Muscle Sites Research Articles

A mouse model of volumetric muscle loss and therapeutic scaffold implantation.

Skeletal myofibers naturally regenerate after damage; however, impaired muscle function can result in cases when a prominent portion of skeletal muscle mass is lost, for example, following traumatic muscle injury. Volumetric muscle loss can be modeled in mice using a surgical model of muscle ablation to study the pathology of volumetric muscle loss and to test experimental treatments, such as the implantation of acellular scaffolds, which promote de novo myogenesis and angiogenesis. Here we provide step-by-step instructions to perform full-thickness surgical ablation, using biopsy punches, and to remove a large volume of the tibialis anterior muscle of the lower limb in mice. This procedure results in a reduction in muscle mass and limited regeneration capacity; the approach is easy to reproduce and can also be applied to larger animal models. For therapeutic applications, we further explain how to implant bioscaffolds into the ablated muscle site. With adequate training and practice, the surgical procedure can be performed within 30 min.

Muscle Hypertrophy and Strength Adaptations to Systematically Varying Resistance Exercises

ABSTRACT We compared the effects of varied and constant resistance exercises on muscular adaptations in young women. Seventy young women (21.8 ± 3.4 yrs, 62.0 ± 12.3 kg, 162.3 ± 5.7 cm) were randomly divided into two groups: constant resistance exercises (CON-RE, n = 38) or varied resistance exercises (VAR-RE, n = 32). The resistance training (RT) was performed thrice a week over 10 weeks. CON-RE performed a 45º leg press and stiff-leg deadlift in every training session, while VAR-RE performed 45º leg press and stiff-leg deadlift in the first training session of the week, hack squat and prone leg curl in the second, and Smith machine squat and seated-leg curl in the third. Both groups performed two sets of 10–15 repetitions maximum per resistance exercise. We measured the muscle thickness of the thigh’s anterior, lateral, and posterior aspects by ultrasonography at different muscle sites (proximo-distal). Muscular strength was analyzed from the one-repetition maximum (1RM) tests in the 45° leg press and leg extension (non-trained exercise). The muscle thickness increased similarly in both groups for all muscles and sites (CON-RE: +7.8–17.7% vs. VAR-RE: +7.5–19.3%, p > .05). The 1RM increased similarly in both groups (CON-RE: +24.4–32.1% vs. VAR-RE: +29.0–30.1%, p > .05). Both RT routines resulted in virtually similar muscular strength gains and hypertrophy. Therefore, both strategies should be considered for the improvement of strength and muscle growth.

Botulinum toxin treatment for hemifacial spasm: harmonising neurological and aesthetic outcomes.

Hemifacial spasm (HFS) represents a challenging cranial movement disorder primarily affecting the facial nerve innervated muscles, with significant prevalence among Asians. Botulinum toxin type A (BoNT/A) injections, established as a primary therapeutic intervention since FDA approval, offer considerable effectiveness in alleviating spasms, albeit accompanied by challenges such as temporary effects and potential adverse events including facial asymmetry. This comprehensive review underscores the crucial need for harmonising neurological benefits and aesthetic outcomes in HFS management. The discussion delves into the interplay between facial aesthetics and neurological objectives in BoNT/A injections, emphasising precise techniques, dosages, and site considerations. Distinct aspects in neurological and aesthetic domains are also examined, including detailing the targeted muscles and injection methodologies for optimal therapeutic and aesthetic results. Importantly, evidence regarding various BoNT/A formulations, recommendations, and reconstitution guidelines in both neurology and aesthetics contexts are provided, along with a schematic approach outlining the stepwise process for BoNT/A injection in HFS treatment, addressing critical areas such as orbicularis oculi muscle sites, eyebrow correction strategies, mid- and lower-face considerations, contralateral injection sites, and post-injection follow-up and complication management. By highlighting the culmination of neurological efficacy and facial esthetics in BoNT/A treatment for HFS patients, this review proposes a holistic paradigm to achieve balanced symptomatic relief and natural aesthetic expression, ultimately enhancing quality of life for individuals grappling with HFS.

Muscle reoxygenation is slower after higher cycling intensity, and is faster and more reliable in locomotor than in accessory muscle sites.

Wearable near-infrared spectroscopy (NIRS) can be used during dynamic exercise to reflect the balance of muscle oxygen delivery and uptake. This study describes the behaviour and reliability of postexercise reoxygenation with NIRS as a function of exercise intensity at four muscle sites during an incremental cycling test. We discuss physiological components of faster and slower reoxygenation kinetics in the context of sport science and clinical applications. We hypothesised that reoxygenation would be slower at higher intensity, and that locomotor muscles would be faster than accessory muscles. We quantified test-retest reliability and agreement for each site. Twenty-one trained cyclists performed two trials of an incremental cycling protocol with 5-min work stages and 1-min rest between stages. NIRS was recorded from the locomotor vastus lateralis and rectus femoris muscles, and accessory lumbar paraspinal and lateral deltoid muscles. Reoxygenation time course was analysed as the half-recovery time (HRT) from the end of work to half of the peak reoxygenation amplitude during rest. Coefficient of variability (CV) between participants, standard error of the measurement (SEM) within participants, and intraclass correlation coefficient (ICC) for test-retest reliability were evaluated at 50%, 75%, and 100% peak workloads. A linear mixed-effects model was used to compare differences between workloads and muscle sites. HRT was slower with increasing workload in the VL, RF, and PS, but not DL. VL had the fastest reoxygenation (lowest HRT) across muscle sites at all workloads (HRT = 8, 12, 17s at 50%, 75%, 100% workload, respectively). VL also had the greatest reliability and agreement. HRT was sequentially slower between muscle sites in the order of VL < RF < PS < DL, and reliability was lower than for the VL. This study highlights the potential for using wearable NIRS on multiple muscle sites during exercise. Reoxygenation kinetics differ between local muscle sites with increasing intensity. Moderate-to-good reliability in the VL support its increasing use in sport science and clinical applications. Lower reliability in other muscle sites suggest they are not appropriate to be used alone, but may add information when combined to better reflect systemic intensity and fatigue during exercise at different intensities.

The semispinalis capitis muscle skull attachment as a superficial external landmark for the location of the transverse dural venous sinuses

IntroductionIdentifiable superficial external landmarks can be used to determine the exact location of the internally located dural venous sinuses, for neurosurgical procedures. Several studies have been conducted to determine a standard method or a consistent reliable landmark, but all reported variations and inconsistencies with the examined landmarks. This study evaluated the relationship between the attachment site of the semispinalis capitis muscles on the external aspect of the skull and the internally located transverse dural venous sinuses. MethodsFifty-one South African skulls were used in this study. The Micro-focus X-ray Radiography and Tomography (MIXRAD) system at Necsa (Nuclear Energy Corporation South Africa) was used to scan and create three-dimensional images of each skull specimen. Pre-determined reference points were placed on the reconstructed images with the VGStudio Max volume rendering software. The relevant distances and locations of the reference points were measured and documented. ResultsThe muscle attachment site was located inferior to the transverse sinuses in all the skulls with a mean distance of 15.99 mm (left side) and 19.43 mm (right side). A statistically significant difference was found between all the measurements comparing the left- and right sides, however, no such difference was found between males and females. ConclusionThe apical attachment of the semispinalis capitis muscle is a good indicator for the internally located transverse dural venous sinus. This study indicates that a point of entry 8–10 mm inferior to this muscle attachment site be used, for safe access to the internal aspect of the posterior cranium.

Unique advantages of dynamic l-[11C]methionine PET/CT for assessing the rate of skeletal muscle protein synthesis: A pilot trial in young men.

Although the standard method to evaluate skeletal muscle protein synthesis (MPS) is muscle biopsy, the method is invasive and problematic for multisite use. We conducted a small pilot study in volunteers to investigate changes in MPS according to skeletal muscle site using a noninvasive method in which 6 healthy young men were given yogurt (containing 20 g milk protein) or water, and 1 h later, l-[11C]methionine ([11C]Met) was administered intravenously. Dynamic PET/CT imaging of their thighs was performed for 60 min. The influx constant Ki of [11C]Met in skeletal muscle protein was calculated as an index of MPS using a Patlak plot, and found to be 0.6%-28% higher after ingesting yogurt than after water in 5 of the 6 volunteer participants, but it was 34% lower in the remaining participant. Overall, this indicated no significant increase in Ki after ingesting milk protein. However, when the quadriceps and hamstring muscles were analyzed separately, we found a significant difference in Ki. This demonstrates the potential of visualizing MPS by calculating the Ki for each voxel and reconstructing it as an image, which presents unique advantages of [11C]Met PET/CT for evaluating MPS, such as site-specificity and visualization.

Modeling the Effects of Protracted Cosmic Radiation in a Human Organ-on-Chip Platform.

Galactic cosmic radiation (GCR) is one of the most serious risks posed to astronauts during missions to the Moon and Mars. Experimental models capable of recapitulating human physiology are critical to understanding the effects of radiation on human organs and developing radioprotective measures against space travel exposures. The effects of systemic radiation are studied using a multi-organ-on-a-chip (multi-OoC) platform containing engineered tissue models of human bone marrow (site of hematopoiesis and acute radiation damage), cardiac muscle (site of chronic radiation damage) and liver (site of metabolism), linked by vascular circulation with an endothelial barrier separating individual tissue chambers from the vascular perfusate. Following protracted neutron radiation, the most damaging radiation component in deep space, a greater deviation of tissue function is observed as compared to the same cumulative dose delivered acutely. Further, by characterizing engineered bone marrow (eBM)-derived immune cells in circulation, 58 unique genes specific to the effects of protracted neutron dosing are identified, as compared to acutely irradiated and healthy tissues. It propose that this bioengineered platform allows studies of human responses to extended radiation exposure in an "astronaut-on-a-chip" model that can inform measures for mitigating cosmic radiation injury.

Assessment of the effects of direct myofascial release in the lateral gastrocnemius muscle of tennis athletes using ShearWave™ elastography

ObjectivesThe purpose of the present study was to utilize ShearWave™ Elastography to assess tissue stiffness by measuring shear wave speed before and after applying the direct Myofascial release (MFR) technique to the lateral gastrocnemius muscle of competitive tennis athletes. MethodsShear wave speed values were measured in the regions of interest within the lateral gastrocnemius fascia and muscle areas from the elastographic images. Measurements were taken in three different situations: before, immediately after and 5 min after MFR protocol. Subsequently, the results from each situation were statistically compared. ResultsThe protocol was administered to a group of eighteen tennis players with a mean age of 18 ± 1.23 years. The shear wave speed values increased for both fascia and muscles sites, after applying the MFR technique: From 3.01 ± 0.64 to 3.33 ± 0.86 m/s in the deep fascia and from 2.23 ± 0.41 to 2.57 ± 0.51 m/s in superficial fascia. In the deep and superficial muscles sites the increases were from 4.12 ± 0.95 to 4.40 ± 1.22 m/s, and from 2.94 ± 0.71 to 3.38 ± 0.95 m/s, respectively. ConclusionThis study showed that after the myofascial manipulation in tennis athletes, the lateral gastrocnemius muscle and fascia tissues stiffness increased, according to elastography, and possible mechanisms were discussed. ShearWave™ Elastography could be utilized to assess the acute effects of applying a direct myofascial release (MFR) technique.

Identification of lipid-modifying drug targets for autoimmune diseases: insights from drug target mendelian randomization

BackgroundsA growing body of evidence has highlighted the interactions of lipids metabolism and immune regulation. Nevertheless, there is still a lack of evidence regarding the causality between lipids and autoimmune diseases (ADs), as well as their possibility as drug targets for ADs.ObjectivesThis study was conducted to comprehensively understand the casual associations between lipid traits and ADs, and evaluate the therapeutic possibility of lipid-lowering drug targets on ADs.MethodsGenetic variants for lipid traits and variants encoding targets of various lipid-lowering drugs were derived from Global Lipid Genetics Consortium (GLGC) and verified in Drug Bank. Summary data of ADs were obtained from MRC Integrative Epidemiology Unit (MER-IEU) database and FinnGen consortium, respectively. The causal inferences between lipid traits/genetic agents of lipid-lowering targets and ADs were evaluated by Mendelian randomization (MR), summary data-based MR (SMR), and multivariable MR (MVMR) analyses. Enrichment analysis and protein interaction network were employed to reveal the functional characteristics and biological relevance of potential therapeutic lipid-lowering targets.ResultsThere was no evidence of causal effects regarding 5 lipid traits and 9 lipid-lowering drug targets on ADs. Genetically proxied 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) inhibition was associated with a reduced risk of rheumatoid arthritis (RA) in both discovery (OR [odds ratio] = 0.45, 95%CI: 0.32, 0.63, P = 6.79 × 10− 06) and replicate datasets (OR = 0.37, 95%CI: 0.23, 0.61, P = 7.81 × 10− 05). SMR analyses supported that genetically proxied HMGCR inhibition had causal effects on RA in whole blood (OR = 0.48, 95%CI: 0.29, 0.82, P = 6.86 × 10− 03) and skeletal muscle sites (OR = 0.75, 95%CI: 0.56, 0.99, P = 4.48 × 10− 02). After controlling for blood pressure, body mass index (BMI), smoking and drinking alchohol, HMGCR suppression showed a direct causal effect on a lower risk of RA (OR = 0.33, 95%CI: 0.40, 0.96, P = 0.042).ConclusionsOur study reveals causal links of genetically proxied HMGCR inhibition (lipid-lowering drug targets) and HMGCR expression inhibition with a decreased risk of RA, suggesting that HMGCR may serve as candidate drug targets for the treatment and prevention of RA.

Mapping lower-limbs muscle vulnerability in patients with ALS: The role of upper and lower motor neurons

BackgroundSeveral studies have reported disproportionate wasting of the flexor muscles of the lower limbs (LL) compared to the extensors in patients with amyotrophic lateral sclerosis (ALS). However, these studies have involved small sample sizes (n 〈100), and their findings have been inconsistent. Thus, it remains uncertain whether a distinct pattern of LL muscle weakness is specific to ALS. AimsTo investigate the muscle weakness pattern in the LL at the knee, ankle, and toes in a large cohort of ALS patients and evaluate the relationship between the pattern of muscle strength and the extent of upper (UMN) and lower (LMN) motoneuron impairment. Material and methodsThe strength of flexor and extensor muscle was evaluated in 1250 legs of newly diagnosed ALS patients at the knee, ankle, and foot toes. UMN and LMN burden were assessed using validated scores. Within-subjects ANOVA considering the type of muscle (flexor/extensor) and anatomical sites (knee/ankle/toes) and mixed-factorial ANOVA were conducted to explore the impact of UMN and LMN impairments on the muscle weakness pattern. ResultsMuscle strength showed a significant decline from proximal to distal regions. Indeed both flexor and extensor muscles at the knee outperformed those at the ankle and toes. Within each site, extensor muscles exhibited less strength than flexor, except at the knee. Patients with heightened UMN impairment showed a more marked difference between flexors and extensors within each site, with extensor muscles being more compromised at the ankle and toes. Higher LMN impairment corresponded to a more pronounced weakness in flexor muscles at the ankle and toes compared to those at the knee. ConclusionsThe extensor muscle at the knee and the flexors at the foot and toes displayed relative resistance to ALS disease. UMN impairment amplified the differences between flexor and extensor muscles within each site, while LMN impairment demonstrated a clear distal-to-proximal vulnerability.

The effect of resistance exercise on multimodal pain thresholds in local and systemic muscle sites.

Dynamic resistance exercise may produce reductions in pain locally at the exercising muscle and systemically at non-exercising sites. However, limited research has examined these changes with multiple noxious stimuli. This study examined changes in heat pain threshold (HPT) and pressure pain threshold (PPT) on different musculature after an upper and lower body exercise to compare local and systemic effects. A crossover design with 28 participants (mean age: 21 ± 4 years, 21 female) completed three sessions. Visit one included baseline quantitative sensory testing and 5-repetition maximum (RM) testing for upper (shoulder press) and lower (leg extension) body. In subsequent sessions, participants performed upper or lower body exercises using an estimated 75% 1-RM with pre/post assessment of HPT and PPT at three sites: deltoid, quadriceps, and low back. A significant three-way interaction was observed for HPT (F (1.71, 3.80) = 2.19, p = 0.036, η2p = 0.12) with significant increases in HPT over the quadriceps (p = 0.043) after leg extension and over the deltoid (p = 0.02) after shoulder press. Significant systemic changes were not observed for HPT or PPT. Local but not systemic effects were demonstrated after an acute bout of exercise. Peripheral pain sensitivity may be more responsive to heat stimuli after resistance exercise.

137Cesium (137Cs) assessment in wild boars from northwestern Italy.

Radionuclide contamination is a serious health issue caused by nuclear experiments and plant accidents, as seen for the Chernobyl and Fukushima nuclear plants. Italy has been especially interested in northwestern alpine regions, as have several other nations. The aim of this work was to indagate 134Cs and 137Cs contamination in wild boars, which were considered bioindicators sampled in the Chisone/Germanasca Valley and the Pellice Valley districts (Piedmont, Italy) in two hunting seasons (2014 and 2016). In the 2014 season, only the livers of the animals (n = 48) were sampled, whereas in 2016, five different anatomical sampling sites were sampled for each animal (n = 16). The analyses were conducted in an accredited laboratory (Agenzia Regionale per la Protezione dell'Ambiente-ARPA) by the aid of an HPGe detector (Ortec) with a relative efficiency of 50%. In general, the contamination levels registered in 2014 were under the detection limit for 134Cs and low for 137Cs (Chisone/Germanasca valley: min: 0.0, max: 23.9 median 11.0 Bq/kg vs Pellice valley: min 0, max: 31.7, median: 9.6 Bq/kg) and no health concern can be supposed. In the first-year samples, the liver showed a negative correlation between age and contamination level. In the second year of sampling, low levels were confirmed (min: 3.1 Bq/kg, max: 113.3; median 17.7 Bq/kg). Multiple sampling from the same animal showed that the diaphragm (median = 27.7 Bq/kg) kidney (27.4) and tongue (27.6) were more contaminated than the liver (17.7) and spleen (15.3). Moreover, a linear mixed model revealed a negative organ-by-age interaction, meaning that interorgan differences in contamination level were greater in younger (5-11 months) than in older (18-36 months) animals. Different feeding habits can be the explanation. Our paper shows that muscle sites (diaphragm and tongue) can be useful for radionuclide pollution surveillance in wild boar populations and that younger animals show more interorgan variability in contamination levels than older animals. More investigations are needed to confirm this correlation and to fulfill the request for more data to achieve better risk assessment.

Immunogenic and toxic effects of graphene oxide nanoparticles in mouse skeletal muscles and human red blood cells

To investigate immunogenic and toxic effects of graphene oxide (GO) nanoparticles in mouse skeletal muscles and in human blood in vitro. GO nanoparticles prepared using a probe sonicator were supended in deionized H2O or PBS, and particle size and surface charge of the nanoparticles were measured with dynamic light scattering (DLS). Different concentrations (0.5, 1.0 and 2.0 mg/mL) of GO suspension or PBS were injected at multiple sites in the gastrocnemius muscle (GN) of C57BL/6 mice, and inflammatory response and immune cell infiltrations were detected with HE and immunofluorescence staining. We also examined the effects of GO nanoparticles on human red blood cell (RBC) morphology, hemolysis and blood coagulation using scanning electron microscope (SEM), spectrophotometry, and thromboelastography (TEG). GO nanoparticles suspended in PBS exhibited better colloidal dispersity, stability and surface charge effects than those in deionized H2O. In mouse GNs, injection of GO suspensions dose- and time-dependently resulted in sustained muscular inflammation and myofiber degeneration at the injection sites, which lasted till 8 weeks after the injection; immunofluorescence staining revealed obvious infiltration of monocytes, macrophages, dendritic cells and CD4+ T cells around the injection sites in mouse GNs. In human RBCs, incubation with GO suspensions at 0.2, 2.0 and 20 mg/mL, but not at 0.002 or 0.02 mg/mL, caused significant alterations of cell morphology and hemolysis. TEG analysis showed significant abnormalities of blood coagulation parameters following treatment with high concentrations of GO. GO nanoparticles can induce sustained inflammatory and immunological responses in mouse GNs and cause RBC hemolysis and blood coagulation impairment, suggesting its muscular toxicity and hematotoxicity at high concentrations.

MeRIP sequencing reveals the regulation of N6-methyladenosine in muscle development between hypertrophic and leaner broilers

Meat production performance is the most important economic trait in broilers, and skeletal muscle, as the largest organ in animals, is directly related to meat production during embryonic and postnatal growth and development. N6-Methyladenosine (m6A) is a chemical modification occurs on RNA adenosine that has been reported to participate in a variety of biological processes in all species. However, there are still few reports on the regulatory role of muscle growth and development in poultry after birth. This study aims to reveal the distribution of m6A modification sites in chicken pectoralis major muscle after birth and find out the regulatory relationship between m6A and muscle development. As representatives of leaner (Xinghua chicken [XH]) and hypertrophic (White Recessive Rock chicken [WRR]) broilers, there are significant differences in body weight, muscle fiber diameter, and muscle fiber cross-sectional area between XH and WRR chickens. RNA sequencing detected a total of 397 differentially expressed genes (DEG) in the pectoralis major muscle of XH and WRR chicken, and these DEGs were mainly enriched in catalytic activity and metabolic pathways. MeRIP sequencing results showed that among all 6,476 differentially modified m6A peaks, about 90% peaks (5,823) were differentially down regulated in XH chickens. The joint analysis of the mRNA and MeRIP sequencing data found 145 DEGs with differential m6A peak, ALKBH5 as a m6A demethylase, was also included. The highly expression of ALKBH5 in the muscle tissue of poultry and differential expression between XH and WRR chickens suggest that ALKBH5 may play a crucial role in regulating muscle development. Our results revealed that there were significant differences in growth rate, body weight, muscle fiber diameter, and fiber cross-section area between WRR and XH chicken, as well as significant differences in m6A methylation level and muscle metabolism level.

Determining Changes in Muscle Size and Architecture After Exercise Training: One Site Does Not Fit all.

Nunes, JP, Blazevich, AJ, Schoenfeld, BJ, Kassiano, W, Costa, BDV, Ribeiro, AS, Nakamura, M, Nosaka, K, and Cyrino, ES. Determining changes in muscle size and architecture after exercise training: One site does not fit all. J Strength Cond Res 38(4): 787-790, 2024-Different methods can be used to assess muscle hypertrophy, but the effects of training on regional changes in muscle size can be detected only using direct muscle measurements such as muscle thickness, cross-sectional area, or volume. Importantly, muscle size increases vary across regions within and between muscles after resistance training programs (i.e., heterogeneous, or nonuniform, muscle hypertrophy). Muscle architectural changes, including fascicle length and pennation angle, after resistance and stretch training programs are also region-specific. In this paper, we show that the literature indicates that a single-site measure of muscle shape does not properly capture the effects achieved after exercise training interventions and that conclusions concerning the magnitude of muscle adaptations can vary substantially depending on the muscle site to be examined. Thus, we propose that measurements of muscle size and architecture should be completed at multiple sites across regions between the agonist muscles within a muscle group and along the length of the muscles to provide an adequate picture of training effects.

Considering Cuteness Enhances Smiling Responses to Infant Faces1,2

AbstractLaboratory and field research has reported that the appearance of infants causes observers to smile. The current study examined whether this smiling response is modulated by the observer's task and evaluative dimension. Thirty‐nine young nulliparous women were asked to rate the cuteness or beauty levels of 6‐month‐old infants' faces using a 7‐point scale in different blocks. Facial electromyograms (EMGs) were recorded of participants' facial muscles related to both smiling (the zygomaticus major [ZM] and orbicularis oculi [OO]) and frowning (the corrugator supercilii [CS]). The results showed that cuteness and beauty ratings were highly correlated with each other (r = .90), indicating that these evaluations were based on similar attractiveness‐related physical features. Facial EMG responses on the smiling muscle sites, ZM and OO, increased significantly from the baseline when participants rated the faces' cuteness, and the responses were larger than when participants rated the faces' beauty. CS activity was not found to have any effect. The perceived cuteness level of the infant faces did not affect the facial EMG responses. Moreover, the magnitude of the smiling response was shown to be much smaller than that associated with voluntary smiling. These findings suggest that facial expressions while viewing infant faces do not exhibit a fixed pattern but are modulated by observers' tasks and that considering cuteness, which is based on more affective evaluations than beauty, can enhance smiling responses.

Adjuvant effects of β-defensin on DNA vaccine OmpC against edwardsiellosis in flounder (Paralichthys olivaceus)

β-defensin of flounder plays an important role in immunomodulation by recruiting immune cells and has a potential vaccine adjuvant effect in addition to its bactericidal activity. In this study, adjuvant effects of β-defensin on DNA vaccine OmpC against edwardsiellosis in flounder (Paralichthys olivaceus) were investigated. The bicistronic eukaryotic expression plasmid pBudCE4.1 plasmid vector with two independent coding regions was selected to construct DNA vaccine of p-OmpC which express only the gene for the outer membrane protein of Edwardsiella tarda and the vaccine of p-OmpC-βdefensin which express both the outer membrane protein of the bacterium and β-defensin of flounder. In vitro and in vivo studies have shown that the constructed plasmids can be expressed in flounder embryonic cell lines and injection sites of muscles. After vaccination by intramuscular injection, both p-OmpC and p-OmpC-βdefensin groups showed significant upregulation of immune-response. Compared to the pBbudCE4.1 and the p-OmpC vaccinated groups, the p-OmpC-βdefensin vaccinated group showed significantly more cell aggregation at the injection site and intense immune response. The proportion of sIgM+ cells, as well as the CD4-1+ and CD4-2+ cells in both spleen and kidney was significantly higher in the p-OmpC-βdefensin vaccinated group at peak time point than in the control groups. The relative survival rate of the p-OmpC-βdefensin vaccine was 74.17%, which was significantly higher than that of the p-OmpC vaccinated group 48.33%. The results in this study determined that β-defensin enhances the responses in cellular and humoral immunity and evokes a high degree of protection against E. tarda, which is a promising candidate for vaccine adjuvant.

Implications of EMG channel count: enhancing pattern recognition online prosthetic testing.

Myoelectric pattern recognition systems have shown promising control of upper limb powered prostheses and are now commercially available. These pattern recognition systems typically record from up to 8 muscle sites, whereas other control systems use two-site control. While previous offline studies have shown 8 or fewer sites to be optimal, real-time control was not evaluated. Six individuals with no limb absence and four individuals with a transradial amputation controlled a virtual upper limb prosthesis using pattern recognition control with 8 and 16 channels of EMG. Additionally, two of the individuals with a transradial amputation performed the Assessment for Capacity of Myoelectric Control (ACMC) with a multi-articulating hand and wrist prosthesis with the same channel count conditions. Users had significant improvements in control when using 16 compared to 8 EMG channels including decreased classification error (p = 0.006), decreased completion time (p = 0.019), and increased path efficiency (p = 0.013) when controlling a virtual prosthesis. ACMC scores increased by more than three times the minimal detectable change from the 8 to the 16-channel condition. The results of this study indicate that increasing EMG channel count beyond the clinical standard of 8 channels can benefit myoelectric pattern recognition users.

Muscle ultrasound to diagnose sarcopenia in chronic kidney disease: a systematic review and bayesian bivariate meta-analysis

ObjectiveThe aim of this systematic review was to assess the diagnostic test accuracy of muscle ultrasound for sarcopenia among chronic kidney disease (CKD) populations.BackgroundSarcopenia has become a worldwide health issue, especially for CKD patients. Conventional techniques of muscle mass assessment often prove limited, thus prompts increasing interest in ultrasound suitability.MethodsWe searched the Cochrane Library, PubMed and Embase for literature published up to June 2023. Ultrasound diagnosis of sarcopenia in CKD patients was included. Two independent investigators used the Quality Assessment Tool for Diagnosis Accuracy Studies (QUADAS-2) to assess the quality. We extracted valuable information from eligible studies. Using a Bayesian bivariate model, we pooled sensitivity and specificity values and summary receiver operating characteristic (SROC) curves.ResultsFive articles, involving 428 participants at various stages of CKD were included. Three studies diagnosed by the cross-sectional area (CSA) of the rectus femoris, while two others by muscle thickness (MT) and shear wave elastography (SWE) from the same muscle, separately. Overall, CSA or SWE had a pooled sensitivity of 0.95 (95% CrI, 0.80, 1.00), and the specificity was 0.73 (95% CrI, 0.55, 0.88) for diagnosing sarcopenia in CKD patients.ConclusionsUltrasound measurements of CSA and SWE were more sensitive for diagnosing sarcopenia in the CKD population than in the general population. Ultrasound assessment from a single peripheral skeletal muscle site may serve as a rapid screening tool for identifying sarcopenic individuals within the CKD population, if a specific cut-off value could be determined.

A Recording Method for Sixteen Nonadult Muscle Entheses

ABSTRACT Bioarchaeology lacks a system for recording the morphology of muscle and ligament attachment sites, called entheses, in growing individuals. Such information is useful in investigating factors that affect bone growth and development, including sex, age, puberty, pathology, and activity. This paper presents a standardized recording method for nonadult entheses based on 29 archaeological individuals of archivally known sex and age-at-death, ranging from two to 17 years. This paper (a) assesses the range of osseous changes of 16 entheses in the upper and lower limbs of growing individuals, and (b) presents a scoring method for each enthesis, which is evaluated through inter-and intra-observer comparisons. Nonadult entheses show a wide range of morphological variation. Method reproducibility is established. This method will allow researchers to further investigate factors affecting bone development in nonadult skeletal remains.