Influence of collision on the flow through in-vitro rigid models of the vocal folds

2003 ◽  
Vol 114 (6) ◽  
pp. 3354-3362 ◽  
Author(s):  
M. Deverge ◽  
X. Pelorson ◽  
C. Vilain ◽  
P.-Y. Lagrée ◽  
F. Chentouf ◽  
...  
Keyword(s):  
Vocal Folds ◽  
Flow Through

Numerical simulation of the flow through in vitro models of the vocal folds

1996 ◽  
Vol 100 (4) ◽  
pp. 2657-2657
Author(s):  
Geert C. J. Hofmans ◽  
Massimo Ranucci ◽  
R. Bosch ◽  
A. Hirschberg
Keyword(s):  
Numerical Simulation ◽  
Vocal Folds ◽  
In Vitro Models ◽  
Flow Through

scholarly journals Concurrent YAP/TAZ and SMAD signaling mediate vocal fold fibrosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryosuke Nakamura ◽  
Nao Hiwatashi ◽  
Renjie Bing ◽  
Carina P. Doyle ◽  
Ryan C. Branski
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Nuclear Accumulation ◽  
Smad Pathway ◽  
Surgical Interventions ◽  
Smad Signaling ◽  
Iatrogenic Damage ◽  
Tgf Β1

AbstractVocal fold (VF) fibrosis is a major cause of intractable voice-related disability and reduced quality of life. Excision of fibrotic regions is suboptimal and associated with scar recurrence and/or further iatrogenic damage. Non-surgical interventions are limited, putatively related to limited insight regarding biochemical events underlying fibrosis, and downstream, the lack of therapeutic targets. YAP/TAZ integrates diverse cell signaling events and interacts with signaling pathways related to fibrosis, including the TGF-β/SMAD pathway. We investigated the expression of YAP/TAZ following vocal fold injury in vivo as well as the effects of TGF-β1 on YAP/TAZ activity in human vocal fold fibroblasts, fibroblast-myofibroblast transition, and TGF-β/SMAD signaling. Iatrogenic injury increased nuclear localization of YAP and TAZ in fibrotic rat vocal folds. In vitro, TGF-β1 activated YAP and TAZ in human VF fibroblasts, and inhibition of YAP/TAZ reversed TGF-β1-stimulated fibroplastic gene upregulation. Additionally, TGF-β1 induced localization of YAP and TAZ in close proximity to SMAD2/3, and nuclear accumulation of SMAD2/3 was inhibited by a YAP/TAZ inhibitor. Collectively, YAP and TAZ were synergistically activated with the TGF-β/SMAD pathway, and likely essential for the fibroplastic phenotypic shift in VF fibroblasts. Based on these data, YAP/TAZ may evolve as an attractive therapeutic target for VF fibrosis.

scholarly journals Syringeal vocal folds do not have a voice in zebra finch vocal development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alyssa Maxwell ◽  
Iris Adam ◽  
Pernille S. Larsen ◽  
Peter G. Sørensen ◽  
Coen P. H. Elemans
Keyword(s):  
Zebra Finch ◽  
Neural Circuit ◽  
Vocal Folds ◽  
Pressure Control ◽  
The Body ◽  
Vocal Development ◽  
Postnatal Maturation ◽  
Song System ◽  
Property Changes

AbstractVocal behavior can be dramatically changed by both neural circuit development and postnatal maturation of the body. During song learning in songbirds, both the song system and syringeal muscles are functionally changing, but it is unknown if maturation of sound generators within the syrinx contributes to vocal development. Here we densely sample the respiratory pressure control space of the zebra finch syrinx in vitro. We show that the syrinx produces sound very efficiently and that key acoustic parameters, minimal fundamental frequency, entropy and source level, do not change over development in both sexes. Thus, our data suggest that the observed acoustic changes in vocal development must be attributed to changes in the motor control pathway, from song system circuitry to muscle force, and not by material property changes in the avian analog of the vocal folds. We propose that in songbirds, muscle use and training driven by the sexually dimorphic song system are the crucial drivers that lead to sexual dimorphism of the syringeal skeleton and musculature. The size and properties of the instrument are thus not changing, while its player is.

Atelocollagen Sponge as a Stem Cell Implantation Scaffold for the Treatment of Scarred Vocal Folds

2010 ◽  
Vol 119 (11) ◽  
pp. 805-810 ◽  
Author(s):  
Satoshi Ohno ◽  
Shigeru Hirano ◽  
Ichiro Tateya ◽  
Shin-Ichi Kanemaru ◽  
Hiroo Umeda ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Stromal Cells ◽  
Fluorescent Protein ◽  
In Vitro Study ◽  
Vocal Folds ◽  
Green Fluorescent ◽  
Cell Implantation

Objectives: Treatment of vocal fold scarring remains a therapeutic challenge. Our group previously reported the efficacy of treating injured vocal folds by implantation of bone marrow—derived stromal cells containing mesenchymal stem cells. Appropriate scaffolding is necessary for the stem cell implant to achieve optimal results. Terudermis is an atelocollagen sponge derived from calf dermis. It has large pores that permit cellular entry and is degraded in vivo. These characteristics suggest that this material may be a good candidate for use as scaffolding for implantation of cells. The present in vitro study investigated the feasibility of using Terudermis as such a scaffold. Methods: Bone marrow—derived stromal cells were obtained from GFP (green fluorescent protein) mouse femurs. The cells were seeded into Terudermis and incubated for 5 days. Their survival, proliferation, and expression of extracellular matrix were examined. Results: Bone marrow—derived stromal cells adhered to Terudermis and underwent significant proliferation. Immunohistochemical examination demonstrated that adherent cells were positive for expression of vimentin, desmin, fibronectin, and fsp1 and negative for beta III tubulin. These findings indicate that these cells were mesodermal cells and attached to the atelocollagen fibers biologically. Conclusions: The data suggest that Terudermis may have potential as stem cell implantation scaffolding for the treatment of scarred vocal folds.

An in vitro setup to test the relevance and the accuracy of low-order vocal folds models

2007 ◽  
Vol 121 (1) ◽  
pp. 479-490 ◽  
Author(s):  
Nicolas Ruty ◽  
Xavier Pelorson ◽  
Annemie Van Hirtum ◽  
Ines Lopez-Arteaga ◽  
Avraham Hirschberg
Keyword(s):  
Vocal Folds ◽  
Low Order

In-vitro characterization of flow through mechanical heart valves

2006 ◽  
Vol 39 ◽  
pp. S306 ◽  
Author(s):  
L.P. Dasi ◽  
H. Simon ◽  
L. Ge ◽  
F. Sotiropoulos ◽  
A. Yoganathan
Keyword(s):  
Heart Valves ◽  
Mechanical Heart Valves ◽  
In Vitro Characterization ◽  
Flow Through

scholarly journals COMPARATIVE DISSOLUTION STUDIES OF WARFARIN SODIUM TABLETS: INFLUENCE OF AGITATION RATE, DISSOLUTION MEDIUM, AND USP APPARATUS

2021 ◽  
pp. 117-123
Author(s):  
JOSE RAUL MEDINA LOPEZ ◽  
LUIS DANIEL MAZON ROMAN ◽  
JUAN MANUEL CONTRERAS JIMENEZ ◽  
JUAN CARLOS RUIZ-SEGURA
Keyword(s):  
In Vitro Release ◽  
Agitation Rate ◽  
Dissolution Medium ◽  
Dissolution Studies ◽  
Warfarin Sodium ◽  
Flow Through ◽  
Vitro Release ◽  
Comparative Dissolution ◽  
Paddle Apparatus

Objective: The aim of this study was to carry out comparative dissolution studies with warfarin sodium reference tablets under the hydrodynamic environments generated by the USP basket and paddle apparatus and flow-through cell using different agitation rates and dissolution media. Methods: Dissolution profiles were obtained with the USP basket and paddle apparatus at 50, 75, and 100 rpm and 900 ml of water as dissolution medium. After this, dissolution profiles of warfarin sodium were obtained with the USP paddle apparatus and flow-through cell method using 0.1 N hydrochloric acid, acetate buffer pH 4.5, phosphate buffer pH 6.8, and water. Spectrophotometric determination at 308 nm was carried out during 30 min. Dissolution profiles were compared with model-independent and model-dependent approaches. Results: Significant differences were found with mean dissolution time and dissolution efficiency at 50 and 75 rpm (*P<0.05). Makoid-Banakar was the best-fit model used to describe the in vitro release performance of warfarin sodium with 50-100 rpm and the USP basket and paddle apparatuses. Significant differences in all calculated parameters were found (*P<0.05) excepting percent dissolved at 30 min with 0.1 N hydrochloric acid and phosphate buffer pH 6.8. Conclusion: More research is necessary to identify the in vitro release performance of poorly soluble drugs under available USP apparatuses considering factors as agitation rate and kind of dissolution media. The knowledge of the in vitro release performance of reference drug products is important for the design of better generic formulations

Sign in / Sign up

Export Citation Format

Share Document