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Sample records for submental muscle complex

  1. Transmylohyoid Submental Intubation in complex maxillofacial trauma: The easiest method is also the safest method

    OpenAIRE

    Ashutosh Kumar Singh; Sanad Dulal; Rajesh Yadav; Ajay Singh Thapa

    2016-01-01

    Background & Objectives: Complex maxillofacial trauma is a common occurrence with high velocity road traffic accidents. Multiple facial bone fracture with loss of reference point for bony reduction requires use of intra-operative intermaxillary fixation to obtain good occlusion which precludes oral intubation. Fractures of nasal bones and ethmoid bones with complex distorted anatomy lead to inability to perform a nasal intubation. In such cases sub-mental intubation can be a safe and easy...

  2. Submental intubation: an alternative and cost-effective technique for complex maxillofacial surgeries.

    Science.gov (United States)

    Kar, Chiradip; Mukherjee, Srijon

    2010-09-01

    Management of airway is a significant issue especially in cases of complex maxillofacial trauma like panfacial fractures or concomitant nasoethmoidal injuries, where the nasotracheal intubation is contraindicated or possess a significant problem. In these cases the only other alternative is tracheostomy. Submental intubation is an alternative to tracheostomy and it can be easily performed with little or lesser post-operative complications. This method involves lesser expenses as it does away with longer post-operative stay in the hospital as required by tracheostomy patients. The patient is orally intubated with a reinforced armoured tube with a detachable plastic gas connector. An incision is made in the submental area of the patient and a tunnel is prepared from this region to the floor of the mouth through which the proximal end of the tube is diverted. Thus the occlusion of the patient can be checked intraoperatively. After completion of the surgery the proximal end in reintroduced onto the oral cavity and the patient is extubated orally. Originally proposed by Altemir in 1986, this method cannot be used in all cases as it is not without limitations. In spite of these, submental intubation can be a useful alternative to tracheostomy, especially in regions where cost cutting is a major factor in health infrastructure. Maxillofacial surgeons addressing major facial trauma surgery may have this procedure in mind before opting for tracheostomy. It avoids a lot of complications associated with tracheostomy.

  3. Transmylohyoid Submental Intubation in complex maxillofacial trauma: The easiest method is also the safest method

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    Ashutosh Kumar Singh

    2016-08-01

    Full Text Available Background & Objectives: Complex maxillofacial trauma is a common occurrence with high velocity road traffic accidents. Multiple facial bone fracture with loss of reference point for bony reduction requires use of intra-operative intermaxillary fixation to obtain good occlusion which precludes oral intubation. Fractures of nasal bones and ethmoid bones with complex distorted anatomy lead to inability to perform a nasal intubation. In such cases sub-mental intubation can be a safe and easy method of securing the intra-operative airway thus avoiding  tracheotomy and its complications.Materials & Methods: Retrospective clinical analytical study was planned in which 25 patients were included. Patient’s age, sex, type of trauma, time taken for procedure and complications were taken as study variables. Results: Average time taken for the procedure was nine minutes and only four out of 25 cases had complications. Conclusion: Sub-mental intubation requires simple skills, less time and is relatively complication free compared to tracheotomy in securing intra-operative airway during surgeries for complex maxillofacial trauma.JCMS Nepal. 2016;12(2:55-9

  4. Submental intubation

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    Sonia Jindal

    2013-01-01

    Full Text Available MacInnis and Baig modified Altemirs′ original technique for sub-mental intubation. Instead of a lateral entry, they described a central entry just anterior to the sub-mental crease that does not carry the risk of damage to the lingual nerves, submandibular ducts and sublingual glands. We describe here our experience with this modified sub-mental intubation that also allows the operating surgeon to provide for a correct midline and optimal esthetics in case of panfacial trauma.

  5. Videoradiography at submental electrical stimulation during apnea in obstructive sleep apnea syndrome; A case report

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    Hillarp, B.; Rosen, I.; Wickstroem, O. (Malmoe Allmaenna Sjukhus (Sweden). Dept. of Diagnostic Radiology Malmoe Allmaenna Sjukhus (Sweden). Dept. of Clinical Neurophysiology)

    1991-05-01

    Percutaneous submental electrical stimulation during sleep may be a new therapeutic method for patients with obstructive sleep apnea syndrome (OSAS). Electrical stimulation to the submental region during obstructive apnea is reported to break the apnea without arousal and to diminish apneic index, time spent in apnea, and oxygen desaturation. The mode of breaking the apnea by electrical stimulation has not yet been shown. However, genioglossus is supposed to be the muscle responsible for breaking the apnea by forward movement of the tongue. To visualize the effect of submental electrical stimulation, one patient with severe OSAS has been examined with videoradiography. Submental electrical stimulation evoked an immediate complex muscle activity in the tongue, palate, and hyoid bone. This was followed by a forward movement of the tongue which consistently broke obstructive apnea without apparent arousal. Time spent in apnea was diminished but intervals between apnea were not affected. (orig.).

  6. The hamstring muscle complex

    NARCIS (Netherlands)

    van der Made, A. D.; Wieldraaijer, T.; Kerkhoffs, G. M.; Kleipool, R. P.; Engebretsen, L.; van Dijk, C. N.; Golanó, P.

    2015-01-01

    The anatomical appearance of the hamstring muscle complex was studied to provide hypotheses for the hamstring injury pattern and to provide reference values of origin dimensions, muscle length, tendon length, musculotendinous junction (MTJ) length as well as width and length of a tendinous

  7. Submental sEMG and Hyoid Movement during Mendelsohn Maneuver, Effortful Swallow, and Expiratory Muscle Strength Training

    Science.gov (United States)

    Wheeler-Hegland, Karen M.; Rosenbek, John C.; Sapienza, Christine M.

    2008-01-01

    Purpose: This study investigated the concurrent biomechanical and electromyographic properties of 2 swallow-specific tasks (effortful swallow and Mendelsohn maneuver) and 1 swallow-nonspecific (expiratory muscle strength training [EMST]) swallow therapy task in order to examine the differential effects of each on hyoid motion and associated…

  8. Cryolipolysis for submental fat reduction in Asians.

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    Suh, Dong Hye; Park, Ji Hyun; Jung, Hae Kyoung; Lee, Sang Jun; Kim, Hyun Joo; Ryu, Hwa Jung

    2018-02-01

    Cryolipolysis is a noninvasive method for the selective reduction of fat, especially proven to be safe and effective in body contouring. There is a demand for reduction in submental fat, which is related not only with a favorable appearance but also with signs of aging. This study evaluated the efficacy and safety of cryolipolysis for subcutaneous fat reduction in the submental area in Asians. Ten healthy Koreans were treated using a cryolipolysis contact device (CoolMini applicator, Zeltiq Aesthetics). The device was applied on the participant's neck twice via two lateral approaches. Patient's body weight was measured, and photographs were taken at baseline and during the follow-up visit after 8 weeks. Participants were examined with ultrasound and the depth of the subcutaneous fat layer was measured. The subjective reduction of submental fat was noted in most of the participants. Reduction of the subcutaneous fat layer depth was confirmed by ultrasound after 8 weeks of treatment. The results of this study indicate that submental fat can be safely and effectively reduced with use of a cryolipolysis applicator. The present study shows that cryolipolysis can be an option for nonsurgical facial contouring.

  9. Accidental Perforation of Submental Flexometallic Tube

    OpenAIRE

    Sundaram, Subbulakshmi; Ramdas, Gowthaman; Paul, Anisha Pauline; Krishnasamy, Sekaran Natesan

    2017-01-01

    Oral and maxillofacial surgeries associated with complications due to endotracheal tube (ETT) damage are being reported in literature increasingly. In this case, we report a rare case of accidental perforation of a flexometallic ETT intraoperatively during an orthognathic corrective surgery, in a 19-year-old female patient in whom submental intubation had been performed. The complication was managed conservatively as the tissue debris created during the osteotomy drilling occluded the damage ...

  10. ATX-101 for reduction of submental fat.

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    Wollina, Uwe; Goldman, Alberto

    2015-04-01

    Facial esthetics are important for self-esteem. Undesired submental fat (SMF) deposits lead to an unappealing submental profile associated with aging and overweight. Compound ATX-101 is a proprietary formulation of purified synthetic deoxycholic acid for pharmacological submental contouring. Review areas covered: This reviews covers anatomy of SMF, biochemistry of deoxycholic acid related to adipose tissue and tissue response to injection of ATX-101. Data from clinical trials were analyzed for efficacy and safety. Published studies using PubMed(©) database 2000 - 2014 have been analyzed. The terms 'deoxycholate', 'deoxycholic acid', 'ATX-101' and 'injection lipolysis' were used. Deoxycholic acid causes adipocyte breakdown and an inflammatory tissue reaction leading to fat cell reduction and limited fibrosis. Four large clinical Phase III trials demonstrated efficacy of ATX-101 in reduction of SMF measured by validated scales and objective measurements. Patients reported improved psychological features and feeling. Adverse effects were mild and temporary. Adipocytolysis of SMF by ATX-101 is an important step forward to the development of approved drugs for reduction of localized fat pads. This could become a growing market.

  11. ATX-101 (deoxycholic acid injection) for reduction of submental fat.

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    Ascher, Benjamin; Fellmann, Jere; Monheit, Gary

    2016-09-01

    The shape and contour of the chin and neck play an important role in facial esthetics. As such, excess fat within the submental area (double chin) can negatively affect facial esthetics and body image. Common treatments for submental contouring include invasive procedures such as surgical rejuvenation and targeted liposuction. Energy devices (lasers, radiofrequency, and ultrasound) may be used to improve submental skin laxity while cryolipolysis was recently cleared in the United States for use in the submental area. However, ATX-101 (deoxycholic acid injection) is the only injectable drug approved in the United States and Canada for reduction of submental fat. The efficacy and safety of ATX-101 have been extensively evaluated in a global clinical development program including multiple Phase I/II studies and four large Phase III trials. Available data from ATX-101 trials are reviewed. Expert commentary: Injectables have been well established for facial rejuvenation. Extending injectable treatment into the chin and neck is a major advance for nonsurgical cosmetic correction. Overall, the evidence supports ATX-101 as a safe and effective, minimally invasive treatment alternative for reduction of submental fat that will provide a major tool for the esthetic physician.

  12. Submental intubation in patients with panfacial fractures: A prospective study

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    Premalatha M Shetty

    2011-01-01

    Full Text Available Submental intubation is an interesting alternative to tracheostomy, especially when short-term postoperative control of airway is desirable with the presence of undisturbed access to oral as well as nasal airways and a good dental occlusion. Submental intubation with midline incision has been used in 10 cases from October 2008 to March 2010 in the Department of Oral and Maxillofacial Surgery, Manipal College of Dental Sciences, Mangalore. All patients had fractures of the jaws disturbing the dental occlusion associated with fracture of the base of the skull, or/and a displaced nasal bone fracture. After standard orotracheal intubation, a passage was created by blunt dissection with a haemostat clamp through the floor of the mouth in the submental area. The proximal end of the orotracheal tube was pulled through the submental incision. Surgery was completed without interference from the endotracheal tube. At the end of surgery, the tube was pulled back to the usual oral route. There were no perioperative complications related to the submental intubation procedure. Average duration of the procedure was less than 6 minutes. Submental intubation is a simple technique associated with low rates of morbidity. It is an attractive alternative to tracheotomy in the surgical management of selected cases of panfacial trauma.

  13. Deoxycholic Acid (ATX-101) for Reduction of Submental Fat.

    Science.gov (United States)

    Dunican, Kaelen C; Patel, Dhiren K

    2016-10-01

    To review trials evaluating purified synthetic deoxycholic acid (DCA; ATX-101) for the reduction of submental fat (SMF). A literature search was conducted using MEDLINE (1946 to week 4 of April 2016) and Evidence Based Medicine Database (1974 to 6 May, 2016). Keywords searched included deoxycholic acid, ATX-101, and submental fat. All human studies published in English that addressed the effects of DCA for the reduction of SMF were selected for analysis. Five phase III, multicenter, randomized, double-blinded clinical trials enrolling more than 1700 patients have demonstrated the efficacy of ATX-101 in the reduction of SMF via a variety of validated scales as well as objective measurements. Purified synthetic DCA 2 mg/cm(2) injected monthly for 4 to 6 treatment sessions demonstrated improvement in scales evaluated by both clinicians and patients. Improvement in skin caliper measurements of SMF and Magnetic Resonance Imaging (MRI) provide objective evidence of the efficacy of ATX-101. Adverse events (AEs) are very common but are transient and localized to the treatment area. Pain at the injection site is the most common AE, occurring in more than 80% of patients treated. Other common AEs include swelling, bruising, numbness, and induration. Appropriate injection technique is patient specific and requires detailed knowledge of the submental anatomy to minimize AEs. ATX-101 is the first pharmacological intervention approved for the reduction of SMF and offers an alternative to invasive measures to improve the submental profile and positively affect patient self-image. © The Author(s) 2016.

  14. Intubación submental: experiencia con 30 casos

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    Luiz Fernando Lobo Leandro

    2015-07-01

    Conclusiones: La intubación submental es una buena alternativa para poder tratar adecuadamente a los pacientes politraumatizados con afección de la cavidad nasal y oral sin tener que realizar una traqueostomía en casos que no la requieran.

  15. Submental artery island flap with simultaneous level I neck dissection.

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    Eskander, Antoine; Strigenz, Daniel; Seim, Nolan; Ozer, Enver

    2018-01-13

    The purpose of this study was to illustrate the submental island flap elevation technique with simultaneous level I neck dissection followed by the inset and reconstruction of an oropharyngeal defect. A 63-year-old patient with a T2N1M0 human papillomavirus-positive squamous cell carcinoma of the tonsil was treated with concurrent chemoradiotherapy (cisplatin + 66 Gy). A local recurrence 2.5 years after treatment was treated surgically and reconstructed with a submental island flap. There were no complications and oral diet was initiated at 2 weeks and the gastrostomy tube was removed 1 month postoperatively. A video demonstration of the submental island flap elevation is included with a focus on how levels 1A and 1B can be dissected safely and this can be viewed online on Head & Neck's home page at http://onlinelibrary.wiley.com/. The submental island flap can be performed safely with a level I neck dissection for head and neck reconstruction. © 2018 Wiley Periodicals, Inc.

  16. Soft-tissue metastasis of osteosarcoma to the submental vestibule.

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    Chen, Y-K; Chen, C-H; Lin, L-M

    2006-11-01

    A case of metastatic osteosarcoma in the submental vestibule of the oral cavity and the lung is described in an 18-year-old male with primary osteosarcoma occurring in the sacrum. Dissemination of osteosarcoma to other organs, especially early to the lung, is common, but its metastasis to the oral mucosa has been rarely reported. The patient presented 6 years after initial diagnosis, suggesting the need for careful long-term follow-up of patients with osteosarcoma. This case also illustrates that immunohistochemical staining of osteocalcin is useful to confirm the histological diagnosis of oral soft-tissue metastasis.

  17. [Intrarenal smooth muscle: histology of a complex urodymamic machine].

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    Arias, L F; Ortiz-Arango, N

    2013-03-01

    To know better the microscopic arrangement of the bundles of smooth muscle in the human renal parenchyma, their distribution and anatomical relationships, trying to make a reconstruction of this muscular system. Five adult human kidneys and one fetal kidney were processed "in toto" with cross sections every 300μm. In the histological sections we identify the smooth muscle fibers trying to determine its insertion, course and anatomical relationship with other structures of the kidney tissue. There are bundles of smooth muscle fibers of variable thickness parallel to the edges of the medullary pyramids, bundles that surrounding the medulla in a spiral course, and bundles that accompany arcuate vessels, the latter being the most abundant and easy to identify. These groups of muscle fibers do not have a precise or constant insertion site, their periodicity is not homogeneous and they are not a direct extension of the muscle of the renal pelvis, although some bundles are in contact with it. There are also unusual and inconstant small muscle fibers no associated to vessels in the interstitium of the cortex and, exceptionally, in the medulla. There is a complex microscopic system of smooth muscle fibers that partially surround the renal medulla and are related to renal pelvic muscles without a direct continuity with them. Although this small muscular system is under-recognized, could be very important in urodynamics. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.

  18. Submental intubation: alternative short-term airway management in maxillofacial trauma.

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    Kumar, Ravi Raja; Vyloppilli, Suresh; Sayd, Shermil; Thangavelu, Annamala; Joseph, Benny; Ahsan, Auswaf

    2016-06-01

    To assess submental route intubation as an alternative technique to a tracheostomy in the management of the airway in cranio-maxillofacial trauma, along with an assessment of its morbidity and complications. Submental intubation was performed in 17 patients who had maxillofacial panfacial trauma and management was done under general anesthesia during a period of one year from 2013 to 2014 at Departments of Oral and Maxillofacial Surgery and Dentistry, the Malankara Orthodox Syrian Church Medical College, Kochi, India. In all 17 cases, the technique of submental intubation was found to be simple and reliable. Hypertrophic scars were noted in three cases, orocutaneous fistula and mucocele in one case each. All these complications were managed comfortably without significant morbidity to the patient. Submental intubation is a good technique that can be used regularly in the management of the airway in cranio-maxillofacial trauma, but with some manageable complications.

  19. Submental thyroid ectopy might cause subclinical hypothyroidism in early childhood

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    Mirjana Kocova

    2016-12-01

    Full Text Available Objective: Thyroid ectopy is a rare condition resulting from abnormal embryologic development and migration of the gland. Sublingual is the most common thyroid ectopy; all other ectopic thyroid locations occur very rare. There are no reports in the literature that describe the clinical course of patients with congenital hypothyroidism due to thyroid ectopy. Methods and Results: We present a child with congenital hypothyroidism detected on neonatal screening which had a subclinical course during follow-up. Scintigraphy revealed submental thyroid ectopy, a rare ectopic location and no orthotopic thyroid gland. Conclusion: Our case is unique because of the rare ectopic thyroid location but also of the unexpected clinical course; however, further thyroid monitoring is required for the therapy adjustment and detection of any changes in the ectopic tissue.

  20. Data mining-based study on sub-mentally healthy state among residents in eight provinces and cities in China.

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    Ni, Hongmei; Yang, Xuming; Fang, Chengquan; Guo, Yingying; Xu, Mingyue; He, Yumin

    2014-08-01

    To apply data mining methods to research on the state of sub-mental health among residents in eight provinces and cities in China and to mine latent knowledge about many conditions through data mining and analysis of data on 3970 sub-mentally healthy individuals selected from 13385 relevant questionnaires. The strategic tree algorithm was used to identify the main manifestations of the state of sub-mental health. The back propogation artificial neural network was used to analyze the main manifestations of sub-healthy mental states of three different degrees. A sub-mental health evaluation model was then established to achieve predictive evaluation results. Using classifications from the Scale of Chinese Sub-healthy State, the main manifestations of sub-mental health selected using the strategic tree were F1101 (Do you lack peace of mind?), F1102 (Are you easily nervous when something comes up?), and F1002 (Do you often sigh?). The relative intensity of manifestations of sub-mental health was highest for F1101, followed by F1102, and then F1002. Through study of the neural network, better differentiation could be made between moderate and severe and between mild and severe states of sub-mental health. The differentiation between mild and moderate sub-mental health states was less apparent. Additionally, the sub-mental health state evaluation model, which could be used to predict states of sub-mental health of different individuals, was established using F1101, F1102, F1002, and the mental self-assessment total score. The main manifestations of the state of sub-mental health can be discovered using data mining methods to research and analyze the latent laws and knowledge hidden in research evidence on the state of sub-mental health. The state of sub-mental health of different individuals can be rapidly predicted using the model established here. This can provide a basis for assessment and intervention for sub-mental health. It can also replace the relatively outdated

  1. Contrast CT-scan for preoperative planning of VSLN (vascularized submental lymph-node) transfer.

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    Mullan, Damian; Kosutic, Damir

    2017-01-01

    Vascularized submental lymph-node (VSLN) transfer is gaining popularity as a reliable donor-site in microsurgical treatment of lymphedema. However, variations in number, location, and blood supply to submental lymph-nodes as well as associate skin-paddle make a predictable flap harvest a challenging task. We analyzed this region on preoperative imaging, to improve accuracy of VSLN transfers. Contrast CT-scan analysis of VSLN-flap areas was performed in 58 patients. Number and location of visibly vascularized lymph nodes as well as submental artery perforators were identified, documented, and compared. About 409 lymph-nodes were found in 50 patients. No significant difference was found in the number of nodes between the right and left side. Significantly more lymph-nodes were found in zones 1B than zones 1A. In eight patients nodes were not identified. In the remaining 50 patients position of the visibly vascularized submental lymph-node was predictable. Significantly less lymph-nodes can be found in zone 1a then zone 1b. Location of visibly vascularized lymph nodes can be identified predictably in relation to bony landmarks. Blood supply to 1a nodes and particularly location of dominant skin perforator is unpredictable due to potential crossover. Contrast CT scan can help identify location and blood supply to submental lymph-nodes in most patients. J. Surg. Oncol. 2017;115:23-26. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Midline submental orotracheal intubation in maxillofacial injuries: A substitute to tracheostomy where postoperative mechanical ventilation is not required

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    Malti Agrawal

    2010-01-01

    Conclusion: There were no significant operative or postoperative complications. Postoperative submental scarring was acceptable [6] . We conclude that midline submental intubation is a simple and useful technique with low morbidity. It can be chosen in selected cases of maxillofacial trauma and is an excellent substitute to tracheostomy where postoperative mechanical ventilation is not required.

  3. Submental fat reduction by mesotherapy using phosphatidylcholine alone vs. phosphatidylcholine and organic silicium: a pilot study.

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    Co, Abigail C; Abad-Casintahan, Maria Flordeliz; Espinoza-Thaebtharm, Agnes

    2007-12-01

    Excess skin and fatty tissues beneath the jaw lead to a double chin deformity. Localized fat deposits in this area are a cause of discomfort and anguish, leading patients to undergo surgical procedures such as liposuction and dermolipectomy to improve the cosmetic effect. Both procedures require anesthesia and an operating room setting and are quite expensive. Fearful of extensive surgery and its complications, patients and physicians seek less invasive methods. Mesotherapy with phosphatidylcholine and other cocktails have been used to treat localized fat deposits. However, there are few published articles regarding its effectiveness and some are even anecdotal. This study aims to determine the efficacy of phosphatidylcholine alone vs. phosphatidylcholine and organic silicium in submental fat reduction. Twelve patients with submental fat deposit with no coexisting morbidity and with informed consent were included in the study. They were submitted to one to five treatment sessions with an average interval of 2 weeks between each session. The medication administered was injected, either pure phosphatidylcholine or a combination of phosphatidylcholine and organic silicium. Baseline measurements of submental fat using vernier caliper and digital photographs of the patients were taken during each treatment session. The occurrence of adverse effects was likewise noted. Results Among the 12 patients, 11 completed the treatment course, and 1 was excluded from the study because of failure to follow up. Both phosphatidylcholine and a combination of phosphatidylcholine and organic silicium were equally effective in reducing submental fat deposits. There was no significant difference as to the rate and degree of reduction. Significant reduction in the thickness of submental fat was achieved after three treatment sessions. Adverse reactions in both groups were mild and transitory ranging from heavy sensation, localized heat, nodulations, and slight bruising that abated 3 to 5

  4. Reliability of surface EMG measurements from the suprahyoid muscle complex

    DEFF Research Database (Denmark)

    Kothari, Mohit; Stubbs, Peter William; Pedersen, Asger Roer

    2017-01-01

    of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy participants over days. Methods: Seventeen healthy participants were recruited. Measurements were performed twice with one week...... between sessions. Single pulse (at 120% and 140% of the resting motor threshold (rMT)) and paired pulse (2 ms and 15 ms paired pulse) transcranial magnetic stimulation (TMS) were used to elicit MEPs in the SMC which were recorded using sEMG. Results: ≈50% of participants (range: 42%-58%; depending...... on stimulus type/intensity) had significantly different MEP values between day 1 and day 2 for single pulse and paired pulse TMS. A large stimulus artefact resulted in MEP responses that could not be assessed in four participants. Conclusions: The assessment of the SMC using sEMG following TMS was poorly...

  5. The Relationship between Submental Surface Electromyography and Hyo-Laryngeal Kinematic Measures of Mendelsohn Maneuver Duration

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    Azola, Alba M.; Greene, Lindsey R.; Taylor-Kamara, Isha; Macrae, Phoebe; Anderson, Cheryl; Humbert, Ianessa A.

    2015-01-01

    Purpose: The Mendelsohn Maneuver (MM) is a commonly prescribed technique that is taught to individuals with dysphagia to improve swallowing ability. Due to cost and safety concerns associated with videofluoroscopy (VFS) use, submental surface electromyography (ssEMG) is commonly used in place of VFS to train the MM in clinical and research…

  6. [Application of improved submental island flap in hypopharyngeal cancer reserved laryngeal function surgery].

    Science.gov (United States)

    Tan, Pingqing; Chen, Jie; Huang, Wenxiao; Bao, Ronghua; Li, Jinyun; Wang, Junqi; Xie, Li; Zhong, Waisheng; Zhang, Hailin

    2015-08-01

    This study aimd to evaluate the application and clinical effect of improved submental island flap in hypopharyngeal cancer reserved laryngeal function surgery. A retrospective review of clinical data was performed on 38 patients of hypopharyngeal cancer reserved laryngeal function using sumental island flaps, by the way of improving in design of vascular pedicle, reconstructive mode of laryngeal and hypopharyngeal function and closing of wound of neck following hypopharyngeal cancer resection. Meanwhile, the effect and prognosis was comprehensively assessed on patients with hypopharyngeal cancer reserved laryngeal function using improved submental island flaps. The submental flaps kept alive in all 38 cases. During the follow-up period, 18 cases were dead, and of them, 7 cases died of the second primary carcinoma, included 4 cases of esophagus cancer, 1 case of cancer of soft palate, 2 cases of nasopharyngeal carcinoma; and 5 cases died of cervical or parapharyngeal lymph nodes recurrence; 2 cases died of hepatic metastasis; and 4 cases died of pulmonary metastasis. The overall 5-years survival rate was 52.6%. Improved submental island flap repairing postoperative defect of hypopharyngeal cancer reserved laryngeal function has many advantages including higher success rate, more security, easy and simple to operate as well as good clinical effects, and is worth to widespread using.

  7. Evaluation of safety and usefulness of submental intubation in panfacial trauma surgery

    OpenAIRE

    Singaram, Mohanavalli; Ganesan, Ilango; Kannan, Radhika; Kumar, Rajesh

    2016-01-01

    Objectives Submental intubation has been advocated as an alternative to classical tracheostomy for certain indicated panfacial trauma surgeries. Surgeons should have various options for airway management in maxillofacial trauma patients. Most maxillofacial injuries involve occlusal derangements, which might require intraoperative occlusal corrections; hence, orotracheal intubation is not ideal. Maxillofacial surgeons generally prefer nasotracheal intubation; however, in cases with concomitant...

  8. A novel method using Seldinger′s technique for submental intubation in major craniomaxillofacial fractures: A case series

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    Shaik Mastan Saheb

    2014-01-01

    Full Text Available Airway management is a challenge to anesthesiologists particularly in maxillofacial surgeries. The oral tracheal tube is unsuitable because it interferes with the surgical field and prevents dental occlusion. Nasotracheal intubation may not always be possible due to structural deformity or trauma to the nasal bones. Tracheostomy and submental intubation have their drawbacks. To overcome these shortcomings we used Percutaneous Dilatational Tracheostomy Kit (PDTK to modify the technique of submental intubation. Serial dilatations were performed over the guide wire before passing the tracheal tube by submental route, using the PDT kit in four patients. Submental intubation could be achieved in all the four cases with this technique and there were no associated complications. Seldinger′s technique is a simple and easy technique with minimal bleeding, imperceptible scar, and more importantly anesthesiologists feel more comfortable because of their familiarity with the Seldinger technique.

  9. The organization of the Golgi complex and microtubules in skeletal muscle is fiber type-dependent

    DEFF Research Database (Denmark)

    Ralston, E; Lu, Z; Ploug, Thorkil

    1999-01-01

    Skeletal muscle has a nonconventional Golgi complex (GC), the organization of which has been a subject of controversy in the past. We have now examined the distribution of the GC by immunofluorescence and immunogold electron microscopy in whole fibers from different rat muscles, both innervated...... of the hindlimb muscles, GC elements as well as microtubules converge toward a common pattern, that of the slow-twitch fibers, in all fibers. Our data suggest that innervation regulates the distribution of microtubules, which in turn organize the Golgi complex according to muscle fiber type....

  10. Complex myograph allows the examination of complex muscle contractions for the assessment of muscle force, shortening, velocity, and work in vivo

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    Ruhschulte Hainer

    2008-07-01

    Full Text Available Abstract Background The devices used for in vivo examination of muscle contractions assess only pure force contractions and the so-called isokinetic contractions. In isokinetic experiments, the extremity and its muscle are artificially moved with constant velocity by the measuring device, while a tetanic contraction is induced in the muscle, either by electrical stimulation or by maximal voluntary activation. With these systems, experiments cannot be performed at pre-defined, constant muscle length, single contractions cannot be evaluated individually and the separate examination of the isometric and the isotonic components of single contractions is not possible. Methods The myograph presented in our study has two newly developed technical units, i.e. a. a counterforce unit which can load the muscle with an adjustable, but constant force and b. a length-adjusting unit which allows for both the stretching and the contraction length to be infinitely adjustable independently of one another. The two units support the examination of complex types of contraction and store the counterforce and length-adjusting settings, so that these conditions may be accurately reapplied in later sessions. Results The measurement examples presented show that the muscle can be brought to every possible pre-stretching length and that single isotonic or complex isometric-isotonic contractions may be performed at every length. The applied forces act during different phases of contraction, resulting into different pre- and after-loads that can be kept constant – uninfluenced by the contraction. Maximal values for force, shortening, velocity and work may be obtained for individual muscles. This offers the possibility to obtain information on the muscle status and to monitor its changes under non-invasive measurement conditions. Conclusion With the Complex Myograph, the whole spectrum of a muscle's mechanical characteristics may be assessed.

  11. Colgajo submental para reconstrucción de defectos oncológicos en cabeza y cuello Submental flap to reconstruct oncologic head and neck defects

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    J. Brunsó Casellas

    2009-08-01

    Full Text Available El colgajo submental es un procedimiento eficaz para la reconstrucción en el territorio maxilofacial. Caracterizado por su delgadez, versatilidad, excelente color y textura y mínima morbilidad en la zona donante, su utilización en lesiones malignas es controvertida, por el riesgo de trasladar enfermedad metastásica cervical a la zona receptora. Material y métodos: Se presentan 3 casos clínicos en los que se ha aplicado en pacientes afectos de un carcinoma epidermoide de cabeza y cuello. Describimos las particularidades anatómicas, y se realiza una revisión de la técnica quirúrgica. Resultados: Fueron óptimos en cuanto a cobertura del defecto, estética y función salvo por una necrosis parcial en uno de ellos. En todos los casos la morbilidad en la zona donante fue mínima. Conclusiones: El colgajo submental es una opción a considerar incluso en pacientes oncológicos sobre todo en los que, por edad avanzada o presentar patología asociada no están indicados procedimientos más agresivos.The submental flap is an effective option for the reconstruction in the maxillofacial territory. Characterized by its thinness, versatility, excellent colour and texture and minimum morbidity in the donor zone, its use in malignant injuries is controverted by the risk of transferring cervical metastasic disease to the receiving zone. Material and methods: we present 3 clinical cases in which it has been used in patients affected by an squamous cell carcinoma of head and neck. In addition, the anatomical particularities are described, and a revision of the surgical technique is made. Results: They were optimal in relation to covering of the defect, aesthetics and function except for a partial necrosis in one of them. In all the cases the morbidity in the donor zone was minimum. Conclusions: The submental flap is an option to consider in oncologic patients, mainly in those whom by advanced age or by the existence of comorbidity advice against the use

  12. Pre-Expanded Submental Island Flap for Resurfacing Middle and Lower Facial Defect.

    Science.gov (United States)

    Ma, Ning; Li, Yang Qun; Tang, Yong; Chen, Wen; Yang, Zhe; Zhao, Mu Xin; Wang, Wei Xin; Xu, Li Si; Feng, Jun

    2016-11-01

    Resurfacing large facial defect is a continuing challenge for plastic surgeons. Skin graft or free flap is hard to obtain satisfactory results or is beyond the skill of most surgeons. The authors performed 13 expended submental island flaps to resurface middle and lower facial defects and achieved satisfactory results. In the first stage operation, the authors implanted one soft tissue expander in the anterior neck region which was expanded over an average of 3 months. In the second stage operation, the authors elevated the expanded submental island flap to resurface facial defect. For the patients who request aesthetic results and allow 2-stage operation, our method provides more satisfactory results. This technique does not require any special skills and is well within the skill of most plastic surgeons.

  13. The development, evidence, and current use of ATX-101 for the treatment of submental fat.

    Science.gov (United States)

    Georgesen, Corey; Lipner, Shari R

    2017-06-01

    ATX-101 (deoxycholic acid) is the first pharmaceutical therapy approved by the FDA for the reduction in submental fat. Deoxycholic acid is an endogenous secondary bile acid that normally solubilizes dietary fat, contributing to its breakdown and absorption within the gut. This article reviews the identification of deoxycholic acid as a lipolytic agent, and the mechanism of action, pharmacokinetics, and pharmacodynamics of ATX-101. In addition to phase I/II trials, four Phase III clinical trials have evaluated safety and efficacy of ATX-101. These studies helped establish the appropriate dosage, administration techniques, warnings, and side effects of ATX-101. ATX-101 is effective in treating submental fat. Adverse events, although common, are mild and transient. © 2017 Wiley Periodicals, Inc.

  14. Toxoplasmosis presented as a submental mass: a common disease, uncommon presentation.

    Science.gov (United States)

    Li, Bo; Zou, Jian; Wang, Wei-Ya; Liu, Shi-Xi

    2015-01-01

    Submental mass secondary to toxoplasmosis is not common in clinical work. A diagnosis of toxoplasmosis is rarely considered by physicians. Here we describe a 50-year-old woman presented with a progressive, painful, submental and left neck swelling for 1 month. After having obtained an insufficient evidence from the fine-needle biopsy, the patient finally received an excisional biopsy which highly indicated the possibility of lymphadenopathy consistent with toxoplasmosis. Diagnosis of toxoplasmosis was finally established by a combination of the pathological criteria, together with the positive serological finding. According to review the clinical presentations, pathological characteristics, diagnostic standard and treatment of this disease, the article aims to remind otolaryngologists who are evaluating a neck mass should be aware of the infectious cause of lymphadenopathy and the possibility of toxoplasmosis.

  15. A test of the submentalizing hypothesis: Apes' performance in a false belief task inanimate control.

    Science.gov (United States)

    Krupenye, Christopher; Kano, Fumihiro; Hirata, Satoshi; Call, Josep; Tomasello, Michael

    2017-01-01

    Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis. In the present study, we implemented the suggested inanimate control of our previous false-belief task. Apes attended well to key events but showed markedly fewer anticipatory looks and no significant tendency to look to the correct location. We thus found no evidence that submentalizing was responsible for apes' anticipatory looks in our false-belief task.

  16. El colgajo submental en reconstrucción de defectos orofaciales

    Directory of Open Access Journals (Sweden)

    Kora Sagüillo

    2015-10-01

    Conclusiones: El colgajo submental constituye una alternativa válida para la reconstrucción de defectos orofaciales, especialmente en aquellos pacientes que por edad o estado general deteriorado requieren tratamientos poco agresivos y con tiempos quirúrgicos reducidos. Requiere descartar la presencia de enfermedad metastásica ganglionar cervical previamente a su realización. Su empleo es controvertido para la reparación de defectos tras resección de tumores con alta linfofilia.

  17. Overview of ATX-101 (Deoxycholic Acid Injection): A Nonsurgical Approach for Reduction of Submental Fat.

    Science.gov (United States)

    Dayan, Steven H; Humphrey, Shannon; Jones, Derek H; Lizzul, Paul F; Gross, Todd M; Stauffer, Karen; Beddingfield, Frederick C

    2016-11-01

    In 2015, ATX-101 (deoxycholic acid injection; Kybella in the United States and Belkyra in Canada; Kythera Biopharmaceuticals, Inc., Westlake Village, CA [an affiliate of Allergan plc, Dublin, Ireland]) was approved as a first-in-class injectable drug for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat. ATX-101 has been evaluated in a clinical development program that included 18 Phase 1 to 3 studies supporting the current indication. Since 2007, the toxicity and safety profiles of ATX-101 have been characterized in numerous preclinical studies, its pharmacokinetics, pharmacodynamics, and optimal treatment paradigm have been defined in multiple Phase 1 and 2 studies, and its efficacy and clinical safety have been confirmed in 4 large Phase 3 trials (2 conducted in Europe and 2 in the United States and Canada [REFINE-1 and REFINE-2]). As subcutaneous injection of deoxycholic acid has been shown to cause adipocytolysis, the reduction in submental fat achieved after ATX-101 treatment is expected to be long lasting. This prediction is confirmed by data from long-term follow-up studies of up to 4 years after last treatment with ATX-101, which demonstrate that the treatment response is maintained over time in most subjects. ATX-101 offers a durable, minimally invasive alternative to liposuction and surgery for addressing submental fullness.

  18. The L-Z complexity of exercise-induced muscle fatigue based on acoustic myographye

    Science.gov (United States)

    Yijian, Min; Xinyuan, Liu; Tingting, Wang

    2014-01-01

    The mechanism of exercise fatigue was investigated during exercise using L-Z complexity of non-linear analysis. Muscle fatigue was induced in the sitting position by lifting the heel under a load. An acoustic myogram of the gastrocnemius was obtained until exhaustion. The different modes of the speed responses were calculated using the L-Z complexity method, which analyzes muscle fibers participation, while the exercise is in progress. The L-Z complexity decreased incrementally with decreases in muscle strength, reaching a minimum value when the muscle was exhausted. Our data indicate that the L-Z complexity method is easy to use and effective at revealing the dynamic characteristics and variations of exercise fatigue. This method could be used to monitor sports training.

  19. Affection of the Respiratory Muscles in Combined Complex I and IV Deficiency.

    Science.gov (United States)

    Finsterer, Josef; Rauschka, Helmut; Segal, Liane; Kovacs, Gabor G; Rolinski, Boris

    2017-01-01

    Combined complex I+IV deficiency has rarely been reported to manifest with the involvement of the respiratory muscles. A 45y male was admitted for hypercapnia due to muscular respiratory insufficiency. He required intubation and mechanical ventilation. He had a previous history of ophthalmoparesis since age 6y, ptosis since age 23y, and anterocollis since at least age 40y. Muscle biopsy from the right deltoid muscle at age 41y was indicative of mitochondrial myopathy. Biochemical investigations revealed a combined complex I+IV defect. Respiratory insufficiency was attributed to mitochondrial myopathy affecting not only the extra-ocular and the axial muscles but also the shoulder girdle and respiratory muscles. In addition to myopathy, he had mitochondrial neuropathy, abnormal EEG, and elevated CSF-protein. Possibly, this is why a single cycle of immunoglobulins was somehow beneficial. For muscular respiratory insufficiency he required tracheostomy and was scheduled for long-term intermittent positive pressure ventilation. Mitochondrial myopathy due to a combined complex I+IV defect with predominant affection of the extra-ocular muscles may progress to involvement of the limb-girdle, axial and respiratory muscles resulting in muscular respiratory insufficiency. In patients with mitochondrial myopathy, neuropathy and elevated cerebrospinal fluid protein, immunoglobulins may be beneficial even for respiratory functions.

  20. The force-length relationship of a muscle-tendon complex : experimental results and model calculations

    NARCIS (Netherlands)

    Bobbert, Maarten F.; Ettema, Gertjan C.; Huijing, Peter A.

    1990-01-01

    Models are useful when studying how architectural and physiological properties of muscle-tendon complexes are related to function, because they allow for the simulation of the behaviour of such complexes during natural movements. In the construction of these models, evaluation of their accuracy is

  1. ATX-101 for reduction of submental fat: A phase III randomized controlled trial.

    Science.gov (United States)

    Humphrey, Shannon; Sykes, Jonathan; Kantor, Jonathan; Bertucci, Vince; Walker, Patricia; Lee, Daniel R; Lizzul, Paul F; Gross, Todd M; Beddingfield, Frederick C

    2016-10-01

    ATX-101, an injectable form of deoxycholic acid, causes adipocytolysis when injected subcutaneously into fat. We sought to evaluate the efficacy and safety of ATX-101. In this phase III trial (REFINE-2), adults dissatisfied with their moderate or severe submental fat (SMF) were randomized to ATX-101 or placebo. Coprimary end points, evaluated at 12 weeks after last treatment, were composite improvements of 1 or more grades and 2 or more grades in SMF observed on both the validated Clinician- and Patient-Reported SMF Rating Scales. Other end points included magnetic resonance imaging-based assessment of submental volume, assessment of psychological impact of SMF, and additional patient-reported outcomes. Among those treated with ATX-101 or placebo (n = 258/treatment group), 66.5% versus 22.2%, respectively, achieved a composite improvement of 1 or more grades (Mantel-Haenszel risk ratio 2.98; 95% confidence interval 2.31-3.85) and 18.6% versus 3.0% achieved a composite improvement of 2 or more grades in SMF (Mantel-Haenszel risk ratio 6.27; 95% confidence interval 2.91-13.52; P ATX-101 were more likely to achieve submental volume reduction confirmed by magnetic resonance imaging, greater reduction in psychological impact of SMF, and satisfaction with treatment (P ATX-101 group and 76.9% in the placebo group were localized to the injection site. Follow-up was limited to 44 weeks. ATX-101 is an alternative treatment for SMF reduction. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  2. A Longitudinal Electromyography Study of Complex Movements in Poststroke Therapy. 2: Changes in Coordinated Muscle Activation.

    Science.gov (United States)

    Hesam-Shariati, Negin; Trinh, Terry; Thompson-Butel, Angelica G; Shiner, Christine T; McNulty, Penelope A

    2017-01-01

    results show less complexity and more co-activation in the muscle activation for patients with low motor-function as a higher number of muscle synergies reflects greater movement complexity and task-related phasic muscle activation. The increased number of synergies and changes within synergies by late-therapy suggests improved motor control and movement quality with more distinct phases of movement.

  3. A Case Report of Sarcoidosis with Presentation of Submental Adenopathy and Renal Failure

    Directory of Open Access Journals (Sweden)

    A. Baradaran

    2003-10-01

    Full Text Available A 68 years old women refer to our clinical of educational hospital because of decrease appetite from 4 months ago , with constipation, polyuria and polydypsia, also she had 10 kg weigh loss during this time. In examination: she had blood pressure of mmHg, 3 small lymph nodes in submental region (1×1cm also palpable spleen. other examinations was totally normal. Befor admission she had evaluated for probable malignany by the resean of her syrptoms, The results y evaluation was: upper Gi-series , upper Gi endo scopy were normal . Abdominal sonograply and CT scan with contrast agents show only mild splenomegaly. Creat= 2.9 mg/dl. BUN=40 mg/dl ca=12.5 mg/dl p=3/06 mg/dl Alp=185(100-240, CFR 35 cc/min . PTH was in normal limit. We evaluated the patient for probable solid tumors of breast and multiple myeloma. The results of evaluation were normal, thus we refer the patient for lymph node biopsy (submental lymphadenopathy. The result was non- caseating granuloma consist of multinuclear Giant cells with asteroid body. Angiotension converting enzym level was high, the patients treated by prednisolon, the syptoms subsided and creatinin decrease to 1.5 mg/dl aft 4 months of treatment.

  4. Diffusion-tensor MRI reveals the complex muscle architecture of the human forearm.

    Science.gov (United States)

    Froeling, Martijn; Nederveen, Aart J; Heijtel, Dennis F R; Lataster, Arno; Bos, Clemens; Nicolay, Klaas; Maas, Mario; Drost, Maarten R; Strijkers, Gustav J

    2012-07-01

    To design a time-efficient patient-friendly clinical diffusion tensor MRI protocol and postprocessing tool to study the complex muscle architecture of the human forearm. The 15-minute examination was done using a 3 T system and consisted of: T(1) -weighted imaging, dual echo gradient echo imaging, single-shot spin-echo echo-planar imaging (EPI) diffusion tensor MRI. Postprocessing comprised of signal-to-noise improvement by a Rician noise suppression algorithm, image registration to correct for motion and eddy currents, and correction of susceptibility-induced deformations using magnetic field inhomogeneity maps. Per muscle one to five regions of interest were used for fiber tractography seeding. To validate our approach, the reconstructions of individual muscles from the in vivo scans were compared to photographs of those dissected from a human cadaver forearm. Postprocessing proved essential to allow muscle segmentation based on combined T(1) -weighted and diffusion tensor data. The protocol can be applied more generally to study human muscle architecture in other parts of the body. The proposed protocol was able to visualize the muscle architecture of the human forearm in great detail and showed excellent agreement with the dissected cadaver muscles. Copyright © 2012 Wiley Periodicals, Inc.

  5. Sarcoglycan complex in masseter and sternocleidomastoid muscles of baboons: an immunohistochemical study

    Directory of Open Access Journals (Sweden)

    G. Cutroneo

    2015-06-01

    Full Text Available The sarcoglycan complex consists of a group of single-pass transmembrane glycoproteins that are essential to maintain the integrity of muscle membranes. Any mutation in each sarcoglycan gene causes a series of recessive autosomal dystrophin-positive muscular dystrophies. Negative fibres for sarcoglycans have never been found in healthy humans and animals. In this study, we have investigated whether the social ranking has an influence on the expression of sarcoglycans in the skeletal muscles of healthy baboons. Biopsies of masseter and sternocleidomastoid muscles were processed for confocal immunohistochemical detection of sarcoglycans. Our findings showed that baboons from different social rankings exhibited different sarcoglycan expression profiles. While in dominant baboons almost all muscles were stained for sarcoglycans, only 55% of muscle fibres showed a significant staining. This different expression pattern is likely to be due to the living conditions of these primates. Sarcoglycans which play a key role in muscle activity by controlling contractile forces may influence the phenotype of muscle fibres, thus determining an adaptation to functional conditions. We hypothesize that this intraspecies variation reflects an epigenetic modification of the muscular protein network that allows baboons to adapt progressively to a different social status.

  6. Sarcoglycan complex in masseter and sternocleidomastoid muscles of baboons: an immunohistochemical study.

    Science.gov (United States)

    Cutroneo, G; Centofanti, A; Speciale, F; Rizzo, G; Favaloro, A; Santoro, G; Bruschetta, D; Milardi, D; Micali, A; Di Mauro, D; Vermiglio, G; Anastasi, G; Trimarchi, F

    2015-06-05

    The sarcoglycan complex consists of a group of single-pass transmembrane glycoproteins that are essential to maintain the integrity of muscle membranes. Any mutation in each sarcoglycan gene causes a series of recessive autosomal dystrophin-positive muscular dystrophies. Negative fibres for sarcoglycans have never been found in healthy humans and animals. In this study, we have investigated whether the social ranking has an influence on the expression of sarcoglycans in the skeletal muscles of healthy baboons. Biopsies of masseter and sternocleidomastoid muscles were processed for confocal immunohistochemical detection of sarcoglycans. Our findings showed that baboons from different social rankings exhibited different sarcoglycan expression profiles. While in dominant baboons almost all muscles were stained for sarcoglycans, only 55% of muscle fibres showed a significant staining. This different expression pattern is likely to be due to the living conditions of these primates. Sarcoglycans which play a key role in muscle activity by controlling contractile forces may influence the phenotype of muscle fibres, thus determining an adaptation to functional conditions. We hypothesize that this intraspecies variation reflects an epigenetic modification of the muscular protein network that allows baboons to adapt progressively to a different social status.

  7. Vascular anatomy is a determining factor of successful submental flap raising: a retrospective study of 70 clinical cases

    Directory of Open Access Journals (Sweden)

    Hung-Che Lin

    2017-09-01

    Full Text Available The vascular anatomy of submental flaps (SFs represents a determining factor in successful SF raising. However, little attention has been focused on the venous return of SFs. Thus, the present study aimed to investigate SF venous return. This study enrolled patients who underwent SF reconstructive surgery in a tertiary referral center between November 2009 and October 2016. The drainage pathway of the SF venous return was routinely identified during the course of our operations to prevent damage during head and neck surgery. The venous return data of 70 patients were reviewed. The size of the flaps ranged from 15 to 84 cm2, and total flap loss was not observed in the case series. All of the submental arteries originated from the facial artery; however, the submental veins of 70 patients returned to either the internal jugular vein (IJV, 72.9% or the external jugular vein (EJV, 27.1%. Our data suggest that drainage of the submental vein into the EJV, which has been previously overlooked, should receive greater attention during SF surgeries. The results support mandatory preservation of the EJV and IJV and indicate that vascular anatomy is a determining factor for successful SF raising.

  8. Multifractal analysis of sEMG signal of the complex muscle activity

    CERN Document Server

    Trybek, Paulina; Nowakowski, Michal; Machura, Lukasz

    2014-01-01

    The neuro--muscular activity while working on laparoscopic trainer is the example of the complex (and complicated) movement. This class of problems are still waiting for the proper theory which will be able to describe the actual properties of the muscle performance. Here we consider the signals obtained from three states of muscle activity: at maximum contraction, during complex movements (at actual work) and in the completely relaxed state. In addition the difference between a professional and an amateur is presented. The Multifractal Detrended Fluctuation Analysis was used in description of the properties the kinesiological surface electromyographic signals (sEMG). We demonstrate the dissimilarity between each state of work for the selected group of muscles as well as between trained and untrained individuals.

  9. A model of the human triceps surae muscle-tendon complex applied to jumping

    NARCIS (Netherlands)

    Bobbert, Maarten F.; Huijing, Peter A.; van Ingen Schenau, Gerrit Jan

    1986-01-01

    The purpose of this study was to gain more insight into the behavior of the muscle-tendon complex of human m. triceps surae in jumping. During one-legged vertical jumps of ten subjects ground reaction forces as well as cinematographic data were registered, and electromyograms were recorded from m.

  10. Nuclear Pores Regulate Muscle Development and Maintenance by Assembling a Localized Mef2C Complex.

    Science.gov (United States)

    Raices, Marcela; Bukata, Lucas; Sakuma, Stephen; Borlido, Joana; Hernandez, Leanora S; Hart, Daniel O; D'Angelo, Maximiliano A

    2017-06-05

    Nuclear pore complexes (NPCs) are multiprotein channels connecting the nucleus with the cytoplasm. NPCs have been shown to have tissue-specific composition, suggesting that their function can be specialized. However, the physiological roles of NPC composition changes and their impacts on cellular processes remain unclear. Here we show that the addition of the Nup210 nucleoporin to NPCs during myoblast differentiation results in assembly of an Mef2C transcriptional complex required for efficient expression of muscle structural genes and microRNAs. We show that this NPC-localized complex is essential for muscle growth, myofiber maturation, and muscle cell survival and that alterations in its activity result in muscle degeneration. Our findings suggest that NPCs regulate the activity of functional gene groups by acting as scaffolds that promote the local assembly of tissue-specific transcription complexes and show how nuclear pore composition changes can be exploited to regulate gene expression at the nuclear periphery. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Dystrophin-glycoprotein complex and vinculin-talin-integrin system in human adult cardiac muscle.

    Science.gov (United States)

    Anastasi, Giuseppe; Cutroneo, Giuseppina; Gaeta, Roberto; Di Mauro, Debora; Arco, Alba; Consolo, Angela; Santoro, Giuseppe; Trimarchi, Fabio; Favaloro, Angelo

    2009-02-01

    Costameres were identified, for the first time, in skeletal and cardiac muscle, as regions associated with the sarcolemma, consisting of densely clustered patches of vinculin; they have many characteristics common to the cell-extracellular matrix-type of adherens junctions. Costameres are considered 'proteic machinery' and they appear to comprise two protein complexes, the dystrophin-glycoprotein complex (DGC) and the vinculin-talin-integrin system. In comparison to skeletal muscle, few studies have focused on cardiac muscle regarding these two complexes, and study is generally relative to dystrophin or to cardiac diseases, such as cardiomyopathies. However, insufficient data are available on these proteins in healthy human cardiomyocytes. For this reason, we performed an immunohistochemical study using human cardiac muscle fibers, in order to define the real distribution and the spatial relationship between the proteins in these two complexes. Our data showed a real costameric distribution of DGC and of the vinculin-talin-integrin system; all tested proteins were present in T-tubule and in intercalated disks. Moreover, our data demonstrated that all tested proteins of DGC colocalized with each other, as all tested components of the vinculin-talin-integrin system, and that all tested proteins of DGC colocalized with all tested proteins of the vinculin-talin-integrin system. Finally, all tested proteins of the two complexes were localized in the region of the sarcolemma over the I band, in 100% of our observations. The present study, for the first time, analyzed the majority of proteins of DGC and of the vinculin-talin-integrin system in cardiac muscle fibers, and it confirmed that DGC and the vinculin-talin-integrin system have a role in the transduction of mechanical force to the extracellular matrix. Finally it attributed a key role in the regulation of action potential duration to cardiac myocytes.

  12. Complex regional pain syndrome type I (RSD): pathology of skeletal muscle and peripheral nerve.

    Science.gov (United States)

    van der Laan, L; ter Laak, H J; Gabreëls-Festen, A; Gabreëls, F; Goris, R J

    1998-07-01

    Reflex sympathetic dystrophy (RSD) (recently reclassified as complex regional pain syndrome type I) is a syndrome occurring in extremities and, when chronic, results in severe disability and untractable pain. RSD may be accompanied by neurologic symptoms even when there is no previous neurologic lesion. There is no consensus as to the pathogenic mechanism involved in RSD. To gain insight into the pathophysiology of RSD, we studied histopathology of skeletal muscle and peripheral nerve from patients with chronic RSD in a lower extremity. In eight patients with chronic RSD, an above-the-knee amputation was performed because of a nonfunctional limb. Specimens of sural nerves, tibial nerves, common peroneal nerves, gastrocnemius muscles, and soleus muscles were obtained from the amputated legs and analyzed by light and electron microscopy. In all patients, the affected leg showed similar neurologic symptoms such as spontaneous pain, hyperpathy, allodynia, paresis, and anesthesia dolorosa. The nerves showed no consistent abnormalities of myelinated fibers. In four patients, the C-fibers showed electron microscopic pathology. In all patients, the gastrocnemius and soleus muscle specimens showed a decrease of type I fibers, an increase of lipofuscin pigment, atrophic fibers, and severely thickened basal membrane layers of the capillaries. In chronic RSD, efferent nerve fibers were histologically unaffected; from afferent fibers, only C-fibers showed histopathologic abnormalities. Skeletal muscle showed a variety of histopathologic findings, which are similar to the histologic abnormalities found in muscles of patients with diabetes.

  13. Salvage irrigation-suction in gracilis muscle repair of complex rectovaginal and rectourethral fistulas.

    Science.gov (United States)

    Chen, Xiao-Bing; Wang, You-Xin; Jiang, Hua; Liao, Dai-Xiang; Yu, Jun-Hui; Luo, Cheng-Hua

    2013-10-21

    To evaluate the efficacy of gracilis muscle transposition and postoperative salvage irrigation-suction in the treatment of complex rectovaginal fistulas (RVFs) and rectourethral fistulas (RUFs). Between May 2009 and March 2012, 11 female patients with complex RVFs and 8 male patients with RUFs were prospectively enrolled. Gracilis muscle transposition was undertaken in all patients and postoperative wound irrigation-suction was performed in patients with early leakage. Efficacy was assessed in terms of the success rate and surgical complications. SF-36 quality of life (QOL) scores and Wexner fecal incontinence scores were compared before and after surgery. The fistulas healed in 14 patients after gracilis muscle transposition; the initial healing rate was 73.7%. Postoperative leakage occurred and continuous irrigation-suction of wounds was undertaken in 5 patients: 4 healed and 1 failed, and postoperative fecal diversions were performed for the patient whose treatment failed. At a median follow-up of 17 mo, the overall healing rate was 94.7%. Postoperative complications occurred in 4 cases. Significant improvement was observed in the quality outcomes framework scores (P irrigation-suction-assisted healing group. Gracilis muscle transposition and postoperative salvage wound irrigation-suction gained a high success rate in the treatment of complex RVFs and RUFs. QOL and fecal incontinence were significantly improved after the successful healing of RVFs and RUFs.

  14. Patent odontogenic sinus tract draining to the midline of the submental region: report of a case.

    Science.gov (United States)

    Urbani, C E; Tintinelli, R

    1996-04-01

    We report a case of a 65-year-old woman with a cutaneous sinus tract located on the midline of the submental region secondary to a periapical abscess of the right lateral mandibular incisor. The lesion was nodulocystic and chronically drained purulent fluid. Previous topical and systemic treatments were uneffective. Radiologic examination of the mandible demonstrated diffuse radiolucency involving the apices of four affected incisors. A further radiologic sinogram revealed both the exact origin and the high grade patency of the fistolous tract. Appropriate conservative endodontic therapy led to quick resolution of the sinus tract within sixteen days. In the presence of a single chronic suppurative or nodulocystic lesion of the face, it is always useful to perform a radiologic evaluation of the maxillary and mandibular regions to promptly exclude a possible odontogenic background.

  15. Complex actions of neurotensin in ascending and sigmoid colonic muscle: Involvement of enteric mediators.

    Science.gov (United States)

    Azriel, Yael; Liu, Lu; Burcher, Elizabeth; Bucher, Elizabeth

    2010-10-10

    The brain-gut peptide neurotensin has complex effects on gastrointestinal smooth muscle. Our objective was to elucidate the mechanisms underlying neurotensin contractions in human colon. Discrete concentration response curves to neurotensin were obtained in strips of circular muscle and taenia coli from "normal" ascending and sigmoid colon segments, in the presence and absence of various pharmacological inhibitors. Potency of neurotensin in all regions was similar (pD(2) ~7). Atropine and the selective muscarinic receptor antagonists, methoctramine and darifenacin, had no effect on neurotensin contractions. In ascending colon circular muscle, responses were enhanced by indomethacin (indicating inhibitory prostaglandin mechanisms) and by tetrodotoxin (TTX), hexamethonium and L-NAME, suggesting nicotinic and enteric inhibitory neurotransmission, with involvement of nitric oxide. In sigmoid circular muscle, neurotensin responses were also enhanced by TTX and hexamethonium, but were attenuated in the presence of mepyramine, MEN10627 and CP99994, suggesting inhibitory neuronal mechanisms and involvement of histamine and tachykinins, respectively; L-NAME and the GABA(B) receptor antagonist, CGP36742, were without effect. The transcripts of NTS1 and NTS3 receptors, but not NTS2 receptors, were detected in sigmoid colon circular muscle and taenia coli. No age and gender differences in NTS1 mRNA expression were found. In conclusion, neurotensin contracts circular muscle strips from ascending and sigmoid regions of the human colon via direct (muscle) and indirect (neuronal/non-neuronal mechanisms). The enteric mediators influenced by neurotensin are regionally specific. In taenia coli strips from both ascending and sigmoid colon, neurotensin contractions were unchanged in the presence of inhibitors, suggesting direct actions only. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Correlation of Utrophin Levels with the Dystrophin Protein Complex and Muscle Fibre Regeneration in Duchenne and Becker Muscular Dystrophy Muscle Biopsies.

    Science.gov (United States)

    Janghra, Narinder; Morgan, Jennifer E; Sewry, Caroline A; Wilson, Francis X; Davies, Kay E; Muntoni, Francesco; Tinsley, Jonathon

    2016-01-01

    Duchenne muscular dystrophy is a severe and currently incurable progressive neuromuscular condition, caused by mutations in the DMD gene that result in the inability to produce dystrophin. Lack of dystrophin leads to loss of muscle fibres and a reduction in muscle mass and function. There is evidence from dystrophin-deficient mouse models that increasing levels of utrophin at the muscle fibre sarcolemma by genetic or pharmacological means significantly reduces the muscular dystrophy pathology. In order to determine the efficacy of utrophin modulators in clinical trials, it is necessary to accurately measure utrophin levels and other biomarkers on a fibre by fibre basis within a biopsy section. Our aim was to develop robust and reproducible staining and imaging protocols to quantify sarcolemmal utrophin levels, sarcolemmal dystrophin complex members and numbers of regenerating fibres within a biopsy section. We quantified sarcolemmal utrophin in mature and regenerating fibres and the percentage of regenerating muscle fibres, in muscle biopsies from Duchenne, the milder Becker muscular dystrophy and controls. Fluorescent immunostaining followed by image analysis was performed to quantify utrophin intensity and β-dystrogylcan and ɣ -sarcoglycan intensity at the sarcolemma. Antibodies to fetal and developmental myosins were used to identify regenerating muscle fibres allowing the accurate calculation of percentage regeneration fibres in the biopsy. Our results indicate that muscle biopsies from Becker muscular dystrophy patients have fewer numbers of regenerating fibres and reduced utrophin intensity compared to muscle biopsies from Duchenne muscular dystrophy patients. Of particular interest, we show for the first time that the percentage of regenerating muscle fibres within the muscle biopsy correlate with the clinical severity of Becker and Duchenne muscular dystrophy patients from whom the biopsy was taken. The ongoing development of these tools to quantify

  17. Expression of dystrophin-glycoprotein complex at the skeletal muscle sarcolemma in Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Lei ZHAO

    2015-07-01

    Full Text Available Background  Eccentric exercise or high tension exercise could cause damage to skeletal muscle structure, resulting in deficiency of dystrophin and secondary loss of dystrophin-glycoprotein complex (DGC from the sarcolemma, which indicated that down-regulation of dystrophin was one of the key points of skeletal muscle injury from eccentric exercise. Duchenne muscular dystrophy (DMD is caused by mutations of DMD gene, resulting in the absence of dystrophin, which means that skeletal muscles of DMD patients after birth are in the natural state of actual path of force transmission which carried high tension from eccentric exercise. This paper investigated systematically whether expression of DGC is associated with progressive muscle weakness in natural history of DMD, and analyzed the expression of DGC at the sarcolemma of 197 confirmed DMD cases (9 days-12 years old.  Methods  The expression of α- and β-dystroglycan (DG, α-, β-, γ- and δ-sarcoglycan (SG and syntrophin at the sarcolemma of DMD patients was analyzed by immunofluorescent staining.  Results  The study showed that there was no relationship between lack of proteins and progressive muscle weakness with increasing age, although expression of α- and β-DG, α-, β-, γ- and δ-SG and syntrophin at the sarcolemma at different stages of 197 DMD patients (9 days-12 years old had different degrees of deficiency.  Conclusions  Deficiency of DGC may occur before birth and DMD patients were recommended to avoid further damage to skeletal muscles from eccentric exercise and high-resistance movement in activities of daily life and rehabilitation training. DOI: 10.3969/j.issn.1672-6731.2015.06.006

  18. Regulation of Muscle Pyruvate Dehydrogenase Complex in Insulin Resistance: Effects of Exercise and Dichloroacetate

    Directory of Open Access Journals (Sweden)

    Dumitru Constantin-Teodosiu

    2013-10-01

    Full Text Available Since the mitochondrial pyruvate dehydrogenase complex (PDC controls the rate of carbohydrate oxidation, impairment of PDC activity mediated by high-fat intake has been advocated as a causative factor for the skeletal muscle insulin resistance, metabolic syndrome, and the onset of type 2 diabetes (T2D. There are also situations where muscle insulin resistance can occur independently from high-fat dietary intake such as sepsis, inflammation, or drug administration though they all may share the same underlying mechanism, i.e., via activation of forkhead box family of transcription factors, and to a lower extent via peroxisome proliferator-activated receptors. The main feature of T2D is a chronic elevation in blood glucose levels. Chronic systemic hyperglycaemia is toxic and can lead to cellular dysfunction that may become irreversible over time due to deterioration of the pericyte cell's ability to provide vascular stability and control to endothelial proliferation. Therefore, it may not be surprising that T2D's complications are mainly macrovascular and microvascular related, i.e., neuropathy, retinopathy, nephropathy, coronary artery, and peripheral vascular diseases. However, life style intervention such as exercise, which is the most potent physiological activator of muscle PDC, along with pharmacological intervention such as administration of dichloroacetate or L-carnitine can prove to be viable strategies for treating muscle insulin resistance in obesity and T2D as they can potentially restore whole body glucose disposal.

  19. The drive for muscle leanness: a complex case with features of muscle dysmorphia and eating disorder not otherwise specified.

    Science.gov (United States)

    Cafri, G; Blevins, N; Thompson, J K

    2006-12-01

    Muscle dysmorphia has been described as a subtype of body dysmorphic disorder in which an individual experiences severe body image disturbance related to muscularity. The current case is of a 20-year-old man who describes a history of muscle dysmorphia in which the nature of the body image concern is related to leanness (i.e., muscularity in the absence of body fat), as opposed to increasing muscle mass, which is how muscle dysmorphia has typically been characterized in the literature. The case illustrates the need to consider this additional facet of body image when diagnosing muscle dysmorphia.

  20. Urethral obstruction malformation complex: a cause of abdominal muscle deficiency and the "prune belly".

    Science.gov (United States)

    Pagon, R A; Smith, D W; Shepard, T H

    1979-06-01

    Abdominal muscle deficiency with a "prune belly" abdomen as been a major feature of the so-called prune belly syndrome, which has been regarded as a specific entity, although the etiology and developmental pathology are not understood. We present evidence that abdominal muscle deficiency is an etiologically nonspecific anatomic defect which is secondary to fetal abdominal distention of various causes. One of the more common causes is urethral obstruction with consequent early bladder distention, causing abdominal distention and other anomalies, a constellation of findings which we have termed the urethral obstruction malformation complex. This interpretation of the etiology of most cases of prune belly syndrome accounts for the male predominance, the observed variability in severity, and the lack of a defined mode of inheritance. Recurrence risk figures need to be redefined for each specific obstructing lesion of the urethra. The possibility of early prenatal diagnosis and management of fetuses with urethral obstruction needs further study.

  1. Magnetic resonance imaging findings of injuries to the calf muscle complex.

    Science.gov (United States)

    Koulouris, George; Ting, Amy Y I; Jhamb, Ashu; Connell, David; Kavanagh, Eoin C

    2007-10-01

    The objective was to describe the imaging findings following acute injury to the calf musculature. We retrospectively reviewed 59 MR examinations in patients who sustained injuries to the calf muscle from April 2001 to September 2004 (48 men, 11 women), with an average age of 31 and 47 years respectively (range in men 20-53; range in women 33-63). Attention was directed to the frequency of muscle involvement, the location of the injury within the musculotendinous unit and the extent of the injury. A total of 79 separate sites of strain injury were identified (39 solitary, 20 dual). Of the 39 isolated strains, injury to the gastrocnemius was most common (19 out of 39; 48.7%), preferentially involving the medial head in 18 cases and the lateral head in 1 case. The soleus was also commonly involved (18 out of 39; 46.2%), with 2 cases (5.1%) of distal avulsions of the plantaris. Of the 20 dual injuries, a combination of gastrocnemius injury with soleus injury was the most frequent finding (12 out of 20; 60%). Dual injuries of both heads of the gastrocnemius muscles were demonstrated in 4 cases (20%), with the soleus and tibialis posterior injured in 3 cases (15%). A combination of soleus and flexor hallucis longus injury was seen in 1 case (5%). This retrospective study utilizing MRI demonstrates that the medial head of the gastrocnemius is the most commonly injured muscle of the calf, closely followed by the soleus, the latter finding rarely reported in the sonographic literature. Dual injuries of the calf muscle complex occur much more commonly than previously reported and may be of prognostic significance.

  2. Characterization of a multiprotein complex involved in excitation-transcription coupling of skeletal muscle.

    Science.gov (United States)

    Arias-Calderón, Manuel; Almarza, Gonzalo; Díaz-Vegas, Alexis; Contreras-Ferrat, Ariel; Valladares, Denisse; Casas, Mariana; Toledo, Héctor; Jaimovich, Enrique; Buvinic, Sonja

    2016-01-01

    Electrical activity regulates the expression of skeletal muscle genes by a process known as "excitation-transcription" (E-T) coupling. We have demonstrated that release of adenosine 5'-triphosphate (ATP) during depolarization activates membrane P2X/P2Y receptors, being the fundamental mediators between electrical stimulation, slow intracellular calcium transients, and gene expression. We propose that this signaling pathway would require the proper coordination between the voltage sensor (dihydropyridine receptor, DHPR), pannexin 1 channels (Panx1, ATP release conduit), nucleotide receptors, and other signaling molecules. The goal of this study was to assess protein-protein interactions within the E-T machinery and to look for novel constituents in order to characterize the signaling complex. Newborn derived myotubes, adult fibers, or triad fractions from rat or mouse skeletal muscles were used. Co-immunoprecipitation, 2D blue native SDS/PAGE, confocal microscopy z-axis reconstruction, and proximity ligation assays were combined to assess the physical proximity of the putative complex interactors. An L6 cell line overexpressing Panx1 (L6-Panx1) was developed to study the influence of some of the complex interactors in modulation of gene expression. Panx1, DHPR, P2Y2 receptor (P2Y2R), and dystrophin co-immunoprecipitated in the different preparations assessed. 2D blue native SDS/PAGE showed that DHPR, Panx1, P2Y2R and caveolin-3 (Cav3) belong to the same multiprotein complex. We observed co-localization and protein-protein proximity between DHPR, Panx1, P2Y2R, and Cav3 in adult fibers and in the L6-Panx1 cell line. We found a very restricted location of Panx1 and Cav3 in a putative T-tubule zone near the sarcolemma, while DHPR was highly expressed all along the transverse (T)-tubule. By Panx1 overexpression, extracellular ATP levels were increased both at rest and after electrical stimulation. Basal mRNA levels of the early gene cfos and the oxidative metabolism

  3. Nuclear antigens in Trichinella spiralis infected muscle cells: nuclear extraction, compartmentalization and complex formation.

    Science.gov (United States)

    Yao, C; Jasmer, D P

    1998-05-01

    Infection of mammalian skeletal muscle cells by Trichinella spiralis induces a series of changes that include: reentry of the terminally differentiated host cell into the cell cycle; suspension of infected cells in apparent G2/M; and transcriptional inactivation of the differentiated skeletal muscle gene program. Cell cycle repositioning and genetic reprogramming are chronic characteristics of host cells that can remain infected for years. Nuclear antigens (NA, 79, 86 and 97 kDa) that localize to host cell nuclei have been detected with antibodies against T. spiralis proteins. Since NA may play a role in regulating the infected cell phenotype, their origin, nuclear compartmentalization, and biochemical properties were investigated. We show that a monoclonal antibody to a defined epitope of T. spiralis glycans binds these NA, which indicates the parasite origin of these proteins. NA were not extracted under conditions that solubilized chromatin from infected cell nuclei. In contrast, NA were coextracted with B lamins (nuclear envelope) by 4 M urea. Urea extraction was pH dependent (8.0), suggesting ionic interaction of NA in protein complexes. Nevertheless, confocal microscopy demonstrated colocalization of NA with host chromatin, and not B lamins. Nuclear protein complexes containing NA were observed under non-reducing conditions, and NA were readily cross-linked in isolated nuclei by succinimidyl protein conjugating reagents. The results establish methods to extract NA from infected cell nuclei for further biochemical analysis, establish the existence of nuclear protein complexes containing NA and demonstrate colocalization of NA with host chromatin. Collectively, the results provide a foundation from which to investigate the role of NA in regulating the T. spiralis infected skeletal muscle cell phenotype.

  4. Elastic properties of muscle-tendon complex in long-distance runners.

    Science.gov (United States)

    Kubo, K; Kanehisa, H; Kawakami, Y; Fukunaga, T

    2000-02-01

    The purpose of this study was to investigate the elastic properties of muscle-tendon complex (MTC) in knee extensor muscles and the capacity for elastic energy utilization in long-distance runners (LDR) by comparing with data obtained from untrained individuals (CON). The elongation (L) of the tendon and aponeurosis of vastus lateralis muscle during isometric knee extension was determined by real-time brightness mode ultrasonography, while the subjects developed a gradually increasing torque from 0 (relaxed) to maximal effort (MVC) within 7 s. In addition, performances in two kinds of maximal vertical jumps, i.e. squatting (SJ) and counter-movement jumps (CMJ), were measured. The relationship between L muscle and force (F) was curvilinear and consisted of an initial region (toe region), characterized by a large increase in L with increasing F, immediately followed by a linear region. The slope of the regression equation for the L-F relationship in the range 50%-100% of MVC was defined as an index of MTC compliance, where the rate of the changes in L to that in muscle F at every 10% of MVC became almost constant. The maximal L (Lmax) and MTC compliance were significantly lower in LDR than in CON: 29.9 (SD 3.9) mm in LDR compared to 33.3 (SD 5.5) mm in CON for Lmax and 1.55 (SD 0.25) x 10(-2) mm.N-1 in LDR compared to 1.88 (SD 0.82) x 10(-2) mm.N-1 in CON for MTC compliance. Also, LDR showed significantly less elastic energy absorption (Ee) than CON, defined as the area below the L-F relationship curve from 0 to 100% of MVC. Not only jump heights but also the differences between the heights in SJ and CMJ, expressed as the percentage of the height in SJ, were significantly lower in LDR than in CON. The augmentation with counter-movement was significantly correlated to either MTC compliance (r = 0.554, P untrained individuals. These elastic profiles of vastus lateralis muscle in LDR may be associated with their lower performances during CMJ.

  5. Complex polysaccharide inclusions in skeletal muscle adjacent to sarcomas in two dogs.

    Science.gov (United States)

    Valentine, B A; Bildfell, R J; Cooper, B J; Giger, U; Fischer, K A

    2002-03-01

    Inclusions of periodic acid-Schiff-positive, amylase resistant material were found within skeletal muscle fibers adjacent to an osteosarcoma in the proximal femur of an 8-year-old intact female Cocker Spaniel dog (dog No. 1) and adjacent to a synovial cell sarcoma of the stifle joint in a 7-year-old spayed female Bouvier des Flandres dog (dog No. 2). Inclusions were pale blue-gray with hematoxylin and eosin stain and formed irregular inclusions, replacing up to approximately 80% of the fiber diameter. Inclusions from dog No. 2 were of non-membrane-bound granular to filamentous material that occasionally formed discrete, elongate electron-dense masses. The features of these inclusions were similar to those of materials previously described as complex polysaccharide, polyglucosan bodies, amylopectin, and Lafora bodies. Evidence for a generalized metabolic disorder was not found in these two dogs, suggesting that storage of complex polysaccharide can occur as a relatively nonspecific response to metabolic alterations in skeletal muscle in a variety of conditions.

  6. Muscle synergies and complexity of neuromuscular control during gait in cerebral palsy.

    Science.gov (United States)

    Steele, Katherine M; Rozumalski, Adam; Schwartz, Michael H

    2015-12-01

    Individuals with cerebral palsy (CP) have impaired movement due to a brain injury near birth. Understanding how neuromuscular control is altered in CP can provide insight into pathological movement. We sought to determine if individuals with CP demonstrate reduced complexity of neuromuscular control during gait compared with unimpaired individuals and if changes in control are related to functional ability. Muscle synergies during gait were retrospectively analyzed for 633 individuals (age range 3.9-70y): 549 with CP (hemiplegia, n=122; diplegia, n=266; triplegia, n=73; quadriplegia, n=88) and 84 unimpaired individuals. Synergies were calculated using non-negative matrix factorization from surface electromyography collected during previous clinical gait analyses. Synergy complexity during gait was compared with diagnosis subtype, functional ability, and clinical examination measures. Fewer synergies were required to describe muscle activity during gait in individuals with CP compared with unimpaired individuals. Changes in synergies were related to functional impairment and clinical examination measures including selective motor control, strength, and spasticity. Individuals with CP use a simplified control strategy during gait compared with unimpaired individuals. These results were similar to synergies during walking among adult stroke survivors, suggesting similar neuromuscular control strategies between these clinical populations. © 2015 Mac Keith Press.

  7. Ultrasonography as a tool to study afferent feedback from the muscle-tendon complex during human walking

    DEFF Research Database (Denmark)

    Cronin, Neil J.; Klint, Richard af; Grey, Michael James

    2011-01-01

    of these receptors to act as length, velocity and force transducers is the complex pattern of interaction between muscle and tendinous tissues, as tendon length is often considerably greater than muscle fibre length in the human lower limb. In essence, changes in muscle-tendon mechanics can influence the firing......In humans, one of the most common tasks in everyday life is walking, and sensory afferent feedback from peripheral receptors, particularly the muscle spindles and Golgi tendon organs (GTO), makes an important contribution to the motor control of this task. One factor that can complicate the ability...... behaviour of afferent receptors, which may in turn affect the motor control. In this review we first summarise research that has incorporated the use of ultrasound-based techniques to study muscle-tendon interaction, predominantly during walking. We then review recent research that has combined this method...

  8. Submental Artery Island Flap in Reconstruction of Harde Plate after wide Surgical Resection of Veruccous Carcinoma. Two case reports

    Directory of Open Access Journals (Sweden)

    Amin Rahpeyma

    2013-06-01

    Full Text Available Introduction: Reconstruction of intraoral soft tissue defects is important in restoring function and esthetic. In large defects, there will be demand for regional pedicle flaps or free flaps. Hard palate separates nasal and oral cavities. Due to the small surface area between flap and remaining palate after surgical resections, optimal blood supply of the flaps for hard palate reconstructions are needed. This article demonstrates immediate reconstruction of two edentulous hemimaxillectomy patients with submental artery Island flap and brief review of this flap discussed. 

  9. A phase I safety and pharmacokinetic study of ATX-101: injectable, synthetic deoxycholic acid for submental contouring.

    Science.gov (United States)

    Walker, Patricia; Fellmann, Jere; Lizzul, Paul F

    2015-03-01

    ATX-101 (deoxycholic acid [DCA] injection) is a proprietary formulation of pure synthetic DCA. When injected into subcutaneous fat, ATX-101 results in focal adipocytolysis, the targeted destruction of fat cells. ATX-101 is undergoing investigation as an injectable drug for contouring the submental area by reducing submental fat (SMF). The purpose of this study was to evaluate the safety and pharmacokinetics (PK) of the maximal therapeutic dose of ATX-101 (100 mg total dose). Following PK evaluation of endogenous DCA, subjects (N=24) received subcutaneous injections of ATX-101 (2 mg/cm2, with or without 0.9% benzyl alcohol) into SMF; PK evaluation was repeated periodically over 24 hours. Endogenous DCA plasma concentrations measured prior to injection were highly variable within and between subjects. Similarly, following ATX-101 injection, DCA plasma concentrations were highly variable, peaked rapidly, and returned to the range observed for endogenous values by 24 hours postdose. All subjects experienced at least 1 adverse event (AE). No death, serious AE, or AE-related discontinuations occurred. The majority of AEs were transient, associated with the area treated, and of mild or moderate severity. No clinically significant changes were reported for laboratory test results, vital signs, or Holter electrocardiograms postdosing. These data support the favorable safety and efficacy observations of ATX-101 as an injectable drug to reduce SMF.

  10. The effect of peculiar complex core balance training on isokinetic muscle functions of the knee and lumbus.

    Science.gov (United States)

    Lee, Myungsun; Han, Gunsoo

    2016-04-01

    [Purpose] This study aimed to investigate the effect of peculiar complex core balance training on the isokinetic muscle function of the knee joint and lumbus to provide fundamental data for establishing a training program that focuses on improving the performance and prevention of injury by developing the core and low extremity muscles. [Subjects and Methods] The participants in this study included a total of ten high school athletes involved in a throwing event for over five years. The subjects were randomly divided into two groups: The experimental group (N=5) and the control group (N=5). The experimental group underwent peculiar complex core balance training. [Results] According to the analysis of covariance, there was a significant effect of peculiar complex core balance training. Therefore, the isokinetic muscle function of the knee joint and lumbus in the experimental group participating in peculiar complex core balance training was significantly increased compared to the control group. [Conclusion] It is concluded that peculiar complex core balance training had a positive effect on the isokinetic muscle function of the knee and lumbus in throwing event athletes.

  11. Management of Patient Experience With ATX-101 (Deoxycholic Acid Injection) for Reduction of Submental Fat.

    Science.gov (United States)

    Dover, Jeffrey S; Kenkel, Jeffrey M; Carruthers, Alastair; Lizzul, Paul F; Gross, Todd M; Subramanian, Meenakshi; Beddingfield, Frederick C

    2016-11-01

    ATX-101 (deoxycholic acid injection; Kythera Biopharmaceuticals, Inc., Westlake Village, CA [an affiliate of Allergan plc, Dublin, Ireland]) was recently approved for submental fat (SMF) reduction in the United States (Kybella) and Canada (Belkyra). The pivotal trials supporting these approvals revealed that ATX-101 is associated with common injection-site treatment reactions consistent with its mechanism of action and administration procedure. The purpose of this study was to evaluate 4 patient experience management paradigms targeting the common injection-site adverse events of pain, swelling/edema, and bruising after a single treatment session with ATX-101. In this double-blind, parallel-group, exploratory Phase 3b study (ClinicalTrials.gov identifier: NCT02007434), subjects with moderate to severe SMF were randomized 4:1 within each paradigm to receive ATX-101 2 mg/cm or placebo. In Paradigm 1, subjects received a cold pack application to the treatment area. In Paradigm 2, in addition to cold pack application, subjects were treated with topical lidocaine and injectable lidocaine containing epinephrine. In Paradigm 3, in addition to the interventions of Paradigm 2, subjects received loratadine and ibuprofen. Subjects in Paradigm 4 received the same interventions in Paradigm 3, plus application of a chin strap. Eighty-three subjects were treated. In ATX-101-treated subjects, peak pain occurred within 1 to 5 minutes of treatment, with median values at these time points ranging from 21.4 to 35.7 mm on a 100-mm pain visual analog scale ("mild"). Pain ratings reduced substantially by 15 minutes; at 4 hours after injection, pain was characterized as mild tenderness or mild achiness. Compared with cold alone, treatment with topical and injectable lidocaine reduced median peak pain by 17%. Addition of ibuprofen and loratadine resulted in a total reduction in pain by 40%. Peak swelling/edema in ATX-101-treated subjects was "modest," with mean values ≤1.7 (on a 0

  12. Analysis of facial and inspiratory muscles performance during breastfeeding.

    Science.gov (United States)

    Ratnovsky, Anat; Carmeli, Yael Nadlin; Elad, David; Zaretsky, Uri; Dollberg, Shaul; Mandel, Dror

    2013-01-01

    Breastfeeding is a dynamic process in which the infant recruits several muscle groups in his face, head and throat. The objective of this study was to explore the relative role of the submental muscle group, the orbicularis oris and the sternocleidomastoid muscles to breastfeeding process and to the relatively high intra-oral vacuum measured during this process. Electromyography (EMG) measurements were conducted on 11 infants (mean age 1.91 ± 1.0 days, mean weight 3364 ± 328 g) using surface electrodes. The EMG data were filtered with a low pass filter to yield the linear envelopes (IEMG). The maximal and mean value and the area under each linear envelope curve were examined. During active suckling significantly higher activity (P< 0.05) of the submental muscle group were measured compared with the orbicularis oris and sternocleidomastoid muscles (mean ± SE values of the maximal linear envelope were 24.4 ± 1 μV, 9.6 ± 0.6 μV and 14 ± 0.7 μV, respectively). These results confirmed that jaw movements have the primary role during breastfeeding, but also revealed that the inspiratory muscles have a substantial contribution to this process and probably have an important role in the generation of intra oral vacuum measured during breastfeeding.

  13. Adults with complex congenital heart disease have impaired skeletal muscle function and reduced confidence in performing exercise training.

    Science.gov (United States)

    Sandberg, Camilla; Thilén, Ulf; Wadell, Karin; Johansson, Bengt

    2015-12-01

    Adults with congenital heart disease (ACHD) usually have reduced aerobic exercise capacity compared with controls. However, their skeletal muscle function is less studied. In this cross-sectional study, unilateral isotonic shoulder flexion, unilateral isotonic heel-lift, maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were tested in 85 patients with ACHD (35 women, mean age 36.8 ± 14.8 years), classed as either 'complex' (n = 43) or 'simple' (n = 42), and 42 age and gender matched controls (16 women, mean age 36.9 ± 14.9). Maximum number of shoulder flexions and heel-lifts were measured. MIP/MEP was tested using a handheld respiratory pressure meter. Exercise self-efficacy, measuring confidence in performing exercise training, was evaluated. Adults with complex lesions performed fewer shoulder flexions compared with controls and patients with simple lesions (28.2 ± 11.1 vs. 63.6 ± 40.4, p heart lesions were independently associated with impaired limb muscle function. Adults with complex congenital heart disease have impaired skeletal muscle function compared with patients with simple lesions and healthy controls. They also had lower confidence in performing exercise training. Thus, this population might have a potential for rehabilitation focusing on improving muscle function and confidence in performing exercise training. © The European Society of Cardiology 2014.

  14. Mammalian target of rapamycin complex 2 regulates muscle glucose uptake during exercise in mice

    DEFF Research Database (Denmark)

    Kleinert, Maximilian; Parker, Benjamin L; Fritzen, Andreas Mæchel

    2017-01-01

    Exercise increases glucose uptake into insulin-resistant muscle. Thus, elucidating the exercise signalling network in muscle may uncover new therapeutic targets. mTORC2, a regulator of insulin-controlled glucose uptake, has been reported to interact with Rac1, which plays a role in exercise......-induced glucose uptake in muscle. Therefore, we tested the hypothesis that mTORC2 activity is necessary for muscle glucose uptake during treadmill exercise. We used mice that specifically lack mTORC2 signalling in muscle, by deletion of the obligatory mTORC2 component, Rictor (Ric mKO). Running capacity...... potential exercise-dependent mTORC2 substrates, including contractile proteins, kinases, transcriptional regulators, actin cytoskeleton regulators and ion-transport proteins. Our study suggests that mTORC2 is a component of the exercise signalling network that regulates muscle glucose uptake and we provide...

  15. Complex coordination of cell plasticity by a PGC-1α-controlled transcriptional network in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Barbara eKupr

    2015-11-01

    Full Text Available Skeletal muscle cells exhibit an enormous plastic capacity in order to adapt to external stimuli. Even though our overall understanding of the molecular mechanisms that underlie phenotypic changes in skeletal muscle cells remains poor, several factors involved in the regulation and coordination of relevant transcriptional programs have been identified in recent years. For example, the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α is a central regulatory nexus in the adaptation of muscle to endurance training. Intriguingly, PGC-1α integrates numerous signaling pathways and translates their activity into various transcriptional programs. This selectivity is in part controlled by differential expression of PGC-1α variants and post-translational modifications of the PGC-1α protein. PGC-1α-controlled activation of transcriptional networks subsequently enables a spatio-temporal specification and hence allows a complex coordination of changes in metabolic and contractile properties, protein synthesis and degradation rates and other features of trained muscle. In this review, we discuss recent advances in our understanding of PGC-1α-regulated skeletal muscle cell plasticity in health and disease.

  16. Rényi entropy and Lempel-Ziv complexity of mechanomyographic recordings of diaphragm muscle as indexes of respiratory effort.

    Science.gov (United States)

    Torres, Abel; Fiz, Jose A; Jane, Raimon; Laciar, Eric; Galdiz, Juan B; Gea, Joaquim; Morera, Josep

    2008-01-01

    The study of the mechanomyographic (MMG) signals of respiratory muscles is a promising technique in order to evaluate the respiratory muscles effort. A new approach for quantifying the relationship between respiratory MMG signals and respiratory effort is presented by analyzing the spatio-temporal patterns in the MMG signal using two non-linear methods: Rényi entropy and Lempel-Ziv (LZ) complexity analysis. Both methods are well suited to the analysis of non-stationary biomedical signals of short length. In this study, MMG signals of the diaphragm muscle acquired by means of a capacitive accelerometer applied on the costal wall were analyzed. The method was tested on an animal model (dogs), and the diaphragmatic MMG signal was recorded continuously while two non anesthetized mongrel dogs performed a spontaneous ventilation protocol with an incremental inspiratory load. The performance in discriminating high and low respiratory effort levels with these two methods was analyzed with the evaluation of the Pearson correlation coefficient between the MMG parameters and respiratory effort parameters extracted from the inspiratory pressure signal. The results obtained show an increase of the MMG signal Rényi entropy and LZ complexity values with the increase of the respiratory effort. Compared with other parameters analyzed in previous works, both Rényi entropy and LZ complexity indexes demonstrates better performance in all the signals analyzed. Our results suggest that these non-linear techniques are useful to detect and quantify changes in the respiratory effort by analyzing MMG respiratory signals.

  17. Complex Polysaccharide Inclusions in Skeletal Muscle Adjacent to Sarcomas in Two Dogs

    National Research Council Canada - National Science Library

    Valentine, B. A; Bildfell, R. J; Cooper, B. J; Giger, U; Fischer, K. A

    2002-01-01

    Inclusions of periodic acid-Schiff-positive, amylase resistant material were found within skeletal muscle fibers adjacent to an osteosarcoma in the proximal femur of an 8-year-old intact female Cocker Spaniel dog (dog No. 1...

  18. Evaluation by blue native polyacrylamide electrophoresis colorimetric staining of the effects of physical exercise on the activities of mitochondrial complexes in rat muscle

    Directory of Open Access Journals (Sweden)

    Molnar A.M.

    2004-01-01

    Full Text Available Blue native polyacrylamide electrophoresis (BN-PAGE is a technique developed for the analysis of membrane complexes. Combined with histochemical staining, it permits the analysis and quantification of the activities of mitochondrial oxidative phosphorylation enzymes using whole muscle homogenates, without the need to isolate muscle mitochondria. Mitochondrial complex activities were measured by emerging gels in a solution containing all specific substrates for NADH dehydrogenase and cytochrome c oxidase enzymes (complexes I and IV, respectively and the colored bands obtained were measured by optique densitometry. The objective of the present study was the application of BN-PAGE colorimetric staining for enzymatic characterization of mitochondrial complexes I and IV in rat muscles with different morphological and biochemical properties. We also investigated these activities at different times after acute exercise of rat soleus muscle. Although having fewer mitochondria than oxidative muscles, white gastrocnemius muscle presented a significantly higher activity (26.7 ± 9.5 in terms of complex I/V ratio compared to the red gastrocnemius (3.8 ± 0.65, P < 0.05 and soleus (9.8 ± 0.9, P < 0.001 muscles. Furthermore, the complex IV/V ratio of white gastrocnemius muscle was always significantly higher when compared to the other muscles. Ninety-five minutes of exhaustive physical exercise induced a decrease in complex I/V and complex IV/V ratios after all resting times (0, 3 and 6 h compared to control (P < 0.05, probably reflecting the oxidative damage due to increasing free radical production in mitochondria. These results demonstrate the possible and useful application of BN-PAGE-histochemical staining to physical exercise studies.

  19. The impact of subacromial impingement syndrome on muscle activity patterns of the shoulder complex: a systematic review of electromyographic studies

    Directory of Open Access Journals (Sweden)

    Smith Toby O

    2010-03-01

    Full Text Available Abstract Background Subacromial impingement syndrome (SIS is a commonly reported cause of shoulder pain. The purpose of this study was to systematically review the literature to examine whether a difference in electromyographic (EMG activity of the shoulder complex exists between people with SIS and healthy controls. Methods Medline, CINAHL, AMED, EMBASE, and grey literature databases were searched from their inception to November 2008. Inclusion, data extraction and trial quality were assessed in duplicate. Results Nine studies documented in eleven papers, eight comparing EMG intensity and three comparing EMG onset timing, representing 141 people with SIS and 138 controls were included. Between one and five studies investigated each muscle totalling between 20 and 182 participants. The two highest quality studies of five report a significant increase in EMG intensity in upper trapezius during scaption in subjects with SIS. There was evidence from 2 studies of a delayed activation of lower trapezius in patients with SIS. There was otherwise no evidence of a consistent difference in EMG activity between the shoulders of subjects with painful SIS and healthy controls. Conclusions A difference may exist in EMG activity within some muscles, in particular upper and lower trapezius, between people with SIS and healthy controls. These muscles may be targets for clinical interventions aiding rehabilitation for people with SIS. These differences should be investigated in a larger, high quality survey and the effects of therapeutically targeting these muscles in a randomised controlled trial.

  20. Surgical correction of blepharoptosis using the levator aponeurosis-Müller's muscle complex readaptation technique: a 15-year experience.

    Science.gov (United States)

    Scuderi, Nicolò; Chiummariello, Stefano; De Gado, Federico; Alfano, Carmine; Scuderi, GianLuca; Recupero, Santi Maria

    2008-01-01

    Palpebral ptosis is defined as abnormal drooping of the upper lid, caused by partial or total reduction in levator muscle function. It may be caused by various abnormalities, both congenital and acquired. The aim of this article is to report the long-term follow-up of results obtained with the levator aponeurosis-Müller's muscle complex readaptation technique. In a clinical study, 144 eyelids (102 patients) affected by congenital or acquired blepharoptosis were treated using the levator aponeurosis-Müller's muscle complex readaptation technique. Degree of ptosis and levator function were measured preoperatively and postoperatively. All patients were followed up for 1 year, 54 of them for 3 years, 22 for 5 years, and 12 for 10 years. Complete correction or mild residual ptosis was achieved in over 83 percent. All ptosis with preoperative levator function greater than 8 mm was completely corrected, whereas eyelids with poor or absent levator function showed a variable degree of postoperative correction and a statistically significant difference. Ptosis correction between eyelids with levator function greater than 8 mm or less than 8 mm was analyzed statistically using the McNemar test for paired data. This surgical technique is effective in both acquired and congenital ptosis. In particular, the authors obtained better results in those with fair to good (> 8 mm) levator function than in those with poor or absent (< or = 8 mm) levator function.

  1. A rare variation of the digastric muscle

    Science.gov (United States)

    KALNIEV, MANOL; KRASTEV, DIMO; KRASTEV, NIKOLAY; VIDINOV, KALIN; VELTCHEV, LUDMIL; APOSTOLOV, ALEXANDER; MILEVA, MILKA

    2013-01-01

    The digastric muscle is composed by two muscle bellies: an anterior and a posterior, joined by an intermediate tendon. This muscle is situated in the anterior region of the neck. The region between the hyoid bone and the mandible is divided by an anterior belly into two triangles: the submandibular situated laterally and the submental triangle which is located medially. We found that the anatomical variations described in the literature relate mainly to the anterior belly and consist of differences in shape and attachment of the muscle. During routine dissection in February 2013 in the section hall of the Department of Anatomy and Histology in Medical University – Sofia we came across a very interesting variation of the digastric muscle. The digastric muscles that presented anatomical variations were photographed using a Sony Cyber-shot DSC-T1 camera, with a Carl Zeiss Vario-Tessar lens. We found out bilateral variation of the digastric muscle in one cadaver. The anterior bellies were very thin and insert to the hyoid bone. Two anterior bellies connect each other and thus they formed a loop. The anatomical variations observed of our study related only to the anterior belly, as previously described by other authors. It is very important to consider the occurrence of the above mentioned variations in the digastric muscle when surgical procedures are performed on the anterior region of the neck. PMID:26527971

  2. Dissection of a Single Rat Muscle-Tendon Complex Changes Joint Moments Exerted by Neighboring Muscles: Implications for Invasive Surgical Interventions

    NARCIS (Netherlands)

    Maas, H.; Baan, G.C.; Huijing, P.A.J.B.M.

    2013-01-01

    The aim of this paper is to investigate mechanical functioning of a single skeletal muscle, active within a group of (previously) synergistic muscles. For this purpose, we assessed wrist angle-active moment characteristics exerted by a group of wrist flexion muscles in the rat for three conditions:

  3. Controlled intermittent shortening contractions of a muscle-tendon complex: muscle fibre damage and effects on force transmission from a single head of rat EDL

    NARCIS (Netherlands)

    Maas, H.; Lehti, T.M.; Tiihonen, V.; Komulainen, J.; Huijing, P.A.J.B.M.

    2005-01-01

    This study was performed to examine effects of prolonged (3 h) intermittent shortening (amplitude 2 mm) contractions (muscles were excited maximally) of head III of rat extensor digitorum longus muscle (EDL III) on indices of muscle damage and on force transmission within the intact anterior crural

  4. Carbohydrate ingestion prior to exercise augments the exercise-induced activation of the pyruvate dehydrogenase complex in human skeletal muscle.

    Science.gov (United States)

    Tsintzas, K; Williams, C; Constantin-Teodosiu, D; Hultman, E; Boobis, L; Greenhaff, P

    2000-09-01

    This study examined the effect of pre-exercise carbohydrate (CHO) ingestion on pyruvate dehydrogenase complex (PDC) activation, acetyl group availability and substrate level phosphorylation (glycogenolysis and phosphocreatine (PCr) hydrolysis) in human skeletal muscle during the transition from rest to steady-state exercise. Seven male subjects performed two 10 min treadmill runs at 70 % maximum oxygen uptake (VO2,max), 1 week apart. Each subject ingested 8 ml (kg body mass (BM))-1 of either a placebo solution (CON trial) or a 5.5 % CHO solution (CHO trial) 10 min before each run. Muscle biopsy samples were obtained from the vastus lateralis at rest and immediately after each trial. Muscle PDC activity was higher at the end of exercise in the CHO trial compared with the CON trial (1.78+/-0.18 and 1.27+/-0.16 mmol min(-1) (kg wet matter (WM))(-1), respectively; P 0.05) and this was accompanied by lower acetylcarnitine (7.1+/-1.2 and 9.1+/-1.1 mmol kg(-1) (dry matter (DM))(-1) in CHO and CON, respectively; Ptransition from rest to steady-state exercise. However, those changes did not affect the contribution of substrate level phosphorylation to ATP resynthesis.

  5. Effects of streptozotocin-induced diabetes and physical training on gene expression of titin-based stretch-sensing complexes in mouse striated muscle.

    Science.gov (United States)

    Lehti, T Maarit; Silvennoinen, Mika; Kivelä, Riikka; Kainulainen, Heikki; Komulainen, Jyrki

    2007-02-01

    In striated muscle, a sarcomeric noncontractile protein, titin, is proposed to form the backbone of the stress- and strain-sensing structures. We investigated the effects of diabetes, physical training, and their combination on the gene expression of proteins of putative titin stretch-sensing complexes in skeletal and cardiac muscle. Mice were divided into control (C), training (T), streptozotocin-induced diabetic (D), and diabetic training (DT) groups. Training groups performed for 1, 3, or 5 wk of endurance training on a motor-driven treadmill. Muscle samples from T and DT groups together with respective controls were collected 24 h after the last training session. Gene expression of calf muscles (soleus, gastrocnemius, and plantaris) and cardiac muscle were analyzed using microarray and quantitative PCR. Diabetes induced changes in mRNA expression of the proteins of titin stretch-sensing complexes in Z-disc (MLP, myostatin), I-band (CARP, Ankrd2), and M-line (titin kinase signaling). Training alleviated diabetes-induced changes in most affected mRNA levels in skeletal muscle but only one change in cardiac muscle. In conclusion, we showed diabetes-induced changes in mRNA levels of several fiber-type-biased proteins (MLP, myostatin, Ankrd2) in skeletal muscle. These results are consistent with previous observations of diabetes-induced atrophy leading to slower fiber type composition. The ability of exercise to alleviate diabetes-induced changes may indicate slower transition of fiber type.

  6. Insulin sensitizing effects of oligomannuronate-chromium (III complexes in C2C12 skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Cui Hao

    Full Text Available BACKGROUND: It was known that the insulin resistance in skeletal muscle is a major pathogenic factor in diabetes mellitus. Therefore prevention of metabolic disorder caused by insulin resistance and improvement of insulin sensitivity are very important for the therapy of type 2 diabetes. In the present study, we investigated the ability of marine oligosaccharides oligomannuronate and its chromium (III complexes from brown alga to enhance insulin sensitivity in C2C12 skeletal muscle cells. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that oligomannuronate, especially its chromium (III complexes, enhanced insulin-stimulated glucose uptake and increased the mRNA expression of glucose transporter 4 (GLUT4 and insulin receptor (IR after their internalization into C2C12 skeletal muscle cells. Additionally, oligosaccharides treatment also significantly enhanced the phosphorylation of proteins involved in both AMP activated protein kinase (AMPK/acetyl-CoA carboxylase (ACC and phosphoinositide 3-kinase (PI3K/protein kinase B (Akt signaling pathways in C2C12 cells, indicating that the oligosaccharides activated both the insulin signal pathway and AMPK pathways as their mode of action. Moreover, oligosaccharides distributed to the mitochondria after internalization into C2C12 cells and increased the expression of transcriptional regulator peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α, carnitine palmitoyl transferase-1 (CPT-1, and phosphorylated acetyl-CoA carboxylase (p-ACC, which suggested that the actions of these oligosaccharides might be associated with mitochondria through increasing energy expenditure. All of these effects of marine oligosaccharides were comparable to that of the established anti-diabetic drug, metformin. In addition, the treatment with oligosaccharides showed less toxicity than that of metformin. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that oligomannuonate and its chromium (III complexes improved

  7. Functional reconstruction of complex tendo Achilles defect by free latissimus dorsi muscle flap

    Directory of Open Access Journals (Sweden)

    Divya N Upadhyaya

    2012-01-01

    Full Text Available Managing the complex tendo Achilles defect involves reconstructing the Achilles tendon as well as providing soft tissue cover to the heel area. The advent of microsurgery has revolutionised the reconstruction of this difficult defect providing a number of options to the reconstructive surgeon. We present a case of complex tendo Achilles defect reconstructed by the latissimus dorsi free flap.

  8. Inverse relationship between the complexity of midfoot kinematics and muscle activation in patients with medial tibial stress syndrome.

    Science.gov (United States)

    Rathleff, M S; Samani, A; Olesen, C G; Kersting, U G; Madeleine, P

    2011-08-01

    Medial tibial stress syndrome is a common overuse injury characterized by pain located on the medial side of the lower leg during weight bearing activities such as gait. The purpose of this study was to apply linear and nonlinear methods to compare the structure of variability of midfoot kinematics and surface electromyographic (SEMG) signals between patients with medial tibial stress syndrome and healthy controls during gait. Fourteen patients diagnosed with medial tibial stress syndrome and 11 healthy controls were included from an orthopaedic clinic. SEMG from tibialis anterior and the soleus muscles as well as midfoot kinematics were recorded during 20 consecutive gait cycles. Permuted sample entropy and permutation entropy were used as a measure of complexity from SEMG signals and kinematics. SEMG signals in patients with medial tibial stress syndrome were characterized by higher structural complexity compared with healthy controls (pkinematics (p=0.01). Assessing the complexity of midfoot kinematics and SEMG activation pattern enabled a precise characterization of gait in patients with medial tibial stress syndrome. The reported inverse relationship in foot kinematics and SEMG complexity most likely point towards separated control processes governing gait variability. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Food restriction increase the expression of mTORC1 complex genes in the skeletal muscle of juvenile pacu (Piaractus mesopotamicus).

    Science.gov (United States)

    Paula, Tassiana Gutierrez de; Zanella, Bruna Tereza Thomazini; Fantinatti, Bruno Evaristo de Almeida; Moraes, Leonardo Nazário de; Duran, Bruno Oliveira da Silva; Oliveira, Caroline Bredariol de; Salomão, Rondinelle Artur Simões; Silva, Rafaela Nunes da; Padovani, Carlos Roberto; Santos, Vander Bruno Dos; Mareco, Edson Assunção; Carvalho, Robson Francisco; Dal-Pai-Silva, Maeli

    2017-01-01

    Skeletal muscle is capable of phenotypic adaptation to environmental factors, such as nutrient availability, by altering the balance between muscle catabolism and anabolism that in turn coordinates muscle growth. Small noncoding RNAs, known as microRNAs (miRNAs), repress the expression of target mRNAs, and many studies have demonstrated that miRNAs regulate the mRNAs of catabolic and anabolic genes. We evaluated muscle morphology, gene expression of components involved in catabolism, anabolism and energetic metabolism and miRNAs expression in both the fast and slow muscle of juvenile pacu (Piaractus mesopotamicus) during food restriction and refeeding. Our analysis revealed that short periods of food restriction followed by refeeding predominantly affected fast muscle, with changes in muscle fiber diameter and miRNAs expression. There was an increase in the mRNA levels of catabolic pathways components (FBXO25, ATG12, BCL2) and energetic metabolism-related genes (PGC1α and SDHA), together with a decrease in PPARβ/δ mRNA levels. Interestingly, an increase in mRNA levels of anabolic genes (PI3K and mTORC1 complex: mTOR, mLST8 and RAPTOR) was also observed during food restriction. After refeeding, muscle morphology showed similar patterns of the control group; the majority of genes were slightly up- or down-regulated in fast and slow muscle, respectively; the levels of all miRNAs increased in fast muscle and some of them decreased in slow muscle. Our findings demonstrated that a short period of food restriction in juvenile pacu had a considerable impact on fast muscle, increasing the expression of anabolic (PI3K and mTORC1 complex: mTOR, mLST8 and RAPTOR) and energetic metabolism genes. The miRNAs (miR-1, miR-206, miR-199 and miR-23a) were more expressed during refeeding and while their target genes (IGF-1, mTOR, PGC1α and MAFbx), presented a decreased expression. The alterations in mTORC1 complex observed during fasting may have influenced the rates of protein

  10. Food restriction increase the expression of mTORC1 complex genes in the skeletal muscle of juvenile pacu (Piaractus mesopotamicus.

    Directory of Open Access Journals (Sweden)

    Tassiana Gutierrez de Paula

    Full Text Available Skeletal muscle is capable of phenotypic adaptation to environmental factors, such as nutrient availability, by altering the balance between muscle catabolism and anabolism that in turn coordinates muscle growth. Small noncoding RNAs, known as microRNAs (miRNAs, repress the expression of target mRNAs, and many studies have demonstrated that miRNAs regulate the mRNAs of catabolic and anabolic genes. We evaluated muscle morphology, gene expression of components involved in catabolism, anabolism and energetic metabolism and miRNAs expression in both the fast and slow muscle of juvenile pacu (Piaractus mesopotamicus during food restriction and refeeding. Our analysis revealed that short periods of food restriction followed by refeeding predominantly affected fast muscle, with changes in muscle fiber diameter and miRNAs expression. There was an increase in the mRNA levels of catabolic pathways components (FBXO25, ATG12, BCL2 and energetic metabolism-related genes (PGC1α and SDHA, together with a decrease in PPARβ/δ mRNA levels. Interestingly, an increase in mRNA levels of anabolic genes (PI3K and mTORC1 complex: mTOR, mLST8 and RAPTOR was also observed during food restriction. After refeeding, muscle morphology showed similar patterns of the control group; the majority of genes were slightly up- or down-regulated in fast and slow muscle, respectively; the levels of all miRNAs increased in fast muscle and some of them decreased in slow muscle. Our findings demonstrated that a short period of food restriction in juvenile pacu had a considerable impact on fast muscle, increasing the expression of anabolic (PI3K and mTORC1 complex: mTOR, mLST8 and RAPTOR and energetic metabolism genes. The miRNAs (miR-1, miR-206, miR-199 and miR-23a were more expressed during refeeding and while their target genes (IGF-1, mTOR, PGC1α and MAFbx, presented a decreased expression. The alterations in mTORC1 complex observed during fasting may have influenced the rates of

  11. Identification of an FHL1 protein complex containing gamma-actin and non-muscle myosin IIB by analysis of protein-protein interactions.

    Directory of Open Access Journals (Sweden)

    Lili Wang

    Full Text Available FHL1 is multifunctional and serves as a modular protein binding interface to mediate protein-protein interactions. In skeletal muscle, FHL1 is involved in sarcomere assembly, differentiation, growth, and biomechanical stress. Muscle abnormalities may play a major role in congenital clubfoot (CCF deformity during fetal development. Thus, identifying the interactions of FHL1 could provide important new insights into its functional role in both skeletal muscle development and CCF pathogenesis. Using proteins derived from rat L6GNR4 myoblastocytes, we detected FHL1 interacting proteins by immunoprecipitation. Samples were analyzed by liquid chromatography mass spectrometry (LC-MS. Dynamic gene expression of FHL1 was studied. Additionally, the expression of the possible interacting proteins gamma-actin and non-muscle myosin IIB, which were isolated from the lower limbs of E14, E15, E17, E18, E20 rat embryos or from adult skeletal muscle was analyzed. Potential interacting proteins isolated from E17 lower limbs were verified by immunoprecipitation, and co-localization in adult gastrocnemius muscle was visualized by fluorescence microscopy. FHL1 expression was associated with skeletal muscle differentiation. E17 was found to be the critical time-point for skeletal muscle differentiation in the lower limbs of rat embryos. We also identified gamma-actin and non-muscle myosin IIB as potential binding partners of FHL1, and both were expressed in adult skeletal muscle. We then demonstrated that FHL1 exists as part of a complex, which binds gamma-actin and non-muscle myosin IIB.

  12. Loss of knee extensor torque complexity during fatiguing isometric muscle contractions occurs exclusively above the critical torque.

    Science.gov (United States)

    Pethick, Jamie; Winter, Samantha L; Burnley, Mark

    2016-06-01

    The complexity of knee extensor torque time series decreases during fatiguing isometric muscle contractions. We hypothesized that because of peripheral fatigue, this loss of torque complexity would occur exclusively during contractions above the critical torque (CT). Nine healthy participants performed isometric knee extension exercise (6 s of contraction, 4 s of rest) on six occasions for 30 min or to task failure, whichever occurred sooner. Four trials were performed above CT (trials S1-S4, S1 being the lowest intensity), and two were performed below CT (at 50% and 90% of CT). Global, central, and peripheral fatigue were quantified using maximal voluntary contractions (MVCs) with femoral nerve stimulation. The complexity of torque output was determined using approximate entropy (ApEn) and the detrended fluctuation analysis-α scaling exponent (DFA-α). The MVC torque was reduced in trials below CT [by 19 ± 4% (means ± SE) in 90%CT], but complexity did not decrease [ApEn for 90%CT: from 0.82 ± 0.03 to 0.75 ± 0.06, 95% paired-samples confidence intervals (CIs), 95% CI = -0.23, 0.10; DFA-α from 1.36 ± 0.01 to 1.32 ± 0.03, 95% CI -0.12, 0.04]. Above CT, substantial reductions in MVC torque occurred (of 49 ± 8% in S1), and torque complexity was reduced (ApEn for S1: from 0.67 ± 0.06 to 0.14 ± 0.01, 95% CI = -0.72, -0.33; DFA-α from 1.38 ± 0.03 to 1.58 ± 0.01, 95% CI 0.12, 0.29). Thus, in these experiments, the fatigue-induced loss of torque complexity occurred exclusively during contractions performed above the CT. Copyright © 2016 the American Physiological Society.

  13. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles.

    Science.gov (United States)

    Tecco, Simona; Baldini, Aberto; Mummolo, Stefano; Marchetti, Enrico; Giuca, Maria Rita; Marzo, Giuseppe; Gherlone, Enrico Felice

    2015-08-01

    This study aimed to assess by surface electromyography (sEMG) the changes in sub-mental, orbicularis oris, and masticatory muscle activity after a lingual frenulectomy. Rehabilitation exercises in subjects with ankyloglossia, characterized by Class I malocclusion, were assessed as well. A total of 24 subjects were selected. Thirteen subjects (mean age 7±2.5years) with Class I malocclusion and ankyloglossia were treated with lingual frenulectomy and rehabilitation exercises, while 11 subjects (mean age 7±0.8years) with normal occlusion and normal lingual frenulum were used as controls. The inclusion criteria for both groups were the presence of mixed dentition and no previous orthodontic treatment. The sEMG recordings were taken at the time of the first visit (T0), and after 1 (T1) and 6months (T2) for the treated group. Recordings were taken at the same time for the control group. Due to the noise inherent with the sEMG recording, special attention was paid to obtain reproducible and standardized recordings. The tested muscles were the masseter, anterior temporalis, upper and lower orbicularis oris, and sub-mental muscles. The sEMG recordings were performed at rest, while kissing, swallowing, opening the mouth, clenching the teeth and during protrusion of the mandible. These recordings were made by placing electrodes in the area of muscle contraction. At T0, the treated group showed different sEMG activity of the muscles with respect to the control group, with significant differences at rest and during some test tasks (pmuscle, from T0 to T2, during maximal voluntary clenching. During swallowing and kissing, the masseter and sub-mental muscles showed a significant increase in their sEMG potentials from T0 to T2. During the protrusion of the mandible, the masseter and anterior temporalis significantly decreased their sEMG activity, while the sub-mental area increased significantly. No significant change was observed in the control group during the follow-up. The s

  14. Comparison between traditional strength training and complex contrast training on repeated sprint ability and muscle architecture in elite soccer players.

    Science.gov (United States)

    Spineti, Juliano; Figueiredo, Tiago; Bastos DE Oliveira, Viviane; Assis, Marcio; Fernandes DE Oliveira, Liliam; Miranda, Humberto; Machado DE Ribeiro Reis, Victor M; Simão, Roberto

    2016-11-01

    The purpose of this study was to compare traditional strength training (TST) and complex contrast training (CCT) on the repeated-shuttle-sprint ability (RSSA), the countermovement squat jump (CMJ) height, the one repetition maximum (1RM) at squat on the Smith machine, and on muscle architecture in young, male elite soccer players. Twenty-two soccer players (mean age 18.4±0.4 years; mean weight 70.2±9.1 kg; mean height 179.9±7.5 cm) who belonged to the under-20 age group were randomly assigned into two groups: CCT (N.=10) or TST (N.=12). During the study period, the soccer players trained with CCT through power exercises performed before high-velocity exercises and TST based on a set-repetition format through daily, undulatory periodization. After statistical analysis (Psoccer players.

  15. Muscle Hyperalgesia Correlates With Motor Function in Complex Regional Pain Syndrome Type 1

    NARCIS (Netherlands)

    van Rooijen, Diana E.; Marinus, Johan; Schouten, Alfred Christiaan; Noldus, Lucas P.J.J.; van Hilten, Jacobus J.

    2013-01-01

    At present it is unclear if disturbed sensory processing plays a role in the development of the commonly observed motor impairments in patients with complex regional pain syndrome (CRPS). This study aims to investigate the relation between sensory and motor functioning in CRPS patients with and

  16. Mitochondrial dysfunction in muscle tissue of complex regional pain syndrome type I patients

    NARCIS (Netherlands)

    Tan, E.C.T.H.; Janssen, A.J.W.M.; Roestenberg, P.M.H.; Heuvel, L.P.W.J. van den; Goris, R.J.A.; Rodenburg, R.J.T.

    2011-01-01

    Reactive oxygen species (ROS) are known to be involved in the pathophysiology of complex regional pain syndrome type I (CRPS I). Since the mitochondrial respiratory chain is a major source of ROS, we hypothesized that mitochondria play a role in the pathophysiology of CRPS I. The hypothesis was

  17. The effect of muscle fatigue and low back pain on lumbar movement variability and complexity.

    Science.gov (United States)

    Bauer, C M; Rast, F M; Ernst, M J; Meichtry, A; Kool, J; Rissanen, S M; Suni, J H; Kankaanpää, M

    2017-04-01

    Changes in movement variability and complexity may reflect an adaptation strategy to fatigue. One unresolved question is whether this adaptation is hampered by the presence of low back pain (LBP). This study investigated if changes in movement variability and complexity after fatigue are influenced by the presence of LBP. It is hypothesised that pain free people and people suffering from LBP differ in their response to fatigue. The effect of an isometric endurance test on lumbar movement was tested in 27 pain free participants and 59 participants suffering from LBP. Movement variability and complexity were quantified with %determinism and sample entropy of lumbar angular displacement and velocity. Generalized linear models were fitted for each outcome. Bayesian estimation of the group-fatigue effect with 95% highest posterior density intervals (95%HPDI) was performed. After fatiguing %determinism decreased and sample entropy increased in the pain free group, compared to the LBP group. The corresponding group-fatigue effects were 3.7 (95%HPDI: 2.3-7.1) and -1.4 (95%HPDI: -2.7 to -0.1). These effects manifested in angular velocity, but not in angular displacement. The effects indicate that pain free participants showed more complex and less predictable lumbar movement with a lower degree of structure in its variability following fatigue while participants suffering from LBP did not. This may be physiological responses to avoid overload of fatigued tissue, increase endurance, or a consequence of reduced movement control caused by fatigue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A-769662 activates AMPK {beta}1-containing complexes but induces glucose uptake through a PI3 kinase-dependent pathway in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Treebak, Jonas Thue; Birk, Jesper Bratz; Hansen, Bo Falck

    2009-01-01

    5'AMP-activated protein kinase (AMPK) regulates several aspects of metabolism. Recently, A-769662 was shown to activate AMPK in skeletal muscle. However, no biological effects of AMPK activation by A-769662 in this tissue have been reported. We hypothesized that A-769662 would increase glucose...... uptake in skeletal muscle. We studied incubated soleus and extensor digitorum longus (EDL) muscles from 129S6/sv and C57BL/6 mice. Glucose uptake increased only in soleus from 129S6/sv when concentrations of A-769662 was 500 microM (~15%, p...-containing complexes were dose-dependently activated by A-769662 in muscles from both genotypes (~100% at 200 microM and 300-600% at 1 mM). The discrepancy between the A-769662-induced AMPK activation pattern and stimulation of glucose uptake suggested these effects were unrelated. A-769662 increased...

  19. Expiratory Muscle Strength Training Evaluated With Simultaneous High Resolution Manometry and Electromyography

    Science.gov (United States)

    Hutcheson, Katherine A.; Hammer, Michael J.; Rosen, Sarah P.; Jones, Corinne A.; McCulloch, Timothy M.

    2017-01-01

    Objective To examine feasibility of a simultaneous high-resolution pharyngeal manometry (HRM) and electromyography (EMG) experimental paradigm to detect swallowing-related patterns of palatal, laryngeal, and pharyngeal muscle activity during expiratory training. Study Design Technical report. Methods Simultaneous HRM, surface submental, and intramuscular EMG were acquired in two healthy participants during five tasks: 10-cc water swallow, maximum expiratory pressure (MEP) testing, and expiratory muscle strength training (EMST) at three pressure levels (sham, 50%, and 75% MEP). Results Experimental conditions were feasible. Velopharyngeal closing pressure, palate EMG activity, and pharyngeal EMG activity increased as expiratory load increased. In contrast, thyroarytenoid EMG activity was low during the expiratory task, consistent with glottic opening during exhalation. Submental EMG patterns were more variable during expiratory tasks. Intraluminal air pressures recorded with HRM were correlated with measured expiratory pressures and target valve-opening pressures of the EMST device. Conclusion Results suggest that a simultaneous HRM/EMG/EMST paradigm may be used to detect previously unquantified swallowing-related muscle activity during EMST, particularly in the palate and pharynx. Our approach and initial findings will be helpful to guide future hypothesis-driven studies and may enable investigators to evaluate other muscle groups active during these tasks. Defining mechanisms of action is a critical next step toward refining therapeutic algorithms using EMST and other targeted treatments for populations with dysphagia and airway disorders. PMID:28083946

  20. Expiratory muscle strength training evaluated with simultaneous high-resolution manometry and electromyography.

    Science.gov (United States)

    Hutcheson, Katherine A; Hammer, Michael J; Rosen, Sarah P; Jones, Corinne A; McCulloch, Timothy M

    2017-04-01

    To examine feasibility of a simultaneous high-resolution pharyngeal manometry (HRM) and electromyography (EMG) experimental paradigm to detect swallowing-related patterns of palatal, laryngeal, and pharyngeal muscle activity during expiratory training. Technical report. Simultaneous HRM, surface submental, and intramuscular EMG were acquired in two healthy participants during five tasks: 10-cc water swallow, maximum expiratory pressure (MEP) testing, and expiratory muscle strength training (EMST) at three pressure levels (sham, 50%, and 75% MEP). Experimental conditions were feasible. Velopharyngeal closing pressure, palate EMG activity, and pharyngeal EMG activity increased as expiratory load increased. In contrast, thyroarytenoid EMG activity was low during the expiratory task, consistent with glottic opening during exhalation. Submental EMG patterns were more variable during expiratory tasks. Intraluminal air pressures recorded with HRM were correlated with measured expiratory pressures and target valve-opening pressures of the EMST device. Results suggest that a simultaneous HRM/EMG/EMST paradigm may be used to detect previously unquantified swallowing-related muscle activity during EMST, particularly in the palate and pharynx. Our approach and initial findings will be helpful to guide future hypothesis-driven studies and may enable investigators to evaluate other muscle groups active during these tasks. Defining mechanisms of action is a critical next step toward refining therapeutic algorithms using EMST and other targeted treatments for populations with dysphagia and airway disorders. 4. Laryngoscope, 127:797-804, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  1. Variation of the mylohyoid: implications for Ludwig angina, cervical contouring, and digastric muscle transfer.

    Science.gov (United States)

    Bender-Heine, Adam; Zdilla, Matthew J

    2017-05-06

    The mylohyoid (MH) musculature separates the sublingual and submandibular spaces and is, therefore, important with regard to the spread of infection and space occupying lesions. Moreover, the MH may be elevated and included in the myocutaneous submental island flap or sutured in conjunction with the platysmas and the anterior bellies of the digastric muscles (ABDMs) to add stability to submental muscular medialization procedures. Therefore, variation in the anatomy of the MH musculature must be considered in the management of the spread of infection and space occupying lesions as well as in surgical planning. This report reviews mylohyoid variations and documents a unique case in which several suprahyoid muscular variations occurred concurrently. The variations included isolated anterior bellies of the mylohyoid inserting into the geniohyoid thereby forming mylo-geniohyoid muscles as well as isolated posterior bellies of the mylohyoid inserting into the ABDM and the intermediate tendon of the digastric muscle thereby forming mylo-digastric muscles. Surgeons operating in the suprahyoid region should be aware of potential anatomical variation of the mylohyoid to develop contingency plans.

  2. Experience of using hippotherapy in complex effects on muscle spirals in children with spastic forms of cerebral palsy.

    Science.gov (United States)

    Strashko, Evhen Y; Kapustianska, Аnna A; Bobyreva, Lyudmyla E

    Matters of physical and medical rehabilitation of children with organic lesions of the nervous system, in particular, with cerebral palsy, are actual in countries around the world. Hippotherapy is neurophysiologically oriented therapy using horses. Determine whether a combination of hippotherapy as a method of rehabilitation in the aftermath of outpatient comprehensive impact on MS on a stationary phase; Study of the effect of hippotherapy as securing and preparation method for learning new postures and movements in children with spastic cerebral palsy forms; The study of the possible optimization of psychophysical state, activation motivations of patients; Determination of the optimal timing of hippotherapy sessions, the number of procedures, the study of possible fatigue factor children. HT classes were conducted at the Ippotsentra "Wind of Change" in the period 2010-2013 the main group of children surveyed (36 people) with spastic forms of cerebral palsy. HT procedure took place twice a day - morning and evening - 30 minutes during 10-12 days. Thus, the proposed integration of the HT program of complex effects on muscle spirals children with spastic cerebral palsy forms is physiologically and anthropologically based on 4-5 day training children adequately transferred the full amount of lessons learned new postures and movements, HT does not cause complications in the somatic and psycho-emotional state of the children, HT enables sensorimotor and psychomotor effects, save and normalize muscle tone for a longer period (up to three months), compared with traditional methods of physiotherapy. HT can serve as a method of learning a new "postures and movements", the preparation of the locomotor apparatus to learn walking.

  3. Vitamin B complex treatment improves motor nerve regeneration and recovery of muscle function in a rodent model of peripheral nerve injury

    Directory of Open Access Journals (Sweden)

    Nedeljković Predrag

    2017-01-01

    Full Text Available It is well known that the peripheral nervous system has a good potential for regeneration. The aim of this study was to explore the effects of vitamin B therapy (with a complex of vitamins B1, B2, B3, B5, B6, and B12 on motor nerve recovery after femoral nerve injury. Our study was conducted on an experimental animal model of femoral nerve injury in rats. All animals used in the experiment were subjected to the same set of analyses. A behavior test was used for the assessment of motor function recovery. Body weight was measured and electromyography was performed in order to assess recovery of quadriceps muscle. Samples of muscles and nerves were used for counting nuclei and determining nuclear density. The results of this study showed enhanced functional recovery, including improved walking, a decreased level of muscle atrophy and better electromyography recovery after administration of vitamin B complex. Further, after 14 days of treatment with the vitamin B complex nuclear nerve and muscle density was significantly lowered. In conclusion, using a model of femoral nerve injury we demonstrated that the application of vitamin B complex improved recovery of motor nerve in rats. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 175033

  4. Immunohistochemical analysis of the oxidative phosphorylation complexes in skeletal muscle from patients with mitochondrial DNA encoded tRNA gene defects.

    NARCIS (Netherlands)

    Paepe, B. De; Smet, J.; Lammens, M.M.Y.; Seneca, S.; Martin, J.J.; Bleecker, J. De; Meirleir, L. de; Lissens, W.; Coster, R. van

    2009-01-01

    BACKGROUND: Mitochondrial diseases display a heterogeneous spectrum of clinical phenotypes and therefore the identification of the underlying gene defect is often a difficult task. AIMS: To develop an immunohistochemical approach to stain skeletal muscle for the five multi-protein complexes that

  5. Soft-Body Muscles for Evolved Virtual Creatures: The Next Step on a Bio-Mimetic Path to Meaningful Morphological Complexity

    DEFF Research Database (Denmark)

    Lessin, Dan; Risi, Sebastian

    2015-01-01

    In the past, evolved virtual creatures (EVCs) have been developed with rigid, segmented bodies, and with soft bodies, but never before with a combination of the two. In nature, however, creatures combining a rigid skeleton and non-rigid muscles are some of the most complex and successful examples...

  6. Muscle hyperalgesia is widespread in patients with complex regional pain syndrome.

    Science.gov (United States)

    van Rooijen, Diana E; Marinus, Johan; van Hilten, Jacobus J

    2013-12-01

    Patients with complex regional pain syndrome (CRPS) frequently show prominent sensory abnormalities in their affected limb, which may extend proximally and even to unaffected body regions. This study examines whether sensory dysfunction is observed in unaffected body parts of CRPS patients, and investigates whether the extent of dysfunction is similar for the various sensory modalities. Quantitative sensory testing was performed in the unaffected extremities and cheeks of 48 patients with CRPS of the arm (31 with dystonia), and the results were compared with values obtained among healthy controls. The most prominent abnormality was the pressure pain threshold, which showed a consistent pattern of higher sensitivity in unaffected contralateral arms and unaffected legs, as well as the cheek, and demonstrated the largest effect sizes. The cheeks of CRPS patients showed thermal hypoesthesia and hyperalgesia as well as a loss of vibration detection. Except for a lower vibration threshold in the contralateral leg of CRPS patients with dystonia, no differences in sensory modalities were found between CRPS patients with and without dystonia. These results point to a general disturbance in central pain processing in patients with CRPS, which may be attributed to impaired endogenous pain control. Since pressure pain is the most deviant sensory abnormality in both unaffected and affected body regions of CRPS patients, this test may serve as an important outcome parameter in future studies and may be used as a tool to monitor the course of the disease. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  7. REFINE-1, a Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Trial With ATX-101, an Injectable Drug for Submental Fat Reduction.

    Science.gov (United States)

    Jones, Derek H; Carruthers, Jean; Joseph, John H; Callender, Valerie D; Walker, Patricia; Lee, Daniel R; Subramanian, Meenakshi; Lizzul, Paul F; Gross, Todd M; Beddingfield, Frederick C

    2016-01-01

    ATX-101, an injectable form of deoxycholic acid, is approved in the United States and Canada for submental fat (SMF) reduction. To report results of REFINE-1, a randomized, double-blind, placebo-controlled, Phase 3 trial investigating the efficacy and safety of ATX-101. Subjects dissatisfied with their moderate or severe SMF received ATX-101 (2 mg/cm) or placebo. Coprimary outcome measures were composite ≥1-grade and ≥2-grade improvements in clinician-assessed and subject-assessed SMF severity using validated scales at 12 weeks after last treatment. Magnetic resonance imaging (MRI) provided an objective measure of submental volume reduction. Patient-reported outcomes were assessed. Among 256 ATX-101-treated and 250 placebo-treated subjects, a ≥1-grade composite response was achieved in 70.0% and 18.6%, and a ≥2-grade composite response in 13.4% and 0%, respectively (p ATX-101 than placebo (46.3% vs 5.3%; p ATX-101-treated subjects reported improvement in the psychological impact of SMF and satisfaction with treatment (p ATX-101-treated subjects reported 1-grade improvement in clinician-assessed SMF after 2 and 4 treatments, respectively. Adverse events (primarily localized to the injection site) were mostly mild or moderate, and transient. Marginal mandibular nerve paresis reported in 4.3% of ATX-101-treated subjects (1.0% of all ATX-101 treatment sessions) was mostly mild, transient, and resolved without sequelae. ATX-101 is a safe and efficacious, first-in-class, injectable drug for SMF reduction.

  8. Reduction of unwanted submental fat with ATX-101 (deoxycholic acid), an adipocytolytic injectable treatment: results from a phase III, randomized, placebo-controlled study.

    Science.gov (United States)

    Rzany, B; Griffiths, T; Walker, P; Lippert, S; McDiarmid, J; Havlickova, B

    2014-02-01

    Unwanted submental fat (SMF) is aesthetically unappealing, but methods of reduction are either invasive or lack evidence for their use. An injectable approach with ATX-101 (deoxycholic acid) is under investigation. To evaluate the efficacy and safety of ATX-101 for the reduction of unwanted SMF. In this double-blind, placebo-controlled, phase III study, 363 patients with moderate/severe SMF were randomized to receive ATX-101 (1 or 2 mg cm(-2) ) or placebo injections into their SMF at up to four treatment sessions ~28 days apart, with a 12-week follow-up. The co-primary efficacy endpoints were the proportions of treatment responders [patients with ≥ 1-point improvement in SMF on the 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS)] and patients satisfied with their face and chin appearance on the Subject Self-Rating Scale (SSRS). Secondary endpoints included skin laxity, calliper measurements and patient-reported outcomes. Adverse events were monitored. Significantly more ATX-101 recipients met the primary endpoint criteria vs. placebo: on the clinician scale, 59·2% and 65·3% of patients treated with ATX-101 1 and 2 mg cm(-2) , respectively, were treatment responders vs. 23·0% for placebo (CR-SMFRS; P ATX-101 vs. placebo. Most adverse events were transient and associated with the treatment area. ATX-101 was effective and well tolerated for nonsurgical SMF reduction. © 2013 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

  9. The complex of PAMAM-OH dendrimer with Angiotensin (1–7) prevented the disuse-induced skeletal muscle atrophy in mice

    Science.gov (United States)

    Márquez-Miranda, Valeria; Abrigo, Johanna; Rivera, Juan Carlos; Araya-Durán, Ingrid; Aravena, Javier; Simon, Felipe; Pacheco, Nicolás; González-Nilo, Fernando Danilo; Cabello-Verrugio, Claudio

    2017-01-01

    Angiotensin (1–7) (Ang-(1–7)) is a bioactive heptapeptide with a short half-life and has beneficial effects in several tissues – among them, skeletal muscle – by preventing muscle atrophy. Dendrimers are promising vehicles for the protection and transport of numerous bioactive molecules. This work explored the use of a neutral, non-cytotoxic hydroxyl-terminated poly(amidoamine) (PAMAM-OH) dendrimer as an Ang-(1–7) carrier. Bioinformatics analysis showed that the Ang-(1–7)-binding capacity of the dendrimer presented a 2:1 molar ratio. Molecular dynamics simulation analysis revealed the capacity of neutral PAMAM-OH to protect Ang-(1–7) and form stable complexes. The peptide coverage ability of the dendrimer was between ~50% and 65%. Furthermore, an electrophoretic mobility shift assay demonstrated that neutral PAMAM-OH effectively bonded peptides. Experimental results showed that the Ang-(1–7)/PAMAM-OH complex, but not Ang-(1–7) alone, had an anti-atrophic effect when administered intraperitoneally, as evaluated by muscle strength, fiber diameter, myofibrillar protein levels, and atrogin-1 and MuRF-1 expressions. The results of the Ang-(1–7)/PAMAM-OH complex being intraperitoneally injected were similar to the results obtained when Ang-(1–7) was systemically administered through mini-osmotic pumps. Together, the results suggest that Ang-(1–7) can be protected for PAMAM-OH when this complex is intraperitoneally injected. Therefore, the Ang-(1–7)/PAMAM-OH complex is an efficient delivery method for Ang-(1–7), since it improves the anti-atrophic activity of this peptide in skeletal muscle. PMID:28331320

  10. Platelet-derived growth factor regulates vascular smooth muscle phenotype via mammalian target of rapamycin complex 1

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jung Min; Yun, Sung Ji; Kim, Young Whan; Jin, Seo Yeon; Lee, Hye Sun [Medical Research Institute, Department of Pharmacology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Song, Sang Heon [Department of Internal Medicine, Pusan National University Hospital, Busan (Korea, Republic of); Shin, Hwa Kyoung [Department of Anatomy, Pusan National University School of Korean Medicine, Yangsan (Korea, Republic of); Bae, Sun Sik, E-mail: sunsik@pusan.ac.kr [Medical Research Institute, Department of Pharmacology, Pusan National University School of Medicine, Yangsan (Korea, Republic of)

    2015-08-14

    Mammalian target of rapamycin complex (mTORC) regulates various cellular processes including proliferation, growth, migration and differentiation. In this study, we showed that mTORC1 regulates platelet-derived growth factor (PDGF)-induced phenotypic conversion of vascular smooth muscle cells (VSMCs). Stimulation of contractile VSMCs with PDGF significantly reduced the expression of contractile marker proteins in a time- and dose-dependent manner. In addition, angiotensin II (AngII)-induced contraction of VSMCs was completely blocked by the stimulation of VSMCs with PDGF. PDGF-dependent suppression of VSMC marker gene expression was significantly blocked by inhibition of phosphatidylinositol 3-kinase (PI3K), extracellular signal-regulated kinase (ERK), and mTOR whereas inhibition of p38 MAPK had no effect. In particular, inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked the PDGF-dependent phenotypic change of VSMCs whereas silencing of Rictor had no effect. In addition, loss of AngII-dependent contraction by PDGF was significantly retained by silencing of Raptor. Inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked PDGF-induced proliferation of VSMCs. Taken together, we suggest that mTORC1 plays an essential role in PDGF-dependent phenotypic changes of VSMCs. - Graphical abstract: Regulation of VSMC phenotype by PDGF-dependent activation of mTORC1. - Highlights: • The expression of contractile marker proteins was reduced by PDGF stimulation. • PDGF-dependent phenotypic conversion of VSMCs was blocked by inhibition of mTOR. • PDGF-induced proliferation of VSMCs was attenuated by inhibition of mTORC1. • mTORC1 plays a critical role in PDGF-dependent phenotypic conversion of VSMCs.

  11. The fibula osteoseptocutaneous flap incorporating the hemisoleus muscle for complex head and neck defects: anatomical study and clinical applications.

    Science.gov (United States)

    Wong, Chin-Ho; Ong, Yee-Siang; Chew, Khong-Yik; Tan, Bien-Keem; Song, Colin

    2009-12-01

    In patients with extensive bone and soft-tissue defects, the inclusion of the hemisoleus muscle with the fibula osteoseptocutaneous flap would provide the needed soft-tissue volume to the flap. This study evaluates the reliability and technical considerations for the inclusion of the hemisoleus with the fibula and skin paddle as a chimeric, peroneal artery-based flap. The location and size of major arterial branches of the peroneal artery supplying the lateral hemisoleus muscle were investigated in 10 cadaveric injected lower limb specimens. The utility of this design was demonstrated in five clinical cases. The lateral hemisoleus was noted to be consistently supplied by large muscle branches from the peroneal artery, soleus vessels 1 (proximal) and 2 (distal). The mean diameter and distance from the origin of the peroneal artery for soleus vessels 1 and 2 were 1.8 mm and 2.1 cm, and 1.6 mm and 6.3 cm, respectively. The fibula osteoseptocutaneous flap incorporating the hemisoleus muscle was performed in five clinical cases. All were successful. Either soleus vessel 1 or soleus vessel 2 can be used as the pedicle to the muscle, depending on the specific reconstructive requirements for the reach and placement of the hemisoleus. The fibula osteoseptocutaneous flap incorporating the hemisoleus muscle can reliably be raised by preserving constant muscle branches that arise from the peroneal artery to supply the lateral hemisoleus. This flap provides the additional bulk in selected cases, with little additional donor-site morbidity.

  12. Phosphoproteome analysis of functional mitochondria isolated from resting human muscle reveals extensive phosphorylation of inner membrane protein complexes and enzymes

    DEFF Research Database (Denmark)

    Zhao, Xiaolu; Leon, Ileana R; Bak, Steffen

    2011-01-01

    . In skeletal muscle, mitochondrial dysfunction is linked to insulin resistance in humans with obesity and type 2 diabetes. We performed a phosphoproteomic study of functional mitochondria isolated from human muscle biopsies with the aim to obtain a comprehensive overview of mitochondrial phosphoproteins....... Future comparative phosphoproteome analysis of mitochondria from healthy and diseased individuals will provide insights into the role of abnormal phosphorylation in pathologies, such as type 2 diabetes....

  13. Your Muscles

    Science.gov (United States)

    ... Should You Go to School? Breast Cancer Your Muscles KidsHealth > For Kids > Your Muscles Print A A ... and skeletal (say: SKEL-uh-tul) muscle. Smooth Muscles Smooth muscles — sometimes also called involuntary muscles — are ...

  14. Optimization of muscle activity for task-level goals predicts complex changes in limb forces across biomechanical contexts.

    Directory of Open Access Journals (Sweden)

    J Lucas McKay

    Full Text Available Optimality principles have been proposed as a general framework for understanding motor control in animals and humans largely based on their ability to predict general features movement in idealized motor tasks. However, generalizing these concepts past proof-of-principle to understand the neuromechanical transformation from task-level control to detailed execution-level muscle activity and forces during behaviorally-relevant motor tasks has proved difficult. In an unrestrained balance task in cats, we demonstrate that achieving task-level constraints center of mass forces and moments while minimizing control effort predicts detailed patterns of muscle activity and ground reaction forces in an anatomically-realistic musculoskeletal model. Whereas optimization is typically used to resolve redundancy at a single level of the motor hierarchy, we simultaneously resolved redundancy across both muscles and limbs and directly compared predictions to experimental measures across multiple perturbation directions that elicit different intra- and interlimb coordination patterns. Further, although some candidate task-level variables and cost functions generated indistinguishable predictions in a single biomechanical context, we identified a common optimization framework that could predict up to 48 experimental conditions per animal (n = 3 across both perturbation directions and different biomechanical contexts created by altering animals' postural configuration. Predictions were further improved by imposing experimentally-derived muscle synergy constraints, suggesting additional task variables or costs that may be relevant to the neural control of balance. These results suggested that reduced-dimension neural control mechanisms such as muscle synergies can achieve similar kinetics to the optimal solution, but with increased control effort (≈2× compared to individual muscle control. Our results are consistent with the idea that hierarchical, task

  15. Evidence for the involvement of muscle tropomyosin in the contractile elements of the coelom-esophagus complex in sea urchin embryos.

    Science.gov (United States)

    Ishimoda-Takagi, T; Chino, I; Sato, H

    1984-10-01

    The sea urchin morphogenesis, especially formation of the coelom-esophagus complex, was observed correlating the distribution of tropomyosin-specific immunofluorescence. Coelomic cells arranged at both sides of the esophagus extended their pseudopods toward the esophagus to form the contractile bands, which surrounded the esophagus and brought about the contraction of the esophagus. The earliest stage at which the tropomyosin-specific immunofluorescence was recognized coincided with the appearance of the coelomic pseudopods. The tropomyosin-specific immunofluorescence located at the contractile bands and the cell bodies from which they derived, when the ectoderm-disrupted embryos were used to investigate the detailed distribution of tropomyosin. The tropomyosin-specific immunofluorescence remained in the same regions when the embryos were stained with the antiserum absorbed with egg tropomyosin, which detected only muscle tropomyosin. From these observations, the coelomic pseudopod-forming cells were conclusively shown to be muscle cells.

  16. Efficacy, patient-reported outcomes and safety profile of ATX-101 (deoxycholic acid), an injectable drug for the reduction of unwanted submental fat: results from a phase III, randomized, placebo-controlled study.

    Science.gov (United States)

    Ascher, B; Hoffmann, K; Walker, P; Lippert, S; Wollina, U; Havlickova, B

    2014-12-01

    Unwanted submental fat (SMF) may result in an unattractive chin profile and dissatisfaction with appearance. An approved and rigorously tested non-surgical method for SMF reduction is lacking. To evaluate the efficacy and safety of ATX-101 for the pharmacological reduction of unwanted SMF in a phase III randomized, double-blind, placebo-controlled study. Patients (n = 360) with moderate or severe SMF were randomized to receive ATX-101 1 or 2 mg/cm(2) or placebo injected into their SMF for up to four treatments ~28 days apart, with a 12-week follow-up. Coprimary efficacy endpoints were the proportions of treatment responders, defined as a ≥1-point reduction in SMF on the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS), and those satisfied with their appearance in association with their face and chin after treatment on the Subject Self-Rating Scale (SSRS score ≥4). Secondary efficacy endpoints included a ≥1-point improvement in SMF on the Patient-Reported Submental Fat Rating Scale (PR-SMFRS) and changes in the Patient-Reported Submental Fat Impact Scale (PR-SMFIS). Additional patient-reported outcomes and changes in the Skin Laxity Rating Scale were recorded. Adverse events (AEs) and laboratory test results were monitored. Compared with placebo, a greater proportion of patients treated with ATX-101 1 and 2 mg/cm(2) showed a ≥1-point improvement in CR-SMFRS (58.3% and 62.3%, respectively, vs. 34.5% with placebo; P ATX-101 1 mg/cm(2) , P ATX-101 2 mg/cm(2) vs. placebo) and emotions and perceived self-image (PR-SMFIS; P ATX-101 was effective and well tolerated, and may be an alternative to surgery for patients desiring improvement of their submental profile. © 2014 The Authors Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of the European Academy of Dermatology and Venereology.

  17. Adrenoceptors promote glucose uptake into adipocytes and muscle by an insulin-independent signaling pathway involving mechanistic target of rapamycin complex 2.

    Science.gov (United States)

    Mukaida, Saori; Evans, Bronwyn A; Bengtsson, Tore; Hutchinson, Dana S; Sato, Masaaki

    2017-02-01

    Uptake of glucose into skeletal muscle and adipose tissue plays a vital role in metabolism and energy balance. Insulin released from β-islet cells of the pancreas promotes glucose uptake in these target tissues by stimulating translocation of GLUT4 transporters to the cell surface. This process is complex, involving signaling proteins including the mechanistic (or mammalian) target of rapamycin (mTOR) and Akt that intersect with multiple pathways controlling cell survival, growth and proliferation. mTOR exists in two forms, mTOR complex 1 (mTORC1), and mTOR complex 2 (mTORC2). mTORC1 has been intensively studied, acting as a key regulator of protein and lipid synthesis that integrates cellular nutrient availability and energy balance. Studies on mTORC2 have focused largely on its capacity to activate Akt by phosphorylation at Ser473, however recent findings demonstrate a novel role for mTORC2 in cellular glucose uptake. For example, agonists acting at β2-adrenoceptors (ARs) in skeletal muscle or β3-ARs in brown adipose tissue increase glucose uptake in vitro and in vivo via mechanisms dependent on mTORC2 but not Akt. In this review, we will focus on the signaling pathways downstream of β-ARs that promote glucose uptake in skeletal muscle and brown adipocytes, and will highlight how the insulin and adrenergic pathways converge and interact in these cells. The identification of insulin-independent mechanisms that promote glucose uptake should facilitate novel treatment strategies for metabolic disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Novel ETF dehydrogenase mutations in a patient with mild glutaric aciduria type II and complex II-III deficiency in liver and muscle.

    Science.gov (United States)

    Wolfe, Lynne A; He, Miao; Vockley, Jerry; Payne, Nicole; Rhead, William; Hoppel, Charles; Spector, Elaine; Gernert, Kim; Gibson, K Michael

    2010-12-01

    We describe a 22-year-old male who developed severe hypoglycemia and lethargy during an acute illness at 4 months of age and subsequently grew and developed normally. At age 4 years he developed recurrent vomiting with mild hyperammonemia and dehydration requiring frequent hospitalizations. Glutaric aciduria Type II was suspected based upon biochemical findings and managed with cornstarch, carnitine and riboflavin supplements. He did not experience metabolic crises between ages 4-12 years. He experienced recurrent vomiting, mild hyperammonemia, and generalized weakness associated with acute illnesses and growth spurts. At age 18 years, he developed exercise intolerance and proximal muscle weakness leading to the identification of multiple acyl-CoA dehydrogenase and complex II/III deficiencies in both skeletal muscle and liver. Subsequent molecular characterization of the ETFDH gene revealed novel heterozygous mutations, p.G274X:c.820 G > T (exon 7) and p.P534L: c.1601 C > T (exon 12), the latter within the iron sulfur-cluster and predicted to affect ubiquinone reductase activity of ETFDH and the docking of ETF to ETFDH. Our case supports the concept of a structural interaction between ETFDH and other enzyme partners, and suggests that the conformational change upon ETF binding to ETFDH may play a key role in linking ETFDH to II/III super-complex formation.

  19. A Pilot Study of the Head Extension Swallowing Exercise: New Method for Strengthening Swallowing-Related Muscle Activity.

    Science.gov (United States)

    Oh, Jong-Chi

    2016-10-01

    This pilot study examined the effect of a new head extension swallowing exercise (HESE) on submental muscle activity and tongue strength in healthy volunteers. Fifteen young adults (10 females and 5 males) were instructed to extend their head backwards as much as possible, and while watching the ceiling, swallowed their saliva every 10 s for a duration of 20 min. Twenty-four treatments were performed over 8 weeks. The outcome variables evaluated at baseline, 4 and 8 weeks of training, and 12-week follow-up included mean and peak submental muscle activation amplitudes during normal and effortful swallowing measured via surface electromyography, and anterior and posterior isometric tongue pressures were measured with the Iowa Oral Performance Instrument. Results indicated that the muscle activation amplitudes during effortful swallowing increased significantly at 4 and 8 weeks compared to baseline (p < 0.025). However, the increases in amplitudes during normal swallowing were minor (nonsignificant) after 8 weeks compared to baseline. The isometric pressures of the tongue tip and the posterior part of the oral tongue were significantly higher at 8 weeks compared to baseline (p < 0.025). Thus, the 8-week HESE protocol significantly improved suprahyoid muscle activity during effortful swallowing as well as the isometric tongue pressures. The HESE appears effective in exercising and strengthening the suprahyoid muscles and tongue muscles in healthy participants. Although encouraging, these results need to be replicated in clinical trials for testing the therapeutic effects of the HESE in older adults and patients with dysphagia who present with decreased hyolaryngeal elevation.

  20. Complexity

    Indian Academy of Sciences (India)

    Rahul Pandit

    2008-10-31

    Oct 31, 2008 ... ”The more complex a thing is, the more you can talk about it.” - attributed to Giorgio Parisi. ▻ ”C'est magnifique, mais ce n'est pas de la science.” (It is magnificent, but not all of it is science.) - attributed ... Earliest examples: theoretical computer science, algorithmic complexity, etc. ▻ Rapid progress after the ...

  1. Midline submental intubation might be the preferred alternative to oral and nasal intubation in elective oral and craniomaxillofacial surgery when indicated.

    Science.gov (United States)

    Jin, Huijun; Patil, Pavan Manohar

    2015-01-01

    No consensus exists to date regarding the best method of controlling the airway for oral or craniomaxillofacial surgery when orotracheal and nasotracheal intubations are unsuccessful or contraindicated. The most commonly used method of tracheostomy has been associated with a high degree of morbidity. Therefore, the present study was conducted to determine the indications, safety, efficacy, time required, drawbacks, complications, and costs of the midline submental intubation (SMI) approach in elective oral and craniomaxillofacial surgical procedures. A retrospective case series study was used to evaluate the surgical, financial, and photographic records of all patients who had undergone oral or craniomaxillofacial operations at Sharda University School of Dental Sciences, Greater Noida, from April 2006 to March 2014. The indications, drawbacks, time required for the procedure, ability to provide a secure airway, intra- and postoperative complications, and additional costs associated with SMI were analyzed. Of the 2,823 patients treated, the present study included 120 patients (97 men and 23 women, aged 19 to 60 years). The average time required for SMI was 10 ± 2 minutes. No episode of intraoperative oxygen desaturation was noted. One intraoperative complication, an injury to the ventral surface of the tongue, was encountered. Two patients developed infection at the skin incision site. No significant additional cost was incurred with the use of SMI. SMI has been successfully used in elective oral and craniomaxillofacial surgical procedures for which oral and nasal intubations were either not indicated or not possible. The advantages include a quick procedure, insignificant complications, the ability to provide a stable airway, and no added costs, making SMI a quick, safe, efficient, and cost-effective alternative in such cases. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  2. Distribution and localization of vinculin-talin-integrin system and dystrophin-glycoprotein complex in human skeletal muscle. Immunohistochemical study using confocal laser scanning microscopy.

    Science.gov (United States)

    Anastasi, G; Amato, A; Tarone, G; Vita, G; Monici, M C; Magaudda, L; Brancaccio, M; Sidoti, A; Trimarchi, F; Favaloro, A; Cutroneo, G

    2003-01-01

    The vinculin-talin-integrin system and the dystrophin-glycoprotein complex (DGC) are two protein systems with structural and signaling functions, allowing interaction between muscle fibers and extracellular matrix. Although numerous studies have been conducted on these systems, their localization and distribution patterns along the nonjunctional sarcolemma are not clear. On this basis, we carried out an indirect immunofluorescence study on the vastus lateralis muscle of human adults not affected by neuromuscular diseases to better define these patterns. Our results showed that all tested proteins of the two systems have a costameric distribution; all tested proteins of the two systems colocalize with each other (about 90-95% of the cases); only alpha-sarcoglycan in a few cases (about 6%) does not colocalize with other proteins; in about 9-10% of the cases, dystrophin and beta-dystroglycan colocalize partially with other proteins; all tested proteins can be localized in different fibers, both in the region of the sarcolemma over I or A bands. The colocalization between the vinculin-talin-integrin and DGC systems may imply their functional interaction involving the structural aspect, by providing a stronger adhesion between sarcolemma and extracellular matrix in well-defined regions of the muscle fiber. Besides, their colocalization may suggest the existence of a mechanism of mutual modulation of the transmitted signals. This reciprocal control may determine, in different conditions, the prevalence of one system over another with a consequent transmission of different messages to the sarcolemma-associated cytoskeleton. Copyright 2003 S. Karger AG, Basel

  3. Muscle atrophy

    Science.gov (United States)

    Muscle wasting; Wasting; Atrophy of the muscles ... There are two types of muscle atrophy: disuse and neurogenic. Disuse atrophy is caused by not using the muscles enough . This type of atrophy can often be ...

  4. Muscle Disorders

    Science.gov (United States)

    Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even ...

  5. Muscle Cramps

    Science.gov (United States)

    Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They often occur after exercise or at night, ... to several minutes. It is a very common muscle problem. Muscle cramps can be caused by nerves ...

  6. Application of Hydrogel in Reconstruction Surgery: Hydrogel/Fat Graft Complex Filler for Volume Reconstruction in Critical Sized Muscle Defects

    Directory of Open Access Journals (Sweden)

    Y. F. Lui

    2016-01-01

    Full Text Available Autogenic fat graft usually suffers from degeneration and volume shrinkage in volume reconstruction applications. How to maintain graft viability and graft volume is an essential consideration in reconstruction therapies. In this presented investigation, a new fat graft transplantation method was developed aiming to improve long term graft viability and volume reconstruction effect by incorporation of hydrogel. The harvested fat graft is dissociated into small fragments and incorporated into a collagen based hydrogel to form a hydrogel/fat graft complex for volume reconstruction purpose. In vitro results indicate that the collagen based hydrogel can significantly improve the survivability of cells inside isolated graft. In a 6-month investigation on artificial created defect model, this hydrogel/fat graft complex filler has demonstrated the ability of promoting fat pad formation inside the targeted defect area. The newly generated fat pad can cover the whole defect and restore its original dimension in 6-month time point. Compared to simple fat transplantation, this hydrogel/fat graft complex system provides much improvement on long term volume restoration effect against degeneration and volume shrinkage. One notable effect is that there is continuous proliferation of adipose tissue throughout the 6-month period. In summary, the hydrogel/fat graft system presented in this investigation demonstrated a better and more significant effect on volume reconstruction in large sized volume defect than simple fat transplantation.

  7. Semiautomatic High-Content Analysis of Complex Images from Cocultures of Vascular Smooth Muscle Cells and Macrophages: A CellProfiler Showcase.

    Science.gov (United States)

    Roeper, Matthias; Braun-Dullaeus, Ruediger C; Weinert, Sönke

    2017-08-01

    Automatization in microscopy, cell culture, and the ease of digital imagery allow obtainment of more information from single samples and upscaling of image-based analysis to high-content approaches. Simple segmentation algorithms of biological imagery are nowadays widely spread in biomedical research, but processing of complex sample structures, for example, variable sample compositions, cell shapes, and sizes, and rare events remains a difficult task. As there is no perfect method for image segmentation and fully automatic image analysis of complex content, we aimed to succeed by identification of unique and reliable features within the sample. Through exemplary use of a coculture of vascular smooth muscle cells (VSMCs) and macrophages (MPs), we demonstrate how rare interactions within this highly variable sample type can be analyzed. Because of limitations in immunocytochemistry in our specific setup, we developed a semiautomatic approach to examine the interaction of lipid-laden MPs with VSMCs under hypoxic conditions based on nuclei morphology by high-content analysis using the open-source software CellProfiler ( www.cellprofiler.org ). We provide evidence that, in comparison with fully automatic analysis, a low threshold within the analysis workflow and subsequent manual control save time, while providing more objective and reliable results.

  8. Results from a pooled analysis of two European, randomized, placebo-controlled, phase 3 studies of ATX-101 for the pharmacologic reduction of excess submental fat.

    Science.gov (United States)

    McDiarmid, James; Ruiz, Jesus Benito; Lee, Daniel; Lippert, Susanne; Hartisch, Claudia; Havlickova, Blanka

    2014-10-01

    The injectable adipocytolytic drug ATX-101 is the first nonsurgical treatment for the reduction of submental fat (SMF) to undergo comprehensive clinical evaluation. This study aimed to confirm the efficacy and safety of ATX-101 for SMF reduction through a post hoc pooled analysis of two large phase 3 studies. Patients with unwanted SMF were randomized to receive 1 or 2 mg/cm(2) of ATX-101 or a placebo injected into their SMF during a maximum of four treatment sessions spaced approximately 28 days apart, with a 12-week follow-up period. The proportions of patients with reductions in SMF of one point or more on the Clinician-Reported SMF Rating Scale (CR-SMFRS) and the proportions of patients satisfied with the appearance of their face and chin [Subject Self-Rating Scale (SSRS) score ≥4] were reported overall and in subgroups. Other efficacy measures included improvements in the Patient-Reported SMF Rating Scale (PR-SMFRS), calliper measurements of SMF thickness, and assessment of skin laxity [Skin Laxity Rating Scale (SLRS)]. Adverse events and laboratory test results were recorded. Significantly greater proportions of the patients had improvements in clinician-reported measures (≥1-point improvement in CR-SMFRS: 58.8 and 63.8 % of the patients who received ATX-101 1 and 2 mg/cm(2), respectively, and 28.6 % of the placebo recipients; p ATX-101 doses vs. placebo) and patient-reported measures (≥1-point improvement in PR-SMFRS: 60.0 and 63.1 % of the patients who received ATX-101 1 and 2 mg/cm(2), respectively, vs. 34.3 % of the placebo recipients; p ATX-101 versus placebo. These improvements correlated moderately with patient satisfaction regarding face and chin appearance (SSRS score ≥4: 60.8 and 65.4 % of the patients who received ATX-101 1 and 2 mg/cm(2), respectively, vs. 29.0 % of the placebo recipients; p ATX-101 was effective irrespective of gender, age, or body mass index. Reduction in SMF with ATX-101 was confirmed by calliper measurements (p ATX-101

  9. Expression and Complex Formation of MMP9, MMP2, NGAL, and TIMP1 in Porcine Myocardium but Not in Skeletal Muscles in Male Pigs with Tachycardia-Induced Systolic Heart Failure

    Science.gov (United States)

    Kiczak, Liliana; Tomaszek, Alicja; Bania, Jacek; Paslawska, Urszula; Zacharski, Maciej; Noszczyk-Nowak, Agnieszka; Janiszewski, Adrian; Skrzypczak, Piotr; Ardehali, Hossein; Jankowska, Ewa A.; Ponikowski, Piotr

    2013-01-01

    Matrix metalloproteinases (MMPs) are involved in the remodeling of extracellular matrix in various tissues. Their functioning could be related to the formation of complexes, containing MMP9, MMP2, tissue inhibitor of metalloproteinases type 1 (TIMP1), and neutrophil gelatinase-associated lipocalin (NGAL). Such complexes have not been investigated in either myocardial or skeletal muscles. We examined 20 male pigs with heart failure (HF), and 5 sham-operated animals. There were no differences in the mRNA expression of MMP9, MMP2, TIMP1, and NGAL between diseased and healthy animals, in either left ventricle (LV) myocardium or skeletal muscles. In LV from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we demonstrated the presence of high molecular weight (HMW) complexes (130, 170, and 220 kDa) containing MMP9, TIMP1, and NGAL (also MMP2 in 220 kDa complex) without proteolytic activity, and a proteolytically active 115 kDa MMP9 form together with 72 and 68 kDa bands (proMMP2 and MMP2). Proteolytically active bands were also spontaneously released from HMW complexes. In skeletal muscles from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we found no HMW complexes, and proteolytic activity was associated with the presence of 72 and 68 kDa bands (proMMP2 and MMP2). PMID:23710440

  10. Expression and complex formation of MMP9, MMP2, NGAL, and TIMP1 in porcine myocardium but not in skeletal muscles in male pigs with tachycardia-induced systolic heart failure.

    Science.gov (United States)

    Kiczak, Liliana; Tomaszek, Alicja; Bania, Jacek; Paslawska, Urszula; Zacharski, Maciej; Noszczyk-Nowak, Agnieszka; Janiszewski, Adrian; Skrzypczak, Piotr; Ardehali, Hossein; Jankowska, Ewa A; Ponikowski, Piotr

    2013-01-01

    Matrix metalloproteinases (MMPs) are involved in the remodeling of extracellular matrix in various tissues. Their functioning could be related to the formation of complexes, containing MMP9, MMP2, tissue inhibitor of metalloproteinases type 1 (TIMP1), and neutrophil gelatinase-associated lipocalin (NGAL). Such complexes have not been investigated in either myocardial or skeletal muscles. We examined 20 male pigs with heart failure (HF), and 5 sham-operated animals. There were no differences in the mRNA expression of MMP9, MMP2, TIMP1, and NGAL between diseased and healthy animals, in either left ventricle (LV) myocardium or skeletal muscles. In LV from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we demonstrated the presence of high molecular weight (HMW) complexes (130, 170, and 220 kDa) containing MMP9, TIMP1, and NGAL (also MMP2 in 220 kDa complex) without proteolytic activity, and a proteolytically active 115 kDa MMP9 form together with 72 and 68 kDa bands (proMMP2 and MMP2). Proteolytically active bands were also spontaneously released from HMW complexes. In skeletal muscles from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we found no HMW complexes, and proteolytic activity was associated with the presence of 72 and 68 kDa bands (proMMP2 and MMP2).

  11. Expression and Complex Formation of MMP9, MMP2, NGAL, and TIMP1 in Porcine Myocardium but Not in Skeletal Muscles in Male Pigs with Tachycardia-Induced Systolic Heart Failure

    Directory of Open Access Journals (Sweden)

    Liliana Kiczak

    2013-01-01

    Full Text Available Matrix metalloproteinases (MMPs are involved in the remodeling of extracellular matrix in various tissues. Their functioning could be related to the formation of complexes, containing MMP9, MMP2, tissue inhibitor of metalloproteinases type 1 (TIMP1, and neutrophil gelatinase-associated lipocalin (NGAL. Such complexes have not been investigated in either myocardial or skeletal muscles. We examined 20 male pigs with heart failure (HF, and 5 sham-operated animals. There were no differences in the mRNA expression of MMP9, MMP2, TIMP1, and NGAL between diseased and healthy animals, in either left ventricle (LV myocardium or skeletal muscles. In LV from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we demonstrated the presence of high molecular weight (HMW complexes (130, 170, and 220 kDa containing MMP9, TIMP1, and NGAL (also MMP2 in 220 kDa complex without proteolytic activity, and a proteolytically active 115 kDa MMP9 form together with 72 and 68 kDa bands (proMMP2 and MMP2. Proteolytically active bands were also spontaneously released from HMW complexes. In skeletal muscles from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we found no HMW complexes, and proteolytic activity was associated with the presence of 72 and 68 kDa bands (proMMP2 and MMP2.

  12. Topographic Anatomy of the Anal Sphincter Complex and Levator Ani Muscle as It Relates to Intersphincteric Resection for Very Low Rectal Disease.

    Science.gov (United States)

    Tsukada, Yuichiro; Ito, Masaaki; Watanabe, Kentaro; Yamaguchi, Kumiko; Kojima, Motohiro; Hayashi, Ryuichi; Akita, Keiichi; Saito, Norio

    2016-05-01

    Intersphincteric resection has become a widely used treatment for patients with rectal cancer. However, the detailed anatomy of the anal canal related to this procedure has remained unclear. The purpose of this study was to clarify the detailed anatomy of the anal canal. This is a descriptive study. Histologic evaluations of paraffin-embedded tissue specimens were conducted at a tertiary referral hospital. Tissue specimens were obtained from cadavers of 5 adults and from 13 patients who underwent abdominoperineal resection for rectal cancer. Sagittal sections from 9 circumferential portions of the cadaveric anal canal (histologic staining) and 3 circumferential portions from patients were studied (immunohistochemistry for smooth and skeletal muscle fibers). Longitudinal fibers between the internal and external anal sphincters consisted primarily of smooth muscle fibers that continued from the longitudinal muscle of the rectum. The levator ani muscle attached directly to the lateral surface of the longitudinal smooth muscle of the rectum. The length of the attachment was longer in the anterolateral portion and shorter in the posterior portion of the anal canal. In the lateral and posterior portions, the levator ani muscle partially overlapped the external anal sphincter; however, there was less overlap in the anterolateral portion. In the posterior portion, thick smooth muscle was present on the surface of the levator ani muscle and it continued to the longitudinal muscle of the rectum. We observed only limited portions in some surgical specimens because of obstruction by tumors. The levator ani muscle attaches directly to the longitudinal muscle of the rectum. The spatial relationship between the smooth and skeletal muscles differed in different portions of the anal canal. For intersphincteric resection, dissection must be performed between the longitudinal muscle of the rectum and the levator ani muscle/external anal sphincter, and the appropriate surgical lines

  13. Muscle Deoxygenation Causes Muscle Fatigue

    Science.gov (United States)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D.

    1999-01-01

    Muscle fatigue is a common musculoskeletal disorder in the work place, and may be a harbinger for more disabling cumulative trauma disorders. Although the cause of fatigue is multifactorial, reduced blood flow and muscle oxygenation may be the primary factor in causing muscle fatigue during low intensity muscle exertion. Muscle fatigue is defined as a reduction in muscle force production, and also occurs among astronauts who are subjected to postural constraints while performing lengthy, repetitive tasks. The objectives of this research are to: 1) develop an objective tool to study the role of decreased muscle oxygenation on muscle force production, and 2) to evaluate muscle fatigue during prolonged glovebox work.

  14. Muscle disorder

    Science.gov (United States)

    Myopathic changes; Myopathy; Muscle problem ... Blood tests sometimes show abnormally high muscle enzymes. If a muscle disorder might also affect other family members, genetic testing may be done. When someone has symptoms and signs ...

  15. Acute exercise induces tumour suppressor protein p53 translocation to the mitochondria and promotes a p53-Tfam-mitochondrial DNA complex in skeletal muscle.

    Science.gov (United States)

    Saleem, Ayesha; Hood, David A

    2013-07-15

    The major tumour suppressor protein p53 plays an important role in maintaining mitochondrial content and function in skeletal muscle. p53 has been shown to reside in the mitochondria complexed with mitochondrial DNA (mtDNA); however, the physiological repercussions of mitochondrial p53 remain unknown. We endeavoured to elucidate whether an acute bout of endurance exercise could mediate an increase in mitochondrial p53 levels. C57Bl6 mice (n = 6 per group) were randomly assigned to sedentary, acute exercise (AE, 15 m min(-1) for 90 min) or acute exercise + 3 h recovery (AER) groups. Exercise concomitantly increased the mRNA content of nuclear-encoded (PGC-1α, Tfam, NRF-1, COX-IV, citrate synthase) and mtDNA-encoded (COX-I) genes in the AE group, and further by ∼5-fold in the AER group. Nuclear p53 protein levels were reduced in the AE and AER groups, while in contrast, the abundance of p53 was drastically enhanced by ∼2.4-fold and ∼3.9-fold in subsarcolemmal and intermyofibrillar mitochondria, respectively, in the AER conditions. Within the mitochondria, the interaction of p53 with mtDNA at the D-loop and with Tfam was elevated by ∼4.6-fold and ∼3.6-fold, respectively, in the AER group. In the absence of p53, the enhanced COX-I mRNA content observed with AE and AER was abrogated. This study is the first to indicate that endurance exercise can signal to localize p53 to the mitochondria where it may serve to positively modulate the activity of the mitochondrial transcription factor Tfam. Our findings help us understand the mechanisms underlying the effects of exercise as a therapeutic intervention designed to trigger the pro-metabolic functions of p53.

  16. Systematic Review and Comparative Meta-Analysis of Outcomes Following Pedicled Muscle versus Fasciocutaneous Flap Coverage for Complex Periprosthetic Wounds in Patients with Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    James M. Economides

    2017-03-01

    Full Text Available BackgroundIn cases of total knee arthroplasty (TKA threatened by potential hardware exposure, flap-based reconstruction is indicated to provide durable coverage. Historically, muscle flaps were favored as they provide vascular tissue to an infected wound bed. However, data comparing the performance of muscle versus fasciocutaneous flaps are limited and reflect a lack of consensus regarding the optimal management of these wounds. The aim of this study was to compare the outcomes of muscle versus fasciocutaneous flaps following the salvage of compromised TKA.MethodsA systematic search and meta-analysis were performed to identify patients with TKA who underwent either pedicled muscle or fasciocutaneous flap coverage of periprosthetic knee defects. Studies evaluating implant/limb salvage rates, ambulatory function, complications, and donor-site morbidity were included in the comparative analysis.ResultsA total of 18 articles, corresponding to 172 flaps (119 muscle flaps and 53 fasciocutaneous flaps were reviewed. Rates of implant salvage (88.8% vs. 90.1%, P=0.05 and limb salvage (89.8% vs. 100%, P=0.14 were comparable in each cohort. While overall complication rates were similar (47.3% vs. 44%, P=0.78, the rates of persistent infection (16.4% vs. 0%, P=0.14 and recurrent infection (9.1% vs. 4%, P=0.94 tended to be higher in the muscle flap cohort. Notably, functional outcomes and ambulation rates were sparingly reported.ConclusionsRates of limb and prosthetic salvage were comparable following muscle or fasciocutaneous flap coverage of compromised TKA. The functional morbidity associated with muscle flap harvest, however, may support the use of fasciocutaneous flaps for coverage of these defects, particularly in young patients and/or high-performance athletes.

  17. Muscle cramps

    Science.gov (United States)

    ... spasm. Muscle cramps can occur while you play tennis or golf, bowl, swim, or do any other exercise. They can also be triggered by: Alcoholism Hypothyroidism (underactive thyroid) Kidney failure Medicines Menstruation Pregnancy Home Care If you have a muscle ...

  18. Modeling Muscles

    Science.gov (United States)

    Goodwyn, Lauren; Salm, Sarah

    2007-01-01

    Teaching the anatomy of the muscle system to high school students can be challenging. Students often learn about muscle anatomy by memorizing information from textbooks or by observing plastic, inflexible models. Although these mediums help students learn about muscle placement, the mediums do not facilitate understanding regarding integration of…

  19. Muscle pain

    African Journals Online (AJOL)

    of muscle or tendons.4,14. Management of muscle pain. Non-Pharmacological Management. The non-pharmacological treatments for muscle pain are illustrated in Figure 1. Treatment modalities include the following. Transcutaneous electrical stimulation (TENS). TENS is a non-invasive procedure used in rehabilitation to.

  20. Muscle aches

    Science.gov (United States)

    ... is most often related to tension, overuse, or muscle injury from exercise or hard physical work. The pain ... common causes of muscle aches and pains are: Injury or trauma, including sprains and strains Overuse including using a muscle too much, too soon before warming up, or ...

  1. Muscle remodeling and the exercise physiology of fish.

    Science.gov (United States)

    McClelland, Grant B

    2012-07-01

    Fish muscle responds to aerobic exercise training and cold acclimation with a more aerobic muscle phenotype than mammalian muscle but through both conserved and distinct molecular events. Differences from mammals in exercise metabolism and diversity in protein isoforms suggest that the regulation of muscle fuel use is more complex in fish. This review considers fish as powerful models for exercise and muscle physiology.

  2. Relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium induced by new nitric oxide donor substances of the nitrosyl-ruthenium complex

    Directory of Open Access Journals (Sweden)

    Joao B. G. Cerqueira

    2008-10-01

    Full Text Available INTRODUCTION: Endothelial dysfunction characterized by endogenous nitric oxide (NO deficiency made 56% of patients affected with erectile dysfunction decline treatment with PDE-5 inhibitors. New forms of treatment are currently being developed for this group of patients. MATERIALS AND METHODS: The study compared the effect of sodium nitroprusside (SNP and two substances of the nitrosyl-ruthenium complex, cis-[Ru(bpy2(SO3(NO]PF-6-9 ("FONO1” and trans-[Ru(NH34(caffeine(NO]C13 ("LLNO1” on relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium. The samples were immersed in isolated baths and precontracted with 0.1 µM phenylephrine (PE and the corresponding relaxation concentration/response curves were plotted. In order to investigate the relaxation mechanisms involved, 100 µM ODQ (a soluble guanylate cyclase-specific inhibitor, 3 µM or 10 µM oxyhemoglobin (an extracellular NO scavenger or 1 mM L-cysteine (a nitrosyl anion-specific scavenger was added to the samples. RESULTS: All the NO donors tested produced a significant level of relaxation in the vascular endothelium. In corpus cavernosum samples, FONO1 produced no significant effect, but LLNO1 and SNP induced dose-dependent relaxation with comparable potency (pEC50 = 6.14 ± 0.08 and 6.4 ± 0.14, respectively and maximum effect (Emax = 82% vs. 100%, respectively. All NO donors were found to activate soluble guanylate cyclase, since the addition of the corresponding inhibitor (100 µM ODQ completely neutralized the relaxation effect observed. The addition of oxyhemoglobin reduced the relaxation effect, but did not inhibit it completely. In aortic vascular endothelium 3 µM oxyhemoglobin decreased the relaxation effect by 26% on the average, while 10 µM oxyhemoglobin reduced it by over 52%. The addition of 100 µM L-cysteine produced no significant inhibiting effect. CONCLUSIONS: These results suggest that LLNO1 and FONO1 are potent vasodilators. LLNO1 was

  3. Muscle dysfunction in cancer patients

    DEFF Research Database (Denmark)

    Christensen, Jesper Frank; Jones, L W; Andersen, J L

    2014-01-01

    implications of muscle dysfunction in cancer patients. The efficacy of exercise training to prevent and/or mitigate cancer-related muscle dysfunction is also discussed. DESIGN: We identified 194 studies examining muscular outcomes in cancer patients by searching PubMed and EMBASE databases. RESULTS: Muscle...... in oncology practice. Significant progress has been made over the last decade in the field of exercise oncology, indicating that exercise training constitutes a potent modulator of skeletal muscle function in patients with cancer. CONCLUSION: There are clear associations between muscle dysfunction...... dysfunction is evident across all stages of the cancer trajectory. The causes of cancer-related muscle dysfunction are complex, but may involve a wide range of tumor-, therapy- and/or lifestyle-related factors, depending on the clinical setting of the individual patient. The main importance of muscle...

  4. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

    Krag, T O; Hauerslev, S; Jeppesen, T D

    2013-01-01

    Mitochondrial myopathies cover a diverse group of disorders in which ragged red and COX-negative fibers are common findings on muscle morphology. In contrast, muscle degeneration and regeneration, typically found in muscular dystrophies, are not considered characteristic features of mitochondrial...... by a dystrophic morphology. The results add to the complexity of the pathogenesis underlying mitochondrial myopathies, and expand the knowledge about the impact of energy deficiency on another aspect of muscle structure and function....

  5. Passive mechanics of canine internal abdominal muscles.

    Science.gov (United States)

    Hwang, Willy; Carvalho, Jason C; Tarlovsky, Isaac; Boriek, Aladin M

    2005-05-01

    The internal abdominal muscles are biaxially loaded in vivo, and therefore length-tension relations along and transverse to the directions of the muscle fibers are important in understanding their mechanical properties. We hypothesized that 1) internal oblique and transversus abdominis form an internal abdominal composite muscle with altered compliance than that of either muscle individually, and 2) anisotropy, different compliances in orthogonal directions, of internal abdominal composite muscle is less pronounced than that of its individual muscles. To test these hypotheses, in vitro mechanical testing was performed on 5 x 5 cm squares of transversus abdominis, internal oblique, and the two muscles together as a composite. These tissues were harvested from the left lateral side of abdominal muscles of eleven mongrel dogs (15-23 kg) and placed in a bath of oxygenated Krebs solution. Each tissue strip was attached to a biaxial mechanical testing device. Each muscle was passively lengthened and shortened along muscle fibers, transverse to fibers, or simultaneously along and transverse to muscle fibers. Both transversus abdominis and internal oblique muscles demonstrated less extensibility in the direction transverse to muscle fibers than along fibers. Biaxial loading caused a stiffening effect that was greater in the direction along the fibers than transverse to the fibers. Furthermore, the abdominal muscle composite was less compliant than either muscle alone in the direction of the muscle fibers. Taken together, our data suggested that the internal abdominal composite tissue has complex mechanical properties that are dependent on the mechanical properties of internal oblique and transversus abdominis muscles.

  6. Tratamiento local de metástasis cutánea facial de cáncer de colon mediante colgajo submentoniano Local management of colon carcinoma metasasis in the face with a submental flap

    Directory of Open Access Journals (Sweden)

    A. Acosta Arencibia

    2010-12-01

    Full Text Available Las metástasis cutáneas de los tumores del aparato digestivo son lesiones infrecuentes que aparecen en pacientes con estadíos avanzados de la enfermedad, frecuentemente ya intervenidos del tumor primario. Son lesiones que aparecen de novo, de características variables y crecimiento rápido; suelen localizarse en tronco o extremidades inferiores y se diagnostican precozmente, lo que hace fácil su extirpación y el cierre directo del defecto. Presentamos el caso de un paciente con cáncer de colon en estadío avanzado con lesión metastásica facial de 6 cm de diámetro en mejilla derecha. Esta lesión ulcerada y maloliente, precisaba curas diarias y empeoraba la calidad de vida del paciente. Se procedió a su extirpación y para cobertura realizamos un colgajo submentoniano ipsilateral con excelente resultado. Este colgajo proporciona un tejido muy parecido al del defecto, creando mínimas secuelas de la zona donante que queda oculta en el área de sombra submandibular, por lo que representa una alternativa terapéutica ideal en defectos faciales de tamaño medio.Cutaneous metastasis of the digestive tract are infrequent lesions appearing in patients with advanced disease. Most of these patients have been already operated of their primary tumour. Lesions are variable in aspect, arising de novo and evolving with rapid growth. They usually lie in the trunk or lower extremities thus facilitating an early diagnosis and management with simple extirpation and direct closure. A case-report of a patient with advanced colonic cancer is here presented. At admission he presented a cutaneous matastasic lesion in the right cheek; it was a 6 cm ulcerated, bad -smelling lesion which needed daily dressings affecting patient's normal life. The lesion was removed using successfully a submental flap as coverage. The submental flap provides a very similar tissue to facial defects, leaving no donor area sequelae which is in addition well hidden, being

  7. Loss of a Clueless-dGRASP complex results in ER stress and blocks Integrin exit from the perinuclear endoplasmic reticulum in Drosophila larval muscle

    NARCIS (Netherlands)

    Wang, Zong-Heng; Rabouille, Catherine; Geisbrecht, Erika R

    2015-01-01

    Drosophila Clueless (Clu) and its conserved orthologs are known for their role in the prevention of mitochondrial clustering. Here, we uncover a new role for Clu in the delivery of integrin subunits in muscle tissue. In clu mutants, αPS2 integrin, but not βPS integrin, abnormally accumulates in a

  8. Muscle Selection for Focal Limb Dystonia

    OpenAIRE

    Barbara Illowsky Karp; Katharine Alter

    2017-01-01

    Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this artic...

  9. The examination of the musculoskeletal system based only on the evaluation of pelvic-hip complex muscle and trunk flexibility may lead to failure to screen children for generalized joint hypermobility.

    Science.gov (United States)

    Czaprowski, Dariusz; Kędra, Agnieszka; Pawłowska, Paulina; Kolwicz-Gańko, Aleksandra; Leszczewska, Justyna; Tyrakowski, Marcin

    2015-01-01

    The aim of the study was to evaluate whether the clinical assessment of the pelvic-hip complex muscle and trunk flexibility is sufficient for diagnosing generalized joint hypermobility (GJH). A cross-sectional study. Center of Body Posture in Olsztyn, North East Poland. The study included 136 females and 113 males aged 10-13 years. In order to assess muscle flexibility, the straight leg raise (SLR) test (for hamstring) and modified Thomas test for one- (O-JHF) and two-joint (T-JHF) hip flexors were performed. To evaluate trunk flexibility the fingertip-to-floor (FTF) and lateral trunk flexion (LTF) tests were used. The GJH occurrence was assessed with the use of nine-point Beighton scale (threshold value ≥5 points for females, ≥4 for males). The analysis was carried out separately for females and males. There were no significant differences between females with versus without GJH, and males with versus without GJH regarding SLR (p = 0.86, p = 0.19 for females and males, respectively), O-JHF (p = 0.89, p = 0.35 for females and males, respectively), T-JHF (p = 0.77, p = 0.4 for females and males, respectively), FTF (p = 0.19, p = 0.84 for females and males, respectively) and LTF (p = 0.58, p = 0.35 for females and males, respectively) tests results. Clinical examination of the pelvic-hip complex muscles and trunk flexibility by use of SLR, O-JHF, T-JHF, FTF and LTF revealed to be insufficient in diagnosing GJH in children aged 10-13 years. Thus, the Beighton scale should be considered a standard element of physiotherapeutic examination of the musculoskeletal system in children and youth.

  10. The examination of the musculoskeletal system based only on the evaluation of pelvic-hip complex muscle and trunk flexibility may lead to failure to screen children for generalized joint hypermobility.

    Directory of Open Access Journals (Sweden)

    Dariusz Czaprowski

    Full Text Available The aim of the study was to evaluate whether the clinical assessment of the pelvic-hip complex muscle and trunk flexibility is sufficient for diagnosing generalized joint hypermobility (GJH.A cross-sectional study.Center of Body Posture in Olsztyn, North East Poland.The study included 136 females and 113 males aged 10-13 years.In order to assess muscle flexibility, the straight leg raise (SLR test (for hamstring and modified Thomas test for one- (O-JHF and two-joint (T-JHF hip flexors were performed. To evaluate trunk flexibility the fingertip-to-floor (FTF and lateral trunk flexion (LTF tests were used. The GJH occurrence was assessed with the use of nine-point Beighton scale (threshold value ≥5 points for females, ≥4 for males. The analysis was carried out separately for females and males.There were no significant differences between females with versus without GJH, and males with versus without GJH regarding SLR (p = 0.86, p = 0.19 for females and males, respectively, O-JHF (p = 0.89, p = 0.35 for females and males, respectively, T-JHF (p = 0.77, p = 0.4 for females and males, respectively, FTF (p = 0.19, p = 0.84 for females and males, respectively and LTF (p = 0.58, p = 0.35 for females and males, respectively tests results.Clinical examination of the pelvic-hip complex muscles and trunk flexibility by use of SLR, O-JHF, T-JHF, FTF and LTF revealed to be insufficient in diagnosing GJH in children aged 10-13 years. Thus, the Beighton scale should be considered a standard element of physiotherapeutic examination of the musculoskeletal system in children and youth.

  11. Defects on endoanal ultrasound and anal incontinence after primary repair of fourth-degree anal sphincter rupture: a study of the anal sphincter complex and puborectal muscle

    DEFF Research Database (Denmark)

    Sakse, A; Secher, N J; Ottesen, M

    2009-01-01

    OBJECTIVES: To perform three-dimensional endoanal ultrasound (EAUS) after primary repair of fourth-degree anal sphincter rupture (ASR) and correlate the sonographic defects with anal incontinence (AI); to measure the axial and sagittal thickness and angle of the puborectal muscle (PRM) as well...... as the length of the anal canal, and then correlate these measures with AI; and to assess the interobserver measurement agreement between an inexperienced and an experienced sonologist. METHODS: EAUS was offered to 84 consecutive women, who were asked to answer a validated questionnaire after fourth-degree ASR...

  12. Skeletal muscle connective tissue

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline

      The connective tissue content of skeletal muscle is believed to be the major factor responsible for defining the eating quality of different meat cuts, although attempts to correlate quantifications based on traditional histological methods have not as yet been able to prove this relation...... composition, the organizational structure of connective tissue, the role of connective tissue in muscle contraction and the generation of force, metabolic regulation of arterial structure focusing on associated collagen changes, and a new highly-specific technique for following in three-dimensions changes...... in the structure of fibrous collagen and myofibers at high-resolution. The results demonstrate that the collagen composition in the extra cellular matrix of Gadus morhua fish muscle is much more complex than previously anticipated, as it contains type III, IV, V  and VI collagen in addition to type I. The vascular...

  13. A Novel Approach to Submandibular Gland Ptosis: Creation of a Platysma Muscle and Hyoid Bone Cradle

    Directory of Open Access Journals (Sweden)

    Robert Lukavsky

    2016-07-01

    Full Text Available Submandibular gland ptosis is a common impediment to obtaining superior surgical aesthetic results in neck lift surgery. Techniques for suspending the submandibular gland have been proposed, but these procedures have the drawbacks of disturbing the floor of the mouth mucosa and periosteum. We present an approach of submandibular gland suspension for the treatment of gland ptosis by employing a platysma and hyoid bone fascia cradle. Our technique was performed on cadaveric models. The platysma muscle and hyoid bone cradle for submandibular gland ptosis was created on the left side of the neck in two cadavers. A submental incision with sharp dissection was performed to raise a supraplatysmal flap. A subplatysmal plane was developed until the submandibular gland was identified. Sutures were used to pexy the platysma to the hyoid bone periosteum and deep cervical fascia, tightening the overlying muscle and in turn elevating the submandibular gland. Submandibular gland ptosis must be corrected in order to achieve exemplary aesthetic results. Our approach of creating a cradle with the platysma and hyoid bone avoids the potential complications of previously described sling procedures, while still maintaining the integrity of the gland and surrounding tissues.

  14. Muscle coordination: the discussion continues

    Science.gov (United States)

    Prilutsky

    2000-01-01

    In this response, the major criticisms of the target article are addressed. Terminology from the target article that may have caused some confusion is clarified. In particular, the tasks that have the basic features of muscle coordination, as identified in the target article, have been limited in scope. A new metabolic optimization criterion suggested by Alexander (2000) is examined for its ability to predict muscle coordination in walking. Issues concerning the validation of muscle force predictions, the rules of muscle coordination, and the role of directional constraints in coordination of two-joint muscles are discussed. It is shown in particular that even in one-joint systems, the forces predicted by the criterion of Crowninshield and Brand (1981) depend upon the muscle moment arms and the physiological cross-sectional areas in much more complex ways than either previously assumed in the target article, or incorrectly derived by Herzog and Ait-Haddou (2000). It is concluded that the criterion of Crowninshield and Brand qualitatively predicts the basic coordination features of the major one- and two-joint muscles in a number of highly skilled, repetitive motor tasks performed by humans under predictable conditions and little demands on stability and accuracy. A possible functional significance of such muscle coordination may be the minimization of perceived effort, muscle fatigue, and/or energy expenditure.

  15. Influence of muscle shortening on the geometry of gastrocnemius medialis muscle of the rat

    NARCIS (Netherlands)

    Zuurbier, C. J.; Huijing, P. A.

    1991-01-01

    For static and dynamic conditions muscle geometry of the musculus gastrocnemius medialis of the rat was compared at different muscle lengths. The dynamic conditions differed with respect to isokinetic shortening velocity (25, 50 and 75 mm/s) of the muscle-tendon complex and in constancy of force

  16. Respiratory diseases and muscle dysfunction.

    Science.gov (United States)

    Gea, Joaquim; Casadevall, Carme; Pascual, Sergi; Orozco-Levi, Mauricio; Barreiro, Esther

    2012-02-01

    Many respiratory diseases lead to impaired function of skeletal muscles, influencing quality of life and patient survival. Dysfunction of both respiratory and limb muscles in chronic obstructive pulmonary disease has been studied in depth, and seems to be caused by the complex interaction of general (inflammation, impaired gas exchange, malnutrition, comorbidity, drugs) and local factors (changes in respiratory mechanics and muscle activity, and molecular events). Some of these factors are also present in cystic fibrosis and asthma. In obstructive sleep apnea syndrome, repeated exposure to hypoxia and the absence of reparative rest are believed to be the main causes of muscle dysfunction. Deconditioning appears to be crucial for the functional impairment observed in scoliosis. Finally, cachexia seems to be the main mechanism of muscle dysfunction in advanced lung cancer. A multidimensional therapeutic approach is recommended, including pulmonary rehabilitation, an adequate level of physical activity, ventilatory support and nutritional interventions.

  17. Muscle Selection for Focal Limb Dystonia

    Directory of Open Access Journals (Sweden)

    Barbara Illowsky Karp

    2017-12-01

    Full Text Available Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.

  18. Muscle Selection for Focal Limb Dystonia.

    Science.gov (United States)

    Karp, Barbara Illowsky; Alter, Katharine

    2017-12-29

    Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.

  19. Muscle strain (image)

    Science.gov (United States)

    A muscle strain is the stretching or tearing of muscle fibers. A muscle strain can be caused by sports, exercise, a ... something that is too heavy. Symptoms of a muscle strain include pain, tightness, swelling, tenderness, and the ...

  20. Proteomic analysis of cellular soluble proteins from human bronchial smooth muscle cells by combining nondenaturing micro 2DE and quantitative LC-MS/MS. 2. Similarity search between protein maps for the analysis of protein complexes.

    Science.gov (United States)

    Jin, Ya; Yuan, Qi; Zhang, Jun; Manabe, Takashi; Tan, Wen

    2015-09-01

    Human bronchial smooth muscle cell soluble proteins were analyzed by a combined method of nondenaturing micro 2DE, grid gel-cutting, and quantitative LC-MS/MS and a native protein map was prepared for each of the identified 4323 proteins [1]. A method to evaluate the degree of similarity between the protein maps was developed since we expected the proteins comprising a protein complex would be separated together under nondenaturing conditions. The following procedure was employed using Excel macros; (i) maps that have three or more squares with protein quantity data were selected (2328 maps), (ii) within each map, the quantity values of the squares were normalized setting the highest value to be 1.0, (iii) in comparing a map with another map, the smaller normalized quantity in two corresponding squares was taken and summed throughout the map to give an "overlap score," (iv) each map was compared against all the 2328 maps and the largest overlap score, obtained when a map was compared with itself, was set to be 1.0 thus providing 2328 "overlap factors," (v) step (iv) was repeated for all maps providing 2328 × 2328 matrix of overlap factors. From the matrix, protein pairs that showed overlap factors above 0.65 from both protein sides were selected (431 protein pairs). Each protein pair was searched in a database (UniProtKB) on complex formation and 301 protein pairs, which comprise 35 protein complexes, were found to be documented. These results demonstrated that native protein maps and their similarity search would enable simultaneous analysis of multiple protein complexes in cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Proteomic analysis of cellular soluble proteins from human bronchial smooth muscle cells by combining nondenaturing micro 2DE and quantitative LC‐MS/MS. 2. Similarity search between protein maps for the analysis of protein complexes

    Science.gov (United States)

    Jin, Ya; Yuan, Qi; Zhang, Jun; Manabe, Takashi

    2015-01-01

    Human bronchial smooth muscle cell soluble proteins were analyzed by a combined method of nondenaturing micro 2DE, grid gel‐cutting, and quantitative LC‐MS/MS and a native protein map was prepared for each of the identified 4323 proteins [1]. A method to evaluate the degree of similarity between the protein maps was developed since we expected the proteins comprising a protein complex would be separated together under nondenaturing conditions. The following procedure was employed using Excel macros; (i) maps that have three or more squares with protein quantity data were selected (2328 maps), (ii) within each map, the quantity values of the squares were normalized setting the highest value to be 1.0, (iii) in comparing a map with another map, the smaller normalized quantity in two corresponding squares was taken and summed throughout the map to give an “overlap score,” (iv) each map was compared against all the 2328 maps and the largest overlap score, obtained when a map was compared with itself, was set to be 1.0 thus providing 2328 “overlap factors,” (v) step (iv) was repeated for all maps providing 2328 × 2328 matrix of overlap factors. From the matrix, protein pairs that showed overlap factors above 0.65 from both protein sides were selected (431 protein pairs). Each protein pair was searched in a database (UniProtKB) on complex formation and 301 protein pairs, which comprise 35 protein complexes, were found to be documented. These results demonstrated that native protein maps and their similarity search would enable simultaneous analysis of multiple protein complexes in cells. PMID:26031785

  2. PT-1 selectively activates AMPK-γ1 complexes in mouse skeletal muscle, but activates all three γ subunit complexes in cultured human cells by inhibiting the respiratory chain

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Ross, Fiona A; Kleinert, Maximilian

    2015-01-01

    AMP-activated protein kinase (AMPK) occurs as heterotrimeric complexes in which a catalytic subunit (α1/α2) is bound to one of two b subunits (β1/β2) and one of three γ subunits (γ1/γ2/γ3). The ability to selectively activate specific isoforms would be a useful research tool, and a promising...

  3. STRUCTURAL ALTERATIONS OF SKELETAL MUSCLE IN COPD

    Directory of Open Access Journals (Sweden)

    Sunita eMathur

    2014-03-01

    Full Text Available Background: Chronic obstructive pulmonary disease (COPD is a respiratory disease associated with a systemic inflammatory response. Peripheral muscle dysfunction has been well characterized in individuals with COPD and results from a complex interaction between systemic and local factors. Objective: In this narrative review, we will describe muscle wasting in people with COPD, the associated structural changes, muscle regenerative capacity and possible mechanisms for muscle wasting. We will also discuss how structural changes relate to impaired muscle function and mobility in people with COPD. Key Observations: Approximately 30-40% of individuals with COPD experience muscle mass depletion. Furthermore, muscle atrophy is a predictor of physical function and mortality in this population. Associated structural changes include a decreased proportion and size of type-I fibers, reduced oxidative capacity and mitochondrial density mainly in the quadriceps. Observations related to impaired muscle regenerative capacity in individuals with COPD include a lower proportion of central nuclei in the presence or absence of muscle atrophy and decreased maximal telomere length, which has been correlated with reduced muscle cross-sectional area. Potential mechanisms for muscle wasting in COPD may include excessive production of reactive oxygen species, altered amino acid metabolism and lower expression of peroxisome proliferator-activated receptors-gamma-coactivator 1-alpha mRNA. Despite a moderate relationship between muscle atrophy and function, impairments in oxidative metabolism only seems weakly related to muscle function. Conclusion: This review article demonstrates the cellular modifications in the peripheral muscle of people with COPD and describes the evidence of its relationship to muscle function. Future research will focus on rehabilitation strategies to improve muscle wasting and maximize function.

  4. Aging and gastrointestinal smooth muscle.

    Science.gov (United States)

    Bitar, Khalil N; Patil, Suresh B

    2004-12-01

    The present review is an attempt to put into perspective the available information on the putative changes in cellular mechanisms of the contractile properties of the aging gastrointestinal (GI) smooth muscle. Information on smooth muscle of the GI tract is scanty. Smooth muscle cells from old rats (32 months old) exhibit limited cell length distribution and diminished contractility. The observed reduced contractile response may be due to the effect of aging on signal transduction pathways, especially an inhibition of the tyrosine kinase-Src kinase pathway, a reduced activation of the PKCalpha pathway, a reduced association of contractile proteins (HSP27-tropomyosin, HSP27-actin, and actin-myosin). Levels of HSP27-phosphorylation are also reduced compared to adult rats. Regulation of GI motility is a complex mechanism of signal transduction and interaction of signaling and contractile proteins. It is suggested that further studies to elucidate the role of HSP27 in aging smooth muscle of the GI tract are needed.

  5. The structure of the muscle protein complex 4Ca{sup 2+} {center_dot}troponin C {center_dot} troponin

    Energy Technology Data Exchange (ETDEWEB)

    Olah, G.A.; Trewhella, J. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    Analysis of scattering data based on a Monte Carlo integration method was used to 2+ obtain a low resolution model of the 4Ca{sup 2+}{circ} troponin C{circ}troponin I complex. This modeling method allows rapid testing of plausible structures where the best fit model can be ascertained by a comparison between model structure scattering profiles and measured scattering data. In the best fit model, troponin I appears as a spiral structure 2+ that wraps around 4Ca{sup 2+}{circ}troponin C which adopts an extended dumbbell conformation similar to that observed in the crystal structures of troponin C. The Monte Carlo modeling method can be applied to other biological systems in which detailed structural information is lacking.

  6. Regulation of insulin-like growth factor-I in skeletal muscle and muscle cells.

    Science.gov (United States)

    Frost, R A; Lang, C H

    2003-03-01

    Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are potent regulators of muscle mass. Transgenic mice that over-express these proteins exhibit dramatically enlarged skeletal muscles. In contrast, malnutrition, critical illness, sepsis, and aging are all associated with a dramatic reduction in muscle mass and function. The circulating concentration of IGF-I and the expression of IGF-I in skeletal muscle are also reduced during catabolic states. Consequently, GH has been used clinically to increase lean body mass in patients with muscle wasting. Likewise, delivery of IGF-I specifically into muscle has been proposed as a genetic therapy for muscle disorders. A better understanding of the regulation of IGF-I expression in skeletal muscle and muscle cells is therefore of importance. Yet, our knowledge in this area has been limited by a lack of GH responsive muscle cells. In addition the IGF-I gene spans over 90 kb of genomic DNA and it exhibits a very complex regulatory pattern. This review will summarize our knowledge of the control of muscle mass by GH, IGF-I, anabolic steroids, exercise and other growth enhancing hormones. We will also highlight recent advances in the regulation of IGF-I and signal transducers and activators of transcription (Stats) by GH. A special emphasis will be placed on the interaction of IGF-I and proinflammatory cytokines in skeletal muscle and muscle cells.

  7. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth muscle cell survival patterns to promote pulmonary arterial hypertension

    Science.gov (United States)

    Aghamohammadzadeh, Reza; Zhang, Ying-Yi; Stephens, Thomas E.; Arons, Elena; Zaman, Paula; Polach, Kevin J.; Matar, Majed; Yung, Lai-Ming; Yu, Paul B.; Bowman, Frederick P.; Opotowsky, Alexander R.; Waxman, Aaron B.; Loscalzo, Joseph; Leopold, Jane A.; Maron, Bradley A.

    2016-01-01

    Activation of the mammalian target of rapamycin complex 1 (mTORC1) subunit Raptor induces cell growth and is a downstream target of Akt. Elevated levels of aldosterone activate Akt, and, in pulmonary arterial hypertension (PAH), correlate with pulmonary arteriole thickening, which suggests that mTORC1 regulation by aldosterone may mediate adverse pulmonary vascular remodeling. We hypothesized that aldosterone-Raptor signaling induces abnormal pulmonary artery smooth muscle cell (PASMC) survival patterns to promote PAH. Remodeled pulmonary arterioles from SU-5416/hypoxia-PAH rats and monocrotaline-PAH rats with hyperaldosteronism expressed increased levels of the Raptor target, p70S6K, which provided a basis for investigating aldosterone-Raptor signaling in human PASMCs. Aldosterone (10−9 to 10−7 M) increased Akt/mTOR/Raptor to activate p70S6K and increase proliferation, viability, and apoptosis resistance in PASMCs. In PASMCs transfected with Raptor–small interfering RNA or treated with spironolactone/eplerenone, aldosterone or pulmonary arterial plasma from patients with PAH failed to increase p70S6K activation or to induce cell survival in vitro. Optimal inhibition of pulmonary arteriole Raptor was achieved by treatment with Staramine-monomethoxy polyethylene glycol that was formulated with Raptor-small interfering RNA plus spironolactone in vivo, which decreased arteriole muscularization and pulmonary hypertension in 2 experimental animal models of PAH in vivo. Up-regulation of mTORC1 by aldosterone is a critical pathobiologic mechanism that controls PASMC survival to promote hypertrophic vascular remodeling and PAH.—Aghamohammadzadeh, R., Zhang, Y.-Y., Stephens, T. E., Arons, E., Zaman, P., Polach, K. J., Matar, M., Yung, L.-M., Yu, P. B., Bowman, F. P., Opotowsky, A. R., Waxman, A. B., Loscalzo, J., Leopold, J. A., Maron, B. A. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery

  8. Engineering vascularized skeletal muscle tissue

    NARCIS (Netherlands)

    Levenberg, Shulamit; Rouwkema, Jeroen; Macdonald, Mara; Garfein, Evan S.; Kohane, Daniel S.; Darland, Diane C.; Marini, Robert; van Blitterswijk, Clemens; Mulligan, Richard C.; D'Amore, Patricia A.; Langer, Robert

    2005-01-01

    One of the major obstacles in engineering thick, complex tissues such as muscle is the need to vascularize the tissue in vitro. Vascularization in vitro could maintain cell viability during tissue growth, induce structural organization and promote vascularization upon implantation. Here we describe

  9. Transitions in cell organization and in expression of contractile and extracellular matrix proteins during development of chicken aortic smooth muscle: evidence for a complex spatial and temporal differentiation program

    Science.gov (United States)

    Yablonka-Reuveni, Zipora; Christ, Bodo; Benson, Janice M.

    2014-01-01

    Whereas the understanding of the mechanisms underlying skeletal and cardiac muscle development has been increased dramatically in recent years, the understanding of smooth muscle development is still in its infancy. This paper summarizes studies on the ontogeny of chicken smooth muscle cells in the wall of the aorta and aortic arch-derived arteries. Employing immunocyto-chemistry with antibodies against smooth muscle contractile and extracellular matrix proteins we trace smooth muscle cell patterning from early development throughout adulthood. Comparing late stage embryos to young and adult chickens we demonstrate, for all the stages analyzed, that the cells in the media of aortic arch-derived arteries and of the thoracic aorta are organized in alternating lamellae. The lamellar cells, but not the interlamellar cells, express smooth muscle specific contractile proteins and are surrounded by basement membrane proteins. This smooth muscle cell organization of lamellar and interlamellar cells is fully acquired by embryonic day 11 (ED11). We further show that, during earlier stages of embryogenesis (ED3 through ED7), cells expressing smooth muscle proteins appear only in the peri-endothelial region of the aortic and aortic arch wall and are organized as a narrow band of cells that does not demonstrate the lamellar-interlamellar pattern. On ED9, infrequent cells organized in lamellar-interlamellar organization can be detected and their frequency increases by ED10. In addition to changes in cell organization, we show that there is a characteristic sequence of contractile and extracellular matrix protein expression during development of the aortic wall. At ED3 the peri-endothelial band of differentiated smooth muscle cells is already positive for smooth muscle alpha actin (αSM-actin) and fibronectin. By the next embryonic day the peri-endothelial cell layer is also positive for smooth muscle myosin light chain kinase (SM-MLCK). Subsequently, by ED5 this peri

  10. AMPK in skeletal muscle function and metabolism

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus; Hingst, Janne R; Fentz, Joachim

    2017-01-01

    Skeletal muscle possesses a remarkable ability to adapt to various physiologic conditions. AMPK is a sensor of intracellular energy status that maintains energy stores by fine-tuning anabolic and catabolic pathways. AMPK's role as an energy sensor is particularly critical in tissues displaying...... highly changeable energy turnover. Due to the drastic changes in energy demand that occur between the resting and exercising state, skeletal muscle is one such tissue. Here, we review the complex regulation of AMPK in skeletal muscle and its consequences on metabolism (e.g., substrate uptake, oxidation......, and storage as well as mitochondrial function of skeletal muscle fibers). We focus on the role of AMPK in skeletal muscle during exercise and in exercise recovery. We also address adaptations to exercise training, including skeletal muscle plasticity, highlighting novel concepts and future perspectives...

  11. The role of muscle weakness in the pathogenesis of osteoarthritis.

    Science.gov (United States)

    Hurley, M V

    1999-05-01

    To date, very few studies have investigated the role of muscle dysfunction in the pathogenesis of osteoarthritis (OA). Using largely indirect evidence, this article hypothesizes that motor and sensory dysfunction of muscle may be important factors in the pathogenesis of articular damage and are not simply a consequence of joint damage. A new paradigm is constructed to better describe the complex interrelationship between muscle sensorimotor dysfunction, joint damage, and disability in OA. If the hypothesis is correct, because muscle is a relatively plastic tissue, maintaining well-conditioned muscles may delay or prevent the onset of OA, and rehabilitation exercise therapy that reverses muscle sensorimotor dysfunction may ameliorate the effects of OA.

  12. Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, William G., E-mail: bp1@bu.edu [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States); Hindson, David F. [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States); Langmore, Susan E. [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States); Speech and Hearing Sciences, Boston University, Boston, Massachusetts (United States); Zumwalt, Ann C. [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)

    2013-03-01

    Purpose: Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials: mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results: Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions

  13. Eye muscle repair - discharge

    Science.gov (United States)

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  14. Muscle strain treatment

    Science.gov (United States)

    Treatment - muscle strain ... Question: How do you treat a muscle strain ? Answer: Rest the strained muscle and apply ice for the first few days after the injury. Anti-inflammatory medicines or acetaminophen ( ...

  15. Extraocular muscle function testing

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003397.htm Extraocular muscle function testing To use the sharing features on this page, please enable JavaScript. Extraocular muscle function testing examines the function of the eye muscles. ...

  16. Rupture of pectoralis major muscle: review article

    Directory of Open Access Journals (Sweden)

    Guity MR

    2010-05-01

    Full Text Available "nBackground: Rupture of pectoralis major muscle is a very rare and often athletic injury. These days in our country this injury occurs more frequently. This could be due to increase in professional participation of amateur people in different types of sport, like body building and weight-lifting (especially bench-pressing without adequate preparation, training and taking necessary precautions. In this article, we have tried to review several aspects of complex anatomy of pectoralis major muscle, epidemiology, mechanism, clinical presentations, imaging modalities, surgical indications and techniques of its rupture. Complex and especial anatomy of pectoralis major muscle, in its humeral insertion particularly, have a major role of its vulnerability to sudden and eccentric contraction as the main mechanism of rupture. Also, restoration of this complex anatomy seems to be important during surgical repair to have normal function of the muscle again.

  17. Are muscle synergies useful for neural control ?

    Directory of Open Access Journals (Sweden)

    Aymar ede Rugy

    2013-03-01

    Full Text Available The observation that the activity of multiple muscles can be well approximated by a few linear synergies is viewed by some as a sign that such low-dimensional modules constitute a key component of the neural control system. Here, we argue that the usefulness of muscle synergies as a control principle should be evaluated in terms of errors produced not only in muscle space, but also in task space. We used data from a force-aiming task in two dimensions at the wrist, using an EMG-driven virtual biomechanics technique that overcomes typical errors in predicting force from recorded EMG, to illustrate through simulation how synergy decomposition inevitably introduces substantial task space errors. Then, we computed the optimal pattern of muscle activation that minimizes summed-squared muscle activities, and demonstrated that synergy decomposition produced similar results on real and simulated data. We further assessed the influence of synergy decomposition on aiming errors in a more redundant system, using the optimal muscle pattern computed for the elbow-joint complex (i.e., 13 muscles acting in two dimensions. Because EMG records are typically not available from all contributing muscles, we also explored reconstructions from incomplete sets of muscles. The redundancy of a given set of muscles had opposite effects on the goodness of muscle reconstruction and on task achievement; higher redundancy is associated with better EMG approximation (lower residuals, but with higher aiming errors. Finally, we showed that the number of synergies required to approximate the optimal muscle pattern for an arbitrary biomechanical system increases with task-space dimensionality, which indicates that the capacity of synergy decomposition to explain behaviour depends critically on the scope of the original database. These results have implications regarding the viability of muscle synergy as a putative neural control mechanism, and also as a control algorithm to

  18. Muscle shape consistency and muscle volume prediction of thigh muscles.

    Science.gov (United States)

    Mersmann, F; Bohm, S; Schroll, A; Boeth, H; Duda, G; Arampatzis, A

    2015-04-01

    The present study investigated the applicability of a muscle volume prediction method using only the muscle length (L(M)), the maximum anatomical cross-sectional area (ACSA(max)), and a muscle-specific shape factor (p) on the quadriceps vastii. L(M), ACSA(max), muscle volume, and p were obtained from magnetic resonance images of the vastus intermedius (VI), lateralis (VL), and medialis (VM) of female (n = 20) and male (n = 17) volleyball athletes. The average p was used to predict muscle volumes (V(p)) using the equation V(p)  = p × ACSA(max)  × L(M). Although there were significant differences in the muscle dimensions between male and female athletes, p was similar and on average 0.582, 0.658, 0.543 for the VI, VL, and VM, respectively. The position of ACSA(max) showed low variability and was at 57%, 60%, and 81% of the thigh length for VI, VL, and VM. Further, there were no significant differences between measured and predicted muscle volumes with root mean square differences of 5-8%. These results suggest that the muscle shape of the quadriceps vastii is independent of muscle dimensions or sex and that the prediction method could be sensitive enough to detect changes in muscle volume related to degeneration, atrophy, or hypertrophy. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Skeletal muscle satellite cells

    Science.gov (United States)

    Schultz, E.; McCormick, K. M.

    1994-01-01

    Evidence now suggests that satellite cells constitute a class of myogenic cells that differ distinctly from other embryonic myoblasts. Satellite cells arise from somites and first appear as a distinct myoblast type well before birth. Satellite cells from different muscles cannot be functionally distinguished from one another and are able to provide nuclei to all fibers without regard to phenotype. Thus, it is difficult to ascribe any significant function to establishing or stabilizing fiber type, even during regeneration. Within a muscle, satellite cells exhibit marked heterogeneity with respect to their proliferative behavior. The satellite cell population on a fiber can be partitioned into those that function as stem cells and those which are readily available for fusion. Recent studies have shown that the cells are not simply spindle shaped, but are very diverse in their morphology and have multiple branches emanating from the poles of the cells. This finding is consistent with other studies indicating that the cells have the capacity for extensive migration within, and perhaps between, muscles. Complexity of cell shape usually reflects increased cytoplasmic volume and organelles including a well developed Golgi, and is usually associated with growing postnatal muscle or muscles undergoing some form of induced adaptive change or repair. The appearance of activated satellite cells suggests some function of the cells in the adaptive process through elaboration and secretion of a product. Significant advances have been made in determining the potential secretion products that satellite cells make. The manner in which satellite cell proliferative and fusion behavior is controlled has also been studied. There seems to be little doubt that cellcell coupling is not how satellite cells and myofibers communicate. Rather satellite cell regulation is through a number of potential growth factors that arise from a number of sources. Critical to the understanding of this form

  20. Calcium regulation of muscle contraction.

    Science.gov (United States)

    Szent-Györgyi, A G

    1975-07-01

    Calcium triggers contraction by reaction with regulatory proteins that in the absence of calcium prevent interaction of actin and myosin. Two different regulatory systems are found in different muscles. In actin-linked regulation troponin and tropomyosin regulate actin by blocking sites on actin required for complex formation with myosin; in myosin-linked regulation sites on myosin are blocked in the absence of calcium. The major features of actin control are as follows: there is a requirement for tropomyosin and for a troponin complex having three different subunits with different functions; the actin displays a cooperative behavior; and a movement of tropomyosin occurs controlled by the calcium binding on troponin. Myosin regulation is controlled by a regulatory subunit that can be dissociated in scallop myosin reversibly by removing divalent cations with EDTA. Myosin control can function with pure actin in the absence of tropomyosin. Calcium binding and regulation of molluscan myosins depend on the presence of regulatory light chains. It is proposed that the light chains function by sterically blocking myosin sites in the absence of calcium, and that the "off" state of myosin requires cooperation between the two myosin heads. Both myosin control and actin control are widely distributed in different organisms. Many invertebrates have muscles with both types of regulation. Actin control is absent in the muscles of molluscs and in several minor phyla that lack troponin. Myosin control is not found in striated vertebrate muscles and in the fast muscles of crustacean decapods, although regulatory light chains are present. While in vivo myosin control may not be excluded from vertebrate striated muscles, myosin control may be absent as a result of mutations of the myosin heavy chain.

  1. DNA in a Tunnel: A Comfy Spot for Recognition - or -The Structure of BsoBI Complexed with DNA. What can we Learn about Function via Structure Determination and how can this be Applied to Bone or Muscle Biology?

    Science.gov (United States)

    vanderWoerd, Mark

    2004-01-01

    The structure and function of a biologically active molecule are related. To understand its function, it is necessary (but not always sufficient) to know the structure of the molecule. There are many ways of relating the molecular function with the structure. Mutation analysis can identify pertinent amino acids of an enzyme, or alternatively structure comparison of the of two similar molecules with different function may lead to understanding which parts are responsible for a functional aspect, or a series of "structural cartoons" - enzyme structure, enzyme plus substrate, enzyme with transition state analog, and enzyme with product - may give insight in the function of a molecule. As an example we will discuss the structure and function of the restriction enzyme BsoBI from Bacillus stearothemzophilus in complex with its cognate DNA. The enzyme forms a unique complex with DNA in that it completely encircles the DNA. The structure reveals the enzyme-DNA contacts, how the DNA is distorted compared with the canonical forms, and elegantly shows how two distinct DNA sequences can be recognized with the same efficiency. Based on the structure we may also propose a hypothesis how the enzymatic mechanism works. The knowledge gained thru studies such as this one can be used to alter the function by changing the molecular structure. Usually this is done by design of inhibitors specifically active against and fitting into an active site of the enzyme of choice. In the case of BsoBI one of the objectives of the study was to alter the enzyme specificity. In bone biology there are many candidates available for molecular study in order to explain, alter, or (temporarily) suspend activity. For example, the understanding of a pathway that negatively regulates bone formation may be a good target for drug design to stimulate bone formation and have good potential as the basis for new countermeasures against bone loss. In principle the same approach may aid muscle atrophy, radiation

  2. Muscle Weakness

    Directory of Open Access Journals (Sweden)

    Ali Al Kaissi MD, MSc

    2017-01-01

    Full Text Available Marked ligamentous hyperlaxity and muscle weakness/wasting associated with awkward gait are the main deficits confused with the diagnosis of myopathy. Seven children (6 boys and 1 girl with an average age of 8 years were referred to our department because of diverse forms of skeletal abnormalities. No definitive diagnosis was made, and all underwent a series of sophisticated investigations in other institutes in favor of myopathy. We applied our methodology through the clinical and radiographic phenotypes followed by targeted genotypic confirmation. Three children (2 boys and 1 girl were compatible with the diagnosis of progressive pseudorheumatoid chondrodysplasia. The genetic mutation was correlated with the WISP 3 gene actively expressed by articular chondrocytes and located on chromosome 6. Klinefelter syndrome was the diagnosis in 2 boys. Karyotyping confirmed 47,XXY (aneuploidy of Klinefelter syndrome. And 2 boys were finally diagnosed with Morquio syndrome (MPS type IV A as both showed missense mutations in the N-acetylgalactosamine-sulfate sulfatase gene. Misdiagnosis can lead to the initiation of a long list of sophisticated investigations.

  3. Skeletal muscle ultrasound.

    NARCIS (Netherlands)

    Pillen, S.; Alfen, N. van

    2011-01-01

    Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. Neuromuscular disorders give rise to structural muscle changes that can be visualized with ultrasound: atrophy can be objectified by measuring muscle thickness, while

  4. Virtual muscle: a computational approach to understanding the effects of muscle properties on motor control.

    Science.gov (United States)

    Cheng, E J; Brown, I E; Loeb, G E

    2000-09-15

    This paper describes a computational approach to modeling the complex mechanical properties of muscles and tendons under physiological conditions of recruitment and kinematics. It is embodied as a software package for use with Matlab and Simulink that allows the creation of realistic musculotendon elements for use in motor control simulations. The software employs graphic user interfaces (GUI) and dynamic data exchange (DDE) to facilitate building custom muscle model blocks and linking them to kinetic analyses of complete musculoskeletal systems. It is scalable in complexity and accuracy. The model is based on recently published data on muscle and tendon properties measured in feline slow- and fast-twitch muscle, and incorporates a novel approach to simulating recruitment and frequency modulation of different fiber-types in mixed muscles. This software is distributed freely over the Internet at http://ami.usc.edu/mddf/virtualmuscle.

  5. Skeletal muscle ultrasound.

    Science.gov (United States)

    Pillen, Sigrid; van Alfen, Nens

    2011-12-01

    Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. Neuromuscular disorders give rise to structural muscle changes that can be visualized with ultrasound: atrophy can be objectified by measuring muscle thickness, while infiltration of fat and fibrous tissue increases muscle echo intensity, i.e. the muscles become whiter on the ultrasound image. Muscle echo intensity needs to be quantified to correct for age-related increase in echo intensity and differences between individual muscles. This can be done by gray scale analysis, a method that can be easily applied in daily clinical practice. Using this technique, it is possible to detect neuromuscular disorders with predictive values of 90%. Only in young children and metabolic myopathies the sensitivity is lower. Ultrasound is a dynamic technique and therefore capable of visualizing normal and pathological muscle movements. Fasciculations can easily be differentiated from other muscle movements. Ultrasound appeared to be even more sensitive in detecting fasciculations compared to Electromyography (EMG) and clinical observations, because it can visualize a large muscle area and deeper located muscles. With improving resolution and frame rate it has recently become clear that also smaller scale spontaneous muscle activity such as fibrillations can be detected by ultrasound. This opens the way to a broader use of muscle ultrasound in the diagnosis of peripheral nerve and muscle disorders.

  6. Skeletal muscle ultrasound

    Directory of Open Access Journals (Sweden)

    Sigrid Pillen

    2010-12-01

    Full Text Available Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. Neuromuscular disorders give rise to structural muscle changes that can be visualized with ultrasound: atrophy can be objectified by measuring muscle thickness, while infiltration of fat and fibrous tissue increase muscle echo intensity, i.e. the muscles become whiter on the ultrasound image. Muscle echo intensity need to be quantified to correct for age-related increase in echo intensity and differences between individual muscles. This can be done by gray scale analysis, a method that can be easily applied in daily clinical practice. Using this technique it is possible to detect neuromuscular disorders with predictive values of 90 percent. Only in young children and metabolic myopathies the sensitivity is lower. Ultrasound is a dynamic technique and therefore capable of visualizing normal and pathological muscle movements. Fasciculations can easily be differentiated from other muscle movements. Ultrasound appeared to be even more sensitive in detecting fasciculations compared to EMG and clinical observations, because it can visualize a large muscle area and deeper located muscles. With improving resolution and frame rate it has recently become clear that also smaller scale spontaneous muscle activity such as fibrillations can be detected by ultrasound. This opens the way to a broader use of muscle ultrasound in the diagnosis of peripheral nerve and muscle disorders.

  7. Cardiac, Skeletal, and smooth muscle mitochondrial respiration

    DEFF Research Database (Denmark)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I

    2014-01-01

    , skeletal, and smooth muscle was harvested from a total of 22 subjects (53±6 yrs) and mitochondrial respiration assessed in permeabilized fibers. Complex I+II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac, skeletal, to smooth muscle (54±1; 39±4; 15......±1 pmol•s(-1)•mg (-1), pindex of mitochondrial density, also fell progressively from cardiac, skeletal, to smooth muscle (222±13; 115±2; 48±2 umol•g(-1)•min(-1), p... per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, Complex I state 2 normalized for CS activity, an index of non-phosphorylating respiration per mitochondrial content, increased progressively from cardiac, skeletal...

  8. [Muscle fiber atrophy].

    Science.gov (United States)

    Nonaka, Ikuya

    2012-01-01

    Muscle fibers have been classified into two major forms of red (slow twitch) and white (fast twitch) muscles. The red muscle utilizes lipid as energy source through mitochondrial metabolism and function to sustain the position against gravity (sometimes called as antigravity muscle). Under microgravity the red muscle is selectively involved. In our unloading study by hindlimb suspension experiment on rats, the one of the representative red muscle of soleus muscle underwent rapid atrophy; they reduced their weights about 50% after 2 week-unloading. In addition, myofibrils were occasionally markedly disorganized with selective thin filament loss. Mitochondria in the degenerated area were decreased in number. The white muscle fibers in the soleus muscle had mostly transformed to the red ones. It took about 1 month to recover morphologically. The satellite cell playing a major role in muscle regeneration was not activated. There still remained unsolved what are the mechanosensors to keep muscle function under normal gravity. Dr Nikawa's group proposed that one of ubiquitin ligases, Cbl-b is activated under microgravity and induces muscle fiber degeneration. There might be many factors to induce muscle atrophy and degeneration under microgravity. Further study is necessary to explore the pathomechanism of muscle atrophy in disused and under immobility conditions.

  9. SYNTHETIC STRANDS OF CARDIAC MUSCLE

    Science.gov (United States)

    Purdy, Joyce E.; Lieberman, Melvyn; Roggeveen, Anne E.; Kirk, R. Gary

    1972-01-01

    Spontaneously active bundles of cardiac muscle (synthetic strands) were prepared from isolated cells of 11–13-day old embryonic chick hearts which were disaggregated with trypsin. Linear orientation of the cells was obtained by plating them on agar-coated culture dishes in which either grooves were cut in the agar film or a thin line of palladium was deposited over the agar. The influence of cell-to-cell and cell-to-substrate interactions was observed with time lapse cinematography and the formation of the synthetic strand was shown to involve both random and guided cell movements, enlargement of aggregates by accretion and coalescence, and the compact linear arrangement of cells along paths of preferential adhesion. Electron microscope investigations of these strands showed that a dispersed population of heart cells organized into an inner core of muscle cells and an outer sheath of fibroblast-like cells. The muscle cells contained well-developed, but widely spaced myofibrils, a developing sarcoplasmic reticulum associated in part with the myofibrils and in part with the sarcolemma, an abundance of nonmembrane bound ribosomes and glycogen, and a prominent Golgi complex. Numerous specialized contacts were observed between the muscle cells in the strand, e.g., fasciae adherentes, desmosomes, and nexuses. A distinct type of muscle cell characterized by its pale appearance was regularly observed in the strand and was noted to be similar to Purkinje cells described in the adult avian conduction system and in developing chick myocardium. The present findings were compared with other observations of the developing myocardium, in situ, and it was concluded that, by a number or criteria, the muscle cells of the strand were differentiating normally and suitably organized for electrophysiological studies. PMID:4656702

  10. [Enzymatic properties in muscle membranes].

    Science.gov (United States)

    Kursky, M D; Grigoryeva, V A

    1975-01-01

    A study in the enzymatic properties of muscle membranes established that sarcolemma of the rabbit skeletal muscles contains the Ca2+-ATPase system which does not require Mg2+ for manifestation of ions activity. By some kinetic properties it differs from ATPase of myosin. The complex Ca-ATP2+ is a substrate of Ca2+-ATPase. Ions of a series of bivalent metals inhibit the latter as well as the passive transport of Ca2+, that may evidence for a definite relation of Ca2+-ATPase with Ca+2 transport in skeletal muscles. Acetyl cholinesterase and AMP-aminohydrolase are strongly bound with the sarcolemma. The sarcolemma structural organization is shown to play a certain role in manifestation of their activity. On the basis of the data obtained when studying the activity in the ATPase systems and dynamics of formation and decay of the intermediate phosphorylated product in the microsomal fraction of cow and rabbit myometrium certain peculiarities are established for the active mechanisms of Ca2+ transport in smooth muscles. A problem is under discussion on the possible active participation of sarcolemma in regulation of Ca2+ concentration in the smooth muscle cells. Two ATPase systems, Mg2+-dependent and Mg2+-dependent Ca2+ activated are found in nuclei; the role of lipids of the skeletal muscles in manifestation of their activity is studied. AMP-amino hydrolase properties are characterized for different areas of the sarcoplasmatic reticulum membranes. The model of E-avitaminous muscular distrophy was used to show disturbances in the structure of sarcolemma and membranes of the sarcoplasmatic reticulum which are accompanied by changes in their ATPase and Ca2+-transporting properties.

  11. Cryopreservation of human skeletal muscle impairs mitochondrial function

    DEFF Research Database (Denmark)

    Larsen, Steen; Wright-Paradis, C; Gnaiger, E

    2012-01-01

    Previous studies have investigated if cryopreservation is a viable approach for functional mitochondrial analysis. Different tissues have been studied, and conflicting results have been published. The aim of the present study was to investigate if mitochondria in human skeletal muscle maintain...... functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity...... of oxidative phosphorylation was significantly (P cryopreserved human skeletal muscle samples. Cryopreservation impaired respiration with substrates linked to Complex I more than for Complex II (P

  12. Eye muscle repair - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100062.htm Eye muscle repair - series—Normal anatomy To use the sharing ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ...

  13. Healthy Muscles Matter

    Science.gov (United States)

    ... jobs A joint showing muscles, ligaments, and tendons. (Representation) Skeletal muscles are connected to your bones by ... food along and push waste out of your body. They also help keep your eyes focused without ...

  14. 3D Finite Element Models of Shoulder Muscles for Computing Lines of Actions and Moment Arms

    Science.gov (United States)

    Webb, Joshua D.; Blemker, Silvia S.; Delp, Scott L.

    2014-01-01

    Accurate representation of musculoskeletal geometry is needed to characterize the function of shoulder muscles. Previous models of shoulder muscles have represented muscle geometry as a collection of line segments, making it difficult to account the large attachment areas, muscle-muscle interactions, and complex muscle fiber trajectories typical of shoulder muscles. To better represent shoulder muscle geometry we developed three-dimensional finite element models of the deltoid and rotator cuff muscles and used the models to examine muscle function. Muscle fiber paths within the muscles were approximated, and moment arms were calculated for two motions: thoracohumeral abduction and internal/external rotation. We found that muscle fiber moment arms varied substantially across each muscle. For example, supraspinatus is considered a weak external rotator, but the three-dimensional model of supraspinatus showed that the anterior fibers provide substantial internal rotation while the posterior fibers act as external rotators. Including the effects of large attachment regions and three-dimensional mechanical interactions of muscle fibers constrains muscle motion, generates more realistic muscle paths, and allows deeper analysis of shoulder muscle function. PMID:22994141

  15. Obturator internus muscle strains

    OpenAIRE

    Byrne, Caoimhe; Alkhayat, Abdullah; O'Neill, Pat; Eustace, Stephen; Kavanagh, Eoin

    2017-01-01

    We report 2 cases of obturator internus muscle strains. The injuries occurred in young male athletes involved in kicking sports. Case 1 details an acute obturator internus muscle strain with associated adductor longus strain. Case 2 details an overuse injury of the bilateral obturator internus muscles. In each case, magnetic resonance imaging played a crucial role in accurate diagnosis.

  16. Obturator internus muscle strains.

    Science.gov (United States)

    Byrne, Caoimhe; Alkhayat, Abdullah; O'Neill, Pat; Eustace, Stephen; Kavanagh, Eoin

    2017-03-01

    We report 2 cases of obturator internus muscle strains. The injuries occurred in young male athletes involved in kicking sports. Case 1 details an acute obturator internus muscle strain with associated adductor longus strain. Case 2 details an overuse injury of the bilateral obturator internus muscles. In each case, magnetic resonance imaging played a crucial role in accurate diagnosis.

  17. Metabolic Diseases of Muscle

    Science.gov (United States)

    ... ing fuel, and no energy is produced for muscle function. 4 Metabolic Diseases of Muscle • ©2011 MDA A ... This slowly progressive disorder causes cardiac disease and muscle weakness in the hips, shoulders, and upper arms and legs. The neck and ...

  18. Obturator internus muscle strains

    Directory of Open Access Journals (Sweden)

    Caoimhe Byrne, MB BCh, BAO

    2017-03-01

    Full Text Available We report 2 cases of obturator internus muscle strains. The injuries occurred in young male athletes involved in kicking sports. Case 1 details an acute obturator internus muscle strain with associated adductor longus strain. Case 2 details an overuse injury of the bilateral obturator internus muscles. In each case, magnetic resonance imaging played a crucial role in accurate diagnosis.

  19. Muscle fibre types of the lumbrical, interossei, flexor, and extensor muscles moving the index finger.

    Science.gov (United States)

    Hwang, Kun; Huan, Fan; Kim, Dae Joong

    2013-09-01

    The aim of this study was to determine the fibre types of the muscles moving the index fingers in humans. Fifteen forearms of eight adult cadavers were used. The sampled muscles were the first lumbrical (LM), first volar interosseous (VI), first dorsal interosseus (DI), second flexor digitorum profundus (FDP), second flexor digitorum superficialis (FDS), and extensor digitorum (ED). Six micrometer thick sections were stained for fast muscle fibres. The procedure was performed by applying mouse monoclonal anti-skeletal myosin antibody (fast) and avidin-biotin peroxidase complex staining. Rectangular areas (0.38 mm × 0.38 mm) were photographed and the boundaries of the muscle areas were marked on the translucent film. The numbers and sizes of the muscle fibres in each part were evaluated by the image analyser program and calculated per unit area (1 mm(2)). The proportion of the fast fibres was significantly (p = 0.012) greater in the intrinsic muscles (55.7 ± 17.1%) than in the extrinsic muscles (45.9 ± 17.1%). Among the six muscles, the VI had a significantly higher portion (59.3%) of fast fibres than the FDS (40.6%) (p = 0.005) or the FDP (45.1%) (p = 0.023). The density of the non-fast fibres was significantly (p = 0.015) greater in the extrinsic muscles (539.2 ± 336.8/mm(2)) than in the intrinsic muscles (383.4 ± 230.4/mm2). Since the non-fast fibres represent less fatigable fibres, it is thought that the extrinsic muscles have higher durability against fatigue, and the intrinsic muscles, including the LM, should move faster than the FDS or FDP because the MP joint should be flexed before the IP joint to grip an object.

  20. The influence of application of complexes of power exercises on indicators of special force of muscles of a shoulder-girdle of sportsmen of the Paralympic national team of Ukraine on cross-country skiing and biathlon during the preparatory period

    Directory of Open Access Journals (Sweden)

    V’yacheslav Mulik

    2015-06-01

    Full Text Available Purpose: the analysis of dynamics of power indicators of Paralympic sportsmen in the preparatory period of a year macrocycle when using complexes of power exercises in the training process which are aimed at the development of muscles of a shoulder-girdle. Material and Methods: members of the national Paralympic team of Ukraine on cross-country skiing and biathlon of two nosology (musculoskeletal device and visual impairment in number of 12 sportsmen (6 men, 6 women took part in the research. The age of sportsmen is 17–29 years old, the sports qualification is CMS (2, MS (4, MSIC (3, and MMS (3. Results: the technique of application of complexes of power exercises of high-speed and power character for muscles of a shoulder-girdle depending on stages of the preparatory period is developed and proved. The results of testing testify to the positive dynamics of indicators, especially at the end of the preparatory period. Conclusions: authors offer the technique of power training of Paralympic sportsmen on the basis of the conducted research, which is based on the use of complexes of special power exercises.

  1. No Muscle Is an Island

    DEFF Research Database (Denmark)

    Kent, Jane A; Ørtenblad, Niels; Hogan, Michael C

    2016-01-01

    Muscle fatigue has been studied with a variety approaches, tools and technologies. The foci of these studies have ranged tremendously, from molecules to the entire organism. Single cell and animal models have been used to gain mechanistic insight into the fatigue process. The theme of this review...... is the concept that the mechanisms of muscle fatigue do not occur in isolation in vivo: muscular work is supported by many complex physiological systems, any of which could fail during exercise and thus contribute to fatigue. To advance our overall understanding of fatigue, a combination of models and approaches...... is necessary. In this review, we examine the roles that neuromuscular properties, intracellular glycogen, oxygen metabolism, and blood flow play in the fatigue process during exercise and pathological conditions....

  2. Muscle glycogenolysis during exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Gavras, H

    1982-01-01

    The interaction of epinephrine and contractions on muscle metabolism was studied in the isolated perfused rat hindquarter. Subtetanic contractions (180/min) through 20 min elicited glycogenolysis and increased phosphorylase a activity. In the soleus, a slow-twitch red muscle, these effects were...... and not significant in the fast-twitch white fibers of the gastrocnemius muscle. However, during less frequent contractions (30/min) epinephrine increased glycogenolysis and phosphorylase a activity in fast-twitch muscle. The data suggest that epinephrine and muscle contractions exert a dual control of muscle...... glycogenolysis during exercise: contractions principally stimulate glycogenolysis early in exercise, and a direct effect of epinephrine on muscle is needed for continued glycogenolysis. In addition, epinephrine increased oxygen consumption and glucose uptake in both resting and electrically stimulated...

  3. Muscle formation during embryogenesis of the polychaete Ophryotrocha diadema (Dorvilleidae – new insights into annelid muscle patterns

    Directory of Open Access Journals (Sweden)

    Paululat Achim

    2008-01-01

    Full Text Available Abstract Background The standard textbook information that annelid musculature consists of oligochaete-like outer circular and inner longitudinal muscle-layers has recently been called into question by observations of a variety of complex muscle systems in numerous polychaete taxa. To clarify the ancestral muscle arrangement in this taxon, we compared myogenetic patterns during embryogenesis of Ophryotrocha diadema with available data on oligochaete and polychaete myogenesis. This work addresses the conflicting views on the ground pattern of annelids, and adds to our knowledge of the evolution of lophotrochozoan taxa. Results Somatic musculature in Ophryotrocha diadema can be classified into the trunk, prostomial/peristomial, and parapodial muscle complexes. The trunk muscles comprise strong bilateral pairs of distinct dorsal and ventral longitudinal strands. The latter are the first to differentiate during myogenesis. They originate within the peristomium and grow posteriorly through the continuous addition of myocytes. Later, the longitudinal muscles also expand anteriorly and form a complex arrangement of prostomial muscles. Four embryonic parapodia differentiate in an anterior-to-posterior progression, significantly contributing to the somatic musculature. Several diagonal and transverse muscles are present dorsally. Some of the latter are situated external to the longitudinal muscles, which implies they are homologous to the circular muscles of oligochaetes. These circular fibers are only weakly developed, and do not appear to form complete muscle circles. Conclusion Comparison of embryonic muscle patterns showed distinct similarities between myogenetic processes in Ophryotrocha diadema and those of oligochaete species, which allows us to relate the diverse adult muscle arrangements of these annelid taxa to each other. These findings provide significant clues for the interpretation of evolutionary changes in annelid musculature.

  4. Skeletal muscle proteomics: current approaches, technical challenges and emerging techniques

    Directory of Open Access Journals (Sweden)

    Ohlendieck Kay

    2011-02-01

    Full Text Available Abstract Background Skeletal muscle fibres represent one of the most abundant cell types in mammals. Their highly specialised contractile and metabolic functions depend on a large number of membrane-associated proteins with very high molecular masses, proteins with extensive posttranslational modifications and components that exist in highly complex supramolecular structures. This makes it extremely difficult to perform conventional biochemical studies of potential changes in protein clusters during physiological adaptations or pathological processes. Results Skeletal muscle proteomics attempts to establish the global identification and biochemical characterisation of all members of the muscle-associated protein complement. A considerable number of proteomic studies have employed large-scale separation techniques, such as high-resolution two-dimensional gel electrophoresis or liquid chromatography, and combined them with mass spectrometry as the method of choice for high-throughput protein identification. Muscle proteomics has been applied to the comprehensive biochemical profiling of developing, maturing and aging muscle, as well as the analysis of contractile tissues undergoing physiological adaptations seen in disuse atrophy, physical exercise and chronic muscle transformation. Biomedical investigations into proteome-wide alterations in skeletal muscle tissues were also used to establish novel biomarker signatures of neuromuscular disorders. Importantly, mass spectrometric studies have confirmed the enormous complexity of posttranslational modifications in skeletal muscle proteins. Conclusions This review critically examines the scientific impact of modern muscle proteomics and discusses its successful application for a better understanding of muscle biology, but also outlines its technical limitations and emerging techniques to establish new biomarker candidates.

  5. Skeletal muscle proteomics: current approaches, technical challenges and emerging techniques

    LENUS (Irish Health Repository)

    Ohlendieck, Kay

    2011-02-01

    Abstract Background Skeletal muscle fibres represent one of the most abundant cell types in mammals. Their highly specialised contractile and metabolic functions depend on a large number of membrane-associated proteins with very high molecular masses, proteins with extensive posttranslational modifications and components that exist in highly complex supramolecular structures. This makes it extremely difficult to perform conventional biochemical studies of potential changes in protein clusters during physiological adaptations or pathological processes. Results Skeletal muscle proteomics attempts to establish the global identification and biochemical characterisation of all members of the muscle-associated protein complement. A considerable number of proteomic studies have employed large-scale separation techniques, such as high-resolution two-dimensional gel electrophoresis or liquid chromatography, and combined them with mass spectrometry as the method of choice for high-throughput protein identification. Muscle proteomics has been applied to the comprehensive biochemical profiling of developing, maturing and aging muscle, as well as the analysis of contractile tissues undergoing physiological adaptations seen in disuse atrophy, physical exercise and chronic muscle transformation. Biomedical investigations into proteome-wide alterations in skeletal muscle tissues were also used to establish novel biomarker signatures of neuromuscular disorders. Importantly, mass spectrometric studies have confirmed the enormous complexity of posttranslational modifications in skeletal muscle proteins. Conclusions This review critically examines the scientific impact of modern muscle proteomics and discusses its successful application for a better understanding of muscle biology, but also outlines its technical limitations and emerging techniques to establish new biomarker candidates.

  6. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    Directory of Open Access Journals (Sweden)

    Matthew Emerson Randolph

    2015-10-01

    Full Text Available The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies, such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some muscular dystrophies. The biology of muscle stem cells varies depending on their embryologic origins and the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease.

  7. Green tea extract attenuates muscle loss and improves muscle function during disuse, but fails to improve muscle recovery following unloading in aged rats

    Science.gov (United States)

    Bennett, Brian T.; Wilson, Joseph C.; Sperringer, Justin; Mohamed, Junaith S.; Edens, Neile K.; Pereira, Suzette L.

    2014-01-01

    In this study we tested the hypothesis that green tea extract (GTE) would improve muscle recovery after reloading following disuse. Aged (32 mo) Fischer 344 Brown Norway rats were randomly assigned to receive either 14 days of hindlimb suspension (HLS) or 14 days of HLS followed by normal ambulatory function for 14 days (recovery). Additional animals served as cage controls. The rats were given GTE (50 mg/kg body wt) or water (vehicle) by gavage 7 days before and throughout the experimental periods. Compared with vehicle treatment, GTE significantly attenuated the loss of hindlimb plantaris muscle mass (−24.8% vs. −10.7%, P muscle function or mass compared with vehicle treatment, animals given green tea via gavage maintained the lower losses of muscle mass that were found during HLS (−25.2% vs. −16.0%, P muscle fiber cross-sectional area loss in both plantaris (−39.9% vs. −23.9%, P muscles after HLS. This green tea-induced difference was not transient but was maintained over the reloading period for plantaris (−45.6% vs. −21.5%, P muscle fiber cross-sectional area (−38.7% vs. −10.9%, P muscles during recovery from HLS compared with vehicle-treated muscles and decreased oxidative stress and abundance of the Bcl-2-associated X protein (Bax), yet this did not further improve muscle recovery in reloaded muscles. These data suggest that muscle recovery following disuse in aging is complex. Although satellite cell proliferation and differentiation are critical for muscle repair to occur, green tea-induced changes in satellite cell number is by itself insufficient to improve muscle recovery following a period of atrophy in old rats. PMID:25414242

  8. Regulatory factors and cell populations involved in skeletal muscle regeneration.

    NARCIS (Netherlands)

    Broek, R.W. Ten; Grefte, S.; Hoff, J.W. von den

    2010-01-01

    Skeletal muscle regeneration is a complex process, which is not yet completely understood. Satellite cells, the skeletal muscle stem cells, become activated after trauma, proliferate, and migrate to the site of injury. Depending on the severity of the myotrauma, activated satellite cells form new

  9. Increased reactive oxygen species production and lower abundance of complex I subunits and carnitine palmitoyltransferase 1B protein despite normal mitochondrial respiration in insulin-resistant human skeletal muscle

    DEFF Research Database (Denmark)

    Lefort, Natalie; Glancy, Brian; Bowen, Benjamin

    2010-01-01

    and palmitoyl-DL-carnitine (both including malate) ROS production were significantly higher in obesity. Mitochondria from obese individuals maintained higher (more negative) extramitochondrial ATP free energy at low metabolic flux, suggesting that stronger mitochondrial thermodynamic driving forces may underlie......OBJECTIVE: The contribution of mitochondrial dysfunction to skeletal muscle insulin resistance remains elusive. Comparative proteomics are being applied to generate new hypotheses in human biology and were applied here to isolated mitochondria to identify novel changes in mitochondrial protein...

  10. Muscle injuries: optimising recovery.

    Science.gov (United States)

    Järvinen, Tero A H; Järvinen, Teppo L N; Kääriäinen, Minna; Aärimaa, Ville; Vaittinen, Samuli; Kalimo, Hannu; Järvinen, Markku

    2007-04-01

    Muscle injuries are one of the most common traumas occurring in sports. Despite their clinical importance, there are only a few clinical studies on the treatment of muscle injuries. Lack of clinical studies is most probably attributable to the fact that there is not only a high heterogeneity in the severity of injuries, but also the injuries take place in different muscles, making it very demanding to carry out clinical trials. Accordingly, the current treatment principles of muscle injuries have either been derived from experimental studies or been tested empirically only. Clinically, first aid for muscle injuries follows the RICE (Rest, Ice, Compression and Elevation) principle. The objective of RICE is to stop the injury-induced bleeding into the muscle tissue and thereby minimise the extent of the injury. Clinical examination should be carried out immediately after the injury and 5-7 days after the initial trauma, at which point the severity of the injury can be assessed more reliably. At that time, a more detailed characterisation of the injury can be made using imaging diagnostic modalities (ultrasound or MRI) if desired. The treatment of injured skeletal muscle should be carried out by immediate immobilisation of the injured muscle (clinically, relative immobility/avoidance of muscle contractions). However, the duration of immobilisation should be limited to a period sufficient to produce a scar of sufficient strength to bear the forces induced by remobilisation without re-rupture and the return to activity (mobilisation) should then be started gradually within the limits of pain. Early return to activity is needed to optimise the regeneration of healing muscle and recovery of the flexibility and strength of the injured skeletal muscle to pre-injury levels. The rehabilitation programme should be built around progressive agility and trunk stabilisation exercises, as these exercises seem to yield better outcome for injured skeletal muscle than programmes based

  11. DRY NEEDLING INCREASES MUSCLE THICKNESS IN A SUBJECT WITH PERSISTENT MUSCLE DYSFUNCTION: A CASE REPORT.

    Science.gov (United States)

    Cross, Kevin M; McMurray, Michael

    2017-06-01

    Muscle dysfunction is very common following musculoskeletal injury. There is very little evidence to suggest that muscle function may be positively impacted by soft tissue interventions, such as dry needling. The purpose of this case report is to describe the immediate effect of dry needling on muscle thickness in a subject after shoulder surgery. A 22 year-old competitive gymnast presented seven months post shoulder surgery with significant impairments and functional limitations. Previous physical therapy focused on restoration of range of motion and strength using general exercise interventions, but the subject had persistent tightness and weakness of musculature of the shoulder complex. A subject-specific physical therapy program including manual physical therapy resulted in significant initial improvement, but lack of flexibility and weakness of the rotator cuff limited progress. Dry needling was used to address persistent myofascial trigger points. Immediately after dry needling the infraspinatus, the muscle's thickness was significantly improved as measured by rehabilitative ultrasound imaging. There was a corresponding increase in force production of external rotation at 90 degrees of abduction. Minimal research exists that validates the potential of dry needling on muscle function, as assessed by muscle thickness measured using rehabilitative ultrasound imaging. The results of this case report suggest that dry needling contributed to improvement in muscle thickness and strength in a subject with muscle dysfunction following an injury. 4.

  12. Muscle Spindles and Locomotor Control-An Unrecognized Falls Determinant?

    Directory of Open Access Journals (Sweden)

    Marks Ray

    2015-10-01

    Full Text Available BACKGROUND: Historically, evidence muscle spindles might be involved in locomotion was provided by their presence in tetrapod antigravity muscles associated with posture and locomotion. Later, Brodal (1962 noted muscle spindles in all muscles of locomotion. To unravel the complexity of the muscle spindle and its role in human locomotor control many investigators have since conducted lesion and/or anaesthesia studies in subhuman species and human contexts. QUESTIONS: How strong is the evidence linking muscle spindles to normal human locomotion and its control? Can a case be made for an association between muscle spindle dysfunction and falls injuries? METHODS: All relevant publications in the leading electronic databases were searched using the key terms muscle afferents, falls, gait, locomotion, muscle spindles. There were numerous related listings, but here only selected reports are examined and discussed because the articles had to be linked in some way to the key question driving the research. RESULTS: Evidence supports a key role for muscle spindles in the control of human locomotion, and by analogy to falls related injuries. CONCLUSION: Future work to explore the role of muscle spindles in the context of falls that occur when walking is warranted.

  13. Proteomics of Skeletal Muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul S

    2016-01-01

    Skeletal muscle is the largest tissue in the human body and plays an important role in locomotion and whole body metabolism. It accounts for ~80% of insulin stimulated glucose disposal. Skeletal muscle insulin resistance, a primary feature of Type 2 diabetes, is caused by a decreased ability...... of muscle to respond to circulating insulin. Physical exercise improves insulin sensitivity and whole body metabolism and remains one of the most promising interventions for the prevention of Type 2 diabetes. Insulin resistance and exercise adaptations in skeletal muscle might be a cause, or consequence......, of altered protein expressions profiles and/or their posttranslational modifications (PTMs). Mass spectrometry (MS)-based proteomics offer enormous promise for investigating the molecular mechanisms underlying skeletal muscle insulin resistance and exercise-induced adaptation; however, skeletal muscle...

  14. Return to play after thigh muscle injury in elite football players: implementation and validation of the Munich muscle injury classification

    Science.gov (United States)

    Ekstrand, Jan; Askling, Carl; Magnusson, Henrik; Mithoefer, Kai

    2013-01-01

    Background Owing to the complexity and heterogeneity of muscle injuries, a generally accepted classification system is still lacking. Aims To prospectively implement and validate a novel muscle injury classification and to evaluate its predictive value for return to professional football. Methods The recently described Munich muscle injury classification was prospectively evaluated in 31 European professional male football teams during the 2011/2012 season. Thigh muscle injury types were recorded by team medical staff and correlated to individual player exposure and resultant time-loss. Results In total, 393 thigh muscle injuries occurred. The muscle classification system was well received with a 100% response rate. Two-thirds of thigh muscle injuries were classified as structural and were associated with longer lay-off times compared to functional muscle disorders (pinjuries) with increasing lay-off time associated with more severe structural injury. Median lay-off time of functional disorders was 5–8 days without significant differences between subgroups. There was no significant difference in the absence time between anterior and posterior thigh injuries. Conclusions The Munich muscle classification demonstrates a positive prognostic validity for return to play after thigh muscle injury in professional male football players. Structural injuries are associated with longer average lay-off times than functional muscle disorders. Subclassification of structural injuries correlates with return to play, while subgrouping of functional disorders shows less prognostic relevance. Functional disorders are often underestimated clinically and require further systematic study. PMID:23645834

  15. Accessory piriformis muscle

    Directory of Open Access Journals (Sweden)

    Sedat Develi

    2017-03-01

    Full Text Available Piriformis muscle originates from facies pelvica of sacrum and inserts on the trochanter major. It is one of the lateral rotator muscles of the hip and a landmark point in the gluteal region since n. ischiadicus descends to the thigh by passing close to the muscle. This contiguity may be associated with the irritation of the nerve which is known as piriformis syndrome. A rare anatomic variation of the muscle which observed on 74 years old male cadaver is discussed in this case report. [Cukurova Med J 2017; 42(1.000: 182-183

  16. MUSCLE INJURIES IN ATHLETES.

    Science.gov (United States)

    Barroso, Guilherme Campos; Thiele, Edilson Schwansee

    2011-01-01

    This article had the aim of demonstrating the physiology, diagnosis and treatment of muscle injuries, focusing on athletes and their demands and expectations. Muscle injuries are among the most common complaints in orthopedic practice, occurring both among athletes and among non-athletes. These injuries present a challenge for specialists, due to the slow recovery, during which time athletes are unable to take part in training and competitions, and due to frequent sequelae and recurrences of the injuries. Most muscle injuries (between 10% and 55% of all injuries) occur during sports activities. The muscles most commonly affected are the ischiotibial, quadriceps and gastrocnemius. These muscles go across two joints and are more subject to acceleration and deceleration forces. The treatment for muscle injuries varies from conservative treatment to surgery. New procedures are being used, like the hyperbaric chamber and the use of growth factors. However, there is still a high rate of injury recurrence. Muscle injury continues to be a topic of much controversy. New treatments are being researched and developed, but prevention through muscle strengthening, stretching exercises and muscle balance continues to be the best "treatment".

  17. Anatomy, function, and rehabilitation of the popliteus musculotendinous complex

    National Research Council Canada - National Science Library

    Nyland, John; Lachman, Narusha; Kocabey, Yavuz; Brosky, Joseph; Altun, Remziye; Caborn, David

    2005-01-01

    We present a clinical commentary of existing evidence regarding popliteus musculotendinous complex anatomy, biomechanics, muscle activation, and kinesthesia as they relate to functional knee joint rehabilitation...

  18. Skeletal muscle development and regeneration.

    NARCIS (Netherlands)

    Grefte, S.; Kuijpers-Jagtman, A.M.; Torensma, R.; Hoff, J.W. Von den

    2007-01-01

    In the late stages of muscle development, a unique cell population emerges that is a key player in postnatal muscle growth and muscle regeneration. The location of these cells next to the muscle fibers triggers their designation as satellite cells. During the healing of injured muscle tissue,

  19. Lectins binding during alloxan-induced diabetes in rat soleus muscle

    African Journals Online (AJOL)

    Membrane structural changes of soleus muscle of alloxan-diabetic rats were detected with a panel of six biotinylated lectins. Samples of muscles were obtained from normal and diabetic rats. The biotinylated lectins in staining were detected by avidin-peroxidase complex. Lectin stainning of soleus muscle cryostat sections ...

  20. Interstitial Cells: Regulators of Smooth Muscle Function

    Science.gov (United States)

    Sanders, Kenton M.; Ward, Sean M.; Koh, Sang Don

    2014-01-01

    Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα+ cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα+ cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues. PMID:24987007

  1. Ischemia causes muscle fatigue

    Science.gov (United States)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D. M.

    2001-01-01

    The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 +/- 9.8 mm Hg) and systolic (106 +/- 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3-5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 +/- 1.2% (SEM), 96 +/- 1.9%, 93 +/- 2.8%, 90 +/- 2.5%, and 86 +/- 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 +/- 0.7% (SEM), 96 +/- 2.7%, 93 +/- 3.1%, 88 +/- 3.2%, and 86 +/- 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P muscle oxygenation (r = 0.78, P muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue.

  2. Exercise, GLUT4, and Skeletal Muscle Glucose Uptake

    DEFF Research Database (Denmark)

    Richter, Erik; Hargreaves, Mark

    2013-01-01

    Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon...... muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions....... Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose...

  3. Development and evolution of the muscles of the pelvic fin.

    Directory of Open Access Journals (Sweden)

    Nicholas J Cole

    2011-10-01

    Full Text Available Locomotor strategies in terrestrial tetrapods have evolved from the utilisation of sinusoidal contractions of axial musculature, evident in ancestral fish species, to the reliance on powerful and complex limb muscles to provide propulsive force. Within tetrapods, a hindlimb-dominant locomotor strategy predominates, and its evolution is considered critical for the evident success of the tetrapod transition onto land. Here, we determine the developmental mechanisms of pelvic fin muscle formation in living fish species at critical points within the vertebrate phylogeny and reveal a stepwise modification from a primitive to a more derived mode of pelvic fin muscle formation. A distinct process generates pelvic fin muscle in bony fishes that incorporates both primitive and derived characteristics of vertebrate appendicular muscle formation. We propose that the adoption of the fully derived mode of hindlimb muscle formation from this bimodal character state is an evolutionary innovation that was critical to the success of the tetrapod transition.

  4. Multifunctional and context-dependent control of vocal acoustics by individual muscles

    DEFF Research Database (Denmark)

    Srivastava, Kyle H; Elemans, Coen P H; Sober, Samuel J

    2015-01-01

    The relationship between muscle activity and behavioral output determines how the brain controls and modifies complex skills. In vocal control, ensembles of muscles are used to precisely tune single acoustic parameters such as fundamental frequency and sound amplitude. If individual vocal muscles...... were dedicated to the control of single parameters, then the brain could control each parameter independently by modulating the appropriate muscle or muscles. Alternatively, if each muscle influenced multiple parameters, a more complex control strategy would be required to selectively modulate a single...... parameter. Additionally, it is unknown whether the function of single muscles is fixed or varies across different vocal gestures. A fixed relationship would allow the brain to use the same changes in muscle activation to, for example, increase the fundamental frequency of different vocal gestures, whereas...

  5. Respiratory muscle strenght and functional capacity in fibromyalgia

    Directory of Open Access Journals (Sweden)

    Fernanda Pesce de Souza

    2015-12-01

    Full Text Available Background: Fibromyalgia (FM is a complex syndrome with skeletal muscle impairment. However, respiratory muscles responses are unknown. Purpose: we aimed to study strength resistance in both respiratory and skeletal muscles in FM and healthy controls. Methods: fifteen women with FM - FG group - (50 ± 11 years and 10 healthy controls - CG - (48 ± 11 years underwent clinical evaluation, skeletal muscle strength and resistance tests, respiratory tests, six-minute walk test and step test. Results: both groups were similar in demographic and anthropometric variables. Respiratory muscle strength was significantly lower in FG (46 ± 6 cm HO compared to CG (80 ± 8 cm HO; p < 0.05. Similarly, 22 skeletal muscle (71 ± 8 vs 167 ± 24 repetitions, p < 0.05 and respiratory muscle strength (29 ± 4 vs 56 ± 6 repetitions, p < 0.05 were lower in FG compared to CG. Moreover, CG showed greater distance on 6 - minute walk test (551 ± 36 vs 460 ± 86 m; p < 0.05 and higher number of steps (102 ± 9 vs 76 ± 13 steps; p < 0.05. Only FG showed significantly correlation between skeletal muscle and respiratory muscle strength (r = 0.64; p < 0.001. Conclusion: FM syndrome showed an impairment in both respiratory muscle strength and resistance, which could impair exercise tolerance in these patients.

  6. Muscle contraction and force

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Risbo, Jens; Pierzynowski, Stefan G.

    2008-01-01

    Muscle contraction studies often focus solely on myofibres and the proteins known to be involved in the processes of sarcomere shortening and cross-bridge cycling, but skeletal muscle also comprises a very elaborate ancillary network of capillaries, which not only play a vital role in terms of nu...... contributor to force transfer within muscular tissue....

  7. Muscles, exercise and obesity

    DEFF Research Database (Denmark)

    Pedersen, Bente K; Febbraio, Mark A

    2012-01-01

    During the past decade, skeletal muscle has been identified as a secretory organ. Accordingly, we have suggested that cytokines and other peptides that are produced, expressed and released by muscle fibres and exert either autocrine, paracrine or endocrine effects should be classified as myokines...

  8. Muscle phosphorylase kinase deficiency

    DEFF Research Database (Denmark)

    Preisler, N; Orngreen, M C; Echaniz-Laguna, A

    2012-01-01

    To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD).......To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD)....

  9. Enzymes and muscle diseases

    Directory of Open Access Journals (Sweden)

    M. Plebani

    2011-09-01

    Full Text Available Skeletal muscle disorders may result in release of muscle enzymes into the circulation and give increased serum enzyme activity. A variety of enzymes routinely determined in the clinical laboratory may be elevated, but creatine kinase is the enzyme present in the highest concentration in muscle, and in every variety of muscle disease is the serum enzyme which shows the greatest incidence and degree of elevation. Aspartate aminotransferase is the enzyme associated most significantly with inflammation. A diagnostic algorithm based on the combined measurement of creatine kinase, aspartate aminotransferase and aldolase has been found to discriminate muscular distrophies from polymyositis and other myopathies. This combination of laboratory tests has diagnostic application and thus allows the clinician to better select patients who need to have a skeletal muscle biopsy as a diagnostic procedure.

  10. Muscle tissue changes with aging

    OpenAIRE

    Pereira, Ana de Fátima; A. J. Silva; Costa, A.M.; Monteiro, A.M.; Bastos, Estela Maria; Marques, M.C.

    2013-01-01

    Sarcopenia is characterized by a progressive generalized decrease of skeletal muscle mass, strength and function with aging. Recent- ly, the genetic determination has been associated with muscle mass and muscle strength in elderly. These two phenotypes of risk are the most commonly recognized and studied for sarcopenia, with heritability ranging from 30 to 85% for muscle strength and 45-90% for muscle mass. It is well known that the development and maintenance of muscle mass in ear...

  11. Computer-aided mechanogenesis of skeletal muscle organs from single cells in vitro

    Science.gov (United States)

    Vanderburgh, Herman H.; Swasdison, Somporn; Karlisch, Patricia

    1991-01-01

    Complex mechanical forces generated in the growing embryo play an important role in organogenesis. Computerized application of similar forces to differentiating skeletal muscle myoblasts in vitro generate three dimensional artificial muscle organs. These organs contain parallel networks of long unbranched myofibers organized into fascicle-like structures. Tendon development is initiated and the muscles are capable of performing directed, functional work. Kinetically engineered organs provide a new method for studying the growth and development of normal and diseased skeletal muscle.

  12. Computer aided mechanogenesis of skeletal muscle organs from single cells in vitro

    Science.gov (United States)

    Vandenburgh, Herman H.; Swasdison, Somporn; Karlisch, Patricia

    1990-01-01

    Complex mechanical forces generated in the growing embryo play an important role in organogenesis. Computerized application of similar forces to differentiating skeletal muscle myoblasts in vitro generate three dimensional artificial muscle organs. These organs contain parallel networks of long unbranched myofibers organized into fascicle-like structures. Tendon development is initiated and the muscles are capable of performing directed, functional work. Kinetically engineered organs provide a new method for studying the growth and development of normal and diseased skeletal muscle.

  13. Structural correlates of speed and endurance in skeletal muscle: the rattlesnake tailshaker muscle

    Science.gov (United States)

    Schaeffer; Conley; Lindstedt

    1996-01-01

    The western diamondback rattlesnake Crotalus atrox can rattle its tail continuously for hours at frequencies approaching 90 Hz. We examined the basis of these fast sustainable contractions using electromyography, data on oxygen uptake and the quantitative ultrastructure of the tailshaker muscle complex. The tailshaker muscle has no apparent unique structures; rather, the relative proportions of the structures common to all skeletal muscles appear to be present (1) to minimize activation, contraction and relaxation times via an extremely high volume density of sarcoplasmic reticulum (26 %) as well as, (2) to maximize ATP resysnthesis via a high volume density of mitochondria (26 %). The high rate of ATP supply is reflected in the in vivo muscle mass-specific oxygen uptake of this group of muscles which, at 585 ml O2 kg-1 min-1 during rattling at 30 °C body temperature, exceeds that reported for other ectotherm and many endotherm muscles. Since the change in oxygen uptake paralleled that of the rattling frequency over the range of measured body temperatures, there was a nearly constant O2 cost per muscle contraction (0.139±0.016 µl O2 g-1). Electromyo-graphic analysis suggests that each of the six muscles that make up the shaker complex may be a single motor unit. Finally, the maximum rate of mitochondrial oxygen uptake is similar to that of various mammals, a hummingbird, a lizard, an anuran amphibian and of isolated mitochondria (at 10 000-40 000 molecules O2 s-1 µm2 of cristae surface area, when normalized to 30 °C), suggesting a shared principle of design of the inner mitochondrial membrane among the vertebrates.

  14. PTRH2 gene mutation causes progressive congenital skeletal muscle pathology.

    Science.gov (United States)

    Doe, Jinger; Kaindl, Angela M; Jijiwa, Mayumi; de la Vega, Michelle; Hu, Hao; Griffiths, Genevieve S; Fontelonga, Tatiana M; Barraza, Pamela; Cruz, Vivian; Van Ry, Pam; Ramos, Joe W; Burkin, Dean J; Matter, Michelle L

    2017-04-15

    Peptidyl-tRNA hydrolase 2 (PTRH2) regulates integrin-mediated pro-survival and apoptotic signaling. PTRH2 is critical in muscle development and regulates myogenic differentiation. In humans a biallelic mutation in the PTRH2 gene causes infantile-onset multisystem disease with progressive muscle weakness. We report here that the Ptrh2 knockout mouse model recapitulates the progressive congenital muscle pathology observed in patients. Ptrh2 null mice demonstrate multiple degenerating and regenerating muscle fibers, increased central nuclei, elevated creatine kinase activity and endomysial fibrosis. This progressive muscle pathology resembles the muscular dystrophy phenotype in humans and mice lacking the α7 integrin. We demonstrate that in normal muscle Ptrh2 associates in a complex with the α7β1 integrin at the sarcolemma and Ptrh2 expression is decreased in α7 integrin null muscle. Furthermore, Ptrh2 expression is altered in skeletal muscle of classical congenital muscular dystrophy mouse models. Ptrh2 levels were up-regulated in dystrophin deficient mdx muscle, which correlates with the elevated levels of the α7β1 integrin observed in mdx muscle and Duchenne muscular dystrophy patients. Similar to the α7 integrin, Ptrh2 expression was decreased in laminin-α2 dyW null gastrocnemius muscle. Our data establishes a PTRH2 mutation as a novel driver of congenital muscle degeneration and identifies a potential novel target to treat muscle myopathies. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. mTORC1 and the regulation of skeletal muscle anabolism and mass.

    Science.gov (United States)

    Adegoke, Olasunkanmi A J; Abdullahi, Abdikarim; Tavajohi-Fini, Pegah

    2012-06-01

    The mass and integrity of skeletal muscle is vital to whole-body substrate metabolism and health. Indeed, defects in muscle metabolism and functions underlie or exacerbate diseases like diabetes, rheumatoid arthritis, and cancer. Physical activity and nutrition are the 2 most important environmental factors that can affect muscle health. At the molecular level, the mammalian target of rapamycin complex 1 (mTORC1) is a critical signalling complex that regulates muscle mass. In response to nutrition and resistance exercise, increased muscle mass and activation of mTORC1 occur in parallel. In this review, we summarize recent findings on mTORC1 and its regulation in skeletal muscle in response to resistance exercise, alone or in combination with intake of protein or amino acids. Because increased activity of the complex is implicated in the development of muscle insulin resistance, obesity, and some cancers (e.g., ovarian, breast), drugs that target mTORC1 are being developed or are in clinical trials. However, various cancers are associated with extensive muscle wasting, due in part to tumour burden and malnutrition. This muscle wasting may also be a side effect of anticancer drugs. Because loss of muscle mass is associated not only with metabolic abnormalities but also dose limiting toxicity, we review the possible implications for skeletal muscle of long-term inhibition of mTORC1, especially in muscle wasting conditions.

  16. Muscle biopsies from human muscle diseases with myopathic pathology reveal common alterations in mitochondrial function.

    Science.gov (United States)

    Sunitha, Balaraju; Gayathri, Narayanappa; Kumar, Manish; Keshava Prasad, Thottethodi Subrahmanya; Nalini, Atchayaram; Padmanabhan, Balasundaram; Srinivas Bharath, Muchukunte Mukunda

    2016-07-01

    Muscle diseases are clinically and genetically heterogeneous and manifest as dystrophic, inflammatory and myopathic pathologies, among others. Our previous study on the cardiotoxin mouse model of myodegeneration and inflammation linked muscle pathology with mitochondrial damage and oxidative stress. In this study, we investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from muscle disease patients, represented by dysferlinopathy (dysfy) (dystrophic pathology; n = 43), polymyositis (PM) (inflammatory pathology; n = 24), and distal myopathy with rimmed vacuoles (DMRV) (distal myopathy; n = 31) were analyzed. Mitochondrial damage (ragged blue and COX-deficient fibers) was revealed in dysfy, PM, and DMRV cases by enzyme histochemistry (SDH and COX-SDH), electron microscopy (vacuolation and altered cristae) and biochemical assays (significantly increased ADP/ATP ratio). Proteomic analysis of muscle mitochondria from all three muscle diseases by isobaric tag for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated down-regulation of electron transport chain (ETC) complex subunits, assembly factors and Krebs cycle enzymes. Interestingly, 80 of the under-expressed proteins were common among the three pathologies. Assay of ETC and Krebs cycle enzyme activities validated the MS data. Mitochondrial proteins from muscle pathologies also displayed higher tryptophan (Trp) oxidation and the same was corroborated in the cardiotoxin model. Molecular modeling predicted Trp oxidation to alter the local structure of mitochondrial proteins. Our data highlight mitochondrial alterations in muscle pathologies, represented by morphological changes, altered mitochondrial proteome and protein oxidation, thereby establishing the role of mitochondrial damage in human muscle diseases. We investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies

  17. Structure and function of human muscle fibres and muscle proteome in physically active older men.

    Science.gov (United States)

    Brocca, Lorenza; McPhee, Jamie S; Longa, Emanuela; Canepari, Monica; Seynnes, Olivier; De Vito, Giuseppe; Pellegrino, Maria Antonietta; Narici, Marco; Bottinelli, Roberto

    2017-07-15

    Loss of muscle mass and strength in the growing population of elderly people is a major health concern for modern societies. This condition, termed sarcopenia, is a major cause of falls and of the subsequent increase in morbidity and mortality. Despite numerous studies on the impact of ageing on individual muscle fibres, the contribution of single muscle fibre adaptations to ageing-induced atrophy and functional impairment is still unsettled. The level of physical function and disuse is often associated with ageing. We studied relatively healthy older adults in order to understand the effects of ageing per se without the confounding impact of impaired physical function. We found that in healthy ageing, structural and functional alterations of muscle fibres occur. Protein post-translational modifications, oxidation and phosphorylation contribute to such alterations more than loss of myosin and other muscle protein content. Contradictory results have been reported on the impact of ageing on structure and functions of skeletal muscle fibres, likely to be due to a complex interplay between ageing and other phenomena such as disuse and diseases. Here we recruited healthy, physically and socially active young (YO) and elderly (EL) men in order to study ageing per se without the confounding effects of impaired physical function. In vivo analyses of quadriceps and in vitro analyses of vastus lateralis muscle biopsies were performed. In EL subjects, our results show that (i) quadriceps volume, maximum voluntary contraction isometric torque and patellar tendon force were significantly lower; (ii) muscle fibres went through significant atrophy and impairment of specific force (isometric force/cross-sectional area) and unloaded shortening velocity; (iii) myosin/actin ratio and myosin content in individual muscle fibres were not altered; (iv) the muscle proteome went through quantitative adaptations, namely an up-regulation of the content of several groups of proteins among

  18. Noncontrast skeletal muscle oximetry.

    Science.gov (United States)

    Zheng, Jie; An, Hongyu; Coggan, Andrew R; Zhang, Xiaodong; Bashir, Adil; Muccigrosso, David; Peterson, Linda R; Gropler, Robert J

    2014-01-01

    The objective of this study was to develop a new noncontrast method to directly quantify regional skeletal muscle oxygenation. The feasibility of the method was examined in five healthy volunteers using a 3 T clinical MRI scanner, at rest and during a sustained isometric contraction. The perfusion of skeletal muscle of the calf was measured using an arterial spin labeling method, whereas the oxygen extraction fraction of the muscle was measured using a susceptibility-based MRI technique. In all volunteers, the perfusion in soleus muscle increased significantly from 6.5 ± 2.0 mL (100 g min)(-1) at rest to 47.9 ± 7.7 mL (100 g min)(-1) during exercise (P oxygen extraction fraction did not change significantly, the rate of oxygen consumption increased from 0.43 ± 0.13 to 4.2 ± 1.5 mL (100 g min)(-1) (P muscle but with greater oxygen extraction fraction increase than the soleus muscle. This is the first MR oximetry developed for quantification of regional skeletal muscle oxygenation. A broad range of medical conditions could benefit from these techniques, including cardiology, gerontology, kinesiology, and physical therapy. Copyright © 2013 Wiley Periodicals, Inc.

  19. Muscle Bioenergetic Considerations for Intrinsic Laryngeal Skeletal Muscle Physiology

    Science.gov (United States)

    Sandage, Mary J.; Smith, Audrey G.

    2017-01-01

    Purpose: Intrinsic laryngeal skeletal muscle bioenergetics, the means by which muscles produce fuel for muscle metabolism, is an understudied aspect of laryngeal physiology with direct implications for voice habilitation and rehabilitation. The purpose of this review is to describe bioenergetic pathways identified in limb skeletal muscle and…

  20. Exercise and Amino Acid Anabolic Cell Signaling and the Regulation of Skeletal Muscle Mass

    OpenAIRE

    Pasiakos, Stefan M.

    2012-01-01

    A series of complex intracellular networks influence the regulation of skeletal muscle protein turnover. In recent years, studies have examined how cellular regulators of muscle protein turnover modulate metabolic mechanisms contributing to the loss, gain, or conservation of skeletal muscle mass. Exercise and amino acids both stimulate anabolic signaling potentially through several intracellular pathways including the mammalian target of rapamycin complex 1 and the mitogen activated protein k...

  1. Postural sway under muscle vibration and muscle fatigue in humans.

    Science.gov (United States)

    Vuillerme, Nicolas; Danion, Frédéric; Forestier, Nicolas; Nougier, Vincent

    2002-11-22

    Separate studies have demonstrated that vibration and fatigue of ankle muscles alter postural control. The purpose of the present experiment was to investigate the effect of ankle muscle vibration on the regulation of postural sway in bipedal stance following ankle muscle fatigue. Center of foot pressure displacements were recorded using a force platform. Results showed a similar increase in postural sway under muscle fatigue as well as under muscle vibration. Interestingly, under muscle fatigue muscle vibration did not induce a further increase in postural sway. Two hypotheses could, at least, account for this observation: (1). fatigued muscles are less sensitive to muscle vibration and (2). the central nervous system relies less upon proprioceptive information originating from fatigued muscles for regulating postural sway.

  2. Sarcoglycan subcomplex in normal and pathological human muscle fibers.

    Science.gov (United States)

    Anastasi, G; Cutroneo, G; Rizzo, G; Favaloro, A

    2007-01-01

    Sarcoglycans are a sub-complex of transmembrane proteins which are part of the dystrophin-glycoprotein complex (DGC). They are expressed above all in the skeletal, cardiac and smooth muscle. Although numerous studies have been conducted on the sarcoglycan sub-complex in skeletal and cardiac muscle, the manner of distribution and localization of these proteins along the non-junctional sarcolemma is still not clear. Furthermore, there are unclear data about the actual role of sarcoglycans in human skeletal muscle affected by sarcoglycanopathies. In our studies on human skeletal muscle, normal and pathological, we determined the localization, distribution and interaction of these glycoproteins. Our results, on normal human skeletal muscle, showed that the sarcoglycans can be localized both in the region of the sarcolemma over the I band and over the A band, hypothesizing a correlation between regions of the sarcolemma occupied by costameres and the metabolic type of the fibers (slow and fast). Our data on skeletal muscle affected by sarcoglycanopathy confirmed the hypothesis of a bidirectional signaling between sarcoglycans and integrins and the interaction of filamin2 with both sarcoglycans and integrins. In addition, we have recently demonstrated, in smooth muscle, the presence of alpha-SG, in contrast with data of other Authors. Finally, we analyzed the association between contractile activity and quantitative correlation between alpha- and epsilon-SG, in order to better define the arrangement of sarcoglycan subcomplex.

  3. Surface electromyography pattern of human swallowing

    Directory of Open Access Journals (Sweden)

    Spadaro Alessandro

    2008-03-01

    Full Text Available Abstract Background The physiology of swallowing is characterized by a complex and coordinated activation of many stomatognathic, pharyngeal, and laryngeal muscles. Kinetics and electromyographic studies have widely investigated the pharyngeal and laryngeal pattern of deglutition in order to point out the differences between normal and dysphagic people. In the dental field, muscular activation during swallowing is believed to be the cause of malocclusion. Despite the clinical importance given to spontaneous swallowing, few physiologic works have studied stomatognathic muscular activation and mandibular movement during spontaneous saliva swallowing. The aim of our study was to investigate the activity patterns of the mandibular elevator muscles (masseter and anterior temporalis muscles, the submental muscles, and the neck muscles (sternocleidomastoid muscles in healthy people during spontaneous swallowing of saliva and to relate the muscular activities to mandibular movement. Methods The spontaneous swallowing of saliva of 111 healthy individuals was analyzed using surface electromyography (SEMG and a computerized kinesiography of mandibular movement. Results Fifty-seven of 111 patients swallowed without occlusal contact (SNOC and 54 individuals had occlusal contact (SOC. The sternocleidomastoid muscles showed a slight, but constant activation during swallowing. The SEMG of the submental and sternocleidomastoid muscles showed no differences between the two groups. The SEMG of the anterior temporalis and masseter muscles showed significant differences (p Conclusion The data suggest that there is not a single "normal" or "typical" pattern for spontaneous saliva swallowing. The polygraph seemed a valuable, simple, non-invasive and reliable tool to study the physiology of swallowing.

  4. Type VI collagen turnover-related peptides—novel serological biomarkers of muscle mass and anabolic response to loading in young men

    DEFF Research Database (Denmark)

    Nedergaard, Anders; Sun, Shu; Karsdal, Morten A

    2013-01-01

    Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflec...

  5. Exercise, GLUT4, and skeletal muscle glucose uptake.

    Science.gov (United States)

    Richter, Erik A; Hargreaves, Mark

    2013-07-01

    Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions. Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose uptake relies on GLUT4 translocation, glucose uptake also depends on muscle GLUT4 expression which is increased following exercise. AMPK and CaMKII are key signaling kinases that appear to regulate GLUT4 expression via the HDAC4/5-MEF2 axis and MEF2-GEF interactions resulting in nuclear export of HDAC4/5 in turn leading to histone hyperacetylation on the GLUT4 promoter and increased GLUT4 transcription. Exercise training is the most potent stimulus to increase skeletal muscle GLUT4 expression, an effect that may partly contribute to improved insulin action and glucose disposal and enhanced muscle glycogen storage following exercise training in health and disease.

  6. Skeletal muscle tissue engineering

    National Research Council Canada - National Science Library

    Bach, A. D; Beier, J. P; Stern‐Staeter, J; Horch, R. E

    2004-01-01

    The reconstruction of skeletal muscle tissue either lost by traumatic injury or tumor ablation or functional damage due to myopathies is hampered by the lack of availability of functional substitution...

  7. Muscle dysmorphia: current insights

    National Research Council Canada - National Science Library

    Tod, David; Edwards, Christian; Cranswick, Ieuan

    2016-01-01

    Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people's beliefs that they have insufficient muscularity, in both the Western and non-Western...

  8. Human airway smooth muscle

    NARCIS (Netherlands)

    J.C. de Jongste (Johan)

    1987-01-01

    textabstractThe function of airway smooth muscle in normal subjects is not evident. Possible physiological roles include maintenance of optimal regional ventilation/perfusion ratios, reduction of anatomic dead space, stabilisation of cartilaginous bronchi, defense against impurities and, less

  9. Muscle function loss

    Science.gov (United States)

    ... myelopathy), or brain damage ( stroke or other brain injury) The loss of muscle function after these types of events can be ... Periodic paralysis Focal nerve injury Polio Spinal cord injury Stroke

  10. On the thermodynamics of smooth muscle contraction

    Science.gov (United States)

    Stålhand, Jonas; McMeeking, Robert M.; Holzapfel, Gerhard A.

    2016-09-01

    Cell function is based on many dynamically complex networks of interacting biochemical reactions. Enzymes may increase the rate of only those reactions that are thermodynamically consistent. In this paper we specifically treat the contraction of smooth muscle cells from the continuum thermodynamics point of view by considering them as an open system where matter passes through the cell membrane. We systematically set up a well-known four-state kinetic model for the cross-bridge interaction of actin and myosin in smooth muscle, where the transition between each state is driven by forward and reverse reactions. Chemical, mechanical and energy balance laws are provided in local forms, while energy balance is also formulated in the more convenient temperature form. We derive the local (non-negative) production of entropy from which we deduce the reduced entropy inequality and the constitutive equations for the first Piola-Kirchhoff stress tensor, the heat flux, the ion and molecular flux and the entropy. One example for smooth muscle contraction is analyzed in more detail in order to provide orientation within the established general thermodynamic framework. In particular the stress evolution, heat generation, muscle shorting rate and a condition for muscle cooling are derived.

  11. Human airway smooth muscle

    OpenAIRE

    Jongste, Johan

    1987-01-01

    textabstractThe function of airway smooth muscle in normal subjects is not evident. Possible physiological roles include maintenance of optimal regional ventilation/perfusion ratios, reduction of anatomic dead space, stabilisation of cartilaginous bronchi, defense against impurities and, less likely, squeezing mucus out of mucous glands and pulling open the alveoli next to the airways1 . Any role of airway smooth muscle is necessarily limited, because an important degree of contraction will l...

  12. An invertebrate smooth muscle with striated muscle myosin filaments

    Science.gov (United States)

    Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger

    2015-01-01

    Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components. PMID:26443857

  13. PDH regulation in skeletal muscle

    DEFF Research Database (Denmark)

    Kiilerich, Kristian

    regulation in human skeletal muscle. 2: Effect of muscle glycogen on PDH regulation in human skeletal muscle at rest and during exercise. 3: The impact of physical inactivity on PDH regulation in human skeletal muscle at rest and during exercise. 4: Elucidating the importance of PGC-1? in PDH regulation...... in mouse skeletal muscle at rest and in response to fasting and during recovery from exercise. The studies indicate that the content of PDH-E1? in human muscle follows the metabolic profile of the muscle, rather than the myosin heavy chain fiber distribution of the muscle. The larger lactate accumulation...... in human skeletal muscle. It may be noted that the increased PDK4 protein associated with elevated plasma FFA occurs already 2 hours after different dietary intake. A week of physical inactivity (bed rest), leading to whole body glucose intolerance, does not affect muscle PDH-E1? content, or the exercise...

  14. Live imaging of muscle histolysis in Drosophila metamorphosis.

    Science.gov (United States)

    Kuleesha, Yadav; Puah, Wee Choo; Wasser, Martin

    2016-05-04

    The contribution of programmed cell death (PCD) to muscle wasting disorders remains a matter of debate. Drosophila melanogaster metamorphosis offers the opportunity to study muscle cell death in the context of development. Using live cell imaging of the abdomen, two groups of larval muscles can be observed, doomed muscles that undergo histolysis and persistent muscles that are remodelled and survive into adulthood. To identify and characterize genes that control the decision between survival and cell death of muscles, we developed a method comprising in vivo imaging, targeted gene perturbation and time-lapse image analysis. Our approach enabled us to study the cytological and temporal aspects of abnormal cell death phenotypes. In a previous genetic screen for genes controlling muscle size and cell death in metamorphosis, we identified gene perturbations that induced cell death of persistent or inhibit histolysis of doomed larval muscles. RNA interference (RNAi) of the genes encoding the helicase Rm62 and the lysosomal Cathepsin-L homolog Cysteine proteinase 1 (Cp1) caused premature cell death of persistent muscle in early and mid-pupation, respectively. Silencing of the transcriptional co-repressor Atrophin inhibited histolysis of doomed muscles. Overexpression of dominant-negative Target of Rapamycin (TOR) delayed the histolysis of a subset of doomed and induced ablation of all persistent muscles. RNAi of AMPKα, which encodes a subunit of the AMPK protein complex that senses AMP and promotes ATP formation, led to loss of attachment and a spherical morphology. None of the perturbations affected the survival of newly formed adult muscles, suggesting that the method is useful to find genes that are crucial for the survival of metabolically challenged muscles, like those undergoing atrophy. The ablation of persistent muscles did not affect eclosion of adult flies. Live imaging is a versatile approach to uncover gene functions that are required for the survival of

  15. Effect of Repeated Food Morsel Splitting on Jaw Muscle Control

    DEFF Research Database (Denmark)

    A, Kumar; Svensson, Krister G; Baad-Hansen, Lene

    2014-01-01

    Mastication is a complex motor task often initiated by splitting of the food morsel between the anterior teeth. Training of complex motor tasks has consistently been shown to trigger neuroplastic changes in corticomotor control and optimization of muscle function. It is not known if training...

  16. Muscle spindle composition and distribution in human young masseter and biceps brachii muscles reveal early growth and maturation.

    Science.gov (United States)

    Osterlund, Catharina; Liu, Jing-Xia; Thornell, Lars-Eric; Eriksson, Per-Olof

    2011-04-01

    Significant changes in extrafusal fiber type composition take place in the human masseter muscle from young age, 3-7 years, to adulthood, in parallel with jaw-face skeleton growth, changes of dentitions and improvement of jaw functions. As motor and sensory control systems of muscles are interlinked, also the intrafusal fiber population, that is, muscle spindles, should undergo age-related changes in fiber type appearance. To test this hypothesis, we examined muscle spindles in the young masseter muscle and compared the result with previous data on adult masseter spindles. Also muscle spindles in the young biceps brachii muscle were examined. The result showed that muscle spindle composition and distribution were alike in young and adult masseter. As for the adult masseter, young masseter contained exceptionally large muscle spindles, and with the highest spindle density and most complex spindles found in the deep masseter portion. Hence, contrary to our hypothesis, masseter spindles do not undergo major morphological changes between young age and adulthood. Also in the biceps, young spindles were alike adult spindles. Taken together, the results showed that human masseter and biceps muscle spindles are morphologically mature already at young age. We conclude that muscle spindles in the human young masseter and biceps precede the extrafusal fiber population in growth and maturation. This in turn suggests early reflex control and proprioceptive demands in learning and maturation of jaw motor skills. Similarly, well-developed muscle spindles in young biceps reflect early need of reflex control in learning and performing arm motor behavior. Copyright © 2011 Wiley-Liss, Inc.

  17. Recombinant Uncarboxylated Osteocalcin Per Se Enhances Mouse Skeletal Muscle Glucose Uptake in both Extensor Digitorum Longus and Soleus Muscles

    Directory of Open Access Journals (Sweden)

    Xuzhu Lin

    2017-11-01

    Full Text Available Emerging evidence suggests that undercarboxylated osteocalcin (ucOC improves muscle glucose uptake in rodents. However, whether ucOC can directly increase glucose uptake in both glycolytic and oxidative muscles and the possible mechanisms of action still need further exploration. We tested the hypothesis that ucOC per se stimulates muscle glucose uptake via extracellular signal-regulated kinase (ERK, adenosine monophosphate-activated protein kinase (AMPK, and/or the mechanistic target of rapamycin complex 2 (mTORC2-protein kinase B (AKT-AKT substrate of 160 kDa (AS160 signaling cascade. Extensor digitorum longus (EDL and soleus muscles from male C57BL/6 mice were isolated, divided into halves, and then incubated with ucOC with or without the pretreatment of ERK inhibitor U0126. ucOC increased muscle glucose uptake in both EDL and soleus. It also enhanced phosphorylation of ERK2 (Thr202/Tyr204 and AS160 (Thr642 in both muscle types and increased mTOR phosphorylation (Ser2481 in EDL only. ucOC had no significant effect on the phosphorylation of AMPKα (Thr172. The inhibition of ucOC-induced ERK phosphorylation had limited effect on ucOC-stimulated glucose uptake and AS160 phosphorylation in both muscle types, but appeared to inhibit the elevation in AKT phosphorylation only in EDL. Taken together, ucOC at the physiological range directly increased glucose uptake in both EDL and soleus muscles in mouse. The molecular mechanisms behind this ucOC effect on muscle glucose uptake seem to be muscle type-specific, involving enhanced phosphorylation of AS160 but limitedly modulated by ERK phosphorylation. Our study suggests that, since ucOC increases muscle glucose uptake without insulin, it could be considered as a potential agent to improve muscle glucose uptake in insulin resistant conditions.

  18. Mimicking muscle activity with electrical stimulation

    Science.gov (United States)

    Johnson, Lise A.; Fuglevand, Andrew J.

    2011-02-01

    Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.

  19. Multifunctional and Context-Dependent Control of Vocal Acoustics by Individual Muscles.

    Science.gov (United States)

    Srivastava, Kyle H; Elemans, Coen P H; Sober, Samuel J

    2015-10-21

    The relationship between muscle activity and behavioral output determines how the brain controls and modifies complex skills. In vocal control, ensembles of muscles are used to precisely tune single acoustic parameters such as fundamental frequency and sound amplitude. If individual vocal muscles were dedicated to the control of single parameters, then the brain could control each parameter independently by modulating the appropriate muscle or muscles. Alternatively, if each muscle influenced multiple parameters, a more complex control strategy would be required to selectively modulate a single parameter. Additionally, it is unknown whether the function of single muscles is fixed or varies across different vocal gestures. A fixed relationship would allow the brain to use the same changes in muscle activation to, for example, increase the fundamental frequency of different vocal gestures, whereas a context-dependent scheme would require the brain to calculate different motor modifications in each case. We tested the hypothesis that single muscles control multiple acoustic parameters and that the function of single muscles varies across gestures using three complementary approaches. First, we recorded electromyographic data from vocal muscles in singing Bengalese finches. Second, we electrically perturbed the activity of single muscles during song. Third, we developed an ex vivo technique to analyze the biomechanical and acoustic consequences of single-muscle perturbations. We found that single muscles drive changes in multiple parameters and that the function of single muscles differs across vocal gestures, suggesting that the brain uses a complex, gesture-dependent control scheme to regulate vocal output. Copyright © 2015 the authors 0270-6474/15/3514183-12$15.00/0.

  20. Evolution of a novel muscle design in sea urchins (Echinodermata: Echinoidea.

    Directory of Open Access Journals (Sweden)

    Alexander Ziegler

    Full Text Available The sea urchin (Echinodermata: Echinoidea masticatory apparatus, or Aristotle's lantern, is a complex structure composed of numerous hard and soft components. The lantern is powered by various paired and unpaired muscle groups. We describe how one set of these muscles, the lantern protractor muscles, has evolved a specialized morphology. This morphology is characterized by the formation of adaxially-facing lobes perpendicular to the main orientation of the muscle, giving the protractor a frilled aspect in horizontal section. Histological and ultrastructural analyses show that the microstructure of frilled muscles is largely identical to that of conventional, flat muscles. Measurements of muscle dimensions in equally-sized specimens demonstrate that the frilled muscle design, in comparison to that of the flat muscle type, considerably increases muscle volume as well as the muscle's surface directed towards the interradial cavity, a compartment of the peripharyngeal coelom. Scanning electron microscopical observations reveal that the insertions of frilled and flat protractor muscles result in characteristic muscle scars on the stereom, reflecting the shapes of individual muscles. Our comparative study of 49 derived "regular" echinoid species using magnetic resonance imaging (MRI shows that frilled protractor muscles are found only in taxa belonging to the families Toxopneustidae, Echinometridae, and Strongylocentrotidae. The onset of lobe formation during ontogenesis varies between species of these three families. Because frilled protractor muscles are best observed in situ, the application of a non-invasive imaging technique was crucial for the unequivocal identification of this morphological character on a large scale. Although it is currently possible only to speculate on the functional advantages which the frilled muscle morphology might confer, our study forms the anatomical and evolutionary framework for future analyses of this unusual

  1. Evolution of a Novel Muscle Design in Sea Urchins (Echinodermata: Echinoidea)

    Science.gov (United States)

    Ziegler, Alexander; Schröder, Leif; Ogurreck, Malte; Faber, Cornelius; Stach, Thomas

    2012-01-01

    The sea urchin (Echinodermata: Echinoidea) masticatory apparatus, or Aristotle's lantern, is a complex structure composed of numerous hard and soft components. The lantern is powered by various paired and unpaired muscle groups. We describe how one set of these muscles, the lantern protractor muscles, has evolved a specialized morphology. This morphology is characterized by the formation of adaxially-facing lobes perpendicular to the main orientation of the muscle, giving the protractor a frilled aspect in horizontal section. Histological and ultrastructural analyses show that the microstructure of frilled muscles is largely identical to that of conventional, flat muscles. Measurements of muscle dimensions in equally-sized specimens demonstrate that the frilled muscle design, in comparison to that of the flat muscle type, considerably increases muscle volume as well as the muscle's surface directed towards the interradial cavity, a compartment of the peripharyngeal coelom. Scanning electron microscopical observations reveal that the insertions of frilled and flat protractor muscles result in characteristic muscle scars on the stereom, reflecting the shapes of individual muscles. Our comparative study of 49 derived “regular” echinoid species using magnetic resonance imaging (MRI) shows that frilled protractor muscles are found only in taxa belonging to the families Toxopneustidae, Echinometridae, and Strongylocentrotidae. The onset of lobe formation during ontogenesis varies between species of these three families. Because frilled protractor muscles are best observed in situ, the application of a non-invasive imaging technique was crucial for the unequivocal identification of this morphological character on a large scale. Although it is currently possible only to speculate on the functional advantages which the frilled muscle morphology might confer, our study forms the anatomical and evolutionary framework for future analyses of this unusual muscle design among

  2. Contributions Concerning Muscle Training in Professionnal Volleyball

    OpenAIRE

    Niculescu Mugurel; Niculescu Ionela; Amzăr E. LuminiŃa

    2011-01-01

    Problem statement: Complex muscle training, less known to our specialists, has proved that, by complying with all the stages proposed, high level results may be achieved. The performances, weaker and weaker, obtained by the Romanian teams call for measures of optimization and Specific Physical Training (SPT) in accordance to technical -tactical training. Physical training should be individualized and multiplied, under this aspect; we may align to the professional volleybal...

  3. Muscle as a secretory organ

    DEFF Research Database (Denmark)

    Pedersen, Bente K

    2013-01-01

    Skeletal muscle is the largest organ in the body. Skeletal muscles are primarily characterized by their mechanical activity required for posture, movement, and breathing, which depends on muscle fiber contractions. However, skeletal muscle is not just a component in our locomotor system. Recent...... evidence has identified skeletal muscle as a secretory organ. We have suggested that cytokines and other peptides that are produced, expressed, and released by muscle fibers and exert either autocrine, paracrine, or endocrine effects should be classified as "myokines." The muscle secretome consists...... of several hundred secreted peptides. This finding provides a conceptual basis and a whole new paradigm for understanding how muscles communicate with other organs such as adipose tissue, liver, pancreas, bones, and brain. In addition, several myokines exert their effects within the muscle itself. Many...

  4. Cancer cachexia decreases specific force and accelerates fatigue in limb muscle

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, B.M. [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States); Frye, G.S.; Ahn, B.; Ferreira, L.F. [1864 Stadium Road, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610 (United States); Judge, A.R., E-mail: arjudge@phhp.ufl.edu [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States)

    2013-06-07

    Highlights: •C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. •C-26 cancer cachexia causes a significant decrease in limb muscle specific force. •C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. •C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. •C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative

  5. An In Vitro Model of Skeletal Muscle Volume Regulation

    OpenAIRE

    Anna Wibberley; Staunton, Caroline A; Feetham, Claire H.; Vereninov, Alexey A.; Richard Barrett-Jolley

    2015-01-01

    Introduction Hypertonic media causes cells to shrink due to water loss through aquaporin channels. After acute shrinkage, cells either regulate their volume or, alternatively, undergo a number of metabolic changes which ultimately lead to cell death. In many cell types, hypertonic shrinkage is followed by apoptosis. Due to the complex 3D morphology of skeletal muscle and the difficulty in obtaining isolated human tissue, we have begun skeletal muscle volume regulation studies using the human ...

  6. Muscle synergy patterns as physiological markers of motor cortical damage

    Science.gov (United States)

    Cheung, Vincent C. K.; Turolla, Andrea; Agostini, Michela; Silvoni, Stefano; Bennis, Caoimhe; Kasi, Patrick; Paganoni, Sabrina; Bonato, Paolo; Bizzi, Emilio

    2012-01-01

    The experimental findings herein reported are aimed at gaining a perspective on the complex neural events that follow lesions of the motor cortical areas. Cortical damage, whether by trauma or stroke, interferes with the flow of descending signals to the modular interneuronal structures of the spinal cord. These spinal modules subserve normal motor behaviors by activating groups of muscles as individual units (muscle synergies). Damage to the motor cortical areas disrupts the orchestration of the modules, resulting in abnormal movements. To gain insights into this complex process, we recorded myoelectric signals from multiple upper-limb muscles in subjects with cortical lesions. We used a factorization algorithm to identify the muscle synergies. Our factorization analysis revealed, in a quantitative way, three distinct patterns of muscle coordination—including preservation, merging, and fractionation of muscle synergies—that reflect the multiple neural responses that occur after cortical damage. These patterns varied as a function of both the severity of functional impairment and the temporal distance from stroke onset. We think these muscle-synergy patterns can be used as physiological markers of the status of any patient with stroke or trauma, thereby guiding the development of different rehabilitation approaches, as well as future physiological experiments for a further understanding of postinjury mechanisms of motor control and recovery. PMID:22908288

  7. From single muscle fiber to whole muscle mechanics: a finite element model of a muscle bundle with fast and slow fibers.

    Science.gov (United States)

    Marcucci, Lorenzo; Reggiani, Carlo; Natali, Arturo N; Pavan, Piero G

    2017-12-01

    Muscles exhibit highly complex, multi-scale architecture with thousands of muscle fibers, each with different properties, interacting with each other and surrounding connective structures. Consequently, the results of single-fiber experiments are scarcely linked to the macroscopic or whole muscle behavior. This is especially true for human muscles where it would be important to understand of how skeletal muscles disorders affect patients' life. In this work, we developed a mathematical model to study how fast and slow muscle fibers, well characterized in single-fiber experiments, work and generate together force and displacement in muscle bundles. We characterized the parameters of a Hill-type model, using experimental data on fast and slow single human muscle fibers, and comparing experimental data with numerical simulations obtained from finite element (FE) models of single fibers. Then, we developed a FE model of a bundle of 19 fibers, based on an immunohistochemically stained cross section of human diaphragm and including the corresponding properties of each slow or fast fiber. Simulations of isotonic contractions of the bundle model allowed the generation of its apparent force-velocity relationship. Although close to the average of the force-velocity curves of fast and slow fibers, the bundle curve deviates substantially toward the fast fibers at low loads. We believe that the present model and the characterization of the force-velocity curve of a fiber bundle represents the starting point to link the single-fiber properties to those of whole muscle with FE application in phenomenological models of human muscles.

  8. Gemelli and obturator internus muscles: different heads of one muscle?

    Science.gov (United States)

    Shinohara, H

    1995-09-01

    The superior gemellus, inferior gemellus, and obturator internus muscles were once regarded as a single muscle judging from their insertion and function. However, current textbooks of anatomy do not treat them as one muscle. In gross anatomy, the classification of muscles depends largely upon the nerve supply, so that the present author re-examined the nerve supply to the three muscles. Fourteen nerve-muscle specimens were taken from 12 cadavers (five males and seven females) and examined with the unaided eye and under a dissecting microscope. (1) The modes of nerve supply to the superior gemellus, inferior gemellus, and obturator internus muscles differed; however, the nerves to the muscles shared the same spinal nerve components. (2) The gemelli formed a muscular pocket ("gemellus pocket") through which obturator internus muscle passed. In light of this knowledge on nerve muscle relationships, the difference in the pattern of nerve supply to the superior gemellus, inferior gemellus, and obturator internus muscles cannot be the basis for stating that the muscle are independent. Rather, their fusion to form the gemellus pocket and their common insertion suggest that they are different heads of one muscle.

  9. Muscle activation of different core exercises.

    Science.gov (United States)

    Oliver, Gretchen D; Dwelly, Priscilla M; Sarantis, Nicholas D; Helmer, Rachael A; Bonacci, Jeffery A

    2010-11-01

    Sport health care professionals are always trying to increase muscle activation while instructing exercises that are functional to the sport performance. However, the traditional core exercises are the ones typically performed. This study examined the muscle activation of the lumbopelvic hip complex during traditional core stability exercises and that of the sports performance movements using the CORE X. Fourteen healthy, college-age men (mean age 20.8 ± 3.9 years; mean height, 177.8 ± 10.9 cm; mean weight, 67.3 ± 9.9 kg) participated. Electromyographic (EMG) data were collected on the following muscles: dominant gluteus maximus, dominant gluteus medius, rectus abdomonis (bilateral), external oblique (bilateral), and multifidis (bilateral). Results revealed a significant difference between the 2 different exercise programs for all muscles investigated except the external obliques (p CORE X showed increased mean muscle activation for the dominant (57.8% maximum voluntary isometric contraction [MVIC]) and nondominant multifidus (56.4% MVIC) and the dominant gluteus maximus (48.3% MVIC) and medius (65.3% MVIC), whereas the traditional core exercises showed greater mean muscle activation for the dominant (45.1% MVIC) and nondominant rectus abdominis (47.4% MVIC) and external oblique (45.8% MVIC and 47.8% MVIC). The investigators were able to determine that while performing movements that mimicked more sports-related activities with the CORE X, there is a greater activation of the core musculature. Coaches, trainers, and athletic trainers should focus on training a core neutral while performing sports-specific movements that can be done with the CORE X.

  10. Muscles and their myokines

    DEFF Research Database (Denmark)

    Pedersen, Bente Klarlund

    2011-01-01

    that a physically active life plays an independent role in the protection against type 2 diabetes, cardiovascular diseases, cancer, dementia and even depression. For most of the last century, researchers sought a link between muscle contraction and humoral changes in the form of an 'exercise factor', which could......In the past, the role of physical activity as a life-style modulating factor has been considered as that of a tool to balance energy intake. Although it is important to avoid obesity, physical inactivity should be discussed in a much broader context. There is accumulating epidemiological evidence...... be released from skeletal muscle during contraction and mediate some of the exercise-induced metabolic changes in other organs such as the liver and the adipose tissue. We have suggested that cytokines or other peptides that are produced, expressed and released by muscle fibres and exert autocrine, paracrine...

  11. Hydraulically actuated artificial muscles

    Science.gov (United States)

    Meller, M. A.; Tiwari, R.; Wajcs, K. B.; Moses, C.; Reveles, I.; Garcia, E.

    2012-04-01

    Hydraulic Artificial Muscles (HAMs) consisting of a polymer tube constrained by a nylon mesh are presented in this paper. Despite the actuation mechanism being similar to its popular counterpart, which are pneumatically actuated (PAM), HAMs have not been studied in depth. HAMs offer the advantage of compliance, large force to weight ratio, low maintenance, and low cost over traditional hydraulic cylinders. Muscle characterization for isometric and isobaric tests are discussed and compared to PAMs. A model incorporating the effect of mesh angle and friction have also been developed. In addition, differential swelling of the muscle on actuation has also been included in the model. An application of lab fabricated HAMs for a meso-scale robotic system is also presented.

  12. in Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Espen E. Spangenburg

    2011-01-01

    Full Text Available Triglyceride storage is altered across various chronic health conditions necessitating various techniques to visualize and quantify lipid droplets (LDs. Here, we describe the utilization of the BODIPY (493/503 dye in skeletal muscle as a means to analyze LDs. We found that the dye was a convenient and simple approach to visualize LDs in both sectioned skeletal muscle and cultured adult single fibers. Furthermore, the dye was effective in both fixed and nonfixed cells, and the staining seemed unaffected by permeabilization. We believe that the use of the BODIPY (493/503 dye is an acceptable alternative and, under certain conditions, a simpler method for visualizing LDs stored within skeletal muscle.

  13. Force feedback reinforces muscle synergies in insect legs.

    Science.gov (United States)

    Zill, Sasha N; Chaudhry, Sumaiya; Büschges, Ansgar; Schmitz, Josef

    2015-11-01

    The nervous system solves complex biomechanical problems by activating muscles in modular, synergist groups. We have studied how force feedback in substrate grip is integrated with effects of sense organs that monitor support and propulsion in insects. Campaniform sensilla are mechanoreceptors that encode forces as cuticular strains. We tested the hypothesis that integration of force feedback from receptors of different leg segments during grip occurs through activation of specific muscle synergies. We characterized the effects of campaniform sensilla of the feet (tarsi) and proximal segments (trochanter and femur) on activities of leg muscles in stick insects and cockroaches. In both species, mechanical stimulation of tarsal sensilla activated the leg muscle that generates substrate grip (retractor unguis), as well as proximal leg muscles that produce inward pull (tibial flexor) and support/propulsion (trochanteral depressor). Stimulation of campaniform sensilla on proximal leg segments activated the same synergistic group of muscles. In stick insects, the effects of proximal receptors on distal leg muscles changed and were greatly enhanced when animals made active searching movements. In insects, the task-specific reinforcement of muscle synergies can ensure that substrate adhesion is rapidly established after substrate contact to provide a stable point for force generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A motor unit-based model of muscle fatigue

    Science.gov (United States)

    2017-01-01

    Muscle fatigue is a temporary decline in the force and power capacity of skeletal muscle resulting from muscle activity. Because control of muscle is realized at the level of the motor unit (MU), it seems important to consider the physiological properties of motor units when attempting to understand and predict muscle fatigue. Therefore, we developed a phenomenological model of motor unit fatigue as a tractable means to predict muscle fatigue for a variety of tasks and to illustrate the individual contractile responses of MUs whose collective action determines the trajectory of changes in muscle force capacity during prolonged activity. An existing MU population model was used to simulate MU firing rates and isometric muscle forces and, to that model, we added fatigue-related changes in MU force, contraction time, and firing rate associated with sustained voluntary contractions. The model accurately estimated endurance times for sustained isometric contractions across a wide range of target levels. In addition, simulations were run for situations that have little experimental precedent to demonstrate the potential utility of the model to predict motor unit fatigue for more complicated, real-world applications. Moreover, the model provided insight into the complex orchestration of MU force contributions during fatigue, that would be unattainable with current experimental approaches. PMID:28574981

  15. Monitoring post mortem changes in porcine muscle through 2-D DIGE proteome analysis of Longissimus muscle exudate

    OpenAIRE

    Di Luca, Alessio; Elia, Giuliano; Mullen, Anne Maria; Hamill, Ruth M

    2013-01-01

    Background Meat quality is a complex trait influenced by a range of factors with post mortem biochemical processes highly influential in defining ultimate quality. High resolution two-dimensional DIfference Gel Electrophoresis (2-D DIGE) and Western blot were applied to study the influence of post mortem meat ageing on the proteome of pork muscle. Exudate collected from the muscle following centrifugation was analysed at three timepoints representing a seven day meat ageing period. Results Th...

  16. Physical Rehabilitation Improves Muscle Function Following Volumetric Muscle Loss Injury

    Science.gov (United States)

    2014-12-19

    tibialis anterior muscle torque . Maximal isometric torque (@ 150Hz) of the tibialis anterior muscle was assessed in vivo following distal extensor...digitorum longus muscle (EDL) tenotomy (see Methods). Average maximal isometric torque normalized to body weight is shown for the uninjured and injured...wheel running promotes ~ 17% improvement in maximal isometric torque , and a ~ 13% increase in weight of the injured muscle , but it did so without

  17. Real-time muscle deformation via decoupled modeling of solid and muscle fiber mechanics.

    Science.gov (United States)

    Berranen, Yacine; Hayashibe, Mitsuhiro; Guiraud, David; Gilles, Benjamin

    2014-01-01

    This paper presents a novel approach for simulating 3D muscle deformations with complex architectures. The approach consists in choosing the best model formulation in terms of computation cost and accuracy, that mixes a volumetric-tissue model based on finite element method (3D FEM), a muscle fiber model (Hill contractile 1D element) and a membrane model accounting for aponeurosis tissue (2D FEM). The separate models are mechanically binded using barycentric embeddings. Our approach allows the computation of several fiber directions in one coarse finite element, and thus, strongly decreases the required finite element resolution to predict muscle deformation during contraction. Using surface registration, fibers tracks of specific architecture can be transferred from a template to subject morphology, and then simulated. As a case study, three different architectures are simulated and compared to their equivalent one dimensional Hill wire model simulations.

  18. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  19. Composition of Muscle Fiber Types in Rat Rotator Cuff Muscles.

    Science.gov (United States)

    Rui, Yongjun; Pan, Feng; Mi, Jingyi

    2016-10-01

    The rat is a suitable model to study human rotator cuff pathology owing to the similarities in morphological anatomy structure. However, few studies have reported the composition muscle fiber types of rotator cuff muscles in the rat. In this study, the myosin heavy chain (MyHC) isoforms were stained by immunofluorescence to show the muscle fiber types composition and distribution in rotator cuff muscles of the rat. It was found that rotator cuff muscles in the rat were of mixed fiber type composition. The majority of rotator cuff fibers labeled positively for MyHCII. Moreover, the rat rotator cuff muscles contained hybrid fibers. So, compared with human rotator cuff muscles composed partly of slow-twitch fibers, the majority of fast-twitch fibers in rat rotator cuff muscles should be considered when the rat model study focus on the pathological process of rotator cuff muscles after injury. Gaining greater insight into muscle fiber types in rotator cuff muscles of the rat may contribute to elucidate the mechanism of pathological change in rotator cuff muscles-related diseases. Anat Rec, 299:1397-1401, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Effects of oblique muscle surgery on the rectus muscle pulley.

    Science.gov (United States)

    Okanobu, Hirotaka; Kono, Reika; Ohtsuki, Hiroshi

    2011-09-01

    To determine the position of rectus muscle pulleys in Japanese eyes and to evaluate the effect of oblique muscle surgery on rectus muscle pulleys. Quasi-coronal plane MRI was used to determine area centroids of the 4 rectus muscles. The area centroids of the rectus muscles were transformed to 2-dimensional coordinates to represent pulley positions. The effects of oblique muscle surgery on the rectus muscle pulley positions in the coronal plane were evaluated in 10 subjects with cyclovertical strabismus and, as a control, pulley locations in 7 normal Japanese subjects were calculated. The mean positions of the rectus muscle pulleys in the coronal plane did not significantly differ from previous reports on normal populations, including Caucasians. There were significant positional shifts of the individual horizontal and vertical rectus muscle pulleys in 3 (100%) patients with inferior oblique advancement, but not in eyes with inferior oblique recession and superior oblique tendon advancement surgery. The surgical cyclorotatory effect was significantly correlated with the change in the angle of inclination formed by the line connecting the vertical rectus muscles (p = 0.0234), but weakly correlated with that of the horizontal rectus muscles. The most important factor that affects the pulley position is the amount of ocular torsion, not the difference in surgical procedure induced by oblique muscle surgery.

  1. Impact of pentadecapeptide BPC 157 on muscle healing impaired by systemic corticosteroid application.

    Science.gov (United States)

    Pevec, Danira; Novinscak, Tomislav; Brcic, Luka; Sipos, Kristijan; Jukic, Ivana; Staresinic, Mario; Mise, Sandro; Brcic, Iva; Kolenc, Danijela; Klicek, Robert; Banic, Tihomir; Sever, Marko; Kocijan, Ana; Berkopic, Lidija; Radic, Bozo; Buljat, Gojko; Anic, Tomislav; Zoricic, Ivan; Bojanic, Ivan; Seiwerth, Sven; Sikiric, Predrag

    2010-03-01

    The effect of systemic and local peptide treatment effective in muscle contusion and then on counteraction of corticosteroid-induced impairment was tested. The pentadecapeptide BPC 157, given without a carrier, improved the healing of transected quadriceps muscle. It also improved muscle healing in rats with muscle crush injury when applied systemically or locally. Importantly, it counteracted corticosteroid-impairment in tendon to bone healing. Thus BPC 157 is proposed as an effective treatment that can improve muscle healing in spite of corticosteroid treatment. After the gastrocnemius muscle complex had been injured, rats received BPC 157 (intraperitoneally or locally as a cream) and/or 6alpha-methylprednisolone (intraperitoneally) only once (immediately after injury, sacrifice at 2 h) or once daily (final dose 24 hours before sacrifice and/or assessment procedure at days 1, 2, 4, 7, and 14). Muscle healing was evaluated functionally, macroscopically, and histologically. Without therapy, crushed gastrocnemius muscle complex controls showed limited improvement. 6alpha-methylprednisolone markedly aggravated healing. In contrast, BPC 157 induced faster muscle healing and full function restoration and improved muscle healing despite systemic corticosteroid treatment when given intraperitoneally or locally and demonstrated functionally, macroscopically, and histologically at all investigated intervals. BPC 157 completely reversed systemic corticosteroid-impaired muscle healing.

  2. Force encoding in muscle spindles during stretch of passive muscle.

    Science.gov (United States)

    Blum, Kyle P; Lamotte D'Incamps, Boris; Zytnicki, Daniel; Ting, Lena H

    2017-09-01

    Muscle spindle proprioceptive receptors play a primary role in encoding the effects of external mechanical perturbations to the body. During externally-imposed stretches of passive, i.e. electrically-quiescent, muscles, the instantaneous firing rates (IFRs) of muscle spindles are associated with characteristics of stretch such as length and velocity. However, even in passive muscle, there are history-dependent transients of muscle spindle firing that are not uniquely related to muscle length and velocity, nor reproduced by current muscle spindle models. These include acceleration-dependent initial bursts, increased dynamic response to stretch velocity if a muscle has been isometric, and rate relaxation, i.e., a decrease in tonic IFR when a muscle is held at a constant length after being stretched. We collected muscle spindle spike trains across a variety of muscle stretch kinematic conditions, including systematic changes in peak length, velocity, and acceleration. We demonstrate that muscle spindle primary afferents in passive muscle fire in direct relationship to muscle force-related variables, rather than length-related variables. Linear combinations of whole muscle-tendon force and the first time derivative of force (dF/dt) predict the entire time course of transient IFRs in muscle spindle Ia afferents during stretch (i.e., lengthening) of passive muscle, including the initial burst, the dynamic response to lengthening, and rate relaxation following lengthening. Similar to acceleration scaling found previously in postural responses to perturbations, initial burst amplitude scaled equally well to initial stretch acceleration or dF/dt, though later transients were only described by dF/dt. The transient increase in dF/dt at the onset of lengthening reflects muscle short-range stiffness due to cross-bridge dynamics. Our work demonstrates a critical role of muscle cross-bridge dynamics in history-dependent muscle spindle IFRs in passive muscle lengthening conditions

  3. Heterotopic muscle pulleys or oblique muscle dysfunction?

    Science.gov (United States)

    Clark, R A; Miller, J M; Rosenbaum, A L; Demer, J L

    1998-02-01

    The description of connective tissue sleeves that function as pulleys for the rectus extraocular muscles (EOMs) suggests that abnormalities of EOM pulley position might provide a mechanical basis for some forms of incomitant strabismus. Pulleys determine the paths and thus the pulling directions of EOMs. High-resolution magnetic resonance images spanning the orbits were obtained in primary position, upgaze, and downgaze for each subject. Paths of the EOMs were measured with reference to the orbital center and permitted inference of pulley locations. Data from 18 orbits of orthotropic subjects defined means and SDs of normal EOM pulley coordinates. Eight patients, aged 17 to 60 years, had heterotopic EOM pulleys, defined as displaced at least 2 SDs from normal. We found one to eight heterotopic pulleys (considering both orbits) in each of four patients who had been diagnosed with marked superior oblique (SO) overaction and mild to marked inferior oblique (IO) underaction. Each patient had superior mislocation of at least one lateral rectus pulley by 1.8 to 4.9 mm. Three patients diagnosed with mild to moderate IO overaction and mild to moderate SO underaction in only one orbit had one to three heterotopic EOM pulleys. Each of those patients had at least one lateral rectus pulley inferiorly dislocated by 1.9 to 4.9 mm. The final patient, who was diagnosed with mild IO underaction and normal SO function bilaterally, had bilateral superior mislocation of the medial rectus pulleys by greater than 2 mm. Computer simulations using the Orbit program (Eidactics, San Francisco) incorporating individually measured pulley positions reproduced the clinical patterns of incomitant strabismus in all cases without postulating abnormalities of oblique muscle innervation or contractility. Heterotopic EOM pulleys can cause patterns of incomitant strabismus that have been attributed to oblique muscle dysfunction. Even isolated mislocations of less than 2 mm, coupled with smaller

  4. MRI appearance of muscle denervation

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, S. [University Hospital of Wales, Department of Radiology, Cardiff (United Kingdom); Venkatanarasimha, N.; Walsh, M.A.; Hughes, P.M. [Derriford Hospital, Department of Radiology, Plymouth (United Kingdom)

    2008-05-15

    Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation. (orig.)

  5. Pelvic floor muscle training exercises

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003975.htm Pelvic floor muscle training exercises To use the sharing features on this page, please enable JavaScript. Pelvic floor muscle training exercises are a series of exercises ...

  6. Making more heart muscle

    NARCIS (Netherlands)

    van den Hoff, Maurice J. B.; Kruithof, Boudewijn P. T.; Moorman, Antoon F. M.

    2004-01-01

    Postnatally, heart muscle cells almost completely lose their ability to divide, which makes their loss after trauma irreversible. Potential repair by cell grafting or mobilizing endogenous cells is of particular interest for possible treatments for heart disease, where the poor capacity for

  7. Muscle biopsy and cell cultures: potential diagnostic tools in hereditary skeletal muscle channelopathies

    Directory of Open Access Journals (Sweden)

    G Meola

    2009-06-01

    Full Text Available Hereditary muscle channelopathies are caused by dominant mutations in the genes encoding for subunits of muscle voltage- gated ion channels. Point mutations on the human skeletal muscle Na+ channel (Nav1.4 give rise to hyperkalemic periodic paralysis, potassium aggravated myotonia, paramyotonia congenita and hypokalemic periodic paralysis type 2. Point mutations on the human skeletal muscle Ca2+ channel give rise to hypokalemic periodic paralysis and malignant hyperthermia. Point mutations in the human skeletal chloride channel ClC-1 give rise to myotonia congenita. Point mutations in the inwardly rectifying K+ channel Kir2.1 give rise to a syndrome characterized by periodic paralysis, severe cardiac arrhythmias and skeletal alterations (Andersen’s syndrome. Involvement of the same ion channel can thus give rise to different phenotypes. In addition, the same mutation can lead to different phenotypes or similar phenotypes can be caused by different mutations on the same or on different channel subtypes. Bearing in mind, the complexity of this field, the growing number of potential channelopathies (such as the myotonic dystrophies, and the time and cost of the genetic procedures, before a biomolecular approach is addressed, it is mandatory to apply strict diagnostic protocols to screen the patients. In this study we propose a protocol to be applied in the diagnosis of the hereditary muscle channelopathies and we demonstrate that muscle biopsy studies and muscle cell cultures may significantly contribute towards the correct diagnosis of the channel involved. DNAbased diagnosis is now a reality for many of the channelopathies. This has obvious genetic counselling, prognostic and therapeutic implications.

  8. Sarcoglycans in human skeletal muscle and human cardiac muscle: a confocal laser scanning microscope study.

    Science.gov (United States)

    Anastasi, G; Cutroneo, G; Trimarchi, F; Rizzo, G; Bramanti, P; Bruschetta, D; Fugazzotto, D; Cinelli, M P; Soscia, A; Santoro, G; Favaloro, A

    2003-01-01

    Sarcoglycans are a subcomplex of transmembrane proteins which are part of the dystrophin-glycoprotein complex. They are expressed in the skeletal, cardiac and smooth muscle. Although numerous studies have been conducted on the sarcoglycan subcomplex in skeletal and cardiac muscle, the manner of the distribution and localization of these proteins along the nonjunctional sarcolemma is not clear. We therefore carried out an indirect immunofluorescence study on surgical biopsies of normal human skeletal muscle and of healthy human atrial myocardium biopsies of patients affected by valvulopathy. Our results indicate that, in skeletal muscle, sarcoglycans have a costameric distribution and all colocalize with each other. Only in a few cases did the alpha-sarcoglycan not colocalize with other sarcoglycans. In addition, these glycoproteins can be localized in different fibers either in the regions of the sarcolemma over band I or band A. In cardiac muscle, our results show a costameric distribution of all proteins examined and, unlike in skeletal muscle, they show a constant colocalization of all sarcoglycans with each other, along with a consistent localization of these proteins in the region of the sarcolemma over band I. In our opinion, this situation seems to confirm the hypothesis of a correlation between the region of the sarcolemma occupied by costameric proteins and the metabolic type, fast or slow, of the muscular fibers. These data, besides opening a new line of research in understanding interactions between the sarcoglycans and other transmembrane proteins, could also be extended to skeletal and cardiac muscles affected by neuromuscular and cardiovascular pathologies to understand possible structural alterations. Copyright 2003 S. Karger AG, Basel

  9. A vertebrate slow skeletal muscle actin isoform

    National Research Council Canada - National Science Library

    Mudalige, Wasana A. K. A; Jackman, Donna M; Waddleton, Deena M; Heeley, David H

    2007-01-01

    Salmonids utilize a unique, class II isoactin in slow skeletal muscle. This actin contains 12 replacements when compared with those from salmonid fast skeletal muscle, salmonid cardiac muscle and rabbit skeletal muscle...

  10. [Muscle weakness in cerebral palsy].

    Science.gov (United States)

    Givon, Uri

    2009-01-01

    Over the last two decades, muscle weakness has been shown to be a major component of cerebral palsy (CP) pathology. Caused by multiple etiologies including variations in the muscle fiber type, pathologic motor unit function, co-contraction of agonists and antagonists, and muscle size and rigidity, weakness interferes with function and leads to limited function and participation. Muscle strength was found to be associated with walking ability and with functional scales. Children with CP were found to be weaker than typically developing children, and differences were found with respect to muscle groups in children with CP. Muscle weakness should be evaluated as objectively as possible to improve the quality of diagnosis and treatment. Manual muscle testing is not sufficient for evaluation, and instrumented muscle testing is validated in CP. Muscle strengthening is an important part of treatment of CP. Several methods of strengthening have been described. Muscle lengthening and other spasticity-modifying therapies have been shown to have a positive effect on muscle strength. Children who participated in muscle strengthening programs had a better quality of life and improved function.

  11. How does passive lengthening change the architecture of the human medial gastrocnemius muscle?

    Science.gov (United States)

    Bolsterlee, Bart; D'Souza, Arkiev; Gandevia, Simon C; Herbert, Robert D

    2017-04-01

    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 -2.5%) and depth (-4.8%). At the fascicle level, muscle architecture measurements obtained at 3,000 locations per muscle showed that for every millimeter increase in muscle-tendon length above the slack length, average fascicle length increased by 0.46 mm, pennation angle decreased by 0.27° (0.17° in the superficial part and 0.37° in the deep part), and fascicle curvature decreased by 0.18 m -1 There was no evidence of systematic variation in architecture along the muscle's long axis at any muscle length. At the fiber level, analysis of the diffusion signal showed that passive lengthening of the muscle increased diffusion along fibers and decreased diffusion across fibers. Using these measurements across scales, we show that the complex shape changes that muscle fibers, whole muscles, and aponeuroses of the medial gastrocnemius undergo in vivo cannot be captured by simple geometrical models. This justifies the need for more complex models that link microstructural changes in muscle fibers to macroscopic changes in architecture. NEW & NOTEWORTHY Novel MRI and DTI techniques revealed changes in three-dimensional architecture of the human medial gastrocnemius during passive lengthening. Whole muscle belly width and depth decreased when the muscle lengthened. Fascicle length, pennation, and curvature changed uniformly or near uniformly along the muscle during passive lengthening

  12. Effects of knee joint angle on global and local strains within human triceps surae muscle: MRI analysis indicating in vivo myofascial force transmission between synergistic muscles.

    Science.gov (United States)

    Huijing, Peter A; Yaman, Alper; Ozturk, Cengizhan; Yucesoy, Can A

    2011-12-01

    Mechanical interactions between muscles have been shown for in situ conditions. In vivo data for humans is unavailable. Global and local length changes of calf muscles were studied to test the hypothesis that local strains may occur also within muscle for which global strain equals zero. For determination of globally induced strain in m. gastrocnemius in dissected human cadavers several knee joint angles were imposed, while keeping ankle joint angle constant and measuring its muscle-tendon complex length changes. In vivo local strains in both gastrocnemius and soleus muscles were calculated using MRI techniques in healthy human volunteers comparing images taken at static knee angles of 173° and 150°. Imposed global strains on gastrocnemius were much smaller than local strains. High distributions of strains were encountered, e.g. overall lengthened muscle contains locally lengthened, as well as shortened areas within it. Substantial strains were not limited to gastrocnemius, but were found also in synergistic soleus muscle, despite the latter muscle-tendon complex length remaining isometric (constant ankle angle: i.e. global strain = 0), as it does not cross the knee. Based on results of animal experiments this effect is ascribed to myofascial connections between these synergistic muscles. The most likely pathway is the neurovascular tract within the anterior crural compartment (i.e. the collagen reinforcements of blood vessels, lymphatics and nerves). However, direct intermuscular transmission of force may also occur via the perimysium shared between the two muscles. Global strains imposed on muscle (joint movement) are not good estimators of in vivo local strains within it: differing in magnitude, as well as direction of length change. Substantial mechanical interaction occurs between calf muscles, which is mediated by myofascial force transmission between these synergistic muscles. This confirms conclusions of previous in situ studies in experimental animals

  13. Muscle spindles in the human bulbospongiosus and ischiocavernosus muscles.

    Science.gov (United States)

    Peikert, Kevin; May, Christian Albrecht

    2015-07-01

    Muscle spindles are crucial for neuronal regulation of striated muscles, but their presence and involvement in the superficial perineal muscles is not known. Bulbospongiosus and ischiocavernosus muscle specimens were obtained from 31 human cadavers. Serial sections were stained with hematoxylin and eosin, Sirius red, antibodies against Podocalyxin, myosin heavy chain isoforms (MyHC-slow tonic, S46; MyHC-2a/2x, A4.74), and neurofilament for the purpose of muscle spindle screening, counting, and characterization. A low but consistent number of spindles were detected in both muscles. The muscles contained few intrafusal fibers, but otherwise showed normal spindle morphology. The extrafusal fibers of both muscles were small in diameter. The presence of muscle spindles in bulbospongiosus and ischiocavernosus muscles supports physiological models of pelvic floor regulation and may provide a basis for further clinical observations regarding sexual function and micturition. The small number of muscle spindles points to a minor level of proprioceptive regulation. © 2014 Wiley Periodicals, Inc.

  14. Nerve-muscle interactions during flight muscle development in Drosophila

    Science.gov (United States)

    Fernandes, J. J.; Keshishian, H.

    1998-01-01

    During Drosophila pupal metamorphosis, the motoneurons and muscles differentiate synchronously, providing an opportunity for extensive intercellular regulation during synapse formation. We examined the existence of such interactions by developmentally delaying or permanently eliminating synaptic partners during the formation of indirect flight muscles. When we experimentally delayed muscle development, we found that although adult-specific primary motoneuron branching still occurred, the higher order (synaptic) branching was suspended until the delayed muscle fibers reached a favourable developmental state. In reciprocal experiments we found that denervation caused a decrease in the myoblast pool. Furthermore, the formation of certain muscle fibers (dorsoventral muscles) was specifically blocked. Exceptions were the adult muscles that use larval muscle fibers as myoblast fusion targets (dorsal longitudinal muscles). However, when these muscles were experimentally compelled to develop without their larval precursors, they showed an absolute dependence on the motoneurons for their formation. These data show that the size of the myoblast pool and early events in fiber formation depend on the presence of the nerve, and that, conversely, peripheral arbor development and synaptogenesis is closely synchronized with the developmental state of the muscle.

  15. No muscle involvement in myoclonus-dystonia caused by epsilon-sarcoglycan gene mutations1

    DEFF Research Database (Denmark)

    Hjermind, L.E.; Vissing, J.; Asmus, F.

    2008-01-01

    homologous and may substitute for one-another in different tissues. We therefore investigated whether mutations in SGCE also cause abnormalities of skeletal and myocardial muscle. Six patients with clinically and genetically verified M-D and no signs of limb-girdle muscular dystrophy were included. Skeletal...... muscle biopsies were obtained from all patients, and endomyocardial muscle biopsy from one of the patients. Morphological and immunohistological investigations were performed and compared with controls. Histological and immunohistological investigations of muscle and clinical assessment of muscle...... strength and mass showed no difference between M-D patients and controls. Our findings indicate that patients with M-D have no signs or symptoms of muscle disease. This suggests a different role of the sarcoglycan complex epsilonbetagammadelta versus alphabetagammadelta complex in humans, as earlier...

  16. The Molecular Basis for Load-Induced Skeletal Muscle Hypertrophy

    Science.gov (United States)

    Marcotte, George R.; West, Daniel W.D.; Baar, Keith

    2016-01-01

    In a mature (weight neutral) animal, an increase in muscle mass only occurs when the muscle is loaded sufficiently to cause an increase in myofibrillar protein balance. A tight relationship between muscle hypertrophy, acute increases in protein balance, and the activity of the mechanistic target of rapamycin complex 1 (mTORC1) was demonstrated 15 years ago. Since then, our understanding of the signals that regulate load-induced hypertrophy has evolved considerably. For example, we now know that mechanical load activates mTORC1 in the same way as growth factors, by moving TSC2 (a primary inhibitor of mTORC1) away from its target (the mTORC activator) Rheb. However, the kinase that phosphorylates and moves TSC2 is different in the two processes. Similarly, we have learned that a distinct pathway exists whereby amino acids activate mTORC1 by moving it to Rheb. While mTORC1 remains at the forefront of load-induced hypertrophy, the importance of other pathways that regulate muscle mass are becoming clearer. Myostatin, is best known for its control of developmental muscle size. However, new mechanisms to explain how loading regulates this process are suggesting that it could play an important role in hypertrophic muscle growth as well. Lastly, new mechanisms are highlighted for how β2 receptor agonists could be involved in load-induced muscle growth and why these agents are being developed as non-exercise-based therapies for muscle atrophy. Overall, the results highlight how studying the mechanism of load-induced skeletal muscle mass is leading the development of pharmaceutical interventions to promote muscle growth in those unwilling or unable to perform resistance exercise. PMID:25359125

  17. Synergizing Engineering and Biology to Treat and Model Skeletal Muscle Injury and Disease.

    Science.gov (United States)

    Bursac, Nenad; Juhas, Mark; Rando, Thomas A

    2015-01-01

    Although skeletal muscle is one of the most regenerative organs in our body, various genetic defects, alterations in extrinsic signaling, or substantial tissue damage can impair muscle function and the capacity for self-repair. The diversity and complexity of muscle disorders have attracted much interest from both cell biologists and, more recently, bioengineers, leading to concentrated efforts to better understand muscle pathology and develop more efficient therapies. This review describes the biological underpinnings of muscle development, repair, and disease, and discusses recent bioengineering efforts to design and control myomimetic environments, both to study muscle biology and function and to aid in the development of new drug, cell, and gene therapies for muscle disorders. The synergy between engineering-aided biological discovery and biology-inspired engineering solutions will be the path forward for translating laboratory results into clinical practice.

  18. Independent specialisation of myosin II paralogues in muscle vs. non-muscle functions during early animal evolution: a ctenophore perspective

    Directory of Open Access Journals (Sweden)

    Dayraud Cyrielle

    2012-07-01

    Full Text Available Abstract Background Myosin II (or Myosin Heavy Chain II, MHCII is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa and striated muscle cells (MHCIIb. Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora. Results We have uncovered three MHCII paralogues in the ctenophore species Pleurobrachia pileus. Phylogenetic analyses indicate that the MHCIIa / MHCIIb duplication is more ancient than the divergence between extant metazoan lineages. The ctenophore MHCIIa gene (PpiMHCIIa has an expression pattern akin to that of "stem cell markers" (Piwi, Vasa… and is expressed in proliferating cells. We identified two MHCIIb genes that originated from a ctenophore-specific duplication. PpiMHCIIb1 represents the exclusively muscular form of myosin II in ctenophore, while PpiMHCIIb2 is expressed in non-muscle cells of various types. In parallel, our phalloidin staining and TEM observations highlight the structural complexity of ctenophore musculature and emphasize the experimental interest of the ctenophore tentacle root, in which myogenesis is spatially ordered and strikingly similar to striated muscle formation in vertebrates. Conclusion MHCIIa expression in putative stem cells/proliferating cells probably represents an ancestral trait, while specific involvement of some MHCIIa genes in smooth muscle fibres is a uniquely derived feature of the vertebrates. That one ctenophore MHCIIb paralogue (PpiMHCIIb2 has retained MHCIIa-like expression features furthermore suggests that muscular

  19. Independent specialisation of myosin II paralogues in muscle vs. non-muscle functions during early animal evolution: a ctenophore perspective.

    Science.gov (United States)

    Dayraud, Cyrielle; Alié, Alexandre; Jager, Muriel; Chang, Patrick; Le Guyader, Hervé; Manuel, Michaël; Quéinnec, Eric

    2012-07-02

    Myosin II (or Myosin Heavy Chain II, MHCII) is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa) and striated muscle cells (MHCIIb). Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora. We have uncovered three MHCII paralogues in the ctenophore species Pleurobrachia pileus. Phylogenetic analyses indicate that the MHCIIa / MHCIIb duplication is more ancient than the divergence between extant metazoan lineages. The ctenophore MHCIIa gene (PpiMHCIIa) has an expression pattern akin to that of "stem cell markers" (Piwi, Vasa…) and is expressed in proliferating cells. We identified two MHCIIb genes that originated from a ctenophore-specific duplication. PpiMHCIIb1 represents the exclusively muscular form of myosin II in ctenophore, while PpiMHCIIb2 is expressed in non-muscle cells of various types. In parallel, our phalloidin staining and TEM observations highlight the structural complexity of ctenophore musculature and emphasize the experimental interest of the ctenophore tentacle root, in which myogenesis is spatially ordered and strikingly similar to striated muscle formation in vertebrates. MHCIIa expression in putative stem cells/proliferating cells probably represents an ancestral trait, while specific involvement of some MHCIIa genes in smooth muscle fibres is a uniquely derived feature of the vertebrates. That one ctenophore MHCIIb paralogue (PpiMHCIIb2) has retained MHCIIa-like expression features furthermore suggests that muscular expression of the other paralogue, PpiMHCIIb1, was

  20. Meshfree Image-Based Reduced Order Modeling of Multiple Muscle Components with Connective Tissue and Fat

    OpenAIRE

    Basava, Ramya Rao

    2015-01-01

    Modeling of anatomically accurate skeletal muscle models is still a challenging area of research to date. In general, muscles have complex architectures with spatially varying fiber orientations. Using the conventional Finite Element analysis, the generated mesh needs to be conformed to the muscle geometry and material interfaces to obtain accurate simulation models. Poorly built meshes can also lead to significant errors in analysis. To alleviate these issues and to provide effective transfo...

  1. [Hardware and software for EMG recording and analysis of respiratory muscles of human].

    Science.gov (United States)

    Solnushkin, S D; Chakhman, V N; Segizbaeva, M O; Pogodin, M A; Aleksandrov, V G

    2014-01-01

    This paper presents a new hardware and software system that allows to not only record the EMG of different groups of the respiratory muscles, but also hold its amplitude-frequency analysis, which allows to determine the change in the contribution to the work of breathing of a respiratory muscles and detect early signs of fatigue of the respiratory muscles. Presented complex can be used for functional diagnostics of breath in patients and healthy people and sportsmen.

  2. Nutritional and contractile regulation of human skeletal muscle protein synthesis and mTORC1 signaling

    OpenAIRE

    Drummond, Micah J.; Dreyer, Hans C.; Fry, Christopher S.; Glynn, Erin L.; Rasmussen, Blake B

    2009-01-01

    In this review we discuss current findings in the human skeletal muscle literature describing the acute influence of nutrients (leucine-enriched essential amino acids in particular) and resistance exercise on muscle protein synthesis and mammalian target of rapamycin complex 1 (mTORC1) signaling. We show that essential amino acids and an acute bout of resistance exercise independently stimulate human skeletal muscle protein synthesis. It also appears that ingestion of essential amino acids fo...

  3. Satellite Cells and the Muscle Stem Cell Niche

    Science.gov (United States)

    Yin, Hang; Price, Feodor

    2013-01-01

    Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process involving the activation of various cellular and molecular responses. As skeletal muscle stem cells, satellite cells play an indispensible role in this process. The self-renewing proliferation of satellite cells not only maintains the stem cell population but also provides numerous myogenic cells, which proliferate, differentiate, fuse, and lead to new myofiber formation and reconstitution of a functional contractile apparatus. The complex behavior of satellite cells during skeletal muscle regeneration is tightly regulated through the dynamic interplay between intrinsic factors within satellite cells and extrinsic factors constituting the muscle stem cell niche/microenvironment. For the last half century, the advance of molecular biology, cell biology, and genetics has greatly improved our understanding of skeletal muscle biology. Here, we review some recent advances, with focuses on functions of satellite cells and their niche during the process of skeletal muscle regeneration. PMID:23303905

  4. Muscle Strength and Poststroke Hemiplegia: A Systematic Review of Muscle Strength Assessment and Muscle Strength Impairment.

    Science.gov (United States)

    Kristensen, Otto H; Stenager, Egon; Dalgas, Ulrik

    2017-02-01

    To systematically review (1) psychometric properties of criterion isokinetic dynamometry testing of muscle strength in persons with poststroke hemiplegia (PPSH); and (2) literature that compares muscle strength in patients poststroke with that in healthy controls assessed by criterion isokinetic dynamometry. A systematic literature search of 7 databases was performed. Included studies (1) enrolled participants with definite poststroke hemiplegia according to defined criteria; (2) assessed muscle strength or power by criterion isokinetic dynamometry; (3) had undergone peer review; and (4) were available in English or Danish. The psychometric properties of isokinetic dynamometry were reviewed with respect to reliability, validity, and responsiveness. Furthermore, comparisons of strength between paretic, nonparetic, and comparable healthy muscles were reviewed. Twenty studies covering 316 PPSH were included. High intraclass correlation coefficient (ICC) inter- and intrasession reliability was reported for isokinetic dynamometry, which was independent of the tested muscle group, contraction mode, and contraction velocity. Slightly higher ICC values were found for the nonparetic extremity. Standard error of the mean (SEM) values showed that a change of 7% to 20% was required for a real group change to take place for most muscle groups, with the knee extensors showing the smallest SEM% values. The muscle strength of paretic muscles showed deficits when compared with both healthy and nonparetic muscles, independent of muscle group, contraction mode, and contraction velocity. Nonparetic muscles only showed minor strength impairments when compared with healthy muscles. Criterion isokinetic dynamometry is a reliable test in persons with stroke, generally showing marked reductions in muscle strength of paretic and, to a lesser degree, nonparetic muscles when compared with healthy controls, independent of muscle group, contraction mode, and contraction velocity. Copyright

  5. Regulation of muscle fiber type and running endurance by PPARdelta.

    Directory of Open Access Journals (Sweden)

    Yong-Xu Wang

    2004-10-01

    Full Text Available Endurance exercise training can promote an adaptive muscle fiber transformation and an increase of mitochondrial biogenesis by triggering scripted changes in gene expression. However, no transcription factor has yet been identified that can direct this process. We describe the engineering of a mouse capable of continuous running of up to twice the distance of a wild-type littermate. This was achieved by targeted expression of an activated form of peroxisome proliferator-activated receptor delta (PPARdelta in skeletal muscle, which induces a switch to form increased numbers of type I muscle fibers. Treatment of wild-type mice with PPARdelta agonist elicits a similar type I fiber gene expression profile in muscle. Moreover, these genetically generated fibers confer resistance to obesity with improved metabolic profiles, even in the absence of exercise. These results demonstrate that complex physiologic properties such as fatigue, endurance, and running capacity can be molecularly analyzed and manipulated.

  6. Role of PKCδ in Insulin Sensitivity and Skeletal Muscle Metabolism

    DEFF Research Database (Denmark)

    Li, Mengyao; Vienberg, Sara G; Bezy, Olivier

    2015-01-01

    metabolism by generating mice in which PKCδ was deleted specifically in muscle using Cre-lox recombination. Deletion of PKCδ in muscle improved insulin signaling in young mice, especially at low insulin doses; however, this did not change glucose tolerance or insulin tolerance tests done with pharmacological......-body insulin sensitivity and muscle insulin resistance and by 15 months of age improved the age-related decline in whole-body glucose tolerance. At 15 months of age, M-PKCδKO mice also exhibited decreased metabolic rate and lower levels of some proteins of the OXPHOS complex suggesting a role for PKCδ......Protein kinase C (PKC)δ has been shown to be increased in liver in obesity and plays an important role in the development of hepatic insulin resistance in both mice and humans. In the current study, we explored the role of PKCδ in skeletal muscle in the control of insulin sensitivity and glucose...

  7. Muscle Dysmorphia: Current Insights

    OpenAIRE

    Tod, D; Edwards,Christian; Cranswick, I

    2016-01-01

    David Tod1 Christian Edwards2 Ieuan Cranswick1 1School of Sport and Exercise Science, Faculty of Science, Liverpool John Moores University, Liverpool, Merseyside, 2Institute of Sport and Exercise Science, University of Worcester, Worcester, Worcestershire, UK Abstract: Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people’s beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scient...

  8. Gene therapy flexes muscle.

    Science.gov (United States)

    VandenDriessche, Thierry

    2005-09-01

    This commentary highlights the promising results of recent studies in animal models of Duchenne muscular dystrophy and amyotrophic lateral sclerosis that have clearly demonstrated the potential of gene therapy for tackling these diseases. In the absence of effective drugs or other treatments, these advances in gene therapy technology represent the best hope for those patients and families that are blighted by these diseases. Diseases characterized by progressive muscle degeneration are often incurable and affect a relatively large number of individuals. The progressive deterioration of muscle function is like the sword of Damocles that constantly reminds patients suffering from these diseases of their tragic fate, since most of them will eventually die from cardiac or pulmonary dysfunction. Some of these disorders are due to mutations in genes that directly influence the integrity of muscle fibers, such as in Duchenne muscular dystrophy (DMD), a recessive X-linked genetic disease. Others result from a progressive neurodegeneration of the motoneurons that are essential for maintaining muscle function, such as in amyotrophic lateral sclerosis (ALS), also commonly known as Lou Gehrig's disease. The genetic basis of DMD is relatively well understood as it is due to mutations in the dystrophin gene that encodes the cognate sarcolemmal protein. In contrast, the cause of ALS is poorly defined, with the exception of some dominantly inherited familial cases of ALS that are due to gain-of-function mutations in the gene encoding superoxide dismutase (SODG93A). Gene therapy for these disorders has been hampered by the inability to achieve widespread gene transfer. Moreover, since familial ALS is due to a dominant gain-of-function mutation, inhibition of gene expression (rather than gene augmentation) would be required to correct the phenotype, which is particularly challenging. Copyright (c) 2005 John Wiley & Sons, Ltd.

  9. Cardiac, skeletal, and smooth muscle mitochondrial respiration: are all mitochondria created equal?

    Science.gov (United States)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I; Trinity, Joel D; Hyngstrom, John R; Garten, Ryan S; Diakos, Nikolaos A; Ives, Stephen J; Dela, Flemming; Larsen, Steen; Drakos, Stavros; Richardson, Russell S

    2014-08-01

    Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial respiration. Therefore, the present study examined mitochondrial respiratory rates in smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscles. Cardiac, skeletal, and smooth muscles were harvested from a total of 22 subjects (53 ± 6 yr), and mitochondrial respiration was assessed in permeabilized fibers. Complex I + II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac to skeletal to smooth muscles (54 ± 1, 39 ± 4, and 15 ± 1 pmol·s(-1)·mg(-1), P respiration rates were normalized by CS (respiration per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, complex I state 2 normalized for CS activity, an index of nonphosphorylating respiration per mitochondrial content, increased progressively from cardiac to skeletal to smooth muscles, such that the respiratory control ratio, state 3/state 2 respiration, fell progressively from cardiac to skeletal to smooth muscles (5.3 ± 0.7, 3.2 ± 0.4, and 1.6 ± 0.3 pmol·s(-1)·mg(-1), P respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation and could potentially alter ROS production.

  10. Dismorfia muscular Muscle dysmorphia

    Directory of Open Access Journals (Sweden)

    Sheila Seleri Marques Assunção

    2002-12-01

    Full Text Available Preocupações mórbidas com a imagem corporal eram tidas até recentemente como problemas eminentemente femininos. Atualmente estas preocupações também têm sido encontradas no sexo masculino. A dismorfia muscular é um subtipo do transtorno dismórfico corporal que ocorre principalmente em homens que, apesar da grande hipertrofia muscular, consideram-se pequenos e fracos. Além de estar associada a prejuízos sociais, ocupacionais, recreativos e em outras áreas do funcionamento do indivíduo, a dismorfia muscular é também um fator de risco para o abuso de esteróides anabolizantes. Este artigo aborda aspectos epidemiológicos, etiológicos e padrões clínicos da dismorfia muscular, além de tecer comentários sobre estratégias de tratamento para este transtorno.Morbid concern over body image was considered, until recently, a female issue. Nowadays, it has been viewed as a common male disorder. Muscle dysmorphia, a subtype of a body dysmorphic disorder, affects men who, despite having clear muscular hypertroph,y see themselves as frail and small. Besides being associated to major social, leisure and occupational dysfunction, muscle dysmorphia is also a risk factor for the abuse of steroids. This article describes epidemiological, etiological and clinical characteristics of muscle dysmorphia and comments on its treatment strategy.

  11. Tendon-muscle crosstalk controls muscle bellies morphogenesis, which is mediated by cell death and retinoic acid signaling.

    Science.gov (United States)

    Rodriguez-Guzman, Maria; Montero, Juan A; Santesteban, Elena; Gañan, Yolanda; Macias, Domingo; Hurle, Juan M

    2007-02-01

    Vertebrate muscle morphogenesis is a complex developmental process, which remains quite yet unexplored at cellular and molecular level. In this work, we have found that sculpturing programmed cell death is a key morphogenetic process responsible for the formation of individual foot muscles in the developing avian limb. Muscle fibers are produced in excess in the precursor dorsal and ventral muscle masses of the limb bud and myofibers lacking junctions with digital tendons are eliminated via apoptosis. Microsurgical experiments to isolate the developing muscles from their specific tendons are consistent with a role for tendons in regulating survival of myogenic cells. Analysis of the expression of Raldh2 and local treatments with retinoic acid indicate that this signaling pathway mediates apoptosis in myogenic cells, appearing also involved in tendon maturation. Retinoic acid inhibition experiments led to defects in muscle belly segmentation and myotendinous junction formation. It is proposed that heterogeneous local distribution of retinoids controlled through Raldh2 and Cyp26A1 is responsible for matching the fleshy and the tendinous components of each muscle belly.

  12. Mitochondrial dysfunction and therapeutic approaches in respiratory and limb muscles of cancer cachectic mice.

    Science.gov (United States)

    Fermoselle, Clara; García-Arumí, Elena; Puig-Vilanova, Ester; Andreu, Antoni L; Urtreger, Alejandro J; de Kier Joffé, Elisa D Bal; Tejedor, Alberto; Puente-Maestu, Luís; Barreiro, Esther

    2013-09-01

    What is the central question of this study? We explored whether experimental cancer-induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles,and whether signalling pathways, proteasome and oxidative stress influence that process. What is the main finding and what is its importance? In cancer cachectic mice, MRC complexes and oxygen consumption were decreased in the diaphragm and gastrocnemius. Blockade of nuclear factor-κB and mitogen-activated protein kinase actions partly restored the muscle mass and force and corrected the MRC dysfunction,while concomitantly reducing tumour burden. Antioxidants improved mitochondrial oxygen consumption without eliciting effects on the loss of muscle mass and force or the tumour size,whereas bortezomib reduced tumour burden without influencing muscle mass and strength or MRC function. Abnormalities in mitochondrial content, morphology and function have been reported in several muscle-wasting conditions. We specifically explored whether experimental cancer-induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles, and whether signalling pathways, proteasomes and oxidative stress may influence that process. We evaluated complex I, II and IV enzyme activities (specific activity assays) and MRC oxygen consumption (polarographic measurements) in diaphragm and gastrocnemius of cachectic mice bearing the LP07 lung tumour, with and without treatment with N-acetylcysteine, bortezomib and nuclear factor-κB (sulfasalazine) and mitogen-activated protein kinases (MAPK, U0126) inhibitors (n = 10 per group for all groups). Whole-body and muscle weights and limb muscle force were also assessed in all rodents at baseline and after 1 month. Compared with control animals, cancer cachectic mice showed a significant reduction in body weight gain, smaller sizes of the diaphragm and gastrocnemius, lower

  13. Monitoring post mortem changes in porcine muscle through 2-D DIGE proteome analysis of Longissimus muscle exudate.

    Science.gov (United States)

    Di Luca, Alessio; Elia, Giuliano; Mullen, Anne Maria; Hamill, Ruth M

    2013-03-20

    Meat quality is a complex trait influenced by a range of factors with post mortem biochemical processes highly influential in defining ultimate quality. High resolution two-dimensional DIfference Gel Electrophoresis (2-D DIGE) and Western blot were applied to study the influence of post mortem meat ageing on the proteome of pork muscle. Exudate collected from the muscle following centrifugation was analysed at three timepoints representing a seven day meat ageing period. The intensity of 136 spots varied significantly (p meat ageing. Since cellular conditions alter with muscle ageing, changes in solubility may also contribute to observed abundance profiles. Muscle exudate provided valuable information about the pathways and processes underlying the post mortem ageing period, highlighting the importance of post mortem modification of proteins and their interaction for the development of meat quality traits.

  14. Smooth muscle cells in bovine cervical ripening and dilatation; contractility, degrading enzymes and inflammation

    NARCIS (Netherlands)

    van Engelen, E.

    2008-01-01

    Cervical ripening is a complex process of modification of cervical tissue that enables dilation of the cervix at parturition. Cervical smooth muscle tissue might play a role by contracting or by secretion of cytokines or MMPs. To assess a contractile role for the cervical smooth muscle cells in

  15. Mechanics of human triceps surae muscle in walking, running and jumping

    NARCIS (Netherlands)

    Hof, AL; Van Zandwijk, JP; Bobbert, AF; Bobbert, M.F.

    Length changes of the muscle-tendon complex (MTC) during activity are in part the result of length changes of the active muscle fibres, the contractile component (CC), and also in part the result of stretch of elastic structures [series-elastic component (SEC)], We used a force platform and

  16. Activation of respiratory muscles during respiratory muscle training.

    Science.gov (United States)

    Walterspacher, Stephan; Pietsch, Fabian; Walker, David Johannes; Röcker, Kai; Kabitz, Hans-Joachim

    2018-01-01

    It is unknown which respiratory muscles are mainly activated by respiratory muscle training. This study evaluated Inspiratory Pressure Threshold Loading (IPTL), Inspiratory Flow Resistive Loading (IFRL) and Voluntary Isocapnic Hyperpnea (VIH) with regard to electromyographic (EMG) activation of the sternocleidomastoid muscle (SCM), parasternal muscles (PARA) and the diaphragm (DIA) in randomized order. Surface EMG were analyzed at the end of each training session and normalized using the peak EMG recorded during maximum inspiratory maneuvers (Sniff nasal pressure: SnPna, maximal inspiratory mouth occlusion pressure: PImax). 41 healthy participants were included. Maximal activation was achieved for SCM by SnPna; the PImax activated predominantly PARA and DIA. Activations of SCM and PARA were higher in IPTL and VIH than for IFRL (pVIH (pVIH differ in activation of inspiratory respiratory muscles. Whereas all methods mainly stimulate accessory respiratory muscles, diaphragm activation was predominant in IPTL. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Physical rehabilitation improves muscle function following volumetric muscle loss injury

    OpenAIRE

    Aurora, Amit; Garg, Koyal; Benjamin T Corona; Walters, Thomas J.

    2014-01-01

    Background Given the clinical practice of prescribing physical rehabilitation for the treatment of VML injuries, the present study examined the functional and histomorphological adaptations in the volumetric muscle loss (VML) injured muscle to physical rehabilitation. Methods Tibialis anterior muscle VML injury was created in Lewis rats (n?=?32), and were randomly assigned to either sedentary (SED) or physical rehabilitation (RUN) group. After 1?week, RUN rats were given unlimited access to v...

  18. Lateral transmission of force is impaired in skeletal muscles of dystrophic mice and very old rats

    Science.gov (United States)

    Ramaswamy, Krishnan S; Palmer, Mark L; van der Meulen, Jack H; Renoux, Abigail; Kostrominova, Tatiana Y; Michele, Daniel E; Faulkner, John A

    2011-01-01

    The dystrophin–glycoprotein complex (DGC) provides an essential link from the muscle fibre cytoskeleton to the extracellular matrix. In dystrophic humans and mdx mice, mutations in the dystrophin gene disrupt the structure of the DGC causing severe damage to muscle fibres. In frog muscles, transmission of force laterally from an activated fibre to the muscle surface occurs without attenuation, but lateral transmission of force has not been demonstrated in mammalian muscles. A unique ‘yoke’ apparatus was developed that attached to the epimysium of muscles midway between the tendons and enabled the measurement of lateral force. We now report that in muscles of young wild-type (WT) mice and rats, compared over a wide range of longitudinal forces, forces transmitted laterally showed little or no decrement. In contrast, for muscles of mdx mice and very old rats, forces transmitted laterally were impaired severely. Muscles of both mdx mice and very old rats showed major reductions in the expression of dystrophin. We conclude that during contractions, forces developed by skeletal muscles of young WT mice and rats are transmitted laterally from fibre to fibre through the DGC without decrement. In contrast, in muscles of dystrophic or very old animals, disruptions in DGC structure and function impair lateral transmission of force causing instability and increased susceptibility of fibres to contraction-induced injury. PMID:21224224

  19. Complex Narratives

    NARCIS (Netherlands)

    Simons, J.; Buckland, W.

    2014-01-01

    In the opening chapter, "Complex Narratives," Jan Simons brings together narratology, game theory, and complexity theory to untangle the intricate nature of complex narratives in contemporary cinema. He presents an overview of the different concepts - forking path narratives, mind-game films,

  20. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  1. Sarcoglycan subcomplex expression in normal human smooth muscle.

    Science.gov (United States)

    Anastasi, Giuseppe; Cutroneo, Giuseppina; Sidoti, Antonina; Rinaldi, Carmen; Bruschetta, Daniele; Rizzo, Giuseppina; D'Angelo, Rosalia; Tarone, Guido; Amato, Aldo; Favaloro, Angelo

    2007-08-01

    The sarcoglycan complex (SGC) is a multimember transmembrane complex interacting with other members of the dystrophin-glycoprotein complex (DGC) to provide a mechanosignaling connection from the cytoskeleton to the extracellular matrix. The SGC consists of four proteins (alpha, beta, gamma, and delta). A fifth sarcoglycan subunit, epsilon-sarcoglycan, shows a wider tissue distribution. Recently, a novel sarcoglycan, the zeta-sarcoglycan, has been identified. All reports about the structure of SGC showed a common assumption of a tetrameric arrangement of sarcoglycans. Addressing this issue, our immunofluorescence and molecular results showed, for the first time, that all sarcoglycans are always detectable in all observed samples. Therefore, one intriguing possibility is the existence of a pentameric or hexameric complex considering zeta-sarcoglycan of SGC, which could present a higher or lower expression of a single sarcoglycan in conformity with muscle type--skeletal, cardiac, or smooth--or also in conformity with the origin of smooth muscle.

  2. Costameric proteins in human skeletal muscle during muscular inactivity.

    Science.gov (United States)

    Anastasi, Giuseppe; Cutroneo, Giuseppina; Santoro, Giuseppe; Arco, Alba; Rizzo, Giuseppina; Bramanti, Placido; Rinaldi, Carmen; Sidoti, Antonina; Amato, Aldo; Favaloro, Angelo

    2008-09-01

    Costameres are regions that are associated with the sarcolemma of skeletal muscle fibres and comprise proteins of the dystrophin-glycoprotein complex and vinculin-talin-integrin system. Costameres play both a mechanical and a signalling role, transmitting force from the contractile apparatus to the extracellular matrix in order to stabilize skeletal muscle fibres during contraction and relaxation. Recently, it was shown that bidirectional signalling occurs between sarcoglycans and integrins, with muscle agrin potentially interacting with both types of protein to enable signal transmission. Although numerous studies have been carried out on skeletal muscle diseases, such as Duchenne muscular dystrophy, recessive autosomal muscular dystrophies and other skeletal myopathies, insufficient data exist on the relationship between costameres and the pathology of the second motor nerve and between costameric proteins and muscle agrin in other conditions in which skeletal muscle atrophy occurs. Previously, we carried out a preliminary study on skeletal muscle from patients with sensitive-motor polyneuropathy, in which we analysed the distribution of sarcoglycans, integrins and agrin by immunostaining only. In the present study, we have examined the skeletal muscle fibres of ten patients with sensitive-motor polyneuropathy. We used immunofluorescence and reverse transcriptase PCR to examine the distribution of vinculin, talin and dystrophin, in addition to that of those proteins previously studied. Our aim was to characterize in greater detail the distribution and expression of costameric proteins and muscle agrin during this disease. In addition, we used transmission electron microscopy to evaluate the structural damage of the muscle fibres. The results showed that immunostaining of alpha 7B-integrin, beta 1D-integrin and muscle agrin appeared to be severely reduced, or almost absent, in the muscle fibres of the diseased patients, whereas staining of alpha 7A

  3. Muscle strength in myasthenia gravis

    DEFF Research Database (Denmark)

    Cejvanovic, S; Vissing, J

    2014-01-01

    is related to disease duration or gender. The aim of this study was to quantify the strength of patients with MG and investigate whether it is related to disease duration. METHODS: Eight muscle groups were tested by manual muscle testing and with a hand-held dynamometer in 38 patients with generalized MG...... and 37 healthy age- and gender-matched controls. The disease duration was recorded and compared with strength measures. RESULTS: On average, muscle strength was decreased by 28% compared with controls (Pstrength measures in individual patients did not differ, suggesting that the muscle...... force reported was not subject to fatigue, but reflected fixed weakness. The male patients showed a greater reduction in muscle force in all eight muscle groups than women with MG (60% vs 77% of normal, Pstrength in shoulder abductors was most affected (51% vs 62...

  4. Paraplegia increases skeletal muscle autophagy.

    Science.gov (United States)

    Fry, Christopher S; Drummond, Micah J; Lujan, Heidi L; DiCarlo, Stephen E; Rasmussen, Blake B

    2012-11-01

    Paraplegia results in significant skeletal muscle atrophy through increases in skeletal muscle protein breakdown. Recent work has identified a novel SIRT1-p53 pathway that is capable of regulating autophagy and protein breakdown. Soleus muscle was collected from 6 male Sprague-Dawley rats 10 weeks after complete T4-5 spinal cord transection (paraplegia group) and 6 male sham-operated rats (control group). We utilized immunoblotting methods to measure intracellular proteins and quantitative real-time polymerase chain reaction to measure the expression of skeletal muscle microRNAs. SIRT1 protein expression was 37% lower, and p53 acetylation (LYS379) was increased in the paraplegic rats (P paraplegia group compared with controls (P paraplegia appears to increase skeletal muscle autophagy independent of SIRT1 signaling. We conclude that chronic paraplegia may cause an increase in autophagic cell death and negatively impact skeletal muscle protein balance. Copyright © 2012 Wiley Periodicals, Inc.

  5. Matrix metalloproteinase-2 ablation in dystrophin-deficient mdx muscles reduces angiogenesis resulting in impaired growth of regenerated muscle fibers.

    Science.gov (United States)

    Miyazaki, Daigo; Nakamura, Akinori; Fukushima, Kazuhiro; Yoshida, Kunihiro; Takeda, Shin'ichi; Ikeda, Shu-ichi

    2011-05-01

    Matrix metalloproteases (MMPs) are a family of endopeptidases classified into subgroups based on substrate preference in normal physiological processes such as embryonic development and tissue remodeling, as well as in various disease processes via degradation of extracellular matrix components. Among the MMPs, MMP-9 and MMP-2 have been reported to be up-regulated in skeletal muscles in the lethal X-linked muscle disorder Duchenne muscular dystrophy (DMD), which is caused by loss of dystrophin. A recent study showed that deletion of the MMP9 gene in mdx, a mouse model for DMD, improved skeletal muscle pathology and function; however, the role of MMP-2 in the dystrophin-deficient muscle is not well known. In this study, we aimed at verifying the role of MMP-2 in the dystrophin-deficient muscle by using mdx mice with genetic ablation of MMP-2 (mdx/MMP-2(-/-)). We found impairment of regenerated muscle fiber growth with reduction of angiogenesis in mdx/MMP-2(-/-) mice at 3 months of age. Expression of vascular endothelial growth factor-A (VEGF-A), an important angiogenesis-related factor, decreased in mdx/MMP-2(-/-) mice at 3 months of age. MMP-2 had not a critical role in the degradation of dystrophin-glycoprotein complex (DGC) components such as β-dystroglycan and β-sarcoglycan in the regeneration process of the dystrophic muscle. Accordingly, MMP-2 may be essential for growth of regenerated muscle fibers through VEGF-associated angiogenesis in the dystrophin-deficient skeletal muscle.

  6. In-Vivo Measurement of Muscle Tension: Dynamic Properties of the MC Sensor during Isometric Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Srđan Đorđević

    2014-09-01

    Full Text Available Skeletal muscle is the largest tissue structure in our body and plays an essential role for producing motion through integrated action with bones, tendons, ligaments and joints, for stabilizing body position, for generation of heat through cell respiration and for blood glucose disposal. A key function of skeletal muscle is force generation. Non-invasive and selective measurement of muscle contraction force in the field and in clinical settings has always been challenging. The aim of our work has been to develop a sensor that can overcome these difficulties and therefore enable measurement of muscle force during different contraction conditions. In this study, we tested the mechanical properties of a “Muscle Contraction” (MC sensor during isometric muscle contraction in different length/tension conditions. The MC sensor is attached so that it indents the skin overlying a muscle group and detects varying degrees of tension during muscular contraction. We compared MC sensor readings over the biceps brachii (BB muscle to dynamometric measurements of force of elbow flexion, together with recordings of surface EMG signal of BB during isometric contractions at 15° and 90° of elbow flexion. Statistical correlation between MC signal and force was very high at 15° (r = 0.976 and 90° (r = 0.966 across the complete time domain. Normalized SD or σN = σ/max(FMC was used as a measure of linearity of MC signal and elbow flexion force in dynamic conditions. The average was 8.24% for an elbow angle of 90° and 10.01% for an elbow of angle 15°, which indicates high linearity and good dynamic properties of MC sensor signal when compared to elbow flexion force. The next step of testing MC sensor potential will be to measure tension of muscle-tendon complex in conditions when length and tension change simultaneously during human motion.

  7. Interaction between muscle aldolase and muscle fructose 1,6-bisphosphatase results in the substrate channeling.

    Science.gov (United States)

    Rakus, Darek; Pasek, Marta; Krotkiewski, Hubert; Dzugaj, Andrzej

    2004-11-30

    Fructose 1,6-bisphosphatase (FBPase) is known to form a supramolecular complex with alpha-actinin and aldolase on both sides of the Z-line in skeletal muscle cells. It has been proposed that association of aldolase with FBPase not only desensitizes muscle FBPase toward AMP inhibition but it also might enable the channeling of intermediates between the enzymes [Rakus et al. (2003) FEBS Lett. 547, 11-14]. In the present paper, we tested the possibility of fructose 1,6-bisphosphate (F1,6-P(2)) channeling between aldolase and FBPase using the approach in which an inactive form of FBPase competed with active FBPase for binding to aldolase and thus decreased the rate of aldolase-FBPase reaction. The results showed that F1,6-P(2) is transferred directly from aldolase to FBPase without mixing with the bulk phase. Further evidence that F1,6-P(2) is channeled from aldolase to FBPase comes from the experiments investigating the inhibitory effect of a high concentration of magnesium ions on aldolase-FBPase activity. FBPase in a complex with aldolase, contrary to free muscle FBPase, was not inhibited by high Mg(2+) concentrations, which suggests that free F1,6-P(2) was not present in the assay mixture during the reaction. A real-time interaction analysis between aldolase and FBPase revealed a dual role of Mg(2+) in the regulation of the aldolase-FBPase complex stability. A physiological concentration of Mg(2+) increased the affinity of muscle FBPase to muscle aldolase, whereas higher concentrations of the cation decreased the concentration of the complex. We hypothesized that the presence of Mg(2+) stabilizes a positively charged cavity within FBPase and that it might enable an interaction with aldolase. Because magnesium decreased the binding constant (K(a)) between aldolase and FBPase in a manner similar to the decrease of K(a) caused by monovalent cations, it is postulated that electrostatic attraction might be a driving force for the complex formation. It is presumed that

  8. Submental dermoid cyst: a case report | Saheeb | Orient Journal of ...

    African Journals Online (AJOL)

    Reason for reporting: This case is reported because it was first diagnosed when the patient was 6 months old but was not treated and presented in the clinic when it was causing aesthetic problems when the patient was 20 years old. Case Report: The patient was a 20-year old male with a sub mental swelling. The swelling ...

  9. Impaired oxygen utilization in skeletal muscle of CRPS I patients.

    NARCIS (Netherlands)

    Tan, E.C.T.H.; Laak, H.J. ter; Hopman, M.T.E.; Goor, H. van; Goris, R.J.A.

    2012-01-01

    BACKGROUND: The purpose of this study was to evaluate oxygen extraction and utilization in end stage chronic complex regional pain syndrome type I (CRPS I) patients undergoing amputation and to relate these to muscle histology of the amputated limb. MATERIALS AND METHODS: In 25 patients with severe

  10. Myosin Heavy Chain Composition of the Human Genioglossus Muscle

    Science.gov (United States)

    Daugherty, Megan; Luo, Qingwei; Sokoloff, Alan J.

    2012-01-01

    Background: The human tongue muscle genioglossus (GG) is active in speech, swallowing, respiration, and oral transport, behaviors encompassing a wide range of tongue shapes and movement speeds. Studies demonstrate substantial diversity in patterns of human GG motor unit activation, but whether this is accompanied by complex expression of muscle…

  11. Association of smooth muscle cell tissue factor with caveolae

    NARCIS (Netherlands)

    Mulder, AB; Smit, JW; Bom, VJJ; Blom, NR; Ruiters, MHJ; Halie, MR; vanderMeer, J

    1996-01-01

    There is still no satisfactory explanation for the low catalytic activity of tissue factor (TF)/factor VII(a) complexes towards coagulation factor X, as found on the apical surface side of cell layers. It has been hypothesized that TF exists in a latent form. Layers of cultured human smooth muscle

  12. Muscle dysmorphia: current insights.

    Science.gov (United States)

    Tod, David; Edwards, Christian; Cranswick, Ieuan

    2016-01-01

    Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people's beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the condition beyond knowledge about their characteristics. Much of the existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples), which are largely confined to Western (North American, British, and Australian) males. Although much research has been undertaken since the term "muscle dysmorphia" entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent to which the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base than currently exists. Future work will help clinicians assist a group of people whose quality of life and health are placed at risk by their muscular preoccupation.

  13. Muscle dysmorphia: current insights

    Directory of Open Access Journals (Sweden)

    Tod D

    2016-08-01

    Full Text Available David Tod1 Christian Edwards2 Ieuan Cranswick1 1School of Sport and Exercise Science, Faculty of Science, Liverpool John Moores University, Liverpool, Merseyside, 2Institute of Sport and Exercise Science, University of Worcester, Worcester, Worcestershire, UK Abstract: Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people’s beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the condition beyond knowledge about their characteristics. Much of the existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples, which are largely confined to Western (North American, British, and Australian males. Although much research has been undertaken since the term “muscle dysmorphia” entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent to which the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base

  14. A review of concepts regarding the origin of respiratory muscle fatigue

    Science.gov (United States)

    Kuraszkiewicz, Bożena; Piotrkiewicz, Maria

    2011-01-01

    In this review, the classification of respiratory muscle fatigue from the perspective of its origin is presented. The fatigue is classified as central or peripheral, and the latter further subdivided into high- and low-frequency fatigue. However, muscle fatigue is a complex process and all three types of fatigue probably occur simultaneously in the overloaded respiratory muscles. The relative importance of each type depends on the duration of respiratory loading and other physiological variables. However, central and high-frequency fatigue resolve rapidly once muscle overload is removed, whereas low-frequency fatigue persists over long time.

  15. Lipolysis in Skeletal Muscle

    DEFF Research Database (Denmark)

    Serup, Annette Karen Lundbeck

    Lipid is stored as triacylglycerol (TG) in lipid droplets and is in skeletal muscle stored as intra muscular triacylglycerol (IMTG). IMTG is considered an energy pool that is utilized by lipolysis during situations with low cellular energy availability, such as exercise. Lipolysis is in skeletal ......, is not an important signaling molecule in the mechanism behind insulin resistance and type 2 diabetes The findings of this PhD thesis are presented in one manuscript and in one published paper. In addition, the thesis comprises unpublished work....

  16. Mechanical Properties of Respiratory Muscles

    Science.gov (United States)

    Sieck, Gary C.; Ferreira, Leonardo F.; Reid, Michael B.; Mantilla, Carlos B.

    2014-01-01

    Striated respiratory muscles are necessary for lung ventilation and to maintain the patency of the upper airway. The basic structural and functional properties of respiratory muscles are similar to those of other striated muscles (both skeletal and cardiac). The sarcomere is the fundamental organizational unit of striated muscles and sarcomeric proteins underlie the passive and active mechanical properties of muscle fibers. In this respect, the functional categorization of different fiber types provides a conceptual framework to understand the physiological properties of respiratory muscles. Within the sarcomere, the interaction between the thick and thin filaments at the level of cross-bridges provides the elementary unit of force generation and contraction. Key to an understanding of the unique functional differences across muscle fiber types are differences in cross-bridge recruitment and cycling that relate to the expression of different myosin heavy chain isoforms in the thick filament. The active mechanical properties of muscle fibers are characterized by the relationship between myoplasmic Ca2+ and cross-bridge recruitment, force generation and sarcomere length (also cross-bridge recruitment), external load and shortening velocity (cross-bridge cycling rate), and cross-bridge cycling rate and ATP consumption. Passive mechanical properties are also important reflecting viscoelastic elements within sarcomeres as well as the extracellular matrix. Conditions that affect respiratory muscle performance may have a range of underlying pathophysiological causes, but their manifestations will depend on their impact on these basic elemental structures. PMID:24265238

  17. Skeletal Muscle Insulin Resistance in Endocrine Disease

    Directory of Open Access Journals (Sweden)

    Melpomeni Peppa

    2010-01-01

    Full Text Available We summarize the existing literature data concerning the involvement of skeletal muscle (SM in whole body glucose homeostasis and the contribution of SM insulin resistance (IR to the metabolic derangements observed in several endocrine disorders, including polycystic ovary syndrome (PCOS, adrenal disorders and thyroid function abnormalities. IR in PCOS is associated with a unique postbinding defect in insulin receptor signaling in general and in SM in particular, due to a complex interaction between genetic and environmental factors. Adrenal hormone excess is also associated with disrupted insulin action in peripheral tissues, such as SM. Furthermore, both hyper- and hypothyroidism are thought to be insulin resistant states, due to insulin receptor and postreceptor defects. Further studies are definitely needed in order to unravel the underlying pathogenetic mechanisms. In summary, the principal mechanisms involved in muscle IR in the endocrine diseases reviewed herein include abnormal phosphorylation of insulin signaling proteins, altered muscle fiber composition, reduced transcapillary insulin delivery, decreased glycogen synthesis, and impaired mitochondrial oxidative metabolism.

  18. Neuroimaging of Muscle Pain in Humans

    Directory of Open Access Journals (Sweden)

    David M. Niddam

    2009-06-01

    Full Text Available Neuroimaging has provided important information on how acute and chronic pain is processed in the human brain. The pain experience is now known to be the final product of activity in distributed networks consisting of multiple cortical and subcortical areas. Due to the complex nature of the pain experience, a single cerebral representation of pain does not exist. Instead, pain depends on the context in which it is experienced and is generated through variable expression of the different aspects of pain in conjunction with modulatory influences. While considerable data have been generated about the supraspinal organization of cutaneous pain, little is known about how nociceptive information from musculoskeletal tissue is processed in the brain. This is in spite of the fact that pain from musculoskeletal tissue is more frequently encountered in clinical practice, poses a bigger diagnostic problem and is insufficiently treated. Differences are known to exist between acute pain from cutaneous and muscular tissue in both psychophysical responses as well as in physiological characteristics. The 2 tissue types also differ in pain sensitivity to the same stimuli and in their response to analgesic substances. In this review, characteristics of acute and chronic muscle pain will be presented together with a brief overview of the methods of induction and psychophysical assessment of muscle pain. Results from the neuroimaging literature concerned with phasic and tonic muscle pain will be reviewed.

  19. Structural model of the muscle spindle.

    Science.gov (United States)

    Lin, Chou-Ching K; Crago, Patrick E

    2002-01-01

    A model of the muscle spindle was developed based on its anatomical structure. The model contains three intrafusal fibers (bag1, bag2, and chain), two efferents (dynamic gamma efferent to the bag1 fiber and static gamma efferent to bag2 and chain fibers), and two afferents [primary (Ia) and secondary (II)]. As in the real muscle spindle, the spindle model, under the modulation of gamma efferents, responds to the extrafusal muscle fiber length. Both outputs (Ia and II afferents) of the model were compared extensively with published data, under both sinusoidal stretch (with different stretch amplitudes and frequencies) and ramp and hold stretch (with different stretch amplitudes and velocities) in three different fusimotor activation conditions (dynamic gamma stimulation, static gamma stimulation, and without gamma stimulation). Model Ia afferent responses fit the published data well with active gamma input, but less well in the passive state. Model II afferent responses also fit the published data, although less quantitative data were available for comparison. The model correctly predicted the fractional power dependence of the primary and secondary ending responses on stretch velocity. The current model provides a powerful tool for simulation studies of neuromusculoskeletal systems, and demonstrates the feasibility of using a structural approach to model complex neurophysiological systems.

  20. Nutritional interventions to preserve skeletal muscle mass

    NARCIS (Netherlands)

    Backx, Evelien M.P.

    2016-01-01

    Muscle mass is the main predictor for muscle strength and physical function. The amount of muscle mass can decline rapidly during periods of reduced physical activity or during periods of energy intake restriction. For athletes, it is important to maintain muscle mass, since the loss of muscle is

  1. Unravelling the complexities of vascular smooth muscle ion channels

    DEFF Research Database (Denmark)

    Jepps, Thomas A

    2017-01-01

    Which ion channel is the most important for regulating vascular tone? Which one is responsible for controlling the resting membrane potential or repolarization? Which channels are recruited by different intracellular signalling pathways or change in certain vascular diseases? Many different ion...... to off-target effects. As cardiovascular diseases are expected to increase worldwide to epidemic proportions, ion channel research and the hunt for the next major therapeutic target to treat different vascular diseases has never been more important. However, I believe that the question we should now...

  2. Role of Muscle Relaxant (Tizanidine) In Painful Muscle Spasm ...

    African Journals Online (AJOL)

    Objective: To evaluate effectiveness and tolerability of Tizanidine in painful muscle spasm of various etiologies. Patients and ... Inclusion criteria included all the patients suffering from painful muscle spasm in back, neck, shoulder, knee or other anatomical sites with onset not more than two days prior to presentation.

  3. Increased muscle perfusion reduces muscle sympathetic nerve activity during handgripping

    NARCIS (Netherlands)

    Joyner, M. J.; Wieling, W.

    1993-01-01

    This study sought to determine whether increasing blood flow to active muscles can blunt the normal rise in muscle sympathetic nerve activity (MSNA) during heavy rhythmic forearm exercise in humans. Subjects performed 5- to 6-min exercise bouts of handgripping (30/min) at 40-50% of maximum voluntary

  4. Trunk extensor muscle fatigue influences trunk muscle activities.

    Science.gov (United States)

    Hoseinpoor, Tahere Seyed; Kahrizi, Sedighe; Mobini, Bahram

    2015-01-01

    Trunk muscles fatigue is one of the risk factors in workplaces and daily activities. Loads would be redistributed among active and passive tissues in a non-optimal manner in fatigue conditions. Therefore, a single tissue might be overloaded with minimal loads and as a result the risk of injury would increase. The goal of this paper was to assess the electromyographic response of trunk extensor and abdominal muscles after trunk extensor muscles fatigue induced by cyclic lifting task. This was an experimental study that twenty healthy women participated. For assessing automatic response of trunk extensor and abdominal muscles before and after the fatigue task, electromyographic activities of 6 muscles: thorasic erector spine (TES), lumbar erector spine (LES), lumbar multifidus (LMF), transverse abdominis/ internal oblique (TrA/IO), rectus abdominis (RA) and external oblique (EO) were recorded in standing position with no load and symmetric axial loads equal to 25% of their body weights. Statistical analysis showed that all the abdominal muscles activity decreased with axial loads after performing fatigue task but trunk extensor activity remained constant. Results of the current study indicated that muscle recruitment strategies changed with muscle fatigue and load bearing, therefore risks of tissue injury may increase in fatigue conditions.

  5. Exercise and amino acid anabolic cell signaling and the regulation of skeletal muscle mass.

    Science.gov (United States)

    Pasiakos, Stefan M

    2012-07-01

    A series of complex intracellular networks influence the regulation of skeletal muscle protein turnover. In recent years, studies have examined how cellular regulators of muscle protein turnover modulate metabolic mechanisms contributing to the loss, gain, or conservation of skeletal muscle mass. Exercise and amino acids both stimulate anabolic signaling potentially through several intracellular pathways including the mammalian target of rapamycin complex 1 and the mitogen activated protein kinase cell signaling cascades. As novel molecular regulators of muscle integrity continue to be explored, a contemporary analysis of the literature is required to understand the metabolic mechanisms by which contractile forces and amino acids affect cellular process that contribute to long-term adaptations and preservation of muscle mass. This article reviews the literature related to how exercise and amino acid availability affect cellular regulators of skeletal muscle mass, especially highlighting recent investigations that have identified mechanisms by which contractile forces and amino acids modulate muscle health. Furthermore, this review will explore integrated exercise and nutrition strategies that promote the maintenance of muscle health by optimizing exercise, and amino acid-induced cell signaling in aging adults susceptible to muscle loss.

  6. HEXIM1 controls satellite cell expansion after injury to regulate skeletal muscle regeneration

    Science.gov (United States)

    Hong, Peng; Chen, Kang; Huang, Bihui; Liu, Min; Cui, Miao; Rozenberg, Inna; Chaqour, Brahim; Pan, Xiaoyue; Barton, Elisabeth R.; Jiang, Xian-Cheng; Siddiqui, M.A.Q.

    2012-01-01

    The native capacity of adult skeletal muscles to regenerate is vital to the recovery from physical injuries and dystrophic diseases. Currently, the development of therapeutic interventions has been hindered by the complex regulatory network underlying the process of muscle regeneration. Using a mouse model of skeletal muscle regeneration after injury, we identified hexamethylene bisacetamide inducible 1 (HEXIM1, also referred to as CLP-1), the inhibitory component of the positive transcription elongation factor b (P-TEFb) complex, as a pivotal regulator of skeletal muscle regeneration. Hexim1-haplodeficient muscles exhibited greater mass and preserved function compared with those of WT muscles after injury, as a result of enhanced expansion of satellite cells. Transplanted Hexim1-haplodeficient satellite cells expanded and improved muscle regeneration more effectively than WT satellite cells. Conversely, HEXIM1 overexpression restrained satellite cell proliferation and impeded muscle regeneration. Mechanistically, dissociation of HEXIM1 from P-TEFb and subsequent activation of P-TEFb are required for satellite cell proliferation and the prevention of early myogenic differentiation. These findings suggest a crucial role for the HEXIM1/P-TEFb pathway in the regulation of satellite cell–mediated muscle regeneration and identify HEXIM1 as a potential therapeutic target for degenerative muscular diseases. PMID:23023707

  7. Exercise and Amino Acid Anabolic Cell Signaling and the Regulation of Skeletal Muscle Mass

    Directory of Open Access Journals (Sweden)

    Stefan M. Pasiakos

    2012-07-01

    Full Text Available A series of complex intracellular networks influence the regulation of skeletal muscle protein turnover. In recent years, studies have examined how cellular regulators of muscle protein turnover modulate metabolic mechanisms contributing to the loss, gain, or conservation of skeletal muscle mass. Exercise and amino acids both stimulate anabolic signaling potentially through several intracellular pathways including the mammalian target of rapamycin complex 1 and the mitogen activated protein kinase cell signaling cascades. As novel molecular regulators of muscle integrity continue to be explored, a contemporary analysis of the literature is required to understand the metabolic mechanisms by which contractile forces and amino acids affect cellular process that contribute to long-term adaptations and preservation of muscle mass. This article reviews the literature related to how exercise and amino acid availability affect cellular regulators of skeletal muscle mass, especially highlighting recent investigations that have identified mechanisms by which contractile forces and amino acids modulate muscle health. Furthermore, this review will explore integrated exercise and nutrition strategies that promote the maintenance of muscle health by optimizing exercise, and amino acid-induced cell signaling in aging adults susceptible to muscle loss.

  8. Complexity Plots

    KAUST Repository

    Thiyagalingam, Jeyarajan

    2013-06-01

    In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  9. Muscle Quality, Strength, and Lower Extremity Physical Performance in the Baltimore Longitudinal Study of Aging.

    Science.gov (United States)

    Chiles Shaffer, N; Fabbri, E; Ferrucci, L; Shardell, M; Simonsick, E M; Studenski, S

    2017-01-01

    Muscle quality is defined as the force generated by each volumetric unit of muscle tissue. No consensus exists on an optimal measure of muscle quality, impeding comparison across studies and implementation in clinical settings. It is unknown whether muscle quality measures that rely on complex and expensive tests, such as isokinetic dynamometry and computerized tomography correlate with lower extremity performance (LEP) any better than measures derived from simpler and less expensive tests, such as grip strength (Grip) and appendicular lean mass (ALM) assessed by DXA. Additionally, whether muscle quality is more strongly associated with LEP than strength has not been fully tested. This study compares the concurrent validity of alternative measures of muscle quality and characterizes their relationship with LEP. We also whether muscle quality correlates more strongly with LEP than strength alone. Cross-sectional analysis. Community. 365 men and 345 women 65 years of age and older in the Baltimore Longitudinal Study of Aging. Thigh cross-sectional area (TCSA), isokinetic and isometric knee extension strength (ID), BMI adjusted ALM (ALMBMI) from DXA, and Grip. Concurrent validity was assessed as the percent variance of different measures of LEP explained by each muscle quality measure. In addition, we compared LEP relationships between each measure of strength and its correspondent value of muscle quality. Confidence intervals for differences in percent variance were calculated by bootstrapping. Grip/ALMBMI explained as much variance as ID/TCSA across all LEP measures in women and most in men. Across all LEP measures, strength explained as much variance of LEP as muscle quality. Grip/ALMBMI and ID/TCSA measures had similar correlations with LEP. Muscle quality did not outperform strength. Although evaluating muscle quality may be useful to assess age-related mechanisms of change in muscle strength, measures of strength alone may suffice to understand the relationship

  10. The interscutularis muscle connectome.

    Directory of Open Access Journals (Sweden)

    Ju Lu

    2009-02-01

    Full Text Available The complete connectional map (connectome of a neural circuit is essential for understanding its structure and function. Such maps have only been obtained in Caenorhabditis elegans. As an attempt at solving mammalian circuits, we reconstructed the connectomes of six interscutularis muscles from adult transgenic mice expressing fluorescent proteins in all motor axons. The reconstruction revealed several organizational principles of the neuromuscular circuit. First, the connectomes demonstrate the anatomical basis of the graded tensions in the size principle. Second, they reveal a robust quantitative relationship between axonal caliber, length, and synapse number. Third, they permit a direct comparison of the same neuron on the left and right sides of the same vertebrate animal, and reveal significant structural variations among such neurons, which contrast with the stereotypy of identified neurons in invertebrates. Finally, the wiring length of axons is often longer than necessary, contrary to the widely held view that neural wiring length should be minimized. These results show that mammalian muscle function is implemented with a variety of wiring diagrams that share certain global features but differ substantially in anatomical form. This variability may arise from the dominant role of synaptic competition in establishing the final circuit.

  11. Amphiphilic block copolymers promote gene delivery in vivo to pathological skeletal muscles.

    Science.gov (United States)

    Richard, Peggy; Bossard, Florian; Desigaux, Lea; Lanctin, Caroline; Bello-Roufai, Mahajoub; Pitard, Bruno

    2005-11-01

    We reported that amphiphilic block copolymers hold promise as nonviral vectors for the delivery of plasmid DNA, ranging from 4.7 to 6.2 kb, to healthy muscle for the production of local or secreted proteins. To evaluate the efficiency of these vectors to deliver large plasmid DNA molecules to pathological muscles, plasmid DNAs of various lengths were complexed with Lutrol or poloxamine 304 and injected intramuscularly into dystrophic muscles. Lutrol-DNA and poloxamine 304-DNA complexes promoted gene transfer into muscles of the naturally occurring mouse model for DMD (mdx) in a dose- and plasmid DNA size-dependent manner. For small plasmid DNAs encoding reporter genes, this improvement over naked DNA was smaller in mdx than in the wild-type control strain. By contrast, Lutrol enabled us to deliver the large plasmid (16.1 kb) encoding the rod-deleted dystrophin in mdx mouse muscle, whereas the same amount of naked DNA did not lead to dystrophin expression, under the same experimental conditions. Lutrol-treated mdx mice showed the production of dystrophin in large numbers of muscle fibers. More importantly, we also found that expressing dystrophin with Lutrol led to restoration of the dystrophin-associated protein complex. Thus, we conclude that block copolymers constitute a novel class of vectors for the delivery of large plasmid DNA not only to healthy muscles but also to pathological muscle tissues.

  12. carbene complexes

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Reaction of oligomeric Cu(I) complexes [Cu{µ-S-C(=NR)(O–Ar–CH3)}]n with Lewis acids gave Cu(I) carbene complexes, which were characterized by 1H and 13C NMR spectroscopy. Cu(I) car- bene complexes could be directly generated from RNCS, Cu(I)–OAr and Lewis acids; this method can be used to ...

  13. Classification and grading of muscle injuries: a narrative review.

    Science.gov (United States)

    Hamilton, Bruce; Valle, Xavier; Rodas, Gil; Til, Luis; Grive, Ricard Pruna; Rincon, Josep Antoni Gutierrez; Tol, Johannes L

    2015-03-01

    A limitation to the accurate study of muscle injuries and their management has been the lack of a uniform approach to the categorisation and grading of muscle injuries. The goal of this narrative review was to provide a framework from which to understand the historical progression of the classification and grading of muscle injuries. We reviewed the classification and grading of muscle injuries in the literature to critically illustrate the strengths, weaknesses, contradictions or controversies. A retrospective, citation-based methodology was applied to search for English language literature which evaluated or utilised a novel muscle classification or grading system. While there is an abundance of literature classifying and grading muscle injuries, it is predominantly expert opinion, and there remains little evidence relating any of the clinical or radiological features to an established pathology or clinical outcome. While the categorical grading of injury severity may have been a reasonable solution to a clinical challenge identified in the middle of the 20th century, it is time to recognise the complexity of the injury, cease trying to oversimplify it and to develop appropriately powered research projects to answer important questions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Mimicking Muscle Nonlinear Force Generation using Electromagnetic Motors

    Science.gov (United States)

    Alvarado, José; Hosoi, Anette

    Animals routinely perform a wide range of mechanical tasks, including locomotion, and continue to inspire solutions in engineering applications. Yet despite numerous technological advances, robotic locomotion lags behind that of animals in terms of versatility and energy economy. One reason for this performance gap lies in actuation: electromagnetic motors are common actuators in engineered systems, whereas animals primarily use muscle. Researchers have long modeled muscle with a nonlinear force-velocity relationship, in contrast to motors' linear behavior. Existing theoretical studies have predicted advantages to nonlinear force generation, including energy economy, stability, and simplified controls. Yet these advantages are difficult to verify experimentally because the force-velocity curve of intact muscle cannot be made linear. Here we establish a physical model system of muscle nonlinearity by programming an electromagnetic motor to exhibit linear and nonlinear behavior. Preliminary experimental and theoretical results show that for the simple task of lifting a weight against gravity, muscle-like nonlinearity merely reduces work output. We anticipate that for more complex mechanical tasks, muscle's nonlinear properties could be mechanically advantageous. Army Research Office Grant #W911NF-14-1-0396.

  15. Classification and grading of muscle injuries: a narrative review

    Science.gov (United States)

    Hamilton, Bruce; Valle, Xavier; Rodas, Gil; Til, Luis; Grive, Ricard Pruna; Rincon, Josep Antoni Gutierrez; Tol, Johannes L

    2015-01-01

    A limitation to the accurate study of muscle injuries and their management has been the lack of a uniform approach to the categorisation and grading of muscle injuries. The goal of this narrative review was to provide a framework from which to understand the historical progression of the classification and grading of muscle injuries. We reviewed the classification and grading of muscle injuries in the literature to critically illustrate the strengths, weaknesses, contradictions or controversies. A retrospective, citation-based methodology was applied to search for English language literature which evaluated or utilised a novel muscle classification or grading system. While there is an abundance of literature classifying and grading muscle injuries, it is predominantly expert opinion, and there remains little evidence relating any of the clinical or radiological features to an established pathology or clinical outcome. While the categorical grading of injury severity may have been a reasonable solution to a clinical challenge identified in the middle of the 20th century, it is time to recognise the complexity of the injury, cease trying to oversimplify it and to develop appropriately powered research projects to answer important questions. PMID:25394420

  16. Impact of placental insufficiency on fetal skeletal muscle growth.

    Science.gov (United States)

    Brown, Laura D; Hay, William W

    2016-11-05

    Intrauterine growth restriction (IUGR) caused by placental insufficiency is one of the most common and complex problems in perinatology, with no known cure. In pregnancies affected by placental insufficiency, a poorly functioning placenta restricts nutrient supply to the fetus and prevents normal fetal growth. Among other significant deficits in organ development, the IUGR fetus characteristically has less lean body and skeletal muscle mass than their appropriately-grown counterparts. Reduced skeletal muscle growth is not fully compensated after birth, as individuals who were born small for gestational age (SGA) from IUGR have persistent reductions in muscle mass and strength into adulthood. The consequences of restricted muscle growth and accelerated postnatal "catch-up" growth in the form of adiposity may contribute to the increased later life risk for visceral adiposity, peripheral insulin resistance, diabetes, and cardiovascular disease in individuals who were formerly IUGR. This review will discuss how an insufficient placenta results in impaired fetal skeletal muscle growth and how lifelong reductions in muscle mass might contribute to increased metabolic disease risk in this vulnerable population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Muscle force compensation among synergistic muscles after fatigue of a single muscle.

    Science.gov (United States)

    Stutzig, Norman; Siebert, Tobias

    2015-08-01

    The aim of this study was to examine control strategies among synergistic muscles after fatigue of a single muscle. It was hypothesized that the compensating mechanism is specific for each fatigued muscle. The soleus (SOL), gastrocnemius lateralis (GL) and medialis (GM) were fatigued in separate sessions on different days. In each experiment, subjects (n = 11) performed maximal voluntary contractions prior to and after fatiguing a single muscle (SOL, GL or GM) while the voluntary muscle activity and torque were measured. Additionally, the maximal single twitch torque of the plantarflexors and the maximal spinal reflex activity (H-reflex) of the SOL, GL and GM were determined. Fatigue was evoked using neuromuscular stimulation. Following fatigue the single twitch torque decreased by -20.1%, -19.5%, and -23.0% when the SOL, GL, or GM, have been fatigued. The maximal voluntary torque did not decrease in any session but the synergistic voluntary muscle activity increased significantly. Moreover, we found no alterations in spinal reflex activity. It is concluded that synergistic muscles compensate each other. Furthermore, it seems that self-compensating mechanism of the fatigued muscles occurred additionally. The force compensation does not depend on the function of the fatigued muscle. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Biomarkers of mitochondrial content in skeletal muscle of healthy young human subjects

    DEFF Research Database (Denmark)

    Larsen, Steen; Nielsen, Joachim; Neigaard Nielsen, Christina

    2012-01-01

    Skeletal muscle mitochondrial content varies extensively between human subjects. Biochemical measures of mitochondrial proteins, enzyme activities and lipids are often used as markers of mitochondrial content and muscle oxidative capacity (OXPHOS). The purpose of this study was to determine how...... closely associated these commonly used biochemical measures are to muscle mitochondrial content and muscle oxidative capacity (OXPHOS).Sixteen young healthy male subjects were recruited for this study. Subjects completed a graded exercise test to determine maximal oxygen uptake (VO(2peak)) and muscle......, mitochondrial DNA content, complex I-V protein content, and complex I-IV activity. Spearman correlation coefficient tests and Lin's concordance tests were applied to assess the absolute and relative association between the markers and mitochondrial content or OXPHOS.Subjects had a large range in VO(2peak...

  19. Design and optimization of multi-class series-parallel linear electromagnetic array artificial muscle.

    Science.gov (United States)

    Li, Jing; Ji, Zhenyu; Shi, Xuetao; You, Fusheng; Fu, Feng; Liu, Ruigang; Xia, Junying; Wang, Nan; Bai, Jing; Wang, Zhanxi; Qin, Xiansheng; Dong, Xiuzhen

    2014-01-01

    Skeletal muscle exhibiting complex and excellent precision has evolved for millions of years. Skeletal muscle has better performance and simpler structure compared with existing driving modes. Artificial muscle may be designed by analyzing and imitating properties and structure of skeletal muscle based on bionics, which has been focused on by bionic researchers, and a structure mode of linear electromagnetic array artificial muscle has been designed in this paper. Half sarcomere is the minimum unit of artificial muscle and electromagnetic model has been built. The structural parameters of artificial half sarcomere actuator were optimized to achieve better movement performance. Experimental results show that artificial half sarcomere actuator possesses great motion performance such as high response speed, great acceleration, small weight and size, robustness, etc., which presents a promising application prospect of artificial half sarcomere actuator.

  20. Protecting Skeletal Muscle with Protein and Amino Acid during Periods of Disuse

    Directory of Open Access Journals (Sweden)

    Elfego Galvan

    2016-07-01

    Full Text Available Habitual sedentary behavior increases risk of chronic disease, hospitalization and poor quality of life. Short-term bed rest or disuse accelerates the loss of muscle mass, function, and glucose tolerance. Optimizing nutritional practices and protein intake may reduce the consequences of disuse by preserving metabolic homeostasis and muscle mass and function. Most modes of physical inactivity have the potential to negatively impact the health of older adults more than their younger counterparts. Mechanistically, mammalian target of rapamycin complex 1 (mTORC1 signaling and muscle protein synthesis are negatively affected by disuse. This contributes to reduced muscle quality and is accompanied by impaired glucose regulation. Simply encouraging increased protein and/or energy consumption is a well-intentioned, but often impractical strategy to protect muscle health. Emerging evidence suggests that leucine supplemented meals may partially and temporarily protect skeletal muscle during disuse by preserving anabolism and mitigating reductions in mass, function and metabolic homeostasis.

  1. Data on mitochondrial function in skeletal muscle of old mice in response to different exercise intensity.

    Science.gov (United States)

    Kang, Chounghun; Lim, Wonchung

    2016-06-01

    Endurance exercise is securely linked to muscle metabolic adaptations including enhanced mitochondrial function ("Effects of exercise on mitochondrial oxygen uptake and respiratory enzyme activity in skeletal muscle" [1], "Effects of exercise on mitochondrial content and function in aging human skeletal muscle" [2]). However, the link between exercise intensity and mitochondrial function in aging muscle has not been fully investigated. In order to understand how strenuous exercise affects mitochondrial function in aged mice, male C57BL/6 mice at age 24 months were randomly assigned to 3 groups: non-exercise (NE), low-intensity (LE) and high-intensity treadmill exercise group (HE). Mitochondrial complex activity and respiration were measured to evaluate mitochondrial function in mouse skeletal muscle. The data described here are related to the research article entitled "Strenuous exercise induces mitochondrial damage in skeletal muscle of old mice" [3].

  2. Muscle Strength and Muscle Mass in Older Patients during Hospitalization : The EMPOWER Study

    NARCIS (Netherlands)

    Van Ancum, Jeanine M; Scheerman, Kira; Pierik, Vincent D; Numans, Siger T; Verlaan, Sjors; Smeenk, Hanne E.; Slee-Valentijn, Monique; Kruizinga, Roeliene C.; Meskers, Carel G M; Maier, Andrea B

    2017-01-01

    BACKGROUND: Low muscle strength and muscle mass are associated with an increased length of hospital stay and higher mortality rate in inpatients. To what extent hospitalization affects muscle strength and muscle mass is unclear. OBJECTIVE: We aimed to assess muscle strength and muscle mass at

  3. Muscle MRI findings in facioscapulohumeral muscular dystrophy.

    Science.gov (United States)

    Gerevini, Simonetta; Scarlato, Marina; Maggi, Lorenzo; Cava, Mariangela; Caliendo, Giandomenico; Pasanisi, Barbara; Falini, Andrea; Previtali, Stefano Carlo; Morandi, Lucia

    2016-03-01

    Facioscapulohumeral muscular dystrophy (FSHD) is characterized by extremely variable degrees of facial, scapular and lower limb muscle involvement. Clinical and genetic determination can be difficult, as molecular analysis is not always definitive, and other similar muscle disorders may have overlapping clinical manifestations. Whole-body muscle MRI examination for fat infiltration, atrophy and oedema was performed to identify specific patterns of muscle involvement in FSHD patients (30 subjects), and compared to a group of control patients (23) affected by other myopathies (NFSHD). In FSHD patients, we detected a specific pattern of muscle fatty replacement and atrophy, particularly in upper girdle muscles. The most frequently affected muscles, including paucisymptomatic and severely affected FSHD patients, were trapezius, teres major and serratus anterior. Moreover, asymmetric muscle involvement was significantly higher in FSHD as compared to NFSHD patients. In conclusion, muscle MRI is very sensitive for identifying a specific pattern of involvement in FSHD patients and in detecting selective muscle involvement of non-clinically testable muscles. Muscle MRI constitutes a reliable tool for differentiating FSHD from other muscular dystrophies to direct diagnostic molecular analysis, as well as to investigate FSHD natural history and follow-up of the disease. Muscle MRI identifies a specific pattern of muscle involvement in FSHD patients. Muscle MRI may predict FSHD in asymptomatic and severely affected patients. Muscle MRI of upper girdle better predicts FSHD. Muscle MRI may differentiate FSHD from other forms of muscular dystrophy. Muscle MRI may show the involvement of non-clinical testable muscles.

  4. Localisation of AMPK γ subunits in cardiac and skeletal muscles.

    Science.gov (United States)

    Pinter, Katalin; Grignani, Robert T; Watkins, Hugh; Redwood, Charles

    2013-12-01

    The trimeric protein AMP-activated protein kinase (AMPK) is an important sensor of energetic status and cellular stress, and mutations in genes encoding two of the regulatory γ subunits cause inherited disorders of either cardiac or skeletal muscle. AMPKγ2 mutations cause hypertrophic cardiomyopathy with glycogen deposition and conduction abnormalities; mutations in AMPKγ3 result in increased skeletal muscle glycogen. In order to gain further insight into the roles of the different γ subunits in muscle and into possible disease mechanisms, we localised the γ2 and γ3 subunits, along with the more abundant γ1 subunit, by immunofluorescence in cardiomyocytes and skeletal muscle fibres. The predominant cardiac γ2 variant, γ2-3B, gave a striated pattern in cardiomyocytes, aligning with the Z-disk but with punctate staining similar to T-tubule (L-type Ca(2+) channel) and sarcoplasmic reticulum (SERCA2) markers. In skeletal muscle fibres AMPKγ3 localises to the I band, presenting a uniform staining that flanks the Z-disk, also coinciding with the position of Ca(2+) influx in these muscles. The localisation of γ2-3B- and γ3-containing AMPK suggests that these trimers may have similar functions in the different muscles. AMPK containing γ2-3B was detected in oxidative skeletal muscles which had low expression of γ3, confirming that these two regulatory subunits may be co-ordinately regulated in response to metabolic requirements. Compartmentalisation of AMPK complexes is most likely dependent on the regulatory γ subunit and this differential localisation may direct substrate selection and specify particular functional roles.

  5. Mechanisms regulating muscle mass during disuse atrophy and rehabilitation in humans.

    Science.gov (United States)

    Marimuthu, Kanagaraj; Murton, Andrew J; Greenhaff, Paul L

    2011-02-01

    Muscle mass loss accompanies periods of bedrest and limb immobilization in humans and requires rehabilitation exercise to effectively restore mass and function. Although recent evidence points to an early and transient rise in muscle protein breakdown contributing to this decline in muscle mass, the driving factor seems to be a reduction in muscle protein synthesis, not least in part due to the development of anabolic resistance to amino acid provision. Although the AKT signaling pathway has been identified in small animals as central to the regulation of muscle protein synthesis, several studies in humans have now demonstrated a disassociation between AKT signaling and muscle protein synthesis during feeding, exercise, and immobilization, suggesting that the mechanisms regulating protein synthesis in human skeletal muscle are more complex than initially thought (at least in non-inflammatory states). During rehabilitation, exercise-induced myogenesis may in part be responsible for the recovery of muscle mass. Rapid and sustained exercise-induced suppression of myostatin mRNA expression, that precedes any gain in muscle mass, points to this, along with other myogenic proteins, as being potential regulators of muscle regeneration during exercise rehabilitation in humans.

  6. Mechanisms underlying the sparing of masticatory versus limb muscle function in an experimental critical illness model.

    Science.gov (United States)

    Aare, Sudhakar; Ochala, Julien; Norman, Holly S; Radell, Peter; Eriksson, Lars I; Göransson, Hanna; Chen, Yi-Wen; Hoffman, Eric P; Larsson, Lars

    2011-12-16

    Acute quadriplegic myopathy (AQM) is a common debilitating acquired disorder in critically ill intensive care unit (ICU) patients that is characterized by tetraplegia/generalized weakness of limb and trunk muscles. Masticatory muscles, on the other hand, are typically spared or less affected, yet the mechanisms underlying this striking muscle-specific difference remain unknown. This study aims to evaluate physiological parameters and the gene expression profiles of masticatory and limb muscles exposed to factors suggested to trigger AQM, such as mechanical ventilation, immobilization, neuromuscular blocking agents, corticosteroids (CS), and sepsis for 5 days by using a unique porcine model mimicking the ICU conditions. Single muscle fiber cross-sectional area and force-generating capacity, i.e., maximum force normalized to fiber cross-sectional area (specific force), revealed maintained masseter single muscle fiber cross-sectional area and specific-force after 5 days' exposure to all triggering factors. This is in sharp contrast to observations in limb and trunk muscles, showing a dramatic decline in specific force in response to 5 days' exposure to the triggering factors. Significant differences in gene expression were observed between craniofacial and limb muscles, indicating a highly complex and muscle-specific response involving transcription and growth factors, heat shock proteins, matrix metalloproteinase inhibitor, oxidative stress responsive elements, and sarcomeric proteins underlying the relative sparing of cranial vs. spinal nerve innervated muscles during exposure to the ICU intervention.

  7. Exercising with blocked muscle glycogenolysis

    DEFF Research Database (Denmark)

    Nielsen, Tue L; Pinós, Tomàs; Brull, Astrid

    2018-01-01

    BACKGROUND: McArdle disease (glycogen storage disease type V) is an inborn error of skeletal muscle metabolism, which affects glycogen phosphorylase (myophosphorylase) activity leading to an inability to break down glycogen. Patients with McArdle disease are exercise intolerant, as muscle glycoge...

  8. [Pyomyositis of hip obturator muscles].

    Science.gov (United States)

    Downey Carmona, F J; Farrington Rueda, D

    2006-10-01

    Obturator internus muscle abscess (pyomyositis) is extremely rare in temperate environments, although there has been a recent reported increase in prevalence. There usually is a delay in diagnosis and onset of treatment. In addition to our case, we reviewed all cases of pyomyositis of hip muscles found in a review of the recent medical literature.

  9. Muscle ultrasound in neuromuscular disorders.

    NARCIS (Netherlands)

    Pillen, S.; Arts, I.M.P.; Zwarts, M.J.

    2008-01-01

    Muscle ultrasound is a useful tool in the diagnosis of neuromuscular disorders, as these disorders result in muscle atrophy and intramuscular fibrosis and fatty infiltration, which can be visualized with ultrasound. Several prospective studies have reported high sensitivities and specificities in

  10. [Muscle metastasis of bronchopulmonary carcinoma].

    Science.gov (United States)

    Di Giorgio, A; Schiffino, L; Canavese, A; Arnone, P; Scarpini, M; Almansour, M

    1999-06-01

    Typical sites of bronchogenic carcinoma metastases are liver, brain, bones or adrenal glands. Rarely and in advanced dissemination phase it could involve the skeletal muscle. Two cases of metastases in the skeletal muscle from bronchogenic carcinoma, one of which revealed this neoplasia, are reported.

  11. Dynamics of smooth muscle contraction

    NARCIS (Netherlands)

    G.A. van Kloeveringe (Gommert)

    1997-01-01

    textabstractSmooth muscle can economically maintain tonus for a long time and in many organs, its purpose is to maintain organ dimensions. It is however relatively slow and also inefficient as far as mechanical work is concerned. Smooth muscle is found in the majority of organs in the human body. It

  12. Techniques for modeling muscle-induced forces in finite element models of skeletal structures.

    Science.gov (United States)

    Grosse, Ian R; Dumont, Elizabeth R; Coletta, Chris; Tolleson, Alex

    2007-09-01

    This work introduces two mechanics-based approaches to modeling muscle forces exerted on curvilinear bone structures and compares the results with two traditional ad hoc methods of muscle loading. These new models use a combination of tensile, tangential, and normal traction loads to account for muscle fibers wrapped around curved bone surfaces. A computer program was written to interface with a commercial finite element analysis tool to automatically apply traction loads to surface faces of elements in muscle attachment regions according to the various muscle modeling methods. We modeled a highly complex skeletal structure, the skull of a Jamaican fruit bat (Artibeus jamaicensis), to compare the four muscle-loading methods. While reasonable qualitative agreement was found in the states of stress of the skull between the four muscle load modeling methods, there were substantial quantitative differences predicted in the stress states in some high stressed regions of the skull. Furthermore, our mechanics-based models required significantly less total applied muscle force to generate a bite-point reaction force identical to those produced by the ad hoc muscle loading models. Although the methods are not validated by in vivo data, we submit that muscle-load modeling methods that account for the underlying physics of muscle wrapping on curved bone surfaces are likely to provide more realistic results than ad hoc approaches that do not. We also note that, due to the geometric complexity of many bone structures--such as the skull analyzed here--load transmission paths are difficult to conceptualize a priori. Consequently, it is difficult to predict spatially where the results of finite element analyses are likely to be compromised by using ad hoc muscle modeling methods. For these reasons, it is recommended that a mechanics-based method be adopted for determination of the proper traction loads to be applied to skeletal structures due to muscular activity. Copyright 2007

  13. Computational Complexity

    Directory of Open Access Journals (Sweden)

    J. A. Tenreiro Machado

    2017-02-01

    Full Text Available Complex systems (CS involve many elements that interact at different scales in time and space. The challenges in modeling CS led to the development of novel computational tools with applications in a wide range of scientific areas. The computational problems posed by CS exhibit intrinsic difficulties that are a major concern in Computational Complexity Theory. [...

  14. Complex narratives

    NARCIS (Netherlands)

    Simons, J.

    2008-01-01

    This paper brings together narratology, game theory, and complexity theory to untangle the intricate nature of complex narratives in contemporary cinema. It interrogates the different terms - forking-path narratives, mind-game films, modular narratives, multiple-draft films, database narratives,

  15. Communication Complexity

    Indian Academy of Sciences (India)

    Jaikumar Radhakrishnan

    Communication complexity. Strategy I. Alice x ∈ {0, 1}n. ⇒. ⇐. Bob y ∈ {0, 1}n. Naive strategy. Alice sends x to Bob. Bob tells Alice if x = y. Cost. Requires n + 1 bits of communication. Jaikumar Radhakrishnan. Communication Complexity ...

  16. Complexity Theory

    Science.gov (United States)

    Lee, William H K.

    2016-01-01

    A complex system consists of many interacting parts, generates new collective behavior through self organization, and adaptively evolves through time. Many theories have been developed to study complex systems, including chaos, fractals, cellular automata, self organization, stochastic processes, turbulence, and genetic algorithms.

  17. Complex derivatives

    Science.gov (United States)

    Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

    2013-03-01

    The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

  18. The Basis of Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Antonio Musarò

    2014-01-01

    Full Text Available Muscle regeneration recapitulates many aspects of embryonic myogenesis and is an important homeostatic process of the adult skeletal muscle, which, after development, retains the capacity to regenerate in response to appropriate stimuli, activating the muscle compartment of stem cells, namely, satellite cells, as well as other precursor cells. Moreover, significant evidence suggests that while stem cells represent an important determinant for tissue regeneration, a “qualified” environment is necessary to guarantee and achieve functional results. It is therefore plausible that the loss of control over these cell fate decisions could lead to a pathological transdifferentiation, leading to pathologic defects in the regenerative process. This review provides an overview about the general aspects of muscle development and discusses the cellular and molecular aspects that characterize the five interrelated and time-dependent phases of muscle regeneration, namely, degeneration, inflammation, regeneration, remodeling, and maturation/functional repair.

  19. NO-sGC Pathway Modulates Ca2+ Release and Muscle Contraction in Zebrafish Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Zhou Xiyuan

    2017-08-01

    Full Text Available Vertebrate skeletal muscle contraction and relaxation is a complex process that depends on Ca2+ ions to promote the interaction of actin and myosin. This process can be modulated by nitric oxide (NO, a gas molecule synthesized endogenously by (nitric oxide synthase NOS isoforms. At nanomolar concentrations NO activates soluble guanylate cyclase (sGC, which in turn activates protein kinase G via conversion of GTP into cyclic GMP. Alternatively, NO post-translationally modifies proteins via S-nitrosylation of the thiol group of cysteine. However, the mechanisms of action of NO on Ca2+ homeostasis during muscle contraction are not fully understood and we hypothesize that NO exerts its effects on Ca2+ homeostasis in skeletal muscles mainly through negative modulation of Ca2+ release and Ca2+ uptake via the NO-sGC-PKG pathway. To address this, we used 5–7 days-post fecundation-larvae of zebrafish, a well-established animal model for physiological and pathophysiological muscle activity. We evaluated the response of muscle contraction and Ca2+ transients in presence of SNAP, a NO-donor, or L-NAME, an unspecific NOS blocker in combination with specific blockers of key proteins of Ca2+ homeostasis. We also evaluate the expression of NOS in combination with dihydropteridine receptor, ryanodine receptor and sarco/endoplasmic reticulum Ca2+ ATPase. We concluded that endogenous NO reduced force production through negative modulation of Ca2+ transients via the NO-sGC pathway. This effect could be reversed using an unspecific NOS blocker or sGC blocker.

  20. Quadriceps muscle reconstruction with free functioning latissimus dorsi muscle flap after oncological resection.

    Science.gov (United States)

    Innocenti, Marco; Abed, Yasser Y; Beltrami, Giovanni; Delcroix, Luca; Balatri, Amerigo; Capanna, Rodolfo

    2009-01-01

    The concept of limb salvage led to increased demand for more complex and sophisticated reconstructive options to achieve better functional and cosmetic outcome. Reconstruction of the total or partial loss of quadriceps muscle after soft tissue sarcomas excision with free functioning latissimus dorsi muscle transfer had become more popular in the last years. Between November 1993 and October 2004, 11 patients with average age 45.5 years underwent excision of quadriceps muscle followed by simultaneous reconstruction with free functioning latissimus dorsi muscle. There were six men and five women. The tumors were high grade in 90.9% of patients and were >10 cm in 81.8% of patients. The tumor extension required the resection of the entire quadriceps in four cases, of three heads in six cases, of only two heads in one case. The average follow up was 69 months. The average time of recovery of the contractile activity of the muscle was 8.3 months after operation. The musculoskeletal tumor society rating score (MTSRS) scored excellent or good in 73% of patients. Three patients (27.3%) died of metastatic disease. Local recurrence occurred in one patient (9.1%). Limb salvage was achieved in all the patients (100%). This method of reconstruction is a reliable technique not only to fill the defect resulting from oncological resection but also to provide better function. Microsurgical reconstruction of soft tissue sarcoma helps to expand the indications of limb salvage by allowing better local control and achieving adequate function and coverage. (c) 2008 Wiley-Liss, Inc.

  1. [Clinical advances of muscle status in osteoarthritis].

    Science.gov (United States)

    Cao, Yue-long; Pang, Jian; Zhan, Hong-sheng; Shi, Yin-yu

    2008-06-01

    This article summarizes relevant clinical studies on muscle status and osteoarthritis. Evidence from many researches have implied the importance of muscle weakness, decreased muscle strength and muscle function as pathological factor in the process of osteoarthritis, and muscle should also be an effective target for the treatment of osteoarthritis. Further study need to be conducted from the angle of muscle to explore the mechanism of osteoarthritis and to develop new drugs.

  2. Vocal production complexity correlates with neural instructions in the oyster toadfish (Opsanus tau)

    DEFF Research Database (Denmark)

    Elemans, C. P. H.; Mensinger, A. F.; Rome, L. C.

    2014-01-01

    Sound communication is fundamental to many social interactions and essential to courtship and agonistic behaviours in many vertebrates. The swimbladder and associated muscles in batrachoidid fishes (midshipman and toadfish) is a unique vertebrate sound production system, wherein fundamental frequ...... across vocal tetrapods have selected for muscles and motorneurons adapted for speed, which can execute complex neural instructions into equivalently complex vocalisations....

  3. Muscling out malaria

    DEFF Research Database (Denmark)

    Hughes, David Peter; Boomsma, Jacobus Jan

    2006-01-01

    ) [2] highlighted the back-to-back articles in Science 3 and 4 that demonstrated the potential biocontrol of malaria by targeting mosquitoes with entomopathogenic fungi (Metarhizium and Beauveria spp.). The wide impact of the original articles and the need to find alternatives to pesticidal control...... where malaria is endemic, humanity cannot afford shortcuts, because any failures owing to poor management or premature implementation will reduce local governmental support rather than enhance it (Andrew Read, pers. commun.). Therefore, if we are to ‘muscle out malaria', well...... of key importance, and the new focus on fungal biocontrol of malaria should therefore act as a catalyst for further research on the basic biology of fungal pathogens. Understanding morphological, biochemical or immune system-based resistance to insect pathogenic fungi will be easier if we know...

  4. Muscle Fiber Conduction Velocity, Muscle Fiber Composition, and Power Performance.

    Science.gov (United States)

    Methenitis, Spyridon; Karandreas, Nikolaos; Spengos, Konstantinos; Zaras, Nikolaos; Stasinaki, Angeliki-Nikoletta; Terzis, Gerasimos

    2016-09-01

    The aim of this study was to explore the relationship between muscle fiber conduction velocity (MFCV), fiber type composition, and power performance in participants with different training background. Thirty-eight young males with different training background participated: sedentary (n = 10), endurance runners (n = 9), power trained (n = 10), and strength trained (n = 9). They performed maximal countermovement jumps (CMJ) and maximal isometric leg press for the measurement of the rate of force development (RFD). Resting vastus lateralis MFCV was measured with intramuscular microelectrodes on a different occasion, whereas muscle fiber type and cross-sectional area (CSA) of vastus lateralis were evaluated through muscle biopsies 1wk later. MFCV, CMJ power, RFD, and % CSA of type II and type IIx fibers were higher for the power-trained group (P power participants. Close correlations were found between MFCV and fiber CSA as well as the % CSA of all fiber types as well as with RFD and CMJ power (r = 0.712-0.943, P power performance. Significant models for the prediction of the % CSA of type IIa and type II as well as the CSA of all muscle fibers based upon MFCV, RFD, and CMJ were revealed (P = 0.000). MFCV is closely associated with muscle fiber % CSA. RFD and jumping power are associated with the propagation of the action potentials along the muscle fibers. This link is regulated by the size and the distribution of type II, and especially type IIx muscle fibers.

  5. Stretching skeletal muscle: chronic muscle lengthening through sarcomerogenesis.

    Directory of Open Access Journals (Sweden)

    Alexander M Zöllner

    Full Text Available Skeletal muscle responds to passive overstretch through sarcomerogenesis, the creation and serial deposition of new sarcomere units. Sarcomerogenesis is critical to muscle function: It gradually re-positions the muscle back into its optimal operating regime. Animal models of immobilization, limb lengthening, and tendon transfer have provided significant insight into muscle adaptation in vivo. Yet, to date, there is no mathematical model that allows us to predict how skeletal muscle adapts to mechanical stretch in silico. Here we propose a novel mechanistic model for chronic longitudinal muscle growth in response to passive mechanical stretch. We characterize growth through a single scalar-valued internal variable, the serial sarcomere number. Sarcomerogenesis, the evolution of this variable, is driven by the elastic mechanical stretch. To analyze realistic three-dimensional muscle geometries, we embed our model into a nonlinear finite element framework. In a chronic limb lengthening study with a muscle stretch of 1.14, the model predicts an acute sarcomere lengthening from 3.09[Formula: see text]m to 3.51[Formula: see text]m, and a chronic gradual return to the initial sarcomere length within two weeks. Compared to the experiment, the acute model error was 0.00% by design of the model; the chronic model error was 2.13%, which lies within the rage of the experimental standard deviation. Our model explains, from a mechanistic point of view, why gradual multi-step muscle lengthening is less invasive than single-step lengthening. It also explains regional variations in sarcomere length, shorter close to and longer away from the muscle-tendon interface. Once calibrated with a richer data set, our model may help surgeons to prevent muscle overstretch and make informed decisions about optimal stretch increments, stretch timing, and stretch amplitudes. We anticipate our study to open new avenues in orthopedic and reconstructive surgery and enhance

  6. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  7. [Muscles and connective tissue: histology].

    Science.gov (United States)

    Delage, J-P

    2012-10-01

    Here, we give some comments about the DVD movies "Muscle Attitudes" from Endovivo productions, the movies up lighting some loss in the attention given to studies on the connective tissue, and especially them into muscles. The main characteristics of the different components in the intra-muscular connective tissue (perimysium, endomysium, epimysium) are shown here with special references to their ordered architecture and special references to their spatial distributions. This connective tissue is abundant into the muscles and is in continuity with the muscles in vicinity, with their tendons and their sheath, sticking the whole on skin. This connective tissue has also very abundant connections on the muscles fibres. It is then assumed that the connective tissue sticks every organs or cells of the locomotion system. Considering the elastic properties of the collagen fibres which are the most abundant component of connective tissue, it is possible to up light a panel of connective tissue associated functions such as the transmission of muscle contractions or the regulation of protein and energetic muscles metabolism. Copyright © 2012. Published by Elsevier SAS.

  8. Mechanics of the respiratory muscles.

    Science.gov (United States)

    De Troyer, André; Boriek, Aladin M

    2011-07-01

    This article examines the mechanics of the muscles that drive expansion or contraction of the chest wall during breathing. The diaphragm is the main inspiratory muscle. When its muscle fibers are activated in isolation, they shorten, the dome of the diaphragm descends, pleural pressure (P(pl)) falls, and abdominal pressure (P(ab)) rises. As a result, the ventral abdominal wall expands, but a large fraction of the rib cage contracts. Expansion of the rib cage during inspiration is produced by the external intercostals in the dorsal portion of the rostral interspaces, the intercartilaginous portion of the internal intercostals (the so-called parasternal intercostals), and, in humans, the scalenes. By elevating the ribs and causing an additional fall in P(pl), these muscles not only help the diaphragm expand the chest wall and the lung, but they also increase the load on the diaphragm and reduce the shortening of the diaphragmatic muscle fibers. The capacity of the diaphragm to generate pressure is therefore enhanced. In contrast, during expiratory efforts, activation of the abdominal muscles produces a rise in P(ab) that leads to a cranial displacement of the diaphragm into the pleural cavity and a rise in P(pl). Concomitant activation of the internal interosseous intercostals in the caudal interspaces and the triangularis sterni during such efforts contracts the rib cage and helps the abdominal muscles deflate the lung. © 2011 American Physiological Society.

  9. Cleaved Slit directs embryonic muscles.

    Science.gov (United States)

    Ordan, Elly; Volk, Talila

    2015-01-01

    The formation of functional musculoskeletal system relies on proper connectivity between muscles and their corresponding tendon cells. In Drosophila, larval muscles are born during early embryonic stages, and elongate toward tendons that are embedded within the ectoderm in later. The Slit/Robo signaling pathway had been implicated in the process of muscle elongation toward tendons. Here we discuss our recent findings regarding the critical contribution of Slit cleavage for immobilization and stabilization of the Slit signal on the tendon cells. Slit cleavage produces 2 polypeptides, the N-terminal Slit-N, which is extremely stable, undergoes oligomerization, and associates with the tendon cell surfaces, and the C-terminal Slit-C, which rapidly degrades. Slit cleavage leads to immobilization of Slit signaling on tendons, leading to a short-range repulsion, which eventually arrest further muscle elongation. Robo2, which is co-expressed with Slit by the tendon cells facilitates Slit cleavage. This activity does not require the cytoplasmic signaling domain of Robo2. We suggest that Robo2-dependent Slit cleavage, and the formation of Slit-N oligomers on the tendon cell surfaces direct muscle elongation, and provide a stop signal for the approaching muscle, through binding to Robo and Robo3 receptors expressed by the muscles.

  10. Electrical activity in muscle pain.

    Science.gov (United States)

    Cobb, C R; deVries, H A; Urban, R T; Luekens, C A; Bagg, R J

    1975-04-01

    The concept of muscle pain-spasm-pain vicious cycle has been challenged on the basis of inability to find electrical activity in the presence of palpable changes in fibrositic muscle. We produced muscle pain in the wrist extensor and paravertebral muscle groups of seven healthy subjects by injection of hypertonic saline (0.3 ml of 6% NaCl solution). The time course of the integrated muscle action potentials, roughly paralleled the time course of the developed pain in all but one subject for each muscle group. EMG recordings were made on one subject using both surface electrodes with amplifier sensitivity of 10 muV/cm and needle electrodes with an amplifier sensitivity of 100 muV/cm. Sequential recording showed clear evidence of electrical activity from the surface electrode and high sensitivity whereas the combination of the needle electrode with lower sensitivity showed no electrical activity whatever. We conclude that even mild muscle spasm is accompanied by muscular hyperactivity which can be evaluated by appropriate EMG techniques. There appears to be no reason to challenge the widely accepted concept of pain-spasm-pain as stated by Travell, Rinzler and Herman.

  11. Muscle channelopathies and electrophysiological approach

    Directory of Open Access Journals (Sweden)

    Cherian Ajith

    2008-01-01

    Full Text Available Myotonic syndromes and periodic paralyses are rare disorders of skeletal muscle characterized mainly by muscle stiffness or episodic attacks of weakness. Familial forms are caused by mutation in genes coding for skeletal muscle voltage ionic channels. Familial periodic paralysis and nondystrophic myotonias are disorders of skeletal muscle excitability caused by mutations in genes coding for voltage-gated ion channels. These diseases are characterized by episodic failure of motor activity due to muscle weakness (paralysis or stiffness (myotonia. Clinical studies have identified two forms of periodic paralyses: hypokalemic periodic paralysis (hypoKPP and hyperkalemic periodic paralysis (hyperKPP, based on changes in serum potassium levels during the attacks, and three distinct forms of myotonias: paramyotonia congenita (PC, potassium-aggravated myotonia (PAM, and myotonia congenita (MC. PC and PAM have been linked to missense mutations in the SCN4A gene, which encodes α subunit of the voltage-gated sodium channel, whereas MC is caused by mutations in the chloride channel gene (CLCN1. Exercise is known to trigger, aggravate, or relieve symptoms. Therefore, exercise can be used as a functional test in electromyography to improve the diagnosis of these muscle disorders. Abnormal changes in the compound muscle action potential can be disclosed using different exercise tests. Five electromyographic (EMG patterns (I-V that may be used in clinical practice as guides for molecular diagnosis are discussed.

  12. Carney Complex

    Science.gov (United States)

    ... at least one of the features listed. Major diagnostic features for Carney Complex Spotty skin pigmentation with ... called large cell calcifying Sertoli cell tumor (LCCST) Thyroid cancer Psammomatous melanotic schwannoma, meaning tumors that grow on ...

  13. Complex Covariance

    Directory of Open Access Journals (Sweden)

    Frieder Kleefeld

    2013-01-01

    Full Text Available According to some generalized correspondence principle the classical limit of a non-Hermitian quantum theory describing quantum degrees of freedom is expected to be the well known classical mechanics of classical degrees of freedom in the complex phase space, i.e., some phase space spanned by complex-valued space and momentum coordinates. As special relativity was developed by Einstein merely for real-valued space-time and four-momentum, we will try to understand how special relativity and covariance can be extended to complex-valued space-time and four-momentum. Our considerations will lead us not only to some unconventional derivation of Lorentz transformations for complex-valued velocities, but also to the non-Hermitian Klein-Gordon and Dirac equations, which are to lay the foundations of a non-Hermitian quantum theory.

  14. Skeletal muscle performance and ageing.

    Science.gov (United States)

    Tieland, Michael; Trouwborst, Inez; Clark, Brian C

    2017-11-19

    The world population is ageing rapidly. As society ages, the incidence of physical limitations is dramatically increasing, which reduces the quality of life and increases healthcare expenditures. In western society, ~30% of the population over 55 years is confronted with moderate or severe physical limitations. These physical limitations increase the risk of falls, institutionalization, co-morbidity, and premature death. An important cause of physical limitations is the age-related loss of skeletal muscle mass, also referred to as sarcopenia. Emerging evidence, however, clearly shows that the decline in skeletal muscle mass is not the sole contributor to the decline in physical performance. For instance, the loss of muscle strength is also a strong contributor to reduced physical performance in the elderly. In addition, there is ample data to suggest that motor coordination, excitation-contraction coupling, skeletal integrity, and other factors related to the nervous, muscular, and skeletal systems are critically important for physical performance in the elderly. To better understand the loss of skeletal muscle performance with ageing, we aim to provide a broad overview on the underlying mechanisms associated with elderly skeletal muscle performance. We start with a system level discussion and continue with a discussion on the influence of lifestyle, biological, and psychosocial factors on elderly skeletal muscle performance. Developing a broad understanding of the many factors affecting elderly skeletal muscle performance has major implications for scientists, clinicians, and health professionals who are developing therapeutic interventions aiming to enhance muscle function and/or prevent mobility and physical limitations and, as such, support healthy ageing. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  15. MUSCLE WASTING AND CARDIAC MUSCLE DAMAGE IN CACHECTIC PATIENTS

    Directory of Open Access Journals (Sweden)

    Claudia Sangiorgi

    2013-04-01

    Full Text Available Muscle wasting is a degeneration of the muscle tissue that can derive from several pathological situations, but most of the times is caused by a condition of cachexia in patients with cancer or other diseases. This degeneration results from a decrease in protein synthesis and an increase in protein degradation. This is caused mainly by the overexpression of ubiquitin-proteosome-system (UPS elements, under the control of factors released in cachexia that lead cells toward a catabolic rather than an anabolic pathway. Both skeletal and cardiac muscles can be affected by muscle wasting and until now an effective treatment is unknown. Only experimental trials of exercise training bring to a recovery of mass loss, but many researchers think that a potential future treatment may be represented by stem cells.

  16. MASTICATORY MUSCLES AND THE SKULL: A COMPARATIVE PERSPECTIVE

    Science.gov (United States)

    HERRING, SUSAN W.

    2007-01-01

    Masticatory muscles are anatomically and functionally complex in all mammals, but relative sizes, orientation of action lines, and fascial subdivisions vary greatly among different species in association with their particular patterns of occlusion and jaw movement. The most common contraction pattern for moving the jaw laterally involves a force couple of protrusor muscles on one side and retrusors on the other. Such asymmetrical muscle usage sets up torques on the skull and combines with occlusal loads to produce bony deformations not only in the tooth-bearing jaw bones, but also in more distant elements such as the braincase. Maintenance of bone in the jaw joint, and probably elsewhere in the skull, is dependent on these loads. PMID:17084804

  17. Skeletal Muscle Na+ Channel Disorders

    Directory of Open Access Journals (Sweden)

    Dina eSimkin

    2011-10-01

    Full Text Available Five inherited human disorders affecting skeletal muscle contraction have been traced to mutations in the gene encoding the voltage-gated sodium channel Nav1.4. The main symptoms of these disorders are myotonia or periodic paralysis caused by changes in skeletal muscle fiber excitability. Symptoms of these disorders vary from mild or latent disease to incapacitating or even death in severe cases. As new human sodium channel mutations corresponding to disease states become discovered, the importance of understanding the role of the sodium channel in skeletal muscle function and disease state grows.

  18. Bigorexia: bodybuilding and muscle dysmorphia.

    Science.gov (United States)

    Mosley, Philip E

    2009-05-01

    Muscle dysmorphia is an emerging condition that primarily affects male bodybuilders. Such individuals obsess about being inadequately muscular. Compulsions include spending hours in the gym, squandering excessive amounts of money on ineffectual sports supplements, abnormal eating patterns or even substance abuse. In this essay, I illustrate the features of muscle dysmorphia by employing the first-person account of a male bodybuilder afflicted by this condition. I briefly outline the history of bodybuilding and examine whether the growth of this sport is linked to a growing concern with body image amongst males. I suggest that muscle dysmorphia may be a new expression of a common pathology shared with the eating disorders.

  19. Mouse Skeletal Muscle Fiber-Type-Specific Macroautophagy and Muscle Wasting Are Regulated by a Fyn/STAT3/Vps34 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Eijiro Yamada

    2012-05-01

    Full Text Available Skeletal muscle atrophy induced by aging (sarcopenia, inactivity, and prolonged fasting states (starvation is predominantly restricted to glycolytic type II muscle fibers and typical spares oxidative type I fibers. However, the mechanisms accounting for muscle fiber-type specificity of atrophy have remained enigmatic. In the current study, although the Fyn tyrosine kinase activated the mTORC1 signaling complex, it also induced marked atrophy of glycolytic fibers with relatively less effect on oxidative muscle fibers. This was due to inhibition of macroautophagy via an mTORC1-independent but STAT3-dependent reduction in Vps34 protein levels and decreased Vps34/p150/Beclin1/Atg14 complex 1. Physiologically, in the fed state endogenous Fyn kinase activity was increased in glycolytic but not oxidative skeletal muscle. In parallel, Y705-STAT3 phosphorylation increased with decreased Vps34 protein levels. Moreover, fed/starved regulation of Y705-STAT3 phosphorylation and Vps34 protein levels was prevented in skeletal muscle of Fyn null mice. These data demonstrate a Fyn/STAT3/Vps34 pathway that is responsible for fiber-type-specific regulation of macroautophagy and skeletal muscle atrophy.

  20. Magnetic resonance imaging assessment of mechanical interactions between human lower leg muscles in vivo.

    Science.gov (United States)

    Yaman, Alper; Ozturk, Cengizhan; Huijing, Peter A; Yucesoy, Can A

    2013-09-01

    Evidence on epimuscular myofascial force transmission (EMFT) was shown for undissected muscle in situ. We hypothesize that global length changes of gastrocnemius muscle-tendon complex in vivo will cause sizable and heterogeneous local strains within all muscles of the human lower leg. Our goal is to test this hypothesis. A method was developed and validated using high-resolution 3D magnetic resonance image sets and Demons nonrigid registration algorithm for performing large deformation analyses. Calculation of strain tensors per voxel in human muscles in vivo allowed quantifying local heterogeneous tissue deformations and volume changes. After hip and knee movement (Δ knee angle ≈ 25 deg) but without any ankle movement, local lengthening within m. gastrocnemius was shown to occur simultaneously with local shortening (maximally by +34.2% and -32.6%, respectively) at different locations. Moreover, similar local strains occur also within other muscles, despite being kept at constant muscle-tendon complex length. This is shown for synergistic m. soleus and deep flexors, as well as for antagonistic anterior crural and peroneal muscle groups: minimum peak lengthening and shortening equaled 23.3% and 25.54%, respectively despite global isometric conditions. These findings confirm our hypothesis and show that in vivo, muscles are in principle not independent mechanically.

  1. Elastic ankle muscle-tendon interactions are adjusted to produce acceleration during walking in humans.

    Science.gov (United States)

    Farris, Dominic James; Raiteri, Brent James

    2017-11-15

    Humans and other cursorial mammals have distal leg muscles with high in-series compliance that aid locomotor economy. This muscle-tendon design is considered sub-optimal for injecting net positive mechanical work. However, humans change speed frequently when walking and any acceleration requires net positive ankle work. The present study unveiled how the muscle-tendon interaction of human ankle plantar flexors are adjusted and integrated with body mechanics to provide net positive work during accelerative walking. We found that for accelerative walking, a greater amount of active plantar flexor fascicle shortening early in the stance phase occurred and was transitioned through series elastic tissue stretch and recoil. Reorientation of the leg during early stance for acceleration allowed the ankle and whole soleus muscle-tendon complex to remain isometric while its fascicles actively shortened, stretching in-series elastic tissues for subsequent recoil and net positive joint work. This muscle-tendon behaviour is fundamentally different from constant-speed walking, where the ankle and soleus muscle-tendon complex undergo a period of negative work to store energy in series elastic tissues before subsequent recoil, minimizing net joint work. Muscles with high in-series compliance can therefore contribute to net positive work for accelerative walking and here we show a mechanism for how in human ankle muscles. © 2017. Published by The Company of Biologists Ltd.

  2. Muscle mass, muscle strength, and muscle fat infiltration as predictors of incident mobility limitations in well-functioning older persons

    NARCIS (Netherlands)

    Visser, M.; Goodpaster, B.H.; Kritchevsky, S.B.; Newman, A.B.; Nevitt, M.C.; Rubin, S.M.; Simonsick, E.M.; Harris, T.B.

    2005-01-01

    BACKGROUND: Lower muscle mass has been correlated with poor physical function; however, no studies have examined this relationship prospectively. This study aims to investigate whether low muscle mass, low muscle strength, and greater fat infiltration into the muscle predict incident mobility

  3. Muscle mass, muscle strength, and muscle fat infiltration as predictors of incident mobility limitations in well-functioning older persons

    NARCIS (Netherlands)

    Visser, M.; Goodpaster, B.H.; Kritchevsky, S.B.; Newman, A.B.; Nevitt, M.C.; Rubin, S.M.; Simonsick, E.M.; Harris, T.B.

    2005-01-01

    .05). Among men and women, associations were similar for blacks and whites. CONCLUSION: Lower muscle mass (smaller cross-sectional thigh muscle area), greater fat infiltration into the muscle, and lower knee extensor muscle strength are associated with increased risk of mobility loss in older men

  4. Muscle mass, muscle strength, and muscle fat infiltration as predictors of incident mobility limitations in well-functioning older persons

    NARCIS (Netherlands)

    Visser, Marjolein; Goodpaster, Bret H; Kritchevsky, Stephen B; Newman, Anne B; Nevitt, Michael; Rubin, Susan M; Simonsick, Eleanor M; Harris, Tamara B

    BACKGROUND: Lower muscle mass has been correlated with poor physical function; however, no studies have examined this relationship prospectively. This study aims to investigate whether low muscle mass, low muscle strength, and greater fat infiltration into the muscle predict incident mobility

  5. Dissociation between short-term unloading and resistance training effects on skeletal muscle Na+,K+-ATPase, muscle function, and fatigue in humans.

    Science.gov (United States)

    Perry, Ben D; Wyckelsma, Victoria L; Murphy, Robyn M; Steward, Collene H; Anderson, Mitchell; Levinger, Itamar; Petersen, Aaron C; McKenna, Michael J

    2016-11-01

    Physical training increases skeletal muscle Na + ,K + -ATPase content (NKA) and improves exercise performance, but the effects of inactivity per se on NKA content and isoform abundance in human muscle are unknown. We investigated the effects of 23-day unilateral lower limb suspension (ULLS) and subsequent 4-wk resistance training (RT) on muscle function and NKA in 6 healthy adults, measuring quadriceps muscle peak torque; fatigue and venous [K + ] during intense one-legged cycling exercise; and skeletal muscle NKA content ([ 3 H]ouabain binding) and NKA isoform abundances (immunoblotting) in muscle homogenates (α 1-3 , β 1-2 ) and in single fibers (α 1-3 , β 1 ). In the unloaded leg after ULLS, quadriceps peak torque and cycling time to fatigue declined by 22 and 23%, respectively, which were restored with RT. Whole muscle NKA content and homogenate NKA α 1-3 and β 1-2 isoform abundances were unchanged with ULLS or RT. However, in single muscle fibers, NKA α 3 in type I (-66%, P = 0.006) and β 1 in type II fibers (-40%, P = 0.016) decreased after ULLS, with other NKA isoforms unchanged. After RT, NKA α 1 (79%, P = 0.004) and β 1 (35%, P = 0.01) increased in type II fibers, while α 2 (76%, P = 0.028) and α 3 (142%, P = 0.004) increased in type I fibers compared with post-ULLS. Despite considerably impaired muscle function and earlier fatigue onset, muscle NKA content and homogenate α 1 and α 2 abundances were unchanged, thus being resilient to inactivity induced by ULLS. Nonetheless, fiber type-specific downregulation with inactivity and upregulation with RT of several NKA isoforms indicate complex regulation of muscle NKA expression in humans. Copyright © 2016 the American Physiological Society.

  6. Electromyography assessment in zygomaticomaxillary complex fractures.

    Science.gov (United States)

    Waheed El-Anwar, Mohammad; Elsheikh, Ezzeddin; Sweed, Ahmed Hassan; Ezzeldin, Nillie

    2015-12-01

    The aim of this study was to assess the activity of the masseter and temporalis muscles using surface electromyography (EMG) in patients with zygomaticomaxillary complex (ZMC) fractures. This prospective study was carried out on 25 patients who had ZMC fractures. Fifteen patients were managed by open reduction and rigid fixation (ORIF) using titanium miniplates. This study, using surface electromyography, analyzed the activity of the masseter and temporalis muscles of 25 patients with ZMC fractures; 15 of them were surgically treated under general anesthesia (GA). Evaluations were made before surgery and 6 weeks after surgery by recording the mean of muscle contraction of 20 motor unit action potential (MUAP) against resistance, and statistical analyses were performed. A significant EMG difference between the normal and ZMC fracture sides was found (P < 0.0001) for both masseter and temporalis muscles and was significantly improved after ORIF. However, postoperative EMV values of the repaired side was significantly less than measured postoperatively in the normal side (P < 0.0001) for both muscles. ZMC fractures significantly diminish muscular activity of the masseter and temporalis and even though significant recovery of muscle activity was revealed after 6 weeks, it is still less than normal activity, highlighting the importance of postoperative rehabilitation.

  7. Evidence for rectus extraocular muscle pulleys in rodents.

    Science.gov (United States)

    Khanna, S; Porter, J D

    2001-08-01

    Extraocular rectus muscle (EOM) pulleys are important determinants of orbital biomechanics in humans. In this study, the authors evaluated orbital connective tissue morphology, specifically characterizing rectus muscle pulleys, in the rat, a species with laterally placed eyes, afoveate vision, and a less complex visuomotor repertoire than primates. Adult rat orbits were paraffin processed and serially sectioned for histochemical and immunohistochemical staining. Frozen sections of enucleated globes with intact EOMs and associated connective tissue were also studied with myosin immunohistochemistry and histochemistry for the mitochondrial enzyme, nicotinamide adenine dinucleotide (NADH)-tetrazolium reductase, to delineate the orbital layer relationship with the pulley tissue. Focal condensations of collagenous connective tissue were found in relationship to the rectus muscles in the equatorial Tenon's fascia, similar to those described as human recti muscle pulleys. The fibroelastic pulley rings were coupled to adjacent EOM pulleys by bands containing collagen and elastin. The coupling of pulleys to the orbital walls was significantly less than that previously described in humans. As in humans, there was a dual insertion of rodent rectus muscles, with the orbital layer inserting on the muscle pulley and the global layer attaching to the sclera. The data support the presence of structures in the rat orbit that are the morphologic equivalent of the human rectus pulley system. Although rodent and human pulleys were similar in many respects, there were species-specific properties that may relate to established differences in orbital anatomy and/or visuomotor behavior. These data extend the rectus muscle pulley concept to rodents and may provide insight into pulley structure-function relationships.

  8. BRANCHED FIBERS FROM OLD FAST-TWITCH DYSTROPHIC MUSCLES ARE THE SITES OF TERMINAL DAMAGE IN MUSCULAR DYSTROPHY.

    Science.gov (United States)

    Kiriaev, Leonit; Kueh, Sindy; Morley, John W; North, Kathryn N; Houweling, Peter J; Head, Stewart I

    2018-02-07

    A striking pathological feature of dystrophinopathies is the presence of morphologically abnormal branched skeletal muscle fibers. The deterioration of muscle contractile function in Duchenne muscular dystrophy is accompanied by both an increase in number and complexity of these branched fibers. We propose that when number and complexity of branched fibers reaches a critical threshold, "tipping point" the branches in and of themselves are the site of contraction-induced rupture. In the present study, we use the dystrophic mdx mouse and littermate controls to study the pre-diseased dystrophic fast-twitch EDL muscle at 2-3-weeks, the peak myonecrotic phase at 6-9 weeks and finally "old" at 58-112 weeks. Using a combination of isolated muscle function contractile measurements coupled with single fiber imaging and confocal microscope imaging of cleared whole muscles we identified a distinct pathophysiology; acute fiber rupture at branch nodes, which occurs in "old" fast-twitch EDL muscle approaching the end stage of the dystrophinopathy muscle disease, where the EDL muscles are entirely composed of complexed branched fibers. This evidence supports our concept of "tipping point" where the number and extent of fiber branching reaches a level where the branching itself terminally compromises muscle function, irrespective of the absence of dystrophin.

  9. Automatic prediction of tongue muscle activations using a finite element model.

    Science.gov (United States)

    Stavness, Ian; Lloyd, John E; Fels, Sidney

    2012-11-15

    Computational modeling has improved our understanding of how muscle forces are coordinated to generate movement in musculoskeletal systems. Muscular-hydrostat systems, such as the human tongue, involve very different biomechanics than musculoskeletal systems, and modeling efforts to date have been limited by the high computational complexity of representing continuum-mechanics. In this study, we developed a computationally efficient tracking-based algorithm for prediction of muscle activations during dynamic 3D finite element simulations. The formulation uses a local quadratic-programming problem at each simulation time-step to find a set of muscle activations that generated target deformations and movements in finite element muscular-hydrostat models. We applied the technique to a 3D finite element tongue model for protrusive and bending movements. Predicted muscle activations were consistent with experimental recordings of tongue strain and electromyography. Upward tongue bending was achieved by recruitment of the superior longitudinal sheath muscle, which is consistent with muscular-hydrostat theory. Lateral tongue bending, however, required recruitment of contralateral transverse and vertical muscles in addition to the ipsilateral margins of the superior longitudinal muscle, which is a new proposition for tongue muscle coordination. Our simulation framework provides a new computational tool for systematic analysis of muscle forces in continuum-mechanics models that is complementary to experimental data and shows promise for eliciting a deeper understanding of human tongue function. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Regulation of Increased Blood Flow (Hyperemia) to Muscles During Exercise: A Hierarchy of Competing Physiological Needs

    Science.gov (United States)

    Joyner, Michael J.; Casey, Darren P.

    2015-01-01

    This review focuses on how blood flow to contracting skeletal muscles is regulated during exercise in humans. The idea is that blood flow to the contracting muscles links oxygen in the atmosphere with the contracting muscles where it is consumed. In this context, we take a top down approach and review the basics of oxygen consumption at rest and during exercise in humans, how these values change with training, and the systemic hemodynamic adaptations that support them. We highlight the very high muscle blood flow responses to exercise discovered in the 1980s. We also discuss the vasodilating factors in the contracting muscles responsible for these very high flows. Finally, the competition between demand for blood flow by contracting muscles and maximum systemic cardiac output is discussed as a potential challenge to blood pressure regulation during heavy large muscle mass or whole body exercise in humans. At this time, no one dominant dilator mechanism accounts for exercise hyperemia. Additionally, complex interactions between the sympathetic nervous system and the microcirculation facilitate high levels of systemic oxygen extraction and permit just enough sympathetic control of blood flow to contracting muscles to regulate blood pressure during large muscle mass exercise in humans. PMID:25834232

  11. Neuromechanical control of the forearm muscles during gripping with sudden flexion and extension wrist perturbations.

    Science.gov (United States)

    Holmes, Michael W R; Tat, Jimmy; Keir, Peter J

    2015-01-01

    The purpose of this study was to investigate how gripping modulates forearm muscle co-contraction prior to and during sudden wrist perturbations. Ten males performed a sub-maximal gripping task (no grip, 5% and 10% of maximum) while a perturbation forced wrist flexion or extension. Wrist joint angles and activity from 11 muscles were used to determine forearm co-contraction and muscle contributions to wrist joint stiffness. Co-contraction increased in all pairs as grip force increased (from no grip to 10% grip), corresponding to a 36% increase in overall wrist joint stiffness. Inclusion of individual muscle contributions to wrist joint stiffness enhanced the understanding of forearm co-contraction. The extensor carpi radialis longus (ECRL) and brevis had the largest stiffness contributions (34.5 ± 1.3% and 20.5 ± 2.3%, respectively), yet muscle pairs including ECRL produced the lowest co-contraction. The muscles contributing most to wrist stiffness were consistent across conditions (ECRL for extensors; Flexor Digitorum Superficialis for flexors), suggesting enhanced contributions rather than muscular redistribution. This work provides investigation of the neuromuscular response to wrist perturbations and gripping demands by considering both co-contraction and muscle contributions to joint stiffness. Individual muscle stiffness contributions can be used to enhance the understanding of forearm muscle control during complex tasks.

  12. Regulatory T cells suppress muscle inflammation and injury in muscular dystrophy

    Science.gov (United States)

    Villalta, S. Armando; Rosenthal, Wendy; Martinez, Leonel; Kaur, Amanjot; Sparwasser, Tim; Tidball, James G.; Margeta, Marta; Spencer, Melissa J.; Bluestone, Jeffrey A.

    2016-01-01

    We examined the hypothesis that regulatory T cells (Tregs) modulate muscle injury and inflammation in the mdx mouse model of Duchenne muscular dystrophy (DMD). Although Tregs were largely absent in the muscle of wildtype mice and normal human muscle, they were present in necrotic lesions, displayed an activated phenotype and showed increased expression of interleukin (IL)-10 in dystrophic muscle from mdx mice. Depletion of Tregs exacerbated muscle injury and the severity of muscle inflammation, which was characterized by an enhanced interferon-gamma (IFNγ) response and activation of M1 macrophages. To test the therapeutic value of targeting Tregs in muscular dystrophy, we treated mdx mice with IL-2/anti-IL-2 complexes (IL-2c), and found that Tregs and IL-10 concentrations were increased in muscle, resulting in reduced expression of cyclooygenase-2 and decreased myofiber injury. These findings suggest that Tregs modulate the progression of muscular dystrophy by suppressing type 1 inflammation in muscle associated with muscle fiber injury, and highlight the potential of Treg-modulating agents as therapeutics for DMD. PMID:25320234

  13. Regulation of increased blood flow (hyperemia) to muscles during exercise: a hierarchy of competing physiological needs.

    Science.gov (United States)

    Joyner, Michael J; Casey, Darren P

    2015-04-01

    This review focuses on how blood flow to contracting skeletal muscles is regulated during exercise in humans. The idea is that blood flow to the contracting muscles links oxygen in the atmosphere with the contracting muscles where it is consumed. In this context, we take a top down approach and review the basics of oxygen consumption at rest and during exercise in humans, how these values change with training, and the systemic hemodynamic adaptations that support them. We highlight the very high muscle blood flow responses to exercise discovered in the 1980s. We also discuss the vasodilating factors in the contracting muscles responsible for these very high flows. Finally, the competition between demand for blood flow by contracting muscles and maximum systemic cardiac output is discussed as a potential challenge to blood pressure regulation during heavy large muscle mass or whole body exercise in humans. At this time, no one dominant dilator mechanism accounts for exercise hyperemia. Additionally, complex interactions between the sympathetic nervous system and the microcirculation facilitate high levels of systemic oxygen extraction and permit just enough sympathetic control of blood flow to contracting muscles to regulate blood pressure during large muscle mass exercise in humans. Copyright © 2015 the American Physiological Society.

  14. Characterizing the Peano fluidic muscle and the effects of its geometry properties on its behavior

    Science.gov (United States)

    Veale, Allan Joshua; Xie, Sheng Quan; Anderson, Iain Alexander

    2016-06-01

    In this work, we explore the basic static and dynamic behavior of a hydraulically actuated Peano muscle and how its geometry affects key static and dynamic performance metrics. The Peano muscle, or pouch motor is a fluid powered artificial muscle. Similar to McKibben pneumatic artificial muscles (PAMs), it has the ability to generate the high forces of biological muscles with the low threshold pressure of pleated PAMs, but in a slim, easily distributed form. We found that Peano muscles have similar characteristics to other PAMs, but produce lower free-strains. A test rig capable of measuring high-speed flow rates with a Venturi tube revealed that their efficiency peaks at about 40% during highly dynamic movements. Peano muscles with more tubes and of a greater size do not move faster. Also, their muscle tubes should have an aspect ratio of at least 1:3 and channel width greater than 20% to maximize performance. These findings suggest that finite element modeling be used to optimize more complex Peano muscle geometries.

  15. Vestigial is required during late-stage muscle differentiation in Drosophila melanogaster embryos.

    Science.gov (United States)

    Deng, Hua; Bell, John B; Simmonds, Andrew J

    2010-10-01

    The somatic muscles of Drosophila develop in a complex pattern that is repeated in each embryonic hemi-segment. During early development, progenitor cells fuse to form a syncytial muscle, which further differentiates via expression of muscle-specific factors that induce specific responses to external signals to regulate late-stage processes such as migration and attachment. Initial communication between somatic muscles and the epidermal tendon cells is critical for both of these processes. However, later establishment of attachments between longitudinal muscles at the segmental borders is largely independent of the muscle-epidermal attachment signals, and relatively little is known about how this event is regulated. Using a combination of null mutations and a truncated version of Sd that binds Vg but not DNA, we show that Vestigial (Vg) is required in ventral longitudinal muscles to induce formation of stable intermuscular attachments. In several muscles, this activity may be independent of Sd. Furthermore, the cell-specific differentiation events induced by Vg in two cells fated to form attachments are coordinated by Drosophila epidermal growth factor signaling. Thus, Vg is a key factor to induce specific changes in ventral longitudinal muscles 1-4 identity and is required for these cells to be competent to form stable intermuscular attachments with each other.

  16. Alternative requirements for Vestigial, Scalloped, and Dmef2 during muscle differentiation in Drosophila melanogaster.

    Science.gov (United States)

    Deng, Hua; Hughes, Sarah C; Bell, John B; Simmonds, Andrew J

    2009-01-01

    Vertebrate development requires the activity of the myocyte enhancer factor 2 (mef2) gene family for muscle cell specification and subsequent differentiation. Additionally, several muscle-specific functions of MEF2 family proteins require binding additional cofactors including members of the Transcription Enhancing Factor-1 (TEF-1) and Vestigial-like protein families. In Drosophila there is a single mef2 (Dmef2) gene as well single homologues of TEF-1 and vestigial-like, scalloped (sd), and vestigial (vg), respectively. To clarify the role(s) of these factors, we examined the requirements for Vg and Sd during Drosophila muscle specification. We found that both are required for muscle differentiation as loss of sd or vg leads to a reproducible loss of a subset of either cardiac or somatic muscle cells in developing embryos. This muscle requirement for Sd or Vg is cell specific, as ubiquitous overexpression of either or both of these proteins in muscle cells has a deleterious effect on muscle differentiation. Finally, using both in vitro and in vivo binding assays, we determined that Sd, Vg, and Dmef2 can interact directly. Thus, the muscle-specific phenotypes we have associated with Vg or Sd may be a consequence of alternative binding of Vg and/or Sd to Dmef2 forming alternative protein complexes that modify Dmef2 activity.

  17. Exercising with a Muscle Disease

    Science.gov (United States)

    ... these muscle- controlling nerve cells. These cells, the theory goes, not only are com- promised by the ... trainer. “They’re better accustomed to people with disabilities and knowing their limits,” she says. “My trainer ...

  18. Muscle power during intravenous sedation

    National Research Council Canada - National Science Library

    Nobuyuki Matsuura

    2017-01-01

    .... Midazolam and propofol are commonly used for intravenous sedation. Although there have been many researches on the effects of midazolam and propofol on vital function and the recovery profile, little is known about muscle power...

  19. Exercise in muscle pain disorders.

    Science.gov (United States)

    Thompson, Jeffrey M

    2012-11-01

    Muscle pain disorders range from local or regional (myofascial pain) to widespread (fibromyalgia). Many people with muscle pain have decreased fitness. Exercise intolerance is a common feature as well, and yet exercise plays an important role in the treatment of muscle pain disorders. Results of studies have shown repeatedly, via multiple modes and methods of delivery, that exercise is at least as effective as the best pharmacologic treatments. An understanding by clinicians and their patients of the unique benefits of a carefully crafted exercise program is one step in the successful management of these often frustrating muscle pain disorders. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  20. Simvastatin effects on skeletal muscle

    DEFF Research Database (Denmark)

    Larsen, Steen; Stride, Nis; Hey-Mogensen, Martin

    2013-01-01

    Glucose tolerance and skeletal muscle coenzyme Q(10) (Q(10)) content, mitochondrial density, and mitochondrial oxidative phosphorylation (OXPHOS) capacity were measured in simvastatin-treated patients (n = 10) and in well-matched control subjects (n = 9)....

  1. Muscle Strength and Poststroke Hemiplegia

    DEFF Research Database (Denmark)

    Kristensen, Otto H; Stenager, Egon; Dalgas, Ulrik

    2017-01-01

    OBJECTIVES: To systematically review (1) psychometric properties of criterion isokinetic dynamometry testing of muscle strength in persons with poststroke hemiplegia (PPSH); and (2) literature that compares muscle strength in patients poststroke with that in healthy controls assessed by criterion...... isokinetic dynamometry. DATA SOURCES: A systematic literature search of 7 databases was performed. STUDY SELECTION: Included studies (1) enrolled participants with definite poststroke hemiplegia according to defined criteria; (2) assessed muscle strength or power by criterion isokinetic dynamometry; (3) had...... undergone peer review; and (4) were available in English or Danish. DATA EXTRACTION: The psychometric properties of isokinetic dynamometry were reviewed with respect to reliability, validity, and responsiveness. Furthermore, comparisons of strength between paretic, nonparetic, and comparable healthy muscles...

  2. Knitting and weaving artificial muscles.

    Science.gov (United States)

    Maziz, Ali; Concas, Alessandro; Khaldi, Alexandre; Stålhand, Jonas; Persson, Nils-Krister; Jager, Edwin W H

    2017-01-01

    A need exists for artificial muscles that are silent, soft, and compliant, with performance characteristics similar to those of skeletal muscle, enabling natural interaction of assistive devices with humans. By combining one of humankind's oldest technologies, textile processing, with electroactive polymers, we demonstrate here the feasibility of wearable, soft artificial muscles made by weaving and knitting, with tunable force and strain. These textile actuators were produced from cellulose yarns assembled into fabrics and coated with conducting polymers using a metal-free deposition. To increase the output force, we assembled yarns in parallel by weaving. The force scaled linearly with the number of yarns in the woven fabric. To amplify the strain, we knitted a stretchable fabric, exhibiting a 53-fold increase in strain. In addition, the textile construction added mechanical stability to the actuators. Textile processing permits scalable and rational production of wearable artificial muscles, and enables novel ways to design assistive devices.

  3. on gastro intestinal smooth muscle

    African Journals Online (AJOL)

    USER

    , Kaduna State. Correspondence author: am.huguma@yahoo.com. ABSTRACT. The effects of the aqueous leaf extract of Combretum micranthum were studied on gastro intestinal smooth muscle of rodents. The extract was screened using ...

  4. Selenoprotein function and muscle disease

    National Research Council Canada - National Science Library

    Lescure, Alain; Rederstorff, Mathieu; Krol, Alain; Guicheney, Pascale; Allamand, Valérie

    2009-01-01

    The crucial role of the trace element selenium in livestock and human health, in particular in striated muscle function, has been well established but the underlying molecular mechanisms remain poorly understood...

  5. Muscle glycogen stores and fatigue

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Westerblad, Håkan; Nielsen, Joachim

    2013-01-01

    function during fatigue is not well understood and a direct cause-and-effect relationship between glycogen and muscle function remains to be established. The use of electron microscopy has revealed that glycogen is not homogeneously distributed in skeletal muscle fibres, but rather localized in distinct......  Studies performed at the beginning of the last century revealed the importance of carbohydrate as a fuel during exercise, and the importance of muscle glycogen on performance has subsequently been confirmed in numerous studies. However, the link between glycogen depletion and impaired muscle...... the sarcoplasmic reticulum (SR). We and others have provided experimental evidence in favour of a direct role of decreased glycogen, localized within the myofibrils, for the reduction in SR Ca2+ release during fatigue. This is consistent with compartmentalized energy turnover and distinctly localized glycogen...

  6. Muscle pain | Mogole | South African Family Practice

    African Journals Online (AJOL)

    Muscle pain, also known as myalgia, is most commonly associated with sprains or strains. It frequently presents as redness at the site of injury, tenderness, swelling and fever. Muscle pain may occur as a result of excitation of the muscle nociceptor due to overuse of the muscle, viral infections or trauma. The most important ...

  7. Redox homeostasis, oxidative stress and disuse muscle atrophy

    Science.gov (United States)

    Pellegrino, Maria Antonietta; Desaphy, Jean-François; Brocca, Lorenza; Pierno, Sabata; Camerino, Diana Conte; Bottinelli, Roberto

    2011-01-01

    Abstract A pivotal role has been ascribed to oxidative stress in determining the imbalance between protein synthesis and degradation leading to muscle atrophy in many pathological conditions and in disuse. However, a large variability in disuse-induced alteration of redox homeostasis through muscles, models and species emerges from the literature. Whereas the causal role of oxidative stress appears well established in the mechanical ventilation model, findings are less compelling in the hindlimb unloaded mice and very limited in humans. The mere coexistence of muscle atrophy, indirect indexes of increased reactive oxygen species (ROS) production and impairment of antioxidant defence systems, in fact, does not unequivocally support a causal role of oxidative stress in the phenomenon. We hypothesise that in some muscles, models and species only, due to a large redox imbalance, the leading phenomena are activation of proteolysis and massive oxidation of proteins, which would become more susceptible to degradation. In other conditions, due to a lower extent and variable time course of ROS production, different ROS-dependent, but also -independent intracellular pathways might dominate determining the variable extent of atrophy and even dispensable protein oxidation. The ROS production and removal are complex and finely tuned phenomena. They are indeed important intracellular signals and redox balance maintains normal muscle homeostasis and can underlie either positive or negative adaptations to exercise. A precise approach to determine the levels of ROS in living cells in various conditions appears to be of paramount importance to define and support such hypotheses. PMID:21320887

  8. Skeletal Muscle Na+ Channel Disorders

    OpenAIRE

    Dina eSimkin; Saïd eBendahhou

    2011-01-01

    Five inherited human disorders affecting skeletal muscle contraction have been traced to mutations in the gene encoding the voltage-gated sodium channel Nav1.4. The main symptoms of these disorders are myotonia or periodic paralysis caused by changes in skeletal muscle fiber excitability. Symptoms of these disorders vary from mild or latent disease to incapacitating or even death in severe cases. As new human sodium channel mutations corresponding to disease states become discovered, the impo...

  9. BPAG1 in muscles: Structure and function in skeletal, cardiac and smooth muscle.

    Science.gov (United States)

    Horie, Masao; Yoshioka, Nozomu; Takebayashi, Hirohide

    2017-09-01

    BPAG1, also known as Dystonin or BP230, belongs to the plakin family of proteins, which has multiple cytoskeleton-binding domains. Several BPAG1 isoforms are produced by a single BPAG1 genomic locus using different promoters and exons. For example, BPAG1a, BPAG1b, and BPAG1e are predominantly expressed in the nervous system, muscle, and skin, respectively. Among BPAG1 isoforms, BPAG1e is well studied because it was first identified as an autoantigen in patients with bullous pemphigoid, an autoimmune skin disease. BPAG1e is a component of hemidesmosomes, the adhesion complexes that promote dermal-epidermal cohesion. In the nervous system, the role of BPAG1a is also well studied because disruption of BPAG1a results in a phenotype identical to that of Dystonia musculorum (dt) mutants, which show progressive motor disorder. However, the expression and function of BPAG1 in muscles is not well studied. The aim of this review is to provide an overview of and highlight some recent findings on the expression and function of BPAG1 in muscles, which can assist future studies designed to delineate the role and regulation of BPAG1 in the dt mouse phenotype and in human hereditary sensory and autonomic neuropathy type 6 (HSAN6). Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Complex chimerism

    Science.gov (United States)

    Ma, Kimberly K.; Petroff, Margaret G.; Coscia, Lisa A.; Armenti, Vincent T.; Adams Waldorf, Kristina M.

    2013-01-01

    Thousands of women with organ transplantation have undergone successful pregnancies, however little is known about how the profound immunologic changes associated with pregnancy might influence tolerance or rejection of the allograft. Pregnant women with a solid organ transplant are complex chimeras with multiple foreign cell populations from the donor organ, fetus, and mother of the pregnant woman. We consider the impact of complex chimerism and pregnancy-associated immunologic changes on tolerance of the allograft both during pregnancy and the postpartum period. Mechanisms of allograft tolerance are likely dynamic during pregnancy and affected by the influx of fetal microchimeric cells, HLA relationships (between the fetus, pregnant woman and/or donor), peripheral T cell tolerance to fetal cells, and fetal minor histocompatibility antigens. Further research is necessary to understand the complex immunology during pregnancy and the postpartum period of women with a solid organ transplant. PMID:23974274

  11. Complex analysis

    CERN Document Server

    Freitag, Eberhard

    2005-01-01

    The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...

  12. Evaluation of muscle hyperactivity of the grimacing muscles by unilateral tight eyelid closure and stapedius muscle tone.

    Science.gov (United States)

    Shiba, Masato; Matsuo, Kiyoshi; Ban, Ryokuya; Nagai, Fumio

    2012-10-01

    Muscle hyperactivity of grimacing muscles, including the orbicularis oculi and corrugator supercilii muscles that cause crow's feet and a glabellar frown line with ageing, cannot be accurately evaluated by surface observation. In 71 subjects, this study investigated the extent to which grimacing muscles are innervated by the bilateral motor cortices, whether the corticofacial projection to the grimacing muscles affects the facially innervated stapedius muscle tone by measuring static compliance of the tympanic membrane, and whether unilateral tight eyelid closure with contraction of the grimacing muscles changes static compliance. Unilateral tight eyelid closure and its subsequent change in the contralateral vertical medial eyebrow position revealed that motor neurons of the orbicularis oculi and corrugator supercilii muscles were innervated by the bilateral motor cortices with weak-to-strong contralateral dominance. The orbicularis oculi, corrugator supercilii, and stapedius muscles innervated by the bilateral motor cortices had increased muscle hyperactivity, which lowered the vertical medial eyebrow position and decreased the static compliance of the tympanic membrane more than those innervated by the unilateral motor cortex. Unilateral enhanced tight eyelid closure with contraction of the grimacing muscles in certain subjects ipsilaterally decreased the static compliance with increased contraction of the stapedius muscle, which probably occurs to immobilise the tympanic membrane and protect the inner ear from loud sound. Evaluation of unilateral tight eyelid closure and the subsequent change in the contralateral vertical medial eyebrow position as well as a measurement of the static compliance for the stapedius muscle tone has revealed muscle hyperactivity of grimacing muscles.

  13. Pectoral muscle segmentation: a review.

    Science.gov (United States)

    Ganesan, Karthikeyan; Acharya, U Rajendra; Chua, Kuang Chua; Min, Lim Choo; Abraham, K Thomas

    2013-04-01

    Mammograms are X-ray images of breasts which are used to detect breast cancer. The pectoral muscle is a mass of tissue on which the breast rests. During routine mammographic screenings, in medio-lateral oblique (MLO) views, the pectoral muscle turns up in the mammograms along with the breast tissues. The pectoral muscle has to be segmented from the mammogram for an effective automated computer aided diagnosis (CAD). This is due to the fact that pectoral muscles have pixel intensities and texture similar to that of breast tissues which can result in awry CAD results. As a result, a lot of effort has been put into the segmentation of pectoral muscles and finding its contour with the breast tissues. To the best of our knowledge, currently there is no definitive literature available which provides a comprehensive review about the current state of research in this area of pectoral muscle segmentation. We try to address this shortcoming by providing a comprehensive review of research papers in this area. A conscious effort has been made to avoid deviating into the area of automated breast cancer detection. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. Morphology of peroneus tertius muscle.

    Science.gov (United States)

    Joshi, S D; Joshi, S S; Athavale, S A

    2006-10-01

    Peroneus tertius (PT) muscle is peculiar to man, and man is the only member among the primates in whom this muscle occurs. The muscle is variable in its development and attachment. Because of functional demands of bipedal gait and plantigrade foot, part of extensor digitorum brevis (EDB) has migrated upwards into the leg from the dorsum of foot. PT is a muscle that evolution is rendering more important. In a total of 110 cadavers, extensor compartment of leg and dorsum of foot were dissected in both the lower limbs and extensor digitorum longus (EDL), and PT muscles were dissected and displayed. PT was found to be absent in 10.5% limbs, the incidence being greater on the right side. The remaining limbs in which the PT muscle was present had a very extensive origin from lower 3/4th of extensor surface of fibula (20% on right and in 17% on left), and the EDL was very much reduced in size. In approximately 12%, the tendon of PT was thick or even thicker than the tendon of EDL. In 4%, the tendon extended beyond fifth metatarsal up to metatarsophalangeal joint of fifth toe, and in 1.5%, it extended up to the proximal phalanx of little toe. In two cases (both on the right side), where PT was absent, it was replaced by a slip from lateral margin of EDL. We conclude that PT, which is preeminently human, is extending its purchase both proximally and distally. Copyright 2006 Wiley-Liss, Inc.

  15. Adductor muscle strains in sport.

    Science.gov (United States)

    Nicholas, Stephen J; Tyler, Timothy F

    2002-01-01

    An in-season adductor muscle strain may be debilitating for the athlete. Furthermore, an adductor strain that is treated improperly could become chronic and career threatening. Any one of the six muscles of the adductor group could be involved. The degree of injury can range from a minor strain (Grade I), where minimal playing time is lost, to a severe strain (Grade III) in which there is complete loss of muscle function. Ice hockey and soccer players seem particularly susceptible to adductor muscle strains. In professional ice hockey players throughout the world, approximately 10% of all injuries are groin strains. These injuries, which have been linked to hip muscle weakness, previous injuries to that area, preseason practice sessions and level of experience, may be preventable if such risk factors can be addressed before each season. Hip-strengthening exercises were shown to be an effective method of reducing the incidence of adductor strains in one closely followed National Hockey League ice hockey team. Despite the identification of risk factors and strengthening intervention for ice hockey players, adductor strains continue to occur throughout sport. Clinicians feel an active training programme, along with completely restoring the strength of the adductor muscle group, is the key to successful rehabilitation. Surgical intervention is available if nonoperative treatment fails for 6 months or longer. Adductor release and tenotomy was reported to have limited success in athletes.

  16. Muscle histochemistry in chronic alcoholism

    Directory of Open Access Journals (Sweden)

    M. L. Ferraz

    1989-06-01

    Full Text Available Twenty-two chronic acoholic patients were assessed by neurologic examination and muscle biopsy. The patients manifested proximal muscular weakness to a variable extent. One case presented as an acute bout of myopathy, according to the Manual Muscle Test, MMT. The most prominent histologic feature observed was muscle atrophy (95.3% better evidenced through the ATPase stain with the predominance of type II A fibers (71.4%. Lack of the mosaic pattern (type grouping seen in 76% of the cases and an important mitochondrial proliferation with intrasarcoplasmatic lipid accumulation in 63% of the patients. In case of acute presentation of muscle weakness the. pathological substrate is quite different, i.e. presence of myositis mainly interstitial characterized by lymphoplasmocytic infiltrate and several spots of necrosis like Zencker degeneration. Based on histologic criteria, our data suggest that: the main determinant of muscle weakness seen in chronic alcoholic patients is neurogenic in origin (alcoholic polineuropathy; the direct toxic action of ethanol under the skeletal muscle is closely related to the mitochondrial metabolism; the so-called acute alcoholic myopathy has probably viral etiology.

  17. Mechanical forces during muscle development.

    Science.gov (United States)

    Lemke, Sandra B; Schnorrer, Frank

    2017-04-01

    Muscles are the major force producing tissue in the human body. While certain muscle types specialize in producing maximum forces, others are very enduring. An extreme example is the heart, which continuously beats for the entire life. Despite being specialized, all body muscles share similar contractile mini-machines called sarcomeres that are organized into regular higher order structures called myofibrils. The major sarcomeric components and their organizational principles are conserved throughout most of the animal kingdom. In this review, we discuss recent progress in the understanding of myofibril and sarcomere development largely obtained from in vivo models. We focus on the role of mechanical forces during muscle and myofibril development and propose a tension driven self-organization mechanism for myofibril formation. We discuss recent technological advances that allow quantification of forces across tissues or molecules in vitro and in vivo. Although their application towards muscle development is still in its infancy, these technologies are likely to provide fundamental new insights into the mechanobiology of muscle and myofibril development in the near future. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Influence of muscle geometry on shortening speed of fibre, aponeurosis and muscle

    NARCIS (Netherlands)

    Zuurbier, C. J.; Huijing, P. A.

    1992-01-01

    The influence of muscle geometry on muscle shortening of the gastrocnemius medialis muscle (GM) of the rat was studied. Using cinematography, GM geometry was studied during isokinetic concentric activity at muscle lengths ranging from 85 to 105% of the optimum muscle length. The shortening speed of

  19. Complex Analysis

    CERN Document Server

    Stein, Elias M

    2009-01-01

    With this second volume, we enter the intriguing world of complex analysis. From the first theorems on, the elegance and sweep of the results is evident. The starting point is the simple idea of extending a function initially given for real values of the argument to one that is defined when the argument is complex. From there, one proceeds to the main properties of holomorphic functions, whose proofs are generally short and quite illuminating: the Cauchy theorems, residues, analytic continuation, the argument principle.With this background, the reader is ready to learn a wealth of additional m

  20. Complex manifolds

    CERN Document Server

    Morrow, James

    2006-01-01

    This book, a revision and organization of lectures given by Kodaira at Stanford University in 1965-66, is an excellent, well-written introduction to the study of abstract complex (analytic) manifolds-a subject that began in the late 1940's and early 1950's. It is largely self-contained, except for some standard results about elliptic partial differential equations, for which complete references are given. -D. C. Spencer, MathSciNet The book under review is the faithful reprint of the original edition of one of the most influential textbooks in modern complex analysis and geometry. The classic

  1. Assessment of muscle fatigue using electromygraphm sensing

    Science.gov (United States)

    Helmi, Muhammad Hazimin Bin; Ping, Chew Sue; Ishak, Nur Elliza Binti; Saad, Mohd Alimi Bin Mohd; Mokhtar, Anis Shahida Niza Binti

    2017-08-01

    Muscle fatigue is condition of muscle decline in ability after undergoing any physical activity. Observation of the muscle condition of an athlete during training is crucial to prevent or minimize injury and able to achieve optimum performance in actual competition. The aim of this project is to develop a muscle monitoring system to detect muscle fatigue in swimming athlete. This device is capable to measure muscle stress level of the swimmer and at the same time provide indication of muscle fatigue level to trainer. Electromyography signal was recorded from the muscle movement while practicing the front crawl stroke repetitively. The time domain data was processed to frequency spectra in order to study the effect of muscle fatigue. The results show that the recorded EMG signal is able to sense muscle fatigue.

  2. Postmortem proteome degradation profiles of longissimus muscle in Yorkshire and Duroc pigs and their relationship with pork quality traits

    NARCIS (Netherlands)

    Pas, te M.F.W.; Jansen, J.; Broekman, K.C.J.A.; Reimert, H.G.M.; Heuven, H.C.M.

    2009-01-01

    Conversion of muscle to meat is regulated by complex interactions of biochemical processes that take place during postmortem storage of the carcass. Enzymatic proteolysis, among other postmortem biochemical phenomena; e.g. glycolysis; changes tough intact muscle tissue into more tender meat.

  3. Empirical Evaluation of Voluntarily Activatable Muscle Synergies

    OpenAIRE

    Togo, Shunta; Imamizu, Hiroshi

    2017-01-01

    The muscle synergy hypothesis assumes that individual muscle synergies are independent of each other and voluntarily controllable. However, this assumption has not been empirically tested. This study tested if human subjects can voluntarily activate individual muscle synergies extracted by non-negative matrix factorization (NMF), the standard mathematical method for synergy extraction. We defined the activation of a single muscle synergy as the generation of a muscle activity pattern vector p...

  4. Myostatin in the Pathophysiology of Skeletal Muscle

    OpenAIRE

    Carnac, Gilles; Vernus, Barbara; Bonnieu, Anne

    2007-01-01

    Myostatin is an endogenous, negative regulator of muscle growth determining both muscle fiber number and size. The myostatin pathway is conserved across diverse species ranging from zebrafish to humans. Experimental models of muscle growth and regeneration have implicated myostatin as an important mediator of catabolic pathways in muscle cells. Inhibition of this pathway has emerged as a promising therapy for muscle wasting. Here we discuss the recent developments and the controversies in myo...

  5. Muscle ultrasound measurements and functional muscle parameters in non-dystrophic myotonias suggest structural muscle changes.

    NARCIS (Netherlands)

    Trip, J.; Pillen, S.; Faber, C.G.; Engelen, B.G.M. van; Zwarts, M.J.; Drost, G.

    2009-01-01

    Patients with non-dystrophic myotonias, including chloride (myotonia congenita) and sodium channelopathies (paramyotonia congenita/potassium aggravated myotonias), may show muscular hypertrophy in combination with some histopathological abnormalities. However, the extent of muscle changes has never

  6. Managing Complexity

    DEFF Research Database (Denmark)

    Maylath, Bruce; Vandepitte, Sonia; Minacori, Patricia

    2013-01-01

    This article discusses the largest and most complex international learning-by-doing project to date- a project involving translation from Danish and Dutch into English and editing into American English alongside a project involving writing, usability testing, and translation from English into Dutch...

  7. phenanthroline complexes

    Indian Academy of Sciences (India)

    structural analyses. Mass spectral studies of the complexes indicate both the compounds to produce identical cationic species viz., [Co(phen)2Cl2]+ in methanol solution. ... Cobalt(III); X-ray structure; Catecholase activity; DNA cleavage; Anti-cancer activity. 1. ..... necrotic as judged by the staining, nuclear morphology.

  8. Lecithin Complex

    African Journals Online (AJOL)

    China). Lecithin from soya bean was a product of. Sangon (Shanghai, China). Methanol of HPLC grade was purchased from Tedia (USA). Other chemicals used were of analytical grade. Preparation of polydatin-lecithin complex. Polydatin (200 mg) and lecithin (400 mg) were dissolved in 50 mL of tetrahydrofuran and stirred.

  9. Complex Criminality

    NARCIS (Netherlands)

    Bruin, D.; Abels, D.; van der Wilt, H.

    2016-01-01

    This book presents a collection of essays on the wide diversity of meanings of complex criminality. These essays were written to commemorate a national gathering of PhD candidates, from criminal law departments of different universities, at the University of Amsterdam on the 6th of June 2014.

  10. Complex Networks

    CERN Document Server

    Evsukoff, Alexandre; González, Marta

    2013-01-01

    In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

  11. peroxo complexes

    Indian Academy of Sciences (India)

    Administrator

    The investigation of dioxygen binding and activation in dinuclear iron complexes has attracted recent interest because of the presence of carboxylate bridged dinuclear iron sites in several biologically important proteins, such as the R2 protein of ribonucleotide reductase, the hydroxylase component of methane ...

  12. carbohydrate complexes

    Indian Academy of Sciences (India)

    ferrocene-carbohydrate conjugates38,39 have lead to the design and study of the cytotoxic activity of metal com- plexes containing carbohydrate ligands. Hence, here we present the detailed synthesis and characteriza- tion of the carbohydrate triazole ligands and their Pd- complexes together with the crystal structures of ...

  13. Ntem Complex

    African Journals Online (AJOL)

    Zena

    New ages were obtained from charnockites and tonalites collected in the So'o Group in the Ntem Complex. The rocks were analyzed for their petrography, tectonics and 207Pb/206Pb zircon minimum ages of their zircons as well as .... Owona, Department of Earth Sciences, Faculty of Science, University of Douala, P.O. Box.

  14. Regulation of autophagy in human skeletal muscle: effects of exercise, exercise training and insulin stimulation.

    Science.gov (United States)

    Fritzen, Andreas M; Madsen, Agnete B; Kleinert, Maximilian; Treebak, Jonas T; Lundsgaard, Anne-Marie; Jensen, Thomas E; Richter, Erik A; Wojtaszewski, Jørgen; Kiens, Bente; Frøsig, Christian

    2016-02-01

    Regulation of autophagy in human muscle in many aspects differs from the majority of previous reports based on studies in cell systems and rodent muscle. An acute bout of exercise and insulin stimulation reduce human muscle autophagosome content. An acute bout of exercise regulates autophagy by a local contraction-induced mechanism. Exercise training increases the capacity for formation of autophagosomes in human muscle. AMPK activation during exercise seems insufficient to regulate autophagosome content in muscle, while mTORC1 signalling via ULK1 probably mediates the autophagy-inhibiting effect of insulin. Studies in rodent muscle suggest that autophagy is regulated by acute exercise, exercise training and insulin stimulation. However, little is known about the regulation of autophagy in human skeletal muscle. Here we investigate the autophagic response to acute one-legged exercise, one-legged exercise training and subsequent insulin stimulation in exercised and non-exercised human muscle. Acute one-legged exercise decreased (Pexercise in human muscle. The decrease in LC3-II/LC3-I ratio did not correlate with activation of 5'AMP activated protein kinase (AMPK) trimer complexes in human muscle. Consistently, pharmacological AMPK activation with 5-aminoimidazole-4-carboxamide riboside (AICAR) in mouse muscle did not affect the LC3-II/LC3-I ratio. Four hours after exercise, insulin further reduced (Pexercised and non-exercised leg in humans. This coincided with increased Ser-757 phosphorylation of Unc51 like kinase 1 (ULK1), which is suggested as a mammalian target of rapamycin complex 1 (mTORC1) target. Accordingly, inhibition of mTOR signalling in mouse muscle prevented the ability of insulin to reduce the LC3-II/LC3-I ratio. In response to 3 weeks of one-legged exercise training, the LC3-II/LC3-I ratio decreased (Pexercise and insulin stimulation reduce muscle autophagosome content, while exercise training may increase the capacity for formation of autophagosomes

  15. Regulation of autophagy in human skeletal muscle: effects of exercise, exercise training and insulin stimulation

    Science.gov (United States)

    Fritzen, Andreas M.; Madsen, Agnete B.; Kleinert, Maximilian; Treebak, Jonas T.; Lundsgaard, Anne‐Marie; Jensen, Thomas E.; Richter, Erik A.; Wojtaszewski, Jørgen; Kiens, Bente

    2016-01-01

    Key points Regulation of autophagy in human muscle in many aspects differs from the majority of previous reports based on studies in cell systems and rodent muscle.An acute bout of exercise and insulin stimulation reduce human muscle autophagosome content.An acute bout of exercise regulates autophagy by a local contraction‐induced mechanism.Exercise training increases the capacity for formation of autophagosomes in human muscle.AMPK activation during exercise seems insufficient to regulate autophagosome content in muscle, while mTORC1 signalling via ULK1 probably mediates the autophagy‐inhibiting effect of insulin. Abstract Studies in rodent muscle suggest that autophagy is regulated by acute exercise, exercise training and insulin stimulation. However, little is known about the regulation of autophagy in human skeletal muscle. Here we investigate the autophagic response to acute one‐legged exercise, one‐legged exercise training and subsequent insulin stimulation in exercised and non‐exercised human muscle. Acute one‐legged exercise decreased (Pexercise in human muscle. The decrease in LC3‐II/LC3‐I ratio did not correlate with activation of 5′AMP activated protein kinase (AMPK) trimer complexes in human muscle. Consistently, pharmacological AMPK activation with 5‐aminoimidazole‐4‐carboxamide riboside (AICAR) in mouse muscle did not affect the LC3‐II/LC3‐I ratio. Four hours after exercise, insulin further reduced (Pexercised and non‐exercised leg in humans. This coincided with increased Ser‐757 phosphorylation of Unc51 like kinase 1 (ULK1), which is suggested as a mammalian target of rapamycin complex 1 (mTORC1) target. Accordingly, inhibition of mTOR signalling in mouse muscle prevented the ability of insulin to reduce the LC3‐II/LC3‐I ratio. In response to 3 weeks of one‐legged exercise training, the LC3‐II/LC3‐I ratio decreased (Pexercise and insulin stimulation reduce muscle autophagosome content, while exercise

  16. Effect of acupuncture depth on muscle pain

    Directory of Open Access Journals (Sweden)

    Kitakoji Hiroshi

    2011-06-01

    Full Text Available Abstract Background While evidence supports efficacy of acupuncture and/or dry needling in treating musculoskeletal pain, it is unclear which needling method is most effective. This study aims to determine the effects of depth of needle penetration on muscle pain. Methods A total of 22 healthy volunteers performed repeated eccentric contractions to induce muscle soreness in their extensor digital muscle. Subjects were assigned randomly to four groups, namely control group, skin group (depth of 3 mm: the extensor digital muscle, muscle group (depth of 10 mm: the extensor digital muscle and non-segmental group (depth of 10 mm: the anterior tibial muscle. Pressure pain threshold and electrical pain threshold of the skin, fascia and muscle were measured at a point 20 mm distal to the maximum tender point on the second day after the exercise. Results Pressure pain thresholds of skin group (depth of 3 mm: the extensor digital muscle and muscle group (depth of 10 mm: the extensor digital muscle were significantly higher than the control group, whereas the electrical pain threshold at fascia of muscle group (depth of 10 mm: the extensor digital muscle was a significantly higher than control group; however, there was no significant difference between the control and other groups. Conclusion The present study shows that acupuncture stimulation of muscle increases the PPT and EPT of fascia. The depth of needle penetration is important for the relief of muscle pain.

  17. Physiological and methodological aspects of rate of force development assessment in human skeletal muscle

    DEFF Research Database (Denmark)

    Rodríguez-Rosell, David; Pareja-Blanco, Fernando; Aagaard, Per

    2018-01-01

    Rate of force development (RFD) refers to the ability of the neuromuscular system to increase contractile force from a low or resting level when muscle activation is performed as quickly as possible, and it is considered an important muscle strength parameter, especially for athletes in sports...... requiring high-speed actions. The assessment of RFD has been used for strength diagnosis, to monitor the effects of training interventions in both healthy populations and patients, discriminate high-level athletes from those of lower levels, evaluate the impairment in mechanical muscle function after acute...... bouts of eccentric muscle actions and estimate the degree of fatigue and recovery after acute exhausting exercise. Notably, the evaluation of RFD in human skeletal muscle is a complex task as influenced by numerous distinct methodological factors including mode of contraction, type of instruction...

  18. Muscle dysfunction in tension-type headache in adolescents and methods of its correction

    Directory of Open Access Journals (Sweden)

    Stepanchenko K.A.

    2017-04-01

    Full Text Available The aim of our study was to investigate the value of myofascial disorders in adolescents with tension-type headaches and evaluation of effectiveness of their treatment using non-drug therapies. A total of 320 adolescents with tension-type headache have been under study. Research of intensity of headache and pain muscle dysfunction was performed. The treatment period was 1 month. We compared treatment by individual adaptive biofeedback based on heart rate variability and pharmacotherapy. Also patients performed the complex of techniques of isometric muscle autocorrection. It was established that with the increase of incidence of headache episodes, the intensity of the local muscle tenderness and the number of muscles, involved in the formation of a painful syndrome increases. Usage of individual adaptive biofeedback was more effective in reducing the severity of muscle dysfunction, than usage of pharmacotherapy, especially in patients with chronic tension-type headache.

  19. Complex chemistry with complex compounds

    Directory of Open Access Journals (Sweden)

    Eichler Robert

    2016-01-01

    Full Text Available In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the investigation of fragile single molecular species by gas-phase chromatography. The latest success with the heaviest group 6 transactinide seaborgium is highlighted. The formation of a very volatile hexacarbonyl compound Sg(CO6 was observed similarly to its lighter homologues molybdenum and tungsten. The interactions of these gaseous carbonyl complex compounds with quartz surfaces were investigated by thermochromatography. Second-generation experiments are under way to investigate the intramolecular bond between the central metal atom of the complexes and the ligands addressing the influence of relativistic effects in the heaviest compounds. Our contribution comprises some aspects of the ongoing challenging experiments as well as an outlook towards other interesting compounds related to volatile complex compounds in the gas phase.

  20. Skeletal Muscle Mitochondrial Function in Polycystic Ovarian Syndrome

    DEFF Research Database (Denmark)

    Rabøl, Rasmus; Svendsen, Pernille Maj; Skovbro, Mette

    2011-01-01

    Objective Polycystic ovarian syndrome (PCOS) is associated with skeletal muscle insulin resistance, which has been linked to decreased mitochondrial function. We measured mitochondrial respiration in lean and obese women with and without PCOS using high-resolution respirometry. Methods...... Hyperinsulinemic euglycemic clamps (40 mU/min/m2) and muscle biopsies were performed on 23 women with PCOS (9 lean (body mass index (BMI) 25 kg/m2)) and 17 age- and weight-matched controls (6 lean and 11 obese). Western blotting and high-resolution respirometry was used to determine mitochondrial function. Results...... Insulin sensitivity decreased with PCOS and increasing body weight. Mitochondrial respiration with substrates for complex I and complex I+II were similar in all groups, and PCOS was not associated with a decrease in mitochondrial content as measured by mtDNA/genomicDNA. We found no correlation between...

  1. The tymbal muscle of cicada has flight muscle-type sarcomeric architecture and protein expression.

    Science.gov (United States)

    Iwamoto, Hiroyuki

    2017-01-01

    The structural and biochemical features of the tymbal (sound-producing) muscle of cicadas were studied by X-ray diffraction and immunochemistry, and compared with those of flight muscles from the same species. The X-ray diffraction pattern of the tymbal muscle was very similar to that of the dorsal longitudinal flight muscle: In both muscles, the 2,0 equatorial reflection is much more intense than the 1,1, indicating that both muscles have a flight muscle-type myofilament lattice. In rigor, the first myosin/actin layer line reflection was finely lattice-sampled, indicating that the contractile proteins are arranged with a crystalline regularity as in asynchronous flight muscles. In contrast, the diffraction pattern from the tensor muscle, which modulates the sound by stressing the tymbal, did not show signs of such high regularity or flight muscle-type filament lattice. Electrophoretic patterns of myofibrillar proteins were also very similar in the tymbal muscle and flight muscles, but distinct from those from the tensor or leg muscles. The antibody raised against the flight muscle-specific troponin-I isoform reacted with an 80-kDa band from both tymbal and flight muscles, but with none of the bands from the tensor or leg muscles. The close similarities of the structural and biochemical profiles between the tymbal and the flight muscles suggest the possibility that a set of flight muscle-specific proteins is diverted to the tymbal muscle to meet its demand for fast, repetitive contractions.

  2. Empirical Evaluation of Voluntarily Activatable Muscle Synergies

    Directory of Open Access Journals (Sweden)

    Shunta Togo

    2017-09-01

    Full Text Available The muscle synergy hypothesis assumes that individual muscle synergies are independent of each other and voluntarily controllable. However, this assumption has not been empirically tested. This study tested if human subjects can voluntarily activate individual muscle synergies extracted by non-negative matrix factorization (NMF, the standard mathematical method for synergy extraction. We defined the activation of a single muscle synergy as the generation of a muscle activity pattern vector parallel to the single muscle synergy vector. Subjects performed an isometric force production task with their right hand, and the 13 muscle activity patterns associated with their elbow and shoulder movements were measured. We extracted muscle synergies during the task using electromyogram (EMG data and the NMF method with varied numbers of muscle synergies. The number (N of muscle synergies was determined by using the variability accounted for (VAF, NVAF and the coefficient of determination (CD, NCD. An additional muscle synergy model with NAD was also considered. We defined a conventional muscle synergy as the muscle synergy extracted by the NVAF, NCD, and NAD. We also defined an extended muscle synergy as the muscle synergy extracted by the NEX> NAD. To examine whether the individual muscle synergy was voluntarily activatable or not, we calculated the index of independent activation, which reflects similarities between a selected single muscle synergy and the current muscle activation pattern of the subject. Subjects were visually feed-backed the index of independent activation, then instructed to generate muscle activity patterns similar to the conventional and extended muscle synergies. As a result, an average of 90.8% of the muscle synergy extracted by the NVAF was independently activated. However, the proportion of activatable muscle synergies extracted by NCD and NAD was lower. These results partly support the assumption of the muscle synergy

  3. Structure and function of the spermathecal complex in the ...

    Indian Academy of Sciences (India)

    Unknown

    scanning and transmission electron microscopy, described here is ultrastructure of the spermathecal complex in the sand fly, Phlebotomus papatasi Scopoli. The spermathecal complexes are paired; each consists of a long spermathecal duct, a cylindrical spermathecal body, and a spherical spermathecal gland. Muscle ...

  4. Muscle strength rather than muscle mass is associated with osteoporosis in older Chinese adults

    Directory of Open Access Journals (Sweden)

    Yixuan Ma

    2018-02-01

    Conclusion: Based on our study, muscle strength rather than muscle mass is negatively associated with OS in older people; thus, we should pay more attention to muscle strength training in the early stage of the OS.

  5. RNAi targeting embryonic myosin heavy chain isoform inhibited bound thrombin-induced migration of vascular smooth muscle cells

    National Research Council Canada - National Science Library

    Sunagawa, Masanori; Shimada, Seiji; Nakamura, Mariko; Kosugi, Tadayoshi

    2009-01-01

    To investigate the effect of bound thrombin, a complex of alpha-thrombin with fibrin fragments derived from clots, on proliferation and migration of cultured rabbit vascular smooth muscle cells, cell...

  6. Shank Muscle Strength Training Changes Foot Behaviour during a Sudden Ankle Supination.

    Directory of Open Access Journals (Sweden)

    Marco Hagen

    Full Text Available The peroneal muscles are the most effective lateral stabilisers whose tension braces the ankle joint complex against excessive supination. The purpose of this study was to identify the morphological and biomechanical effects of two machine-based shank muscle training methods.Twenty-two healthy male recreationally active sports students performed ten weeks of single-set high resistance strength training with 3 training sessions per week. The subjects conducted subtalar pronator/supinator muscle training (ST with the right leg by using a custom-made apparatus; the left foot muscles were exercised with machine-based talocrural plantar and dorsiflexor training (TT. Muscle strength (MVIC, muscle volume and foot biomechanics (rearfoot motion, ground reaction forces, muscle reaction times during a sudden ankle supination were recorded before and after the intervention.Compared to TT, ST resulted in significantly higher pronator (14% vs. 8%, P<0.01 and supinator MVIC (25% vs. 12%, P<0.01. During sudden foot inversions, both ST and TT resulted in reduced supination velocity (-12%; P<0.01. The muscle reaction onset time was faster after the training in peroneus longus (PL (P<0.01. Muscle volume of PL (P<0.01 and TA (P<0.01 increased significantly after both ST and TT.After both ST and TT, the ankle joint complex is mechanically more stabilised against sudden supinations due to the muscle volume increase of PL and TA. As the reduced supination velocities indicate, the strength training effects are already present during free-fall. According to a sudden ankle supination in standing position, both machine-based dorsiflexor and pronator strength training is recommended for enhancing the mechanical stability of the ankle.

  7. RETARDATION OF MUSCLE GROWTH IN CASTRATED MALE MICE:

    African Journals Online (AJOL)

    the absolute weights and the muscle mass indices of the muscles of castrated males were ... Muscles, Mice. INTRODUCTION rat levator ani muscles. It was noted that the hypertrophy of the muscle was a result. Muscles of adult male mice are invariably of increase in myofibrilar material .... (1976): Skeletal muscle cellularity.

  8. Managing Complexity

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  9. Complex Questions Promote Complex Thinking

    Science.gov (United States)

    Degener, Sophie; Berne, Jennifer

    2017-01-01

    Intermediate-grade teachers often express concerns about meeting the Common Core State Standards for Reading, primarily because of the emphasis on deep understanding of complex texts. No matter how difficult the text, if teachers demand little of the reading, student meaning making is not challenged. This article offers a tool for teachers to…

  10. Polyneuronal Innervation of Single Muscle Fibers in Cat Eye Muscle: Inferior Oblique

    OpenAIRE

    Dimitrova, Diana M.; Allman, Brian L.; Shall, Mary S.; Goldberg, Stephen J.

    2009-01-01

    Single muscle fibers with multiple axonal endplates (multiply innervated fibers) are normally present in adult extraocular muscles (EOMs), while most other mammalian skeletal muscles contain fibers with a single myoneural junction. Recent findings by others led us to investigate for the presence of polyneuronal innervation (innervation of a single muscle fiber by >1 motoneuron) in the inferior oblique (IO) muscle of pentobarbital anesthetized cats. The IO muscle nerve branches, as they course...

  11. Teres major muscle - insertion footprint.

    Science.gov (United States)

    Dancker, Malte; Lambert, Simon; Brenner, Erich

    2017-05-01

    Teres major muscle (TM) and latissimus dorsi muscle (LD) are frequently used in muscle transfers around the shoulder girdle. Some authors have suggested harvesting techniques in which the muscle is detached in continuity with a bone segment. Information on the bony attachment footprint of these muscles is lacking. The purpose of this study was to investigate the region of attachment of the TM to facilitate safe and complete harvesting with a bone segment where it is indicated, and to determine the relationship of the TM footprint with that of the LD. Twenty-eight upper extremities of 14 human cadavers (six female, eight male) were investigated during the students' dissection course in the winter term 2012. The attachment footprints were photographed and the images were processed with ImageJ Version 1.46r. The TM attachment footprint at the crest of the lesser tubercle had an average dimension of 187 ± 89 mm2 . It was 49.6 ± 7.9 mm long and 7.4 ± 2.5 mm wide. The bony attachment of the LD within the bicipital groove, just below the tendon of the long head of the biceps muscle, had an area of 94 ± 37 mm2 . It was 36.5 ± 8 mm long and 3.7 ± 1.2 mm wide. Both muscles were separated by 4.4 ± 1.7 mm and their attachments overlapped in the craniocaudal direction by 24.4 ± 12.4 mm. Earlier studies have investigated the dimensions of the muscles' tendons close to the attachment not the bony attachment itself. The dimension of the attachment of the TM was larger than that of the LD. The ratio between the footprint areas was approximately 2:1. This information should be considered by surgeons undertaking transfers, which include a bony segment of the muscle insertion. © 2017 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

  12. Striated Muscle Function, Regeneration, and Repair

    Science.gov (United States)

    Shadrin, I.Y.; Khodabukus, A.; Bursac, N.

    2016-01-01

    As the only striated muscle tissues in the body, skeletal and cardiac muscle share numerous structural and functional characteristics, while exhibiting vastly different size and regenerative potential. Healthy skeletal muscle harbors a robust regenerative response that becomes inadequate after large muscle loss or in degenerative pathologies and aging. In contrast, the mammalian heart loses its regenerative capacity shortly after birth, leaving it susceptible to permanent damage by acute injury or chronic disease. In this review, we compare and contrast the physiology and regenerative potential of native skeletal and cardiac muscles, mechanisms underlying striated muscle dysfunction, and bioengineering strategies to treat muscle disorders. We focus on different sources for cellular therapy, biomaterials to augment the endogenous regenerative response, and progress in engineering and application of mature striated muscle tissues in vitro and in vivo. Finally, we discuss the challenges and perspectives in translating muscle bioengineering strategies to clinical practice. PMID:27271751

  13. The Skeletal Muscle Satellite Cell

    Science.gov (United States)

    2011-01-01

    The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell’s indispensable role in muscle repair has been reaffirmed. PMID:22147605

  14. Muscle pathology in juvenile dermatomyositis

    Directory of Open Access Journals (Sweden)

    Edenilson Eduardo Calore

    Full Text Available OBJECTIVE: To study muscle biopsies, using histochemistry, on ten children with infantile dermatomyositis. DESIGN: Series of ten patients (of whom eight patients had received treatment and two had not were submitted to muscle biopsy in order to diagnose possible inflammatory myopathy or to detect recurrences. PLACE OF DEVELOPMENT OF THE STUDY: Public Health Service of São Paulo State. PARTICIPANTS: children with clinical features of inflammatory myopathy. INTERVENTION: biopsies were performed on the vastus lateralis using local anesthetic. Histochemistry was performed according to standardized methods. RESULTS: Architectural changes of the muscle fibers, necrosis of variable intensity and accentuated evidence of regeneration were observed in patients who had not received treatment (2 cases and in one case where muscular weakness persisted in spite of corticosteroid therapy. Necrosis and regeneration were minimal or absent in cases treated for one year or more (4 cases. In 3 cases with clinical and laboratorial recurrences, muscle necrosis and architectural changes were detected. CONCLUSIONS: It was concluded that muscle biopsy could aid in diagnosing infantile dermatomyositis as well as in detecting recurrences even in cases without clinical activity of the disease.

  15. Unilateral Absence of Plantaris muscle in Ethiopian Cadavers – a case report

    OpenAIRE

    Hafte Assefa Beyene; Birhane Alem Berihu; Yared godefa; Gebrekidan Gebregzabher

    2016-01-01

    Plantaris is the largest muscle in mammals other than primates. It runs alongside the gastrosoleus complex, and continues along the medial aspect of the Achilles tendon (AT) before inserting onto the greater tuberosity of the calcaneus. The plantaris muscle is vestigial in human beings and has much clinical importance. It is known to present several anatomical variations in terms of its occurrence, origin, course, relation with surrounding neurovascular structures and insertion. It may be abs...

  16. Myoanatomy and anterior muscle regeneration of the fireworm Eurythoe cf. complanata (Annelida: Amphinomidae).

    Science.gov (United States)

    Weidhase, Michael; Bleidorn, Christoph; Beckers, Patrick; Helm, Conrad

    2016-03-01

    Amphinomidae or so-called "fireworms" are known for their inflammatory substances and their regeneration ability. Recent transcriptome-based molecular analyses revealed that these remarkable annelids are a basal branching taxon outside the annelid main radiation (Pleistoannelida). Although several studies dealing with analyses of the morphology of these annelids have been published, detailed investigations of the anterior muscle regeneration and the musculature in general are largely lacking for amphinomids. Using histology, phalloidin labeling together with subsequent confocal laser scanning microscopy (cLSM), and further light microscopic image acquisition of different regeneration stages, we here present the first morphological study describing the myoanatomy and muscular regeneration. During anterior muscular regeneration, longitudinal muscle bundles develop prior to transverse muscle fibers and segment boundaries. Additionally, Eurythoe cf. complanata develops an independent muscular ring surrounding the mouth opening in an early stage of regeneration. Detailed investigation of adult body wall musculature and the parapodial muscle complex in amphinomids show that E. cf. complanata bears well-developed dorsal and ventral longitudinal muscle bundles as well as outer transverse muscles comparable to the pattern described for several Pleistoannelida. Furthermore, the biramous parapodia possess a complex meshwork of distinct muscle fibers allowing detailed comparisons with other annelid families. © 2015 Wiley Periodicals, Inc.

  17. Sarcoglycan subcomplex in normal human smooth muscle: an immunohistochemical and molecular study.

    Science.gov (United States)

    Anastasi, Giuseppe; Cutroneo, Giuseppina; Sidoti, Antonina; Santoro, Giuseppe; D'Angelo, Rosalia; Rizzo, Giuseppina; Rinaldi, Carmen; Giacobbe, Oddone; Bramanti, Placido; Navarra, Giuseppe; Amato, Aldo; Favaloro, Angelo

    2005-09-01

    The sarcoglycans are transmembrane components of the dystrophin-glycoprotein complex, which links the cytoskeleton to the extracellular matrix in adult muscle fibers. Sarcoglycans seem to be functionally and pathologically as important as dystrophin. In the skeletal and cardiac muscle, the sarcoglycan subcomplex is a heterotetrameric unit composed of the transmembrane glycoproteins alpha-, beta-, gamma- and delta-sarcoglycan. A fifth sarcoglycan with significant homology to alpha-sarcoglycan, epsilon-sarcoglycan, has been identified; this sarcoglycan is expressed in both muscle and non-muscle cells. It is hypothesized that epsilon-sarcoglycan might replace alpha-sarcoglycan in smooth muscle, forming a novel sarcoglycan subcomplex consisting of epsilon-, beta-, gamma-, and delta-sarcoglycan. Recently, zeta-sarcoglycan, a novel sarcoglycan highly related to gamma-sarcoglycan and delta-sarcoglycan, has been identified. On this basis, growing evidence suggests that there are two types of sarcoglycan complex; one, in skeletal and cardiac muscle, consisting of alpha-, beta-, gamma- and delta-sarcoglycan; and the other, in smooth muscle, containing beta-, delta-, zeta- and epsilon-sarcoglycan. epsilon-sarcoglycan may be substituted for alpha-sarcoglycan in a subset of striated muscle complexes. Our results, obtained with immunofluorescence semi-quantitative analysis and molecular methods on smooth muscle biopsies of human adult gastroenteric tract, show for the first time that alpha-sarcoglycan fluorescence is also always detectable in smooth muscle, although its staining pattern is lower than epsilon-sarcoglycan. Normal alpha-sarcoglycan staining was detected at times, whereas there was reduced, but clearly detectable staining for epsilon-sarcoglycan. Moreover, gamma-sarcoglycan staining is always detectable in all analyzed biopsies. On the basis of our results, we would be able to hypothesize the existence of a pentameric or, considering zeta-sarcolgycan, a hexameric

  18. Troponin T3 expression in skeletal and smooth muscle is required for growth and postnatal survival: Characterization of Tnnt3tm2a(KOMP)Wtsi mice

    OpenAIRE

    Ju, Yawen; Li, Jie; Xie, Chao; Ritchlin, Christopher T; Xing, Lianping; Hilton, Matthew J.; Schwarz, Edward M.

    2013-01-01

    The troponin complex, which consists of three regulatory proteins (troponin C, troponin I and troponin T), is known to regulate muscle contraction in skeletal and cardiac muscle, but its role in smooth muscle remains controversial. Troponin T3 (TnnT3) is a fast skeletal muscle troponin believed to be expressed only in skeletal muscle cells. To determine the in vivo function and tissue specific expression of Tnnt3, we obtained the heterozygous Tnnt3+/flox/lacZ mice from Knockout Mouse Project ...

  19. Opposing effects of nitric oxide and prostaglandin inhibition on muscle mitochondrial VO2 during exercise

    DEFF Research Database (Denmark)

    Boushel, Robert C; Fuentes, Teresa; Hellsten, Ylva

    2012-01-01

    -dependent manner, and thus inhibition of NO and PG may regulate both muscle oxygen delivery and utilization. The purpose of this study was to examine the independent and combined effects of NO and PG blockade (L-NMMA and indomethacin respectively) on mitochondrial respiration in human muscle following knee...... respiration primarily at complex I of the respiratory chain while blockade of NO by addition of L-NMMA counteracts the inhibition of Indo. This metabolic effect in concert with a reduction of blood flow likely accounts for in-vivo changes in muscle O(2) consumption during combined blockade of NO and PG....

  20. Coordination of metabolic plasticity in skeletal muscle.

    Science.gov (United States)

    Hood, David A; Irrcher, Isabella; Ljubicic, Vladimir; Joseph, Anna-Maria

    2006-06-01

    -subunit complexes of the respiratory chain, when combined with nuclear-encoded protein subunits. The expansion of skeletal muscle mitochondria during organelle biogenesis involves the assembly of an interconnected network system (i.e. a mitochondrial reticulum). This expansion of membrane size is influenced by the balance between mitochondrial fusion and fission. Thus, mitochondrial biogenesis is an adaptive process that requires the coordination of multiple cellular events, including the transcription of two genomes, the synthesis of lipids and proteins and the stoichiometric assembly of multisubunit protein complexes into a functional respiratory chain. Impairments at any step can lead to defective electron transport, a subsequent failure of ATP production and an inability to maintain energy homeostasis.

  1. Mercury speciation and selenium in toothed-whale muscles.

    Science.gov (United States)

    Sakamoto, Mineshi; Itai, Takaaki; Yasutake, Akira; Iwasaki, Toshihide; Yasunaga, Genta; Fujise, Yoshihiro; Nakamura, Masaaki; Murata, Katsuyuki; Chan, Hing Man; Domingo, José L; Marumoto, Masumi

    2015-11-01

    Mercury accumulates at high levels in marine mammal tissues. However, its speciation is poorly understood. The main goal of this investigation was to establish the relationships among mercury species and selenium (Se) concentrations in toothed-whale muscles at different mercury levels. The concentrations of total mercury (T-Hg), methylmercury (MeHg), inorganic mercury (I-Hg) and Se were determined in the muscles of four toothed-whale species: bottlenose dolphins (n=31), Risso's dolphins (n=30), striped dolphins (n=29), and short-finned pilot whales (n=30). In each species, the MeHg concentration increased with increasing T-Hg concentration, tending to reach a plateau. In contrast, the proportion of MeHg in T-Hg decreased from 90-100% to 20-40%. The levels of T-Hg and Se showed strong positive correlations. Se/I-Hg molar ratios rapidly decreased with the increase of I-Hg and reached almost 1 in all species. These results suggested that the demethylated MeHg immediately formed Se/I-Hg equimolar complex of mercury selenide (HgSe) in their muscles. In addition, an X-ray absorption fine structure analysis (XAFS) of a bottlenose dolphin muscle confirmed that the dominant chemical form of the Se/I-Hg equimolar complex was HgSe. HgSe was mainly localized in cells near the endomysium using electron probe microanalysis (EPMA). These results suggested that the demethylated MeHg finally deposits within muscle cells of bottlenose dolphin as an inert HgSe. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Synthetic strands of cardiac muscle. Formation and ultrastructure.

    Science.gov (United States)

    Purdy, J E; Liebeman, M; Roggeveen, A E; Kirk, R G

    1972-12-01

    Spontaneously active bundles of cardiac muscle (synthetic strands) were prepared from isolated cells of 11-13-day old embryonic chick hearts which were disaggregated with trypsin. Linear orientation of the cells was obtained by plating them on agar-coated culture dishes in which either grooves were cut in the agar film or a thin line of palladium was deposited over the agar. The influence of cell-to-cell and cell-to-substrate interactions was observed with time lapse cinematography and the formation of the synthetic strand was shown to involve both random and guided cell movements, enlargement of aggregates by accretion and coalescence, and the compact linear arrangement of cells along paths of preferential adhesion. Electron microscope investigations of these strands showed that a dispersed population of heart cells organized into an inner core of muscle cells and an outer sheath of fibroblast-like cells. The muscle cells contained well-developed, but widely spaced myofibrils, a developing sarcoplasmic reticulum associated in part with the myofibrils and in part with the sarcolemma, an abundance of nonmembrane bound ribosomes and glycogen, and a prominent Golgi complex. Numerous specialized contacts were observed between the muscle cells in the strand, e.g., fasciae adherentes, desmosomes, and nexuses. A distinct type of muscle cell characterized by its pale appearance was regularly observed in the strand and was noted to be similar to Purkinje cells described in the adult avian conduction system and in developing chick myocardium. The present findings were compared with other observations of the developing myocardium, in situ, and it was concluded that, by a number or criteria, the muscle cells of the strand were differentiating normally and suitably organized for electrophysiological studies.

  3. Exercise Promotes Healthy Aging of Skeletal Muscle

    DEFF Research Database (Denmark)

    Cartee, Gregory D; Hepple, Russell T; Bamman, Marcas M

    2016-01-01

    Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes...... caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial...... respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle....

  4. Partial muscle carnitine palmitoyltransferase-A deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Ross, N.S.; Hoppel, C.L.

    1987-01-02

    After initiation of ibuprofen therapy, a 45-year-old woman developed muscle weakness and tenderness with rhabdomyolysis, culminating in respiratory failure. A muscle biopsy specimen showed a vacuolar myopathy, and markedly decreased muscle carnitine content and carnitine palmitoyltransferase activity. Following recovery, muscle carnitine content was normal but carnitine palmitoyltransferase activity was still abnormally low. The ratio of palmitoyl-coenzyme A plus carnitine to palmitoylcarnitine oxidation by muscle mitochondria isolated from the patient was markedly decreased. The authors conclude that transiently decreased muscle carnitine content interacted with partial deficiency of carnitine palmitoyltransferase-A to produce rhabdomyolysis and respiratory failure and that ibuprofen may have precipitated the clinical event.

  5. Epigenetics of cancer-associated muscle catabolism.

    Science.gov (United States)

    Carr, Ryan M; Enriquez-Hesles, Elisa; Olson, Rachel Lo; Jatoi, Aminah; Doles, Jason; Fernandez-Zapico, Martin E

    2017-09-25

    Cancer patients are commonly affected by cachexia, a wasting process involving muscle and fat. Specifically, loss of the muscle compartment has been associated with poor prognosis and suboptimal response to therapy. Nutritional support has been ineffective in treating this process leading to investigations into the underlying molecular processes governing muscle catabolism. In this commentary, we discuss the molecular mechanisms of cancer-associated muscle metabolism and the epigenetic processes responsible for the muscle wasting phenotype. Ultimately, we highlight how the epigenome may serve as a promising therapeutic target in reversing cancer-associated muscle catabolism.

  6. Pelvic floor muscle rehabilitation using biofeedback.

    Science.gov (United States)

    Newman, Diane K

    2014-01-01

    Pelvic floor muscle exercises have been recommended for urinary incontinence since first described by obstetrician gynecologist Dr. Arnold Kegel more than six decades ago. These exercises are performed to strengthen pelvic floor muscles, provide urethral support to prevent urine leakage, and suppress urgency. In clinical urology practice, expert clinicians also teach patients how to relax the muscle to improve bladder emptying and relieve pelvic pain caused by muscle spasm. When treating lower urinary tract symptoms, an exercise training program combined with biofeedback therapy has been recommended as first-line treatment. This article provides clinical application of pelvic floor muscle rehabilitation using biofeedback as a technique to enhance pelvic floor muscle training.

  7. Vitamin D and muscle function.

    Science.gov (United States)

    Dawson-Hughes, Bess

    2017-10-01

    Muscle weakness is a hallmark of severe vitamin D deficiency, but the effect of milder vitamin D deficiency or insufficiency on muscle mass and performance and risk of falling is uncertain. In this presentation, I review the evidence that vitamin D influences muscle mass and performance, balance, and risk of falling in older adults. Special consideration is given to the impact of both the starting 25-hydroxyvitamin D [25(OH)D] level and the dose administered on the clinical response to supplemental vitamin D in older men and women. Based on available evidence, older adults with serum 25(OH)D levels vitamin D dose range of 800-1000 IU per day has been effective in many studies; lower doses have generally been ineffective and several doses above this range have increased the risk of falls. In conclusion, older adults with serum 25(OH)D levels vitamin D. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Quadriceps and hamstring muscle activity during cycling as measured with intramuscular electromyography.

    Science.gov (United States)

    da Silva, Julio Cézar Lima; Tarassova, O; Ekblom, M M; Andersson, E; Rönquist, G; Arndt, A

    2016-09-01

    The aim of this study was to describe thigh muscle activation during cycling using intramuscular electromyographic recordings of eight thigh muscles, including the biceps femoris short head (BFS) and the vastus intermedius (Vint). Nine experienced cyclists performed an incremental test (start at 170 W and increased by 20 W every 2 min) on a bicycle ergometer either for a maximum of 20 min or to fatigue. Intramuscular electromyography (EMG) of eight muscles and kinematic data of the right lower limb were recorded during the last 20 s in the second workload (190 W). EMG data were normalized to the peak activity occurring during this workload. Statistical significance was assumed at p ≤ 0.05. The vastii showed a greater activation during the 1st quadrant compared to other quadrants. The rectus femoris (RF) showed a similar activation, but with two bursts in the 1st and 4th quadrants in three subjects. This behavior may be explained by the bi-articular function during the cycling movement. Both the BFS and Vint were activated longer than, but in synergy with their respective agonistic superficial muscles. Intramuscular EMG was used to verify muscle activation during cycling. The activation pattern of deep muscles (Vint and BFS) could, therefore, be described and compared to that of the more superficial muscles. The complex coordination of quadriceps and hamstring muscles during cycling was described in detail.

  9. Inspiratory Muscle Training and Functional Capacity in Patients Undergoing Cardiac Surgery.

    Science.gov (United States)

    Cordeiro, André Luiz Lisboa; Melo, Thiago Araújo de; Neves, Daniela; Luna, Julianne; Esquivel, Mateus Souza; Guimarães, André Raimundo França; Borges, Daniel Lago; Petto, Jefferson

    2016-04-01

    Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery.

  10. Characterization of intercostal muscle pathology in canine degenerative myelopathy: a disease model for amyotrophic lateral sclerosis.

    Science.gov (United States)

    Morgan, Brandie R; Coates, Joan R; Johnson, Gayle C; Bujnak, Alyssa C; Katz, Martin L

    2013-12-01

    Dogs homozygous for missense mutations in the SOD1 gene develop a late-onset neuromuscular disorder called degenerative myelopathy (DM) that has many similarities to amyotrophic lateral sclerosis (ALS). Both disorders are characterized by widespread progressive declines in motor functions, accompanied by atrophic changes in the descending spinal cord tracts. Some forms of ALS are also associated with SOD1 mutations. In end-stage ALS, death usually occurs as a result of respiratory failure from severe functional impairment of respiratory muscles. The mechanisms that lead to this loss of function are not known. Dogs with DM are euthanized at all stages of disease progression, providing an opportunity to characterize the onset and progression of any pathological changes in the respiratory muscles that may precede respiratory failure. To characterize such potential disease-related pathology, we evaluated intercostal muscles from Boxer and Pembroke Welsh Corgi dogs that were euthanized at various stages of DM disease progression. DM was found to result in intercostal muscle atrophy, fibrosis, increased variability in muscle fiber size and shape, and alteration in muscle fiber type composition. This pathology was not accompanied by retraction of the motor neuron terminals from the muscle acetylcholine receptor complexes, suggesting that the muscle atrophy did not result from physical denervation. These findings provide a better understanding of the mechanisms that likely lead to respiratory failure in at least some forms of ALS and will be useful in the development and evaluation of potential therapeutic interventions using the DM model. Copyright © 2013 Wiley Periodicals, Inc.

  11. Inspiratory Muscle Training and Functional Capacity in Patients Undergoing Cardiac Surgery

    Science.gov (United States)

    Cordeiro, André Luiz Lisboa; de Melo, Thiago Araújo; Neves, Daniela; Luna, Julianne; Esquivel, Mateus Souza; Guimarães, André Raimundo França; Borges, Daniel Lago; Petto, Jefferson

    2016-01-01

    Introduction Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. Objective To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. Methods This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. Results 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). Conclusion We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery. PMID:27556313

  12. Osteoprotegerin and β2-Agonists Mitigate Muscular Dystrophy in Slow- and Fast-Twitch Skeletal Muscles.

    Science.gov (United States)

    Dufresne, Sébastien S; Boulanger-Piette, Antoine; Frenette, Jérôme

    2017-03-01

    Our recent work showed that daily injections of osteoprotegerin (OPG)-immunoglobulin fragment complex (OPG-Fc) completely restore the function of fast-twitch extensor digitorum longus muscles in dystrophic mdx mice, a murine model of Duchenne muscular dystrophy. However, despite marked improvements, OPG-Fc was not as effective in preventing the loss of function of slow-twitch soleus and diaphragm muscles. Because β 2 -agonists enhance the function of slow- and fast-twitch dystrophic muscles and because their use is limited by their adverse effects on bone and cardiac tissues, we hypothesized that OPG-Fc, a bone and skeletal muscle protector, acts synergistically with β 2 -agonists and potentiates their positive effects on skeletal muscles. We observed that the content of β 2 -adrenergic receptors, which are mainly expressed in skeletal muscle, is significantly reduced in dystrophic muscles but is rescued by the injection of OPG-Fc. Most important, OPG-Fc combined with a low dose of formoterol, a member of a new generation of β 2 -agonists, histologically and functionally rescued slow-twitch dystrophic muscles. This combination of therapeutic agents, which have already been tested and approved for human use, may open up new therapeutic avenues for Duchenne muscular dystrophy and possibly other neuromuscular diseases. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  13. A Novel Approach to Measuring Muscle Mechanics in Vehicle Collision Conditions.

    Science.gov (United States)

    Krašna, Simon; Đorđević, Srđan; Hribernik, Marija; Trajkovski, Ana

    2017-06-14

    The aim of the study was to evaluate a novel approach to measuring neck muscle load and activity in vehicle collision conditions. A series of sled tests were performed on 10 healthy volunteers at three severity levels to simulate low-severity frontal impacts. Electrical activity-electromyography (EMG)-and muscle mechanical tension was measured bilaterally on the upper trapezius. A novel mechanical contraction (MC) sensor was used to measure the tension on the muscle surface. The neck extensor loads were estimated based on the inverse dynamics approach. The results showed strong linear correlation (Pearson's coefficient = 0.821) between the estimated neck muscle load and the muscle tension measured with the MC sensor. The peak of the estimated neck muscle force delayed 0.2 ± 30.6 ms on average vs. the peak MC sensor signal compared to the average delay of 61.8 ± 37.4 ms vs. the peak EMG signal. The observed differences in EMG and MC sensor collected signals indicate that the MC sensor offers an additional insight into the analysis of the neck muscle load and activity in impact conditions. This approach enables a more detailed assessment of the muscle-tendon complex load of a vehicle occupant in pre-impact and impact conditions.

  14. The bile duct ligated rat: A relevant model to study muscle mass loss in cirrhosis.

    Science.gov (United States)

    Bosoi, Cristina R; Oliveira, Mariana M; Ochoa-Sanchez, Rafael; Tremblay, Mélanie; Ten Have, Gabriella A; Deutz, Nicolaas E; Rose, Christopher F; Bemeur, Chantal

    2017-04-01

    Muscle mass loss and hepatic encephalopathy (complex neuropsychiatric disorder) are serious complications of chronic liver disease (cirrhosis) which impact negatively on clinical outcome and quality of life and increase mortality. Liver disease leads to hyperammonemia and ammonia toxicity is believed to play a major role in the pathogenesis of hepatic encephalopathy. However, the effects of ammonia are not brain-specific and therefore may also affect other organs and tissues including muscle. The precise pathophysiological mechanisms underlying muscle wasting in chronic liver disease remains to be elucidated. In the present study, we characterized body composition as well as muscle protein synthesis in cirrhotic rats with hepatic encephalopathy using the 6-week bile duct ligation (BDL) model which recapitulates the main features of cirrhosis. Compared to sham-operated control animals, BDL rats display significant decreased gain in body weight, altered body composition, decreased gastrocnemius muscle mass and circumference as well as altered muscle morphology. Muscle protein synthesis was also significantly reduced in BDL rats compared to control animals. These findings demonstrate that the 6-week BDL experimental rat is a relevant model to study liver disease-induced muscle mass loss.

  15. Rat diaphragm mitochondria have lower intrinsic respiratory rates than mitochondria in limb muscles.

    Science.gov (United States)

    Garcia-Cazarin, Mary L; Gamboa, Jorge L; Andrade, Francisco H

    2011-06-01

    The mitochondrial content of skeletal muscles is proportional to activity level, with the assumption that intrinsic mitochondrial function is the same in all muscles. This may not hold true for all muscles. For example, the diaphragm is a constantly active muscle; it is possible that its mitochondria are intrinsically different compared with other muscles. This study tested the hypothesis that mitochondrial respiration rates are greater in the diaphragm compared with triceps surae (TS, a limb muscle). We isolated mitochondria from diaphragm and TS of adult male Sprague Dawley rats. Mitochondrial respiration was measured by polarography. The contents of respiratory complexes, uncoupling proteins 1, 2, and 3 (UCP1, UCP2, and UCP3), and voltage-dependent anion channel 1 (VDAC1) were determined by immunoblotting. Complex IV activity was measured by spectrophotometry. Mitochondrial respiration states 3 (substrate and ADP driven) and 5 (uncoupled) were 27 ± 8% and 24 ± 10%, respectively, lower in diaphragm than in TS (P lower rates, despite a higher content of respiratory complexes. The results invalidate our initial hypothesis and indicate that mitochondrial content is not the only determinant of aerobic capacity in the diaphragm. We propose that UCP1 and VDAC1 play a role in regulating diaphragm aerobic capacity.

  16. Evaluation of probabilistic methods to predict muscle activity: implications for neuroprosthetics

    Science.gov (United States)

    Johnson, Lise A.; Fuglevand, Andrew J.

    2009-10-01

    Functional electrical stimulation (FES) involves artificial activation of muscles with surface or implanted electrodes to restore motor function in paralyzed individuals. Currently, FES-based prostheses produce only a limited range of movements due to the difficulty associated with identifying patterns of muscle activity needed to evoke more complex behaviour. Here we test three probability-based models (Bayesian density estimation, polynomial curve fitting and dynamic neural network) that use the trajectory of the hand to predict the electromyographic (EMG) activities of 12 arm muscles during complex two- and three-dimensional movements. Across most conditions, the neural network model yielded the best predictions of muscle activity. For three-dimensional movements, the predicted patterns of muscle activity using the neural network accounted for 40% of the variance in the actual EMG signals and were associated with an average root-mean-squared error of 6%. These results suggest that such probabilistic models could be used effectively to predict patterns of muscle stimulation needed to produce complex movements with an FES-based neuroprosthetic.

  17. Alpha 7 integrin preserves the function of the extensor digitorum longus muscle in dystrophin-null mice.

    Science.gov (United States)

    Hakim, Chady H; Burkin, Dean J; Duan, Dongsheng

    2013-11-01

    The dystrophin-associated glycoprotein complex (DGC) and the α7β1-integrin complex are two independent protein complexes that link the extracellular matrix with the cytoskeleton in muscle cells. These associations stabilize the sarcolemma during force transmission. Loss of either one of these complexes leads to muscular dystrophy. Dystrophin is a major component of the DGC. Its absence results in Duchenne muscular dystrophy (DMD). Because α7-integrin overexpression has been shown to ameliorate muscle histopathology in mouse models of DMD, we hypothesize that the α7β1-integrin complex can help preserve muscle function. To test this hypothesis, we evaluated muscle force, elasticity, and the viscous property of the extensor digitorum longus muscle in 19-day-old normal BL6, dystrophin-null mdx4cv, α7-integrin-null, and dystrophin/α7-integrin double knockout mice. While nominal changes were found in single knockout mice, contractility and passive properties were significantly compromised in α7-integrin double knockout mice. Our results suggest that DGC and α7β1-integrin complexes may compensate each other to maintain normal skeletal muscle function. α7β1-Integrin upregulation may hold promise to treat not only histological, but also physiological, defects in DMD.

  18. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  19. Complex variables

    CERN Document Server

    Taylor, Joseph L

    2011-01-01

    The text covers a broad spectrum between basic and advanced complex variables on the one hand and between theoretical and applied or computational material on the other hand. With careful selection of the emphasis put on the various sections, examples, and exercises, the book can be used in a one- or two-semester course for undergraduate mathematics majors, a one-semester course for engineering or physics majors, or a one-semester course for first-year mathematics graduate students. It has been tested in all three settings at the University of Utah. The exposition is clear, concise, and lively

  20. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.