Mechanisms regulating muscle regeneration: insights into the interrelated and time-dependent phases of tissue healing

Despite a massive body of knowledge which has been produced related to the mechanisms guiding muscle regeneration, great interest still moves the scientific community toward the study of different aspects of skeletal muscle homeostasis, plasticity, and regeneration. Indeed, the lack of effective therapies for several physiopathologic conditions suggests that a comprehensive knowledge of the different aspects of cellular behavior and molecular pathways, regulating each regenerative stage, has to be still devised. Hence, it is important to perform even more focused studies, taking the advantage of robust markers, reliable techniques, and reproducible protocols. Here, we provide an overview about the general aspects of muscle regeneration and discuss the different approaches to study the interrelated and time-dependent phases of muscle healing

Systematic Human Reliability Analysis (SHRA): A New Approach to Evaluate Human Error Probability (HEP) in a Nuclear Plant

Emergency management in industrial plants is a fundamental issue to ensure the safety of operators. The emergency management analyses two fundamental aspects: the system reliability and the human reliability. System reliability is the capability of ensuring the functional properties within a variability of work conditions, considering the possible deviations due to unexpected events. However, system reliability is strongly related to the reliability of its weakest component. The complexity of the processes could generate incidental situations and the worker appears (human reliability) to be the weakest part of the whole system. The complexity of systems influences operator’s ability to take decisions during emergencies. The aim of the present research is to develop a new approach to evaluate human error probability (HEP), called Systematic Human Reliability Analysis (SHRA). The proposed approach considers internal and external factors that affect operator’s ability. The new approach is based on Nuclear Action Reliability Assessment (NARA), Simplified Plant Analysis Risk Human Reliability (SPAR-H) and on the Performance Shaping Factors (PSFs) relationship. The present paper analysed some shortcomings related to literature approaches, especially the limitations of the working time. We estimated HEP, after 8 hours (work standard) during emergency conditions. The correlations between the advantages of these three methodologies allows proposing a HEP analysis during accident scenarios emergencies. SHRA can be used to estimate human reliability during emergencies. SHRA has been applied in a nuclear accident scenario, considering 24 hours of working time. The SHRA results highlight the most important internal and external factors that affect operator’s ability

Quality Checks Logit Human Reliability (LHR): A New Model to Evaluate Human Error Probability (HEP)

In the years, several approaches for human reliability analysis (HRA) have been developed. The aim of the present research is to propose a hybrid model to evaluate Human Error Probability (HEP). The new approach is based on logit-normal distribution, Nuclear Action Reliability Assessment (NARA), and Performance Shaping Factors (PSFs) relationship. In the research, shortcomings related to literature approaches are analyzed, especially the limitations of the working time. For this reason, PSFs after 8 hours (work standard) during emergency conditions were estimated. Therefore, the correlation between the advantages of these three methodologies allows proposing a HEP analysis during accident scenarios and emergencies; a fundamental issue to ensure the safety and reliability in industrial plants is emergency Mmnagement (EM). Applying EM methodology, two main aspects are analyzed: system reliability and human reliability. System reliability is strongly related to the reliability of its weakest component. During incidental situations, the weakest parts of the whole system are workers (human reliability) and accidental scenarios influence the operator's ability to make decisions. This article proposes a new approach called Logit Human Reliability (LHR) that considers internal and external factors to estimate human reliability during emergencies. LHR has been applied in a pharmaceutical accident scenario, considering 24 hours of working time (more than 8 working hours). The results highlighted that the LHR method gives output data more in conformity with data banks than the conventional methods during the stress phase in an accident scenario

Modelling three-dimensional cancer-associated cachexia and therapy: the molecular basis and therapeutic potential of interleukin-6 transignalling blockade

Background: Causes and mechanisms underlying cancer cachexia are not fully understood, and currently, no therapeutic approaches are available to completely reverse the cachectic phenotype. Interleukin-6 (IL-6) has been extensively described as a key factor in skeletal muscle physiopathology, exerting opposite roles through different signalling pathways. Methods: We employed a three-dimensional ex vivo muscle engineered tissue (X-MET) to model cancer-associated cachexia and to study the effectiveness of selective inhibition of IL-6 transignalling in counteracting the cachectic phenotype. Conditioned medium (CM) derived from C26 adenocarcinoma cells was used as a source of soluble factors contributing to the establishment of cancer cachexia in the X-MET model. A dose of 1.2 ng/mL of glycoprotein-130 fused chimaera (gp130Fc) was added to cachectic culture medium to neutralize IL-6 transignalling. Results: C26-conditioned medium induced a cachectic-like phenotype in the X-MET, leading to a decline of muscle mass (−60%; P < 0.001), a reduction in myosin expression (−92.4%; P < 0.005) and a reduction of the contraction frequency spectrum (−94%). C26-conditioned medium contains elevated amounts of IL-6 (8.61 ± 4.09 pg/mL) and IL6R (56.85 ± 10.96 pg/mL). These released factors activated the signal transducer and activator of transcription 3 (STAT3) signalling in the C26_CM X-MET system (phosphorylated STAT3/TOTAL +54.6%; P < 0.005), which in turn promote an enhancement of Il-6 (+69.2%; P < 0.05) and Il6r (+43%; P < 0.05) gene expression, suggesting the induction of a feed-forward loop. The selective neutralization of IL-6 transignalling, by gp130Fc, in C26_CM X-MET prevented the hyperactivation of STAT3 (−55.8%; P < 0.005), countered the reduction of cross-sectional area (+28.2%; P < 0.05) and reduced the expression of proteolytic factors including muscle ring finger-1 (−88%; P < 0.005) and ATROGIN1 (−92%; P < 0.05), thus preserving the robustness and increasing the contractile force (+20%) of the three-dimensional muscle system. Interestingly, the selective inhibition of IL-6 transignalling modulated gene regulatory networks involved in myogenesis and apoptosis, normalizing the expression of pro-apoptotic miRNAs, including miR-31 (−53.2%; P < 0.05) and miR-34c (−65%; P < 0.005), and resulting in the reduction of apoptotic pathways highlighted by the sensible reduction of cleaved caspase 3 (−92.5%; P < 0.005) in gp130Fc-treated C26_CM X-MET. Conclusions: IL-6 transignalling appeared as a promising target to counter cancer cachexia-related alterations. The X-MET model has proven to be a reliable drug-screening tool to identify novel therapeutic approaches and to test them in preclinical studies, significantly reducing the use of animal models

A hybrid model to evaluate human error probability (HEP) in a pharmaceutical plant

The aim of the present research is to propose a hybrid model to evaluate Human Error Probability (HEP) called Logit Human Reliability (LHR). The new approach is based on logit normal distribution, Nuclear Action Reliability Assessment (NARA), and Performance Shaping Factors (PSFs) relationship. The present paper analyzed some shortcomings related to literature approaches, especially the limitations of the working time. We estimated PSFs after 8 hours (work standard) during emergency conditions. Therefore, the correlation between the advantages of these three methodologies allows proposing a HEP analysis during accident scenario and emergencies. The proposed approach considers internal and external factors that affect the operator's ability. LHR has been applied in a pharmaceutical accident scenario, considering 24 hours of working time (more than 8 working hours)

Reliability estimation of reinforced slopes to prioritize maintenance actions

Geosynthetics are extensively utilized to improve the stability of geotechnical structures and slopes in urban areas. Among all existing geosynthetics, geotextiles are widely used to reinforce unstable slopes due to their capabilities in facilitating reinforcement and drainage. To reduce settlement and increase the bearing capacity and slope stability, the classical use of geotextiles in embankments has been suggested. However, several catastrophic events have been reported, including failures in slopes in the absence of geotextiles. Many researchers have studied the stability of geotextile-reinforced slopes (GRSs) by employing different methods (analytical models, numerical simulation, etc.). The presence of source-to-source uncertainty in the gathered data increases the complexity of evaluating the failure risk in GRSs since the uncertainty varies among them. Consequently, developing a sound methodology is necessary to alleviate the risk complexity. Our study sought to develop an advanced risk-based maintenance (RBM) methodology for prioritizing maintenance operations by addressing fluctuations that accompany event data. For this purpose, a hierarchical Bayesian approach (HBA) was applied to estimate the failure probabilities of GRSs. Using Markov chain Monte Carlo simulations of likelihood function and prior distribution, the HBA can incorporate the aforementioned uncertainties. The proposed method can be exploited by urban designers, asset managers, and policymakers to predict the mean time to failures, thus directly avoiding unnecessary maintenance and safety consequences. To demonstrate the application of the proposed methodology, the performance of nine reinforced slopes was considered. The results indicate that the average failure probability of the system in an hour is 2.8 ≥ 105 during its lifespan, which shows that the proposed evaluation method is more realistic than the traditional methods

Preliminary realization of an electric-powered hydraulic pump system for a waste compactor truck and a techno-economic analysis

Most industrial trucks are equipped with hydraulic systems designed for specic operations, for which the required power is supplied by the internal combustion engine (ICE). The largest share of the power consumption is required by the hydraulic system during idling operations, and, consequently, the current literature focuses on energy saving strategies for the hydraulic system rather than making the vehicle traction more efficient. This study presents the preliminary realization of an electric-powered hydraulic pump system (e-HPS) that drives the lifting of the dumpster and the garbage compaction in a waste compactor truck, rather than traditional ICE-driven hydraulic pump systems (ICE-HPSs). The different components of the e-HPS are described and the battery pack was modelled using the kinetic battery model. The end-of-life of the battery pack was determined to assess the economic feasibility of the proposed e-HPS for the truck lifespan, using numerical simulations. The aim was twofold: To provide an implementation method to retrofit the e-HPS to a conventional waste compactor truck and to assess its economic feasibility, investigating fuel savings during the use phase and the consequent reduction of CO2 emissions. Results show that the total lifespan cost saving achieved a value of 65,000. Furthermore, total CO2 emissions for the e-HPS were about 80% lower than those of the ICE-HPS, highlighting that the e-HPS can provide significant environmental benefits in an urban context

Engineered extracellular vesicle decoy receptor-mediated modulation of the IL6 trans-signalling pathway in muscle

The cytokine interleukin 6 (IL6) is a key mediator of inflammation that contributes to skeletal muscle pathophysiology. IL6 activates target cells by two main mechanisms, the classical and trans-signalling pathways. While classical signalling is associated with the anti-inflammatory activities of the cytokine, the IL6 trans-signalling pathway mediates chronic inflammation and is therefore a target for therapeutic intervention. Extracellular vesicles (EVs) are natural, lipid-bound nanoparticles, with potential as targeted delivery vehicles for therapeutic macromolecules. Here, we engineered EVs to express IL6 signal transducer (IL6ST) decoy receptors to selectively inhibit the IL6 trans-signalling pathway. The potency of the IL6ST decoy receptor EVs was optimized by inclusion of a GCN4 dimerization domain and a peptide sequence derived from syntenin-1 which targets the decoy receptor to EVs. The resulting engineered EVs were able to efficiently inhibit activation of the IL6 trans-signalling pathway in reporter cells, while having no effect on the IL6 classical signalling. IL6ST decoy receptor EVs, were also capable of blocking the IL6 trans-signalling pathway in C2C12 myoblasts and myotubes, thereby inhibiting the phosphorylation of STAT3 and partially reversing the anti-differentiation effects observed when treating cells with IL6/IL6R complexes. Treatment of a Duchenne muscular dystrophy mouse model with IL6ST decoy receptor EVs resulted in a reduction in STAT3 phosphorylation in the quadriceps and gastrocnemius muscles of these mice, thereby demonstrating in vivo activity of the decoy receptor EVs as a potential therapy. Taken together, this study reveals the IL6 trans-signalling pathway as a promising therapeutic target in DMD, and demonstrates the therapeutic potential of IL6ST decoy receptor EVs

Sam68 splicing regulation contributes to motor unit establishment in the postnatal skeletal muscle

RNA-binding proteins orchestrate the composite life of RNA molecules and impact most physiological processes, thus underlying complex phenotypes. The RNA-binding protein Sam68 regulates differentiation processes by modulating splicing, polyadenylation, and stability of select transcripts. Herein, we found that Sam68-/- mice display altered regulation of alternative splicing in the spinal cord of key target genes involved in synaptic functions. Analysis of the motor units revealed that Sam68 ablation impairs the establishment of neuromuscular junctions and causes progressive loss of motor neurons in the spinal cord. Importantly, alterations of neuromuscular junction morphology and properties in Sam68-/- mice correlate with defects in muscle and motor unit integrity. Sam68-/- muscles display defects in postnatal development, with manifest signs of atrophy. Furthermore, fast-twitch muscles in Sam68-/- mice show structural features typical of slow-twitch muscles, suggesting alterations in the metabolic and functional properties of myofibers. Collectively, our data identify a key role for Sam68 in muscle development and suggest that proper establishment of motor units requires timely expression of synaptic splice variants

Early molecular diagnosis of aspergillosis in a patient with acute myeloid leukaemia

Diagnosis of invasive fungal infection remains challenging. Here we report a case of early diagnosis of invasive aspergillosis in a neutropenic patient affected by acute myeloid leukaemia, achieved through the detection of Aspergillus fumigatus species-specific ribonucleic acid sequences by a sensitive multiplex real-time polymerase chain reaction-based molecular assay. Thanks to the early diagnosis, targeted therapy was promptly established and the severe fungal infection controlled, allowing the patient to subsequently receive allogeneic hematopoietic stem cell transplantation from a haploidentical donor, her only curative option. Also in this instance, targeted secondary antifungal prophylaxis with voriconazole avoided any other fungal infection afterwards. This report suggests how the implementation of molecular assays in combination with routine diagnostic procedures, can improve microbiological diagnosis in sepsis, particularly in case of fungal infection, difficult to detect with standard microbiological culture methods