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strain muscle

Christof B Clemen, Günther E K Benderoth, Andreas Schmidt, Frank Hübner, Thomas J Vogl, Gerhard Silber
In this study, useful methods for active human skeletal muscle material parameter determination are provided. First, a straightforward approach to the implementation of a transversely isotropic hyperelastic continuum mechanical material model in an invariant formulation is presented. This procedure is found to be feasible even if the strain energy is formulated in terms of invariants other than those predetermined by the software's requirements. Next, an appropriate experimental setup for the observation of activation-dependent material behavior, corresponding data acquisition, and evaluation is given...
September 28, 2016: Journal of the Mechanical Behavior of Biomedical Materials
Alessia Cicenia, Floriana Santangelo, Lucrezia Gambardella, Lucia Pallotta, Valerio Iebba, Annunziata Scirocco, Massimo Marignani, Guglielmo Tellan, Marilia Carabotti, Enrico Stefano Corazziari, Serena Schippa, Carola Severi
BACKGROUND: Some beneficial effects of probiotics may be due to secreted probiotic-derived factors, identified as "postbiotic" mediators. The aim of this study was to evaluate whether supernatants harvested from Lactobacillus rhamnosus GG (LGG) cultures (ATCC53103 strain) protect colonic human smooth muscle cells (HSMCs) from lipopolysaccharide (LPS)-induced myogenic damage. MATERIALS AND METHODS: LGG was grown in de Man, Rogosa, Share medium at 37°C and samples were collected in middle and late exponential, stationary, and overnight phases...
November 2016: Journal of Clinical Gastroenterology
Pavlos E Evangelidis, Garry J Massey, Richard A Ferguson, Patrick C Wheeler, Matthew T G Pain, Jonathan P Folland
Hamstrings muscle fiber composition may be predominantly fast-twitch and could explain the high incidence of hamstrings strain injuries. However, hamstrings muscle composition in vivo, and its influence on knee flexor muscle function, remains unknown. We investigated biceps femoris long head (BFlh) myosin heavy chain (MHC) composition from biopsy samples, and the association of hamstrings composition and hamstrings muscle volume (using MRI) with knee flexor maximal and explosive strength. Thirty-one young men performed maximal (concentric, eccentric, isometric) and explosive (isometric) contractions...
October 13, 2016: Scandinavian Journal of Medicine & Science in Sports
Joseph D Lamplot, Matthew J Matava
Quadriceps and hamstring injuries occur frequently in football and are generally treated conservatively. While return to competition following hamstring strains is relatively quick, a high rate of injury recurrence highlights the importance of targeted rehabilitation and conditioning. This review describes the clinical manifestations of thigh-related soft-tissue injuries seen in football players. Two of these-muscle strains and contusions-are relatively common, while a third condition-the Morel-Lavallée lesion-is a rare, yet relevant injury...
September 2016: American Journal of Orthopedics
E David Bell, Anthony J Donato, Kenneth L Monson
Cerebral blood vessels are vital to maintaining the health of the brain. Traumatic brain injury (TBI) commonly results in autoregulatory dysfunction and associated failure of cerebral vessels to maintain homeostasis in the brain. While post-injury changes to brain biochemistry are known to contribute to this dysfunction, tissue deformation may also directly alter vascular smooth muscle cell (SMC) function. As a first step toward understanding stretch-induced dysfunction, this study investigates the effect of overstretch on the contractile behavior of SMCs in middle cerebral arteries (MCAs)...
September 22, 2016: Journal of the Mechanical Behavior of Biomedical Materials
M Moazzem Hossain, Guangyi Zhao, Moon-Sook Woo, James H-C Wang, Jian-Ping Jin
Cell traction force (CTF) plays a critical role in controlling cell shape, enabling cell motility, and maintaining cellular homeostasis in many biological processes such as angiogenesis, development, wound healing, and cancer metastasis. Calponin is an actin filament-associated cytoskeletal protein in smooth muscles and multiple types of non-muscle cells. An established biochemical function of calponin is the inhibition of myosin ATPase in smooth muscle cells. Vertebrates have three calponin isoforms. Among them, calponin 2 is expressed in epithelial cells, endothelial cells, macrophages, myoblasts and fibroblasts, and plays a role in regulating cytoskeleton activities such as cell adhesion, migration and cytokinesis...
October 13, 2016: Biochemistry
Kristin L Popp, William McDermott, Julie M Hughes, Stephanie A Baxter, Steven D Stovitz, Moira A Petit
PURPOSE: To determine differences in bone geometry, estimates of bone strength, muscle size and bone strength relative to load, in women runners with and without a history of stress fracture. METHODS: We recruited 32 competitive distance runners aged 18-35, with (SFX, n=16) or without (NSFX, n=16) a history of stress fracture for this case-control study. Peripheral quantitative computed tomography (pQCT) was used to assess volumetric bone mineral density (vBMD, mg/mm(3)), total (ToA) and cortical (CtA) bone areas (mm(2)), and estimated compressive bone strength (bone strength index; BSI, mg/mm(4)) at the distal tibia...
October 10, 2016: Bone
Velizar Bumbarov, Natalia Golender, Diza Rotenberg, Jacob Brenner
Orbiviruses, some of which are virulent in ruminant species, are transmitted by blood- sucking insects. They can cause the smallest blood vessels to leak, leading to oedema, which is presented as Bluetongue (BT) and/or Epizootic haemorrhagic diseases (EHD). Other clinical manifestations include big-muscle necrosis, excessive scialorrea, and coronitis. Pathology and laboratory testing can con rm the involvement of orbivirus. Bluetongue infection in naïve sheep can elicit the 'classical signs' of the disease and, therefore, can warn of Bluetongue virus' (BTV) attacks and of increased vector activity...
September 30, 2016: Veterinaria Italiana
Lorenzo Marcucci, Carlo Reggiani
Almost 60 years ago Andrew Huxley with his seminal paper (Huxley, 1957) laid the foundation of modern muscle modeling, linking chemical to mechanical events. He described mechanics and energetics of muscle contraction through the cyclical attachment and detachment of myosin motors to the actin filament with ad-hoc assumptions on the dependence of the rate constants on the strain of the myosin motors. That relatively simple hypothesis is still present in recent models, even though with several modifications to adapt the model to the different experimental constraints which became subsequently available...
2016: Frontiers in Physiology
Michal Bencze, Michal Behuliak, Anna Vavřínová, Josef Zicha
AIMS: The goal of our study was to reveal the important mechanism(s) responsible for the enhanced contractility of isolated arteries from animals suffering genetic hypertension. MAIN METHODS: Contractile force of endothelium-denuded arteries, modulated by various interventions, was measured by wire myography. KEY FINDINGS: Spontaneously hypertensive rat (SHR) and Wistar-Kyoto rat (WKY) arteries were stimulated by norepinephrine, increased extracellular K(+) or tyramine...
October 6, 2016: Life Sciences
Geoffrey J Kerr, Matthew R McCann, Jennifer K Branch, Anusha Ratneswaran, Michael A Pest, David W Holdsworth, Frank Beier, S Jeffrey Dixon, Cheryle A Séguin
OBJECTIVE: Whole-body vibration (WBV) platforms are commercially available devices that are used clinically as potential treatments for numerous musculoskeletal conditions based on their reported ability to increase bone mineral density and muscle strength. Despite widespread use, there is an alarming lack of understanding of the direct effects of WBV on joint health. Previous work by our lab demonstrated that repeated exposure to WBV using protocols that model those used clinically, induces intervertebral disc degeneration and osteoarthritis-like damage in the knee of skeletally mature, male mice of a single outbred strain (CD-1)...
October 6, 2016: Osteoarthritis and Cartilage
Giovanni Nardo, Maria Chiara Trolese, Giuseppe de Vito, Roberta Cecchi, Nilo Riva, Giorgia Dina, Paul R Heath, Angelo Quattrini, Pamela J Shaw, Vincenzo Piazza, Caterina Bendotti
BACKGROUND: Increasing evidence suggests that the immune system has a beneficial role in the progression of amyotrophic lateral sclerosis (ALS) although the mechanism remains unclear. Recently, we demonstrated that motor neurons (MNs) of C57SOD1(G93A) mice with slow disease progression activate molecules classically involved in the cross-talk with the immune system. This happens a lot less in 129SvSOD1(G93A) mice which, while expressing the same amount of transgene, had faster disease progression and earlier axonal damage...
October 7, 2016: Journal of Neuroinflammation
Xiaogang Gu, Qingxia Fan, Feng Yang, Le Cai, Nan Zhang, Wenbin Zhou, Weiya Zhou, Sishen Xie
Hybrid hydro-responsive actuators are developed by infiltrating carbon nanotube yarns using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). These actuators demonstrate impressive rotation and contraction in response to water due to volumetric expansion of the helical arrangement of carbon nanotubes. The total torsional stroke is 3720 revolutions per m and the simultaneously generated contractive strain reaches 24% at a paddle-to-yarn mass ratio of 350. The contraction output can furthermore be significantly enhanced by constraining the rotational motion and it reaches 68% with an applied stress of 1 MPa...
October 7, 2016: Nanoscale
Scott D Wagner, Tomofumi Kurobe, Bruce G Hammock, Chelsea H Lam, Gary Wu, Natalia Vasylieva, Shirley J Gee, Bruce D Hammock, Swee J Teh
Pesticides in urban runoff are a major source of pollutants in aquatic ecosystems. Fipronil, a phenylpyrazole insecticide, found in structural pest control products, turf grass control, and home pet flea medication, has recently increased in use and is commonly detected in urban runoff. However, little is known about the effects of fipronil on aquatic organisms at early developmental stages. Here, we evaluated toxicity of fipronil to embryos of Japanese Medaka (Oryzias latipes, Qurt strain) using a high-throughput 96-well plate toxicity test...
January 2017: Chemosphere
Fengli An, Jianlin Wang
In order to explore the effect of strain on diverging post-hatch muscle properties, muscle regulation during embryo development was investigated in selected and unselected breeds. Four broiler strains were used: JingNing (JN) chicken (a Chinese native chicken), HuangYu (HY) broiler, BaiYu (BY) broiler and Hyline layer (commercial crossbred chickens). Results showed that the four breeds had almost the same characteristic during different incubation periods. BY broilers moved more than JN and Hyline layers from Hamburger & Hamilton stage (HH)24 to HH31 (P < 0...
October 6, 2016: Animal Science Journal, Nihon Chikusan Gakkaihō
Kishore K Bokka, Edwin C Jesudason, David Warburton, Sharon R Lubkin
Peristalsis begins in the lung as soon as the smooth muscle (SM) forms, and persists until birth. As the prenatal lung is filled with liquid, SM action can, through lumen pressure, deform tissues far from the immediately adjacent tissues. Stretching of embryonic tissues has been shown to have potent morphogenetic effects. We hypothesize that these effects are at work in lung morphogenesis. In order to refine that broad hypothesis in a quantitative framework, we geometrically analyse cell shapes in an epithelial tissue, and individual cell deformations resulting from peristaltic waves that completely occlude the airway...
October 6, 2016: Interface Focus
Janet A Smereck, Argyro Papafilippaki, Sawali Sudarshan
Bench press exercise, which involves repetitive lifting of weights to full arm extension while lying supine on a narrow bench, has been associated with complications ranging in acuity from simple pectoral muscle strain, to aortic and coronary artery dissection. A 39-year-old man, physically fit and previously asymptomatic, presented with acute chest pain following bench press exercise. Diagnostic evaluation led to the discovery of critical multivessel coronary occlusive disease, and subsequently, highly elevated levels of lipoprotein (a)...
2016: Open Access Emergency Medicine: OAEM
Yasuko Kamiya, Tadao Hasegawa, Yasuhiko Takegami, Kazuhiro Horiba, Shotaro Ando, Yuka Torii, Hiroyuki Kidokoro, Taichi Kato, Jun Natsume, Jun-Ich Kawada, Yoshinori Ito
Primary abscess of the iliopsoas muscle in children is uncommon, especially due to Streptococcus pyogenes (group A streptococcus: GAS), which causes a variety of diseases ranging from pharyngitis to invasive life-threatening infection. We present primary iliopsoas abscess in a nine-year-old boy presenting with fever, mild disturbance of consciousness, limp, and pain in the right loin. Magnetic resonance imaging and isolation of GAS from both blood and abscess samples led us to the confirmative diagnosis. The patient recovered after treatment comprising drainage and intravenous antibiotics...
September 27, 2016: Journal of Infection and Chemotherapy: Official Journal of the Japan Society of Chemotherapy
Hendrik H G Hansen, Gert Jan de Borst, Michiel L Bots, Frans L Moll, Gerard Pasterkamp, Chris L de Korte
BACKGROUND AND PURPOSE: Carotid plaque rupture is a major cause of stroke. Key issue for risk stratification is early identification of rupture-prone plaques. A noninvasive technique, compound ultrasound strain imaging, was developed providing high-resolution radial deformation/strain images of atherosclerotic plaques. This study aims at in vivo validation of compound ultrasound strain imaging in patients by relating the measured strains to typical features of vulnerable plaques derived from histology after carotid endarterectomy...
September 29, 2016: Stroke; a Journal of Cerebral Circulation
Stuart R Young, Bruce Gardiner, Arash Mehdizadeh, Jonas Rubenson, Brian Umberger, David W Smith
While it is known that musculotendon units adapt to their load environments, there is only a limited understanding of tendon adaptation in vivo. Here we develop a computational model of tendon remodeling based on the premise that mechanical damage and tenocyte-mediated tendon damage and repair processes modify the distribution of its collagen fiber lengths. We explain how these processes enable the tendon to geometrically adapt to its load conditions. Based on known biological processes, mechanical and strain-dependent proteolytic fiber damage are incorporated into our tendon model...
September 2016: PLoS Computational Biology
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