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"Muscle fiber"

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
David Rizo-Roca, Juan Gabriel Ríos-Kristjánsson, Cristian Núñez-Espinosa, Estela Santos-Alves, Ines O Goncalves, Jose Magalhaes, Antonio A Ascensao, Teresa Pagès, Ginés Viscor, Joan Ramon Torrella
Unaccustomed eccentric exercise leads to muscle morphological and functional alterations, including microvasculature damage, the repair of which is modulated by hypoxia. Here we present the effects of intermittent hypobaric hypoxia and exercise on recovery from eccentric-induced muscle damage (EEIMD). Soleus muscles from trained rats were excised pre- (CTRL) and 1, 3, 7 and 14 days after a double session of EEIMD protocol. A recovery treatment consisting of one of the following protocols was applied one day after the EEIMD: passive normobaric recovery (PNR), a 4-hour daily exposure to passive hypobaric hypoxia at 4000m (PHR) or hypobaric hypoxia exposure followed by aerobic exercise (AHR)...
October 20, 2016: Journal of Applied Physiology
Alan Pestronk, Richard Keeling, Rati Choksi
OBJECTIVE: We studied mitochondrial impairment as a factor in the pathologic equivalent of sarcopenia, muscle fiber atrophy associated with increased age. METHODS: Mitochondrial oxidative enzyme activities and coenzyme Q10 levels were measured in frozen human proximal limb muscles with combined age and atrophy, age alone, atrophy alone, denervation, immune myopathies, and mitochondrial disorders with ophthalmoplegia. RESULTS: Sarcopenia (age and atrophy) had reduced mean activities of mitochondrial Complexes I, II, and II+III, with severe reduction of Complex I activity in 54% of patients...
October 19, 2016: Muscle & Nerve
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
Sampath K Gollapudi, Murali Chandra
Many studies have demonstrated that depressed myofilament Ca(2+) sensitivity is common to dilated cardiomyopathy (DCM) in humans. However, it remains unclear whether a single determinant-such as myofilament Ca(2+) sensitivity-is sufficient to characterize all cases of DCM because the severity of disease varies widely with a given mutation. Because dynamic features dominate in the heart muscle, alterations in dynamic contractile parameters may offer better insight on the molecular mechanisms that underlie disparate effects of DCM mutations on cardiac phenotypes...
2016: Frontiers in Physiology
Bowen Gao, Qingxiong Yu, Feng Xie, Lingling Sheng, Xiyuan Mao, Qingfeng Li, Hainan Zhu
BACKGROUND: Conventional reconstructive methods fail to achieve satisfactory results in total eyelid defect cases. Vascularized composite tissue allotransplantation might provide both good appearance and function for these patients. The structure of the eyelid is exceptional because it simultaneously consists of skin, connective tissue, the striated muscle, fiber structure, aponeuroses, and mucosa. Thus, before clinical application of eyelid allotransplantation, more experiments are needed to clarify the impact of ischemia, immunal suppressive agents, and deinnervation effects on these sophisticated structures...
October 13, 2016: Ophthalmic Plastic and Reconstructive Surgery
Y M Zheng, W Z Li, Z X Wang, W Zhang, H Lv, J X Xiao, Y Yuan
OBJECTIVE: To report thigh muscle magnetic resonance imaging (MRI) tests of four Chinese patients with dystrophinopathy with edema changes in adductor longus muscles that mimics adductor enthesopathy. METHODS: Four boys, who were from four unrelated families and aged from 5 to 11 years, were investigated because of the clinical manifestations including myalgia or muscle weakness or the incidental findings of elevated serum creatine kinase levels, and were diagnosed with dystrophinopathy by gene test of Duchenne muscular dystrophy (DMD)...
October 18, 2016: Beijing da Xue Xue Bao. Yi Xue Ban, Journal of Peking University. Health Sciences
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
Christoph Zinner, David Morales-Alamo, Niels Ørtenblad, Filip J Larsen, Tomas A Schiffer, Sarah J Willis, Miriam Gelabert-Rebato, Mario Perez-Valera, Robert Boushel, Jose A L Calbet, Hans-Christer Holmberg
To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training...
2016: Frontiers in Physiology
Michela De Bellis, Roberta Carbonara, Julien Roussel, Alessandro Farinato, Ada Massari, Sabata Pierno, Marilena Muraglia, Filomena Corbo, Carlo Franchini, Maria Rosaria Carratù, Annamaria De Luca, Diana Conte Camerino, Jean-François Desaphy
Although the sodium channel blocker, mexiletine, is the first choice drug in myotonia, some myotonic patients remain unsatisfied due to contraindications, lack of tolerability, or incomplete response. More therapeutic options are thus needed for myotonic patients, which require clinical trials based on solid preclinical data. In previous structure-activity relationship studies, we identified two newly-synthesized derivatives of tocainide, To040 and To042, with greatly enhanced potency and use-dependent behavior in inhibiting sodium currents in frog skeletal muscle fibers...
October 12, 2016: Neuropharmacology
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
Sébastien Aubry, Jean-Philippe Nueffer, Mathieu Carrié
In highly anisotropic biological tissues such as muscle or tendons, calculating Young's modulus from the shear wave speed (csw) by using shear wave elastography (SWE) involves a complex transversally isotropic rheological model not yet used in common practice. To our knowledge, the effect of muscle anisotropy on csw of intra-muscular lesions has not yet been investigated. The objective of our study was to define the effect of an anisotropic medium on csw of intra-muscular gelatinous inclusions. We conducted a prospective monocentric, in vitro study in order to examine the quantitative and qualitative SWE behavior of a 9-mm gelatinous intra-muscular implant depending on the orientation of the probe relative to the muscle fibers...
October 11, 2016: Ultrasound in Medicine & Biology
A Burdzinska, B Dybowski, W Zarychta-Wisniewska, A Kulesza, R Zagozdzon, Z Gajewski, L Paczek
Cell therapy is emerging as an alternative treatment of stress urinary incontinence. However, many aspects of the procedure require further optimization. A large animal model is needed to reliably test cell delivery methods. In this study we aim to determine suitability of the goat as an experimental animal for testing intraurethral autologous cell transplantation in terms of urethral anatomy and cell culture parameters. The experiments were performed in 12 mature/aged female goats. Isolated caprine muscle derived cells (MDC) were myogenic in vitro and mesenchymal stem cells (MSC) population was able to differentiate into adipo-, osteo- and chondrogenic lineages...
October 14, 2016: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
Mugundhan Krishnan, C Selvaraj, S Sivakumar
Centronuclear myopathy (CNM) is a rare congenital myopathy that is characterized by centrally placed nuclei in the muscle fibers. Three forms of the disease are clinically recognized. The severe neonatal form, the childhood onset form, and an adult-onset form. We report a 50 year old male patient with centronuclear myopathy (CNM) in whom the disease manifested itself in the fifth decade of life without any family history of such illness.
June 2016: Journal of the Association of Physicians of India
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
Victor Longo, Jon A Jacobson, David P Fessell, Kenneth Mautner
The purpose of this series was to retrospectively characterize the ultrasound findings of delayed-onset muscle soreness (DOMS). The Institutional Review Board approved our study, and informed consent was waived. A retrospective search of radiology reports using the key phrase "delayed-onset muscle soreness" and key word "DOMS" from 2001 to 2015 and teaching files was completed to identify cases. The sonograms were reviewed by 3 fellowship-trained musculoskeletal radiologists by consensus. Sonograms were retrospectively characterized with respect to echogenicity (hypoechoic, isoechoic, or hyperechoic), distribution of muscle involvement, and intramuscular pattern (focal versus diffuse and well defined versus poorly defined)...
October 13, 2016: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
X Cui, R Liu, H Cui, G Zhao, M Zheng, Q Li, J Liu, Z Liu, J Wen
Capons and ovariectomized chickens are birds that have been gonadectomized to improve the meat quality. This study investigated the effects of caponization and ovariectomy on physical, chemical, and fatty acid and amino acid profiles of meat from Beijing-You chickens (a Chinese local breed) at market age (17 wk). All birds (20 capons, 20 ovariectomized, and 40 controls) were reared under the same conditions. Breast muscle fiber diameter and area were significantly smaller and the fiber density was higher in capons and ovariectomized chickens than in controls (P < 0...
October 12, 2016: Poultry Science
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
Kamil Kowalski, Aleksandra Kołodziejczyk, Maria Helena Sikorska, Jagoda Płaczkiewicz, Paulina Cichosz, Magdalena Kowalewska, Wladyslawa Streminska, Katarzyna Janczyk-Ilach, Marta Koblowska, Anna Fogtman, Roksana Iwanicka-Nowicka, Maria A Ciemerych, Edyta Brzoska
The skeletal muscle regeneration occurs due to the presence of tissue specific stem cells - satellite cells. These cells, localized between sarcolemma and basal lamina, are bound to muscle fibers and remain quiescent until their activation upon muscle injury. Due to pathological conditions, such as extensive injury or dystrophy, skeletal muscle regeneration is diminished. Among the therapies aiming to ameliorate skeletal muscle diseases are transplantations of the stem cells. In our previous studies we showed that Sdf-1 (stromal derived factor -1) increased migration of stem cells and their fusion with myoblasts in vitro...
October 13, 2016: Cell Adhesion & Migration
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