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1.
Auris Nasus Larynx ; 50(4): 601-606, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36604259

RESUMO

OBJECTIVE: The prognostic role of pretreatment C-reactive protein (CRP) has been reported for head and neck cancer. However, little is known about the relationship between the changes in CRP levels during treatment and prognosis. This study aimed to investigate the correlation between CRP elevation during concurrent chemoradiotherapy (CCRT) and survival outcomes. METHODS: The medical records of patients with oropharyngeal, hypopharyngeal, and laryngeal cancer treated with CCRT at the University of Tsukuba Hospital and National Hospital Organization Mito Medical Center from April 2014 to December 2019 were retrospectively reviewed. Patients were divided into normal (<0.3 mg/dl) and elevated (≥0.3 mg/dl) CRP groups according to the CRP level after the first cycle of cisplatin. The primary endpoint was progression-free survival (PFS). RESULTS: A total of 74 patients were enrolled, of whom 36 (49%) showed elevated CRP levels after the first cycle of cisplatin. The 3-year PFS was 83.3% and 61.0% in the normal and elevated CRP groups, respectively, showing significant differences between the two groups. CONCLUSION: Elevated CRP levels after the first cycle of cisplatin is an objective predictive marker for survival in patient with head and neck squamous cell carcinoma treated with CCRT.


Assuntos
Cisplatino , Neoplasias de Cabeça e Pescoço , Humanos , Cisplatino/uso terapêutico , Proteína C-Reativa/metabolismo , Estudos Retrospectivos , Neoplasias de Cabeça e Pescoço/terapia , Quimiorradioterapia
2.
Redox Rep ; 28(1): 2161224, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36661237

RESUMO

Cisplatin-induced ototoxicity is caused by reactive oxygen species. It has been recognized that estradiol (E2) regulates redox balance. However, little is known about the protective mechanisms of E2 against cisplatin-induced ototoxicity. In this study, we investigated the effect of E2 on nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated hair cell protection using the organ of Corti isolated from mice. The organ of Corti collected from C57BL/6 mice at 3-5 postnatal days was used in all experiments. The organ of Corti was exposed to 20 µM cisplatin with/without 100 nM E2 to examine the effect of E2 on cisplatin-induced hair cell loss. The mRNA expression of Nrf2 and the phase II detoxification gene after E2 and cisplatin treatment was analyzed using quantitative real-time PCR. E2 significantly reduces cisplatin-induced cochlear hair cell death. In addition, 100 nM E2 increased the mRNA expression of Nrf2 and phase II detoxification genes in the organ of Corti under cisplatin treatment. Our results suggest that E2 activates Nrf2, phase II detoxification enzymes and exerts a protective effect against cisplatin-induced ototoxicity.


Assuntos
Antineoplásicos , Ototoxicidade , Camundongos , Animais , Cisplatino/toxicidade , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Ototoxicidade/metabolismo , Estradiol/farmacologia , Estradiol/metabolismo , Apoptose , Camundongos Endogâmicos C57BL , Células Ciliadas Auditivas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , RNA Mensageiro/metabolismo , RNA Mensageiro/farmacologia , Antineoplásicos/toxicidade
3.
Hear Res ; 261(1-2): 67-74, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20074632

RESUMO

Gentamicin induces outer hair cell death through the apoptotic pathway. It has been reported that this death pathway of outer hair cells is mediated by specific apoptotic enzymes including c-jun N-terminal kinase (JNK) and caspases. 17beta-Estradiol (E2), the most potent estrogen, is known to function as an antiapoptotic agent to prevent the death of various cell types. The purpose of the present study was to examine the effects of E2 on gentamicin-induced apoptotic cell death in outer hair cells. The basal turn organ of Corti explants from p3 or p4 rats were maintained in a tissue culture and exposed to 100muM gentamicin for 48h. The effects of E2 on gentamicin-induced outer hair cell loss, JNK activation, and staining for terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling (TUNEL) were examined. E2 significantly decreased gentamicin-induced outer hair cell loss in a dose-dependent manner. JNK activation and TUNEL staining were observed in organ of Corti explants exposed to gentamicin, and staining levels were significantly decreased by E2 treatment. The results indicate that, through the inhibition of JNK and subsequent apoptotic reactions, E2 decreases outer hair cell loss induced by gentamicin ototoxicity.


Assuntos
Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Cóclea/efeitos dos fármacos , Estradiol/farmacologia , Gentamicinas/farmacologia , MAP Quinase Quinase 4/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Antibacterianos/toxicidade , Apoptose/fisiologia , Caspases/fisiologia , Células Cultivadas , Cóclea/citologia , Cóclea/fisiologia , Relação Dose-Resposta a Droga , Gentamicinas/toxicidade , Células Ciliadas Auditivas/citologia , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/fisiologia , MAP Quinase Quinase 4/fisiologia , Modelos Animais , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia
5.
Tohoku J Exp Med ; 218(1): 41-7, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19398872

RESUMO

Excessive calcium entry into cells leads to cell death, and voltage-gated calcium channels (VGCCs) are responsible for the calcium entry in the central nervous system. VGCC blockers inhibit excessive calcium entry and protect the central nervous system against various types of injury. The purpose of the present study was to identify the type of calcium channels that is responsible for acoustic injury of the cochlea. The effects of L- and T-type VGCC blockers on acoustic injury were examined. Female ddY mice, at 8 weeks of age, were used in this study. The animals were subjected to a 4-kHz pure tone of 128-dB sound pressure level (SPL) for 4 hours through an open field system inside a sound-exposure box. A L-type or T-type VGCC blocker was administered immediately before acoustic overexposure. The hearing ability was evaluated using the auditory brainstem response (ABR). ABR is an electrical signal evoked from the brainstem by the sound. After the final ABR measurement at two weeks after acoustic overexposure, cell nuclei in the organ of Corti were stained with propidium iodide, and hair cell loss was calculated in a region 3.66 mm from the apex. Each of four L-type VGCC blockers tested, i.e. diltiazem, verapamil, nicardipine and nimodipine, significantly improved shifts of the ABR threshold from the pre-exposure levels. In addition, each L-type VGCC blocker consistently decreased hair cell loss, but not a given T-type calcium blocker. The present findings suggest that the L-type VGCC is involved in the pathogenesis of acoustic injury in the cochlea.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Cóclea/patologia , Perda Auditiva Provocada por Ruído , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Perda Auditiva Provocada por Ruído/metabolismo , Perda Auditiva Provocada por Ruído/patologia , Camundongos
6.
Tohoku J Exp Med ; 216(1): 53-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18719338

RESUMO

Acoustic injury is a common cause of hearing loss for people in industrial societies. Cyclooxygenase (COX) and lipoxygenase (LOX) are two important enzymes involved in arachidonic acid metabolism. Two COX isozymes are characterized, COX-1 and COX-2, that differ in terms of regulatory mechanisms of expression. Although COX-1, COX-2, and LOX are expressed in cochlea, their roles played in cochlear acoustic injury have not fully been evaluated. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit either COX or LOX, or both. This study evaluated the effects of NSAIDs on the functional recovery of the cochlea after acoustic injury. Mice were exposed to a 4-kHz pure tone of 128 dB SPL (sound pressure level) for 4 hours and received one of the following drugs for two weeks after acoustic overexposure: indomethacin (COX-1 inhibitor), meloxicam, SC58125, and CAY10404 (COX-2 inhibitors), and nordihydroguaiaretic acid (LOX inhibitor). The hearing ability was evaluated using an auditory brainstem response (ABR) before and after overexposure. The ABR threshold shifts, defined as subtraction between ABR thresholds before and after overexposure, were compared among the control and the medication groups at one and two weeks after acoustic overexposure. Treatment of mice with either indomethacin or nordihydroguaiaretic acid decreased the ABR threshold shifts after overexposure, indicating that COX-1 and LOX inhibitors exhibited protective effects against acoustic injury. In contrast, COX-2 inhibitors, meloxicam, SC58125, and CAY10404, showed no noticeable effects on the ABR threshold shifts. These findings suggest that COX-1 and LOX are involved in the pathogenesis of acoustic injury in cochlea.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Cóclea/efeitos dos fármacos , Perda Auditiva Provocada por Ruído/prevenção & controle , Fármacos Neuroprotetores/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Limiar Auditivo/efeitos dos fármacos , Cóclea/patologia , Ciclo-Oxigenase 1/uso terapêutico , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Inibidores de Ciclo-Oxigenase/farmacologia , Inibidores de Ciclo-Oxigenase/uso terapêutico , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/patologia , Perda Auditiva Provocada por Ruído/fisiopatologia , Indometacina/farmacologia , Indometacina/uso terapêutico , Isoxazóis/farmacologia , Isoxazóis/uso terapêutico , Inibidores de Lipoxigenase/farmacologia , Inibidores de Lipoxigenase/uso terapêutico , Masoprocol/farmacologia , Masoprocol/uso terapêutico , Meloxicam , Camundongos , Camundongos Endogâmicos , Fármacos Neuroprotetores/farmacologia , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Sulfonas/farmacologia , Sulfonas/uso terapêutico , Tiazinas/farmacologia , Tiazinas/uso terapêutico , Tiazóis/farmacologia , Tiazóis/uso terapêutico
7.
Neurosci Lett ; 418(1): 18-21, 2007 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-17353094

RESUMO

Gamma-aminobutyric acid (GABA) is one of major inhibitory neurotransmitter in the central nervous system and constitutes the cochlear efferent system. Glutamate excitotoxicity is implicated in the pathogenesis of acoustic injury of the cochlea. The present work investigated whether GABA(A) agonist muscimol can alleviate acoustic injury. Mice were exposed to a 4 kHz pure tone of 128 dB SPL for 4h. Muscimol and/or bicuculline, a GABA(A) antagonist, were intraperitoneally administered immediately before the onset of acoustic overexposure. The threshold shifts of the auditory brainstem response (ABR) and cochlear morphology after acoustic overexposure were then evaluated. Muscimol significantly decreased the ABR threshold shift and inhibited swelling of the afferent dendrites induced by acoustic overexposure. In addition, bicuculline inhibited the effects of muscimol. These findings suggest that activation of GABA(A) receptors reduces acoustic injury of the cochlea.


Assuntos
Cóclea/efeitos dos fármacos , Agonistas GABAérgicos/uso terapêutico , Agonistas de Receptores de GABA-A , Células Ciliadas Auditivas/efeitos dos fármacos , Muscimol/uso terapêutico , Ruído/efeitos adversos , Animais , Bicuculina/farmacologia , Cóclea/patologia , Dendritos/efeitos dos fármacos , Dendritos/patologia , Antagonistas GABAérgicos/farmacologia , Células Ciliadas Auditivas/patologia , Perda Auditiva Provocada por Ruído/prevenção & controle , Camundongos , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/patologia , Receptores de GABA-A/efeitos dos fármacos
8.
Tohoku J Exp Med ; 211(3): 297-302, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17347556

RESUMO

Polymorphous low-grade adenocarcinoma (PLGA) of the salivary gland is a disease entity that is a recently described form of adenocarcinoma. PLGA most commonly arises in the minor salivary glands. We report two cases of PLGA of the parotid gland. Case 1: A 52-year-old female visited the University of Tsukuba Hospital with a painless mass in the left parotid region. A superficial parotidectomy and postoperative radiotherapy were performed. The patient has been free from disease for 50 months. Case 2: A 55-year-old female initially noticed a painless slowly growing mass in the left parotid region. The tumor was removed with a superficial parotidectomy. The local recurrence was found 6 years after the initial surgery. The recurrent tumor was removed, and radiotherapy was administered thereafter. The patient has been free from the disease for 33 months since the last treatment. The treatment for the primary lesion is crucial for the prognosis since metastasis to the regional lymph node or to distant region is unusual in PLGA. Although surgical extirpation is the recommended modality for treatment of PLGA, wide resection with a safety margin is often difficult in the parotid gland because of the presence of the facial nerve. Our two cases were successfully treated with surgery and postoperative radiotherapy. Although our literature search revealed 32 previously reported cases of PLGA of the parotid gland, only five of the 32 cases were treated postoperative radiotherapy. We highlight the importance of postoperative radiotherapy for PLGA of the parotid gland.


Assuntos
Adenocarcinoma/radioterapia , Neoplasias Parotídeas/radioterapia , Adenocarcinoma/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Glândula Parótida/patologia , Glândula Parótida/cirurgia , Neoplasias Parotídeas/cirurgia , Período Pós-Operatório
9.
Otol Neurotol ; 27(8): 1176-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16980917

RESUMO

HYPOTHESIS: This study aims to investigate the therapeutic time window of methylprednisolone in acoustic injury. BACKGROUND: Although glucocorticoids have been widely used in the treatment of acoustic injury, the therapeutic time window of glucocorticoids in acoustic injury has never been examined. METHODS: Mice were exposed to 4-kHz pure tone of 128-dB sound pressure level for 4 hours. Auditory brainstem response was examined before, immediately after, and 2 weeks after acoustic overexposure. RESULTS: Methylprednisolone significantly improved the auditory brainstem response threshold shifts 2 weeks after acoustic overexposure when it was administered before or immediately after acoustic overexposure, but not when administered 3 hours after acoustic overexposure. CONCLUSION: The present findings suggest that methylprednisolone possesses protective effects against acoustic injury of the cochlea with a short therapeutic time window.


Assuntos
Limiar Auditivo/efeitos dos fármacos , Glucocorticoides/administração & dosagem , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Metilprednisolona/administração & dosagem , Análise de Variância , Animais , Audiometria de Resposta Evocada , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Glucocorticoides/uso terapêutico , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/patologia , Metilprednisolona/uso terapêutico , Camundongos , Ruído/efeitos adversos , Fatores de Tempo , Resultado do Tratamento
10.
Auris Nasus Larynx ; 33(4): 455-60, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16899348

RESUMO

OBJECTIVE: The pathogenesis of eosinophilic otitis media is not yet fully understood. The purpose of this paper is to describe the clinical course of our two patients with eosinophilic otitis media and to discuss the pathogenesis and treatment of this intractable condition. METHODS: Two cases of eosinophilic otitis media were treated with ramatroban. RESULTS: The middle ear effusion has been well controlled in both patients for more than 1 year with minimal corticosteroid therapy. CONCLUSIONS: Our experience suggests that the pathogenesis of eosinophilic otitis media is related to the pharmaceutical effects of ramatroban, i.e., inhibition of the thromboxane A2 receptor (TP) and the chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2).


Assuntos
Carbazóis/uso terapêutico , Eosinofilia/tratamento farmacológico , Otite Média com Derrame/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Sulfonamidas/uso terapêutico , Administração Tópica , Betametasona/uso terapêutico , Eosinofilia/complicações , Feminino , Glucocorticoides/uso terapêutico , Humanos , Pessoa de Meia-Idade , Otite Média com Derrame/complicações , Receptores de Tromboxanos/antagonistas & inibidores
11.
J Pharmacol Sci ; 99(2): 191-4, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16210774

RESUMO

The present study was performed to determine effects of dehydroepiandrosterone sulfate (DHEAS), a neurosteroid, on acoustic injury. Albino guinea pigs were exposed to a 2 kHz pure tone of 120 or 125 dB sound pressure level for 10 min immediately after intravenous administration of DHEAS. Statistically significant improvement in the compound action potential threshold shifts and in amplitude reduction of distortion-product otoacoustic emissions was observed 1 week after the acoustic overexposure in the animals treated with DHEAS. The present results suggest that DHEAS has a protective effect against acoustic injury of the cochlea.


Assuntos
Cóclea , Sulfato de Desidroepiandrosterona/farmacologia , Perda Auditiva Provocada por Ruído/prevenção & controle , Substâncias Protetoras/farmacologia , Estimulação Acústica , Animais , Sulfato de Desidroepiandrosterona/administração & dosagem , Potenciais Evocados Auditivos/efeitos dos fármacos , Cobaias , Substâncias Protetoras/administração & dosagem
12.
Auris Nasus Larynx ; 32(4): 431-4, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16139456

RESUMO

Large-cell undifferentiated carcinoma (LCUC) arising in the submandibular gland is so rare that there have been only a few reported cases. We encountered a 65-year-old Japanese male, whose left submandibular gland was enlarged due to LCUC. Exenteration of the left submandibular gland together with selective neck dissection was performed, followed by postoperative radiotherapy. Current literature concerning the histopathological and clinical features of this neoplasm was reviewed.


Assuntos
Carcinoma/cirurgia , Neoplasias da Glândula Submandibular/cirurgia , Idoso , Carcinoma/diagnóstico , Carcinoma/radioterapia , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias da Glândula Submandibular/diagnóstico , Neoplasias da Glândula Submandibular/radioterapia , Tomografia Computadorizada por Raios X
13.
Hear Res ; 209(1-2): 86-90, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16084678

RESUMO

This study examined the effect of immunosuppressants, cyclosporin A, FK506 and rapamycin on functional recovery of the cochlea after acoustic overexposure, in guinea pigs and mice. Thirty guinea pigs were exposed to a 2 kHz pure tone at 120 dB SPL for 10 min. The compound action potential threshold shift induced by acoustic overexposure was examined. Twenty-five mice were exposed to a 4 kHz pure tone at 128 dB SPL for 4h. Auditory brainstem response was used to examine the hearing threshold shift. In both the guinea pig and mouse experiments, cyclosporin A and FK506, intraperitonally given just before acoustic overexposure, significantly decreased the hearing threshold shift one or two weeks after acoustic overexposure. However, neither rapamycin nor the FK506 and rapamycin combined treatment groups showed improvement of the threshold shift. The present findings suggest that these two calcineurin inhibitors have a protective effect against acoustic injury of the cochlea, whereas the non-calcineurin inhibitor, rapamycin, not only has no effect against acoustic injury, but rather blocked the effect of FK506. This indicated a possible role of calcineurin against acoustic injury.


Assuntos
Inibidores de Calcineurina , Cóclea/fisiopatologia , Perda Auditiva Provocada por Ruído/fisiopatologia , Substâncias Protetoras/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Análise de Variância , Animais , Audiometria de Tons Puros/métodos , Tronco Encefálico/fisiologia , Cóclea/efeitos dos fármacos , Cóclea/patologia , Ciclosporina/farmacologia , Eletrofisiologia , Feminino , Cobaias , Células Ciliadas Auditivas Externas/efeitos dos fármacos , Células Ciliadas Auditivas Externas/patologia , Perda Auditiva Provocada por Ruído/patologia , Imunossupressores/farmacologia , Camundongos , Camundongos Endogâmicos , Sirolimo/farmacologia , Especificidade da Espécie , Tacrolimo/antagonistas & inibidores , Tacrolimo/farmacologia
14.
Auris Nasus Larynx ; 30(4): 421-3, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14656570

RESUMO

Nevoid basal cell carcinoma syndrome, also referred to as Gorlin-Goltz syndrome, is a rare autosomal dominant disorder characterized by multiple basal cell carcinomas, jaw cysts, palmar or plantar pits, ectopic calcification of the falx cerebri, and various skeletal developmental abnormalities. A minority of basal cell carcinomas demonstrate aggressive behavior and involve the craniofacial bones in nevoid basal cell carcinoma syndrome. A non-familial case of nevoid basal cell carcinoma syndrome with a basal cell carcinoma of the eyelid invading to the ethmoid sinus is reported.


Assuntos
Síndrome do Nevo Basocelular/patologia , Seio Etmoidal/patologia , Neoplasias Palpebrais/patologia , Neoplasias dos Seios Paranasais/patologia , Idoso , Síndrome do Nevo Basocelular/genética , Neoplasias Palpebrais/genética , Feminino , Humanos , Imageamento por Ressonância Magnética , Invasividade Neoplásica , Neoplasias Orbitárias/genética , Neoplasias Orbitárias/patologia , Neoplasias dos Seios Paranasais/genética , Linhagem , Tomografia Computadorizada por Raios X
15.
Tohoku J Exp Med ; 200(4): 195-202, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14580150

RESUMO

We investigated effects of poly(ADP-ribose) synthetase (PARS) inhibitors on acoustic trauma. Albino guinea pigs were intravenously given 3-aminobenzamide, nicotinamide or 3-aminobenzoic acid (an inactive analog of 3-aminobenzamide) just prior to exposure to a 2 kHz pure tone of 120 dB sound pressure level (SPL) for 10 minutes. The threshold of the compound action potential (CAP) and the amplitude of distortion-product otoacoustic emissions (DPOAEs) were measured before and 4 hours after the acoustic overexposure. Statistically significant decreases in the CAP threshold shifts and significant increases in the DPOAE amplitudes were observed 4 hours after the acoustic overexposure in the animals treated with 3-aminobenzamide or nicotinamide, whereas 3-aminobenzoic acid did not exert any protective effect. These results strongly suggest that excessive activation of PARS is involved in generation of the acoustic trauma.


Assuntos
Cóclea/patologia , Perda Auditiva Provocada por Ruído/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Estimulação Acústica/efeitos adversos , Potenciais de Ação/fisiologia , Aminobenzoatos/administração & dosagem , Aminobenzoatos/metabolismo , Animais , Benzamidas/administração & dosagem , Benzamidas/química , Benzamidas/metabolismo , Ativação Enzimática , Cobaias , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Niacinamida/administração & dosagem , Niacinamida/metabolismo , Emissões Otoacústicas Espontâneas , Inibidores de Poli(ADP-Ribose) Polimerases , meta-Aminobenzoatos
16.
Hear Res ; 180(1-2): 51-6, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12782352

RESUMO

This study aimed to evaluate the effects of steroidal drugs on the functional recovery of the cochlea after transient ischemia. Albino guinea pigs were subjected to transient cochlear ischemia of 30 min duration, and the threshold shifts of the compound action potential (CAP) from the pre-ischemic values were evaluated 4 h after ischemia. Pre-ischemic administration of a glucocorticoid, prednisolone or methylprednisolone, significantly ameliorated the post-ischemic CAP threshold shifts as compared with control animals at a relatively wide range of doses. Post-ischemic administration of these glucocorticoids also exhibited protective effects. Pre-ischemic administration of dehydroepiandrosterone sulfate significantly decreased the post-ischemic CAP threshold shifts 4 h after ischemia. The present results indicate that glucocorticoids and dehydroepiandrosterone sulfate possess therapeutic effects against ischemic injury of the cochlea, such as idiopathic sudden sensorineural hearing loss.


Assuntos
Cóclea/irrigação sanguínea , Cóclea/fisiopatologia , Sulfato de Desidroepiandrosterona/farmacologia , Glucocorticoides/farmacologia , Isquemia/fisiopatologia , Potenciais de Ação/efeitos dos fármacos , Análise de Variância , Animais , Limiar Diferencial/efeitos dos fármacos , Cobaias , Metilprednisolona/farmacologia , Prednisolona/farmacologia
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