The Effect of the Fascia on the Stress Distribution in Skeletal Muscle

2010 ◽  
Author(s):  
Angelica Maria Ramirez ◽  
Begoña Calvo Calzada ◽  
Jorge Grasa
Keyword(s):  
Skeletal Muscle ◽  
Connective Tissue ◽  
Skeletal Muscles ◽  
Body Force ◽  
Anatomical Structure ◽  
The Body ◽  
Force Generation ◽  
Fibre Bundles ◽  
Muscle Shortening ◽  
Whole Muscle

The human and vertebrate interaction with the environment is done primarily through the movement. This is possible due the skeletal muscle: anatomical structure able to contract voluntarily. The skeletal muscles are made up of contractile proteins which slide one over another allowing the muscle shortening and the body force generation. This protein structure of actin and myosin maintains its organization through the connective tissue that surrounds it (endomysium, perimysium and epimysium), creating arrays of myofibrils, fibre bundles, fascicles until conform the whole muscle. All this connective tissue extends to the ends of the muscle to form the tendon.

Change in skeletal muscle index and its prognostic significance in conversion therapy for initially unresectable colorectal cancer.

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 56-56
Author(s):  
Hiroaki Nozawa ◽  
Shigenobu Emoto ◽  
Koji Murono ◽  
Yasutaka Shuno ◽  
Soichiro Ishihara
Keyword(s):  
Colorectal Cancer ◽  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscles ◽  
Systemic Chemotherapy ◽  
Stage Iv ◽  
The Body ◽  
Pharmacological Intervention ◽  
Conversion Therapy ◽  
Skeletal Muscle Index

56 Background: Systemic chemotherapy can cause loss of skeletal muscle mass in colorectal cancer (CRC) patients in the neoadjuvant and palliative settings. However, it is largely unknown how the body composition is changed by chemotherapy rendering unresectable CRC to resectable disease or how it affects the prognosis. This study aimed at elucidating the effects of systemic chemotherapy on skeletal muscles and survival in stage IV CRC patients who underwent conversion therapy. Methods: We reviewed 98 stage IV CRC patients who received systemic chemotherapy in our hospital. According to the treatment setting, patients were divided into the ‘Conversion’, ‘Neoadjuvant chemotherapy (NAC)’, and ‘Palliation’ groups. The cross-sectional area of skeletal muscles at the third lumbar level and changes in the skeletal muscle index (SMI), defined as the area divided by height squared, during chemotherapy were compared among patient groups. The effects of these parameters on prognosis were analyzed in the Conversion group. Results: The mean SMI increased by 8.0% during chemotherapy in the Conversion group (n = 38), whereas it decreased by 6.2% in the NAC group (n = 18) and 3.7% in the Palliation group (n = 42, p < 0.0001). Moreover, patients with increased SMI during chemotherapy had a better overall survival (OS) than those whose SMI decreased in the Conversion group (p = 0.021). The increase in SMI was an independent predictor of favorable OS on multivariate analysis (hazard ratio: 0.26). Conclusions: Stage IV CRC patients who underwent conversion to resection often had an increased SMI. As such an increase in SMI further conveys a survival benefit in conversion therapy, it may be important to make efforts to preserve muscle mass by meticulous approaches, such as nutritional support, muscle exercise programs, and pharmacological intervention even during chemotherapy in patients with metastatic CRC.

scholarly journals Change in skeletal muscle index and its prognostic significance in patients who underwent successful conversion therapy for initially unresectable colorectal cancer: observational study

2020 ◽  
Vol 13 ◽  
pp. 175628482097119
Author(s):  
Hiroaki Nozawa ◽  
Shigenobu Emoto ◽  
Koji Murono ◽  
Yasutaka Shuno ◽  
Kazushige Kawai ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Skeletal Muscle ◽  
Systemic Therapy ◽  
Skeletal Muscles ◽  
Prognostic Significance ◽  
Stage Iv ◽  
The Body ◽  
Conversion Therapy ◽  
Cross Sectional ◽  
Skeletal Muscle Index

Background: Systemic therapy can cause loss of skeletal muscle mass in colorectal cancer (CRC) patients in the neoadjuvant and palliative settings. However, it is unknown how the body composition is changed by chemotherapy rendering unresectable CRC to resectable disease or how it affects the prognosis. This study aimed at elucidating the effects of systemic therapy on skeletal muscles and survival in stage IV CRC patients who underwent conversion therapy. Methods: We reviewed 98 stage IV CRC patients who received systemic therapy in our hospital. According to the treatment setting, patients were divided into the conversion, neoadjuvant chemotherapy (NAC), and palliation groups. The cross-sectional area of skeletal muscles at the third lumbar level and changes in the skeletal muscle index (SMI), defined as the area divided by height squared, during systemic therapy were compared among patient groups. The effects of these parameters on prognosis were analyzed in the conversion group. Results: The mean SMI increased by 9.4% during systemic therapy in the conversion group ( n = 38), whereas it decreased by 5.9% in the NAC group ( n = 18) and 3.7% in the palliation group ( n = 42, p < 0.0001). Moreover, patients with increased SMI during systemic therapy had a better overall survival (OS) than those whose SMI decreased in the conversion group ( p = 0.025). The increase in SMI was an independent predictor of favorable OS on multivariate analysis (hazard ratio 0.25). Conclusions: Stage IV CRC patients who underwent conversion to resection often had an increased SMI. On the other hand, a decrease in the SMI during systemic therapy was a negative prognostic factor in such patients.

Effects of altitude acclimatization on rat myoglobin. Changes in myoglobin content of skeletal and cardiac muscle

1959 ◽  
Vol 196 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Adam Anthony ◽  
Eugene Ackerman ◽  
G. K. Strother
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Cardiac Muscle ◽  
Water Content ◽  
Skeletal Muscles ◽  
The Body ◽  
Continuous Exposure ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Muscle Weight

Analyses were made of myoglobin content of rat skeletal and cardiac muscle following continuous exposure to simulated altitudes of 18,000 feet for a 2–10-week period. About five dozen rats were used. Acclimatization was associated with an increase in the myoglobin concentration of thigh, diaphragm, gastrocnemius and heart muscles. Total myoglobin content, however, increased during acclimatization in cardiac muscle but not in the three skeletal muscles. This finding together with the body weight changes and muscle weight changes suggested that the increases in myoglobin concentration of skeletal muscle may be merely a reflection of a decreased water content of muscles.

scholarly journals Understanding the extraocular muscles: connective tissue, motor endplates and the cytoskeleton

2020 ◽  
Vol 42 (5) ◽  
pp. 52-57
Author(s):  
Jing-Xia Liu ◽  
Nils Dennhag ◽  
Fatima Pedrosa Domellöf
Keyword(s):  
Visual Acuity ◽  
Connective Tissue ◽  
Coping Strategies ◽  
Skeletal Muscles ◽  
Premature Death ◽  
Extraocular Muscles ◽  
The Body ◽  
Motor Endplates ◽  
Severe Handicap ◽  
Future Treatment

We constantly direct our eyes to the object of interest with the help of the extraocular muscles, and thereby use foveal fixation to attain the best possible visual acuity. The muscles around the eye are rather different from other skeletal muscles, being, for example, simultaneously the fastest muscles in the body and impossible to exhaust. The most exciting property of the extraocular muscles is their unique response to disease, as they often remain unaffected in muscle conditions which lead to severe handicap and premature death. Understanding the coping strategies that allow the extraocular muscles to remain unaffected may provide clues for the future treatment of severe diseases such as muscle dystrophies.

scholarly journals Evaluation of Skeletal Muscle Function and Effects of Early Rehabilitation during Acute Heart Failure: Rationale and Study Design

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Kinga Węgrzynowska-Teodorczyk ◽  
Agnieszka Siennicka ◽  
Krystian Josiak ◽  
Robert Zymliński ◽  
Monika Kasztura ◽  
...  
Keyword(s):  
Heart Failure ◽  
Skeletal Muscle ◽  
Acute Heart Failure ◽  
Muscle Tissue ◽  
Muscle Function ◽  
Skeletal Muscles ◽  
Group Versus ◽  
The Body ◽  
Skeletal Muscle Function ◽  
Peripheral Tissues

Background. Acute heart failure (AHF) is associated with disturbances of the peripheral perfusion leading to the dysfunction of many organs. Consequently, an episode of AHF constitutes a “multiple organ failure” which may also affect the skeletal muscles. However, the abnormalities within skeletal muscles during AHF have not been investigated so far. The aim of this project is to comprehensively evaluate skeletal muscles (at a functional and tissue level) during AHF. Methods. The study will include ≥63 consecutive AHF patients who will be randomized into 2 groups: ≥42 with cardiac rehabilitation group versus ≥21 with standard pharmacotherapy alone. The following tests will be conducted on the first and last day of hospitalization, at rest and after exercise, and 30 days following the discharge: clinical evaluation, medical interview, routine physical examination, echocardiography, and laboratory tests (including the assessment of NT-proBNP, inflammatory markers, and parameters reflecting the status of the kidneys and the liver); hemodynamic evaluation, noninvasive determination of cardiac output and systemic vascular resistance using the impedance cardiography; evaluation of biomarkers reflecting myocyte damage, immunochemical measurements of tissue-specific enzymatic isoforms; evaluation of skeletal muscle function, using surface electromyography (sEMG) (maximum tonus of the muscles will be determined along with the level of muscular fatigability); evaluation of muscle tissue perfusion, assessed on the basis of the oxygenation level, with noninvasive direct continuous recording of perfusion in peripheral tissues by local tissue oximetry, measured by near-infrared spectroscopy (NIRS). Results and Conclusions. Our findings will demonstrate that the muscle tissue is another area of the body which should be taken into consideration in the course of treatment of AHF, requiring a development of targeted therapeutic strategies, such as a properly conducted rehabilitation.

Effects of in vivo-like activation frequency on the length-dependent force generation of skeletal muscle fibre bundles

1998 ◽  
Vol 77 (6) ◽  
pp. 503-510 ◽  
Author(s):  
C. J. Zuurbier ◽  
M. B. E. Lee-de Groot ◽  
W. J. Van der Laarse ◽  
P. A. Huijing
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibre ◽  
Skeletal Muscle Fibre ◽  
Force Generation ◽  
Fibre Bundles

scholarly journals Requirement for PINCH in Skeletal Myoblast Differentiation

2021 ◽  
Author(s):  
Siyi Xie ◽  
Chushan Fang ◽  
Yujie Gao ◽  
Jie Yan ◽  
Lina Luo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Molecular Mechanisms ◽  
Myogenic Differentiation ◽  
Critical Role ◽  
The Body ◽  
Myoblast Differentiation ◽  
Skeletal Myogenesis ◽  
Congenital Myopathies

Abstract Background: Skeletal muscle is composed of bundles of myofibers ensheathed by extracellular matrix networks. Malformation of skeletal muscle during embryonic development results in congenital myopathies. Disease mechanisms of congenital myopathies remain unclear. PINCH, an adaptor of focal adhesion complex, plays essential roles in multiple cellular processes and organogenesis. Elucidation of the molecular mechanisms underlying skeletal myogenesis will offer new insights into pathogenesis of myopathies.Methods: We generated muscle-specific PINCH knock-out mice to study the functional role of PINCH in skeletal myogenesis. Histologic and Transmission Electron Microscopy analysis demonstrated that Impaired myogenic differentiation and maturation in mice with PINCH1 being ablated in skeletal muscle progenitors, and Ablation of PINCH1 and PINCH2 resulted in reduced size of muscle fibers and impaired multinucleation; Cell culture and immunostaining showed that defects in myoblast fusion and cytoskeleton assembly in PINCH double mutant mice; Western blotting showed that defects in expression of cytoskeleton proteins and proteins involved in myogenesis in DMUT skeletal muscles.Results: Double ablation of PINCH1 and PINCH2 resulted in early postnatal lethality with reduced size of skeletal muscles and detachment of diaphragm muscles from the body wall. Myofibers of PINCH mutant myofibers failed to undergo multinucleation and exhibited disrupted sarcomere structures. The mutant myoblasts in culture were able to adhere to newly formed myotubes, but impeded in cell fusion and subsequent sarcomere genesis and cytoskeleton organization. Consistent with this, expression of integrin β1 and some cytoskeleton proteins, and phosphorylation of ERK and AKT were significantly reduced in PINCH mutants. Expression of MRF4, the most highly expressed myogenic factor at late stages of myogenesis, was abolished in PINCH mutants, that could contribute to observed phenotypes. In addition, mice with PINCH1 being ablated in myogenic progenitors exhibited only mild centronuclear myopathic changes, suggesting a compensatory role of PINCH2 in myogenic differentiation, indicating a critical role of PINCH proteins in myogenic differentiation.Conclusion: Our results demonstrated an essential role of PINCH in skeletal myogenic differentiation.

scholarly journals IL-13-driven pulmonary emphysema leads to skeletal muscle dysfunction attenuated by endurance exercise

2020 ◽  
Vol 128 (1) ◽  
pp. 134-148 ◽  
Author(s):  
Joseph Balnis ◽  
Tanner C. Korponay ◽  
Catherine E. Vincent ◽  
Diane V. Singer ◽  
Alejandro P. Adam ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Animal Model ◽  
Pulmonary Emphysema ◽  
Skeletal Muscles ◽  
Force Generation ◽  
Chronic Obstructive ◽  
Muscle Dysfunction ◽  
Obstructive Pulmonary Disease ◽  
Skeletal Muscle Dysfunction ◽  
Generation Capacity

Patients with chronic obstructive pulmonary disease (COPD) usually develop skeletal muscle dysfunction, which represents a major comorbidity in these patients and is strongly associated with mortality and other poor outcomes. Although clinical data indicates that accelerated protein degradation and metabolic disruption are common associations of muscle dysfunction in COPD, there is very limited data on the mechanisms regulating the process, in part, due to the lack of research performed on a validated animal model of pulmonary emphysema. This model deficiency complicates the translational value of data generated with highly reductionist settings. Here, we use an established transgenic animal model of COPD based on inducible IL-13-driven pulmonary emphysema (IL-13TG) to interrogate the mechanisms of skeletal muscle dysfunction. Skeletal muscles from these emphysematous mice develop most features present in COPD patients, including atrophy, decreased oxygen consumption, and reduced force-generation capacity. Analysis of muscle proteome indicates downregulation of succinate dehydrogenase C (SDH-C), which correlates with reduced enzymatic activity, also consistent with previous clinical observations. Ontology terms identified with human data, such as ATP binding/bioenergetics are also downregulated in this animal’s skeletal muscles. Moreover, chronic exercise can partially restore muscle mass, metabolic and force-generation capacity, and SDH activity in COPD mice. We conclude that this animal model of COPD/emphysema is an adequate platform to further investigate mechanisms of muscle dysfunction in this setting and demonstrates multiple approaches that can be used to address specific mechanisms regulating this process. NEW & NOTEWORTHY Skeletal muscle dysfunction is a relevant comorbidity in patients with chronic obstructive pulmonary disease (COPD). Mechanistic research in the area has so far been accomplished with models based on specific exposures to otherwise healthy animals, and no investigation using an established and validated animal model of COPD has been accomplished. We present an animal model of COPD that was previously shown to recapitulate pulmonary functional and histologic features present in patients with COPD, and demonstrates most of the features present in patients with pulmonary emphysema-associated muscle dysfunction, which we proposed as an adequate tool to develop mechanistic research in the area.

scholarly journals Effect of xanthine oxidase-generated extracellular superoxide on skeletal muscle force generation

2010 ◽  
Vol 298 (1) ◽  
pp. R2-R8 ◽  
Author(s):  
M. C. Gomez-Cabrera ◽  
G. L. Close ◽  
A. Kayani ◽  
A. McArdle ◽  
J. Viña ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Polyethylene Glycol ◽  
Cytochrome C ◽  
Extracellular Space ◽  
Superoxide Anion ◽  
Skeletal Muscles ◽  
Muscle Force ◽  
Force Production ◽  
Force Generation ◽  
Isometric Contractions

Skeletal muscle contractions increase superoxide anion in skeletal muscle extracellular space. We tested the hypotheses that 1) after an isometric contraction protocol, xanthine oxidase (XO) activity is a source of superoxide anion in the extracellular space of skeletal muscle and 2) the increase in XO-derived extracellular superoxide anion during contractions affects skeletal muscle contractile function. Superoxide anion was monitored in the extracellular space of mouse gastrocnemius muscles by following the reduction of cytochrome c in muscle microdialysates. A 15-min protocol of nondamaging isometric contractions increased the reduction of cytochrome c in microdialysates, indicating an increase in superoxide anion. Mice treated with the XO inhibitor oxypurinol showed a smaller increase in superoxide anions in muscle microdialysates following contractions than in microdialysates from muscles of vehicle-treated mice. Intact extensor digitorum longus (EDL) and soleus muscles from mice were also incubated in vitro with oxypurinol or polyethylene glycol-tagged Cu,Zn-SOD. Oxypurinol decreased the maximum tetanic force produced by EDL and soleus muscles, and polyethylene glycol-tagged Cu,Zn-SOD decreased the maximum force production by the EDL muscles. Neither agent influenced the rate of decline in force production when EDL or soleus muscles were repeatedly electrically stimulated using a 5-min fatiguing protocol (stimulation at 40 Hz for 0.1 s every 5 s). Thus these studies indicate that XO activity contributes to the increased superoxide anion detected within the extracellular space of skeletal muscles during nondamaging contractile activity and that XO-derived superoxide anion or derivatives of this radical have a positive effect on muscle force generation during isometric contractions of mouse skeletal muscles.

scholarly journals The Role of GSK-3β in the Regulation of Protein Turnover, Myosin Phenotype, and Oxidative Capacity in Skeletal Muscle under Disuse Conditions

2021 ◽  
Vol 22 (10) ◽  
pp. 5081
Author(s):  
Timur M. Mirzoev ◽  
Kristina A. Sharlo ◽  
Boris S. Shenkman
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Protein Turnover ◽  
Skeletal Muscles ◽  
Glycogen Synthase ◽  
Oxidative Capacity ◽  
The Body ◽  
Vital Functions ◽  
Wide Range ◽  
Gsk 3Β

Skeletal muscles, being one of the most abundant tissues in the body, are involved in many vital processes, such as locomotion, posture maintenance, respiration, glucose homeostasis, etc. Hence, the maintenance of skeletal muscle mass is crucial for overall health, prevention of various diseases, and contributes to an individual’s quality of life. Prolonged muscle inactivity/disuse (due to limb immobilization, mechanical ventilation, bedrest, spaceflight) represents one of the typical causes, leading to the loss of muscle mass and function. This disuse-induced muscle loss primarily results from repressed protein synthesis and increased proteolysis. Further, prolonged disuse results in slow-to-fast fiber-type transition, mitochondrial dysfunction and reduced oxidative capacity. Glycogen synthase kinase 3β (GSK-3β) is a key enzyme standing at the crossroads of various signaling pathways regulating a wide range of cellular processes. This review discusses various important roles of GSK-3β in the regulation of protein turnover, myosin phenotype, and oxidative capacity in skeletal muscles under disuse/unloading conditions and subsequent recovery. According to its vital functions, GSK-3β may represent a perspective therapeutic target in the treatment of muscle wasting induced by chronic disuse, aging, and a number of diseases.

Sign in / Sign up

Export Citation Format

Share Document