Left Gastrocnemius Research Articles

Aging Is Associated With Impaired Postprandial Response of Skeletal Muscle Protein Synthesis to High-Intensity Muscle Contraction in Mice.

The purpose of this study was to investigate whether aging alters the effect of nutritional status on contraction-induced muscle protein metabolism. In an overnight fasted or fed states, the right gastrocnemius muscle of young (3 months) and aged (24 months) male C57BL/6J mice was isometrically contracted via percutaneous electrical stimulation. The left gastrocnemius muscle served as a control. In the fasted state, there were no differences in basal or contraction-induced muscle protein synthesis between young and old mice. However, in the fed state, basal muscle protein synthesis was greater in young mice, and contraction increased muscle protein synthesis only in young mice. In the fed state, although phosphorylation of 4E-BP1 was similarly increased by contraction in both ages, the increase in phosphorylation of p70S6K was greater in young mice. Our results indicate that aging impairs the ability to integrate signals from muscle contraction and nutrition, leading to aging-induced anabolic resistance to muscle contraction in the postprandial state.

Small Cell Lymphoma of the Gastrocnemius Muscle: A Case Report

Introduction: The primary localization of non-Hodgkin lymphoma of the muscle is rare. Only the biopsy allows the certainty diagnosis. The aim was to report a first case of small cell lymphoma of the gastrocnemius in Mali and to do a review of the literature. Clinical Observation: It was about a 34-year-old woman who consulted 3 months after the onset of symptoms for swelling and pain in the left calf. On clinical examination there was a hard, painful and warm mass in the left calf, with paresthesias in the tibial nerve territory associated with partial functional impotence of the leg. The ultrasound revealed a hyper echogenic and heterogeneous non-vascularized mass of the left gastrocnemius muscle measuring 65 × 45 × 40 mm non-vascularized on color Doppler and pulsed in favor of myositis. Magnetic resonance imaging (MRI) concluded in a well-limited heterogeneous cystic mass in the left gastrocnemius muscle respecting the bone of benign appearance: remodeled Baker’s cyst? Considering the radioclinical unconformity, thoraco-abdominal CT was performed and revealed pulmonary metastasis. The biopsy carried out concluded with a small cell lymphoma of the gastrocnemial muscle. Marginal resection was performed associated with adjuvant chemotherapy. The advancement at 9 months was satisfactory.

Triptolide Attenuates Muscular Inflammation and Oxidative Stress in a Delayed-Onset Muscle Soreness Animal Model

Delayed-onset muscle soreness (DOMS) is associated with exercise-induced muscle damage and inflammation, which is mainly caused by prolonged eccentric exercise in humans. Triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, has been used for treating autoimmune and inflammatory diseases in clinical practice. However, whether triptolide attenuates acute muscle damage is still unclear. Here, we examined the effect of triptolide on carrageenan-induced DOMS in rats. Rats were injected with 3% of carrageenan into their muscles to induce acute left gastrocnemius muscular damage, and triptolide treatment attenuated carrageenan-induced acute muscular damage without affecting hepatic function. Triptolide can significantly decrease lipid hydroperoxide and nitric oxide (NO) levels, proinflammatory cytokine production, and the activation of nuclear factor (NF)-ĸB, as well as increase a reduced form of glutathione levels in carrageenan-treated rat muscles. At the enzyme levels, triptolide reduced the inducible nitric oxide synthase (iNOS) expression and muscular myeloperoxidase (MPO) activity in carrageenan-treated DOMS rats. In conclusion, we show that triptolide can attenuate muscular damage by inhibiting muscular oxidative stress and inflammation in a carrageenan-induced rat DOMS model.

Dry needling with electrical stimulation for the treatment of a pediatric patient with spastic cerebral palsy: a case report

The patient was a 6-year-old child with spastic quadriplegic cerebral palsy (CP) categorized with the gross motor function classification system (GMFCS) as a level IV and a Modified Modified Ashworth Scale (MMAS) of 2 for the bilateral hamstring and hip adductor muscles, and 3 for the bilateral gastrocnemius muscles. This patient’s limited range of motion significntly affected the caregiver’s ability to perform activities of daily living (ADLs). Dry needling (DN) is considered a standard treatment (TX) when treating adults with poor range of motion. This article aims to place intramuscular electrical stimulation (IMES), the delivery of an electrical current through a monofilament needle into targeted trigger points (TrPs) within the context of treating children with spastic CP. Following IMES TXs over 32 months that totaled 12 left hamstring TXs, 13 right hamstring TXs, 13 hip adductor TXs, 21 left gastrocnemius TXs, and 18 right gastrocnemius TXs, the patient demonstrated an increase in passive range of motion (PROM) of the hamstring, hip adductors, and gastrocnemius muscles. These gains equated to ease in ADLs. Both the Pediatric Evaluation of Disability Inventory (PEDI, PEDI-Caregiver Assistance Scale) and the Goal Attainment Scale (GAS) demonstrated decreased caregiver burden. The child’s GMFCS level and the MMAS did not change. Further data collection related to treating children with spasticity using IMES is indicated to validate this type of TX with this patient population.

가상현실을 이용한 공간지각훈련이 성인의 뇌 기능과 하지의 근 활성도 및 균형능력에 미치는 영향

Purpose: The purpose of this study is to compare and analyze the effects on brain function, muscle activity, and balance ability after applying acute training of VR, VRT, and TE.BR Method: The subjects of the study were healthy male adults, who were fully informed about the purpose and method of this study and voluntarily expressed their intention to participate (N=20). The same subjects were applied for each training. The subjects were trained for 60 minutes each time at 1 week intervals. Measurement variables were brain function (fp1, fp2, T4, T5, pZ), muscle activity and balance ability (static balance and dynamic balance). All statistics were analyzed by SPSS version 25.0. A one-way repeated ANOVA was performed to confirm the difference in muscle activity during exercise according to the type of training, and the Bonferroni method was used for prost-hoc analysis. On the other hand, a two-way repeated ANOVA was conducted to verify the difference between EEG before and after training application. A paired t-test was performed to confirm the difference between before and after the applied exercise method. All statistical significance levels were set at p.05.BR Results: The results of this study are as follows. 1) VR and VRT showed statistically significant changes between times and, according to post-hoc test, VR and VRT showed a positive effect compared to TE. 2) The muscle activity of the lower extremities showed statistically significant changes in the right and left tibialis anterior, biceps femoris and gastrocnemius in TE. 3) The balance ability in both static and dynamic balance was not significantly different.BR Conclusion: In summary, the findings in this study confirm that VT and VTR have a positive effect on brain function. It can be recommended for new training.

RNA Sequencing Reveals Transcriptional Changes in Muscle Tissue in Response to Muscle Pain in Exercised and Sedentary Mice

Exercise produces analgesia through multiple peripheral, spinal, and supraspinal pathways. However, uncovering these pathways one by one is time consuming, biased based on prior literature, and requires significant number animals to be tested. RNA sequencing allows for discovery of numerous transcriptional differences and can lead to the discovery of novel nociceptive pathways. The purpose of this study was to measure transcriptional differences in response to muscle pain between sedentary and exercised animals. Male and female C57/Black6 mice were grouped as pain free, sedentary with muscle pain model, and exercised with muscle pain model. The muscle pain model was induced with 2 intramuscular injections of acidic saline (20μl, pH 5.0±0.1) combined with 6 minutes of fatiguing muscle contractions delivered to the left gastrocnemius muscle. For exercise, animals were individually housed with 24hr access to a running wheel for 8 weeks prior to induction of the pain model. The left gastrocnemius muscle was harvested 24hrs after induction of the pain model and RNA was extracted. Bulk RNA sequencing was performed on an Illumina NovaSeq 6000. Differentially expressed genes (DEGs) were generated based on raw counts at the gene and transcript level using DESeq2. Within each sex, DEGs were determined between the pain free and sedentary groups and between exercised and sedentary with pain model groups. DEGs were then imported into iPathwayGuide commercial software and results were compared between sexes. Between pain free and sedentary in pain animals 160 DEGs were discovered in males and 661 were discovered in females. Between exercised and sedentary groups with the muscle pain model, 13 DEGs were discovered in males and 195 in females. iPathwayGuide analysis for all data sets revealed activation of immune system pathways including chemokine signaling, cytokine-cytokine receptor interaction, and antigen processing and presentation. Future work will confirm results with qPCR and behavioral pharmacology. Grant support from NIH AR073187.

Associations Between Heart Rate and Skeletal Muscle Oxygen Saturation (SmO₂) in Upper and Lower Extremities During Self‐Paced Walking

This study aims to determine the association between heart rate and skeletal muscle oxygen saturation (SmO₂) during 30 minutes of self‐paced walking on 4 different days. It was hypothesized that there would be a significant association between heart rate and SmO₂, as increased exercise intensity would result in increased peripheral muscle O₂ consumption and increased heart rate. Participants (age= 18‐40) were recruited from Clarkson University as part of an ongoing larger study and informed consent was signed. Heart rate was measured using a pulse oximeter after every five minute interval of the 30 minute walking period and was recorded in an online survey on surveymonkey.com. The muscle oxygen monitor (MOXY) near infrared sensors were placed on the left and right medial gastrocnemius heads as well as on the left biceps brachii muscle to record SmO₂ levels. Data was analyzed using a bivariate Pearson correlation to determine if there was a significant correlation between SmO₂ and heart rate while walking. Heart rate was negatively associated with SmO₂ in the left medial gastrocnemius head (R= ‐0.139, p= 0.044, n= 211) while there was no significant relationship seen in the right medial gastrocnemius head (p> 0.05). In the left biceps brachii muscle, there was a positive association between heart rate and SmO₂ (R= 0.148, p= 0.035, n= 204). The findings of our study suggest that as walking intensity increases, O₂ consumption in the upper and lower extremities has a weak, but significant association with heart rate. These findings suggest that as blood is shunted from the upper extremity to lower extremity to meet lower extremity demands during walking, O₂ utilization by muscles in the upper extremity is decreased. Further research is needed to elucidate how these relationships change when performing activities that require both upper and lower extremity muscles as well as with varying intensities of exercise.

Elucidating the Role of Testosterone in the Descending Pain Pathway after Activity-induced Pain

We developed an activity-induced musculoskeletal pain model that produces behavioral sex differences in which females develop widespread hyperalgesia of longer duration, while males develop localized pain for shorter durations. Previously, we determined that testosterone mediates the behavioral phenotype in male and female mice, and that there are sex-dependent differences in expression of SERT in the RVM with females showing increased expression. The current study examined the role of RVM in mediating the testosterone-dependent behavioral phenotype and SERT expression. The pain model was induced by two injections (pH 5.0 saline) into the left gastrocnemius muscle combined with 6 minutes of fatiguing muscle contraction. Hyperalgesia was tested with withdrawal threshold of the gastrocnemius using force sensitive tweezers. To determine if testosterone mediates antinociception centrally, we implanted a guide cannula into the RVM and microinjected drugs to modulate sex hormone receptors in male and female mice. We also tested whether systemic changes in sex hormones modulated SERT in the RVM and whether blockade of SERT in the RVM modulates pain behavior. Blockade of either estrogen receptors (p<.01) or aromatase (p<.05) in the RVM resulted in contralateral hyperalgesia in male mice but had no effect in female mice (p=.457). In females, activation of androgen receptors with dihydrotestosterone reversed the behavioral phenotype causing unilateral hyperalgesia (p<.05). Also, systemic testosterone reduced the increased SERT expression in the RVM in female mice (p=.009); there was no change in gonadectomized males (p=.915). Microinjection of a SERT inhibitor into the RVM reversed ipsilateral hyperalgesia in both male (p<.05) and female (p<.05) mice. Our data suggests that males convert testosterone in the RVM to estrogen to protect from development of widespread hyperalgesia. Conversely, activation of androgen receptors in the RVM in female mice leads to antinociception which may be through modulation of SERT expression. Grant support from AR073187.

Select Androgen Receptor Modulator Microparticle Formulation Reverses Muscle Hyperalgesia in Mouse Model of Widespread Muscle Pain

There is a need for the generation of non-opioid analgesics for chronic pain. The analgesic effects of testosterone have been demonstrated in preclinical and clinical studies. However, treatment with testosterone is not clinically feasible due to adverse effects. Select androgen receptor modulators (SARMs) were developed to overcome adverse effects of testosterone by selectively activating androgen receptors associated with anabolic effects while minimizing activation of androgenic effects. The purpose of this study was to develop a SARM-loaded microparticle formulation with a long-term release profile and test its efficacy in a preclinical model of chronic muscle pain. Chronic muscle pain was induced by 2 intramuscular injections of acidic saline (20μl, pH 4.0±0.1) spaced 5 days apart were delivered into the left gastrocnemius muscle of C57/BL6J male and female mice. Muscle withdrawal thresholds (MWT) were assessed with force sensitive tweezers applied to the gastrocnemius muscle before and weekly for 4 weeks after induction of the model. Efficacy of SARM ((s)-3-(4-cyanophenoxy)-n-(4-cyano-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide) was tested through daily systemic injection of the drug (25mg/kg, s.c.) or two injections of SARM loaded poly(lactic-co-glycolic acid) (PLGA) microparticles (200mg, s.c.; 24hr, 1wk). Drug release profiles from the SARM microparticle formulation was assessed both in vitro and in vivo via HPLC-UV. Liver and cardiac toxicity was analyzed from serum samples from animals receiving SARM microparticles. Statistical analysis for MWT was performed with repeated measures ANOVA compared with vehicle treatment. Both daily administration of SARMs and two injections of SARM microparticles alleviated decreased MWT bilaterally in both sexes (p<0.01). In vitro and in vivo release studies showed SARM was steadily released from microparticles for 4 weeks. Toxicity panels revealed no adverse effects of SARM microparticle treatment. The current study shows SARMs can alleviate muscle pain and SARM loaded microparticles increase clinical utility of administration due to fewer injections and long-term release profiles. Grant support from NIH AR073187 and P30CA086862.

Histomorphological and functional contralateral symmetry in the gastrocnemius muscles of the laboratory rat.

It is usual in anatomical and physiological research to assess the effects of some intervention on extremities (e.g., training programmes or injury recovery protocols) using one muscle for the intervention and its contralateral as control. However, the existence of laterality (left‐handedness or right‐handedness) in athletes of different specialities is widely recognized. In rats, gastrocnemius is one of the muscles most widely used because of its importance in locomotion and high relative limb mass. Since we have not found studies reporting laterality assessment on the morphology and function in rat gastrocnemius, our study aimed to evaluate the fibre histochemical, morphometrical and muscle force contractile properties between right and left gastrocnemius of the laboratory rat. Fibre‐type proportion, fibre morphometrical measurements, muscle capillarization and muscle force properties were analysed in the right and left gastrocnemius of six male rats. No statistically significant differences (p = 0.265) were found in gastrocnemius to body weight ratio (‰) between right (6.55 ± 0.40) and left (6.49 ± 0.40) muscles. The muscles analysed showed a great degree of heterogeneity in fibre type distribution, having three clearly distinguished regions named red, mixed and white. In the three regions, there were no statistical differences in fibre type proportions between right and left gastrocnemius, as is indicated by the p‐values (from 0.203 to 0.941) obtained after running t‐Student paired tests for each fibre type. When analysing fibre cross‐sectional area, individual fibre capillarization and fibre circularity, no significant differences between right and left gastrocnemius in any of these morphometrical parameters were found in any muscle region or fibre type. Most of the p‐values (70%) resulting from running t‐Student paired tests were higher than 0.400, and the lowest p‐value was 0.115. Seemingly, global capillary and fibre densities were not statistically different between right and left sides in all muscle regions with p‐values ranging from 0.337 to 0.812. Force parameters normalized to gastrocnemius mass (mN g−1) did not show any significant difference between right (PF = 74.0 ± 13.4, TF = 219.4 ± 13.0) and left (PF = 70.9 ± 10.7, TF = 213.0 ± 18.0) muscles with p = 0.623 (PF) and p = 0.514 (TF). Twitch time parameters (ms) also lacked significant differences between the two sides (CT: 43.4 ± 8.6 vs. 45.0 ± 14.3, p = 0.639; HRT: 77.6 ± 15.0 vs. 82.3 ± 25.3, p = 0.475). Finally, both muscles also showed similar (p = 0.718) fatigue properties. We did find an absence of laterality at the morphological and functional levels, which raises the possibility of using right and left gastrocnemius muscles interchangeably for experimental designs where one muscle is used to analyse data after a physiological intervention and its contralateral muscle plays the control role, thus allowing unbiased paired comparisons to derive accurate conclusions.

Microsurgical Transplantation of Pedicled Muscles in an Isolation Chamber—A Novel Approach to Engineering Muscle Constructs via Perfusion-Decellularization

Decellularized whole muscle constructs represent an ideal scaffold for muscle tissue engineering means as they retain the network and proteins of the extracellular matrix of skeletal muscle tissue. The presence of a vascular pedicle enables a more efficient perfusion-based decellularization protocol and allows for subsequent recellularization and transplantation of the muscle construct in vivo. The goal of this study was to create a baseline for transplantation of decellularized whole muscle constructs by establishing an animal model for investigating a complete native muscle isolated on its pedicle in terms of vascularization and functionality. The left medial gastrocnemius muscles of 5 male Lewis rats were prepared and raised from their beds for in situ muscle stimulation. The stimulation protocol included twitches, tetanic stimulation, fatigue testing, and stretching of the muscles. Peak force, maximum rate of contraction and relaxation, time to maximum contraction and relaxation, and maximum contraction and relaxation rate were determined. Afterwards, muscles were explanted and transplanted heterotopically in syngeneic rats in an isolation chamber by microvascular anastomosis. After 2 weeks, transplanted gastrocnemius muscles were exposed and stimulated again followed by intravascular perfusion with a contrast agent for µCT analysis. Muscle constructs were then paraffin embedded for immunohistological staining. Peak twitch and tetanic force values all decreased significantly after muscle transplantation while fatigue index and passive stretch properties did not differ between the two groups. Vascular analysis revealed retained perfused vessels most of which were in a smaller radius range of up to 20 µm and 45 µm. In this study, a novel rat model of heterotopic microvascular muscle transplantation in an isolation chamber was established. With the assessment of in situ muscle contraction properties as well as vessel distribution after 2 weeks of transplantation, this model serves as a base for future studies including the transplantation of perfusion-decellularized muscle constructs.

Sustained Compression with a Pneumatic Cuff on Skeletal Muscles Promotes Muscle Blood Flow and Relieves Muscle Stiffness.

(1) Purpose: This study aimed to examine whether a pneumatic cuff could promote muscle blood flow and improve muscle stiffness by continuously compressing muscles with air pressure in healthy college students. (2) Method: Twenty-one healthy collegiate students participated in this study. The probe of the near-infrared spectrometer was attached to the upper surface of the left gastrocnemius muscle, and a cuff was wrapped around the left lower leg. The cuff was inflated to 200 mmHg. After 10 min, the cuff was deflated, and the patient rested for 10 min. Muscle stiffness and fatigue were assessed before and after the intervention. (3) Results: During 10 min of continuous compression, StO2 continued to decrease until seven min of compression. After 10 min of continuous compression, StO2 was 30.8 ± 10.4%, which was approximately half of 69.2 ± 6.1% at rest. After the release of the pneumatic cuff compression, the StO2 remained higher than that at rest from 1 to 10 min. Muscle hardness was 19.0 ± 8.0 before intervention was 8.7 ± 4.8 after the intervention. Muscle fatigue was 6.6 ± 1.7 cm before the intervention and 4.0 ± 1.6 cm after the intervention. (4) Conclusions: This study suggests that sustained muscle compression using a pneumatic cuff can promote muscle blood flow and improve muscle stiffness and fatigue.

VEGF alleviates lower limb ischemia in diabetic mice by altering muscle fiber types.

Lower limb ischemia caused by diabetic foot (DF) is one of the most serious complications of diabetes. The therapeutic role of VEGF in DF is well documented. However, the mechanism for action of VEGF is still not clear. The present study aimed to explore the effects of VEGF-mediated skeletal muscle fiber type switch in angiogenesis and the treatment of DF. C57BL/6 mice housed in cages equipped with a voluntary running wheel were used to access VEGF protein level and citrate synthase activity (by ELISA) as well as muscle fiber type changes (by immunofluorescence) in the gastrocnemius muscle. C57BL/6 mice were fed on a high-fat diet for 6 weeks and then injected with streptozocin to induce diabetic lower limb ischemia model. Control adenovirus (Ad-GFP) or Ad-VEGF-GFP were then injected into the left gastrocnemius of the ischemic diabetic mice. Blood flow perfusion was examined by laser Doppler imaging at 1, 3, 7 and 14 days after adenovirus transduction. On day 14, all mice were anesthetized and sacrificed. VEGF expression levels, citrate synthase activity and muscle fiber type changes in the gastrocnemius muscle were assayed by ELISA and immunofluorescence analysis of myosin heavy chain IIa (MHCIIa) expression, respectively. Transwell assays were performed to determine whether VEGF-treated C2C12 myotubes played a role on tubule formation and migration of HUVECs. It was found that VEGF levels and citrate synthase activity were upregulated after voluntary exercise, along with the increased frequency of oxidized muscle fibers. Notably, adenovirus-mediated VEGF overexpression in the muscle also increased the frequency of oxidized (MHCIIa-positive) muscle fibers, enhanced citrate synthase activity and ameliorated lower limb ischemia in diabetic mice. VEGF treatment enhanced the phosphorylation of PI3K, Akt and AMPK (assayed by western blotting), as well as glucose consumption and metabolism (assayed by western blotting and glucose uptake assay), in the C2C12 myotubes. Interestingly, VEGF-treated C2C12 myotubes promoted the migration and tubule formation of HUVEC cells. The present findings suggest that skeletal muscle fiber conversion might be a potential approach for VEGF-mediated angiogenesis and disease treatment, which may provide new options for the prevention and treatment of DF.

Comparison of Muscle Activity During 200 m Indoor Curve and Straight Sprinting in Elite Female Sprinters.

The purpose of this study was to assess whether peak surface electromyography (sEMG) amplitude of selected lower limb muscles differed during a) curve and straight sprinting, b) sprinting in inside and outside lanes between lower limbs. Eleven well-trained female sprinters (personal best: 24.1 ± 1.1 s) were included in a randomized within-subject design study, in which participants underwent two experimental conditions: all-out 200 m indoor sprints in the innermost and outermost lane. Peak sEMG amplitude was recorded bilaterally from gastrocnemius medialis, biceps femoris, gluteus maximus, tibialis anterior, and vastus lateralis muscles. Left gastrocnemius medialis peak sEMG amplitude was significantly higher than for the right leg muscle during curve (p = 0.011) and straight sprinting (p < 0.001) when sprinting in the inside lane, and also significantly higher when sprinting in the inside vs. outside lane for both curve and straight sprinting (p = 0.037 and p = 0.027, respectively). Moreover, left biceps femoris peak sEMG amplitude was significantly higher during straight sprinting in the inside vs. outside lane (p = 0.006). Furthermore, right and left vastus lateralis peak sEMG amplitude was significantly higher during curve sprinting in the inside lane (p = 0.001 and p = 0.004, respectively) and for the left leg muscle peak sEMG amplitude was significantly higher during curve compared to straight sprinting in the outside lane (p = 0.024). Results indicate that curve sprinting creates greater demands mainly for the gastrocnemius medialis of the inner than the outer leg, but the degree of these requirements seems to depend on the radius of the curve, thus significant changes were noted during sprinting in the inside lane, but not in the outside lane.

Investigation of surface electromyography amplitude values during stair climbing task in children with Duchenne muscular dystrophy.

The aims of this study were (a) to examine the surface electromyography (sEMG) amplitude values of the lower limb muscles during stair climbing both between different functional levels of Duchenne muscular dystrophy (DMD), in comparison with healthy children, and (b) to investigate the relationships between sEMG amplitudes and physical performance. sEMG amplitudes of the lower limbs of twenty-one children with DMD between levels I and III according to the Brooke Lower Extremity Functional Classification Scale and eleven healthy peers were evaluated by using sEMG during stair climbing task. Physical performance was evaluated by 6-min walk test and ascending 4-step timed performance test. The lower limb sEMG amplitude values of children with DMD were statistically higher than healthy children (p < 0.001). sEMG amplitudes of the right (p = 0.01) and left (p = 0.003) biceps femoris, the right (p < 0.001) and left (p = 0.001) gastrocnemius medialis, and the right vastus lateralis (p = 0.02) muscles were higher in children with levels 2-3 than those in level 1. Moderate-to-strong relations were found between the gastrocnemius medialis and biceps femoris sEMG amplitudes and physical performance assessments (p < 0.05). Increased sEMG amplitude values in the lower limbs during stair climbing task are thought to be caused by the effort to compensate for progressive muscle weakness and are associated with lower physical performance in children with DMD. Further, sEMG amplitude values are determined to increase as the functional level deteriorates. NCT04287582 ( https://clinicaltrials.gov/ct2/show/NCT04287582?term=merve+bora&draw=2&rank=1 ).

Effect of Experimentally Induced Chronic Kidney disease on Skeletal, Cardiac and Smooth Muscle fibers of albino rat

Abstract Background Chronic kidney disease (CKD), or chronic renal failure (CRF) as it was historically termed, includes all degrees of decreased renal function, starting from mild, and moderate, to severe chronic kidney failure. Skeletal muscle atrophy frequently complicates the course of CKD and is associated with excess morbidity and mortality. Cardiovascular diseases have been reported to be the leading causes of death in CKD patients. Chronic Kidney Disease was also reported to be associated with an increased incidence of acid-related gastrointestinal disorders. Aim of the work The aim of this study was to investigate the effect of chronic kidney disease experimentally induced by gentamicin intramuscular injection on the histological structure of gastrocnemius skeletal muscle, left ventricular cardiac muscle and smooth muscle fibers of lower esophagus. Materials and methods Twenty male adult Wistar albino rats were randomly and equally divided into two groups. Group I (control group) received physiological saline intramuscular injection, once daily for 28 consecutive days, in a dose equivalent to that taken in group II. Group II (Gentamicin-treated group) were given Gentamicin intramuscular injection for induction of CKD. Gentamicin was given as Gentamycin sulfate, 40 mg/ml (Sandoz, Switzerland), once daily, in a dose of 80 mg/kg/day for 28 days to induce CKD. After 28 days of the first injection of gentamicin, rats were anaesthetized and blood samples were collected to measure the level of serum urea and creatinine. The left kidneys, the middle third of left gastrocnemius muscle, the lateral wall of left ventricle (LV) and the gastroesophageal junction of all rats of both groups (I and II) were processed for light microscopic study. The middle third of left gastrocnemius muscle, the lateral wall of left ventricle (LV) were further processed for transmission electron microscopic study. Histomorphometrical and statistical analysis were also done. Results The LM examination revealed moderate obliteration of glomeruli, dilatation in some renal tubules and collapse in others, mainly in distal convoluted tubules, with significant fibrosis of renal parenchyma. Serum urea and creatinine levels were increased significantly. The skeletal muscle fibers of the rats in group II (CKD) showed focal areas of myofibers degeneration with siginificant fibrosis. The cardiac muscle fibers of the rats in the group II (CKD) showed focal areas of cardiomyocytes degeneration and other areas of significantly hypertrophied fibers. The smooth muscle fibers of the lower esophageal sphincter of the rats in group II (CKD) showed no significant structural changes compared with the control group, however, the myenetric plexus showed multiple pyknotic and karyolitic nuclei with vacuolated cytoplasm. In addition, insignificant increase in the amount of collagen fibers was observed in almost all layers. Conclusion CKD produced moderate atrophy of skeletal muscle fibers, significant increase in the cardiomyocyte size and no significant structural effect of smooth muscle fibers of the lower esophageal sphincter.

Zhuanggu Zhitong Capsule alleviates osteosarcopenia in rats by up-regulating PI3K/Akt/Bcl2 signaling pathway

Background and aimsOsteosarcopenia (OS), characterized by the coexistence of osteoporosis (OP) and sarcopenia (SP), is associated with high morbidity and mortality in the elderly. Nevertheless, its pathogenesis and treatment remain unclear. The aim of this study was to investigate the effect and mechanism of Zhuanggu Zhitong Capsule (ZGZT) in OS rats. MethodsAll the related targets of OS, corresponding targets for bioactive ingredients of ZGZT, intersection targets of ZGZT against OS, and signaling pathways were predicted and analyzed by network pharmacology. Next, a rat OS model was established by ovariectomy (OVX) and injection of dexamethasone (DXM). Rats were then randomly divided into a Control group, a Sham operation group, an OS model group, an OS+ZGZT group, and an OS+E2 group. The drug was given for 12 weeks. During treatment, body weight, forelimb grip and body composition were measured. In addition, bone mineral density (BMD) and micro CT were used to assess the left femur. After treatment, the left femur, left gastrocnemius, and left soleus, as well as uterus, liver, and kidney, were separated and analyzed using Histomorphology, Western blot, and quantitative real-time PCR (qRT-PCR). ResultsZGZT could effectively improve the phenotypes of OS by increasing forelimb grip strength, percentage lean mass of the whole body (SMI) or appendicular lean (RSMI), BMD, levels of bone formation markers, improving the microstructure of femur, and decreasing apoptotic rate in femur and gastrocnemius in OS rats by up-regulating PI3K/Akt/Bcl2 signal pathway. ConclusionsZGZT may be a new treatment option for the prevention and treatment of OS.

테니스 플랫 서브 후 스플릿 스텝 동작의 근활성도 비교분석

The purpose of this study was to compare and analyze the muscle activity of the split-step motion after a tennis flat serve. This study obtained the following results. First, in phase 1 of the skilled and unskilled, the average muscle activity was significant in the left and right spinal erect muscles, left rectus femoris, right medial large muscles, left and right lateral vastus muscles, right biceps femoris, left and right tibialis anterior muscles, and right gastrocnemius It appeared to show a difference. And the maximum muscle activity of Phase 1 was found to be significantly different in the right vertebral erection muscle, medial vastus muscle, lateral vastus muscle, and biceps femoris. Second, the average muscle activity in phase 2 of the skilled and the unskilled showed a significant difference in the left and right medial latissimus, biceps femoris, gastrocnemius, and right lateral vastus. And the maximum muscle activity of phase2 was found to be significantly different in the left rectus femoris, right medial latissimus, lateral latissimus dorsi, and gastrocnemius. Third, the average muscle activity in phase 3 of the skilled and the unskilled showed a significant difference in the left and right rectus femoris, the right medial vastus, lateral vastus, tibialis anterior, and gastrocnemius. And the maximum muscle activity of phase3 showed significant differences in the right rectus femoris, medial latissimus, biceps femoris, and gastrocnemius. Fourth, the average muscle activity in phase 4 of the skilled and the unskilled showed a significant difference in the left rectus femoris, medial latissimus, tibialis anterior, and gastrocnemius. In addition, the maximum muscle activity of phase 4 showed a significant difference in the left rectus femoris and tibialis anterior muscles.

Effects of low vs. high frequency local vibration on mild-moderate muscle spasticity: Ultrasonographical and functional evaluation in patients with multiple sclerosis

BackgroundLocal vibration (LV) is a physiotherapy application that aims to reduce spasticity. The study aimed to compare the effects of 50 Hz vs. 100 Hz LV on mild-moderate spasticity, functional performance and muscle architecture. MethodsThirty-three patients were randomly divided into three groups: 50 Hz LV group, 100 Hz LV group and the control group. Physical therapy was applied for one hour a day, three days a week, for a total of eight weeks. LV was applied to the right and left medial gastrocnemius muscles for five minutes. Clinical (spasticity, ankle joint position sense, balance, gait) and ultrasonographic (gastrocnemius fascicle length and pennation angle) measurements were performed before and after treatment. ResultsThe study was completed with 27 patients. The decrease in spasticity and the increase in fascicle length were found to be statistically significant in the 50 Hz group (both p<0.05). Ankle joint position sense, single-leg stance time, limits of stability/postural sway range in the medio-lateral direction significantly improved in the vibration treatment groups (all p<0.05). The antero-posterior limits of stability and postural sway showed significant improvement in all groups (all p<0.05). While the 50 Hz group showed significant improvement for all walking parameters; velocity, step length and base of support values improved in the 100 Hz group (all p<0.05). The exercise group showed significant improvement only for single support and stance phase percentages of the gait cycle (both p<0.05). According to between group comparisons, significant difference was found only in medio-lateral limits of stabillity (p<0.05). Medio-lateral limits of stabillity scores were better for the 50 Hz group than the 100 Hz and exercise group. ConclusionOur findings show that LV does not have any substantial effect except for medio-lateral limits of stability. Clinical Trial NumberNCT04192786.

Diagnosis and Control for the Second Degree of Lateral Gastrocnemius Muscle Tear in High-School Soccer Player: A Case Report

This case study presents the epidemiology, etiology, diagnostic criteria, therapeutic intervention and modification, and rehabilitation of a lateral gastrocnemius tear in high school male soccer player. The patient injured his left gastrocnemius during soccer practice without contact. His injured leg was controlled with heel pad for equine to reduce the stress on injured gastrocnemius muscle for the initial of two weeks. The patient returned to regular practice 8 weeks after injury.