Establishment and Validation of a Predictive Model for Sarcopenia Based on 2-D Ultrasound and Shear Wave Elastography in the Medial Gastrocnemius Muscle.

OBJECTIVE: To develop and validate a predictive model for sarcopenia. METHODS: A total of 240 subjects who visited our hospital between August 2021 and May 2023 were randomly divided by time of entry into a training set containing 2/3 of patients and a validation set containing 1/3 of patients. The muscle thickness (MT), echo intensity (EI), and shear wave velocity (SWV) of the medial gastrocnemius muscle were measured. Indicators that were meaningful in the univariate analysis in the training set were included in a binary logistic regression to derive a regression model, and the model was evaluated using a consistency index, calibration plot, and clinical validity curve. Diagnostic efficacy and clinical applicability were compared between the model and unifactorial indicators. RESULTS: Four meaningful variables, age, body mass index (BMI), MT, and SWV, were screened into the predictive model. The model was Logit Y = 21.292 + 0.065 × Age - 0.411 × BMI - 0.524 × MT - 3.072 × SWV. The model was well differentiated with an internally validated C-index of 0.924 and an external validation C-index of 0.914. The calibration plot predicted probabilities against actual probabilities showed excellent agreement. The specificity, sensitivity, and Youden's index of the model were 73.80%, 97.40%, and 71.20%, respectively, when using the diagnostic cut-off value of >0.279 for sarcopenia. The logistic model had higher diagnostic efficacy (p < 0.001) and higher net clinical benefit (p < 0.001) over the same threshold range compared to indicators. CONCLUSION: The logistic model of sarcopenia has been justified to have good discriminatory, calibrated, and clinical validity, and has higher diagnostic value than indicators.

Coincidence between the distribution of myofascial trigger points and the presence of blood vessels in the gastrocnemius muscle: Implications for invasive procedures.

PURPOSE: The gastrocnemius venous system presents different anatomical variants. There have been described four locations of myofascial trigger points (MTrPs) in this muscle. However, no studies have analyzed the coincidence between vessels and MTrPs present in the gastrocnemius. Therefore, the main objective was to study the anatomical variability of the venous system by ultrasound and its coincidence with the location of the MTrPs. METHODS: A total of 100 lower limbs were studied. The gastrocnemius vessels were analyzed one by one by sector (medial, central, and lateral), quantifying the number of vessels, their distribution, and the coincidence with MTrPs. RESULTS: All muscle heads showed at least one vessel per section. A large variability was observed, from one to eight vessels per muscle head, with the most frequent number being three in the gastrocnemius medialis and two in the gastrocnemius lateralis. In all cases, the location of the vessels coincided with the MTrPs. CONCLUSIONS: The proximal gastrocnemius venous pattern is very variable between subjects in number of vessels and distribution, which has made it impossible to define a "safe" approach window for invasive procedures without ultrasound guidance. The coincidence between the clinical location of MTrPs of the gastrocnemius and the presence of vessels is total.

The value of multi-modal ultrasound in the assessment of sarcopenia in maintenance hemodialysis patients.

INTRODUCTION: Sarcopenia is one of the common complications in maintenance hemodialysis (MHD) patients and is associated with poor prognosis. We aimed to study the validity and reliability of ultrasound in the assessment of sarcopenia in MHD patients. METHODS: MHD patients were categorized into the sarcopenia group and the non-sarcopenia group according to the diagnostic criteria of the Asian Working Group on Sarcopenia (AWGS) 2019. Ultrasonography of the left medial head of the gastrocnemius muscle was performed in MHD and healthy controls to obtain muscle thickness (MT), pinnation angle (PA), fascicle length (FL), cross-sectional area (CSA), echo intensity (EI), elastic modulus (E), shear wave velocity (SWV), and microvascular velocity (MV). Compare the differences in ultrasound parameters among different groups, and determine the cut-off values suitable for diagnosing sarcopenia in MHD patients. RESULTS: The MT, CSA, PA, and MV in the sarcopenia group were lower than those in the non-sarcopenia group and the control group; while the EI was higher, the FL of the sarcopenia group was lower than that of the non-sarcopenia group, while the E and SWV of the sarcopenia group were higher than those of the control group. Receiver operating characteristic curve analyses indicated that ultrasound combined index had a good diagnostic value, model Y = 13.511-0.121*MT-0.609*CSA-0.172*PA+0.011*EI-2.205*MV(P < 0.05), with a cut-off value of 0.69. CONCLUSIONS: Multi-modal ultrasound is a safe, non-invasive, and real-time imaging examination method, and can provide information on muscle structure, stiffness, and perfusion, which is expected to be a promising potential tool for predicting sarcopenia in MHD patients.

Transcriptome sequencing and bioinformatics analysis of gastrocnemius muscle in type 2 diabetes mellitus rats.

OBJECTIVE: Type 2 diabetes mellitus (T2DM) is one of the high risk factors for sarcopenia. However, the pathogenesis of diabetic sarcopenia has not been fully elucidated. This study obtained transcriptome profiles of gastrocnemius muscle in normal and T2DM rats based on high-throughput sequencing technology, which may provide new ideas for exploring the pathogenesis of diabetic sarcopenia. METHODS: Twelve adult male Sprague-Dawley rats were randomly divided into Control group and T2DM group, and gastrocnemius muscle tissue was retained for transcriptome sequencing and real-time quantitative polymerase chain reaction (qRT-PCR) 6 months later. Screening differentially expressed genes (DEGs), Cluster analysis, gene ontology (GO) functional annotation analysis and Kyoto Encyclopedia of Genes and Gnomes (KEGG) functional annotation and enrichment analysis were performed for DEGs. Six DEGs related to apoptosis were selected for qTR-PCR verification. RESULTS: Transcriptomic analysis showed that there were 1016 DEGs between the gastrocnemius muscle of T2DM and normal rats, among which 665 DEGs were up-regulated and 351 DEGs were down-regulated. GO analysis showed that the extracellular matrix organization was the most enriched in biological processes, with 26 DEGs. The extracellular matrix with 35 DEGs was the most abundant cellular component. The extracellular matrix structural constituent, with 26 DEGs, was the most enriched in molecular functions. The highest number of DEGs enriched in biological processes, cellular components and molecular functions were positive regulation of transcription by RNA polymerase II, nucleus and metal ion binding, respectively. There were 78, 230 and 89 DEGs respectively. KEGG pathway enrichment analysis showed that ECM-receptor interaction, PI3K-Akt signaling pathway and TGF-ß signaling pathway(p < 0.001) had higher enrichment degree and number of DEGs. qRT-PCR results showed that the fold change of Map3k14, Atf4, Pik3r1, Il3ra, Gadd45b and Bid were 1.95, 3.25, 2.97, 2.38, 0.43 and 3.6, respectively. The fold change of transcriptome sequencing were 3.45, 2.21, 2.59, 5.39, 0.49 and 2.78, respectively. The transcriptional trends obtained by qRT-PCR were consistent with those obtained by transcriptome sequencing. CONCLUSIONS: Transcriptomic analysis was used to obtain the "gene profiles" of gastrocnemius muscle of T2DM and normal rats. qRT-PCR verification showed that the genes related to apoptosis were differentially expressed. These DEGs and enrichment pathways may provide new ideas for exploring the pathogenesis of diabetic sarcopenia.

Influence of preconditioning on morphological and mechanical properties of human Achilles tendon in vivo.

The present study aimed 1) to verify whether the effect of preconditioning was observed in the measured variables during the measurement of the human tendon in vivo (i.e., repeated contractions with breaks between trials) and 2) to determine the changes in tendon properties and their mechanisms due to submaximal repetitive contractions. Twelve healthy males participated in this study. To eliminate the effects of preconditioning, the participants rested on the measurement bed for 2 h before the start of both experiment-1 and experiment-2. In experiment-1, the measurements of elongation and hysteresis of the Achilles tendon for ramp and ballistic conditions were repeated ten times every 2 min. In experiment-2, participants performed submaximal repetitive contractions at 50 % of MVC and a frequency of 1 Hz for 10 min with a 30 s break every 2 min. Tendon mechanical properties were measured during contractions (starting 30 s and last 20 s of every 2 min), and the mean and coefficient variation (CV) of echogenicity were assessed during a 30-s rest every 2 min. In experiment-1, no significant differences in elongation and hysteresis of the tendon for ramp and ballistic contractions were found among the trials. In experiment 2, there were no significant differences in tendon elongation and hysteresis among all measurement times. Mean echogenicity increased significantly after 2 min, and CV of echogenicity decreased significantly after 4 min. These results suggest that preconditioning does not affect the elongation and hysteresis of the Achilles tendon in measuring tendon mechanical properties and submaximal repetitive contractions.

Popliteal vein entrapment syndrome associated with an accessory slip of the lateral head of the gastrocnemius muscle.

Popliteal vein entrapment syndrome (PVES) is a rare subtype of popliteal entrapment syndrome that leads to symptoms of chronic venous stasis. We report a case of isolated PVES in a young patient associated with an accessory slip of the lateral head of the gastrocnemius muscle. The patient underwent resection of the anomalous muscle, and the symptoms were relieved postoperatively. PVES should be considered in young patients with unexplained symptoms or signs of venous stasis. Surgical resection of the causative lesion compressing the popliteal vein is indicated for selected patients.

Case Report: Popliteal artery entrapment syndrome as a cause of deep vein thrombosis and subsequent popliteal artery occlusion.

Background: Popliteal artery entrapment syndrome (PAES) is a relatively rare cause of arterial insufficiency in young and physically active individuals; however, deep vein thrombosis (DVT) can develop in association with PAES. Case report: A 47-year-old man presented with a 6-day history of left leg swelling and discomfort which was diagnosed as DVT extending to the distal femoral vein and pulmonary embolism on computed tomography (CT). PAES was not suspected at this time, and the patient was administered anticoagulants for 1 year. Two years after the DVT diagnosis, the patient developed sudden-onset left calf claudication for 1 week. Repeat CT angiography showed popliteal artery (PA) occlusion caused by PA displacement from an abnormally lateral insertion of the medial gastrocnemius head. A retrospective review of the initial CT scan confirmed this, as well as compression of the popliteal vein between the displaced medial head and the normal lateral head of the gastrocnemius. The patient eventually underwent myotomy and resection of the PA with an interposition graft. Conclusion: This case underscores the potential of PAES as a rare etiology of DVT, emphasizing the importance of considering it in the differential diagnosis of DVT in younger patients lacking common predisposing factors.

A bilateral gastrocnemius tertius coexisting with a unilateral two-headed plantaris muscle.

The current cadaveric report aims to present a coexistence of two uncommon variants of the posterior leg compartment. The variations were detected, during classical dissection in an 84-year-old donated male cadaver. On the left lower limb, the gastrocnemius muscle was identified as having a third head that was attached to the lateral head. This variant is known as gastrocnemius tertius muscle and was bilaterally identified. The left-sided plantaris muscle had two distinct heads that fused into a common tendon that was inserted into the calcaneal tuberosity. Knowledge of these variants is important, due to their close relationship with the popliteal neurovascular bundle. Clinicians should be aware, to avoid pitfalls and take them into account in their differential diagnosis.

Resveratrol relieves HFD-induced insulin resistance in skeletal muscle tissue through antioxidant capacity enhancement and the Nrf2-Keap1 signaling pathway.

BACKGROUND: Resveratrol has received much attention due to its beneficial effects including antioxidant activity. The purpose of this study was to investigate the therapeutic effects of resveratrol treatment on oxidative stress and insulin resistance in the skeletal muscle of high-fat diet (HFD)-fed animals. METHODS AND RESULTS: A total of 30 six-week-old C57BL/6J mice were randomly allocated to three groups (10 animals in each group): The control group in which mice were fed a normal chow diet (NCD); the HFD group in which mice were fed an HFD for 26 weeks; and the HFD-resveratrol group in which HFD was replaced by a resveratrol supplemented-HFD (400 mg/kg diet) after 10 weeks of HFD feeding. At the end of this period, gastrocnemius muscle samples were examined to determine insulin resistance and the oxidative status in the presence of HFD and resveratrol. Resveratrol supplementation in HFD-fed mice reduced body and adipose tissue weight, improved insulin sensitivity, and decreased oxidative stress as indicated by lower malonaldehyde (MDA) levels and higher total antioxidant capacity. The supplement also increased the expression and activity of antioxidative enzymes in gastrocnemius muscle and modulated Nrf2 and Keap1 expression levels. CONCLUSIONS: These results suggest that resveratrol is effective in improving the antioxidant defense system of the skeletal muscle in HFD-fed mice, indicating its therapeutic potential to combat diseases associated with insulin resistance and oxidative stress.

Effects of gait retraining using minimalist shoes on the medial gastrocnemius muscle-tendon unit behavior and dynamics during running.

The effects of a 12-week gait retraining program on the adaptation of the medial gastrocnemius (MG) and muscle-tendon unit (MTU) were investigated. 26 runners with a rearfoot strike pattern (RFS) were randomly assigned to one of two groups: gait retraining (GR) or control group (CON). MG ultrasound images, marker positions, and ground reaction forces (GRF) were collected twice during 9 km/h of treadmill running before and after the intervention. Ankle kinetics and the MG and MTU behavior and dynamics were quantified. Runners in the GR performed gradual 12-week gait retraining transitioning to a forefoot strike pattern. After 12-week, (1) ten participants in each group completed the training; eight participants in GR transitioned to non-RFS with reduced foot strike angles; (2) MG fascicle contraction length and velocity significantly decreased after the intervention for both groups, whereas MG forces increased after intervention for both groups; (3) significant increases in MTU stretching length for GR and peak MTU recoiling velocity for both groups were observed after the intervention, respectively; (4) no significant difference was found for all parameters of the series elastic element. Gait retraining might potentially influence the MG to operate at lower fascicle contraction lengths and velocities and produce greater peak forces. The gait retraining had no effect on SEE behavior and dynamics but did impact MTU, suggesting that the training was insufficient to induce mechanical loading changes on SEE behavior and dynamics.

Bilateral Gastrocnemius Muscle Flap for Bilateral Defects of Knee Joint in Schatzker Type V & VI Proximal Tibial Condyle Fractures.

Bilateral defects around the knee joint following fracture of the proximal tibia (Schatzker type V & VI) are difficult to reconstruct because of the unavailability of local tissue. A bicondylar proximal tibial fracture requires a bilateral approach and dual plates for fracture fixation. Because of extensive dissection during plating and extended zone of trauma, the suture lines occasionally dehisce resulting in soft tissue defects on both sides of the proximal tibia. Because of its bilateral nature, the defect requires 2 flaps. We are reporting 2 cases of suture dehiscence after fixation of bicondylar fracture of the proximal tibia which required reconstruction with bilateral gastrocnemius flaps. This reconstruction is a simple option that helps in providing stable coverage. The first case was followed up for a period of 5 years and the second case was followed up for a minimum period of 6 months. Both cases demonstrated well-healed flaps, united bone and no donor side morbidity. Bilateral gastrocnemius muscle flaps can be used simultaneously for 2 separate defects on both sides of the knee without significant donor site morbidly. This reconstructive option provides stable coverage, reduces the infection and promotes bony union thus helping in early ambulation.

Il est difficile de reconstruire des anomalies bilatérales autour de l'articulation du genou après une fracture du tibia proximal (classification de Schatzker de types V et VI) à cause de l'absence de tissus locaux. Il faut une approche bilatérale pour soigner une fracture des plateaux du tibia proximal et deux plaques pour fixer la fracture. En raison de la dissection importante pendant l'installation des plaques et de la zone étendue du traumatisme, il arrive que les lignes de suture s'ouvrent, ce qui entraîne des anomalies des tissus mous des deux côtés du tibia proximal. Parce qu'elle est bilatérale, l'anomalie doit être corrigée par deux lambeaux. Les chercheurs rendent compte de deux cas de déhiscence des sutures après la fixation d'une fracture des plateaux du tibia proximal qui a dû être reconstruite par des lambeaux bilatéraux du muscle gastrocnémien. Cette reconstruction est une option simple qui contribue à une couverture stable. Le premier cas a été suivi pendant une période de cinq ans et le deuxième, pendant une période minimale de six mois. Dans les deux cas, les lambeaux ont bien guéri, l'os s'est uni et il n'y avait pas de morbidité au site du donneur. Il est possible d'utiliser simultanément les lambeaux bilatéraux du muscle gastrocnémien pour corriger deux anomalies distinctes des deux côtés du genou sans provoquer de morbidité importante au site du donneur. Cette possibilité reconstructive assure une couverture stable, réduit l'infection, favorise l'union osseuse et contribue donc à une ambulation précoce.

(-)-epicatechin treatment did not modify the thermogenic pathway in the gastrocnemius muscle of male rat offspring obeses by programming.

The aim of this study was to analyse the expression of genes related to the regulation of energy metabolism in skeletal muscle tissue by comparing male offspring in two age groups [at 110 and 245 postnatal days (pnd)] from a mother with obesity induced by a high-fat diet and (-)-epicatechin (Epi) administration. Four groups of six male offspring from different litters were randomly selected for the control groups [C and offspring of mothers with maternal obesity (MO)] or Epi intervention groups. We evaluated the effect of Epi on gastrocnemius tissue by analysing the mRNA and protein expression levels of Fndc5/irisin, Pgc-1α, Ucp3, and Sln. Epi significantly increased the Pgc-1α protein in the MO group of offspring at 110 pnd (p < 0.036, MO vs. MO+Epi), while at 245 pnd, Epi increased Fndc5/irisin mRNA expression in the MO+Epi group versus the MO group (p = 0.006).No differences were detected in Fndc5/irisin, Ucp3 or Sln mRNA or protein levels (including Pgc-1α mRNA) in the offspring at 110 pnd or in Pgc-1α, Ucp3, or Sln mRNA or protein levels (including Fndc5/irisin protein) at 245 pnd among the experimental groups. In conclusion, (-)-epicatechin treatment increased Fndc5/irisin mRNA expression and Pgc-α protein levels in the gastrocnemius muscle of offspring at postnatal days 110 and 245. Furthermore, it is suggested that the flavonoid effect in a model of obesity and its impact on thermogenesis in skeletal muscle are regulated by a different pathway than Fndc5/irisin.

Aerobic Exercise Modulates Proteomic Profiles in Gastrocnemius Muscle of db/db Mice, Ameliorating Sarcopenia.

Type-2 diabetes mellitus (T2DM)-induced sarcopenia is intertwined with diminished insulin sensitivity and extracellular matrix (ECM) remodeling in skeletal muscle and other organs. Physical activities such as aerobic exercise play a crucial role in regulating blood glucose levels, insulin sensitivity, metabolic pathways, oxidative stress, fibrosis, ECM remodeling, and muscle regeneration by modulating differentially expressed protein (DEP) levels. The objectives of our research were to investigate the effect of six weeks of aerobic exercise on the gastrocnemius and soleus muscle of db/db mice's DEP levels compared to those of sedentary db/db mice. A total of eight db/db mice were divided into two groups (n = 4 per group), namely sedentary mice (SED) and exercise-trained mice (ET), of which the latter were subjected to six weeks of a moderate-intensity aerobic exercise intervention for five days per week. After the exercise intervention, biochemical tests, including analyses of blood glucose and HbA1c levels, were performed. Histological analysis using H & E staining on tissue was performed to compare morphological characters. Gastrocnemius and soleus muscles were dissected and processed for proteomic analysis. Data were provided and analyzed based on the DEPs using the label-free quantification (LFQ) algorithm. Functional enrichment analysis and Ingenuity Pathway Analysis (IPA) were employed as bioinformatics tools to elucidate the molecular mechanisms involved in the DEPs and disease progression. Significantly reduced blood glucose and HbA1c levels and an increased cross-sectional area (CSA) of gastrocnemius muscle fibers were seen in the ET group after the exercise interventions due to upregulations of metabolic pathways. Using proteomics data analysis, we found a significant decrease in COL1A1, COL4A2, ENG, and LAMA4 protein levels in the ET gastrocnemius, showing a significant improvement in fibrosis recovery, ECM remodeling, and muscle regeneration via the downregulation of the TGF-ß signaling pathway. Upregulated metabolic pathways due to ET-regulated DEPs in the gastrocnemius indicated increased glucose metabolism, lipid metabolism, muscle regeneration, and insulin sensitivity, which play a crucial role in muscle regeneration and maintaining blood glucose and lipid levels. No significant changes were observed in the soleus muscle due to the type of exercise and muscle fiber composition. Our research suggests that engaging in six weeks of aerobic exercise may have a positive impact on the recovery of T2DM-induced sarcopenia, which might be a potential candidate for mitigation, prevention, and therapeutic treatment in the future.

Both acute glyphosate and the aminomethylphosphonic acid intoxication decreased the acetylcholinesterase activity in rat hippocampus, prefrontal cortex and gastrocnemius muscle.

It has been reported that glyphosate, one of the most common herbicides used in agriculture, impairs locomotion and cognition. Glyphosate has a variable half-life in soil up to biotic and/or abiotic factors transform the molecule in metabolites such as the aminomethylphosphonic acid (AMPA) that has a longer half-life. In this study, female Sprague Dawley rats were acutely exposed to different doses of glyphosate or AMPA (i.e. 10, 56 or 100 mg/kg) and, subsequently, the acetylcholinesterase (AChE) activity was measured in the hippocampus, prefrontal cortex (PFC) and the gastrocnemius muscle. Both glyphosate and AMPA produced a similar decrease in the AChE activity in all the tissues tested. These results suggest that interference with normal cholinergic neurotransmission may be one of the mechanisms involved in glyphosate-induced motor alterations in rats. Moreover, our results highlight the biological importance of AMPA as a molecule with anticholinesterase action in brain and skeletal muscle. To our knowledge, this is the first report showing in vivo that AMPA, the major metabolite of glyphosate, behaves as an organophosphate.

Fatty infiltration of gastrocnemius-soleus muscle complex: Considerations for myosteatosis rehabilitation.

Although previous studies have reported fatty infiltration of the gastrocnemius-soleus complex, little is known about the volumetric distribution and patterns of fatty infiltration. The purpose of this anatomical study was to document and quantify the frequency, distribution, and pattern of fatty infiltration of the gastrocnemius-soleus complex. One hundred formalin-embalmed specimens (mean age 78.1 ± 12.3 years; 48F/52M) were serially dissected to document the frequency, distribution, and pattern of fatty infiltration in the medial and lateral heads of gastrocnemius and soleus muscles. Fatty infiltration was found in 23% of specimens, 13 unilaterally (8F/5M) and 10 (5M/5F) bilaterally. The fatty infiltration process was observed to begin medially from the medial aspect of the medial head of gastrocnemius and medial margin of soleus and then progressed laterally throughout the medial head of gastrocnemius and the marginal, anterior, and posterior soleus. The lateral head of gastrocnemius remained primarily muscular in all specimens. Microscopically, the pattern of infiltration was demonstrated as intramuscular with intact aponeuroses, and septa. The remaining endo-, peri-, and epimysium preserved the overall contour of the gastrocnemius-soleus complex, even in cases of significant fatty replacement. Since the external contour of the calf is preserved, the presence of fatty infiltration may be underdiagnosed in the clinic without imaging. Myosteatosis is associated with gait and balance challenges in the elderly, which can impact quality of life and result in increased risk of falling. The findings of the study have implications in the rehabilitation management of elderly patients with sarcopenia and myosteatosis.

Oyster (Ostrea Plicatula Gmelin) Peptides Improve Exercise Endurance Capacity via Activating AMPK and HO-1.

OBJECTIVE: Previous studies have shown that oyster peptides (OPs) have antioxidant and anti-fatigue activities. This study aimed to investigate the effects of OPs on swimming endurance in mice and the underlying mechanisms. METHODS: The mice were subjected to gavage with OPs and subjected to exercise training. After 14 days, various biochemical indicators in the blood and gastrocnemius muscle of mice were assessed, and real-time PCR was utilized to detect the level of signal pathway regulation by OPs in the gastrocnemius muscle. Molecular docking technology was employed to observe the potential active components in OPs that regulate signal pathways. RESULTS: In this study, OPs supplementation combined with and without exercise significantly extended swimming time compared to the sedentary group. OPs supplementation with exercise also increased glycogen levels and decreased blood urea nitrogen, lactate dehydrogenase, and lactic acid levels. Additionally, mice in the exercise with OPs group exhibited higher activities of antioxidant enzymes. OPs can upregulate metabolic regulatory factors such as AMP-activated protein kinase, peroxisome proliferator-activated receptor gamma coactivator-1 alpha, peroxisome proliferator-activated receptor delta, and glucose transporter 4, thereby increasing energy supply during exercise. Additionally, OPs enhances the expression of heme oxygenase 1 and superoxide dismutase 2, thereby reducing oxidative stress during physical activity. Molecular docking analyses revealed that peptides found in OPs formed hydrogen bonds with AMPK and HO-1, indicating that they can exert bioactivity by activating target proteins such as AMPK and HO-1. CONCLUSIONS: OPs supplementation improved energy reserves, modulated energy metabolism pathways, and coordinated antioxidative stress responses, ultimately enhancing swimming endurance. These findings suggest that OPs have the potential to improve exercise levels by promoting metabolism and improving energy utilization efficiency.

Quantitative study of the popliteal fossa in the human fetus.

The popliteal fossa presents an extensive diamond-shaped topographical element on the posterior aspect of the knee. With the use of classical anatomical dissection, digital image analysis of NIS Elements AR 3.0 and statistics we morphometrically analyzed the size of the popliteal fossa in human fetuses aged 17-29 weeks of gestation. Morphometric parameters of the popliteal fossa increased logarithmically with fetal age: y = -44.421 + 24.301 × ln (Age) for length of superomedial boundary, y = -41.379 + 22.777 × ln (Age) for length of superolateral boundary, y = -39.019 + 20.981 × ln (Age) for inferomedial boundary, y = -37.547 + 20.319 × ln (Age), for length of inferolateral boundary, y = -28.915 + 15.822 × ln (Age) for transverse diameter, y = -69.790 + 38.73 × ln (Age) for vertical diameter and y = -485.631 + 240.844 × ln (Age) for projection surface area. Out of the four angles of the popliteal fossa the medial one was greatest, the inferior one the smallest, while the lateral one was somewhat smaller than the medial one and approximately three times greater than the superior one, with no difference with fetal age. In terms of morphometric parameters the popliteal fossa in the human fetus displays neither male-female nor right-left differences. In the popliteal fossa, growth patterns of its four boundaries, vertical and transverse diameters, and projection surface area all follow natural logarithmic functions. All the morphometric data is considered age-specific reference intervals, which may be conducive in the diagnostics of congenital abnormalities in the human fetus.

iMS-Bmal1-/- mice show evident signs of sarcopenia that are counteracted by exercise and melatonin therapies.

Sarcopenia is an age-related disease characterized by a reduction in muscle mass, strength, and function and, therefore, a deterioration in skeletal muscle health and frailty. Although the cause of sarcopenia is still unknown and, thus, there is no treatment, increasing evidence suggests that chronodisruption, particularly alterations in Bmal1 clock gene, can lead to those deficits culminating in sarcopenia. To gain insight into the cause and mechanism of sarcopenia and the protective effect of a therapeutic intervention with exercise and/or melatonin, the gastrocnemius muscles of male and female skeletal muscle-specific and inducible Bmal1 knockout mice (iMS-Bmal1-/- ) were examined by phenotypic tests and light and electron microscopy. Our results revealed a disruption of the normal activity/rest rhythm, a drop in skeletal muscle function and mass, and increased frailty in male and female iMS-Bmal1-/- animals compared to controls. A reduction in muscle fiber size and increased collagenous tissue were also detected, accompanied by reduced mitochondrial oxidative capacity and a compensatory shift towards a more oxidative fiber type. Electron microscopy further supports mitochondrial impairment in mutant mice. Melatonin and exercise ameliorated the damage caused by loss of Bmal1 in mutant mice, except for mitochondrial damage, which was worsened by the latter. Thus, iMS-Bmal1-/- mice let us to identify Bmal1 deficiency as the responsible for the appearance of sarcopenia in the gastrocnemius muscle. Moreover, the results support the exercise and melatonin as therapeutic tools to counteract sarcopenia, by a mechanism that does not require the presence of Bmal1.

Do the fasciae of the soleus have a role in plantar fasciitis?

Plantar fasciitis is a chronic, self-limiting, and painful disabling condition affecting the inferomedial aspect of the heel, usually extending toward the metatarsophalangeal joints. There is compelling evidence for a strong correlation between Achilles tendon (AT) loading and plantar aponeurosis (PA) tension. In line with this, tightness of the AT is found in almost 80% of patients affected by plantar fasciitis. A positive correlation has also been reported between gastrocnemius-soleus tightness and heel pain severity in this condition. Despite its high prevalence, the exact etiology and pathological mechanisms underlying plantar heel pain remain unclear. Therefore, the aim of the present paper is to discuss the anatomical and biomechanical substrates of plantar fasciitis with special emphasis on the emerging, though largely neglected, fascial system. In particular, the relationship between the fascia, triceps surae muscle, AT, and PA will be analyzed. We then proceed to discuss how structural and biomechanical alterations of the muscle-tendon-fascia complex due to muscle overuse or injury can create the conditions for the onset of PA pathology. A deeper knowledge of the possible molecular mechanisms underpinning changes in the mechanical properties of the fascial system in response to altered loading and/or muscle contraction could help healthcare professionals and clinicians refine nonoperative treatment strategies and rehabilitation protocols for plantar fasciitis.

Azilsartan prevents muscle loss and fast- to slow-twitch muscle fiber shift in natural ageing sarcopenic rats.

Sarcopenia is a musculoskeletal disease that reduces muscle mass and strength in older individuals. The study investigates the effects of azilsartan (AZL) on skeletal muscle loss in natural sarcopenic rats. Male Sprague-Dawley rats aged 4-6 months and 18-21 months were selected as young-matched control and natural-aged (sarcopenic) rats, respectively. Rats were allocated into young and old control (YC and OC) and young and old AZL treatment (YT and OT) groups, which received vehicles and AZL (8 mg/kg, orally) for 6 weeks. Rats were then sacrificed after muscle function analysis. Serum and gastrocnemius (GN) muscles were isolated for further endpoints. AZL significantly improved muscle grip strength and antioxidant levels in sarcopenic rats. AZL also restored the levels of insulin, testosterone, and muscle biomarkers such as myostatin and creatinine kinase in sarcopenic rats. Furthermore, AZL treatment improved the cellular and ultrastructure of GN muscle and prevented the shift of type II (glycolytic) myofibers to type I (oxidative) myofibers. The results showed that AZL intervention restored protein synthesis in natural sarcopenic rats by increasing p-Akt-1 and decreasing muscle RING-finger protein-1 and tumor necrosis factor alpha immunoexpressions. In conclusion, the present findings showed that AZL could be an effective intervention in treating age-related muscle impairments.