Developmental Dynamics of the Larval Muscle System of Bay Scallop(Argopecten irradians)

Though the larval development of bivalves has been extensively studied for commercial purposes,the dynamic development of larval muscle system remains largely unknown.In this study,we characterized the larval muscle system at different developmental stages(D-shaped veligers,umbo veligers and spats)in the bay scallop(Argopecten irradians)by phalloidin staining and under a confocal microscopy.The functional muscles are initially established at the early stage of veligers,which have four pairs of velar retractors and one anterior adductor.At the veliger stage,the velum and posterior retractor muscles are functionally important for velar contractility but undergo an irreversible shrink until they disappear at the end of the larval stage.During metamorphosis,three crucial modifications take place in the larval muscle system.The metamorphosis process involves the gradual degeneration of velum retractors,mantle margin development from an unfolded to a three-fold state,and remodeling of the adductor muscle system from dimyarian(two adductors)to monomyarian condition(one adductor)as in juveniles/adults.All retractor muscles are composed of striated muscle,but both anterior and posterior adductors have smooth and striated components.These findings highlight that the morphological changes at different stages are typical features of myogenesis in scallops.The present knowledge on the developmental dynamics of myogenesis in the bay scallop will not only improve our understanding of phenotypic diversity of larval myoanatomy in bivalves,but also provide useful information on the larval culture in hatcheries.

NONLINEAR MODELING AND CONTROLLING OF ARTIFICIAL MUSCLE SYSTEM USING NEURAL NETWORKS

The pneumatic artificial muscles are widely used in the fields of medicalrobots, etc. Neural networks are applied to modeling and controlling of artificial muscle system. Asingle-joint artificial muscle test system is designed. The recursive prediction error (RPE)algorithm which yields faster convergence than back propagation (BP) algorithm is applied to trainthe neural networks. The realization of RPE algorithm is given. The difference of modeling ofartificial muscles using neural networks with different input nodes and different hidden layer nodesis discussed. On this basis the nonlinear control scheme using neural networks for artificialmuscle system has been introduced. The experimental results show that the nonlinear control schemeyields faster response and higher control accuracy than the traditional linear control scheme.

Precise Positioning of Pneumatic Artificial Muscle Systems

Pneumatic artificial muscles (PAMs) currently possess a high power-to-weight ratio, a high power-to-volume ratio, and a high degree of safety. They have therefore been applied to many power assist devices and positioning mechanisms such as bionic robots, welfare devices, and parallel manipulators. However, the significant nonlinear characteristics of PAM mechanisms limit their positioning accuracies. The accuracies are generally lower than 5 μm, which preclude the PAM from precision systems. Nevertheless, enhancing the positioning accuracy is desired to extend the application fields of PAMs. This study aims to clarify a practical controller design method to achieve the precise positioning of PAM systems. As the first step of this research, a linear motion mechanism with a pair of McKibben PAMs was constructed and a conventional dynamic model for this system is introduced. The dynamic model is used to explain the basic characteristics of the PAM mechanism and discuss the necessary characteristics for precise positioning. Then open-loop step and sinusoidal responses of the PAM mechanism were examined by experimental and simulated results. Next, for precise positioning, the practical controller design procedure is discussed and determined based on the measured open-loop responses. The proposed controller design procedure can be easily implemented into PAM mechanisms without an exact dynamic model. The positioning performance of such a system was experimentally evaluated. The experimental results show that although the positioning accuracy depends on the target position, the positioning error is lower than 1 μm even in the worst case and the positioning resolution can be set to 0.5 μm.

Cerebral and muscle tissue oxygenation during exercise in healthy adults: A systematic review

Background:Near-infrared spectroscopy(NIRS)technology has allowed for the measurement of cerebral and skeletal muscle oxygenation simultaneously during exercise.Since this technology has been growing and is now successfully used in laboratory and sports settings,this systematic review aimed to synthesize the evidence and enhance an integrative understanding of bloodflow adjustments and oxygen(O_(2))changes(i.e.,the balance between O_(2) delivery and O_(2) consumption)within the cerebral and muscle systems during exercise.Methods:A systematic review was conducted using PubMed,Embase,Scopus,and Web of Science databases to search for relevant studies that simultaneously investigated cerebral and muscle hemodynamic changes using the near-infrared spectroscopy system during exercise.This review considered manuscripts written in English and available before February 9,2023.Each step of screening involved evaluation by 2 inde-pendent authors,with disagreements resolved by a third author.The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the methodological quality of the studies.Results:Twenty studies were included,of which 80%had good methodological quality,and involved 290 young or middle-aged adults.Different types of exercises were used to assess cerebral and muscle hemodynamic changes,such as cycling(n=11),treadmill(n=1),knee extension(n=5),isometric contraction of biceps brachii(n=3),and duet swim routines(n=1).The cerebral hemodynamics anal-ysis was focused on the frontal cortex(n=20),while in the muscle,the analysis involved vastus lateralis(n=18),gastrocnemius(n=3),biceps brachii(n=5),deltoid(n=1),and intercostal muscle(n=1).Overall,muscle deoxygenation increases during exercise,reaching a plateau in voluntary exhaustion,while in the brain,oxyhemoglobin concentration increases with exercise intensity,reaching a plateau or declining at the exhaustion point.Conclusion:Muscle and cerebral oxygenation respond differently to exercise,with muscle increasing O_(2) utilization and cerebral tissue increasing O_(2) delivery during exercise.However,at the exhaustion point,both muscle and cerebral oxygenation become compromised.This is characterized by a reduction in bloodflow and a decrease in O_(2) extraction in the muscle,while in the brain,oxygenation reaches a plateau or decline,potentially resulting in motor failure during exercise.

Automated body composition analysis system based on chest CT for evaluating content of muscle and adipose

Objective To establish a body composition analysis system based on chest CT,and to observe its value for evaluating content of chest muscle and adipose.Methods T7—T8 layer CT images of 108 pneumonia patients were collected(segmented dataset),and chest CT data of 984 patients were screened from the COVID 19-CT dataset(10 cases were randomly selected as whole test dataset,the remaining 974 cases were selected as layer selection dataset).T7—T8 layer was classified based on convolutional neural network(CNN)derived networks,including ResNet,ResNeXt,MobileNet,ShuffleNet,DenseNet,EfficientNet and ConvNeXt,then the accuracy,precision,recall and specificity were used to evaluate the performance of layer selection dataset.The skeletal muscle(SM),subcutaneous adipose tissue(SAT),intermuscular adipose tissue(IMAT)and visceral adipose tissue(VAT)were segmented using classical fully CNN(FCN)derived network,including FCN,SegNet,UNet,Attention UNet,UNET++,nnUNet,UNeXt and CMUNeXt,then Dice similarity coefficient(DSC),intersection over union(IoU)and 95 Hausdorff distance(HD)were used to evaluate the performance of segmented dataset.The automatic body composition analysis system was constructed based on optimal layer selection network and segmentation network,the mean absolute error(MAE),root mean squared error(RMSE)and standard deviation(SD)of MAE were used to evaluate the performance of automatic system for testing the whole test dataset.Results The accuracy,precision,recall and specificity of DenseNet network for automatically classifying T7—T8 layer from chest CT images was 95.06%,84.83%,92.27%and 95.78%,respectively,which were all higher than those of the other layer selection networks.In segmentation of SM,SAT,IMAT and overall,DSC and IoU of UNet++network were all higher,while 95HD of UNet++network were all lower than those of the other segmentation networks.Using DenseNet as the layer selection network and UNet++as the segmentation network,MAE of the automatic body composition analysis system for predicting SM,SAT,IMAT,VAT and MAE was 27.09,6.95,6.65 and 3.35 cm 2,respectively.Conclusion The body composition analysis system based on chest CT could be used to assess content of chest muscle and adipose.Among them,the UNet++network had better segmentation performance in adipose tissue than SM.

Effects of respiratory muscle training on post-stroke rehabilitation:A systematic review and meta-analysis

BACKGROUND Stroke often results in significant respiratory dysfunction in patients.Respiratory muscle training(RMT)has been proposed as a rehabilitative intervention to address these challenges,but its effectiveness compared to routine training remains debated.This systematic review and meta-analysis aim to evaluate the effects of RMT on exercise tolerance,muscle strength,and pulmonary function in post-stroke patients.AIM To systematically assess the efficacy of RMT in improving exercise tolerance,respiratory muscle strength,and pulmonary function in patients recovering from a stroke,and to evaluate whether RMT offers a significant advantage over routine training modalities in enhancing these critical health outcomes in the post-stroke population.METHODS Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines,a comprehensive search across PubMed,Embase,Web of Science,and the Cochrane Library was conducted on October 19,2023,without temporal restrictions.Studies were selected based on the predefined inclusion and exclusion criteria focusing on various forms of RMT,control groups,and outcome measures[including forced expiratory volume in the first second(FEV1),forced vital capacity(FVC),maximal voluntary ventilation(MVV),peak expiratory flow(PEF),maximal inspiratory pressure(MIP),maximal expiratory pressure(MEP),and 6-min walking test(6MWT)].Only randomized controlled trials(RCTs)were included.Data extraction and quality assessment were conducted independently by two reviewers using the Cochrane Collaboration's risk of bias tool.Statistical analyses,including those using the fixed-effect and random-effects models,sensitivity analysis,and publication bias assessment,were performed using Review Manager software.RESULTS A total of 15 RCTs were included.Results indicated significant improvements in MIP(12.51 cmH2O increase),MEP(6.24 cmH2O increase),and various pulmonary function parameters(including FEV1,FVC,MVV,and PEF).A substantial increase in 6MWT distance(22.26 meters)was also noted.However,the heterogeneity among studies was variable,and no significant publication bias was detected.CONCLUSION RMT significantly enhances walking ability,respiratory muscle strength(MIP and MEP),and key pulmonary function parameters(FEV1,FVC,MVV,and PEF)in post-stroke patients.These findings support the incorporation of RMT into post-stroke rehabilitative protocols.

Crosstalk among canonical Wnt and Hippo pathway members in skeletal muscle and at the neuromuscular junction

Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review.

Effect of external and internal cues on core muscle activation during the Sahrmann five-level core stability test

BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.

Assessment of skeletal muscle alterations and circulating myokines in metabolic dysfunction-associated steatotic liver disease:A crosssectional study

BACKGROUND Skeletal muscle alterations(SMAs)are being increasingly recognized in patients with metabolic dysfunctionassociated steatotic liver disease(MASLD)and appear to be associated with deleterious outcomes in these patients.However,their actual prevalence and pathophysiology remain to be elucidated.AIM To determine the prevalence of SMAs and to assess the significance of circulating myokines as biomarkers in patients with MASLD.METHODS Skeletal muscle strength and muscle mass were measured in a cross-sectional study in a cohort of 62 patients fulfilling MASLD criteria,recruited from the outpatient clinics of a tertiary level hospital.The degree of fibrosis and liver steatosis was studied using abdominal ultrasound and transitional elastography.Anthropometric and metabolic characteristics as well as serum levels of different myokines were also determined in the MASLD cohort.Statistical analysis was performed comparing results according to liver fibrosis and steatosis.RESULTS No significant differences were found in both skeletal muscle strength and skeletal muscle mass in patients with MASLD between different stages of liver fibrosis.Interestingly,serum levels of fibroblast growth factor-21(FGF21)were significantly higher in patients with MASLD with advanced hepatic fibrosis(F3-F4)than in those with lower fibrosis stages(F0-F2)(197.49±198.27 pg/mL vs 95.62±83.67 pg/mL;P=0.049).In addition,patients with MASLD with severe hepatosteatosis(S3)exhibited significantly higher serum levels of irisin(1116.87±1161.86 pg/mL)than those with lower grades(S1-S2)(385.21±375.98 pg/mL;P=0.001).CONCLUSION SMAs were uncommon in the patients with MASLD studied.Higher serum levels of irisin and FGF21 were detected in patients with advanced liver steatosis and fibrosis,respectively,with potential implications as biomarkers.

Causal relationship between lipid profile and muscle atrophy:A bi-directional Mendelian randomization study

Background:The aim of this study was to analyze the bi-directional causal relation-ship between lipid profile and characteristics related to muscle atrophy by using a bi-directional Mendelian randomization(MR)analysis.Methods:The appendicular lean mass(ALM),whole body fat-free mass(WBFFM)and trunk fat-free mass(TFFM)were used as genome-wide association study(GWAS)data for evaluating muscle mass;the usual walking pace(UWP)and low grip strength(LGS)were used as GWAS data for evaluating muscle strength;and the triglycerides(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL),low density lipo-protein cholesterol(LDL),apolipoprotein A-1(Apo A-1),and apolipoprotein B(Apo B)were used as GWAS data for evaluating lipid profile.For specific investigations,we mainly employed inverse variance weighting for causal estimation and MR-Egger for pleiotropy analysis.Results:MR results showed that the lipid profile predicted by genetic variants was negatively correlated with muscle mass,positively correlated with UWP,and was not causally correlated with LGS.On the other hand,the muscle mass predicted by genetic variants was negatively correlated with lipid profile,the UWP predicted by genetic variants was mainly positively correlated with lipid profile,while the LGS pre-dicted by genetic variants had no relevant causal relationship with lipid profile.Conclusions:Findings of this MR analysis suggest that hyperlipidemia may affect muscle mass and lead to muscle atrophy,but has no significant effect on muscle strength.On the other hand,increased muscle mass may reduce the incidence of dyslipidemia.

Platelet-rich plasma for muscle injuries: A systematic review of the basic science literature

BACKGROUND Platelet-rich plasma(PRP) is an increasingly used biologic adjunct for muscle injuries, as it is thought to expedite healing. Despite its widespread use, little is known regarding the mechanisms by which PRP produces its efficacious effects in some patients.AIM To clarify the effects of PRP on muscular pathologies at the cellular and tissue levels by evaluating the basic science literature.METHODS A systematic review of PubMed/MEDLINE and EMBASE databases was performed using the Preferred Reporting Items for Systematic Reviews and MetaAnalyses(PRISMA) guidelines and checklist. Level III in vivo and in vitro studies examining PRP effects on muscles, myocytes and/or myoblasts were eligible for inclusion. Extracted data included PRP preparation methods and study results.RESULTS Twenty-three studies were included(15 in vivo, 6 in vitro, 2 in vitro/in vivo). Only one reported a complete PRP cytology(platelets, and red and white blood cell counts). Five in vitro studies reported increased cellular proliferation, four reported increased gene expression, and three reported increased cellular differentiation. Five in vivo studies reported increased gene expression, three reported superior muscle regeneration, and seven reported improved histological quality of muscular tissue.CONCLUSION The basic science literature on the use of PRP in muscle pathology demonstrates that PRP treatment confers several potentially beneficial effects on healing in comparison to controls. Future research is needed to determine optimal cytology,dosing, timing, and delivery methods of PRP for muscle pathologies.

THE ROLE OF BRAIN-STEM DISCENDING INHIBITORY SYSTEM IN THE ANTINOCICEPTIVE EFFECT ELICITED BY MUSCLE SPINDLE AFFERENTS

Objective To analyse the antinociceptive effect of muscle spindle afferents and the involved mechanism.Methods The single unit of wide dynamic range neurons in the spinal cord dorsal horn were recorded extracelluarly.The effects of muscle spindle afferents elicited by intravenous administration of succinylcholine on nociceptive responses (C fibres evoked responses,C responses) of WDR neurons were observed before and after bilateral lesions of ventrolateral periaqueduct gray .And the effects of muscle spindle afferents on the spontaneous discharge of the tail flick related cell in the rostral ventro medial medulla and on the spontaneous discharge of the PAG neurons were observed.Results The C responses of WDR neurons were significantly inhibited by muscle spindle afferents,and the inhibitory effects were reduced by bilateral lesions of ventrolateral PAG.The spontaneous discharge of the off cell in the RVM was excited while the on cell was inhibited by intravenous administration of Sch.The spontaneous discharge of the PAG neurons were excited by muscle spindle afferents.Conclusion Muscle spindle afferents show a distinct effect of antinociception.PAG RVM descending inhibitory system may play an important role in this nociceptive modulative mechanism.

ACTA2 mutation is responsible for multisystemic smooth muscle dysfunction syndrome with seizures:A case report and review of literature

BACKGROUND ACTA2 gene is a specific gene that encodes actinα2.Multisystem smooth muscle dysfunction syndrome(MSMDS)is a multisystem disease characterized by aortic and cerebrovascular lesions caused by ACTA2 gene mutations.There have been many reports of cardiac,pulmonary and cerebrovascular lesions caused by MSMDS;however,few studies have focused on seizures caused by MSMDS.CASE SUMMARY Our patient was a girl aged 7 years and 8 mo with recurrent cough,asthma and seizures for 7 years.She was diagnosed with severe pneumonia,congenital heart disease,cardiac insufficiency,and malnutrition in the local hospital.Cardiac ultrasonography revealed congenital heart disease,patent ductus arteriosus(with a diameter of 0.68 cm),left coronary arteriectasis,patent oval foramen(0.12 cm),tricuspid and pulmonary regurgitation,and pulmonary hypertension.Cerebral magnetic resonance imaging and magnetic resonance angiography indicated stiffness in the brain vessels,together with multiple aberrant signaling shadows in bilateral paraventricular regions.A heterozygous mutation(c.536G>A)was identified in the ACTA2 gene,resulting in generation of p.R179H.Finally,the girl was diagnosed with MSMDS combined with epilepsy.The patient had 4 episodes of seizures before treatment,and no onset of seizure was reported after oral administration of sodium valproate for 1 year.CONCLUSION MSMDS has a variety of clinical manifestations and unique cranial imaging features.Cerebrovascular injury and white matter injury may lead to seizures.Gene detection can confirm the diagnosis and prevent missed diagnosis or misdiagnosis.

Dynamic compressive response of porcine muscle measured using a split Hopkinson bar system with a pair of PVDF force transducers

The classic metallic Split Hopkinson Pressure Bar(SHPB)cannot capture the transmitted signal accurately when measuring soft biological tissue,because of the very low wave impedance and strength of this material.So the dynamic compressive response of porcine muscle has been investigated by using a modified SHPB.The forces on both ends of the sample measured using Polyvinylidene fluor(PVDF)transducers were applied to calculate the stress in the specimen instead of the strain gauge signal on the transmitted bar.Moreover,a circular cardboard disk pulse shaper was applied for generating a suitable incident pulse to achieve stress equilibrium and constant strain rates in the specimens.Then,the dynamic mechanical properties of porcine muscle parallel and perpendicular to the fiber directions were measured,and the stress equilibrium process during loading was analyzed,as well as the inertia-induced extra stress being corrected.Furthermore,quasi-static tests were conducted at two different strain rates to investigate the strain rate dependence using a universal material testing machine.The results show that the stress-strain curves are sensitive to strain rate in the two different loading directions.The compressive stress perpendicular to the fiber direction is stiffer than that parallel to the fiber direction.In addition,a strain rate-dependent constitutive model was developed based on the mechanical response of the muscle at different strain rates and fitted to the experimental data.The results show that the overall fit is good,and the constitutive model could describe the muscle's dynamic mechanical properties.

Discrete-time sliding mode control with power rate exponential reaching law of a pneumatic artificial muscle system

This paper develops a discrete-time sliding mode controller with a power rate exponential reaching law approach to enhance the performance of a pneumatic artificial muscle system in both reaching time and chattering reduction.The proposed method dynamically adapts to the variation of the switching function,which is based on an exponential term and a power rate term of the sliding surface.Thus,the controlled system can achieve high tracking performance while still obtain chattering-free control.Moreover,the effectiveness of the proposed method is validated through multiple experimental tests,focused on a dual pneumatic artificial muscle system.Finally,experimental results show the effectiveness of the proposed approach in this paper.

Dual-Ion Co-Regulation System Enabling High-Performance Electrochemical Artificial Yarn Muscles with Energy-Free Catch States

Artificial yarn muscles show great potential in applications requiring low-energy consumption while maintaining high performance. However, conventional designs have been limited by weak ion-yarn muscle interactions and inefficient “rocking-chair” ion migration. To address these limitations, we present an electrochemical artificial yarn muscle design driven by a dual-ion co-regulation system. By utilizing two reaction channels, this system shortens ion migration pathways, leading to faster and more efficient actuation. During the charging/discharging process, PF_6~- ions react with carbon nanotube yarn, while Li~+ ions react with an Al foil. The intercalation reaction between PF_6~- and collapsed carbon nanotubes allows the yarn muscle to achieve an energy-free high-tension catch state. The dual-ion coordinated yarn muscles exhibit superior contractile stroke, maximum contractile rate, and maximum power densities, exceeding those of “rocking-chair” type ion migration yarn muscles. The dual-ion co-regulation system enhances the ion migration rate during actuation, resulting in improved performance. Moreover, the yarn muscles can withstand high levels of isometric stress, displaying a stress of 61 times that of skeletal muscles and 8 times that of “rocking-chair” type yarn muscles at higher frequencies. This technology holds significant potential for various applications, including prosthetics and robotics.

Effect of preoperative inspiratory muscle training on postoperative outcomes in patients undergoing cardiac surgery:A systematic review and meta-analysis

BACKGROUND Cardiovascular disease is the most prevalent disease worldwide and places a great burden on the health and economic welfare of patients.Cardiac surgery is an important way to treat cardiovascular disease,but it can prolong mechanical ventilation time,intensive care unit(ICU)stay,and postoperative hospitalization for patients.Previous studies have demonstrated that preoperative inspiratory muscle training could decrease the incidence of postoperative pulmonary complications.AIM To explore the effect of preoperative inspiratory muscle training on mechanical ventilation time,length of ICU stay,and duration of postoperative hospitalization after cardiac surgery.METHODS A literature search of PubMed,Web of Science,Cochrane Library,EMBASE,China National Knowledge Infrastructure,WanFang,and the China Science and Technology journal VIP database was performed on April 13,2022.The data was independently extracted by two authors.The inclusion criteria were:(1)Randomized controlled trial;(2)Accessible as a full paper;(3)Patients who received cardiac surgery;(4)Preoperative inspiratory muscle training was implemented in these patients;(5)The study reported at least one of the following:Mechanical ventilation time,length of ICU stay,and/or duration of postoperative hospitalization;and(6)In English language.RESULTS We analyzed six randomized controlled trials with a total of 925 participants.The pooled mean difference of mechanical ventilation time was-0.45 h[95%confidence interval(CI):-1.59-0.69],which was not statistically significant between the intervention group and the control group.The pooled mean difference of length of ICU stay was 0.44 h(95%CI:-0.58-1.45).The pooled mean difference of postoperative hospitalization was-1.77 d in the intervention group vs the control group[95%CI:-2.41-(-1.12)].CONCLUSION Preoperative inspiratory muscle training may decrease the duration of postoperative hospitalization for patients undergoing cardiac surgery.More high-quality studies are needed to confirm our conclusion.

Multisystem smooth muscle dysfunction syndrome in a Chinese girl:A case report and review of the literature

BACKGROUND Multisystemic smooth muscle dysfunction syndrome(MSMDS) is a rare genetic disease worldwide. The main mutation is the actin alpha 2(ACTA2) gene p.R179 H. In this paper, we report a Chinese MSMDS patient and systematically review the previous literature.CASE SUMMARY Here, we report a 9.6-month-old Chinese girl who was diagnosed with MSMDS based on her history and symptoms, such as recurrent cough, wheezing, and complications with congenital fixed dilated pupils. Chest high-resolution computed tomography revealed inhomogeneous lung transparency, obvious exudative lesions, and some lung fissures that were markedly thickened. Cranial magnetic resonance imaging excluded bleeding and infarction but showed abnormal signals in the centrum ovale majus and bilateral periventricular regions. Echocardiography only showed patent foramen ovale, and no patent ductus arteriosus, pulmonary artery dilatation, or pulmonary hypertension was found. Bronchoscopy indicated moderate bronchial malacia. These examinations in conjunction with the typical eye abnormality suggested a diagnosis of MSMDS, and sequencing of exon 6 of the ACTA2 gene demonstrated the heterozygous mutation c.536 G>A, p.R179 H. However, her parents' gene analyses were normal.CONCLUSION MSMDS is a rare genetic disease mainly caused by the mutation of the ACTA2 gene p.R179 H. Early genetic diagnosis should be performed for children presenting with congenital fixed dilated pupils and patent ductus arteriosus.During the process of diagnosis and treatment, clinicians should be on high alert for cerebrovascular, cardiovascular, and pulmonary complications.

Muscle strength and non-alcoholic fatty liver disease/metabolicassociated fatty liver disease

This editorial comments on an article published in a recent issue of World Journal of Gastroenterology,entitled“Association of low muscle strength with metabolic dysfunction-associated fatty liver disease:A nationwide study”.We focused on the association between muscle strength and the incidence of non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD),as well as the mechanisms underlying the correlation and related clinical applications.NAFLD,which is now redefined as MAFLD,is one of the most common chronic liver diseases globally with an increasing prevalence and is characterized by malnutrition,which may contribute to decreased muscle strength.Reduction of muscle strength reportedly has a pathogenesis similar to that of NAFLD/MAFLD,including insulin resistance,inflammation,sedentary behavior,as well as insufficient vitamin D.Multiple studies have focused on the relationship between sarcopenia or muscle strength and NAFLD.However,studies investigating the relationship between muscle strength and MAFLD are limited.Owing to the shortage of specific medications for NAFLD/MAFLD treatment,early detection is essential.Furthermore,the relationship between muscle strength and NAFLD/MAFLD suggests that improvements in muscle strength may have an impact on disease prevention and may provide novel insights into treatments including dietary therapy,as well as tailored physical activity.

Pathophysiological changes of muscle after ischemic stroke:a secondary consequence of stroke injury

Sufficient clinical evidence suggests that the damage caused by ischemic stroke to the body occurs not only in the acute phase but also during the recovery period,and that the latter has a greater impact on the long-term prognosis of the patient.However,current stroke studies have typically focused only on lesions in the central nervous system,ignoring secondary damage caused by this disease.Such a phenomenon arises from the slow progress of pathophysiological studies examining the central nervous system.Further,the appropriate therapeutic time window and benefits of thrombolytic therapy are still controversial,leading scholars to explore more pragmatic intervention strategies.As treatment measures targeting limb symptoms can greatly improve a patient’s quality of life,they have become a critical intervention strategy.As the most vital component of the limbs,skeletal muscles have become potential points of concern.Despite this,to the best of our knowledge,there are no comprehensive reviews of pathophysiological changes and potential treatments for post-stroke skeletal muscle.The current review seeks to fill a gap in the current understanding of the pathological processes and mechanisms of muscle wasting atrophy,inflammation,neuroregeneration,mitochondrial changes,and nutritional dysregulation in stroke survivors.In addition,the challenges,as well as the optional solutions for individualized rehabilitation programs for stroke patients based on motor function are discussed.