A Wireless Multi-Layered EMG/MMG/NIRS Sensor for Muscular Activity Evaluation.

A wireless multi-layered sensor that allows electromyography (EMG), mechanomyography (MMG) and near-infrared spectroscopy (NIRS) measurements to be carried out simultaneously is presented. The multi-layered sensor comprises a thin silver electrode, transparent piezo-film and photosensor. EMG and MMG measurements are performed using the electrode and piezo-film, respectively.

Enzymatically modified isoquercitrin supplementation intensifies plantaris muscle fiber hypertrophy in functionally overloaded mice.

Background: Enzymatically modified isoquercitrin (EMIQ) is produced from rutin using enzymatic hydrolysis followed by treatment with glycosyltransferase in the presence of dextrin to add glucose residues. EMIQ is absorbed in the same way as quercetin, a powerful antioxidant reported to prevent disused muscle atrophy by targeting mitochondria and to have ergogenic effects. The present study investigated the effect of EMIQ on skeletal muscle hypertrophy induced by functional overload.

Functional Overload Enhances Satellite Cell Properties in Skeletal Muscle.

Skeletal muscle represents a plentiful and accessible source of adult stem cells. Skeletal-muscle-derived stem cells, termed satellite cells, play essential roles in postnatal growth, maintenance, repair, and regeneration of skeletal muscle. Although it is well known that the number of satellite cells increases following physical exercise, functional alterations in satellite cells such as proliferative capacity and differentiation efficiency following exercise and their molecular mechanisms remain unclear.

Effect of AMPK activation on monocarboxylate transporter (MCT)1 and MCT4 in denervated muscle.

It is now evident that exercise training leads to increases in monocarboxylate transporter (MCT)1 and MCT4, but little is known about the mechanisms of coupling muscle contraction with these changes. The aim of this study was to investigate the effect of 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) induced activation of AMP-activated protein kinase (AMPK) on MCT1, MCT4, and GLUT4 in denervated muscle. Protein levels of MCT4 and GLUT4 after 10 days of denervation were significantly decreased in mice gastrocnemius muscle, while MCT1 protein levels were not altered.

Intrinsic ability of adult stem cell in skeletal muscle: an effective and replenishable resource to the establishment of pluripotent stem cells.

Adult stem cells play an essential role in mammalian organ maintenance and repair throughout adulthood since they ensure that organs retain their ability to regenerate. The choice of cell fate by adult stem cells for cellular proliferation, self-renewal, and differentiation into multiple lineages is critically important for the homeostasis and biological function of individual organs. Responses of stem cells to stress, injury, or environmental change are precisely regulated by intercellular and intracellular signaling networks, and these molecular events cooperatively define the ability of stem cell throughout life.

Monitoring neurodegeneration in diabetes using adult neural stem cells derived from the olfactory bulb.

Introduction: Neurons have the intrinsic capacity to produce insulin, similar to pancreatic cells. Adult neural stem cells (NSCs), which give rise to functional neurons, can be established and cultured not only by intracerebral collection, which requires difficult surgery, but also by collection from the olfactory bulb (OB), which is relatively easy. Adult neurogenesis in the hippocampus (HPC) is significantly decreased in diabetes patients.

The insulin regulatory network in adult hippocampus and pancreatic endocrine system.

There is a very strong correlation between the insulin-mediated regulatory system of the central nervous system and the pancreatic endocrine system. There are many examples of the same transcriptional factors being expressed in both regions in their embryonic development stages. Hormonal signals from the pancreatic islets influence the regulation of energy homeostasis by the brain, and the brain in turn influences the secretions of the islets.

Fundamental study of detection of muscle hypertrophy-oriented gene doping by myostatin knock down using RNA interference.

To investigate the feasibility of developing a method for detection of gene doping in power-athletes, we devised an experimental model system. Myostatin is a potent negative regulator of skeletal muscle development and growth, and myostatin-knockout mice exhibit a double-muscle phenotype. To achieve knockdown, we constructed plasmids expressing short hairpin interfering RNAs (shRNAs) against myostatin.

Effects of citrulline supplementation on fatigue and exercise performance in mice.

During high-intensity exercise, the concentration of ammonia is augmented in skeletal muscle. Ammonia activates phosphofructokinase and prevents oxidation of pyruvate to acetyl CoA, thus leading to exhaustion. Citrulline is an amino acid component of the urea cycle in the liver, along with ornithine and arginine.

Expression of monocarboxylate transporter (MCT) 1 and MCT4 in overloaded mice plantaris muscle.

A number of studies have shown that changes in muscle contractile activity regulate the expression of monocarboxylate transporters (MCTs) in the skeletal muscle. The aim of this study was to investigate the effect of functional overload on MCT1 and MCT4 protein expression. Plantaris muscles were functionally overloaded for 15 days by ablation of the synergistic muscles.

Reduction of ribosome biogenesis with activation of the mTOR pathway in denervated atrophic muscle.

Mammalian target of rapamycin (mTOR) pathway positively regulates the cell growth through ribosome biogenesis in many cell type. In general, myostatin is understood to repress skeletal muscle hypertrophy through inhibition of mTOR pathway and myogenesis. However, these relationships have not been clarified in skeletal muscle undergoing atrophy.

Simple method for the identification of oxidative fibers in skeletal muscle.

Skeletal muscle is composed of several different types of myofiber: slow oxidative (SO), fast glycolytic oxidative and fast glycolytic. However, the classification is usually determined by myosin heavy chain typing rather than by metabolic index. In this study, the oxidative metabolic index was investigated as a possible method of myofiber typing.