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Muscle physiology

Vanessa Pereira Lima, Vinicius C Iamonti, Marcelo Velloso, Tania Janaudis-Ferreira
PURPOSE: The mechanisms underlying physiological limitations during arm activity in individuals with chronic obstructive pulmonary disease (COPD) are unknown. The objective of this systematic review was to describe cardiorespiratory responses, symptoms, chest wall kinematics, muscle activity, and lung volumes during arm activity in individuals with COPD relative to the responses of healthy controls. METHODS: Original research articles that compared cardiorespiratory responses, symptoms, muscle activity, chest wall kinematics, and lung function during arm activity between individuals with COPD and healthy controls were identified after searches of 5 electronic databases and reference lists of pertinent articles...
November 2016: Journal of Cardiopulmonary Rehabilitation and Prevention
Shu-Fang Chang
PURPOSE: We investigated the relationships among geriatric syndrome, physiological functions, and body composition in community-dwelling older people with varying nutritional statuses. Other factors correlated with nutritional status in community-dwelling older people were also explored. BACKGROUND: The World Health Organization has initiated preventive programs for addressing malnutrition. However, few studies have focused on the correlations among geriatric syndrome, physiological functions, and body composition in older people at risk of malnutrition...
October 25, 2016: Journal of Nursing Scholarship
J Pingel, E M Bartels, J B Nielsen
Muscle contractures are common in patients with central motor lesions, but the mechanisms responsible for the development of contractures are still unclear. Increased or decreased neural activation, protracted placement of a joint with the muscle in a short position and muscle atrophy have been suggested to be involved, but none of these mechanisms are sufficient to explain the development of muscle contractures alone. Here we propose that changes in tissue homeostasis in the neuro-muscular-tendon-connective tissue complex is at the heart of the development of contractures, and that an integrated physiological understanding of the interaction between neural, mechanical and metabolic factors, as well as genetic and epigenetic factors, is necessary in order to unravel the mechanisms that result in muscle contractures...
October 24, 2016: Journal of Physiology
Ni-Na Song, Wen-Xie Xu
Gastrointestinal smooth muscle layer contains two kinds of interstitial cells with special differentiation, i.e., interstitial cells of Cajal (ICC) and platelet-derived growth factor receptor α-positive (PDGFRα(+)) cells. The ICC and PDGFRα(+) cells contact with smooth muscle cells (SMCs) by gap junctions and regulate contractive function of the SMCs. Therefore, these three kinds of cells constitute a functional syncytium, i.e., the SMC, ICC and PDGFRα(+) cells syncytium (SIP syncytium). Various neurotransmitters, humoral factors, endogenous bioactive molecules, as well as drugs regulate gastrointestinal motility through the SIP syncytium...
October 25, 2016: Sheng Li Xue Bao: [Acta Physiologica Sinica]
Mireia Esplugas, Alex Lluch-Bergada, Nathalie Mobargha, Manuel Llusa-Perez, Elisabet Hagert, Marc Garcia-Elias
Purpose In the presence of early osteoarthritis, changes to the trapeziometacarpal joint (TMJ) often result in pain and is associated with joint instability and a tendency of dorsoradial subluxation. In these instances, arthroscopy may be indicated to: (1) assess the extent of cartilage disease and the laxity of ligaments and to (2) treat TMJ instability. The purpose of our study was to biomechanically analyze which ligaments are the primary stabilizers of the TMJ. Methods Overall, 11 fresh-frozen human cadaver specimens were dissected and attached to a testing device with the thumb positioned in neutral abduction, neutral flexion, and neutral opposition...
November 2016: Journal of Wrist Surgery
M C Gouveia, J P Vella, F R Cafeo, F L Affonso Fonseca, M R Bacci
OBJECTIVE: Irisin is a muscle-secreted protein released into the circulation by cleavage of fibronectin type III domain containing protein 5(FNDC5). Since its discovery in 2012, it has been the subject of many researches due to its physiological role. It is believed that understanding irisin's function may be the key to comprehend many diseases and their development. The aim of this study is to perform a systematic review in order to establish whether there is an association of irisin's levels with obesity, diabetes mellitus, non-alcoholic steatohepatitis, chronic kidney disease and cancer in terms of prognosis...
October 2016: European Review for Medical and Pharmacological Sciences
M Cebová, M Košútová, O Pecháňová
Gasotransmitters represent a subfamily of the endogenous gaseous signaling molecules that include nitric oxide (NO), carbon monoxide (CO), and hydrogen sulphide (H(2)S). These particular gases share many common features in their production and function, but they fulfill their physiological tasks in unique ways that differ from those of classical signaling molecules found in tissues and organs. These gasotransmitters may antagonize or potentiate each other's cellular effects at the level of their production, their downstream molecular targets and their direct interactions...
October 24, 2016: Physiological Research
Yongcheng Pan, Lusi Zhang, Qiong Liu, Ying Li, Hui Guo, Yu Peng, Hexiang Peng, Beisha Tang, Zhengmao Hu, Jingping Zhao, Kun Xia, Jia-Da Li
AMPD1 is an adenosine monophosphate deaminase that catalyzes the deamination of AMP to IMP. To understand the physiological function of AMPD1, we obtained a strain of Ampd1 mutant mice from KOMP repository, which was generated by a knockout-first strategy. An elevated AMP level and almost complete lack of IMP was detected in the skeletal muscle of E18.5 Ampd1(tm1a/tm1a) mice. However, Ampd1(tm1a/tm1a) mice died in 2 days postnatally, which was contradicting to previous reports. After removal of the knockout-first cassette and critical exon, mice homozygous for the Ampd1(tm1c/tm1c) and Ampd1(tm1d/tm1d) alleles survived to adulthood...
October 24, 2016: Scientific Reports
Ana B García-Redondo, Andrea Aguado, Ana M Briones, Mercedes Salaices
Reactive oxygen species (ROS) are key signaling molecules that regulate vascular function and structure in physiological conditions. A misbalance between the production and detoxification of ROS increases oxidative stress that is involved in the vascular remodeling associated with cardiovascular diseases such as hypertension by affecting inflammation, hypertrophy, migration, growth/apoptosis and extracellular matrix protein turnover. The major and more specific source of ROS in the cardiovascular system is the NADPH oxidase (NOX) family of enzymes composed of seven members (NOX1-5, DUOX 1/2)...
October 20, 2016: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
Carlos A Aguilar, Ramona Pop, Anna Shcherbina, Alain Watts, Ronald W Matheny, Davide Cacchiarelli, Woojin M Han, Eunjung Shin, Shadi A Nakhai, Young C Jang, Christopher T Carrigan, Casey A Gifford, Melissa A Kottke, Marcella Cesana, Jackson Lee, Maria L Urso, Alexander Meissner
Following injury, adult skeletal muscle undergoes a well-coordinated sequence of molecular and physiological events to promote repair and regeneration. However, a thorough understanding of the in vivo epigenomic and transcriptional mechanisms that control these reparative events is lacking. To address this, we monitored the in vivo dynamics of three histone modifications and coding and noncoding RNA expression throughout the regenerative process in a mouse model of traumatic muscle injury. We first illustrate how both coding and noncoding RNAs in tissues and sorted satellite cells are modified and regulated during various stages after trauma...
October 20, 2016: Stem Cell Reports
Alexey Kamenskiy, Andreas Seas, Paul Deegan, William Poulson, Eric Anttila, Sylvie Sim, Anastasia Desyatova, Jason MacTaggart
Femoropopliteal artery (FPA) mechanics play a paramount role in pathophysiology and the artery's response to therapeutic interventions, but data on FPA mechanical properties are scarce. Our goal was to characterize human FPAs over a wide population to derive a constitutive description of FPA aging to be used for computational modeling. Fresh human FPA specimens ([Formula: see text]) were obtained from [Formula: see text] predominantly male (80 %) donors 54±15 years old (range 13-82 years). Morphometric characteristics including radius, wall thickness, opening angle, and longitudinal pre-stretch were recorded...
October 22, 2016: Biomechanics and Modeling in Mechanobiology
Justin X Nicoll, Andrew C Fry, Andrew J Galpin, Adam J Sterczala, Donald B Thomason, Christopher A Moore, Lawrence W Weiss, Loren Z F Chiu
PURPOSE: Many physiological maladaptations persist after overreaching and overtraining resistance exercise (RE). However, no studies have investigated changes in mitogen-activated protein kinases (MAPK) after overtraining in humans, despite their critical role regulating exercise-induced muscular adaptations. The purpose of this study was to describe the changes in total and resting phosphorylation status of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK) and p38-MAPK following a period of RE overreaching or overtraining...
October 22, 2016: European Journal of Applied Physiology
Katarina Lazic, Jelena Petrovic, Jelena Ciric, Aleksandar Kalauzi, Jasna Saponjic
Postoperative sleep disorders, particularly the REM sleep disorder, may have a significant deleterious impact on postoperative outcomes and may contribute to the genesis of certain delayed postoperative complications. We have followed the effect of distinct anesthesia regimens (ketamine/diazepam vs. pentobarbital) over 6days following the induction of a stable anesthetized state in adult male Wistar rats, chronically instrumented for sleep recording. In order to compare the effect of both anesthetics in the physiological controls vs...
October 19, 2016: Physiology & Behavior
John D Chan, Dan Zhang, Xiaolong Liu, Magdalena Z Zarowiecki, Matthew Berriman, Jonathan S Marchant
The robust regenerative capacity of planarian flatworms depends on the orchestration of signaling events from early wounding responses through the stem cell enacted differentiative outcomes that restore appropriate tissue types. Acute signaling events in excitable cells play an important role in determining regenerative polarity, rationalized by the discovery that sub-epidermal muscle cells express critical patterning genes known to control regenerative outcomes. These data imply a dual conductive (neuromuscular signaling) and instructive (anterior-posterior patterning) role for Ca(2+) signaling in planarian regeneration...
October 19, 2016: Biochimica et Biophysica Acta
Michiko Nanao-Hamai, Bo-Kyung Son, Tsuyoshi Hashizume, Sumito Ogawa, Masahiro Akishita
Vascular calcification is one of the major complications of cardiovascular disease and is an independent risk factor for myocardial infarction and cardiac death. Postmenopausal women have a higher prevalence of vascular calcification compared with premenopausal women, suggesting protective effects of estrogen (E2). However, the underlying mechanisms of its beneficial effects remain unclear. In the present study, we examined the inhibitory effects of E2 on vascular smooth muscle cell (VSMC) calcification, and found that growth arrest-specific gene 6 (Gas6), a crucial molecule in vascular calcification, is transactivated by estrogen receptor α (ERα) in response to E2...
October 19, 2016: Biochemical and Biophysical Research Communications
Ellen L Mintz, Juliana A Passipieri, Daniel Y Lovell, George J Christ
Despite the regenerative capacity of skeletal muscle, permanent functional and/or cosmetic deficits (e.g., volumetric muscle loss (VML) resulting from traumatic injury, disease and various congenital, genetic and acquired conditions are quite common. Tissue engineering and regenerative medicine technologies have enormous potential to provide a therapeutic solution. However, utilization of biologically relevant animal models in combination with longitudinal assessments of pertinent functional measures are critical to the development of improved regenerative therapeutics for treatment of VML-like injuries...
October 7, 2016: Journal of Visualized Experiments: JoVE
Victor M Niemeijer, Ruud F Spee, Thijs Schoots, Pieter F F Wijn, Hareld M Kemps
The extent and speed of transient skeletal muscle deoxygenation during exercise onset in chronic heart failure (CHF) patients is related to impairments of local O2 delivery and utilization. This study examined the physiological background of submaximal exercise performance in 19 moderately impaired CHF patients (Weber class A, B, and C) compared with 19 matched healthy control (HC) subjects by measuring skeletal muscle oxygenation (SmO2) changes during cycling exercise. All subjects performed two subsequent moderate-intensity 6-minute exercise tests (bout 1 and 2) with measurements of pulmonary oxygen uptake kinetics, and SmO2 using near infrared (NIR) spatially resolved spectroscopy (SRS) at the vastus lateralis for determination of absolute oxygenation values, amplitudes, kinetics (mean response time for onset), and deoxygenation overshoot characteristics...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Matthias Jacob, Daniel Chappell, Bernhard F Becker
Oxygen delivery to cells is the basic prerequisite of life. Within the human body, an ingenious oxygen delivery system, comprising steps of convection and diffusion from the upper airways via the lungs and the cardiovascular system to the microvascular area, bridges the gap between oxygen in the outside airspace and the interstitial space around the cells. However, the complexity of this evolutionary development makes us prone to pathophysiological problems. While those problems related to respiration and macrohemodynamics have already been successfully addressed by modern medicine, the pathophysiology of the microcirculation is still often a closed book in daily practice...
October 21, 2016: Critical Care: the Official Journal of the Critical Care Forum
Jeffrey J Widrick, Matthew Alexander, Benjamin Sanchez, Devin Gibbs, Genri Kawahara, Alan Beggs, Louis Kunkel
Sapje zebrafish lack the protein dystrophin and are the smallest vertebrate model of Duchenne muscular dystrophy (DMD). Their small size makes them ideal for large-scale drug discovery screens. However, the extent that sapje mimic the muscle dysfunction of higher vertebrate models of DMD is unclear. We used an optical birefringence assay to differentiate affected dystrophic sapje larvae from their unaffected siblings and then studied trunk muscle contractility at 4-7 days post fertilization. Preparation cross-sectional area (CSA) was similar for affected and unaffected larvae, yet tetanic forces of affected preparations were only 30-60% of normal...
October 7, 2016: Physiological Genomics
Daryl C Yang, Jennifer R Deuis, Daniel Dashevsky, James Dobson, Timothy N W Jackson, Andreas Brust, Bing Xie, Ivan Koludarov, Jordan Debono, Iwan Hendrikx, Wayne C Hodgson, Peter Josh, Amanda Nouwens, Gregory J Baillie, Timothy J C Bruxner, Paul F Alewood, Kelvin Kok Peng Lim, Nathaniel Frank, Irina Vetter, Bryan G Fry
Millions of years of evolution have fine-tuned the ability of venom peptides to rapidly incapacitate both prey and potential predators. Toxicofera reptiles are characterized by serous-secreting mandibular or maxillary glands with heightened levels of protein expression. These glands are the core anatomical components of the toxicoferan venom system, which exists in myriad points along an evolutionary continuum. Neofunctionalisation of toxins is facilitated by positive selection at functional hotspots on the ancestral protein and venom proteins have undergone dynamic diversification in helodermatid and varanid lizards as well as advanced snakes...
October 18, 2016: Toxins
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