Browsing by Subject "Muscle weakness"

Now showing 1 - 7 of 7
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    Assessment of muscle mass and strength in mice
    (SpringerNature, 2015-08-19) Bonetto, Andrea; Andersson, Daniel C.; Waning, David L.; Department of Surgery, IU School of Medicine
    Muscle weakness is an important phenotype of many diseases that is linked to impaired locomotion and increased mortality. The force that a muscle can generate is determined predominantly by muscle size, fiber type and the excitation-contraction coupling process. Here we describe methods for the histological assessment of whole muscle to determine fiber cross-sectional area and fiber type, determination of changes in myocyte size using C2C12 cells, in vivo functional tests and measurement of contractility in dissected whole muscles. The extensor digitorum longus and soleus muscles are ideally suited for whole-muscle contractility, and dissection of these muscles is described.
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    Bone Pain and Muscle Weakness in Cancer Patients
    (Springer, 2017-04) Milgrom, Daniel P.; Lad, Neha L.; Koniaris, Leonidas G.; Zimmers, Teresa A.; Surgery, School of Medicine
    PURPOSE OF REVIEW: In this article, we will discuss the current understanding of bone pain and muscle weakness in cancer patients. We will describe the underlying physiology and mechanisms of cancer-induced bone pain (CIBP) and cancer-induced muscle wasting (CIMW), as well as current methods of diagnosis and treatment. We will discuss future therapies and research directions to help patients with these problems. RECENT FINDINGS: There are several pharmacologic therapies that are currently in preclinical and clinical testing that appear to be promising adjuncts to current CIBP and CIMW therapies. Such therapies include resiniferitoxin, which is a targeted inhibitor of noceciptive nerve fibers, and selective androgen receptor modulators, which show promise in increasing lean mass. CIBP and CIMW are significant causes of morbidity in affected patients. Current management is mostly palliative; however, targeted therapies are poised to revolutionize how these problems are treated.
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    Cancer-associated muscle weakness: What’s bone got to do with it?
    (SpringerNature, 2015-05-20) Waning, David L.; Guise, Theresa A.; Department of Medicine, IU School of Medicine
    Cancer-associated muscle weakness is an important paraneoplastic syndrome for which there is currently no treatment. Tumor cells commonly metastasize to bone in advanced cancer to disrupt normal bone remodeling and result in morbidity that includes muscle weakness. Tumor in bone stimulates excessive osteoclast activity, which causes the release of growth factors stored in the mineralized bone matrix. These factors fuel a feed-forward vicious cycle of tumor growth in bone and bone destruction. Recent evidence indicates that these bone-derived growth factors can act systemically to cause muscle weakness. Muscle weakness can be caused by reduced muscle mass or reduced muscle function; in advanced disease, it is likely due to a combination of both reduced quantity and quality of muscle. In this review, we discuss possible mechanisms that lead to skeletal muscle weakness due to bone metastases.
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    Erratum: Muscle weakness caused by cancer and chemotherapy is associated with loss of motor unit connectivity
    (e-Century Publishing, 2022-03-15) Huot, Joshua R.; Pin, Fabrizio; Bonetto, Andrea; Surgery, School of Medicine
    [This corrects the article on p. 2990 in vol. 11, PMID: 34249440.].
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    Investigating Late-Onset Pompe Prevalence in Neuromuscular Medicine Academic Practices: The IPaNeMA Study
    (Wolters Kluwer, 2021-10-18) Wencel, Marie; Shaibani, Aziz; Goyal, Namita A.; Dimachkie, Mazen M.; Trivedi, Jaya; Johnson, Nicholas E.; Gutmann, Laurie; Wicklund, Matthew P.; Bandyopadhay, Sankar; Genge, Angela L.; Freimer, Miriam L.; Goyal, Neelam; Pestronk, Alan; Florence, Julaine; Karam, Chafic; Ralph, Jeffrey W.; Rasheed, Zinah; Hays, Melissa; Hopkins, Steve; Mozaffar, Tahseen; Neurology, School of Medicine
    Background and objectives: We investigated the prevalence of late-onset Pompe disease (LOPD) in patients presenting to 13 academic, tertiary neuromuscular practices in the United States and Canada. Methods: All successive patients presenting with proximal muscle weakness or isolated hyperCKemia and/or neck muscle weakness to these 13 centers were invited to participate in the study. Whole blood was tested for acid alpha-glucosidase (GAA) assay through the fluorometric method, and all cases with enzyme levels of ≤10 pmoL/punch/h were reflexed to molecular testing for mutations in the GAA gene. Clinical and demographic information was abstracted from their clinical visit and, along with study data, entered into a purpose-built REDCap database, and analyzed at the University of California, Irvine. Results: GAA enzyme assay results were available on 906 of the 921 participants who consented for the study. LOPD was confirmed in 9 participants (1% prevalence). Another 9 (1%) were determined to have pseudodeficiency of GAA, whereas 19 (1.9%) were found to be heterozygous for a pathogenic GAA mutation (carriers). Of the definite LOPD participants, 8 (89%) were Caucasian and were heterozygous for the common leaky (IVS1) splice site mutation in the GAA gene (c -32-13T>G), with a second mutation that was previously confirmed to be pathogenic. Discussion: The prevalence of LOPD in undiagnosed patients meeting the criteria of proximal muscle weakness, high creatine kinase, and/or neck weakness in academic, tertiary neuromuscular practices in the United States and Canada is estimated to be 1%, with an equal prevalence rate of pseudodeficiency alleles.
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    Muscle weakness caused by cancer and chemotherapy is associated with loss of motor unit connectivity
    (e-Century Publishing, 2021-06-15) Huot, Joshua R.; Pin, Fabrizio; Bonetto, Andrea; Surgery, School of Medicine
    Skeletal muscle wasting and weakness caused by cancer and its treatments (known as “cachexia”) drastically impair quality of life and worsen survival outcomes in cancer patients. There are currently no approved treatments for cachexia. Hence, further investigation into the causes of cachexia induced by cancer and chemotherapy is warranted. Here, we sought to investigate skeletal muscle wasting, weakness and loss of motor unit function in mice bearing cancers or administered chemotherapeutics. Mice bearing colorectal cancers, including C26, MC38 and HCT116, and mice receiving the chemotherapeutics folfiri and cisplatin were assessed for in vivo and ex vivo muscle force, and for in vivo electrophysiological indices of motor unit connectivity, including compound muscle action potential and motor unit number estimation (MUNE). In vivo and ex vivo muscle force, as well as MUNE were reduced in C26, MC38, HCT116 hosts, and in mice receiving folfiri and cisplatin compared to their respective experimental controls. In addition, MUNE was correlated with muscle force and muscle mass in all experimental conditions, while assessment of neuromuscular junction (NMJ) protein expression and changes in presynaptic morphology suggested that cancer and chemotherapy significantly alter muscle innervation. The present results demonstrate that the loss of motor unit connectivity may contribute to skeletal muscle wasting and weakness that occur with cancer and chemotherapy.
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    Osteolytic Breast Cancer Causes Skeletal Muscle Weakness in an Immunocompetent Syngeneic Mouse Model
    (Frontiers Media, 2017-12-19) Regan, Jenna N.; Mikesell, Carter; Reiken, Steven; Xu, Haifang; Marks, Andrew R.; Mohammad, Khalid S.; Guise, Theresa A.; Waning, David L.; Medicine, School of Medicine
    Muscle weakness and cachexia are significant paraneoplastic syndromes of many advanced cancers. Osteolytic bone metastases are common in advanced breast cancer and are a major contributor to decreased survival, performance, and quality of life for patients. Pathologic fracture caused by osteolytic cancer in bone (OCIB) leads to a significant (32%) increased risk of death compared to patients without fracture. Since muscle weakness is linked to risk of falls which are a major cause of fracture, we have investigated skeletal muscle response to OCIB. Here, we show that a syngeneic mouse model of OCIB (4T1 mammary tumor cells) leads to cachexia and skeletal muscle weakness associated with oxidation of the ryanodine receptor and calcium (Ca2+) release channel (RyR1). Muscle atrophy follows known pathways via both myostatin signaling and expression of muscle-specific ubiquitin ligases, atrogin-1 and MuRF1. We have identified a mechanism for skeletal muscle weakness due to increased oxidative stress on RyR1 via NAPDH oxidases [NADPH oxidase 2 (Nox2) and NADPH oxidase 4 (Nox4)]. In addition, SMAD3 phosphorylation is higher in muscle from tumor-bearing mice, a critical step in the intracellular signaling pathway that transmits TGFβ signaling to the nucleus. This is the first time that skeletal muscle weakness has been described in a syngeneic model of OCIB and represents a unique model system in which to study cachexia and changes in skeletal muscle.