In situ immunofluorescent staining of autophagy in muscle stem cells

Increasing evidence points to autophagy as a crucial regulatory process to preserve tissue homeostasis. It is known that autophagy is involved in skeletal muscle development and regeneration, and the autophagic process has been described in several muscular pathologies and agerelated muscle disorders. A recently described block of the autophagic process that correlates with the functional exhaustion of satellite cells during muscle repair supports the notion that active autophagy is coupled with productive muscle regeneration. These data uncover the crucial role of autophagy in satellite cell activation during muscle regeneration in both normal and pathological conditions, such as muscular dystrophies. Here, we provide a protocol to monitor the autophagic process in the adult Muscle Stem Cell (MuSC) compartment during muscle regenerative conditions. This protocol describes the setup methodology to perform in situ immunofluorescence imaging of LC3, an autophagy marker, and MyoD, a myogenic lineage marker, in muscle tissue sections from control and injured mice. The methodology reported allows for monitoring the autophagic process in one specific cell compartment, the MuSC compartment, which plays a central role in orchestrating muscle regeneration

SVtL: System Verification through Logic: tool support for verifying sliced hierarchical statecharts

SVtL is the core of a slicing-based verification environment for UML statechart models. We present an overview of the SVtL software architecture. Special attention is paid to the slicing approach. Slicing reduces the complexity of the verification approach, based on removing pieces of the model that are not of interest during verification. In [18] a slicing algorithm has been proposed for statecharts, but it was not able to handle orthogonal regions efficiently. We optimize this algorithm by removing false dependencies, relying on the broadcasting mechanism between different parts of the statechart model

Investigation of genomic DNA methylation by ultraviolet resonant Raman spectroscopy

Cytosine plays a preeminent role in DNA methylation, an epigenetic mechanism that regulates gene expression, the misregulation of which can lead to severe diseases. Several methods are nowadays employed for assessing the global DNA methylation levels, but none of them combines simplicity, high sensitivity, and low operating costs to be translated into clinical applications. Ultraviolet (UV) resonant Raman measurements at excitation wavelengths of 272 nm, 260 nm, 250 nm, and 228 nm have been carried out on isolated deoxynucleoside triphosphates (dNTPs), on a dNTP mixture as well as on genomic DNA (gDNA) samples, commercial from salmon sperm and non-commercial from B16 murine melanoma cell line. The 228 nm excitation wavelength was identified as the most suitable energy for enhancing cytosine signals over the other DNA bases. The UV Raman measurements performed at this excitation wavelength on hyper-methylated and hypo-methylated DNA from Jurkat leukemic T-cell line have revealed significant spectral differences with respect to gDNA isolated from salmon sperm and mouse melanoma B16 cells. This demonstrates how the proper choice of the excitation wavelength, combined with optimized extraction protocols, makes UV Raman spectroscopy a suitable technique for highlighting the chemical modifications undergone by cytosine nucleotides in gDNA upon hyper- and hypo-methylation events

Monte Carlo simulations in the unconstrained ensemble

The unconstrained ensemble describes completely open systems whose control parameters are chemical potential, pressure, and temperature. For macroscopic systems with short-range interactions, thermodynamics prevents the simultaneous use of these intensive variables as control parameters, because they are not independent and cannot account for the system size. When the range of the interactions is comparable with the size of the system, however, these variables are not truly intensive and may become independent, so equilibrium states defined by the values of these parameters may exist. Here, we derive a Monte Carlo algorithm for the unconstrained ensemble and show that simulations can be performed using chemical potential, pressure, and temperature as control parameters. We illustrate the algorithm by applying it to physical systems where either the system has long-range interactions or is confined by external conditions. The method opens up an avenue for the simulation of completely open systems exchanging heat, work, and matter with the environment

Corticospinal and intracortical responses from both motor cortices following unilateral concentric versus eccentric contractions

Cross-education is the phenomenon where training of one limb can cause neuromuscular adaptations in the opposite untrained limb. This effect has been reported to be greater after eccentric (ECC) than concentric (CON) strength training; however, the underpinning neurophysiological mechanisms remain unclear. Thus, we compared responses to transcranial magnetic stimulation (TMS) in both motor cortices following single sessions of unilateral ECC and CON exercise of the elbow flexors. Fourteen healthy adults performed three sets of 10 ECC and CON right elbow flexor contractions at 75 % of respective maximum on separate days. Elbow flexor maximal voluntary isometric contraction (MVIC) torques were measured before and after exercise, and responses to single- and paired-pulse TMS were recorded from the non-exercised left and exercised right biceps brachii. Pre-exercise and post-exercise responses for ECC and CON were compared by repeated measures analyses of variance (ANOVAs). MVIC torque of the exercised arm decreased (p \u3c 0.01) after CON ( − 30 ± 14 %) and ECC ( − 39 ± 13 %) similarly. For the non-exercised left biceps brachii, resting motor threshold (RMT) decreased after CON only ( − 4.2 ± 3.9 % of maximum stimulator output [MSO], p \u3c 0.01), and intracortical facilitation (ICF) decreased (−15.2 ± 20.0 %, p = 0.038) after ECC only. For the exercised right biceps, RMT increased after ECC (8.6 ± 6.2 % MSO, p = 0.014) but not after CON (6.4 ± 8.1% MSO, p = 0.066). Thus, unilateral ECC and CON elbow flexor exercise modulated excitability differently for the non-exercised hemisphere. These findings suggest that responses after a single bout of exercise may not reflect longer term adaptations

The Agreement Between a Portable Contact-Mat and Force-Plates During Bilateral Vertical Jumps

International Journal of Exercise Science 15(1): 632-644, 2022. Force plates are commonly used when assessing vertical jumping performance but are not always affordable or practical tools for all testing situations. Twenty-four participants volunteered to take part in a study investigating the agreement between bilateral force plates and a new commercially available contact mat that records jump height, flight-time (FT), and FT of individual limbs during both countermovement (CMJ) and squat (SJ) jumps. Each participant performed six jumps of each type while standing on a contact mat placed upon a pair of in-ground force plates. When compared to the force plate via ordinary least products regression, the contact mat agreed with force plate CMJ and SJ jump height, individual limb FT during CMJs, and left-leg FT during SJs. The bilateral contact mat provided valid assessment of individual limb FT during CMJs, but not SJs. Practitioners can therefore use a bilateral contact mat interchangeably with bilateral force plates to measure SJ and CMJ performance

Study protocol: Investigating the feasibility of a hybrid delivery of home-based cluster set resistance training for individuals previously treated for lung cancer

Background: Symptom burden remains a critical concern for individuals with non-small cell lung cancer (NSCLC) following the completion of treatment. The most common symptom clusters, dyspnea (shortness of breath) and fatigue, can contribute to physical decline, reductions in quality of life, and a higher risk of comorbidities and mortality. Dyspnea is a primary limiter of exercise capacity in individuals with lung cancer, resulting in exercise avoidance and an accelerated physical decline. As such, designing resistance training with cluster sets to mitigate symptoms of dyspnea and fatigue may result in improved exercise tolerance. Thus, maintaining the exercise stimulus via cluster sets, combined with improved tolerance of the exercise, could result in the maintenance of physical function and quality of life. The purpose of this study is to investigate the feasibility and preliminary efficacy of a hybrid-delivery home-based cluster-set resistance training program in individuals with NSCLC. Methods: Individuals with NSCLC (n = 15), within 12 months of completion of treatment, will be recruited to participate in this single-arm feasibility trial. Participants will complete 8 weeks of home-based resistance training designed to minimize dyspnea and fatigue. The hybrid delivery of the program will include supervised sessions in the participants’ home and virtual supervision via video conferencing. The primary outcome of feasibility will be quantified by recruitment rates, retention, acceptability, and intervention fidelity. Exploratory outcomes (dyspnea, fatigue, quality of life, physical function, and body composition) will be assessed pre- and post-intervention. Discussion: This study will provide important data on the feasibility of delivering this intervention and inform procedures for a future randomized controlled trial. Trial registration: Record not yet publi

Sprint cycling rate of torque development associates with strength measurement in trained cyclists

Purpose: A cyclist’s rate of force/torque development (RFD/RTD) and peak force/torque can be measured during single-joint or whole-body isometric tests, or during cycling. However, there is limited understanding of the relationship between these measures, and of the mechanisms that contribute to each measure. Therefore, we examined the: (i) relationship between quadriceps central and peripheral neuromuscular function with RFD/RTD in isometric knee extension, isometric mid-thigh pull (IMTP), and sprint cycling; and (ii) relationship among RFD/RTD and peak force/torque between protocols. Methods: Eighteen trained cyclists completed two familiarisation and two experimental sessions. Each session involved an isometric knee extension, IMTP, and sprint cycling protocol, where peak force/torque, average and peak RFD/RTD, and early (0 – 100 ms) and late (0–200 ms) RFD/RTD were measured. Additionally, measures of quadriceps central and peripheral neuromuscular function were assessed during the knee extension. Results: Strong relationships were observed between quadriceps early EMG activity (EMG50/M) and knee extension RTD (r or ρ = 0.51 – 0.65) and IMTP late RFD (r = 0.51), and between cycling early or late RTD and peak twitch torque (r or ρ = 0.70 – 0.75). Strong-to-very strong relationships were observed between knee extension, IMTP, and sprint cycling for peak force/torque, early and late RFD/RTD, and peak RFD/RTD (r or ρ = 0.59 – 0.80). Conclusion: In trained cyclists, knee extension RTD or IMTP late RFD are related to measures of quadriceps central neuromuscular function, while cycling RTD is related to measures of quadriceps peripheral neuromuscular function. Further, the strong associations among force/torque measures between tasks indicate a level of transferability across tasks