Evaluation of eye tissue elasticity by means of sound propagation speed measuring in vivo

2015 ◽  
Author(s):  
Joao Crispim ◽  
Adriano Bogar ◽  
Norma Allemann ◽  
Jarbas C. C. Neto ◽  
Wallace Chamon
Keyword(s):  
Sound Propagation ◽  
Propagation Speed ◽  
Tissue Elasticity

Assessment of Restored Tissue Elasticity in Prolonged in vivo Animal Tissue Healing: Comparing Fibrin Sealant to Suturing

2020 ◽  
pp. 79-90
Author(s):  
J. F. Lontz ◽  
J. M. Verderamo ◽  
J. Camac ◽  
I. Arikan ◽  
D. Arikan ◽  
...  
Keyword(s):  
Fibrin Sealant ◽  
Animal Tissue ◽  
Tissue Elasticity ◽  
Tissue Healing

Tissue Elasticity Estimation with Optical Coherence Elastography: Toward Mechanical Characterization of In Vivo Soft Tissue

2005 ◽  
Vol 33 (11) ◽  
pp. 1631-1639 ◽  
Author(s):  
Ahmad S. Khalil ◽  
Raymond C. Chan ◽  
Alexandra H. Chau ◽  
Brett E. Bouma ◽  
Mohammad R. Kaazempur Mofrad
Keyword(s):  
Soft Tissue ◽  
Mechanical Characterization ◽  
Optical Coherence ◽  
Tissue Elasticity

scholarly journals Comparison of the effects of e-cigarette vapor with cigarette smoke on lung function and inflammation in mice

2018 ◽  
Vol 315 (5) ◽  
pp. L662-L672 ◽  
Author(s):  
Constantinos Glynos ◽  
Sofia-Iris Bibli ◽  
Paraskevi Katsaounou ◽  
Athanasia Pavlidou ◽  
Christina Magkou ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cigarette Smoke ◽  
Inflammatory Responses ◽  
Electronic Cigarettes ◽  
Ambient Air ◽  
Lavage Fluid ◽  
Pulmonary Mechanics ◽  
Tissue Elasticity ◽  
Stress Markers

Electronic cigarettes (e-cigs) are advertised as a less harmful nicotine delivery system or as a new smoking cessation tool. We aimed to assess the in vivo effects of e-cig vapor in the lung and to compare them to those of cigarette smoke (CS). We exposed C57BL/6 mice for either 3 days or 4 wk to ambient air, CS, or e-cig vapor containing 1) propylene glycol/vegetable glycerol (PG:VG-Sol; 1:1), 2) PG:VG with nicotine (G:VG-N), or 3) PG:VG with nicotine and flavor (PG:VG-N+F) and determined oxidative stress, inflammation, and pulmonary mechanics. E-cig vapors, especially PG:VG-N+F, increased bronchoalveolar lavage fluid (BALF) cellularity, Muc5ac production, as well as BALF and lung oxidative stress markers at least comparably and in many cases more than CS. BALF protein content at both time points studied was only elevated in the PG:VG-N+F group. After 3 days, PG:VG-Sol altered tissue elasticity, static compliance, and airway resistance, whereas after 4 wk CS was the only treatment adversely affecting these parameters. Airway hyperresponsiveness in response to methacholine was increased similarly in the CS and PG:VG-N+F groups. Our findings suggest that exposure to e-cig vapor can trigger inflammatory responses and adversely affect respiratory system mechanics. In many cases, the added flavor in e-cigs exacerbated the detrimental effects of e-cig vapor. We conclude that both e-cig vaping and conventional cigarette smoking negatively impact lung biology.

scholarly journals TMIC-13. FEELING THE FORCE: DIFFERENCES IN THE MECHANOREGULATED MIGRATION OF HIGH GRADE GLIOMA BETWEEN INDIVIDUAL CELLS AND THOSE IN CONTACT WITH OTHER TUMOUR CELLS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi249-vi250
Author(s):  
Thuvarahan Jegathees ◽  
Victoria Prior ◽  
Geraldine O’Neill
Keyword(s):  
Cell Migration ◽  
Single Cell ◽  
Primary Tumour ◽  
Automated Image Analysis ◽  
Migration And Invasion ◽  
Tumour Mass ◽  
High Grade ◽  
Migratory Behaviour ◽  
Tissue Elasticity

Abstract A major limitation in the treatment of High Grade Gliomas (HGG) is their highly disseminating nature. While it is increasingly appreciated that the mechanical properties of the extracellular matrix, (measured as tissue elasticity, Young’s modulus, E), can independently cue cancer cell migration and invasion, to date there has been little consideration of this mechanism in HGG invasion. This is particularly important given that the brain parenchyma is a mechanically soft tissue (E values varying between 1 - 10 kPa). By measuring single cell migration we have previously demonstrated that molecular subclasses of HGGs exhibit different rigidity-sensitive and -insensitive migration. Following these findings, the present project aimed to determine whether these mechanosensitive phenotypes are maintained in the dissemination of multicellular tumour spheroids (MCTSs) that represent in vivo organisation of the primary tumour bulk. Therefore MCTSs composed of primary patient-derived HGG cells with pre-established single cell mechanosensitive phenotypes were cultured on mechanically tuneable polyacrylamide hydrogels, mimicking the range of physiological tissue rigidities. Bright-field time-lapse images were then captured over a period of 48 hours, 6 images per hour. In order to quantitate the migratory behaviours, we adapted a previously published automated image analysis program to segment the MCTS images into proliferative and migratory regions. Our analysis suggests that the cellular mechano-phenotype is affected by contact with neighbouring cells, as the migratory response to tissue stiffness is quantitatively different in the MCTSs. Our results highlight different migratory behaviour between HGG cells within the primary tumour mass versus individual cells that escape. Our results reveal the complex migratory behaviour of HGG cells and suggests that successful anti-invasive therapies will need different strategies depending on tumour cell location.

Effects of compressive lesions on intraoperative human spinal cord elasticity

2021 ◽  
pp. 1-10
Author(s):  
Amro Al-Habib ◽  
Wajda Alhothali ◽  
Abdulrahman Albakr ◽  
Sherif Elwatidy ◽  
Ghaida Alawaji ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Dura Mater ◽  
Shear Wave Elastography ◽  
Conus Medullaris ◽  
Tissue Elasticity ◽  
External Compression ◽  
Human Spinal Cord ◽  
Bone Removal ◽  
The Impact

OBJECTIVE Although evaluating tissue elasticity has various clinical applications, spinal cord elasticity (SCE) in humans has never been well documented. In this study, the authors aimed to evaluate the impact of compression on human SCE in vivo. METHODS The authors prospectively assessed SCE using intraoperative shear wave elastography (SWE). All consecutive patients undergoing spinal cord (SC) decompression (laminectomy or corpectomy) between June 2018 and June 2019 were included. After intraoperative exposure of the patient’s dura mater, at least three SWE measurements of the SC and its coverings were performed. Intraoperative neurological monitoring in the form of motor and somatosensory evoked potentials was utilized. Cases were divided into two groups based on the state of SC compression following bone removal (laminectomy or corpectomy): patients with adequate decompression (the decompressed SC group [DCG]) following bone removal and patients with remining compression, e.g., compressing tumor or instability (the compressed SC group [COG]). RESULTS A total of 25 patients were included (8 females and 17 males) with a mean age of 48.28 ± 21.47 years. Most cases were degenerative diseases (10 cases) followed by tumors (6 cases), and the compression was observed at cervical (n = 14), thoracic (n = 9), and conus medullaris (n = 2) levels. The COG (6 cases) expressed significantly higher elasticity values, i.e., greater stiffness (median 93.84, IQR 75.27–121.75 kPa) than the decompressed SC in DCG (median 9.35, IQR 6.95–11.22 kPa, p < 0.001). Similarly, the compressed dura mater in the COG was significantly stiffer (mean ± SD 121.83 ± 70.63 kPa) than that in the DCG (29.78 ± 18.31 kPa, p = 0.042). Following SC decompression in COG, SCE values were significantly reduced (p = 0.006; adjusted for multiple comparisons). Intraoperative monitoring demonstrated no worsening from the baseline. CONCLUSIONS The current study is to the authors’ knowledge the first to quantitatively demonstrate increased stiffness (i.e., elasticity value) of the human SC and dura mater in response to external compression in vivo. It appears that SCE is a dynamic phenomenon and is reduced following decompression. Moreover, the evaluation of human SCE using the SWE technique is feasible and safe. Information from future studies aiming to further define SCE could be valuable in the early and accurate diagnosis of the compressed SC.

Variable Timescales of Repeated Spike Patterns in Synfire Chain with Mexican-Hat Connectivity

2007 ◽  
Vol 19 (9) ◽  
pp. 2468-2491 ◽  
Author(s):  
Kosuke Hamaguchi ◽  
Masato Okada ◽  
Kazuyuki Aihara
Keyword(s):  
Planck Equation ◽  
Propagation Speed ◽  
Feedforward Network ◽  
Synfire Chain ◽  
Mexican Hat ◽  
The Relationship ◽  
Spike Patterns ◽  
Integrate And Fire Neuron

Repetitions of precise spike patterns observed both in vivo and in vitro have been reported for more than a decade. Studies on the spike volley (a pulse packet) propagating through a homogeneous feedforward network have demonstrated its capability of generating spike patterns with millisecond fidelity. This model is called the synfire chain and suggests a possible mechanism for generating repeated spike patterns (RSPs). The propagation speed of the pulse packet determines the temporal property of RSPs. However, the relationship between propagation speed and network structure is not well understood. We studied a feedforward network with Mexican-hat connectivity by using the leaky integrate-and-fire neuron model and analyzed the network dynamics with the Fokker-Planck equation. We examined the effect of the spatial pattern of pulse packets on RSPs in the network with multistability. Pulse packets can take spatially uniform or localized shapes in a multistable regime, and they propagate with different speeds. These distinct pulse packets generate RSPs with different timescales, but the order of spikes and the ratios between interspike intervals are preserved. This result indicates that the RSPs can be transformed into the same template pattern through the expanding or contracting operation of the timescale.

scholarly journals Extracellular Matrix and the Production of Cultured Meat

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3116
Author(s):  
Khurshid Ahmad ◽  
Jeong-Ho Lim ◽  
Eun-Ju Lee ◽  
Hee-Jin Chun ◽  
Shahid Ali ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Mechanical Stability ◽  
Culture Media ◽  
Low Cost ◽  
Meat Products ◽  
Meat Production ◽  
Tissue Elasticity ◽  
Cultured Meat ◽  
Tissue Scaffolding

Cultured meat production is an evolving method of producing animal meat using tissue engineering techniques. Cells, chemical factors, and suitable biomaterials that serve as scaffolds are all essential for the cultivation of muscle tissue. Scaffolding is essential for the development of organized meat products resembling steaks because it provides the mechanical stability needed by cells to attach, differentiate, and mature. In in vivo settings, extracellular matrix (ECM) ensures substrates and scaffolds are provided for cells. The ECM of skeletal muscle (SM) maintains tissue elasticity, creates adhesion points for cells, provides a three-dimensional (3D) environment, and regulates biological processes. Consequently, creating mimics of native ECM is a difficult task. Animal-derived polymers like collagen are often regarded as the gold standard for producing scaffolds with ECM-like properties. Animal-free scaffolds are being investigated as a potential source of stable, chemically defined, low-cost materials for cultured meat production. In this review, we explore the influence of ECM on myogenesis and its role as a scaffold and vital component to improve the efficacy of the culture media used to produce cultured meat.

scholarly journals Spatial distribution of loose connective tissues on the anterior hip joint capsule: a combination of cadaveric and in-vivo study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masahiro Tsutsumi ◽  
Akimoto Nimura ◽  
Hajime Utsunomiya ◽  
Shintarou Kudo ◽  
Keiichi Akita
Keyword(s):  
Spatial Distribution ◽  
Vastus Lateralis ◽  
Morphological Characteristics ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Joint Capsule ◽  
Tissue Elasticity ◽  
Fat Pad ◽  
Anterior Portion

AbstractRecently, pathological changes in the fat pad on the anterior inferior iliac spine (AIIS), between the proximal rectus femoris and joint capsule, have been highlighted as a cause of anterior hip pain. However, precise fat pad features, such as the spatial distribution distal to the AIIS, histological features, and in vivo tissue elasticity, remain unclear. This study aimed to investigate the morphological characteristics of the fat pad on the AIIS. Four hips from four cadaveric donors were both macroscopically and histologically investigated, and eight hips from four volunteers were assessed using ultrasonography. The fat pad on the AIIS was also surrounded by the iliopsoas and gluteus minimus, extending distally to the superficial portion of the vastus lateralis, and the anterior portion of the gluteus maximus tendon. Histological analysis revealed that the fat pad was composed of loose connective tissue. Based on the ultrasonography, the shear wave velocity in the fat pad was significantly lower than that in the joint capsule. Conclusively, the pathological adhesion between the joint capsule and pericapsular muscles, if caused by fat pad fibrosis, may occur following the abovementioned fat pad spatial distribution.

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