Thoracic surgeons utilizing minimally invasive techniques for lung nodule resection often rely on localization markers to determine precise nodule location intraoperatively. Transbronchial or transthoracic injection of indocyanine green (ICG) dye has become a popular technique. However, surgery must be performed immediately as dye will dissipate to surrounding tissue.
View Article and Find Full Text PDFIdentifying new genes responsible for non-syndromic hearing loss remains a critical goal, as many individuals with hereditary deafness still lack a molecular diagnosis despite comprehensive genetic testing. The tectorial membrane (TM) is a specialized, collagen-rich, acellular matrix of the inner ear, essential for stimulating mechanosensitive hair cell bundles during sound transduction, and its structural integrity is critical for frequency tuning and auditory sensitivity. Although mutations in genes encoding a number of non-collagenous proteins found in the TM (TECTA, CEACAM16, OTOG, OTOGL) have been identified as deafness genes, definitive evidence implicating β-tectorin (TECTB) in human hearing loss has been lacking.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
December 2019
Collision with wind turbines is a conservation concern for eagles with population abundance implications. The development of acoustic alerting technologies to deter eagles from entering hazardous air spaces is a potentially significant mitigation strategy to diminish associated morbidity and mortality risks. As a prelude to the engineering of deterrence technologies, auditory function was assessed in bald eagles (Haliaeetus leucocephalus), as well as in red-tailed hawks (Buteo jamaicensis).
View Article and Find Full Text PDFInput-output (IO) properties of cochlear transduction are frequently determined by analyzing the average discharge rates of auditory nerve fibers (ANFs) in response to relatively long tonal stimulation. The ANFs in cats have spontaneous discharge rates (SRs) that are bimodally distributed, peaking at low (<0.5 spikes/s) and high (∼60 spikes/s) rates, and rate-level characteristics differ depending upon SR.
View Article and Find Full Text PDFGermline mutations in Mir96, one of three co-expressed polycistronic miRNA genes (Mir96, Mir182, Mir183), cause hereditary hearing loss in humans and mice. Transgenic FVB/NCrl- Tg(GFAP-Mir183,Mir96,Mir182)MDW1 mice (Tg), which overexpress this neurosensory-specific miRNA cluster in the inner ear, were developed as a model system to identify, in the aggregate, target genes and biologic processes regulated by the miR-183 cluster. Histological assessments demonstrate Tg homozygotes have a modest increase in cochlear inner hair cells (IHCs).
View Article and Find Full Text PDFMicroRNAs (miRNAs), a class of short non-coding RNAs that regulate the expression of mRNA targets, are important regulators of cellular senescence and aging. We questioned which miRNAs are involved in age-related degeneration of the organ of Corti (OC), the auditory sensory epithelium that transduces mechanical stimuli to electrical activity in the inner ear. Degeneration of the OC is generally accepted as the main cause of age-related hearing loss (ARHL), a progressive loss of hearing in individuals as they grow older.
View Article and Find Full Text PDFJ Acoust Soc Am
March 2013
This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha's Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, represented by the number of sequential states in the HMM.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
August 2012
Otoacoustic emissions (sound emitted from the ear) allow cochlear function to be probed noninvasively. The emissions evoked by pure tones, known as stimulus-frequency emissions (SFOAEs), have been shown to provide reliable estimates of peripheral frequency tuning in a variety of mammalian and non-mammalian species. Here, we apply the same methodology to explore peripheral auditory function in the largest member of the cat family, the tiger (Panthera tigris).
View Article and Find Full Text PDFVocal production requires active control of the respiratory system, larynx and vocal tract. Vocal sounds in mammals are produced by flow-induced vocal fold oscillation, which requires vocal fold tissue that can sustain the mechanical stress during phonation. Our understanding of the relationship between morphology and vocal function of vocal folds is very limited.
View Article and Find Full Text PDFAdult mammalian auditory hair cells (HCs) and their associated supporting cells (SCs) do not proliferate, and HC death leads to irreversible neurosensory hearing loss and balance impairment. In nonmammalian vertebrates, loss of HCs induces mitotic proliferation of adjacent nonsensory SCs and/or direct SC transdifferentiation to generate replacement cells. This results in the structural and functional recovery of the nonmammalian sensory systems.
View Article and Find Full Text PDFJ Exp Biol
November 2010
Despite the functional importance of loud, low-pitched vocalizations in big cats of the genus Panthera, little is known about the physics and physiology of the mechanisms producing such calls. We investigated laryngeal sound production in the laboratory using an excised-larynx setup combined with sound-level measurements and pressure-flow instrumentation. The larynges of five tigers (three Siberian or Amur, one generic non-pedigreed tiger with Bengal ancestry and one Sumatran), which had died of natural causes, were provided by Omaha's Henry Doorly Zoo over a five-year period.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2009
Beta(cyto)-actin and gamma(cyto)-actin are ubiquitous proteins thought to be essential building blocks of the cytoskeleton in all non-muscle cells. Despite this widely held supposition, we show that gamma(cyto)-actin null mice (Actg1(-/-)) are viable. However, they suffer increased mortality and show progressive hearing loss during adulthood despite compensatory up-regulation of beta(cyto)-actin.
View Article and Find Full Text PDFJ Assoc Res Otolaryngol
December 2008
It is well known that failure to treat severe congenital hypothyroidism leads to profound auditory disability, and it has been suggested that an intracochlear defect, or defects, associated with the condition diminishes the efficacy of an active, physiologically vulnerable nonlinear transduction process commonly referred to as cochlear amplification. We address this question directly by tracking the development of threshold-frequency (tuning) curves and two-tone suppression in hypothyroid, Tshr mutant mice born to hypothyroid dams and comparing those findings with findings observed in euthyroid mice. Like sharp tuning, two-tone suppression is a product of transduction nonlinearity and is a useful indicator of the functional status of cochlear amplification.
View Article and Find Full Text PDFJ Neurophysiol
January 2008
It is generally believed that the micromechanics of active cochlear transduction mature later than passive elements among altricial mammals. One consequence of this developmental order is the loss of transduction linearity, because an active, physiologically vulnerable process is superimposed on the passive elements of transduction. A triad of sensory advantage is gained as a consequence of acquiring active mechanics; sensitivity and frequency selectivity (frequency tuning) are enhanced and dynamic operating range increases.
View Article and Find Full Text PDFThe human Usher syndrome (USH) is the most frequent cause of combined deaf-blindness. USH is genetically heterogeneous with at least 12 chromosomal loci assigned to three clinical types, USH1-3. Although these USH types exhibit similar phenotypes in human, the corresponding gene products belong to very different protein classes and families.
View Article and Find Full Text PDFThyroid hormone (TH or T3) and TH-receptor beta (TRbeta) have been reported to be relevant for cochlear development and hearing function. Mutations in the TRbeta gene result in deafness associated with resistance to TH syndrome. The effect of TRalpha1 on neither hearing function nor cochlear T3 target genes has been described to date.
View Article and Find Full Text PDFTshrhyt/hyt mutant mice express a point mutation in the gene encoding the thyrotropin receptor, and affected animals are congenitally hypothyroid and profoundly deaf as a consequence when the condition is untreated. In this investigation, a previously unrecognized developmental stage was identified in the hypothyroid, mutant progeny of hypothyroid dams by tracking developmental changes in the auditory brainstem response (ABR). ABR thresholds develop rapidly in normal, euthyroid animals, decreasing as much as 80 dB between P12 (postnatal day 12) and P15, with mature sensitivity being gradually acquired by P18.
View Article and Find Full Text PDFSensory hair bundles in the inner ear are composed of stereocilia that can be interconnected by a variety of different link types, including tip links, horizontal top connectors, shaft connectors, and ankle links. The ankle link antigen is an epitope specifically associated with ankle links and the calycal processes of photoreceptors in chicks. Mass spectrometry and immunoblotting were used to identify this antigen as the avian ortholog of the very large G-protein-coupled receptor VLGR1, the product of the Usher syndrome USH2C (Mass1) locus.
View Article and Find Full Text PDFJ Acoust Soc Am
April 2006
The development of the auditory brainstem response was studied to quantitatively assess its dependence on stimulus frequency and level. Responses were not observed to stimuli > or =16 kHz on P12, however, the full range of responsive frequencies included in the study was observed by P14. Response thresholds were high on P12, exceeding 100 dB SPL for all stimuli tested.
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