Muscle diseases

2011 ◽  
Author(s):  
David Hilton-Jones
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscle Fibre ◽  
Disease Process ◽  
Intimate Relationship ◽  
Pathological Process ◽  
The Other ◽  
Everyday Clinical Practice ◽  
Type Distribution ◽  
Fibre Type Distribution ◽  
Motor Nerves

This chapter is concerned with those disorders in which the primary pathological process affects skeletal muscle, for which in everyday clinical practice the term myopathy is convenient shorthand. However, it must be stressed that diseases of the motor nerves and neuromuscular junction can produce an identical clinical picture to several of the myopathies, and this will be emphasized many times throughout the chapter when considering differential diagnosis. Indeed sometimes, despite one’s best efforts, one is left uncertain as to whether the primary disease process is in the nerves or muscles—it may be that in some conditions the disease process directly affects both nerves and muscles. The intimate relationship, both structural and functional, between nerves and the muscles they innervate means that disease of one may have a profound effect on the other—the most striking example is the change that occurs to skeletal muscle fibre-type distribution in denervation.

Variability in skeletal muscle fibre characteristics during repeated muscle biopsy sampling in human vastus lateralis

2020 ◽  
Vol 45 (4) ◽  
pp. 368-375 ◽  
Author(s):  
Joshua P. Nederveen ◽  
George Ibrahim ◽  
Stephen A. Fortino ◽  
Tim Snijders ◽  
Dinesh Kumbhare ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Biopsy ◽  
Fibre Type ◽  
Vastus Lateralis ◽  
Cross Sectional Area ◽  
Muscle Fibres ◽  
Sectional Area ◽  
Cross Sectional ◽  
Type Distribution ◽  
Fibre Type Distribution

The percutaneous muscle biopsy procedure is an invaluable tool for characterizing skeletal muscle and capillarization. Little is known about methodological or biological variation stemming from the technique in heterogeneous muscle. Five muscle biopsies were taken from the vastus lateralis of a group of young men (n = 29, 22 ± 1 years) over a 96-h period. We investigated the repeatability of fibre distribution, indices of muscle capillarization and perfusion, and myofibre characteristics. No differences between the biopsies were reported in myofibre type distribution, cross-sectional area (CSA), and perimeter. Capillary-to-fibre perimeter exchange index and individual capillary-fibre contacts were unchanged with respect to the location of the muscle biopsy and index of capillarization. The variability in the sampling distribution of fibre type specific muscle CSA increased when fewer than 150 muscle fibres were quantified. Variability in fibre type distribution increased when fewer than 150 muscle fibres were quantified. Myofibre characteristics and indices of capillarization are largely consistent throughout the vastus lateralis when assessed via the skeletal muscle biopsy technique. Novelty Markers of muscle capillarization and perfusion were unchanged across multiple sites of the human vastus lateralis. Myofibre characteristics such as muscle cross-sectional area, perimeter, and fibre type distribution were also unchanged. Variation of muscle CSA was higher when fewer than 150 muscle fibres were quantified.

Effect of long-term testosterone therapy on molecular regulators of skeletal muscle mass and fibre-type distribution in aging men with subnormal testosterone

Metabolism ◽  
2020 ◽  
Vol 112 ◽  
pp. 154347
Author(s):  
Rikke Kruse ◽  
Stine J. Petersson ◽  
Louise L. Christensen ◽  
Jonas M. Kristensen ◽  
Rugivan Sabaratnam ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Fibre Type ◽  
Skeletal Muscle Mass ◽  
Testosterone Therapy ◽  
Type Distribution ◽  
Aging Men ◽  
Fibre Type Distribution

scholarly journals Problems of Pathogenesis and Pathogenetic Therapy of COVID-19 from the Perspective of the General Theory of Pathological Systems (General Pathological Processes)

2021 ◽  
Vol 22 (14) ◽  
pp. 7582
Author(s):  
Evgenii Gusev ◽  
Alexey Sarapultsev ◽  
Desheng Hu ◽  
Valeriy Chereshnev
Keyword(s):  
Systemic Inflammation ◽  
Pathological Process ◽  
The State ◽  
The Other ◽  
Low Grade ◽  
Metabolic Dysfunction ◽  
The Metabolic Syndrome ◽  
Other Hand ◽  
Pathogenetic Therapy ◽  
Fundamental Medicine

The COVID-19 pandemic examines not only the state of actual health care but also the state of fundamental medicine in various countries. Pro-inflammatory processes extend far beyond the classical concepts of inflammation. They manifest themselves in a variety of ways, beginning with extreme physiology, then allostasis at low-grade inflammation, and finally the shockogenic phenomenon of “inflammatory systemic microcirculation”. The pathogenetic core of critical situations, including COVID-19, is this phenomenon. Microcirculatory abnormalities, on the other hand, lie at the heart of a specific type of general pathological process known as systemic inflammation (SI). Systemic inflammatory response, cytokine release, cytokine storm, and thrombo-inflammatory syndrome are all terms that refer to different aspects of SI. As a result, the metabolic syndrome model does not adequately reflect the pathophysiology of persistent low-grade systemic inflammation (ChSLGI). Diseases associated with ChSLGI, on the other hand, are risk factors for a severe COVID-19 course. The review examines the role of hypoxia, metabolic dysfunction, scavenger receptors, and pattern-recognition receptors, as well as the processes of the hemophagocytic syndrome, in the systemic alteration and development of SI in COVID-19.

scholarly journals Skeletal muscle fiber size and fiber type distribution in human cancer: Effects of weight loss and relationship to physical function

2016 ◽  
Vol 35 (6) ◽  
pp. 1359-1365 ◽  
Author(s):  
Michael J. Toth ◽  
Damien M. Callahan ◽  
Mark S. Miller ◽  
Timothy W. Tourville ◽  
Sarah B. Hackett ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Weight Loss ◽  
Physical Function ◽  
Muscle Fiber ◽  
Human Cancer ◽  
Fiber Type ◽  
Skeletal Muscle Fiber ◽  
Type Distribution ◽  
Fiber Size ◽  
Fiber Type Distribution

Cloning and mapping of human PKIB and PKIG, and comparison of tissue expression patterns of three members of the protein kinase inhibitor family, including PKIA

2000 ◽  
Vol 349 (2) ◽  
pp. 403-407 ◽  
Author(s):  
Lihua ZHENG ◽  
Long YU ◽  
Qiang TU ◽  
Min ZHANG ◽  
Hua HE ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Nuclear Export ◽  
Kinase Inhibitor ◽  
Expression Patterns ◽  
Nuclear Export Signal ◽  
Tissue Expression ◽  
Protein Kinase Inhibitor ◽  
The Other ◽  
Dependent Protein

Two novel members of the human cAMP-dependent protein kinase inhibitor (PKI) gene family, PKIB and PKIG, were cloned. The deduced proteins showed 70% and 90% identity with mouse PKIβ and PKIγ respectively. Both the already identified pseudosubstrate site and leucine-rich nuclear export signal motifs were defined from the 11 PKIs of different species. The PKIB and PKIG genes were mapped respectively to chromosome 6q21-22.1, using a radiation hybrid GB4 panel, and to chromosome 20q13.12-13.13, using a Stanford G3 panel. Northern-blot analysis of three PKI isoforms, including the PKIA identified previously, revealed significant differences in their expression patterns. PKIB had two transcripts of 1.9 kb and 1.4 kb. The former transcript was abundant in both placenta and brain and the latter was expressed most abundantly in placenta, highly in brain, heart, liver, pancreas, moderately in kidney, skeletal muscle and colon, and very little in the other eight tissues tested. PKIG was widely expressed as a 1.5-kb transcript with the highest level in heart, hardly detectable in thymus and peripheral blood leucocytes and was moderately expressed in the other tissues, with slightly different levels. However, PKIA was specifically expressed as two transcripts of 3.3 kb and 1.5 kb in heart and skeletal muscle. The distinct expression patterns of the three PKIs suggest that their roles in various tissues are probably different.

Nitrendipine blocks high potassium contractures but not twitches in rat skeletal muscle

1988 ◽  
Vol 66 (9) ◽  
pp. 1210-1213 ◽  
Author(s):  
G. B. Frank ◽  
L. Konya ◽  
T. Subrahmanyam Sudha
Keyword(s):  
Skeletal Muscle ◽  
Calcium Ions ◽  
Calcium Uptake ◽  
Channel Blocker ◽  
Mechanical Response ◽  
Extracellular Calcium ◽  
The Other ◽  
Rat Skeletal Muscle ◽  
Potassium Depolarization ◽  
High Potassium

The effects of the organic calcium channel blocker nitrendipine was tested on electrically evoked twitches and on potassium depolarization-induced contractures of rat lumbricalis muscles. Nitrendipine (10−7 to 5 × 10−5 M) blocked only the potassium contractures. It was concluded that blocking calcium uptake through the slow voltage-senstitive calcium channels during potassium depolarization blocks the mechanical response of the muscle. Thus extracellular calcium ions are required for the excitation–contraction (E–C) coupling during depolarization contractures. On the other hand, electrically evoked twitches were not affected by nitrendipine; therefore, extracellular calcium ions entering via the slow voltage-sensitive channels are not required for E–C coupling during the twitch.

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