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Muscle Pathology (muscle + pathology)

Distribution by Scientific Domains

Medical Sciences	62%
Life Sciences	37%

Selected Abstracts

Pure quadriceps myopathy in two sisters

EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2003
I. Mahjneh
The authors carried out a clinical, laboratory and muscle computed tomographgy CT follow-up study of 18,21 years on two sisters affected by quadriceps myopathy (QM). The onset in the fourth decade was a weakness in the thighs. During the follow-up study, the patients showed only vasti muscles involvement, normal creatine kinase (CK) levels, myopathic muscle biopsy and electromyography (EMG) and normal membrane protein expression on immunocytochemical analysis. Therefore, all muscle pathologies known to have quadriceps involvement as a leading feature have been ruled out. We conclude that our patients have pure QM with probable autosomal recessive inheritance. [source]

A cytoskeletal tropomyosin can compromise the structural integrity of skeletal muscle

CYTOSKELETON, Issue 9 2009
Anthony J. Kee
Abstract We have identified a number of extra-sarcomeric actin filaments defined by cytoskeletal tropomyosin (Tm) isoforms. Expression of a cytoskeletal Tm (Tm3) not normally present in skeletal muscle in a transgenic mouse resulted in muscular dystrophy. In the present report we show that muscle pathology in this mouse is late onset (between 2 and 6 months of age) and is predominately in the back and paraspinal muscles. In the Tm3 mice, Evans blue dye uptake in muscle and serum levels of creatine kinase were markedly increased following downhill exercise, and the force drop following a series of lengthening contractions in isolated muscles (extensor digitorum longus) was also significantly increased in these mice. These results demonstrate that expression of an inappropriate Tm in skeletal muscle results in increased susceptibility to contraction-induced damage. The extra-sarcomeric actin cytoskeleton therefore may have an important role in protecting the muscle from contractile stress. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source]

EFNS guideline on diagnosis and management of limb girdle muscular dystrophies

EUROPEAN JOURNAL OF NEUROLOGY, Issue 12 2007
F. Norwood
The limb girdle muscular dystrophies (LGMD) are termed as such as they share the characteristic feature of muscle weakness predominantly affecting the shoulder and pelvic girdles; their classification has been completely revised in recent years because of elucidation of many of the underlying genetic and protein alterations in the various subtypes. An array of diagnostic measures is possible but with varying ease of use and availability. Several aspects of muscle cell function appear to be involved in the causation of muscle pathology. These cellular variations may confer some specific clinical features thus permitting recognition of the LGMD subtype and hence directing appropriate levels of monitoring and intervention. Despite an extensive literature on the individual limb girdle dystrophies, these publications may be impenetrable for the general neurologist in this increasingly complex field. The proposed guidelines suggest an approach to the diagnosis and monitoring of the limb girdle dystrophies in a manner accessible to general neurologists. [source]

Molecular and muscle pathology in a series of caveolinopathy patients,

HUMAN MUTATION, Issue 1 2005
Luigi Fulizio
Abstract Mutations in the caveolin-3 gene (CAV3) cause limb girdle muscular dystrophy (LGMD) type 1C (LGMD1C) and other muscle phenotypes. We screened 663 patients with various phenotypes of unknown etiology, for caveolin-3 protein deficiency, and we identified eight unreported caveolin-deficient patients (from seven families) in whom four CAV3 mutations had been detected (two are unreported). Following our wide screening, we estimated that caveolinopathies are 1% of both unclassified LGMD and other phenotypes, and demonstrated that caveolin-3 protein deficiency is a highly sensitive and specific marker of primary caveolinopathy. This is the largest series of caveolinopathy families in whom the effect of gene mutations has been analyzed for protein level and phenotype. We showed that the same mutation could lead to heterogeneous clinical phenotypes and muscle histopathological changes. To study the role of the Golgi complex in the pathological pathway of misfolded caveolin-3 oligomers, we performed a histopathological study on muscle biopsies from caveolinopathy patients. We documented normal caveolin-3 immunolabeling at the plasmalemma in some regenerating fibers showing a proliferation of the Golgi complex. It is likely that caveolin-3 overexpression occurring in regenerating fibers (compared with caveolin-deficient adult fibers) may lead to an accumulation of misfolded oligomers in the Golgi and to its consequent proliferation. Hum Mutat 25:82,89, 2005. © 2004 Wiley-Liss, Inc. [source]

Myotonic dystrophy 1 in the nervous system: From the clinic to molecular mechanisms

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 1 2008
Mario Bermúdez de León
Abstract Myotonic dystrophy type 1 (DM1) is a dominant neuromuscular disorder caused by the expansion of trinucleotide CTG repeats in the 3,-untranslated region (3,-UTR) of the DMPK gene. Prominent features of classical DM1 are muscle wasting and myotonia, whereas mental retardation is distinctive for congenital DM1. The main nervous system symptoms of DM1 are cognitive impairment, neuroendocrine dysfunction, and personality and behavior abnormalities. It is thought that expansion of CTG repeats causes DM1 pathology through different molecular mechanisms; however, a growing body of evidence indicates that an RNA gain-of-function mechanism plays a major role in the disease development. At the skeletal muscle level, three main molecular events can be distinguished in this model: 1) formation of nuclear foci that are composed at least of mutant DMPK mRNA and recruited RNA-binding proteins, such as splicing regulators and transcription factors; 2) disturbance of alternative splicing of specific genes; and 3) impairment of cell differentiation. Contrasting with the substantial advances in understanding DM1 muscle pathology, the molecular basis of DM1 in the nervous system has just started to be revealed. This review focuses in the DM1 nervous system pathology and provides an overview of the genetic and molecular studies analyzing the effects of the DMPK gene CUG expanded repeats on cell function in neuronal systems. A comparison between the molecular mechanisms of DM1 in the skeletal muscle and those identified in DM1 nervous system models is provided. Finally, future directions in the study of DM1 in the nervous system are discussed. © 2007 Wiley-Liss, Inc. [source]

Calibrated quantitative ultrasound imaging of skeletal muscle using backscatter analysis

MUSCLE AND NERVE, Issue 1 2008
Craig M. Zaidman MD
Abstract We evaluated the ability of an ultrasound method, which can characterize cardiac muscle pathology and has reliability across different imaging systems, to obtain calibrated quantitative estimates of backscatter of skeletal muscle. Our procedure utilized a tissue-mimicking phantom to establish a linear relationship between ultrasound grayscale and backscatter levels. We studied skeletal muscles of 82 adults: 45 controls and 37 patients with hereditary myopathies. We found that skeletal muscle ultrasound backscatter levels varied with probe orientation, age, and muscle contraction and pathology. Reliability was greater with the probe in longitudinal compared with transverse planes. Backscatter levels were higher in those >40 years of age, in muscle extension than flexion, and in myopathic patients than controls. Calibrated measurements of muscle backscatter have sensitivity and specificity in identifying and reliably measuring levels of skeletal muscle pathology. Muscle Nerve 38: 893,898, 2008 [source]

Priapism: Pathogenesis, Epidemiology, and Management

THE JOURNAL OF SEXUAL MEDICINE, Issue 1pt2 2010
Gregory A. Broderick MD
ABSTRACT Introduction., Priapism describes a persistent erection arising from dysfunction of mechanisms regulating penile tumescence, rigidity, and flaccidity. A correct diagnosis of priapism is a matter of urgency requiring identification of underlying hemodynamics. Aims., To define the types of priapism, address its pathogenesis and epidemiology, and develop an evidence-based guideline for effective management. Methods., Six experts from four countries developed a consensus document on priapism; this document was presented for peer review and debate in a public forum and revisions were made based on recommendations of chairpersons to the International Consultation on Sexual Medicine. This report focuses on guidelines written over the past decade and reviews the priapism literature from 2003 to 2009. Although the literature is predominantly case series, recent reports have more detailed methodology including duration of priapism, etiology of priapism, and erectile function outcomes. Main Outcome Measures., Consensus recommendations were based on evidence-based literature, best medical practices, and bench research. Results., Basic science supporting current concepts in the pathophysiology of priapism, and clinical research supporting the most effective treatment strategies are summarized in this review. Conclusions., Prompt diagnosis and appropriate management of priapism are necessary to spare patients ineffective interventions and maximize erectile function outcomes. Future research is needed to understand corporal smooth muscle pathology associated with genetic and acquired conditions resulting in ischemic priapism. Better understanding of molecular mechanisms involved in the pathogenesis of stuttering ischemic priapism will offer new avenues for medical intervention. Documenting erectile function outcomes based on duration of ischemic priapism, time to interventions, and types of interventions is needed to establish evidence-based guidance. In contrast, pathogenesis of nonischemic priapism is understood, and largely attributable to trauma. Better documentation of onset of high-flow priapism in relation to time of injury, and response to conservative management vs. angiogroaphic or surgical interventions is needed to establish evidence-based guidance. Broderick GA, Kadioglu A, Bivalacqua TJ, Ghanem H, Nehra A, and Shamloul R. Priapism: Pathogenesis, epidemiology and management. J Sex Med 2010;7:476,500. [source]

Pattern of skeletal muscle involvement in primary dysferlinopathies: a whole-body 3.0-T magnetic resonance imaging study

ACTA NEUROLOGICA SCANDINAVICA, Issue 2 2009
K. Kesper
Objectives and methods,,, Mutations in the gene encoding dysferlin cause limb girdle muscular dystrophy type 2B (LGMD2B), distal Miyoshi myopathy (MM), and a rare form of distal anterior compartment myopathy. To study the correlations between clinical manifestations and muscle imaging changes we conducted a 3.0-T magnetic resonance imaging (MRI) study in six German patients with primary dysferlinopathies defined by absence of dysferlin expression in muscle (MM, n = 3; LGMD2B, n = 2; hyperCKemia without clinical symptoms, n = 1). Results,,, Patients with manifest myopathy had widespread muscular pathology. In analogy to previous imaging studies, we confirmed an involvement of the anterior and posterior thigh compartments and a predominant involvement of posterior lower legs. However, our whole-body MRI study further provided evidence of signal alterations in the glutei, erector spinae and shoulder girdle muscles. Correlation of clinical findings with imaging demonstrated the potential of MRI to detect subclinical muscle pathology. Conclusions,,, Whole-body 3.0-T MRI is a non-invasive method to demonstrate various degrees of skeletal muscle alterations and disease progression in muscular dystrophies. Furthermore, whole-body high-field MRI may serve as a helpful diagnostic tool in differentiating primary dysferlinopathies from other forms of LGMD and distal myopathies. [source]