RESUMO
No abstract available.
Assuntos
COVID-19 , Furina , Enzima de Conversão de Angiotensina 2 , Animais , Furina/metabolismo , Humanos , Camundongos , Bulbo Olfatório , SARS-CoV-2 , Serina EndopeptidasesRESUMO
BACKGROUND: Some patients with multiple system atrophy (MSA) require surgical interventions such as tracheostomy and aspiration prevention. Few studies have investigated the postoperative clinical course of MSA patients. The aim of this study was to determine a management strategy for dysphagia and respiratory disorder in MSA. METHODS: From 2001 to 2014, 18 MSA patients (13 males and 5 females, 52-76 years) underwent tracheostomy (TR, n = 11) or laryngeal closure (LC, n = 12). Five patients underwent LC following TR. Vocal fold impairment, the degree of dysphagia and pre/post-operative oral ingestion, and postoperative survival time were evaluated retrospectively. Swallowing function was assessed using the penetration aspiration scale (PAS). RESULTS: TR was performed due to respiratory disorder in seven patients and due to dysphagia in four patients. PAS scores ranged 1-8 in TR patients and 7-8 in LC patients. Seven of 11 patients who underwent TR displayed worsened PAS scores, and no patients displayed improved PAS scores following TR. All patients who underwent LC regained complete or partial oral intake after surgery. There were no significant differences in postoperative survival time between the two groups. CONCLUSIONS: Considering the impacts of TR and LC on survival time, postoperative feeding and swallowing, LC is a good option for treating MSA patients with dysphagia.
Assuntos
Transtornos de Deglutição/cirurgia , Laringoplastia , Atrofia de Múltiplos Sistemas/cirurgia , Complicações Pós-Operatórias/fisiopatologia , Traqueostomia , Idoso , Transtornos de Deglutição/fisiopatologia , Feminino , Humanos , Laringoplastia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Traqueostomia/efeitos adversos , Resultado do TratamentoRESUMO
BACKGROUND: Chronic rhinosinusitis (CRS) can be classified into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays more intense eosinophilic infiltration and the presence of Th2 cytokines. Mucosal eosinophilia is associated with more severe symptoms and often requires multiple surgeries because of recurrence; however, even in eosinophilic CRS (ECRS), clinical course is variable. In this study, we wanted to set objective clinical criteria for the diagnosis of refractory CRS. METHODS: This was a retrospective study conducted by 15 institutions participating in the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC). We evaluated patients with CRS treated with endoscopic sinus surgery (ESS), and risk of recurrence was estimated using Cox proportional hazard models. Multiple logistic regression models and receiver operating characteristics curves were constructed to create the diagnostic criterion for ECRS. RESULTS: We analyzed 1716 patients treated with ESS. To diagnose ECRS, the JESREC scoring system assessed unilateral or bilateral disease, the presence of nasal polyps, blood eosinophilia, and dominant shadow of ethmoid sinuses in computed tomography (CT) scans. The cutoff value of the score was 11 points (sensitivity: 83%, specificity: 66%). Blood eosinophilia (>5%), ethmoid sinus disease detected by CT scan, bronchial asthma, aspirin, and nonsteroidal anti-inflammatory drugs intolerance were associated significantly with recurrence. CONCLUSION: We subdivided CRSwNP in non-ECRS, mild, moderate, and severe ECRS according to our algorithm. This classification was significantly correlated with prognosis. It is notable that this algorithm may give useful information to clinicians in the refractoriness of CRS before ESS or biopsy.
Assuntos
Rinite/classificação , Rinite/epidemiologia , Sinusite/classificação , Sinusite/epidemiologia , Adulto , Distribuição por Idade , Idade de Início , Idoso , Algoritmos , Doença Crônica , Estudos de Coortes , Eosinofilia/imunologia , Feminino , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Rinite/imunologia , Medição de Risco , Índice de Gravidade de Doença , Distribuição por Sexo , Sinusite/imunologia , Adulto JovemRESUMO
BACKGROUND: Chronic rhinosinusitis with nasal polyps is generally characterized by local Th2 inflammation and is categorized into two subtypes in Japan: eosinophilic chronic rhinosinusitis (similar to chronic rhinosinusitis with nasal polyps in western countries) and non-eosinophilic chronic rhinosinusitis (characterized by Th1-dominant inflammation). OBJECTIVE: To investigate local IgE production and class switch recombination to IgE in these two subtypes of chronic rhinosinusitis with nasal polyps. METHODS: The identity of IgE-positive cells was determined using double-immunofluorescent staining for IgE and cell-type-specific molecular markers. To investigate the local class switch recombination to IgE and IgE synthesis in the mucosa, we performed real-time polymerase chain reaction to examine the mRNA expression of Th2 cytokines and class-switch-related molecules, including IL-4, IL-5, IL-13, ε germline gene transcripts, IgE mature transcript, IgG mature transcript, RAG1, RAG2 and activation-induced cytidine deaminase in eosinophilic polyps, non-eosinophilic polyps and controls. RESULTS: The concentrations of total IgE and number of IgE-positive cells were significantly higher in the eosinophilic polyps compared with control and non-eosinophilic polyps. IgE-positive cells were predominantly mast cells in eosinophilic polyps and significantly correlated with the number of FcεR1-positive cells in the subepithelial layer. IL-5 and IL-13 mRNA and ε germline gene transcripts expression levels were significantly higher in eosinophilic polyps compared with control and non-eosinophilic polyps. In contrast, the number of plasma cells and the expression of IgG mature transcripts were increased in non-eosinophilic polyps compared with eosinophilic polyps. RAG2 mRNA was significantly increased in both eosinophilic and non-eosinophilic polyps compared with control mucosa. CONCLUSION AND CLINICAL RELEVANCE: The current study suggests local class switching to IgE, production of IgE and IgE localization to the surface of mast cells in eosinophilic chronic rhinosinusitis in the Japanese population. The difference in the IgE-related profiles between eosinophilic chronic rhinosinusitis and non-eosinophilic chronic rhinosinusitis suggests heterogeneity in the pathogenesis of chronic rhinosinusitis with nasal polyps.
Assuntos
Switching de Imunoglobulina/genética , Imunoglobulina E/genética , Imunoglobulina E/imunologia , Pólipos Nasais/etiologia , Rinite/complicações , Sinusite/complicações , Adulto , Idoso , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Doença Crônica , Citocinas/genética , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Eosinófilos/imunologia , Feminino , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Switching de Imunoglobulina/imunologia , Imunoglobulina E/metabolismo , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/imunologia , Mucosa Nasal/metabolismo , Mucosa Nasal/patologia , Pólipos Nasais/diagnóstico , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenótipo , Receptores de IgE/genética , Receptores de IgE/metabolismo , Rinite/diagnóstico , Sinusite/diagnósticoRESUMO
We examined the effects of blood flow-restricted, low-intensity resistance exercise (termed kaatsu) using an elastic band for resistance on muscle activation. Nine men performed triceps extension and biceps flexion exercises (four sets respectively) using an elastic band for resistance with blood flow restriction (BFR) or CON (unrestricted blood flow). During a BFR session, subjects wore pressure cuffs inflated to 170-260 mmHg on the proximal region of both arms. Surface electromyography (EMG) was recorded from the triceps brachii and biceps brachii muscles, and mean integrated EMG (iEMG) was analyzed. Blood lactate concentration was obtained before (Pre) and immediately after two exercises (Post). During triceps extension and biceps flexion exercises, muscle activation increased progressively (P < 0.05) under BFR (46% and 69%, respectively) but not under CON (12% and 23%, respectively). Blood lactate concentration at Post was higher (P < 0.05) under BFR than under CON (3.6 and 2.1 mmol/L, respectively). Blood lactate concentration at Post was significantly correlated with increased iEMG in both triceps extension (r = 0.65, P < 0.01) and biceps flexion exercises (r = 0.52, P < 0.05). We conclude that kaatsu training using elastic bands for resistance enhances muscle activation and may be an effective method to promote muscle hypertrophy in older adults or patients with a low level of activity.
Assuntos
Braço/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Treinamento Resistido/métodos , Adulto , Braço/irrigação sanguínea , Eletromiografia , Humanos , Ácido Láctico/sangue , Masculino , Músculo Esquelético/irrigação sanguínea , Adulto JovemRESUMO
Previous studies have shown that blood flow-restricted low-intensity resistance training (BFR-RT) causes muscle hypertrophy while maintaining arterial function in young adults. We examined the effects of BFR-RT on muscle size and arterial stiffness in older adults. Healthy subjects (ages 61-84 years) were divided into BFR-RT (n = 9) or non-training control (CON; n = 10) groups. The BFR-RT group performed 20% and 30%, respectively, of one-repetition maximal (1-RM) knee extension and leg press exercises, 2 days/wk for 12 weeks. The BFR-RT group wore elastic cuffs (120-270 mmHg) on both legs during training. Magnetic resonance imaging-measured muscle cross-sectional area (CSA), 1-RM strength, chair stand (CS) test, and cardio-ankle vascular index testing (CAVI), an index of arterial stiffness, were measured before and 3-5 days after the final training session. Muscle CSA of the quadriceps (8.0%), adductors (6.5%), and gluteus maximus (4.4%), leg extension and leg press 1-RM strength (26.1% and 33.4%), and CS performance (18.3%) improved (P < 0.05) in the BFR-RT group, but not in the CON group. In CAVI testing, there were no changes in both two groups. In conclusion, BFR-RT improves muscle CSA as well as maximal muscle strength, but does not negatively affect arterial stiffness or humeral coagulation factors in older adults.
Assuntos
Exercício Físico/fisiologia , Músculo Quadríceps/anatomia & histologia , Músculo Quadríceps/fisiologia , Treinamento Resistido/métodos , Rigidez Vascular , Idoso , Idoso de 80 Anos ou mais , Teste de Esforço , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Força Muscular , Músculo Quadríceps/irrigação sanguíneaRESUMO
AIM: To describe the features of chronic sinusitis associated with the use of tumour necrosis factor (TNF) inhibitors. METHODOLOGY: A retrospective review of the medical records between 2003 and 2011 revealed that five patients had developed chronic sinusitis after the start of TNF inhibitor administration and required rhinological evaluation and treatment. RESULTS: The incidence of refractory sinusitis associated with TNF inhibitors was approximately 2%. Of the five patients identified, four patients were medicated with etanercept and one with infliximab. The maxillary sinus was most commonly involved and cultures of the sinus discharge revealed Pseudomonas aeruginosa in three cases. Two patients showed improvement of sinusitis with antibiotic medication, despite the continuous use of TNF inhibitor, while in two other patients, sinusitis was resistant to antibiotic medication. Another patient who had developed recurrence of sinusitis after complete remission of previous chronic sinusitis by endoscopic sinus surgery showed remission only after cessation of TNF inhibitor. CONCLUSION: Chronic sinusitis associated with TNF inhibitors is considered to be a new disease entity, and it will become more common due to the increasing use of TNF inhibitors.
Assuntos
Anticorpos Monoclonais/efeitos adversos , Antirreumáticos/efeitos adversos , Imunoglobulina G/efeitos adversos , Sinusite Maxilar/etiologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto , Artrite Reumatoide/tratamento farmacológico , Doença Crônica , Suscetibilidade a Doenças/imunologia , Etanercepte , Feminino , Humanos , Infliximab , Sinusite Maxilar/diagnóstico por imagem , Pessoa de Meia-Idade , Radiografia , Receptores do Fator de Necrose Tumoral , Estudos Retrospectivos , Fator de Necrose Tumoral alfa/imunologiaRESUMO
We previously demonstrated that an artificial protein, TAT-FNK, has antiapoptotic effects against cochlear hair cell (HC) damage caused by ototoxic agents when applied systemically. To examine the feasibility of topical protein therapy for inner ear disorders, we investigated whether gelatin sponge soaked with TAT-FNK and placed on the guinea pig round window membrane (RWM) could deliver the protein to the cochlea and attenuate aminoglycoside (AG)-induced cochlear damage in vivo. First, we found that the immunoreactivity of TAT-myc-FNK was distributed throughout the cochlea. The immunoreactivity was observed from 1-24 h after application. When Tat-FNK was applied 1 h before ototoxic insult (a combination of kanamycin sulfate and ethacrynic acid), auditory brainstem response threshold shifts and the extent of HC death were significantly attenuated. When cochlear organotypic cultures prepared from P5 rats were treated with kanamycin, TAT-FNK significantly reduced the extent of caspase-9 activation and HC death. These findings indicate that TAT-FNK topically applied on the RWM can enter the cochlea by diffusion and effectively prevent AG-induced apoptosis of cochlear HCs by suppressing the mitochondrial caspase-9 pathway.
Assuntos
Aminoglicosídeos/toxicidade , Apoptose/efeitos dos fármacos , Cóclea/efeitos dos fármacos , Produtos do Gene tat/farmacologia , Doenças do Labirinto/prevenção & controle , Proteínas Serina-Treonina Quinases/farmacologia , Proteínas Recombinantes de Fusão/administração & dosagem , Administração Tópica , Animais , Caspase 9/metabolismo , Cóclea/metabolismo , Ácido Etacrínico/farmacologia , Ácido Etacrínico/toxicidade , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Produtos do Gene tat/administração & dosagem , Cobaias , Células Ciliadas Auditivas/efeitos dos fármacos , Canamicina/farmacologia , Doenças do Labirinto/induzido quimicamente , Fármacos Neuroprotetores , Proteínas Serina-Treonina Quinases/administração & dosagem , Ratos , Proteínas Recombinantes de Fusão/farmacologia , Janela da Cóclea , Proteínas Supressoras de TumorRESUMO
The promontory stimulation test (PST) using a needle electrode has been used to evaluate the sense of the auditory nerve as a preoperative examination for cochlear implant in adults. Because this is a painful test, it is not suitable for children. It has been reported that children with inner ear anomaly showed poorer outcomes of hearing after cochlear implant. Electroaudiometry developed by Med-El Corporation, which is noninvasive, is a more suitable procedure for young children. Patients were three children less than five years old with inner ear anomaly. Two patients showed common cavity, and one showed narrow IAC with hypoplastic cochlear anomaly. By using Electroaudiometry, we analyzed electro-neural hearing of these children before cochlear implant, and compared their hearing after cochlear implant. Three children seemed to have residural electro-neural hearing because the dynamic range between stimulus level (SL) and uncomfortable level (UCL) was detected by using Electroaudiometry. After cochlear implant, their pure-tone audiograms showed moderate hearing thresholds, and their hearing detection and speech perception improved. These results suggest that Electroaudiometry is available for evaluating electro-neural hearing in young children with inner ear anomaly. It can provide useful information for a successful cochlear implant and evaluation of postoperative performances.
Assuntos
Estimulação Acústica , Audiometria/métodos , Implantes Cocleares , Perda Auditiva/diagnóstico , Estimulação Acústica/instrumentação , Audiometria/instrumentação , Pré-Escolar , Meato Acústico Externo , Eletrodos , Expressão Facial , Feminino , Perda Auditiva/fisiopatologia , Perda Auditiva/terapia , Humanos , Masculino , Valor Preditivo dos TestesRESUMO
CONCLUSION: Although overall improvement was not so dramatic due to a lack of retention, session by session advancement of matching pitch for targeted MIDI (Musical Instrument Digital Interface) sound was predominantly obvious. It was proved that The YUBA Method worked to improve singing ability for patients with cochlear implants. OBJECTIVES: This study sought to verify whether or not the Yuba theory and method improved the singing ability of patients with cochlear implants. SUBJECTS AND METHODS: Based on diagnosis, the instructor experimented to improve matching pitch of singing for three patients with cochlear implants using The YUBA Method. The mean fundamental frequencies and standard deviation of singing were then compared with before and after instructions to patients. The instruction was given for over 40 days at the University of Tokyo Hospital. RESULTS: For each patient, the mean fundamental frequencies of their singing approached the mean MIDI specified frequencies as references for tests done in all three songs. Overall, the SD between fundamental frequencies of their singing and reference MIDI sounds became smaller.
Assuntos
Percepção Auditiva/fisiologia , Implantes Cocleares , Surdez/reabilitação , Música , Qualidade da Voz/fisiologia , Treinamento da Voz , Voz/fisiologia , Adulto , Biorretroalimentação Psicológica , Surdez/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Recently, nanocarriers that transport bioactive substances to a target site in the body have attracted considerable attention and undergone rapid progression in terms of the state of the art. However, few nanocarriers can enter the brain via a systemic route through the blood-brain barrier (BBB) to efficiently reach neurons. Here we prepare a self-assembled supramolecular nanocarrier with a surface featuring properly configured glucose. The BBB crossing and brain accumulation of this nanocarrier are boosted by the rapid glycaemic increase after fasting and by the putative phenomenon of the highly expressed glucose transporter-1 (GLUT1) in brain capillary endothelial cells migrating from the luminal to the abluminal plasma membrane. The precisely controlled glucose density on the surface of the nanocarrier enables the regulation of its distribution within the brain, and thus is successfully optimized to increase the number of nanocarriers accumulating in neurons.There are only a few examples of nanocarriers that can transport bioactive substances across the blood-brain barrier. Here the authors show that by rapid glycaemic increase the accumulation of a glucosylated nanocarrier in the brain can be controlled.
Assuntos
Glicemia/metabolismo , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Portadores de Fármacos/farmacocinética , Animais , Encéfalo/irrigação sanguínea , Portadores de Fármacos/metabolismo , Feminino , Glucose/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Glicosilação , Humanos , Camundongos Endogâmicos BALB C , Micelas , Microscopia Confocal , Nanopartículas/metabolismo , Neurônios/metabolismo , Polímeros/química , Polímeros/metabolismoRESUMO
Gene transfer has been performed in a variety of organs. In the mammalian inner ear, viral vectors have been used to introduce exogenous reporter genes via the scala tympani into the cochlea. While scala tympani inoculation is clinically feasible, it is not without risks. Moreover, transgene expression has so far been restricted to the cochlear tissues in the perilymphatic spaces that are contiguous with the scala tympani. To achieve gene transfer of vestibular organs and cells surrounding the endolymphatic space, and to extend the clinical utility of inner ear gene therapy, we developed a new surgical approach for vector inoculation. A replication-deficient adenoviral vector, Ad.RSVntlacZ, was injected into the guinea pig endolymphatic sac. A large number of blue (LacZ-positive) cells was observed in the endolymphatic sac and duct, the vestibule, and the ampulla. Blue cells were also detected in the cochlea, mainly in cells bordering the endolymphatic space: marginal cells in the stria vascularis and supporting cells in the organ of Corti. These findings indicate that inoculation of viral vectors into the endolymphatic sac can provide efficient gene transfer into a variety of cell types that are not accessible via scala tympani inoculation.
Assuntos
Orelha Interna/metabolismo , Saco Endolinfático , Técnicas de Transferência de Genes , Adenoviridae/genética , Animais , Orelha Interna/anatomia & histologia , Genes Reporter , Terapia Genética/métodos , Vetores Genéticos , Cobaias , MasculinoRESUMO
Using dot-blot hybridization and Southern blotting, the authors detected a point mutation at nucleotide pair (np) 3243 in mitochondrial DNA from temporal bone sections of a woman with diabetes and deafness. The mutation could not be detected with agarose gel electrophoresis, suggesting that the degree of heteroplasmy is low. Histologically, there was marked degeneration of the stria vascularis and outer hair cells throughout the cochlea, as well as a reduction of spiral ganglion cells in the base. These findings suggest that the mutation affects these inner ear structures preferentially and that deafness can occur even when the proportion of np 3243 mutation is low.
Assuntos
DNA Mitocondrial/análise , Mutação Puntual/genética , RNA de Transferência de Leucina/genética , Osso Temporal/patologia , Cóclea/patologia , Diabetes Mellitus Tipo 1/complicações , Feminino , Perda Auditiva Neurossensorial/complicações , Humanos , Pessoa de Meia-IdadeRESUMO
This study shows distributions of lacZ-positive cells in the vestibular labyrinthine explants of young guinea pigs with mature ears. When adenovirus lacZ vectors were administered to the vestibular labyrinth following removal of the otoconial membrane, lacZ-positive cells were observed in the mesothelial cells in the perilymphatic space, in the sensory and supporting cells in the utricle and ampulla, and in the transitional and dark cells in the ampulla. When the otoconial membrane was preserved, lacZ-positive cells were not distributed in the utricular sensory epithelium. These findings suggest that adenovirus vectors can transform a variety of vestibular epithelial cells, but that it is difficult for adenovirus vectors to pass through the otoconial membrane.
Assuntos
Adenoviridae/genética , Orelha Interna/citologia , Vetores Genéticos , Transfecção/métodos , Animais , Células Cultivadas , Orelha Interna/fisiologia , Cobaias , Técnicas In Vitro , Óperon Lac , Sáculo e Utrículo/citologia , Sáculo e Utrículo/fisiologia , TransplantesRESUMO
Tissue injury by reactive oxygen species (ROS) may play a role in noise-induced hearing loss (NIHL). Since iron is involved in ROS generation, we studied if an iron chelator, deferoxamine mesylate (DFO), alone or in combination with mannitol, a hydroxyl scavenger and weak iron chelator, attenuates NIHL. Further, we investigated if glial cell line-derived neurotrophic factor (GDNF) provides additive or synergistic protection of the cochlea from acoustic trauma when given together with DFO and mannitol. Pigmented female guinea pigs were exposed to noise (4 kHz octave band, 115 dB SPL, 5 h). One hour before, immediately after, and 5 h after noise exposure, subjects received an injection of 5 ml saline/kg (control, group I), 100 mg DFO/kg (group II), 15 mg mannitol/kg (group III), or both DFO and mannitol (group IV and V). Animals in group V underwent implantation of an osmotic pump filled with GDNF (100 ng/ml) in the left ear 4 days before noise. Each treatment afforded some protection from noise damage. Group I showed significantly greater outer hair cell loss and threshold shifts at two or more frequencies compared to groups II through V. GDNF provided an additive functional, but not morphological, protection with DFO and mannitol. These findings indicate that iron chelators can attenuate NIHL, as do ROS scavengers, supporting the notion that ROS generation plays a role in NIHL. Additional functional protection provided with GDNF suggests that GDNF may attenuate noise-induced cochlear damage through a mechanism that is additive with antioxidants.
Assuntos
Cóclea/efeitos dos fármacos , Sequestradores de Radicais Livres/administração & dosagem , Quelantes de Ferro/farmacologia , Fatores de Crescimento Neural , Proteínas do Tecido Nervoso/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Ruído/efeitos adversos , Animais , Limiar Auditivo/efeitos dos fármacos , Desferroxamina/administração & dosagem , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Cobaias , Perda Auditiva Provocada por Ruído/etiologia , Injeções Intraperitoneais , Injeções SubcutâneasRESUMO
A potential mechanism of hearing loss due to acoustic overstimulation is the generation of reactive oxygen species (ROS). ROS not removed by antioxidant defenses could be expected to cause significant damage to the sensory cells of the cochlea. We studied the influence of the antioxidant glutathione (GSH) on noise-induced hearing loss by using l-buthionine-[S,R]-sulfoximine (BSO), an inhibitor of GSH synthesis, and 2-oxothiazolidine-4-carboxylate (OTC), a cysteine prodrug, which promotes rapid restoration of GSH when GSH is acutely depleted. Pigmented female guinea pigs were exposed to broadband noise (102 dB SPL, 3 h/day, 5 days) while receiving daily injections of BSO, OTC, or saline. By weeks 2 and 3 after noise exposure, BSO-treated animals showed significantly greater threshold shifts above 12 kHz than saline-treated subjects, whereas OTC-treated animals showed significantly smaller threshold shifts at 12 kHz than controls. Histologically assessed noise-induced damage to the organ of Corti, predominantly basal turn row 1 outer hair cells, was most pronounced in BSO-treated animals. High performance liquid chromatographic analysis showed that OTC significantly increased cysteine levels, but not GSH levels, in the cochlea. These findings show that GSH inhibition increases the susceptibility of the cochlea to noise-induced damage and that replenishing GSH, presumably by enhancing availability of cysteine, attenuates noise-induced cochlear damage.
Assuntos
Antioxidantes/uso terapêutico , Glutationa/fisiologia , Perda Auditiva Provocada por Ruído/prevenção & controle , Pró-Fármacos/uso terapêutico , Tiazóis/uso terapêutico , Animais , Limiar Auditivo , Butionina Sulfoximina/uso terapêutico , Cromatografia Líquida de Alta Pressão , Cóclea/efeitos dos fármacos , Cóclea/metabolismo , Cóclea/patologia , Cisteína/metabolismo , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Glutationa/metabolismo , Cobaias , Perda Auditiva Provocada por Ruído/patologia , Ácido Pirrolidonocarboxílico , TiazolidinasRESUMO
Previous studies have shown that depletion of endogenous glutathione (GSH) potentiates noise-induced hearing loss (NIHL), whereas replenishment of GSH attenuates NIHL (Yamasoba et al., Brain Res. 784 (1998) 82-90). Since these findings indicate an important role of GSH in protection from NIHL, we assessed the influence of intense sound exposure (broadband noise, 105 dB SPL, 5 h) on GSH and cysteine levels in the guinea pig cochlea using high performance liquid chromatography. GSH levels were significantly increased in the lateral wall 2 and 4 h post-exposure and returned to normal 6 h post-exposure. GSH levels in the sensory epithelium and modiolus did not show significant changes following noise. Cysteine levels were unchanged in any of the cochlear segments. For the cochlea as a whole, intense sound exposure did not significantly change GSH or cysteine levels throughout the 6-h measurement period post-exposure. These results indicate that GSH synthesis is markedly upregulated selectively in the lateral wall by noise exposure, presumably in response to the robust consumption of GSH, as it is utilized in scavenging reactive oxygen species.
Assuntos
Cóclea/enzimologia , Cóclea/efeitos da radiação , Glutationa/biossíntese , Ruído , Animais , Cromatografia Líquida de Alta Pressão , Cisteína/metabolismo , Feminino , Cobaias , Distribuição TecidualRESUMO
The incidence of auditory disturbances in vertebrobasilar insufficiency (VBI) is considered much rarer than vestibular disturbances, but no routine audiometric test results for VBI patients have been published. To determine the incidence of deafness associated with VBI and the sites predominantly involved in deafness, we studied 70 vertiginous patients with VBI using a routine audiological examination and magnetic resonance imaging (MRI). MRI detected a lacunar infarct involving the cochlear nuclei in one patient, but lacunae did not involve central auditory structures in the other patients. Twenty-five patients experienced tinnitus, deafness, or both, during vertigo episodes. Audiological examinations confirmed the development of unilateral deafness in 15 (21%) patients, involving the cochlea in 14 and cochlear nuclei in one. These findings indicate that hearing loss occurs in approximately one-fifth of VBI patients, much less frequently than vestibular disturbances, and that deafness associated with VBI mainly involves the cochlea.
Assuntos
Vias Auditivas/irrigação sanguínea , Artéria Basilar/fisiopatologia , Tronco Encefálico/irrigação sanguínea , Surdez/etiologia , Orelha Interna/irrigação sanguínea , Insuficiência Vertebrobasilar/complicações , Idoso , Idoso de 80 Anos ou mais , Audiometria , Vias Auditivas/patologia , Vias Auditivas/fisiopatologia , Artéria Basilar/patologia , Tronco Encefálico/patologia , Tronco Encefálico/fisiopatologia , Núcleo Coclear/irrigação sanguínea , Núcleo Coclear/patologia , Núcleo Coclear/fisiopatologia , Surdez/patologia , Surdez/fisiopatologia , Orelha Interna/patologia , Orelha Interna/fisiopatologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Insuficiência Vertebrobasilar/patologia , Insuficiência Vertebrobasilar/fisiopatologia , Vertigem/etiologia , Vertigem/patologia , Vertigem/fisiopatologiaRESUMO
We report a patient with definite multiple sclerosis (MS) who developed unilateral sudden hearing loss coincident with exacerbation of central nervous system symptoms. Involvement of the peripheral cochlear nerve, suggested by auditory findings including auditory brainstem response, was confirmed by magnetic resonance imaging. The clinical, electrophysiological and neuroradiological abnormalities disappeared in response to steroid pulse therapy. These findings suggest that acute inflammatory demyelinative lesion of the peripheral cochlear nerve can occur in MS, manifesting sudden hearing loss.
Assuntos
Doenças Cocleares/etiologia , Perda Auditiva Central/etiologia , Esclerose Múltipla/complicações , Neurite (Inflamação)/complicações , Doença Aguda , Adulto , Doenças Cocleares/diagnóstico , Potenciais Evocados Auditivos do Tronco Encefálico , Perda Auditiva Central/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Esclerose Múltipla/diagnóstico , Condução Nervosa/fisiologia , Neurite (Inflamação)/diagnósticoRESUMO
We studied the effect of chronic treatment with kanamycin on the basement membrane (BM) anionic sites in the cochlea and endolymphatic sac using polyethyleneimine (PEI) as a cationic tracer. Albino guinea pigs weighing 250-300 g received kanamycin (400 mg/kg/day, i.m.) for 10 or 17 consecutive days. The number of BM anionic sites as derived from the PEI area was not affected in Reissner's membrane, spiral prominence, basilar membrane or endolymphatic sac, whereas it was significantly decreased in the stria vascularis and spiral limbus, being more marked in the guinea pigs treated for 17 days than in those treated for 10 days. The number of BM anionic sites in these regions did not recover until 6 weeks after kanamycin treatment. These findings suggest that chronically administered kanamycin may selectively and progressively affect the BM anionic sites in the stria vascularis and spiral limbus, resulting in disruption of a barrier function in the cochlea, and that severely impaired BM anionic sites in the cochlea may not recover.