Adaptation of the Cardiac Myofiber Orientations Through Deformation: Computational Analysis of the Myocardial Structure

2008 ◽  
Author(s):  
Wilco Kroon ◽  
Tammo Delhaas ◽  
Peter Bovendeerd ◽  
Theo Arts
Keyword(s):  
Oxygen Consumption ◽  
Mechanical Loading ◽  
Computational Analysis ◽  
Mechanical Load ◽  
Mechanical Factors ◽  
Myocardial Structure

The distribution of mechanical load throughout the wall is very sensitive to the myofiber orientation [1]. Yet, heterogeneity myofiber shortening, metabolism as well as oxygen consumption is limited, indicating heterogeneity in mechanical load is limited [2,4]. This suggests that mechanical loading is able to control the myofiber direction. However, the relation between mechanical loading and the myocardial structure remains unclear. Understanding this relation may be useful to gain additional knowledge about the role of mechanical factors in (patho-)physiology of the myocardial structure.

scholarly journals An Overview of the Role of Mechanical Stretching in the Progression of Lung Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Fengying Gong ◽  
Yuchao Yang ◽  
Liangtao Wen ◽  
Congrong Wang ◽  
Jingjun Li ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Progression ◽  
Mechanical Load ◽  
Tumor Development ◽  
Physical Factors ◽  
Mechanical Factors ◽  
Tissue Characteristics ◽  
The Relationship ◽  
Mechanical Stretching

Cells and tissues in the human body are subjected to mechanical forces of varying degrees, such as tension or pressure. During tumorigenesis, physical factors, especially mechanical factors, are involved in tumor development. As lung tissue is influenced by movements associated with breathing, it is constantly subjected to cyclical stretching and retraction; therefore, lung cancer cells and lung cancer-associated fibroblasts (CAFs) are constantly exposed to mechanical load. Thus, to better explore the mechanisms involved in lung cancer progression, it is necessary to consider factors involved in cell mechanics, which may provide a more comprehensive analysis of tumorigenesis. The purpose of this review is: 1) to provide an overview of the anatomy and tissue characteristics of the lung and the presence of mechanical stimulation; 2) to summarize the role of mechanical stretching in the progression of lung cancer; and 3) to describe the relationship between mechanical stretching and the lung cancer microenvironment, especially CAFs.

scholarly journals Impact of Mechanical Load on the Expression Profile of Synovial Fibroblasts from Patients with and without Osteoarthritis

2019 ◽  
Vol 20 (3) ◽  
pp. 585 ◽  
Author(s):  
Agnes Schröder ◽  
Ute Nazet ◽  
Dominique Muschter ◽  
Susanne Grässel ◽  
Peter Proff ◽  
...  
Keyword(s):  
Mechanical Loading ◽  
Mechanical Load ◽  
Synovial Fibroblasts ◽  
Gene And Protein Expression ◽  
Factor Expression ◽  
Proinflammatory Factor ◽  
Cox 2 ◽  
Pg E2 ◽  
Proinflammatory Factors

Osteoarthritis (OA) affects the integrity of the entire joint including the synovium. The most abundant cells in the synovium are fibroblasts (SF). Excessive mechanical loading might contribute to OA pathogenesis. Here, we investigate the effects of mechanical loading on SF derived from non-OA (N-SF) and OA patients (OA-SF). We treated N-SF and OA-SF with or without mechanical loading for 48h after 24h of preincubation. Then we assessed gene and protein expression of proinflammatory factors (TNFα, COX-2, PG-E2, IL-6), extracellular matrix (ECM) components (COL1, FN1) and glycosaminoglycans (GAGs) via RT-qPCR, ELISA, DMMB assay and HPLC. Mechanical loading significantly increased TNFα and PG-E2 secretion by N-SF and OA-SF, whereas in OA-SF IL-6 secretion was reduced. COL1 and FN1 secretion were downregulated in N-SF during loading. OA-SF secreted less COL1 compared to N-SF under control conditions. In contrast, OA-SF in general expressed more FN1. GAG synthesis was upregulated in N-SF, but not in OA-SF during loading with OA-SF displaying a higher charge density than N-SF. Mechanical loading enhanced proinflammatory factor expression and GAG synthesis and decreased secretion of ECM components in N-SFs, indicating a contributing role of SF to OA development.

scholarly journals The Role of the Pathogen Dose and PI3Kγ in Immunometabolic Reprogramming of Microglia for Innate Immune Memory

2021 ◽  
Vol 22 (5) ◽  
pp. 2578
Author(s):  
Trim Lajqi ◽  
Christian Marx ◽  
Hannes Hudalla ◽  
Fabienne Haas ◽  
Silke Große ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Immune Tolerance ◽  
Immune Cells ◽  
Low Dose ◽  
Innate Immune ◽  
Immune Memory ◽  
Innate Immune Cells ◽  
Atp Production ◽  
Dose Dependent

Microglia, the innate immune cells of the CNS, exhibit long-term response changes indicative of innate immune memory (IIM). Our previous studies revealed IIM patterns of microglia with opposing immune phenotypes: trained immunity after a low dose and immune tolerance after a high dose challenge with pathogen-associated molecular patterns (PAMP). Compelling evidence shows that innate immune cells adopt features of IIM via immunometabolic control. However, immunometabolic reprogramming involved in the regulation of IIM in microglia has not been fully addressed. Here, we evaluated the impact of dose-dependent microglial priming with ultra-low (ULP, 1 fg/mL) and high (HP, 100 ng/mL) lipopolysaccharide (LPS) doses on immunometabolic rewiring. Furthermore, we addressed the role of PI3Kγ on immunometabolic control using naïve primary microglia derived from newborn wild-type mice, PI3Kγ-deficient mice and mice carrying a targeted mutation causing loss of lipid kinase activity. We found that ULP-induced IIM triggered an enhancement of oxygen consumption and ATP production. In contrast, HP was followed by suppressed oxygen consumption and glycolytic activity indicative of immune tolerance. PI3Kγ inhibited glycolysis due to modulation of cAMP-dependent pathways. However, no impact of specific PI3Kγ signaling on immunometabolic rewiring due to dose-dependent LPS priming was detected. In conclusion, immunometabolic reprogramming of microglia is involved in IIM in a dose-dependent manner via the glycolytic pathway, oxygen consumption and ATP production: ULP (ultra-low-dose priming) increases it, while HP reduces it.

Application of Polymer Microspheres for Assessing the Role of Mechanical Factors in the Formation of Neutrophilic Extracellular Traps

2021 ◽  
Vol 16 (1) ◽  
pp. 96-102
Author(s):  
L. Yu. Basyreva ◽  
E. A. Fedorova ◽  
V. A. Polonskiy ◽  
I. V. Skopintsev ◽  
A. L. Luss ◽  
...  
Keyword(s):  
Polymer Microspheres ◽  
Extracellular Traps ◽  
Mechanical Factors

Synapsin Regulates Basal Synaptic Strength, Synaptic Depression, and Serotonin-Induced Facilitation of Sensorimotor Synapses in Aplysia

2007 ◽  
Vol 98 (6) ◽  
pp. 3568-3580 ◽  
Author(s):  
Diasinou Fioravante ◽  
Rong-Yu Liu ◽  
Anne K. Netek ◽  
Leonard J. Cleary ◽  
John H. Byrne
Keyword(s):  
Synaptic Plasticity ◽  
Synaptic Vesicle ◽  
Transmitter Release ◽  
Computational Analysis ◽  
Spontaneous Recovery ◽  
Synaptic Strength ◽  
Short Term ◽  
Homosynaptic Depression ◽  
Heterosynaptic Plasticity

Synapsin is a synaptic vesicle-associated protein implicated in the regulation of vesicle trafficking and transmitter release, but its role in heterosynaptic plasticity remains elusive. Moreover, contradictory results have obscured the contribution of synapsin to homosynaptic plasticity. We previously reported that the neuromodulator serotonin (5-HT) led to the phosphorylation and redistribution of Aplysia synapsin, suggesting that synapsin may be a good candidate for the regulation of vesicle mobilization underlying the short-term synaptic plasticity induced by 5-HT. This study examined the role of synapsin in homosynaptic and heterosynaptic plasticity. Overexpression of synapsin reduced basal transmission and enhanced homosynaptic depression. Although synapsin did not affect spontaneous recovery from depression, it potentiated 5-HT–induced dedepression. Computational analysis showed that the effects of synapsin on plasticity could be adequately simulated by altering the rate of Ca2+-dependent vesicle mobilization, supporting the involvement of synapsin not only in homosynaptic but also in heterosynaptic forms of plasticity by regulating vesicle mobilization.

Evidence against local neural mechanism for intestinal postprandial hyperemia

1983 ◽  
Vol 245 (3) ◽  
pp. H437-H446 ◽  
Author(s):  
R. A. Nyhof ◽  
C. C. Chou
Keyword(s):  
Oxygen Consumption ◽  
Oleic Acid ◽  
Neural Mechanism ◽  
Jejunal Mucosa ◽  
Vasoactive Substances ◽  
Before And After ◽  
Anesthetized Dogs ◽  
Postprandial Hyperemia

The role of local intestinal nerves in the nutrient-induced intestinal hyperemia was investigated in jejunal segments of anesthetized dogs by comparing the hyperemic effect of intraluminal glucose and oleic acid solutions before and after mucosal anesthesia and infusions of methysergide, hexamethonium, and tetrodotoxin. Methysergide, hexamethonium, and tetrodotoxin all failed to alter either the vascular or metabolic responses to luminal placement of glucose or oleic acid. The increases in blood flow and oxygen uptake produced by glucose or oleic acid, however, were blocked or attenuated after exposing the mucosa to dibucaine. The effect was norepinephrine due to an altered vascular response to vasoactive substances as dibucaine did not alter vascular responses to isoproterenol or norepinephrine. Dibucaine, however, inhibited active transport and increased passive transport of glucose across rat intestinal sacs in vitro. Oxygen consumption of the canine jejunal mucosa was also inhibited by dibucaine in vitro. It seems that inhibition of the nutrient-induced intestinal hyperemia by dibucaine is due, at least in part, to its effect on oxygen consumption and glucose transport of the mucosal epithelial cells. Nutrient-induced hyperemia appears not to be neurally mediated but more closely related to metabolism.

The role of nervous system in adaptive response of bone to mechanical loading

2018 ◽  
Vol 234 (6) ◽  
pp. 7771-7780 ◽  
Author(s):  
Yini Qiao ◽  
Yang Wang ◽  
Yimei Zhou ◽  
Fulin Jiang ◽  
Tu Huang ◽  
...  
Keyword(s):  
Nervous System ◽  
Mechanical Loading ◽  
Adaptive Response

A Study of the Role of Heterogeneities in the Initial Stages of Corrosion of Glazes Using Dynamic Imaging Microellipsometry (DIM)

1996 ◽  
Vol 462 ◽  
Author(s):  
B.E. McCarthy ◽  
P.B. Vandiver ◽  
J. Kruger
Keyword(s):  
Residual Stress ◽  
Dynamic Imaging ◽  
Corrosion Process ◽  
Ceramic Production ◽  
Stress Fields ◽  
Process Dynamic ◽  
Glazed Ceramic ◽  
Mechanical Factors

ABSTRACTCommon processes used in glazed ceramic production often result in a glaze with a heterogeneous microstructure. Heterogeneities may be due to residual batch materials, intentionally added colorants and opacifiers and/or the products of devitrification and phase separation. To study the effect of heterogeneities in the corrosion process, dynamic imaging microellipsometry was used in-situ in aqueous solutions to measure spatially and temporally resolved changes in the surface of glasses (model glazes). The measurements showed increased durability near inclusions. Residual stress fields surrounding the heterogeneities influenced the results. Decoupling of chemical and mechanical factors causing this increased durability was not possible.

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