly reduced in the organ of Corti. CONCLUSIONS: Oral supplementation of the natural radical scavenger ascorbic acid reduces the NO-production rate in the inner ear in noisy conditions. This finding supports the concept of inner ear protection by ascorbic acid supplementation.


Assuntos
Ácido Ascórbico/farmacologia , Orelha Interna/metabolismo , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Ruído/efeitos adversos , Animais , Ácido Ascórbico/sangue , Cóclea/metabolismo , Potenciais Evocados Auditivos , Cobaias , Masculino , Órgão Espiral/metabolismo , Estudos Prospectivos , Distribuição Aleatória
8.
Laryngoscope ; 117(12): 2244-50, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17909448

RESUMO

OBJECTIVES: The intratympanic application of a low dosage of gentamicin is increasingly favored as treatment for Ménière's disease. While posttreatment observations have confirmed a long-term success of the therapy of vertigo attacks, clear differences in the posttreatment recovery interval can be observed. In addition to differences in central-vestibular compensation, the degree of peripheral vestibular damage, i.e., to the saccule, utricle, and semicircular canal ampullae, varies among patients. This study provides comprehensive pre- and posttreatment results from unilateral functional tests of the individual vestibular receptors and of the cochlea in patients with Ménière's disease. STUDY DESIGN: Prospective clinical study. METHODS: Nineteen patients with unilateral Ménière's disease were treated by intratympanic application of gentamicin by injection of 0.3 mL (12 mg) through the tympanic membrane under local anesthesia. Tests were performed immediately previous to treatment and subsequently in the periods 4 to 8 weeks and 12 to 16 weeks after treatment. Unilateral saccular function was tested by means of acoustic-click, vestibular-evoked myogenic potentials (VEMP), and unilateral utricular function by subjective visual vertical (SVV) during unilateral centrifugation. Bithermal caloric testing was performed to assess unilateral semicircular canal function. RESULTS: Prior to gentamicin treatment, the caloric response from the diseased ear was normal in 3 patients, below normal in 14 patients, and in 2 cases almost completely absent. VEMP responses could be recorded bilaterally in 13 patients; while in 6, no VEMPs could be measured from the diseased ear. Utricular function measured by SVV estimation was found to be normal in 11 patients and marginally abnormal in 2 patients. In six cases, the SVV was clearly underestimated during centrifugation of the diseased side. The posttreatment findings demonstrate that VEMPs were absent in all treated patients, and the caloric response was abnormally low in all but one case. In contrast, only 12 of 19 patients produced abnormal SVV responses. CONCLUSION: The results demonstrate that incremental, intratympanic application of gentamicin effectively eliminates semicircular canal and saccular function. In contrast, utricular function appears to be maintained in 30 to 40% of cases.


Assuntos
Antibacterianos/administração & dosagem , Gentamicinas/administração & dosagem , Doença de Meniere/tratamento farmacológico , Membrana dos Otólitos/fisiopatologia , Administração Tópica , Adulto , Idoso , Relação Dose-Resposta a Droga , Eletromiografia , Potenciais Evocados Auditivos/efeitos dos fármacos , Feminino , Seguimentos , Humanos , Masculino , Doença de Meniere/fisiopatologia , Membrana dos Otólitos/efeitos dos fármacos , Estudos Prospectivos , Resultado do Tratamento , Membrana Timpânica
9.
Otol Neurotol ; 28(8): 1120-3, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18043437

RESUMO

OBJECTIVE: This study sets out to demonstrate the normal developmental steps of the tegmen tympani and thus explains the typical localization of congenital tegmental defects. SPECIMENS: For this study, 79 macerated and formalin-fixed human temporal bones from 14th fetal week to adults were observed and prepared. INTERVENTION: Macroscopic and microscopic examination of the prenatal and postnatal changes of the tegmen tympani during its development. MAIN OUTCOME MEASURE: Temporal bones from 14th fetal week to adults underwent descriptive anatomic studies to understand the normal development of the tegmen tympani and to find a possible cause of its congenital defects. RESULTS: The medial part of the tegmen tympani develops from the otic capsule during chondral ossification, thus forming the tegmental process of the petrous part. The lateral part shows membranous ossification. The tegmental process cases a temporary bony dehiscence lateral to the geniculate ganglion between the 23rd and 25th fetal week. CONCLUSION: Congenital defects develop near the geniculate ganglion and seem to be due to an incomplete development of tegmental process of otic capsule. Because of that, congenital lesion of the tegmen tympani can be defined as an inner ear defect.


Assuntos
Orelha Média/anormalidades , Orelha Média/patologia , Adulto , Pré-Escolar , Orelha Média/crescimento & desenvolvimento , Feminino , Gânglio Geniculado/embriologia , Gânglio Geniculado/crescimento & desenvolvimento , Humanos , Lactente , Recém-Nascido , Masculino , Osteogênese/fisiologia , Gravidez , Osso Temporal/embriologia , Osso Temporal/crescimento & desenvolvimento , Osso Temporal/patologia , Perfuração da Membrana Timpânica/congênito , Perfuração da Membrana Timpânica/patologia
10.
Acta Otolaryngol ; 127(8): 839-42, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17762995

RESUMO

CONCLUSION: Condition-5-score (C5S) and condition-6-score (C6S) of computerized dynamic platform posturography (CDPP) can detect the presence of a functional deficit of the lateral semicircular canal (and the superior vestibular nerve), irrespective of the central vestibular compensatory status, in vestibular schwannoma (VS) patients. OBJECTIVES: To test whether CDPP findings differ between VS patients with and without asymmetry on caloric and/or rotational ENG studies. PATIENTS AND METHODS: This was a retrospective review of 216 consecutive patients with VS. C5S and C6S of CDPP (Equitest) were compared among patients with normal caloric and rotational studies, patients with asymmetry on caloric studies and normal rotational studies, and patients with asymmetric caloric and rotational studies using the Wilcoxon-Mann-Whitney test. RESULTS: C5S and C6S of VS patients with normal caloric and rotational studies were significantly higher than in VS patients with either asymmetry on both rotational and caloric test results (p<0.001 for both C5S and C6S) or normal rotational studies and asymmetry on caloric testing (p<0.001 for both C5S and C6S). Neither C5S nor C6S were significantly different between patients with asymmetry on caloric testing and normal rotational studies and patients with asymmetry on both rotational and caloric testing.


Assuntos
Neuroma Acústico/fisiopatologia , Postura/fisiologia , Vestíbulo do Labirinto/fisiopatologia , Adolescente , Adulto , Idoso , Eletronistagmografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Prognóstico , Estudos Retrospectivos , Rotação , Índice de Gravidade de Doença
11.
Laryngoscope ; 126(1): E29-34, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25946598

RESUMO

OBJECTIVES/HYPOTHESIS: Dexamethasone is widely used in the treatment of various inner ear diseases. However, knowledge about its direct impact on glucocorticoid receptor (GR) expression is still limited. STUDY DESIGN: Prospective animal study in male guinea pigs. METHODS: A therapeutic concentration of dexamethasone (8 mg/mL) or a physiological concentration of NaCl (0.9% solution) were intratympanically injected into the ears of guinea pigs (n = 10 in each case) 14 hours prior to 90 dB noise exposure (1 hour). Eighteen ears were exposed to noise only. Seven untreated ears were used as controls. Auditory brainstem responses were recorded prior to noise exposure or treatment and 2 hours thereafter. The cochleae were removed from the bullae, transferred to fixative, and embedded in paraffin. GR expression was identified immunohistochemically in the cochlea. Local staining intensities were quantified for seven regions by a computer. RESULTS: Dexamethasone application significantly lowered noise-induced hearing loss. Statistically significant alterations in the average GR expression levels were identified exclusively in the spiral ligament. Comparing GR expression at the level of individual ear, numerous highly significant local associations were identified in the other six cochlear regions. CONCLUSIONS: The intratympanic application of dexamethasone is suitable for supporting cochlear homeostasis under stress conditions. The lateral wall, mainly responsible for potassium recycling, seems to be the main target in glucocorticoid therapy.


Assuntos
Cóclea/metabolismo , Dexametasona/administração & dosagem , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Receptores de Glucocorticoides/biossíntese , Animais , Cóclea/efeitos dos fármacos , Modelos Animais de Doenças , Glucocorticoides/administração & dosagem , Cobaias , Perda Auditiva Provocada por Ruído/metabolismo , Perda Auditiva Provocada por Ruído/fisiopatologia , Injeção Intratimpânica , Masculino , Estudos Prospectivos , Receptores de Glucocorticoides/efeitos dos fármacos
12.
J Vestib Res ; 15(2): 59-64, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15951619

RESUMO

The otolith mass of the saccules and utricles of plaice, Pleuronectes platessa (n = 39) and turbot, Psetta maxima (n = 21) was measured using an electronic microbalance. In the right-eyed plaice, the left utricular otoliths were found to be significantly heavier than the right (p < 0.0001), whereas no significant difference was found between left and right saccular otoliths (p < 0.751). In the left-eyed turbot, both the right utricular and saccular otoliths were found to be significantly heavier (in both cases, p < 0.0001). While the gene and regulative protein responsible for the peripheral biomineralisation process have been identified, it remains unclear how the symmetry between the right and left otoliths in fish species is regulated. Here it is likely that an additional central mechanism is involved. It must be assumed that similar processes govern the systematic asymmetry observed in flatfish such as the plaice and turbot. Taken together these findings are strongly suggestive of concomitant CNS modification and metamorphic plasticity, presumably represented in genetic code.


Assuntos
Linguados/fisiologia , Lateralidade Funcional/fisiologia , Membrana dos Otólitos/fisiologia , Sáculo e Utrículo/fisiologia , Animais , Linguado , Plasticidade Neuronal/fisiologia , Tamanho do Órgão , Membrana dos Otólitos/anatomia & histologia , Sáculo e Utrículo/anatomia & histologia
13.
Hear Res ; 326: 40-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25882166

RESUMO

Intratympanic gentamicin therapy has become a popular treatment modality for Ménière's disease (MD) through controlled elimination of vertigo spells caused by the balance organ. However, the known ototoxic properties of aminoglycosides lead to cochlear damage. In order to gain more information about cellular preferences for aminoglycoside accumulation within the cochlea, gentamicin was immuno histochemically localized by light microscopy in male guinea pigs 1 and 7 days after intratympanic application (n = 8 ears/incubation time). Differences in the gentamicin-specific cellular storage capacities were quantified by determination of the local immuno staining intensities. Gentamicin was detected in every cochlear cell type, but with spatiotemporal variability. One day after application, an intense staining reaction was found in all cell types except the spiral ganglion cells and the stria vascularis. Six days later, gentamicin staining intensities were additionally reduced in the nerve fibers and the spiral ligament. Statistic analysis revealed strong cellular associations in respect to aminoglycoside accumulation. Furthermore, associations with recorded hearing losses were identified comparing the cellular gentamicin content in the organ of Corti, in the stria vascularis, in the spiral ganglion cells and in fibrocytes of the Limbus. In the lateral wall, clear differences in cellular gentamicin accumulation were found between type I fibrocytes of the spiral ligament compared with basal and intermediate cells of the stria vascularis. This finding was unexpected as these three cell types belong to a well-developed gap-junction system which normally enables unhampered cell communication. Cellular differences in local gentamicin storage capacities, transport processes and inherent diffusion barriers are discussed.


Assuntos
Cóclea/metabolismo , Gentamicinas/farmacocinética , Animais , Transporte Biológico Ativo , Cóclea/citologia , Cóclea/efeitos dos fármacos , Junções Comunicantes/metabolismo , Gentamicinas/administração & dosagem , Gentamicinas/toxicidade , Cobaias , Humanos , Imuno-Histoquímica , Injeção Intratimpânica , Masculino , Doença de Meniere/tratamento farmacológico , Modelos Animais , Distribuição Tecidual
14.
Acta Otolaryngol ; 123(4): 488-92, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12797583

RESUMO

OBJECTIVE: Although the occurrence of motion sickness is largely attributed to sensory conflict, the reasons for the highly variable inter-individual susceptibility to motion sickness remain unclear. One cause may be asymmetry between otoconial masses in the right and left inner ear. This hypothesis has been supported by experiments in fish under conditions of prolonged weightlessness and parabolic flight. In swordtail fish (Xiphophorus helleri) we examined the extent to which a Coriolis force environment, which has a strong motion sickness-triggering effect, disturbs swimming behaviour or produces motion sickness. MATERIAL AND METHODS: In a sealed aquarium, fish (n = 22) were subjected to Coriolis stimulation by constant vertical axis rotation, combined with pendular oscillation around a horizontal axis. RESULTS: Initially, at low stimulus intensity, all fish showed active compensatory swimming behaviour. However, while the majority (n = 19) maintained active compensation movements at higher stimulus levels, the others (n = 3) entered a passive uncoordinated state, from which they recovered again after reduction of stimulus intensity. On examination of the otoconial mass, we found asymmetries between the right and left utricles in all three cases and between the saccules in one case. CONCLUSION: We conclude that a lateral preponderance of the otoconial masses in the utricle or saccule promotes motion sickness under experimental conditions. The utricle appears to play a more important role in this than the saccule.


Assuntos
Enjoo devido ao Movimento/fisiopatologia , Membrana dos Otólitos/fisiologia , Sáculo e Utrículo/fisiologia , Animais , Força Coriolis , Ciprinodontiformes , Enjoo devido ao Movimento/etiologia , Natação/fisiologia
15.
Acta Otolaryngol ; 122(4): 386-91, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12125994

RESUMO

It has taken many decades to arrive at today's concept of cupula mechanics in the stimulation of endolymphatic flows on the hair cells in the ampullae of the semicircular canal. While Steinhausen assumed free swing-door movement of the cupula in the 1930s, Hillman was the first to demonstrate firm cupula attachment to the ampulla wall as a physiological necessity in the 1970s. In contrast to the present clinical concepts of acute peripheral vestibular functional disorders (circulatory disturbances, viral or bacterial infection, altered electrolytes in the endolymph), this study examines the extent to which an impaired attachment mechanism can trigger peripheral vestibular disorders. For this purpose, we used a pigeon model (n = 8), in which mechanical detachment of the cupula from the ampulla wall was achieved by means of a targeted pressure increase in the ampulla of the lateral semicircular canal. In two additional animals the labyrinth was completely destroyed on one side in order to directly compare partial and complete vestibular disorders. In this way partial damage to the lateral semicircular canal ampulla presents a clinical picture whose symptoms are very similar to those of an idiopathic vestibular disorder in humans. Their intensity and course of compensation differ markedly from the symptoms of complete vestibular destruction. Subsequent histological examination revealed that the hair cells remained intact during the experimental detachment of the cupula. Our results thus show that only altered cupula mechanics seem to trigger the clinical picture of a peripheral vestibular disorder. This may result in completely new approaches to differential diagnosis and the therapy of vestibular neuronitis.


Assuntos
Orelha Interna/fisiopatologia , Neuronite Vestibular/etiologia , Neuronite Vestibular/fisiopatologia , Animais , Fenômenos Biomecânicos , Columbidae , Diagnóstico Diferencial , Eletrólitos/análise , Endolinfa/química , Microscopia Eletrônica , Pressão , Canais Semicirculares/fisiopatologia , Canais Semicirculares/ultraestrutura , Neuronite Vestibular/diagnóstico
16.
Biol Sci Space ; 16(1): 22-6, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12120624

RESUMO

The review briefly describes the structure and function of complex carbohydrates of glycoproteins and proteoglycans both in general and with particular respect to the potential roles sugar chains may play in the cupula, i.e. the molecular organization of these constituents, their biophysical properties, and their biological functions.


Assuntos
Glicoproteínas/química , Proteoglicanas/química , Canais Semicirculares/fisiologia , Animais , Sequência de Carboidratos , Carboidratos/química , Carboidratos/fisiologia , Endolinfa/fisiologia , Glicoproteínas/fisiologia , Proteoglicanas/fisiologia
18.
Auris Nasus Larynx ; 38(6): 671-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21616617

RESUMO

OBJECTIVE: Gentamicin application is an important therapeutic option to control vertigo spells in Ménière's disease. However, even in the case of low-dose intratympanic application, gentamicin might contribute to a pathological NO-increase leading to cochlear damage and hearing impairment. The study was performed to evaluate the nitric oxide (NO) reducing capacity of doxycycline in the inner ear after NO-induction by gentamicin. METHODS: In a prospective animal study, a single dose of gentamicin (10mg/kg body weight) was injected intratympanically into male guinea pigs (n=48). The auditory brainstem responses (ABRs) were recorded prior to application and 3, 5 and 7 days afterwards. The organ of Corti and the lateral wall of 42 animals were isolated after 7 days and incubated separately for 6h in cell culture medium. Doxycycline was adjusted to organ cultures of 5 animals. Two NOS inhibitors, N(G)-Nitro-l-arginine methyl ester (l-NAME) and NG-monomethyl-l-arginine monoacetate (l-NMMA), were applied in three different concentrations to the organ cultures of 30 animals in total (5 animals per concentration). As controls, seven animals received no further substance except gentamicin. The NO-production was quantified by chemiluminescence. Additional six gentamicin-treated animals were used for immunohistochemical studies. RESULTS: The ABRs declined continuously from the first to the seventh day after gentamicin application. Doxycycline reduced NO-production in the lateral wall by 54% (p=.029) comparable to the effect of the applied nitric oxide inhibitors. In the organ of Corti, NO-production was reduced by about 41% showing no statistical significance in respect to great inter-animal variations. CONCLUSION: The application of doxycycline might offer a new therapeutic approach to prevent NO-induced cochlea damage through ototoxic substances.


Assuntos
Doxiciclina/farmacologia , Orelha Interna/metabolismo , Óxido Nítrico/biossíntese , Animais , Citoproteção/efeitos dos fármacos , Orelha Interna/efeitos dos fármacos , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Gentamicinas/farmacologia , Cobaias , Imuno-Histoquímica , Luminescência , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Técnicas de Cultura de Órgãos , Órgão Espiral/metabolismo , Estudos Prospectivos , Regulação para Cima , ômega-N-Metilarginina/farmacologia
19.
Acta Otolaryngol ; 130(6): 702-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20082563

RESUMO

CONCLUSIONS: The findings demonstrate that an enduring unilateral utricular dysfunction, possibly together with canal hypofunction, can occur after labyrinthine disease or injury. They also suggest that unilateral, isolated utricular dysfunction - or utricle paresis - can occur, representing a novel entity in the differential diagnosis of peripheral vestibular function. The occurrence of subjective visual vertical (SVV) asymmetry in the presence of symmetric vestibular evoked myogenic potentials (VEMPs) also confirms that the information from the utricles, rather than the saccules, dominates SVV estimation. OBJECTIVES: To determine the incidence of unilateral utricular hypofunction. METHODS: The retrospective clinical study deals with a selection of those vestibular patients who showed pathological responses to utricle testing. Peripheral vestibular function was examined in a group of 110 patients. Utricular function was evaluated by estimation of SVV during unilateral centrifugation. Bithermal caloric testing was performed to assess unilateral semicircular canal function. Saccular function was tested by measurement of VEMPs. RESULTS: A total of 46 patients were found with asymmetric SVV findings (p < 0.001 for healthy versus lesioned ear), but symmetric caloric responses and VEMPs. Statistical testing also verified that their SVV asymmetry factors were significantly higher than those calculated for caloric responses and VEMPs (p < 0.001).


Assuntos
Lateralidade Funcional/fisiologia , Doenças do Labirinto/diagnóstico , Doença de Meniere/diagnóstico , Sáculo e Utrículo/fisiopatologia , Testes de Função Vestibular , Adolescente , Adulto , Testes Calóricos , Diagnóstico Diferencial , Eletromiografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Cinestesia/fisiologia , Doenças do Labirinto/fisiopatologia , Masculino , Doença de Meniere/fisiopatologia , Pessoa de Meia-Idade , Músculos do Pescoço/inervação , Orientação/fisiologia , Membrana dos Otólitos/fisiopatologia , Equilíbrio Postural/fisiologia , Propriocepção/fisiologia , Processamento de Sinais Assistido por Computador , Nervo Vestibular/fisiopatologia , Adulto Jovem
20.
Laryngoscope ; 120(10): 2125-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20824779

RESUMO

OBJECTIVES/HYPOTHESIS: Intratympanic application of gentamicin is an important therapeutic option to control vertigo spells in Ménière's disease. Low doses eliminate the function of semicircular canal ampullae (SCCA) and saccule in most patients, although utricular function is maintained in many cases. Local alteration in free radical production might be responsible for these differences. Therefore, the gentamicin-induced nitric oxide (NO) production was determined in an animal model using separate organ cultures of SCCA, saccule, and utricle. STUDY DESIGN: Prospective pilot study in male guinea pigs. METHODS: SCCA, saccule, and utricle of 28 guinea pigs were isolated and incubated separately for 6 hours in cell culture medium. Gentamicin was administered in two different concentrations (0.4 mg/mL and 0.8 mg/mL) to organ cultures of 16 animals. Tissues from 12 animals were used as controls. Nitric oxide was quantified by chemiluminescence. RESULTS: Gentamicin led to an NO increase of about 70% in the saccule, an NO reduction of more than 70% in SCCA, and an NO reduction of 36% in the utricle. CONCLUSIONS: The selective effects of gentamicin on the NO production in the different sensory areas of the vestibular organ have to be taken into account in the therapy of Ménière's disease.


Assuntos
Gentamicinas/farmacologia , Óxido Nítrico/metabolismo , Membrana dos Otólitos/efeitos dos fármacos , Canais Semicirculares/efeitos dos fármacos , Animais , Cobaias , Modelos Lineares , Masculino , Membrana dos Otólitos/metabolismo , Projetos Piloto , Estudos Prospectivos , Canais Semicirculares/metabolismo
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