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muscle architecture

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https://www.readbyqxmd.com/read/28104754/how-does-passive-lengthening-change-the-architecture-of-the-human-medial-gastrocnemius-muscle
#1
Bart Bolsterlee, Arkiev D'Souza, Simon C Gandevia, Robert D Herbert
There are few comprehensive investigations of the changes in muscle architecture that accompany muscle contraction or change in muscle length in vivo. For this study, we measured changes in the three-dimensional architecture of the human medial gastrocnemius at the whole-muscle level, the fascicle level and the fiber level using anatomical MRI and diffusion tensor imaging (DTI). Data were obtained from eight subjects under relaxed conditions at three muscle lengths. At the whole muscle level, a 5.1% increase in muscle belly length resulted in a reduction in both muscle width (mean change -2...
January 19, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28097524/pubovisceralis-muscle-fiber-architecture-determination-comparison-between-biomechanical-modeling-and-diffusion-tensor-imaging
#2
Sofia Brandão, Marco Parente, Elisabete Silva, Thuane Da Roza, Teresa Mascarenhas, João Leitão, João Cunha, Renato Natal Jorge, Rita Gouveia Nunes
Biomechanical analysis of pelvic floor dysfunction requires knowledge of certain biomechanical parameters, such as muscle fiber direction, in order to adequately model function. Magnetic resonance (MR) diffusion tensor imaging (DTI) provides an estimate of overall muscle fiber directionality based on the mathematical description of water diffusivity. This work aimed at evaluating the concurrence between pubovisceralis muscle fiber representations obtained from DTI, and the maximum principal stress lines obtained through the finite element method...
January 17, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28093066/predictive-performance-of-genomic-selection-methods-for-carcass-traits-in-hanwoo-beef-cattle-impacts-of-the-genetic-architecture
#3
Hossein Mehrban, Deuk Hwan Lee, Mohammad Hossein Moradi, Chung IlCho, Masoumeh Naserkheil, Noelia Ibáñez-Escriche
BACKGROUND: Hanwoo beef is known for its marbled fat, tenderness, juiciness and characteristic flavor, as well as for its low cholesterol and high omega 3 fatty acid contents. As yet, there has been no comprehensive investigation to estimate genomic selection accuracy for carcass traits in Hanwoo cattle using dense markers. This study aimed at evaluating the accuracy of alternative statistical methods that differed in assumptions about the underlying genetic model for various carcass traits: backfat thickness (BT), carcass weight (CW), eye muscle area (EMA), and marbling score (MS)...
January 4, 2017: Genetics, Selection, Evolution: GSE
https://www.readbyqxmd.com/read/28070887/diversity-in-the-organization-of-elastin-bundles-and-intramembranous-muscles-in-bat-wings
#4
Jorn A Cheney, Justine J Allen, Sharon M Swartz
Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology...
January 10, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/28063610/ultrasound-measurements-of-skeletal-muscle-architecture-are-associated-with-strength-and-functional-capacity-in-older-adults
#5
Isaac Selva Raj, Stephen R Bird, Anthony J Shield
The goal of this study was to determine whether ultrasound measures of muscle architecture can be used to infer strength and functional capacity in older adults. Thirty-six healthy older adults (aged 68.2 ± 5.3 y) undertook isokinetic dynamometry for isometric and isokinetic concentric knee extensor strength, the 6-m fast walk, timed up and go, stair climb and descent and vertical jump tests. Longitudinal brightness-mode ultrasound scans (probe frequency, 10 MHz) of the vastus lateralis, vastus intermedius, rectus femoris and gastrocnemius medialis were obtained, and muscle architecture measures (thickness, fascicle pennation angle and fascicle length) were correlated with the aforementioned strength and functional measures...
January 4, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28063595/the-mitochondrial-targeted-peptide-ss-31-improves-glomerular-architecture-in-mice-of-advanced-age
#6
Mariya T Sweetwyne, Jeffrey W Pippin, Diana G Eng, Kelly L Hudkins, Ying Ann Chiao, Matthew D Campbell, David J Marcinek, Charles E Alpers, Hazel H Szeto, Peter S Rabinovitch, Stuart J Shankland
Although age-associated changes in kidney glomerular architecture have been described in mice and man, the mechanisms are unknown. It is unclear if these changes can be prevented or even reversed by systemic therapies administered at advanced age. Using light microscopy and transmission electron microscopy, our results showed glomerulosclerosis with injury to mitochondria in glomerular epithelial cells in mice aged 26 months (equivalent to a 79-year-old human). To test the hypothesis that reducing mitochondrial damage in late age would result in lowered glomerulosclerosis, we administered the mitochondrial targeted peptide, SS-31, to aged mice...
January 4, 2017: Kidney International
https://www.readbyqxmd.com/read/28060301/cryosectioning-of-contiguous-regions-of-a-single-mouse-skeletal-muscle-for-gene-expression-and-histological-analyses
#7
Aaron M Beedle
With this method, consecutive cryosections are collected to enable both microscopy applications for tissue histology and enrichment of RNA for gene expression using adjacent regions from a single mouse skeletal muscle. Typically, it is challenging to achieve adequate homogenization of small skeletal muscle samples because buffer volumes may be too low for efficient grinding applications, yet without sufficient mechanical disruption, the dense tissue architecture of muscle limits penetration of buffer reagents, ultimately causing low RNA yield...
December 12, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28054418/could-the-peristaltic-transition-zone-be-caused-by-non-uniform-esophageal-muscle-fiber-architecture-a-simulation-study
#8
W Kou, J E Pandolfino, P J Kahrilas, N A Patankar
BACKGROUND: Based on a fully coupled computational model of esophageal transport, we analyzed how varied esophageal muscle fiber architecture and/or dual contraction waves (CWs) affect bolus transport. Specifically, we studied the luminal pressure profile in those cases to better understand possible origins of the peristaltic transition zone. METHODS: Two groups of studies were conducted using a computational model. The first studied esophageal transport with circumferential-longitudinal fiber architecture, helical fiber architecture and various combinations of the two...
January 5, 2017: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
https://www.readbyqxmd.com/read/28049266/does-vitamin-d-affect-muscle-strength-and-architecture-an-isokinetic-and-ultrasonographic-study
#9
Murat Kara, Timur Ekiz, Özgür Kara, Tülay Tiftik, Fevziye Ünsal Malas, Sibel Özbudak Demir, Neşe Özgirgin
BACKGROUND AND OBJECTIVES: The objective of this study was to explore the association between 25- hydroxyvitamin D (25(OH)D) and muscle strength/architecture. METHODS AND STUDY DESIGN: Thirty patients (27 women, 3 men) were allocated into Group I (n=15, mean age; 44.4±9.4 years) and Group II (n=15, mean age; 39.0±9.9 years) according to the median of 25(OH)D (<13.7 ng/mL vs >13.7 ng/mL, respectively). Peak torque/body weight of the knee flexor/extensor muscles at 60°/sec and 180°/sec and those of ankle flexor/ extensor muscles at 30°/sec and 90°/sec were evaluated by using a Biodex System 3 Pro Multijoint System isokinetic dynamometer...
January 2017: Asia Pacific Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28036147/capillary-endothelial-cells-as-coordinators-of-skeletal-muscle-blood-flow-during-active-hyperaemia
#10
Coral L Murrant, Iain R Lamb, Nicole M Novielli
In this invited review we explore the burgeoning possibility of capillary endothelial cells as coordinators of skeletal muscle blood flow in response to muscle contraction. he idea that the capillary is an active vascular unit in the microcirculation starkly diverges from the traditional dogma that seats arterioles as the central controllers of blood flow during exercise, this review aims to incite discussion as we revisit and rethink the role of capillary endothelial cells in skeletal muscle. We discuss the potential for a mismatch in the architectural relationships between the arteriolar microvasculature and contracting motor units that would negate consistent communication between them...
December 30, 2016: Microcirculation: the Official Journal of the Microcirculatory Society, Inc
https://www.readbyqxmd.com/read/28028847/muscle-excitability-during-sustained-maximal-voluntary-contractions-by-a-separate-analysis-of-the-m-wave-phases
#11
J Rodriguez-Falces, N Place
This study was designed to examine separately the changes in the first and second phases of the muscle compound action potential (M-wave) during and after a sustained 3-minutes maximal voluntary contraction (MVC). M-waves were evoked by supramaximal single shocks to the femoral nerve given at 10-seconds intervals throughout a sustained isometric 3-minutes MVC and also during six brief MVCs performed throughout a 30-minutes recovery period. The amplitude, duration, and area of the M-wave first and second phases, together with muscle conduction velocity and force, were measured...
December 28, 2016: Scandinavian Journal of Medicine & Science in Sports
https://www.readbyqxmd.com/read/28026793/a-wireless-semg-based-body-machine-interface-for-assistive-technology-devices
#12
Cheikh Latyr Fall, Gabriel Gagnon-Turcotte, J F Dube, Jean Simon Gagne, Yanick Delisle, Alexandre Campeau-Lecours, Clement Gosselin, Benoit Gosselin
Assistive Technology (AT) tools and appliances are being more and more widely used and developed worldwide to improve the autonomy of people living with disabilities and ease the interaction with their environments. This paper describes an intuitive and wireless surface electromyography (sEMG) based body-machine interface for AT tools. Spinal cord injuries (SCIs) at C5-C8 levels affect patients' arms, forearms, hands and fingers control. Thus, using classical AT control interfaces (keypads, joysticks, etc.) is often difficult or impossible...
December 21, 2016: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/28006074/openeyesim-a-biomechanical-model-for-simulation-of-closed-loop-visual-perception
#13
Alexander Priamikov, Maria Fronius, Bertram Shi, Jochen Triesch
We introduce OpenEyeSim, a detailed three-dimensional biomechanical model of the human extraocular eye muscles including a visualization of a virtual environment. The main purpose of OpenEyeSim is to serve as a platform for developing models of the joint learning of visual representations and eye-movement control in the perception-action cycle. The architecture and dynamic muscle properties are based on measurements of the human oculomotor system. We show that our model can reproduce different types of eye movements...
December 1, 2016: Journal of Vision
https://www.readbyqxmd.com/read/28003562/a-novel-diffusion-tensor-mri-approach-for-skeletal-muscle-fascicle-length-measurements
#14
Jos Oudeman, Valentina Mazzoli, Marco A Marra, Klaas Nicolay, Mario Maas, Nico Verdonschot, Andre M Sprengers, Aart J Nederveen, Gustav J Strijkers, Martijn Froeling
Musculoskeletal (dys-)function relies for a large part on muscle architecture which can be obtained using Diffusion-Tensor MRI (DT-MRI) and fiber tractography. However, reconstructed tracts often continue along the tendon or aponeurosis when using conventional methods, thus overestimating fascicle lengths. In this study, we propose a new method for semiautomatic segmentation of tendinous tissue using tract density (TD). We investigated the feasibility and repeatability of this method to quantify the mean fascicle length per muscle...
December 2016: Physiological Reports
https://www.readbyqxmd.com/read/28002649/toward-modeling-locomotion-using-electromyography-informed-3d-models-application-to-cerebral-palsy
#15
REVIEW
M Sartori, J W Fernandez, L Modenese, C P Carty, L A Barber, K Oberhofer, J Zhang, G G Handsfield, N S Stott, T F Besier, D Farina, D G Lloyd
This position paper proposes a modeling pipeline to develop clinically relevant neuromusculoskeletal models to understand and treat complex neurological disorders. Although applicable to a variety of neurological conditions, we provide direct pipeline applicative examples in the context of cerebral palsy (CP). This paper highlights technologies in: (1) patient-specific segmental rigid body models developed from magnetic resonance imaging for use in inverse kinematics and inverse dynamics pipelines; (2) efficient population-based approaches to derive skeletal models and muscle origins/insertions that are useful for population statistics and consistent creation of continuum models; (3) continuum muscle descriptions to account for complex muscle architecture including spatially varying material properties with muscle wrapping; (4) muscle and tendon properties specific to CP; and (5) neural-based electromyography-informed methods for muscle force prediction...
December 21, 2016: Wiley Interdisciplinary Reviews. Systems Biology and Medicine
https://www.readbyqxmd.com/read/28002411/structure-of-a-clc-chloride-ion-channel-by-cryo-electron-microscopy
#16
Eunyong Park, Ernest B Campbell, Roderick MacKinnon
CLC proteins transport chloride (Cl(-)) ions across cellular membranes to regulate muscle excitability, electrolyte movement across epithelia, and acidification of intracellular organelles. Some CLC proteins are channels that conduct Cl(-) ions passively, whereas others are secondary active transporters that exchange two Cl(-) ions for one H(+). The structural basis underlying these distinctive transport mechanisms is puzzling because CLC channels and transporters are expected to share the same architecture on the basis of sequence homology...
December 21, 2016: Nature
https://www.readbyqxmd.com/read/27995902/plant-inspired-adaptive-structures-and-materials-for-morphing-and-actuation-a-review
#17
Suyi Li, K W Wang
Plants exhibit a variety of reversible motions, from the slow opening of pine cones to the impulsive closing of Venus flytrap leaves. These motions are achieved without muscles and they have inspired a wide spectrum of engineered materials and structures. This review summarizes the recent developments of plant-inspired adaptive structures and materials for morphing and actuation. We begin with a brief overview of the actuation strategies and physiological features associated to these plant movements, showing that different combinations of these strategies and features can lead to motions with different deformation characteristics and response speeds...
December 20, 2016: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/27994928/a-solitary-fibrous-tumor-of-the-subglottic-larynx-case-report-and-literature-review
#18
Sung-Joon Park, Young Hen Lee, Ki Yeol Lee, Kyoung Ho Oh, Younghye Kim
BACKGROUND: Solitary fibrous tumors (SFT) arising from the larynx are extremely rare; most occur in the supraglottic larynx. CASE REPORT: Herein, we detail a new case of a subglottic SFT presenting as a well-encapsulated soft-tissue tumor with hoarseness. It showed isoattenuation, similar to the adjacent muscle on pre-contrast computed tomography (CT) images, and strong, heterogeneous enhancement following contrast material administration, which may reflect hypervascularity...
November 2016: Balkan Medical Journal
https://www.readbyqxmd.com/read/27989621/binding-of-myomesin-to-obscurin-like-1-at-the-muscle-m-band-provides-a-strategy-for-isoform-specific-mechanical-protection
#19
Stefano Pernigo, Atsushi Fukuzawa, Amy E M Beedle, Mark Holt, Adam Round, Alessandro Pandini, Sergi Garcia-Manyes, Mathias Gautel, Roberto A Steiner
The sarcomeric cytoskeleton is a network of modular proteins that integrate mechanical and signaling roles. Obscurin, or its homolog obscurin-like-1, bridges the giant ruler titin and the myosin crosslinker myomesin at the M-band. Yet, the molecular mechanisms underlying the physical obscurin(-like-1):myomesin connection, important for mechanical integrity of the M-band, remained elusive. Here, using a combination of structural, cellular, and single-molecule force spectroscopy techniques, we decode the architectural and functional determinants defining the obscurin(-like-1):myomesin complex...
January 3, 2017: Structure
https://www.readbyqxmd.com/read/27982040/gene-discovery-in-amyotrophic-lateral-sclerosis-implications-for-clinical-management
#20
REVIEW
Ammar Al-Chalabi, Leonard H van den Berg, Jan Veldink
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease predominantly affecting upper and lower motor neurons. The disease leads to relentlessly progressive weakness of voluntary muscles, with death typically resulting from diaphragmatic failure within 2-5 years. Since the discovery of mutations in SOD1, which account for ∼2% of ALS cases, increasing efforts have been made to understand the genetic component of ALS risk, with the expectation that this insight will not only aid diagnosis and classification, but also guide personalized treatment and reveal the mechanisms that cause motor neuron death...
December 16, 2016: Nature Reviews. Neurology
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