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Outer hair cell functioning in infants with iron deficiency anemia

Sundagumaran H, Seethapathy J

Int J Pediatr Otorhinolaryngol, 2020 Nov;138:110393.

PMID: 33152983 DOI: 10.1016/j.ijporl.2020.110393

BACKGROUND: Distortion product otoacoustic emissions (DPOAE) in infants with Iron Deficiency Anemia (IDA) helps in understanding the cochlear status especially the functioning of outer hair cells.

OBJECTIVES: To analyze the presence of DPOAE across frequencies and DP amplitude in infants with and without IDA.

METHOD: DPOAE were recorded on 40 infants with IDA and 40 infants without IDA in the age range of 6-24 months. Cubic DPOAEs (2f1-f2) were measured at six f2 frequencies (1500 Hz, 2000 Hz, 3000 Hz, 4500 Hz, 6000 Hz & 8000 Hz) with primary tone stimulus of intensity L1 equal to 65 dBSPL and L2 equal to 55 dBSPL. Immittance audiometry was performed using 226 Hz probe tone prior to DPOAE recording to ascertain normal middle ear functioning.

RESULTS: DPOAEs were present in all infants with and without IDA across frequencies tested. DP amplitude across the frequencies did not show any statistically significant difference (p hair cell functioning as there were no changes observed in the DPOAE amplitude levels between infants with IDA and infants without IDA. Iron status does not seem to have a direct effect on outer hair cell functioning in infants. However, fine structure DPOAEs can reveal even more precise changes (if any) that are caused due to iron deficiency.

Matched MeSH terms: Hair Cells, Auditory, Outer*

Fulltext Effect of Growth Factor Supplementation on the Hair Cell Specific Markers of Cells Harvested from Basilar Membrane

Ubaidah MA, Chua KH, Ami M, Zainal A, Saim A, Saim L, et al.

J Int Adv Otol, 2015 Apr;11(1):23-9.

PMID: 26223713 DOI: 10.5152/iao.2015.539

Loss of auditory hair cells is a major cause of deafness. The presence of auditory progenitor cells in the inner ear raises the hope for mammalian inner ear cell regeneration. In this study, we aimed to investigate the effect of growth factor supplementations, namely a combination of epidermal growth factor (EGF), insulin-like growth factor (IGF), and beta (β)-fibroblast growth factor (βFGF), on the expression of hair cell-specific markers by cells harvested from the cochlear membrane. This would provide an insight into the capability of these cells to differentiate into hair cells.

Matched MeSH terms: Hair Cells, Auditory/cytology; Hair Cells, Auditory/metabolism*

Fulltext Modeling and simulation of artificial hair cell sensor for underwater applications

M.N.M. Nawi, A.A. Manaf, M.R. Arshad

ASM Science Journal, 2013;7(2):144-151.

MyJurnal

This article uses finite volume and finite element methods for optimization of the artificial hair cell sensor. The performance of the sensor was investigated for different materials such as sicon and polysilicon and by varying hair cell dimensions including width and length. The silicon material which has low young modulus was proposed based on the simulation performance. The performance of the hair cell sensor was achieved by increasing the hair cell length while increasing the width did not significantly influence the performance. The
performance of the sensor was studied for its viscous force, deflection, von mises stress and sensitivity. From the simulation, the hair cell with a length of 1600 µm and 80 µm width was suggested for the subsequent analysis. Another way to improve the performance was by modifying the hair cell geometry and it was proved that the modified hair cell was more sensitive, based on the deflection. The angle of flow that hit the hair cell also affected the deflection of the sensor where the zero angle flow which was parallel to the substrate was the most effective angle. The limitations of the performance of hair cell for various fluid velocity were also discussed in this paper.

Matched MeSH terms: Hair Cells, Auditory

Derivation of cochlea hair cell for in vitro expansion and characterization

Ibnubaidah MA, Chua KH, Mazita A, Azida ZN, Aminuddin BS, Ruszymah BH, et al.

Med J Malaysia, 2008 Jul;63 Suppl A:115-6.

PMID: 19025012

A potential cure for hearing loss would be to regenerate hair cells by stimulating cells of the damaged inner ear sensory epithelia to proliferate and differentiate into hair cells. Here, we investigated the possibility to isolate, culture-expand and characterize the cells from the cochlea membrane of adult mice. Our results showed that the cultured cells isolated from mouse cochlea membrane were heterogenous in nature. Morphologically there were epithelial like cells, hair cell like, nerve cell like and fibroblastic cells observed in the culture. The cultured cells were immunopositive for specific hair cell markers including Myosin 7a, Calretinin and Espin.

Matched MeSH terms: Hair Cells, Auditory/cytology*

The development of a fast method for recording Schroeder-phase masking functions

Rahmat S, O'Beirne GA

Hear Res, 2015 Dec;330(Pt A):125-33.

PMID: 26209881 DOI: 10.1016/j.heares.2015.07.013

Schroeder-phase masking complexes have been used in many psychophysical experiments to examine the phase curvature of cochlear filtering at characteristic frequencies, and other aspects of cochlear nonlinearity. In a normal nonlinear cochlea, changing the "scalar factor" of the Schroeder-phase masker from -1 through 0 to +1 results in a marked difference in the measured masked thresholds, whereas this difference is reduced in ears with damaged outer hair cells. Despite the valuable information it may give, one disadvantage of the Schroeder-phase masking procedure is the length of the test - using the conventional three-alternative forced-choice technique to measure a masking function takes around 45 min for one combination of probe frequency and intensity. As an alternative, we have developed a fast method of recording these functions which uses a Békésy tracking procedure. Testing at 500 Hz in normal hearing participants, we demonstrate that our fast method: i) shows good agreement with the conventional method; ii) shows high test-retest reliability; and iii) shortens the testing time to 8 min.

Matched MeSH terms: Hair Cells, Auditory, Outer/physiology*

Fulltext Updated parameters and expanded simulation options for a model of the auditory periphery

Zilany MS, Bruce IC, Carney LH

J Acoust Soc Am, 2014 Jan;135(1):283-6.

PMID: 24437768 DOI: 10.1121/1.4837815

A phenomenological model of the auditory periphery in cats was previously developed by Zilany and colleagues [J. Acoust. Soc. Am. 126, 2390-2412 (2009)] to examine the detailed transformation of acoustic signals into the auditory-nerve representation. In this paper, a few issues arising from the responses of the previous version have been addressed. The parameters of the synapse model have been readjusted to better simulate reported physiological discharge rates at saturation for higher characteristic frequencies [Liberman, J. Acoust. Soc. Am. 63, 442-455 (1978)]. This modification also corrects the responses of higher-characteristic frequency (CF) model fibers to low-frequency tones that were erroneously much higher than the responses of low-CF model fibers in the previous version. In addition, an analytical method has been implemented to compute the mean discharge rate and variance from the model's synapse output that takes into account the effects of absolute refractoriness.

Matched MeSH terms: Hair Cells, Auditory, Inner/physiology*

Relation of distortion product otoacoustic emission with tinnitus

Ami M, Abdullah A, Awang MA, Liyab B, Saim L

Laryngoscope, 2008 Apr;118(4):712-7.

PMID: 18176342 DOI: 10.1097/MLG.0b013e318161e521

To investigate cochlear outer hair cell function based on distortion product otoacoustic emission (DPOAE) in patients with tinnitus.

Matched MeSH terms: Hair Cells, Auditory, Outer/physiology*

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