Search PubMedSearch

SEARCH · Search PubMed

Results for “muscle damage”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

199 records · Page 3Linked to original sources

Effects of faba bean-based crisping culture on phenotypic characteristics, muscle quality, and serum metabolome in Nile tilapia: Screening biomarkers to assess the degree of crisping.

Feeding Nile tilapia (Oreochromis niloticus) a faba bean-based crisping diet enhances muscle hardness (crispness) and overall flesh quality. However, the underlying mechanisms and reliable biomarkers remain insufficiently defined. This study integrated phenotypic traits, muscle texture, collagen content, serum antioxidant enzyme activities (SOD, CAT, and GSH-Px), MDA levels, and serum metabolomics to understand the determinants of muscle crisping. Fish were assigned to a crisping diet or a control group for 90&#xa0;days. Individuals in the crisping group were implanted with passive integrated transponder (PIT) tags to enable correlation analyses among phenotypic traits (body weight/length/frame changes), serum indicators (NAM, FAD, and GSH-Px) and muscle hardness. Compared with controls, the crisping diet significantly increased muscle hardness, gumminess, and chewiness, accompanied by elevated collagen content. Antioxidant profiles were altered, with higher activities of serum SOD and CAT, together with elevated MDA levels and reduced GSH-Px activity (P&#xa0;<&#xa0;0.05). Metabolomic analysis identified 830 differential metabolites (682 upregulated and 148 downregulated), predominantly comprising carboxylic acids and derivatives, glycerophospholipids, and benzene derivatives. Enrichment analysis indicated significant involvement in general metabolic pathways, ATP-binding cassette (ABC) transporters, amino acid biosynthesis, and glycine, serine, and threonine metabolism (P&#xa0;<&#xa0;0.05). Notably, acetylpyruvate was upregulated in glutathione metabolism, nicotinate and nicotinamide metabolism, and galactose metabolism; pantothenic acid was upregulated in glycine, serine, and threonine metabolism; whereas &#x3b4;-tocotrienol was downregulated. Correlation analysis revealed weak negative associations between muscle hardness and phenotypic traits (body weight/length/frame changes D5-7, D5-10, D7-8) (P&#xa0;<&#xa0;0.05). In contrast, serum NAM and FAD were weakly positively correlated with muscle hardness, whereas GSH-Px showed a weak negative correlation (P&#xa0;<&#xa0;0.05). Collectively, these findings suggest that body weight, body length, frame measurements (D5-7, D5-10, and D7-8), and serum NAM, FAD, and GSH-Px are associated with the degree of muscle crispness in Nile tilapia fed a faba bean-based crisping diet and may serve as candidate biomarkers under these culture conditions.

Animals

Compound muscle action potential amplitudes in newborn screen positive spinal muscular atrophy.

OBJECTIVE: To evaluate the utility of compound muscle action potential (CMAP) amplitudes as biomarkers of disease severity in newborn screening (NBS)-positive infants with spinal muscular atrophy (SMA). METHODS: We conducted a retrospective review of 21 infants identified through SMA NBS (11 with 2 SMN2 copies and 10 with 3 SMN2 copies). Baseline and serial right median, ulnar, and fibular motor nerve CMAP amplitudes (millivolts, mV) were obtained during the study. Functional outcomes were assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND). RESULTS: At baseline, infants with 2 SMN2 copies demonstrated significantly lower median, ulnar, and fibular CMAP amplitudes compared with infants with 3 SMN2 copies (p&#xa0;<&#xa0;0.05). In contrast, baseline CHOP-INTEND scores did not differ significantly between the two groups. Prior to genetic confirmation, a right median CMAP amplitude&#xa0;&#x2265;3.2&#xa0;mV predicted&#xa0;&#x2265;3 SMN2 copies. Following treatment, right median and fibular CMAP amplitudes demonstrated significant improvement over time, including in analyses accounting for SMN2 copies number. CONCLUSION: CMAP amplitudes obtained from multiple upper- and lower-extremity motor nerves provided objective electrophysiological measures that distinguished infants with two versus three SMN2 copies, despite similar baseline CHOP-INTEND scores. Furthermore, CMAP abnormalities were detectable in some cases before confirmatory genetic testing results became available. Serial CMAP measurements demonstrated significant longitudinal changes following treatment, whereas functional assessments approached ceiling values, supporting the potential value of electrophysiological monitoring in the era of disease-modifying therapies. SIGNIFICANCE: CMAP assessment is a useful adjunct in the evaluation of infants identified through SMA NBS.

Humans

The impact of acute sleep fragmentation on muscle blood flow responses to handgrip exercise.

Sleep fragmentation is reported to impair resting vascular function. The aim of this study was to test the hypothesis that acute sleep fragmentation would impair muscle blood flow during exercise. Twenty adults (10 females and 10 males) participated in a randomized crossover study that included one night of habitual sleep and one night of fragmented sleep. Sleep was assessed at home using wrist actigraphy. Arousals from sleep were increased by an audio alarm sounding every 30 min. The morning following each sleep condition, participants performed single handgrip contractions and rhythmic handgrip exercise at 15%, 30%, and 45% MVC. Forearm blood flow (FBF) was measured using Doppler ultrasound. Nightly awakenings and wake after sleep onset significantly increased by 18% and 43%, respectively, after fragmented sleep, leading to lower sleep duration (P < 0.001). Peak FBF and total hyperemic responses following single contractions were similar between sleep conditions (all P > 0.05). During rhythmic handgrip exercise, brachial artery dilation was reduced after fragmented sleep (main effect: 5.5 &#xb1; 4.8 vs. 3.3 &#xb1; 3.7%; P = 0.01), leading to a lower FBF response to rhythmic exercise (main effect: 122 &#xb1; 58 vs. 110 &#xb1; 56 mL/min; P = 0.04). Endothelial sensitivity to shear rate was similar between sleep conditions (habitual vs. fragmented: 0.039 &#xb1; 0.024 vs. 0.042 &#xb1; 0.031%/s-1; P = 0.77). In summary, acute sleep fragmentation decreases skeletal muscle blood flow during exercise. This finding suggests that blunted oxygen delivery may be a contributing factor for exercise performance deficits after disturbed sleep.NEW & NOTEWORTHY We demonstrate that one night of fragmented sleep decreases steady-state blood flow and vascular conductance during low- to moderate-intensity handgrip exercise. This impairment was not due to an impaired rapid vasodilation to single contractions nor altered endothelial sensitivity to shear rate as these variables were unchanged after acute sleep fragmentation. These results reveal a negative impact of disrupted sleep on the steady-state muscle vasodilatory response to rhythmic contractions.

Humans

Effects of blood flow restriction training combined with plyometric training on lower limb muscle strength and motor unit recruitment in basketball players: An experimental study.

OBJECTIVE: Previous studies have shown that plyometric training (PT) improves neuromuscular function and explosive power but not maximal strength. Blood flow restriction training (BFR) combined with low-intensity resistance training (RT) increases muscle mass and strength. This study investigated the effects of PT, and BFR combined with PT on lower-limb muscle function. METHODS: Twenty elite basketball players were randomly assigned to two groups: PT-alone group (PT, n&#x202f;=&#x202f;10) and BFR combine with PT group (PT-BFR, n&#x202f;=&#x202f;10). All participants underwent bodyweight-based plyometric training three times per week for eight weeks. Peak torque values for hip and knee flexion and extension, as well as root mean square (RMS) values derived from electromyography, were measured before and after the intervention. RESULTS: After the 8-week intervention, both groups showed significant improvements in knee flexion and extension peak torque at 180&#xb0;/s (all p&#x202f;<&#x202f;0.01). Between-group comparisons revealed greater gains in the PT-BFR group for hip extension and flexion at 60&#xb0;/s (p&#x202f;=&#x202f;0.036-0.002; &#x3b7;p2 = 0.225-0.233). RMS of the rectus femoris increased significantly more in the PT-BFR group than in the PT group (right: p&#x2009;=&#x2009;0.004, &#x3b7;p2 = 0.385; left: p&#x2009;=&#x2009;0.020, &#x3b7;p2 = 0.266), whereas no significant changes were observed in the gastrocnemius, tibialis anterior, or biceps femoris (all p&#x2009;>&#x2009;0.05). CMJ height also improved more in the PT-BFR group, with a significant group &#xd7;&#x2009;time interaction (p&#x2009;=&#x2009;0.042, &#x3b7;p2 = 0.210). CONCLUSION: Both training protocols enhanced bilateral lower-limb strength, with notable gains in the non-dominant leg; however, the magnitude did not differ substantially between groups. In contrast, compared with PT alone, BFR combined with PT produced superior enhancements in lower-limb muscle strength and neuromuscular recruitment. These findings suggest that when PT is employed to improve explosive power, it may be effectively combined with BFR to further augment muscular strength.

Humans

Effects of blood flow restriction training combined with resistance training on lower-limb strength and sport-specific performance in athletes: a systematic review and meta-analysis.

BACKGROUND: In contemporary sports science, athletes and coaches continuously explore strategies to reduce training load and injury risk while increasing muscular strength and sport-specific performance. This meta-analysis evaluated the effects of blood flow restriction training (BFRT) combined with resistance training (RT) on lower-limb muscle strength and sport-specific performance in athletes. METHODS: Relevant randomized controlled trials (RCTs) were systematically searched across major databases (e.g. PubMed, Web of Science, Cochrane, CNKI, Wanfang Data, and Embase) from inception until November 2024. Two independent reviewers carefully assessed the studies. Data analysis was carried out using RevMan 5.4 software, which included heterogeneity testing, meta-analysis, subgroup analysis, and assessment of publication bias. RESULTS: Ten RCTs (181 athletes; 91 in the BFRT and RT group, 90 in the control group) were included. Outcomes determined BFRT combined with RT yielded notable enhancements in lower-limb muscle strength (SMD = 1.09, 95% CI [0.52, 1.66], p&#x2009;<&#x2009;0.05) and muscle hypertrophy (MD = 1.09, 95% CI [0.10, 2.09], p&#x2009;<&#x2009;0.05) compared to control training. However, no significant improvement in sport-specific performance was found (SMD = 0.11, 95% CI [-0.18, 0.40], p&#x2009;=&#x2009;0.46). Substantial heterogeneity was observed for strength outcomes (I2 = 75%), whereas low heterogeneity was observed for sport-specific performance and hypertrophy outcomes (I2 = 0%). No evidence of significant publication bias was detected. CONCLUSION: BFRT combined with RT appears to provide effective augmentation of lower-limb muscle strength and hypertrophy in athletes compared to RT or conventional training alone. It may be prudent to integrate this approach systematically into training cycles to optimize physiological muscle stimulation and training outcomes, despite not directly improving sport-specific performance.

Humans

Intravesical mitomycin-C administered immediately before transurethral resection of bladder tumor in non-muscle-invasive bladder cancer: Clinical outcomes and molecular predictors from over 3 years of extended follow-up in a phase II trial.

PURPOSE: To evaluate the long-term outcomes and molecular correlates of response after immediate preoperative intravesical chemotherapy (IPeIC) with mitomycin-C (MMC) in patients with non-muscle-invasive bladder cancer (NMIBC). MATERIALS AND METHODS: In this single-center, open-label, randomized phase II trial, 33 patients received two split doses of IPeIC/MMC (40 mg/20 mL), whereas 38 patients underwent transurethral resection of bladder tumor (TURBT) alone. The primary endpoint was 3-year recurrence-free survival (RFS), and secondary endpoints included progression-free survival (PFS). Exploratory RNA sequencing was performed on IPeIC-treated patients (three with recurrence, 25 without) using a Monte Carlo-based resampling strategy. RESULTS: The median follow-up durations were comparable between the intervention (60.0 months) and control arms (60.4 months). IPeIC/MMC reduced recurrence risk by 76.8% versus TURBT alone (p=0.024), yielding a 3-year RFS rate of 90.7% versus 78.6%. On multivariable analysis, IPeIC/MMC independently improved RFS (hazard ratio [HR] 0.266, p=0.044). IPeIC was associated with superior PFS, with 3-year and 5-year rates of 100% versus 92.1% and 85.8%, respectively, in the controls (HR 0.078, p=0.014). Exploratory transcriptomics identified low Glutathione S-transferase Mu 1 (GSTM1) expression as the factor most strongly associated with recurrence. CONCLUSIONS: IPeIC/MMC is associated with improved long-term oncological outcomes compared with TURBT alone and represents a safe prophylactic option for patients with NMIBC who are unable to receive standard immediate postoperative intravesical chemotherapy because of safety concerns or practical constraints. The GSTM1 findings are hypothesis-generating and support future biomarker-driven validation studies.

Aged

Responsiveness of muscle mass gain to different load intensities of resistance training in older women: A randomized crossover study.

BACKGROUND: Aging is associated with progressive declines in skeletal muscle mass (SMM) and substantial interindividual variability in adaptations to resistance training (RT). However, whether training load intensity influences hypertrophic responsiveness in older adults remains unclear. OBJECTIVE: To investigate the effects of two commonly prescribed RT loading schemes (15RM and 10RM) on estimated SMM adaptations and responsiveness in older women. METHODS: Twenty-seven older women (67.7&#xa0;&#xb1;&#xa0;4.9&#xa0;years; 65.7&#xa0;&#xb1;&#xa0;10.6&#xa0;kg; 154.5&#xa0;&#xb1;&#xa0;5.8&#xa0;cm) completed two 8-week RT interventions performed at 15RM and 10RM in a randomized crossover design, separated by a 12-week detraining period. Estimated SMM was assessed using dual-energy X-ray absorptiometry. Responsiveness was operationally defined using the standard error of measurement, and participants were classified as responders (RP) or non-responders (N-RP) according to changes in estimated SMM. RESULTS: Both loading schemes promoted significant and comparable increases in estimated SMM (15RM: +0.62&#xa0;&#xb1;&#xa0;0.4&#xa0;kg vs. 10RM: +0.43&#xa0;&#xb1;&#xa0;0.3&#xa0;kg). Overall, 61.1% of participants were classified as responders in at least one condition, whereas 38.9% were classified as non-responders. Responsiveness status was consistent across conditions for most participants, with 48.1% classified as responders under both loading schemes and 25.9% as non-responders under both conditions. Only seven participants (25.9%) changed responsiveness status between interventions. No clear pattern indicated a greater likelihood of responsiveness with either loading scheme. CONCLUSIONS: Results suggest that both the 10RM and 15RM RT protocols significantly increase estimated SMM in older women, with no significant differences between training conditions. Although substantial interindividual variability in adaptive responses exists, training load intensity does not appear to meaningfully influence responsiveness status in most individuals. These findings suggest that both loading schemes can be effectively prescribed to promote SMM gains in older women.

Aged

Intramuscular Fat Infiltration and Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

BACKGROUND: Intramuscular fat infiltration (IMFI) is considered to be closely associated with knee osteoarthritis (KOA); however, its overall association, muscle-specific involvement, and clinical relevance remain unclear. OBJECTIVE: To quantify the association between IMFI and KOA, identify affected muscle groups, and evaluate prognostic value. METHODS: We searched PubMed, Web of Science, Scopus, and Embase up to December 2025 for observational studies. Two reviewers independently screened, extracted data, and assessed bias (NOS/JBI). Pooled standardized mean differences (SMDs) were calculated using random-effects models, with subgroup and sensitivity analyses. RESULTS: Seventeen studies were included. IMFI was significantly higher in KOA patients than controls (SMD&#xa0;=&#xa0;0.63, 95% CI 0.41-0.85, I2&#xa0;=&#xa0;84.7%). Anatomically, the anterior thigh muscles (rectus femoris, vastus lateralis, vastus medialis) demonstrated a significant pooled effect (SMD&#xa0;=&#xa0;0.96, 95% CI 0.66-1.25, I2&#xa0;=&#xa0;3.2%) and showed the strongest pooled association, whereas posterior, medial, and composite measures did not demonstrate significant associations. At the individual muscle level, a single study reported a notable association for the semimembranosus (SMD&#xa0;=&#xa0;1.25, 95% CI 0.57-1.93); however, this finding is based on limited evidence and requires confirmation in future studies. Subgroup by imaging modality: CT demonstrated a significant association (SMD&#xa0;=&#xa0;0.59, 95% CI 0.28-0.90), while MRI and ultrasound did not show significant associations. Elevated IMFI was also associated with reduced muscle strength, higher KOA incidence, structural progression, and increased knee replacement risk. CONCLUSION: A moderate positive association exists between IMFI and KOA, with notable muscle-specific heterogeneity. Anterior thigh muscles show the strongest pooled association, whereas individual muscle findings require further confirmation. These findings suggest that IMFI may represent a promising potential marker warranting further prospective investigation for risk stratification, though causality and its role in modifying disease progression remain to be established.

Humans

Application of 13C MRS demonstrates carbohydrate feeding spares muscle but not liver glycogen utilization during high-intensity interval exercise.

We examined liver and muscle glycogen utilization during high-intensity interval cycling, and the impact of carbohydrate (CHO) feeding, using noninvasive 13C magnetic resonance spectroscopy (MRS). Following 24 h of standardized dietary intake, nine male cyclists completed 8 &#xd7; 5-min intervals (1-min recovery), ingesting either placebo (PLA), 60 g maltodextrin (CHO), or 60 g maltodextrin plus caffeine, taurine, l-theanine, l-citrulline, and citicoline (CHO+) in a randomized crossover design. 13C MRS and 1H imaging were performed pre- and postexercise to determine liver and muscle glycogen and liver volume, respectively. Liver glycogen utilization was not significantly different between trials (P = 0.101) despite lower postexercise plasma glucagon concentrations in CHO and CHO+ (P = 0.001). In contrast, muscle glycogen utilization was significantly lower (&#x223c;40%) with CHO feeding compared with PLA (P = 0.006), yet this sparing effect was not evident with CHO+ (P = 0.073) in accordance with a higher mean power output during the late intervals (+2.8%, P = 0.046). Plasma glucose was comparable between trials (P = 0.175), whereas plasma lactate was higher in CHO+ versus CHO (P = 0.003), alongside lower blood bicarbonate (P = 0.005), base excess (P < 0.001), and total CO2 (P = 0.004). These findings demonstrate preferential use of skeletal muscle glycogen during high-intensity interval training (HIIT), which is attenuated under conditions of CHO feeding. This sparing effect is, however, not evident with the coingestion of a caffeine-containing multi-ingredient blend, potentially due to an increased capacity to sustain higher power outputs resulting in greater glycogen utilization.NEW & NOTEWORTHY Using 13C MRS, we provide data demonstrating preferential use of skeletal muscle glycogen during HIIT. Furthermore, data show muscle glycogen utilization is attenuated with CHO feeding, yet sparing is not evident when coingesting a caffeine-containing formulation, potentially reflecting increased capacity to perform more total work rather than a direct metabolic effect of caffeine. In contrast, liver glycogen utilization was not significantly different with CHO feeding despite a modest reduction of &#x223c;5 g versus placebo.

Male

Hydroxyl Radical Inactivation of Vesicle-Cloaked and Free Murine Norovirus: Linking Biomolecular Oxidation to Lifecycle Disruption and Infectivity Loss.

Hydroxyl radicals (&#x2022;OH) play a central role in inactivating human viruses during advanced oxidation processes for water and wastewater treatment, solar disinfection, and natural attenuation in sunlit aquatic environments. Human norovirus, a leading cause of gastroenteritis, is efficiently transmitted through water and exhibits strong environmental persistence. The recent discovery of vesicle-cloaked virus clusters (viral vesicles) further challenges water treatment and reuse, particularly for norovirus elimination. We investigated &#x2022;OH inactivation kinetics and mechanisms of murine norovirus 1 (MNV-1), a human norovirus surrogate, in free-virus and vesicle-cloaked forms. &#x2022;OH rapidly inactivated both MNV-1 vesicles and free MNV-1 with second rate constants of &#x223c;1010 M-1 s-1; however, the vesicle membrane provided a 2.24-fold protective effect to cloaked MNV-1, resulting in slower inactivation kinetics than those of free MNV-1. &#x2022;OH oxidized viral capsid proteins and genomes together with vesicle proteins and lipids, resulting in impaired CD300lf receptor and cell-based binding, disrupted genome replication, and diminished viral assembly. Despite these biochemical and functional impairments, most vesicle structures remained largely intact following &#x2022;OH exposure. This study establishes a quantitative framework linking biomolecular damage to viral infectivity loss through functional impairment and lifecycle disruption, providing mechanistic insights into advance water disinfection strategies and public health protection.

Norovirus

Effect of knee and hip joint positions on passive stiffness of the rectus femoris and vastus lateralis in healthy individuals.

Passive muscle stiffness is a key determinant of musculoskeletal function and is influenced by structural components such as titin, connective tissue, and fascia. However, the effects of joint position, muscle depth, and sex on quadriceps passive stiffness remain unclear. To investigate the passive stiffness of the rectus femoris (RF) and vastus lateralis (VL) under different joint configurations, muscle depths, and between sexes using shear wave elastography (SWE). Thirty-six healthy young adults (18 men and 18 women) participated in this randomized crossover study. Passive stiffness was assessed in four positions of knee flexion: supine with 60&#xb0; (SUP60), supine with 20&#xb0; (SUP20), sitting with 60&#xb0; (SIT60), and sitting with 20&#xb0; (SIT20). SWE measurements (m/s) were obtained from 30 regions of interest (ROIs) per muscle, categorized into superficial, intermediate, and deep levels. Data were analyzed using Generalized Estimating Equations (GEE). A significant effect of position was observed, with higher stiffness values in the SUP60 condition for both RF and VL (p&#x2009;<&#x2009;0.001). Superficial regions consistently exhibited greater stiffness compared to intermediate and deep regions across all positions (p&#x2009;<&#x2009;0.001). Additionally, men demonstrated significantly higher stiffness values than women (p&#x2009;<&#x2009;0.001). Significant interactions were found between position and muscle, as well as position and depth. Quadriceps passive stiffness is influenced by joint position, muscle depth, and sex. The SUP60 position elicits the highest stiffness, while superficial muscle regions are consistently stiffer. These findings highlight the non-uniform mechanical behavior of the quadriceps and may have implications for clinical assessment, rehabilitation, and exercise prescription. Clinical trial registration: This study was registered at Clinicaltrials.gov in June 06th, 2023. Register number NCT05905406. Link to access https//clinicaltrials.gov/study/NCT05905406.

Humans

Comparing the Effects of Push and Hold Isometric Training on Strength and Musculotendinous Adaptations: A Within-Subject Randomized Controlled Trial.

Lum, D, Oranchuk, DJ, Chen, SE, and Kong, PW. Comparing the effects of push and hold isometric training on strength and musculotendinous adaptations: A within-subject randomized controlled trial. J Strength Cond Res 40(9): 1050-1058, 2026-Despite recent interest in delineating pushing (PIMA) and holding (HIMA) isometric muscle actions, training-induced adaptations have not been examined. As such, we compared the strength and morphological adaptations between PIMA and HIMA training. Twenty limbs across 10 adults (5 men, 5 women, age: 31.4 &#xb1; 6.5 years) were randomly assigned to PIMA or HIMA conditions and underwent 12 training sessions over 6 weeks. PIMA required subjects to exert force against a fixed lever while the HIMA limb maintained a set joint angle while resisting an isotonic lever. During each contraction, subjects had to exert force at 70% of maximal voluntary contraction for 20 seconds at an 80&#xb0; knee angle, for 4-6 repetitions. Subjects completed isometric, concentric, and eccentric knee extension assessments for both limbs before and after the intervention. Pre- and postintervention ultrasound scans were performed to determine quadriceps muscle architecture and patellar tendon thickness. Increased isometric torque was found following both conditions (p < 0.05, g = 0.30-0.36), while concentric (p < 0.05, g = 0.31) and eccentric (p < 0.01, g = 0.50) torque only increased following PIMA. Both conditions increased muscle thickness (p < 0.05, g = 0.27-0.88) and vastus lateralis fascicle length (p < 0.05, g = 0.20-0.31). Only HIMA increased patellar tendon thickness (p < 0.05, g = 0.12). The increase in total quadriceps (p < 0.05, g = 0.46) and especially rectus femoris (p < 0.05, g = 1.44) thickness was greater in HIMA. The results suggest that PIMA may be more effective at improving strength, while HIMA may be superior for inducing morphological adaptations. Larger sample sizes and more ecologically valid training programs are warranted to further elucidate potential differences between different isometric types.

Humans

Lower-limb electromyographic responses across four recumbent cycling configurations in healthy young men.

Recumbent cycling provides an adjustable configuration in which backrest angle and crank-axis height can alter lower-limb loading. Backrest angle changes the orientation of the active musculature relative to gravity, whereas crank-axis height modifies the foot-pedal interface and the ankle lever arm. Whether such positioning is associated with differences in lower-limb electromyographic (EMG) activation across both factors together has not been examined. Using a randomized crossover design, fifty-nine healthy young men cycled at 100&#xa0;W and 50&#xa0;rpm under four conditions combining two backrest angles (30&#xb0;, 75&#xb0;) and two crank-axis heights (Rh, high, 77&#xa0;cm; Rl, low, 45&#xa0;cm). Surface EMG from the rectus femoris (RF), biceps femoris (BF), and gastrocnemius medialis (GAS) was analyzed for root mean square (RMS) amplitude, absolute onset sequence, and relative recruitment timing (%Sequence, derived using Telescan software and referenced to RF). RMS amplitude did not differ across conditions for any muscle (all p&#xa0;&#x2265;&#xa0;0.356), and absolute onset sequence showed no condition effect (all p&#xa0;&#x2265;&#xa0;0.197). For GAS %Sequence, the Greenhouse-Geisser-corrected omnibus test was significant (F(1.32, 76.56)&#xa0;=&#xa0;28.45, p&#xa0;<&#xa0;0.001), driven by a within-30&#xb0; contrast in which %Sequence was lower under Rl than Rh (paired t(58)&#xa0;=&#xa0;10.39, Holm-adjusted p&#xa0;<&#xa0;0.0001; mean difference 22.0 percentage points, 95&#xa0;% CI [17.8, 26.3]; dz&#xa0;=&#xa0;1.35). Because %Sequence is referenced to RF, this exploratory shift should be interpreted cautiously. Lower-limb activation may be constrained by the closed-chain nature of pedaling, whereas distal recruitment timing may be sensitive to crank-axis height and the foot-pedal interface.

Humans

Efficacy of a multimodal conservative rehabilitation program for bladder control in individuals with incomplete spinal cord injury: A randomized controlled trial.

ObjectiveThe study aimed to evaluate the efficacy of a multimodal intervention on urodynamic outcomes, urinary incontinence severity, and pelvic floor muscle strength in individuals with overactive bladder after incomplete spinal cord injury.MethodsA single-blind randomized controlled trial was conducted on 74 male participants diagnosed with overactive bladder and incomplete spinal cord injury. Participants were randomly assigned to an experimental group or a control group. Treatment was conducted for 8 weeks, three sessions per week. Outcomes were assessed at baseline, post-intervention, and the 8-week follow-up.ResultsThe experimental group showed significantly greater improvements in the measured outcomes compared with the control group (P&#x2009;<&#x2009;0.001).ConclusionIncorporating a multimodal regimen demonstrated significant efficacy in enhancing bladder capacity, continence, and muscle function in individuals with overactive bladder due to incomplete spinal cord injury.Clinical trial registry (ID: NCT07008157).https://clinicaltrials.gov/study/NCT07008157?cond=Spinal%20Cord%20Injuries&intr=Multimodal%20Rehabilitation%20Program&viewType=Card&rank=1.

Humans

Effects of free-weight resistance training based on hexagonal barbell deadlift in older women: A 24-week randomized controlled trial.

PURPOSE: This randomized controlled trial examined effects of a 24-week hexagonal barbell deadlift (HBDL)-based free-weight resistance training program on body composition, trunk muscle function, and functional performance in older women. METHODS: Thirty-two women (67.6&#xa0;&#xb1;&#xa0;6.3&#xa0;years) were randomly assigned to an HBDL group (DG, n&#xa0;=&#xa0;16) or control group (CG, n&#xa0;=&#xa0;16). DG trained twice weekly for 24&#xa0;weeks under supervision. Primary outcomes were body composition and isokinetic trunk peak torque and average power at 60&#xb0;/s and 120&#xb0;/s. Secondary outcomes were isokinetic knee function, mobility, and maximal isotonic strength. Between-group differences after the intervention were examined by analysis of covariance (&#x3b1;&#xa0;=&#xa0;0.05). RESULTS: After intervention, DG showed greater trunk lean mass (+0.4&#xa0;kg vs. -0.2&#xa0;kg, p&#xa0;=&#xa0;0.006) than CG, and reductions in body fat percentage (-1.4% vs. +0.3%, p&#xa0;=&#xa0;0.003), total fat mass (-1.1&#xa0;kg vs. +0.3&#xa0;kg, p&#xa0;=&#xa0;0.013), and regional fat mass (trunk, gluteal, thigh; all p&#xa0;<&#xa0;0.05). Trunk extensor peak torque at 60&#xb0;/s (+26.0% vs. -6.3%, p&#xa0;<&#xa0;0.001) and average power at 60&#xb0;/s (+38.1% vs. -7.6%, p&#xa0;<&#xa0;0.001) and 120&#xb0;/s (+33.2% vs. +0.1%, p&#xa0;=&#xa0;0.002) improved significantly. DG also showed better eyes-closed static balance and 6-min walk performance (both p&#xa0;<&#xa0;0.05). Whole-body lean mass and lower-limb isokinetic strength did not differ between groups. Attendance was 89.6% with no adverse events. CONCLUSION: HBDL-based free-weight resistance training is a safe, feasible, and effective strategy to improve body composition, trunk extensor function, and mobility in older women.

Humans

Deciphering S-nitrosylation-regulated metabolic networks in postmortem beef based on label-free modificomics: Identification of ferroptosis as a novel quality-related pathway.

This study elucidated the molecular mechanisms of S-nitrosylation on postmortem beef metabolism and quality based on the label-free modificomics. Varying degrees of S-nitrosylation were exogenously induced in beef semimembranosus (SM) muscle. Results indicated that a high S-nitrosylation level significantly increased beef pH and Warner-Bratzler shear force (WBSF) while reducing centrifugal loss (P&#xa0;<&#xa0;0.05). A total of 828&#xa0;S-nitrosylated proteins and 1458 modification sites were identified, of which 114 sites on 81 proteins (DSNPs) exhibited differential modification abundance, representing an increase of 125% compared with previous proteomics studies. DSNPs were mainly involved in glycolysis, the tricarboxylic acid cycle, oxidative phosphorylation, calcium signaling, cell structure, and ferroptosis. Notably, this study provides the first evidence in postmortem muscle that S-nitrosylation regulates key ferroptosis-related proteins, including ACSL, CP, and TF, offering new insights into the link between S-nitrosylation and the ferroptosis pathway in meat. Correlation analysis demonstrated that TF was significantly negatively correlated with pH and WBSF, but positively correlated with centrifugal loss (P&#xa0;<&#xa0;0.05). Collectively, protein S-nitrosylation critically modulates postmortem beef quality through the coordinated regulation of multiple metabolic processes. More importantly, the identification of ferroptosis as a S-nitrosylation-sensitive pathway provides a new perspective for regulating meat quality through protein post-translational modifications.

Animals

Developmental roles of LSD1/KDM1A-like (LDL) proteins in plants.

LYSINE-SPECIFIC DEMETHYLASE 1-like (LDL) proteins are conserved FAD-dependent amine oxidases that serve as pivotal regulators in plants. While animal systems typically rely on a single LSD1/KDM1A enzyme, the Arabidopsis thaliana genome encodes an expanded family of LDL homologues (FLD, LDL1, LDL2, and LDL3), resulting in substantial subfunctionalization and specialized recruitment mechanisms. This review explores the diverse developmental roles of plant LDLs, ranging from flowering time and circadian clock regulation to heterochromatin maintenance and epigenetic regulation. We discuss the redundant roles of FLD, LDL1, and LDL2 in repressing the floral repressor FLC and their nonredundant specialized function within the CCA1/LHY-TOC1 circadian feedback loop. A central focus of our review is the emerging mechanism of transcription-coupled demethylation, in which LDLs associate with the phosphorylated C-terminal domain of RNA polymerase II to modify chromatin cotranscriptionally within gene bodies. By integrating findings from Arabidopsis thaliana and crops such as tomato and soybean, we illustrate how the diversified LDL-mediated regulatory toolkit facilitates precise, gene-specific regulation. Ultimately, the LDL family represents a cornerstone of the sophisticated epigenetic strategies that regulate plant phenotypic plasticity in response to developmental and environmental cues.

Circadian clock

A system-level metastable model of cancer evolution: integrating replication stress, cell cycle deregulation and chromosomal instability.

INTRODUCTION: Cancer cell proliferation occurs within the context of persistent genomic instability. In this review, we propose the RS-CCD-CIN axis as a systems-level framework in which replication stress (RS), cell cycle deregulation (CCD) and chromosomal instability (CIN) form an interdependent triad that shapes tumour evolution. This axis represents a constrained metastable state in which genomic instability is tolerated and buffered. The objective of this review is to synthesize the current understanding of how the RS-CCD-CIN axis contributes to tumour heterogeneity, adaptability and therapy response. DISCUSSION: Evidence indicates that RS, CCD and CIN operate as a dynamic, interconnected network rather than as independent processes. Replication stress induces DNA damage and mutagenesis, while partial checkpoint disruption permits cells with unresolved lesions to proliferate. Chromosomal instability generates both structural and numerical alterations, contributing to intratumoural heterogeneity. Together, these processes facilitate adaptation to environmental and therapeutic pressures. Extrachromosomal DNA, micronuclei formation and cytosolic DNA signalling, including the cGAS-STING pathway, connect genomic instability to adaptive responses and immune modulation. Single-cell and spatial profiling reveal temporal and spatial variability in RS, CCD and CIN states, highlighting the limitations of static biomarkers. Therapeutically, targeting individual components often yields limited durability, whereas approaches that simultaneously perturb multiple aspects of the RS-CCD-CIN axis may improve clinical outcomes. CONCLUSIONS: This review highlights the RS-CCD-CIN axis as a fragile and metastable architecture that supports cancer evolution, while also being susceptible to collapse. A deeper understanding of this interconnected framework may inform the development of therapeutic strategies and enhance the management of resistance.

Humans