RESUMEN
Objective: To evaluate the effectiveness and safety of 0.05% cyclosporine A and 0.1% tacrolimus eye drops in treating severe dry eye associated with chronic graft-versus-host disease (cGVHD). Methods: This non-randomized concurrent control trial enrolled 83 eyes from 83 patients with cGVHD-associated severe dry eye. The treatment had two phases. During the initial shock treatment period (0-3 months), 44 patients received 0.05% cyclosporine A eye drops (4 times/day; group A) and 39 patients received 0.1% tacrolimus eye drops (twice/day; group B) alongside basic treatment. In the maintenance treatment period (3-6 months), both groups used 0.05% cyclosporine A eye drops (twice/day) and sodium hyaluronate. Examinations were conducted at 1, 3, and 6 months after treatment initiation, assessing the Ocular Surface Disease Index (OSDI), corneal fluorescein staining (CFS) score, and fluorescein tear break-up time (BUT) for efficacy. visual acuity and intraocular pressure (IOP) were evaluated for safety, and patients' post-medication irritation symptoms were recorded. Results: The study included 52 males and 31 females, aged (28.57±15.67) years. After 1 month of treatment, the CFS score in group A significantly decreased from 10.0 (6.0, 14.0) to 5.0 (3.0, 8.5) (P<0.001). in group B, the CFS score also significantly decreased from 10.0 (6.0, 15.0) to 6.0 (2.0, 10.0), and the BUT increased from 2.0 (1.0, 2.0) s to 2.0 (1.8, 3.3) s (P<0.001). No significant OSDI decrease was observed in either group. No significant differences were found in OSDI, CFS score, and BUT between the two groups. After 3 months, group A showed significant improvement in OSDI, CFS score, and BUT (P<0.05), while group B only demonstrated significant CFS score decrease (P<0.05). OSDI was significantly lower in group A than group B (P<0.05). No significant differences were noted in CFS score and BUT between groups. After 6 months, OSDI, CFS score, and BUT were 18.9 (9.3, 34.2), 7.0 (3.0, 8.5), and 2.0 (1.0, 3.0) s in group A, and 10.9 (3.6, 35.4), 5.5 (2.8, 10.0), and 2.0 (1.0, 10.0) s in group B. In both groups, CFS scores significantly decreased and BUT increased (P<0.05). Visual acuity improved significantly in group A at 1, 3, and 6 months (P<0.05), while no significant changes were seen in group B. Irritation symptoms were transient and self-resolving in both groups. Conclusions: Both 0.05% cyclosporine A and 0.1% tacrolimus eye drops, when combined with local glucocorticoids, exhibited significant anti-inflammatory effects, effectively and safely treating severe dry eye in cGVHD patients. Although the onset of 0.05% cyclosporine A was slower than 0.1% tacrolimus, it offered more stable long-term effects and better symptom improvement.
Asunto(s)
Síndrome de Bronquiolitis Obliterante , Síndromes de Ojo Seco , Femenino , Humanos , Masculino , Ciclosporina/uso terapéutico , Síndromes de Ojo Seco/tratamiento farmacológico , Fluoresceínas/uso terapéutico , Soluciones Oftálmicas/uso terapéutico , Tacrolimus/uso terapéutico , LágrimasRESUMEN
Occupational exposure to diacetyl can lead to bronchiolitis obliterans. In this paper, two patients with severe obstructive ventilation disorder who were exposed to diacetyl at a fragrance and flavours factory were analyzed. The clinical manifestations were cough and shortness of breath. One of them showed Mosaic shadows and uneven perfusion in both lungs on CT, while the other was normal. Field investigation found that 4 of the 8 workers in the factory were found to have obstructive ventilation disorder, and 2 had small airway dysfunction. This paper summarizes the diagnostic process of patients in order to improve the understanding of airway dysfunction caused by occupational exposure to diacetyl and promote the development of relevant standards.
Asunto(s)
Bronquiolitis Obliterante , Enfermedades Profesionales , Exposición Profesional , Humanos , Diacetil/efectos adversos , Enfermedades Profesionales/diagnóstico , Exposición Profesional/efectos adversos , Pulmón , Bronquiolitis Obliterante/inducido químicamente , Bronquiolitis Obliterante/diagnósticoRESUMEN
OBJECTIVE: To study the expression of linc00601 in hepatocellular carcinoma (HCC) tissues and cells, and to study the biological function and downstream mechanism of linc00601 in HCC using in vitro experiments. PATIENTS AND METHODS: The expression of linc00601 in HCC was predicted via bioinformatics, and the expression of linc00601 in HCC tissues and cells was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). After interference with the expression of linc00601, the interference efficiency was determined using qRT-PCR, and the changes in HCC cell proliferation, cycle distribution, and apoptosis were determined through Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. Finally, the expressions of molecular markers in downstream signaling pathway were determined through Western blotting. RESULTS: It was found via bioinformatics that the expression of linc00601 was upregulated in HCC. The results of qRT-PCR revealed that the expression of linc00601 was upregulated in 36 cases of HCC tissues compared with that in para-carcinoma tissues, and it was also upregulated in HCC cells. According to the results of CCK-8 assay, HCC cell proliferation was inhibited after interference with the expression of linc00601. In the si-linc00601 group, the apoptosis rate rose, and the cell cycle was arrested at the G1/G0 phase compared with those in the si-NC group. The results of Western blotting revealed that after the knockdown of linc00601 in HCC cells, the expressions of molecular markers (p-P38, p-ERK) in the downstream mitogen-activated protein kinase (MAPK) signaling pathway were downregulated. CONCLUSIONS: Linc00601 is upregulated in HCC, which promotes the development of HCC via activating the MAPK signaling pathway.
Asunto(s)
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Sistema de Señalización de MAP Quinasas , ARN Largo no Codificante/metabolismo , Regulación hacia Arriba , Carcinoma Hepatocelular/patología , Células Cultivadas , Humanos , Neoplasias Hepáticas/patología , ARN Largo no Codificante/genéticaRESUMEN
Acoustic overstimulation traumatizes the cochlea, resulting in auditory dysfunction. As a consequence of acoustic injury, the immune system in the cochlea is activated, leading to the production of inflammatory mediators and the infiltration of immune cells. However, the molecular mechanisms responsible for initiating these immune responses remain unclear. Here, we investigate the functional role of Toll-like receptor 4 (Tlr4), a cellular receptor that activates the innate immune system, in the regulation of cochlear responses to acoustic overstimulation. Using a Tlr4 knockout mouse model, we examined how Tlr4 deficiency affects sensory cell pathogenesis, auditory dysfunction and cochlear immune activity. We demonstrate that Tlr4 knockout does not affect sensory cell viability under physiological conditions, but reduces the level of sensory cell damage and cochlear dysfunction after acoustic injury. Together, these findings suggest that Tlr4 promotes sensory cell degeneration and cochlear dysfunction after acoustic injury. Acoustic injury provokes a site-dependent inflammatory response in both the organ of Corti and the tissues of the lateral wall and basilar membrane. Tlr4 deficiency affects these inflammatory responses in a site-dependent manner. In the organ of Corti, loss of Tlr4 function suppresses the production of interleukin 6 (Il6), a pro-inflammatory molecule, after acoustic injury. By contrast, the production of inflammatory mediators, including Il6, persists in the lateral wall and basilar membrane. In addition to immune molecules, Tlr4 knockout inhibits the expression of major histocompatibility complex class II, an antigen-presenting molecule, in macrophages, suggesting that Tlr4 participates in the antigen-presenting function of macrophages after acoustic trauma. Together, these results suggest that Tlr4 regulates multiple aspects of the immune response in the cochlea and contributes to cochlear pathogenesis after acoustic injury.
Asunto(s)
Cóclea/inmunología , Cóclea/patología , Pérdida Auditiva Provocada por Ruido/inmunología , Pérdida Auditiva Provocada por Ruido/patología , Receptor Toll-Like 4/metabolismo , Animales , Regulación de la Expresión Génica , Pérdida Auditiva Provocada por Ruido/genética , Antígenos de Histocompatibilidad Clase II/metabolismo , Inflamación/genética , Inflamación/patología , Mediadores de Inflamación/metabolismo , Macrófagos/metabolismo , Macrófagos/patología , Ratones Endogámicos C57BL , Ratones Noqueados , Monocitos/metabolismo , Monocitos/patología , Ruido , Órgano Espiral/metabolismo , Órgano Espiral/patología , Ovalbúmina , Receptor Toll-Like 4/deficienciaRESUMEN
The immune response is an important component of the cochlear response to stress. As an important player in the cochlear immune system, the basilar membrane immune cells reside on the surface of the scala tympani side of the basilar membrane. At present, the immune cell properties in this region and their responses to stress are not well understood. Here, we investigated the functional role of these immune cells in the immune response to acoustic overstimulation. This study reveals that tissue macrophages are present in the entire length of the basilar membrane under steady-state conditions. Notably, these cells in the apical and the basal sections of the basilar membrane display distinct morphologies and immune protein expression patterns. Following acoustic trauma, monocytes infiltrate into the region of the basilar membrane, and the infiltrated cells transform into macrophages. While monocyte infiltration and transformation occur in both the apical and the basal sections of the basilar membrane, only the basal monocytes and macrophages display a marked increase in the expression of major histocompatibility complex (MHC) II and class II transactivator (CIITA), a MHC II production cofactor, suggesting the site-dependent activation of antigen-presenting function. Consistent with the increased expression of the antigen-presenting proteins, CD4(+) T cells, the antigen-presenting partner, infiltrate into the region of the basilar membrane where antigen-presenting proteins are upregulated. Further pathological analyses revealed that the basal section of the cochlea displays a greater level of sensory cell damage, which is spatially correlated with the region of antigen-presenting activity. Together, these results suggest that the antigen-presenting function of the mononuclear phagocyte population is activated in response to acoustic trauma, which could bridge the innate immune response to adaptive immunity.
Asunto(s)
Membrana Basilar/inmunología , Sistema Mononuclear Fagocítico/inmunología , Ruido/efectos adversos , Estimulación Acústica , Animales , Antígenos/inmunología , Membrana Basilar/citología , Membrana Basilar/metabolismo , Linfocitos T CD4-Positivos/inmunología , Femenino , Genes MHC Clase II , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Ratones Endogámicos C57BL , Monocitos/inmunología , Monocitos/metabolismo , Sistema Mononuclear Fagocítico/metabolismoRESUMEN
Carboplatin preferentially destroys inner hair cells (IHCs) and type-I spiral ganglion neurons while sparing outer hair cells (OHCs). Loss of IHCs and type-I ganglion cells is associated with a significant reduction of the compound action potential (CAP). However, the cochlear microphonic (CM) potential and distortion product otoacoustic emissions (DPOAEs) remain normal, indicating that the OHCs are functionally intact. In the vestibular system, carboplatin selectively destroys type-I hair cells and their afferent neurons. Damage of type-I vestibular hair cells and their afferent terminals is associated with significant depression of nystagmus induced by cold, caloric stimulation. Histochemical studies revealed a rapid decrease in succinate dehydrogenase (SDH) staining in IHCs soon after carboplatin treatment, and staining intensity remained depressed in surviving IHCs for at least 1 month after carboplatin treatment. These results suggest that carboplatin depresses the metabolic function in surviving IHCs. Several lines of evidence suggest that free radicals may contribute to carboplatin-induced sensory cell damage. Intracochlear infusion of L-buthionine-[S,R]-sulfoximine (BSO), which depletes intracellular glutathione (GSH), increases IHC and OHC loss. Previous in vitro studies have shown that neurotrophin 4/5 (NT-4/5) promotes the survival of spiral ganglion neurons from cisplatin ototoxicity. In vivo perfusion of NT-4/5 promoted the survival of spiral ganglion neurons, but did not protect the hair cells.
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Potenciales de Acción/efectos de los fármacos , Antineoplásicos/efectos adversos , Carboplatino/efectos adversos , Células Ciliadas Auditivas Internas/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Chinchilla , Cóclea/efectos de los fármacos , Cóclea/fisiología , Sordera/inducido químicamente , Sordera/tratamiento farmacológico , Sordera/prevención & control , Células Ciliadas Auditivas Internas/fisiología , Células Ciliadas Auditivas Externas/efectos de los fármacos , Células Ciliadas Auditivas Externas/fisiología , Células Ciliadas Vestibulares/efectos de los fármacos , Células Ciliadas Vestibulares/fisiología , Factores de Crecimiento Nervioso/uso terapéutico , Especies Reactivas de Oxígeno/fisiologíaRESUMEN
It has been found that 'conditioning' noise exposures can render the inner ear more resistant to traumatic noise exposures. To explore the possible mechanisms underlying this phenomenon, filamentous actin (F-actin), labeled by rhodamine-phalloidin, was examined in the chinchilla cochlea using confocal fluorescence microscopy. The conditioning noise was 0.5 kHz octave band noise (OBN) at 90 dB SPL for 6 h/day and the high-level noise was the same noise but at 105 dB SPL for 4 h. A variety of pathological changes were found in the chinchilla cochlea after exposure to noise. Subjects exposed to conditioning noise (1 day or 10 days) and only high-level noise showed an increase in F-actin labeling than unexposed controls. By contrast, subjects who had 5 days quiet after the 10-day conditioning exposure exhibited a decrease in F-actin labeling. Interestingly, subjects exposed to high-level noise with prior 10-day conditioning exposure also showed a decrease in F-actin labeling in the cuticular plate and the stereocilia. The F-actin decreases in the stereocilia and the cuticular plates may decrease the mechanical rigidity of the organ of Corti. A more pliable organ of Corti may have reduced the possibility of fracture or ripping of cell junctions during the motion of the basilar membrane induced by acoustic overstimulation.
Asunto(s)
Actinas/metabolismo , Células Ciliadas Auditivas Externas/metabolismo , Núcleo Vestibular Lateral/metabolismo , Estimulación Acústica , Animales , Membrana Basilar/fisiología , Chinchilla , Cóclea/metabolismo , Uniones Comunicantes/fisiología , Células Ciliadas Auditivas Externas/fisiología , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Microscopía Confocal , Microscopía Fluorescente , Emisiones Otoacústicas Espontáneas , Faloidina/química , Faloidina/metabolismo , Rodaminas/química , Rodaminas/metabolismoRESUMEN
The alteration endocochlear potential (EP) in response to total cochlear ischemia induced by various experimental manipulations has been studied. However, the effect of restricted areal damage to the microvessels (restricted to small area in the lateral wall of a cochlear turn) on the EP value is still unknown. In the current investigation we adopted a photochemical method to produce a focal (i.e., restricted area) microvessel injury in the lateral wall of the guinea pig cochlea and examined the effect of these insults on EP recorded in the same region. The small area of the microvessel lesion (small fenestra: approximately 0.2 x 0.4 mm2) induced by photoactivation did not yield significant EP changes, suggesting that damage to such a small area of microcirculation in the lateral wall of the cochlea has no statistically significant effects on EP values. In subjects with a large area of the microvessel lesion (large fenestra: approximately 0.2 x 0.8 mm2), a decrease in the EP value (mean +/- SEM 7.9 +/- 0.8 mV) was noted. However, the control group animals with a large fenestra but without microvessel lesion also displayed a decrease (8.6 +/- 0.8 mV) in EP. In the current study we were unable to differentiate whether the EP changes in animals with the large fenestra microvessel lesions were caused by the cochlear blood flow decrease or by the surgical preparation. However, the results of this study indicated if the EP value was affected by the large area of the microvessel lesion, the level of decrease would not be large. That is, the EP decrease was less than the EP change in the control group (mean: 8.6 mV). Considering the dependence of EP on blood flow, the data of this study suggest that compensatory mechanisms in the cochlea may maintain the EP following a focal lesion in the lateral wall of the cochlea. This study also indicates that the photochemical method provides a reliable approach to produce the animal model with the focal microvessel lesion in the lateral wall of the cochlea.
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Cóclea/irrigación sanguínea , Potenciales Microfónicos de la Cóclea/fisiología , Isquemia/fisiopatología , Animales , Cóclea/lesiones , Cóclea/fisiopatología , Modelos Animales de Enfermedad , Cobayas , Microcirculación/patología , Microcirculación/fisiopatología , FotoquímicaRESUMEN
The present study was conducted to examine the re-establishment of IHC/VIII nerve synapses following kainic acid (KA) excitotoxicity and to discern if the re-organized afferent could render not only a normal auditory threshold but also a normal supra-threshold function. KA (60 mM) applied to the intact round window membrane in chinchilla destroyed postsynaptic endings of the auditory nerve, depressed the input-output (I/O) functions of auditory evoked potentials (EVP) and produced an average loss of sensitivity of over 80 dB at 4, 8, and 16 kHz, with less substantial losses (40-60 dB) at lower frequencies. However, there was no significant difference in 2f1-f2 distortion-product otoacoustic emissions (DPOAE) before and after the application of KA. The nerve endings went through a sequence of swelling, degeneration and recovery over a 3-5 day period at higher frequency. Auditory sensitivity and supra-threshold response returned accordingly. In contrast, complete recovery at lower frequencies (1 and 2 kHz) required more than 5 days. The results provide strong evidence that (1) excitotoxically damaged cochlear afferent neurons can recover and render both a normal EVP threshold and EVP I/O function and (2) afferent innervation to IHCs is not necessary for DPOAE generation.
Asunto(s)
Agonistas de Aminoácidos Excitadores/toxicidad , Ácido Kaínico/toxicidad , Neuronas Aferentes/efectos de los fármacos , Sinapsis/efectos de los fármacos , Nervio Vestibulococlear/efectos de los fármacos , Animales , Umbral Auditivo/efectos de los fármacos , Umbral Auditivo/fisiología , Chinchilla , Cóclea/efectos de los fármacos , Cóclea/inervación , Cóclea/fisiopatología , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Agonistas de Aminoácidos Excitadores/administración & dosificación , Femenino , Células Ciliadas Auditivas Internas/citología , Células Ciliadas Auditivas Internas/efectos de los fármacos , Células Ciliadas Auditivas Internas/patología , Pérdida Auditiva Sensorineural/inducido químicamente , Pérdida Auditiva Sensorineural/fisiopatología , Ácido Kaínico/administración & dosificación , Masculino , Microscopía Confocal , Neuronas Aferentes/citología , Emisiones Otoacústicas Espontáneas/efectos de los fármacos , Ventana Redonda/efectos de los fármacos , Nervio Vestibulococlear/citologíaRESUMEN
Previous work has shown that the cochlear efferent system may play a role in protecting the ear from noise-induced temporary threshold shifts (TTS) following exposures to a single tone or series of moderate-level noises ('toughening'). However, whether the olivocochlear bundle (OCB) is important in decreasing noise-induced permanent threshold shifts (PTS) remains an open question. The importance of the OCB in decreasing the ear's susceptibility to noise, as reflected by 2f1-f2 distortion product otoacoustic emissions, was assessed by sectioning both the ipsilateral and contralateral divisions of the efferent system and exposing chinchillas while awake to an octave band noise (4 kHz) at a low level (85 dB SPL) for 10 days (6 h/day) and then at a high level (95 dB SPL) for 48 h. Complete de-efferentation was verified by cochlear acetylcholinesterase staining. The ears that were de-efferent showed substantially more TTS, greater PTS and larger cochlear lesions of outer hair cells. The results suggest that the efferent system may influence the ear's ability to develop resistance to noise trauma.
Asunto(s)
Umbral Auditivo/fisiología , Cóclea/inervación , Pérdida Auditiva Provocada por Ruido/patología , Neuronas Eferentes/patología , Emisiones Otoacústicas Espontáneas , Animales , Chinchilla , Cóclea/citología , Cóclea/patología , Femenino , Células Ciliadas Auditivas Externas/citología , Células Ciliadas Auditivas Externas/patología , Pérdida Auditiva Provocada por Ruido/fisiopatología , Masculino , Microscopía Confocal , Neuronas Eferentes/citología , Neuronas Eferentes/fisiologíaRESUMEN
The aim of this experiment was to determine if buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, enhances the ototoxicity of carboplatin. Osmotic pumps were used to infuse BSO into the right cochleas of 12 adult chinchillas for 14 days. The left cochleas served as controls. Animals were assigned to three groups: a drug control group that did not receive carboplatin, a group that received a single dose of carboplatin (25 mg/kg i.p.), and a group that received a double dose of carboplatin (25 mg/kg i.p. x 2), with 4 days between injections. Carboplatin was administered after three days of BSO pre-treatment. Ototoxicity was assessed with evoked potentials recorded from electrodes implanted in the inferior colliculi (ICPs), distortion product otoacoustic emissions (DPOAEs), and cochleograms. BSO infusion itself caused no long-term functional or morphological changes. One of four animals treated with it single dose of carboplatin showed a significant loss of inner hair cells (IHCs), with greater loss in the BSO-treated ear. All animals in the double-dose carboplatin group showed marked differences between BSO-treated and control ears. Average IHC losses were 59% in BSO-treated ears vs. 18% in control ears. Moreover, BSO-treated ears sustained significantly greater outer hair cell (OHC) losses than control ears (37% vs. 2%, respectively). ICP and DPOAE response amplitudes were reduced slightly in BSO-treated ears relative to control ears, consistent with their greater hair cell loss. The results clearly show that BSO can enhance carboplatin ototoxicity in the chinchilla, supporting a role of GSH and reactive oxygen species in platinum ototoxicity.
Asunto(s)
Antineoplásicos/envenenamiento , Butionina Sulfoximina/farmacología , Carboplatino/envenenamiento , Cóclea/efectos de los fármacos , Animales , Butionina Sulfoximina/administración & dosificación , Supervivencia Celular/efectos de los fármacos , Chinchilla , Sinergismo Farmacológico , Potenciales Evocados/efectos de los fármacos , Células Ciliadas Auditivas Internas/efectos de los fármacos , Células Ciliadas Auditivas Internas/patología , Colículos Inferiores/fisiopatología , Bombas de Infusión , Emisiones Otoacústicas Espontáneas/efectos de los fármacos , Valores de ReferenciaRESUMEN
Reactive oxygen species, which are cytotoxic to living tissues, are thought to be partly responsible for noise-induced hearing loss. In this study R-phenylisopropyladenosine (R-PIA), a stable non-hydrolyzable adenosine analogue which has been found effective in upregulating antioxidant enzyme activity levels, was topologically applied to the round window of the right ears of chinchillas. Physiological saline was applied to the round window of the left ears (control). The animals were then exposed to a 4 kHz octave band noise at 105 dB SPL for 4 h. Inferior colliculus evoked potential thresholds and distortion product otoacoustic emissions (DPOAE) were measured and hair cell damage was documented. The mean threshold shifts immediately after the noise exposure were 70-90 dB at frequencies between 2 and 16 kHz. There were no significant differences in threshold shifts at this point between the R-PIA-treated and control ears. By 4 days after noise exposure, however, the R-PIA-treated ears showed 20-30 dB more recovery than saline-treated ears at frequencies between 4 and 16 kHz. More importantly, threshold measurements made 20 days after noise exposure showed 10-15 dB less permanent threshold shifts in R-PIA-treated ears. The amplitudes of DPOAE also recovered to a greater extent and outer hair cell losses were less severe in the R-PIA-treated ears. The results suggest that administration of R-PIA facilitates the recovery process of the outer hair cell after noise exposure.
Asunto(s)
Adenosina/análogos & derivados , Pérdida Auditiva Provocada por Ruido/prevención & control , Adenosina/farmacología , Animales , Umbral Auditivo/efectos de los fármacos , Chinchilla , Cóclea/efectos de los fármacos , Cóclea/patología , Cóclea/fisiopatología , Potenciales Evocados Auditivos/efectos de los fármacos , Células Ciliadas Auditivas Internas/efectos de los fármacos , Células Ciliadas Auditivas Internas/patología , Células Ciliadas Auditivas Externas/efectos de los fármacos , Células Ciliadas Auditivas Externas/patología , Pérdida Auditiva Provocada por Ruido/etiología , Pérdida Auditiva Provocada por Ruido/metabolismo , Ruido/efectos adversos , Emisiones Otoacústicas Espontáneas/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Factores de TiempoRESUMEN
The role of the olivocochlear bundle (OCB) in modulating noise-induced permanent injury to the auditory periphery was studied by completely sectioning the OCB fibers in chinchillas and exposing the animals while awake to a broad-band noise at 105 dB SPL for 6 h. Outer hair cell (OHC) function was assessed by measuring 2f1-f2 distortion product otoacoustic emissions (DPOAE) at frequencies from 1.2 to 9.6 kHz and cochlear microphonics (CM) at frequencies from 1 to 8 kHz. As a result of de-efferentation, the CM was decreased but the DPOAEs were unchanged in de-efferented ears as compared with efferented control and sham-operated ears. Following noise exposure, the ears that were de-efferented showed significantly more depression of DPOAE input/output functions and greater decrement of CM amplitude. The differences between de-efferented and efferent-innervated ears were evident across all the frequencies. The cochlear lesions of the OHCs reflected by traditional cytocochleograms, however, were minimal in both efferented and de-efferented ears. The results indicate that cochlear de-efferentation decreases the CM in chinchilla and increases the ear's susceptibility to noise-induced permanent hearing damage. More importantly, de-efferentation increases susceptibility at low frequencies as well as high frequencies.
Asunto(s)
Cóclea/inervación , Cóclea/fisiopatología , Pérdida Auditiva Provocada por Ruido/etiología , Animales , Vías Auditivas/lesiones , Vías Auditivas/fisiopatología , Chinchilla , Enfermedad Crónica , Cóclea/lesiones , Potenciales Microfónicos de la Cóclea , Desnervación , Vías Eferentes/lesiones , Vías Eferentes/fisiopatología , Células Ciliadas Auditivas Externas/lesiones , Células Ciliadas Auditivas Externas/fisiopatología , Pérdida Auditiva Provocada por Ruido/patología , Pérdida Auditiva Provocada por Ruido/fisiopatologíaRESUMEN
Cells can die by two distinct pathways: apoptosis and necrosis. To explore whether intense noise can induce hair cell (HC) death via the apoptotic pathway, we systematically examined morphological changes in guinea pig cochlear HC nuclei stained with Hoechst 33342, a fluorescent dye specifically labelling the nuclear DNA. A narrow band noise centred at 4 kHz with levels at 110 dB, 115 dB or 120 dB (SPL) was applied for 4 h and the exposed cochleae were collected at various intervals (3 h, 3 or 14 days) after the noise exposure. Auditory function was monitored by measuring thresholds of auditory brain stem responses. In the noise-damaged cochleae, there were two major types of nuclear changes, nuclear condensation appeared as karyorrhexis or karyopyknosis and nuclear swelling. Karyorrhexis and karyopyknosis predominately appeared in the severely damaged cochlear region in the animals exposed to 120 dB noise and examined 3 h after the noise exposure. In contrast, swelling of nuclei occurred in all of the noise-exposed cochleae, and was the feature change in the animals exposed to 110 and 115 dB noise. This pathological change persisted at least for 14 days after the noise exposure. The typical changes of karyorrhexis and karyopyknosis noted in the animals exposed to 120 dB noise were morphologically similar to those nuclear changes described in previous studies for apoptosis, suggesting that the apoptotic process may be involved in intense noise-induced HC death.
Asunto(s)
Apoptosis/fisiología , Cóclea/patología , Células Ciliadas Auditivas/patología , Ruido/efectos adversos , Animales , Umbral Auditivo/fisiología , Modelos Animales de Enfermedad , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Cobayas , Pérdida Auditiva Provocada por Ruido/diagnóstico , Pérdida Auditiva Provocada por Ruido/etiología , Distribución Aleatoria , Índice de Severidad de la EnfermedadRESUMEN
The role of glutathione in carboplatin ototoxicity was investigated in the chinchilla. Chinchillas hearing was tested with both distortion product otoacoustic emissions (DPOAE) and evoked potentials recorded from a chronic electrode in the inferior colliculus (IC). All subjects had an osmotic pump fitted to their right ear and it received buthionine sulfoximine (BSO) at a dose of 15 mM delivered at 5 ml per hour for 14 days. A group (N=4) was given a double dose of carboplatin (25 mg/kg i.p. for 2 days). The pump was implanted three days before the carboplatin dose. The BSO treated ears showed a greater loss in both evoked potential and DPOAE measures, as well as substantially fewer missing hair cells. The results implicate reactive oxygen species (ROS) as a common factor in ototoxic reactions because suppression of glutathione antioxidant leads to greater ototoxic reactions.
RESUMEN
From the root of Scutellaria amoena C.H. Wright, two new flavonoids (I, II) and six known flavonoids (III-VIII) were isolated. On the basis of spectroscopic analysis (UV, 1HNMR, 13CNMR, MS and CD) and chemical evidences, the structures of I and II were elucidated as (2S)-2',5,6'-trihydroxy-7-methoxyflavanone-2'-O-beta-D-glucopyrano side (I) and (2R, 3R)-2',3,5,7-tetrahydroxyflavanone (II) respectively. The other six known compounds were identified as (2S)-5,7,8-trihydroxyflavanone (III), (2S)-2',5,6',7-tetrahydroxyflavanone (IV), (2R, 3R)-2',3,5,6',7-pentahydroxyflavanone (V), 2',5,6',7-tetrahydroxyflavone (VI) norwogonin (VII) and oroxylin-A (VIII) respectively. Compounds III-VIII were obtained from this plant for the first time.
Asunto(s)
Medicamentos Herbarios Chinos/análisis , Flavanonas , Flavonoides/aislamiento & purificación , Fenómenos Químicos , QuímicaRESUMEN
A new flavonol glycoside, C27H28O10, mp 151-152 degrees C (MeOH), named acuminatin (I), was isolated from the aerial part of Epimedium acuminatum Franch in addition to four known compounds. By means of UV, FAB-MS, EI-MS, 1HNMR, 13CNMR and chemical evidences, the structure of acuminatin was established as 6", 6"-dimethylpyrano (2", 3": 7, 8) 4'-methyl kaempferol-3-O-alpha-L-rhamnopyranoside. The known compounds were identified as kaempferol-3-O-alpha-L-rhamnopyranoside (II), quercitrin (III), hyperin (IV) and daucosterol (V).
Asunto(s)
Medicamentos Herbarios Chinos/química , Flavonoides/aislamiento & purificación , Glicósidos/aislamiento & purificación , Flavonoides/química , Glicósidos/química , Estructura Molecular , Quercetina/análogos & derivados , Quercetina/química , Quercetina/aislamiento & purificaciónRESUMEN
In containing our studies on the flavonoids from Scutellaria amoena C.H. Wright, a new flavanone (I) and six known compounds (II-VII) were isolated from the roots of this plant. On the basis of spectroscopic analysis (UV, 1H NMR, 13C NMR, MS and CD) and chemical evidence, the structure of the new compound was elucidated as (2S) -2',5,6'-trihydroxy-7-methoxyflavanone (I) and named scuteamoenin, the other six known compounds were identified as (2R,3R) -3,5,7-trihydroxyflavanone (II), 2',3,5,6,7-pentahydroxyflavone (III), 2',5,7-trihydroxy-6-methoxyflavone (IV), skullcaflavone II (V), chrysin (VI) and beta-sitosterol (VII) respectively. Compounds II-VII were obtained from this plant for the first time.
Asunto(s)
Medicamentos Herbarios Chinos/química , Flavanonas , Flavonoides/aislamiento & purificación , Flavonoides/químicaRESUMEN
A diterpenoid-lactone, white thin crystals, C20H24O3, m/z: 312 (M+), mp 222-223 degrees C, UV lambda max (EtOH) 217 (log epsilon 4.36) nm, has been isolated from the ethyl acetate extract of the roots of Tripterygium wilfordii Hook. f., in a yield of 0.025%. Its structure was elucidated by spectral analysis (UV, IR, MS, 1HNMR and 13CNMR) and X-ray SCD. It is the known triptophenolide with revision of structure. Triptophenlolide was shown to have obvious inhibiting effects on lymphocyte and IgG (P less than 0.01) when mice and rats were given ig 1.5 mg/kg. The total complements in blood serum was increased. When BALB/C mice were given ig 1.5 mg/kg, the ear oedema induced by dimethyl benzene was significantly inhibited (P less than 0.01); The ear oedema induced by croton oil in SD rats at a dose of ig 1.0 mg/kg was also significantly inhibited (P less than 0.05). The vitamin C content of the adrenal gland was reduced in mice at a dose of 1.5 mg/kg. The ig LD50 of triptophenolide was greater than 30 mg/kg.
Asunto(s)
Diterpenos/síntesis química , Medicamentos Herbarios Chinos/química , Animales , Diterpenos/aislamiento & purificación , Diterpenos/farmacología , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Ratas , Ratas Endogámicas , TripterygiumRESUMEN
A new isoflavone, named eurycarpin A and a new natural product isoflavone named eurycarpin B have been isolated from the roots of Glycyrrhiza eurycarpa P. C. Li. Their structures were determined to be 7,2',4'-trihydroxy-3'-(3,3-dimethylallyl) isoflavone(I) and 7,2'-dihydroxy-6",6"-dimethylpyrano-(2",3":4',3') isoflavone(II) on the basis of spectroscopic analysis (UV, EI-MS, 1HNMR, 13CNMR, NOE difference and HMBC). In addition, three known isoflavones, licoisoflavone A, calycosin and formononetin, were obtained for the first time from this plant.