Read by QxMD icon Read

Muscle fiber type

J R Jakobsen, A L Mackey, A B Knudsen, M Koch, M Kjaer, M R Krogsgaard
The myotendinous junction (MTJ) is a common site of strain injury and yet understanding of its composition and ability to adapt to loading is poor. The main aims of this study were to determine the profile of selected collagens and macrophage density in human MTJ and adjoining muscle fibers, and to investigate whether heavy exercise loading would alter this profile. Fifteen individuals scheduled for anterior cruciate ligament repair surgery were randomized into three groups: control, acute or 4 weeks heavy resistance training...
October 26, 2016: Scandinavian Journal of Medicine & Science in Sports
Alexis V Mickelson, Sampath K Gollapudi, Murali Chandra
The present study investigated the functional consequences of the human hypertrophic cardiomyopathy (HCM) mutation, A28V, in cardiac troponin T (TnT). The A28V mutation is located within the N-terminus of TnT, a region known to be important for full activation of cardiac thin filaments. The functional consequences of the A28V mutation in TnT remain unknown. Given how α- and β-myosin heavy chain (MHC) isoforms differently alter the effect of the N-terminus of TnT, we hypothesized that the A28V-induced effects would be differently modulated by α- and β-MHC isoforms...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Anand Pandey, Vipin Gupta, Shailendra P Singh, Vijendra Kumar, Rajesh Verma
A trophic ulcer is a pressure ulcer caused by external trauma to a part of the body that is compromised due to disease, vascular insufficiency, or loss of afferent nerve fibers. Spinal dysraphism (ie, neural tube defects [NTD]) such as meningomyelocele is a risk factor for developing these ulcers in adults and pediatric patients. Information regarding the occurrence of trophic ulcers in pediatric patients with NTD is lacking. A review of the English-language literature on skin/neuropathic ulcers in patients with NTDs, irrespective of study design, published between 1975 and 2014, was undertaken using the PubMed database...
December 2015: Ostomy/wound Management
Sree Vamsee Chintapalli, Srinivas Jayanthi, Prema L Mallipeddi, Ravi Kumar Gundampati, Suresh Kumar Thallapuranam Krishnaswamy, Damian B van Rossum, Andriy Anishkin, Sean H Adams
Previous research has indicated that long-chain fatty acids can bind myoglobin (Mb) in an oxygen dependent manner. This suggests that Oxy-Mb may play an important role in fuel delivery in Mb-rich muscle fibers (e.g., type I fibers and cardiomyocytes), and raises the possibility that Mb also serves as an acylcarnitine binding protein. We report for the first time the putative interaction and affinity characteristics for different chain lengths of both fatty acids and acylcarnitines with Oxy-Mb using molecular dynamic simulations and isothermal titration calorimetry experiments...
October 7, 2016: Journal of Biological Chemistry
Alessandra Ruggieri, Simona Saredi, Simona Zanotti, Maria Barbara Pasanisi, Lorenzo Maggi, Marina Mora
Mutations in the DNAJB6 gene have been associated with the autosomal dominant limb girdle muscular dystrophy type 1D (LGMD1D), a disorder characterized by abnormal protein aggregates and rimmed vacuoles in muscle fibers. DNAJB6 is a ubiquitously expressed Hsp40 co-chaperone characterized by a J domain that specifies Hsp70 functions in the cellular environment. DNAJB6 is also a potent inhibitor of expanded polyglutamine (polyQ) aggregation preventing aggregate toxicity in cells. In DNAJB6-mutated patients this anti-aggregation property is significantly reduced, albeit not completely lost...
2016: Frontiers in Molecular Biosciences
M Hirschvogel, M Bassilious, L Jagschies, S M Wildhirt, M W Gee
A model for patient-specific cardiac mechanics simulation is introduced, incorporating a 3-dimensional finite element model of the ventricular part of the heart which is coupled to a reduced-order 0-dimensional closed-loop vascular system, heart valve and atrial chamber model.The ventricles are modeled by a nonlinear orthotropic passive material law. The electrical activation is mimicked by a prescribed parametrized active stress acting along a generic muscle fiber orientation. Our activation function is constructed such that the start of ventricular contraction and relaxation as well as the active stress curve's slope are parameterized...
October 15, 2016: International Journal for Numerical Methods in Biomedical Engineering
Brady K Huang, Eric Y Chang
OBJECTIVE: To describe infraspinatus tendon injuries with associated intramuscular edema in light of more recently elucidated anatomical knowledge. MATERIAL AND METHODS: A retrospective review was performed to identify MRI cases with infraspinatus tendon injury accompanied by muscle edema. MR images were reviewed to evaluate the location of the injury, to assess the degree of tendon retraction, and to assess for muscular changes. Clinical and surgical data were reviewed when available...
October 14, 2016: Skeletal Radiology
Malek Kammoun, Philippe Pouletaut, Francis Canon, Malayannan Subramaniam, John R Hawse, Muriel Vayssade, Sabine F Bensamoun
As transforming growth factor (TGF)-β inducible early gene-1 is highly expressed in skeletal muscle, the effect of TIEG1 gene deletion on the passive mechanical properties of slow and fast twitch muscle fibers was analyzed. Twenty five muscle fibers were harvested from soleus (Sol) and extensor digitorum longus (EDL) muscles from TIEG1-/- (N = 5) and control (N = 5) mice. Mechanical tests were performed on fibers and the dynamic and static stresses were measured. A viscoelastic Hill model of 3rd order was used to fit the experimental relaxation test data...
2016: PloS One
Yoo Kim, Daeyoung Kim, Yeonhwa Park
Previously, it was reported that conjugated linoleic acid (CLA) with exercise training potentially improved endurance capacity via the peroxisome proliferator-activated receptor δ (PPARδ)-mediated mechanism in mice. This study determined the role of exercise and/or CLA in endurance capacity and PPARδ-associated regulators. Male 129Sv/J mice were fed either control (soybean oil) or CLA (0.5%) containing diets for 4 weeks and were further divided into sedentary or training regimes. CLA supplementation significantly reduced body weight and fat mass independent of exercise during the experimental period...
September 7, 2016: Journal of Nutritional Biochemistry
Svitlana Pasteuning-Vuhman, Johanna Boertje-van der Meulen, Maaike van Putten, Maurice Overzier, Peter Ten Dijke, Szymon M Kiełbasa, Wibowo Arindrarto, Ron Wolterbeek, Ksenia V Lezhnina, Ivan V Ozerov, Aleksandr M Aliper, Willem M Hoogaars, Annemieke Aartsma-Rus, Cindy J M Loomans
Skeletal muscle fibrosis and impaired muscle regeneration are major contributors to muscle wasting in Duchenne muscular dystrophy (DMD). Muscle growth is negatively regulated by myostatin (MSTN) and activins. Blockage of these pathways may improve muscle quality and function in DMD. Antisense oligonucleotides (AONs) were designed specifically to block the function of ALK4, a key receptor for the MSTN/activin pathway in skeletal muscle. AON-induced exon skipping resulted in specific Alk4 down-regulation, inhibition of MSTN activity, and increased myoblast differentiation in vitro Unexpectedly, a marked decrease in muscle mass (10%) was found after Alk4 AON treatment in mdx mice...
October 12, 2016: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Benjamin Fabian, Katharina Schneeberg, Rolf Georg Beutel
Genetically modified organisms are crucial for our understanding of gene regulatory networks, physiological processes and ontogeny. With modern molecular genetic techniques allowing the rapid generation of different Drosophila melanogaster mutants, efficient in-depth morphological investigations become an important issue. Anatomical studies can elucidate the role of certain genes in developmental processes and point out which parts of gene regulatory networks are involved in evolutionary changes of morphological structures...
October 6, 2016: Arthropod Structure & Development
Lauren M Sparks, Leanne M Redman, Kevin E Conley, Mary-Ellen Harper, Andrew Hodges, Alexey Eroshkin, Sheila R Costford, Meghan E Gabriel, Fanchao Yi, Cherie Shook, Heather H Cornnell, Eric Ravussin, Steven R Smith
CONTEXT: Reduced mitochondrial coupling (P/O) is associated with sedentariness and insulin resistance. Interpreting the physiological relevance of P/O measured in vitro is challenging. OBJECTIVE: To evaluate muscle mitochondrial function and associated transcriptional profiles in non-obese healthy individuals distinguished by their in vivo P/O. DESIGN: Individuals from an ancillary study of CALERIE Phase 2 were assessed at baseline. SETTING: The study was performed at Pennington Biomedical Research Center in Baton Rouge, LA, USA...
October 6, 2016: Journal of Clinical Endocrinology and Metabolism
E S Rizzi, D M Dourado, R Matias, J A I Muller, J F Guilhermino, A T G Guerrero, D L Moreira, B A K Silva, M Barbosa-Ferreira
Impaired wound healing represents a serious complication in some pathologies and the use of plant extracts has proved to improve tissue repair. The objectives of this study were to evaluate the healing potential of the ointment of Sebastiana hispida compared with Aluminum-Gallium Indium-Phosphide Laser (InGaAlP) in surgically induced wounds in rats and to perform the phytochemical analysis. The phytochemical analysis was performed in the classic way and also by HPLC. A controlled study was developed with 80 rats (200-250 g) in which a linear excision was performed in the dorsal region after shaving, measuring 2 cm × 1 cm (epidermis and dermis) exposing the muscle fascia...
October 3, 2016: Brazilian Journal of Biology, Revista Brasleira de Biologia
Sarah H White, Mary M McDermott, Robert L Sufit, Kate Kosmac, Alex W Bugg, Marta Gonzalez-Freire, Luigi Ferrucci, Lu Tian, Lihui Zhao, Ying Gao, Melina R Kibbe, Michael H Criqui, Christiaan Leeuwenburgh, Charlotte A Peterson
BACKGROUND: Patients with lower extremity peripheral artery disease (PAD) have decreased mobility, which is not fully explained by impaired blood supply to the lower limb. Additionally, reports are conflicted regarding fiber type distribution patterns in PAD, but agree that skeletal muscle mitochondrial respiration is impaired. METHODS: To test the hypothesis that reduced muscle fiber oxidative activity and type I distribution are negatively associated with walking performance in PAD, calf muscle biopsies from non-PAD (n = 7) and PAD participants (n = 26) were analyzed immunohistochemically for fiber type and size, oxidative activity, markers of autophagy, and capillary density...
September 29, 2016: Journal of Translational Medicine
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
Divya Mohan, Amy Lewis, Mehul S Patel, Katrina J Curtis, Jen Y Lee, Nicholas S Hopkinson, Ian B Wilkinson, Paul R Kemp, Michael I Polkey
INTRODUCTION: Quadriceps dysfunction is important in chronic obstructive pulmonary disease (COPD), with an associated increased proportion of type II fibers. Investigation of protein synthesis and degradation has yielded conflicting results, possibly due to study of whole biopsy samples, whereas signalling may be fiber-specific. Our objective was to develop a method for fiber-specific gene expression analysis. METHODS: 12 COPD and 6 healthy subjects underwent quadriceps biopsy...
September 28, 2016: Muscle & Nerve
Kenia López-García, Silvia Mariscal-Tovar, Martín Alejandro Serrano-Meneses, Francisco Castelán, Margarita Martínez-Gómez, Ismael Jiménez-Estrada
AIMS: We analyzed the effect of multiparity on the fiber type composition of two skeletal muscles involved in the maintenance of the micturition process, the pelvic pubococcygeus (Pc) and perineal bulbospongiosus (Bs) muscles in nulliparous and multiparous rabbits (Oryctolagus cuniculus). METHODS: We used the basic ATPase and NADH-TR techniques to identify and characterize slow, intermediate, and fast fiber types and glycolitic and oxidative fibers in muscles, respectively...
September 27, 2016: Neurourology and Urodynamics
Oscar Aze, Étienne Odjardias, Xavier Devillard, Barnabé Akplogan, Paul Calmels, Pascal Giraux
OBJECTIVE: Corticospinal tract damage is responsible for motor function impairment after stroke. However, many processes seem to induce muscle damage, which may limit rehabilitation achievement. To achieve a systematic literature review of human muscular modifications due to post-strike hemiplegia. This review considers structural (histological, biochemical) and physiological modifications and their functional consequences over 1 year after stroke. MATERIAL/PATIENTS AND METHODS: Literature search on PubMed, Embase and Cochrane databases for papers published before February 2016 combining the following keywords cerebral stroke, hemiplegic, atrophy, muscle structure, paresis, skeletal muscle fiber type, motor unit, oxidative stress, strength, motor control led to select forty articles...
September 2016: Annals of Physical and Rehabilitation Medicine
Claire Mietton, Laurent Schaeffer, Nathalie Streichenberger, Vincent Cunin, Berrouz Kassai, Isabelle Poirot
OBJECTIVE: Botulinum toxin is one of the treatments available to treat spasticity in patients with cerebral palsy (CP) from 2 years of age. The long-term action of the toxin on the neuromuscular junction (NMJ) and muscle structure is still unknown. We formulated the hypothesis that repeated injections of botulinum toxin could modify muscle structure. The main aim of our 3-year monocentric descriptive study is to evaluate the long-term effect of repeated injections of botulinum toxin on the muscle and the neuromuscular junction in patients with CP...
September 2016: Annals of Physical and Rehabilitation Medicine
Dorien Goubert, Jessica Van Oosterwijck, Mira Meeus, Lieven Danneels
BACKGROUND: Lumbar muscle dysfunction due to pain might be related to altered lumbar muscle structure. Macroscopically, muscle degeneration in low back pain (LBP) is characterized by a decrease in cross-sectional area and an increase in fat infiltration in the lumbar paraspinal muscles. In addition microscopic changes, such as changes in fiber distribution, might occur. Inconsistencies in results from different studies make it difficult to draw firm conclusions on which structural changes are present in the different types of non-specific LBP...
September 2016: Pain Physician
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"