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BMC Musculoskeletal Disorders Mar 2022Cerebral palsy (CP) is caused by a static lesion to the brain occurring in utero or up to the first 2 years of life; it often manifests as musculoskeletal impairments... (Review)
Review
Cerebral palsy (CP) is caused by a static lesion to the brain occurring in utero or up to the first 2 years of life; it often manifests as musculoskeletal impairments and movement disorders including spasticity and contractures. Variable manifestation of the pathology across individuals, coupled with differing mechanics and treatments, leads to a heterogeneous collection of clinical phenotypes that affect muscles and individuals differently. Growth of muscles in CP deviates from typical development, evident as early as 15 months of age. Muscles in CP may be reduced in volume by as much as 40%, may be shorter in length, present longer tendons, and may have fewer sarcomeres in series that are overstretched compared to typical. Macroscale and functional deficits are likely mediated by dysfunction at the cellular level, which manifests as impaired growth. Within muscle fibres, satellite cells are decreased by as much as 40-70% and the regenerative capacity of remaining satellite cells appears compromised. Impaired muscle regeneration in CP is coupled with extracellular matrix expansion and increased pro-inflammatory gene expression; resultant muscles are smaller, stiffer, and weaker than typical muscle. These differences may contribute to individuals with CP participating in less physical activity, thus decreasing opportunities for mechanical loading, commencing a vicious cycle of muscle disuse and secondary sarcopenia. This narrative review describes the effects of CP on skeletal muscles encompassing substantive changes from whole muscle function to cell-level effects and the effects of common treatments. We discuss growth and mechanics of skeletal muscles in CP and propose areas where future work is needed to understand these interactions, particularly the link between neural insult and cell-level manifestation of CP.
Topics: Cerebral Palsy; Contracture; Humans; Muscle Fibers, Skeletal; Muscle Spasticity; Muscle, Skeletal
PubMed: 35272643
DOI: 10.1186/s12891-022-05110-5 -
Anatomical Record (Hoboken, N.J. : 2007) Jun 2022Kangaroo rats (Dipodomys spp.) use specialized bipedal hopping like that of kangaroos. In contrast to kangaroos that have elastic tendons capable of storing energy,...
Kangaroo rats (Dipodomys spp.) use specialized bipedal hopping like that of kangaroos. In contrast to kangaroos that have elastic tendons capable of storing energy, kangaroo rats have inelastic tendons that are unable to store large amounts of energy. Thus, the musculature of the ankle joint provides the greatest power contribution to kangaroo rat hopping. Skeletal muscle can be characterized by several fiber types, including slow twitch (Type I) and fast twitch (Type II) fibers. Fast fibers are found in higher concentration in muscles that perform quick, dynamic movements, whereas slow fibers are found in higher proportion in muscles that perform slow, endurant movements. Using fiber type specific antibodies, we identified four pure (Types I, IIA, IIB, and IIX) and two hybrid (Types I/IIA and IIA/IIX) fiber types in six hindlimb muscles from three kangaroo rats (Dipodomys merriami) to investigate the relationship between fiber composition and hindlimb muscle function. Hindlimb muscles (except soleus) were dominated by Type IIB fibers, which were largest in cross-sectional area, and are known to be best suited for rapid and explosive movements. Oxidative Type IIA and Type IIX fibers were found at moderate concentrations and likely function in maintaining continual saltatory locomotion. Thus, kangaroo rats can use these two fiber type populations as "gears" for both endurant and explosive behaviors.
Topics: Animals; Dipodomys; Hindlimb; Immunohistochemistry; Locomotion; Muscle Fibers, Fast-Twitch; Muscle Fibers, Skeletal; Muscle Fibers, Slow-Twitch; Muscle, Skeletal; Potoroidae
PubMed: 34605198
DOI: 10.1002/ar.24791 -
Sheng Li Xue Bao : [Acta Physiologica... Aug 2018The decline in skeletal muscle mass and function with age is referred as sarcopenia. It is characterized by the muscle fiber's quality, strength, muscle endurance and... (Review)
Review
The decline in skeletal muscle mass and function with age is referred as sarcopenia. It is characterized by the muscle fiber's quality, strength, muscle endurance and metabolic ability decreasing as well as the fat and connective tissue growing. Previous studies have shown that sarcopenia in itself features decreased number and cross-sectional area of muscle fibers and the net degradation of protein, which results from the joint effects of multiple factors such as the exacerbation of inflammation, oxidative stress injury, mitochondrial dysfunction, abnormal autophagy and dysregulation of muscle quality regulatory factors. In this review, we systematically displayed the molecular mechanism of sarcopenia, which will be helpful to deepen our understanding of sarcopenia and provide potential targets for the prevention and treatment of sarcopenia.
Topics: Aged; Aging; Autophagy; Humans; Inflammation; Mitochondria; Muscle, Skeletal; Oxidative Stress; Sarcopenia
PubMed: 30112570
DOI: No ID Found -
International Journal of Molecular... Jul 2022Facial nerve paralysis interferes with mimetic muscle function. To reconstruct natural facial movement, free muscle flaps are transplanted as new muscles. However, it is...
Facial nerve paralysis interferes with mimetic muscle function. To reconstruct natural facial movement, free muscle flaps are transplanted as new muscles. However, it is difficult to maintain resting tonus. A dual innervation technique in which other nerves such as the hypoglossal nerve or contralateral facial nerve are added is often applied. Using 10-week-old rats ( = 10), the masseteric and hypoglossal nerves were cut, and the distal stump of the masseteric nerve and the proximal stump of the hypoglossal nerve were then sutured (suture group). In the other group, the masseteric nerve was cut and cauterized (cut group). Immunohistochemistry and microarray were performed on the extracted masseter muscle. The immunohistochemistry results suggested that the muscles in the suture group obtained oxidative characteristics. The microarray showed the genes involved in mitochondrial function, including Perm1. In summary, our data support the validity of the dualinnervation technique for facial paralysis treatment.
Topics: Animals; Facial Muscles; Facial Nerve; Facial Paralysis; Hypoglossal Nerve; Muscle Fibers, Skeletal; Rats
PubMed: 35887204
DOI: 10.3390/ijms23147856 -
Acta Biomaterialia May 2022Skeletal muscle tissue shows a clear asymmetry with regard to the passive stresses under tensile and compressive deformation, referred to as tension-compression...
Skeletal muscle tissue shows a clear asymmetry with regard to the passive stresses under tensile and compressive deformation, referred to as tension-compression asymmetry (TCA). The present study is the first one reporting on TCA at different length scales, associated with muscle tissue and muscle fibres, respectively. This allows for the first time the comparison of TCA between the tissue and one of its individual components, and thus to identify the length scale at which this phenomenon originates. Not only the passive stress-stretch characteristics were recorded, but also the volume changes during the axial tension and compression experiments. The study reveals clear differences in the characteristics of TCA between fibres and tissue. At tissue level TCA increases non-linearly with increasing deformation and the ratio of tensile to compressive stresses at the same magnitude of strain reaches a value of approximately 130 at 13.5% deformation. At fibre level instead it initially drops to a value of 6 and then rises again to a TCA of 14. At a deformation of 13.5%, the tensile stress is about 6 times higher. Thus, TCA is about 22 times more expressed at tissue than fibre scale. Moreover, the analysis of volume changes revealed little compressibility at tissue scale whereas at fibre level, especially under compressive stress, the volume decreases significantly. The data collected in this study suggests that the extracellular matrix has a distinct role in amplifying the TCA, and leads to more incompressible tissue behaviour. STATEMENT OF SIGNIFICANCE: This article analyses and compares for the first time the tension-compression asymmetry (TCA) displayed by skeletal muscle at tissue and fibre scale. In addition, the volume changes of tissue and fibre specimens with application of passive tensile and compressive loads are studied. The study identifies a key role of the extracellular matrix in establishing the mechanical response of skeletal muscle tissue: It contributes significantly to the passive stress, it is responsible for the major part of tissue-scale TCA and, most probably, prevents/balances the volume changes of muscle fibres during deformation. These new results thus shed light on the origin of TCA and provide new information to be used in microstructure-based approaches to model and simulate skeletal muscle tissue.
Topics: Biomechanical Phenomena; Muscle Fibers, Skeletal; Muscle, Skeletal; Pressure; Stress, Mechanical
PubMed: 35339701
DOI: 10.1016/j.actbio.2022.03.034 -
Poultry Science Aug 2021This study evaluated the effects of muscle fiber characteristics on meat quality traits in 45 female fast- and slow-growing ducks. Three duck breeds at typical market...
This study evaluated the effects of muscle fiber characteristics on meat quality traits in 45 female fast- and slow-growing ducks. Three duck breeds at typical market ages were selected and slaughtered, including fast-growing ducks (Cherry Valley duck) and slow-growing ducks (Small-sized Beijing duck and Liancheng White duck). M. pectoralis major (PM), m. soleus (SOL), m. gastrocnemius (GAS) and m. extensor digitorum longus (EDL) were used to assess muscle fiber characteristics as well as meat quality properties. The results showed that the fiber compositions in PM, GAS, and EDL muscles only consisted of fast-twitch fibers irrespective of the breeds, while a low percentage of slow-twitch fibers were observed in slow-growing ducks (17.03% and 29.14%). The significant clear differences of fiber diameter, fiber density and fiber cross-sectional area (CSA) was observed among three duck breeds. Small-sized Beijing ducks had the highest diameter and cross-sectional fiber area coupled with a dramatically lowest fiber density when compared to other 2 breeds both in breast and leg muscles. In addition, the meat quality traits such as moisture content, release water, and intramuscular fat content were significantly affected by the breeds. Slow-growing ducks, especially Liancheng White ducks, exhibited higher release water, intramuscular fat content, as well as lower moisture content (P < 0.05) compared to the fast-growing ducks. The lower pH value and shear force tended to be present in breast of Liancheng White ducks (P < 0.05). The higher protein content and collagen content were detected in breast of Liancheng White ducks and the leg muscle of Small-sized Beijing ducks (P < 0.05), respectively. Finally, the correlation coefficients between muscle fiber characteristics and meat quality showed that the diameter, density and CSA of fibers had a moderate or significant correlation with pH, shear force value, moisture content, and protein content of meat in fast-growing ducks. In slow-growing ducks, muscle fiber characteristics had a moderate or significant correlation with pH, shear force value, release water, protein content, and intramuscular fat content of meat. These results indicated that muscle fiber characteristics is a useful parameter to explain in parts the variation of meat quality including pH, shear force value, and protein content of meat, both in slow-growing ducks and fast-growing ducks.
Topics: Animals; Chickens; Ducks; Female; Meat; Muscle Fibers, Skeletal; Muscle, Skeletal; Pectoralis Muscles
PubMed: 34174572
DOI: 10.1016/j.psj.2021.101264 -
Function (Oxford, England) 2022Murine exercise models can provide information on factors that influence muscle adaptability with aging, but few translatable solutions exist. Progressive weighted wheel...
Murine exercise models can provide information on factors that influence muscle adaptability with aging, but few translatable solutions exist. Progressive weighted wheel running (PoWeR) is a simple, voluntary, low-cost, high-volume endurance/resistance exercise approach for training young mice. In the current investigation, aged mice (22-mo-old) underwent a modified version of PoWeR for 8 wk. Muscle functional, cellular, biochemical, transcriptional, and myonuclear DNA methylation analyses provide an encompassing picture of how muscle from aged mice responds to high-volume combined training. Mice run 6-8 km/d, and relative to sedentary mice, PoWeR increases plantarflexor muscle strength. The oxidative soleus of aged mice responds to PoWeR similarly to young mice in every parameter measured in previous work; this includes muscle mass, glycolytic-to-oxidative fiber type transitioning, fiber size, satellite cell frequency, and myonuclear number. The oxidative/glycolytic plantaris adapts according to fiber type, but with modest overall changes in muscle mass. Capillarity increases markedly with PoWeR in both muscles, which may be permissive for adaptability in advanced age. Comparison to published PoWeR RNA-sequencing data in young mice identified conserved regulators of adaptability across age and muscles; this includes which associates with muscle vasculature. and gene expression is upregulated after PoWeR simultaneous with a hypomethylated promoter CpG in myonuclear DNA, which could have implications for innervation and capillarization. A promoter CpG in is hypomethylated by late-life exercise in myonuclei, consistent with findings in muscle tissue. PoWeR and the data herein are a resource for uncovering cellular and molecular regulators of muscle adaptation with aging.
Topics: Mice; Animals; Muscle Fibers, Skeletal; Motor Activity; Muscle, Skeletal; Physical Conditioning, Animal; Adaptation, Physiological
PubMed: 35774589
DOI: 10.1093/function/zqac027 -
Muscle & Nerve Apr 2021In adult males, cross-sectional area (CSA) for type II muscle fibers is generally larger than for type I fibers. In this cross-sectional study the aim was to compare...
BACKGROUND
In adult males, cross-sectional area (CSA) for type II muscle fibers is generally larger than for type I fibers. In this cross-sectional study the aim was to compare sex-related CSAs of various muscle fiber types during childhood-to-adulthood transition.
METHODS
Percutaneous biopsy samples were obtained from vastus lateralis in 10-y-old children (10 males and 5 females) and in young adults (9 males and 7 females). Fiber types were classified by myofibrillar ATPase and CSAs from NADH-dehydrogenase staining.
RESULTS
Type IIA were larger than type I fibers in adult males, but not in adult females or children (age x sex x fiber type, P < .002). When including all participants, body weight and sex explained 78% of the variation in type IIA CSA but only body weight contributed for type I.
CONCLUSIONS
Sex-specific patterns in CSA of the muscle fiber types appears to develop during the transition from childhood to adulthood.
Topics: Adolescent; Adult; Age Factors; Body Weight; Child; Cross-Sectional Studies; Female; Humans; Male; Muscle Fibers, Fast-Twitch; Muscle Fibers, Skeletal; Muscle, Skeletal; Quadriceps Muscle; Sex Factors; Young Adult
PubMed: 33347630
DOI: 10.1002/mus.27151 -
Biological Reviews of the Cambridge... Aug 2022The size and arrangement of fibres play a determinate role in the kinetic and energetic performance of muscles. Extrapolations between fibre architecture and performance... (Review)
Review
The size and arrangement of fibres play a determinate role in the kinetic and energetic performance of muscles. Extrapolations between fibre architecture and performance underpin our understanding of how muscles function and how they are adapted to power specific motions within and across species. Here we provide a synopsis of how this 'fibre to function' paradigm has been applied to understand muscle design, performance and adaptation in animals. Our review highlights the widespread application of the fibre to function paradigm across a diverse breadth of biological disciplines but also reveals a potential and highly prevalent limitation running through past studies. Specifically, we find that quantification of muscle architectural properties is almost universally based on an extremely small number of fibre measurements. Despite the volume of research into muscle properties, across a diverse breadth of research disciplines, the fundamental assumption that a small proportion of fibre measurements can accurately represent the architectural properties of a muscle has never been quantitatively tested. Subsequently, we use a combination of medical imaging, statistical analysis, and physics-based computer simulation to address this issue for the first time. By combining diffusion tensor imaging (DTI) and deterministic fibre tractography we generated a large number of fibre measurements (>3000) rapidly for individual human lower limb muscles. Through statistical subsampling simulations of these measurements, we demonstrate that analysing a small number of fibres (n < 25) typically used in previous studies may lead to extremely large errors in the characterisation of overall muscle architectural properties such as mean fibre length and physiological cross-sectional area. Through dynamic musculoskeletal simulations of human walking and jumping, we demonstrate that recovered errors in fibre architecture characterisation have significant implications for quantitative predictions of in-vivo dynamics and muscle fibre function within a species. Furthermore, by applying data-subsampling simulations to comparisons of muscle function in humans and chimpanzees, we demonstrate that error magnitudes significantly impact both qualitative and quantitative assessment of muscle specialisation, potentially generating highly erroneous conclusions about the absolute and relative adaption of muscles across species and evolutionary transitions. Our findings have profound implications for how a broad diversity of research fields quantify muscle architecture and interpret muscle function.
Topics: Animals; Computer Simulation; Diffusion Tensor Imaging; Muscle Fibers, Skeletal; Muscle, Skeletal; Running
PubMed: 35388613
DOI: 10.1111/brv.12856 -
Meat Science Jun 2023Muscle fiber type, fiber cross-sectional area (CSA), enzyme activities (citrate synthase (CS), 3-hydroxyacetyl Co A dehydrogenase (3HAD), lactate dehydrogenase (LDH) and...
Muscle fiber type, fiber cross-sectional area (CSA), enzyme activities (citrate synthase (CS), 3-hydroxyacetyl Co A dehydrogenase (3HAD), lactate dehydrogenase (LDH) and phosphofructokinase (PFK)) and glycogen content were analyzed in the M. iliotibialis cranialis (ITC), M. iliotibialis lateralis, M. gastrocnemius (G) and M. fibularis longus (FL) muscles from 24 ostriches. Type I and II fiber proportions were similar across the 4 muscles, but the ITC had overall the smallest fibers. CS activity was the highest in the ITC, but similar between the remainder of the muscles. 3HAD activities were very low in all muscles, ranging between 1.9 and 2.7 μmol/min/g protein, indicating poor β-oxidation. The ITC also had the lowest PFK activity. Glycogen content averaged ∼85 mmol/kg dry weight across the muscles with large intramuscular variations. The 4 ostrich muscles present with low fat oxidation capacity and low glycogen content, which could have significant implications on meat quality attributes.
Topics: Animals; Struthioniformes; Muscle Fibers, Skeletal; Muscle, Skeletal; L-Lactate Dehydrogenase; Citrate (si)-Synthase; Glycogen; Metabolome
PubMed: 36898231
DOI: 10.1016/j.meatsci.2023.109156