#Muscle Atrophy


Muscle synergy differences between voluntary and reactive backward stepping

Reactive stepping responses are essential to prevent falls after a loss of balance. It has previously been well described that both voluntary and reactive step training could improve the efficacy of reactive stepping in different populations. However, the effect of aging on neuromuscular control during voluntary and reactive stepping remains unclear. Electromyography (EMG) signals during both backward voluntary stepping in response to an auditory cue and backward reactive stepping elicited by a forward slip-like treadmill perturbation during stance were recorded in ten healthy young adults and ten healthy older adults. Using muscle synergy analysis, we extracted the muscle synergies for both voluntary and reactive stepping. Our results showed that fewer muscle synergies were used during reactive stepping than during voluntary stepping in both young and older adults. Minor differences in the synergy structure were observed for both voluntary and reactive stepping between age groups. Our results indicate that there is a low similarity of muscle synergies between voluntary stepping and reactive stepping and that aging had a limited effect on the structure of muscle synergies. This study enhances our understanding of the neuromuscular basis of both voluntary and reactive stepping as well as the potential effect of aging on neuromuscular control during balance tasks.
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Analysis of long intergenic non-coding RNAs transcriptomic profiling in skeletal muscle growth during porcine embryonic development

Skeletal muscle growth plays a critical role during porcine muscle development stages. Genome-wide transcriptome analysis reveals that long intergenic non-coding RNAs (lincRNAs) are implicated as crucial regulator involving in epigenetic regulation. However, comprehensive analysis of lincRNAs in embryonic muscle development stages remain still elusive. Here, we investigated the transcriptome profiles of Duroc embryonic muscle tissues from days 33, 65, and 90 of gestation using RNA-seq, and 228 putative lincRNAs were identified. Moreover, these lincRNAs exhibit the characteristics of shorter transcripts length, longer exons, less exon numbers and lower expression level compared with protein-coding transcripts. Expression profile analysis showed that a total of 120 lincRNAs and 2638 mRNAs were differentially expressed. In addition, we also performed quantitative trait locus (QTL) mapping analysis for differentially expressed lincRNAs (DE lincRNAs), 113 of 120 DE lincRNAs were localized on 2200 QTLs, we observed many QTLs involved in growth and meat quality traits. Furthermore, we predicted potential target genes of DE lincRNAs in cis or trans regulation. Gene ontology and pathway analysis reveals that potential targets of DE lincRNAs mostly were enriched in the processes and pathways related to tissue development, MAPK signaling pathway, Wnt signaling pathway, TGF-beta signaling pathway and insulin signaling pathway, which involved in skeletal muscle physiological functions. Based on cluster analysis, co-expression network analysis of DE lincRNAs and their potential target genes indicated that DE lincRNAs highly regulated protein-coding genes associated with skeletal muscle development. In this study, many of the DE lincRNAs may play essential roles in pig muscle growth and muscle mass. Our study provides crucial information for further exploring the molecular mechanisms of lincRNAs during skeletal muscle development.
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Passive repetitive stretching is associated with greater muscle mass and cross-sectional area in the sarcopenic muscle

Mechanical stimulation has benefits for muscle mass and function. Passive stretching is widely performed in clinical rehabilitation medicine. However, the hypertrophic effects of passive repetitive stretching on senescent skeletal muscles against muscle atrophy remain unknown. We used senescence-accelerated model SAM-P8 mice. The gastrocnemius muscle was passively repetitive stretched by manual ankle dorsiflexion for 15 min, 5 days a week for 2 weeks under deep anesthesia. We examined the effects of passive stretching on muscle mass, myofiber cross-sectional area, muscle fiber type composition, satellite cell and myonuclei content, signaling pathways involved in muscle protein synthesis, and myogenic regulatory factors. The gastrocnemius muscle weight and fiber cross-sectional area of the stretched side was found greater compared with that of the unstretched side. Passive repetitive stretching increased the mRNA expression level of Akt, p70S6K, 4E-BP1, Myf5, myogenin, MuRF1.The phosphorylation level of p70S6K significantly increased in the stretched muscles, whereas of Akt and 4E-BP1 remained unchanged, compared to the unstretched side. The Pax7+ cells and myonuclei content did not differ between the stretched and unstretched muscles. These findings suggest that the hypertrophic or suppressed atrophic observation in the stretched muscles are mainly attributable to the protein turnover provoked by stretching. These findings are applicable to clinical muscle strengthening and sarcopenia prevention.

What's blood flow restriction training and why are Olympic athletes using it?

A few U.S. Olympic athletes have been spotted exercising with bands wrapped around their arms or legs causing many to wonder if this is a new trend. The New York Times reported that swimmer Michael Andrew and marathoner Galen Rupp use these “tourniquet-like bands” during training. While this might seem odd to a casual observer, these straps are likely used for what’s known as blood flow restriction training. This training relies on slowing the blood flow to a muscle by using a strap or cuff while a person lifts 15 to 30% of their normal lifting weight.
Aerospace & DefenseAustralian News

How Chinese astronauts stay healthy in space

BEIJING, July 26 (Xinhua) -- Three Chinese astronauts have been living and working in China's space station core module Tianhe for more than a month. They are scheduled to stay in space for three months. The astronauts have been exercising, maintaining healthy diets and undergoing regular check-ups to reduce the...

The Absolute Best Leg Exercises For Men

7 Workouts For Building Mass in the Glutes, Hamstrings and Quads. Leg-day tends to divide bodybuilders. There are those who really enjoy a hard leg-based workout and those who’d rather replace leg day with chest day. With so many methods and pieces of equipment at our disposal, it can be challenging to know where to start.

Deep-learning framework and computer assisted fatty infiltration analysis for the supraspinatus muscle in MRI

Occupation ratio and fatty infiltration are important parameters for evaluating patients with rotator cuff tears. We analyzed the occupation ratio using a deep-learning framework and studied the fatty infiltration of the supraspinatus muscle using an automated region-based Otsu thresholding technique. To calculate the amount of fatty infiltration of the supraspinatus muscle using an automated region-based Otsu thresholding technique. The mean Dice similarity coefficient, accuracy, sensitivity, specificity, and relative area difference for the segmented lesion, measuring the similarity of clinician assessment and that of a deep neural network, were 0.97, 99.84, 96.89, 99.92, and 0.07, respectively, for the supraspinatus fossa and 0.94, 99.89, 93.34, 99.95, and 2.03, respectively, for the supraspinatus muscle. The fatty infiltration measure using the Otsu thresholding method significantly differed among the Goutallier grades (Grade 0; 0.06, Grade 1; 4.68, Grade 2; 20.10, Grade 3; 42.86, Grade 4; 55.79, p < 0.0001). The occupation ratio and fatty infiltration using Otsu thresholding demonstrated a moderate negative correlation (ρ = − 0.75, p < 0.0001). This study included 240 randomly selected patients who underwent shoulder magnetic resonance imaging (MRI) from January 2015 to December 2016. We used a fully convolutional deep-learning algorithm to quantitatively detect the fossa and muscle regions by measuring the occupation ratio of the supraspinatus muscle. Fatty infiltration was objectively evaluated using the Otsu thresholding method. The proposed convolutional neural network exhibited fast and accurate segmentation of the supraspinatus muscle and fossa from shoulder MRI, allowing automatic calculation of the occupation ratio. Quantitative evaluation using a modified Otsu thresholding method can be used to calculate the proportion of fatty infiltration in the supraspinatus muscle. We expect that this will improve the efficiency and objectivity of diagnoses by quantifying the index used for shoulder MRI.
Diseases & Treatmentsurgence.tv

what do we know about this symptom?

Patients who develop severe Covid-19 may exhibit neuromuscular symptoms such as muscle weakness after illness. Photo: Bigstock. The Covid-19 has accumulated a series of symptoms that appear even after the infectious period of the disease. The most recent are muscle lesions, or myopathies, which are characterized by symptoms of muscle weakness or even pain.

Eggs' unique qualities benefit consumers of all ages

Eggs can be bring specific benefits to consumers of all ages and ever more are being produced. As one of the best quality and most affordable sources of animal proteins, eggs make a major contribution to feeding our growing world population from infancy through to retirement. Since 2000, the global...

Ingredient Spotlight: Neuropeptides

Argireline, a so-called neuropeptide, was relatively new when I started Truth In Aging. It quickly caught on and was joined by a host of others that promised not only Botox-like effects, but also to mimic snake venom. I was skeptical for a long time, dismissing that these actually worked. And if they did, wouldn’t such effects ultimately result in muscle atrophy, as Botox does?

Early Work Supports Apitegromab’s Safety as SMA Muscle Therapy

A series of toxicology studies in rats and macaque monkeys confirmed the safety and tolerability of apitegromab, an investigational spinal muscular atrophy (SMA) therapy, supporting its ongoing assessment in patient trials, a study reported. The study, “Preclinical Safety Assessment and Toxicokinetics of Apitegromab, an Antibody Targeting Proforms of Myostatin for...

The Ultimate Guide to Active Stretching

Expand the results of your flexibility training? It’s time to activate your active stretching routine. This type of stretching offers some pretty sweet perks for all fitness levels. Here’s a deep dive into the biggest benefits, plus how it stacks up to other types of stretching. Active stretching involves contracting...
Diseases & Treatmentsverywellhealth.com

Types of Neuromuscular Disorders

Neuromuscular disorders are conditions that affect the nerves that send electrical signals to muscles to control movement. When the nerves are damaged, communication between the nerves and muscles becomes disrupted. This results in significant muscle weakness, wasting, and loss of function. Nerves communicate with muscles through the release of neurotransmitters...
Diseases & TreatmentsPosted by

This Can Lead to "Fatal" Heart Attack, Say Doctors Now

"One Love! One Heart! Let's get together and feel all right," sang Bob Marley. But without a heart, one can forget about love or frankly — anything else. The good news is that if you manage to avoid certain mistakes and adopt a couple of simple rules you can keep your heart in mint condition for years. Love your heart and you will feel all right. Read on, and to ensure your health and the health of others, don't miss these Sure Signs You Have "Long" COVID and May Not Even Know It.
Diseases & TreatmentsHealthline

Treatment Options for Myasthenia Gravis, Plus Support and Tips

Treatment options for generalized myasthenia gravis (gMG) include medication, surgery, or a combination of therapies. Most people with gMG lead full, active lives with an effective treatment. You can also reduce symptoms through lifestyle modifications, such as resting during the day, reducing stress, and eating nutritious meals. Generalized myasthenia gravis...

‘Wearable Cyborg’ Helps Improve Walking Ability, Muscle Strength

A wearable cybernetic leg significantly improved the gait and ability to perform walking exercises of people with neuromuscular disorders, such as spinal muscular atrophy (SMA), as compared to a conventional hoist, according to a recent clinical trial. The trial’s results were published in an article, titled “Cybernic treatment with wearable...
Diseases & Treatmentssmanewstoday.com

Adult-onset SMA Form, With VRK1 Mutations, Found in 2 Hispanics

Two mutations in the VRK1 gene were found in two unrelated Hispanic adults, with symptoms suggestive of an atypical form of adult-onset spinal muscular atrophy (SMA), according to a case report. While VRK1 mutations are mainly associated with pediatric-onset neuromuscular conditions marked by brain abnormalities and cognitive problems, these new...