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Abstract Objective: The present study aimed to perform a morphological and morphometric analysis of cochlear structures of C57BL/6J mice receiving oral melatonin for a 12-month period. Methods: 32 male C57BL/6J were divided into control and melatonin groups. Control received saline and ethanol solution and melatonin group, 50 μL of 10 mg of melatonin/kg/day orally for a 12-month period. After de experiment the animals were sacrificed into a 40% concentration of CO2 chamber, and the blades were morphological and morphometrically analyzed. Results: The melatonin group revealed a higher median density of viable cells (45 ± 10.28 cells/100 μm2, 31-73, vs. 32 ± 7.47 cells/100 μm2, 25-48). The median area of stria vascularis was 55.0 ± 12.27 cells/100 μm2 (38-80) in the control, and 59.0 ± 16.13 cells/100 μm2 (40-134) in the melatonin group. The morphometric analysis of the spiral ligament reveals a higher median of total viable neurons in the melatonin (41 ± 7.47 cells/100 μm2, 27-60) than in the control group (31 ± 5.68 cells/100 μm2, 21-44). Conclusion: Although melatonin is a potent antioxidant, it does not completely neutralize the occurrence of presbycusis; however, it may delay the onset of this condition. Level of evidence: 3.
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Background: Presbycusis is a slow, progressive, age-related sensorineural hearing loss, which is insidious, slow, progressive and irreversible disease and usually affects high pitch sound. It can be associated with various factors. Obesity is such a modifiable factor and its independent role with age-related hearing loss needs to be explored.Methods: This is a prospective study carried out over a period of three years in department of otorhinolaryngology at study institute. It included 1000 cases with symmetrical sensorineural hearing loss.Results: Among obese cases, high frequency hearing loss was found in significantly large number of cases. The most common audiogram in both male and female was Abrupt high tone loss type, irrespective of presence or absence of obesity.Conclusions: Obesity is a modifiable factor which has a significant association with high frequency hearing loss among the elderly population.
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Introducción: El envejecimiento en Cuba constituye el principal problema demográfico y la Hipoacusia es una de las condiciones crónicas más frecuentes en los adultos mayores. Objetivo: Describir las características clínico-epidemiológicas de los pacientes de la tercera edad con Hipoacusia atendidos en el Hospital Universitario General Calixto García en el período de septiembre de 2015 hasta septiembre de 2016. Material y Método: Se realizó un estudio descriptivo, transversal en el Hospital Universitario General Calixto García durante el período de septiembre de 2015 hasta septiembre de 2016. La población (N) estuvo constituida por 387 pacientes de la tercera edad, quienes asistieron a consulta en el período estudiado. Resultados: Predominó la Hipoacusia en los pacientes con edades entre 65 y 79 años (67,2 por ciento) y el sexo masculino fue el más afectado con esta discapacidad (69,5 por ciento). La Hipoacusia en el anciano se asoció con frecuencia a otras afecciones crónicas como las enfermedades cardiovasculares. La Presbiacusia o Hipoacusia asociada a la edad fue la causa más frecuente de sordera. Conclusiones: La Hipoacusia resultó ser una discapacidad frecuente en los pacientes masculinos de la tercera edad. La misma estuvo asociada a enfermedades crónicas no trasmisibles. Las perdidas auditivas neurosensoriales y mixtas, de moderada y severa intensidad, fueron las más frecuentemente encontradas en la audiometría tonal(AU)
Introduction: Aging constitutes the main demographic problem in Cuba, and hearing loss is one of the most frequent chronic conditions in older adults. Objective: To describe the clinical and epidemiological characteristics of elderly patients with hearing loss, treated in Calixto Gracía University Hospital during the period from September 2015 to September 2016. Material and Method: A descriptive cross-sectional study was conducted in Calixto Garcia University Hospital during the period from September 2015 to September 2016. The population (N) was composed of 387 elderly patients, who went to the doctor´s office during the period under study. Results: Hearing loss predominated in patients aged from 65 to 79 years (67,2 percent), and the male sex was the most affected by this disability (69,5 percent). Hearing loss in the elderly was frequently associated with other chronic conditions such as cardiovascular diseases. Age-related hearing loss (Presbycusis) or hearing loss associated with age was the most frequent cause of deafness. Conclusions: Hearing loss was a frequent disability in male elderly patients. It was associated with non-communicable chronic diseases. Sensorineural and mixed hearing losses of moderate and severe intensity were the most frequent ones found in the tonal audiometry(AU)
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Humans , Aged , Aged, 80 and over , Presbycusis/epidemiology , Hearing Loss, Mixed Conductive-Sensorineural/complications , Hearing Loss, Mixed Conductive-Sensorineural/etiology , Hearing Loss, Mixed Conductive-Sensorineural/epidemiology , Hearing Loss/epidemiology , Health of the Elderly , Epidemiology, Descriptive , Cross-Sectional Studies , Early Diagnosis , Hearing Loss, Mixed Conductive-Sensorineural/rehabilitationABSTRACT
Objective This study was designed to investigate the expression and potential role of the protein phosphatase 1 (PP1) impairment in D -galactose-induced inner ear aging mouse model .Methods Forty Kunming mice were randomly divided into two groups :the control group and D -galactose group ,20 mice for each .The D-galactose group mice were treated with a daily subcutaneous injection of the D -galactose solutions (800 mg · kg -1 · d-1 ) or an equal volume of normal saline(for the control group) in the nape back for 8 weeks .Eight weeks after D-galactose administration ,the effects of were measured by total Superoxide Dismutase (SOD) activity and Malon-dialdehyde (MDA) level in plasma .Immunofluoresence was performed to detect the location of the PP1 expression in the cochlea .Real-time PCR was performed to detect the level of PP1 mRNA in cochlea .A Western blot analysis was performed to analyze the protein levels of protein phosphates 1 nuclear targeting subunit (PNUTS) ,PP1 and caspase-3 in the inner ear .Results The MDA level was more significantly increased in the D -galactose group than in the control group ;however ,the total SOD activity was significantly decreased in the plasma of D -galactose- induced aging mice(P<0 .01) .The results showed that PP1 was predominantly localized in the nucleus and cyto-plasm of the hair cell ,spiral ganglion cell and stria vascularis cell .And the protein levels of PP1 and caspase-3 sig-nificantly increased ,and the level of PNUTS was decreased in the cochlea of the D -galactose group when compared to the control group .Conclusion PP1 contributes to the development of D -galactose-induced aging mice .
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Objective To investigate the expression of transmembrane protein 16A (TMEM16A)in the cochlea of guinea pigs and its relationship with the age-related hearing loss.Methods We used auditory brainstem response (ABR)to explore the changes of hearing in guinea pigs of different age (groups of 2 w,3 m,1 y,and D-galactose).The distribution and expression of TMEM16A in the cochlea were detected by immunofluorescence and Western blot.Results ABR threshold was gradually increased,with significant difference between D-gal and the other three groups (P <0.01).TMEM16A was expressed in the cochlear striae vascularis at different ages,and the expression increased with age before 1 y (P <0.05). However, its level was increased in D-gal group and significantly differed from that in 3 m and 1 y groups (P < 0.05 ).Conclusion The change in TMEM16A expression in the cochlear striae vascularis of guinea pigs may be related to age-related hearing loss.
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Objective To investigate the expression of transmembrane protein 16A (TMEM16A)in the cochlea of guinea pigs and its relationship with the age-related hearing loss.Methods We used auditory brainstem response (ABR)to explore the changes of hearing in guinea pigs of different age (groups of 2 w,3 m,1 y,and D-galactose).The distribution and expression of TMEM16A in the cochlea were detected by immunofluorescence and Western blot.Results ABR threshold was gradually increased,with significant difference between D-gal and the other three groups (P <0.01).TMEM16A was expressed in the cochlear striae vascularis at different ages,and the expression increased with age before 1 y (P <0.05). However, its level was increased in D-gal group and significantly differed from that in 3 m and 1 y groups (P < 0.05 ).Conclusion The change in TMEM16A expression in the cochlear striae vascularis of guinea pigs may be related to age-related hearing loss.
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Objective To investigate the expression of adaptin-2(AP-2) in different stages of mouse coch‐lea and its probable role in the auditory generation and formation .Methods Mice were divided into 4 experimental groups by age (7 days old ,15 days old ,35 days old ,16 months old) ,which respectively represented the newborn mice ,developmental mice ,mature mice and old mice .Auditory brainstem response (ABR) ,laser scanning confocal microscopy (LSCM) ,immune-fluroscence histochemistry and qRT - PCR were used in this study .Results For the 15 days old ,35 days old ,16 months old groups ,ABR average threshold was 18 .67 ± 1 .21 dB nHL ,13 .83 ± 1 .47 dB nHL ,37 .83 ± 7 .68 dB nHL ,respectively ,for the 7 days old groups no responses were observed .The AP-2 im‐munoreactivity was found in all the stages of mice cochlea inner hair cell (IHC) cytoplasm ,especially in IHC basal part ,nearby the ribbon synapse .For the 7 days old ,15 days old ,35 days old ,16 months old groups ,immune-flu‐roscence histochemistry IMV(intensity mean value)were 190 .91 ± 17 .27 ,494 .06 ± 27 .63 ,838 .41 ± 38 .23 ,682 .65 ± 72 .22 ,respectively .For the 7 days old ,15 days old ,35 days old ,16 months old groups ,mRNA RQ(relative quantity)were 0 .53 ± 0 .09 ,1 .03 ± 0 .02 ,1 .00 ± 0 .09 ,1 .03 ± 0 .06 ,respectively .Developmental mice expressed significantly higher than those of the newborn in the AP -2 protein expression level which was measured by immuno -fluores‐cence histochemistry and qRT PCR(P 0 .05) ,but mature mice had significant advantages by immuno-fluorescence histochemistry .Conclusion AP-2 protein expression level may closely related to the au‐ditory formation and maintenance because its expression gradually increases with age in mice .
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Objective This study aimed to define research status of age -related hearing loss ,and provide the basis and direction for future research .Methods We have retrieved all relevant literatures on age -related hearing loss from Pubmed ,and conduct an objective analysis of the existing literatures by Bibliometric analytics and co -word analysis method using co -occurrence bibliographic information mining system and SPSS22 .0 software for data analysis .Results There were a large number of articles and journals about presbycusis and age -related hearing loss .Many countries were involved in the research .Literatures and core authors were mainly from developed coun‐tries such as Europe and the United States .The quantity and quality of Chinese literatures were in a leading position in Asia .The researches focused on the common characteristics of patients ,the epidemiology ,characteristics of hear‐ing ,treatment and laboratory studies .There were some new research directions in recent 5 years ,such as factors as‐sociated with the younger ages before developing presbycusis ,standard design and use of questionnaires ,prevention and control .Conclusion Age-related hearing loss will continue to be a hot topic with growing focus on micro and macro development of multi -disciplinary cooperation .The penetration will be the trend for the future research while the prevention will become a new focus of research .
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Age-related hearing loss (presbycusis) is characterized by an increased hearing threshold and poor speech understanding in a noisy environment, slowed central processing of acoustic information, and impaired localization of sound sources. Presbycusis seriously affects the older people's quality of life. Particularly, hearing loss in the elderly contributes to social isolation, depression, and loss of self-esteem. Current amplification methods related to auditory rehabilitation can provide improved communication ability to users. But, simple auditory rehabilitation is ineffective in managing the central auditory processing disorder and the psychosocial problem of presbycusis. The evaluation of central auditory processing disorder and psychosocial disorder in presbycusis should not be overlooked while providing auditory rehabilitation.
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Aged , Humans , Acoustics , Cochlea , Communication , Depression , Ear, Inner , Hearing , Hearing Loss , Language Development Disorders , Presbycusis , Quality of Life , Social IsolationABSTRACT
BACKGROUND: Age-related hearing loss is a common degenerative disorder among older individuals that warrants attention in a society with an aging population. The objectives of this study were to investigate age-related hearing loss and to estimate the prevalence of age-related hearing loss in Korea using a healthcare center-based study. METHODS: Persons older than 50 years of age visiting a selected health promotion center were recruited (n=10,118). Pure tone audiometry was performed on the subjects, and the average hearing thresholds were obtained using 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz for the six-dimension method. RESULTS: The prevalences of age-related hearing loss for subjects older than 65 years were 36.8% at a cutoff of > or =26 dBHL and 10.1% at a cutoff of > or =41 dBHL. When age and gender were corrected for, the estimated prevalences of age related hearing loss for those subjects greater than 65 years in the general population were 45.8% at a cutoff value of > or =26 dBHL and 14.8% at a cutoff value of > or =41 dBHL. CONCLUSION: Our study provides important information concerning age-related hearing loss in Korea. The estimated prevalence of age-related hearing loss in the general population in Korea was high.
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Humans , Aging , Audiometry , Delivery of Health Care , Health Promotion , Hearing , Hearing Loss , Korea , PrevalenceABSTRACT
Objective To establish the mice model of AHL, to investigate the relationship between AHL and the cytoactive factors of the cochlear hair cells in C57BL/6J mice, and to classify the presbycusis models of the C57BL/6J mice. Methods C57BL/6J mice were divided into 6 experimental groups by age (A: 3 months old(m), B: 8 m, C: 9 m, D: 10 m, F: 17 m, G: 18 m) . The auditory functions mice were measured by auditory brainstem response (ABR) with the stimulus click and toneburst at 6 kHz and 8 kHz. 3 months later, Groups C , G, E and H were tested again for ABR. After ABR testing, the cytoactive of the hair cells was detected by succinate dehydrogenase staining and surface preparation technique(two mice from each group except groups C and G). Results The ABR thresholds elevated with age, and the marked change of the cochlea was the degeneration of the cytoactive of the cochlear hair cells, especially those of the outer hair cells. In the beginning, the basement of the basal membrane suffered from the mitochondrion degeneration in the outer hair cells, then it spread to the top region. Subsequently, the inner hair cells were involved. Conclusion C57BL/6J mouse was a typical animal model for the AHL,and the main change of the cochlea was the degeneration of the hair cells, especially the outer hair cells. Thus, C57BL/6J mice can be used as a suitable animal model for the study of presbycusis.
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Objective To explore the changes of superoxide dismutase(SOD),malondialdehyde(MDA) and apoptosis in the auditory cortex,the cochlear nuclei and the cochlea of the rats with age-related hearing loss,and to understand the relationship between oxidative damage and apoptosis with presbyacusis.Methods Three-month-old rats(ABR 20?5 dB SPL) and eighteen-month-old rats(ABR 55?10 dB SPL) were used in the study.T-SOD activity was measured by xanthine oxidase(XO) method.The MDA level was examined by the thibabituric acid(TBA) method.Apoptosis was examined by Annexin V-FITC/PI staining with flow cytometry(FCM).Results The SOD activities decreased and the MDA levels increased significantly in the auditory cortex,the cochlear nuclei and the cochlea of the eighteen-month-old rats(P
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Objective To assess the dynamic age-related hearing loss of inbred mouse C57 and BALB/c strains via distortion product otoacoustic emissions(DPOAE). Methods DPOAE levels were evaluated in C57 and BALB/c of 20,30,60,90,120,150,180 days old respectively,with the conditions that two pure tones,which stimulated the DPOAE,were at frequencies(f 1,f 2,f 1/f 2=1.22)and levels(L 1=70 dB SPL,L 2=65 dB SPL).Results DPOAE levels of C57 and BALB/c gradually decreased with age.From 60 days old,DPOAE levels of the two strains were dramatically decreased at 4.0,6.0,8.0 kHz( P