Audiology by Alexandros G. Sfakianakis: 05/02/17

Τρίτη 2 Μαΐου 2017

Apoptosis in Vocal Fold Polyps

Publication date: Available online 2 May 2017
Source:Journal of Voice
Author(s): Abdul-Latif Hamdan, Georges Tabet, Zein Saadeddin, Rachel Btaiche, Ibrahim Khalifeh
ObjectiveTo examine the degree of apoptosis and its role in the pathogenesis of polyps of the vocal folds.Material and MethodA review of the pathology department's archives for patients diagnosed with vocal fold polyps between 2010 and 2016 has been conducted. As a control group, gross and microscopically intact vocal fold from laryngectomy specimens was collected. A total of 61 vocal fold polyps from 51 patients and 41 unremarkable vocal folds from the control group were identified. Microscopically, the parameters studied were as follows: apoptosis, mitosis, inflammation, and exocytosis. Apoptotic index (number of apoptotic cells) was determined by the number of apoptotic cells per millimeter square in the epithelium. Apoptotic cells were readily identified by deeply shrunken eosinophilic cells detached from the surrounding environment with pyknotic-degenerated nuclei.ResultsIn polyps, the apoptotic index was statistically higher than the control group (ρ = 0.000). In addition, the increased apoptotic index in polyps showed a statistically proportional increase in mitotic index, inflammation, and exocytosis, which were significantly higher compared to control group.ConclusionAs a key for several therapeutic modalities, manipulation of apoptosis can be a future route for approaching vocal fold polyps by deciphering the complex signal pathways that allow the specified apoptotic cell to be targeted without damaging its surrounding counterpart.

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Potential Causative Factors for Saccular Disorders: Association with Smoking and Other Laryngeal Pathologies

Publication date: Available online 2 May 2017
Source:Journal of Voice
Author(s): Oded Cohen, Sharon Tzelnick, Yael Shapira Galitz, Hagit Shoffel-Havakuk, Moshe Hain, Doron Halperin, Yonatan Lahav
ObjectiveTo describe risk factors, clinical presentation, and outcome of patients with saccular disorders.Study DesignCase control with chart reviewMethodsA single center retrospective study. Case group included all adult patients, presenting with saccular disorders (saccular cyst or laryngocele), between the years 2010 and 2015. A matched group of patients with vocal fold cyst served as the control.ResultsTwenty-nine patients met the inclusion criteria: 15 males and 14 females; the mean age was 60.5(±11.2). The median follow-up period was 10 months (range 2–48). Overall, 75.9% (22) had a positive smoking history; 55.2% (16) were active and 20.7% (6) were past smokers. The median pack- years of all smokers in the saccular disorder group was 40 (range 1–67). Saccular disorder patients demonstrated significantly higher prevalence of active smoking when compared to control patients (55.2% versus 17.9%, P = 0.014).Sixty-nine percent of the patients had some synchronous vocal fold comorbidity. The leading vocal fold comorbidity was Reinke's edema in 41% (12). Synchronous vocal fold comorbidities were significantly more prevalent in smokers compared with nonsmokers—82% (18 of 22) and 29% (2 of 7), respectively (P = 0.008).Surgical treatment was performed on 26 patients; all of whom underwent complete resection, either by endoscopic (92%), external (4%), or combined external and endoscopic (4%) approaches. There was a single case of recurrence (4%), 10 months following initial resection.ConclusionSaccular disorders are associated with smoking and synchronous vocal fold comorbidity. Complete resection is recommended as surgical outcome is excellent.

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Erratum

Audiol Neurotol 2016;21:406

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Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells.

Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells.

Nat Biotechnol. 2017 May 01;:

Authors: Koehler KR, Nie J, Longworth-Mills E, Liu XP, Lee J, Holt JR, Hashino E

Abstract
The derivation of human inner ear tissue from pluripotent stem cells would enable in vitro screening of drug candidates for the treatment of hearing and balance dysfunction and may provide a source of cells for cell-based therapies of the inner ear. Here we report a method for differentiating human pluripotent stem cells to inner ear organoids that harbor functional hair cells. Using a three-dimensional culture system, we modulate TGF, BMP, FGF, and WNT signaling to generate multiple otic-vesicle-like structures from a single stem-cell aggregate. Over 2 months, the vesicles develop into inner ear organoids with sensory epithelia that are innervated by sensory neurons. Additionally, using CRISPR-Cas9, we generate an ATOH1-2A-eGFP cell line to detect hair cell induction and demonstrate that derived hair cells exhibit electrophysiological properties similar to those of native sensory hair cells. Our culture system should facilitate the study of human inner ear development and research on therapies for diseases of the inner ear.

PMID: 28459451 [PubMed - as supplied by publisher]

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Feedback Synthesizes Neural Codes for Motion.

Feedback Synthesizes Neural Codes for Motion.

Curr Biol. 2017 Apr 22;:

Authors: Clarke SE, Maler L

Abstract
In senses as diverse as vision, hearing, touch, and the electrosense, sensory neurons receive bottom-up input from the environment, as well as top-down input from feedback loops involving higher brain regions [1-4]. Through connectivity with local inhibitory interneurons, these feedback loops can exert both positive and negative control over fundamental aspects of neural coding, including bursting [5, 6] and synchronous population activity [7, 8]. Here we show that a prominent midbrain feedback loop synthesizes a neural code for motion reversal in the hindbrain electrosensory ON- and OFF-type pyramidal cells. This top-down mechanism generates an accurate bidirectional encoding of object position, despite the inability of the electrosensory afferents to generate a consistent bottom-up representation [9, 10]. The net positive activity of this midbrain feedback is additionally regulated through a hindbrain feedback loop, which reduces stimulus-induced bursting and also dampens the ON and OFF cell responses to interfering sensory input [11]. We demonstrate that synthesis of motion representations and cancellation of distracting signals are mediated simultaneously by feedback, satisfying an accepted definition of spatial attention [12]. The balance of excitatory and inhibitory feedback establishes a "focal" distance for optimized neural coding, whose connection to a classic motion-tracking behavior provides new insight into the computational roles of feedback and active dendrites in spatial localization [13, 14].

PMID: 28457872 [PubMed - as supplied by publisher]

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