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Yun D, Shen Y, Lentz JJ. Verification of Estimated Output Signal-to-Noise Ratios From a Phase Inversion Technique Using a Simulated Hearing Aid. Am J Audiol 2023; 32:197-209. [PMID: 36706459 PMCID: PMC10166192 DOI: 10.1044/2022_aja-22-00023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/15/2022] [Accepted: 10/24/2022] [Indexed: 01/28/2023] Open
Abstract
PURPOSE The signal-to-noise ratio (SNR) for speech presented in background noise may vary after being processed by digital hearing aids with nonlinear signal processing algorithms, such as wide dynamic range compression (WDRC). A phase inversion technique has been previously developed to assess the output SNR of hearing aids. However, systematic validations of this technique have not been conducted. This study aims to validate the phase inversion technique. METHOD A simulated hearing aid with multichannel WDRC was implemented, from which the output SNRs, computed via shadow filtering, for connected speech in background noise were directly computed. The agreement between the shadow filter output SNRs and those estimated using the phase inversion technique for the same stimuli was utilized to validate the phase inversion technique. The background noise was 2- or 20-talker babble noise, and the speech stimuli were presented at SNRs of -10 to +10 dB at the input of the simulated hearing aid. The simulated hearing aid was configured to provide amplification for four representative audiograms, and the WDRC was set to be fast or slow acting. To investigate the effects of additive noise, independent of the presented noise stimulus, on the phase inversion estimated output SNR, the same simulated hearing aid was implemented with an additive Gaussian noise at its input (45 and 60 dB SPL). RESULTS Results showed that the phase inversion technique could either overestimate or underestimate output SNR, depending on the test condition; the estimation errors tended to coincide with temporal landmarks, such as natural pauses between consecutive sentences or fricatives; and increasing the simulated noise led to poorer estimates of output SNR. CONCLUSIONS Results imply that the accuracy of the phase inversion technique is dependent on the test conditions. Thus, the phase inversion technique should be used with caution, and its validity should be evaluated further.
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Affiliation(s)
- Donghyeon Yun
- Department of Speech, Language and Hearing Sciences, Indiana University Bloomington
| | - Yi Shen
- Department of Speech and Hearing Sciences, University of Washington, Seattle
| | - Jennifer J. Lentz
- Department of Speech, Language and Hearing Sciences, Indiana University Bloomington
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Robillard KN, de Vrieze E, van Wijk E, Lentz JJ. Altering gene expression using antisense oligonucleotide therapy for hearing loss. Hear Res 2022; 426:108523. [PMID: 35649738 DOI: 10.1016/j.heares.2022.108523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 04/20/2022] [Accepted: 05/14/2022] [Indexed: 12/12/2022]
Abstract
Hearing loss affects more than 430 million people, worldwide, and is the third most common chronic physical condition in the United States and Europe (GBD Hearing Loss Collaborators, 2021; NIOSH, 2021; WHO, 2021). The loss of hearing significantly impacts motor and cognitive development, communication, education, employment, and overall quality of life. The inner ear houses the sensory organs for both hearing and balance and provides an accessible target for therapeutic delivery. Antisense oligonucleotides (ASOs) use various mechanisms to manipulate gene expression and can be tailor-made to treat disorders with defined genetic targets. In this review, we discuss the preclinical advancements within the field of the highly promising ASO-based therapies for hereditary hearing loss disorders. Particular focus is on ASO mechanisms of action, preclinical studies on ASO treatments of hearing loss, timing of therapeutic intervention, and delivery routes to the inner ear.
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Affiliation(s)
| | - Erik de Vrieze
- Department of Otorhinolaryngology, RUMC, Geert Grooteplein 10, Route 855, GA, Nijmegen 6525, the Netherlands; Donders Institute for Brain, Cognition, and Behavior, RUMC, Nijmegen, NL
| | - Erwin van Wijk
- Department of Otorhinolaryngology, RUMC, Geert Grooteplein 10, Route 855, GA, Nijmegen 6525, the Netherlands; Donders Institute for Brain, Cognition, and Behavior, RUMC, Nijmegen, NL.
| | - Jennifer J Lentz
- Neuroscience Center of Excellence, LSUHSC, New Orleans, LA, USA; Department of Otorhinolaryngology, LSUHSC, 2020 Gravier Street, Lions Building, Room 795, New Orleans, LA, USA.
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Lentz JJ, Townsend JT. Merging the Psychophysical Function With Response Times for Auditory Detection of One vs. Two Tones. Front Psychol 2022; 13:910740. [PMID: 36160519 PMCID: PMC9493485 DOI: 10.3389/fpsyg.2022.910740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/16/2022] [Indexed: 11/14/2022] Open
Abstract
The purpose of this study is to take preliminary steps to unify psychoacoustic techniques with reaction-time methodologies to address the perceptual mechanisms responsible for the detection of one vs. multiple sounds. We measured auditory redundancy gains for auditory detection of pure tones widely spaced in frequency using the tools of Systems Factorial Technology to evince the system architecture and workload capacity in two different scenarios (SOFT and LOUD). We adopted an experimental design in which the presence or absence of a target at each of two frequencies was combined factorially with two stimulus levels. Replicating previous work, results did not allow an assessment of system architecture due to a failure to observe factor influence at the level of distribution ordering for dual-target stimuli for both SOFT and LOUD scenarios. All subjects demonstrated very modest redundancy gains for the dual-target compared to the single-target stimuli, and results were similar for both LOUD and SOFT. We propose that these results can be predicted by a mental architecture that falls into the class of integrated subadditive parallel systems, using a well-supported assumption that reaction time is driven by loudness. We demonstrate that modeled loudness of the experimental sounds (which ranged between about 0.2 and 14 sones) is highly correlated with mean reaction time (r = −0.87), and we provide a proof-of-concept model based on Steven’s Power law that predicts both a failure of distributional ordering for dual-target stimuli and very modest redundancy gains.
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Affiliation(s)
- Jennifer J. Lentz
- Department of Speech, Program in Cognitive Sciences, Language and Hearing Sciences, Indiana University, Bloomington, IN, United States
- *Correspondence: Jennifer J. Lentz,
| | - James T. Townsend
- Department of Psychological and Brain Sciences, Program in Cognitive Sciences, Indiana University, Bloomington, IN, United States
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Humes LE, Kidd GR, Lentz JJ. Differences Between Young and Older Adults in Working Memory and Performance on the Test of Basic Auditory Capabilities †. Front Psychol 2022; 12:804891. [PMID: 35095690 PMCID: PMC8790016 DOI: 10.3389/fpsyg.2021.804891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/13/2021] [Indexed: 11/29/2022] Open
Abstract
The Test of Basic Auditory Capabilities (TBAC) is a battery of auditory-discrimination tasks and speech-identification tasks that has been normed on several hundred young normal-hearing adults. Previous research with the TBAC suggested that cognitive function may impact the performance of older adults. Here, we examined differences in performance on several TBAC tasks between a group of 34 young adults with a mean age of 22.5 years (SD = 3.1 years) and a group of 115 older adults with a mean age of 69.2 years (SD = 6.2 years) recruited from the local community. Performance of the young adults was consistent with prior norms for this age group. Not surprisingly, the two groups differed significantly in hearing loss and working memory with the older adults having more hearing loss and poorer working memory than the young adults. The two age groups also differed significantly in performance on six of the nine measures extracted from the TBAC (eight test scores and one average test score) with the older adults consistently performing worse than the young adults. However, when these age-group comparisons were repeated with working memory and hearing loss as covariates, the groups differed in performance on only one of the nine auditory measures from the TBAC. For eight of the nine TBAC measures, working memory was a significant covariate and hearing loss never emerged as a significant factor. Thus, the age-group deficits observed initially on the TBAC most often appeared to be mediated by age-related differences in working memory rather than deficits in auditory processing. The results of these analyses of age-group differences were supported further by linear-regression analyses with each of the 9 TBAC scores serving as the dependent measure and age, hearing loss, and working memory as the predictors. Regression analyses were conducted for the full set of 149 adults and for just the 115 older adults. Working memory again emerged as the predominant factor impacting TBAC performance. It is concluded that working memory should be considered when comparing the performance of young and older adults on auditory tasks, including the TBAC.
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Affiliation(s)
- Larry E. Humes
- Department of Speech, Language, and Hearing Sciences, Indiana University, Bloomington, IN, United States
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Lentz JJ, Humes LE, Kidd GR. Differences in Auditory Perception Between Young and Older Adults When Controlling for Differences in Hearing Loss and Cognition. Trends Hear 2022; 26:23312165211066180. [PMID: 34989641 PMCID: PMC8753078 DOI: 10.1177/23312165211066180] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study was designed to examine age effects on various auditory perceptual skills using a large group of listeners (155 adults, 121 aged 60-88 years and 34 aged 18-30 years), while controlling for the factors of hearing loss and working memory (WM). All subjects completed 3 measures of WM, 7 psychoacoustic tasks (24 conditions) and a hearing assessment. Psychophysical measures were selected to tap phenomena thought to be mediated by higher-level auditory function and included modulation detection, modulation detection interference, informational masking (IM), masking level difference (MLD), anisochrony detection, harmonic mistuning, and stream segregation. Principal-components analysis (PCA) was applied to each psychoacoustic test. For 6 of the 7 tasks, a single component represented performance across the multiple stimulus conditions well, whereas the modulation-detection interference (MDI) task required two components to do so. The effect of age was analyzed using a general linear model applied to each psychoacoustic component. Once hearing loss and WM were accounted for as covariates in the analyses, estimated marginal mean thresholds were lower for older adults on tasks based on temporal processing. When evaluated separately, hearing loss led to poorer performance on roughly 1/2 the tasks and declines in WM accounted for poorer performance on 6 of the 8 psychoacoustic components. These results make clear the need to interpret age-group differences in performance on psychoacoustic tasks in light of cognitive declines commonly associated with aging, and point to hearing loss and cognitive declines as negatively influencing auditory perceptual skills.
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Affiliation(s)
- Jennifer J. Lentz
- Department of Speech, Language and Hearing Sciences, Indiana University, Bloomington, IN, USA
| | - Larry E. Humes
- Department of Speech, Language and Hearing Sciences, Indiana University, Bloomington, IN, USA
| | - Gary R. Kidd
- Department of Speech, Language and Hearing Sciences, Indiana University, Bloomington, IN, USA
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Nelson NL, Killion MC, Lentz JJ, Kidd GR. Hearing Protection Success: Musicians Have a Favorable Response to Hearing Protection and Listeners Are Unable to Identify Music Produced by Musicians Wearing Hearing Protection. J Am Acad Audiol 2021; 31:763-770. [PMID: 33740821 DOI: 10.1055/s-0040-1719128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Musicians are known to be at risk for developing hearing sensitivity and hearing-related problems given their occupational exposure to high-level sound. Among options for hearing conservation, earplugs are an effective and inexpensive choice. Adoption rates for musicians' earplugs remains consistently low, however, given concerns about the impact of hearing protection on their own performance as well as concerns that the resultant music will be a negative experience for listeners. In fact, few studies have (1) examined musicians' attitudes about using hearing protection while performing themselves and (2) determined whether music played by musicians wearing hearing protection sounds different to listeners. PURPOSE The purposes of this study were (1) to evaluate how wearing musicians' earplugs affected musicians' perception of their performance while they were playing, and (2) to examine whether listeners can distinguish a difference between music recorded by musicians playing with and without earplugs. RESEARCH DESIGN Experiment 1: student musicians were recorded playing under two conditions (with and without wearing earplugs) and then were surveyed about their experience. Experiment 2: musically experienced and naïve listeners were presented with musical samples played by musicians with and without earplugs in an ABX format. Listeners responded by indicating whether the third stimulus (X) was conditionally identical to the first (A) or second stimulus (B). RESULTS Experiment 1: while performing, musicians always preferred the no earplugs condition. The majority, however, rated the overall experience of playing with earplugs as generally positive. Experiment 2: listeners were unable to hear a difference between the two recordings. DISCUSSION In this experiment, musicians rated their experience playing without hearing protection more favorably than their experience playing with hearing protection, but most musicians rated their experience with hearing protection as generally positive. The inability of listeners to distinguish a difference in music played with and without hearing protection suggests that the listening experience may not be adversely impacted by hearing protection worn by the performers. CONCLUSION Earplugs are an inexpensive, noninvasive strategy for hearing conservation for musicians, and this study indicates that barriers to wearing hearing protection might be less problematic than previously reported.
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Affiliation(s)
- Nancy L Nelson
- Indiana University Department of Speech, Language and Hearing Sciences, Bloomington, Indiana
| | | | - Jennifer J Lentz
- Indiana University Department of Speech, Language and Hearing Sciences, Bloomington, Indiana
| | - Gary R Kidd
- Indiana University Department of Speech, Language and Hearing Sciences, Bloomington, Indiana
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Lentz JJ, He Y. Perceptual Dimensions Underlying Tinnitus-Like Sounds. J Speech Lang Hear Res 2020; 63:3560-3566. [PMID: 32946329 PMCID: PMC8060060 DOI: 10.1044/2020_jslhr-19-00327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 05/03/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
Purpose The goal of this study was to establish the perceptual underpinnings of the terms that are commonly used by patients when describing the quality of their tinnitus. Method Using a free-classification method, 15 subjects with normal hearing placed 60 different tinnitus-like sounds into similarity clusters on a grid. Multidimensional scaling, hierarchical clustering, and acoustic analyses were used to determine the acoustic underpinnings of the perceptual dimensions and perceptual similarity. Results Multidimensional scaling revealed three different perceptual dimensions (pitch, modulation depth + spectral elements, and envelope rate). Hierarchical clustering revealed five explicit similarity clusters: tonal, steady noise, pulsatile, low-frequency fluctuating noise, and high-frequency fluctuating. Conclusions Results are consistent with tinnitus perceptions falling into a small set of categories that can be characterized by their acoustics. As a result, there is the potential to develop different tools to assess tinnitus using a variety of different sounds.
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Affiliation(s)
- Jennifer J. Lentz
- Department of Speech, Language and Hearing Sciences, Indiana University Bloomington
| | - Yuan He
- Department of Speech, Language and Hearing Sciences, Indiana University Bloomington
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Lentz JJ, Pan B, Ponnath A, Tran CM, Nist-Lund C, Galvin A, Goldberg H, Robillard KN, Jodelka FM, Farris HE, Huang J, Chen T, Zhu H, Zhou W, Rigo F, Hastings ML, Géléoc GSG. Direct Delivery of Antisense Oligonucleotides to the Middle and Inner Ear Improves Hearing and Balance in Usher Mice. Mol Ther 2020; 28:2662-2676. [PMID: 32818431 PMCID: PMC7704764 DOI: 10.1016/j.ymthe.2020.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/05/2020] [Accepted: 08/02/2020] [Indexed: 12/16/2022] Open
Abstract
Usher syndrome is a syndromic form of hereditary hearing impairment that includes sensorineural hearing loss and delayed-onset retinitis pigmentosa (RP). Type 1 Usher syndrome (USH1) is characterized by congenital profound sensorineural hearing impairment and vestibular areflexia, with adolescent-onset RP. Systemic treatment with antisense oligonucleotides (ASOs) targeting the human USH1C c.216G>A splicing mutation in a knockin mouse model of USH1 restores hearing and balance. Herein, we explore the effect of delivering ASOs locally to the ear to treat hearing and vestibular dysfunction associated with Usher syndrome. Three localized delivery strategies were investigated in USH1C mice: inner ear injection, trans-tympanic membrane injection, and topical tympanic membrane application. We demonstrate, for the first time, that ASOs delivered directly to the ear correct Ush1c expression in inner ear tissue, improve cochlear hair cell transduction currents, restore vestibular afferent irregularity, spontaneous firing rate, and sensitivity to head rotation, and successfully recover hearing thresholds and balance behaviors in USH1C mice. We conclude that local delivery of ASOs to the middle and inner ear reach hair cells and can rescue both hearing and balance. These results also demonstrate the therapeutic potential of ASOs to treat hearing and balance deficits associated with Usher syndrome and other ear diseases.
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Affiliation(s)
- Jennifer J Lentz
- Department of Otorhinolaryngology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
| | - Bifeng Pan
- Department of Otolaryngology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Abhilash Ponnath
- Department of Otorhinolaryngology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Christopher M Tran
- Department of Otorhinolaryngology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Carl Nist-Lund
- Department of Otolaryngology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Alice Galvin
- Department of Otolaryngology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hannah Goldberg
- Department of Otolaryngology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Katelyn N Robillard
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Francine M Jodelka
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Hamilton E Farris
- Department of Otorhinolaryngology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Jun Huang
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Tianwen Chen
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Hong Zhu
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Wu Zhou
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92008, USA
| | - Michelle L Hastings
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Gwenaëlle S G Géléoc
- Department of Otolaryngology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Lentz JJ. Does a pitch rating method converge on the frequencies within tonal stimuli? J Acoust Soc Am 2020; 148:EL99. [PMID: 32752780 PMCID: PMC7386946 DOI: 10.1121/10.0001640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/06/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
This study determined how well the "perceived spectrum," estimated using a pitch similarity rating method, reflected the spectrum and pitch of seven different tonal sounds. The perceived spectrum well-matched the acoustic spectrum for pure tones ranging from 1 to 12 kHz, it also matched the broad frequency range for two complex tones with periodicity pitches of 1 and 2 kHz, but it did not reflect the pitch of the complex tones. These results suggest that while this method may not measure the pitch of sounds, it may be useful for measuring the general perceived frequency range of sounds.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech, Language and Hearing Sciences and the Program in Cognitive Science, Indiana University, Bloomington, Indiana 47405,
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Wang L, Kempton JB, Jiang H, Jodelka FM, Brigande AM, Dumont RA, Rigo F, Lentz JJ, Hastings ML, Brigande JV. Fetal antisense oligonucleotide therapy for congenital deafness and vestibular dysfunction. Nucleic Acids Res 2020; 48:5065-5080. [PMID: 32249312 PMCID: PMC7229850 DOI: 10.1093/nar/gkaa194] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/13/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Disabling hearing loss impacts ∼466 million individuals worldwide with 34 million children affected. Gene and pharmacotherapeutic strategies to rescue auditory function in mouse models of human deafness are most effective when administered before hearing onset, after which therapeutic efficacy is significantly diminished or lost. We hypothesize that preemptive correction of a mutation in the fetal inner ear prior to maturation of the sensory epithelium will optimally restore sensory function. We previously demonstrated that transuterine microinjection of a splice-switching antisense oligonucleotide (ASO) into the amniotic cavity immediately surrounding the embryo on embryonic day 13-13.5 (E13-13.5) corrected pre-mRNA splicing in the juvenile Usher syndrome type 1c (Ush1c) mouse mutant. Here, we show that this strategy only marginally rescues hearing and partially rescues vestibular function. To improve therapeutic outcomes, we microinjected ASO directly into the E12.5 inner ear. A single intra-otic dose of ASO corrects harmonin RNA splicing, restores harmonin protein expression in sensory hair cell bundles, prevents hair cell loss, improves hearing sensitivity, and ameliorates vestibular dysfunction. Improvements in auditory and vestibular function were sustained well into adulthood. Our results demonstrate that an ASO pharmacotherapeutic administered to a developing organ system in utero preemptively corrects pre-mRNA splicing to abrogate the disease phenotype.
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Affiliation(s)
- Lingyan Wang
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - J Beth Kempton
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Han Jiang
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Francine M Jodelka
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Alev M Brigande
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Rachel A Dumont
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010 USA
| | - Jennifer J Lentz
- Department of Otorhinolaryngology, Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Michelle L Hastings
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - John V Brigande
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
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Elison JR, Weinstein JE, Sheets KG, Regan CE, Lentz JJ, Reinoso M, Gordon WC, Bazan NG. Platelet-Activating Factor (PAF) Receptor Antagonism Modulates Inflammatory Signaling in Experimental Uveitis. Curr Eye Res 2018; 43:821-827. [PMID: 29641916 DOI: 10.1080/02713683.2018.1454476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The phospholipid mediator platelet-activating factor (PAF) activates an inflammatory response that includes arachidonic acid release and prostaglandin production in the eye, increasing vascular permeability and inflammation. The purpose of this study is to investigate the action of LAU-0901, a novel PAF receptor antagonist, on experimental uveitis. METHODS Uveitis was induced in Lewis rats by lipopolysaccharide treatment. LAU-0901 was then delivered systemically in different concentrations at plus 4 and 16 hours, or vehicle injected as controls. Additional animals were used for histological analyses of untreated, uveitis, and uveitis-plus-LAU-0901 retinas. Conventional histological and immunohistochemical methods were employed. A slit lamp and Spectral Domain-Ocular Coherence Tomography (SD-OCT) retinal imager was used for anterior segment photography and posterior pole OCT. Rats were euthanized 4 hours after the second LAU-0901 injection in this 24-hour model. Aqueous humor was collected and quantified, and also analyzed for tumor necrosis factor alpha (TNF-α). RESULTS Uveitic eyes demonstrated hypopyon formation, leukocyte infiltration, and an increase in aqueous protein and TNF-α levels. LAU-0901 treatment resulted in a dose-dependent reduction in inflammation, reflected by reduced total protein levels (up to a 64% reduction). Moreover, hypopyon was prevented, leukocytes were absent in vitreous and aqueous humor, and TNF-α levels were reduced by 91%. CONCLUSIONS The PAF receptor antagonist LAU-0901 decreases ocular inflammation in a rat model of anterior uveitis in a dose-dependent manner, suggesting that use of this molecule may provide a means to attenuate inflammation onset and offer a future alternative or adjunctive treatment for ocular inflammation.
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Affiliation(s)
- Jasmine R Elison
- a Department of Ophthalmology, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA
| | - Jessica E Weinstein
- b Department of Ophthalmology , University of Washington , Seattle , WA , USA
| | | | - Cornelius E Regan
- a Department of Ophthalmology, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA
| | - Jennifer J Lentz
- a Department of Ophthalmology, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA.,d Neuroscience Center of Excellence, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA
| | - Maria Reinoso
- a Department of Ophthalmology, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA
| | - William C Gordon
- a Department of Ophthalmology, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA.,d Neuroscience Center of Excellence, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA
| | - Nicolas G Bazan
- a Department of Ophthalmology, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA.,d Neuroscience Center of Excellence, School of Medicine , Louisiana State University Health Sciences Center , New Orleans , LA , USA
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12
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Ponnath A, Depreux FF, Jodelka FM, Rigo F, Farris HE, Hastings ML, Lentz JJ. Rescue of Outer Hair Cells with Antisense Oligonucleotides in Usher Mice Is Dependent on Age of Treatment. J Assoc Res Otolaryngol 2018; 19:1-16. [PMID: 29027038 PMCID: PMC5783922 DOI: 10.1007/s10162-017-0640-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 09/04/2017] [Indexed: 12/29/2022] Open
Abstract
The absence of functional outer hair cells is a component of several forms of hereditary hearing impairment, including Usher syndrome, the most common cause of concurrent hearing and vision loss. Antisense oligonucleotide (ASO) treatment of mice with the human Usher mutation, Ush1c c.216G>A, corrects gene expression and significantly improves hearing, as measured by auditory-evoked brainstem responses (ABRs), as well as inner and outer hair cell (IHC and OHC) bundle morphology. However, it is not clear whether the improvement in hearing achieved by ASO treatment involves the functional rescue of outer hair cells. Here, we show that Ush1c c.216AA mice lack OHC function as evidenced by the absence of distortion product otoacoustic emissions (DPOAEs) in response to low-, mid-, and high-frequency tone pairs. This OHC deficit is rescued by treatment with an ASO that corrects expression of Ush1c c.216G>A. Interestingly, although rescue of inner hairs cells, as measured by ABR, is achieved by ASO treatment as late as 7 days after birth, rescue of outer hair cells, measured by DPOAE, requires treatment before post-natal day 5. These results suggest that ASO-mediated rescue of both IHC and OHC function is age dependent and that the treatment window is different for the different cell types. The timing of treatment for congenital hearing disorders is of critical importance for the development of drugs such ASO-29 for hearing rescue.
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Affiliation(s)
- Abhilash Ponnath
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, 2020 Gravier Street, 8th Floor, New Orleans, LA, 70112, USA
| | - Frederic F Depreux
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Francine M Jodelka
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA, 92010, USA
| | - Hamilton E Farris
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, 2020 Gravier Street, 8th Floor, New Orleans, LA, 70112, USA
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA, 70112, USA
- Department of Otolaryngology and Biocommunications, Louisiana State University Health Sciences Center, 533 Bolivar Street, New Orleans, LA, 70112, USA
| | - Michelle L Hastings
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA.
| | - Jennifer J Lentz
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, 2020 Gravier Street, 8th Floor, New Orleans, LA, 70112, USA.
- Department of Otolaryngology and Biocommunications, Louisiana State University Health Sciences Center, 533 Bolivar Street, New Orleans, LA, 70112, USA.
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Vijayakumar S, Depreux FF, Jodelka FM, Lentz JJ, Rigo F, Jones TA, Hastings ML. Rescue of peripheral vestibular function in Usher syndrome mice using a splice-switching antisense oligonucleotide. Hum Mol Genet 2018. [PMID: 28633508 DOI: 10.1093/hmg/ddx234] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Usher syndrome type 1C (USH1C/harmonin) is associated with profound retinal, auditory and vestibular dysfunction. We have previously reported on an antisense oligonucleotide (ASO-29) that dramatically improves auditory function and balance behavior in mice homozygous for the harmonin mutation Ush1c c.216G > A following a single systemic administration. The findings were suggestive of improved vestibular function; however, no direct vestibular assessment was made. Here, we measured vestibular sensory evoked potentials (VsEPs) to directly assess vestibular function in Usher mice. We report that VsEPs are absent or abnormal in Usher mice, indicating profound loss of vestibular function. Strikingly, Usher mice receiving ASO-29 treatment have normal or elevated vestibular response thresholds when treated during a critical period between postnatal day 1 and 5, respectively. In contrast, treatment of mice with ASO-29 treatment at P15 was minimally effective at rescuing vestibular function. Interestingly, ASO-29 treatment at P1, P5 or P15 resulted in sufficient vestibular recovery to support normal balance behaviors, suggesting a therapeutic benefit to balance with ASO-29 treatment at P15 despite the profound vestibular functional deficits that persist with treatment at this later time. These findings provide the first direct evidence of an effective treatment of peripheral vestibular function in a mouse model of USH1C and reveal the potential for using antisense technology to treat vestibular dysfunction.
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Affiliation(s)
- Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, 304 Barkley Memorial Center, Lincoln, NE 68583, USA
| | - Frederic F Depreux
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Francine M Jodelka
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Jennifer J Lentz
- Department of Otorhinolaryngology, Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Timothy A Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, 304 Barkley Memorial Center, Lincoln, NE 68583, USA
| | - Michelle L Hastings
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
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Lentz JJ, Walker MA, Short CE, Skinner KG. Audiometric Testing With Pulsed, Steady, and Warble Tones in Listeners With Tinnitus and Hearing Loss. Am J Audiol 2017; 26:328-337. [PMID: 28892822 DOI: 10.1044/2017_aja-17-0009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/12/2017] [Indexed: 11/09/2022] Open
Abstract
PURPOSE This study evaluated the American Speech-Language-Hearing Association's recommendation that audiometric testing for patients with tinnitus should use pulsed or warble tones. Using listeners with varied audiometric configurations and tinnitus statuses, we asked whether steady, pulsed, and warble tones yielded similar audiometric thresholds, and which tone type was preferred. METHOD Audiometric thresholds (octave frequencies from 0.25-16 kHz) were measured using steady, pulsed, and warble tones in 61 listeners, who were divided into 4 groups on the basis of hearing and tinnitus status. Participants rated the appeal and difficulty of each tone type on a 1-5 scale and selected a preferred type. RESULTS For all groups, thresholds were lower for warble than for pulsed and steady tones, with the largest effects above 4 kHz. Appeal ratings did not differ across tone type, but the steady tone was rated as more difficult than the warble and pulsed tones. Participants generally preferred pulsed and warble tones. CONCLUSIONS Pulsed tones provide advantages over steady and warble tones for patients regardless of hearing or tinnitus status. Although listeners preferred pulsed and warble tones to steady tones, pulsed tones are not susceptible to the effects of off-frequency listening, a consideration when testing listeners with sloping audiograms.
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Affiliation(s)
- Jennifer J. Lentz
- Department of Speech and Hearing Sciences, Indiana University, Bloomington
| | - Matthew A. Walker
- Department of Speech and Hearing Sciences, Indiana University, Bloomington
| | - Ciara E. Short
- Department of Speech and Hearing Sciences, Indiana University, Bloomington
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15
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Humes LE, Kidd GR, Lentz JJ. Corrigendum: Auditory and cognitive factors underlying individual differences in aided speech-understanding among older adults. Front Syst Neurosci 2016; 10:91. [PMID: 27843432 PMCID: PMC5105598 DOI: 10.3389/fnsys.2016.00091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 10/28/2016] [Indexed: 11/25/2022] Open
Affiliation(s)
- Larry E Humes
- Department of Speech and Hearing Sciences, Indiana University Bloomington, IN, USA
| | - Gary R Kidd
- Department of Speech and Hearing Sciences, Indiana University Bloomington, IN, USA
| | - Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University Bloomington, IN, USA
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16
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Depreux FF, Wang L, Jiang H, Jodelka FM, Rosencrans RF, Rigo F, Lentz JJ, Brigande JV, Hastings ML. Antisense oligonucleotides delivered to the amniotic cavity in utero modulate gene expression in the postnatal mouse. Nucleic Acids Res 2016; 44:9519-9529. [PMID: 27683224 PMCID: PMC5175366 DOI: 10.1093/nar/gkw867] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 12/18/2022] Open
Abstract
Congenital diseases account for a large portion of pediatric illness. Prenatal screening and diagnosis permit early detection of many genetic diseases. Fetal therapeutic strategies to manage disease processes in utero represent a powerful new approach for clinical care. A safe and effective fetal pharmacotherapy designed to modulate gene expression ideally would avoid direct mechanical engagement of the fetus and present an external reservoir of drug. The amniotic cavity surrounding the fetus could serve as an ideal drug reservoir. Antisense oligonucleotides (ASOs) are an established tool for the therapeutic modulation of gene expression. We hypothesize that ASOs administered to the amniotic cavity will gain entry to the fetus and modulate gene expression. Here, we show that an ASO targeting MALAT1 RNA, delivered by transuterine microinjection into the mouse amniotic cavity at embryonic day 13-13.5, reduces target RNA expression for up to 4 weeks after birth. A similarly delivered ASO targeting a causal splice site mutation for Usher syndrome corrects gene expression in the inner ear, a therapeutically relevant target tissue. We conclude that intra-amniotic delivery of ASOs is well tolerated and produces a sustained effect on postnatal gene expression. Transuterine delivery of ASOs is an innovative platform for developing fetal therapeutics to efficaciously treat congenital disease.
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Affiliation(s)
- Frederic F Depreux
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Lingyan Wang
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Han Jiang
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Francine M Jodelka
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Robert F Rosencrans
- Neuroscience Center of Excellence, LSU Health Sciences Center, New Orleans, LA 70112, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Jennifer J Lentz
- Neuroscience Center of Excellence, LSU Health Sciences Center, New Orleans, LA 70112, USA.,Department of Otorhinolaryngology, LSU Health Sciences Center, New Orleans, LA 70112, USA
| | - John V Brigande
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Michelle L Hastings
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
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Lentz JJ, Valentine S. Across-frequency processing of modulation phase differences in hearing-impaired listeners. J Acoust Soc Am 2015; 138:EL205-EL211. [PMID: 26428814 PMCID: PMC4560714 DOI: 10.1121/1.4929624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/19/2015] [Accepted: 08/12/2015] [Indexed: 06/05/2023]
Abstract
Two experiments tested the influence of hearing impairment (HI) on representing across-frequency temporal coherence. In one experiment, HI listeners demonstrated similar abilities to normal-hearing listeners in detecting across-frequency differences in modulation phase. In another, spectral-shape discrimination was detrimentally affected by modulation phase disparities imposed on spectral components. Spectral-shape discrimination by HI listeners was less influenced by the disparities, suggesting that hearing loss alters the representation of envelope phase. Results suggest that multiple approaches may be necessary to determine alterations associated with hearing loss—detection tasks may not be sufficient to elucidate distortions to temporal envelope associated with hearing loss.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405, USA ,
| | - Susie Valentine
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405, USA ,
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Lentz JJ, He Y, Townsend JT. A new perspective on binaural integration using response time methodology: super capacity revealed in conditions of binaural masking release. Front Hum Neurosci 2014; 8:641. [PMID: 25202254 PMCID: PMC4141468 DOI: 10.3389/fnhum.2014.00641] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 08/01/2014] [Indexed: 11/17/2022] Open
Abstract
This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time (RT) distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180° out of phase with respect to the other ear. Accuracy-based measurements have demonstrated a much lower signal detection threshold for the dichotic vs. the diotic conditions, but accuracy-based techniques do not allow for assessment of system dynamics or resource allocation across time. Further, RTs allow comparisons between these conditions at the same signal-to-noise ratio. Here, we apply a reaction-time based capacity coefficient, which provides an index of workload efficiency and quantifies the resource allocations for single ear vs. two ear presentations. We demonstrate that the release from masking generated by the addition of an identical stimulus to one ear is limited-to-unlimited capacity (efficiency typically less than 1), consistent with less gain than would be expected by probability summation. However, the dichotic presentation leads to a significant increase in workload capacity (increased efficiency)-most specifically at lower signal-to-noise ratios. These experimental results provide further evidence that configural processing plays a critical role in binaural masking release, and that these mechanisms may operate more strongly when the signal stimulus is difficult to detect, albeit still with nearly 100% accuracy.
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Affiliation(s)
- Jennifer J. Lentz
- Department of Speech and Hearing Sciences, Indiana UniversityBloomington, IN, USA
| | - Yuan He
- Department of Speech and Hearing Sciences, Indiana UniversityBloomington, IN, USA
| | - James T. Townsend
- Department of Psychological and Brain Sciences, Indiana UniversityBloomington, IN, USA
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Humes LE, Kidd GR, Lentz JJ. Auditory and cognitive factors underlying individual differences in aided speech-understanding among older adults. Front Syst Neurosci 2013; 7:55. [PMID: 24098273 PMCID: PMC3787592 DOI: 10.3389/fnsys.2013.00055] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 09/09/2013] [Indexed: 11/13/2022] Open
Abstract
This study was designed to address individual differences in aided speech understanding among a relatively large group of older adults. The group of older adults consisted of 98 adults (50 female and 48 male) ranging in age from 60 to 86 (mean = 69.2). Hearing loss was typical for this age group and about 90% had not worn hearing aids. All subjects completed a battery of tests, including cognitive (6 measures), psychophysical (17 measures), and speech-understanding (9 measures), as well as the Speech, Spatial, and Qualities of Hearing (SSQ) self-report scale. Most of the speech-understanding measures made use of competing speech and the non-speech psychophysical measures were designed to tap phenomena thought to be relevant for the perception of speech in competing speech (e.g., stream segregation, modulation-detection interference). All measures of speech understanding were administered with spectral shaping applied to the speech stimuli to fully restore audibility through at least 4000 Hz. The measures used were demonstrated to be reliable in older adults and, when compared to a reference group of 28 young normal-hearing adults, age-group differences were observed on many of the measures. Principal-components factor analysis was applied successfully to reduce the number of independent and dependent (speech understanding) measures for a multiple-regression analysis. Doing so yielded one global cognitive-processing factor and five non-speech psychoacoustic factors (hearing loss, dichotic signal detection, multi-burst masking, stream segregation, and modulation detection) as potential predictors. To this set of six potential predictor variables were added subject age, Environmental Sound Identification (ESI), and performance on the text-recognition-threshold (TRT) task (a visual analog of interrupted speech recognition). These variables were used to successfully predict one global aided speech-understanding factor, accounting for about 60% of the variance.
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Affiliation(s)
- Larry E Humes
- Department of Speech and Hearing Sciences, Indiana University Bloomington, IN, USA
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20
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Lentz JJ, Jodelka FM, Hinrich AJ, McCaffrey KE, Farris HE, Spalitta MJ, Bazan NG, Duelli DM, Rigo F, Hastings ML. Rescue of hearing and vestibular function by antisense oligonucleotides in a mouse model of human deafness. Nat Med 2013; 19:345-50. [PMID: 23380860 PMCID: PMC3657744 DOI: 10.1038/nm.3106] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 01/28/2013] [Indexed: 12/17/2022]
Abstract
Hearing impairment is the most common sensory disorder, with congenital hearing
impairment present in ~1 in 1000 newborns1,
and yet there is no cellular cure for deafness. Hereditary deafness is often mediated by the
developmental failure or degeneration of cochlear hair cells2. Until now, it was not known whether such congenital failures could be mitigated by
therapeutic intervention3-5. Here we show that hearing and vestibular function can be rescued in a mouse model
of human hereditary deafness. An antisense oligonucleotide (ASO) was used to correct defective
pre–mRNA splicing of transcripts from the mutated
USH1C.216G>A gene, which causes human Usher syndrome
(Usher), the leading genetic cause of combined deafness and blindness6,7. Treatment of neonatal mice with a
single systemic dose of ASO partially corrects USH1C.216G>A splicing,
increases protein expression, improves stereocilia organization in the cochlea, and rescues cochlear
hair cells, vestibular function and hearing in mice. Our results demonstrate the therapeutic
potential of ASOs in the treatment of deafness and provide evidence that congenital deafness can be
effectively overcome by treatment early in development to correct gene expression.
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Affiliation(s)
- Jennifer J Lentz
- Neuroscience Center and Department of Otorhinolaryngology & Biocommunications, Louisiana State University Health Sciences Center (LSUHSC), New Orleans, Louisiana, USA.
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Abstract
PURPOSE In this study, the authors sought to determine whether reduced audible bandwidth associated with hearing loss contributes to difficulty benefiting from an onset asynchrony between sounds. METHOD Synthetic double-vowel identification was measured for normal-hearing listeners and listeners with hearing loss. One vowel (Target 2) was 250 ms in duration, and one (Target 1) varied in duration. The vowels had the same offset, and an onset asynchrony between the vowels ranged between 0 and 200 ms. Listeners identified both vowels in their perceived order. The scoring metrics used were as follows: Target 1 correctly identified in the correct position, Target 2 correctly identified in the correct position, ordered double-vowel identification, and unordered double-vowel identification. The same experiment was conducted with vowels low-pass filtered at 900 Hz simulating reduced audible bandwidth. RESULTS For all scoring metrics, increases in onset asynchrony led to better vowel identification. Listeners with hearing loss benefited less from onset asynchrony than normal-hearing listeners only for Target 2 identification. Filtering the vowels reduced onset asynchrony benefit for all scoring categories and for both groups. CONCLUSION Results implicate reduced audible bandwidth in difficulties of listeners when using onset asynchrony for sound segregation. Therefore, listeners with a reduced audible bandwidth may have communication difficulties in natural environments.
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Shen Y, Lentz JJ. The effect of temporal asymmetry on amplitude modulation detection using pure-tone carriers (L). J Acoust Soc Am 2011; 130:2635-2638. [PMID: 22087889 DOI: 10.1121/1.3643813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The effect of temporal asymmetry on amplitude modulation detection was studied using sawtooth modulators with rising (ramped) or falling (damped) temporal envelopes within each period of modulation. For pure-tone carriers, damped modulation was more detectable than ramped modulation for a 5-kHz carrier (by a threshold difference of 3.2 dB on average) but not for a 1-kHz carrier. The threshold difference obtained at 5 kHz between the ramped and damped modulators was consistent across modulation rates (8-128 Hz). This carrier frequency dependence suggests that the effect of temporally asymmetry on modulation detection originates from envelope-based, within-channel mechanisms.
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Affiliation(s)
- Yi Shen
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405-7000, USA.
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Phillips JB, Blanco-Sanchez B, Lentz JJ, Tallafuss A, Khanobdee K, Sampath S, Jacobs ZG, Han PF, Mishra M, Titus TA, Williams DS, Keats BJ, Washbourne P, Westerfield M. Harmonin (Ush1c) is required in zebrafish Müller glial cells for photoreceptor synaptic development and function. Dis Model Mech 2011; 4:786-800. [PMID: 21757509 PMCID: PMC3209648 DOI: 10.1242/dmm.006429] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Usher syndrome is the most prevalent cause of hereditary deaf-blindness, characterized by congenital sensorineural hearing impairment and progressive photoreceptor degeneration beginning in childhood or adolescence. Diagnosis and management of this disease are complex, and the molecular changes underlying sensory cell impairment remain poorly understood. Here we characterize two zebrafish models for a severe form of Usher syndrome, Usher syndrome type 1C (USH1C): one model is a mutant with a newly identified ush1c nonsense mutation, and the other is a morpholino knockdown of ush1c. Both have defects in hearing, balance and visual function from the first week of life. Histological analyses reveal specific defects in sensory cell structure that are consistent with these behavioral phenotypes and could implicate Müller glia in the retinal pathology of Usher syndrome. This study shows that visual defects associated with loss of ush1c function in zebrafish can be detected from the onset of vision, and thus could be applicable to early diagnosis for USH1C patients.
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Lentz JJ, Shen Y. Investigating temporal asymmetry using masking period patterns and models of peripheral auditory processing. J Acoust Soc Am 2011; 129:3194-3205. [PMID: 21568421 DOI: 10.1121/1.3573979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Two experiments were conducted in conjunction with modeling to evaluate the role of peripheral nonlinearity and neural adaptation in the perception of temporally asymmetric sounds. In both experiments, maskers were broadband noises amplitude modulated with ramped and damped exponential modulators that repeated at 40 Hz. Masking period patterns (MPPs) were constructed by measuring detection threshold of a 5-ms, 1000-Hz tone burst as function of the signal's onset delay. Experiment I showed that varying modulator half-life from 1 to 16 ms led to differences in the damped and the ramped MPPs that were largest at the short half-lives and diminished at the longer half-lives. When masker level was varied (experiment II), the largest difference between ramped and damped MPPs occurred at moderate stimulus levels. Two peripheral auditory models were evaluated, one a simple auditory filter followed by a power-law nonlinearity and another, a model of auditory nerve processing [J. Acoust. Soc. Am. 126, 2390-2412 (2009)] that includes neural adaptation. Neither models predicted differences between the ramped and damped MPPs, providing indirect support that the central auditory system has a role in perceptual temporal asymmetry.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405-7000, USA.
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Shen Y, Lentz JJ. Effect of fast-acting compression on modulation detection interference for normal hearing and hearing impaired listeners. J Acoust Soc Am 2010; 127:3654-65. [PMID: 20550264 DOI: 10.1121/1.3418684] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
To determine the effects of hearing loss and fast-acting compression on auditory grouping based on across-frequency modulation, modulation detection interference (MDI) was measured in listeners with normal hearing and hearing loss. MDI, the increase in the amplitude-modulation detection threshold of a target presented with an interferer distant in frequency, was measured using a 500-Hz target and a 2140-Hz interferer, both modulated with narrow-band noises of the same bandwidth. The two modulated tones were presented at equal loudness levels to listeners with normal hearing and hearing loss in the absence (Exp. 1) and in the presence (Exp. 2) of fast-acting compression applied to the interferer. Modulation detection thresholds increased with increasing modulation depth of the interferer by similar amounts for the two groups of listeners, suggesting that across-frequency grouping based on amplitude modulation is not altered by hearing impairment. Compression provided an additional increase in thresholds for both groups, indicating that compression algorithms might alter across-frequency grouping cues. Partial support for an idea that compression's effect of sharpening the onsets after each envelope valley is provided by a third experiment which found somewhat greater interference produced by square-wave modulation than sine-wave modulation at larger interferer modulation depths.
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Affiliation(s)
- Yi Shen
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405-7000, USA.
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Lentz JJ, Gordon WC, Farris HE, MacDonald GH, Cunningham DE, Robbins CA, Tempel BL, Bazan NG, Rubel EW, Oesterle EC, Keats BJ. Deafness and retinal degeneration in a novel USH1C knock-in mouse model. Dev Neurobiol 2010; 70:253-67. [PMID: 20095043 DOI: 10.1002/dneu.20771] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Usher syndrome is the leading cause of combined deaf-blindness, but the molecular mechanisms underlying the auditory and visual impairment are poorly understood. Usher I is characterized by profound congenital hearing loss, vestibular dysfunction, and progressive retinitis pigmentosa beginning in early adolescence. Using the c.216G>A cryptic splice site mutation in Exon 3 of the USH1C gene found in Acadian Usher I patients in Louisiana, we constructed the first mouse model that develops both deafness and retinal degeneration. The same truncated mRNA transcript found in Usher 1C patients is found in the cochleae and retinas of these knock-in mice. Absent auditory-evoked brainstem responses indicated that the mutant mice are deaf at 1 month of age. Cochlear histology showed disorganized hair cell rows, abnormal bundles, and loss of both inner and outer hair cells in the middle turns and at the base. Retinal dysfunction as evident by an abnormal electroretinogram was seen as early as 1 month of age, with progressive loss of rod photoreceptors between 6 and 12 months of age. This knock-in mouse reproduces the dual sensory loss of human Usher I, providing a novel resource to study the disease mechanism and the development of therapies.
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Affiliation(s)
- Jennifer J Lentz
- Department of Genetics, LSU Health Sciences Center, New Orleans, Louisiana, USA.
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Abstract
Two masking experiments were conducted to behaviorally estimate auditory-filter phase curvatures at different stimulus levels. Maskers were harmonic complexes consisting of equal-amplitude tones and phase spectra with varied curvatures. In Experiment 1, sinusoidal signal thresholds were measured at 2 and 4 kHz at fixed masker levels ranging from 50 to 90 dB sound pressure level (SPL). In Experiment 2, the masker level that just masked a sinusoidal signal at 2 and 4 kHz was measured at fixed signal levels of 25, 38, and 50 dB SPL. For both experiments, the estimated phase curvature approached zero (became less negative) with increasing stimulus level. This shift could suggest that the off-frequency phase characteristic of the auditory filter has an increasingly greater role on the estimated auditory-filter phase curvature at higher stimulus levels. This explanation is supported through the use of psychophysical modeling.
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Affiliation(s)
- Yi Shen
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, IN 47405-7000, USA.
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28
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Abstract
PURPOSE To investigate the effects of hearing loss on auditory stream segregation of broadband inharmonic sounds. METHOD Auditory stream segregation by listeners with normal and impaired hearing was measured for 6-component inharmonic sounds ("A" and "B") using objective and subjective methods. Components in the A stimuli ranged between 1000 and 4000 Hz, whereas B stimuli were generated at the same frequency ratio but scaled upward in frequency relative to the A stimuli. In Experiment 1, streaming was measured by having listeners detect a delay inserted into a sequence of A and B stimuli (A_B_A_B_...) for B stimuli with different frequencies. In Experiment 2, streaming was measured using an ABA_ABA_... sequence, and the frequency of the B stimulus decreased until listeners reported that they could "no longer hear two separate streams." RESULTS Experiment 1 indicated no significant differences between groups in the size of the just detectable delay and no significant interactions between group and the scaling factor between the B and A stimuli. Experiment 2 revealed no significant differences in streaming abilities between normal-hearing and hearing-impaired groups. CONCLUSIONS Overall, results indicate that listeners with normal and impaired hearing have similar auditory streaming abilities for broadband inharmonic complex stimuli.
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Affiliation(s)
- Susie Valentine
- Starkey Hearing Research Center, 2150 Shattuck Ave., Suite 408, Berkeley, CA 94704, USA.
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29
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Abstract
This study evaluated whether weights for spectral-shape discrimination depend on overall stimulus level and signal strength (the degree of spectral-shape change between two stimuli). Five listeners discriminated between standard stimuli that were the sum of six equal-amplitude tones and signal stimuli created by decreasing the amplitudes of three low-frequency components and increasing the amplitudes of three high-frequency components. Weighting functions were influenced by stimulus level in that the relative contribution of the low-frequency (decremented) components to the high-frequency (incremented) components decreased with increasing stimulus level. Although individual variability was present, a follow-up experiment suggested that the level dependence was due to greater reliance on high-frequency components rather than incremented components. Excitation-pattern analyses indicated that the level dependence is primarily, but not solely, driven by cochlear factors. In general, different signal strengths had no effect on the weighting functions (when normalized), but two of the five listeners showed variability in the shape of the weighting function across signal strengths. Results suggest that the effects of stimulus level on weighting functions and individual variability in the shapes of the weighting functions should be considered when comparing weighting functions across conditions and groups that might require different stimulus levels and signal strengths.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405, USA
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Abstract
This study determined whether listeners with hearing loss received reduced benefits due to an onset asynchrony between sounds. Seven normal-hearing listeners and 7 listeners with hearing impairment (HI) were presented with 2 synthetic, steady-state vowels. One vowel (the late-arriving vowel) was 250 ms in duration, and the other (the early-arriving vowel) varied in duration between 350 and 550 ms. The vowels had simultaneous offsets, and therefore an onset asynchrony between the 2 vowels ranged between 100 and 300 ms. The early-arriving and late-arriving vowels also had either the same or different fundamental frequencies. Increases in onset asynchrony and differences in fundamental frequency led to better vowel-identification performance for both groups, with listeners with HI benefiting less from onset asynchrony than normal-hearing listeners. The presence of fundamental frequency differences did not influence the benefit received from onset asynchrony for either group. Excitation pattern modeling indicated that the reduced benefit received from onset asynchrony was not easily predicted by the reduced audibility of the vowel sounds for listeners with HI. Therefore, suprathreshold factors such as loss of the cochlear nonlinearity, reduced temporal integration, and the perception of vowel dominance probably play a greater role in the reduced benefit received from onset asynchrony in listeners with HI.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, 200 S. Jordan Avenue, Bloomington, IN 47405, USA.
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31
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Abstract
Spectral-shape discrimination thresholds were measured in the presence and absence of noise to determine whether normal-hearing and hearing-impaired listeners rely primarily on spectral peaks in the excitation pattern when discriminating between stimuli with different spectral shapes. Standard stimuli were the sum of 2, 4, 6, 8, 10, 20, or 30 equal-amplitude tones with frequencies fixed between 200 and 4000 Hz. Signal stimuli were generated by increasing and decreasing the levels of every other standard component. The function relating the spectral-shape discrimination threshold to the number of components (N) showed an initial decrease in threshold with increasing N and then an increase in threshold when the number of components reached 10 and 6, for normal-hearing and hearing-impaired listeners, respectively. The presence of a 50-dB SPL/Hz noise led to a 1.7 dB increase in threshold for normal-hearing listeners and a 3.5 dB increase for hearing-impaired listeners. Multichannel modeling and the relatively small influence of noise suggest that both normal-hearing and hearing-impaired listeners rely on the peaks in the excitation pattern for spectral-shape discrimination. The greater influence of noise in the data from hearing-impaired listeners is attributed to a poorer representation of spectral peaks.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405, USA.
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32
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Abstract
Masking by harmonic complexes depends on the frequency content of the masker and its phase spectrum. Harmonic complexes created with negative Schroeder phases (component phases decreasing with increasing frequency) produce more masking than those with positive Schroeder phases (increasing phase) in humans, but not in birds. The masking differences in humans have been attributed to interactions between the masker phase spectrum and the phase characteristic of the basilar membrane. In birds, the similarity in masking by positive and negative Schroeder maskers, and reduced masking by cosine-phase maskers (constant phase), suggests a phase characteristic that does not change much along the basilar papilla. To evaluate this possibility, the rate of phase change across masker bandwidth was varied by systematically altering the Schroeder algorithm. Humans and three species of birds detected tones added in phase to a single component of a harmonic complex. As observed in earlier studies, the minimum amount of masking in humans occurred for positive phase gradients. However, minimum masking in birds occurred for a shallow negative phase gradient. These results suggest a cochlear delay in birds that is reduced compared to that found in humans, probably related to the shorter avian basilar epithelia.
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Affiliation(s)
- Amanda M Lauer
- Department of Psychology, University of Maryland, College Park, Maryland 20742, USA.
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33
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Abstract
Profile-analysis thresholds were measured in the presence and absence of overall level variation at different stimulus levels to determine whether nonlinear changes in the shape of the edges of excitation pattern peaks contribute to poorer spectral-shape sensitivity observed under roving levels. Roving levels decreased sensitivity for stimuli having few components separated widely in frequency to a greater extent than for stimuli having more densely spaced components. The stimulus level did not influence sensitivity when overall level variation was absent, suggesting that listeners rely on peaks in the excitation patterns and not the edges of the peaks (as would have been predicted by the near miss to Weber's law). Because the edges of the peaks were not used in the absence of roving levels, it follows that the larger rove effects for sparse stimuli were not likely due to excitation pattern inconstancy.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, 200 S. Jordan Avenue, Bloomington, Indiana 47405, USA.
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34
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Henning GB, Richards VM, Lentz JJ. The effect of diotic and dichotic level-randomization on the binaural masking-level difference. J Acoust Soc Am 2005; 118:3229-40. [PMID: 16334902 DOI: 10.1121/1.2047167] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Detection thresholds for tones in narrow-band noise were measured for two binaural configurations: N(o)S(o) and N(o)S(pi). The 30-Hz noise band had a mean overall level of 65 dB SPL and was centered on 250, 500, or 5000 Hz. Signals and noise were simultaneously gated for 500, 110, or 20 ms. Three conditions of level randomization were tested: (1) no randomization; (2) diotic randomization--the stimulus level (common to both ears) was randomly chosen from an uniformly distributed 40-dB range every presentation interval; and (3) dichotic randomization--the stimulus levels for each ear were each independently and randomly chosen from the 40-dB range. Regardless of binaural configuration, level randomization had small effects on thresholds at 500 and 110 ms, implying that binaural masking-level differences (BMLDs) do not depend on interaural level differences for individual stimuli. For 20-ms stimuli, both diotic and dichotic randomization led to markedly poorer performance than at 500- and 110-ms durations; BMLDs diminished with no randomization and dichotic randomization but not with diotic randomization. The loss of BMLDs at 20 ms, with degrees-of-freedom (2WT) approximately 1, implies that changes in intracranial parameters occurring during the course of the observation interval are necessary for BMLDs when mean-level and mean-intracranial-position cues have been made unhelpful.
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Affiliation(s)
- G Bruce Henning
- Hearing Research Center, Biomedical Engineering Department, Boston University, Boston, Massachusetts 02215, USA
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35
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Dreisbach LE, Leek MR, Lentz JJ. Perception of spectral contrast by hearing-impaired listeners. J Speech Lang Hear Res 2005; 48:910-21. [PMID: 16378482 DOI: 10.1044/1092-4388(2005/063)] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Accepted: 12/16/2004] [Indexed: 05/05/2023]
Abstract
The ability to discriminate the spectral shapes of complex sounds is critical to accurate speech perception. Part of the difficulty experienced by listeners with hearing loss in understanding speech sounds in noise may be related to a smearing of the internal representation of the spectral peaks and valleys because of the loss of sensitivity and an accompanying reduction in frequency resolution. This study examined the discrimination by hearing-impaired listeners of highly similar harmonic complexes with a single spectral peak located in 1 of 3 frequency regions. The minimum level difference between peak and background harmonics required to discriminate a small change in the spectral center of the peak was measured for peaks located near 2, 3, or 4 kHz. Component phases were selected according to an algorithm thought to produce either highly modulated (positive Schroeder) or very flat (negative Schroeder) internal waveform envelopes in the cochlea. The mean amplitude difference between a spectral peak and the background components required for discrimination of pairs of harmonic complexes (spectral contrast threshold) was from 4 to 19 dB greater for listeners with hearing impairment than for a control group of listeners with normal hearing. In normal-hearing listeners, improvements in threshold were seen with increasing stimulus level, and there was a strong effect of stimulus phase, as the positive Schroeder stimuli always produced lower thresholds than the negative Schroeder stimuli. The listeners with hearing loss showed no consistent spectral contrast effects due to stimulus phase and also showed little improvement with increasing stimulus level, once their sensitivity loss was overcome. The lack of phase and level effects may be a result of the more linear processing occurring in impaired ears, producing poorer-than-normal frequency resolution, a loss of gain for low amplitudes, and an altered cochlear phase characteristic in regions of damage.
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Affiliation(s)
- Laura E Dreisbach
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA 92182-1518, USA.
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36
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Mannick EE, Cote RL, Schurr JR, Krowicka HS, Sloop GD, Zapata-Velandia A, Correa H, Ruiz B, Horswell R, Lentz JJ, Byrne P, Gastanaduy MM, Hornick CA, Liu Z. Altered phenotype of dextran sulfate sodium colitis in interferon regulatory factor-1 knock-out mice. J Gastroenterol Hepatol 2005; 20:371-80. [PMID: 15740479 DOI: 10.1111/j.1440-1746.2005.03573.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND AND AIMS Interferon regulatory factor-1 (IRF-1) is a transcription factor with antiviral, proinflammatory and tumor suppressor properties. We examined the role of IRF-1 in dextran sulfate sodium colitis, a murine model of inflammatory bowel disease, to determine if absence of the gene would protect against colitis. METHODS C57BL/6J mice with a targeted disruption of IRF-1 and wild-type C57BL/6J controls received five 7-day cycles of 2% dextran sulfate sodium alternating with five 7-day cycles of water. Colonic tissue was formalin fixed for histological analysis and total RNA extracted for gene chip and SYBR green real-time polymerase chain reaction (PCR) analysis. RESULTS Histological analysis revealed increased distortion of crypt architecture in the dextran sulfate sodium-treated, IRF-1 -/- animals as compared to dextran sulfate sodium-treated wild-type animals. Five of 15 dextran sulfate sodium-treated IRF-1 -/- mice, but only one of 14 dextran sulfate sodium-treated wild-type mice, developed colonic dysplasia. Microarray analysis comparing colonic gene expression in IRF-1 -/- and wild-type animals revealed decreased expression of caspases, genes involved in antigen presentation, and tumor suppressor genes in the IRF-1 -/- animals. Increased expression of genes involved in carcinogenesis and immunoglobulin and complement genes was also noted in the knock-out animals. CONCLUSIONS Absence of IRF-1 is not protective in dextran sulfate sodium colitis.
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Mannick EE, Schurr JR, Zapata A, Lentz JJ, Gastanaduy M, Cote RL, Delgado A, Correa P, Correa H. Gene expression in gastric biopsies from patients infected with Helicobacter pylori. Scand J Gastroenterol 2004; 39:1192-200. [PMID: 15742995 DOI: 10.1080/00365520410003588] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Helicobacter pylori infection has protean effects on gene expression in the host gastric mucosa, which have been investigated by gene chip analysis in vitro. In this study the effects of H. pylori infection on host gene expression in the gastric antral mucosa in patients were examined. METHODS One gastric antral biopsy was obtained from a total of 18 untreated patients undergoing routine endoscopic evaluation of chronic abdominal complaints. Nine patients had histologic evidence of H. pylori infection and 9 age- and sex-matched patients had no histologic evidence of H. pylori infection. A microarray analysis was performed using a gene chip containing 35,000 human expressed sequence tags on RNA extracted from endoscopic, gastric antral biopsies, and average gene expression among infected and uninfected patients was compared. RESULTS Underexpressed genes in infected patients' mucosa included gastric intrinsic factor and several metallothionein isoforms. Overexpressed genes in infected patients' mucosa comprised MHC Class II molecules, immunoglobulin and B-cell activation genes, as well as genes known to induce apoptosis. Changes in expression were confirmed for a subset of genes by SYBR green real-time PCR. CONCLUSIONS Microarray analysis of antral biopsies from patients with and without H. pylori infection revealed differential expression of metal regulatory, immunity and inflammation-related genes.
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Affiliation(s)
- E E Mannick
- Louisiana State University, Stanley S Scott Cancer and Depts of Pathology and Genetics, New Orlands, Louisiana 70112, USA.
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38
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Lentz JJ, Leek MR, Molis MR. The effect of onset asynchrony on profile analysis by normal-hearing and hearing-impaired listeners. J Acoust Soc Am 2004; 116:2289-2297. [PMID: 15532660 DOI: 10.1121/1.1787125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effect of onset asynchrony on discrimination of spectral shape was evaluated for hearing-impaired and normal-hearing listeners. Stimuli were the sum of four tones equally spaced on a logarithmic frequency scale. The standard stimulus had tones of equal amplitude, and the signal stimulus had two adjacent components increased in level, and the other two components decreased in level. Thresholds for discrimination between the standard and signal stimuli were measured as a function of an onset asynchrony among the components of 0, 50, and 200 ms. Hearing-impaired and normal-hearing listeners had similar thresholds when the stimulus components were widely spaced in frequency, but hearing-impaired listeners had much higher thresholds for narrowly spaced components. Excitation pattern analyses indicated that listeners may use spectral peaks in the stimulus rather than the change in excitation across the full stimulus bandwidth for spectral shape discrimination tasks. Increasing temporal asynchrony of components resulted in increased thresholds for both groups of listeners to a greater extent in the wide span than the narrow span. Reduced effects of onset asynchrony in the narrow span suggest that spectral resolvability of components plays an important role in the processing of onset asynchrony across frequency.
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Affiliation(s)
- Jennifer J Lentz
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405, USA.
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39
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Mannick EE, Bonomolo JC, Horswell R, Lentz JJ, Serrano MS, Zapata-Velandia A, Gastanaduy M, Himel JL, Rose SL, Udall JN, Hornick CA, Liu Z. Gene expression in mononuclear cells from patients with inflammatory bowel disease. Clin Immunol 2004; 112:247-57. [PMID: 15308118 DOI: 10.1016/j.clim.2004.03.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Accepted: 03/17/2004] [Indexed: 01/16/2023]
Abstract
OBJECTIVES Discovery of Nod2 as the inflammatory bowel disease 1 (IBD1) susceptibility gene has brought to light the significance of mononuclear cells in inflammatory bowel disease pathogenesis. The purpose of this study was to examine changes in gene expression in peripheral blood mononuclear cells in patients with untreated Crohn's disease (CD) and ulcerative colitis (UC) as compared to patients with other inflammatory gastrointestinal disorders and to healthy controls. METHODS We used a 2400 gene cDNA glass slide array (MICROMAX) to examine gene expression in peripheral blood mononuclear cells from seven patients with Crohn's disease, five patients with ulcerative colitis, 10 patients with other inflammatory gastrointestinal disorders, and 22 age- and sex-matched controls. Results. Novel categories of genes differentially expressed in Crohn's disease and ulcerative colitis patients included genes regulating hematopoietic cell differentiation and leukemogenesis, lipid raft-associated signaling, the actin cytoskeleton, and vesicular trafficking. CONCLUSIONS Altered gene expression in mononuclear cells may contribute to inflammatory bowel disease pathogenesis.
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40
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Zapata-Velandia A, Ng SS, Brennan RF, Simonsen NR, Gastanaduy M, Zabaleta J, Lentz JJ, Craver RD, Correa H, Delgado A, Pitts AL, Himel JR, Udall JN, Schmidt-Sommerfeld E, Brown RF, Athas GB, Keats BB, Mannick EE. Association of the T allele of an intronic single nucleotide polymorphism in the colony stimulating factor 1 receptor with Crohn's disease: a case-control study. J Immune Based Ther Vaccines 2004; 2:6. [PMID: 15144560 PMCID: PMC428583 DOI: 10.1186/1476-8518-2-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Accepted: 05/14/2004] [Indexed: 11/10/2022]
Abstract
BACKGROUND: Polymorphisms in several genes (NOD2, MDR1, SLC22A4) have been associated with susceptibility to Crohn's disease. Identification of the remaining Crohn's susceptibility genes is essential for the development of disease-specific targets for immunotherapy. Using gene expression analysis, we identified a differentially expressed gene on 5q33, the colony stimulating factor 1 receptor (CSF1R) gene, and hypothesized that it is a Crohn's susceptibility gene. The CSF1R gene is involved in monocyte to macrophage differentiation and in innate immunity. METHODS: Patients provided informed consent prior to entry into the study as approved by the Institutional Review Board at LSU Health Sciences Center. We performed forward and reverse sequencing of genomic DNA from 111 unrelated patients with Crohn's disease and 108 controls. We also stained paraffin-embedded, ileal and colonic tissue sections from patients with Crohn's disease and controls with a polyclonal antibody raised against the human CSF1R protein. RESULTS: A single nucleotide polymorphism (A2033T) near a Runx1 binding site in the eleventh intron of the colony stimulating factor 1 receptor was identified. The T allele of this single nucleotide polymorphism occurred in 27% of patients with Crohn's disease but in only 13% of controls (X2 = 6.74, p < 0.01, odds ratio (O.R.) = 2.49, 1.23 < O.R. < 5.01). Using immunohistochemistry, positive staining with a polyclonal antibody to CSF1R was observed in the superficial epithelium of ileal and colonic tissue sections. CONCLUSIONS: We conclude that the colony stimulating factor receptor 1 gene may be a susceptibility gene for Crohn's disease.
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Affiliation(s)
- Adriana Zapata-Velandia
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - San-San Ng
- Louisiana State University Department of Genetics, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - Rebecca F Brennan
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
| | - Neal R Simonsen
- Louisiana State University School of Public Health, New Orleans, LA, 70112 USA
| | - Mariella Gastanaduy
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - Jovanny Zabaleta
- Louisiana State University Department of Pathology, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - Jennifer J Lentz
- Louisiana State University Department of Genetics, New Orleans, LA 70112, USA
| | - Randall D Craver
- Louisiana State University Department of Pathology, New Orleans, LA 70112, USA
| | - Hernan Correa
- Louisiana State University Department of Pathology, New Orleans, LA 70112, USA
| | - Alberto Delgado
- Louisiana State University Department of Pathology, New Orleans, LA 70112, USA
| | - Angela L Pitts
- Louisiana State University Department of Genetics, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - Jane R Himel
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - John N Udall
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
| | | | - Raynorda F Brown
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
| | - Grace B Athas
- Louisiana State University Department of Pathology, New Orleans, LA 70112, USA
| | - Bronya B Keats
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
| | - Elizabeth E Mannick
- Louisiana State University Department of Pediatrics, New Orleans, LA 70112, USA
- Stanley S. Scott Cancer Center, New Orleans, LA 70112, USA
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Kim HJ, Lentz JJ, Sornasse T, Mannick EE. DECREASED EXPRESSION OF CYTOTOXIC T-CELL ACTIVATION GENES IN PERIPHERAL BLOOD MONONUCLEAR CELLS FROM PATIENTS WITH CROHNʼS DISEASE. J Investig Med 2004. [DOI: 10.1097/00042871-200401001-00746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kim HJ, Lentz JJ, Sornasse T, Mannick EE. 193 DECREASED EXPRESSION OF CYTOTOXIC T-CELL ACTIVATION GENES IN PERIPHERAL BLOOD MONONUCLEAR CELLS FROM PATIENTS WITH CROHN'S DISEASE. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Zapata-Velandia AM, Ng SS, Brennan R, Gastanaduy MM, Byrne P, Lentz JJ, Udall JN, Brown R, Schmidt-Sommerfeld E, Sornasse T, Keats BJ, Mannick EE. 195 PREVALENCE OF A SINGLE NUCLEOTIDE POLYMORPHISM IN FLJ21425 IN LOUISIANA PATIENTS WITH CROHN'S DISEASE. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
The ability to discriminate between sounds with different spectral shapes was evaluated for normal-hearing and hearing-impaired listeners. Listeners discriminated between a standard stimulus and a signal stimulus in which half of the standard components were decreased in level and half were increased in level. In one condition, the standard stimulus was the sum of six equal-amplitude tones (equal-SPL), and in another the standard stimulus was the sum of six tones at equal sensation levels re: audiometric thresholds for individual subjects (equal-SL). Spectral weights were estimated in conditions where the amplitudes of the individual tones were perturbed slightly on every presentation. Sensitivity was similar in all conditions for normal-hearing and hearing-impaired listeners. The presence of perturbation and equal-SL components increased thresholds for both groups, but only small differences in weighting strategy were measured between the groups depending on whether the equal-SPL or equal-SL condition was tested. The average data suggest that normal-hearing listeners may rely more on the central components of the spectrum whereas hearing-impaired listeners may have been more likely to use the edges. However, individual weighting functions were quite variable, especially for the HI listeners, perhaps reflecting difficulty in processing changes in spectral shape due to hearing loss. Differences in weighting strategy without changes in sensitivity suggest that factors other than spectral weights, such as internal noise or difficulty encoding a reference stimulus, also may dominate performance.
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Affiliation(s)
- Jennifer J Lentz
- Army Audiology and Speech Center, Walter Reed Army Medical Center, Washington, DC 20307, USA.
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Abstract
The ability to discriminate between sounds with different spectral shapes was evaluated for normal-hearing and hearing-impaired listeners. Listeners detected a 920-Hz tone added in phase to a single component of a standard consisting of the sum of five tones spaced equally on a logarithmic frequency scale ranging from 200 to 4200 Hz. An overall level randomization of 10 dB was either present or absent. In one subset of conditions, the no-perturbation conditions, the standard stimulus was the sum of equal-amplitude tones. In the perturbation conditions, the amplitudes of the components within a stimulus were randomly altered on every presentation. For both perturbation and no-perturbation conditions, thresholds for the detection of the 920-Hz tone were measured to compare sensitivity to changes in spectral shape between normal-hearing and hearing-impaired listeners. To assess whether hearing-impaired listeners relied on different regions of the spectrum to discriminate between sounds, spectral weights were estimated from the perturbed standards by correlating the listener's responses with the level differences per component across two intervals of a two-alternative forced-choice task. Results showed that hearing-impaired and normal-hearing listeners had similar sensitivity to changes in spectral shape. On average, across-frequency correlation functions also were similar for both groups of listeners, suggesting that as long as all components are audible and well separated in frequency, hearing-impaired listeners can use information across frequency as well as normal-hearing listeners. Analysis of the individual data revealed, however, that normal-hearing listeners may be better able to adopt optimal weighting schemes. This conclusion is only tentative, as differences in internal noise may need to be considered to interpret the results obtained from weighting studies between normal-hearing and hearing-impaired listeners.
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Affiliation(s)
- Jennifer J Lentz
- Army Audiology and Speech Center, Walter Reed Army Medical Center, Washington, DC 20307, USA.
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Rosen HR, McHutchison JG, Conrad AJ, Lentz JJ, Marousek G, Rose SL, Zaman A, Taylor K, Chou S. Tumor necrosis factor genetic polymorphisms and response to antiviral therapy in patients with chronic hepatitis C. Am J Gastroenterol 2002; 97:714-20. [PMID: 11922568 DOI: 10.1111/j.1572-0241.2002.05552.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Hepatitis C virus (HCV) is the major causal agent of non-A, non-B hepatitis and the leading indication for liver transplantation worldwide. The emerging field of immunogenetics has confirmed the significant role of heritability in host immune responses to infectious pathogens. Both the major and non-major histocompatibility complex genes are increasingly identified as candidate genes hypothesized to influence the susceptibility to, or the course of, a particular disease. We hypothesized that polymorphisms within the major histocompatibility complex class III region that encode for tumor necrosis factors (TNF)-alpha and TNF-beta might be predictive of response to antiviral therapy in patients with chronic hepatitis C. METHODS A total of 155 subjects, including 110 HCV-seropositive individuals undergoing antiviral therapy and 45 ethnically similar HCV-negative controls, were studied. The HCV-positive patients had undergone antiviral treatment with either interferon monotherapy (n = 73) or in combination with ribavirin (n = 37) and were categorized as either nonresponders, sustained responders, or relapsers. Sixty (55%) patients had genotype 1 (1a or 1b). Genomic DNA was extracted, followed by polymerase chain reaction amplification and sequencing for two promoter TNF-alpha variants (at positions -238 and -308), as well as restriction fragment length analysis for four polymorphic loci within the TNF-beta gene (NcoI, TNFc, aa13, aa26). RESULTS Although there was a trend toward higher frequency of the A allele in the TNF 238 promoter among HCV-infected patients (12% vs 4%), there were no significant differences in the distribution of the genotypic polymorphisms between patients and controls. Patients with the TNF 238 A allele had higher pretreatment viral loads as compared with patients homozygous for the wild type allele (7.2 x 10(6) +/- 4.2 x 10(6) copies/ml vs 3.8 x 10(6) +/- 0.34 x 10(6) copies/ml, p = 0.03). However, there was no association between TNF genetic markers, including multiple haplotypic combinations, and response to therapy. In addition, there was no correlation with these polymorphic loci and histological severity of liver disease. CONCLUSIONS Although previous work has suggested potential roles for TNF in the pathogenesis of HCV infection, we were unable to identify any link between TNF genetic polymorphisms and histological severity or response to antiviral therapy.
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Affiliation(s)
- Hugo R Rosen
- Division of Gastroenterology, Portland VAMC and Oregon Health Sciences University, 97207, USA
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Abstract
Harmonic complexes with identical component frequencies and amplitudes but different phase spectra may be differentially effective as maskers. Such harmonic waveforms, constructed with positive or negative Schroeder phases, have similar envelopes and identical long-term power spectra, but the positive Schroeder-phase waveform is typically a less effective masker than the negative Schroeder-phase waveform. These masking differences have been attributed to an interaction between the masker phase spectrum and the phase characteristic of the basilar membrane. To explore this relationship, the gradient of stimulus phase change across masker bandwidth was varied by systematically altering the Schroeder-phase algorithm. Observers detected a signal tone added in-phase to a single component of a masker whose frequencies ranged from 200 to 5000 Hz, with a fundamental frequency of 100 Hz. For signal frequencies of 1000-4000 Hz, differences in masking across the harmonic complexes could be as large as 5-10 dB for phase gradients changing by only 10%. The phase gradient that resulted in a minimum amount of masking varied with signal frequency, with low frequencies masked least effectively by stimuli with rapidly changing component phases and high frequencies masked by stimuli with more shallow phase gradients. A gammachirp filter was implemented to model these results, predicting the qualitative changes in curvature of the phase-byfrequency function estimated from the empirical data: In some cases, small modifications to the gammachirp filter produced better quantitative predictions of curvature changes across frequency, but this filter, as implemented here, was unable to accurately represent all the data.
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Affiliation(s)
- J J Lentz
- Army Audiology and Speech Center, Walter Reed Army Medical Center, Washington, DC 20307, USA.
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Rosen HR, Lentz JJ, Rose SL, Rabkin J, Corless CL, Taylor K, Chou S. Donor polymorphism of tumor necrosis factor gene: relationship with variable severity of hepatitis C recurrence after liver transplantation. Transplantation 1999; 68:1898-902. [PMID: 10628771 DOI: 10.1097/00007890-199912270-00014] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Hepatitis C-related liver failure is the leading indication for liver transplantation worldwide. Although histologic recurrence is identified in the majority of patients, the spectrum of allograft injury is wide. To date, most studies have focused on the contribution of immunosuppression and viral factors. We hypothesized that the allograft plays a significant role in determining timing and severity of hepatitis C virus (HCV) recurrence. The purpose of this analysis was to determine if genetic polymorphisms of the tumor necrosis factor (TNF) locus were associated with the highly variable severity of HCV recurrence. METHODS Thirty-one HCV-seropositive liver transplant recipients with long-term follow-up were studied. Genomic DNA was extracted from archived donor spleens which corresponded to each patient. We performed polymerase chain reaction amplification, followed by sequencing for two promoter TNF-alpha variants (at positions -238 and -308), and restriction fragment length analysis for four polymorphic loci within the TNF-beta gene (NcoI, TNFc, aa13, and aa26). RESULTS The relative prevalence of polymorphisms corresponded to distributions previously reported in normal control populations. Twenty-two of 31 (71%) patients received a donor liver homozygous for the wild type allele (TNF1) at the -308 TNF-alpha promoter region. The interval to histologic recurrence was significantly shorter and severity of HCV allograft hepatitis was significantly greater in patients with one or two TNF308.2 alleles. At last follow-up biopsy, 5 of 9 (56%) patients with a TNF308.2 donor liver had evidence of severe histological activity index as compared to 2 of 22 (9%) of patients receiving a donor liver homozygous for the TNF1 allele (P = 0.01). There was no correlation between rejection rates and the presence of any TNF-alpha or TNF-beta alleles. TNF-beta polymorphisms within the donor liver did not correlate with severity of HCV recurrence. CONCLUSIONS The donor TNF-alpha promoter genotype may influence the inflammatory response to HCV reinfection of the graft and contribute to accelerated graft injury. If the association between this genetic marker (TNF308.2) and disease progression is confirmed, it could improve our understanding of HCV pathogenesis and influence donor selection and patient management.
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Affiliation(s)
- H R Rosen
- Department of Medicine, Portland Veterans Affairs Medical Center and Oregon Health Sciences University, USA
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Lentz JJ, Richards VM, Matiasek MR. Different auditory filter bandwidth estimates based on profile analysis, notched noise, and hybrid tasks. J Acoust Soc Am 1999; 106:2779-2792. [PMID: 10573893 DOI: 10.1121/1.428137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Auditory filter bandwidths were estimated in three experiments. The first experiment was a profile-analysis experiment. The stimuli were composed of sinusoidal components ranging in frequency from 200 to 5000 Hz. The standard stimulus was the sum of equal-amplitude tones, and the signal stimulus had a power spectrum that varied up-down ... up-down. The number of components ranged from four to 60. Interval-by-interval level randomization prevented the change in level of a single component from reliably indicating the change from standard to signal. The second experiment was a notched-noise experiment in which the 1000-Hz tone to be detected was added to a noise with a notch arithmetically centered at 1000 Hz. Detection thresholds were estimated both in the presence of and in the absence of level randomization. In the third, hybrid, experiment a 1000-Hz tone was to be detected, and the masker was composed of equal-amplitude sinusoidal components ranging in frequency from 200 to 5000 Hz. For this experiment, thresholds were estimated both in the presence and absence of level variation. For both the notched-noise and hybrid experiments, only modest effects of level randomization were obtained. A variant of Durlach et al.'s channel model ["Towards a model for discrimination of broadband signals," J. Acoust. Soc. Am. 80, 63-72 (1986)] was used to estimate auditory filter bandwidths for all three experiments. When a two-parameter roex(p,r) filter weighting function was used to fit the data, bandwidth estimates were approximately two to three times as large for the two detection tasks than for the profile-analysis task.
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Affiliation(s)
- J J Lentz
- Department of Bioengineering, University of Pennsylvania, Philadelphia 19104, USA
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Abstract
In the first experiment, two measurements were compared--sensitivity to across-frequency changes in level and sensitivity to across-frequency changes in the modulation phase of SAM tones. For the level task, multi-tone stimuli composed of 2-80 tones ranging in frequency from 200 to 5000 Hz were used. For the phase task, the same frequency range was used, and 2-80 SAM tones were tested. For the level task, observers discriminated between a multi-tone, equal-amplitude standard and one of two signals--a one-step or an up-down signal. The one-step signal had higher levels at low frequencies and lower levels at high frequencies. The up-down signal had components with levels that varied high-low-high-low. For the phase task, the standard was the sum of SAM tones with identical modulator phases across frequency. The one-step signal had a common modulator phase at low frequencies and a different common modulator phase at high frequencies. The up-down signal had modulator phases that varied lag-lead-lag-lead. The results suggest that sensitivity to across-frequency changes in level and modulation phase reflect similar initial processing stages. In a second experiment, SAM tones were used, and psychometric functions were measured for the level task, the phase task, and a condition in which changes in level and modulator phase were both present. The standard was "flat," and an up-down signal was to be detected. For one observer, the data suggest that level and phase information are independently represented. For the other two observers, interactions between the two features of the stimuli are apparent. A multiple-looks model was moderately successful in accounting for the data.
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Affiliation(s)
- V M Richards
- Department of Psychology, University of Pennsylvania, Philadelphia 19104, USA
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