Swimming in fishes is powered by myotomal red, white and pink skeletal muscle. Slow swimming is powered by the red (slow-twitch muscle), fast speeds are achieved by the white (fast-twitch) muscle and pink muscle apparently serves an intermediate function. In recent years, the physiological properties and molecular composition of red (slow) and white (fast) muscle fibers have been well studied, while the intermediate pink muscle, which falls in a thin sheet between the superficial red muscle and deeper white muscle, has received less attention. The goal of this study is to determine the contractile properties of red, pink, and white muscle and to establish the molecular basis of fiber type variations in contractile properties in a sheepshead (Archosargus probatocephalus). Isometric and isovelocity muscle mechanics experiments demonstrated a general pattern of increasing contractile speed from red to pink to white muscle, although red and pink muscle did not differ significantly for most contraction kinetics variables. As myosin heavy chain (MyHC) is the most important structural protein found in the muscle fibers, MyHC content was examined through immunohistochemistry. Myosin antibodies suggest a gradient in myosin content corresponding to differences in muscle contraction kinetics.
Introduction: Military body fat standards were implemented in the 1980s to prevent obesity and associated poor military readiness. In the past 2 decades, enforcement of existing Army body composition standards has been eroded by the steady increase in national obesity rates, the demand for new recruits especially during the 2007 surge in Iraq, and the COVID epidemic in 2020. The diminishing qualified recruit pool puts a new focus on accession standards.
Department of Emergency Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, China.
Aortic dissection (AD) represents a critical condition characterised by a tear in the inner lining of the aorta, leading to the leakage of blood into the layers of the aortic wall, posing a significant risk to life. However, the pathogenesis is unclear. In this study, scRNA-seq was applied to cells derived from aortas of both AD and non-AD donors (control) to unveil the cellular landscape.
Background: Dual-task activities, which involve performing two separate tasks simultaneously, often result in reduced motor function and daily activity performance among individuals with knee osteoarthritis (OA).
Objective: This study aimed to investigate the impact of single- and dual-task conditions on muscle strength and performance in individuals with knee OA and examine how cognitive load influences physical task performance in this population.
Methods: Sixty patients with knee OA were included.
Introduction: Duchenne muscular dystrophy (DMD) is a severe X-linked disorder characterized by progressive muscle weakness and eventual death due to cardiomyopathy or respiratory complications. Currently, there is no cure for DMD, with standard treatments primarily focusing on symptom management. Using immunosuppressive measures and optimized vector designs allow for gene therapies to better address the underlying genetic cause of the disease.
Creatine monohydrate supplementation (CrM) is a safe and effective intervention for improving certain aspects of sport, exercise performance, and health across the lifespan. Despite its evidence-based pedigree, several questions and misconceptions about CrM remain. To initially address some of these concerns, our group published a narrative review in 2021 discussing the scientific evidence as to whether CrM leads to water retention and fat accumulation, is a steroid, causes hair loss, dehydration or muscle cramping, adversely affects renal and liver function, and if CrM is safe and/or effective for children, adolescents, biological females, and older adults.
