Mechanisms and Management of Fatigue in Health and Disease: Symposium Introduction

2004 ◽  
Vol 29 (3) ◽  
pp. 264-273 ◽  
Author(s):  
Howard J. Green
Keyword(s):  
Muscle Cell ◽  
Mechanical Response ◽  
Exercise Intolerance ◽  
Free Calcium ◽  
Neural Activation ◽  
Membrane Excitability ◽  
Cell Contractility ◽  
Health And Disease ◽  
Underlying Mechanisms

Exercise intolerance is a condition commonly experienced by both the healthy and those with disease. Yet we have only a limited understanding of the underlying mechanisms and, consequently, the management of this condition. In this Symposium, a major objective was to address the role of the muscle cell in weakness and fatigue. We have focused on addressing the advances made in characterizing the basis of muscle cell contractility with particular respect to the processes and proteins involved in excitation and contraction, and how these processes can be modified during repetitive activity. Three reviews are provided on this subject. Each addresses a specific link in the cascade of events from neural activation of the muscle to the generation of force. In the first review the processes involved in signal transduction in the sarcolemma and T-tubule, and which regulate membrane excitability, are examined. The second review analyzes the sarcoplasmic reticulum regulation of the intracellular messenger that controls the myofibrillar complex, namely free calcium. The final review in this series deals with the events regulating actin-myosin behaviour and the mechanical response. All reviews place special emphasis on how different sites can be modified by repetitive activity and, as a consequence, how they can represent a potential source of fatigue. Since it is important to understand the nature, manifestations, and measurement of weakness and fatigue, a comprehensive review on these topics is also provided. Key words: weakness, muscle, measurement, excitation, contraction

scholarly journals Effects of Probiotics on Human Health and Disease: A Review

2021 ◽  
Vol 48 (1) ◽  
pp. 95-100
Author(s):  
A. Amiri ◽  
F. Firoozeh ◽  
M. Zibaei ◽  
A. Khaledi
Keyword(s):  
Human Health ◽  
Digestive System ◽  
Intestinal Microflora ◽  
Normal Flora ◽  
Beneficial Effects ◽  
Prevention And Treatment ◽  
Health And Disease ◽  
The Subject ◽  
Underlying Mechanisms

Abstract Alteration of the gut microbiome in order to achieve a balance in the normal flora of the intestine could be very beneficial in maintaining the health of the human. Probiotics are living microbial supplements that are added to the diet and have beneficial effects on the host by improving the balance of the intestinal microflora. The purpose of this study is to review previous studies on the effects of probiotics on human health and various diseases. The Farsi and English electronic databases such as, SID, Iranmedex, Magiran, Google Scholar, PubMed and ISI Web of Knowledge were searched and the published articles that have studied the effects of probiotics on the prevention and treatment of various diseases were included in the study. The review of published articles related to the subject showed that consumption of probiotics, prebiotics and proper diet have the significant effects on the health of the digestive system and has reduced and improved symptoms of different disorders and diseases. Further research is needed to better understand the underlying mechanisms of probiotic function and confirm the role of the probiotics in preventing and treating various types of cancers and other diseases.

scholarly journals Role of APD-Ribosylation in Bone Health and Disease

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1201 ◽  
Author(s):  
Wang ◽  
Mbalaviele
Keyword(s):  
Bone Development ◽  
Adenosine Diphosphate ◽  
Signaling Networks ◽  
Post Translational Modification ◽  
Cell Behaviors ◽  
Adp Ribosylation ◽  
Protein Functions ◽  
Health And Disease ◽  
Underlying Mechanisms

The transfer of adenosine diphosphate (ADP)-ribose unit(s) from nicotinamide adenine dinucleotide (NAD+) to acceptor proteins is known as ADP-ribosylation. This post-translational modification (PTM) unavoidably alters protein functions and signaling networks, thereby impacting cell behaviors and tissue outcomes. As a ubiquitous mechanism, ADP-ribosylation affects multiple tissues, including bones, as abnormal ADP-ribosylation compromises bone development and remodeling. In this review, we describe the effects of ADP-ribosylation in bone development and maintenance, and highlight the underlying mechanisms.

From early nutrition and later development...to underlying mechanisms and optimal health

1997 ◽  
Vol 78 (s2) ◽  
pp. S113-S123 ◽  
Author(s):  
M. J. Dauncey
Keyword(s):  
Detailed Knowledge ◽  
Early Nutrition ◽  
Optimal Health ◽  
Health And Disease ◽  
Underlying Mechanisms ◽  
The Way

‘Life is a country that the old have seen, and lived in. Those who have to travel through it can only learn the way from them.’Joseph Joubert, 1842This quotation is perhaps especially appropriate when considering the extensive contributions made by Professor McCance and Dr Widdowson to the field of early nutrition and later development. A detailed knowledge of their work in this area is of undoubted value both in interpreting many recent findings and in the design of new investigations. The first part of this paper presents a brief overview of some of their most significant studies. Their implications at both the fundamental and applied levels are then discussed, especially in relation to the role of nutrition in health and disease. Finally, potential mechanisms by which development may be modified by early nutrition are considered.

Platelets and neurovascular inflammation

2013 ◽  
Vol 110 (11) ◽  
pp. 888-893 ◽  
Author(s):  
Triantafyllos Chavakis ◽  
Harald F. Langer
Keyword(s):  
Immune Responses ◽  
Thrombus Formation ◽  
Inflammatory Cells ◽  
Autoimmune Encephalomyelitis ◽  
Central Nervous Tissue ◽  
Endothelial Inflammation ◽  
Health And Disease ◽  
Underlying Mechanisms ◽  
Experimental Autoimmune

SummaryPlatelets participate in haemostasis and in thrombus formation in health and disease. Moreover, they contribute to inflammation and cooperate with immune cells in a magnitude of inflammatory/immune responses. Although the inflammatory response has been recognised to be critical in neuronal diseases such as Alzheimer´s disease or multiple sclerosis and its mouse counterpart, experimental autoimmune encephalomyelitis, the participation of platelets in these diseases is poorly investigated so far. Emerging studies, however, point to an interesting crosstalk between platelets and neuroinflammation. For instance, when the integrity of the blood brain barrier is compromised, platelets may be relevant for endothelial inflammation, as well as recruitment and activation of inflammatory cells, thereby potentially contributing to central nervous tissue pathogenesis. This review summarises recent insights in the role of platelets for neurovascular inflammation and addresses potential underlying mechanisms, by which platelets may affect the pathophysiology of neurovascular diseases.

scholarly journals The Obligatory Role of the Acetylcholine-Induced Endothelium-Dependent Contraction in Hypertension: Can Arachidonic Acid Resolve this Inflammation?

2020 ◽  
Vol 26 (30) ◽  
pp. 3723-3732 ◽  
Author(s):  
Jonnelle M. Edwards ◽  
Cameron G. McCarthy ◽  
Camilla F. Wenceslau
Keyword(s):  
Arachidonic Acid ◽  
G Protein ◽  
Vascular Inflammation ◽  
Arachidonic Acid Metabolism ◽  
G Protein Coupled Receptors ◽  
Free Calcium ◽  
Underlying Mechanisms ◽  
Transient Elevation ◽  
G Protein Coupled

The endothelium produces many substances that can regulate vascular tone. Acetylcholine is a widely used pharmacological tool to assess endothelial function. In general, acetylcholine binds to G-protein coupled muscarinic receptors that mediate a transient elevation in intracellular, free calcium. This intracellular rise in calcium is responsible for triggering several cellular responses, including the synthesis of nitric oxide, endothelium- derived hyperpolarizing factor, and eicosanoids derived from arachidonic acid. Endothelial arachidonic acid metabolism is also an important signaling pathway for mediating inflammation. Therefore, in conditions with sustained and excessive inflammation such as hypertension, arachidonic acid serves as a substrate for the synthesis of several vasoconstrictive metabolites, predominantly via the cyclooxygenase and lipoxygenase enzymes. Cyclooxygenase and lipoxygenase products can then activate G-protein coupled receptors expressed on vascular smooth muscle cells to causes contractile responses. As a result, acetylcholine-induced contraction due to arachidonic acid is a commonly observed feature of endothelial dysfunction and vascular inflammation in hypertension. In this review, we will critically analyze the literature supporting this concept, as well as address the potential underlying mechanisms, including the possibility that arachidonic acid signaling is diverted away from the synthesis of pro-resolving metabolites in conditions such as hypertension.

Change in Mechanical Response of Arterial Elastin due to Glycation

2012 ◽  
Author(s):  
Beth Stephen ◽  
Theresa A. Good ◽  
L. D. Timmie Topoleski
Keyword(s):  
Soft Tissues ◽  
Mechanical Response ◽  
Tensile Load ◽  
Material Response ◽  
Biochemical Processes ◽  
High Stiffness ◽  
Health And Disease ◽  
Low Stiffness ◽  
The Individual

Collagen and elastin are the primary load-bearing components of arteries. Elastin is a low strength, highly elastic, fibrous material and collagen is a stiffer material, generally present as wavy fibers when unstretched. Together, they account for the material response of arteries under tensile load. Arteries, and other soft tissues, exhibit a two-part material response to tensile load. There is an initial low stiffness response at low stretch followed by a high stiffness response at higher stretch. It has been proposed that the low stiffness response is dominated by the elastin in the material and the high stiffness response is dominated by collagen [1]. The elastin accounts for the initial low stiffness response of the material, until the wavy collagen fibers straighten and become engaged, at which point the material transitions to its higher stiffness response. It is important to understand the role of the individual collagen and elastin components and how they contribute to the overall mechanical response of the arteries. Further, it is important to understand how specific biochemical processes that occur with age and disease affect the mechanical response of the individual collagen and elastin components and consequently the overall mechanical response of the arteries. This knowledge will increase our understanding of arterial mechanical response and how this response changes arterial function in health and disease.

scholarly journals The Interplay between Oxidative Stress, Exercise, and Pain in Health and Disease: Potential Role of Autonomic Regulation and Epigenetic Mechanisms

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1166
Author(s):  
Jolien Hendrix ◽  
Jo Nijs ◽  
Kelly Ickmans ◽  
Lode Godderis ◽  
Manosij Ghosh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Chronic Pain ◽  
Potential Role ◽  
Mechanisms Of Action ◽  
Autonomic Regulation ◽  
Epigenetic Mechanisms ◽  
Confounding Factors ◽  
Health And Disease ◽  
Underlying Mechanisms

Oxidative stress can be induced by various stimuli and altered in certain conditions, including exercise and pain. Although many studies have investigated oxidative stress in relation to either exercise or pain, the literature presents conflicting results. Therefore, this review critically discusses existing literature about this topic, aiming to provide a clear overview of known interactions between oxidative stress, exercise, and pain in healthy people as well as in people with chronic pain, and to highlight possible confounding factors to keep in mind when reflecting on these interactions. In addition, autonomic regulation and epigenetic mechanisms are proposed as potential mechanisms of action underlying the interplay between oxidative stress, exercise, and pain. This review highlights that the relation between oxidative stress, exercise, and pain is poorly understood and not straightforward, as it is dependent on the characteristics of exercise, but also on which population is investigated. To be able to compare studies on this topic, strict guidelines should be developed to limit the effect of several confounding factors. This way, the true interplay between oxidative stress, exercise, and pain, and the underlying mechanisms of action can be revealed and validated via independent studies.

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

Response Interference as a Mechanism Underlying Implicit Measures

2008 ◽  
Vol 24 (4) ◽  
pp. 218-225 ◽  
Author(s):  
Bertram Gawronski ◽  
Roland Deutsch ◽  
Etienne P. LeBel ◽  
Kurt R. Peters
Keyword(s):  
Task Performance ◽  
Psychological Research ◽  
Implicit Measures ◽  
Mediation Model ◽  
Response Interference ◽  
Relevant Evidence ◽  
Moderated Mediation Model ◽  
Stimulus Features ◽  
Underlying Mechanisms

Over the last decade, implicit measures of mental associations (e.g., Implicit Association Test, sequential priming) have become increasingly popular in many areas of psychological research. Even though successful applications provide preliminary support for the validity of these measures, their underlying mechanisms are still controversial. The present article addresses the role of a particular mechanism that is hypothesized to mediate the influence of activated associations on task performance in many implicit measures: response interference (RI). Based on a review of relevant evidence, we argue that RI effects in implicit measures depend on participants’ attention to association-relevant stimulus features, which in turn can influence the reliability and the construct validity of these measures. Drawing on a moderated-mediation model (MMM) of task performance in RI paradigms, we provide several suggestions on how to address these problems in research using implicit measures.

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