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Sample records for extraocular muscle pareses

  1. A functional SNP in the regulatory region of the decay-accelerating factor gene associates with extraocular muscle pareses in myasthenia gravis

    KAUST Repository

    Heckmann, J M

    2009-08-13

    Complement activation in myasthenia gravis (MG) may damage muscle endplate and complement regulatory proteins such as decay-accelerating factor (DAF) or CD55 may be protective. We hypothesize that the increased prevalence of severe extraocular muscle (EOM) dysfunction among African MG subjects reported earlier may result from altered DAF expression. To test this hypothesis, we screened the DAF gene sequences relevant to the classical complement pathway and found an association between myasthenics with EOM paresis and the DAF regulatory region c.-198CG SNP (odds ratio8.6; P0.0003). This single nucleotide polymorphism (SNP) results in a twofold activation of a DAF 5?-flanking region luciferase reporter transfected into three different cell lines. Direct matching of the surrounding SNP sequence within the DAF regulatory region with the known transcription factor-binding sites suggests a loss of an Sp1-binding site. This was supported by the observation that the c.-198CG SNP did not show the normal lipopolysaccharide-induced DAF transcriptional upregulation in lymphoblasts from four patients. Our findings suggest that at critical periods during autoimmune MG, this SNP may result in inadequate DAF upregulation with consequent complement-mediated EOM damage. Susceptible individuals may benefit from anti-complement therapy in addition to immunosuppression. © 2010 Macmillan Publishers Limited. All rights reserved.

  2. Extraocular muscle architecture in hawks and owls.

    Science.gov (United States)

    Plochocki, Jeffrey H; Segev, Tamar; Grow, Wade; Hall, Margaret I

    2018-02-06

    A complete and accurate understanding of extraocular muscle function is important to the veterinary care of the avian eye. This is especially true for birds of prey, which rely heavily on vision for survival and yet are prone to ocular injury and disease. To better understand the function of extraocular muscles in birds of prey, we studied extraocular muscle architecture grossly and histologically. This sample was composed of two each of the following species: red-tailed hawk (Buteo jamaicensis), Harris's hawk (Parabuteo unicinctus), great horned owl (Bubo virginianus), and barn owl (Tyto alba). All extraocular muscles were dissected and weighed. To analyze muscle fiber architecture, the superior oblique and quadratus muscles were dissected, weighed, and sectioned at 5 μm thickness in the transverse plane. We calculated the physiologic cross-sectional area and the ratio of muscle mass to predicted effective maximum tetanic tension. Hawk and owl extraocular muscles exhibit significant physiological differences that play roles in ocular movements and closure of the nictitating membrane. Owls, which do not exhibit extraocular movement, have muscle architecture suited to stabilize the position of a massive, tubular eye that protrudes significantly from the orbit. Hawks, which have a more globose eye that is largely contained within the orbit, do not require as much muscular stability and instead have muscle architecture that facilitates rapid eye movement. © 2018 American College of Veterinary Ophthalmologists.

  3. Congenital Fibrosis of the Extraocular Muscles

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    Leyla Niyaz

    2014-08-01

    Full Text Available Congenital fibrosis of the extraocular muscles (CFEOM is a rare disorder characterized by hereditary non-progressive restrictive strabismus and blepharoptosis. Although most of the cases are bilateral and isolated, some patients may have systemic findings. CFEOM is divided into three groups as CFEOM 1, 2, and 3 according to the phenotype. Primary responsible genes are KIF21A for CFEOM type 1 and 3 and PHOX2A/ARIX gene for CFEOM type 2. Studies suggest that abnormal innervation of the extraocular muscles is the cause of muscle fibrosis. Early treatment is important because of the risk of amblyopia. Surgery is the primary treatment option for strabismus and blepharoptosis. (Turk J Ophthalmol 2014; 44: 312-5

  4. Bilateral metastases to extraocular muscles from lobular breast carcinoma.

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    Kouvaris, John R; Gkongkou, Penelope V; Papadimitriou, Christos A; Papacharalampous, Xenofon N; Antypas, Christos E; Balafouta, Myrsini J; Vlahos, Lambros J

    2008-07-01

    Metastastic carcinoma to extraocular muscles is extremely rare, but even more so is the case of a bilateral one. A 50-year-old woman with a history of mastectomy for a T4N1M0 right breast carcinoma was referred to us with diplopia due to bilateral extraocular muscle metastases, 5 years post mastectomy. Multiple metastases to the whole body were also present. A combination of high-dose irradiation, hormonotherapy and chemotherapy were performed. Despite the multidisciplinary treatment approach, the diplopia persisted. A literature review revealed only 4 cases of bilateral metastases to extraocular muscles. The present case is the second attributed to lobular carcinoma and the only one treated with a high dose of radiotherapy combined with systemic therapy. In a cancer patient, any orbital change must be examined for the possibility of an extraocular metastasis. Conclusions affecting the optimal treatment policy of extraocular muscle metastases are difficult to determine, due to the small number of reported cases. (c) 2008 S. Karger AG, Basel

  5. Fatigue resistance of rat extraocular muscles does not depend on creatine kinase activity

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    Hayeß Katrin

    2005-08-01

    Full Text Available Abstract Background Creatine kinase (CK links phosphocreatine, an energy storage system, to cellular ATPases. CK activity serves as a temporal and spatial buffer for ATP content, particularly in fast-twitch skeletal muscles. The extraocular muscles are notoriously fast and active, suggesting the need for efficient ATP buffering. This study tested the hypotheses that (1 CK isoform expression and activity in rat extraocular muscles would be higher, and (2 the resistance of these muscles to fatigue would depend on CK activity. Results We found that mRNA and protein levels for cytosolic and mitochondrial CK isoforms were lower in the extraocular muscles than in extensor digitorum longus (EDL. Total CK activity was correspondingly decreased in the extraocular muscles. Moreover, cytoskeletal components of the sarcomeric M line, where a fraction of CK activity is found, were downregulated in the extraocular muscles as was shown by immunocytochemistry and western blotting. CK inhibition significantly accelerated the development of fatigue in EDL muscle bundles, but had no major effect on the extraocular muscles. Searching for alternative ATP buffers that could compensate for the relative lack of CK in extraocular muscles, we determined that mRNAs for two adenylate kinase (AK isoforms were expressed at higher levels in these muscles. Total AK activity was similar in EDL and extraocular muscles. Conclusion These data indicate that the characteristic fatigue resistance of the extraocular muscles does not depend on CK activity.

  6. Traumatic avulsion of extraocular muscles: case reports

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    Nilza Minguini

    2013-04-01

    Full Text Available We described the clinical, surgical details and results (motor and sensory of the retrieving procedure of traumatically avulsed muscles in three patients with no previous history of strabismus or diplopia seen in the Department of Ophthalmology, State University of Campinas, Brazil. The slipped muscle portion was reinserted at the original insertion and under the remaining stump, which was sutured over the reinserted muscle. For all three cases there was recovery of single binocular vision and stereopsis.

  7. MRI estimation of extraocular muscle swelling in dysthyroid ophthalmopathy

    International Nuclear Information System (INIS)

    Watanabe, Yoshihiro; Kakisu, Yonetsugu; Hatakeyama, Masayuki; Asanagi, Kaoru

    1988-01-01

    The thickness and width of superior, inferior and medial rectus muscles were measured via T1-weighted coronal images using a 0.5 T superconducting MRI (magnetic resonance imaging) system in 10 patients with dysthyroid ophthalmopathy and 27 normal orbits. Lateral rectus muscles were not measured because the partial volume effect obscured their contours. Patients were divided into 3 groups according to the severity of ophthalmopathy. Group A had no ophthalmopathy, group B had corneal involvement or restricted eye movement, group C had optic nerve involvement. Mean muscle thickness increased in the order A, B and C. Mean rectus muscle width was normal in group A, but dramatically increased in group C, results suggesting that swelling of the extraocular muscles is a characteristic pathologic change in dysthyroid ophthalmopathy. It is concluded that MRI is a safe and useful method of evaluating the severity of and prognosing dysthyroid ophthalmopathy. (author)

  8. Congenital fibrosis of the extraocular muscles

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    Pascale Cooymans

    2010-01-01

    Conclusions : CFEOM is a rare, congenital, and non-progressive disorder with multiple extra ocular muscle restrictions. CFEOM can be associated with neuro-radiological abnormalities; its diagnosis and classification is defined by clinical characteristics and genetics. Options for treatment are limited and difficult.

  9. Morphometry of extraocular muscles in Basedow disease by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Michiko; Ohtsuka, Kenji; Hashimoto, Masato [Sapporo Medical Coll. (Japan)

    1996-01-01

    We measured the thickness of extraocular muscles in 35 patients diagnosed as Basedow disease by physicians. We used the coronal images of computed tomography in measuring the thickness at four points for each muscle. The mean thickness was 3.2{+-}1.0 mm for superior rectus, 3.4{+-}0.8 mm for medial rectus and 4.1 mm{+-}13 mm for inferior rectus. These values were significantly larger than in normal eyes (p<0.01). The value for inferior rectus was significantly larger than for the other two muscles (p<0.01). Thickness of inferior rectus at its posterior portion was significantly correlated with limitation of supraduction of the affected eye (r=0.7). (author).

  10. Evaluating the Microcirculation of Normal Extraocular Muscles Using Quantitative Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

    Science.gov (United States)

    Guo, Yu; Huo, Lei; Wang, Penghui; Huang, Lixiang; Chai, Chao; Sun, Fengyuan; Xia, Shuang; Shen, Wen

    2016-01-01

    The purpose of this work was to evaluate the microcirculation of normal extraocular muscles using quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) (DCE-MRI). The institutional review board approved the study. Forty-eight eyes were examined using quantitative DCE-MRI on a 3-T MRI system. Quantitative parameters, including the volume transfer constant (Ktrans), the fractional volume of extravascular extracellular space (Ve), and the rate constant (Kep) of each extraocular muscles, were analyzed. The type of DEC time-intensity curve (TIC) was evaluated. The parameters of bilateral extraocular muscles were compared using the Wilcoxon test. The difference in quantitative values of different extraocular muscles was compared using independent-samples Kruskal-Wallis test. No statistical differences of parameters were found between the left and right extraocular muscles (P > 0.05). Volume transfer constant values in medial rectus (MR) muscles and inferior rectus (IR) muscles were significantly higher than those in the lateral rectus (LR) muscles and superior rectus (SR) muscles (P difference was not significant (P > 0.05). In the 4 extraocular muscles, the Ve values of MR are the largest, followed by the IR, LR, and SR values. The DCE time-intensity curves of extraocular muscles are type II or type III. Medial rectus and IR are mainly type III, and LR and SR are mainly type II. The quantitative DCE-MRI can be used as an important and noninvasive technique to evaluate the microcirculation of extraocular muscles. Further investigations for other extraocular muscles diseases by using quantitative DCE-MRI are warranted.

  11. Myocyte Dedifferentiation Drives Extraocular Muscle Regeneration in Adult Zebrafish.

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    Saera-Vila, Alfonso; Kasprick, Daniel S; Junttila, Tyler L; Grzegorski, Steven J; Louie, Ke'ale W; Chiari, Estelle F; Kish, Phillip E; Kahana, Alon

    2015-07-01

    The purpose of this study was to characterize the injury response of extraocular muscles (EOMs) in adult zebrafish. Adult zebrafish underwent lateral rectus (LR) muscle myectomy surgery to remove 50% of the muscle, followed by molecular and cellular characterization of the tissue response to the injury. Following myectomy, the LR muscle regenerated an anatomically correct and functional muscle within 7 to 10 days post injury (DPI). Following injury, the residual muscle stump was replaced by a mesenchymal cell population that lost cell polarity and expressed mesenchymal markers. Next, a robust proliferative burst repopulated the area of the regenerating muscle. Regenerating cells expressed myod, identifying them as myoblasts. However, both immunofluorescence and electron microscopy failed to identify classic Pax7-positive satellite cells in control or injured EOMs. Instead, some proliferating nuclei were noted to express mef2c at the very earliest point in the proliferative burst, suggesting myonuclear reprogramming and dedifferentiation. Bromodeoxyuridine (BrdU) labeling of regenerating cells followed by a second myectomy without repeat labeling resulted in a twice-regenerated muscle broadly populated by BrdU-labeled nuclei with minimal apparent dilution of the BrdU signal. A double-pulse experiment using BrdU and 5-ethynyl-2'-deoxyuridine (EdU) identified double-labeled nuclei, confirming the shared progenitor lineage. Rapid regeneration occurred despite a cell cycle length of 19.1 hours, whereas 72% of the regenerating muscle nuclei entered the cell cycle by 48 hours post injury (HPI). Dextran lineage tracing revealed that residual myocytes were responsible for muscle regeneration. EOM regeneration in adult zebrafish occurs by dedifferentiation of residual myocytes involving a muscle-to-mesenchyme transition. A mechanistic understanding of myocyte reprogramming may facilitate novel approaches to the development of molecular tools for targeted therapeutic

  12. Extraocular muscle surgery for extorsion after macular translocation surgery new surgical technique and clinical management.

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    Holgado, Sandra; Enyedi, Laura B; Toth, Cynthia A; Freedman, Sharon F

    2006-01-01

    To report a new extraocular muscle surgery procedure for large-angle extorsion, and clinical management of subjective tilt and diplopia after full macular translocation (MT360). Consecutive retrospective case series. Seven patients with downward MT360 were evaluated after MT360, both before (preoperative) and after (postoperative) extraocular muscle surgery, with at least 6 months' follow-up. Information gathered included demographics, visual acuity, ocular motility, torsion by Maddox rod, ocular history, and symptoms of visual disturbance. Surgery on extraocular muscles was performed based on the magnitude of torsion measured after MT360 surgery. Maddox rod testing of torsion after MT360, and both preoperative and postoperative extraocular muscle surgery. Mean preoperative torsion was reduced from 45.4+/-11.3 degrees to 8.3+/-4.8 degrees (at 6 months after MT360) (P = 0.03). Extraocular muscle surgery slightly reduced the mean hypertropia of the operated eye (preoperative, 20+/-10 prism diopters [PD], vs. postoperative, 11+/-6 PD) (P = 0.06). Mean exotropia was affected minimally by extraocular muscle surgery (preoperative, 22+/-31 PD, vs. postoperative, 20+/-24 PD). Three patients required a second extraocular muscle surgery (performed on the fellow eye) to correct residual extorsion and diplopia. Overall, 85% (6/7) of patients were free of both diplopia and tilt after 1 or 2 extraocular muscle surgeries. Although our patients continued to have significant horizontal/vertical strabismus postoperatively, the extraocular muscle surgery performed was successful in reducing the torsional misalignment enough such that the remaining diplopia could be successfully ignored or suppressed.

  13. Magnetic resonance imaging of human extraocular muscles in convergence.

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    Demer, Joseph L; Kono, Reika; Wright, Weldon

    2003-04-01

    Extraocular muscle (EOM) paths during asymmetrical convergence were evaluated by tri-planar, contrast-enhanced magnetic resonance imaging of the orbits of eight young adults during binocular fixation of a target aligned to one eye at 800 and 15 cm distance. Cross sections and paths of EOMs were determined from area centroids. In convergence, the aligned eye rotated and translated negligibly, while its inferior oblique (IO) muscle exhibited significant contractile thickening. There were no significant contractile changes in the cross sections of aligned eye rectus or superior oblique (SO) muscles in convergence. The converging eye rotated nasally 22.4 degrees but translated negligibly. The converging eye medial (MR) and lateral rectus (LR) muscles exhibited large contractile cross-section changes, and the IO showed significant contractile thickening, while the vertical rectus muscles and the SO did not. Anterior paths of three aligned eye rectus EOMs could be determined in convergence and shifted consistent with a 1.9 degrees extorsion of the rectus pulley array. Such extorsional reconfiguration of the rectus pulleys would move the pulleys in coordination with globe extorsion and avoid imparting torsional action to these EOMs. Extorsional rectus pulley shift in convergence is inconsistent with the reconfiguration predicted to explain the temporal tilting of Listing's planes, instead suggesting that this temporal tilting is due to variations in oblique EOM innervation. Absence of globe translation in convergence argues against overall EOM co-contraction. The reconfiguration of EOM geometry in convergence has important implications for single-unit studies of neural control.

  14. Functional anatomy of the extraocular muscles during vergence.

    Science.gov (United States)

    Demer, Joseph L; Clark, Robert A; Crane, Benjamin T; Tian, Jun-Ru; Narasimhan, Anita; Karim, Shaheen

    2008-01-01

    Magnetic resonance imaging (MRI) now enables precise visualisation of the mechanical state of the living human orbit, enabling inferences about the effects of mechanical factors on ocular kinematics. We used 3-dimensional (3D) magnetic search coil recordings and MRI to investigate the mechanical state of the orbit during vergence in humans. Horizontal convergence of 23 degrees from a remote to a near target aligned on one eye was geometrically ideal, and was associated with lens thickening and extorsion of the rectus pulley array of the aligned eye with superior oblique muscle relaxation and inferior oblique muscle contraction. There was no rectus muscle co-contraction. Subjective fusion through a 1 degree vertical prism caused a clockwise (CW) torsion in both eyes, as well as variable vertical and horizontal vergences that seldom corresponded to prism amount or direction. MRI under these conditions did not show consistent torsion of the rectus pulley array, but a complex pattern of changes in rectus extraocular muscle (EOM) crossections, consistent with co-contraction. Binocular fusion during vergence is accomplished by complex, 3D eye rotations seldom achieving binocular retinal correspondence. Vergence eye movements are sometimes associated with changes in rectus EOM pulling directions, and may sometimes be associated with co-contraction. Thus, extraretinal information about eye position would appear necessary to interpret binocular correspondence, and to avoid diplopia.

  15. Site-dependent distribution of macrophages in normal human extraocular muscles

    NARCIS (Netherlands)

    Schmidt, E. D.; van der Gaag, R.; Mourits, M. P.; Koornneef, L.

    1993-01-01

    PURPOSE: Clinical data indicate that extraocular muscles have different susceptibilities for some orbital immune disorders depending on their anatomic location. The resident immunocompetent cells may be important mediators in the local pathogenesis of such disorders so the distribution of these

  16. Contractile Force of Human Extraocular Muscle: A Theoretical Analysis

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    Hongmei Guo

    2016-01-01

    Full Text Available Aim. The length-contractile force relationships of six human extraocular muscles (EOMs in primary innervations should be determined during eye movement modeling and surgery of clinical EOMs. This study aims to investigate these relationships. Method. The proposal is based on the assumption that six EOMs have similar constitutive relationships, with the eye suspended in the primary position. The constitutive relationships of EOMs are obtained by optimizing from previous experimental data and the theory of mechanical equilibrium using traditional model. Further, simulate the existing experiment of resistance force, and then compare the simulated results with the existing experimental results. Finally, the mechanical constitutive relationships of EOMs are obtained. Results. The results show that the simulated resistance forces from the other four EOMs except for the horizontal recti well agree with previous experimental results. Conclusion. The mechanical constitutive relationships of six EOMs in primary innervations are obtained, and the rationality of the constitutive relationships is verified. Whereafter, the active stress-strain relationships of the six EOMs in the primary innervations are obtained. The research results can improve the eye movement model to predict the surgical amounts of EOMs before EOM surgery more precisely.

  17. Determinants of Extraocular Muscle Volume in Patients with Graves' Disease

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    Samer El-Kaissi

    2012-01-01

    Full Text Available Background. To examine factors contributing to extraocular muscle (EOM volume enlargement in patients with Graves’ hyperthyroidism. Methods. EOM volumes were measured with orbital magnetic resonance imaging (MRI in 39 patients with recently diagnosed Graves’ disease, and compared to EOM volumes of 13 normal volunteers. Thyroid function tests, uptake on thyroid scintigraphy, anti-TSH-receptor antibody positivity and other parameters were then evaluated in patients with EOM enlargement. Results. 31/39 patients had one or more enlarged EOM, of whom only 2 patients had clinical EOM dysfunction. Compared to Graves’ disease patients with normal EOM volumes, those with EOM enlargement had significantly higher mean serum TSH (0.020±0.005 versus 0.007±0.002 mIU/L; P value 0.012, free-T4 (52.9±3.3 versus 41.2±1.7 pmol/L; P value 0.003 and technetium uptake on thyroid scintigraphy (13.51±1.7% versus 8.55±1.6%; P value 0.045. There were no differences between the 2 groups in anti-TSH-receptor antibody positivity, the proportion of males, tobacco smokers, or those with active ophthalmopathy. Conclusions. Patients with recently diagnosed Graves’ disease and EOM volume enlargement have higher serum TSH and more severe hyperthyroidism than patients with normal EOM volumes, with no difference in anti-TSH-receptor antibody positivity between the two groups.

  18. The enlarged extraocular muscle: to relax, reflect or refer?

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    Shafi, F; Mathewson, P; Mehta, P; Ahluwalia, H S

    2017-04-01

    PurposeExtraocular muscle enlargement (EOME) is most commonly associated with thyroid eye disease, but there are other causes. We report our outcomes of investigating and managing non-thyroid-related EOME (NTR-EOME).MethodsRetrospective consecutive case series. Sixteen patients identified by clinical features and orbital imaging. Patient demographics, radiological features, and adjuvant tests including biopsy and final diagnosis were recorded.ResultsMean age at presentation 59.3 years (range 24-89 years). Mean follow-up 3.2 years (range 3 months to 5.5 years). Superior rectus (SR) was most commonly involved muscle (8/16 cases) followed by lateral rectus (4/16). Of the 16 cases, 14 were associated with underlying systemic neoplasia (5 lymphoma, 5 metastatic carcinoma, and 4 presumed paraneoplastic syndrome). All SR enlargement was associated with underlying neoplasia. All patients underwent orbital imaging followed by systemic imaging based on clinical index of suspicion (14/16 patients (13 full body CT (FBCT), 1 mammography)). Positive systemic radiological findings were detected in 12/14 cases. Of the remaining 2 patients, 1 underwent full body positron emission tomography-computed tomography (FBPET-CT), which detected thyroid carcinoma, and the second patient underwent FBCT for staging following orbital biopsy showing lymphoma. Four patients (25%) died within 3 years of follow-up due to disseminated systemic malignancy.ConclusionsAll cases of NTR-EOME should be viewed with a high level of clinical suspicion for systemic neoplasia, especially when the SR is involved. FBCT can help to identify a primary systemic cause. FBPET-CT is best reserved for cases negative on FBCT or for staging and monitoring systemic disease. NTR-EOME can be associated with significant mortality (25%), hence warrants prompt and thorough systemic investigation.

  19. Transcriptional and functional differences in stem cell populations isolated from Extraocular and Limb muscles

    DEFF Research Database (Denmark)

    Pacheco-Pinedo, Eugenia Cristina; Budak, Murat T; Zeiger, Ulrike

    2008-01-01

    The extraocular muscles (EOMs) are a distinct muscle group that displays an array of unique contractile, structural and regenerative properties. They also have differential sensitivity to certain diseases and are enigmatically spared in Duchenne muscular dystrophy (DMD). The EOMs are so distinct...

  20. MAGNETIC RESONANCE IMAGING CONTRAST ENHANCEMENT OF EXTRA-OCULAR MUSCLES IN DOGS WITH NO CLINICAL EVIDENCE OF ORBITAL DISEASE

    NARCIS (Netherlands)

    JOSLYN, S.; Richards, S.; Boroffka, S.A.E.B.; Mitchell, M.; Hammond, G.; Sullivan, M.T.

    2013-01-01

    Enhancement of extra-ocular muscles has been reported in cases of orbital pathology in both veterinary and medical magnetic resonance imaging.We have also observed this finding in the absence of orbital disease. The purpose of this retrospective study was to describe extra-ocular muscle contrast

  1. Bilateral metastatic melanoma to the extraocular-muscles simulating thyroid eye disease.

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    Almeida, Ana Catarina; Fung, Adrian; Guedes, Marta Esteves; Costa, João Marques

    2012-10-30

    We report a case of bilateral metastatic melanoma to the extraocular muscles that simulated thyroid eye disease. A 71-year-old man presented with bilateral painless axial proptosis, lid retraction and left gaze restriction. Orbital CT scan demonstrated enlargement of the extraocular muscles with tendon sparing, consistent with thyroid eye disease. However, thyroid function tests and antithyroid antibodies were normal. Systemic review including orbital MRI scan determined the correct diagnosis of metastatic melanoma to the orbit. Metastatic melanoma to the orbit can simulate thyroid eye disease.

  2. Pitx2 regulates myosin heavy chain isoform expression and multi-innervation in extraocular muscle.

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    Zhou, Yuefang; Liu, Dan; Kaminski, Henry J

    2011-09-15

    Extraocular muscle is fundamentally distinct from other skeletal muscle and demonstrates specific anatomical divisions, unique innervation, diverse myosin isoform expression patterns, a distinct genomic profile and differential involvement in neuromuscular disorders. The paired-like homeodomain transcription factor 2 (Pitx2) is known to regulate the formation of extraocular muscle development and in this report we show that its expression in adulthood also defines certain extraocular muscle traits. We found that expression of slow-MyHC and slow-tonic MyHC, along with contractile regulatory proteins troponin I and troponin T, is reduced during the first 3 weeks after birth in mice with conditional knockout of Pitx2, designated Pitx2(Δflox/Δflox). En grappe endplates, which are normally only found on slow-MyHC expressing fibres, were not identified in the Pitx2(Δflox/Δflox) extraocular muscle, suggesting that altered innervation was responsible for the loss in slow-MyHC expression. Extraocular muscle (EOM)-specific MyHC expressing fibres were dramatically reduced at P14 and rarely detected at 3 months in the Pitx2(Δflox/Δflox) mice. 2A-MyHC fibres, which are excluded from mid-belly region in wild-type mice, dominated the orbital layer with no apparent longitudinal variation in the Pitx2(Δflox/Δflox) mice. Pure 2X-MyHC fibres, only present at distal ends in the wild-type mice, populated the outer global layer in the mid-belly region of the Pitx2(Δflox/Δflox) mice. Pitx2 influences slow-MyHC, slow-tonic MyHC and EOM-MyHC expression in extraocular muscle and its absence leads to increased expression of 2X-MyHC and 2A-MyHC. Precise definition of the regulation of MyHC isoforms in extraocular muscle may allow their rational manipulation, in order to alter muscle contractility for therapeutic purposes.

  3. Volume measurement of the horizontal extraocular muscles using magnetic resonance imaging

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    Nishida, Yasuhiro; Hayashi, Osamu; Nishida, Eri; Murata, Toyotaka; Aoki, Yoshiko; Inatomi, Akihiro; Kani, Kazutaka (Shiga Univ. of Medical Science, Otsu (Japan)); Mabuchi, Norihisa; Furutani, Yoshiaki

    1993-07-01

    The volume of the horizontal extraocular muscles of 11 normal adults and three patients with ophthalmoplegia was measured using magnetic resonance imaging (MRI). The MRI examinations were carried out with a Signa Advantage, 1.5 tesla superconductive magnetic system manufactured by General Electric. This method employs the spin echo technique with a 3.0 mm gapless slice, a 350 ms. repetition time, and a 17.0 ms. echo time. The MRI films were projected and magnified on Kent paper using an overhead projector. Then the shapes of the horizontal extraocular muscles were traced. The volume of the muscles was measured as the total weight of Kent papers which were cut out from muscle shapes in all the slices. The average volume of the normal medial and lateral rectus muscles was 690[+-]87 mm[sup 3] and 734[+-]77 mm[sup 3], respectively. Two cases of peripheral nerve palsy showed typical atrophy of the paretic muscles. A case of orbital myositis showed typical hypertrophy of the inflamed muscles. This measurement may prove useful in the analysis and evaluation of extraocular muscles, especially in ophthalmoplesia.(author).

  4. Use of extraocular muscle flaps in the correction of orbital implant exposure.

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    Hsueh-Yen Chu

    Full Text Available PURPOSES: The study is to describe a new surgical technique for correcting large orbital implant exposure with extraocular muscle flaps and to propose a treatment algorithm for orbital implant exposure. METHODS: In a retrospective study, seven patients with orbital implant exposure were treated with extraocular muscle flaps. All data were collected from patients in Chang Gung Memorial Hospital, Taiwan during 2007-2012. All surgeries were performed by one surgeon (Y.J.T. Patient demographics, the original etiology, details of surgical procedures, implant types, and follow-up interval were recorded. Small exposure, defined as exposure area smaller than 3 mm in diameter, was treated conservatively first with topical lubricant and prophylactic antibiotics. Larger defects were managed surgically. RESULTS: Seven patients consisting of two males and five females were successfully treated for orbital implant exposure with extraocular muscle flaps. The average age was 36.4 (range, 3-55 years old. Five patients were referred from other hospitals. One eye was enucleated for retinoblastoma. The other six eyes were eviscerated, including one for endophthalmitis and five for trauma. Mean follow-up time of all seven patients was 19.5 (range, 2-60 months. No patient developed recurrence of exposure during follow-up. All patients were fitted with an acceptable prosthesis and had satisfactory cosmetic and functional results. CONCLUSIONS: The most common complication of orbital implant is exposure, caused by breakdown of the covering layers, leading to extrusion. Several methods were reported to manage the exposed implants. We report our experience of treating implant exposure with extraocular muscle flaps to establish a well-vascularized environment that supplies both the wrapping material and the overlying ocular surface tissue. We believe it can work as a good strategy to manage or to prevent orbital implant exposure.

  5. Magnetic resonance imaging in dissociated strabismus complex demonstrates generalized hypertrophy of rectus extraocular muscles.

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    Rajab, Ghada Z; Suh, Soh Youn; Demer, Joseph L

    2017-06-01

    Dissociated strabismus complex (DSC) is an enigmatic form of strabismus that includes dissociated vertical deviation (DVD) and dissociated horizontal deviation (DHD). We employed magnetic resonance imaging (MRI) to evaluate the extraocular muscles in DSC. We studied 5 patients with DSC and mean age of 25 years (range, 12-42 years), and 15 age-matched, orthotropic control subjects. All patients had DVD; 4 also had DHD. We employed high-resolution, surface coil MRI with thin, 2 mm slices and central target fixation. Volumes of the rectus and superior oblique muscles in the region 12 mm posterior to 4 mm anterior to the globe-optic nerve junction were measured in quasi-coronal planes in central gaze. Patients with DSC had no structural abnormalities of rectus muscles or rectus pulleys or the superior oblique muscle but exhibited modest, statistically significant increased volume of all rectus muscles ranging from 20% for medial rectus to 9% for lateral rectus (P muscles. DSC is associated with generalized rectus extraocular muscle hypertrophy in the absence of other orbital abnormalities. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  6. Genomic profiling reveals Pitx2 controls expression of mature extraocular muscle contraction-related genes.

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    Zhou, Yuefang; Gong, Bendi; Kaminski, Henry J

    2012-04-18

    To assess the influence of the Pitx2 transcription factor on the global gene expression profile of extraocular muscle (EOM) of mice. Mice with a conditional knockout of Pitx2, designated Pitx2(Δflox/Δflox) and their control littermates Pitx2(flox/flox), were used. RNA was isolated from EOM obtained at 3, 6, and 12 weeks of age and processed for microarray-based profiling. Pairwise comparisons were performed between mice of the same age and differentially expressed gene lists were generated. Select genes from the profile were validated using real-time quantitative polymerase chain reaction and protein immunoblot. Ultrastructural analysis was performed to evaluate EOM sarcomeric structure. The number of differentially expressed genes was relatively small. Eleven upregulated and 23 downregulated transcripts were identified common to all three age groups in the Pitx2-deficient extraocular muscle compared with littermate controls. These fell into a range of categories including muscle-specific structural genes, transcription factors, and ion channels. The differentially expressed genes were primarily related to muscle contraction. We verified by protein and ultrastructural analysis that myomesin 2 was expressed in the Pitx2-deficient mice, and this was associated with development of M lines evident in their orbital region. The global transcript expression analysis uncovered that Pitx2 primarily regulates a relatively select number of genes associated with muscle contraction. Pitx2 loss led to the development of M line structures, a feature more typical of other skeletal muscle.

  7. Crotoxin in humans: analysis of the effects on extraocular and facial muscles

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    Geraldo de Barros Ribeiro

    2012-12-01

    Full Text Available PURPOSE: Crotoxin is the main neurotoxin of South American rattlesnake Crotalus durissus terrificus. The neurotoxic action is characterized by a presynaptic blockade. The purpose of this research is to assess the ability of crotoxin to induce temporary paralysis of extraocular and facial muscles in humans. METHODS: Doses of crotoxin used ranged from 2 to 5 units (U, each unit corresponding to one LD50. We first applied 2U of crotoxin in one of the extraocular muscles of 3 amaurotic individuals to be submitted to ocular evisceration. In the second stage, we applied crotoxin in 12 extraocular muscles of 9 patients with strabismic amblyopia. In the last stage, crotoxin was used in the treatment of blepharospasm in another 3 patients. RESULTS: No patient showed any systemic side effect or change in vision or any eye structure problem after the procedure. The only local side effects observed were slight conjunctival hyperemia, which recovered spontaneously. In 2 patients there was no change in ocular deviation after 2U crotoxin application. Limitation of the muscle action was observed in 8 of the 12 applications. The change in ocular deviation after application of 2U of crotoxin (9 injections was in average 15.7 prism diopters (PD. When the dose was 4U (2 applications the change was in average 37.5 PD and a single application of 5U produced a change of 16 PD in ocular deviation. This effect lasted from 1 to 3 months. Two of the 3 patients with blepharospasm had the hemifacial spasm improved with crotoxin, which returned after 2 months. CONCLUSIONS: This study provides data suggesting that crotoxin may be a useful new therapeutic option for the treatment of strabismus and blepharospasm. We expect that with further studies crotoxin could be an option for many other medical areas.

  8. Combination management by C-arm fluoroscopy and extraocular muscle severance for penetrating ocular trauma with a retrobulbar foreign body.

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    Hatano, Makoto; Kimura, Kazuhiro; Nomi, Norimasa; Teranishi, Shinichiro; Orita, Tomoko; Fujitsu, Youichiro; Sonoda, Koh-Hei

    2016-06-01

    We report here the successful removal of a retrobulbar metallic foreign body in a patient with penetrating ocular trauma by a transconjunctival approach and combination management with C-arm fluoroscopy and extraocular muscle severance. A 37-year-old man sustained a penetrating injury to the right eye while using an iron hammer. Initial slitlamp examination revealed a corneoscleral laceration, iridocele, anterior chamber collapse, and a traumatic cataract. Visual acuity in the right eye was limited to the perception of hand motion. Computed tomography revealed an orbital foreign body in the retrobulbar area. The patient underwent corneoscleral suturing, severance of extraocular muscles, removal of the foreign body with guidance by C-arm fluoroscopy, pars plana lensectomy, and pars plana vitrectomy. Combination management with C-arm fluoroscopy and extraocular muscle severance may thus be a suitable approach to the removal of a retrobulbar metallic foreign body.

  9. Surgically mismanaged ptosis in a patient with congenital fibrosis of the extraocular muscles type I.

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    Tawfik, Hatem A; Rashad, Mohamed A

    2012-10-01

    Fibrosis syndromes comprise a rare form of severe limitation of ocular motility. An 11-year-old girl was referred for the correction of eyelid retraction. The eyelid retraction occurred immediately following levator resection surgery performed by a plastic surgeon who missed the restrictive extraocular muscle abnormalities. On examination, both eyes were fixed in an infraducted position (20 prism diopters (Δ)), with a chin-up position and significant lagophthalmos. Bilateral 12-mm inferior rectus recession with adjustable sutures was performed, which resulted in significant reduction of lagophthalmos and elimination of the head tilt.

  10. Evaluation of dysthyroid optic neuropathy using T2-relaxation time of extraocular muscle as parameter

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    Yu, Fumihiko; Maeda, Toshine; Inoue, Toyoko; Inoue, Yoichi [Olympia Eye Hospital, Tokyo (Japan)

    2001-11-01

    The T2 value of magnetic resonance imaging (MRI) is useful in evaluating the activity of dysthyroid ophthlamopathy. We applied this method in evaluating dysthyroid optic neuropathy in 15 affected eyes of 15 patients. Another group of 40 eyes of 20 patients of dysthyroid opthalmopathy without hypertrophy of extraocular muscles served as control. The T2 value in dysthyroid optic neuropathy significantly decreased following treatment with corticosteroid but the value was still higher than that in control eyes. The findings show that the T2 value of MRI is useful in evaluating the therapeutic effect of dysthyroid optic neuropathy. (author)

  11. Abnormalities of the oculomotor nerve in congenital fibrosis of the extraocular muscles and congenital oculomotor palsy.

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    Lim, Key Hwan; Engle, Elizabeth C; Demer, Joseph L

    2007-04-01

    High-resolution magnetic resonance imaging (MRI) can now directly demonstrate innervation to extraocular muscles and quantify optic nerve size. A quantitative MRI technique was developed to study the oculomotor nerve (CN3) and applied to congenital fibrosis of extraocular muscles (CFEOM) and congenital oculomotor palsy. The subarachnoid portions of the CN3s were imaged with a 1.5-T MRI scanner and conventional head coils, acquiring heavily T(2)-weighted oblique axial planes 1-mm thick and parallel to the optic chiasm. Thirteen normal subjects, 14 with CFEOM, and 3 with congenital CN3 palsy were included. Digital image analysis was used to measure CN3 diameter, which was correlated with motility findings. In CFEOM, CN3 diameter was bilaterally subnormal in eight subjects, unilaterally subnormal in three subjects, and normal in three subjects. Mean +/- SD CN3 diameter in CFEOM was 1.14 +/- 0.61 mm, significantly smaller than the diameter in normal subjects, which measured 2.01 +/- 0.36 mm (P congenital CN3 palsy showed bilateral CN3 hypoplasia, but CN3 diameter was normal in two other subjects with congenital CN3 palsy. Unilateral or bilateral hypoplasia of CN3 is quantitatively demonstrable using MRI in many cases of CFEOM and occasionally in congenital CN3 palsy. Variations in CN3 diameter in CFEOM and congenital CN3 palsy suggest mechanistic heterogeneity of these disorders that may be clarified by further imaging and genetic studies.

  12. Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study.

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    Miao, Wen; Man, Fengyuan; Wu, Shaoqin; Lv, Bin; Wang, Zhenchang; Xian, Junfang; Sabel, Bernhard A; He, Huiguang; Jiao, Yonghong

    2015-01-01

    To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1) patients using multimodal MRI imaging. T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender-matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls. Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (pabnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1.

  13. Single motor unit activity in human extraocular muscles during the vestibulo-ocular reflex

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    Weber, Konrad P; Rosengren, Sally M; Michels, Rike; Sturm, Veit; Straumann, Dominik; Landau, Klara

    2012-01-01

    Motor unit activity in human eye muscles during the vestibulo-ocular reflex (VOR) is not well understood, since the associated head and eye movements normally preclude single unit recordings. Therefore we recorded single motor unit activity following bursts of skull vibration and sound, two vestibular otolith stimuli that elicit only small head and eye movements. Inferior oblique (IO) and inferior rectus (IR) muscle activity was measured in healthy humans with concentric needle electrodes. Vibration elicited highly synchronous, short-latency bursts of motor unit activity in the IO (latency: 10.5 ms) and IR (14.5 ms) muscles. The activation patterns of the two muscles were similar, but reciprocal, with delayed activation of the IR muscle. Sound produced short-latency excitation of the IO muscle (13.3 ms) in the eye contralateral to the stimulus. Simultaneous needle and surface recordings identified the IO as the muscle of origin of the vestibular evoked myogenic potential (oVEMP) thus validating the physiological basis of this recently developed clinical test of otolith function. Single extraocular motor unit recordings provide a window into neural activity in humans that can normally only be examined using animal models and help identify the pathways of the translational VOR from otoliths to individual eye muscles. PMID:22526888

  14. Bilateral extraocular muscles enlargement from Kimura′s disease of the orbit

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    Allan Christian Pieroni Gonçalves

    2016-01-01

    Full Text Available Kimura′s disease (KD is a rare chronic inflammatory disease of unclear etiology, characterized by subcutaneous nodules, mainly in the head and neck region, frequently associated with regional lymphadenopathy. Orbital involvement is infrequent and when it occurs, usually affects the eyelid or the lacrimal gland. We report a case of a 44-year-old man that presented with bilateral slowly progressive proptosis that was initially misdiagnosed as Graves′ Ophthalmopathy. 15 months of worsening proptosis and the development of facial and temporal swelling led to further investigation. Computed tomography and magnetic resonance imaging showed enlargement of all recti muscles and diffuse orbital infiltration. An orbital biopsy was performed and was consistent with the diagnosis of KD. Long term oral corticosteroid showed marked improvement of proptosis and facial swelling. This case serves to emphasize that KD should be included in the differential diagnosis of inflammatory diseases of the orbit, even when characterized by predominant involvement of the extraocular muscles.

  15. Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study.

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    Wen Miao

    Full Text Available To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1 patients using multimodal MRI imaging.T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender-matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls.Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (p<0.001 uncorrected in the left precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus.CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1.

  16. Abnormally Small Neuromuscular Junctions in the Extraocular Muscles From Subjects With Idiopathic Nystagmus and Nystagmus Associated With Albinism.

    Science.gov (United States)

    McLoon, Linda K; Willoughby, Christy L; Anderson, Jill S; Bothun, Erick D; Stager, David; Felius, Joost; Lee, Helena; Gottlob, Irene

    2016-04-01

    Infantile nystagmus syndrome (INS) is often associated with abnormalities of axonal outgrowth and connectivity. To determine if this manifests in extraocular muscle innervation, specimens from children with idiopathic INS or INS and albinism were examined and compared to normal age-matched control extraocular muscles. Extraocular muscles removed during normal surgery on children with idiopathic INS or INS and albinism were immunostained for neuromuscular junctions, myofiber type, the immature form of the acetylcholine receptor, and brain-derived neurotrophic factor (BDNF) and compared to age-matched controls. Muscles from both the idiopathic INS and INS and albinism groups had neuromuscular junctions that were 35% to 71% smaller based on myofiber area and myofiber perimeter than found in age-matched controls, and this was seen on both fast and slow myosin heavy chain isoform-expressing myofibers (all P albinism showed a 7-fold increase in neuromuscular junction numbers on fast myofibers expressing the immature gamma subunit of the acetylcholine receptor. The extraocular muscles from both INS subgroups showed a significant increase in the number and size of slow myofibers compared to age-matched controls. Brain-derived neurotrophic factor was expressed in control muscle but was virtually absent in the INS muscles. These studies suggest that, relative to the final common pathway, INS is not the same between different patient etiologies. It should be possible to modulate these final common pathway abnormalities, via exogenous application of appropriate drugs, with the hope that this type of treatment may reduce the involuntary oscillatory movements in these children.

  17. The extraocular muscle stem cell niche is resistant to ageing and disease

    Science.gov (United States)

    Formicola, Luigi; Marazzi, Giovanna; Sassoon, David A.

    2014-01-01

    Specific muscles are spared in many degenerative myopathies. Most notably, the extraocular muscles (EOMs) do not show clinical signs of late stage myopathies including the accumulation of fibrosis and fat. It has been proposed that an altered stem cell niche underlies the resistance of EOMs in these pathologies, however, to date, no reports have provided a detailed characterization of the EOM stem cell niche. PW1/Peg3 is expressed in progenitor cells in all adult tissues including satellite cells and a subset of interstitial non-satellite cell progenitors in muscle. These PW1-positive interstitial cells (PICs) include a fibroadipogenic progenitor population (FAP) that give rise to fat and fibrosis in late stage myopathies. PICs/FAPs are mobilized following injury and FAPs exert a promyogenic role upon myoblasts in vitro but require the presence of a minimal population of satellite cells in vivo. We and others recently described that FAPs express promyogenic factors while satellite cells express antimyogenic factors suggesting that PICs/FAPs act as support niche cells in skeletal muscle through paracrine interactions. We analyzed the EOM stem cell niche in young adult and aged wild-type mice and found that the balance between PICs and satellite cells within the EOM stem cell niche is maintained throughout life. Moreover, in the adult mdx mouse model for Duchenne muscular dystrophy (DMD), the EOM stem cell niche is unperturbed compared to normal mice, in contrast to Tibialis Anterior (TA) muscle, which displays signs of ongoing degeneration/regeneration. Regenerating mdx TA shows increased levels of both PICs and satellite cells, comparable to normal unaffected EOMs. We propose that the increase in PICs that we observe in normal EOMs contributes to preserving the integrity of the myofibers and satellite cells. Our data suggest that molecular cues regulating muscle regeneration are intrinsic properties of EOMs. PMID:25520657

  18. The extraocular muscle stem cell niche is resistant to ageing and disease

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    Luigi eFormicola

    2014-12-01

    Full Text Available Specific muscles are spared in many degenerative myopathies. Most notably, the extraocular muscles (EOMs do not show clinical signs of late stage myopathies including the accumulation of fibrosis and fat. It has been proposed that an altered stem cell niche underlies the resistance of EOMs in these pathologies, however, to date, no reports have provided a detailed characterization of the EOM stem cell niche. PW1/Peg3 is expressed in progenitor cells in all adult tissues including satellite cells and a subset of interstitial non-satellite cell progenitors in muscle. These PW1-positive interstitial cells (PICs include a fibroadipogenic progenitor population (FAPs that give rise to fat and fibrosis in late stage myopathies. PICs/FAPs are mobilized following injury and FAPs exert a promyogenic role upon myoblasts in vitro but require the presence of a minimal population of satellite cells in vivo. We and others recently described that FAPs express promyogenic factors while satellite cells express antimyogenic factors suggesting that PICs/FAPs act as support niche cells in skeletal muscle through paracrine interactions. We analyzed the EOM stem cell niche in young adult and aged wild-type mice and found that the balance between PICs and satellite cells within the EOM stem cell niche is maintained throughout life. Moreover, in the adult mdx mouse model for Duchenne muscular dystrophy, the EOM stem cell niche is unperturbed compared to normal mice, in contrast to Tibialis Anterior (TA muscle, which displays signs of ongoing degeneration/regeneration. Regenerating mdx TA shows increased levels of both PICs and satellite cells, comparable to normal unaffected EOMs. We propose that the increase in PICs that we observe in normal EOMs contributes to preserving the integrity of the myofibers and satellite cells. Our data suggest that molecular cues regulating muscle regeneration are intrinsic properties of EOMs.

  19. Study of crotoxin on the induction of paralysis in extraocular muscle in animal model

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    Geraldo de Barros Ribeiro

    2012-10-01

    Full Text Available PURPOSE: Crotoxin is the major toxin of the venom of the South American rattlesnake Crotalus durissus terrificus, capable of causing a blockade of the neurotransmitters at the neuromuscular junction. The objective of this study was to appraise the action and effectiveness of the crotoxin induced paralysis of the extraocular muscle and to compare its effects with the botulinum toxin type A (BT-A. METHODS: The crotoxin, with LD50 of 1.5 µg, was injected into the superior rectus muscle in ten New Zealand rabbits. The concentration variance was 0.015 up to 150 µg. Two rabbits received 2 units of botulinum toxin type A for comparative analysis. The evaluation of the paralysis was performed using serial electromyography. After the functional recovery of the muscles, which occurred after two months, six rabbits were sacrificed for anatomopathology study. RESULTS: The animals did not show any evidence of systemic toxicity. Transitory ptosis was observed in almost every animal and remained up to fourteen days. These toxins caused immediate blockade of the electrical potentials. The recovery was gradual in the average of one month with regeneration signs evident on the electromyography. The paralysis effect of the crotoxin on the muscle was proportional to its concentration. The changes with 1.5 µg crotoxin were similar to those produced by the botulinum toxin type A. The histopathology findings were localized to the site of the injection. No signs of muscle fiber's necrosis were seen in any sample. The alterations induced by crotoxin were also proportional to the concentration and similar to botulinum toxin type A in concentration of 1.5 µg. CONCLUSION: Crotoxin was able to induce transitory paralysis of the superior rectus muscle. This effect was characterized by reduction of action potentials and non-specific signs of fibrillation. Crotoxin, in concentration of 1.5 µg was able to induce similar effects as botulinum toxin type A.

  20. Ocular vestibular-evoked myogenic potentials (oVEMPs) require extraocular muscles but not facial or cochlear nerve activity.

    Science.gov (United States)

    Chihara, Yasuhiro; Iwasaki, Shinichi; Ushio, Munetaka; Fujimoto, Chisato; Kashio, Akinori; Kondo, Kenji; Ito, Ken; Asakage, Takahiro; Yamasoba, Tatsuya; Kaga, Kimitaka; Murofushi, Toshihisa

    2009-03-01

    Cervical vestibular evoked myogenic potentials (cVEMPs) have been found to be useful for clinical testing of vestibular function. Recently, investigators showed that short-latency, initially negative surface EMG potentials can be recorded around the extraocular muscles (oVEMPs) in response to air-conducted sound (ACS), bone-conducted vibration (BCV), and head taps. Although these evoked potentials, which are located around the eyes, most likely originate primarily from the otolith-ocular pathway, the possibility of contamination by other nerve activities cannot be completely eliminated. The purpose of the present study was to clarify the origin of oVEMPs by examining these possibilities using clinical findings. Twelve healthy subjects and 15 patients were enrolled. Of the 15 patients, 3 patients had undergone exenteration of the unilateral intraorbital contents, one had undergone exenteration of the right eyeball with preservation of extraocular muscles, 5 had facial palsy, and 6 had profound hearing loss. ACS and/or BCV were used in these subjects. Exenteration of the unilateral intraorbital contents resulted in absence of myogenic potentials on the affected side. On the other hand, exenteration of the eyeball with preservation of extraocular muscles did not have a major impact on the responses. There were no significant differences in the waveforms between healthy subjects and patients with facial palsy or profound hearing loss. The results suggested that short-latency, initially negative evoked potentials recorded below the eyes are not affected by cochlear or facial nerve activities and are dependent on the presence of extraocular muscles. This study provides the evidence that oVEMPs originate from exraocular muscles activated through the vestibulo-ocular pathway.

  1. Dystrophic changes in extraocular muscles after gamma irradiation in mdx:utrophin(+/- mice.

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    Abby A McDonald

    Full Text Available Extraocular muscles (EOM have a strikingly different disease profile than limb skeletal muscles. It has long been known that they are spared in Duchenne (DMD and other forms of muscular dystrophy. Despite many studies, the cause for this sparing is not understood. We have proposed that differences in myogenic precursor cell properties in EOM maintain normal morphology over the lifetime of individuals with DMD due to either greater proliferative potential or greater resistance to injury. This hypothesis was tested by exposing wild type and mdx:utrophin(+/- (het mouse EOM and limb skeletal muscles to 18 Gy gamma irradiation, a dose known to inhibit satellite cell proliferation in limb muscles. As expected, over time het limb skeletal muscles displayed reduced central nucleation mirrored by a reduction in Pax7-positive cells, demonstrating a significant loss in regenerative potential. In contrast, in the first month post-irradiation in the het EOM, myofiber cross-sectional areas first decreased, then increased, but ultimately returned to normal compared to non-irradiated het EOM. Central nucleation significantly increased in the first post-irradiation month, resembling the dystrophic limb phenotype. This correlated with decreased EECD34 stem cells and a concomitant increase and subsequent return to normalcy of both Pax7 and Pitx2-positive cell density. By two months, normal het EOM morphology returned. It appears that irradiation disrupts the normal method of EOM remodeling, which react paradoxically to produce increased numbers of myogenic precursor cells. This suggests that the EOM contain myogenic precursor cell types resistant to 18 Gy gamma irradiation, allowing return to normal morphology 2 months post-irradiation. This supports our hypothesis that ongoing proliferation of specialized regenerative populations in the het EOM actively maintains normal EOM morphology in DMD. Ongoing studies are working to define the differences in the myogenic

  2. Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

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    Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.; Daniel, Mark L.; Cu, Sharon R.; McLoon, Linda K., E-mail: mcloo001@tc.umn.edu

    2011-04-01

    The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry, EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin{sup -/-} (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a

  3. Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

    International Nuclear Information System (INIS)

    Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.; Daniel, Mark L.; Cu, Sharon R.; McLoon, Linda K.

    2011-01-01

    The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry, EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin -/- (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a subpopulation of

  4. Extra-ocular muscle MRI in genetically-defined mitochondrial disease

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    Pitceathly, Robert D.S.; Morrow, Jasper M.; Hanna, Michael G. [UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, MRC Centre for Neuromuscular Diseases, London (United Kingdom); Sinclair, Christopher D.J.; Yousry, Tarek A.; Thornton, John S. [UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, MRC Centre for Neuromuscular Diseases, London (United Kingdom); UCL Institute of Neurology, Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, London (United Kingdom); Woodward, Cathy; Sweeney, Mary G. [National Hospital for Neurology and Neurosurgery, Neurogenetics Unit, London (United Kingdom); Rahman, Shamima [UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, MRC Centre for Neuromuscular Diseases, London (United Kingdom); UCL Institute of Child Health, Mitochondrial Research Group, Clinical and Molecular Genetics Unit, London (United Kingdom); Plant, Gordon T.; Ali, Nadeem [National Hospital for Neurology and Neurosurgery, Department of Neuro-ophthalmology, London (United Kingdom); Moorfields Eye Hospital, Department of Neuro-ophthalmology, London (United Kingdom); Bremner, Fion [National Hospital for Neurology and Neurosurgery, Department of Neuro-ophthalmology, London (United Kingdom); Davagnanam, Indran [National Hospital for Neurology and Neurosurgery, The Lysholm Department of Neuroradiology, London (United Kingdom)

    2016-01-15

    Conventional and quantitative MRI was performed in patients with chronic progressive external ophthalmoplegia (CPEO), a common manifestation of mitochondrial disease, to characterise MRI findings in the extra-ocular muscles (EOMs) and investigate whether quantitative MRI provides clinically relevant measures of disease. Patients with CPEO due to single mitochondrial DNA deletions were compared with controls. Range of eye movement (ROEM) measurements, peri-orbital 3 T MRI T1-weighted (T1w) and short-tau-inversion-recovery (STIR) images, and T2 relaxation time maps were obtained. Blinded observers graded muscle atrophy and T1w/STIR hyperintensity. Cross-sectional areas and EOM mean T2s were recorded and correlated with clinical parameters. Nine patients and nine healthy controls were examined. Patients had reduced ROEM (patients 13.3 , controls 49.3 , p < 0.001), greater mean atrophy score and increased T1w hyperintensities. EOM mean cross-sectional area was 43 % of controls and mean T2s were prolonged (patients 75.6 ± 7.0 ms, controls 55.2 ± 4.1 ms, p < 0.001). ROEM correlated negatively with EOM T2 (rho = -0.89, p < 0.01), whilst cross-sectional area failed to correlate with any clinical measures. MRI demonstrates EOM atrophy, characteristic signal changes and prolonged T2 in CPEO. Correlation between elevated EOM T2 and ROEM impairment represents a potential measure of disease severity that warrants further evaluation. (orig.)

  5. Quantitative analysis of the structure of the human extraocular muscle pulley system.

    Science.gov (United States)

    Kono, Reika; Poukens, Vadims; Demer, Joseph L

    2002-09-01

    Extraocular muscle (EOM) paths are constrained by connective tissue pulleys serving as functional origins. The quantitative structural features of pulleys and their intercouplings and orbital suspensions remain undetermined. This study was designed to quantify the composition of EOM pulleys and suspensory tissues. Five human orbits, ages 33 weeks gestation to 93 years, were imaged intact by magnetic resonance (MRI), serially sectioned at 10 micro m thickness, and stained for collagen, elastin, and smooth muscle (SM). With MRI used as a reference, digital images of sections were geometrically corrected for shrinkage and processing deformations, and normalized to standard normal adult globe diameter. EOM pulleys, interconnections, suspensory tissues, and entheses were quantitatively analyzed for collagen, elastin, and SM thickness and density. Rectus and inferior oblique pulleys had uniform structural features in all specimens, comprising a dense EOM encirclement by collagen 1 to 2 mm thick. Elastin distribution varied, but was greatest in the orbital suspension of the medial rectus pulley and in a band from it to the inferior rectus pulley. This region corresponded to maximum SM density. Structural features of pulleys, intercouplings, and entheses were similar among specimens. The major mechanical couplings to the osseous orbit were near the medial and lateral rectus pulleys. Quantitative analysis of structure and composition of EOM pulleys and their suspensions is consistent with in vivo MRI observations showing discrete inflections in EOM paths that shift predictably with gaze. Focal SM distributions in the suspensions suggest distinct roles in stiffening as well as shifting rectus pulleys.

  6. Extra-ocular muscle MRI in genetically-defined mitochondrial disease

    International Nuclear Information System (INIS)

    Pitceathly, Robert D.S.; Morrow, Jasper M.; Hanna, Michael G.; Sinclair, Christopher D.J.; Yousry, Tarek A.; Thornton, John S.; Woodward, Cathy; Sweeney, Mary G.; Rahman, Shamima; Plant, Gordon T.; Ali, Nadeem; Bremner, Fion; Davagnanam, Indran

    2016-01-01

    Conventional and quantitative MRI was performed in patients with chronic progressive external ophthalmoplegia (CPEO), a common manifestation of mitochondrial disease, to characterise MRI findings in the extra-ocular muscles (EOMs) and investigate whether quantitative MRI provides clinically relevant measures of disease. Patients with CPEO due to single mitochondrial DNA deletions were compared with controls. Range of eye movement (ROEM) measurements, peri-orbital 3 T MRI T1-weighted (T1w) and short-tau-inversion-recovery (STIR) images, and T2 relaxation time maps were obtained. Blinded observers graded muscle atrophy and T1w/STIR hyperintensity. Cross-sectional areas and EOM mean T2s were recorded and correlated with clinical parameters. Nine patients and nine healthy controls were examined. Patients had reduced ROEM (patients 13.3 , controls 49.3 , p < 0.001), greater mean atrophy score and increased T1w hyperintensities. EOM mean cross-sectional area was 43 % of controls and mean T2s were prolonged (patients 75.6 ± 7.0 ms, controls 55.2 ± 4.1 ms, p < 0.001). ROEM correlated negatively with EOM T2 (rho = -0.89, p < 0.01), whilst cross-sectional area failed to correlate with any clinical measures. MRI demonstrates EOM atrophy, characteristic signal changes and prolonged T2 in CPEO. Correlation between elevated EOM T2 and ROEM impairment represents a potential measure of disease severity that warrants further evaluation. (orig.)

  7. Localization of motoneurons innervating the extraocular muscles in Salamandra salamandra L. (Amphibia, Urodela).

    Science.gov (United States)

    Naujoks-Manteuffel, C; Manteuffel, G; Himstedt, W

    1986-12-01

    The central innervation patterns of the extraocular muscles were investigated in the European fire salamander Salamandra salamandra L. by means of the horseradish peroxidase method. The ipsilateral portion of the nucleus nervi oculomotorii, which is located in the rostral ventral tegmentum mesencephali, supplies the musculi recti inferior and medialis and the musculus obliquus inferior without a clear somatotopic representation of the motoneurons. The musculus rectus superior is innervated mainly by a contralateral portion of this nucleus. A definite nucleus Edinger-Westphal could not be recognized. The nucleus nervi trochlearis, which rostrally joins the nucleus nervi oculomotorii with a gap of only about 40 micron between the nuclei, is situated completely contralateral to the musculus obliquus superior supplied by it. The nucleus nervi abducentis, innervating the musculus rectus lateralis, and the nucleus accessorius nervi abducentis, supplying the musculus retractor bulbi, are found in the ipsilateral medulla oblongata and exhibit a large rostrocaudal extension from the eighth cranial nerve to the first root of the vagus nerve. Dendrites of the nucleus nervi oculumotorii and of the nucleus accessorius nervi abducentis extend into neuropil areas receiving primary sensory afferents.

  8. Retinal Dysfunction in Patients with Congenital Fibrosis of the Extraocular Muscles Type 2.

    Science.gov (United States)

    Khan, Arif O; Almutlaq, Mohammed; Oystreck, Darren T; Engle, Elizabeth C; Abu-Amero, Khaled; Bosley, Thomas

    2016-06-01

    Congenital fibrosis of the extraocular muscles type 2 (CFEOM2) is a distinct non-syndromic form of congenital incomitant strabismus secondary to orbital dysinnervation from recessive mutations in the gene PHOX2A. The phenotype includes bilateral ptosis, very large angle exotropia, ophthalmoplegia, and poorly-reactive pupils. Other than amblyopia, afferent visual dysfunction has not been considered part of CFEOM2; however, we have repeatedly observed non-amblyopic subnormal vision in affected patients. The purpose of this study was to document this recurrent feature of the phenotype. A retrospective case series (2002-2012). Eighteen patients (four families) were identified; all affected individuals had confirmed homozygous recessive PHOX2A mutations except one individual for whom genetic testing was not done because of multiple genetically confirmed family members. Age at assessment ranged from 5-62 years old (median 10 years old). All patients had decreased best-corrected visual acuity not completely explainable by amblyopia in both the preferred and non-preferred eye. In those patients who had further ancillary testing, visual fields (five patients) and electroretinography (10 patients) confirmed abnormalities not ascribable to amblyopia. In addition to a distinct form of congenital incomitant strabismus, the phenotype of CFEOM2 includes subnormal vision consistent with retinal dysfunction. This could be the direct result of PHOX2A mutations or a secondary effect of orbital dysinnervation.

  9. The role of Pitx2 in maintaining the phenotype of myogenic precursor cells in the extraocular muscles.

    Science.gov (United States)

    Hebert, Sadie L; Daniel, Mark L; McLoon, Linda K

    2013-01-01

    Many differences exist between extraocular muscles (EOM) and non-cranial skeletal muscles. One striking difference is the sparing of EOM in various muscular dystrophies compared to non-cranial skeletal muscles. EOM undergo continuous myonuclear remodeling in normal, uninjured adults, and distinct transcription factors are required for the early determination, development, and maintenance of EOM compared to limb skeletal muscle. Pitx2, a bicoid-like homeobox transcription factor, is required for the development of EOM and the maintenance of characteristic properties of the adult EOM phenotype, but is not required for the development of limb muscle. We hypothesize that these unique properties of EOM contribute to the constitutive differences between EOM and non-craniofacial skeletal muscles. Using flow cytometry, CD34(+)/Sca1(-/)CD45(-/)CD31(-) cells (EECD34 cells) were isolated from extraocular and limb skeletal muscle and in vitro, EOM EECD34 cells proliferated faster than limb muscle EECD34 cells. To further define these myogenic precursor cells from EOM and limb skeletal muscle, they were analyzed for their expression of Pitx2. Western blotting and immunohistochemical data demonstrated that EOM express higher levels of Pitx2 than limb muscle, and 80% of the EECD34 cells expressed Pitx2. siRNA knockdown of Pitx2 expression in EECD34 cells in vitro decreased proliferation rates and impaired the ability of EECD34 cells to fuse into multinucleated myotubes. High levels of Pitx2 were retained in dystrophic and aging mouse EOM and the EOM EECD34 cells compared to limb muscle. The differential expression of Pitx2 between EOM and limb skeletal muscle along with the functional changes in response to lower levels of Pitx2 expression in the myogenic precursor cells suggest a role for Pitx2 in the maintenance of constitutive differences between EOM and limb skeletal muscle that may contribute to the sparing of EOM in muscular dystrophies.

  10. The role of Pitx2 in maintaining the phenotype of myogenic precursor cells in the extraocular muscles.

    Directory of Open Access Journals (Sweden)

    Sadie L Hebert

    Full Text Available Many differences exist between extraocular muscles (EOM and non-cranial skeletal muscles. One striking difference is the sparing of EOM in various muscular dystrophies compared to non-cranial skeletal muscles. EOM undergo continuous myonuclear remodeling in normal, uninjured adults, and distinct transcription factors are required for the early determination, development, and maintenance of EOM compared to limb skeletal muscle. Pitx2, a bicoid-like homeobox transcription factor, is required for the development of EOM and the maintenance of characteristic properties of the adult EOM phenotype, but is not required for the development of limb muscle. We hypothesize that these unique properties of EOM contribute to the constitutive differences between EOM and non-craniofacial skeletal muscles. Using flow cytometry, CD34(+/Sca1(-/CD45(-/CD31(- cells (EECD34 cells were isolated from extraocular and limb skeletal muscle and in vitro, EOM EECD34 cells proliferated faster than limb muscle EECD34 cells. To further define these myogenic precursor cells from EOM and limb skeletal muscle, they were analyzed for their expression of Pitx2. Western blotting and immunohistochemical data demonstrated that EOM express higher levels of Pitx2 than limb muscle, and 80% of the EECD34 cells expressed Pitx2. siRNA knockdown of Pitx2 expression in EECD34 cells in vitro decreased proliferation rates and impaired the ability of EECD34 cells to fuse into multinucleated myotubes. High levels of Pitx2 were retained in dystrophic and aging mouse EOM and the EOM EECD34 cells compared to limb muscle. The differential expression of Pitx2 between EOM and limb skeletal muscle along with the functional changes in response to lower levels of Pitx2 expression in the myogenic precursor cells suggest a role for Pitx2 in the maintenance of constitutive differences between EOM and limb skeletal muscle that may contribute to the sparing of EOM in muscular dystrophies.

  11. Determination of slow-tonic MyHC immunoreactivity is an important step in the evaluation of muscle spindles in porcine extraocular muscles

    Czech Academy of Sciences Publication Activity Database

    Friedrich, C.; Lemm, B.; Soukup, Tomáš; Asmussen, G.

    2007-01-01

    Roč. 85, č. 1 (2007), s. 54-64 ISSN 0014-4835 R&D Projects: GA ČR GA304/05/0327 Grant - others:MYORES(XE) LSHG-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Source of funding: R - rámcový projekt EK Keywords : muscle spindles * porcine extraocular muscles * immunocytochemistry Subject RIV: ED - Physiology Impact factor: 2.651, year: 2007

  12. Expression of schizophrenia biomarkers in extraocular muscles from patients with strabismus: an explanation for the link between exotropia and schizophrenia?

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    Andrea B. Agarwal

    2017-12-01

    Full Text Available Recent studies have implicated exotropia as a risk factor for schizophrenia. We determined whether schizophrenia biomarkers have abnormal levels of expression in extraocular muscles from patients with strabismus and explored whether differences in gene expression between medial and lateral rectus muscles may explain the specific association of schizophrenia with exotropia but not esotropia. Samples from horizontal extraocular muscles were obtained during strabismus surgery and compared with age- and muscle type-matched normal muscles from organ donors. We used PCR arrays to identify differences in gene expression among 417 signaling molecules. We then focused on established schizophrenia-related growth factors, cytokines, and regulators of the extracellular matrix. Among 36 genes with significantly altered gene expression in dysfunctional horizontal rectus muscles, over one third were schizophrenia-related: CTGF, CXCR4, IL1B, IL10RA, MIF, MMP2, NPY1R, NRG1, NTRK2, SERPINA3, TIMP1, TIMP2, and TNF (adjusted p value ≤ 0.016667. By PCR array, expression of three of these genes was significantly different in medial rectus muscles, while eleven were significantly altered in lateral rectus muscles. Comparing baseline levels between muscle types, three schizophrenia-related genes (NPY1R, NTRK2, TIMP2 had lower levels of expression in medial rectus muscles. Despite the surprisingly large number of schizophrenia-related genes with altered gene expression levels in dysfunctional muscles, the lack of specificity for medial rectus muscles undermines a model of shared, region-specific gene expression abnormalities between exotropia and schizophrenia, but rather suggests consideration of the alternative model: that exotropia-induced aberrant early visual experiences may enable and/or contribute as a causative factor to the development of schizophrenia.

  13. Functional imaging of human extraocular muscles in head tilt dependent hypertropia.

    Science.gov (United States)

    Demer, Joseph L; Kung, Jennifer; Clark, Robert A

    2011-05-09

    Although alteration in hypertropia induced by head tilt is considered a clinical criterion for diagnosis of superior oblique (SO) palsy, the mechanism of this head-tilt-dependent hypertropia (HTDHT) is unclear. In this study, magnetic resonance imaging (MRI) was used to study extraocular muscle (EOM) responses to head tilt in HTDHT. Orbital MRI was used to study 16 normal subjects and 22 subjects with HTDT, of whom 12 had unilateral SO atrophy and 10 had "masquerading" SO palsy with normal SO size. Sizes and paths of all EOMs were compared in 90° roll tilts. Normal subjects exhibited the expected 3° to 7° physiologic extorsion of all four rectus pulleys in the orbit up-versus-down roll positions, corresponding to ocular counterrolling. In orbits with SO atrophy, the lateral (LR) and inferior rectus (IR) pulleys paradoxically intorted by approximately 2°. Subjects with HTDHT but normal SO size exhibited reduced or reversed extorsion of the medial, superior, and LR pulleys, whereas pulley shift was normal in nonhypertropic fellow orbits in HTDHT. In normal subjects and in SO atrophy, the inferior oblique (IO) muscle contracted in the orbit up-versus-down roll position, but paradoxically relaxed in HTDHT without SO atrophy. The ipsilesional IR and LR pulleys shift abnormally during head tilt in HTDHT with SO atrophy. In HTDHT without SO atrophy, the ipsilesional MR, SO, and LR pulleys shift abnormally, and the IO relaxes paradoxically during head tilt. These widespread alterations in EOM pulling directions suggest that complex neural adjustments to the otolith-ocular reflexes mediate HTDHT.

  14. Diffusion-weighted magnetic resonance imaging of extraocular muscles in patients with Grave's ophthalmopathy using turbo field echo with diffusion-sensitized driven-equilibrium preparation.

    Science.gov (United States)

    Hiwatashi, A; Togao, O; Yamashita, K; Kikuchi, K; Momosaka, D; Honda, H

    2018-03-20

    The purpose of this study was to correlate diffusivity of extraocular muscles, measured by three-dimensional turbo field echo (3DTFE) magnetic resonance (MR) imaging using diffusion-sensitized driven-equilibrium preparation, with their size and activity in patients with Grave's ophthalmopathy. Twenty-three patients with Grave's ophthalmopathy were included. There were 17 women and 6 men with a mean age of 55.8±12.6 (SD) years (range: 26-83 years). 3DTFE with diffusion-sensitized driven-equilibrium MR images were obtained with b-values of 0 and 500s/mm 2 . The apparent diffusion coefficient (ADC) of extraocular muscles was measured on coronal reformatted MR images. Signal intensities of extraocular muscles on conventional MR images were compared to those of normal-appearing white matter, and cross-sectional areas of the muscles were also measured. The clinical activity score was also evaluated. Statistical analyses were performed with Pearson correlation and Mann-Whitney U tests. On 3DTFE with diffusion-sensitized driven-equilibrium preparation, the mean ADC of the extraocular muscles was 2.23±0.37 (SD)×10 -3 mm2/s (range: 1.70×10 -3 -3.11×10 -3 mm 2 /s). There was a statistically significant moderate correlation between ADC and the size of the muscles (r=0.61). There were no statistically significant correlations between ADC and signal intensity on conventional MR and the clinical activity score. 3DTFE with diffusion-sensitized driven-equilibrium preparation technique allows quantifying diffusivity of extraocular muscles in patients with Grave's ophthalmopathy. The diffusivity of the extraocular muscles on 3DTFE with diffusion-sensitized driven-equilibrium preparation MR images moderately correlates with their size. Copyright © 2018. Published by Elsevier Masson SAS.

  15. Strabismus surgery in congenital fibrosis of the extraocular muscles: a paradigm.

    Science.gov (United States)

    Sener, Emin Cumhur; Taylan Sekeroglu, Hande; Ural, Ozlem; Oztürk, Banu Turgut; Sanaç, Ali Sefik

    2014-12-01

    Congenital fibrosis of extraocular muscles (CFEOM) is a rare group of disorders with variable phenotypes that result from aberrant innervation to the EOMs leading to synergistic vertical and/or horizontal deviations. We report our experience with the surgical management of patients with CFEOM. We reviewed the clinical findings, the surgical management, and outcomes of 52 consecutive CFEOM patients operated by one surgeon at a university hospital setting between 1993 and 2014. Patients were divided into CFEOM1, 2, or 3 based on clinical and/or molecular genetic findings. Thirty-seven (71.2%) cases were bilateral and 15 (28.8%) were unilateral. Six of the bilateral cases had CFEOM2, and the rest of the patients had either CFEOM1 or CFEOM3. The median age at the first surgery was 10 (1-43) years. Twenty-five were females and 27 were males. Nineteen patients had previous strabismus and/or ptosis surgeries elsewhere. The mean number of operations at our center was 1.6 ± 0.7 (1-4). A temporary stay suture was used in eight patients and permanently in seven. Of the 40 patients with abnormal head position, 18 achieved excellent, 15 good, and seven poor outcomes and ocular alignment in primary position following the latest surgery was excellent in 19, good in 18, and poor in 14 of the patients, as defined in the "Methods" section of the paper. Although patients with CFEOM present significant strabismus surgical challenges because of EOM dysinnervation, fibrosis, and/or heterotopia, satisfactory alignment and improvement of the head posture can be attained in a significant proportion of patients using an individually tailored surgical approach.

  16. Isolation of Mouse Periocular Tissue for Histological and Immunostaining Analyses of the Extraocular Muscles and Their Satellite Cells.

    Science.gov (United States)

    Stuelsatz, Pascal; Yablonka-Reuveni, Zipora

    2016-01-01

    The extraocular muscles (EOMs) comprise a group of highly specialized skeletal muscles controlling eye movements. Although a number of unique features of EOMs including their sparing in Duchenne muscular dystrophy have drawn a continuous interest, knowledge about these hard to reach muscles is still limited. The goal of this chapter is to provide detailed methods for the isolation and histological analysis of mouse EOMs. We first introduce in brief the basic anatomy and established nomenclature of the extraocular primary and accessory muscles. We then provide a detailed description with step-by-step images of our procedure for isolating (and subsequently cryosectioning) EOMs while preserving the integrity of their original structural organization. Next, we present several useful histological protocols frequently used by us, including: (1) a method for highlighting the general organization of periocular tissue, using the MyoD(Cre) × R26(mTmG) reporter mouse that elegantly distinguishes muscle (MyoD(Cre)-driven GFP(+)) from the non-myogenic constituents (Tomato(+)); (2) analysis by H&E staining, allowing for example, detection of the pathological features of the dystrophin-null phenotype in affected limb and diaphragm muscles that are absent in EOMs; (3) detection of the myogenic progenitors (i.e., satellite cells) in their native position underneath the myofiber basal lamina using Pax7/laminin double immunostaining. The EOM tissue harvesting procedure described here can also be adapted for isolating and studying satellite cells and other cell types. Overall, the methods described in this chapter should provide investigators the necessary tools for entering the EOM research field and contribute to a better understanding of this highly specialized muscle group and its complex micro-anatomy.

  17. Extraocular muscle cysticercosis mimicking idiopathic orbital inflammation: case report Cisticercose muscular extra-ocular simulando inflamação idiopática orbitária: relato de caso

    Directory of Open Access Journals (Sweden)

    Hélio Angotti-Neto

    2007-06-01

    Full Text Available Presentation of one case of extraocular muscle enlargement caused by cysticercosis, its clinical, diagnostic and treatment aspects, and review of the literature on this theme. A female 38-year-old patient with extraocular muscle enlargement and a small cystic lesion at the superior rectus muscle insertion was treated with oral prednisone for almost one year, with a non-specific inflammation of right orbit diagnosis. There were important ocular motility restriction and pain. Computerized tomography disclosed a superior rectus muscle thickening with a small cystic and apparently empty lesion at the muscle's insertion. Excisional biopsy and histopathological study confirmed the clinical suspicion of cysticercosis. There was partial resolution of the restricted motility. Extraocular muscle cysticercosis is the most common site of this disease when involving the orbit. Oral albendazole and prednisone are efficient, but a long history of disease can lead to important residual ocular motility restriction.Apresentação de um caso de aumento de músculo extra-ocular causado por cisticercose, seus aspectos diagnósticos, clínicos, tratamento e revisão da literatura sobre o tema. Paciente de 38 anos do sexo feminino com aumento de músculo reto superior e pequena lesão cística foi tratada por um ano com prednisona oral com o diagnóstico de inflamação inespecífica da órbita. Havia importante restrição da motilidade ocular e dor. Tomografia computadorizada demonstrou espessamento do reto superior e pequena lesão cística, aparentemente sem conteúdo, na inserção do músculo. Biópsia excisional e estudo histopatológico confirmaram a suspeita de cisticercose. Houve melhora parcial da restrição de motilidade. A cisticercose de músculo extra-ocular é a mais frequente forma orbitária da doença. Tratamento clínico com albendazol e prednisona é eficiente, mas um atraso no diagnóstico pode levar a importante restrição residual na

  18. Adaptation of slow myofibers: the effect of sustained BDNF treatment of extraocular muscles in infant nonhuman primates.

    Science.gov (United States)

    Willoughby, Christy L; Fleuriet, Jérome; Walton, Mark M; Mustari, Michael J; McLoon, Linda K

    2015-06-01

    We evaluated promising new treatment options for strabismus. Neurotrophic factors have emerged as a potential treatment for oculomotor disorders because of diverse roles in signaling to muscles and motor neurons. Unilateral treatment with sustained release brain-derived neurotrophic factor (BDNF) to a single lateral rectus muscle in infant monkeys was performed to test the hypothesis that strabismus would develop in correlation with extraocular muscle (EOM) changes during the critical period for development of binocularity. The lateral rectus muscles of one eye in two infant macaques were treated with sustained delivery of BDNF for 3 months. Eye alignment was assessed using standard photographic methods. Muscle specimens were analyzed to examine the effects of BDNF on the density, morphology, and size of neuromuscular junctions, as well as myofiber size. Counts were compared to age-matched controls. No change in eye alignment occurred with BDNF treatment. Compared to control muscle, neuromuscular junctions on myofibers expressing slow myosins had a larger area. Myofibers expressing slow myosin had larger diameters, and the percentage of myofibers expressing slow myosins increased in the proximal end of the muscle. Expression of BDNF was examined in control EOM, and observed to have strongest immunoreactivity outside the endplate zone. We hypothesize that the oculomotor system adapted to sustained BDNF treatment to preserve normal alignment. Our results suggest that BDNF treatment preferentially altered myofibers expressing slow myosins. This implicates BDNF signaling as influencing the slow twitch properties of EOM.

  19. Evidence of an asymmetrical endophenotype in congenital fibrosis of extraocular muscles type 3 resulting from TUBB3 mutations.

    Science.gov (United States)

    Demer, Joseph L; Clark, Robert A; Tischfield, Max A; Engle, Elizabeth C

    2010-09-01

    Orbital magnetic resonance imaging (MRI) was used to investigate the structural basis of motility abnormalities in congenital fibrosis of the extraocular muscles type 3 (CFEOM3), a disorder resulting from missense mutations in TUBB3, which encodes neuron-specific beta-tubulin isotype III. Ophthalmic examinations in 13 volunteers from four CFEOM3 pedigrees and normal control subjects, were correlated with TUBB3 mutation and MRI findings that demonstrated extraocular muscle (EOM) size, location, contractility, and innervation. Volunteers included clinically affected and clinically unaffected carriers of R262C and D417N TUBB3 amino acid substitutions and one unaffected, mutation-negative family member. Subjects with CFEOM3 frequently had asymmetrical blepharoptosis, limited vertical duction, variable ophthalmoplegia, exotropia, and paradoxical abduction in infraduction. MRI demonstrated variable, asymmetrical levator palpebrae superioris and superior rectus EOM atrophy that correlated with blepharoptosis, deficient supraduction, and small orbital motor nerves. Additional EOMs exhibited variable hypoplasia that correlated with duction deficit, but the superior oblique muscle was spared. Ophthalmoplegia occurred only when the subarachnoid width of CN3 was muscle misinnervation by CN3. Optic nerve (ON) cross sections were subnormal, but rectus pulley locations were normal. CFEOM3 caused by TUBB3 R262C and D417N amino acid substitutions features abnormalities of EOM innervation and function that correlate with subarachnoid CN3 hypoplasia, occasional abducens nerve hypoplasia, and subclinical ON hypoplasia that can resemble CFEOM1. Clinical and MRI findings in CFEOM3 are more variable than those in CFEOM1 and are often asymmetrical. Apparent LR innervation by the inferior rectus motor nerve is an overlapping feature of Duane retraction syndrome and CFEOM1. These findings suggest that CFEOM3 is an asymmetrical, variably penetrant, congenital cranial dysinnervation disorder

  20. Phenothiourea sensitizes zebrafish cranial neural crest and extraocular muscle development to changes in retinoic acid and IGF signaling.

    Directory of Open Access Journals (Sweden)

    Brenda L Bohnsack

    Full Text Available 1-Phenyl 2-thiourea (PTU is a tyrosinase inhibitor commonly used to block pigmentation and aid visualization of zebrafish development. At the standard concentration of 0.003% (200 µM, PTU inhibits melanogenesis and reportedly has minimal other effects on zebrafish embryogenesis. We found that 0.003% PTU altered retinoic acid and insulin-like growth factor (IGF regulation of neural crest and mesodermal components of craniofacial development. Reduction of retinoic acid synthesis by the pan-aldehyde dehydrogenase inhibitor diethylbenzaldehyde, only when combined with 0.003% PTU, resulted in extraocular muscle disorganization. PTU also decreased retinoic acid-induced teratogenic effects on pharyngeal arch and jaw cartilage despite morphologically normal appearing PTU-treated controls. Furthermore, 0.003% PTU in combination with inhibition of IGF signaling through either morpholino knockdown or pharmacologic inhibition of tyrosine kinase receptor phosphorylation, disrupted jaw development and extraocular muscle organization. PTU in and of itself inhibited neural crest development at higher concentrations (0.03% and had the greatest inhibitory effect when added prior to 22 hours post fertilization (hpf. Addition of 0.003% PTU between 4 and 20 hpf decreased thyroxine (T4 in thyroid follicles in the nasopharynx of 96 hpf embryos. Treatment with exogenous triiodothyronine (T3 and T4 improved, but did not completely rescue, PTU-induced neural crest defects. Thus, PTU should be used with caution when studying zebrafish embryogenesis as it alters the threshold of different signaling pathways important during craniofacial development. The effects of PTU on neural crest development are partially caused by thyroid hormone signaling.

  1. Structural functional associations of the orbit in thyroid eye disease: Kalman filters to track extraocular rectal muscles

    Science.gov (United States)

    Chaganti, Shikha; Nelson, Katrina; Mundy, Kevin; Luo, Yifu; Harrigan, Robert L.; Damon, Steve; Fabbri, Daniel; Mawn, Louise; Landman, Bennett

    2016-03-01

    Pathologies of the optic nerve and orbit impact millions of Americans and quantitative assessment of the orbital structures on 3-D imaging would provide objective markers to enhance diagnostic accuracy, improve timely intervention, and eventually preserve visual function. Recent studies have shown that the multi-atlas methodology is suitable for identifying orbital structures, but challenges arise in the identification of the individual extraocular rectus muscles that control eye movement. This is increasingly problematic in diseased eyes, where these muscles often appear to fuse at the back of the orbit (at the resolution of clinical computed tomography imaging) due to inflammation or crowding. We propose the use of Kalman filters to track the muscles in three-dimensions to refine multi-atlas segmentation and resolve ambiguity due to imaging resolution, noise, and artifacts. The purpose of our study is to investigate a method of automatically generating orbital metrics from CT imaging and demonstrate the utility of the approach by correlating structural metrics of the eye orbit with clinical data and visual function measures in subjects with thyroid eye disease. The pilot study demonstrates that automatically calculated orbital metrics are strongly correlated with several clinical characteristics. Moreover, it is shown that the superior, inferior, medial and lateral rectus muscles obtained using Kalman filters are each correlated with different categories of functional deficit. These findings serve as foundation for further investigation in the use of CT imaging in the study, analysis and diagnosis of ocular diseases, specifically thyroid eye disease.

  2. Magnetic resonance imaging of differential compartmental function of horizontal rectus extraocular muscles during conjugate and converged ocular adduction.

    Science.gov (United States)

    Demer, Joseph L; Clark, Robert A

    2014-08-15

    Activity in horizontal rectus extraocular muscles (EOMs) was investigated by magnetic resonance imaging (MRI) of humans during asymmetric convergence to a monocularly aligned target at 15-cm distance or monocular fixation of afocal targets placed over a wide range of conjugate abduction through adduction. Cross sections and posterior partial volumes (PPVs) of EOMs were determined from quasi-coronal image planes and were separately analyzed in the inferior vs. superior compartments, defined by lines bisecting their maximum vertical dimensions. Both inferior and superior compartments of medial (MR) and lateral (LR) rectus exhibited contractile changes in PPV and maximum cross section for both asymmetric convergence and a comparable range of conjugate adduction. Both LR compartments, and the inferior MR compartment, exhibited similar decreases in contractility correlating with relaxation during both convergence and conjugate adduction. In contrast, the superior MR compartment exhibited roughly three times the contractility in conjugate adduction as in similar-magnitude convergence. In the aligned eye that did not move during convergence, summed contractility in all compartments of MR and LR exhibited corelaxation consistent with published EOM force measurements in this paradigm (Miller JM, Bockisch CJ, Pavlovski DS. J Neurophysiol 87: 2421-2433, 2002; Miller JM, Davison RC, Gamlin PD. J Neurophysiol 105: 2863-2873, 2011). The superior MR compartment also exhibited significantly greater contractility than the other compartments over the maximum achievable horizontal globe rotation from abduction to adduction. These findings suggest that the superior MR compartment is controlled differentially from the inferior compartment and suggest that its activity is reduced during convergence as a component of generally altered extraocular mechanics. Copyright © 2014 the American Physiological Society.

  3. Dacryoadenitis and extraocular muscle inflammation associated with contact lens-related Acanthamoeba keratitis: A case report and review of the literature.

    Science.gov (United States)

    Sengor, Tomris; Yuzbasioglu, Erdal; Aydın Kurna, Sevda; Irkec, Murat; Altun, Ahmet; Kökcen, Kubra; Yalcin, Nazli Gul

    2017-02-01

    The present report discusses a new case of dacryoadenitis with extraocular muscle inflammation associated with Acanthamoeba keratitis (AK) in a contact lens wearer. A 41-year-old male, who has worn silicone hydrogel contact lenses on an extended basis for about 10 years, attended with the complaints of vision disturbance, hyperemia, and pain in his right eye. His history revealed that 1.5 month ago, he had been diagnosed with allergic conjunctivitis and had used steroid eye drops. Biomicroscopic examination revealed eyelid edema, chemosis, and ring infiltration, radial keratoneuritis and an epithelial defect in the cornea. Magnetic resonance imaging demonstrated enlarged lacrimal gland with edematous changes consistent with inflammation due to dacryoadenitis. There were also thickening and edema of the right superior oblique and lateral rectus muscle. The treatment protocol for AK was applied with no specific treatment for dacryoadenitis. After 4 months of the treatment, dacryoadenitis and keratitis regressed. Dacryoadenitis and extraocular muscle inflammation may accompany AK more frequently than expected and previously known. The evaluation of the lacrimal gland and extraocular muscles in presence of AK might be beneficial for understanding better the exact clinical picture and course of the keratitis.

  4. Orbital T-Cell Lymphoma with Discrete Enlargements of All Extraocular Muscles Bilaterally in Patient with Moon Face Countenance

    Directory of Open Access Journals (Sweden)

    Hideaki Kawakami

    2017-01-01

    Full Text Available Purpose. To report our findings in a case of orbital T-cell lymphoma in which all of the extraocular muscles (EOMs were bilaterally and discretely enlarged and the patient had a moon face countenance. Case. A 59-year-old woman presented with visual disturbances in her left eye, hyperemia in both eyes, and a moon face countenance. Examinations showed limited upward gaze in the right eye, blepharoptosis, hypertropia, and limited downward and rightward gaze in the left eye. Slit-lamp examination showed only chemosis and hyperemia of both eyes. Magnetic resonance imaging with contrast revealed discrete enlargements of the muscle bellies in all EOMs without abnormalities of the orbital fat in both eyes. Blood examinations excluded thyroid- and IgG4-related ophthalmopathy, and EOM biopsy revealed peripheral T-cell lymphoma. After beginning aggressive chemotherapy, the enlarged EOMs, limited eye motility, and moon face countenance improved. Unfortunately, the patient died of sepsis during the chemotherapy. Conclusions. A lymphoma should be included in the differential diagnosis of eyes with enlarged EOMs. Because lymphomas can lead to death, it is important for clinicians to consider lymphomas in eyes with enlarged EOMs.

  5. Crotoxin in humans: analysis of the effects on extraocular and facial muscles Crotoxina em humanos: estudo da ação em músculos extraoculares e faciais

    Directory of Open Access Journals (Sweden)

    Geraldo de Barros Ribeiro

    2012-12-01

    Full Text Available PURPOSE: Crotoxin is the main neurotoxin of South American rattlesnake Crotalus durissus terrificus. The neurotoxic action is characterized by a presynaptic blockade. The purpose of this research is to assess the ability of crotoxin to induce temporary paralysis of extraocular and facial muscles in humans. METHODS: Doses of crotoxin used ranged from 2 to 5 units (U, each unit corresponding to one LD50. We first applied 2U of crotoxin in one of the extraocular muscles of 3 amaurotic individuals to be submitted to ocular evisceration. In the second stage, we applied crotoxin in 12 extraocular muscles of 9 patients with strabismic amblyopia. In the last stage, crotoxin was used in the treatment of blepharospasm in another 3 patients. RESULTS: No patient showed any systemic side effect or change in vision or any eye structure problem after the procedure. The only local side effects observed were slight conjunctival hyperemia, which recovered spontaneously. In 2 patients there was no change in ocular deviation after 2U crotoxin application. Limitation of the muscle action was observed in 8 of the 12 applications. The change in ocular deviation after application of 2U of crotoxin (9 injections was in average 15.7 prism diopters (PD. When the dose was 4U (2 applications the change was in average 37.5 PD and a single application of 5U produced a change of 16 PD in ocular deviation. This effect lasted from 1 to 3 months. Two of the 3 patients with blepharospasm had the hemifacial spasm improved with crotoxin, which returned after 2 months. CONCLUSIONS: This study provides data suggesting that crotoxin may be a useful new therapeutic option for the treatment of strabismus and blepharospasm. We expect that with further studies crotoxin could be an option for many other medical areas.OBJETIVO: A crotoxina é a principal neurotoxina da cascavel sul-americana Crotalus durissus terrificus e sua ação neurotóxica caracteriza-se por um bloqueio pr

  6. Specific Metabolic Properties of Rat Oculorotatory Extraocular Muscles Can Be Linked to Their Low Force Requirements

    Czech Academy of Sciences Publication Activity Database

    Asmussen, G.; Punkt, K.; Bartsch, B.; Soukup, Tomáš

    2008-01-01

    Roč. 49, č. 11 (2008), s. 4865-4871 ISSN 0146-0404 R&D Projects: GA ČR(CZ) GA304/08/0256; GA ČR(CZ) GA304/05/0327 Grant - others:EC(XE) LSH-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : oculomotor mechanics * muscle fiber types * cytophotometry Subject RIV: ED - Physiology Impact factor: 3.582, year: 2008

  7. Myopathic Alterations in Extraocular Muscle of Rats Subchronically Fed Pyridostigmine Bromide

    Science.gov (United States)

    1990-01-01

    pre- soleus and extensor digitorum longus , the myopathy exposure antidote for nerve poisons that irreversibly consists of large diameter vacuoles in...By transmission electron microscopy, 35- diaphragm, extensor digitorum longus and soleusrat EoM Bny tranpsiss i lectons icroscopymuscles of the rat...end plates of rat soleus and extensor muscles. Macmillan Pub. Co., New York, p. 123. Exp. Neurol. 89: 96-114. Fcesion ’or INTIS CRA& VIC TAD El U d’-OU

  8. Signal intensity and T2 time of extraocular muscles in assessment of their physiological status in MR imaging in healthy subjects

    International Nuclear Information System (INIS)

    Pająk, Michał; Loba, Piotr; Wieczorek-Pastusiak, Julia; Antosik-Biernacka, Aneta; Stefańczyk, Ludomir; Majos, Agata

    2012-01-01

    Lack of standardised orbital MR protocols leads to a situation, when each institution/centre may arbitrarily choose sequence parameters. Therefore, the results obtained and published by the authors may not be compared freely, and what is most important may not be considered fully reliable. Signal intensity (IS) and T2 time (T2) are important parameters in estimation of inflammatory processes of extraocular muscles in the clinical practice. The aim of this study was to determine the reference values (i.e. cut-off values) for absolute signal intensity and T2 relaxation time in healthy subjects, their relativised values to white matter (WM) and temporal muscles (TM) and to evaluate the correlation between those parameters. The orbital examination was performed in healthy volunteers according to the protocol prepared in the Radiology-Imaging Diagnostic Department of the Medical University of Lodz for patients with suspected/diagnosed thyroid orbitopathy. Using two of the standard sequences IS and T2 time were calculated for the muscles and two relativisation tissues in realtion to WM and TM. Subsequently cut-off values for healthy volunteers were calculated. The differences between muscles for IS, IS MAX, IS/TM, IS/WM, IS MAX/TM, IS MAX/WM and T2 MAX/WM were not statistically significant. Therefore one cut-off value of these parameters for all the rectus muscles was calculated. T2-relaxation time and T2 relativised to white matter had to be calculated separately for each muscle. No statistical correlation was found between IS and T2-time for extraocular muscles in healthy volunteers. We calculated the reference ranges (cut-off values) for absolute IS and T2-time values and relativised parameters. In the clinical practice the objectification of IS and T2-time values should be done to WM, than to IS or T2 of the temporal muscle. The T2 MAX/WM seems to have the highest clinical utility for the assessment of the pathophysiological status of extraocular muscles

  9. [Central nervous system abnormalities related to congenital fibrosis of extraocular muscles].

    Science.gov (United States)

    Moguel-Ancheita, Silvia; Rodríguez-Garcidueñas, Wendolyn

    2009-01-01

    We undertook this study to describe central nervous system (CNS) abnormalities associated with congenital cranial dysinnervation disorders (CCDD). This was a retrospective, observational, transversal and descriptive study including patients with congenital fibrotic strabismus. We analyzed clinical files of patients from 2001 to 2006. Neurological lesions were reported. Restrictive strabismus was demonstrated in all cases. Sixteen patients were included: nine males and seven females. Different neurological lesions were reported: corpus callosum anomalies, severe cortipathy, epilepsy, cavum vergae, nystagmus, occipital subarachnoid cyst, and hydrocephalus. Mental retardation was reported in 56% of patients. Different malformations were reported: genital malformations, trigonocephalus, camptodactyly, mild facial hypoplasia, low set ears, and agenesis of left ear. Blepharoptosis was present in 81% of patients. The most frequent form of strabismus was exotropia (56%), hypotropia in 37.5%, hypertropia 18.7%, "A" pattern 18.7%, and esotropia in 6.25%. Affection was cranial nerve III, 93.75%; cranial nerve VI, 6.25%; cranial nerve VII, 6.25%; and lesion to cranial nerve II in eight cases (50%). We have suggested that failure in early stages of embryology of the CNS can lead to the development of paralytic strabismus and generate secondary fibrotic changes, not only in muscle structures but also in other orbital tissues. That is the reason why we have used the term "congenital fibrotic strabismus" to report cases included in CCDD. We have demonstrated the strong association of mental retardation and neurological alterations. Multidisciplinary rehabilitation is relevant for these patients.

  10. Effects of extraocular muscle surgery in children with monocular blindness and bilateral nystagmus.

    Science.gov (United States)

    Sturm, Veit; Hejcmanova, Marketa; Landau, Klara

    2014-11-20

    Monocular infantile blindness may be associated with bilateral horizontal nystagmus, a subtype of fusion maldevelopment nystagmus syndrome (FMNS). Patients often adopt a significant anomalous head posture (AHP) towards the fixing eye in order to dampen the nystagmus. This clinical entity has also been reported as unilateral Ciancia syndrome. The aim of the study was to ascertain the clinical features and surgical outcome of patients with FMNS with infantile unilateral visual loss. In this retrospective case series, nine consecutive patients with FMNS with infantile unilateral visual loss underwent strabismus surgery to correct an AHP and/or improve ocular alignment. Outcome measures included amount of AHP and deviation at last follow-up. Eye muscle surgery according to the principles of Kestenbaum resulted in a marked reduction or elimination of the AHP. On average, a reduction of AHP of 1.3°/mm was achieved by predominantly performing combined horizontal recess-resect surgery in the intact eye. In cases of existing esotropia (ET) this procedure also markedly reduced the angle of deviation. A dosage calculation of 3 prism diopters/mm was established. We advocate a tailored surgical approach in FMNS with infantile unilateral visual loss. In typical patients who adopt a significant AHP accompanied by a large ET, we suggest an initial combined recess-resect surgery in the intact eye. This procedure regularly led to a marked reduction of the head turn and ET. In patients without significant strabismus, a full Kestenbaum procedure was successful, while ET in a patient with a minor AHP was corrected by performing a bimedial recession.

  11. Extraocular muscle function testing

    Science.gov (United States)

    ... will keep looking at the same object no matter which eye is covered. How to Prepare for ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  12. Extraocular Muscles Tension, Tonus, and Proprioception in Infantile Strabismus: Role of the Oculomotor System in the Pathogenesis of Infantile Strabismus—Review of the Literature

    Directory of Open Access Journals (Sweden)

    Costantino Schiavi

    2016-01-01

    Full Text Available The role played by the extraocular muscles (EOMs in the etiology of concomitant infantile strabismus is still debated and it has not yet definitively established if the sensory anomalies in concomitant strabismus are a consequence or a primary cause of the deviation. The commonest theory supposes that most strabismus results from abnormal innervation of the EOMs, but the cause of this dysfunction and its origin, whether central or peripheral, are still unknown. The interaction between sensory factors and innervational factors, that is, esotonus, accommodation, convergence, divergence, and vestibular reflexes in visually immature infants with family predisposition, is suspected to create conditions that prevent binocular alignment from stabilizing and strengthening. Some role in the onset of fixation instability and infantile strabismus could be played by the feedback control of eye movements and by dysfunction of eye muscle proprioception during the critical period of development of the visual sensory system. A possible role in the onset, maintenance, or worsening of the deviation of abnormalities of muscle force which have their clinical equivalent in eye muscle overaction and underaction has been investigated under either isometric or isotonic conditions, and in essence no significant anomalies of muscle force have been found in concomitant strabismus.

  13. Study of crotoxin on the induction of paralysis in extraocular muscle in animal model Estudo da crotoxina na indução de paralisia da musculatura extraocular em modelo animal

    Directory of Open Access Journals (Sweden)

    Geraldo de Barros Ribeiro

    2012-10-01

    Full Text Available PURPOSE: Crotoxin is the major toxin of the venom of the South American rattlesnake Crotalus durissus terrificus, capable of causing a blockade of the neurotransmitters at the neuromuscular junction. The objective of this study was to appraise the action and effectiveness of the crotoxin induced paralysis of the extraocular muscle and to compare its effects with the botulinum toxin type A (BT-A. METHODS: The crotoxin, with LD50 of 1.5 µg, was injected into the superior rectus muscle in ten New Zealand rabbits. The concentration variance was 0.015 up to 150 µg. Two rabbits received 2 units of botulinum toxin type A for comparative analysis. The evaluation of the paralysis was performed using serial electromyography. After the functional recovery of the muscles, which occurred after two months, six rabbits were sacrificed for anatomopathology study. RESULTS: The animals did not show any evidence of systemic toxicity. Transitory ptosis was observed in almost every animal and remained up to fourteen days. These toxins caused immediate blockade of the electrical potentials. The recovery was gradual in the average of one month with regeneration signs evident on the electromyography. The paralysis effect of the crotoxin on the muscle was proportional to its concentration. The changes with 1.5 µg crotoxin were similar to those produced by the botulinum toxin type A. The histopathology findings were localized to the site of the injection. No signs of muscle fiber's necrosis were seen in any sample. The alterations induced by crotoxin were also proportional to the concentration and similar to botulinum toxin type A in concentration of 1.5 µg. CONCLUSION: Crotoxin was able to induce transitory paralysis of the superior rectus muscle. This effect was characterized by reduction of action potentials and non-specific signs of fibrillation. Crotoxin, in concentration of 1.5 µg was able to induce similar effects as botulinum toxin type A.OBJETIVO: A

  14. Autologous grafting of extraocular muscles: experimental study in rabbits Transplante autólogo de musculatura ocular extrínseca: estudo experimental em coelhos

    Directory of Open Access Journals (Sweden)

    Jorge Meireles-Teixeira

    2005-06-01

    Full Text Available PURPOSE: To evaluate the feasibility of autologous extraocular muscle grafting as a type of muscle expansion surgery. METHODS: The left superior rectus muscle of twenty-nine rabbits was resected and this fragment was attached to the endpoint of the respective right superior rectus (test group. Thereafter, the superior rectus of the left eye was reattached to the sclera (control group. Both groups were examined during different postoperative periods in order to assess their outcomes. RESULTS: The presence of hyperemia was slightly more frequent in the grafted group. Secretion and muscle atrophy were negligible in both groups. Fibrosis was greater in grafted animals. These muscles were weaker than the control muscles, although the force required to split muscular parts was always greater than the physiological one. CONCLUSIONS: This surgical technique was reliable and useful if one intends to achieve muscle expansion without the intrinsic risks of dealing with heterologous/artificial materials.OBJETIVO: Avaliar a viabilidade do uso de segmentos de músculos oculares extrínsecos como expansores de tendões musculares. MÉTODOS: Vinte e nove coelhos tiveram seu músculo reto superior esquerdo ressecado e o fragmento de cada um foi transplantado para o reto superior contralateral (grupo-teste. Então, o reto superior esquerdo foi reinserido na esclera (grupo-controle. Os animais foram então examinados em diversos períodos pós-operatórios, até os seus sacrifícios, para que se avaliasse o desenrolar dessa técnica cirúrgica. RESULTADOS: A hiperemia foi maior entre os testes. A secreção e a atrofia muscular foram mínimas nos dois grupos. Houve maior presença de fibrose no grupo-teste, mas não tão expressiva a ponto de inviabilizar os efeitos da cirurgia. Esses músculos também se romperam mais facilmente do que os do grupo-controle, porém, a força de rompimento foi sempre bem maior do que aquela presente numa contração muscular normal

  15. Accommodation: The role of the external muscles of the eye: A consideration of refractive errors in relation to extraocular malfunction.

    Science.gov (United States)

    Hargrave, B K

    2014-11-01

    Speculation as to optical malfunction has led to dissatisfaction with the theory that the lens is the sole agent in accommodation and to the suggestion that other parts of the eye are also conjointly involved. Around half-a-century ago, Robert Brooks Simpkins suggested that the mechanical features of the human eye were precisely such as to allow for a lengthening of the globe when the eye accommodated. Simpkins was not an optical man but his theory is both imaginative and comprehensive and deserves consideration. It is submitted here that accommodation is in fact a twofold process, and that although involving the lens, is achieved primarily by means of a give - and - take interplay between adducting and abducting external muscles, whereby an elongation of the eyeball is brought about by a stretching of the delicate elastic fibres immediately behind the cornea. The three muscles responsible for convergence (superior, internal and inferior recti) all pull from in front backwards, while of the three abductors (external rectus and the two obliques) the obliques pull from behind forwards, allowing for an easy elongation as the eye turns inwards and a return to its original length as the abducting muscles regain their former tension, returning the eye to distance vision. In refractive errors, the altered length of the eyeball disturbs the harmonious give - and - take relationship between adductors and abductors. Such stresses are likely to be perpetuated and the error exacerbated. Speculation is not directed towards a search for a possible cause of the muscular imbalance, since none is suspected. Muscles not used rapidly lose tone, as evidenced after removal of a limb from plaster. Early attention to the need for restorative exercise is essential and results usually impressive. If flexibility of the external muscles of the eyes is essential for continuing good sight, presbyopia can be avoided and with it the supposed necessity of glasses in middle life. Early attention

  16. Evaluation of rectus extraocular muscles using dynamic contrast-enhanced MR imaging in patients with Graves' ophthalmopathy for assessment of disease activity

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hong; Wang, Zhenchang; Xian, Junfang; Li, Jing; Chen, Qinghua (Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China)), Email: cjr.wzhch@vip.163.com; Ai, Likun (Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing (China))

    2012-02-15

    Background. It is important to assess the activity of Graves' ophthalmopathy (GO) for planning optimal treatment strategy. Dynamic contrast-enhanced MR imaging (DCE-MRI) is a technique for assessment of microcirculation status. The correlation between disease activity and the microcirculation characteristics of extraocular muscles (EOMs) has been demonstrated in GO. Purpose. To investigate the changes of rectus EOMs in patients with active vs. inactive GO using DCE-MRI, and to evaluate the value of DCE-MRI in assessing the activity of GO. Material and Methods. Rectus EOMs of 20 healthy controls, 18 patients with active GO, and 16 patients with inactive GO were studied. The signal intensity (SI) of rectus EOMs on T{sub 2}W images was evaluated. Regions of interest were placed on each rectus on DCE-MRI images. The DCE-MRI parameters including time to peak enhancement (T{sub peak}), enhancement ratio (ER), and wash-out ratio (WR) were calculated. Results. There were significant differences in SI and T{sub peak}, ER and WR values among the three groups (P = 0.000). However, there was no significant difference in SI between the active and inactive groups (P = 0.07). Tpeak values of each rectus were significantly increased in inactive group compared with the active group (P < 0.05). ER and WR values of the inferior rectus and WR values of the superior rectus in inactive group were significantly lower than those in active group (P < 0.05). There was significant correlation between clinical activity score (CAS) and minimum Tpeak (minT{sub peak}), maximum ER (maxER) and maximum WR (maxWR) (P < 0.001). The cut-off values of minT{sub peak}, maxER and maxWR were 156.98s, 1.31 and 13.50% respectively, giving positive predictive values of 68.00%, 88.90%, and 94.44% for the assessment of disease activity. Conclusion. DCE-MRI could demonstrate the micro circulatory changes of rectus EOMs in both active and inactive GO, and this MRI method is a useful tool in differentiating

  17. Lymphomas and metastases of the extra-ocular musculature

    Energy Technology Data Exchange (ETDEWEB)

    Surov, Alexey; Behrmann, Curd; Koesling, Sabrina [Martin Luther University of Halle-Wittenberg, Department of Radiology, Halle (Germany); Holzhausen, Hans-Juergen [Martin Luther University of Halle-Wittenberg, Department of Pathology, Halle (Germany)

    2011-11-15

    The involvement of extra-ocular muscles in malignant diseases has been described only sporadically. The purpose of this study was to estimate the prevalence of orbital muscle lymphoma and metastases and to analyse their radiological findings. In the time period from January 2000 to January 2010, 11 patients with extra-ocular muscle malignancies (EOMM) were retrospectively identified in the radiological database of our institution. There were four women and seven men with a median age of 58 years (range, 47 to 72 years). In three patients non-Hodgkin lymphoma (NHL), in seven cases intramuscular metastases of solid tumours and in one patient plasmacytoma of orbital muscles were diagnosed. In all, magnetic resonance imaging (MRI) was performed on 11 patients using a 1.5-T MRI scanner (Magnetom Vision Sonata Upgrade, Siemens, Germany). The diagnosis of EOMM was confirmed histopathologically by muscle biopsy in all cases. The prevalence of orbital muscle involvement in plasmacytoma was 0.3%, in NHL 0.4% and in carcinomas 0.1%. Clinically, EOMM presented as painless proptosis and motility disturbance. Medial and lateral rectus muscles were involved in most patients. On T2-weighted images, the lesions were isointense or mixed iso-to-hyperintense in comparison to the unaffected musculature. On T1-weighted images, all tumours were homogeneously isointense. After intravenous administration of contrast medium, most lesions showed moderate heterogeneous enhancement. Lymphomas and metastases are rare lesions of the extra-ocular musculature with a prevalence below 0.5%. Their radiological and clinical signs are non-specific and include painless muscle enlargement or masses. They should be considered in the differential diagnosis of diseases of extra-ocular muscles. (orig.)

  18. Image Findings of a Rare Case of Neuroendocrine Tumor Metastatic to Orbital Extraocular Muscle in Gallium-68 DOTANOC Positron Emission Tomography/Computed Tomography and Therapy with Lutetium-177 DOTATATE.

    Science.gov (United States)

    Kamaleshwaran, Koramadai Karuppusamy; Joseph, Jephy; Upadhya, Indra; Shinto, Ajit Sugunan

    2017-01-01

    Metastatic tumor is one of several etiologies of space-occupying masses in the orbit that accounts for 1-13% of all orbital masses. In the adult patient population, breast cancer is the most common tumor to metastasize to the orbit, followed by metastasis from the lung, prostate, and gastrointestinal tract. Carcinoid tumors are rare neuroendocrine neoplasms derived from enterochromaffin cells, which are found primarily in the gastrointestinal tract and bronchial tree. Liver metastases are the classic presentation of distant disease. Although rare, metastatic carcinoid to the extraocular muscles (EOMs) has been relatively well described in both retrospective case reports and clinical series in the ophthalmology literature, but not in nuclear medicine. Positron emission tomography/computed tomography (PET/CT) using Ga-68-labeled somatostatin-analogues have shown superiority over other modalities for imaging of Neuroendocrine tumor We describe a case of bilateral EOM metastasis from carcinoid lung in Ga-68 DOTANOC PET/CT and treatment with Lu -177 DOTATATE.

  19. Histotopographical study of human periocular elastic fibers using aldehyde-fuchsin staining with special reference to the sleeve and pulley system for extraocular rectus muscles.

    Science.gov (United States)

    Osanai, Hajime; Murakami, Gen; Ohtsuka, Aiji; Suzuki, Daisuke; Nakagawa, Takashi; Tatsumi, Haruyuki

    2009-09-01

    The aim of this study was to investigate the detailed configuration of periocular elastic fibers. Semiserial paraffin sections were made using 40 whole orbital contents from 27 elderly cadavers and stained by the aldehyde-fuchsin method. Periocular tissues were classified into three types according to directions of the elastic fibers, i.e., tissues containing anteroposteriorly running elastic fibers, those with mediolateral fibers, and those with meshwork of fibers. Anteroposterior elastic fiber-dominant tissue was seen in the upper eyelid and newly defined pulley plate for the medial and lateral recti (MR, LR). Mediolateral fibers were predominant in the central part of the inferior rectus pulley. In the pulley plates for the MR and LR, anteroposteriorly running fibers encased the striated muscle. Tenon's capsule and the epimysium of the recti were mediolateral fiber-dominant. However, at the entrance of the muscle terminal where Tenon's capsule reflects and continues to the epimysium, composite elastic fibers provided a meshwork-like skeleton. The elastic mesh was also seen around the lacrimal canaliculi. The pulley for the recti seemed to be composed of two parts--a connective tissue plate encasing the recti and specialized Tenon's capsule at an entrance or porta of the muscle. For both parts, elastic fibers were major functional components. The anteroposterior elastic fibers in the MR and LR pulley plates, especially, seemed to receive anteroposteriorly directed stress and tension from these striated muscles. The elastic interfaces seemed to prevent any concentration of stress that would interfere with periocular striated muscle functions, including hypothetical active pulleys.

  20. 4D-visualization of the orbit based on dynamic MRI with special focus on the extra-ocular muscles and the optic nerves

    International Nuclear Information System (INIS)

    Kober, C.; Boerner, B.I.; Buitrago, C.; Klarhoefer, M.; Scheffler, K.; Kunz, C.; Zeilhofer, H.F.

    2007-01-01

    By recording time dependent patients' behaviour, dynamic radiology is dedicated to capturing functional anatomy. Dynamic ''quasi-continuous'' MRI data of lateral eye movements of a healthy volunteer were acquired using SE imaging sequence (Siemens, 1.5 T). By means of combined application of several image processing and visualization techniques, namely shaded and transparent surface reconstruction as well as direct volume rendering, 4D-visualization of the dynamics of the extra ocular muscles was possible. Though the original MRI data were quite coarse vascular structures could be recognized to some extent. For the sake of 4D-visualization of the optic nerve, the optic cavity was opened by axial clipping of the visualization. Superimposition of the original MRI slices to the visualization, either transparently or opaque, served as validation and comparison to conventional diagnosis. For facilitation of the analysis of the visualization results, stereoscopic rendering was rated as quite significant especially in the clinical setting. (orig.)

  1. 21 CFR 886.3340 - Extraocular orbital implant.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Extraocular orbital implant. 886.3340 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3340 Extraocular orbital implant. (a) Identification. An extraocular orbital implant is a nonabsorbable device intended to be implanted during scleral...

  2. Behandling af idiopatisk perifer facialisparese, også kaldet Bells parese

    DEFF Research Database (Denmark)

    Meyer, Martin Willy; Hahn, Christoffer Holst

    2013-01-01

    Bell's palsy is defined as an idiopathic peripheral facial nerve paralysis of sudden onset. It affects 11-40 persons per 100,000 per annum. Many patients recover without intervention; however, up to 30% have poor recovery of facial muscle control and experience facial disfigurement. The aim...... of this study was to make an overview of which pharmacological treatments have been used to improve outcomes. The available evidence from randomized controlled trials shows significant benefit from treating Bell's palsy with corticosteroids but shows no benefit from antivirals....

  3. Restrictive extraocular myopathy: A presenting feature of acromegaly

    Directory of Open Access Journals (Sweden)

    Steven Heireman

    2011-01-01

    Full Text Available A 45-year-old man presented with binocular diplopia in primary gaze for 1 year. Orthoptic evaluation showed 10-prism diopter right eye hypotropia and 6-prism diopter right eye esotropia. The elevation and abduction of the right eye were mechanically restricted. This was associated with systemic features suggestive of acromegaly. Magnetic resonance imaging (MRI of the brain demonstrated a pituitary macroadenoma. An elevated serum insulin-like growth factor I level and the failure of growth hormone suppression after an oral glucose load biochemically confirmed the diagnosis of acromegaly. Computed tomography (CT of the orbit demonstrated bilateral symmetrical enlargement of the medial rectus and inferior rectus muscle bellies. All tests regarding Graves-Basedow disease were negative. Although rare, diplopia due to a restrictive extraocular myopathy could be the presenting symptom of acromegaly.

  4. [Clinical observation of extraocular extension of choroidal melanoma].

    Science.gov (United States)

    Wang, Yi; Li, Yue-yue; Su, Fan; Xiao, Li-hua

    2011-03-01

    To evaluate the clinical features, diagnostic methods and treatment of extraocular extension of choroidal melanoma. It was a retrospective case series study. The records of 12 consecutive cases with extraocular extension of choroidal melanoma confirmed by pathologic examination were analyzed with special attention to the case histories, clinical manifestations, imaging findings, treatment and follow up results. Four patients were misdiagnosed as glaucoma. Another 4 patients were confirmed the diagnosis of melanoma and 3 of them received the operations of transscleral local resection. The common clinical manifestations included: impaired vision, exophthalmos, blepharoptosis, limited ocular motility, conjunctival hyperemia, and increased ocular or orbital pressure, etc. Characteristic sign was raised mass on the surface of sclera. All cases underwent orbital MRI preoperatively, 6 underwent ocular B-scan echography, and 6 underwent orbital CT scanning to evaluate for extraocular extension of tumor. Typical ultrasonography revealed the discontinued ocular wall and an intraocular mass with a continuous hypoechoic extraocular mass. In some cases the extraocular mass showed hypoechoic with medium echo area. CT scan showed a well-defined homogeneous intraconal mass connecting with intraocular lesion in 6 cases, which could infiltrate eye or optic nerve. The MR signal features of intraocular tumors with extraocular extension showed 4 patterns in all patients. The typical pattern was the tumor showed hyperintensity on T(1) and hypointensity on T(2)-weighted image. The maximum diameter of extraocular tumor was measured over 4 mm in 9 cases. MRI was useful for demonstrating multiple extraocular lesions, remote metastatic lesion or micro extraocular tumor, of which minimal diameter was 3 mm in our cases. Orbital exenteration was performed in 11 cases and ocular enucleation with excision of extraocular tumor was in 1 cases. Microscopic examination showed the epithelioid

  5. PROGRAMMED CELL DEATH IN EXTRAOCULAR MUSCLE TENDON/SCLERA PRECURSORS

    Science.gov (United States)

    AbstractPurpose: This study was designed to examine the occurrence of natural cell death in the periocular mesenchyme of mouse embryos. Methods: Vital staining with LysoTracker Red and Nile blue sulphate as well as terminal nick end labeling (TUNEL) were utiliz...

  6. Genetics Home Reference: congenital fibrosis of the extraocular muscles

    Science.gov (United States)

    ... Ophthalmol. 2008 Jan-Feb;23(1):3-8. doi: 10.1080/08820530701745181. Review. Citation on PubMed Lu S, Zhao C, Zhao K, Li N, Larsson C. Novel and recurrent KIF21A mutations in congenital fibrosis of the ... doi: 10.1001/archopht.126.3.388. Citation on ...

  7. A noninvasive electromagnetic perturbation approach to probe extraocular proprioception.

    Science.gov (United States)

    Bohlen, Martin O; Chen, Lewis L

    2016-02-01

    Extraocular proprioception has been shown to participate in spatial perception and binocular alignment. Yet the physiological approaches used to study this sensory signal are limited because proprioceptive signaling takes place at the same time as visuomotor signaling. It is critical to dissociate this sensory signal from other visuomotor events that accompany eye movements. We present a novel noninvasive and quantifiable method for probing extraocular proprioception independent of other visuomotor processing by attaching a rare-earth magnet to a real-time model eye and placing an electromagnet ball. It can be applied to produce the discrepancy between the intended and the executed eye movements, so that proprioceptive reafference signals are dissociated from corollary motor discharges and other visuomotor events. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  8. Extra-ocular retinoblastoma: about 12 cases followed at the Mohamed VI university hospital of Marrakech.

    Science.gov (United States)

    Leila, Soltani; Ibtissam, Hajji; Hafsa, Essafi; Abdeljalil, Moutaouakil

    2016-01-01

    Retinoblastoma is the most frequent childhood intraocular tumor. The aim of our study is to evaluate the clinical features and management of extra-ocular retinoblastoma in the Mohamed VI university hospital of Marrakech. Retrospective case series, the patient's records were reviewed for patient and tumor features, ocular management, histopathological findings, and patient survival. Over a period of three years, 35 eyes were diagnosed with retinoblastoma; 12 children (16 eyes) (46%) had extra-ocular retinoblastoma. Mean age was 27 months, 60% were males. Six cases had unilateral tumor, five bilateral and one case of trilateral retinoblastoma. There was no positive family history, proptosis was the mean mode of presentation (41,6%) followed by staphyloma (25%) orbital cellulitis (25%) and hyphema(8,3%). The median lag period was 18 months. On imaging and histopathological analysis, there was extrascleral involvement in 41.6%, involvement of orbital part of optic nerve (75%), of orbital muscles (50%) and eyelids in 16.6%. the surgical treatment included according to the degree of extension enucleation (75%) or exenteration (25%) associated to chemotherapy in all cases and one case of external beam radiation. There were 2 cases of orbital recurrence, one death and no metastases at 30 months follow-up.Orbital retinoblastoma still stands as a tall challenge requiring multi-modal and multi-disciplinary approach. Although the survival has increased over the last few years, lack of access to medical facilities, lack of education about the need for early medical attention and cultural resistance to enucleation continue to contribute to an epidemic of extra ocular disease at diagnosis in the developing world.

  9. Intraocular and extraocular hemorrhage associated with ligature release of non-valved glaucoma drainage implant

    Directory of Open Access Journals (Sweden)

    Michelle Go

    2017-04-01

    Conclusions and importance: This is the first report of a rare occurrence of intraocular and extraocular hemorrhage associated following spontaneous release of ligature of a non-valved glaucoma drainage implant. The presumed mechanism was sudden shallowing of the anterior chamber resulting in the tube irritating uveal vasculature. We do not have an explanation for the extraocular blood.

  10. Norrie disease: extraocular clinical manifestations in 56 patients.

    Science.gov (United States)

    Smith, Sharon E; Mullen, Thomas E; Graham, Dionne; Sims, Katherine B; Rehm, Heidi L

    2012-08-01

    Norrie disease (ND) is an X-linked recessive disorder characterized by congenital blindness, progressive sensorineural hearing loss and cognitive impairment. The ocular phenotype has been well described, while the extraocular manifestations of the disorder are not well understood. We present the data from the Norrie Disease Registry, which consists of 56 patients with detailed clinical histories and genotype data. This study represents the largest, detailed investigation into the phenotypic spectrum of ND to date and more importantly expands knowledge of the extraocular clinical manifestations. We identify several novel aspects of the syndrome that will improve the management of these patients. In particular, we expand our understanding of the neurologic manifestations in ND and identify a chronic seizure disorder in approximately 10% of all patients. In addition, details of the hearing phenotype are described including the median age of onset (12 years of age) and how genotype affects onset. Moreover, we find vascular disease to be a significant component of ND; and vascular health should be, in the future, a component of patient clinical care. In summary, the results expand our understanding of the phenotypic variability and genotypic heterogeneity in ND patients. Copyright © 2012 Wiley Periodicals, Inc.

  11. Syndrome of Continuous Muscle Fibre Activity

    African Journals Online (AJOL)

    1974-08-10

    Aug 10, 1974 ... acquired nature of the disorder. 5. Air. Med. l., 48, 1601 (1974). In 1961 the electromyographic and clinical findings of two ... Electromyography de- monstrates the state of continuous activity of the muscles. ... voluntary movements fatigue very rapidly. The extra-ocular. Fig. 3. Spontaneous motor unit activity.

  12. [A case of malignant lymphoma with a metastasis to the lateral rectus muscle].

    Science.gov (United States)

    Yokoji, H; Nakamura, S; Ikeda, T

    1997-06-01

    We reported a 75-year-old woman with malignant lymphoma who had a metastasis to the right lateral rectus muscle. She was well until two months earlier, when a tumor in the left thigh began to enlarge. Ten days before admission, she noticed medial deviation of the right eyeball. Neurological examination showed the right esotropia with isolated paralysis of the right lateral gaze. She denied double vision. MR imaging demonstrated a swelling of the right lateral rectus muscle. Gallium scanning revealed abnormal accumulation in the right orbit and the left thigh. The tumor in the left thigh was histologically diagnosed as non-Hodgkin's lymphoma, diffuse large cell type. Discrete extraocular muscle metastasis is rare and unreported for malignant lymphoma. Reported cases of breast and thyroid cancers metastatic to the extraocular muscles did not develop diplopia similar to our case. The rapid growth of metastases to the extraocular muscles produces a large visual axes deviation, therefore no diplopia may be elicited.

  13. The planarianTRPA1homolog mediates extraocular behavioral responses to near-ultraviolet light.

    Science.gov (United States)

    Birkholz, Taylor R; Beane, Wendy S

    2017-07-15

    Although light is most commonly thought of as a visual cue, many animals possess mechanisms to detect light outside of the eye for various functions, including predator avoidance, circadian rhythms, phototaxis and migration. Here we confirm that planarians (like Caenorhabditis elegans , leeches and Drosophila larvae) are capable of detecting and responding to light using extraocular photoreception. We found that, when either eyeless or decapitated worms were exposed to near-ultraviolet (near-UV) light, intense wild-type photophobic behaviors were still observed. Our data also revealed that behavioral responses to green wavelengths were mediated by ocular mechanisms, whereas near-UV responses were driven by extraocular mechanisms. As part of a candidate screen to uncover the genetic basis of extraocular photoreception in the planarian species Schmidtea mediterranea , we identified a potential role for a homolog of the transient receptor potential channel A1 ( TRPA1 ) in mediating behavioral responses to extraocular light cues. RNA interference (RNAi) to Smed-TrpA resulted in worms that lacked extraocular photophobic responses to near-UV light, a mechanism previously only identified in Drosophila These data show that the planarian TRPA1 homolog is required for planarian extraocular-light avoidance and may represent a potential ancestral function of this gene. TRPA1 is an evolutionarily conserved detector of temperature and chemical irritants, including reactive oxygen species that are byproducts of UV-light exposure. Our results suggest that planarians possess extraocular photoreception and display an unconventional TRPA1-mediated photophobic response to near-UV light. © 2017. Published by The Company of Biologists Ltd.

  14. The planarian TRPA1 homolog mediates extraocular behavioral responses to near-ultraviolet light

    Science.gov (United States)

    Birkholz, Taylor R.

    2017-01-01

    ABSTRACT Although light is most commonly thought of as a visual cue, many animals possess mechanisms to detect light outside of the eye for various functions, including predator avoidance, circadian rhythms, phototaxis and migration. Here we confirm that planarians (like Caenorhabditis elegans, leeches and Drosophila larvae) are capable of detecting and responding to light using extraocular photoreception. We found that, when either eyeless or decapitated worms were exposed to near-ultraviolet (near-UV) light, intense wild-type photophobic behaviors were still observed. Our data also revealed that behavioral responses to green wavelengths were mediated by ocular mechanisms, whereas near-UV responses were driven by extraocular mechanisms. As part of a candidate screen to uncover the genetic basis of extraocular photoreception in the planarian species Schmidtea mediterranea, we identified a potential role for a homolog of the transient receptor potential channel A1 (TRPA1) in mediating behavioral responses to extraocular light cues. RNA interference (RNAi) to Smed-TrpA resulted in worms that lacked extraocular photophobic responses to near-UV light, a mechanism previously only identified in Drosophila. These data show that the planarian TRPA1 homolog is required for planarian extraocular-light avoidance and may represent a potential ancestral function of this gene. TRPA1 is an evolutionarily conserved detector of temperature and chemical irritants, including reactive oxygen species that are byproducts of UV-light exposure. Our results suggest that planarians possess extraocular photoreception and display an unconventional TRPA1-mediated photophobic response to near-UV light. PMID:28495872

  15. The predictive factors of diplopia and extraocular movement limitations in isolated pure blow-out fracture.

    Science.gov (United States)

    Kasaee, Abolfazl; Mirmohammadsadeghi, Arash; Kazemnezhad, Fatemeh; Eshraghi, Bahram; Akbari, Mohammad Reza

    2017-03-01

    To evaluate the predictive factors for development of diplopia and extraocular muscle movement (EOM) limitations in the patients with isolated pure blow-out fracture. One hundred thirty-two patients with isolated pure blow-out fracture were included. The diagnosis was done with computed tomography scan. Possible predictive factors were analyzed with logistic regression. The cases that underwent surgery were assigned in the surgical group, and other cases were assigned in the non-surgical group. Receiver operating characteristic (ROC) curve analysis was used in the surgical group to evaluate the power of time interval from trauma to the surgery to predict persistence of 6 months postoperative diplopia and EOM limitation. At the first visit, 45 of 60 cases (75%) in the surgical group and 15 of 72 cases (20.8%) in the nonsurgical group had diplopia. After 6 months follow-up, 7 cases (11.7%) in the surgical group and 1 case (1.4%) in the nonsurgical group had persistent diplopia. Type of fracture was significantly associated with first visit diplopia (P = 0.01) and EOM limitations (P = 0.06). In the surgical group, type of fracture (P = 0.02 for both) and time interval from trauma to the surgery (P = 0.006 and 0.004, respectively) were significantly associated with 1 month diplopia and EOM limitations. Only time interval from trauma to the surgery (P = 0.04) was significantly associated with 3 months EOM limitation. In the ROC curve analysis, if the surgery was done before 4.5 (sensitivity = 87.5% and specificity = 61.3%) and 7.5 (sensitivity = 87.5% and specificity = 66.9%) days, risk of 6 months postoperative diplopia and EOM limitation was reduced, respectively. In the early postoperative period, a higher rate of diplopia was observed in the patients with combined inferior and medial wall fractures and longer time intervals from trauma to the surgery. The best time for blow-out fracture surgery was within 4.5 days after the trauma.

  16. Extraocular surgery for implantation of an active subretinal visual prosthesis with external connections: feasibility and outcome in seven patients.

    Science.gov (United States)

    Besch, D; Sachs, H; Szurman, P; Gülicher, D; Wilke, R; Reinert, S; Zrenner, E; Bartz-Schmidt, K U; Gekeler, F

    2008-10-01

    Due to low energy levels in microphotodiode-based subretinal visual prostheses, an external power supply is mandatory. We report on the surgical feasibility and the functional outcome of the extraocular part of an approach to connect a subretinal prosthesis to an extracorporeal connector in the retro-auricular space via a trans-scleral, transchoroidal cable. Seven volunteers with retinitis pigmentosa received an active subretinal implant; energy was supplied by gold wires on a trans-sclerally, transchoroidally implanted polyimide foil leading to the lateral orbital rim where it was fixated and connected to a silicone cable. The cable was implanted subperiostally beneath the temporal muscle using a trocar to the retro-auricular space where it penetrated the skin for connection to a stimulator. To avoid subretinal movement of the implant, three tension relief points have been introduced. All implantations were performed as planned without complications, and no serious adverse events occurred in the postoperative period. Fixation of the implants was stable throughout the entire study duration of 4 weeks; permanent skin penetration proved to be uncomplicated. Motility was minimally restricted in downgaze and ab-/adduction. Explantation was uneventful. The above-described procedure provides a method for stable fixation of a subretinal device with a trans-scleral, transchoroidal cable connection to an extracorporeal connector.

  17. Choroidal malignant melanoma with no extraocular extension presenting as orbital cellulitis.

    Science.gov (United States)

    Nalcaci, Serhad; Palamar, Melis; Yaman, Banu; Akalin, Taner; Mentes, Jale

    2016-10-01

    This report describes a patient with choroidal malignant melanoma presenting as orbital cellulitis without extraocular tumor extension. It is an interventional case report with histopathologic correlation. A 68-year-old male presented with a 3-day history of painful hyperemia and swelling in the right eye. The examination showed edematous eyelids, mechanical ptosis and chemosis with conjunctival injection. B-scan ultrasonography showed a mass with medium level echogenicity that filled the vitreous cavity. Magnetic resonance imaging showed a solid choroidal mass with hemorrhagic and inflammatory changes with no obvious extraocular extension. Due to these suggestive findings of choroidal melanoma the right eye was enucleated. A spindle cell choroidal melanoma including intense pigmentation and necrosis was confirmed by histopathological examination. Although rare; choroidal melanoma may present as orbital cellulitis, particularly when the tumor is necrotic.

  18. An application of dynamic CT for diagnosis of abnormal external ocular muscle movement

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Kazumi; Ogura, Yuuko; Takeshita, Gen; Koga, Sukehiko (Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine); Katada, Kazuhiro; Anno, Hirofumi

    1993-10-01

    To evaluate the movements of retrobulbar structures radiologically, we have developed a new technique called external ocular muscle movement CT (EOM CT), in which dynamic CT scanning is performed while the patient performs controlled eye movements. This new technique was applied in one volunteer and 72 patients with external ophthalmoplegia due to orbital mass lesion, hyperthyroid ophthalmopathy, blowout fracture, and other retrobulbar lesions. EOM CT permits the assessment of extraocular muscle contraction in cases of blowout fracture, the evaluation of muscular contraction in hypertrophy of the extraocular muscles, and the diagnosis of adhesions between the extraocular muscles and intraorbital masses. Radiation dose to the lens from EOM CT was measured using a phantom and TLD, and was compared with that of conventional CT scanning with a 5 mm slice thickness. The dose to the lens from EOM CT was three times higher than that for conventional CT in axial scanning, but in the coronal section of the retrobulbar region, the dose to the lens from EOM CT decreases to one twelfth of that of conventional CT. EOM CT promises to be a powerful modality for functional evaluation of the extraocular muscles and other retrobulbar structures. (author).

  19. Densities of orbital fat and extraocular muscles in graves orbitopathy patients and controls

    NARCIS (Netherlands)

    Regensburg, Noortje I.; Wiersinga, Wilmar M.; Berendschot, Tos T. J. M.; Saeed, Peerooz; Mourits, Maarten P.

    2011-01-01

    To investigate CT densities of orbital soft tissue volumes in patients with Graves orbitopathy (GO) and to compare these with the densities of controls. Observational case series. Of 95 patients with GO and 150 controls, soft tissue volumes, mean densities, and ratios of fat volume to orbital volume

  20. Extraocular light via the ear canal does not acutely affect human circadian physiology, alertness and psychomotor vigilance performance.

    Science.gov (United States)

    Bromundt, Vivien; Frey, Sylvia; Odermatt, Jonas; Cajochen, Christian

    2014-04-01

    We aimed at testing potential effects of extraocular bright light via the ear canals on human evening melatonin levels, sleepiness and psychomotor vigilance performance. Twenty healthy young men and women (10/10) kept a regular sleep-wake cycle during the 2-week study. The volunteers reported to the laboratory on three evenings, 2 h 15 min before usual bedtime, on average at 21:45 h. They were exposed to three different light conditions, each lasting for 12 min: extraocular bright light via the ear canal, ocular bright light as an active control condition and a control condition (extraocular light therapy device with completely blacked out LEDs). The timing of exposure was on average from 22:48 to 23:00 h. During the 2-h protocol, saliva samples were collected in 15-min intervals for melatonin assays along with subjective sleepiness ratings, and the volunteers performed a 10-min visual psychomotor vigilance task (PVT) prior to and after each light condition. The evening melatonin rise was significantly attenuated after the 12-min ocular bright light exposure while no significant changes were observed after the extraocular bright light and sham light condition. Subjective sleepiness decreased immediately over a short period only after ocular light exposure. No significant differences were observed for mean reaction times and the number of lapses for the PVT between the three light conditions. We conclude that extraocular transcranial light exposure in the late evening does not suppress melatonin, reduce subjective sleepiness or improve performance, and therefore, does not acutely influence the human circadian timing system.

  1. Inferior oblique muscle paresis as a sign of myasthenia gravis.

    Science.gov (United States)

    Almog, Yehoshua; Ben-David, Merav; Nemet, Arie Y

    2016-03-01

    Myasthenia gravis may affect any of the six extra-ocular muscles, masquerading as any type of ocular motor pathology. The frequency of involvement of each muscle is not well established in the medical literature. This study was designed to determine whether a specific muscle or combination of muscles tends to be predominantly affected. This retrospective review included 30 patients with a clinical diagnosis of myasthenia gravis who had extra-ocular muscle involvement with diplopia at presentation. The diagnosis was confirmed by at least one of the following tests: Tensilon test, acetylcholine receptor antibodies, thymoma on chest CT scan, or suggestive electromyography. Frequency of involvement of each muscle in this cohort was inferior oblique 19 (63.3%), lateral rectus nine (30%), superior rectus four (13.3%), inferior rectus six (20%), medial rectus four (13.3%), and superior oblique three (10%). The inferior oblique was involved more often than any other muscle (pgravis can be difficult, because the disease may mimic every pupil-sparing pattern of ocular misalignment. In addition diplopia caused by paresis of the inferior oblique muscle is rarely encountered (other than as a part of oculomotor nerve palsy). Hence, when a patient presents with vertical diplopia resulting from an isolated inferior oblique palsy, myasthenic etiology should be highly suspected. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Sushruta in 600 B.C. introduced extraocular expulsion of lens material.

    Science.gov (United States)

    Grzybowski, Andrzej; Ascaso, Francisco J

    2014-03-01

    It is generally accepted that Jacques Daviel introduced in the 18th century the extracapsular technique of extraction of the lens while the couching method of cataract operation had already been practiced since ancient times. Present study analyses the first known cataract surgery description in three translations into English from the original Sanskrit Sushruta textbook and all the available literature on the subject. We found evidences that some sort of extraocular expulsion of lens material through a limbal puncture (paracentesis) was described by the Indian surgeon. Nevertheless, this incision cannot be considered as a classic extracapsular procedure because it was not large enough to allow the extraction of the entire lens. © 2013 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  3. Extraocular motoneurons of the adult rat show higher levels of vascular endothelial growth factor and its receptor Flk-1 than other cranial motoneurons.

    Directory of Open Access Journals (Sweden)

    Silvia Silva-Hucha

    Full Text Available Recent studies show a relationship between the deficit of vascular endothelial growth factor (VEGF and motoneuronal degeneration, such as that occurring in amyotrophic lateral sclerosis (ALS. VEGF delivery protects motoneurons from cell death and delayed neurodegeneration in animal models of ALS. Strikingly, extraocular motoneurons show lesser vulnerability to neurodegeneration in ALS compared to other cranial or spinal motoneurons. Therefore, the present study investigates possible differences in VEGF and its main receptor VEGFR-2 or Flk-1 between extraocular and non-extraocular brainstem motoneurons. We performed immunohistochemistry and Western blot to determine the presence of VEGF and Flk-1 in rat motoneurons located in the three extraocular motor nuclei (abducens, trochlear and oculomotor and to compare it to that observed in two other brainstem nuclei (hypoglossal and facial that are vulnerable to degeneration. Extraocular motoneurons presented higher amounts of VEGF and its receptor Flk-1 than other brainstem motoneurons, and thus these molecules could be participating in their higher resistance to neurodegeneration. In conclusion, we hypothesize that differences in VEGF availability and signaling could be a contributing factor to the different susceptibility of extraocular motoneurons, when compared with other motoneurons, in neurodegenerative diseases.

  4. Complete inferior rectus muscle transection secondary to orbital blowout fracture.

    Science.gov (United States)

    Carrere, Jonathan M; Lewis, Kyle T

    2018-01-05

    Complete extraocular muscle transection is uncommon in the setting of blunt trauma. We report a case of a 53-year-old male that developed diplopia after hitting his face directly on a concrete slab after a fall. On examination, he had a right hypertropia with a complete infraduction deficit. A CT scan of the face showed an orbital floor blowout fracture with complete inferior rectus transection. On surgical exploration, the distal and proximal ends of the muscle were identified and sutured together, and the floor fracture was repaired. At his post-operative visits, the patient had a persistent infraduction deficit, but subjectively had improved diplopia.

  5. Extraocular Source of Oligodendrocytes Contribute to Retinal Myelination and Optokinetic Responses in Zebrafish.

    Science.gov (United States)

    Tian, Chen; Zou, Suqi; Hu, Bing

    2016-04-01

    There is no myelination in most mammalian retinas, and if it does happen, it is always accompanied by eye disease. Although lower vertebrates are born with myelin, the precise temporal dynamics of myelination in which oligodendrocytes (OLs) are involved, the origin of OLs, their behaviors in myelination, and their function in retinas have not yet been clearly elaborated. Therefore, we focus on these aspects to study the oligodendrocytes and myelin sheath in the zebrafish retina. Retinal whole mount, immunohistochemistry, and optic nerve retrograde labeling were performed to monitor the myelination. Taking advantage of whole eye eversion and transplantation techniques, we studied the retinal origin of OLs. By optic nerve transplantation, we can observe single OLs in zebrafish retina. The optokinetic reflex (OKR) behavior test and the lysophosphatidylcholine (LPC)-induced retinal demyelination model were used to test the function of the myelin. First, we demonstrated that myelination starts at 28 dpf in zebrafish retinas. Second, we directly proved that all the OLs in zebrafish retinas migrated from the optic nerve rather than from a domestic source. Third, we found that compared with adult OLs, younger OLs tend to generate longer but a fewer number of internodes. Finally, we found that the myelin in zebrafish eyes is functionally relevant to the elegant OKR. Our data suggest that the extraocular source of OLs first appeared at 28 dpf in zebrafish retina and then gradually developed with age, which contribute to optokinetic responses.

  6. Ocular and extraocular expression of opsins in the rhopalium of Tripedalia cystophora (Cnidaria: Cubozoa.

    Directory of Open Access Journals (Sweden)

    Jan Bielecki

    Full Text Available A growing body of work on the neuroethology of cubozoans is based largely on the capabilities of the photoreceptive tissues, and it is important to determine the molecular basis of their light sensitivity. The cubozoans rely on 24 special purpose eyes to extract specific information from a complex visual scene to guide their behavior in the habitat. The lens eyes are the most studied photoreceptive structures, and the phototransduction in the photoreceptor cells is based on light sensitive opsin molecules. Opsins are photosensitive transmembrane proteins associated with photoreceptors in eyes, and the amino acid sequence of the opsins determines the spectral properties of the photoreceptors. Here we show that two distinct opsins (Tripedalia cystophora-lens eye expressed opsin and Tripedalia cystophora-neuropil expressed opsin, or Tc-leo and Tc-neo are expressed in the Tripedalia cystophora rhopalium. Quantitative PCR determined the level of expression of the two opsins, and we found Tc-leo to have a higher amount of expression than Tc-neo. In situ hybridization located Tc-leo expression in the retinal photoreceptors of the lens eyes where the opsin is involved in image formation. Tc-neo is expressed in a confined part of the neuropil and is probably involved in extraocular light sensation, presumably in relation to diurnal activity.

  7. Isolated abscess in superior rectus muscle in a child

    Directory of Open Access Journals (Sweden)

    Sushank Ashok Bhalerao

    2015-01-01

    Full Text Available Pyomyositis is a primary bacterial infection of striated muscles nearly always caused by Staphylococcus aureus. Development of the intramuscular abscess involving the extra-ocular muscles (EOMs remains an extremely rare process. We herein present a case of isolated EOM pyomyositis involving superior rectus muscle in a 2-year male child who was referred with complaints of swelling in left eye (LE and inability to open LE since last 1-month. Orbital computed tomography (CT scan showed a well-defined, hypo-dense, peripheral rim-enhancing lesion in relation to left superior rectus muscle suggestive of left superior rectus abscess. The abscess was drained through skin approach. We concluded that pyomyositis of EOM should be considered in any patient presenting with acute onset of orbital inflammation and characteristic CT or magnetic resonance imaging features. Management consists of incision and drainage coupled with antibiotic therapy.

  8. 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.

  9. Displacement of rectus muscle pulleys by torsional muscle surgery for treatment of full macular translocation-induced incyclotropia.

    Science.gov (United States)

    Kono, Reika; Ohtsuki, Hiroshi; Okanobu, Hirotaka; Kinugasa, Kazushi

    2005-07-01

    To elucidate the coronal plane locations of extraocular muscle (EOM) pulleys following torsional muscle surgery. Case report. A 76-year-old man underwent advancement of the anterior part of the inferior oblique muscle to treat full macular translocation-induced incyclotropia. Postoperatively, magnetic resonance imaging was used to obtain contiguous, 2-mm-thick coronal orbital images. On each MRI image, the cross-sectional area and center of the EOM was computed, and all rectus EOM positions were translated to the coordinate origin at the area centroid of the globe at the level of pulleys. The superior rectus pulley was displaced temporally, and the lateral rectus pulley was displaced inferiorly more than 2 SD from normal subjects. Coronal plane locations of EOM pulleys of the ipsilateral eye showed extorsion compared with that of the contralesional eye. Torsional muscle surgery causes an extorsional shift of the superior and lateral rectus pulleys.

  10. The oculomotor system of decapod cephalopods: eye muscles, eye muscle nerves, and the oculomotor neurons in the central nervous system.

    Science.gov (United States)

    Budelmann, B U; Young, J Z

    1993-04-29

    Fourteen extraocular eye muscles are described in the decapods Loligo and Sepioteuthis, and thirteen in Sepia; they are supplied by four eye muscle nerves. The main action of most of the muscles is a linear movement of the eyeball, only three muscles produce strong rotations. The arrangement, innervation and action of the decapod eye muscles are compared with those of the seven eye muscles and seven eye muscle nerves in Octopus. The extra muscles in decapods are attached to the anterior and superior faces of the eyes. At least, the anterior muscles, and presumably also the superior muscles, are concerned with convergent eye movements for binocular vision during fixation and capture of prey by the tentacles. The remaining muscles are rather similar in the two cephalopod groups. In decapods, the anterior muscles include conjunctive muscles; these cross the midline and each presumably moves both eyes at the same time during fixation. In the squids Loligo and Sepioteuthis there is an additional superior conjunctive muscle of perhaps similar function. Some of the anterior muscles are associated with a narrow moveable plate, the trochlear cartilage; it is attached to the eyeball by trochlear membranes. Centripetal cobalt fillings showed that all four eye muscle nerves have fibres that originate from somata in the ipsilateral anterior lateral pedal lobe, which is the oculomotor centre. The somata of the individual nerves show different but overlapping distributions. Bundles of small presumably afferent fibres were seen in two of the four nerves. They do not enter the anterior lateral pedal lobe but run to the ventral magnocellular lobe; some afferent fibres enter the brachio-palliovisceral connective and run perhaps as far as the palliovisceral lobe.

  11. Distal mdx muscle groups exhibiting up-regulation of utrophin and rescue of dystrophin-associated glycoproteins exemplify a protected phenotype in muscular dystrophy

    Science.gov (United States)

    Dowling, Paul; Culligan, Kevin; Ohlendieck, Kay

    2002-02-01

    Unique unaffected skeletal muscle fibres, unlike necrotic torso and limb muscles, may pave the way for a more detailed understanding of the molecular pathogenesis of inherited neuromuscular disorders and help to develop new treatment strategies for muscular dystrophies. The sparing of extraocular muscle in Duchenne muscular dystrophy is mostly attributed to the special protective properties of extremely fast-twitching small-diameter fibres, but here we show that distal muscles also represent a particular phenotype that is more resistant to necrosis. Immunoblot analysis of membranes isolated from the well established dystrophic animal model mdx shows that, in contrast to dystrophic limb muscles, the toe musculature exhibits an up-regulation of the autosomal dystrophin homologue utrophin and a concomitant rescue of dystrophin-associated glycoproteins. Thus distal mdx muscle groups provide a cellular system that naturally avoids myofibre degeneration which might be useful in the search for naturally occurring compensatory mechanisms in inherited skeletal muscle diseases.

  12. The posterior cricoarytenoid muscle is spared from MuRF1-mediated muscle atrophy in mice with acute lung injury.

    Directory of Open Access Journals (Sweden)

    D Clark Files

    Full Text Available Skeletal muscle wasting in acute lung injury (ALI patients increases the morbidity and mortality associated with this critical illness. The contribution of laryngeal muscle wasting to these outcomes is unknown, though voice impairments and aspiration are common in intensive care unit (ICU survivors. We evaluated the intrinsic laryngeal abductor (PCA, posterior cricoarytenoid, adductor (CT, cricothyroid and limb (EDL, extensor digitorum longus muscles in a mouse model of ALI.Escherichia coli lipopolysaccharides were instilled into the lungs of adult male C57Bl6J mice (ALI mice. Limb and intrinsic laryngeal muscles were analyzed for fiber size, type, protein expression and myosin heavy chain (MyHC composition by SDS-PAGE and mass spectroscopy.Marked muscle atrophy occurred in the CT and EDL muscles, while the PCA was spared. The E3 ubiquitin ligase muscle ring finger-1 protein (MuRF1, a known mediator of limb muscle atrophy in this model, was upregulated in the CT and EDL, but not in the PCA. Genetic inhibition of MuRF1 protected the CT and EDL from ALI-induced muscle atrophy. MyHC-Extraocular (MyHC-EO comprised 27% of the total MyHC in the PCA, distributed as hybrid fibers throughout 72% of PCA muscle fibers.The vocal cord abductor (PCA contains a large proportion of fibers expressing MyHC-EO and is spared from muscle atrophy in ALI mice. The lack of MuRF1 expression in the PCA suggests a previously unrecognized mechanism whereby this muscle is spared from atrophy. Atrophy of the vocal cord adductor (CT may contribute to the impaired voice and increased aspiration observed in ICU survivors. Further evaluation of the sparing of muscles involved in systemic wasting diseases may lead to potential therapeutic targets for these illnesses.

  13. Aggressive Extraocular Sebaceous Carcinoma of the Scalp Involving the Brain in a Patient With Muir-Torre Syndrome.

    Science.gov (United States)

    Hadravsky, Ladislav; Kazakov, Dmitry V; Stehlik, Jan; Michal, Michal; Curik, Romuald; Krupa, Petr; Skalova, Alena; Kacerovska, Denisa

    2016-08-01

    This article reports an unusual case of aggressive extraocular sebaceous carcinoma located on the scalp with subsequent usurpation of the bone and penetrating through the bone and meninges to the brain in a 56-year-old man affected by Muir-Torre syndrome. Microscopically, the sebaceous neoplasm was located in the middle to deep dermis without any connection to the epidermis and showed a multinodular growth with neoplastic nodules with a central comedo-type necrosis separated from each other by fibrovascular stroma. The nodules were composed of varying proportions of mature sebaceous cells and atypical basaloid cells with high degree of atypia, including high nuclear/cytoplasmic ratio, nuclear pleomorphism, macronucleoli, atypical mitoses, and necrosis. The neoplasm was totally removed. Histopathological examinations of the recurrent lesion showed identical morphological features and, in addition, signs of the tumors growing through the periosteum were noted. In the final excision specimen, both the dura mater and the brain tissue were infiltrated by the sebaceous carcinoma. The diagnosis of Muir-Torre syndrome was confirmed by molecular genetic investigation that revealed an identical germline mutation in MSH2 gene in several family members, some of whom had colorectal tumors.

  14. 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 ... It is a very common muscle problem. Muscle cramps can be caused by nerves that malfunction. Sometimes ...

  15. 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.

  16. Differential RNA Expression Profile of Skeletal Muscle Induced by Experimental Autoimmune Myasthenia Gravis in Rats

    Directory of Open Access Journals (Sweden)

    Henry Kaminski

    2016-11-01

    Full Text Available The differential susceptibility of skeletal muscle by myasthenia gravis (MG is not well understood. We utilized RNA expression profiling of extraocular muscle (EOM, diaphragm (DIA, and extensor digitorum (EDL of rats with experimental autoimmune MG (EAMG to evaluate the hypothesis that muscles respond differentially to injury produced by EAMG. EAMG was induced in female Lewis rats by immunization with acetylcholine receptor purified from the electric organ of the Torpedo. Six weeks later after rats had developed weakness and serum antibodies directed against the AChR, animals underwent euthanasia and RNA profiling performed on DIA, EDL, and EOM. Profiling results were validated by qPCR. Across the three muscles between the experiment and control groups, three hundred and fifty-nine probes (1.16% with greater than 2 fold changes in expression in 7 of 9 series pairwise comparisons from 31,090 probes were identified with approximately two-thirds being increased. The three muscles shared 16 genes with increased expression and 6 reduced expression. Functional annotation demonstrated that these common expression changes fell predominantly into categories of metabolism, stress response, and signaling. Evaluation of specific gene function indicated that EAMG led to a change to oxidative metabolism. Genes related to muscle regeneration and suppression of immune response were activated. Evidence of a differential immune response among muscles was not evident. Each muscle had a distinct RNA profile but with commonality in gene categories expressed that are focused on muscle repair, moderation of inflammation, and oxidative metabolism.

  17. Muscle pain

    African Journals Online (AJOL)

    Key Summary Points. • Muscle pain, known as myalgia, can be in one targeted area or across many muscles, occurring with overexertion or overuse of these muscles. • Pain can be classified as acute or chronic pain and further categorized as nociceptive or neuropathic. • Causes of muscle pain include stress, physical ...

  18. Skeletal Muscle Channelopathies: Rare Disorders with Common Pediatric Symptoms.

    Science.gov (United States)

    Matthews, Emma; Silwal, Arpana; Sud, Richa; Hanna, Michael G; Manzur, Adnan Y; Muntoni, Francesco; Munot, Pinki

    2017-09-01

    To ascertain the presenting symptoms of children with skeletal muscle channelopathies to promote early diagnosis and treatment. Retrospective case review of 38 children with a skeletal muscle channelopathy attending the specialist pediatric neuromuscular service at Great Ormond Street Hospital over a 15-year period. Gait disorder and leg cramps are a frequent presentation of myotonic disorders (19 of 29). Strabismus or extraocular myotonia (9 of 19) and respiratory and/or bulbar symptoms (11 of 19) are common among those with sodium channelopathy. Neonatal hypotonia was observed in periodic paralysis. Scoliosis and/or contractures were demonstrated in 6 of 38 children. School attendance or ability to engage fully in all activities was often limited (25 of 38). Children with skeletal muscle channelopathies frequently display symptoms that are uncommon in adult disease. Any child presenting with abnormal gait, leg cramps, or strabismus, especially if intermittent, should prompt examination for myotonia. Those with sodium channel disease should be monitored for respiratory or bulbar complications. Neonatal hypotonia can herald periodic paralysis. Early diagnosis is essential for children to reach their full educational potential. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Expression and identification of 10 sarcomeric MyHC isoforms in human skeletal muscles of different embryological origin. Diversity and similarity in mammalian species.

    Science.gov (United States)

    Mascarello, Francesco; Toniolo, Luana; Cancellara, Pasqua; Reggiani, Carlo; Maccatrozzo, Lisa

    2016-09-01

    In the mammalian genome, among myosin heavy chain (MyHC) isoforms a family can be identified as sarcomeric based on their molecular structure which allows thick filament formation. In this study we aimed to assess the expression of the 10 sarcomeric isoforms in human skeletal muscles, adopting this species as a reference for comparison with all other mammalian species. To this aim, we set up the condition for quantitative Real Time PCR assay to detect and quantify MyHC mRNA expression in a wide variety of human muscles from somitic, presomitic and preotic origin. Specific patterns of expression of the following genes MYH1, MYH2, MYH3, MYH4, MYH6, MYH7, MYH8, MYH13, MYH14/7b and MYH15 were demonstrated in various muscle samples. On the same muscle samples which were analysed for mRNA expression, the corresponding MyHC proteins were studied with SDS PAGE and Western blot. The mRNA-protein comparison allowed the identification of 10 distinct proteins based on the electrophoretic migration rate. Three groups were formed based on the migration rate: fast migrating comprising beta/slow/1, alpha cardiac and fast 2B, slow migrating comprising fast 2X, fast 2A and two developmental isoforms (NEO and EMB), intermediate migrating comprising EO MyHC, slow B (product of MYH15), slow tonic (product of MYH14/7b). Of special interest was the demonstration of a protein band corresponding to 2B-MyHC in laryngeal muscles and the finding that all 10 isoforms are expressed in extraocular muscles. These latter muscles are the unique localization for extraocular, slow B (product of MYH15) and slow tonic (product of MYH14/7b). Copyright © 2016 Elsevier GmbH. All rights reserved.

  20. Short-term effects of botulinum toxin on the lateral rectus muscle of the cat.

    Science.gov (United States)

    Dimitrova, Diana M; Shall, Mary S; Goldberg, Stephen J

    2002-12-01

    Botulinum toxin type A (BTX) is often used as an alternative to surgery for the treatment of strabismus and many other motor or cosmetic problems. Although numerous studies established BTX as a powerful transmission-blocking agent at the neuromuscular junction, no evaluation of extraocular muscle (EOM) contractile properties after administration of BTX exists. Some anatomical studies on EOM fiber types suggested a long-term preferential effect of BTX on orbital layer, singly innervated muscle fibers. In this study, we examined the short-term effects of BTX on the contractile properties of normal lateral rectus muscle to determine the functional effect of BTX on muscle-force output over time. Measurements of muscle tension and the corresponding EMG evoked by stimulation of nerve VI were made hourly for up to 18 h following BTX administration. An intramuscular BTX injection of 2 U caused a dramatic decrease in maximum twitch and tetanic tension of the muscle in response to different frequencies of stimulation. This suppression developed gradually over time, with a concomitant reduction of EMG amplitude. No significant changes in muscle-speed-related characteristics (e.g., twitch contraction time, fusion frequency) were found. The results suggest a functional effect of BTX on all muscle fiber types, although, with the dose used, we did not observe complete muscle paralysis within the time of recording. The time course of muscle tension suppression by BTX also was frequency dependent, with the lower stimulation frequencies being more affected, suggesting that implementation of higher frequencies could still produce adequate eye movements.

  1. Muscle biopsy.

    Science.gov (United States)

    Meola, G; Bugiardini, E; Cardani, R

    2012-04-01

    Muscle biopsy is required to provide a definitive diagnosis in many neuromuscular disorders. It can be performed through an open or needle technique under local anesthesia. The major limitations of the needle biopsy technique are the sample size, which is smaller than that obtained with open biopsy, and the impossibility of direct visualization of the sampling site. However, needle biopsy is a less invasive procedure than open biopsy and is particularly indicated for diagnosis of neuromuscular disease in infancy and childhood. The biopsied muscle should be one affected by the disease but not be too weak or too atrophic. Usually, in case of proximal muscle involvement, the quadriceps and the biceps are biopsied, while under suspicion of mitochondrial disorder, the deltoid is preferred. The samples must be immediately frozen or fixed after excision to prevent loss of enzymatic reactivity, DNA depletion or RNA degradation. A battery of stainings is performed on muscle sections from every frozen muscle biopsy arriving in the pathology laboratory. Histological, histochemical, and histoenzymatic stainings are performed to evaluate fiber atrophy, morphological, and structural changes and metabolic disorders. Moreover, immunohistochemistry and Western blotting analysis may be used for expression analysis of muscle proteins to obtain a specific diagnosis. There are myopathies that do not need muscle biopsy since a genetic test performed on a blood sample is enough for definitive diagnosis. Muscle biopsy is a useful technique which can make an enormous contribution in the field of neuromuscular disorders but should be considered and interpreted together with the patient's family and clinical history.

  2. Getting Muscles

    Science.gov (United States)

    ... re thinking about aren't possible for kids. Superheroes, of course, aren't real, and professional athletes ... can make you stronger. Why? Because you're using your muscles when you do it. Eat Strong ...

  3. Muscle cramps

    Science.gov (United States)

    ... the lower leg/calf Back of the thigh (hamstrings) Front of the thigh (quadriceps) Cramps in the ... Names Cramps - muscle Images Chest stretch Groin stretch Hamstring stretch Hip stretch Thigh stretch Triceps stretch References ...

  4. Referred pain elicited by manual exploration of the lateral rectus muscle in chronic tension-type headache.

    Science.gov (United States)

    Fernández-de-Las-Peñas, César; Cuadrado, Maria Luz; Gerwin, Robert D; Pareja, Juan A

    2009-01-01

    To analyze the presence of referred pain elicited by manual examination of the lateral rectus muscle in patients with chronic tension-type headache (CTTH). A case-control blinded study. It has been found previously that the manual examination of the superior oblique muscle can elicit referred pain to the head in some patients with migraine or tension-type headache. However, a referred pain from other extraocular muscles has not been investigated. Fifteen patients with CTTH and 15 healthy subjects without headache history were included. A blinded assessor performed a manual examination focused on the search for myofascial trigger points (TrPs) in the right and left lateral rectus muscles. TrP diagnosis was made when there was referred pain evoked by maintained pressure on the lateral corner of the orbit (anatomical projection of the lateral rectus muscle) for 20 seconds, and increased referred pain while the subject maintained a medial gaze on the corresponding side (active stretching of the muscle) for 15 seconds. On each side, a 10-point numerical pain rate scale was used to assess the intensity of referred pain at both stages of the examination. Ten patients with CTTH (66.6%) had referred pain that satisfied TrPs diagnostic criteria, while only one healthy control (0.07%) reported referred pain upon the examination of the lateral rectus muscles (P < 0.001). The elicited referred pain was perceived as a deep ache located at the supraorbital region or the homolateral forehead. Pain was evoked on both sides in all subjects with TrPs, with no difference in pain intensity between the right and the left. The average pain intensity was significantly greater in the patient group (P < 0.001). All CTTH patients with referred pain recognized it as the frontal pain that they usually experienced during their headache attacks, which was consistent with active TrPs. In some patients with CTTH, the manual examination of lateral rectus muscle TrPs elicits a referred pain that

  5. Prognostic Factors of Orbital Fractures with Muscle Incarceration

    Directory of Open Access Journals (Sweden)

    Seung Chan Lee

    2017-09-01

    Full Text Available Background Among the various signs and symptoms of orbital fractures, certain clinical findings warrant immediate surgical exploration, including gaze restriction, computed tomographic (CT evidence of entrapment, and prolonged oculocardiac reflex. Despite proper surgical reconstruction, prolonged complications such as diplopia and gaze restriction can occur. This article evaluated the prognostic factors associated with prolonged complications of orbital fractures with muscle incarceration. Methods The medical records of 37 patients (37 orbits with an orbital fracture with muscle incarceration from January 2001 to January 2015 were reviewed. The presence of Incarcerated muscle was confirmed via CT, as well as by intraoperative findings. Various factors potentially contributing to complications lasting for over 1 year after the injury were categorized and analyzed, including age, cause of injury, injury-to-operation time, operative time, fracture type, nausea, vomiting and other concomitant symptoms and injuries. Results All patients who presented with extraocular muscle limitations, positive CT findings, and/or a positive forced duction test underwent surgery. Of the 37 patients, 9 (24% exhibited lasting complications, such as diplopia and gaze restriction. The mean follow-up period was 18.4 months (range, 1–108 months, while that of patients who experienced prolonged complications was 30.1 months (range, 13–36 months. Two factors were significantly associated with prolonged complications: injury-to-operation time and nausea/vomiting. Loss of vision, worsening of motility, and implant complication did not occur. Conclusions Patients who present with gaze limitations, with or without other signs of a blow-out fracture, require a thorough evaluation and emergent surgery. A better prognosis is expected with a shorter injury-to-operation time and lack of nausea and vomiting at the initial presentation.

  6. Postulating a role for connective tissue elements in inferior oblique muscle overaction (an American Ophthalmological Society thesis).

    Science.gov (United States)

    Stager, David; McLoon, Linda K; Felius, Joost

    2013-09-01

    To compare the localization and density of collagens I, IV, VI, and elastin, the major protein components of connective tissue, in the inferior oblique muscle of patients with overelevation in adduction and in controls and to characterize changes that develop following surgery. Biomechanical studies suggest that the connective tissue matrix plays a critical role in extraocular muscle function, determining tensile strength and force transmission during contraction. Prospective laboratory-based case-control study of inferior oblique muscle specimens from 31 subjects: 16 with primary inferior oblique overaction, 6 with craniofacial dysostosis, and 9 normal controls. Collagen I, IV, VI, and elastin were localized and quantified using immunohistochemical staining. Densities were compared using analysis of variance and post hoc comparisons. In primary inferior oblique overaction, all connective tissue components in unoperated specimens were elevated compared to controls (P.27) but increased collagen I. In unoperated craniofacial dysostosis specimens, only elastin was elevated (P=.03), whereas density of collagens IV and VI was lower in previously operated vs unoperated specimens (P=.015). Elevated collagen and elastin levels in the cohort with primary inferior oblique overaction are consistent with the clinical finding of muscle stiffness. Contrarily, normal connective tissue densities in craniofacial dysostosis support the hypothesis that overelevation in this group reflects anomalous muscle vectors rather than tissue changes. Surgical intervention was associated with changes in the connective tissue matrix in both cohorts. These results have ramifications for treating patients with overelevation in adduction.

  7. Differential expression of genes involved in the calcium homeostasis in masticatory muscles of MDX mice.

    Science.gov (United States)

    Kunert-Keil, C H; Gredes, T; Lucke, S; Botzenhart, U; Dominiak, M; Gedrange, T

    2014-04-01

    Duchenne Muscular Dystrophy (DMD) and its murine model, mdx, are characterized by Ca(2+) induced muscle damage and muscle weakness followed by distorted dentofacial morphology. In both, DMD patients and in mdx mice, could be proven so far that only the extraocular muscles (EOM) are not affected by muscular dystrophy. The EOMs are protected against calcium overload by enhanced expression of genes involved in the Ca(2+) homeostasis. We could recently demonstrate that masticatory muscles of mdx mice are differentially affected by muscle dystrophy. The dystrophic masseter and temporalis shows muscle histology comparable to all other skeletal muscles in this animal model, whereas dystrophic tongue muscles seem to develop a milder phenotype. Due to this fact it is to hypothesize that an altered Ca(2+) homeostasis seems to underlie the mdx masticatory muscle pathology. Aim of this study was to examine the mRNA and protein levels of the sarcoplasmic reticulum Ca(2+) ATPases SERCA1 and SERCA2, the plasma membrane Ca(2+) ATPases Atp2b1 and Atp2b4, the sodium/calcium exchanger NCX1, the ryanodine receptor 1, parvalbumin, sarcolipin, phospholamban and the L-type Ca(2+) channel alpha-1 subunit (Cacna1s) in Musculus masseter, temporalis, and tongue of 100 day old control and mdx mice. In mdx masseter muscle significant increased mRNA levels of NCX1 and Cacna1s were found compared to control mice. In contrast, the mRNA amount of RYR1 was significant reduced in mdx temporalis muscle, whereas ATP2b4 was significant increased. In mdx tongue a down-regulation of the ATP2b1, sarcolipin and parvalbumin mRNA expression was found, whereas the phospholamban mRNA level was significantly increased compared to controls. These data were verified by western blot analyses. Our findings revealed that mdx masticatory muscles showed an unequally altered expression of genes involved in the Ca(2+) homeostasis that can support the differences in masticatory muscles response to dystrophin deficiency.

  8. Rhizotomibehandling af børn med svaer spastisk cerebral parese

    DEFF Research Database (Denmark)

    Illum, Niels Ove; Torp-Pedersen, Lisbeth; Midholm, Steen

    2006-01-01

    or posterior rhizotomy (SDR) approach, afferent sensory nerve fibers are cut while efferent motor fibers are preserved. In this way spasticity is reduced and motor functions can improve. SDR is an established treatment method, and the first Danish study is reported. MATERIAL AND METHODS: Twenty Danish children......INTRODUCTION: Severe spasticity is a limiting factor for motor development in children with spastic cerebral palsy. Botulinum toxin, intrathecal baclofen and peroral baclofen all reduce spasticity but might also limit improvements in functional development over time. In the selective dorsal...... with severe spastic cerebral palsy were evaluated, operated on and trained over a 10-year period from 1992 to 2002. Those on whom operation was performed ranged from 4 to 16 years of age (median 8 years), and training and follow-up took place during the ensuing 60 months. At time of operation, 20-40% of 100...

  9. Eye muscle proprioception is represented bilaterally in the sensorimotor cortex

    Science.gov (United States)

    Balslev, Daniela; Albert, Neil B.; Miall, Chris

    2016-01-01

    The cortical representation of eye position is still uncertain. In the monkey a proprioceptive representation of the extraocular muscles (EOM) of an eye were recently found within the contralateral central sulcus. In humans, we have previously shown a change in the perceived position of the right eye after a virtual lesion with rTMS over the left somatosensory area. However, it is possible that the proprioceptive representation of the EOM extends to other brain sites, which were not examined in these previous studies. The aim of this fMRI study was to sample the whole brain to identify the proprioceptive representation for the left and the right eye separately. Data were acquired while passive eye movement was used to stimulate EOM proprioceptors in the absence of a motor command. We also controlled for the tactile stimulation of the eyelid by removing from the analysis voxels activated by eyelid touch alone. For either eye, the brain area commonly activated by passive and active eye movement was located bilaterally in the somatosensory area extending into the motor and premotor cytoarchitectonic areas. We suggest this is where EOM proprioception is processed. The bilateral representation for either eye contrasts with the contralateral representation of hand proprioception. We suggest that the proprioceptive representation of the two eyes next to each other in either somatosensory cortex and extending into the premotor cortex reflects the integrative nature of the eye position sense, which combines proprioceptive information across the two eyes with the efference copy of the oculomotor command. PMID:21391252

  10. Muscle channelopathies.

    Science.gov (United States)

    Statland, Jeffrey; Phillips, Lauren; Trivedi, Jaya R

    2014-08-01

    Skeletal muscle channelopathies are rare heterogeneous diseases with marked genotypic and phenotypic variability. Despite advances in understanding of the molecular pathology of these disorders, the diverse phenotypic manifestations remain a challenge in diagnosis and therapeutics. These disorders can cause lifetime disability and affect quality of life. There is no treatment of these disorders approved by the US Food and Drug Administration at this time. Recognition and treatment of symptoms might reduce morbidity and improve quality of life. This article summarizes the clinical manifestations, diagnostic studies, pathophysiology, and treatment options in nondystrophic myotonia, congenital myasthenic syndrome, and periodic paralyses. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Imaging of muscle injuries

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, G.Y. [Iowa Univ., Iowa City, IA (United States). Dept. of Radiology; Brandser, E.A. [Iowa Univ., Iowa City, IA (United States). Dept. of Radiology; Kathol, M.H. [Iowa Univ., Iowa City, IA (United States). Dept. of Radiology; Tearse, D.S. [Iowa Univ., Iowa City, IA (United States). Dept. of Orthopaedic Surgery; Callaghan, J.J. [Iowa Univ., Iowa City, IA (United States). Dept. of Orthopaedic Surgery

    1996-01-01

    Although skeletal muscle is the single largest tissue in the body, there is little written about it in the radiologic literature. Indirect muscle injuries, also called strains or tears, are common in athletics, and knowing the morphology and physiology of the muscle-tendon unit is the key to the understanding of these injuries. Eccentric muscle activation produces more tension within the muscle tan when it is activated concentrically, making it more susceptible to tearing. Injuries involving the muscle belly tend to occur near the myotendinous junction. In adolescents, the weakest link in the muscle-tendon-bone complex is the apophysis. Traditionally, plain radiography has been the main diagnostic modality for evaluation of these injuries; however, with the advent of MRI it has become much easier to diagnose injuries primarily affecting the soft tissues. This article reviews the anatomy and physiology of the muscle-tendon unit as they relate to indirect muscle injuries. Examples of common muscle injuries are illustrated. (orig.)

  12. Fetal development of the pulley for muscle insertion tendons: A review and new findings related to the tensor tympani tendon.

    Science.gov (United States)

    Rodríguez-Vázquez, Jose Francisco; Honkura, Yohei; Katori, Yukio; Murakami, Gen; Abe, Hiroshi

    2017-01-01

    The existence of hard tissue pulleys that act to change the direction of a muscle insertion tendon is well known in the human body. These include (1) the trochlea for the extraocular obliquus superior muscle, (2) the pterygoid hamulus for the tensor veli palatini muscle, (3) the deep sulcus on the plantar aspect of the cuboid bone for the peroneus longus tendon, (4) the lesser sciatic notch for the obturator internus muscle, and (5) the bony trochleariformis process for the tensor tympani muscle tendon. In addition, (6) the stapedius muscle tendon shows a lesser or greater angulation at the pyramidal eminence of the temporal bone. Our recent studies have shown that the development of pulleys Nos. 1 and 2 can be explained by a change in the topographical relationship between the pulley and the tendon, that of pulley No. 3 by the rapidly growing calcaneus pushing the tendon, and that of pulley No. 4 by migration of the insertion along the sciatic nerve and gluteus medius tendon. Therefore, in Nos. 1-4, an initially direct tendon curves secondarily and obtains an attachment to the pulley. In case No. 6, the terminal part of the stapedius tendon originates secondarily from the interzone mesenchymal tissue of the incudostapedial joint. In the case of pulley No. 5, we newly demonstrated that its initial phase of development was similar to No. 6, but the tensor tympani tendon achieved a right-angled turn under guidance by a specific fibrous tissue and it migrated along the growing malleus manubrium. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Engineering Skeletal Muscle Repair

    OpenAIRE

    Juhas, Mark; Bursac, Nenad

    2013-01-01

    Healthy skeletal muscle has a remarkable capacity for regeneration. Even at a mature age, muscle tissue can undergo a robust rebuilding process that involves the formation of new muscle cells and extracellular matrix and the re-establishment of vascular and neural networks. Understanding and reverse-engineering components of this process is essential for our ability to restore loss of muscle mass and function in cases where the natural ability of muscle for self-repair is exhausted or impaire...

  14. Three-dimensional interactive and stereotactic atlas of head muscles and glands correlated with cranial nerves and surface and sectional neuroanatomy.

    Science.gov (United States)

    Nowinski, Wieslaw L; Chua, Beng Choon; Johnson, Aleksandra; Qian, Guoyu; Poh, Lan Eng; Yi, Su Hnin Wut; Bivi, Aminah; Nowinska, Natalia G

    2013-04-30

    Three-dimensional (3D) relationships between head muscles and cranial nerves innervating them are complicated. Existing sources present these relationships in illustrations, radiologic scans, or autopsy photographs, which are limited for learning and use. Developed electronic atlases are limited in content, quality, functionality, and/or presentation. We create a truly 3D interactive, stereotactic and high quality atlas, which provides spatial relationships among head muscles, glands and cranial nerves, and correlates them to surface and sectional neuroanatomy. The head muscles and glands were created from a 3T scan by contouring them and generating 3D models. They were named and structured according to Terminologia anatomica. The muscles were divided into: extra-ocular, facial, masticatory and other muscles, and glands into mouth and other glands. The muscles, glands (and also head) were placed in a stereotactic coordinate system. This content was integrated with cranial nerves and neuroanatomy created earlier. To explore this complex content, a scalable user interface was designed with 12 modules including central nervous system (cerebrum, cerebellum, brainstem, spinal cord), cranial nerves, muscles, glands, arterial system, venous system, tracts, deep gray nuclei, ventricles, white matter, visual system, head. Anatomy exploration operations include compositing/decompositing, individual/group selection, 3D view-index mapping, 3D labeling, highlighting, distance measuring, 3D brain cutting, and axial/coronal/sagittal triplanar display. To our best knowledge, this is the first truly 3D, stereotactic, interactive, fairly complete atlas of head muscles, and the first attempt to create a 3D stereotactic atlas of glands. Its use ranges from education of students and patients to research to potential clinical applications. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  15. Healthy Muscles Matter

    Science.gov (United States)

    ... do. Exercising, getting enough rest, and eating a balanced diet will help to keep your muscles healthy for ... keep your muscles in good health. Eating a balanced diet will help manage your weight and provide a ...

  16. 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.

  17. the sternalis muscle

    African Journals Online (AJOL)

    2009-08-17

    Aug 17, 2009 ... scan of the chest wall was performed to gain clarity of the mam- mographic findings (Figs 1a, 1b and 2). The CT scan demonstrated a flattened band of muscle density lying anterior to the medial margin of the pectoralis muscle. This structure was separated from the underlying pectoralis muscle by a thin ...

  18. Image Findings of a Rare Case of Neuroendocrine Tumor Metastatic to Orbital Extraocular Muscle in Gallium-68 DOTANOC Positron Emission Tomography/Computed Tomography and Therapy with Lutetium-177 DOTATATE

    OpenAIRE

    Kamaleshwaran, Koramadai Karuppusamy; Joseph, Jephy; Upadhya, Indra; Shinto, Ajit Sugunan

    2017-01-01

    Metastatic tumor is one of several etiologies of space-occupying masses in the orbit that accounts for 1-13% of all orbital masses. In the adult patient population, breast cancer is the most common tumor to metastasize to the orbit, followed by metastasis from the lung, prostate, and gastrointestinal tract. Carcinoid tumors are rare neuroendocrine neoplasms derived from enterochromaffin cells, which are found primarily in the gastrointestinal tract and bronchial tree. Liver metastases are the...

  19. Enlargement of the superior rectus and superior oblique muscles causes intorsion in Graves' eye disease.

    Science.gov (United States)

    Wei, Yan; Kang, Xiao Li; Del Monte, Monte A

    2016-09-01

    To review the prevalence of preoperative and postoperative intorsion in patients with strabismus and Graves' eye disease (GED), and to correlate the intorsion with coexisting superior rectus (SR) and superior oblique (SO) muscle enlargement as a possible mechanism causing intorsion in these patients. Charts of consecutive patients with GED who underwent strabismus surgery between 1 January 2010 and 1 April 2013 were retrospectively reviewed. Of these, patients with orbital CT or MRI scan were identified for further analysis. Clinical characteristics documented included age, gender, horizontal and vertical deviation, subjective torsional deviation, specific extraocular muscles (EOMs) operated upon, EOM enlargement on CT/MRI scans and width and thickness of SO, SR group and inferior rectus (IR). Charts of 45 patients (14 males and 31 females) were reviewed. Mean age was 56.8±12.5 years. Of these, seven (15.6%) patients demonstrated intorsion, and 38 (84.4%) patients demonstrated extorsion preoperatively. But after strabismus surgery, 15 (39.5%) of the 38 patients with preoperative extorsion demonstrated postoperative intorsion and 23 (60.5%) patients continued to show postoperative extorsion. On analysis of CT/MRI scans in these patients, only an increase in the thickness of SR group and the thickness/width of SO muscle were significantly associated with preoperative and postoperative intorsion; while age, gender, preoperative horizontal or vertical deviation and IR recession were unrelated to preoperative or postoperative intorsion. Postoperative intorsion was also associated with smaller degrees of preoperative extorsion (extorsion (<3.5°) in the presence of tight IRs should be carefully evaluated for possible SR and/or SO involvement by CT or MRI scan to predict those at risk for and plan for prevention/treatment of postoperative intorsion. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please

  20. Eye muscle surgery for infantile nystagmus syndrome in the first two years of life

    Directory of Open Access Journals (Sweden)

    Richard W Hertle

    2009-11-01

    Full Text Available Richard W Hertle1, Joost Felius2, Dongsheng Yang1, Matthew Kaufman11The UPMC and Children’s Hospital of Pittsburgh Eye Centers and The Laboratory of Visual and Ocular Motor Physiology Pittsburgh, PA, USA; 2The Retina Foundation of the Southwest, Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USAPurpose: To report visual and elctrophysioloigcal effects of eye muscle surgery in young patients with infantile nystagmus syndrome (INS.Methods: Prospective, interventional case cohort of 19 patients aged under 24 months who were operated on for combinations of strabismus, an anomalous head posture, and nystagmus. All patients were followed at least nine months. Outcome measures, part of an institutionally approved study, included Teller acuity, head position, strabismic deviation, and eye movement recordings, from which waveform types and a nystagmus optimal foveation fraction (NOFF. Computerized parametric and nonparametric statistical analysis of data were perfomed using standard software on both individual and group data.Results: Age averaged 17.7 months (13.1-month follow-up. Thirteen (68% patients had associated optic nerve or retinal disease. 42% had amblyopia, 68% had refractive errors. Group means in binocular Teller acuity (P < 0.05, strabismic deviation (P < 0.05, head posture (P < 0.001, and the NOFF measures (P < 0.01 from eye movement recordings improved in all patients. There was a change in null zone waveforms to more favorable jerk types. There were no reoperations or surgical complications.Conclusions: Surgery on the extraocular muscles in patients aged less than two years with INS results in improvements in multiple aspects of ocular motor and visual function.Keywords: infantile nystagmus, anomalous head posture, eye muscle surgery

  1. Lipolysis in Skeletal Muscle

    DEFF Research Database (Denmark)

    Serup, Annette Karen Lundbeck

    of AMPK in regulation of lipid handling and lipolysis in the basal non-contracting state and during muscle contractions in skeletal muscle. To evaluate the role of AMPK, we measured protein expression and phosphorylation as well as gene expression of proteins important for regulation of lipid handling...... and lipolysis in skeletal muscle from wildtype mice and mice overexpressing a kinase dead AMPKα2 construct (AMPKα2 KD) in the basal non-contracting state and during in situ stimulated muscle contractions. We found, that IMTG levels were ~50% lower in AMPKα2 KD in the basal resting state, explained by a lower....... IMTG was in wildtype mice reduced with ~50% after muscle contractions with no effect of contractions in AMPKα2 KD mice. Concomitantly, ATGL was phosphorylated at ser406 and HSL on ser565 with muscle contractions in an AMPK dependent manner, suggesting that these sites actives lipolysis during muscle...

  2. 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.

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

    Science.gov (United States)

    Randolph, Matthew E.; Pavlath, Grace K.

    2015-01-01

    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 (MDs), 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 MDs. The biology of muscle stem cells varies depending on 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. PMID:26500547

  4. CT, Magnetic Resonance, and {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/CT Imaging Features of Mucosa-Associated Lymphoid Tissue Lymphoma Involving Medial Rectus Muscle: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kwon; Choe, Mi Sun [Dongsan Medical Center, Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2013-06-15

    We report a case of mucosa-associated lymphoid tissue (MALT) lymphoma involving the medial rectus muscle in a 47-year-old man along with CT, MRI, 18 F-fluorodeoxy-glucose positron emission tomography/CT ( 18 F-FDG PET/CT), and pathologic features. The lesion was manifested as a fusiform enlargement isolated to the right medial rectus muscle with involvement of its tendinous insertion. The lesion was isoattenuating to the brain on non-enhanced CT images, showing as isointense to gray matter on fast spin echo T1- and T2-weighted images with fat saturation, and showed homogeneous enhancement on contrast-enhanced CT and MR images. The maximum stan- dardized uptake value on 18 F-FDG PET/CT was 4.9 g/mL. The results of histological and immunohistochemical examinations of the specimen obtained by biopsy of the right medial rectus muscle were consistent with MALT lymphoma. It should be noted that the extraocular muscle (EOM) is a rare location for the involvement of MALT lympho- ma, and MALT lymphoma of the EOM may mimic thyroid orbitopathy.

  5. CT, Magnetic Resonance, and 18F-Fluorodeoxyglucose Positron Emission Tomography/CT Imaging Features of Mucosa-Associated Lymphoid Tissue Lymphoma Involving Medial Rectus Muscle: A Case Report

    International Nuclear Information System (INIS)

    Lee, Sang Kwon; Choe, Mi Sun

    2013-01-01

    We report a case of mucosa-associated lymphoid tissue (MALT) lymphoma involving the medial rectus muscle in a 47-year-old man along with CT, MRI, 18 F-fluorodeoxy-glucose positron emission tomography/CT ( 18 F-FDG PET/CT), and pathologic features. The lesion was manifested as a fusiform enlargement isolated to the right medial rectus muscle with involvement of its tendinous insertion. The lesion was isoattenuating to the brain on non-enhanced CT images, showing as isointense to gray matter on fast spin echo T1- and T2-weighted images with fat saturation, and showed homogeneous enhancement on contrast-enhanced CT and MR images. The maximum stan- dardized uptake value on 18 F-FDG PET/CT was 4.9 g/mL. The results of histological and immunohistochemical examinations of the specimen obtained by biopsy of the right medial rectus muscle were consistent with MALT lymphoma. It should be noted that the extraocular muscle (EOM) is a rare location for the involvement of MALT lympho- ma, and MALT lymphoma of the EOM may mimic thyroid orbitopathy.

  6. The hamstring muscle complex.

    Science.gov (United States)

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

    2015-07-01

    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 inscription in the semitendinosus muscle known as the raphe. Fifty-six hamstring muscle groups were dissected in prone position from 29 human cadaveric specimens with a median age of 71.5 (range 45-98). Data pertaining to origin dimensions, muscle length, tendon length, MTJ length and length as well as width of the raphe were collected. Besides these data, we also encountered interesting findings that might lead to a better understanding of the hamstring injury pattern. These include overlapping proximal and distal tendons of both the long head of the biceps femoris muscle and the semimembranosus muscle (SM), a twist in the proximal SM tendon and a tendinous inscription (raphe) in the semitendinosus muscle present in 96 % of specimens. No obvious hypothesis can be provided purely based on either muscle length, tendon length or MTJ length. However, it is possible that overlapping proximal and distal tendons as well as muscle architecture leading to a resultant force not in line with the tendon predispose to muscle injury, whereas the presence of a raphe might plays a role in protecting the muscle against gross injury. Apart from these architectural characteristics that may contribute to a better understanding of the hamstring injury pattern, the provided reference values complement current knowledge on surgically relevant hamstring anatomy. IV.

  7. 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".

  8. An artificial muscle computer

    Science.gov (United States)

    Marc O'Brien, Benjamin; Alexander Anderson, Iain

    2013-03-01

    We have built an artificial muscle computer based on Wolfram's "2, 3" Turing machine architecture, the simplest known universal Turing machine. Our computer uses artificial muscles for its instruction set, output buffers, and memory write and addressing mechanisms. The computer is very slow and large (0.15 Hz, ˜1 m3); however by using only 13 artificial muscle relays, it is capable of solving any computable problem given sufficient memory, time, and reliability. The development of this computer shows that artificial muscles can think—paving the way for soft robots with reflexes like those seen in nature.

  9. 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

  10. 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.

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

    Science.gov (United States)

    2014-12-19

    muscle , but it did so without significant morphological adaptations (e.g., no hypertrophy and hyperplasia). Wheel running up-regulated metabolic genes...been shown to foster regeneration of injured muscle [5,32,33] and promote hypertrophy (i.e., increased protein synthesis or muscle weight) in muscle ...remaining muscle tissue. Strengthening of synergist muscles can partially compensate for the loss of function due to VML injury. Compensatory hypertrophy

  12. Muscles, exercise and obesity

    DEFF Research Database (Denmark)

    Pedersen, Bente K; Febbraio, Mark A

    2012-01-01

    of yet unidentified factors, secreted from muscle cells, which may influence cancer cell growth and pancreas function. Many proteins produced by skeletal muscle are dependent upon contraction; therefore, physical inactivity probably leads to an altered myokine response, which could provide a potential...

  13. Proteomics of Skeletal Muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul

    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 m...

  14. 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

  15. 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)....

  16. [Diabetic muscle infarction].

    Science.gov (United States)

    ter Bals, Edske; van der Woude, Henk-Jan; Smets, Yves F C

    2013-01-01

    Diabetic muscle infarction is a rare complication of diabetes mellitus that typically presents in the thigh; microvascular abnormalities may play a role. A 32-year-old female presented at the outpatient clinic with a painful, swollen thigh. She had suffered from type 1 diabetes for 22 years. The patient was admitted to the nephrology ward for further evaluation. Deep-venous thrombosis and abscess were excluded with echography. After additional investigations - MRI and a biopsy of skin, muscle and fascia - the diagnosis diabetic muscle infarction was made. The patient was treated with bed rest and analgesics. With hindsight, the muscle biopsy was not actually required in reaching a diagnosis. The diagnosis 'diabetic muscle infarction' is made on the basis of clinical presentation in combination with MRI findings. The treatment consists of bed rest and analgesics.

  17. A muscle model for hybrid muscle activation

    Directory of Open Access Journals (Sweden)

    Klauer Christian

    2015-09-01

    Full Text Available To develop model-based control strategies for Functional Electrical Stimulation (FES in order to support weak voluntary muscle contractions, a hybrid model for describing joint motions induced by concurrent voluntary-and FES induced muscle activation is proposed. It is based on a Hammerstein model – as commonly used in feedback controlled FES – and exemplarily applied to describe the shoulder abduction joint angle. Main component of a Hammerstein muscle model is usually a static input nonlinearity depending on the stimulation intensity. To additionally incorporate voluntary contributions, we extended the static non-linearity by a second input describing the intensity of the voluntary contribution that is estimated by electromyography (EMG measurements – even during active FES. An Artificial Neural Network (ANN is used to describe the static input non-linearity. The output of the ANN drives a second-order linear dynamical system that describes the combined muscle activation and joint angle dynamics. The tunable parameters are adapted to the individual subject by a system identification approach using previously recorded I/O-data. The model has been validated in two healthy subjects yielding RMS values for the joint angle error of 3.56° and 3.44°, respectively.

  18. Respiratory Muscle Plasticity

    Science.gov (United States)

    Gransee, Heather M.; Mantilla, Carlos B.; Sieck, Gary C.

    2014-01-01

    Muscle plasticity is defined as the ability of a given muscle to alter its structural and functional properties in accordance with the environmental conditions imposed on it. As such, respiratory muscle is in a constant state of remodeling, and the basis of muscle’s plasticity is its ability to change protein expression and resultant protein balance in response to varying environmental conditions. Here, we will describe the changes of respiratory muscle imposed by extrinsic changes in mechanical load, activity, and innervation. Although there is a large body of literature on the structural and functional plasticity of respiratory muscles, we are only beginning to understand the molecular-scale protein changes that contribute to protein balance. We will give an overview of key mechanisms regulating protein synthesis and protein degradation, as well as the complex interactions between them. We suggest future application of a systems biology approach that would develop a mathematical model of protein balance and greatly improve treatments in a variety of clinical settings related to maintaining both muscle mass and optimal contractile function of respiratory muscles. PMID:23798306

  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. Painful unilateral temporalis muscle enlargement: reactive masticatory muscle hypertrophy.

    Science.gov (United States)

    Katsetos, Christos D; Bianchi, Michael A; Jaffery, Fizza; Koutzaki, Sirma; Zarella, Mark; Slater, Robert

    2014-06-01

    An instance of isolated unilateral temporalis muscle hypertrophy (reactive masticatory muscle hypertrophy with fiber type 1 predominance) confirmed by muscle biopsy with histochemical fiber typing and image analysis in a 62 year-old man is reported. The patient presented with bruxism and a painful swelling of the temple. Absence of asymmetry or other abnormalities of the craniofacial skeleton was confirmed by magnetic resonance imaging and cephalometric analyses. The patient achieved symptomatic improvement only after undergoing botulinum toxin injections. Muscle biopsy is key in the diagnosis of reactive masticatory muscle hypertrophy and its distinction from masticatory muscle myopathy (hypertrophic branchial myopathy) and other non-reactive causes of painful asymmetric temporalis muscle enlargement.

  1. Muscle Disorders - Multiple Languages

    Science.gov (United States)

    ... Health Information Translations Spanish (español) Expand Section Muscle Disorders: MedlinePlus Health Topic - English ... Health Information Translations Characters not displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  2. Neurogenic muscle cramps.

    Science.gov (United States)

    Katzberg, Hans D

    2015-08-01

    Muscle cramps are sustained, painful contractions of muscle and are prevalent in patients with and without medical conditions. The objective of this review is to present updates on the mechanism, investigation and treatment of neurogenic muscle cramps. PubMed and Embase databases were queried between January 1980 and July 2014 for English-language human studies. The American Academy of Neurology classification of studies (classes I-IV) was used to assess levels of evidence. Mechanical disruption, ephaptic transmission, disruption of sensory afferents and persistent inward currents have been implicated in the pathogenesis of neurogenic cramps. Investigations are directed toward identifying physiological triggers or medical conditions predisposing to cramps. Although cramps can be self-limiting, disabling or sustained muscle cramps should prompt investigation for underlying medical conditions. Lifestyle modifications, treatment of underlying conditions, stretching, B-complex vitamins, diltiezam, mexiletine, carbamazepine, tetrahydrocannabinoid, leveteracitam and quinine sulfate have shown evidence for treatment.

  3. 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

  4. Water and Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Enrico Grazi

    2008-08-01

    Full Text Available The interaction between water and the protein of the contractile machinery as well as the tendency of these proteins to form geometrically ordered structures provide a link between water and muscle contraction. Protein osmotic pressure is strictly related to the chemical potential of the contractile proteins, to the stiffness of muscle structures and to the viscosity of the sliding of the thin over the thick filaments. Muscle power output and the steady rate of contraction are linked by modulating a single parameter, a viscosity coefficient. Muscle operation is characterized by working strokes of much shorter length and much quicker than in the classical model. As a consequence the force delivered and the stiffness attained by attached cross-bridges is much larger than usually believed.

  5. Muscle glycogenolysis during exercise

    DEFF Research Database (Denmark)

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

    1982-01-01

    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...

  6. Pneumatic Muscle Actuator Control

    National Research Council Canada - National Science Library

    Lilly, John

    2000-01-01

    This research is relevant to the Air Fore mission because pneumatic muscle actuation devices arc advantageous for certain types of robotics as well as for strength and/or mobility assistance for humans...

  7. 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...

  8. 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...... 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....

  9. 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...

  10. 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.

  11. Foot muscles strengthener

    Directory of Open Access Journals (Sweden)

    Boris T. Glavač

    2012-04-01

    Full Text Available Previous experience in the correction of flat feet consisted of the use of insoles for shoes and exercises with toys, balls, rollers, inclined planes, etc. A device for strengthening foot muscles is designed for the correction of flat feet in children and, as its name suggests, for strengthening foot muscles in adults. The device is made of wood and metal, with a mechanism and technical solutions, enabling the implementation of specific exercises to activate muscles responsible for the formation of the foot arch. It is suitable for home use with controlled load quantities since it has calibrated springs. The device is patented with the Intellectual Property Office, Republic of Serbia, as a petty patent.

  12. CREB is activated by muscle injury and promotes muscle regeneration.

    Science.gov (United States)

    Stewart, Randi; Flechner, Lawrence; Montminy, Marc; Berdeaux, Rebecca

    2011-01-01

    The cAMP response element binding protein (CREB) plays key roles in differentiation of embryonic skeletal muscle progenitors and survival of adult skeletal muscle. However, little is known about the physiologic signals that activate CREB in normal muscle. Here we show that CREB phosphorylation and target genes are induced after acute muscle injury and during regeneration due to genetic mutation. Activated CREB localizes to both myogenic precursor cells and newly regenerating myofibers within regenerating areas. Moreover, we found that signals from damaged skeletal muscle tissue induce CREB phosphorylation and target gene expression in primary mouse myoblasts. An activated CREB mutant (CREBY134F) potentiates myoblast proliferation as well as expression of early myogenic transcription factors in cultured primary myocytes. Consistently, activated CREB-YF promotes myoblast proliferation after acute muscle injury in vivo and enhances muscle regeneration in dystrophic mdx mice. Our findings reveal a new physiologic function for CREB in contributing to skeletal muscle regeneration.

  13. Rectus abdominis muscle endometriosis

    International Nuclear Information System (INIS)

    Goker, A.

    2014-01-01

    Endometriosis is characterized by an abnormal existence of functional endometrial tissue outside the uterine cavity, typically occuring within the pelvis of women in reproductive age. We report two cases with endometriosis of the abdominal wall; the first one in the rectus abdominis muscle and the second one in the surgical scar of previous caesarean incision along with the rectus abdominis muscle. Pre-operative evaluation included magnetic resonance imaging. The masses were dissected free from the surrounding tissue and excised with clear margins. Diagnosis of the excised lesions were verified by histopathology. (author)

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

    International Nuclear Information System (INIS)

    Okanobu, Hirotaka; Kono, Reika; Ohtsuki, Hiroshi

    2011-01-01

    The purpose of this study was 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. (author)

  15. 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.

  16. 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

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

    Directory of Open Access Journals (Sweden)

    Kyle P Blum

    2017-09-01

    Full Text Available 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

  18. 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 ...

  19. 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.)

  20. Extraocular myositis in a female puppy

    African Journals Online (AJOL)

    2015-04-27

    Apr 27, 2015 ... ventral, ventromedial or medial strabismus have been reported (Allgoewer et al., 2000). The pathogenesis of this condition is not fully understood, but the one dominant histopathologic picture of the condition is that of mononuclear cellular infiltration (Carpenter et al.,. 1989; Ramsey et al., 1995; Evans et al., ...

  1. Muscle contraction and force

    DEFF Research Database (Denmark)

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

    2008-01-01

    of nutrient delivery and waste product removal, but are also tethered to surrounding fibres by collagen "wires". This paper therefore addresses aspects of the ancillary network of skeletal muscle at both a microscopic and functional level in order to better understand its role holistically as a considerable...

  2. 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

  3. 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......-like fashion, exerting specific endocrine effects on other organs. Other myokines work via paracrine mechanisms, exerting local effects on signalling pathways involved in muscle metabolism. It has been suggested that myokines may contribute to exercise-induced protection against several chronic diseases....

  4. [Primary muscle cramps].

    Science.gov (United States)

    Serratrice, G

    2008-05-01

    Primary muscle cramps, without known cause, are very frequent especially in the elderly and during the night. They are different from secondary cramps. Likewise they are to be separated from several syndromes erroneously quoted as cramps. The pathophysiological mechanism seems due to result from an initial dysfunction in the distal part of the motoneuron. When the cramps are severe, differential diagnosis with amyotrophic lateral sclerosis may be difficult. Quinine is the best empiric treatment largely used in spite of moderate side effects.

  5. MUSCLE TENSION DYSPHONIA

    Directory of Open Access Journals (Sweden)

    Irena Hočevar Boltežar

    2004-07-01

    Full Text Available Background. Muscle tension dysphonia (MTD is the cause of hoarseness in almost one half of the patients with voice disorders. The otorhinolaryngologic examination discovers no evident organic lesions in the larynx at least in the beginning of the voice problems. The reason for the hoarse voice is a disordered and maladjusted activity of the muscles taking part in phonation and/or articulation. In some patients, the irregular function of the larynx results in mucosal lesions on vocal folds. The factors participating in the development of MTD, directly or indirectly influence the quality of laryngeal mucosa, the activity of the phonatory muscles and/or increase of the vocal load. In the diagnostics and treatment of the MTD a phoniatrician, a speech and language therapist and a psychologist closely cooperate with the patient who must take an active role. The treatment is a long-lasting one but resulted in a high percentage of clinical success.Conclusions. Most likely, MTD is not a special disease but only a reflection of any disorder in the complicated system of regulation and realization of phonation. The prognosis of treatment is good when all unfavourable factors participating in development of MTD are eliminated and a proper professional voice- and psychotherapy started.

  6. 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.

  7. 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.

  8. Reinnervation of Paralyzed Muscle by Nerve Muscle Endplate Band Grafting

    Science.gov (United States)

    2016-10-01

    x 3 mm), a nerve branch, intramuscular nerve terminals, and a motor endplate (MEP) band with numerous neuromuscular junctions. The superficial ...when muscle was stretched at optimal tension of 0.8 N. Maximal muscle force was calculated as average muscle contraction to 5 stimulation currents...force during the 200-millisecond contraction was identified, as well as initial passive tension before stimulation. The difference between themaximal

  9. Nuclear Positioning in Muscle Development and Disease

    OpenAIRE

    Eric eFolker; Mary eBaylies

    2013-01-01

    Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, th...

  10. Pneumatic Artificial Muscles Based on Biomechanical Characteristics of Human Muscles

    Directory of Open Access Journals (Sweden)

    N. Saga

    2006-01-01

    Full Text Available This article reports the pneumatic artificial muscles based on biomechanical characteristics of human muscles. A wearable device and a rehabilitation robot that assist a human muscle should have characteristics similar to those of human muscle. In addition, since the wearable device and the rehabilitation robot should be light, an actuator with a high power to weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Therefore, an artificial muscle actuator has been developed in which high-strength carbon fibres have been built into the silicone tube. However, its contraction rate is smaller than the actual biological muscles. On the other hand, if an artificial muscle that contracts axially is installed in a robot as compactly as the robot hand, big installing space is required. Therefore, an artificial muscle with a high contraction rate and a tendon-driven system as a compact actuator were developed, respectively. In this study, we report on the basic structure and basic characteristics of two types of actuators.

  11. Transplantation of Devitalized Muscle Scaffolds is Insufficient for Appreciable De Novo Muscle Fiber Regeneration After Volumetric Muscle Loss Injury

    Science.gov (United States)

    2014-10-10

    minced muscle grafts were shown to support de novo skeletal muscle regeneration. For instance, devitalized whole extensor digitorum longus (EDL) muscle...antero- lateral aspect of the ankle, and the distal EDL muscle tendon and extensor hallicus longus (EHL) muscle was isolated and severed above the

  12. Exercising with blocked muscle glycogenolysis

    DEFF Research Database (Denmark)

    Nielsen, Tue L; Pinós, Tomàs; Brull, Astrid

    2018-01-01

    of expression and activation of proteins involved in glycolytic flux revealed that in glycolytic, but not oxidative muscle from exercised McArdle mice, the glycolytic flux had changed compared to that in wild-type mice. Specifically, exercise triggered in glycolytic muscle a differentiated activation of insulin......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 glycogen......-derived glucose is unavailable during exercise. Metabolic adaptation to blocked muscle glycogenolysis occurs at rest in the McArdle mouse model, but only in highly glycolytic muscle. However, it is unknown what compensatory metabolic adaptations occur during exercise in McArdle disease. METHODS: In this study, 8...

  13. 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...

  14. PDH regulation in skeletal muscle

    DEFF Research Database (Denmark)

    Kiilerich, Kristian

    is determined by the overall content / activity of the regulatory proteins PDH kinase (PDK), of which there are 4 isoforms, and PDH phosphatase (PDP), of which there are 2 isoforms. The overall aim of the PhD project was to elucidate 4 issues. 1: Role of muscle type in resting and exercise-induced PDH...... in arm than leg muscles during exercise in humans may be the result of lower PDH-E1? content and not a muscle type dependent difference in PDH regulation. Both low muscle glycogen and increased plasma FFA are associated with upregulation of PDK4 protein and less exercise-induced increase in PDHa activity...... 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...

  15. Unorthodox angiogenesis in skeletal muscle.

    Science.gov (United States)

    Egginton, S; Zhou, A L; Brown, M D; Hudlická, O

    2001-02-16

    The morphological pattern of angiogenesis occurring in mature, differentiated skeletal muscle in response to chronically increased muscle blood flow, muscle stretch or repetitious muscle contractions was examined to determine (a) whether capillary neoformation follows the generally accepted temporal paradigm, and (b) how the growth pattern is influenced by mechanical stimuli. Adult rats were treated for a maximum of 14 days either with the vasodilator prazosin, to elevate skeletal muscle blood flow, or underwent surgical removal of one ankle flexor, to induce compensatory overload in the remaining muscles, or had muscles chronically stimulated by implanted electrodes. Extensor digitorum longus and/or extensor hallucis proprius muscles were removed at intervals and processed for electron microscopy. A systematic examination of capillaries and their ultrastructure characterised the sequence of morphological changes indicative of angiogenesis, i.e., basement membrane disruption, endothelial cell (EC) sprouting and proliferation [immunogold labelling after bromodeoxyuridine (BrdU) incorporation]. Capillary growth in response to increased blood flow occurred by luminal division without sprouting or basement membrane (BM) breakage. In stretched muscles, EC proliferation and abluminal sprouting gave rise to new capillaries, with BM loss only at sprout tips. These distinct mechanisms appear to be additive as in chronically stimulated muscles (increased blood flow with repetitive stretch and shortening during muscle contractions) both forms of capillary growth occurred. Endothelial cell numbers per capillary profile, mitotic EC nuclei, and BrdU labelling confirmed cell proliferation prior to overt angiogenesis. Physiological angiogenesis within adult skeletal muscle progresses by mechanisms that do not readily conform to the consensus view of capillary growth, derived mainly from observations made during development, pathological vessel growth, or from in vitro systems. The

  16. Immunology Guides Skeletal Muscle Regeneration

    OpenAIRE

    F. Andrea Sass; Michael Fuchs; Matthias Pumberger; Sven Geissler; Georg N. Duda; Carsten Perka; Katharina Schmidt-Bleek

    2018-01-01

    Soft tissue trauma of skeletal muscle is one of the most common side effects in surgery. Muscle injuries are not only caused by accident-related injuries but can also be of an iatrogenic nature as they occur during surgical interventions when the anatomical region of interest is exposed. If the extent of trauma surpasses the intrinsic regenerative capacities, signs of fatty degeneration and formation of fibrotic scar tissue can occur, and, consequentially, muscle function deteriorates or is d...

  17. Muscle necrosis - computer tomography aspects

    International Nuclear Information System (INIS)

    Franze, I.; Goebel, N.; Stuckmann, G.

    1985-01-01

    In four patients muscle necroses were observed. In two patients these were caused by intraoperative positioning, in one by having worked with a pneumatic hammer and in one possibly by alcohol. CT showed hypodense areas in the affected muscles which were - in the state of subacute necroses - surrounded by hyperaemic borders. The diagnosis was confirmed by puncture or biopsy. After six months hypodense areas were still perceptible in the atrophic muscles of two patients. (orig.) [de

  18. 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

  19. Muscle damage and muscle remodeling: no pain, no gain?

    Science.gov (United States)

    Flann, Kyle L; LaStayo, Paul C; McClain, Donald A; Hazel, Mark; Lindstedt, Stan L

    2011-02-15

    Skeletal muscle is a dynamic tissue that responds adaptively to both the nature and intensity of muscle use. This phenotypic plasticity ensures that muscle structure is linked to patterns of muscle use throughout the lifetime of an animal. The cascade of events that result in muscle restructuring - for example, in response to resistance exercise training - is often thought to be initiated by muscle damage. We designed this study to test the hypothesis that symptomatic (i.e. detectable) damage is a necessary precursor for muscle remodeling. Subjects were divided into two experimental populations: pre-trained (PT) and naive (NA). Demonstrable muscle damage was avoided in the PT group by a three-week gradual 'ramp-up' protocol. By contrast, the NA group was subjected to an initial damaging bout of exercise. Both groups participated in an eight-week high-force eccentric-cycle ergometry program (20 min, three times per week) designed to equate the total work done during training between the groups. The NA group experienced signs of damage, absent in the PT group, as indicated by greater than five times higher levels of plasma creatine kinase (CK) and self-reporting of initial perceived soreness and exertion, yet muscle size and strength gains were not different for the two groups. RT-PCR analysis revealed similar increases in levels of the growth factor IGF-1Ea mRNA in both groups. Likewise, the significant (Pmuscle volume) were equal in both groups. Finally, strength increases were identical for both groups (PT=25% and NA=26% improvement). The results of this study suggest that muscle rebuilding - for example, hypertrophy - can be initiated independent of any discernible damage to the muscle.

  20. Turning scar into muscle.

    Science.gov (United States)

    de Carvalho, Antonio Carlos Campos; Carvalho, Adriana Bastos

    2012-09-26

    After the demonstration that somatic cells could be reprogrammed to a pluripotent state, exciting new prospects were opened for the cardiac regeneration field. It did not take long for the development of strategies to convert somatic cells directly into cardiomyocytes. Despite the intrinsic difficulties of cell reprogramming, such as low efficiency, the therapeutic possibilities created by the ability to turn scar into muscle are enormous. Here, we discuss some of the major advances and strategies used in direct cardiac reprogramming and examine discrepancies and concerns that still need to be resolved in the field.

  1. Contractures and muscle disease.

    Science.gov (United States)

    Walters, R Jon

    2016-08-01

    Contractures are one of a handful of signs in muscle disease, besides weakness and its distribution, whose presence can help guide us diagnostically, a welcome star on the horizon. Contractures are associated with several myopathies, some with important cardiac manifestations, and consequently are important to recognise; their presence may also provide us with a potential satisfying 'penny dropping' diagnostic moment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Lipoxygenase in chicken muscle

    International Nuclear Information System (INIS)

    Grossman, S.; Bergman, M.; Sklan, D.

    1988-01-01

    The presence of lipoxygenase-type enzymes was demonstrated in chick muscles. Examination of the oxidation products of [ 14 C]arachidonic acid revealed the presence of 15-lipoxygenase. The enzyme was partially purified by affinity chromatography on linoleoyl-aminoethyl-Sepharose. The enzyme was stable on frozen storage, and activity was almost completely preserved after 12-month storage at -20 degree C. During this period the content of cis,cis-1,4-pentadiene fatty acids decreased slightly. It is suggested that lipoxygenase may be responsible for some of the oxidative changes occurring in fatty acids on frozen storage of chicken meat

  3. Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration

    DEFF Research Database (Denmark)

    Mackey, Abigail L.; Magnan, Mélanie; Chazaud, Bénédicte

    2017-01-01

    Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence...

  4. 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

  5. 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.

  6. Aspects of smooth muscle function in molluscan catch muscle.

    Science.gov (United States)

    Twarog, B M

    1976-10-01

    1) Catch in Mytilus ABRM may be a specialization of a mechanism common to all muscles that gives rise to stretch resistance in the resting state. Catch appears to be due to actin myosin interaction. Since this interaction is regulated by nerves, it provides a convenient model for studying resting stretch resistance. 2) Studies of the structure of Mytilus ABRM revela two types of intercellular connections: a) direct connections between muscle fibers [these nexal (gap) junctions interconnect the muscle cells electrically]; b) muscle fiber-collagen-muscle fiber connections [these provide mechanical connections between muscle cells via collagen fibers]. The structure of Mytilus ABRM supports speculation that smooth muscle filaments are organized into contractile units. 3) A rise in cAMP levels occurs in response to the relaxing transmitter, serotonin. It is not certain whether the cAMP system directly controls the ability of the contractile proteins to interact or whether it regulates intracellular levels of Ca2+. 4) Calcium ions in activation are derived from two sources: an internal source, probably the sarcoplasmic reticulum, and an external source, across the muscle membrane. 5) The nature of catch remains in question, although most evidence favors the linkage hypothesis.

  7. Skeletal muscle sodium channelopathies.

    Science.gov (United States)

    Nicole, Sophie; Fontaine, Bertrand

    2015-10-01

    This is an update on skeletal muscle sodium channelopathies since knowledge in the field have dramatically increased in the past years. The relationship between two phenotypes and SCN4A has been confirmed with additional cases that remain extremely rare: severe neonatal episodic laryngospasm mimicking encephalopathy, which should be actively searched for since patients respond well to sodium channel blockers; congenital myasthenic syndromes, which have the particularity to be the first recessive Nav1.4 channelopathy. Deep DNA sequencing suggests the contribution of other ion channels in the clinical expressivity of sodium channelopathies, which may be one of the factors modulating the latter. The increased knowledge of channel molecular structure, the quantity of sodium channel blockers, and the availability of preclinical models would permit a most personalized choice of medication for patients suffering from these debilitating neuromuscular diseases. Advances in the understanding of the molecular structure of voltage-gated sodium channels, as well as availability of preclinical models, would lead to improved medical care of patients suffering from skeletal muscle, as well as other sodium channelopathies.

  8. 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.

  9. Building Muscles, Keeping Muscles: Protein Turnover During Space Flight

    Science.gov (United States)

    Ferrando, Arny; Bloomberg, Jacob; Lee, Angie (Technical Monitor)

    2002-01-01

    As we age we lose muscle mass and strength. The problem is a matter of use it or lose it and more - a fact to which any active senior can attest. An imbalance in the natural cycle of protein turnover may be a contributing factor to decreased muscle mass. But the answer is not so simple, since aging is associated with changes in hormones, activity levels, nutrition, and often, disease. The human body constantly uses amino acids to build muscle protein, which then breaks down and must be replaced. When protein turnover gets out of balance, so that more protein breaks down than the body can replace, the result is muscle loss. This is not just the bane of aging, however. Severely burned people may have difficulty building new muscle long after the burned skin has been repaired. Answers to why we lose muscle mass and strength - and how doctors can fix it - may come from space. Astronauts usually eat a well-balanced diet and maintain an exercise routine to stay in top health. During long-duration flight, they exercise regularly to reduce the muscle loss that results from being in a near-weightless environment. Despite these precautions, astronauts lose muscle mass and strength during most missions. They quickly recover after returning to Earth - this is a temporary condition in an otherwise healthy population. Members of the STS-107 crew are participating in a study of the effects of space flight, hormone levels, and stress on protein turnover. When we are under stress, the body responds with a change in hormone levels. Researchers hypothesize that this stress-induced change in hormones along with the near-weightlessness might result in the body synthesizing less muscle protein, causing muscles to lose their strength and size. Astronauts, who must perform numerous duties in a confined and unusual environment, experience some stress during their flight, making them excellent candidates for testing the researchers' hypothesis.

  10. Skeletal muscle regeneration is modulated by inflammation

    Directory of Open Access Journals (Sweden)

    Wenjun Yang

    2018-04-01

    Full Text Available Skeletal muscle regeneration is a complex process orchestrated by multiple steps. Recent findings indicate that inflammatory responses could play central roles in bridging initial muscle injury responses and timely muscle injury reparation. The various types of immune cells and cytokines have crucial roles in muscle regeneration process. In this review, we briefly summarise the functions of acute inflammation in muscle regeneration. The translational potential of this article: Immune system is closely relevant to the muscle regeneration. Understanding the mechanisms of inflammation in muscle regeneration is therefore critical for the development of effective regenerative, and therapeutic strategies in muscular disorders. This review provides information for muscle regeneration research regarding the effects of inflammation on muscle regeneration. Keywords: Chronic muscle disorders, Cytokines, Immune cells, Inflammation, Muscle regeneration, Muscle stem cells

  11. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

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

    2013-01-01

    myopathies. We investigated regeneration in muscle biopsies from 61 genetically well-defined patients affected by mitochondrial myopathy. Our results show that the perturbed energy metabolism in mitochondrial myopathies causes ongoing muscle regeneration in a majority of patients, and some were even affected...

  12. 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

  13. Human skeletal muscle biochemical diversity.

    Science.gov (United States)

    Tirrell, Timothy F; Cook, Mark S; Carr, J Austin; Lin, Evie; Ward, Samuel R; Lieber, Richard L

    2012-08-01

    The molecular components largely responsible for muscle attributes such as passive tension development (titin and collagen), active tension development (myosin heavy chain, MHC) and mechanosensitive signaling (titin) have been well studied in animals but less is known about their roles in humans. The purpose of this study was to perform a comprehensive analysis of titin, collagen and MHC isoform distributions in a large number of human muscles, to search for common themes and trends in the muscular organization of the human body. In this study, 599 biopsies were obtained from six human cadaveric donors (mean age 83 years). Three assays were performed on each biopsy - titin molecular mass determination, hydroxyproline content (a surrogate for collagen content) and MHC isoform distribution. Titin molecular mass was increased in more distal muscles of the upper and lower limbs. This trend was also observed for collagen. Percentage MHC-1 data followed a pattern similar to collagen in muscles of the upper extremity but this trend was reversed in the lower extremity. Titin molecular mass was the best predictor of anatomical region and muscle functional group. On average, human muscles had more slow myosin than other mammals. Also, larger titins were generally associated with faster muscles. These trends suggest that distal muscles should have higher passive tension than proximal ones, and that titin size variability may potentially act to 'tune' the protein's mechanotransduction capability.

  14. 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.

  15. MR imaging of muscle diseases

    International Nuclear Information System (INIS)

    Kaiser, W.A.; Zeitler, E.; Schalke, B.C.G.

    1986-01-01

    Because of high soft-tissue contrast, MR imaging is especially suitable for the investigation of muscle diseases. Between March 1984 and March 1986, 76 patients with different types of muscle diseases were examined using a 1-T superconductive magnet (Siemens Magnetom). Studied were 14 patients with progressive muscular dystrophy (including carriers), 32 patients with myositis, four patients with myotonic dystrophy, six patients with spinal muscular atrophy, and 20 patients with other muscle diseases, including metabolic disorders. MR imaging showed typical signal patterns in affected muscle groups. These patterns can be used in the differential diagnosis, in biopsy planning, or in evaluation of response to therapy. The T1/T2 ratio especially seems to indicate very early stages of muscle disease

  16. Eccentric exercise-induced muscle damage impairs muscle glycogen repletion.

    Science.gov (United States)

    O'Reilly, K P; Warhol, M J; Fielding, R A; Frontera, W R; Meredith, C N; Evans, W J

    1987-07-01

    Five healthy untrained young male subjects were studied before, immediately after, and 10 days after a 45-min bout of eccentric exercise on a cycle ergometer (201 W). The subjects were sedentary at all other times and consumed a eucaloric meat-free diet. Needle biopsies of the vastus lateralis muscle were examined for intracellular damage and glycogen content. Immediately after exercise, muscle samples showed myofibrillar tearing and edema. At 10 days, there was myofibrillar necrosis, inflammatory cell infiltration, and no evidence of myofibrillar regeneration. Glycogen utilization during the exercise bout was 33 mmol glycosyl units/kg muscle, consistent with the metabolic intensity of 44% of maximal O2 uptake; however, the significant glycogen use by type II fibers contrasted with concentric exercise performed at this intensity. At 10 days after exercise, muscle glycogen was still depleted, in both type I and II fibers. It is possible that the alterations in muscle ultrastructures were related to the lack of repletion of muscle glycogen. Damage produced by eccentric exercise was more persistent than previously reported, indicating that more than 10 days may be necessary for recovery of muscle ultrastructure and carbohydrate reserves.

  17. 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...... that collagen plays a significant role in determining the tenderness of meat. What are we missing? Therefore, fundamental aspects of connective tissue research have been the centre of attention throughout this thesis. A holistic view has been applied, glancing at this complex tissue which has many facets...... in this thesis that alpha-ketoglutarate, a tricarboxylic acid cycle metabolite, has the potential to control the metabolism of this particular tissue. Finally, a new microscopic method is introduced which allows the study of thermal denaturation of fibrillar collagen and myofibers in real time without any label...

  18. Bulk muscles, loose cables.

    Science.gov (United States)

    Liyanage, Chamari R D G; Kodali, Venkata

    2014-10-17

    The accessibility and usage of body building supplements is on the rise with stronger internet marketing strategies by the industry. The dangers posed by the ingredients in them are underestimated. A healthy young man came to the emergency room with palpitations and feeling unwell. Initial history and clinical examination were non-contributory to find the cause. ECG showed atrial fibrillation. A detailed history for any over the counter or herbal medicine use confirmed that he was taking supplements to bulk muscle. One of the components in these supplements is yohimbine; the onset of symptoms coincided with the ingestion of this product and the patient is symptom free after stopping it. This report highlights the dangers to the public of consuming over the counter products with unknown ingredients and the consequential detrimental impact on health. 2014 BMJ Publishing Group Ltd.

  19. 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...

  20. Skeletal muscle connective tissue

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline

    that collagen plays a significant role in determining the tenderness of meat. What are we missing? Therefore, fundamental aspects of connective tissue research have been the centre of attention throughout this thesis. A holistic view has been applied, glancing at this complex tissue which has many facets......  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....... Collagen, being the major protein in connective tissue, has been extensively investigated with regard to its relation to meat tenderness, but the results have been rather conflicting. Meat from older animals is tougher than that from younger animals, and changes in the properties of the collagen due...

  1. Physics of muscle contraction

    Science.gov (United States)

    Caruel, M.; Truskinovsky, L.

    2018-03-01

    In this paper we report, clarify and broaden various recent efforts to complement the chemistry-centered models of force generation in (skeletal) muscles by mechanics-centered models. The physical mechanisms of interest can be grouped into two classes: passive and active. The main passive effect is the fast force recovery which does not require the detachment of myosin cross-bridges from actin filaments and can operate without a specialized supply of metabolic fuel (ATP). In mechanical terms, it can be viewed as a collective folding-unfolding phenomenon in the system of interacting bi-stable units and modeled by near equilibrium Langevin dynamics. The active force generation mechanism operates at slow time scales, requires detachment and is crucially dependent on ATP hydrolysis. The underlying mechanical processes take place far from equilibrium and are represented by stochastic models with broken time reversal symmetry implying non-potentiality, correlated noise or multiple reservoirs. The modeling approaches reviewed in this paper deal with both active and passive processes and support from the mechanical perspective the biological point of view that phenomena involved in slow (active) and fast (passive) force generation are tightly intertwined. They reveal, however, that biochemical studies in solution, macroscopic physiological measurements and structural analysis do not provide by themselves all the necessary insights into the functioning of the organized contractile system. In particular, the reviewed body of work emphasizes the important role of long-range interactions and criticality in securing the targeted mechanical response in the physiological regime of isometric contractions. The importance of the purely mechanical micro-scale modeling is accentuated at the end of the paper where we address the puzzling issue of the stability of muscle response on the so called ‘descending limb’ of the isometric tetanus.

  2. 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

  3. 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.

  4. Immunology Guides Skeletal Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    F. Andrea Sass

    2018-03-01

    Full Text Available Soft tissue trauma of skeletal muscle is one of the most common side effects in surgery. Muscle injuries are not only caused by accident-related injuries but can also be of an iatrogenic nature as they occur during surgical interventions when the anatomical region of interest is exposed. If the extent of trauma surpasses the intrinsic regenerative capacities, signs of fatty degeneration and formation of fibrotic scar tissue can occur, and, consequentially, muscle function deteriorates or is diminished. Despite research efforts to investigate the physiological healing cascade following trauma, our understanding of the early onset of healing and how it potentially determines success or failure is still only fragmentary. This review focuses on the initial physiological pathways following skeletal muscle trauma in comparison to bone and tendon trauma and what conclusions can be drawn from new scientific insights for the development of novel therapeutic strategies. Strategies to support regeneration of muscle tissue after injury are scarce, even though muscle trauma has a high incidence. Based on tissue specific differences, possible clinical treatment options such as local immune-modulatory and cell therapeutic approaches are suggested that aim to support the endogenous regenerative potential of injured muscle tissues.

  5. Immunology Guides Skeletal Muscle Regeneration.

    Science.gov (United States)

    Sass, F Andrea; Fuchs, Michael; Pumberger, Matthias; Geissler, Sven; Duda, Georg N; Perka, Carsten; Schmidt-Bleek, Katharina

    2018-03-13

    Soft tissue trauma of skeletal muscle is one of the most common side effects in surgery. Muscle injuries are not only caused by accident-related injuries but can also be of an iatrogenic nature as they occur during surgical interventions when the anatomical region of interest is exposed. If the extent of trauma surpasses the intrinsic regenerative capacities, signs of fatty degeneration and formation of fibrotic scar tissue can occur, and, consequentially, muscle function deteriorates or is diminished. Despite research efforts to investigate the physiological healing cascade following trauma, our understanding of the early onset of healing and how it potentially determines success or failure is still only fragmentary. This review focuses on the initial physiological pathways following skeletal muscle trauma in comparison to bone and tendon trauma and what conclusions can be drawn from new scientific insights for the development of novel therapeutic strategies. Strategies to support regeneration of muscle tissue after injury are scarce, even though muscle trauma has a high incidence. Based on tissue specific differences, possible clinical treatment options such as local immune-modulatory and cell therapeutic approaches are suggested that aim to support the endogenous regenerative potential of injured muscle tissues.

  6. Skeletal muscle performance and ageing.

    Science.gov (United States)

    Tieland, Michael; Trouwborst, Inez; Clark, Brian C

    2018-02-01

    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.

  7. Quinine for muscle cramps.

    Science.gov (United States)

    El-Tawil, Sherif; Al Musa, Tarique; Valli, Haseeb; Lunn, Michael P T; Brassington, Ruth; El-Tawil, Tariq; Weber, Markus

    2015-04-05

    Muscle cramps can occur anywhere and for many reasons. Quinine has been used to treat cramps of all causes. However, controversy continues about its efficacy and safety. This review was first published in 2010 and searches were updated in 2014. To assess the efficacy and safety of quinine-based agents in treating muscle cramps. On 27 October 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE. We searched reference lists of articles up to 2014. We also searched for ongoing trials in November 2014. Randomised controlled trials of people of all ages with muscle cramps in any location and of any cause, treated with quinine or its derivatives. Three review authors independently selected trials for inclusion, assessed risk of bias and extracted data. We contacted study authors for additional information. For comparisons including more than one trial, we assessed the quality of the evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). We identified 23 trials with a total of 1586 participants. Fifty-eight per cent of these participants were from five unpublished studies. Quinine was compared to placebo (20 trials, n = 1140), vitamin E (four trials, n = 543), a quinine-vitamin E combination (three trials, n = 510), a quinine-theophylline combination (one trial, n = 77), and xylocaine injections into the gastrocnemius muscle (one trial, n = 24). The most commonly used quinine dosage was 300 mg/day (range 200 to 500 mg). We found no new trials for inclusion when searches were updated in 2014.The risk of bias in the trials varied considerably. All 23 trials claimed to be randomised, but only a minority described randomisation and allocation concealment adequately.Compared to placebo, quinine significantly reduced cramp number over two weeks by 28%, cramp intensity by 10%, and cramp days by 20%. Cramp duration was not significantly affected.A significantly greater number of people

  8. Elicitability of muscle cramps in different leg and foot muscles.

    Science.gov (United States)

    Minetto, Marco Alessandro; Botter, Alberto

    2009-10-01

    To explore the efficacy of muscle motor point stimulation in eliciting muscle cramps, 11 subjects underwent eight sessions of electrical stimulation of the following muscles bilaterally: abductor hallucis flexor hallucis brevis, and both heads of the gastrocnemius muscles. Bursts of 150 square wave stimuli (duration: 152 micros; current intensity: 30% supramaximal) were applied. The stimulation frequency was increased from 4 pulses per second (pps) at increments of 2 pps until a cramp was induced. The number of cramps that could be elicited was smaller in flexor hallucis brevis than in abductor hallucis (16 vs. 22 out of 22 trials each; P cramp susceptibility, and the intermuscle variability in the elicitability profile for electrically induced cramps supports the use of the proposed method for cramp research.

  9. The calf muscle pump revisited.

    Science.gov (United States)

    Williams, Katherine J; Ayekoloye, Olufemi; Moore, Hayley M; Davies, Alun H

    2014-07-01

    Chronic venous disease (CVD) defines the spectrum of manifestations of venous disease that originate as a result of ambulatory venous hypertension. Thus far, the role of the calf muscle pump in the development and potentiation of CVD has been overlooked and understated in the clinical setting, with much greater emphasis placed on reflux and obstruction. The aim of this review is to explore the level of significance that calf muscle pump function or dysfunction bears on the development and potentiation of CVD. EMBASE and MEDLINE databases were searched with keywords "calf" AND "muscle" AND "pump" AND "venous" AND "insufficiency" AND ("lower limb*" OR "leg*"), screened for cross-sectional and longitudinal studies relating to chronic venous insufficiency, highlighting the role of the calf muscle pump in CVD and the extent to which the calf muscle pump is impaired in these cases. This resulted in the inclusion of 10 studies. Compared with healthy subjects, patients with CVD have a reduced ejection fraction (15.9%; P calf muscle pump ejection ability as well as poor venous competence. Calf muscle pump dysfunction is present in 55% of patients with CVD in the literature, but this did not reach significance on meta-analysis. Isotonic exercise programs in patients with active and healed ulcers have been shown to increase calf muscle pump function but not venous competence. Calf muscle pump failure is a therapeutic target in the treatment of CVD. Evidence suggests that isotonic exercise treatment may be an effective method of increasing the hemodynamic performance of the calf muscle pump. This review emphasizes the requirement for more attention to be placed on the treatment of calf muscle pump failure in cases of CVD by use of exercise treatment programs or other methods, which may be of clinical importance in managing symptomatic disease. To establish this in routine clinical practice, these results would need to be replicated in appropriate clinical trials. It would

  10. 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.

  11. Diabetic muscle infarction: radiologic evaluation

    International Nuclear Information System (INIS)

    Chason, D.P.; Fleckenstein, J.L.; Burns, D.K.; Rojas, G.

    1996-01-01

    Four patients with severe diabetes mellitus presenting with acute thigh pain, tenderness, and swelling were evaluated by imaging techniques and biopsy. Edema in the affected muscles was seen in two patients with MRI studies. Femoral artery calcification and mild muscle swelling was present in one patient who underwent CT. Decreased echogenicity was seen in the involved muscle in a patient studied with ultrasound. Serum enzymes were normal or mildly elevated in three patients (not reported in one). Biopsy demonstrated necrosis and regenerative change in all cases. MRI, although nonspecific, is the best imaging technique to suggest the diagnosis of DMI in the appropriate clinical setting, thereby obviating biopsy. (orig./MG)

  12. 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

  13. Muscle strength and muscle endurance: with and without creatine supplementation

    OpenAIRE

    KEBRIT, Daniel; RANI, Sangeeta

    2014-01-01

    Creatine is one of the legal ergogenic aids which are used by athletes here and there. A number of studies assured that it has a positive effect in high intensity short duration intensity exercise performances. This study tried to evaluate the effect of creatine monohydrate supplements on muscle strength and muscle endurance. Twenty subjects (CG= 10 and EG= 10) were participated in three months of exercise training. In this study complete randomized design was used. The EG consumed creatine a...

  14. Muscle soreness and delayed-onset muscle soreness.

    Science.gov (United States)

    Lewis, Paul B; Ruby, Deana; Bush-Joseph, Charles A

    2012-04-01

    Immediate and delayed-onset muscle soreness differ mainly in chronology of presentation. Both conditions share the same quality of pain, eliciting and relieving activities and a varying degree of functional deficits. There is no single mechanism for muscle soreness; instead, it is a culmination of 6 different mechanisms. The developing pathway of DOMS begins with microtrauma to muscles and then surrounding connective tissues. Microtrauma is then followed by an inflammatory process and subsequent shifts of fluid and electrolytes. Throughout the progression of these events, muscle spasms may be present, exacerbating the overall condition. There are a multitude of modalities to manage the associated symptoms of immediate soreness and DOMS. Outcomes of each modality seem to be as diverse as the modalities themselves. The judicious use of NSAIDs and continued exercise are suggested to be the most reliable methods and recommended. This review article and each study cited, however, represent just one part of the clinician's decisionmaking process. Careful affirmation of temporary deficits from muscle soreness is not to be taken lightly, nor is the advisement and medical management of muscle soreness prescribed by the clinician.

  15. Ethanol Exposure Causes Muscle Degeneration in Zebrafish

    Directory of Open Access Journals (Sweden)

    Elizabeth C. Coffey

    2018-03-01

    Full Text Available Alcoholic myopathies are characterized by neuromusculoskeletal symptoms such as compromised movement and weakness. Although these symptoms have been attributed to neurological damage, EtOH may also target skeletal muscle. EtOH exposure during zebrafish primary muscle development or adulthood results in smaller muscle fibers. However, the effects of EtOH exposure on skeletal muscle during the growth period that follows primary muscle development are not well understood. We determined the effects of EtOH exposure on muscle during this phase of development. Strikingly, muscle fibers at this stage are acutely sensitive to EtOH treatment: EtOH induces muscle degeneration. The severity of EtOH-induced muscle damage varies but muscle becomes more refractory to EtOH as muscle develops. NF-kB induction in muscle indicates that EtOH triggers a pro-inflammatory response. EtOH-induced muscle damage is p53-independent. Uptake of Evans blue dye shows that EtOH treatment causes sarcolemmal instability before muscle fiber detachment. Dystrophin-null sapje mutant zebrafish also exhibit sarcolemmal instability. We tested whether Trichostatin A (TSA, which reduces muscle degeneration in sapje mutants, would affect EtOH-treated zebrafish. We found that TSA and EtOH are a lethal combination. EtOH does, however, exacerbate muscle degeneration in sapje mutants. EtOH also disrupts adhesion of muscle fibers to their extracellular matrix at the myotendinous junction: some detached muscle fibers retain beta-Dystroglycan indicating failure of muscle end attachments. Overexpression of Paxillin, which reduces muscle degeneration in zebrafish deficient for beta-Dystroglycan, is not sufficient to rescue degeneration. Taken together, our results suggest that EtOH exposure has pleiotropic deleterious effects on skeletal muscle.

  16. Compensatory Hypertrophy of Skeletal Muscle: Contractile Characteristics

    Science.gov (United States)

    Ianuzzo, C. D.; Chen, V.

    1977-01-01

    Describes an experiment using rats that demonstrates contractile characteristics of normal and hypertrophied muscle. Compensatory hypertrophy of the plantaris muscle is induced by surgical removal of the synergistic gastrocnemium muscle. Includes methods for determination of contractile properties of normal and hypertrophied muscle and…

  17. 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 ...

  18. Quantitative muscle ultrasonography in amyotrophic lateral sclerosis.

    NARCIS (Netherlands)

    Arts, I.M.P.; Rooij, F.G. van; Overeem, S.; Pillen, S.; Janssen, H.M.; Schelhaas, H.J.; Zwarts, M.J.

    2008-01-01

    In this study, we examined whether quantitative muscle ultrasonography can detect structural muscle changes in early-stage amyotrophic lateral sclerosis (ALS). Bilateral transverse scans were made of five muscles or muscle groups (sternocleidomastoid, biceps brachii/brachialis, forearm flexor group,

  19. Diabetic muscle infarction: atypical MR appearance

    International Nuclear Information System (INIS)

    Sharma, P.; Mangwana, S.; Kapoor, R.K.

    2000-01-01

    We describe a case of diabetic muscle infarction which had atypical features of hyperintensity of the affected muscle on T1-weighted images. Biopsy was performed which revealed diffuse extensive hemorrhage within the infarcted muscle. We believe increased signal intensity on T1-weighted images should suggest hemorrhage within the infarcted muscle. (orig.)

  20. Unconventional Functions of Muscles in Planarian Regeneration.

    Science.gov (United States)

    Cutie, Stephen; Hoang, Alison T; Payumo, Alexander Y; Huang, Guo N

    2017-12-18

    Muscles are traditionally considered in the context of force generation. Scimone et al. (2017), reporting in Nature, now examine muscles in a developmental setting and find unexpected roles for distinct planarian muscle fibers. The authors show that muscles provide patterning signals to promote regeneration and guide tissue growth after injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Exercise-induced muscle modifications

    International Nuclear Information System (INIS)

    Kerviler, E. de; Willig, A.L.; Jehenson, P.; Duboc, D.; Syrota, A.

    1990-01-01

    This paper compares changes in muscle proton T2 after exercise in normal subjects and in patients with muscular glycogenoses. Four patients suffering from muscular glycogenosis and eight normal volunteers were studied. Muscle T2s were measured in forearm muscles at rest and after exercise, with a 0.5-T imager. The exercise was performed with handgrips and was evaluated by P-31 spectroscopy (end-exercise decrease in pH and phosphocreatine) performed with a 2-T magnet. In normal subjects, a relative T2 increase, ranging from 14% to 44%, was observed in the exercised muscles. In the patients, who cannot produce lactate during exercise, weak pH variation occurred, and only a slight T2 increase (7% - 9%) was observed

  2. 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)....

  3. Muscle dysfunction in cancer patients

    DEFF Research Database (Denmark)

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

    2014-01-01

    dysfunction in cancer patients lies in the correlation to vital clinical end points such as cancer-specific and all-cause mortality, therapy complications and quality of life (QoL). Such associations strongly emphasize the need for effective therapeutic countermeasures to be developed and implemented......BACKGROUND: Muscle dysfunction is a prevalent phenomenon in the oncology setting where patients across a wide range of diagnoses are subject to impaired muscle function regardless of tumor stage and nutritional state. Here, we review the current evidence describing the degree, causes and clinical...... 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 Activation and Movement Coordination.

    OpenAIRE

    Ljung, Carl

    2014-01-01

    The purpose of this project was to empirically develop a method of using electromyography to identify how humans coordinate their muscles during certain sequences of movement and the effect of an injured anterior cruciate ligament to muscle coordination. In this study, more simple movements of the lower extremities are examined and relatively accurate hypothesizes can be made solely based on anatomical theory. However, a general method for electromyographic studies would open up the possibili...

  5. Determinants of muscle carnosine content.

    Science.gov (United States)

    Harris, R C; Wise, J A; Price, K A; Kim, H J; Kim, C K; Sale, C

    2012-07-01

    The main determinant of muscle carnosine (M-Carn) content is undoubtedly species, with, for example, aerobically trained female vegetarian athletes [with circa 13 mmol/kg dry muscle (dm)] having just 1/10th of that found in trained thoroughbred horses. Muscle fibre type is another key determinant, as type II fibres have a higher M-Carn or muscle histidine containing dipeptide (M-HCD) content than type I fibres. In vegetarians, M-Carn is limited by hepatic synthesis of β-alanine, whereas in omnivores this is augmented by the hydrolysis of dietary supplied HCD's resulting in muscle levels two or more times higher. β-alanine supplementation will increase M-Carn. The same increase in M-Carn occurs with administration of an equal molar quantity of carnosine as an alternative source of β-alanine. Following the cessation of supplementation, M-Carn returns to pre-supplementation levels, with an estimated t1/2 of 5-9 weeks. Higher than normal M-Carn contents have been noted in some chronically weight-trained subjects, but it is unclear if this is due to the training per se, or secondary to changes in muscle fibre composition, an increase in β-alanine intake or even anabolic steroid use. There is no measureable loss of M-Carn with acute exercise, although exercise-induced muscle damage may result in raised plasma concentrations in equines. Animal studies indicate effects of gender and age, but human studies lack sufficient control of the effects of diet and changes in muscle fibre composition.

  6. 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

  7. 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.

  8. Variability of femoral muscle attachments.

    Science.gov (United States)

    Duda, G N; Brand, D; Freitag, S; Lierse, W; Schneider, E

    1996-09-01

    Analytical and experimental models of the musculoskeletal system often assume single values rather than ranges for anatomical input parameters. The hypothesis of the present study was that anatomical variability significantly influences the results of biomechanical analyses, specifically regarding the moment arms of the various thigh muscles. Insertions and origins of muscles crossing or attaching to the femur were digitized in six specimens. Muscle volumes were measured; muscle attachment area and centroid location were computed. To demonstrate the influence of inter-individual anatomic variability on a mechanical modeling parameter, the corresponding range of muscle moment arms were calculated. Standard deviations, as a percentage of the mean, were about 70% for attachment area and 80% for muscle volume and attachment centroid location. The resulting moment arms of the m. gluteus maximus and m. rectus femoris were especially sensitive to anatomical variations (SD 65%). The results indicate that sensitivity to anatomical variations should be analyzed in any investigation simulating musculoskeletal interactions. To avoid misinterpretations, investigators should consider using several anatomical configurations rather than relying on a mean data set.

  9. 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.

  10. Mitochondrial respiration in hummingbird flight muscles.

    OpenAIRE

    Suarez, R K; Lighton, J R; Brown, G S; Mathieu-Costello, O

    1991-01-01

    Respiration rates of muscle mitochondria in flying hummingbirds range from 7 to 10 ml of O2 per cm3 of mitochondria per min, which is about 2 times higher than the range obtained in the locomotory muscles of mammals running at their maximum aerobic capacities (VO2max). Capillary volume density is higher in hummingbird flight muscles than in mammalian skeletal muscles. Mitochondria occupy approximately 35% of fiber volume in hummingbird flight muscles and cluster beneath the sarcolemmal membra...

  11. 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

  12. 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.

  13. Role of muscle pulleys in producing eye position-dependence in the angular vestibuloocular reflex: a model-based study

    Science.gov (United States)

    Thurtell, M. J.; Kunin, M.; Raphan, T.; Wall, C. C. (Principal Investigator)

    2000-01-01

    It is well established that the head and eye velocity axes do not always align during compensatory vestibular slow phases. It has been shown that the eye velocity axis systematically tilts away from the head velocity axis in a manner that is dependent on eye-in-head position. The mechanisms responsible for producing these axis tilts are unclear. In this model-based study, we aimed to determine whether muscle pulleys could be involved in bringing about these phenomena. The model presented incorporates semicircular canals, central vestibular pathways, and an ocular motor plant with pulleys. The pulleys were modeled so that they brought about a rotation of the torque axes of the extraocular muscles that was a fraction of the angle of eye deviation from primary position. The degree to which the pulleys rotated the torque axes was altered by means of a pulley coefficient. Model input was head velocity and initial eye position data from passive and active yaw head impulses with fixation at 0 degrees, 20 degrees up and 20 degrees down, obtained from a previous experiment. The optimal pulley coefficient required to fit the data was determined by calculating the mean square error between data and model predictions of torsional eye velocity. For active head impulses, the optimal pulley coefficient varied considerably between subjects. The median optimal pulley coefficient was found to be 0.5, the pulley coefficient required for producing saccades that perfectly obey Listing's law when using a two-dimensional saccadic pulse signal. The model predicted the direction of the axis tilts observed in response to passive head impulses from 50 ms after onset. During passive head impulses, the median optimal pulley coefficient was found to be 0.21, when roll gain was fixed at 0.7. The model did not accurately predict the alignment of the eye and head velocity axes that was observed early in the response to passive head impulses. We found that this alignment could be well predicted if

  14. Novel muscle spindles containing muscle fibers devoid of sensory innervation in the extensor digitorum longus muscle of aged rats.

    Science.gov (United States)

    Desaki, Junzo; Nishida, Naoya

    2008-04-01

    We examined the structural features of muscle spindles at the equatorial and juxtaequatorial regions in the extensor digitorum longus muscle of adult (12 months) and aged (25 months) rats. In aged muscle spindles, the lamellated layers of the spindle capsule were a little increased in number compared to those in the adult ones. Two novel muscle spindles were observed in the aged muscle. In one muscle spindle, the spindle capsule contained four thin intrafusal muscle fibers invested by the inner capsule and two muscle fibers between the layers of the spindle capsule. Serial semithin sections revealed that the latter lacked the investment of the spindle capsule at the polar region. The other muscle spindle contained four intrafusal muscle fibers: two thin sensory-innervated muscle fibers invested by the inner capsule and two thick muscle fibers similar in structural features to neighboring extrafusal muscle fibers and lacking sensory innervation within the wide periaxial space. These findings suggest that two muscle fibers between the layers of the spindle capsule may be invested by the newly formed capsular cells during aging, while two thick fibers within the periaxial space may fail to receive the sensory innervation during the early development and follow the course of extrafusal fiber differentiation.

  15. 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

  16. 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.

  17. 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.

  18. Inspiratory muscle training attenuates the human respiratory muscle metaboreflex

    Science.gov (United States)

    Witt, Jonathan D; Guenette, Jordan A; Rupert, Jim L; McKenzie, Donald C; Sheel, A William

    2007-01-01

    We hypothesized that inspiratory muscle training (IMT) would attenuate the sympathetically mediated heart rate (HR) and mean arterial pressure (MAP) increases normally observed during fatiguing inspiratory muscle work. An experimental group (Exp, n = 8) performed IMT 6 days per week for 5 weeks at 50% of maximal inspiratory pressure (MIP), while a control group (Sham, n = 8) performed IMT at 10% MIP. Pre- and post-training, subjects underwent a eucapnic resistive breathing task (RBT) (breathing frequency = 15 breaths min−1, duty cycle = 0.70) while HR and MAP were continuously monitored. Following IMT, MIP increased significantly (P inspiratory work. We attribute our findings to a reduced activity of chemosensitive afferents within the inspiratory muscles and may provide a mechanism for some of the whole-body exercise endurance improvements associated with IMT. PMID:17855758

  19. Inspiratory muscle training for asthma.

    Science.gov (United States)

    Silva, Ivanizia S; Fregonezi, Guilherme A F; Dias, Fernando A L; Ribeiro, Cibele T D; Guerra, Ricardo O; Ferreira, Gardenia M H

    2013-09-08

    In some people with asthma, expiratory airflow limitation, premature closure of small airways, activity of inspiratory muscles at the end of expiration and reduced pulmonary compliance may lead to lung hyperinflation. With the increase in lung volume, chest wall geometry is modified, shortening the inspiratory muscles and leaving them at a sub-optimal position in their length-tension relationship. Thus, the capacity of these muscles to generate tension is reduced. An increase in cross-sectional area of the inspiratory muscles caused by hypertrophy could offset the functional weakening induced by hyperinflation. Previous studies have shown that inspiratory muscle training promotes diaphragm hypertrophy in healthy people and patients with chronic heart failure, and increases the proportion of type I fibres and the size of type II fibres of the external intercostal muscles in patients with chronic obstructive pulmonary disease. However, its effects on clinical outcomes in patients with asthma are unclear. To evaluate the efficacy of inspiratory muscle training with either an external resistive device or threshold loading in people with asthma. We searched the Cochrane Airways Group Specialised Register of trials, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and reference lists of included studies. The latest search was performed in November 2012. We included randomised controlled trials that involved the use of an external inspiratory muscle training device versus a control (sham or no inspiratory training device) in people with stable asthma. We used standard methodological procedures expected by The Cochrane Collaboration. We included five studies involving 113 adults. Participants in four studies had mild to moderate asthma and the fifth study included participants independent of their asthma severity. There were substantial differences between the studies, including the training protocol, duration of training sessions (10 to 30

  20. Laughing: a demanding exercise for trunk muscles.

    Science.gov (United States)

    Wagner, Heiko; Rehmes, Ulrich; Kohle, Daniel; Puta, Christian

    2014-01-01

    Social, psychological, and physiological studies have provided evidence indicating that laughter imposes an increased demand on trunk muscles. It was the aim of this study to quantify the activation of trunk muscles during laughter yoga in comparison with crunch and back lifting exercises regarding the mean trunk muscle activity. Muscular activity during laughter yoga exercises was measured by surface electromyography of 5 trunk muscles. The activation level of internal oblique muscle during laughter yoga is higher compared to the traditional exercises. The multifidus, erector spinae, and rectus abdominis muscles were nearly half activated during laughter yoga, while the activation of the external oblique muscle was comparable with the crunch and back lifting exercises. Our results indicate that laughter yoga has a positive effect on trunk muscle activation. Thus, laughter seems to be a good activator of trunk muscles, but further research is required whether laughter yoga is a good exercise to improve neuromuscular recruitment patterns for spine stability.

  1. 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

  2. Nuclear Positioning in Muscle Development and Disease

    Directory of Open Access Journals (Sweden)

    Eric eFolker

    2013-12-01

    Full Text Available Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, the nuclei are often clustered within the center of the muscle cell. Although this phenotype has been acknowledged for several decades, it is often ignored as a contributor to muscle weakness. Rather, these nuclei are taken only as a sign of muscle repair. Here we review the evidence that mispositioned myonuclei are not merely a symptom of muscle disease but also a cause. Additionally, we review the working models for how myonuclei move from two different perspectives, from that of the nucleus and from that of the cytoskeleton. We further compare and contrast these mechanisms with the mechanisms of nuclear movement in other cell types both to draw general themes for nuclear movement and to identify muscle-specific considerations. Finally, we focus on factors that can be linked to muscle disease and find that genes that regulate myonuclear movement and positioning have been linked to muscular dystrophy. Although the cause-effect relationship is largely speculative, recent data indicate that the position of nuclei should no longer be considered only a means to diagnose muscle disease.

  3. Diagnosis of skeletal muscle channelopathies.

    Science.gov (United States)

    Spillane, Jennifer; Fialho, Doreen; Hanna, Michael G

    2013-11-01

    Skeletal muscle channelopathies are rare disorders of muscle membrane excitability. Their episodic nature may result in diagnostic difficulty and delays in diagnosis. Advances in diagnostic clinical electrophysiology combined with DNA-based diagnosis have improved diagnostic accuracy and efficiency. Ascribing pathogenic status to identified genetic variants in muscle channel genes may be complex and functional analysis, including molecular expression, may help with this. Accurate clinical and genetic diagnosis enables genetic counselling, advice regarding prognosis and aids treatment selection. An approach to accurate and efficient diagnosis is outlined. The importance of detailed clinical evaluation including careful history, examination and family history is emphasised. The role of specialised electrodiagnostics combined with DNA testing and molecular expression is considered. New potential biomarkers including muscle MRI using MRC Centre protocols are discussed. A combined diagnostic approach using careful clinical assessment, specialised neurophysiology and DNA testing will now achieve a clear diagnosis in most patients with muscle channelopathies. An accurate diagnosis enables genetic counselling and provides information regarding prognosis and treatment selection. Genetic analysis often identifies new variants of uncertain significance. In this situation, functional expression studies as part of a diagnostic service will enable determination of pathogenic status of novel genetic variants.

  4. Muscle channelopathies and related diseases.

    Science.gov (United States)

    Fontaine, Bertrand

    2013-01-01

    Muscle channelopathies and related disorders are neuromuscular disorders predominantly of genetic origin which are caused by mutations in ion channels or genes that play a role in muscle excitability. They include different forms of periodic paralysis which are characterized by acute and reversible attacks of muscle weakness concomitant to changes in blood potassium levels. These disorders may also present as distinguishable myotonic syndromes (slowed muscle relaxation) which have in common lack of involvement of dystrophic changes of the muscle, in contrast to dystrophia myotonica. Recent advances have been made in the diagnosis of these different disorders, which require, in addition to a careful clinical evaluation, detailed EMG and molecular study. Although these diseases are rare, they deserve attention since patients may benefit from drugs which can dramatically improve their condition. Patients may have atypical presentations, sometimes life-threatening, which may delay a proper diagnosis, mostly in the first months of life. The creation of specialized reference centers in the Western world has greatly benefited the proper recognition of these neuromuscular diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. 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

  6. Regeneration of muscle fibers in the extensor digitorum longus muscle of the aged rat.

    Science.gov (United States)

    Desaki, Junzo

    2008-04-01

    Regeneration of muscle fibers was observed in the extensor digitorum longus (EDL) muscle of aged (24 and 27 months) Wistar rats. The aged muscles consisted almost exclusively of medium-sized muscle fibers. In addition to degenerating and/or atrophied muscle fibers, very small muscle fibers <10 mum in diameter were observed in some muscle bundles which sporadically distributed in the muscle. In the degenerating muscle fibers, satellite cells mostly appeared to be normal, possibly surviving within the scaffold of basal lamina to form new (regenerating) muscle fibers. However, some of the satellite cells were degenerated and destroyed, suggesting the decrease in number of muscle fibers. On the other hand, very small muscle fibers existed between small and/or medium-sized muscle fibers or in the wide interstitial spaces between them solitarily or in small groups. In addition, immature muscle cells having a centrally located nucleus and sporadically distributed myofilaments were observed among the small and/or medium-sized muscle fibers and partially lacked a layer of basal lamina. These immature muscle cells were often closely apposed to fibroblasts with some slender cytoplasmic processes and/or to each other without an interposing basal lamina. These findings suggest that in addition to satellite cells within the basal lamina tubes, some of the regenerating muscle fibers in the aged EDL muscle may be originated from mesenchymal cells such as fibroblasts in the interstitial spaces.

  7. A further observation of muscle spindles in the extensor digitorum longus muscle of the aged rat.

    Science.gov (United States)

    Desaki, Junzo; Nishida, Naoya

    2010-01-01

    We observed three novel muscle spindles in the extensor digitorum longus muscle of the aged (20 months) rat. Two muscle spindles of the three contained thin muscle fibers lacking sensory innervation between the layers of the spindle capsule and within the periaxial space, respectively. The other one contained sensory-innervated thin muscle fibers with an indistinct equatorial nucleation between the layers of the spindle capsule. These findings suggest that the occurrence of thin muscle fibers may be intimately related to the degeneration and regeneration of extrafusal muscle fibers during aging and that these newly formed thin muscle fibers may often fail to receive sensory innervation.

  8. Evaluation of muscle function of the extensor digitorum longus muscle ex vivo and tibialis anterior muscle in situ in mice.

    Science.gov (United States)

    Hakim, Chady H; Wasala, Nalinda B; Duan, Dongsheng

    2013-02-09

    Body movements are mainly provided by mechanical function of skeletal muscle. Skeletal muscle is composed of numerous bundles of myofibers that are sheathed by intramuscular connective tissues. Each myofiber contains many myofibrils that run longitudinally along the length of the myofiber. Myofibrils are the contractile apparatus of muscle and they are composed of repeated contractile units known as sarcomeres. A sarcomere unit contains actin and myosin filaments that are spaced by the Z discs and titin protein. Mechanical function of skeletal muscle is defined by the contractile and passive properties of muscle. The contractile properties are used to characterize the amount of force generated during muscle contraction, time of force generation and time of muscle relaxation. Any factor that affects muscle contraction (such as interaction between actin and myosin filaments, homeostasis of calcium, ATP/ADP ratio, etc.) influences the contractile properties. The passive properties refer to the elastic and viscous properties (stiffness and viscosity) of the muscle in the absence of contraction. These properties are determined by the extracellular and the intracellular structural components (such as titin) and connective tissues (mainly collagen) (1-2). The contractile and passive properties are two inseparable aspects of muscle function. For example, elbow flexion is accomplished by contraction of muscles in the anterior compartment of the upper arm and passive stretch of muscles in the posterior compartment of the upper arm. To truly understand muscle function, both contractile and passive properties should be studied. The contractile and/or passive mechanical properties of muscle are often compromised in muscle diseases. A good example is Duchenne muscular dystrophy (DMD), a severe muscle wasting disease caused by dystrophin deficiency (3). Dystrophin is a cytoskeletal protein that stabilizes the muscle cell membrane (sarcolemma) during muscle contraction (4). In the

  9. Exercise Promotes Healthy Aging of Skeletal Muscle

    Science.gov (United States)

    Cartee, Gregory D.; Hepple, Russell T.; Bamman, Marcas M.; Zierath, Juleen R.

    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. PMID:27304505

  10. 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.

  11. Partial muscle carnitine palmitoyltransferase-A deficiency

    International Nuclear Information System (INIS)

    Ross, N.S.; Hoppel, C.L.

    1987-01-01

    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

  12. 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.

  13. The arrangement of muscle fibers and tendons in two muscles used for growth studies.

    Science.gov (United States)

    Stickland, N C

    1983-01-01

    The arrangement of muscle fibres and tendons was examined in the soleus muscle of rats from 6 to 175 days post partum. The muscle was seen to change from a simple structure, with mean fibre length of approximately 90% of complete muscle length, to a unipennate structure, with mean fibre length of only about 60% of muscle length. The dog pectineus muscle was also investigated and found to have a bipennate structure throughout postnatal growth. The arrangement of muscle fibres in both these muscles is such that it might be difficult (particularly in the older animals) to cut a transverse section through all the fibres contained in the muscle; some fibres might not enter the plane of section. Results on muscle fibre number in these muscles at different ages may therefore be misleading.

  14. Muscle cramps in liver disease.

    Science.gov (United States)

    Mehta, Shivang S; Fallon, Michael B

    2013-11-01

    Muscle cramps are common in patients with liver disease and adversely influence quality of life. The exact mechanisms by which they occur remain unclear, although a number of pathophysiological events unique to liver disease may contribute. Clinical studies have identified alterations in 3 areas: nerve function, energy metabolism, and plasma volume/electrolytes. Treatments have focused on these particular areas with varied results. This review will focus on the clinical features of muscle cramps in patients with liver disease and review potential mechanisms and current therapies. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

  15. Muscle after spinal cord injury

    DEFF Research Database (Denmark)

    Biering-Sørensen, Bo; Kristensen, Ida Bruun; Kjaer, Michael

    2009-01-01

    The morphological and contractile changes of muscles below the level of the lesion after spinal cord injury (SCI) are dramatic. In humans with SCI, a fiber-type transformation away from type I begins 4-7 months post-SCI and reaches a new steady state with predominantly fast glycolytic IIX fibers...... years after the injury. There is a progressive drop in the proportion of slow myosin heavy chain (MHC) isoform fibers and a rise in the proportion of fibers that coexpress both the fast and slow MHC isoforms. The oxidative enzymatic activity starts to decline after the first few months post-SCI. Muscles...

  16. 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...... 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...

  17. 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.

  18. Muscle phosphoglycerate mutase deficiency revisited

    DEFF Research Database (Denmark)

    Naini, Ali; Toscano, Antonio; Musumeci, Olimpia

    2009-01-01

    storage disease type X and novel mutations in the gene encoding the muscle subunit of PGAM (PGAM2). DESIGN: Clinical, pathological, biochemical, and molecular analyses. SETTING: Tertiary care university hospitals and academic institutions. Patients A 37-year-old Danish man of Pakistani origin who had...... PGAM deficiency, and molecular studies revealed 2 novel homozygous mutations, a nonsense mutation and a single nucleotide deletion. Pathological studies of muscle showed mild glycogen accumulation but prominent tubular aggregates in both patients. CONCLUSIONS: We found that glycogen storage disease...

  19. Neural effects of muscle stretching on the spinal reflexes in multiple lower-limb muscles.

    Science.gov (United States)

    Masugi, Yohei; Obata, Hiroki; Inoue, Daisuke; Kawashima, Noritaka; Nakazawa, Kimitaka

    2017-01-01

    While previous studies have shown that muscle stretching suppresses monosynaptic spinal reflex excitability in stretched muscles, its effects on non-stretched muscles is still largely unknown. The purpose of this study was to examine the effects of muscle stretching on monosynaptic spinal reflex in non-stretched muscles. Ten healthy male subjects participated in this study. Muscle stretching of the right triceps surae muscle was performed using a motor torque device for 1 minute. Three different dorsiflexion torques (at approximately 5, 10, and 15 Nm) were applied during muscle stretching. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded in both the lower-limb muscles before, during, and at 0 and 5 min following muscle stretching. The amplitudes of the spinal reflexes in both the stretched and non-stretched muscles in the right (ipsilateral) leg were smaller during stretching compared to before, and at 0 and 5 min after stretching. Furthermore, the degree of reduction in the amplitude of the spinal reflexes in the right (ipsilateral) leg muscles increased significantly as the dorsiflexion torque (i.e., stretching of the right triceps surae muscles) increased. In contrast, reduction in the amplitude of the spinal reflexes with increasing dorsiflexion torque was not seen in the left (contralateral) leg muscles. Our results clearly indicate that muscle stretching has inhibitory effects on monosynaptic spinal reflexes, not only in stretched muscles, but also in non-stretched muscles of the ipsilateral leg.

  20. PLASTICITY OF SKELETAL MUSCLE STUDIED BY STEREOLOGY

    Directory of Open Access Journals (Sweden)

    Ida Eržen

    2011-05-01

    Full Text Available The present contribution provides an overview of stereological methods applied in the skeletal muscle research at the Institute of Anatomy of the Medical Faculty in Ljubljana. Interested in skeletal muscle plasticity we studied three different topics: (i expression of myosin heavy chain isoforms in slow and fast muscles under experimental conditions, (ii frequency of satellite cells in young and old human and rat muscles and (iii capillary supply of rat fast and slow muscles. We analysed the expression of myosin heavy chain isoforms within slow rat soleus and fast extensor digitorum longus muscles after (i homotopic and heterotopic transplantation of both muscles, (ii low frequency electrical stimulation of the fast muscle and (iii transposition of the fast nerve to the slow muscle. The models applied were able to turn the fast muscle into a completely slow muscle, but not vice versa. One of the indicators for the regenerative potential of skeletal muscles is its satellite cell pool. The estimated parameters, number of satellite cells per unit fibre length, corrected to the reference sarcomere length (Nsc/Lfib and number of satellite cells per number of nuclei (myonuclei and satellite cell nuclei (Nsc/Nnucl indicated that the frequency of M-cadherin stained satellite cells declines in healthy old human and rat muscles compared to young muscles. To access differences in capillary densities among slow and fast muscles and slow and fast muscle fibres, we have introduced Slicer and Fakir methods, and tested them on predominantly slow and fast rat muscles. Discussing three different topics that require different approach, the present paper reflects the three decades of the development of stereological methods: 2D analysis by simple point counting in the 70's, the disector in the 80's and virtual spatial probes in the 90's. In all methods the interactive computer assisted approach was utilised.

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

    African Journals Online (AJOL)

    More prolonged or regular cramps may be treated with drugs. Tizanidine which is an agonist at á ... 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. The patients suffering from ...

  2. Myofascial force transmisison between antagonistic rat lower limb muscles: effects of single muscle or muscle group lengthening

    NARCIS (Netherlands)

    Meijer, Hanneke J.M; Rijkelijkhuizen, Josina M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  3. Myofascial force transmission between antagonistic rat lower limb muscles: Effects of single muscle or muscle group lengthening.

    NARCIS (Netherlands)

    Meijer, H.J.M.; Rijkelijkhuizen, J.M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  4. Bones, Muscles, and Joints: The Musculoskeletal System

    Science.gov (United States)

    ... Skeletal muscles are called striated (pronounced: STRY-ay-ted) because they are made up of fibers that ... blood through your body. When we smile and talk, muscles are helping us communicate, and when we ...

  5. Measurement and Treatment of Passive Muscle Stiffness

    DEFF Research Database (Denmark)

    Kirk, Henrik

    This PhD thesis is based on research conducted at the University of Copenhagen and Helene Elsass Center from 2012 to 2015. Measurements and treatment of passive muscle stiffness in people with cerebral palsy (CP) comprise the focus of the thesis. The thesis summarizes the results from four studies......, which aimed to investigate: 1) The development of a clinical method to evaluate and distinguish neural (reflex mediated stiffness) and non-neural (passive muscle stiffness) components of muscle stiffness in adults with CP by objective and reliable measurements. 2) The association between increased...... passive muscle, muscle strength and gait function in adults with CP 3) The effect of resistance training and gait training accordingly on muscle strength, passive muscle stiffness and functional gait in adults with CP. The first part of the thesis defines reflex mediated stiffness and passive muscle...

  6. Magnetic resonance imaging of facial muscles

    Energy Technology Data Exchange (ETDEWEB)

    Farrugia, M.E. [Department of Clinical Neurology, University of Oxford, Radcliffe Infirmary, Oxford (United Kingdom)], E-mail: m.e.farrugia@doctors.org.uk; Bydder, G.M. [Department of Radiology, University of California, San Diego, CA 92103-8226 (United States); Francis, J.M.; Robson, M.D. [OCMR, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford (United Kingdom)

    2007-11-15

    Facial and tongue muscles are commonly involved in patients with neuromuscular disorders. However, these muscles are not as easily accessible for biopsy and pathological examination as limb muscles. We have previously investigated myasthenia gravis patients with MuSK antibodies for facial and tongue muscle atrophy using different magnetic resonance imaging sequences, including ultrashort echo time techniques and image analysis tools that allowed us to obtain quantitative assessments of facial muscles. This imaging study had shown that facial muscle measurement is possible and that useful information can be obtained using a quantitative approach. In this paper we aim to review in detail the methods that we applied to our study, to enable clinicians to study these muscles within the domain of neuromuscular disease, oncological or head and neck specialties. Quantitative assessment of the facial musculature may be of value in improving the understanding of pathological processes occurring within facial muscles in certain neuromuscular 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

    in cardiac, skeletal, and smooth muscle suggest all mitochondria are created equal, the contrasting RCR and non-phosphorylating respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation...

  8. The characteristics of a pneumatic muscle

    Directory of Open Access Journals (Sweden)

    Pietrala Dawid

    2017-01-01

    Full Text Available The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics. It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics. It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics. The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  9. The characteristics of a pneumatic muscle

    Science.gov (United States)

    Pietrala, Dawid

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  10. Magnetic resonance imaging of facial muscles

    International Nuclear Information System (INIS)

    Farrugia, M.E.; Bydder, G.M.; Francis, J.M.; Robson, M.D.

    2007-01-01

    Facial and tongue muscles are commonly involved in patients with neuromuscular disorders. However, these muscles are not as easily accessible for biopsy and pathological examination as limb muscles. We have previously investigated myasthenia gravis patients with MuSK antibodies for facial and tongue muscle atrophy using different magnetic resonance imaging sequences, including ultrashort echo time techniques and image analysis tools that allowed us to obtain quantitative assessments of facial muscles. This imaging study had shown that facial muscle measurement is possible and that useful information can be obtained using a quantitative approach. In this paper we aim to review in detail the methods that we applied to our study, to enable clinicians to study these muscles within the domain of neuromuscular disease, oncological or head and neck specialties. Quantitative assessment of the facial musculature may be of value in improving the understanding of pathological processes occurring within facial muscles in certain neuromuscular disorders

  11. Study on distribution of terminal branches of the facial nerve in mimetic muscles (orbicularis oculi muscle and orbicularis oris muscle).

    Science.gov (United States)

    Mitsukawa, Nobuyuki; Moriyama, Hiroshi; Shiozawa, Kei; Satoh, Kaneshige

    2014-01-01

    There have been many anatomical reports to date regarding the course of the facial nerve to the mimetic muscles. However, reports are relatively scarce on the detailed distribution of the terminal branches of the facial nerve to the mimetic muscles. In this study, we performed detailed examination of the terminal facial nerve branches to the mimetic muscles, particularly the branches terminating in the orbicularis oculi muscle and orbicularis oris muscle. Examination was performed on 25 Japanese adult autopsy cases, involving 25 hemifaces. The mean age was 87.4 years (range, 60-102 years). There were 12 men and 13 women (12 left hemifaces and 13 right hemifaces). In each case, the facial nerve was exposed through a preauricular skin incision. The main trunk of the facial nerve was dissected from the stylomastoid foramen. A microscope was used to dissect the terminal branches to the periphery and observe them. The course and distribution were examined for all terminal branches of the facial nerve. However, focus was placed on the course and distribution of the zygomatic branch, buccal branch, and mandibular branch to the orbicularis oculi muscle and orbicularis oris muscle. The temporal branch was distributed to the orbicularis oculi muscle in all cases and the marginal mandibular branch was distributed to the orbicularis oris muscle in all cases. The zygomatic branch was distributed to the orbicularis oculi muscle in all cases, but it was also distributed to the orbicularis oris muscle in 10 of 25 cases. The buccal branch was not distributed to the orbicularis oris muscle in 3 of 25 cases, and it was distributed to the orbicularis oculi muscle in 8 cases. There was no significant difference in the variations. The orbicularis oculi muscle and orbicularis oris muscle perform particularly important movements among the facial mimetic muscles. According to textbooks, the temporal branch and zygomatic branch innervate the orbicularis oculi muscle, and the buccal branch

  12. Exercise Promotes Healthy Aging of Skeletal Muscle

    DEFF Research Database (Denmark)

    Cartee, Gregory D; Hepple, Russell T; Bamman, Marcas M

    2016-01-01

    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....

  13. Muscle fatigue: general understanding and treatment

    Science.gov (United States)

    Wan, Jing-jing; Qin, Zhen; Wang, Peng-yuan; Sun, Yang; Liu, Xia

    2017-01-01

    Muscle fatigue is a common complaint in clinical practice. In humans, muscle fatigue can be defined as exercise-induced decrease in the ability to produce force. Here, to provide a general understanding and describe potential therapies for muscle fatigue, we summarize studies on muscle fatigue, including topics such as the sequence of events observed during force production, in vivo fatigue-site evaluation techniques, diagnostic markers and non-specific but effective treatments. PMID:28983090

  14. Muscle fatigue: general understanding and treatment

    OpenAIRE

    Wan, Jing-jing; Qin, Zhen; Wang, Peng-yuan; Sun, Yang; Liu, Xia

    2017-01-01

    Muscle fatigue is a common complaint in clinical practice. In humans, muscle fatigue can be defined as exercise-induced decrease in the ability to produce force. Here, to provide a general understanding and describe potential therapies for muscle fatigue, we summarize studies on muscle fatigue, including topics such as the sequence of events observed during force production, in vivo fatigue-site evaluation techniques, diagnostic markers and non-specific but effective treatments.

  15. 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...

  16. The characteristics of a pneumatic muscle

    OpenAIRE

    Pietrala Dawid

    2017-01-01

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles s...

  17. 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.

  18. Muscle mechanics and neuromuscular control

    NARCIS (Netherlands)

    Hof, AL

    The purpose of this paper is to demonstrate that the properties of the mechanical system, especially muscle elasticity and limb mass, to a large degree determine force output and movement. This makes the control demands of the central nervous system simpler and more robust. In human triceps surae, a

  19. Aging of Skeletal Muscle Fibers

    Science.gov (United States)

    Miljkovic, Natasa; Lim, Jae-Young; Miljkovic, Iva

    2015-01-01

    Aging has become an important topic for scientific research because life expectancy and the number of men and women in older age groups have increased dramatically in the last century. This is true in most countries of the world including the Republic of Korea and the United States. From a rehabilitation perspective, the most important associated issue is a progressive decline in functional capacity and independence. Sarcopenia is partly responsible for this decline. Many changes underlying the loss of muscle mass and force-generating capacity of skeletal muscle can be understood at the cellular and molecular levels. Muscle size and architecture are both altered with advanced adult age. Further, changes in myofibers include impairments in several physiological domains including muscle fiber activation, excitation-contraction coupling, actin-myosin cross-bridge interaction, energy production, and repair and regeneration. A thorough understanding of these alterations can lead to the design of improved preventative and rehabilitative interventions, such as personalized exercise training programs. PMID:25932410

  20. Evaluation of isokinetic muscle performance.

    Science.gov (United States)

    Watkins, M P; Harris, B A

    1983-03-01

    The development and availability of isokinetic testing equipment, recording systems, and systems for computer analysis have improved the quality and quantity of information about specific skeletal muscle performance. The value of both isokinetic exercise and instrumentation designed to objectively record muscle performance characteristics is becoming more widely recognized, especially by professional members of the sports medicine community. The present demand for appropriate equipment is high and new instrumentation for this purpose is being developed. Current instrumentation continues to be modified and improved. The information gained from carefully designed testing protocols is useful and necessary for understanding the role of specific muscle groups in athletic performance and for determining the readiness of the athlete to resume training or competition following injury or deconditioning. With expanded profile data about the muscle performance characteristics of various categories of athletes, training or rehabilitation programs may be adapted to meet the strength, speed, and endurance requirements of a given sport, which may enhance the quality of participation and prevent the occurrence of injury or reinjury.

  1. Excitation of Mytilus smooth muscle.

    Science.gov (United States)

    Twarog, B M

    1967-10-01

    1. Membrane potentials and tension were recorded during nerve stimulation and direct stimulation of smooth muscle cells of the anterior byssus retractor muscle of Mytilus edulis L.2. The resting potential averaged 65 mV (range 55-72 mV).3. Junction potentials reached 25 mV and decayed to one half maximum amplitude in 500 msec. Spatial summation and facilitation of junction potentials were observed.4. Action potentials, 50 msec in duration and up to 50 mV in amplitude were fired at a membrane potential of 35-40 mV. No overshoot was observed.5. Contraction in response to neural stimulation was associated with spike discharge. Measurement of tension and depolarization in muscle bundles at high K(+) indicated that tension is only produced at membrane potentials similar to those achieved by spike discharge.6. Blocking of junction potentials, spike discharge and contraction by methantheline, an acetylcholine antagonist, supports the hypothesis that the muscle is excited by cholinergic nerves. However, evidence of a presynaptic action of methantheline complicates this argument.

  2. Novel Analog For Muscle Deconditioning

    Science.gov (United States)

    Ploutz-Snyder, Lori; Ryder, Jeff; Buxton, Roxanne; Redd. Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle; Fiedler, James; Ploutz-Snyder, Robert; Bloomberg, Jacob

    2011-01-01

    Existing models (such as bed rest) of muscle deconditioning are cumbersome and expensive. We propose a new model utilizing a weighted suit to manipulate strength, power, or endurance (function) relative to body weight (BW). Methods: 20 subjects performed 7 occupational astronaut tasks while wearing a suit weighted with 0-120% of BW. Models of the full relationship between muscle function/BW and task completion time were developed using fractional polynomial regression and verified by the addition of pre-and postflightastronaut performance data for the same tasks. Splineregression was used to identify muscle function thresholds below which task performance was impaired. Results: Thresholds of performance decline were identified for each task. Seated egress & walk (most difficult task) showed thresholds of leg press (LP) isometric peak force/BW of 18 N/kg, LP power/BW of 18 W/kg, LP work/BW of 79 J/kg, isokineticknee extension (KE)/BW of 6 Nm/kg, and KE torque/BW of 1.9 Nm/kg.Conclusions: Laboratory manipulation of relative strength has promise as an appropriate analog for spaceflight-induced loss of muscle function, for predicting occupational task performance and establishing operationally relevant strength thresholds.

  3. Muscle fatigue in fibromyalgia is in the brain, not in the muscles

    DEFF Research Database (Denmark)

    Bandak, Elisabeth; Amris, Kirstine; Bliddal, Henning

    2013-01-01

    To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC).......To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC)....

  4. Integrated expression analysis of muscle hypertrophy identifies Asb2 as a negative regulator of muscle mass

    Science.gov (United States)

    Davey, Jonathan R.; Watt, Kevin I.; Parker, Benjamin L.; Chaudhuri, Rima; Ryall, James G.; Cunningham, Louise; Qian, Hongwei; Sartorelli, Vittorio; Chamberlain, Jeffrey; James, David E.

    2016-01-01

    The transforming growth factor-β (TGF-β) signaling network is a critical regulator of skeletal muscle mass and function and, thus, is an attractive therapeutic target for combating muscle disease, but the underlying mechanisms of action remain undetermined. We report that follistatin-based interventions (which modulate TGF-β network activity) can promote muscle hypertrophy that ameliorates aging-associated muscle wasting. However, the muscles of old sarcopenic mice demonstrate reduced response to follistatin compared with healthy young-adult musculature. Quantitative proteomic and transcriptomic analyses of young-adult muscles identified a transcription/translation signature elicited by follistatin exposure, which included repression of ankyrin repeat and SOCS box protein 2 (Asb2). Increasing expression of ASB2 reduced muscle mass, thereby demonstrating that Asb2 is a TGF-β network–responsive negative regulator of muscle mass. In contrast to young-adult muscles, sarcopenic muscles do not exhibit reduced ASB2 abundance with follistatin exposure. Moreover, preventing repression of ASB2 in young-adult muscles diminished follistatin-induced muscle hypertrophy. These findings provide insight into the program of transcription and translation events governing follistatin-mediated adaptation of skeletal muscle attributes and identify Asb2 as a regulator of muscle mass implicated in the potential mechanistic dysfunction between follistatin-mediated muscle growth in young and old muscles. PMID:27182554

  5. Muscle strength in patients with chronic pain

    NARCIS (Netherlands)

    van Wilgen, C.P.; Akkerman, L.; Wieringa, J.; Dijkstra, P.U.

    2003-01-01

    Objective: To analyse the influence of chronic pain on muscle strength. Design: Muscle strength of patients with unilateral nonspecific chronic pain, in an upper or lower limb, were measured according to a standardized protocol using a hand-held dynamometer. Before and after muscle strength

  6. Mechanical modeling of skeletal muscle functioning

    NARCIS (Netherlands)

    van der Linden, B.J.J.J.

    1998-01-01

    For movement of body or body segments is combined effort needed of the central nervous system and the muscular-skeletal system. This thesis deals with the mechanical functioning of skeletal muscle. That muscles come in a large variety of geometries, suggest the existence of a relation between muscle

  7. Kinetics of glucose transport in rat muscle

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Vinten, Jørgen

    1987-01-01

    The effects of insulin and prior muscle contractions, respectively, on 3-O-methylglucose (3-O-MG) transport in skeletal muscle were studied in the perfused rat hindquarter. Initial rates of entry of 3-O-MG in red gastrocnemius, soleus, and white gastrocnemius muscles as a function of perfusate 3-O...

  8. Muscle MRI findings in facioscapulohumeral muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Gerevini, Simonetta; Caliendo, Giandomenico; Falini, Andrea [IRCCS San Raffaele Scientific Institute, Neuroradiology Unit, Head and Neck Department, Milan (Italy); Scarlato, Marina; Previtali, Stefano Carlo [IRCCS San Raffaele Scientific Institute, Department of Neurology, INSPE and Division of Neuroscience, Milan (Italy); Maggi, Lorenzo; Pasanisi, Barbara; Morandi, Lucia [Fondazione IRCCS Istituto Neurologico ' ' Carlo Besta' ' , Neuromuscular Diseases and Neuroimmunology Unit, Milan (Italy); Cava, Mariangela [IRCCS San Raffaele Scientific Institute, Department of Radiology and Center for Experimental Imaging, Milan (Italy)

    2016-03-15

    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. (orig.)

  9. Exporting vector muscles for facial animation

    NARCIS (Netherlands)

    Bui, T.D.; Butz, Andreas; Kruger, Antonio; Heylen, Dirk K.J.; Olivier, Patrick; Nijholt, Antinus; Poel, Mannes

    2003-01-01

    In this paper we introduce a method of exporting vector muscles from one 3D face to another for facial animation. Starting from a 3D face with an extended version of Waters’ linear muscle system, we transfer the linear muscles to a target 3D face.We also transfer the region division, which is used

  10. Buckling Pneumatic Linear Actuators Inspired by Muscle

    OpenAIRE

    Yang, Dian; Verma, Mohit Singh; So, Ju-Hee; Mosadegh, Bobak; Keplinger, Christoph; Lee, Benjamin; Khashai, Fatemeh; Lossner, Elton Garret; Suo, Zhigang; Whitesides, George McClelland

    2016-01-01

    The mechanical features of biological muscles are difficult to reproduce completely in synthetic systems. A new class of soft pneumatic structures (vacuum-actuated muscle-inspired pneumatic structures) is described that combines actuation by negative pressure (vacuum), with cooperative buckling of beams fabricated in a slab of elastomer, to achieve motion and demonstrate many features that are similar to that of mammalian muscle.

  11. Redox Control of Skeletal Muscle Regeneration.

    Science.gov (United States)

    Le Moal, Emmeran; Pialoux, Vincent; Juban, Gaëtan; Groussard, Carole; Zouhal, Hassane; Chazaud, Bénédicte; Mounier, Rémi

    2017-08-10

    Skeletal muscle shows high plasticity in response to external demand. Moreover, adult skeletal muscle is capable of complete regeneration after injury, due to the properties of muscle stem cells (MuSCs), the satellite cells, which follow a tightly regulated myogenic program to generate both new myofibers and new MuSCs for further needs. Although reactive oxygen species (ROS) and reactive nitrogen species (RNS) have long been associated with skeletal muscle physiology, their implication in the cell and molecular processes at work during muscle regeneration is more recent. This review focuses on redox regulation during skeletal muscle regeneration. An overview of the basics of ROS/RNS and antioxidant chemistry and biology occurring in skeletal muscle is first provided. Then, the comprehensive knowledge on redox regulation of MuSCs and their surrounding cell partners (macrophages, endothelial cells) during skeletal muscle regeneration is presented in normal muscle and in specific physiological (exercise-induced muscle damage, aging) and pathological (muscular dystrophies) contexts. Recent advances in the comprehension of these processes has led to the development of therapeutic assays using antioxidant supplementation, which result in inconsistent efficiency, underlying the need for new tools that are aimed at precisely deciphering and targeting ROS networks. This review should provide an overall insight of the redox regulation of skeletal muscle regeneration while highlighting the limits of the use of nonspecific antioxidants to improve muscle function. Antioxid. Redox Signal. 27, 276-310.

  12. The arrangement of muscle fibers and tendons in two muscles used for growth studies.

    OpenAIRE

    Stickland, N C

    1983-01-01

    The arrangement of muscle fibres and tendons was examined in the soleus muscle of rats from 6 to 175 days post partum. The muscle was seen to change from a simple structure, with mean fibre length of approximately 90% of complete muscle length, to a unipennate structure, with mean fibre length of only about 60% of muscle length. The dog pectineus muscle was also investigated and found to have a bipennate structure throughout postnatal growth. The arrangement of muscle fibres in both these mus...

  13. Inspiratory muscle training in type 2 diabetes with inspiratory muscle weakness.

    Science.gov (United States)

    Corrêa, Ana Paula S; Ribeiro, Jorge P; Balzan, Fernanda Machado; Mundstock, Lorena; Ferlin, Elton Luiz; Moraes, Ruy Silveira

    2011-07-01

    Patients with type 2 diabetes mellitus may present weakness of the inspiratory muscles. We tested the hypothesis that inspiratory muscle training (IMT) could improve inspiratory muscle strength, pulmonary function, functional capacity, and autonomic modulation in patients with type 2 diabetes and weakness of the inspiratory muscles. Maximal inspiratory muscle pressure (PImax) was evaluated in a sample of 148 patients with type 2 diabetes. Of these, 25 patients with PImaxinspiratory muscle endurance time, pulmonary function, peak oxygen uptake, and HR variability were evaluated before and after intervention. The prevalence of inspiratory muscle weakness was 29%. IMT significantly increased the PImax (118%) and the inspiratory muscle endurance time (495%), with no changes in pulmonary function, functional capacity, or autonomic modulation. There were no significant changes with placebo-IMT. Patients with type 2 diabetes may frequently present inspiratory muscle weakness. In these patients, IMT improves inspiratory muscle function with no consequences in functional capacity or autonomic modulation.

  14. Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

    DEFF Research Database (Denmark)

    Vinge, O; Edvardsen, L; Jensen, F

    1996-01-01

    In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... muscle protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

  15. In cirrhotic patients reduced muscle strength is unrelated to muscle capacity for ATP turnover suggesting a central limitation

    DEFF Research Database (Denmark)

    Gam, Christiane Marie Bourgin; Nielsen, H B; Secher, Niels H.

    2011-01-01

      We investigated whether in patients with liver cirrhosis reduced muscle strength is related to dysfunction of muscle mitochondria.......  We investigated whether in patients with liver cirrhosis reduced muscle strength is related to dysfunction of muscle mitochondria....

  16. Relationship between neck muscles functions and hand muscles strenght in musicians

    OpenAIRE

    Vaina, Mindaugas

    2016-01-01

    Relationship Between Neck Muscles Functions and Hand Muscles Strenght in Musicians The aim of research work: to determine the relationship between musicians hand muscle strength, fatigue and neck strength, endurance and movement amplitude. Tasks of work: 1. To evaluate and compare the musicians playing with string and wind instruments neck muscle strength, endurance, range of motion, hand muscle strength and fatigue between the groups as well as commonly used standards. 2. To determine the re...

  17. How the condition of occlusal support affects the back muscle force and masticatory muscle activity?

    OpenAIRE

    石岡, 克; 河野, 正司; Ishioka, Masaru; Kohno, Shoji

    2002-01-01

    This study was conducted to determine how the condition of occlusal support affects the back muscle force and masticatory muscle activity. Two groups of subjects were enlisted: sport-trained group and normal group. While electrodes of the electromyography (EMG) were attached to the surface of the masticatory muscles, each subject's back muscle force was recorded during upper body stretching using a back muscle force-measuring device. The task was performed under four different occlusal suppor...

  18. Novel biomarkers of changes in muscle mass or muscle pathology

    DEFF Research Database (Denmark)

    Arvanitidis, Athanasios

    after radiotherapy, before and during the training period. TNNT1 levels were significantly elevated in the patient group compared to the control group, even before engaging in any form of physical activity. After engaging in physical training, the biomarker levels further increased through time......Muscle protein turnover is a dynamic equilibrium that regulates the body composition and homeostasis through various cytokines and proteases. When the balance between protein synthesis and protein degradation is altered, proper muscle function and regeneration is being hampered, affecting patient...... significantly affect several of the biomarkers levels measured in this study, most prominently CRPM and PINP, indicative of significantly altered turnover of extracellular matrix components and CRPM. C3M correlated with Interferon gene score, in PM and DM, and CRPM with MMT8 score in DM. We further developed...

  19. Bone marrow mesenchymal cells improve muscle function in a skeletal muscle re-injury model.

    Directory of Open Access Journals (Sweden)

    Bruno M Andrade

    Full Text Available Skeletal muscle injury is the most common problem in orthopedic and sports medicine, and severe injury leads to fibrosis and muscle dysfunction. Conventional treatment for successive muscle injury is currently controversial, although new therapies, like cell therapy, seem to be promise. We developed a model of successive injuries in rat to evaluate the therapeutic potential of bone marrow mesenchymal cells (BMMC injected directly into the injured muscle. Functional and histological assays were performed 14 and 28 days after the injury protocol by isometric tension recording and picrosirius/Hematoxilin & Eosin staining, respectively. We also evaluated the presence and the fate of BMMC on treated muscles; and muscle fiber regeneration. BMMC treatment increased maximal skeletal muscle contraction 14 and 28 days after muscle injury compared to non-treated group (4.5 ± 1.7 vs 2.5 ± 0.98 N/cm2, p<0.05 and 8.4 ± 2.3 vs. 5.7 ± 1.3 N/cm2, p<0.05 respectively. Furthermore, BMMC treatment increased muscle fiber cross-sectional area and the presence of mature muscle fiber 28 days after muscle injury. However, there was no difference in collagen deposition between groups. Immunoassays for cytoskeleton markers of skeletal and smooth muscle cells revealed an apparent integration of the BMMC within the muscle. These data suggest that BMMC transplantation accelerates and improves muscle function recovery in our extensive muscle re-injury model.

  20. Synchronous monitoring of muscle dynamics and muscle force for maximum isometric tetanus

    Science.gov (United States)

    Zakir Hossain, M.; Grill, Wolfgang

    2010-03-01

    Skeletal muscle is a classic example of a biological soft matter . At both macro and microscopic levels, skeletal muscle is exquisitely oriented for force generation and movement. In addition to the dynamics of contracting and relaxing muscle which can be monitored with ultrasound, variations in the muscle force are also expected to be monitored. To observe such force and sideways expansion variations synchronously for the skeletal muscle a novel detection scheme has been developed. As already introduced for the detection of sideways expansion variations of the muscle, ultrasonic transducers are mounted sideways on opposing positions of the monitored muscle. To detect variations of the muscle force, angle of pull of the monitored muscle has been restricted by the mechanical pull of the sonic force sensor. Under this condition, any variation in the time-of-flight (TOF) of the transmitted ultrasonic signals can be introduced by the variation of the path length between the transducers. The observed variations of the TOF are compared to the signals obtained by ultrasound monitoring for the muscle dynamics. The general behavior of the muscle dynamics and muscle force shows almost an identical concept. Since muscle force also relates the psychological boosting-up effects, the influence of boosting-up on muscle force and muscle dynamics can also be quantified form this study. Length-tension or force-length and force-velocity relationship can also be derived quantitatively with such monitoring.

  1. 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.

  2. 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.

  3. Cytokines: muscle protein and amino acid metabolism

    DEFF Research Database (Denmark)

    van Hall, Gerrit

    2012-01-01

    raises TNF-α and IL-6 to moderate levels, has only identified IL-6 as a potent cytokine, decreasing systemic amino acid levels and muscle protein metabolism. The marked decrease in circulatory and muscle amino acid concentrations was observed with a concomitant reduction in both the rates of muscle...... of IL-6 on the regulation of muscle protein metabolism but indirectly via IL-6 reducing amino acid availability. SUMMARY: Recent studies suggest that the best described cytokines TNF-α and IL-6 are unlikely to be the major direct mediators of muscle protein loss in inflammatory diseases. However...

  4. Pathophysiology of muscle contractures in cerebral palsy.

    Science.gov (United States)

    Mathewson, Margie A; Lieber, Richard L

    2015-02-01

    Patients with cerebral palsy present with a variety of adaptations to muscle structure and function. These pathophysiologic symptoms include functional deficits such as decreased force production and range of motion, in addition to changes in muscle structure such as decreased muscle belly size, increased sarcomere length, and altered extracellular matrix structure and composition. On a cellular level, patients with cerebral palsy have fewer muscle stem cells, termed satellite cells, and altered gene expression. Understanding the nature of these changes may present opportunities for the development of new muscle treatment therapies. Published by Elsevier Inc.

  5. Human skeletal muscle releases leptin in vivo

    DEFF Research Database (Denmark)

    Wolsk, Emil; Grøndahl, Thomas Sahl; Pedersen, Bente Klarlund

    2012-01-01

    Leptin is considered an adipokine, however, cultured myocytes have also been found to release leptin. Therefore, as proof-of-concept we investigated if human skeletal muscle synthesized leptin by measuring leptin in skeletal muscle biopsies. Following this, we quantified human skeletal muscle...... was unaltered. During saline infusion the adipose tissue release averaged 0.8 ± 0.3 ng min(-1) 100g tissue(-1) whereas skeletal muscle release was 0.5 ± 0.1 ng min(-1) 100g tissue(-1). In young healthy humans, skeletal muscle contribution to whole body leptin production could be substantial given the greater...

  6. Procedural Options for Measuring Muscle Strength

    Directory of Open Access Journals (Sweden)

    Mindova S.

    2016-10-01

    Full Text Available The aim of the present study was to provide alternative means of measurement and evaluation of muscle strength in rehabilitation practice and diagnostics. In the last few years many electronic devices for evaluation of muscle strength have developed. Contemporary studies have shown that in addition to the standard manual muscle testing muscle strength can be assessed more objectively and analytically using electronic dynamometers and equipment. The strain gauges are used as a tool of precision in the industry that allows measurement of mechanical loads by dynamometers. By using these tools is possible to obtain continuous digital measurement and recording of muscle strength.

  7. AMPK in skeletal muscle function and metabolism

    DEFF Research Database (Denmark)

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

    2018-01-01

    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...

  8. Muscle cramp susceptibility increases following a volitionally induced muscle cramp.

    Science.gov (United States)

    Miller, Kevin C; Long, Blaine C; Edwards, Jeffrey E

    2017-12-01

    Muscle cramping may increase peripheral nervous system excitability. It is unknown if, and how long, cramp susceptibility is affected by previous cramping. We tested whether volitionally induced muscle cramps (VIMCs) lowered cramp threshold frequency (TF c ) and how long TF c was affected post-VIMC. Fifteen cramp-prone participants volitionally induced a flexor hallucis brevis (FHB) cramp on 4 separate days. FHB TF c was measured before VIMC (i.e., baseline) and 5, 30, and 60 min post-VIMC. VIMC electromyography (EMG) amplitude, VIMC duration, and perceived VIMC intensity were measured to ensure consistency of VIMC between days. VIMC EMG amplitude, duration, and perceived intensity were similar between days (P > 0.05). VIMC lowered TF c ; baseline TF c (18 ± 6 Hz) was higher than 5-min (14 ± 6 Hz), 30-min (14 ± 5 Hz), and 60-min TF c (14 ± 5 Hz; P cramp susceptibility. Clinicians should apply treatments for at least 60 min postcramp to decrease the probability of cramp recurrence. Muscle Nerve 56: E95-E99, 2017. © 2017 Wiley Periodicals, Inc.

  9. Architectural differences between the hamstring muscles.

    Science.gov (United States)

    Kellis, Eleftherios; Galanis, Nikiforos; Kapetanos, George; Natsis, Konstantinos

    2012-08-01

    The purpose of this study was to understand the detailed architectural properties of the human hamstring muscles. The long (BFlh) and short (BFsh) head of biceps femoris, semimembranosus (SM) and semitendinosus (ST) muscles were dissected and removed from their origins in eight cadaveric specimens (age 67.8±4.3 years). Mean fiber length, sarcomere length, physiological cross-section area and pennation angle were measured. These data were then used to calculate a similarity index (δ) between pairs of muscles. The results indicated moderate similarity between BFlh and BFsh (δ=0.54) and between BFlh and SM (δ=0.35). In contrast, similarity was low between SM and ST (δ=0.98) and between BFlh and SM (δ=1.17). The fascicle length/muscle length ratio was higher for the ST (0.58) and BFsh (0.50) compared with the BFlh (0.27) and SM (0.22). There were, however, high inter-correlations between individual muscle architecture values, especially for muscle thickness and fascicle length data sets. Prediction of the whole hamstring architecture was achieved by combining data from all four muscles. These data show different designs of the hamstring muscles, especially between the SM and ST (medial) and BFlh and BFsh (lateral) muscles. Modeling the hamstrings as one muscle group by assuming uniform inter-muscular architecture yields less accurate representation of human hamstring muscle function. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Lactate and force production in skeletal muscle

    DEFF Research Database (Denmark)

    Kristensen, Michael; Albertsen, Janni; Rentsch, Maria

    2005-01-01

    Lactic acid accumulation is generally believed to be involved in muscle fatigue. However, one study reported that in rat soleus muscle (in vitro), with force depressed by high external K+ concentrations a subsequent incubation with lactic acid restores force and thereby protects against fatigue...... muscle. Three incubation solutions were used: 20 mm Na-lactate (which acidifies internal pH), 12 mm Na-lactate +8 mm lactic acid (which mimics the pH changes during muscle activity), and 20 mm lactic acid (which acidifies external pH more than internal pH). All three solutions improved force in K+-depressed...... development in repetitively stimulated muscle (Na-lactate had a negative effect). It is concluded that although lactate/lactic acid incubation regains force in K+-depressed resting muscle, a similar incubation has no or a negative effect on force development in active muscle. It is suggested...

  11. Satellite cells in human skeletal muscle plasticity.

    Science.gov (United States)

    Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

    2015-01-01

    Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

  12. Scapular kinematic and shoulder muscle activity alterations after serratus anterior muscle fatigue.

    Science.gov (United States)

    Umehara, Jun; Kusano, Ken; Nakamura, Masatoshi; Morishita, Katsuyuki; Nishishita, Satoru; Tanaka, Hiroki; Shimizu, Itsuroh; Ichihashi, Noriaki

    2018-02-23

    Although the serratus anterior muscle has an important role in scapular movement, no study to date has investigated the effect of serratus anterior fatigue on scapular kinematics and shoulder muscle activity. The purpose of this study was to clarify the effect of serratus anterior fatigue on scapular movement and shoulder muscle activity. The study participants were 16 healthy men. Electrical muscle stimulation was used to fatigue the serratus anterior muscle. Shoulder muscle strength and endurance, scapular movement, and muscle activity were measured before and after the fatigue task. The muscle activity of the serratus anterior, upper and lower trapezius, anterior and middle deltoid, and infraspinatus muscles was recorded, and the median power frequency of these muscles was calculated to examine the degree of muscle fatigue. The muscle endurance and median power frequency of the serratus anterior muscle decreased after the fatigue tasks, whereas the muscle activities of the serratus anterior, upper trapezius, and infraspinatus muscles increased. External rotation of the scapula at the shoulder elevated position increased after the fatigue task. Selective serratus anterior fatigue due to electric muscle stimulation decreased the serratus anterior endurance at the flexed shoulder position. Furthermore, the muscle activities of the serratus anterior, upper trapezius, and infraspinatus increased and the scapular external rotation was greater after serratus anterior fatigue. These results suggest that the rotator cuff and scapular muscle compensated to avoid the increase in internal rotation of the scapula caused by the dysfunction of the serratus anterior muscle. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  13. 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....

  14. An Artificial Muscle Ring Oscillator

    OpenAIRE

    O’Brien, Benjamin Marc; Anderson, Iain Alexander

    2012-01-01

    Dielectric elastomer artificialmuscles have great potential for the creation of novel pumps, motors, and circuitry. Control of these devices requires an oscillator, either as a driver or clock circuit, which is typically provided as part of bulky, rigid, and costly external electronics. Oscillator circuits based on piezo-resistive dielectric elastomer switch technology provide a way to embed oscillatory behavior into artificial muscle devices. Previous oscillator circuits were not digital, ab...

  15. Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Naffaa, Lena [American University of Beirut, Department of Diagnostic Radiology, P.O. Box 11-0236, Riad El-Solh, Beirut (Lebanon); Moukaddam, Hicham [Saint Rita Medical Center, Lima, OH (United States); Samim, Mohammad [New York University, Department of Radiology, Hospital for Joint Disease, New York, NY (United States); Lemieux, Aaron [University of California, San Diego School of Medicine, La Jolla, CA (United States); Smitaman, Edward [University of California, San Diego, Teleradiology and Education Center, San Diego, CA (United States)

    2017-03-15

    Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s) - this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities. (orig.)

  16. Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics

    International Nuclear Information System (INIS)

    Naffaa, Lena; Moukaddam, Hicham; Samim, Mohammad; Lemieux, Aaron; Smitaman, Edward

    2017-01-01

    Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s) - this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities. (orig.)

  17. Channelopathies of skeletal muscle excitability.

    Science.gov (United States)

    Cannon, Stephen C

    2015-04-01

    Familial disorders of skeletal muscle excitability were initially described early in the last century and are now known to be caused by mutations of voltage-gated ion channels. The clinical manifestations are often striking, with an inability to relax after voluntary contraction (myotonia) or transient attacks of severe weakness (periodic paralysis). An essential feature of these disorders is fluctuation of symptoms that are strongly impacted by environmental triggers such as exercise, temperature, or serum K(+) levels. These phenomena have intrigued physiologists for decades, and in the past 25 years the molecular lesions underlying these disorders have been identified and mechanistic studies are providing insights for therapeutic strategies of disease modification. These familial disorders of muscle fiber excitability are "channelopathies" caused by mutations of a chloride channel (ClC-1), sodium channel (NaV1.4), calcium channel (CaV1.1), and several potassium channels (Kir2.1, Kir2.6, and Kir3.4). This review provides a synthesis of the mechanistic connections between functional defects of mutant ion channels, their impact on muscle excitability, how these changes cause clinical phenotypes, and approaches toward therapeutics. © 2015 American Physiological Society.

  18. Postinjection Muscle Fibrosis from Lupron

    Directory of Open Access Journals (Sweden)

    Erica Everest

    2015-01-01

    Full Text Available We describe the case of a 6.5-year-old girl with central precocious puberty (CPP, which signifies the onset of secondary sexual characteristics before the age of eight in females and the age of nine in males as a result of stimulation of the hypothalamic-pituitary-gonadal axis. Her case is likely related to her adoption, as children who are adopted internationally have much higher rates of CPP. She had left breast development at Tanner Stage 2, adult body odor, and mildly advanced bone age. In order to halt puberty and maximize adult height, she was prescribed a gonadotropin releasing hormone analog, the first line treatment for CPP. She was administered Lupron (leuprolide acetate Depot-Ped (3 months intramuscularly. After her second injection, she developed swelling and muscle pain at the injection site on her right thigh. She also reported an impaired ability to walk. She was diagnosed with muscle fibrosis. This is the first reported case of muscle fibrosis resulting from Lupron injection.

  19. Optimizing calf muscle pump function.

    Science.gov (United States)

    Lattimer, Christopher R; Franceschi, Claude; Kalodiki, Evi

    2017-01-01

    Background The tip toe manoeuvre has been promoted as the gold standard plethysmography test for measuring calf muscle pump function. The aim was to compare the tip toe manoeuvre, dorsiflexion manoeuvre and a body weight transfer manoeuvre using the ejection fraction of air-plethysmography and evaluate which has the best pumping effect. Methods Sixty-six archived tracings on 22 legs were retrieved from an air-plethysmography workshop and analysed. Pumping performance was measured using the calf volume reduction after each manoeuvre. Results Expressed as median [inter-quartile range], body weight transfer manoeuvres resulted in a significantly greater ejection fraction (%) than tip toe manoeuvres at 59.7 [53.5-63.9] versus 42.6 [30.5-52.6], P calf muscle pump with a 40.1% relative increase in the ejection fraction compared to a tip toe manoeuvre. Exercises which involve body weight transfers from one leg to the other may be more important in optimizing calf muscle pump function than ankle movement exercises.

  20. Nutrition and Muscle in Cirrhosis.

    Science.gov (United States)

    Anand, Anil C

    2017-12-01

    As the cirrhosis progresses, development of complication like ascites, hepatic encephalopathy, variceal bleeding, kidney dysfunction, and hepatocellular carcinoma signify increasing risk of short term mortality. Malnutrition and muscle wasting (sarcopenia) is yet other complications that negatively impact survival, quality of life, and response to stressors, such as infection and surgery in patients with cirrhosis. Conventionally, these are not routinely looked for, because nutritional assessment can be a difficult especially if there is associated fluid retention and/or obesity. Patients with cirrhosis may have a combination of loss of skeletal muscle and gain of adipose tissue, culminating in the condition of "sarcopenic obesity." Sarcopenia in cirrhotic patients has been associated with increased mortality, sepsis complications, hyperammonemia, overt hepatic encephalopathy, and increased length of stay after liver transplantation. Assessment of muscles with cross-sectional imaging studies has become an attractive index of nutritional status evaluation in cirrhosis, as sarcopenia, the major component of malnutrition, is primarily responsible for the adverse clinical consequences seen in patients with liver disease. Cirrhosis is a state of accelerated starvation, with increased gluconeogenesis that requires amino acid diversion from other metabolic functions. Protein homeostasis is disturbed in cirrhosis due to several factors such as hyperammonemia, hormonal, and cytokine abnormalities, physical inactivity and direct effects of ethanol and its metabolites. New approaches to manage sarcopenia are being evolved. Branched chain amino acid supplementation, Myostatin inhibitors, and mitochondrial protective agents are currently in various stages of evaluation in preclinical studies to prevent and reverse sarcopenia, in cirrhosis.

  1. Muscle power during intravenous sedation

    Directory of Open Access Journals (Sweden)

    Nobuyuki Matsuura

    2017-11-01

    Full Text Available Intravenous sedation is effective to reduce fear and anxiety in dental treatment. It also has been used for behavior modification technique in dental patients with special needs. 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. This review discusses the effects of intravenous sedation using midazolam and propofol on both grip strength and bite force. During light propofol sedation, grip strength increases slightly and bite force increases in a dose-dependent manner. Grip strength decreases while bite force increases during light midazolam sedation, and also during light sedation using a combination of midazolam and propofol. Flumazenil did not antagonise the increase in bite force by midazolam. These results may suggest following possibilities; (1 Activation of peripheral benzodiazepine receptors located within the temporomandibular joint region and masticatory muscles may be the cause of increasing bite force. (2 Propofol limited the long-latency exteroceptive suppression (ES2 period during jaw-opening reflex. Thus, control of masticatory muscle contraction, which is thought to have a negative feedback effect on excessive bite force, may be depressed by propofol.

  2. Stress-induced Skeletal Muscle Gadd45a Expression Reprograms Myonuclei and Causes Muscle Atrophy*

    Science.gov (United States)

    Ebert, Scott M.; Dyle, Michael C.; Kunkel, Steven D.; Bullard, Steven A.; Bongers, Kale S.; Fox, Daniel K.; Dierdorff, Jason M.; Foster, Eric D.; Adams, Christopher M.

    2012-01-01

    Diverse stresses including starvation and muscle disuse cause skeletal muscle atrophy. However, the molecular mechanisms of muscle atrophy are complex and not well understood. Here, we demonstrate that growth arrest and DNA damage-inducible 45a protein (Gadd45a) is a critical mediator of muscle atrophy. We identified Gadd45a through an unbiased search for potential downstream mediators of the stress-inducible, pro-atrophy transcription factor ATF4. We show that Gadd45a is required for skeletal muscle atrophy induced by three distinct skeletal muscle stresses: fasting, muscle immobilization, and muscle denervation. Conversely, forced expression of Gadd45a in muscle or cultured myotubes induces atrophy in the absence of upstream stress. We show that muscle-specific ATF4 knock-out mice have a reduced capacity to induce Gadd45a mRNA in response to stress, and as a result, they undergo less atrophy in response to fasting or muscle immobilization. Interestingly, Gadd45a is a myonuclear protein that induces myonuclear remodeling and a comprehensive program for muscle atrophy. Gadd45a represses genes involved in anabolic signaling and energy production, and it induces pro-atrophy genes. As a result, Gadd45a reduces multiple barriers to muscle atrophy (including PGC-1α, Akt activity, and protein synthesis) and stimulates pro-atrophy mechanisms (including autophagy and caspase-mediated proteolysis). These results elucidate a critical stress-induced pathway that reprograms muscle gene expression to cause atrophy. PMID:22692209

  3. Cyclic muscle twitch contraction inhibits immobilization-induced muscle contracture and fibrosis in rats.

    Science.gov (United States)

    Yoshimura, Ayana; Sakamoto, Junya; Honda, Yuichiro; Kataoka, Hideki; Nakano, Jiro; Okita, Minoru

    2017-09-01

    We investigated the effects of cyclic muscle twitch contraction caused by neuromuscular electrical stimulation (NMES) on immobilization-induced muscle contracture and fibrosis in rats. Twenty-nine rats were divided into control, immobilization, and immobilization with muscle contraction groups. The ankle joints of the immobilization and muscle contraction rats were fixed in full plantar flexion with a plaster cast for 4 weeks. In the muscle contraction group, cyclic muscle twitch contraction of the soleus muscle was induced using a commercial device (1 Hz, 4 ± 2 mA, 60 min/day, 5 times/week) with the ankle joint immobilized. The dorsiflexion range of ankle joint motion in the muscle contraction group was significantly greater than that in the immobilization group. The expressions of fibrosis-related genes (i.e., hypoxia inducible factor-1α, transforming growth factor-β1, α-smooth muscle actin, and types I and III collagen) were significantly decreased in the muscle contraction group compared to the immobilization group. The fluorescence intensities of type I and type III collagen in the perimysium and endomysium in the muscle contraction group were significantly decreased compared to the immobilization group. These results suggest that cyclic muscle twitch contraction induced by NMES might alleviate skeletal muscle fibrosis, reducing immobilization-induced muscle contracture.

  4. Muscle size explains low passive skeletal muscle force in heart failure patients.

    Science.gov (United States)

    Panizzolo, Fausto Antonio; Maiorana, Andrew J; Naylor, Louise H; Dembo, Lawrence G; Lloyd, David G; Green, Daniel J; Rubenson, Jonas

    2016-01-01

    Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF). However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL), both in CHF patients and age- and physical activity-matched control participants. Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging) with a musculoskeletal model. We found reduced passive SOL forces (∼30%) (at the same relative levels of muscle stretch) in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized) and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening.

  5. Muscle oxygenation and fascicle length during passive muscle stretching in ballet-trained subjects.

    Science.gov (United States)

    Otsuki, A; Fujita, E; Ikegawa, S; Kuno-Mizumura, M

    2011-07-01

    Muscle stretching transiently decreases muscle-blood flow corresponding to a muscle extension. It may disturb a balance between muscular oxygen demand and oxygen supply to muscles and reduce muscle oxygenation. However, muscle-stretching training may improve blood circulatory condition, resulting in the maintained muscle oxygenation during muscle stretching. The aim of this study was to investigate changes in muscle-blood volume (tHb) and tissue oxygenation index (TOI) during muscle stretching determined by using near-infrared spectroscopy (NIRS) in ballet-trained (BT) and untrained (C) subjects. 11 BT women who regularly perform muscle stretching and 11 C women participated in this study. Fascicle lengths, tHb and TOI in the tibialis anterior muscle were measured during passive plantar flexion from ankle joint angles of 120° (baseline) to 140°, 160°, the maximal comfortable position without pain (CP), and the maximal position (MP). At 160°, the % fascicle-length change from baseline was significantly lower in the BT than the C group, however, for the changes in tHb and TOI the significant interaction effect between the 2 groups was not detected. On the other hand, although the increases in the fascicle length from baseline to CP and MP were greater in BT than C, the tHb and TOI reductions were comparable between groups. We concluded that it appears that BT can extend their muscles without excessive reduction in muscle-blood volume and muscle oxygenation at relatively same but absolutely greater muscle-stretching levels than C. The attenuation in these indices during high-level muscle stretching may be associated with the repetitive muscle stretching of long-term ballet training. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Space travel directly induces skeletal muscle atrophy

    Science.gov (United States)

    Vandenburgh, H.; Chromiak, J.; Shansky, J.; Del Tatto, M.; Lemaire, J.

    1999-01-01

    Space travel causes rapid and pronounced skeletal muscle wasting in humans that reduces their long-term flight capabilities. To develop effective countermeasures, the basis of this atrophy needs to be better understood. Space travel may cause muscle atrophy indirectly by altering circulating levels of factors such as growth hormone, glucocorticoids, and anabolic steroids and/or by a direct effect on the muscle fibers themselves. To determine whether skeletal muscle cells are directly affected by space travel, tissue-cultured avian skeletal muscle cells were tissue engineered into bioartificial muscles and flown in perfusion bioreactors for 9 to 10 days aboard the Space Transportation System (STS, i.e., Space Shuttle). Significant muscle fiber atrophy occurred due to a decrease in protein synthesis rates without alterations in protein degradation. Return of the muscle cells to Earth stimulated protein synthesis rates of both muscle-specific and extracellular matrix proteins relative to ground controls. These results show for the first time that skeletal muscle fibers are directly responsive to space travel and should be a target for countermeasure development.

  7. The regulation of catch in molluscan muscle.

    Science.gov (United States)

    Twarog, B M

    1967-07-01

    Molluscan catch muscles are smooth muscles. As with mammalian smooth muscles, there is no transverse ordering of filaments or dense bodies. In contrast to mammalian smooth muscles, two size ranges of filaments are present. The thick filaments are long as well as large in diameter and contain paramyosin. The thin filaments contain actin and appear to run into and join the dense bodies. Vesicles are present which may be part of a sarcoplasmic reticulum. Neural activation of contraction in Mytilus muscle is similar to that observed in mammalian smooth muscles, and in some respects to frog striated muscle. The relaxing nerves, which reduce catch, are unique to catch muscles. 5-Hydroxytryptamine, which appears to mediate relaxation, specifically blocks catch tension but increases the ability of the muscle to fire spikes. It is speculated that Mytilus muscle actomyosin is activated by a Ca(++)-releasing mechanism, and that 5-hydroxytryptamine may reduce catch and increase excitability by influencing the rate of removal of intracellular free Ca(++).

  8. Muscle activity characterization by laser Doppler Myography

    International Nuclear Information System (INIS)

    Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Tomasini, Enrico Primo

    2013-01-01

    Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin

  9. Muscle activity characterization by laser Doppler Myography

    Science.gov (United States)

    Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Primo Tomasini, Enrico

    2013-09-01

    Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin.

  10. Synchronous monitoring of muscle dynamics and electromyogram

    Science.gov (United States)

    Zakir Hossain, M.; Grill, Wolfgang

    2011-04-01

    A non-intrusive novel detection scheme has been implemented to detect the lateral muscle extension, force of the skeletal muscle and the motor action potential (EMG) synchronously. This allows the comparison of muscle dynamics and EMG signals as a basis for modeling and further studies to determine which architectural parameters are most sensitive to changes in muscle activity. For this purpose the transmission time for ultrasonic chirp signal in the frequency range of 100 kHz to 2.5 MHz passing through the muscle under observation and respective motor action potentials are recorded synchronously to monitor and quantify biomechanical parameters related to muscle performance. Additionally an ultrasonic force sensor has been employed for monitoring. Ultrasonic traducers are placed on the skin to monitor muscle expansion. Surface electrodes are placed suitably to pick up the potential for activation of the monitored muscle. Isometric contraction of the monitored muscle is ensured by restricting the joint motion with the ultrasonic force sensor. Synchronous monitoring was initiated by a software activated audio beep starting at zero time of the subsequent data acquisition interval. Computer controlled electronics are used to generate and detect the ultrasonic signals and monitor the EMG signals. Custom developed software and data analysis is employed to analyze and quantify the monitored data. Reaction time, nerve conduction speed, latent period between the on-set of EMG signals and muscle response, degree of muscle activation and muscle fatigue development, rate of energy expenditure and motor neuron recruitment rate in isometric contraction, and other relevant parameters relating to muscle performance have been quantified with high spatial and temporal resolution.

  11. Individual muscle control using an exoskeleton robot for muscle function testing.

    Science.gov (United States)

    Ueda, Jun; Ming, Ding; Krishnamoorthy, Vijaya; Shinohara, Minoru; Ogasawara, Tsukasa

    2010-08-01

    Healthy individuals modulate muscle activation patterns according to their intended movement and external environment. Persons with neurological disorders (e.g., stroke and spinal cord injury), however, have problems in movement control due primarily to their inability to modulate their muscle activation pattern in an appropriate manner. A functionality test at the level of individual muscles that investigates the activity of a muscle of interest on various motor tasks may enable muscle-level force grading. To date there is no extant work that focuses on the application of exoskeleton robots to induce specific muscle activation in a systematic manner. This paper proposes a new method, named "individual muscle-force control" using a wearable robot (an exoskeleton robot, or a power-assisting device) to obtain a wider variety of muscle activity data than standard motor tasks, e.g., pushing a handle by hand. A computational algorithm systematically computes control commands to a wearable robot so that a desired muscle activation pattern for target muscle forces is induced. It also computes an adequate amount and direction of a force that a subject needs to exert against a handle by his/her hand. This individual muscle control method enables users (e.g., therapists) to efficiently conduct neuromuscular function tests on target muscles by arbitrarily inducing muscle activation patterns. This paper presents a basic concept, mathematical formulation, and solution of the individual muscle-force control and its implementation to a muscle control system with an exoskeleton-type robot for upper extremity. Simulation and experimental results in healthy individuals justify the use of an exoskeleton robot for future muscle function testing in terms of the variety of muscle activity data.

  12. Measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography.

    Science.gov (United States)

    Chino, Kentaro; Akagi, Ryota; Dohi, Michiko; Takahashi, Hideyuki

    2014-09-01

    The B-mode ultrasound image that can measure muscle architecture is displayed side by side with the ultrasound strain elastogram that can assess muscle hardness. Consequently, muscle architecture can be measured concurrently with muscle hardness using ultrasound strain elastography. To demonstrate the measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography. Concurrent measurements of muscle architectural parameters (muscle thickness, pennation angle, and fascicle length) and muscle hardness of the medial gastrocnemius were performed with ultrasound strain elastography. Separate measurements of the muscle architectural parameters were also performed for use as reference values for the concurrent measurements. Both types of measurements were performed twice at 20° dorsiflexion, neutral position, and 30° plantar flexion. Coefficients of variance of the muscle architectural parameters obtained from the concurrent measurements (≤7.6%) were significantly higher than those obtained from the separate measurements (≤2.4%) (all P  0.05). The use of ultrasound strain elastography for the concurrent measurement of muscle architecture and muscle hardness is feasible. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. An analysis on muscle tone of lower limb muscles on flexible flat foot.

    Science.gov (United States)

    Um, Gi-Mai; Wang, Joong-San; Park, Si-Eun

    2015-10-01

    [Purpose] The aim of this study was to examine differences in the muscle tone and stiffness of leg muscles according to types of flexible flat foot. [Subjects and Methods] For 30 subjects 10 in a normal foot group (NFG), 10 in group with both flexible flat feet (BFFG), and 10 in a group with flexible flat feet on one side (OFFG), myotonometry was used to measure the muscle tone and stiffness of the tibialis anterior muscle (TA), the rectus femoris muscle (RF), the medial gastrocnemius (MG), and the long head of the biceps femoris muscle (BF) of both lower extremities. [Results] In the measurement results, only the stiffness of TA and MG of the NFG and the BFFG showed significant differences. The muscle tone and stiffness were highest in the BFFG, followed by the OFFG and NFG, although the difference was insignificant. In the case of the OFFG, there was no significant difference in muscle tone and stiffness compared to that in the NGF and the BFFG. Furthermore, in the NFG, the non-dominant leg showed greater muscle tone and stiffness than the dominant leg, although the difference was insignificant. [Conclusion] During the relax condition, the flexible flat foot generally showed a greater muscle tone and stiffness of both lower extremities compared to the normal foot. The stiffness was particularly higher in the TA and MG muscles. Therefore, the muscle tone and stiffness of the lower extremity muscles must be considered in the treatment of flat foot.

  14. Can Measured Synergy Excitations Accurately Construct Unmeasured Muscle Excitations?

    Science.gov (United States)

    Bianco, Nicholas A; Patten, Carolynn; Fregly, Benjamin J

    2018-01-01

    Accurate prediction of muscle and joint contact forces during human movement could improve treatment planning for disorders such as osteoarthritis, stroke, Parkinson's disease, and cerebral palsy. Recent studies suggest that muscle synergies, a low-dimensional representation of a large set of muscle electromyographic (EMG) signals (henceforth called "muscle excitations"), may reduce the redundancy of muscle excitation solutions predicted by optimization methods. This study explores the feasibility of using muscle synergy information extracted from eight muscle EMG signals (henceforth called "included" muscle excitations) to accurately construct muscle excitations from up to 16 additional EMG signals (henceforth called "excluded" muscle excitations). Using treadmill walking data collected at multiple speeds from two subjects (one healthy, one poststroke), we performed muscle synergy analysis on all possible subsets of eight included muscle excitations and evaluated how well the calculated time-varying synergy excitations could construct the remaining excluded muscle excitations (henceforth called "synergy extrapolation"). We found that some, but not all, eight-muscle subsets yielded synergy excitations that achieved >90% extrapolation variance accounted for (VAF). Using the top 10% of subsets, we developed muscle selection heuristics to identify included muscle combinations whose synergy excitations achieved high extrapolation accuracy. For 3, 4, and 5 synergies, these heuristics yielded extrapolation VAF values approximately 5% lower than corresponding reconstruction VAF values for each associated eight-muscle subset. These results suggest that synergy excitations obtained from experimentally measured muscle excitations can accurately construct unmeasured muscle excitations, which could help limit muscle excitations predicted by muscle force optimizations.

  15. Alternating Hypotropia with Pseudoptosis: A New Phenotype of Congenital Cranial Dysinnervation Disorder

    Directory of Open Access Journals (Sweden)

    Fady Sedarous

    2018-02-01

    Full Text Available Congenital cranial dysinnervation disorders, also known as CCDDs, are characterized by aberrant innervation to extraocular and facial muscles resulting in unusual forms of incomitant strabismus. Anomalous innervation to extraocular muscles can result in a wide variety of phenotypes causing various clinical conditions such as Duane syndrome, congenital fibrosis of the extraocular muscles, and Möbius syndrome. We report a case of bilateral dysinnervation disorder causing atypical ocular movements in both eyes as the patient changes fixation from one eye to the other and from right gaze to left gaze that fits with the wider diagnosis of CCDDs.

  16. [Inspiratory muscles strength training in recreational athletes].

    Science.gov (United States)

    Kellens, I; Cannizzaro, F; Gouilly, P; Crielaard, J-M

    2011-05-01

    Respiratory muscles strength and endurance influence athletic performance. Besides conventional spirometry, sniff test, inspiratory and expiratory maximal pressures can directly assess respiratory muscle strength. Respiratory muscles can be train through a device offering inspiratory and expiratory resistance. Nineteen subjects aged 18 to 30 years and practicing leisure sport trained inspiratory muscles on Powerbreathe(®) for eight weeks. Resistance was set at 85% of maximal inspiratory pressure determined during a preliminary session. Evaluation was made trough voluntary and non-invasive methods on Macro 5000(®) (PI max, PE max and sniff test). An increase of 21.77% of the maximum inspiratory pressure, 17% of the maximum expiratory pressure and 18% of the sniff test are recorded after eight weeks of training. A specific training of inspiratory muscles (Powerbreathe(®) Sports performance) increases the power of these muscles (voluntary and non-invasive tests). Copyright © 2011 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  17. Mechanisms of exertional fatigue in muscle glycogenoses

    DEFF Research Database (Denmark)

    Vissing, John; Haller, Ronald G

    2012-01-01

    Exertional fatigue early in exercise is a clinical hallmark of muscle glycogenoses, which is often coupled with painful muscle contractures and episodes of myoglobinuria. A fundamental biochemical problem in these conditions is the impaired generation of ATP to fuel muscle contractions, which...... relates directly to the metabolic defect, but also to substrate-limited energy deficiency, as exemplified by the "second wind" phenomenon in McArdle disease. A number of secondary events may also play a role in inducing premature fatigue in glycogenoses, including (1) absent or blunted muscle acidosis......, which may be important for maintaining muscle membrane excitability by decreasing chloride permeability, (2) loss of the osmotic effect related to lactate accumulation, which may account for absence of the normal increase in water content of exercised muscle, and thus promote higher than normal...

  18. [Molecular mechanisms of skeletal muscle hypertrophy].

    Science.gov (United States)

    Astratenkova, I V; Rogozkin, V A

    2014-06-01

    Enzymes Akt, AMPK, mTOR, S6K and PGC-1a coactivator take part in skeletal muscles in the regulation of synthesis of proteins. The expression of these proteins is regulated by growth factors, hormones, nutrients, mechanical loading and leads to an increase in muscle mass and skeletal muscle hypertrophy. The review presents the results of studies published in the past four years, which expand knowledge on the effects of various factors on protein synthesis in skeletal muscle. The attention is focused on the achievements that reveal and clarify the signaling pathways involved in the regulation of protein synthesis in skeletal muscle. The central place is taken by mTOR enzyme which controls and regulates the main stages of the cascade of reactions of muscle proteins providing synthesis in the conditions of human life. coactivator PGC-1a.

  19. Signaling pathways controlling skeletal muscle mass

    Science.gov (United States)

    Egerman, Marc A.

    2014-01-01

    The molecular mechanisms underlying skeletal muscle maintenance involve interplay between multiple signaling pathways. Under normal physiological conditions, a network of interconnected signals serves to control and coordinate hypertrophic and atrophic messages, culminating in a delicate balance between muscle protein synthesis and proteolysis. Loss of skeletal muscle mass, termed “atrophy”, is a diagnostic feature of cachexia seen in settings of cancer, heart disease, chronic obstructive pulmonary disease, kidney disease, and burns. Cachexia increases the likelihood of death from these already serious diseases. Recent studies have further defined the pathways leading to gain and loss of skeletal muscle as well as the signaling events that induce differentiation and post-injury regeneration, which are also essential for the maintenance of skeletal muscle mass. In this review, we summarize and discuss the relevant recent literature demonstrating these previously undiscovered mediators governing anabolism and catabolism of skeletal muscle. PMID:24237131

  20. Radioisotope scanning in inflammatory muscle disease

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.B.; Swift, T.R.; Spies, S.M.

    1976-06-01

    Fourteen whole-body rectilinear bone scans using technetium 99m-polyphosphate were done in nine patients with well-documented inflammatory myopathy (either polymyositis or dermatomyositis). In all nine patients the scans showed evidence of increased muscle labeling. Muscle uptake was markedly increased in one patient, moderately increased in two patients, and minimally increased in six patients. The degree of muscle labeling correlated with the severity of the muscle weakness at the time the scan was done. In four patients, who received high-dose corticosteroid treatment, muscle uptake was decreased following therapy. These findings suggest that radioisotope scanning may be useful in the diagnosis and management of patients with inflammatory muscle diseases.

  1. Experimental knee pain reduces muscle strength

    DEFF Research Database (Denmark)

    Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

    2011-01-01

    Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

  2. Modelling of pneumatic muscle actuator using Hill's model with different approximations of static characteristics of artificial muscle

    OpenAIRE

    Piteľ Ján; Tóthová Mária

    2016-01-01

    For modelling and simulation of pneumatic muscle actuators the mathematical dependence of the muscle force on the muscle contraction at different pressures in the muscles is necessary to know. For this purpose the static characteristics of the pneumatic artificial muscle type FESTO MAS-20-250N used in the experiments were approximated. In the paper there are shown some simulation results of the pneumatic muscle actuator dynamics using modified Hill's muscle model, in which four different appr...

  3. Familial muscle cramps with autosomal dominant transmission.

    Science.gov (United States)

    Van den Bergh, P; Bulcke, J A; Dom, R

    1980-01-01

    A family is described with generalized muscle cramps inherited as an autosomal dominant trait and with maximal expression during adolescence. The age of onset varies between 10 and 15 years. Muscle enzymes are elevated with a peak level between 15 and 25 years. The complaints seem to disappear after the age of 25 years. EMG and muscle biopsies suggest a neurogenic origin of the cramps.

  4. Muscle Synergy-Driven Robust Motion Control.

    Science.gov (United States)

    Min, Kyuengbo; Iwamoto, Masami; Kakei, Shinji; Kimpara, Hideyuki

    2018-04-01

    Humans are able to robustly maintain desired motion and posture under dynamically changing circumstances, including novel conditions. To accomplish this, the brain needs to optimize the synergistic control between muscles against external dynamic factors. However, previous related studies have usually simplified the control of multiple muscles using two opposing muscles, which are minimum actuators to simulate linear feedback control. As a result, they have been unable to analyze how muscle synergy contributes to motion control robustness in a biological system. To address this issue, we considered a new muscle synergy concept used to optimize the synergy between muscle units against external dynamic conditions, including novel conditions. We propose that two main muscle control policies synergistically control muscle units to maintain the desired motion against external dynamic conditions. Our assumption is based on biological evidence regarding the control of multiple muscles via the corticospinal tract. One of the policies is the group control policy (GCP), which is used to control muscle group units classified based on functional similarities in joint control. This policy is used to effectively resist external dynamic circumstances, such as disturbances. The individual control policy (ICP) assists the GCP in precisely controlling motion by controlling individual muscle units. To validate this hypothesis, we simulated the reinforcement of the synergistic actions of the two control policies during the reinforcement learning of feedback motion control. Using this learning paradigm, the two control policies were synergistically combined to result in robust feedback control under novel transient and sustained disturbances that did not involve learning. Further, by comparing our data to experimental data generated by human subjects under the same conditions as those of the simulation, we showed that the proposed synergy concept may be used to analyze muscle synergy

  5. [Autocontrol of muscle relaxation with vecuronium].

    Science.gov (United States)

    Sibilla, C; Zatelli, R; Marchi, M; Zago, M

    1990-01-01

    The optimal conditions for maintaining desired levels of muscle relaxation with vecuronium are obtained by means of the continuous infusion (I.V.) technique. A frequent correction of the infusion flow is required, since it is impossible to predict the exact amount for the muscle relaxant in single case. In order to overcome such limits the authors propose a very feasible infusion system for the self-control of muscle relaxation; furthermore they positively consider its possible daily clinical application.

  6. Insulin binding to individual rat skeletal muscles

    International Nuclear Information System (INIS)

    Koerker, D.J.; Sweet, I.R.; Baskin, D.G.

    1990-01-01

    Studies of insulin binding to skeletal muscle, performed using sarcolemmal membrane preparations or whole muscle incubations of mixed muscle or typical red (soleus, psoas) or white [extensor digitorum longus (EDL), gastrocnemius] muscle, have suggested that red muscle binds more insulin than white muscle. We have evaluated this hypothesis using cryostat sections of unfixed tissue to measure insulin binding in a broad range of skeletal muscles; many were of similar fiber-type profiles. Insulin binding per square millimeter of skeletal muscle slice was measured by autoradiography and computer-assisted densitometry. We found a 4.5-fold range in specific insulin tracer binding, with heart and predominantly slow-twitch oxidative muscles (SO) at the high end and the predominantly fast-twitch glycolytic (FG) muscles at the low end of the range. This pattern reflects insulin sensitivity. Evaluation of displacement curves for insulin binding yielded linear Scatchard plots. The dissociation constants varied over a ninefold range (0.26-2.06 nM). Binding capacity varied from 12.2 to 82.7 fmol/mm2. Neither binding parameter was correlated with fiber type or insulin sensitivity; e.g., among three muscles of similar fiber-type profile, the EDL had high numbers of low-affinity binding sites, whereas the quadriceps had low numbers of high-affinity sites. In summary, considerable heterogeneity in insulin binding was found among hindlimb muscles of the rat, which can be attributed to heterogeneity in binding affinities and the numbers of binding sites. It can be concluded that a given fiber type is not uniquely associated with a set of insulin binding parameters that result in high or low binding

  7. Insulin binding to individual rat skeletal muscles

    Energy Technology Data Exchange (ETDEWEB)

    Koerker, D.J.; Sweet, I.R.; Baskin, D.G. (Univ. of Washington, Seattle (USA))

    1990-10-01

    Studies of insulin binding to skeletal muscle, performed using sarcolemmal membrane preparations or whole muscle incubations of mixed muscle or typical red (soleus, psoas) or white (extensor digitorum longus (EDL), gastrocnemius) muscle, have suggested that red muscle binds more insulin than white muscle. We have evaluated this hypothesis using cryostat sections of unfixed tissue to measure insulin binding in a broad range of skeletal muscles; many were of similar fiber-type profiles. Insulin binding per square millimeter of skeletal muscle slice was measured by autoradiography and computer-assisted densitometry. We found a 4.5-fold range in specific insulin tracer binding, with heart and predominantly slow-twitch oxidative muscles (SO) at the high end and the predominantly fast-twitch glycolytic (FG) muscles at the low end of the range. This pattern reflects insulin sensitivity. Evaluation of displacement curves for insulin binding yielded linear Scatchard plots. The dissociation constants varied over a ninefold range (0.26-2.06 nM). Binding capacity varied from 12.2 to 82.7 fmol/mm2. Neither binding parameter was correlated with fiber type or insulin sensitivity; e.g., among three muscles of similar fiber-type profile, the EDL had high numbers of low-affinity binding sites, whereas the quadriceps had low numbers of high-affinity sites. In summary, considerable heterogeneity in insulin binding was found among hindlimb muscles of the rat, which can be attributed to heterogeneity in binding affinities and the numbers of binding sites. It can be concluded that a given fiber type is not uniquely associated with a set of insulin binding parameters that result in high or low binding.

  8. Heat stress inhibits skeletal muscle hypertrophy

    OpenAIRE

    Frier, Bruce C.; Locke, Marius

    2007-01-01

    Heat shock proteins (Hsps) are molecular chaperones that aid in protein synthesis and trafficking and have been shown to protect cells/tissues from various protein damaging stressors. To determine the extent to which a single heat stress and the concurrent accumulation of Hsps influences the early events of skeletal muscle hypertrophy, Sprague-Dawley rats were heat stressed (42°C, 15 minutes) 24 hours prior to overloading 1 plantaris muscle by surgical removal of the gastrocnemius muscle. The...

  9. Targeted Muscle Reinnervation and Advanced Prosthetic Arms

    OpenAIRE

    Cheesborough, Jennifer E.; Smith, Lauren H.; Kuiken, Todd A.; Dumanian, Gregory A.

    2015-01-01

    Targeted muscle reinnervation (TMR) is a surgical procedure used to improve the control of upper limb prostheses. Residual nerves from the amputated limb are transferred to reinnervate new muscle targets that have otherwise lost their function. These reinnervated muscles then serve as biological amplifiers of the amputated nerve motor signals, allowing for more intuitive control of advanced prosthetic arms. Here the authors provide a review of surgical techniques for TMR in patients with eith...

  10. Role of Smooth Muscle in Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    Stephen M Collins

    1996-01-01

    Full Text Available The notion that smooth muscle function is altered in inflammation is prompted by clinical observations of altered motility in patients with inflammatory bowel disease (IBD. While altered motility may reflect inflammation-induced changes in intrinsic or extrinsic nerves to the gut, changes in gut hormone release and changes in muscle function, recent studies have provided in vitro evidence of altered muscle contractility in muscle resected from patients with ulcerative colitis or Crohn’s disease. In addition, the observation that smooth muscle cells are more numerous and prominent in the strictured bowel of IBD patients compared with controls suggests that inflammation may alter the growth of intestinal smooth muscle. Thus, inflammation is associated with changes in smooth muscle growth and contractility that, in turn, contribute to important symptoms of IBD including diarrhea (from altered motility and pain (via either altered motility or stricture formation. The involvement of smooth muscle in this context may be as an innocent bystander, where cells and products of the inflammatory process induce alterations in muscle contractility and growth. However, it is likely that intestinal muscle cells play a more active role in the inflammatory process via the elaboration of mediators and trophic factors, including cytokines, and via the production of collagen. The concept of muscle cells as active participants in the intestinal inflammatory process is a new concept that is under intense study. This report summarizes current knowledge as it relates to these two aspects of altered muscle function (growth and contractility in the inflamed intestine, and will focus on mechanisms underlying these changes, based on data obtained from animal models of intestinal inflammation.

  11. Muscle changes in aging: understanding sarcopenia.

    Science.gov (United States)

    Siparsky, Patrick N; Kirkendall, Donald T; Garrett, William E

    2014-01-01

    Muscle physiology in the aging athlete is complex. Sarcopenia, the age-related decrease in lean muscle mass, can alter activity level and affect quality of life. This review addresses the microscopic and macroscopic changes in muscle with age, recognizes contributing factors including nutrition and changes in hormone levels, and identifies potential pharmacologic agents in clinical trial that may aid in the battle of this complex, costly, and disabling problem. Level 5.

  12. Magnesium for skeletal muscle cramps.

    Science.gov (United States)

    Garrison, Scott R; Allan, G Michael; Sekhon, Ravneet K; Musini, Vijaya M; Khan, Karim M

    2012-09-12

    Skeletal muscle cramps are common and often presented to physicians in association with pregnancy, advanced age, exercise or disorders of the motor neuron (such as amyotrophic lateral sclerosis). Magnesium supplements are marketed for the prophylaxis of cramps but the efficacy of magnesium for this indication has never been evaluated by systematic review. To assess the effects of magnesium supplementation compared to no treatment, placebo control or other cramp therapies in people with skeletal muscle cramps.   We searched the Cochrane Neuromuscular Disease Group Specialized Register (11 October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 3), MEDLINE (January 1966 to September 2011), EMBASE (January 1980 to September 2011), LILACS (January 1982 to September 2011), CINAHL Plus (January 1937 to September 2011), AMED (January 1985 to October 2011) and SPORTDiscus (January 1975 to September 2011). Randomized controlled trials (RCTs) of magnesium supplementation (in any form) to prevent skeletal muscle cramps in any patient group (i.e. all clinical presentations of cramp). We considered comparisons of magnesium with no treatment, placebo control, or other therapy. Two authors independently selected trials for inclusion and extracted data. Two authors assessed risk of bias. We attempted to contact all study authors and obtained patient level data for three of the included trials, one of which was unpublished. All data on adverse effects were collected from the included RCTs. We identified seven trials (five parallel, two cross-over) enrolling a total of 406 individuals amongst whom 118 cross-over participants additionally served as their own controls. Three trials enrolled women with pregnancy-associated leg cramps (N = 202) and four trials enrolled idiopathic cramp sufferers (N = 322 including cross-over controls). Magnesium was compared to placebo in six trials and to no treatment in one trial.For idiopathic cramps (largely older

  13. A variation of the extensor hallucis longus muscle (accessory extensor digiti secundus muscle).

    Science.gov (United States)

    Tezer, Murat; Cicekcibasi, Aynur Emine

    2012-06-01

    An accessory muscle adjacent to the extensor hallucis longus muscle (EHL) was observed between the EHL and the extensor digitorum longus muscle (EDL) in the anterior side of both legs of the cadaver of a 72-year-old male, during educational dissection, and it was observed that the tendon of this muscle extended to the second toe. The tendon of this muscle united with the second toe tendon of the EDL. These common tendons appeared before reaching the toe media phalanxes and extended to the related media phalanxes of toe. However, an additional tendon separating from this accessory muscle tendon united with the EHL tendon at the left foot. This accessory muscle, unlike the variations identified to date, is considered to extend to the second toe, and the name "accessory extensor digiti secundus muscle" is offered.

  14. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT-4 content

    DEFF Research Database (Denmark)

    Asp, S; Rohde, T; Richter, Erik

    1997-01-01

    the marathon and decreased to 148 +/- 39 mmol/kg dry weight immediately afterward. Despite a carbohydrate-rich diet (containing at least 7 g carbohydrate.kg body mass-1.day-1), the muscle glycogen concentration remained 30% lower than before-race values 2 days after the race, whereas it had returned to before......Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies...... were obtained from the lateral head of the gastrocnemius muscle before, immediately after, and 1, 2, and 7 days after the marathon, as were venous blood samples. Muscle GLUT-4 content was unaltered over the experimental period. Muscle glycogen concentration was 758 +/- 53 mmol/kg dry weight before...

  15. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT-4 content

    DEFF Research Database (Denmark)

    Asp, S; Rohde, T; Richter, Erik

    1997-01-01

    Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies...... were obtained from the lateral head of the gastrocnemius muscle before, immediately after, and 1, 2, and 7 days after the marathon, as were venous blood samples. Muscle GLUT-4 content was unaltered over the experimental period. Muscle glycogen concentration was 758 +/- 53 mmol/kg dry weight before......-race levels 7 days after the race. We conclude that the total GLUT-4 protein content is unaltered in the lateral gastrocnemius after a competitive marathon and that the slow recovery of muscle glycogen after the race apparently involves factors other than changes in the total content of this protein....

  16. Core muscle activity during suspension exercises.

    Science.gov (United States)

    Mok, Nicola W; Yeung, Ella W; Cho, Jeran C; Hui, Samson C; Liu, Kimee C; Pang, Coleman H

    2015-03-01

    Suspension exercise has been advocated as an effective means to improve core stability among healthy individuals and those with musculoskeletal complaints. However, the activity of core muscles during suspension exercises has not been reported. In this study, we investigated the level of activation of core muscles during suspension exercises within young and healthy adults. The study was conducted in a controlled laboratory setting. Surface electromyographic (sEMG) activity of core muscles (rectus abdominis, external oblique, internal oblique/transversus abdominis, and superficial lumbar multifidus) during four suspension workouts (hip abduction in plank, hamstring curl, chest press, and 45° row) was investigated. Muscle activity during a 5-s hold period of the workouts was measured by sEMG and normalized to the individual's maximal voluntary isometric contraction (MVIC). Different levels of muscle activation were observed during the hip abduction in plank, hamstring curl, and chest press. Hip abduction in plank generated the highest activation of most abdominal muscles. The 45° row exercise generated the lowest muscle activation. Among the four workouts investigated, the hip abduction in plank with suspension was found to have the strongest potential strengthening effect on core muscles. Also, suspension training was found to generate relatively high levels of core muscle activation when compared with that among previous studies of core exercises on stable and unstable support surfaces. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  17. Novel Ultrasound Assessment of Dynamic Muscle

    Data.gov (United States)

    National Aeronautics and Space Administration — Substantial research shows that skeletal muscle undergoes atrophy during spaceflight. Because maintenance of the musculoskeletal system is of crucial importance for...

  18. [Asymmetric hypertrophy of the masticatory muscles].

    Science.gov (United States)

    Arzul, L; Corre, P; Khonsari, R H; Mercier, J-M; Piot, B

    2012-06-01

    Hypertrophy of the masticatory muscles most commonly affects the masseter. Less common cases of isolated or associated temporalis hypertrophy are also reported. Parafunctional habits, and more precisely bruxism, can favor the onset of the hypertrophy. This condition is generally idiopathic and can require both medical and/or surgical management. A 29-year-old patient was referred to our department for an asymmetric swelling of the masticatory muscles. Physical examination revealed a bilateral hypertrophy of the masticatory muscles, predominantly affecting the right temporalis and the left masseter. Major bruxism was assessed by premature dental wearing. The additional examinations confirmed the isolated muscle hypertrophy. Benign asymmetric hypertrophy of the masticatory muscles promoted by bruxism was diagnosed. Treatment with injections of type A botulinum toxin was conducted in association with a splint and relaxation. Its effectiveness has been observed at six months. Few cases of unilateral or bilateral temporalis hypertrophy have been reported, added to the more common isolated masseter muscles hypertrophy. The diagnosis requires to rule out secondary hypertrophies and tumors using Magnetic Resonance Imaging. The condition is thought to be favoured by parafunctional habits such as bruxism. The conservative treatment consists in reducing the volume of the masticatory muscles using intramuscular injections of type A botulinum toxin. Other potential conservative treatments are wearing splints and muscle relaxant drugs. Surgical procedures aiming to reduce the muscle volume and/or the bone volume (mandibular gonioplasty) can be proposed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  19. Engineered Muscle Actuators: Cells and Tissues

    National Research Council Canada - National Science Library

    Dennis, Robert G; Herr, Hugh; Parker, Kevin K; Larkin, Lisa; Arruda, Ellen; Baar, Keith

    2007-01-01

    .... Our primary objectives were to engineer living skeletal muscle actuators in culture using integrated bioreactors to guide tissue development and to maintain tissue contractility, to achieve 50...

  20. Sex hormones and skeletal muscle weakness

    DEFF Research Database (Denmark)

    Sipilä, Sarianna; Narici, Marco; Kjaer, Michael

    2013-01-01

    in fast muscle function (power), and accumulation of fat in skeletal muscle. Further HRT raises the protein synthesis rate in skeletal muscle after resistance training, and has an anabolic effect upon connective tissue in both skeletal muscle and tendon, which influences matrix structure and mechanical...... properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal...

  1. A Case of Tensor Fasciae Suralis Muscle

    OpenAIRE

    Miyauchi, Ryosuke; Kurihara, Kazushige; Tachibana, Gen

    1985-01-01

    An anomalous muscle was found on the dorsum of the right lower limb of a 67-year-old Japanese male. It originated by two heads from the semitendinosus and long head of the biceps femoris and ran distally to insert into the deep surface of the sural fascia. The origin, insertion and location of the muscle were compared with those of the various supernumerary muscles hitherto published. The muscle is consequently regarded as being the tensor fasciae suralis. This is the fifth case in Japan.

  2. Cellular and molecular mechanisms of muscle atrophy

    Directory of Open Access Journals (Sweden)

    Paolo Bonaldo

    2013-01-01

    Full Text Available Skeletal muscle is a plastic organ that is maintained by multiple pathways regulating cell and protein turnover. During muscle atrophy, proteolytic systems are activated, and contractile proteins and organelles are removed, resulting in the shrinkage of muscle fibers. Excessive loss of muscle mass is associated with poor prognosis in several diseases, including myopathies and muscular dystrophies, as well as in systemic disorders such as cancer, diabetes, sepsis and heart failure. Muscle loss also occurs during aging. In this paper, we review the key mechanisms that regulate the turnover of contractile proteins and organelles in muscle tissue, and discuss how impairments in these mechanisms can contribute to muscle atrophy. We also discuss how protein synthesis and degradation are coordinately regulated by signaling pathways that are influenced by mechanical stress, physical activity, and the availability of nutrients and growth factors. Understanding how these pathways regulate muscle mass will provide new therapeutic targets for the prevention and treatment of muscle atrophy in metabolic and neuromuscular diseases.

  3. Update on new muscle glycogenosis

    DEFF Research Database (Denmark)

    Laforêt, Pascal; Malfatti, Edoardo; Vissing, John

    2017-01-01

    and pathological features of the three most recently described muscle glycogenoses caused by recessive mutations in GYG1, RBCK1 and PGM1. The three involved enzymes play different roles in glycogen metabolism. Glycogenin-1 (GYG1) is involved in the initial steps of glycogen synthesis, whereas phosphoglucomutase...... with abnormal storage material in the heart, but most cases present with a polyglucosan body myopathy without cardiac involvement. SUMMARY: The recent identification of new glycogenosis not only allows to improve the knowledge of glycogen metabolism, but also builds bridges with protein glycosylation and immune...

  4. Markov process of muscle motors

    International Nuclear Information System (INIS)

    Kondratiev, Yu; Pechersky, E; Pirogov, S

    2008-01-01

    We study a Markov random process describing muscle molecular motor behaviour. Every motor is either bound up with a thin filament or unbound. In the bound state the motor creates a force proportional to its displacement from the neutral position. In both states the motor spends an exponential time depending on the state. The thin filament moves at a velocity proportional to the average of all displacements of all motors. We assume that the time which a motor stays in the bound state does not depend on its displacement. Then one can find an exact solution of a nonlinear equation appearing in the limit of an infinite number of motors

  5. Relative activity of respiratory muscles during prescribed inspiratory muscle training in healthy people

    OpenAIRE

    Jung, Ju-hyeon; Kim, Nan-soo

    2016-01-01

    [Purpose] This study aimed to determine the effects of different intensities of inspiratory muscle training on the relative respiratory muscle activity in healthy adults. [Subjects and Methods] Thirteen healthy male volunteers were instructed to perform inspiratory muscle training (0%, 40%, 60%, and 80% maximal inspiratory pressure) on the basis of their individual intensities. The inspiratory muscle training was performed in random order of intensities. Surface electromyography data were col...

  6. Muscle MRI Findings in Childhood/Adult Onset Pompe Disease Correlate with Muscle Function.

    Directory of Open Access Journals (Sweden)

    Sebastián Figueroa-Bonaparte

    Full Text Available Enzyme replacement therapy has shown to be effective for childhood/adult onset Pompe disease (AOPD. The discovery of biomarkers useful for monitoring disease progression is one of the priority research topics in Pompe disease. Muscle MRI could be one possible test but the correlation between muscle MRI and muscle strength and function has been only partially addressed so far.We studied 34 AOPD patients using functional scales (Manual Research Council scale, hand held myometry, 6 minutes walking test, timed to up and go test, time to climb up and down 4 steps, time to walk 10 meters and Motor Function Measure 20 Scale, respiratory tests (Forced Vital Capacity seated and lying, Maximun Inspiratory Pressure and Maximum Expiratory Pressure, daily live activities scales (Activlim and quality of life scales (Short Form-36 and Individualized Neuromuscular Quality of Life questionnaire. We performed a whole body muscle MRI using T1w and 3-point Dixon imaging centered on thighs and lower trunk region.T1w whole body muscle MRI showed a homogeneous pattern of muscle involvement that could also be found in pre-symptomatic individuals. We found a strong correlation between muscle strength, muscle functional scales and the degree of muscle fatty replacement in muscle MRI analyzed using T1w and 3-point Dixon imaging studies. Moreover, muscle MRI detected mild degree of fatty replacement in paraspinal muscles in pre-symptomatic patients.Based on our findings, we consider that muscle MRI correlates with muscle function in patients with AOPD and could be useful for diagnosis and follow-up in pre-symptomatic and symptomatic patients under treatment.Muscle MRI correlates with muscle function in patients with AOPD and could be useful to follow-up patients in daily clinic.

  7. The number and choice of muscles impact the results of muscle synergy analyses

    Directory of Open Access Journals (Sweden)

    Katherine Muterspaugh Steele

    2013-08-01

    Full Text Available One theory for how humans control movement is that muscles are activated in weighted groups or synergies. Studies have shown that electromyography (EMG from a variety of tasks can be described by a low-dimensional space thought to reflect synergies. These studies use algorithms, such as nonnegative matrix factorization, to identify synergies from EMG. Due to experimental constraints, EMG can rarely be taken from all muscles involved in a task. However, it is unclear if the choice of muscles included in the analysis impacts estimated synergies. The aim of our study was to evaluate the impact of the number and choice of muscles on synergy analyses. We used a musculoskeletal model to calculate muscle activations required to perform an isometric upper-extremity task. Synergies calculated from the activations from the musculoskeletal model were similar to a prior experimental study. To evaluate the impact of the number of muscles included in the analysis, we randomly selected subsets of between 5 and 29 muscles and compared the similarity of the synergies calculated from each subset to a master set of synergies calculated from all muscles. We determined that the structure of synergies is dependent upon the number and choice of muscles included in the analysis. When five muscles were included in the analysis, the similarity of the synergies to the master set was only 0.57 ± 0.54; however, the similarity improved to over 0.8 with more than ten muscles. We identified two methods, selecting dominant muscles from the master set or selecting muscles with the largest maximum isometric force, which significantly improved similarity to the master set and can help guide future experimental design. Analyses that included a small subset of muscles also over-estimated the variance accounted for (VAF by the synergies compared to an analysis with all muscles. Thus, researchers should use caution using VAF to evaluate synergies when EMG is measured from a small

  8. Sumoylated α-skeletal muscle actin in the skeletal muscle of adult rats.

    Science.gov (United States)

    Uda, Munehiro; Kawasaki, Hiroaki; Iizumi, Kyoichi; Shigenaga, Ayako; Baba, Takeshi; Naito, Hisashi; Yoshioka, Toshitada; Yamakura, Fumiyuki

    2015-11-01

    Skeletal muscles are composed of two major muscle fiber types: slow-twitch oxidative fibers and fast-twitch glycolytic fibers. The proteins in these muscle fibers are known to differ in their expression, relative abundance, and post-translational modifications. In this study, we report a previously unreported post-translational modification of α-skeletal muscle actin in the skeletal muscles of adult male F344 rats in vivo. Using two-dimensional electrophoresis (2D-PAGE), we first examined the differences in the protein expression profiles between the soleus and plantaris muscles. We found higher intensity protein spots at approximately 60 kDa and pH 9 on 2D-PAGE for the soleus muscle compared with the plantaris muscle. These spots were identified as α-skeletal muscle actin by liquid chromatography-nanoelectrospray ionization-tandem mass spectrometry and western blot analyses. In addition, we found that the 60 kDa α-skeletal muscle actin is modified by small ubiquitin-like modifier (SUMO) 1, using 2D-PAGE and western blot analyses. Furthermore, we found that α-skeletal muscle actin with larger molecular weight was localized in the nuclear and cytosol of the skeletal muscle, but not in the myofibrillar fraction by the combination of subcellular fractionation and western blot analyses. These results suggest that α-skeletal muscle actin is modified by SUMO-1 in the skeletal muscles, localized in nuclear and cytosolic fractions, and the extent of this modification is much higher in the slow muscles than in the fast muscles. This is the first study to show the presence of SUMOylated actin in animal tissues.

  9. Muscle-specific GSK-3β ablation accelerates regeneration of disuse-atrophied skeletal muscle.

    Science.gov (United States)

    Pansters, Nicholas A M; Schols, Annemie M W J; Verhees, Koen J P; de Theije, Chiel C; Snepvangers, Frank J; Kelders, Marco C J M; Ubags, Niki D J; Haegens, Astrid; Langen, Ramon C J

    2015-03-01

    Muscle wasting impairs physical performance, increases mortality and reduces medical intervention efficacy in chronic diseases and cancer. Developing proficient intervention strategies requires improved understanding of the molecular mechanisms governing muscle mass wasting and recovery. Involvement of muscle protein- and myonuclear turnover during recovery from muscle atrophy has received limited attention. The insulin-like growth factor (IGF)-I signaling pathway has been implicated in muscle mass regulation. As glycogen synthase kinase 3 (GSK-3) is inhibited by IGF-I signaling, we hypothesized that muscle-specific GSK-3β deletion facilitates the recovery of disuse-atrophied skeletal muscle. Wild-type mice and mice lacking muscle GSK-3β (MGSK-3β KO) were subjected to a hindlimb suspension model of reversible disuse-induced muscle atrophy and followed during recovery. Indices of muscle mass, protein synthesis and proteolysis, and post-natal myogenesis which contribute to myonuclear accretion, were monitored during the reloading of atrophied muscle. Early muscle mass recovery occurred more rapidly in MGSK-3β KO muscle. Reloading-associated changes in muscle protein turnover were not affected by GSK-3β ablation. However, coherent effects were observed in the extent and kinetics of satellite cell activation, proliferation and myogenic differentiation observed during reloading, suggestive of increased myonuclear accretion in regenerating skeletal muscle lacking GSK-3β. This study demonstrates that muscle mass recovery and post-natal myogenesis from disuse-atrophy are accelerated in the absence of GSK-3β. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Low Intensity Vibration as a Treatment for Traumatic Muscle Injury

    Science.gov (United States)

    2016-08-01

    improving muscle healing, thereby reducing joint stiffness and increasing mobility of polytrauma patients. 15. SUBJECT TERMS Skeletal muscle repair ...and increasing mobility of polytrauma patients. 2. KEYWORDS Skeletal muscle repair , low-intensity vibration, monocytes/macrophages, endothelial...areas of bright contrast represent inflammation (indicated by red arrow) and edema within the muscle while darker areas show normal muscle tissue

  11. Glycogen synthesis in human gastrocnemius muscle is not representative of whole-body muscle glycogen synthesis

    NARCIS (Netherlands)

    Serlie, Mireille J. M.; de Haan, Jacco H.; Tack, Cees J.; Verberne, Hein J.; Ackermans, Mariette T.; Heerschap, Arend; Sauerwein, Hans P.

    2005-01-01

    The introduction of C-13 magnetic resonance spectroscopy (MRS) has enabled noninvasive measurement of muscle glycogen synthesis in humans. Conclusions based on measurements by the MRS technique assume that glucose metabolism in gastrocnemius muscle is representative for all skeletal muscles and thus

  12. Glycogen synthesis in human gastrocnemius muscle is not representative of whole-body muscle glycogen synthesis.

    NARCIS (Netherlands)

    Serlie, M.J.; Haan, J.H.A. de; Tack, C.J.J.; Verberne, H.J.; Ackermans, M.T.; Heerschap, A.; Sauerwein, H.P.

    2005-01-01

    The introduction of 13C magnetic resonance spectroscopy (MRS) has enabled noninvasive measurement of muscle glycogen synthesis in humans. Conclusions based on measurements by the MRS technique assume that glucose metabolism in gastrocnemius muscle is representative for all skeletal muscles and thus

  13. Objective evaluation of muscle strength in infants with hypotonia and muscle weakness

    NARCIS (Netherlands)

    Reus, L.; Vlimmeren, L.A. van; Staal, J.B.; Janssen, A.J.W.M.; Otten, B.J.; Pelzer, B.J.; Nijhuis-Van der Sanden, M.W.G.

    2013-01-01

    The clinical evaluation of an infant with motor delay, muscle weakness, and/or hypotonia would improve considerably if muscle strength could be measured objectively and normal reference values were available. The authors developed a method to measure muscle strength in infants and tested 81

  14. Muscle activation during selected strength exercises in women with chronic neck muscle pain

    DEFF Research Database (Denmark)

    Andersen, L.L.; Kjaer, M.; Andersen, C.H.

    2008-01-01

    Background and Purpose. Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this stud), was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) (lu...

  15. Zilpaterol hydrochloride affects cellular muscle metabolism and lipid components of ten different muscles in feedlot heifers

    Science.gov (United States)

    This study determined if zilpaterol hydrochloride (ZH) altered muscle metabolism and lipid components of ten muscles. Crossbred heifers were either supplemented with ZH (n = 9) or not (Control; n = 10). Muscle tissue was collected (adductor femoris, biceps femoris, gluteus medius, infraspinatus, lat...

  16. Muscle insulin sensitivity and glucose metabolism are controlled by the intrinsic muscle clock

    DEFF Research Database (Denmark)

    Dyar, Kenneth A.; Ciciliot, Stefano; Wright, Lauren E.

    2014-01-01

    Circadian rhythms control metabolism and energy homeostasis, but the role of the skeletal muscle clock has never been explored. We generated conditional and inducible mouse lines with muscle-specific ablation of the core clock gene Bmal1. Skeletal muscles from these mice showed impaired insulin-s...

  17. Reorganization of muscle synergies during multidirectional reaching in the horizontal plane with experimental muscle pain.

    Science.gov (United States)

    Muceli, Silvia; Falla, Deborah; Farina, Dario

    2014-04-01

    Muscle pain induces a complex reorganization of the motor strategy which cannot be fully explained by current theories. We tested the hypothesis that the neural control of muscles during reaching in the presence of nociceptive input is determined by a reorganization of muscle synergies with respect to control conditions. Muscle pain was induced by injection of hypertonic saline into the anterior deltoid muscle of eight men. Electromyographic (EMG) signals were recorded from 12 upper limb muscles as subjects performed a reaching task before (baseline) and after the injection of hypertonic (pain) saline, and after the pain sensation vanished. The EMG envelopes were factorized in muscle synergies, and activation signals extracted for each condition. Nociceptive stimulation resulted in a complex muscle reorganization without changes in the kinematic output. The anterior deltoid muscle activity decreased in all subjects while the changes in other muscles were subject specific. Three synergies sufficed to describe the EMG patterns in each condition, suggesting that reaching movements remain modular in the presence of experimental pain. Muscle reorganization in all subjects was accompanied by a change in the activation signals compatible with a change in the central drive to muscles. One, two or three synergies were shared between the baseline and painful conditions, depending on the subject. These results indicate that nociceptive stimulation may induce a reorganization of modular control in reaching. We speculate that such reorganization may be due to the recruitment of synergies specific to the painful condition.

  18. Lack of CFTR in skeletal muscle predisposes to muscle wasting and diaphragm muscle pump failure in cystic fibrosis mice.

    Directory of Open Access Journals (Sweden)

    Maziar Divangahi

    2009-07-01

    Full Text Available Cystic fibrosis (CF patients often have reduced mass and strength of skeletal muscles, including the diaphragm, the primary muscle of respiration. Here we show that lack of the CF transmembrane conductance regulator (CFTR plays an intrinsic role in skeletal muscle atrophy and dysfunction. In normal murine and human skeletal muscle, CFTR is expressed and co-localized with sarcoplasmic reticulum-associated proteins. CFTR-deficient myotubes exhibit augmented levels of intracellular calcium after KCl-induced depolarization, and exposure to an inflammatory milieu induces excessive NF-kB translocation and cytokine/chemokine gene upregulation. To determine the effects of an inflammatory environment in vivo, sustained pulmonary infection with Pseudomonas aeruginosa was produced, and under these conditions diaphragmatic force-generating capacity is selectively reduced in Cftr(-/- mice. This is associated with exaggerated pro-inflammatory cytokine expression as well as upregulation of the E3 ubiquitin ligases (MuRF1 and atrogin-1 involved in muscle atrophy. We conclude that an intrinsic alteration of function is linked to the absence of CFTR from skeletal muscle, leading to dysregulated calcium homeostasis, augmented inflammatory/atrophic gene expression signatures, and increased diaphragmatic weakness during pulmonary infection. These findings reveal a previously unrecognized role for CFTR in skeletal muscle function that may have major implications for the pathogenesis of cachexia and respiratory muscle pump failure in CF patients.

  19. Resistance training induces qualitative changes in muscle morphology, muscle architecture, and muscle function in elderly postoperative patients

    DEFF Research Database (Denmark)

    Suetta, Charlotte; Andersen, Jesper L; Dalgas, Ulrik

    2008-01-01

    Although the negative effects of bed rest on muscle strength and muscle mass are well established, it still remains a challenge to identify effective methods to restore physical capacity of elderly patients recovering from hospitalization. The present study compared different training regimes...... degrees /s (P thickness increased by 15% (P

  20. Exercise-Associated Muscle Cramps

    Science.gov (United States)

    Miller, Kevin C.; Stone, Marcus S.; Huxel, Kellie C.; Edwards, Jeffrey E.

    2010-01-01

    Context: Exercise-associated muscle cramps (EAMC) are a common condition experienced by recreational and competitive athletes. Despite their commonality and prevalence, their cause remains unknown. Theories for the cause of EAMC are primarily based on anecdotal and observational studies rather than sound experimental evidence. Without a clear cause, treatments and prevention strategies for EAMC are often unsuccessful. Evidence Acquisition: A search of Medline (EBSCO), SPORTDiscus, and Silverplatter (CINHAL) was undertaken for journal articles written in English between the years 1955 and 2008. Additional references were collected by a careful analysis of the citations of others’ research and textbooks. Results: Dehydration/electrolyte and neuromuscular causes are the most widely discussed theories for the cause of EAMC; however, strong experimental evidence for either theory is lacking. Conclusions: EAMC are likely due to several factors coalescing to cause EAMC. The variety of treatments and prevention strategies for EAMC are evidence of the uncertainty in their cause. Acute EAMC treatment should focus on moderate static stretching of the affected muscle followed by a proper medical history to determine any predisposing conditions that may have triggered the onset of EAMC. Based on physical findings, prevention programs should be implemented to include fluid and electrolyte balance strategies and/or neuromuscular training. PMID:23015948

  1. Muscle GLUT4 in cirrhosis

    DEFF Research Database (Denmark)

    Holland-Fischer, Peter; Andersen, Per Heden; Lund, Sten

    2007-01-01

    BACKGROUND/AIMS: The insulin-dependent glucose transporter GLUT4 mediates 50-80% of whole body glucose uptake, but its relation to the frequent glucose intolerance in patients with liver cirrhosis is unknown. METHODS: Thirty patients and seven healthy controls underwent a 2-h oral glucose tolerance...... test and later a muscle biopsy. Levels of GLUT4 total protein and mRNA content were determined in muscle biopsies by polyclonal antibody labelling and RT-PCR, respectively. RESULTS: GLUT4 protein content in the cirrhosis group was not different from that of the controls, but at variance...... with the control subjects it correlated closely with measures of glucose tolerance (R(2)=0.45; p=0.003). GLUT4 mRNA of the patients with cirrhosis was reduced to 56% of control value (95% ci: 27-86%; p=0.015) and was inversely related to the level of basal hyper-insulinemia (R(2)=0.39; p=0.004). CONCLUSIONS...

  2. Muscle GLUT4 in cirrhosis

    DEFF Research Database (Denmark)

    Holland-Fischer, Peter; Andersen, Per Heden; Lund, Sten

    2007-01-01

    BACKGROUND/AIMS: The insulin-dependent glucose transporter GLUT4 mediates 50-80% of whole body glucose uptake, but its relation to the frequent glucose intolerance in patients with liver cirrhosis is unknown. METHODS: Thirty patients and seven healthy controls underwent a 2-h oral glucose tolerance...... test and later a muscle biopsy. Levels of GLUT4 total protein and mRNA content were determined in muscle biopsies by polyclonal antibody labelling and RT-PCR, respectively. RESULTS: GLUT4 protein content in the cirrhosis group was not different from that of the controls, but at variance...... with the control subjects it correlated closely with measures of glucose tolerance (R(2)=0.45; p=0.003). GLUT4 mRNA of the cirrhosis patients was reduced to 56% of control value (95% ci: 27-86%; p=0.015) and was inversely related to the level of basal hyper-insulinemia (R(2)=0.39; p=0.004). CONCLUSIONS...

  3. Gender differences in MR muscle tractography

    International Nuclear Information System (INIS)

    Okamoto, Yoshikazu; Minami, Manabu; Kunimatsu, Akira; Kono, Tatsuo; Sonobe, Jyunichi; Kujiraoka, Yuka

    2010-01-01

    Tractography of skeletal muscle can clearly reveal the 3-dimensional course of muscle fibers, and the procedure has great potential and could open new fields for diagnostic imaging. Studying this technique for clinical application, we noticed differences in the number of visualized tracts among volunteers and among muscles in the same volunteer. To comprehend why the number of visualized tracts varied so that we could acquire consistently high quality tractography of muscle fiber, we started to examine whether differences in individual parameters affected tractography visualization. The purpose of this study was to determine whether there are gender- and age-specific differences that differentiate the muscles by gender and age in MR tractography of skeletal muscle fiber. We divided 33 healthy volunteers by gender and age among 3 groups, A (13 younger men, aged 20 to 36 years), B (11 younger women, 25 to 39 years), and C (9 older men, 50 to 69), and we obtained from each volunteer tractographs of 8 fibers, including the bilateral gastrocnemius medialis (GCM), gastrocnemius lateralis (GCL), soleus (SOL), and anterior tibialis (AT) muscles. We classified the fibers into 5 grades depending on the extent of visualized tracts and used Mann-Whitney U-test to compare scores by gender (Group A versus B) and age (Group A versus C). Muscle tracts were significantly better visualized in women than men (median total visual score, 34 versus 24, P<0.05). In particular, the SOL muscles showed better visualization in the right (4.0 in women, 1.0 in men, P<0.05) and left (3.0 in women, 1.0 in men, P<0.05). Difference by age was not significant. The GCL was the highest scored muscle in all groups. Our results suggest that group differences, especially by gender, affected visualization of tractography of muscle fiber of the calf. (author)

  4. Regulatory T cells and skeletal muscle regeneration.

    Science.gov (United States)

    Schiaffino, Stefano; Pereira, Marcelo G; Ciciliot, Stefano; Rovere-Querini, Patrizia

    2017-02-01

    Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti-inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1-to-M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL-33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL-33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin-deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg-cell population but exacerbated by Treg-cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging. © 2016 Federation of European Biochemical Societies.

  5. Muscle type-specific responses to NAD+ salvage biosynthesis promote muscle function in Caenorhabditis elegans.

    Science.gov (United States)

    Vrablik, Tracy L; Wang, Wenqing; Upadhyay, Awani; Hanna-Rose, Wendy

    2011-01-15

    Salvage biosynthesis of nicotinamide adenine dinucleotide (NAD(+)) from nicotinamide (NAM) lowers NAM levels and replenishes the critical molecule NAD(+) after it is hydrolyzed. This pathway is emerging as a regulator of multiple biological processes. Here we probe the contribution of the NAM-NAD(+) salvage pathway to muscle development and function using Caenorhabditis elegans. C. elegans males with mutations in the nicotinamidase pnc-1, which catalyzes the first step of this NAD(+) salvage pathway, cannot mate due to a spicule muscle defect. Multiple muscle types are impaired in the hermaphrodites, including body wall muscles, pharyngeal muscles and vulval muscles. An active NAD(+) salvage pathway is required for optimal function of each muscle cell type. However, we found surprising muscle-cell-type specificity in terms of both the timing and relative sensitivity to perturbation of NAD(+) production or NAM levels. Active NAD(+) biosynthesis during development is critical for function of the male spicule protractor muscles during adulthood, but these muscles can surprisingly do without salvage biosynthesis in adulthood under the conditions examined. The body wall muscles require ongoing NAD(+) salvage biosynthesis both during development and adulthood for maximum function. The vulval muscles do not function in the presence of elevated NAM concentrations, but NAM supplementation is only slightly deleterious to body wall muscles during development or upon acute application in adults. Thus, the pathway plays distinct roles in different tissues. As NAM-NAD(+) biosynthesis also impacts muscle differentiation in vertebrates, we propose that similar complexities may be found among vertebrate muscle cell types. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans

    Science.gov (United States)

    Wakabayashi, Hitoshi; Nishimura, Takayuki; Wijayanto, Titis; Watanuki, Shigeki; Tochihara, Yutaka

    2017-07-01

    This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature ( P < 0.05). This result indicated that repeated local muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

  7. Muscle-specific expression of hypoxia-inducible factor in human skeletal muscle

    DEFF Research Database (Denmark)

    Mounier, Rémi; Pedersen, Bente Klarlund; Plomgaard, Peter

    2010-01-01

    Skeletal muscle is well known to exhibit a high degree of plasticity depending on environmental changes, such as various oxygen concentrations. Studies of the oxygen-sensitive subunit alpha of hypoxia-inducible factor-1 (HIF-1) are difficult owing to the large variety of functionally diverse muscle......alpha protein level. Interestingly, none of the HIF-1alpha target genes, like the most studied angiogenic factor involved in muscle angiogenesis, vascular endothelial growth factor (VEGF), exhibited a muscle fibre-specific-related mRNA expression at rest in normoxia. However, soleus presented...... here, support a key role for HIF-1alpha for maintaining muscle homeostasis in non-hypoxic conditions....

  8. Changes in muscle strength and morphology after muscle unloading in Special Forces missions

    DEFF Research Database (Denmark)

    Thorlund, J B; Jakobsen, O; Madsen, T

    2011-01-01

    The purpose of the present study was to determine the changes in maximal muscle strength, rapid force capacity, jumping performance and muscle morphology following a Special Forces military operation involving 8 days of muscle unloading. Nine male Special Forces soldiers were tested before (pre......) and immediately after (post1) an 8-day simulated special support and reconnaissance (SSR) mission and after 3 h of active recovery (post2). Maximal muscle strength (MVC) and rate of force development (RFD) were measured along with maximal counter movement jump height (JH). Muscle biopsies were obtained from...

  9. Genetics Home Reference: myostatin-related muscle hypertrophy

    Science.gov (United States)

    ... Conditions Myostatin-related muscle hypertrophy Myostatin-related muscle hypertrophy Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description Myostatin-related muscle hypertrophy is a rare condition characterized by reduced body ...

  10. Proteomic signature of muscle atrophy in rainbow trout

    Science.gov (United States)

    Muscle deterioration arises as a physiological response to elevated energetic demands of fish sexual maturation and spawning. Previously, we used this model to characterize the transcriptomic mechanisms associated with muscle degradation in fish and identified potential biological markers of muscle...

  11. Autosomal Recessive Myotonia Congenita, A Muscle ...

    African Journals Online (AJOL)

    Background: The muscle diseases are frequently encountered in medical clinics in Nigeria. In many cases however they are not optimally managed. The ion channel diseases, 'channelopathies', are a group of muscle disorders that share a lot of clinical similarity. Misdiagnosis can occur especially in resource poor settings ...

  12. Genetics Home Reference: rippling muscle disease

    Science.gov (United States)

    ... JP, Fricke B, Meinck HM, Torbergsen T, Engels H, Voss B, Vorgerd M. Homozygous mutations in caveolin-3 cause a severe form of rippling muscle disease. Ann Neurol. 2003 Apr;53(4):512-20. Citation on PubMed Lamb GD. Rippling muscle disease may be caused by " ...

  13. Lower limb asymmetry in mechanical muscle function

    DEFF Research Database (Denmark)

    Jordan, M J; Aagaard, Per; Herzog, W

    2015-01-01

    ) for kinetic impulse (CMJ and SJ phase-specific kinetic impulse AI). Dual x-ray absorptiometry scanning was used to assess asymmetry in lower body muscle mass. Compared with controls, ACL-R skiers had increased AI in muscle mass (P 

  14. Respiratory muscle training in Duchenne muscular dystrophy.

    OpenAIRE

    Rodillo, E; Noble-Jamieson, C M; Aber, V; Heckmatt, J Z; Muntoni, F; Dubowitz, V

    1989-01-01

    Twenty two boys with Duchenne muscular dystrophy were entered into a randomised double blind crossover trial to compare respiratory muscle training with a Triflow II inspirometer and 'placebo' training with a mini peak flow meter. Supine posture was associated with significantly impaired lung function, but respiratory muscle training showed no benefit.

  15. Bone muscle interactions and vitamin D

    NARCIS (Netherlands)

    Gunton, J.E.; Girgis, C.M.; Baldock, P.A.; Lips, P.

    2015-01-01

    Beyond the established roles of vitamin D in bone and mineral homeostasis, we are becoming increasingly aware of its diverse effects in skeletal muscle. Subjects with severe vitamin D deficiency or mutations of the vitamin D receptor develop generalized atrophy of muscle and bone, suggesting

  16. Neuromuscular imaging in inherited muscle diseases

    International Nuclear Information System (INIS)

    Wattjes, Mike P.; Kley, Rudolf A.; Fischer, Dirk

    2010-01-01

    Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. (orig.)

  17. Neuromuscular imaging in inherited muscle diseases

    Energy Technology Data Exchange (ETDEWEB)

    Wattjes, Mike P. [VU University Medical Center, Department of Radiology, De Boelelaan 1117, HV, Amsterdam (Netherlands); Kley, Rudolf A. [Klinken Bergmannsheil, Ruhr-University, Department of Neurology, Neuromuscular Centre Ruhrgebiet, Bochum (Germany); Fischer, Dirk [University Hospital of Basel, Department of Neurology, Basel (Switzerland); University Children' s Hospital Basel, Department of Neuropaediatrics, Basel (Switzerland)

    2010-10-15

    Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. (orig.)

  18. Interleukin-6 myokine signaling in skeletal muscle

    DEFF Research Database (Denmark)

    Muñoz-Cánoves, Pura; Scheele, Camilla; Pedersen, Bente K

    2013-01-01

    Interleukin (IL)-6 is a cytokine with pleiotropic functions in different tissues and organs. Skeletal muscle produces and releases significant levels of IL-6 after prolonged exercise and is therefore considered as a myokine. Muscle is also an important target of the cytokine. IL-6 signaling has...

  19. Electrical stimulation counteracts muscle decline in seniors.

    Science.gov (United States)

    Kern, Helmut; Barberi, Laura; Löfler, Stefan; Sbardella, Simona; Burggraf, Samantha; Fruhmann, Hannah; Carraro, Ugo; Mosole, Simone; Sarabon, Nejc; Vogelauer, Michael; Mayr, Winfried; Krenn, Matthias; Cvecka, Jan; Romanello, Vanina; Pietrangelo, Laura; Protasi, Feliciano; Sandri, Marco; Zampieri, Sandra; Musaro, Antonio

    2014-01-01

    The loss in muscle mass coupled with a decrease in specific force and shift in fiber composition are hallmarks of aging. Training and regular exercise attenuate the signs of sarcopenia. However, pathologic conditions limit the ability to perform physical exercise. We addressed whether electrical stimulation (ES) is an alternative intervention to improve muscle recovery and defined the molecular mechanism associated with improvement in muscle structure and function. We analyzed, at functional, structural, and molecular level, the effects of ES training on healthy seniors with normal life style, without routine sport activity. ES was able to improve muscle torque and functional performances of seniors and increased the size of fast muscle fibers. At molecular level, ES induced up-regulation of IGF-1 and modulation of MuRF-1, a muscle-specific atrophy-related gene. ES also induced up-regulation of relevant markers of differentiating satellite cells and of extracellular matrix remodeling, which might guarantee shape and mechanical forces of trained skeletal muscle as well as maintenance of satellite cell function, reducing fibrosis. Our data provide evidence that ES is a safe method to counteract muscle decline associated with aging.

  20. 38 CFR 4.78 - Muscle function.

    Science.gov (United States)

    2010-07-01

    ... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected... DISABILITIES Disability Ratings The Organs of Special Sense § 4.78 Muscle function. (a) Examination of muscle...

  1. Thyroid hormones and muscle metabolism in dogs.

    Science.gov (United States)

    Kruk, B; Brzezinska, Z; Kaciuba-Uscilko, H; Nazar, K

    1988-10-01

    Muscle contents of ATP, ADP, AMP, creatine phosphate and creatine as well as glycogen, some glycolytic intermediates, pyruvate and lactate were compared in the intact, thyroidectomized and triiodothyronine (T3) treated dogs under resting conditions. After thyroidectomy muscle glycogen, glucose 1-phosphate and glucose 6-phosphate contents were significantly elevated while in T3-treated animals these variables were decreased in comparison with control dogs. Muscle free glucose was not altered by thyroidectomy but T3 treatment significantly increased its content. Muscle lactate content was elevated both in hypo- and hyperthyroid animals. Muscle ATP and total adenine nucleotide contents were significantly increased in hyperthyroid dogs while no differences were found between the three groups in the muscle creatine phosphate content. It is assumed that in T3-treated animals carbohydrate catabolism is enhanced in the resting skeletal muscle in spite of high tissue ATP content. Muscle metabolite alterations in hypothyroid dogs seem to reflect the hypometabolism accompanied by a diminished rate of glycogenolysis with inhibited rate of pyruvate oxidation or decreased rate of lactate removal from the cells.

  2. Calpain 3 is important for muscle regeneration

    DEFF Research Database (Denmark)

    Hauerslev, Simon; Sveen, Marie-Louise; Duno, Morten

    2012-01-01

    Limb girdle muscular dystrophy (LGMD) type 2A is caused by mutations in the CAPN3 gene and complete lack of functional calpain 3 leads to the most severe muscle wasting. Calpain 3 is suggested to be involved in maturation of contractile elements after muscle degeneration. The aim of this study...

  3. Quantitative phosphoproteomic analysis of postmortem muscle development

    DEFF Research Database (Denmark)

    Huang, Honggang

    and myofibrillar proteins from PM porcine muscle. Generally, the porcine muscle with fast pH decline rate had the highest phosphorylation level at 1 h PM, but lowest at 24 h PM, whereas the group with slow pH decline rate showed the reverse case. The protein phosphorylation level of sarcoplasmic proteins...

  4. 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

  5. Muscle activation patterns in posttraumatic neck pain

    NARCIS (Netherlands)

    Nederhand, Marcus Johannes

    2003-01-01

    As an important consequence of our research, we question the relevance of the criteria of the WAD injury severity classification system. We showed that the musculoskeletal signs in WAD grade II are not characterized by muscle spasm, (i.e. increase of muscle activity), but rather by a decrease in

  6. Proficiency test for paracitides in salmon muscle

    NARCIS (Netherlands)

    Elbers, I.J.W.

    2012-01-01

    The aim of this proficiency study was to give laboratories the possibility to evaluate or demonstrate their competence for the analysis of parasiticides in salmon muscle. This study also provided an evaluation of the methods applied for the quantitative analysis of parasiticides in salmon muscle.

  7. Sympathetic actions on the skeletal muscle.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2010-01-01

    The sympathetic nervous system (SNS) modulates several functions in skeletal muscle fibers, including metabolism, ionic transport across the membrane, and contractility. These actions, together with the sympathetic control of other organ systems, support intense motor activity. However, some SNS actions on skeletal muscles may not always be functionally advantageous. Implications for motor control and sport performance are discussed.

  8. Regulation of skeletal muscle glycogenolysis during exercise

    DEFF Research Database (Denmark)

    Hargreaves, M; Richter, Erik

    1988-01-01

    Muscle-glycogen breakdown during exercise is influenced by both local and systemic factors. Contractions per se increase glycogenolysis via a calcium-induced, transient increase in the activity of phosphorylase a, and probably also via increased concentrations of Pi. In fast-twitch muscle...

  9. Inspiratory muscle training increases inspiratory muscle strength in patients weaning from mechanical ventilation: a systematic review.

    Science.gov (United States)

    Moodie, Lisa; Reeve, Julie; Elkins, Mark

    2011-01-01

    Does inspiratory muscle training improve inspiratory muscle strength and endurance, facilitate weaning, improve survival, and reduce the rate of reintubation and tracheostomy in adults receiving mechanical ventilation? Systematic review of randomised or quasi-randomised controlled trials. Adults over 16 years of age receiving mechanical ventilation. Inspiratory muscle training versus sham or no inspiratory muscle training. Data were extracted regarding inspiratory muscle strength and endurance, the duration of unassisted breathing periods, weaning success and duration, reintubation and tracheostomy, survival, adverse effects, and length of stay. Three studies involving 150 participants were included in the review. The studies varied in time to commencement of the training, the device used, the training protocol, and the outcomes measured. Inspiratory muscle training significantly increased inspiratory muscle strength over sham or no training (weighted mean difference 8 cmH(2)O, 95% CI 6 to 9). There were no statistically significant differences between the groups in weaning success or duration, survival, reintubation, or tracheostomy. Inspiratory muscle training was found to significantly increase inspiratory muscle strength in adults undergoing mechanical ventilation. Despite data from a substantial pooled cohort, it is not yet clear whether the increase in inspiratory muscle strength leads to a shorter duration of mechanical ventilation, improved weaning success, or improved survival. Further large randomised studies are required to clarify the impact of inspiratory muscle training on patients receiving mechanical ventilation. PROSPERO CRD42011001132. Copyright © 2011 Australian Physiotherapy Association. Published by .. All rights reserved.

  10. Changes in predicted muscle coordination with subject-specific muscle parameters for individuals after stroke.

    Science.gov (United States)

    Knarr, Brian A; Reisman, Darcy S; Binder-Macleod, Stuart A; Higginson, Jill S

    2014-01-01

    Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke.

  11. Association of muscle hardness with muscle tension dynamics: a physiological property.

    Science.gov (United States)

    Murayama, Mitsuyoshi; Watanabe, Kotaro; Kato, Ryoko; Uchiyama, Takanori; Yoneda, Tsugutake

    2012-01-01

    This study aimed to investigate the relationship between muscle hardness and muscle tension in terms of length-tension relationship. A frog gastrocnemius muscle sample was horizontally mounted on the base plate inside a chamber and was stretched from 100 to 150% of the pre-length, in 5% increments. After each step of muscle lengthening, electrical field stimulation for induction of tetanus was applied using platinum-plate electrodes positioned on either side of the muscle submerged in Ringer's solution. The measurement of muscle hardness, i.e., applying perpendicular distortion, was performed whilst maintaining the plateau of passive and tetanic tension. The relationship between normalised tension and normalised muscle hardness was evaluated. The length-hardness diagram could be created from the modification with the length-tension diagram. It is noteworthy that muscle hardness was proportional to passive and total tension. Regression analysis revealed a significant correlation between muscle hardness and passive and total tension, with a significant positive slope (passive tension: r = 0.986, P hardness depends on muscle tension in most ranges of muscle length in the length-tension diagram.

  12. Denervation of rabbit gastrocnemius and soleus muscles: effect on muscle-specific enolase.

    Science.gov (United States)

    Nozais, M; Merkulova, T; Keller, A; Janmot, C; Lompré, A M; D'Albis, A; Lucas, M

    1999-07-01

    We report here, for the first time, the expression of the muscle-specific isoform of the glycolytic enzyme, enolase (EC 4.2.1. 11) (beta enolase), in rabbit skeletal muscles. We have analysed the fast-twitch gastrocnemius and the slow-twitch soleus muscles during normal postnatal development and following denervation. We show that, in rabbit, as already described in rodents, beta enolase gene expression behaves as a good marker of the fast-twitch fibers. In soleus muscle, the beta enolase transcript level is 10-20% of that found in gastrocnemius. Denervation, performed at 8 postnatal days, induces an important drop of beta enolase transcript levels in both developing soleus and gastrocnemius muscles, with a 80% decrease observed 1 week after denervation in the operated muscles, as compared to the corresponding contralateral muscles. Thereafter, the beta enolase transcript level continues to decrease in the fast-twitch muscle, with the beta enolase subunit being detectable only in the atrophic fast-twitch fibers. In contrast, the beta transcript level tends to increase in the denervated slow-twitch muscle, reaching about 50% of that in contralateral soleus, at 7 weeks after surgery. The level of beta enolase transcripts still expressed after denervation seems to stabilize at the same low level in both types of inactive muscles. This suggests that the small fraction of beta enolase expression which is not controlled by the nerve, or by the contractile activity imposed by it, is independent of the muscle phenotype.

  13. LEGS AND TRUNK MUSCLE HYPERTROPHY FOLLOWING WALK TRAINING WITH RESTRICTED LEG MUSCLE BLOOD FLOW

    Directory of Open Access Journals (Sweden)

    Mikako Sakamaki

    2011-06-01

    Full Text Available We examined the effect of walk training combined with blood flow restriction (BFR on the size of blood flow-restricted distal muscles, as well as, on the size of non-restricted muscles in the proximal limb and trunk. Nine men performed walk training with BFR and 8 men performed walk training alone. Training was conducted two times a day, 6 days/wk, for 3 wk using five sets of 2-min bouts (treadmill speed at 50 m/min, with a 1-min rest between bouts. After walk training with BFR, MRI-measured upper (3.8%, P < 0.05 and lower leg (3.2%, P < 0. 05 muscle volume increased significantly, whereas the muscle volume of the gluteus maximus (-0.6% and iliopsoas (1.8% and the muscle CSA of the lumber L4-L5 (-1.0 did not change. There was no significant change in muscle volume in the walk training alone. Our results suggest that the combination of leg muscle blood flow restriction with slow walk training elicits hypertrophy only in the distal blood flow restricted leg muscles. Exercise intensity may be too low during BFR walk training to increase muscle mass in the non- blood flow restricted muscles (gluteus maximus and other trunk muscles.

  14. Electric pulse stimulation of cultured murine muscle cells reproduces gene expression changes of trained mouse muscle.

    Directory of Open Access Journals (Sweden)

    Nathalie Burch

    2010-06-01

    Full Text Available Adequate levels of physical activity are at the center of a healthy lifestyle. However, the molecular mechanisms that mediate the beneficial effects of exercise remain enigmatic. This gap in knowledge is caused by the lack of an amenable experimental model system. Therefore, we optimized electric pulse stimulation of muscle cells to closely recapitulate the plastic changes in gene expression observed in a trained skeletal muscle. The exact experimental conditions were established using the peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha as a marker for an endurance-trained muscle fiber. We subsequently compared the changes in the relative expression of metabolic and myofibrillar genes in the muscle cell system with those observed in mouse muscle in vivo following either an acute or repeated bouts of treadmill exercise. Importantly, in electrically stimulated C2C12 mouse muscle cells, the qualitative transcriptional adaptations were almost identical to those in trained muscle, but differ from the acute effects of exercise on muscle gene expression. In addition, significant alterations in the expression of myofibrillar proteins indicate that this stimulation could be used to modulate the fiber-type of muscle cells in culture. Our data thus describe an experimental cell culture model for the study of at least some of the transcriptional aspects of skeletal muscle adaptation to physical activity. This system will be useful for the study of the molecular mechanisms that regulate exercise adaptation in muscle.

  15. Comparative transcriptome analysis of fast twitch muscle and slow twitch muscle in Takifugu rubripes.

    Science.gov (United States)

    Gao, Kailun; Wang, Zhicheng; Zhou, Xiaoxu; Wang, Haoze; Kong, Derong; Jiang, Chen; Wang, Xiuli; Jiang, Zhiqiang; Qiu, Xuemei

    2017-12-01

    Fast twitch muscle and slow twitch muscle are two important organs of Takifugu rubripes. Both tissues are of ectodermic origin, and the differences between the two muscle fibers reflect the differences in their myofibril protein composition and molecular structure. In order to identify and characterize the gene expression profile in the two muscle fibers of T. rubripes, we generated 54 million and 44 million clean reads from the fast twitch muscle and slow twitch muscle, respectively, using RNA-Seq and identified a total of 580 fast-muscle-specific genes, 1533 slow-muscle-specific genes and 11,806 genes expressed by both muscles. Comparative transcriptome analysis of fast and slow twitch muscles allowed the identification of 1508 differentially expressed genes, of which 34 myosin and 30 ubiquitin family genes were determined. These differentially expressed genes (DEGs) were also analyzed by Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. In addition, alternative splicing analysis was also performed. The generation of larger-scale transcriptomic data presented in this work would enrich the genetic resources of Takifugu rubripes, which could be valuable to comparative studies of muscles. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Human muscle spindle sensitivity reflects the balance of activity between antagonistic muscles.

    Science.gov (United States)

    Dimitriou, Michael

    2014-10-08

    Muscle spindles are commonly considered as stretch receptors encoding movement, but the functional consequence of their efferent control has remained unclear. The "α-γ coactivation" hypothesis states that activity in a muscle is positively related to the output of its spindle afferents. However, in addition to the above, possible reciprocal inhibition of spindle controllers entails a negative relationship between contractile activity in one muscle and spindle afferent output from its antagonist. By recording spindle afferent responses from alert humans using microneurography, I show that spindle output does reflect antagonistic muscle balance. Specifically, regardless of identical kinematic profiles across active finger movements, stretch of the loaded antagonist muscle (i.e., extensor) was accompanied by increased afferent firing rates from this muscle compared with the baseline case of no constant external load. In contrast, spindle firing rates from the stretching antagonist were lowest when the agonist muscle powering movement (i.e., flexor) acted against an additional resistive load. Stepwise regressions confirmed that instantaneous velocity, extensor, and flexor muscle activity had a significant effect on spindle afferent responses, with flexor activity having a negative effect. Therefore, the results indicate that, as consequence of their efferent control, spindle sensitivity (gain) to muscle stretch reflects the balance of activity between antagonistic muscles rather than only the activity of the spindle-bearing muscle. Copyright © 2014 the authors 0270-6474/14/3413644-12$15.00/0.

  17. Action of Obestatin in Skeletal Muscle Repair: Stem Cell Expansion, Muscle Growth, and Microenvironment Remodeling

    Science.gov (United States)

    Gurriarán-Rodríguez, Uxía; Santos-Zas, Icía; González-Sánchez, Jessica; Beiroa, Daniel; Moresi, Viviana; Mosteiro, Carlos S; Lin, Wei; Viñuela, Juan E; Señarís, José; García-Caballero, Tomás; Casanueva, Felipe F; Nogueiras, Rubén; Gallego, Rosalía; Renaud, Jean-Marc; Adamo, Sergio; Pazos, Yolanda; Camiña, Jesús P

    2015-01-01

    The development of therapeutic strategies for skeletal muscle diseases, such as physical injuries and myopathies, depends on the knowledge of regulatory signals that control the myogenic process. The obestatin/GPR39 system operates as an autocrine signal in the regulation of skeletal myogenesis. Using a mouse model of skeletal muscle regeneration after injury and several cellular strategies, we explored the potential use of obestatin as a therapeutic agent for the treatment of trauma-induced muscle injuries. Our results evidenced that the overexpression of the preproghrelin, and thus obestatin, and GPR39 in skeletal muscle increased regeneration after muscle injury. More importantly, the intramuscular injection of obestatin significantly enhanced muscle regeneration by simulating satellite stem cell expansion as well as myofiber hypertrophy through a kinase hierarchy. Added to the myogenic action, the obestatin administration resulted in an increased expression of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) and the consequent microvascularization, with no effect on collagen deposition in skeletal muscle. Furthermore, the potential inhibition of myostatin during obestatin treatment might contribute to its myogenic action improving muscle growth and regeneration. Overall, our data demonstrate successful improvement of muscle regeneration, indicating obestatin is a potential therapeutic agent for skeletal muscle injury and would benefit other myopathies related to muscle regeneration. PMID:25762009

  18. Needle muscle biopsy: technique validation and histological and histochemical methods for evaluating canine skeletal muscles

    Directory of Open Access Journals (Sweden)

    Sérgio de Almeida Braga

    2017-05-01

    Full Text Available This study evaluated the needle muscle biopsy technique using a 6G Bergström percutaneous needle combined with histological and histochemical methods to analyze the skeletal muscle of dogs. There are few studies about canine skeletal muscles and a lack of reports in the literature about tissue collection and analysis for canine species. Evaluation of 32 German Shepherd samples collected from the gluteus medius, at a depth of 3 cm, was performed. The choice of gluteus medius and the 3-cm depth provided good quantity fragments with sufficient sizes (3–5 mm, which permitted optimal visualization of muscle fibers. Myosin ATPase, at pH 9.4, 4.6, and 4.3, and SDH reactions revealed that all muscle samples analyzed had fibers in the classic mosaic arrangement, enabling counting and typification. The mean percentages of fibers were 29.95% for type I and 70.05% for type II. On the basis of these results, we concluded that the percutaneous needle biopsy technique for canine skeletal muscles is a safe and easy procedure that obtains fragments of proper sizes, thereby enabling the study of muscle fibers. Standardization of the muscle of choice and the depth of muscle sample collection significantly contributed to this success. This is an important method to evaluate muscle fiber types of dogs and diagnose important diseases affecting the skeletal muscles.

  19. Changes in Predicted Muscle Coordination with Subject-Specific Muscle Parameters for Individuals after Stroke

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    Brian A. Knarr

    2014-01-01

    Full Text Available Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke.

  20. Acute effects of static stretching on muscle-tendon mechanics of quadriceps and plantar flexor muscles.

    Science.gov (United States)

    Bouvier, Tom; Opplert, Jules; Cometti, Carole; Babault, Nicolas

    2017-07-01

    This study aimed to determine the acute effects of static stretching on stiffness indexes of two muscle groups with a contrasting difference in muscle-tendon proportion. Eleven active males were tested on an isokinetic dynamometer during four sessions randomly presented. Two sessions were dedicated to quadriceps and the two others to triceps surae muscles. Before and immediately after the stretching procedure (5 × 30 s), gastrocnemius medialis and rectus femoris fascicle length and myotendinous junction elongation were determined using ultrasonography. Passive and maximal voluntary torques were measured. Fascicle and myotendinous junction stiffness indexes were calculated. After stretching, maximal voluntary torque similarly decreased for both muscle groups. Passive torque significantly decreased on triceps surae and remained unchanged on quadriceps muscles. Fascicle length increased similarly for both muscles. However, myotendinous junction elongation remained unchanged for gastrocnemius medialis and increased significantly for rectus femoris muscle. Fascicle stiffness index significantly decreased on medial gastrocnemius and remained unchanged on rectus femoris muscle. In contrast, myotendinous junction stiffness index similarly decreased on both muscles. Depending on the muscle considered, the present results revealed different acute stretching effects. This muscle dependency appeared to affect primarily fascicle stiffness index rather than the myotendinous junction.

  1. Regulation of skeletal muscle oxidative capacity and muscle mass by SIRT3.

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    Ligen Lin

    Full Text Available We have previously reported that the expression of mitochondrial deacetylase SIRT3 is high in the slow oxidative muscle and that the expression of muscle SIRT3 level is increased by dietary restriction or exercise training. To explore the function of SIRT3 in skeletal muscle, we report here the establishment of a transgenic mouse model with muscle-specific expression of the murine SIRT3 short isoform (SIRT3M3. Calorimetry study revealed that the transgenic mice had increased energy expenditure and lower respiratory exchange rate (RER, indicating a shift towards lipid oxidation for fuel usage, compared to control mice. The transgenic mice exhibited better exercise performance on treadmills, running 45% further than control animals. Moreover, the transgenic mice displayed higher proportion of slow oxidative muscle fibers, with increased muscle AMPK activation and PPARδ expression, both of which are known regulators promoting type I muscle fiber specification. Surprisingly, transgenic expression of SIRT3M3 reduced muscle mass up to 30%, likely through an up-regulation of FOXO1 transcription factor and its downstream atrophy gene MuRF-1. In summary, these results suggest that SIRT3 regulates the formation of oxidative muscle fiber, improves muscle metabolic function, and reduces muscle mass, changes that mimic the effects of caloric restriction.

  2. Muscle fiber population and biochemical properties of whole body muscles in Thoroughbred horses.

    Science.gov (United States)

    Kawai, Minako; Minami, Yoshio; Sayama, Yukiko; Kuwano, Atsutoshi; Hiraga, Atsushi; Miyata, Hirofumi

    2009-10-01

    We examine the muscle fiber population and metabolic properties of skeletal muscles from the whole body in Thoroughbred horses. Postmortem samples were taken from 46 sites in six Thoroughbred horses aged between 3 and 6 years. Fiber type population was determined on muscle fibers stained with monoclonal antibody to each myosin heavy chain isoform and metabolic enzyme activities were determined spectrophotometrically. Histochemical analysis demonstrated that most of the muscles had a high percentage of Type IIa fibers. In terms of the muscle characteristic in several parts of the horse body, the forelimb muscles had a higher percentage of Type IIa fiber and a significantly lower percentage of Type IIx fiber than the hindlimb muscles. The muscle fiber type populations in the thoracic and trunk portion were similar to those in the hindlimb portion. Biochemical analysis indicated high succinate dehydrogenase activity in respiratory-related muscle and high phosphofructokinase activity in hindlimbs. We suggested that the higher percentage of Type IIa fibers in Thoroughbred racehorses is attributed to training effects. To consider further the physiological significance of each part of the body, data for the recruitment pattern of each muscle fiber type during exercise are needed. The muscle fiber properties in this study combined with the recruitment data would provide fundamental information for physiological and pathological studies in Thoroughbred horses.

  3. Mediators on human airway smooth muscle.

    Science.gov (United States)

    Armour, C; Johnson, P; Anticevich, S; Ammit, A; McKay, K; Hughes, M; Black, J

    1997-01-01

    1. Bronchial hyperresponsiveness in asthma may be due to several abnormalities, but must include alterations in the airway smooth muscle responsiveness and/or volume. 2. Increased responsiveness of airway smooth muscle in vitro can be induced by certain inflammatory cell products and by induction of sensitization (atopy). 3. Increased airway smooth muscle growth can also be induced by inflammatory cell products and atopic serum. 4. Mast cell numbers are increased in the airways of asthmatics and, in our studies, in airway smooth muscle that is sensitized and hyperresponsive. 5. We propose that there is a relationship between mast cells and airway smooth muscle cells which, once an allergic process has been initiated, results in the development of critical features in the lungs in asthma.

  4. Intraurethral Injection of Autologous Minced Skeletal Muscle

    DEFF Research Database (Denmark)

    Gräs, Søren; Klarskov, Niels; Lose, Gunnar

    2014-01-01

    PURPOSE: Intraurethral injection of in vitro expanded autologous skeletal muscle derived cells is a new regenerative therapy for stress urinary incontinence. We examined the efficacy and safety of a simpler alternative strategy using freshly harvested, minced autologous skeletal muscle tissue...... noted. CONCLUSIONS: Intraurethral injection of minced autologous muscle tissue is a simple surgical procedure that appears safe and moderately effective in women with uncomplicated stress urinary incontinence. It compares well to a more complicated regenerative strategy using in vitro expanded muscle...... with its inherent content of regenerative cells. MATERIALS AND METHODS: A total of 20 and 15 women with uncomplicated and complicated stress urinary incontinence, respectively, received intraurethral injections of minced autologous skeletal muscle tissue and were followed for 1 year. Efficacy was assessed...

  5. ACUTE EXERCISE-INDUCED MUSCLE INJURY

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    Andrew J McKune

    2012-03-01

    Full Text Available While much research has recently been focussing on the chronic effects of overtraining, the acute damaging effects of individual eccentric exercise bouts on muscle remain of interest and underlie long-term training effects. Systemic markers of muscle damage are limited in terms of sensitivity and reliability. A clearer insight into the extent of the damage and mechanisms involved are being obtained from ultrastructural, functional and molecular examination of the muscle. There are currently indications that while the initial muscle damage may appear to have negative consequences in the short term, intense eccentric exercise appears to initiate a remodelling process and promote favourable adaptation of muscle following training, which has applications for promoting health, rehabilitation and sports performance.

  6. Exercise in muscle glycogen storage diseases

    DEFF Research Database (Denmark)

    Preisler, Nicolai Rasmus; Haller, Ronald G; Vissing, John

    2015-01-01

    oxidation. Such changes may be detrimental for persons with GSD from a metabolic perspective. However, exercise may alter skeletal muscle substrate metabolism in ways that are beneficial for patients with GSD, such as improving exercise tolerance and increasing fatty acid oxidation. In addition, a regular......Glycogen storage diseases (GSD) are inborn errors of glycogen or glucose metabolism. In the GSDs that affect muscle, the consequence of a block in skeletal muscle glycogen breakdown or glucose use, is an impairment of muscular performance and exercise intolerance, owing to 1) an increase...... in glycogen storage that disrupts contractile function and/or 2) a reduced substrate turnover below the block, which inhibits skeletal muscle ATP production. Immobility is associated with metabolic alterations in muscle leading to an increased dependence on glycogen use and a reduced capacity for fatty acid...

  7. Lactate metabolism: bioenergetics and muscle fatigue review

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    Romulo Cássio de Moraes Bertuzzi

    2009-04-01

    Full Text Available The purpose of this study was to present the main events regarding the muscle lactate metabolism to aid the understanding about utilization of the blood lactate concentrations (BLC on the estimative of lactic anaerobic metabolism and its likely relationship to the acute muscle fatigue. Traditionally, the increase of BLC was associated to the insufficient mitochondrial O2 supply. However, recent studies showed that increase of BLC can be due the action of another agent such as epinephrine and inorganic phosphate. In the same way, the relationship between BLC and acute muscle fatigue has been supported by increase in cellular acidosis. Nevertheless, recent studies have shown that cellular acidosis can restore the force in isolated and electrically stimulated muscle fibers. These findings suggest that utilization of the BLC on the estimative of lactic anaerobic metabolism should be used with caution and the relationship between BLC and acute muscle fatigue can only be a casual phenomenon.

  8. Increased muscle glucose uptake during contractions

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Richter, Erik

    1984-01-01

    We reinvestigated the prevailing concept that muscle contractions only elicit increased muscle glucose uptake in the presence of a so-called "permissive" concentration of insulin (Berger et al., Biochem. J. 146: 231-238, 1975; Vranic and Berger, Diabetes 28: 147-163, 1979). Hindquarters from rats...... in severe ketoacidosis were perfused with a perfusate containing insulin antiserum. After 60 min perfusion, electrical stimulation increased glucose uptake of the contracting muscles fivefold. Also, subsequent contractions increased glucose uptake in hindquarters from nondiabetic rats perfused for 1.5 h......-methylglucose uptake increased during contractions and glucose uptake was negative at rest and zero during contractions. An increase in muscle transport and uptake of glucose during contractions does not require the presence of insulin. Furthermore, glucose transport in contracting muscle may only increase if glycogen...

  9. A hybrid static optimisation method to estimate muscle forces during muscle co-activation.

    Science.gov (United States)

    Son, Jongsang; Hwang, Sungjae; Kim, Youngho

    2012-01-01

    The general static optimisation (GSO) process is one of various muscle force estimation methods due to its low computational requirements. However, it can show biased muscle force estimation under muscle co-contraction. In the present study, we introduced a novel hybrid static optimisation (HSO) method to estimate reasonable muscle forces during muscle co-activation movements using more specific equality constraints, i.e. agonist and antagonist muscle moments predicted from a new correlation coefficient approach. The new method was evaluated for heel-rise movements. We found that the proposed method improved the potential of antagonist muscle force estimation in comparison to the GSO solutions. The proposed HSO method could be applied in biomechanics and rehabilitation, for example.

  10. Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

    Science.gov (United States)

    Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

    2017-07-22

    Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Muscle activation during selected strength exercises in women with chronic neck muscle pain

    DEFF Research Database (Denmark)

    Andersen, Lars L; Kjaer, Michael; Andersen, Christoffer H

    2008-01-01

    selected strengthening exercises in women undergoing rehabilitation for chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia). SUBJECTS: The subjects were 12 female workers (age=30-60 years) with a clinical diagnosis of trapezius myalgia and a mean baseline pain intensity of 5......BACKGROUND AND PURPOSE: Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this study was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) during...... muscle pain. Several of the strength exercises had high activation of neck and shoulder muscles in women with chronic neck pain. These exercises can be used equally in the attempt to achieve a beneficial treatment effect on chronic neck muscle pain....

  12. Single Muscle Fiber Proteomics Reveals Fiber-Type-Specific Features of Human Muscle Aging

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    Marta Murgia

    2017-06-01

    Full Text Available Skeletal muscle is a key tissue in human aging, which affects different muscle fiber types unequally. We developed a highly sensitive single muscle fiber proteomics workflow to study human aging and show that the senescence of slow and fast muscle fibers is characterized by diverging metabolic and protein quality control adaptations. Whereas mitochondrial content declines with aging in both fiber types, glycolysis and glycogen metabolism are upregulated in slow but downregulated in fast muscle fibers. Aging mitochondria decrease expression of the redox enzyme monoamine oxidase A. Slow fibers upregulate a subset of actin and myosin chaperones, whereas an opposite change happens in fast fibers. These changes in metabolism and sarcomere quality control may be related to the ability of slow, but not fast, muscle fibers to maintain their mass during aging. We conclude that single muscle fiber analysis by proteomics can elucidate pathophysiology in a sub-type-specific manner.

  13. The expression of HSP in human skeletal muscle. Effects of muscle fiber phenotype and training background

    DEFF Research Database (Denmark)

    Folkesson, Mattias; Mackey, Abigail L; Langberg, Henning

    2013-01-01

    AIM: Exercise-induced adaptations of skeletal muscle are related to training mode and can be muscle fibre type specific. This study aimed to investigate heat shock protein expression in type I and type II muscle fibres in resting skeletal muscle of subjects with different training backgrounds...... HSPs in human skeletal muscle is influenced by muscle fibre phenotype. The fibre type specific expression of HSP70 is influenced by resistance and endurance training whereas those of αB-crystallin and HSP27 are influenced only by endurance training suggesting the existence of a training......-modality specific action on the adaptive processes including heat shock proteins in human skeletal muscle. This article is protected by copyright. All rights reserved....

  14. Rupture of Plantaris Muscle - A Mimic: MRI Findings

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    T N Gopinath

    2012-01-01

    Full Text Available Calf muscle trauma commonly involves the gastrocnemius and soleus muscles. Plantaris muscle is a vestigial muscle coursing through the calf. Similar clinical features may be seen with injury to the plantaris muscle. It can also mimic other conditions like deep vein thrombosis, rupture of Baker′s cyst, and tumors. MRI is helpful in identifying and characterizing it. We report two cases of ruptured plantaris muscle seen on MRI.

  15. The sag response in human muscle contraction.

    Science.gov (United States)

    Smith, Ian C; Ali, Jahaan; Power, Geoffrey A; Herzog, Walter

    2018-03-08

    We examined how muscle length and time between stimuli (inter-pulse interval, IPI) influence declines in force (sag) seen during unfused tetani in the human adductor pollicis muscle. A series of 16-pulse contractions were evoked with IPIs between 1 × and 5 × the twitch time to peak tension (TPT) at large (long muscle length) and small (short muscle length) thumb adduction angles. Unfused tetani were mathematically deconstructed into a series of overlapping twitch contractions to examine why sag exhibits length- and IPI-dependencies. Across all IPIs tested, sag was 62% greater at short than long muscle length, and sag increased as IPI was increased at both muscle lengths. Force attributable to the second stimulus increased as IPI was decreased. Twitch force declined from maximal values across all IPI tested, with the greatest reductions seen at short muscle length and long IPI. At IPI below 2 × TPT, the twitch with highest force occurred earlier than the peak force of the corresponding unfused tetani. Contraction-induced declines in twitch duration (TPT + half relaxation time) were only observed at IPI longer than 1.75 × TPT, and were unaffected by muscle length. Sag is an intrinsic feature of healthy human adductor pollicis muscle. The length-dependence of sag is related to greater diminution of twitch force at short relative to long muscle length. The dependence of sag on IPI is related to IPI-dependent changes in twitch duration and twitch force, and the timing of peak twitch force relative to the peak force of the associated unfused tetanus.

  16. Morphological Study Of Palmaris Longus Muscle

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    Humberto Ferreira Arquez

    2017-07-01

    Full Text Available Background: The palmaris longus is one of the most variable muscle in the human body, this variations are important not only for the anatomist but also radiologist, orthopaedic, plastic surgeons, clinicians, therapists. In view of this significance is performed this study with the purpose to determine the morphological variations of palmaris longus muscle. Methods and Findings: A total of 17 cadavers with different age groups were used for this study. The upper limbs region (34 sides were dissected carefully and photographed in the Morphology Laboratory at the University of Pamplona. Of the 34 limbs studied, 30 showed normal morphology of the Palmaris longus muscle (PL (88,2%; PL was absent in 3 subjects (8,85% of all examined forearm. Unilateral absence was found in 1 male subject (2,95% of all examined forearm; bilateral agenesis was found in 2 female subjects (5,9% of all examined forearm. Duplicated PL muscle was found in 1 male subject (2,95 % of all examined forearm. The palmaris longus muscle was innervated by branches of the median nerve .The accessory palmaris longus muscle was supplied by the deep branch of the ulnar nerve.  Palmaris longus muscle is a muscle located in the superficial layer of the anterior compartment of the forearm. It has a small belly arising from the medial epicondyle of the humerus, and its long thin tendon inserts into the palmar aponeurosis in the hand, the muscle has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies. Conclusions: The anatomical variations of the palmaris longus muscle must be documented of their clinical significance and their potential use in orthopaedic and reconstructive surgery.

  17. Mechanisms regulating skeletal muscle growth and atrophy.

    Science.gov (United States)

    Schiaffino, Stefano; Dyar, Kenneth A; Ciciliot, Stefano; Blaauw, Bert; Sandri, Marco

    2013-09-01

    Skeletal muscle mass increases during postnatal development through a process of hypertrophy, i.e. enlargement of individual muscle fibers, and a similar process may be induced in adult skeletal muscle in response to contractile activity, such as strength exercise, and specific hormones, such as androgens and β-adrenergic agonists. Muscle hypertrophy occurs when the overall rates of protein synthesis exceed the rates of protein degradation. Two major signaling pathways control protein synthesis, the IGF1-Akt-mTOR pathway, acting as a positive regulator, and the myostatin-Smad2/3 pathway, acting as a negative regulator, and additional pathways have recently been identified. Proliferation and fusion of satellite cells, leading to an increase in the number of myonuclei, may also contribute to muscle growth during early but not late stages of postnatal development and in some forms of muscle hypertrophy in the adult. Muscle atrophy occurs when protein degradation rates exceed protein synthesis, and may be induced in adult skeletal muscle in a variety of conditions, including starvation, denervation, cancer cachexia, heart failure and aging. Two major protein degradation pathways, the proteasomal and the autophagic-lysosomal pathways, are activated during muscle atrophy and variably contribute to the loss of muscle mass. These pathways involve a variety of atrophy-related genes or atrogenes, which are controlled by specific transcription factors, such as FoxO3, which is negatively regulated by Akt, and NF-κB, which is activated by inflammatory cytokines. © 2013 The Authors Journal compilation © 2013 FEBS.

  18. Respiratory muscle training increases respiratory muscle strength and reduces respiratory complications after stroke: a systematic review

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    Kênia KP Menezes

    2016-07-01

    Full Text Available Question: After stroke, does respiratory muscle training increase respiratory muscle strength and/or endurance? Are any benefits carried over to activity and/or participation? Does it reduce respiratory complications? Design: Systematic review of randomised or quasi-randomised trials. Participants: Adults with respiratory muscle weakness following stroke. Intervention: Respiratory muscle training aimed at increasing inspiratory and/or expiratory muscle strength. Outcome measures: Five outcomes were of interest: respiratory muscle strength, respiratory muscle endurance, activity, participation and respiratory complications. Results: Five trials involving 263 participants were included. The mean PEDro score was 6.4 (range 3 to 8, showing moderate methodological quality. Random-effects meta-analyses showed that respiratory muscle training increased maximal inspiratory pressure by 7 cmH2O (95% CI 1 to 14 and maximal expiratory pressure by 13 cmH2O (95% CI 1 to 25; it also decreased the risk of respiratory complications (RR 0.38, 95% CI 0.15 to 0.96 compared with no/sham respiratory intervention. Whether these effects carry over to activity and participation remains uncertain. Conclusion: This systematic review provided evidence that respiratory muscle training is effective after stroke. Meta-analyses based on five trials indicated that 30 minutes of respiratory muscle training, five times per week, for 5 weeks can be expected to increase respiratory muscle strength in very weak individuals after stroke. In addition, respiratory muscle training is expected to reduce the risk of respiratory complications after stroke. Further studies are warranted to investigate whether the benefits are carried over to activity and participation. Registration: PROSPERO (CRD42015020683. [Menezes KKP, Nascimento LR, Ada L, Polese JC, Avelino PR, Teixeira-Salmela LF (2016 Respiratory muscle training increases respiratory muscle strength and reduces respiratory

  19. Changes in muscle fiber contractility and extracellular matrix production during skeletal muscle hypertrophy.

    Science.gov (United States)

    Mendias, Christopher L; Schwartz, Andrew J; Grekin, Jeremy A; Gumucio, Jonathan P; Sugg, Kristoffer B

    2017-03-01

    Skeletal muscle can adapt to increased mechanical loads by undergoing hypertrophy. Transient reductions in whole muscle force production have been reported during the onset of hypertrophy, but contractile changes in individual muscle fibers have not been previously studied. Additionally, the extracellular matrix (ECM) stores and transmits forces from muscle fibers to tendons and bones, and determining how the ECM changes during hypertrophy is important in understanding the adaptation of muscle tissue to mechanical loading. Using the synergist ablation model, we sought to measure changes in muscle fiber contractility, collagen content, and cross-linking, and in the expression of several genes and activation of signaling proteins that regulate critical components of myogenesis and ECM synthesis and remodeling during muscle hypertrophy. Tissues were harvested 3, 7, and 28 days after induction of hypertrophy, and nonoverloaded rats served as controls. Muscle fiber specific force (sF o ), which is the maximum isometric force normalized to cross-sectional area, was reduced 3 and 7 days after the onset of mechanical overload, but returned to control levels by 28 days. Collagen abundance displayed a similar pattern of change. Nearly a quarter of the transcriptome changed over the course of overload, as well as the activation of signaling pathways related to hypertrophy and atrophy. Overall, this study provides insight into fundamental mechanisms of muscle and ECM growth, and indicates that although muscle fibers appear to have completed remodeling and regeneration 1 mo after synergist ablation, the ECM continues to be actively remodeling at this time point. NEW & NOTEWORTHY This study utilized a rat synergist ablation model to integrate changes in single muscle fiber contractility, extracellular matrix composition, activation of important signaling pathways in muscle adaption, and corresponding changes in the muscle transcriptome to provide novel insight into the basic

  20. Muscle metaboreflex-induced vasoconstriction in the ischemic active muscle is exaggerated in heart failure.

    Science.gov (United States)

    Kaur, Jasdeep; Senador, Danielle; Krishnan, Abhinav C; Hanna, Hanna W; Alvarez, Alberto; Machado, Tiago M; O'Leary, Donal S

    2018-01-01

    When oxygen delivery to active muscle is insufficient to meet the metabolic demand during exercise, metabolites accumulate and stimulate skeletal muscle afferents, inducing a reflex increase in blood pressure, termed the muscle metaboreflex. In healthy individuals, muscle metaboreflex activation (MMA) during submaximal exercise increases arterial pressure primarily via an increase in cardiac output (CO), as little peripheral vasoconstriction occurs. This increase in CO partially restores blood flow to ischemic muscle. However, we recently demonstrated that MMA induces sympathetic vasoconstriction in ischemic active muscle, limiting the ability of the metaboreflex to restore blood flow. In heart failure (HF), increases in CO are limited, and metaboreflex-induced pressor responses occur predominantly via peripheral vasoconstriction. In the present study, we tested the hypothesis that vasoconstriction of ischemic active muscle is exaggerated in HF. Changes in hindlimb vascular resistance [femoral arterial pressure ÷ hindlimb blood flow (HLBF)] were observed during MMA (via graded reductions in HLBF) during mild exercise with and without α 1 -adrenergic blockade (prazosin, 50 µg/kg) before and after induction of HF. In normal animals, initial HLBF reductions caused metabolic vasodilation, while reductions below the metaboreflex threshold elicited reflex vasoconstriction, in ischemic active skeletal muscle, which was abolished after α 1 -adrenergic blockade. Metaboreflex-induced vasoconstriction of ischemic active muscle was exaggerated after induction of HF. This heightened vasoconstriction impairs the ability of the metaboreflex to restore blood flow to ischemic muscle in HF and may contribute to the exercise intolerance observed in these patients. We conclude that sympathetically mediated vasoconstriction of ischemic active muscle during MMA is exaggerated in HF. NEW & NOTEWORTHY We found that muscle metaboreflex-induced vasoconstriction of the ischemic active

  1. Muscle size explains low passive skeletal muscle force in heart failure patients

    Directory of Open Access Journals (Sweden)

    Fausto Antonio Panizzolo

    2016-09-01

    Full Text Available Background Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF. However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL, both in CHF patients and age- and physical activity-matched control participants. Methods Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging with a musculoskeletal model. Results We found reduced passive SOL forces (∼30% (at the same relative levels of muscle stretch in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. Discussion These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening.

  2. Muscle satellite cells are functionally impaired in myasthenia gravis: consequences on muscle regeneration.

    Science.gov (United States)

    Attia, Mohamed; Maurer, Marie; Robinet, Marieke; Le Grand, Fabien; Fadel, Elie; Le Panse, Rozen; Butler-Browne, Gillian; Berrih-Aknin, Sonia

    2017-12-01

    Myasthenia gravis (MG) is a neuromuscular disease caused in most cases by anti-acetyl-choline receptor (AChR) autoantibodies that impair neuromuscular signal transmission and affect skeletal muscle homeostasis. Myogenesis is carried out by muscle stem cells called satellite cells (SCs). However, myogenesis in MG had never been explored. The aim of this study was to characterise the functional properties of myasthenic SCs as well as their abilities in muscle regeneration. SCs were isolated from muscle biopsies of MG patients and age-matched controls. We first showed that the number of Pax7+ SCs was increased in muscle sections from MG and its experimental autoimmune myasthenia gravis (EAMG) mouse model. Myoblasts isolated from MG muscles proliferate and differentiate more actively than myoblasts from control muscles. MyoD and MyoG were expressed at a higher level in MG myoblasts as well as in MG muscle biopsies compared to controls. We found that treatment of control myoblasts with MG sera or monoclonal anti-AChR antibodies increased the differentiation and MyoG mRNA expression compared to control sera. To investigate the functional ability of SCs from MG muscle to regenerate, we induced muscle regeneration using acute cardiotoxin injury in the EAMG mouse model. We observed a delay in maturation evidenced by a decrease in fibre size and MyoG mRNA expression as well as an increase in fibre number and embryonic myosin heavy-chain mRNA expression. These findings demonstrate for the first time the altered function of SCs from MG compared to control muscles. These alterations could be due to the anti-AChR antibodies via the modulation of myogenic markers resulting in muscle regeneration impairment. In conclusion, the autoimmune attack in MG appears to have unsuspected pathogenic effects on SCs and muscle regeneration, with potential consequences on myogenic signalling pathways, and subsequently on clinical outcome, especially in the case of muscle stress.

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

    International Nuclear Information System (INIS)

    Pearson, William G.; Hindson, David F.; Langmore, Susan E.; Zumwalt, Ann C.

    2013-01-01

    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

  4. Triglyceride metabolism in exercising muscle.

    Science.gov (United States)

    Watt, Matthew J; Cheng, Yunsheng

    2017-10-01

    Triglycerides are stored within lipid droplets in skeletal muscle and can be hydrolyzed to produce fatty acids for energy production through β-oxidation and oxidative phosphorylation. While there was some controversy regarding the quantitative importance of intramyocellular triglyceride (IMTG) as a metabolic substrate, recent advances in proton magnetic resonance spectroscopy and confocal microscopy support earlier tracer and biopsy studies demonstrating a substantial contribution of IMTG to energy production, particularly during moderate-intensity endurance exercise. This review provides an update on the understanding of IMTG utilization during exercise, with a focus on describing the key regulatory proteins that control IMTG breakdown and how these proteins respond to acute exercise and in the adaptation to exercise training. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The influence of inspiratory muscle work history and specific inspiratory muscle training upon human limb muscle fatigue

    Science.gov (United States)

    McConnell, Alison K; Lomax, Michelle

    2006-01-01

    The purpose of this study was to assess the influence of the work history of the inspiratory muscles upon the fatigue characteristics of the plantar flexors (PF). We hypothesized that under conditions where the inspiratory muscle metaboreflex has been elicited, PF fatigue would be hastened due to peripheral vasoconstriction. Eight volunteers undertook seven test conditions, two of which followed 4 week of inspiratory muscle training (IMT). The inspiratory metaboreflex was induced by inspiring against a calibrated flow resistor. We measured torque and EMG during isometric PF exercise at 85% of maximal voluntary contraction (MVC) torque. Supramaximal twitches were superimposed upon MVC efforts at 1 min intervals (MVCTI); twitch interpolation assessed the level of central activation. PF was terminated (Tlim) when MVCTI was inspiratory muscle work (6.28 ± 2.24 min; P = 0.009). Resting the inspiratory muscles for 30 min restored the PF Tlim to control. After 4 weeks, IMT, inspiratory muscle work at the same absolute intensity did not influence PF Tlim, but Tlim was significantly shorter at the same relative intensity. The data are the first to provide evidence that the inspiratory muscle metaboreflex accelerates the rate of calf fatigue during PF, and that IMT attenuates this effect. PMID:16973699

  6. Mechanics of Vascular Smooth Muscle.

    Science.gov (United States)

    Ratz, Paul H

    2015-12-15

    Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress-development, sustained stress-maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip-catch bond, and a regulated two-step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress-strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure-function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM. Copyright © 2015 John Wiley & Sons, Inc.

  7. In vivo passive mechanical behaviour of muscle fascicles and tendons in human gastrocnemius muscle-tendon units.

    Science.gov (United States)

    Herbert, Robert D; Clarke, Jillian; Kwah, Li Khim; Diong, Joanna; Martin, Josh; Clarke, Elizabeth C; Bilston, Lynne E; Gandevia, Simon C

    2011-11-01

    Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly 'buckled' at short lengths. When the gastrocnemius muscle-tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle-tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle-tendon lengths. The muscle-tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle-tendon lengths whereas other fascicles remain slack over a large range of muscle-tendon lengths. This suggests muscle fascicles are progressively 'recruited' and contribute sequentially to muscle-tendon stiffness during passive lengthening of the muscle-tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (tendon length. The contribution of muscle fascicles to muscle-tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle-tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack.

  8. Muscle-derived Decellularised Extracellular Matrix Improves Functional Recovery in a Rat Latissimus Dorsi Muscle Defect Model

    Science.gov (United States)

    2013-12-01

    in vivo torque production from EMG in mouse muscles injured by eccentric contractions. J Physiol 1999;515(Pt 2):609e19. 27. Gamba PG, Conconi MT, Lo... Muscle -derived decellularised extracellular matrix improves functional recovery in a rat latissimus dorsi muscle defect model Xiaoyu K. Chen a,b...maxillary injuries; Muscle function; Skeletal muscle ; Volumetric muscle loss Summary Purpose: Craniofacial maxillary injuries represent nearly 30% of all

  9. Extraocular spectral photosensitivity in the tentacles of Hydra vulgaris.

    Science.gov (United States)

    Guertin, S; Kass-Simon, G

    2015-06-01

    Previous electrophysiological studies on the cnidarian Hydra vulgaris have shown that hydra have a highly developed and specific photoresponse despite their lack of any structure recognizable as a traditional photoreceptor. In an effort to identify the site of hydra's photoreceptors, we recorded extracellularly from single excised tentacles and from ablated hypostomes lacking tentacles in absolute darkness and during exposure to light of various wavelengths. During recording, after an initial period of absolute darkness, tentacles or hypostomes were exposed to light from 450nm to 600nm, red, and white light. Exposure to light caused a change in the pattern and frequency of impulses in the tentacles that varied with color. The number of large tentacle pulses (TPs) increased at 550 and 600nm relative to darkness, whereas the number of small tentacle pulses (STPs) tended to decrease in 500nm light. Impulse frequency was significantly different among the different wavelengths. In addition to bursts of tentacle contraction pulses, long trains of pulses were observed. A change in lighting caused a switch from bursting to trains or vice versa. In contrast to excised tentacles, no change in electrical activity was seen in ablated hypostomes at any of the wavelengths relative to each other or relative to darkness. These results indicate that isolated tentacles can distinguish among and respond to various colors across the visible spectrum and suggest that electromagnetic information is transmitted from the tentacles to the hypostome where it may be integrated by the hypostomal nervous system, ultimately contributing to hydra's photoreceptive behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Modelling of pneumatic muscle actuator using Hill's model with different approximations of static characteristics of artificial muscle

    Directory of Open Access Journals (Sweden)

    Piteľ Ján

    2016-01-01

    Full Text Available For modelling and simulation of pneumatic muscle actuators the mathematical dependence of the muscle force on the muscle contraction at different pressures in the muscles is necessary to know. For this purpose the static characteristics of the pneumatic artificial muscle type FESTO MAS-20-250N used in the experiments were approximated. In the paper there are shown some simulation results of the pneumatic muscle actuator dynamics using modified Hill's muscle model, in which four different approximations of static characteristics of artificial muscle were used.

  11. Pneumatic Muscles Actuated Lower-Limb Orthosis Model Verification with Actual Human Muscle Activation Patterns

    Directory of Open Access Journals (Sweden)

    Dzahir M.A.M

    2017-01-01

    Full Text Available A review study was conducted on existing lower-limb orthosis systems for rehabilitation which implemented pneumatic muscle type of actuators with the aim to clarify the current and on-going research in this field. The implementation of pneumatic artificial muscle will play an important role for the development of the advanced robotic system. In this research a derivation model for the antagonistic mono- and bi-articular muscles using pneumatic artificial muscles of a lower limb orthosis will be verified with actual human’s muscle activities models. A healthy and young male 29 years old subject with height 174cm and weight 68kg was used as a test subject. Two mono-articular muscles Vastus Medialis (VM and Vastus Lateralis (VL were selected to verify the mono-articular muscle models and muscle synergy between anterior muscles. Two biarticular muscles Rectus Femoris (RF and Bicep Femoris (BF were selected to verify the bi-articular muscle models and muscle co-contraction between anterior-posterior muscles. The test was carried out on a treadmill with a speed of 4.0 km/h, which approximately around 1.25 m/s for completing one cycle of walking motion. The data was collected for about one minute on a treadmill and 20 complete cycles of walking motion were successfully recorded. For the evaluations, the mathematical model obtained from the derivation and the actual human muscle activation patterns obtained using the surface electromyography (sEMG system were compared and analysed. The results shown that, high correlation values ranging from 0.83 up to 0.93 were obtained in between the derivation model and the actual human muscle’s model for both mono- and biarticular muscles. As a conclusion, based on the verification with the sEMG muscle activities data and its correlation values, the proposed derivation models of the antagonistic mono- and bi-articular muscles were suitable to simulate and controls the pneumatic muscles actuated lower limb

  12. Muscle Fibre Types, Ubiquinone Content and Exercise Capacity in Hypertension and Effort Angina

    DEFF Research Database (Denmark)

    Karlsson, Jan; Diamant, Bertil; Folkers, Karl

    1991-01-01

    Farmakologi, hypertension, IHD, skeletal muscle fibre composition, muscle coenzyme Q10, ischaemic heart disease, effort angina, muscle fibre lesion, muscle ubiquinone......Farmakologi, hypertension, IHD, skeletal muscle fibre composition, muscle coenzyme Q10, ischaemic heart disease, effort angina, muscle fibre lesion, muscle ubiquinone...

  13. Inflammatory response during slow- and fast-twitch muscle regeneration.

    Science.gov (United States)

    Zimowska, Malgorzata; Kasprzycka, Paulina; Bocian, Katarzyna; Delaney, Kamila; Jung, Piotr; Kuchcinska, Kinga; Kaczmarska, Karolina; Gladysz, Daria; Streminska, Wladyslawa; Ciemerych, Maria Anna

    2017-03-01

    Skeletal muscles are characterized by their unique ability to regenerate. Injury of a so-called fast-twitch muscle, extensor digitorum longus (EDL), results in efficient regeneration and reconstruction of the functional tissue. In contrast, slow-twitch muscle (soleus) fails to properly reconstruct and develops fibrosis. This study focuses on soleus and EDL muscle regeneration and associated inflammation. We determined differences in the activity of neutrophils and M1 and M2 macrophages using flow cytometry and differences in the levels of proinflammatory cytokines using Western blotting and immunolocalization at different times after muscle injury. Soleus muscle repair is accompanied by increased and prolonged inflammation, as compared to EDL. The proinflammatory cytokine profile is different in the soleus and ED muscles. Muscle repair efficiency differs by muscle fiber type. The inflammatory response affects the repair efficiency of slow- and fast-twitch muscles. Muscle Nerve 55: 400-409, 2017. © 2016 Wiley Periodicals, Inc.

  14. Muscle damage and its relationship with muscle fatigue during a half-iron triathlon.

    Directory of Open Access Journals (Sweden)

    Juan Del Coso

    Full Text Available BACKGROUND: To investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon. METHODOLOGY/PRINCIPAL FINDINGS: We recruited 25 trained triathletes (36±7 yr; 75.1±9.8 kg for the study. Before and just after the race, jump height and leg muscle power output were measured during a countermovement jump on a force platform to determine leg muscle fatigue. Body weight, handgrip maximal force and blood and urine samples were also obtained before and after the race. Blood myoglobin and creatine kinase concentrations were determined as markers of muscle damage. RESULTS: Jump height (from 30.3±5.0 to 23.4±6.4 cm; P0.05 but significantly correlated with myoglobin concentration (r = 0.65; P<0.001 and creatine kinase concentration (r = 0.54; P<0.001. CONCLUSIONS/SIGNIFICANCE: During a half-iron distance triathlon, the capacity of leg muscles to produce force was notably diminished while arm muscle force output remained unaffected. Leg muscle fatigue was correlated with blood markers of muscle damage suggesting that muscle breakdown is one of the most relevant sources of muscle fatigue during a triathlon.

  15. Fetal muscle-derived cells can repair dystrophic muscles in mdx mice

    International Nuclear Information System (INIS)

    Auda-Boucher, Gwenola; Rouaud, Thierry; Lafoux, Aude; Levitsky, Dmitri; Huchet-Cadiou, Corinne; Feron, Marie; Guevel, Laetitia; Talon, Sophie; Fontaine-Perus, Josiane; Gardahaut, Marie-France

    2007-01-01

    We have previously reported that CD34 + cells purified from mouse fetal muscles can differentiate into skeletal muscle in vitro and in vivo when injected into muscle tissue of dystrophic mdx mice. In this study, we investigate the ability of such donor cells to restore dystrophin expression, and to improve the functional muscle capacity of the extensor digitorum longus muscle (EDL) of mdx mice. For this purpose green fluorescent-positive fetal GFP + /CD34 + cells or desmin + / - LacZ/CD34 + cells were transplanted into irradiated or non-irradiated mdx EDL muscle. Donor fetal muscle-derived cells predominantly fused with existing fibers. Indeed more than 50% of the myofibers of the host EDL contained donor nuclei delivering dystrophin along 80-90% of the length of their sarcolemma. The presence of significant amounts of dystrophin (about 60-70% of that found in a control wild-type mouse muscle) was confirmed by Western blot analyses. Dystrophin expression also outcompeted that of utrophin, as revealed by a spatial shift in the distribution of utrophin. At 1 month post-transplant, the recipient muscle appeared to have greater resistance to fatigue than control mdx EDL muscle during repeated maximal contractions

  16. Korean mistletoe (Viscum album coloratum) extract regulates gene expression related to muscle atrophy and muscle hypertrophy.

    Science.gov (United States)

    Jeong, Juseong; Park, Choon-Ho; Kim, Inbo; Kim, Young-Ho; Yoon, Jae-Min; Kim, Kwang-Soo; Kim, Jong-Bae

    2017-01-21

    Korean mistletoe (Viscum album coloratum) is a semi-parasitic plant that grows on various trees and has a diverse range of effects on biological functions, being implicated in having anti-tumor, immunostimulatory, anti-diabetic, and anti-obesity properties. Recently, we also reported that Korean mistletoe extract (KME) improves endurance exercise in mice, suggesting its beneficial roles in enhancing the capacity of skeletal muscle. We examined the expression pattern of several genes concerned with muscle physiology in C2C12 myotubes cells to identify whether KME inhibits muscle atrophy or promotes muscle hypertrophy. We also investigated these effects of KME in denervated mice model. Interestingly, KME induced the mRNA expression of SREBP-1c, PGC-1α, and GLUT4, known positive regulators of muscle hypertrophy, in C2C12 cells. On the contrary, KME reduced the expression of Atrogin-1, which is directly involved in the induction of muscle atrophy. In animal models, KME mitigated the decrease of muscle weight in denervated mice. The expression of Atrogin-1 was also diminished in those mice. Moreover, KME enhanced the grip strength and muscle weight in long-term feeding mice. Our results suggest that KME has beneficial effects on muscle atrophy and muscle hypertrophy.

  17. Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells.

    Science.gov (United States)

    Dirja, Bayu Tirta; Yoshie, Susumu; Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Nomoto, Yukio; Wada, Ikuo; Hazama, Akihiro; Omori, Koichi

    2016-01-01

    Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

  18. Exercise-induced muscle glucose uptake in mice with graded, muscle-specific GLUT-4 deletion

    Science.gov (United States)

    Howlett, Kirsten F; Andrikopoulos, Sofianos; Proietto, Joseph; Hargreaves, Mark

    2013-01-01

    To investigate the importance of the glucose transporter GLUT-4 for muscle glucose uptake during exercise, transgenic mice with skeletal muscle GLUT-4 expression approximately 30–60% of normal (CON) and approximately 5–10% of normal (KO) were generated using the Cre/Lox system and compared with wild-type (WT) mice during approximately 40 min of treadmill running (KO: 37.7 ± 1.3 min; WT: 40 min; CON: 40 min, P = 0.18). In WT and CON animals, exercise resulted in an overall increase in muscle glucose uptake. More specifically, glucose uptake was increased in red gastrocnemius of WT mice and in the soleus and red gastrocnemius of CON mice. In contrast, the exercise-induced increase in muscle glucose uptake in all muscles was completely abolished in KO mice. Muscle glucose uptake increased during exercise in both red and white quadriceps of WT mice, while the small increases in CON mice were not statistically significant. In KO mice, there was no change at all in quadriceps muscle glucose uptake. No differences in muscle glycogen use during exercise were observed between any of the groups. However, there was a significant increase in plasma glucose levels after exercise in KO mice. The results of this study demonstrated that a reduction in skeletal muscle GLUT-4 expression to approximately 10% of normal levels completely abolished the exercise-induced increase in muscle glucose uptake. PMID:24303141

  19. Calcium's Role in Mechanotransduction during Muscle Development

    Directory of Open Access Journals (Sweden)

    Tatiana Benavides Damm

    2014-01-01

    Full Text Available Mechanotransduction is a process where cells sense their surroundings and convert the physical forces in their environment into an appropriate response. Calcium plays a crucial role in the translation of such forces to biochemical signals that control various biological processes fundamental in muscle development. The mechanical stimulation of muscle cells may for example result from stretch, electric and magnetic stimulation, shear stress, and altered gravity exposure. The response, mainly involving changes in intracellular calcium concentration then leads to a cascade of events by the activation of downstream signaling pathways. The key calcium-dependent pathways described here include the nuclear factor of activated T cells (NFAT and mitogen-activated protein kinase (MAPK activation. The subsequent effects in cellular homeostasis consist of cytoskeletal remodeling, cell cycle progression, growth, differentiation, and apoptosis, all necessary for healthy muscle development, repair, and regeneration. A deregulation from the normal process due to disuse, trauma, or disease can result in a clinical condition such as muscle atrophy, which entails a significant loss of muscle mass. In order to develop therapies against such diseased states, we need to better understand the relevance of calcium signaling and the downstream responses to mechanical forces in skeletal muscle. The purpose of this review is to discuss in detail how diverse mechanical stimuli cause changes in calcium homeostasis by affecting membrane channels and the intracellular stores, which in turn regulate multiple pathways that impart these effects and control the fate of muscle tissue.

  20. Respiratory muscle function in interstitial lung disease.

    Science.gov (United States)

    Walterspacher, Stephan; Schlager, Daniel; Walker, David J; Müller-Quernheim, Joachim; Windisch, Wolfram; Kabitz, Hans-Joachim

    2013-07-01

    Interstitial lung diseases limit daily activities, impair quality of life and result in (exertional) dyspnoea. This has mainly been attributed to a decline in lung function and impaired gas exchange. However, the contribution of respiratory muscle dysfunction to these limitations remains to be conclusively investigated. Interstitial lung disease patients and matched controls performed body plethysmography, a standardised 6-min walk test, volitional tests (respiratory drive (P0.1), global maximal inspiratory mouth occlusion pressure (PImax), sniff nasal pressure (SnPna) and inspiratory muscle load) and nonvolitional tests on respiratory muscle function and strength (twitch mouth and transdiaphragmatic pressure during bilateral magnetic phrenic nerve stimulation (TwPmo and TwPdi)). 25 patients and 24 controls were included in the study. PImax and SnPna remained unaltered (both p>0.05), whereas P0.1 and the load on the inspiratory muscles were higher (both prespiratory muscle strength remains preserved. Central respiratory drive and the load imposed on the inspiratory muscles are increased. Whether impaired respiratory muscle function impacts morbidity and mortality in interstitial lung disease patients needs to be investigated in future studies.

  1. Satellite cells in human skeletal muscle plasticity

    Directory of Open Access Journals (Sweden)

    Tim eSnijders

    2015-10-01

    Full Text Available Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodelling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodelling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodelling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

  2. GLUT-3 expression in human skeletal muscle

    Science.gov (United States)

    Stuart, C. A.; Wen, G.; Peng, B. H.; Popov, V. L.; Hudnall, S. D.; Campbell, G. A.

    2000-01-01

    Muscle biopsy homogenates contain GLUT-3 mRNA and protein. Before these studies, it was unclear where GLUT-3 was located in muscle tissue. In situ hybridization using a midmolecule probe demonstrated GLUT-3 within all muscle fibers. Fluorescent-tagged antibody reacting with affinity-purified antibody directed at the carboxy-terminus demonstrated GLUT-3 protein in all fibers. Slow-twitch muscle fibers, identified by NADH-tetrazolium reductase staining, possessed more GLUT-3 protein than fast-twitch fibers. Electron microscopy using affinity-purified primary antibody and gold particle-tagged second antibody showed that the majority of GLUT-3 was in association with triads and transverse tubules inside the fiber. Strong GLUT-3 signals were seen in association with the few nerves that traversed muscle sections. Electron microscopic evaluation of human peripheral nerve demonstrated GLUT-3 within the axon, with many of the particles related to mitochondria. GLUT-3 protein was found in myelin but not in Schwann cells. GLUT-1 protein was not present in nerve cells, axons, myelin, or Schwann cells but was seen at the surface of the peripheral nerve in the perineurium. These studies demonstrated that GLUT-3 mRNA and protein are expressed throughout normal human skeletal muscle, but the protein is predominantly found in the triads of slow-twitch muscle fibers.

  3. Gait Variability Related to Muscle Quality and Muscle Power Output in Frail Nonagenarian Older Adults.

    Science.gov (United States)

    Martinikorena, Ion; Martínez-Ramírez, Alicia; Gómez, Marisol; Lecumberri, Pablo; Casas-Herrero, Alvaro; Cadore, Eduardo L; Millor, Nora; Zambom-Ferraresi, Fabricio; Idoate, Fernando; Izquierdo, Mikel

    2016-02-01

    Frailty has become the center of attention of basic, clinical, and demographic research because of its incidence level and the gravity of adverse outcomes with age. Moreover, with advanced age, motor variability increases, particularly in gait. Muscle quality and muscle power seem to be closely associated with performance on functional tests in frail populations. Insight into the relationships among muscle power, muscle quality, and functional capacity could improve the quality of life in this population. In this study, the relationship between the quality of the muscle mass and muscle strength with gait performance in a frail population was examined. Twenty-two institutionalized frail elderly individuals (93.1 ± 3.6) participated in this study. Muscle quality was measured by segmenting areas of high- and low-density fibers as observed in computed tomography images. The assessed functional outcomes were leg strength and power, velocity of gait, and kinematic gait parameters obtained from a tri-axial inertial sensor. Our results showed that a greater number of high-density fibers, specifically those of the quadriceps femoris muscle, were associated with better gait performance in terms of step time variability, regularity, and symmetry. Additionally, gait variability was associated with muscle power. In contrast, no significant relationship was observed between gait velocity and either muscle quality or muscle power. Gait pattern disorders could be explained by a deterioration of the lower limb muscles. It is known that an impaired gait is an important predictor of falls in older populations; thus, the loss of muscle quality and power could underlie the impairments in motor control and balance that lead to falls and adverse outcomes. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  4. Genetics Home Reference: isolated Duane retraction syndrome

    Science.gov (United States)

    ... Encyclopedia: Extraocular Muscle Function Testing Health Topic: Eye Movement Disorders Genetic and Rare Diseases Information Center (1 link) Duane syndrome Additional NIH Resources (1 link) National Human Genome Research Institute: Learning About Duane Syndrome Educational Resources (9 links) American ...

  5. Abnormality of Auricular Muscles in Congenital Auricular Deformities.

    Science.gov (United States)

    Yotsuyanagi, Takatoshi; Yamauchi, Makoto; Yamashita, Ken; Sugai, Asuka; Gonda, Ayako; Kitada, Ayaka; Saito, Tamotsu; Urushidate, Satoshi

    2015-07-01

    It has been suggested that there is a close association of abnormality in auricular muscles with various congenital auricular deformities. However, there has been no investigation to determine what muscles are involved and how they affect the deformity. The authors examined abnormalities of auricular muscles for patients with various auricular deformities. The authors examined 77 auricles of 62 patients with congenital auricular deformities, including cryptotia, Stahl's ear, prominent ear, lop ear, and others. The superior and posterior auricular muscles from the extrinsic auricular muscle group and the auricular oblique and transverse muscles from the auricular intrinsic muscle group were investigated. The authors found characteristic features of the abnormality of the muscle for each auricular deformity. In nearly all cases of cryptotia, abnormality was found in the superior auricular, auricular oblique, and auricular transverse muscles. Abnormal insertion was found mainly in the superior auricular muscle and was the main cause of cryptotia. In Stahl's ear, the major abnormality was abnormal insertion of the auricular transverse muscle, which creates an abnormal cartilaginous prominence in the scapha. The abnormality in cases of prominent ear was clearly limited mostly to the auricular transverse muscle and, in some cases, to the posterior auricular muscle. In lop ear, abnormality was mostly found in the auricular transverse muscle, with elongation, and in the superior auricular or auricular oblique muscle in some cases. There is a tendency for a specific muscle abnormality to be found in each deformity. It is important to identify the abnormal muscle and correct the abnormality during the operation.

  6. Evaluation of normal masseter muscles on ultrasonography

    International Nuclear Information System (INIS)

    Hwang, Hyoung Zoo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

    2008-01-01

    To assess the internal echo intensity and morphological variability of masseter muscles on ultrasonography and to establish diagnostic criterion of estimation. Participants consisted of 50 young adults (male 25, female 25) without pathologic conditions and with full natural dentitions. Sonographic examinations were done with real time ultrasound equipment as Logiq 500 (GE Medical Systems, Seoul, Korea) at 3 parts according to lines paralleling with ala-tragus line as reference line. The thickness and area of masseter muscles according to reference line in cross-sectional images were measured at rest and at maximum contraction. The visibility and width of the internal echogenic intensity of the masseter muscles were also assessed and the muscle appearance was classified into 4 types. Data were statistically analyzed by paired t-test and x2-test. 1. When comparing the thickness and area of masseter muscles concerning with gender, there was few significant difference between right and left sides, however, there were significant differences between males and females except for the greatest thickness of left side. 2. The changes of the greatest thickness and the area between rest and maximum contraction showed that the part of the least thickness manifested more increase at maximum contraction. 3. Each part the manifestations of the internal echogenic intensity of the masseter muscles were different depending on the locations. But there was no statistically significance. Changes of muscles thickness with contraction and internal echogenic intensity with locations showed great disparity within the masseter muscles, which will be diagnostic criteria for pathophysiologic and anatomic changes of masseter muscles.

  7. Increased skeletal muscle capillarization enhances insulin sensitivity

    DEFF Research Database (Denmark)

    Åkerström, Thorbjörn; Laub, Lasse; Vedel, Kenneth

    2014-01-01

    that Prazosin was cleared from the blood stream. Whole-body insulin sensitivity was measured in conscious, unrestrained rats by hyperinsulinemic euglycemic clamp. Tissue specific insulin sensitivity was assessed by administration of 2-deoxy-[(3)H]-Glucose during the plateau phase of the clamp. Whole-body...... was enhanced independent of improvements in skeletal muscle insulin signaling to glucose uptake and glycogen synthesis, suggesting that the improvement in insulin-stimulated muscle glucose uptake could be due to improved diffusion conditions for glucose in the muscle. The Prazosin treatment did not affect...

  8. Optimal Control of Isometric Muscle Dynamics

    Directory of Open Access Journals (Sweden)

    Robert Rockenfeller

    2015-03-01

    Full Text Available We use an indirect optimal control approach to calculate the optimal neural stimulation needed to obtain measured isometric muscle forces. The neural stimulation of the nerve system is hereby considered to be a control function (input of the system ’muscle’ that solely determines the muscle force (output. We use a well-established muscle model and experimental data of isometric contractions. The model consists of coupled activation and contraction dynamics described by ordinary differential equations. To validate our results, we perform a comparison with commercial optimal control software.

  9. Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration.

    Science.gov (United States)

    Mackey, Abigail L; Magnan, Mélanie; Chazaud, Bénédicte; Kjaer, Michael

    2017-08-01

    Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. The extent of cross-talk between fibroblasts, as the source of matrix protein, and satellite cells in humans is unknown. We studied this in human muscle biopsies and cell-culture studies. We observed a strong stimulation of myogenesis by human fibroblasts in cell culture. In biopsies collected 30 days after a muscle injury protocol, fibroblast number increased to four times control levels, where fibroblasts were found to be preferentially located immediately surrounding regenerating muscle fibres. These novel findings indicate an important role for fibroblasts in supporting the regeneration of muscle fibres, potentially through direct stimulation of satellite cell differentiation and fusion, and contribute to understanding of cell-cell cross-talk during physiological and pathological muscle remodelling. Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence on fibroblast activity. However, the influence of fibroblasts on satellite cells and muscle regeneration in humans is unknown. The purpose of this study was to investigate this in vitro and during in vivo regeneration in humans. Following a muscle injury protocol in young healthy men (n = 7), the number of fibroblasts (TCF7L2+), satellite cells (Pax7+), differentiating myogenic cells (myogenin+) and regenerating fibres (neonatal/embryonic myosin+) was determined from biopsy cross-sections. Fibroblasts and myogenic precursor cells (MPCs) were also isolated from human skeletal muscle (n = 4) and co-cultured using different cell ratios, with the two cell populations either in direct contact with each other or separated by a permeable

  10. The influence of inspiratory muscle work history and specific inspiratory muscle training upon human limb muscle fatigue

    OpenAIRE

    McConnell, AK; Lomax, M

    2006-01-01

    This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 2006 The Authors. The purpose of this study was to assess the influence of the work history of the inspiratory muscles upon the fatigue characteristics of the plantar flexors (PF). We hypothesized that under conditions where the inspiratory muscle metaboreflex has been elicited, PF fatigue would be hastened due to peripheral vasoconstriction. Eight volu...

  11. Testosterone enhances C-14 2-deoxyglucose uptake by striated muscle. [sex hormones and muscle

    Science.gov (United States)

    Toop, J.; Max, S. R.

    1982-01-01

    The effect of testosterone propionate (TP) on C-14 2-deoxyglucose (C-14 2DG) uptake was studied in the rat levator ani muscle in vivo using the autoradiographic technique. Following a delay of 1 to 3 h after injecting TP, the rate of C-14 2DG uptake in experimental animals began to increase and continued to increase for at least 20 h. The label, which corresponds to C-14 2-deoxyglucose 6-phosphate, as demonstrated by chromatographic analysis of muscle extracts, was uniformly distributed over the entire muscle and was predominantly in muscle fibers, although nonmuscular elements were also labeled. The 1 to 3 h time lag suggests that the TP effect may be genomic, acting via androgen receptors, rather than directly on muscle membranes. Acceleration of glucose uptake may be an important early event in the anabolic response of the rat levator ani muscle to androgens.

  12. Muscle protein analysis. II. Two-dimensional electrophoresis of normal and diseased human skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Giometti, C.S. (Argonne National Lab., IL); Barany, M.; Danon, M.J.; Anderson, N.G.

    1980-07-01

    High-resolution two-dimensional electrophoresis was used to analyze the major proteins of normal and pathological human-muscle samples. The normal human-muscle pattern contains four myosin light chains: three that co-migrate with the myosin light chains from rabbit fast muscle (extensor digitorum longus), and one that co-migrates with the light chain 2 from rabbit slow muscle (soleus). Of seven Duchenne muscular dystrophy samples, four yielded patterns with decreased amounts of actin and myosin relative to normal muscle, while three samples gave patterns comparable to that for normal muscle. Six samples from patients with myotonic dystrophy also gave normal patterns. In nemaline rod myopathy, in contrast, the pattern was deficient in two of the fast-type myosin light chains.

  13. Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans

    Science.gov (United States)

    Cui, J.; Wilson, T. E.; Shibasaki, M.; Hodges, N. A.; Crandall, C. G.

    2001-01-01

    To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative (P baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.

  14. Stiff muscle fibers in calf muscles of patients with cerebral palsy lead to high passive muscle stiffness.

    Science.gov (United States)

    Mathewson, Margie A; Chambers, Henry G; Girard, Paul J; Tenenhaus, Mayer; Schwartz, Alexandra K; Lieber, Richard L

    2014-12-01

    Cerebral palsy (CP), caused by an injury to the developing brain, can lead to alterations in muscle function. Subsequently, increased muscle stiffness and decreased joint range of motion are often seen in patients with CP. We examined mechanical and biochemical properties of the gastrocnemius and soleus muscles, which are involved in equinus muscle contracture. Passive mechanical testing of single muscle fibers from gastrocnemius and soleus muscle of patients with CP undergoing surgery for equinus deformity showed a significant increase in fiber stiffness (p<0.01). Bundles of fibers that included their surrounding connective tissues showed no stiffness difference (p=0.28).). When in vivo sarcomere lengths were measured and fiber and bundle stiffness compared at these lengths, both fibers and bundles of patients with CP were predicted to be much stiffer in vivo compared to typically developing (TD) individuals. Interestingly, differences in fiber and bundle stiffness were not explained by typical biochemical measures such as titin molecular weight (a giant protein thought to impact fiber stiffness) or collagen content (a proxy for extracellular matrix amount). We suggest that the passive mechanical properties of fibers and bundles are thus poorly understood. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  15. Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

    International Nuclear Information System (INIS)

    Chatterjee, Somik; Yin, Hongshan; Nam, Deokhwa; Li, Yong; Ma, Ke

    2015-01-01

    Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1 −/− mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation

  16. Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Somik [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yin, Hongshan [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Cardiovascular Medicine, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050051, Hebei (China); Nam, Deokhwa [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Li, Yong [Department of Pediatric Surgery, Center for Stem Cell Research and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030 (United States); Ma, Ke, E-mail: kma@houstonmethodist.org [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States)

    2015-02-01

    Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1{sup −/−} mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation.

  17. Neuropathic Pain-like Alterations in Muscle Nociceptor Function Associated with Vibration-induced Muscle Pain

    OpenAIRE

    Chen, Xiaojie; Green, Paul G.; Levine, Jon D.

    2010-01-01

    We recently developed a rodent model of the painful muscle disorders induced by occupational exposure to vibration. In the present study we used this model to evaluate the function of sensory neurons innervating the vibration-exposed gastrocnemius muscle. Activity of 74 vibration-exposed and 40 control nociceptors, with mechanical receptive fields in the gastrocnemius muscle, were recorded. In vibration-exposed rats ~15% of nociceptors demonstrated an intense and long-lasting barrage of actio...

  18. Detection of muscle gap by L-BIA in muscle injuries: clinical prognosis.

    Science.gov (United States)

    Nescolarde, L; Yanguas, J; Terricabras, J; Lukaski, H; Alomar, X; Rosell-Ferrer, J; Rodas, G

    2017-06-21

    Sport-related muscle injury classifications are based basically on imaging criteria such as ultrasound (US) and magnetic resonance imaging (MRI) without consensus because of a lack of clinical prognostics for return-to-play (RTP), which is conditioned upon the severity of the injury, and this in turn with the muscle gap (muscular fibers retraction). Recently, Futbol Club Barcelona's medical department proposed a new muscle injury classification in which muscle gap plays an important role, with the drawback that it is not always possible to identify by MRI. Localized bioimpedance measurement (L-BIA) has emerged as a non-invasive technique for supporting US and MRI to quantify the disrupted soft tissue structure in injured muscles. To correlate the severity of the injury according to the gap with the RTP, through the percent of change in resistance (R), reactance (Xc) and phase-angle (PA) by L-BIA measurements in 22 muscle injuries. After grouping the data according to the muscle gap (by MRI exam), there were significant differences in R between grade 1 and grade 2f (myotendinous or myofascial muscle injury with feather-like appearance), as well as between grade 2f and grade 2g (myotendinous or myofascial muscle injury with feather and gap). The Xc and PA values decrease significantly between each grade (i.e. 1 versus 2f, 1 versus 2g and 2f versus 2g). In addition, the severity of the muscle gap adversely affected the RTP with significant differences observed between 1 and 2g as well as between 2f and 2g. These results show that L-BIA could aid MRI and US in identifying the severity of an injured muscle according to muscle gap and therefore to accurately predict the RTP.

  19. An Autologous Muscle Tissue Expansion Approach for the Treatment of Volumetric Muscle Loss

    Science.gov (United States)

    2015-07-01

    DOI: 10.1089/ biores.2015.0009. Abbreviations Used ANOVA¼ analysis of variance ECM¼ extracellular matrix EDL¼ extensor digitorum longus TA¼ tibialis...muscle VML injury VML was surgically created in similar fashion to that previously reported.2,13,17 The TA and underlying ex- tensor digitorum longus ...made at the antero-lateral aspect of the ankle and the distal EDL muscle tendon and extensor hallicus longus muscle was isolated and severed above the

  20. Histological evidence for muscle insertion in extant amniote femora: implications for muscle reconstruction in fossils.

    Science.gov (United States)

    Petermann, Holger; Sander, Martin

    2013-04-01

    Since the 19th century, identification of muscle attachment sites on bones has been important for muscle reconstructions, especially in fossil tetrapods, and therefore has been the subject of numerous biological and paleontological studies. At the microscopic level, in histological thin sections, the only features that can be used reliably for identifying tendon-bone or muscle-tendon-bone interactions are Sharpey's fibers. Muscles, however, do not only attach to the bone indirectly with tendons, but also directly. Previous studies failed to provide new indicators for muscle attachment, or to address the question of whether muscles with direct attachment can be identified histologically. However, histological identification of direct muscle attachments is important because these attachments do not leave visible marks (e.g. scars and rugosities) on the bone surface. We dissected the right hind limb and mapped the muscle attachment sites on the femur of one rabbit (Oryctolagus cuniculus), one Alligator mississippiensis, and one turkey (Meleagris cuniculus). We then extracted the femur and prepared four histological thin sections for the rabbit and the turkey and five histological thin sections for the alligator. Sharpey's fibers, vascular canal orientation, and a frayed periosteal margin can be indicators for indirect but also direct muscle attachment. Sharpey's fibers can be oriented to the cutting plane of the thin section at high angles, and two Sharpey's fibers orientations can occur in one area, possibly indicating a secondary force axis. However, only about 60% of mapped muscle attachment sites could be detected in thin sections, and frequently histological features suggestive of muscle attachment occurred outside mapped sites. While these insights should improve our ability to successfully identify and reconstruct muscles in extinct species, they also show the limitations of this approach. © 2013 The Authors Journal of Anatomy © 2013 Anatomical Society.