Thigh Muscle Research Articles

Autoantibody-Based Clinicoradiopathologic Phenotyping of Idiopathic Inflammatory Myopathies: An Indian Cohort.

We aim to characterize the clinical, pathological, laboratory and imaging features of various antibody defined IIM subgroups in Indian population. 103 patients who satisfied 2017 ACR/ EULAR Classification criteria for IIM, and tested seropositive for myositis antibodies using Immunoblot technique were retrospectively identified. Patients were classified into following subgroups - Mi2B group, SRP group, Anti RNA Synthetase antibody group (Jo 1, PL 7, PL 12, OJ), multiple MSA, only MAA group (U1RNP, Ro 52, SS-A, SS-B, PM Scl 75, PM Scl 100). Clinical, laboratory, histopathology and imaging parameters were compared among different groups. Ro52 (n = 31; 22.46%) was the most common autoantibody seen in our cohort followed by Mi2B (n = 26; 18.84%) and SRP (n = 20; 14.49%). Skin manifestations (p = 0.053) and joint involvement (p = 0.023) were seen more frequently among Mi2B and MAA sub groups. Three out of 4 patients with persisting antibody positivity on serial measurements developed clinical relapse between 2 and 3 years after the initial episode. Remaining 2 patients showed declining titres of antibodies and developed no clinical relapses during follow up period of 5 and 6 years. Among histopathology features, perifascicular atrophy was found to be more prevalent among Mi2B (55.6%) and MAA subgroups (31.3%) (p value = 0.037). In thigh muscle MRI, Mi2B group showed a pattern of diffuse involvement of affected muscles without regional preference, with sparing of hamstring group. SRP group showed characteristic pattern of edema involving peripheral regions of Quadriceps femoris and central regions of Adductor group along with severe atrophy involving hamstring and adductor compartment muscles. ILD was seen in 27.5% of patients who underwent CT Chest. 3 patients were found to have underlying malignancy at the time of diagnosis of myositis (Mi2B = 2 and PM Scl = 1). Classification of IIM patients based on myositis antibodies yields subgroups with certain differences in clinical, laboratory, histopathological and imaging features.

Lower limb muscle activity during neurointerface control: neurointerface based on motor imagery of walking

The question of the activity of muscles that provide the realization of imaginary movement is essential in the rehabilitation of motor disorders using neurointerfaces. The literature data on this issue are contradictory. The paper analyzes the EMG activity of the shin and thigh muscles of 40 healthy volunteers when working with a neurointerface based on kinesthetic motor imagery of walking in place and supplemented with the «Biokin» robotic limb movement device (mechanotherapy), activated in case of successful motor imagery. It is shown that working with a neurointerface, on average for subjects, leads to an increase in muscle activity when motor imagery of walking compared to rest, and activation of the mechanical training device (AM) further increases muscle activity, with its effect being more pronounced in the muscles of the leg from which motor imagery of walking begins. The nature of muscle reactions to the task of motor imagery of walking is individual. AM when working with a neurointerface, the number of subjects with pronounced EMG activity increases, as does the number of significant correlations between the activity of the muscles of the lower limbs. Thus, the use of neurointerfaces based on motor imagery of walking and the addition of AM as feedback allows activating the muscles of the lower extremities, which is important in clinical practice in the rehabilitation of movements.

Experimental Study of Products Based on Biocompatible Polymer Material from Methacrylic Oligomers as a Potential Barrier for Preventing Adhesions in Cardiac Surgery.

The effectiveness and safety of two types of samples based on a biocompatible polymer material made of methacrylic oligomers (Reperen) as a potential antiadhesion pericardial barrier were evaluated in in vitro and in vivo experiments. Two kinds of samples, reinforced with a polyamide mesh and without reinforcement, were used. In in vitro experiments, no adhesion and aggregation of human fibroblasts to the test samples were detected. In in vivo experiments, the samples implanted to rats into the thigh muscles were easily separated from the surrounding tissues 1, 2, and 3 weeks after implantation, being weakly fixed only in the area of the edges. Histological examination at week 2 after implantation revealed no differences between the experimental and control groups. At week 1 and 3, fibrosis and inflammation were more pronounced in animals of the control group (with simulated implantation). The properties demonstrated by both samples of Reperen barriers (with and without polyamide mesh reinforcement) in vivo and in vitro allow considering them as a potential antiadhesion pericardial barrier for clinical use.

Arthroscopically assisted suture osteosynthesis of tibial eminence fractures in children and adolescents

The surgical goal is the arthroscopically assisted, closed reduction, and suture osteosynthesis of fractures of the tibial eminence in children and adolescents. Fractures of the tibial eminence type (II)-III according to Meyers & McKeever or typeIV according to Zaricznyj. Fracture of the tibial eminence typeI, conservatively treatable fracture typeII according to Meyers & McKeever and ligamentous rupture of the anterior cruciate ligament. Supine position. Securing the leg with alateral support on the thigh and aroll to support the foot in90° kneeflexion. Unwrap for blood evacuation with cuff on the thigh. Creation of the anterolateral portal and filling of the joint with Ringer's solution. Usually, extensive irrigation of the hemarthrosis is required first to gain visibility. Then the anteromedial portal is created. Adiagnostic walk-around is performed to rule out concomitant injuries to the cartilage and menisci. The fracture bed is then debrided with the shaver and the fracture is reduced on atrial basis using the cruciate ligament targeting device. Remove the cruciate ligament targeting device and reinforce the anterior cruciate ligament (ACL) with asuture shuttle forceps with two 1PolysorbTM sutures (Medtronic, Minneapolis, MN, USA), which are discharged and secured via the anteromedial portal. Now reinsert the cruciate ligament targeting device via the anteromedial portal. This is set to an angle of a good 60°. The image converter is used for control. Skin incision in the area of the 3 mm drill sleeve. Now a 2.4 mm cannulated drill with a core is used to predrill into the joint medial to the tibial eminence, strictly epiphyseal depending on the age. After removing the core of the drill, a wire loop is inserted into the joint, grasped with the forceps and also passed out via the anteromedial portal. Now remove the drill while leaving the wire loop in place. The medial thread legs are now threaded through the lasso loop and passed out distally via the drill channel. The analogous procedure is performed via the anterolateral portal so that the legs of both sutures meet ventrally at the tibial epiphysis/metaphysis. Now complete extension of the knee, reduction of the fracture with the cruciate ligament targeting device, under image converter control hand-tight knotting and, thus, firm reduction of the fracture. Suction of the joint. Layered wound closure. Application of a femoral cast sleeve in full extension. Removal of the osteosynthesis material is unnecessary with this method. Immobilization is in the femoral cast sleeve for 6 weeks. Removal of the femoral cast sleeve and radiological consolidation control 6 weeks postoperatively. Then start physiotherapy to restore the anatomical range of motion and strengthen thigh muscles. We operated on 10 patients between 2019 and 2022. Of these, 60% were boys. Age ranged from 5-14 years with a median of 8 years and a mean of 8.6 years. The right and left knee were affected half each; 20% of the patients presented a type II injury and 80% a type III according to Meyers & McKeever. One patient had to be revised in the course due to a cyclops lesion. One patient also presented a partial ACL rupture intraoperatively, but this has not shown any clinical relevance in the postoperative course to date. In the Lysholm score, we achieved a mean of 90.4 points and a median of 97.5 points. The International Knee Documentation Committee (IKDC) score resulted in a mean of 90.9% and a median of 90.25%. In addition, the pre- and postoperative tibial slope and the postoperative range-of-motion values were collected.

Urinary pentosidine as a potential biomarker of muscle and physical performance in young adult men

Pentosidine is representative of the cross-linked structure of advanced glycation end products (AGEs) and has been suggested as a biomarker to assess bone and muscle quality. As studies on pentosidine in young adult men remain limited, we aimed to clarify the associations of urinary pentosidine with musculoskeletal status and physical performance in young men. Participants in this study comprised 32 men (age range: 19–39 years). Anthropometric measurements (body composition by InBody 430; stiffness index by ultrasound), muscle performance (grip strength by dynamometer, thigh muscle thickness by ultrasound), physical performance (functional reach test, 30-s chair stand test, and timed up and go test), and urinary biomarkers (pentosidine, N-telopeptide of type I collagen, and creatinine) were measured. In partial correlation analysis adjusted for age and height, higher urinary pentosidine levels were significantly associated with lower fat-free mass index (rho = − 0.368, p = 0.046), grip strength (rho = − 0.433, p = 0.017), rectus femoris thickness (rho = − 0.393, p = 0.032), and anterior thigh thickness (rho = − 0.416, p = 0.022), and a marginally inverse correlation was noted between urinary pentosidine levels and functional reach test (rho = − 0.327, p = 0.078). Our findings suggest that pentosidine correlates inversely with a few muscle and physical performance indicators. Pending future validations, urinary pentosidine may be a biomarker of AGEs in young men.

Effect of dietary supplementation with oregano oil premix on the antioxidant status, performance, and meat quality in slow-growth broiler chickens

This study investigated the influence of dietary supplementation with oregano oil premix on the antioxidant status, performance, and meat quality of slow-growth genotype chickens raised under a commercial production system. The study included two groups, with nine replicates: Group A) 54.000 broilers raised in free-range farms and fed the basal diet, and Group B) 27.000 broilers raised in free-range farms and fed the basal diet supplemented with oregano oil premix. Oregano oil was blended with a standard premix (120 g/ton), which was then mixed with the feed (amount adjusted on the growth stage). The results showed that serum total antioxidant capacity (TAC) was significantly higher (p ≤ 0.05) in the non-supplemented group compared to the dietary-supplemented group with oregano oil premix. In contrast, thigh muscle total antioxidant capacity was significantly increased in the supplemented group compared to the non-supplemented group (p ≤ 0.05). There were no differences in serum and thigh muscle Thiobarbituric Acid Reactive Substances (TBARS) and performance parameters between the two groups. Chickens fed with the oregano oil premix exhibited increased protein and ash content, pH value, and higher smell, taste, and colour scores compared to the non-supplemented group. Summarising, our large-scale in field study showed that incorporating oregano oil premix in slow-growth and free-range chickens’ diet improves the thigh muscle total antioxidant capacity and meat quality. The results indicate that the oregano oil premix positively impacts the nutritional value of the final product. However, more research is needed under in field conditions to draw a safer conclusion.

Association Between Standard Gait Measures and Anterior Quadriceps Muscle Thickness as Measured by Point of Care Ultrasound (POCUS)

Background: Gait parameters and sarcopenia both predict falls risk among older adults. Our objective was to evaluate whether fast, easy-to-obtain measures of anterior thigh muscle by point of care ultrasound (POCUS) are significantly associated with standard gait measures. Methods: All subjects were referred from ambulatory geriatric medicine clinics at an academic center. Quadriceps muscle thickness was measured by a portable ultrasound device. Gait variables were measured by the patient in comfortable walking shoes walking for six minutes. The primary response variables were gait variables, and the predictor variables were age, biological sex, body mass index, and muscle thickness. Univariate and multivariate regression analyses were performed. Results: A total of 150 participants were recruited from geriatric medicine clinics (65 women, 84 men). Muscle thickness was measured in 149 participants, and the mean (SD) was 1.91 (0.52) (median 1.82 cm, 0.96 to 3.68 cm). Univariate analysis of gait parameters with age showed a statistically significant correlation with gait speed (R2=0.16, P < 0.000), average stride length (R2=0.142, P < 0.000), and average stride velocity (R2=0.182, P < 0.000). Among all the gait variables, average swing time (P = 0.010) and average stance time (P = 0.010) were correlated significantly with muscle thickness. For multivariate analysis with age and gait variables, age was a significant independent variable for all gait variables that were significant in univariate analysis. Conclusion: POCUS showed a significant association with average swing time, average stance time, and step time variability. Although more work needs to be done, POCUS has the potential to be a rapid screening tool for gait assessment.

EXTH-15. AN EGFRVIII RNA-LNP VACCINE PROTOTYPE ACHIEVES TUMOUR CLEARANCE IN A GBM MOUSE MODEL

Abstract Glioblastoma (GBM) is an aggressive high-grade glioma that is fatal despite standard-of-care therapy. Recurrent somatic alterations that form neoantigens represent opportunities for targeted therapeutic intervention. Using human EGFRvIII as a prototypical structural alteration and neoantigen, we tested the potential of a mRNA-LNP vaccine approach to improve the survival of mice with EGFRvIII-driven GBM. To generate the model, we used in vivo electroporation to introduce genetic alterations (EGFRvIII-OE/CDKN2A-KO/PTEN-KO) into periventricular cells of early postnatal C3H mice, then propagated cells from the subsequent tumours to create implantable cell lines. Following orthotopic implantation, the resulting syngeneic tumours faithfully recapitulate histologic features of GBM with infiltrative growth, mitoses, necrosis, and vascular proliferation. Also like human GBM, the models are sensitive to but not cured by temozolomide chemotherapy and are resistant to immune checkpoint blockade. We delivered mRNA-LNP vaccines against EGFRvIII into the thigh muscle of tumour-bearing mice on days 7, 10, 14, 21, and 36 after tumour cell implant. We observed no tumour in vaccine-treated mice compared to significant tumour burden in control vector-treated animals by MR imaging at day 30 post-tumour cell implant. By day 37, all control-treated mice had died, whereas vaccine-treated mice cleared their tumours with no tumour burden detectable by histology at day 150 (N= 5 per group, **p= 0.0023). In a follow-up experiment with vaccine or control treatment on days 10, 14, 18, and 25 post-cell implants, all control mice had died by day 39. Further, vaccine-treated surviving animals were re-challenged with tumour cell implant into the contralateral hemisphere on day 42 and remain alive as of day 90. Our ongoing proof-of-principle work demonstrates that neoantigen driver mutations in high-grade glioma models can be targeted with an mRNA lipid vaccine. We hope this pre-clinical work will lead to early-phase clinical trials.

A Neglected Point: Frailty in Older Adults with Differentiated Thyroid Cancer.

This study investigated the risk of frailty in older adults with differentiated thyroid cancer (DTC) and the effect of thyroid- stimulating hormone (TSH) levels on frailty. This single-center, cross-sectional study included 70 DTC patients aged ≥60 years with stable TSH levels during the previous year while receiving levothyroxine. Frailty was assessed using the fried frailty phenotype (FFP). Anterior thigh muscle thickness was measured by ultrasound, and the sonographic thigh adjustment ratio (STAR) index was calculated. Muscle strength was measured using a hand dynamometer. Physical activity was determined by the physical activity scale for the elderly (PASE). The median (interquartile range) age and follow-up time were 65 years (62 to 71) and 11 years (7.0 to 14.2), respectively. The median TSH level was 1.10 μIU/mL (0.49 to 1.62), and 58.6% of patients were prefrail/frail. Muscle mass and strength were reduced in 35.7% and 17.2% of patients, respectively. TSH levels were lower in those with prefrailty/frailty (P=0.002), low muscle mass (P=0.014), and low strength (P=0.037) than in their normal counterparts. TSH levels correlated negatively with FFP (P= 0.001) and positively with the STAR index (P=0.034). TSH below 1.325 μIU/mL was associated with an increased frailty risk (area under the curve=0.719; P=0.001). Low TSH, female sex, low handgrip strength, and low PASE leisure time scores emerged as independent predictors of frailty (P<0.05). Older adults with lower TSH levels due to DTC are at high frailty risk and have low muscle mass and strength. Therefore, TSH targets should be set based on a comprehensive evaluation with consideration of the risk-benefit ratio.

Positive association of the thigh muscle thickness to intracellular-water ratio with handgrip strength, but not with the risk of mortality in hospitalized cancer patients: a longitudinal study.

This study explored the relationship between handgrip strength, muscle thickness, and the intracellular water ratio (MT/ICW) in cancer patients. It aimed to identify a cut-off point for the MT/ICW ratio that might influence survival. Conducted as an exploratory, longitudinal study in a public hospital, it included patients from 2018 to 2022, with follow-up until August 31, 2023. The cut-off for the MT/ICW ratio was determined based on its sensitivity for mortality. Results indicated that patients with an MT/ICW ratio >0.97 had significantly lower extracellular water percentages and greater muscle thickness. A positive association was found between the MT/ICW ratio and handgrip strength, even after adjusting for age, sex, extracellular water, and body mass index. However, patients with an MT/ICW ratio ≤0.97 showed no significant mortality risk. In conclusion, MT/ICW ratio >0.97 mm/L in hospitalized cancer patients was positively associated with handgrip strength, but not risk of mortality.

Effects of Postural Conditions During Magnetic Resonance Imaging on Thigh Muscle Size.

Magnetic resonance imaging (MRI) is the gold standard for measuring muscle size. However, postural conditions for thigh musculature have not been standardized across studies, with some employing supine or prone positions and the thigh either placed on the examination table or suspended to avoid contact. In either case, the thigh is compressed or sagged by gravity, potentially affecting muscle size. This study aimed to examine the effects of postural conditions on thigh muscle size. Twenty Olympic-style weightlifters and 20 untrained controls (10 men and 10 women in each group) underwent 3-Tesla MRI in the supine and prone positions, with the thigh in compressed and suspended conditions to determine the maximal anatomical cross-sectional area (ACSAmax) and muscle volume of 15 thigh muscle groups/individual muscles. Postural conditions changed the ACSAmax of the quadriceps (range of postural-related changes: 1.0%-7.9%), hamstrings (0.8%-19.1%), and adductors (2.4%-19.2%). Regardless of measurement position, the total volume of thigh muscles decreased under compressed conditions (0.6%-3.8%). Quadriceps and adductors decreased in muscle volume under compressed conditions (0.9%-4.0% and 0.8%-6.6%), while hamstrings increased (1.4%-9.3%). Male weightlifters, who possessed the largest thigh muscle volume, showed greater postural-related changes in the muscle volume of quadriceps, hamstrings, and adductors than the other subgroups. Therefore, postural conditions during MRI substantially change thigh muscle size, and the magnitude of the change depends on muscle size. Our results provide invivo evidence of the compressive behavior of thigh muscles and a new technical perspective for assessing thigh muscle size.

Associations between skeletal muscle phenotype, positional role, and on-ice performance in elite male ice hockey players.

We evaluated associations between muscle phenotype, positional role, and on-ice performance in male U20 Danish national team ice hockey players. Sixteen players (10 forwards, six defensemen) participated in a game with activity tracking. Resting thigh muscle biopsies were analyzed for metabolic enzyme activity and protein expression linked to performance. On-ice intermittent exercise capacity, repeated sprint ability, and maximal isometric knee-extensor torque were also assessed. No significant position-specific muscle phenotype characteristics were found, but forwards generally exhibited higher levels of several membrane proteins (p = 0.100-0.991). NAKα2, NAK∑, KATP, ClC-1, and NHE1 showed significant correlations with total distance (r = 0.52-0.59, p = 0.016-0.046), however, within positions these only persisted for KATP (r = 0.70, p = 0.024) and NAKα2 (r = 0.57, p = 0.085) in forwards, where CS enzyme activity also displayed a strong association with distance covered (r = 0.75, p = 0.019). For high-intensity skating, NAKα2 (r = 0.56, p = 0.025) and KATP (r = 0.50, p = 0.048) similarly exhibited the strongest associations, persisting within forwards (r = 0.63, p = 0.052 and r = 0.72; p = 0.018, respectively). In conclusion, although several muscle proteins involved in ion and metabolic regulation were associated with performance, only NAKα2 and KATP displayed consistent relationships within positions. Moreover, CS enzyme activity was strongly related to total distance within forwards, coherent with the proposed importance of oxidative capacity in intense intermittent exercise.

Fermented By-Products of Banana Wine Production Improve Slaughter Performance, Meat Quality, and Flavor Fingerprint of Domestic Chicken.

This study aimed to compare the effects of incorporating fermented feed into daily diets on the slaughter performance, meat quality, and flavor compounds of 120 domestic chickens over a 140-day period. A total of five groups (n = 24), including the control group (CK) of the Guangxi Partridge chickens received a standard base diet. The other four groups were provided with pellets that had been added with 10% fermented banana peel (Pe-10), 20% fermented banana peel (Pe-20), 10% fermented banana pulp residue (Pu-10), and 20% fermented banana pulp residue (Pu-20). The flavor compounds in the meat samples of the chickens in these groups were determined using the gas chromatographic method. The results demonstrated that the chickens in the Pe-10, Pe-20, Pu-10, and Pu-20 groups exhibited pectoral muscle percentages, thigh muscle percentages, and total fatty acid content of chest meat that were higher than those observed in the CK group. The moisture content, meat color, carcass weight, total net weight, and abdominal fat percentage of the meat samples in these experimental groups exhibited no notable differences. The flavor compounds in the meat samples of the chickens fed with the two concentrations of fermented banana peel and banana residue were found to be significantly different from those in the control group, with p-values less than 0.05. As the quantity of fermented banana peel incorporated into the daily ration was increased from 10% to 20%, a notable alteration in the flavor compounds present in the chicken samples was observed. The chickens that were provided with fermented banana peels and pulps in their diets exhibited superior slaughter performance and meat quality, particularly in the case of the Pu-10 group, in comparison to the control chickens.

Comparing A-mode ultrasound and computed tomography for assessing cancer-related sarcopenia: A cross-sectional study.

A-mode ultrasound (US) is a potential method for directly measuring muscle thickness in patients with cancer, but its utility remains underexplored. We aimed to evaluate the feasibility of using A-mode US to assess muscle thickness, compare it with computed tomography (CT)-derived results, and assess its ability to diagnose sarcopenia. A cross-sectional analysis was conducted with hospitalized patients with cancer. Muscle cross-sectional area (CSA) was derived from CT scans. Biceps muscle thickness (BMT) and thigh muscle thickness (TMT) by A-mode US were assessed. BMT + TMT were also combined as an additional phenotype. Muscle strength was assessed using handgrip strength (HGS) test. Sarcopenia was defined as low muscle mass (CT- and US-derived) + low HGS. We included 120 patients (53.3% women, 45% older adults, and 85.8% with disease stages III-IV). TMT alone and the combined approach (BMT + TMT) were weak and positively correlated and significantly associated with muscle CSA, explaining 35% of CSA variability (R2 = 0.35). TMT individual and combined with BMT exhibited the highest accuracy for men (area under the curve >0.70). Sarcopenia diagnosed by BMT + TMT exhibited the highest frequency (34%) and moderate agreement with CT-derived sarcopenia (κ = 0.48). A-mode US has the potential to be a feasible tool for diagnosing sarcopenia in clinical practice at the bedside for patients with cancer despite the need for further improvements in the tool's accuracy. Our main findings suggest that combining measurements of BMT and TMT may enhance its clinical significance in diagnosing sarcopenia.

The acute cross-education effect of foam rolling on the thigh muscles in patients after total knee arthroplasty

IntroductionIn the early postoperative period after total knee arthroplasty (TKA), joint range of motion (ROM) limitation and increased stiffness due to pain are commonly observed. Previous studies have reported that a single bout of foam rolling (FR) can acutely increase ROM and pain threshold on the contralateral (non-intervention) side in healthy participants. In this study, we aimed to expand this knowledge for TKA rehabilitation and investigated the acute effects of FR intervention on the non-operative side on ROM, stiffness, and pain of the operative side in postoperative patients within the first week after TKA.Materials and methodsThe study employed a randomized crossover design: 20 patients (mean age 75.0 ± 7.8 years) in the first postoperative week after TKA were divided alternately into Roll_Break and Break_Roll groups in the order of prescription. In the Roll_Break group, after the initial evaluation, a 180-s (60-s × three sets) FR intervention using a roller massager by a physiotherapist for the knee extensors was performed on the contralateral side (non-operative side), followed by the measurement. Afterwards, after 180-s of supine at rest, the measurement was performed again (i.e., control phase). In the Break_Roll group, after the initial evaluation, each patient was placed in a seated resting position for 180-s, and then another measurement was performed (i.e., control phase). After this, the FR intervention was performed for 180-s, and then the measurement was performed again. The intensity of the FR intervention was set to the maximum intensity that did not cause pain. We measured pain using the visual analogue scale at rest and during the knee joint ROM measurements, knee joint active movement ROM, knee joint passive ROM, and stiffness during the knee joint active movement.ResultsAll outcome variables showed significant improvements after the FR intervention (intervention phase) when compared pre- to post-intervention, and significantly favourable effects were found compared to the control condition.ConclusionThe results showed significant improvements in ROM, pain, and stiffness of the operative side after the FR intervention on the non-operative side. For future therapy approaches for TKA patients, FR treatment of the non-operative side should be employed in the first weeks after surgery.

Evaluating Muscle Mass Changes in Critically Ill Patients: Rehabilitation Outcomes Measured by Ultrasound and Bioelectrical Impedance.

The loss of muscle mass is common in critically ill patients and is associated with poor prognosis, and efforts have been made to mitigate muscle loss through rehabilitation. This study aimed to evaluate changes in muscle mass in critically ill patients following rehabilitation. We enrolled 53 patients expected to stay in the ICU for more than 7 days, dividing them into rehabilitation (15 patients) and no rehabilitation groups (38 patients). Muscle mass was measured using ultrasound and bioelectrical impedance analysis (BIA). Baseline characteristics and comorbidities showed no statistical differences between the two groups. Initial measurements of muscles showed no significant differences between the groups in rectus femoris thickness, total anterior thigh muscle thickness, cross-sectional area, echogenicity, or in-body skeletal muscle mass at baseline and 7 days. However, at 14 days, significant differences emerged. The rehabilitation group had greater rectus femoris thickness (1.42 cm vs. 0.81 cm, p = 0.007) and total anterior thigh muscle thickness (3.79 cm vs. 2.32 cm, p = 0.007) compared to the no rehabilitation group. Additionally, the rehabilitation group experienced a significantly smaller reduction in rectus femoris cross-sectional area (-4.6% vs. -22.8%, p = 0.021). Although survival rates were higher in the rehabilitation group (73.3% vs. 52.6%), this difference was not statistically significant (p = 0.096). Our findings suggest that rehabilitation in critically ill patients is associated with a slower rate of muscle loss, particularly in the cross-sectional area of the rectus femoris muscle, which may be beneficial for patient recovery.

Molecular determinants of skeletal muscle force loss in response to 5days of dry immersion in human.

Astronauts in Earth's orbit experience microgravity, resulting in a decline of skeletal muscle mass and function. On Earth, models simulating microgravity have shown that the extent of the loss in muscle force is greater than the loss in muscle mass. The reasons behind this disproportionate loss of muscle force are still poorly understood. In the present study, we hypothesize that alongside the loss in skeletal muscle mass, modifications in the expression profile of genes encoding critical determinants of resting membrane potential, excitation-contraction coupling and Ca2+ handling contribute to the decline in skeletal muscle force. Healthy male volunteers (n=18) participated in a 5-day dry immersion (DI) study, an Earth-based model of simulated microgravity. Muscle force measurement and MRI analysis of the cross-sectional area of thigh muscles were performed before and after DI. Biopsies of the vastus lateralis skeletal muscle performed before and after DI were used for the determination Ca2+ properties of isolated muscle fibres, molecular and biochemical analyses. The extent of the decline in force, measured as maximal voluntary contraction of knee extensors (-11.1%, P<0.01) was higher than the decline in muscle mass (-2.5%, P<0.01). The decline in muscle mass was molecularly supported by a significant repression of the anabolic IGF-1/Akt/mTOR pathway (-19.9% and -40.9% in 4E-BP1 and RPS6 phosphorylation, respectively), a transcriptional downregulation of the autophagy-lysosome pathway and a downregulation in the mRNA levels of myofibrillar protein slow isoforms. At the single fibre level, biochemical and tension-pCa curve analyses showed that the loss in force was independent of fibre type (-11% and -12.3% in slow and fast fibres, respectively) and Ca2+ activation properties. Finally, we showed a significant remodelling in the expression of critical players of resting membrane potential (aquaporin 4: -24.9%, ATP1A2: +50.4%), excitation-contraction coupling (CHRNA1: +75.1%, CACNA2D1: -23.5%, JPH2: -24.2%, TRDN: -15.6%, S100A1: +27.2%), and Ca2+ handling (ATP2A2: -32.5%, CASQ1: -15%, ORAI1: -36.2%, ATP2B1: -19.1%). These findings provide evidence that a deregulation in the expression profile of critical molecular determinants of resting membrane potential, excitation-contraction coupling, and Ca2+ handling could be involved in the loss of muscle force induced by DI. They also provide the paradigm for the understanding of muscle force loss during prolonged bed rest periods as those encountered in intensive care unit.

Population pharmacokinetics of cabotegravir following intramuscular thigh injections in adults with and without HIV.

Cabotegravir intramuscular gluteal injection is approved for HIV treatment (with rilpivirine) and prevention. Thigh muscle is a potential alternative injection site. We aim to characterize cabotegravir pharmacokinetics and its association with demographics following intramuscular thigh injection in comparison with gluteal injection using population pharmacokinetic (PPK) analysis. Fourteen HIV-negative participants received 600 mg single thigh injection in phase 1 study 208832 and 118 participants with HIV received thigh injections 400 mg monthly 4× or 600 mg once-every-2-months 2× after ≥3 years of gluteal injections in phase 3b study ATLAS-2M provided 1,249 cabotegravir concentrations from 366 thigh injections and 1,998 concentrations from 1,618 gluteal injections. The established gluteal PPK model was modified by adding thigh injection compartment and fit to pharmacokinetic data following both gluteal and thigh injections, enabling within-person comparison in ATLAS-2M. Gluteal parameters were fixed. Similar to the gluteal absorption rate constant (KAgluteal), the thigh absorption rate constant (KAthigh) was slower in females than males and in participants with higher BMI. KAthigh was strongly correlated with KAgluteal (correlation coefficient 0.766), best described by the additive linear relationship KAthigh = KAgluteal + 0.0002527 h-1. Terminal half-life of thigh injection was 26% (male) and 39% (female) shorter than gluteal injection. Relative bioavailability of thigh to gluteal was estimated to be 89.9%. The impact of covariates on cabotegravir exposure following thigh injections was ≤35%. In conclusion, cabotegravir absorption following thigh injection was correlated with, faster than, and 10% less bioavailable than gluteal injection, and correlated with sex and BMI. The cabotegravir thigh PPK model can inform dosing strategies and future study design.

Blood Flow Restriction Training and Its Use in Rehabilitation After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

Background/Objectives: Anterior cruciate ligament (ACL) reconstruction (ACLR) is often followed by significant muscle atrophy and subsequent loss of strength. Blood flow restriction training (BFRT) has recently emerged as a potential mode of rehabilitation to mitigate these effects. The goal of this systematic review was to evaluate the efficacy of BFRT in functional recovery when compared to traditional rehabilitation methods. Methods: A literature review was conducted across July and August 2024 using multiple databases that reported randomised controlled trials comparing BFRT to traditional rehabilitation methods. Primary outcomes were changes to thigh muscle mass and knee extensor/flexor strength with secondary outcomes consisting of patient-reported functional measures (IKDC and Lysholm scores). The RoB-2 tool was used to assess the risk of bias. Results: Eight studies met the inclusion criteria; however, substantial heterogeneity prevented a meta-analysis being conducted for the primary outcomes. Three out of the five studies measuring muscle mass reported significant (p &lt; 0.05) findings favouring BFRT. There was variation amongst the strength improvements, but BFRT was generally favoured over the control. Meta analysis of the secondary outcomes showed significant improvements (p &lt; 0.05) favouring BFRT despite moderate heterogeneity. Conclusions: BFRT shows promise for maintaining muscle mass and improving patient reported outcomes following ACL reconstruction. However, the high risk of bias limits the strength of these conclusions. Further high-quality research needs to be conducted to establish optimal BFRT protocols for this cohort and to determine if BFRT has a place in ACL rehabilitation.

Insect Meal as a Dietary Protein Source for Pheasant Quails: Performance, Carcass Traits, Amino Acid Profile and Mineral Contents in Muscles.

The aim of the study was to determine the effects of replacing soybean meal with insect meal on the body weight and the chemical composition of selected muscle groups of common pheasant females and males, including the mineral composition and the amino acid profile of the thigh and breast muscles. The study was conducted on three feeding groups, namely one control and two experimental groups. In the control group, plant feed components were used, which are commonly used to feed pheasants in confined breeding facilities. In the experimental groups, 100 g (group II) and 200 g (group III) portions of insect meal were introduced instead of the plant-protein components. The experiment used a preparation of insect larvae (Hermetia illucens) containing approximately 52% crude protein. The pheasant diet supplementation applied contributed to an increase in the proportion of muscles in the carcasses, with the highest effectiveness obtained for a 20% addition of insect meal. Lower and significant differences were noted in the feed conversion by birds from the experimental groups, as compared to the control group. The chemical composition of the birds' muscles also changed. The experimental groups exhibited higher protein and fat contents and a lower water content. No significant changes in the amino acid profile or the mineral composition of the muscles were noted. The few exceptions concerned the methionine levels in both muscle groups and the isoleucine levels in the breast muscles. In most cases, the mineral composition did not vary significantly (p < 0.05). When supplementing the diet of breeding pheasants for improving meatiness, a 20% addition of insect meal is recommended, which affects the production effect of this trait while reducing feed consumption and maintaining the fatty acid profile.