Dynamics of Human Coronary Arterial Motion and Its Potential Role in Coronary Atherogenesis

2000 ◽  
Vol 122 (5) ◽  
pp. 488-492 ◽  
Author(s):  
Zhaohua Ding ◽  
Morton H. Friedman
Keyword(s):  
Coronary Arteries ◽  
Potential Role ◽  
Fluid Dynamic ◽  
Mechanical Forces ◽  
Motion Patterns ◽  
Coefficients Of Variation ◽  
Motion Parameters ◽  
Arterial Motion ◽  
Vessel Axis

Mechanical forces have been widely recognized to play an important role in the pathogenesis of atherosclerosis. Since coronary arterial motion modulates both vessel wall mechanics and fluid dynamics, it is hypothesized that certain motion patterns might be atherogenic by generating adverse wall mechanical forces or fluid dynamic environments. To characterize the dynamics of coronary arterial motion and explore its implications in atherogenesis, a system was developed to track the motion of coronary arteries in vivo, and employed to quantify the dynamics of four right coronary arteries (RCA) and eight left anterior descending (LAD) coronary arteries. The analysis shows that: (a) The motion parameters vary among individuals, with coefficients of variation ranging from 0.25 to 0.59 for axially and temporally averaged values of the parameters; (b) the motion parameters of individual vessels vary widely along the vessel axis, with coefficients of variation as high as 2.28; (c) the LAD exhibits a greater axial variability in torsion, a measure of curve “helicity,” than the RCA; (d) in comparison with the RCA, the LAD experiences less displacement p=0.009, but higher torsion p=0.03. These results suggest that: (i) the variability of certain motion parameters, particularly those that exhibit large axial variations, might be related to variations in susceptibility to atherosclerosis among different individuals and vascular regions; and (ii) differences in motion parameters between the RCA and LAD might relate to differences in their susceptibility to atherosclerosis. [S0148-0731(00)00405-2]

Flow recirculation zone length and shear rate are differentially affected by stenosis severity in human coronary arteries

2013 ◽  
Vol 304 (4) ◽  
pp. H559-H566 ◽  
Author(s):  
Ashkan Javadzadegan ◽  
Andy S. C. Yong ◽  
Michael Chang ◽  
Austin C. C. Ng ◽  
John Yiannikas ◽  
...  
Keyword(s):  
Shear Rate ◽  
Coronary Arteries ◽  
Recirculation Zone ◽  
Fluid Dynamic ◽  
Zone Length ◽  
Flow Recirculation ◽  
Stenosis Severity ◽  
Recirculation Zones ◽  
The Relationship

Flow recirculation zones and shear rate are associated with distinct pathogenic biological pathways relevant to thrombosis and atherogenesis. The interaction between stenosis severity and lesion eccentricity in determining the length of flow recirculation zones and peak shear rate in human coronary arteries in vivo is unclear. Computational fluid dynamic simulations were performed under resting and hyperemic conditions on computer-generated models and three-dimensional (3-D) reconstructions of coronary arteriograms of 25 patients. Boundary conditions for 3-D reconstructions simulations were obtained by direct measurements using a pressure-temperature sensor guidewire. In the computer-generated models, stenosis severity and lesion eccentricity were strongly associated with recirculation zone length and maximum shear rate. In the 3-D reconstructions, eccentricity increased recirculation zone length and shear rate when lesions of the same stenosis severity were compared. However, across the whole population of coronary lesions, eccentricity did not correlate with recirculation zone length or shear rate ( P = not signficant for both), whereas stenosis severity correlated strongly with both parameters ( r = 0.97, P < 0.001, and r = 0.96, P < 0.001, respectively). Nonlinear regression analyses demonstrated that the relationship between stenosis severity and peak shear was exponential, whereas the relationship between stenosis severity and recirculation zone length was sigmoidal, with an apparent threshold effect, demonstrating a steep increase in recirculation zone length between 40% and 60% diameter stenosis. Increasing stenosis severity and lesion eccentricity can both increase flow recirculation and shear rate in human coronary arteries. Flow recirculation is much more sensitive to mild changes in the severity of intermediate stenoses than is peak shear.

Patient-Specific Stented Coronary Bifurcations: Numerical Analysis of Near-Wall Quantities and the Bulk Flow

2013 ◽  
Author(s):  
Claudio Chiastra ◽  
Stefano Morlacchi ◽  
Diego Gallo ◽  
Umberto Morbiducci ◽  
Rubén Cárdenes ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Shear Stress ◽  
Coronary Arteries ◽  
Fluid Dynamic ◽  
Patient Specific ◽  
Wall Region ◽  
Stent Restenosis ◽  
Local Measurements ◽  
In Stent Restenosis

The mechanisms and the causes of the in-stent restenosis process in coronary arteries are not fully understood. One of the most relevant phenomena, which seems to be associated to this process, is an altered hemodynamics in the stented wall region [1]. In vivo local measurements of velocities and their gradients in human coronary arteries are very difficult and can hardly be applied to successfully investigate the fluid dynamic field [1]. Alternatively, virtual models of blood flow in patient-specific coronary arteries allow the study of local fluid dynamics and the computation of the wall shear stress (WSS) and other quantities which can be related to the risk of restenosis.

Bradykinin-Induced Vasodilation Is Impaired at the Atherosclerotic Site but Is Preserved at the Spastic Site of Human Coronary Arteries In Vivo

Circulation ◽  
1995 ◽  
Vol 92 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Takeshi Kuga ◽  
Kensuke Egashira ◽  
Masahiro Mohri ◽  
Hiroyuki Tsutsui ◽  
Yasuhiko Harasawa ◽  
...  
Keyword(s):  
Coronary Arteries

scholarly journals Conifers Phytochemicals: A Valuable Forest with Therapeutic Potential

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3005
Author(s):  
Kanchan Bhardwaj ◽  
Ana Sanches Silva ◽  
Maria Atanassova ◽  
Rohit Sharma ◽  
Eugenie Nepovimova ◽  
...  
Keyword(s):  
Experimental Data ◽  
Potential Role ◽  
Therapeutic Potential ◽  
Fungal Infections ◽  
Cell Damage ◽  
Cancer Growth ◽  
Naturally Occurring ◽  
Antioxidant Effects

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.

scholarly journals Molecular and Cellular Mechanisms of Metformin in Cervical Cancer

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2545
Author(s):  
Ya-Hui Chen ◽  
Po-Hui Wang ◽  
Pei-Ni Chen ◽  
Shun-Fa Yang ◽  
Yi-Hsuan Hsiao
Keyword(s):  
Cervical Cancer ◽  
Potential Role ◽  
Treatment Options ◽  
Cellular Mechanisms ◽  
Anticancer Effects ◽  
Clinical Benefits ◽  
Underlying Mechanisms

Cervical cancer is one of the major gynecologic malignancies worldwide. Treatment options include chemotherapy, surgical resection, radiotherapy, or a combination of these treatments; however, relapse and recurrence may occur, and the outcome may not be favorable. Metformin is an established, safe, well-tolerated drug used in the treatment of type 2 diabetes; it can be safely combined with other antidiabetic agents. Diabetes, possibly associated with an increased site-specific cancer risk, may relate to the progression or initiation of specific types of cancer. The potential effects of metformin in terms of cancer prevention and therapy have been widely studied, and a number of studies have indicated its potential role in cancer treatment. The most frequently proposed mechanism underlying the diabetes–cancer association is insulin resistance, which leads to secondary hyperinsulinemia; furthermore, insulin may exert mitogenic effects through the insulin-like growth factor 1 (IGF-1) receptor, and hyperglycemia may worsen carcinogenesis through the induction of oxidative stress. Evidence has suggested clinical benefits of metformin in the treatment of gynecologic cancers. Combining current anticancer drugs with metformin may increase their efficacy and diminish adverse drug reactions. Accumulating evidence is indicating that metformin exerts anticancer effects alone or in combination with other agents in cervical cancer in vitro and in vivo. Metformin might thus serve as an adjunct therapeutic agent for cervical cancer. Here, we reviewed the potential anticancer effects of metformin against cervical cancer and discussed possible underlying mechanisms.

The Role of Mechanical Tension in Neurons

2010 ◽  
Vol 1274 ◽  
Author(s):  
Taher Saif ◽  
Jagannathan Rajagopalan ◽  
Alireza Tofangchi
Keyword(s):  
Mechanical Response ◽  
Mechanical Forces ◽  
Active Tension ◽  
Mechanical Tension ◽  
Deformation Response ◽  
Linear Force ◽  
Tension Regulation ◽  
Over Time

AbstractWe used high resolution micromechanical force sensors to study the in vivo mechanical response of embryonic Drosophila neurons. Our experiments show that Drosophila axons have a rest tension of a few nN and respond to mechanical forces in a manner characteristic of viscoelastic solids. In response to fast externally applied stretch they show a linear force-deformation response and when the applied stretch is held constant the force in the axons relaxes to a steady state value over time. More importantly, when the tension in the axons is suddenly reduced by releasing the external force the neurons actively restore the tension, sometimes close to their resting value. Along with the recent findings of Siechen et al (Proc. Natl. Acad. Sci. USA 106, 12611 (2009)) showing a link between mechanical tension and synaptic plasticity, our observation of active tension regulation in neurons suggest an important role for mechanical forces in the functioning of neurons in vivo.

scholarly journals Identification of the MuRF1 skeletal muscle ubiquitylome through quantitative proteomics

Function ◽  
2021 ◽  
Author(s):  
Leslie M Baehr ◽  
David C Hughes ◽  
Sarah A Lynch ◽  
Delphi Van Haver ◽  
Teresa Mendes Maia ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Potential Role ◽  
Ubiquitin Proteasome System ◽  
In Vivo Electroporation ◽  
Adult Mice ◽  
Expression Of Genes ◽  
Regulation Of Metabolism ◽  
Ubiquitin Proteasome

Abstract MuRF1 (TRIM63) is a muscle-specific E3 ubiquitin ligase and component of the ubiquitin proteasome system. MuRF1 is transcriptionally upregulated under conditions that cause muscle loss, in both rodents and humans, and is a recognized marker of muscle atrophy. In this study, we used in vivo electroporation to determine if MuRF1 overexpression alone can cause muscle atrophy and, in combination with ubiquitin proteomics, identify the endogenous MuRF1 substrates in skeletal muscle. Overexpression of MuRF1 in adult mice increases ubiquitination of myofibrillar and sarcoplasmic proteins, increases expression of genes associated with neuromuscular junction instability, and causes muscle atrophy. A total of 169 ubiquitination sites on 56 proteins were found to be regulated by MuRF1. MuRF1-mediated ubiquitination targeted both thick and thin filament contractile proteins, as well as, glycolytic enzymes, deubiquitinases, p62, and VCP. These data reveal a potential role for MuRF1 in not only the breakdown of the sarcomere, but also the regulation of metabolism and other proteolytic pathways in skeletal muscle.

Detection of In Vivo Dynamic 3-D Motion Patterns in the Wrist Joint

2009 ◽  
Vol 56 (4) ◽  
pp. 1236-1244 ◽  
Author(s):  
B. Carelsen ◽  
R. Jonges ◽  
S.D. Strackee ◽  
M. Maas ◽  
P. van Kemenade ◽  
...  
Keyword(s):  
Wrist Joint ◽  
Motion Patterns
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