Assessment of age-related differences in decomposition-based quantitative EMG in the intrinsic hand muscles: A multivariate approach
CLINICAL NEUROPHYSIOLOGY
Authors: Tsang, Philemon; MacDermid, Joy C.; Miller, Thomas A.; Doherty, Timothy J.; Ross, Douglas C.
Abstract
Objective: Decomposition-based quantitative electromyography (DQEMG) is one method of measuring neuromuscular physiology in human muscles. The objective of the current study is to compare the neuromuscular physiology of a typical aging population in the intrinsic hand muscles. Methods: Measurements of DQEMG were detected with a standard concentric needle and surface EMG from the intrinsic hand muscles. DQEMG was obtained from the first dorsal interosseous (FDI), the abductor digiti minimi (ADM) and fourth dorsal interosseous (4DI). Multivariate analysis of variance (MANOVA) were performed for the surface and intramuscular EMG measures to identify age differences in motor unit properties. Results: Large differences were observed between the age groups for the canonical intramuscular and surface EMG variables. Older adults demonstrated a large decrease in motor unit number estimation in the ADM and FDI. Likewise, medium to large decreases in motor unit stability were observed in the FDI, ADM and 4DI. Conclusions: With aging, there are decreases in motor unit number estimation and stability in the intrinsic hand muscles. Using a multivariate approach allows for age-related differences and the relationship between the variables to be further elucidated. Significance: Multivariate analysis of DQEMG may be useful for identifying patterns of change in neuromuscular physiology with age-related changes to hand musculature. This may potentially lead to future prognostic biomarkers of age-related changes to hand muscles. (C) 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
Porcine acellular dermal matrix accelerates wound healing through miR-124-3p.1 and miR-139-5p
CYTOTHERAPY
Authors: Chen, Xiaodong; Yang, Ronghua; Wang, Jingru; Ruan, Shubin; Lin, Zepeng; Xin, Qi; Yang, Ridong; Xie, Julin
Abstract
Background aims: Cutaneous wound management is a major health problem and imposes a huge economic burden worldwide. Previous studies have demonstrated that wound healing is a highly coordinated process including epithelialization, angiogenesis, remodeling and scarring. This progression requires self-renewal, preservation and repair properties of stem cells. However, our understanding of the detailed internal regulatory mechanism following injury and the means to accelerate wound healing are limited. Methods: Our previous research revealed that porcine acellular dermal matrix (ADM) effectively promotes wound healing and scar formation through epidermal stem cells (ESCs), and this process is relevant to the alteration of internal miRNA levels. In this study, we investigated the regulatory function of porcine ADM treatment on miRNAs in ESCs. Results: We report that the treatment of porcine ADM reduced the levels of miR-124-3p.1 and miR-139-5p in wounds. MiR-124-3p.1 and miR-139-5p inhibited the expression of JAG1 and Notch1, respectively, by directly targeting miRNAs in ESCs. Conclusions: This work demonstrates that porcine ADM induced down-regulation of miR-124-3p.1/139-5p in wounds and up-regulation of JAG1/Notch1 in ESCs, thus enhancing cutaneous wound healing. (c) 2020 International Society for Cell and Gene Therapy. Published by Elsevier Inc. All rights reserved.