Axial Rotation of the Lower Limb Under Torsional Loading: I. Static and Dynamic Measurements in Vivo

2008 ◽  
pp. 277-277-14 ◽  
Author(s):  
ML Hull ◽  
C Johnson
Keyword(s):  
Lower Limb ◽  
Axial Rotation ◽  
Dynamic Measurements ◽  
Torsional Loading

scholarly journals The Venoarteriolar Reflex Significantly Reduces Contralateral Perfusion as Part of the Lower Limb Circulatory Homeostasis in vivo

2018 ◽  
Vol 9 ◽  
Author(s):  
Henrique Silva ◽  
Hugo A. Ferreira ◽  
Hugo P. da Silva ◽  
L. Monteiro Rodrigues
Keyword(s):  
Lower Limb

A Robust and Subject-Specific Hemodynamic Model of the Lower Limb Based on Noninvasive Arterial Measurements

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Laurent Dumas ◽  
Tamara El Bouti ◽  
Didier Lucor
Keyword(s):  
Cardiovascular Diseases ◽  
Arterial Stiffness ◽  
Lower Limb ◽  
Developed Countries ◽  
Numerical Approach ◽  
Subject Specific ◽  
Hemodynamic Model ◽  
Quantification Analysis ◽  
Stiffness Distribution

Cardiovascular diseases are currently the leading cause of mortality in the population of developed countries, due to the constant increase in cardiovascular risk factors, such as high blood pressure, cholesterol, overweight, tobacco use, lack of physical activity, etc. Numerous prospective and retrospective studies have shown that arterial stiffening is a relevant predictor of these diseases. Unfortunately, the arterial stiffness distribution across the human body is difficult to measure experimentally. We propose a numerical approach to determine the arterial stiffness distribution of an arterial network using a subject-specific one-dimensional model. The proposed approach calibrates the optimal parameters of the reduced-order model, including the arterial stiffness, by solving an inverse problem associated with the noninvasive in vivo measurements. An uncertainty quantification analysis has also been carried out to measure the contribution of the model input parameters variability, alone or by interaction with other inputs, to the variation of clinically relevant hemodynamic indices, here the arterial pulse pressure. The results obtained for a lower limb model, demonstrate that the numerical approach presented here can provide a robust and subject-specific tool to the practitioner, allowing an early and reliable diagnosis of cardiovascular diseases based on a noninvasive clinical examination.

scholarly journals The yeast silent information regulator Sir4p anchors and partitions plasmids.

1997 ◽  
Vol 17 (12) ◽  
pp. 7061-7068 ◽  
Author(s):  
A Ansari ◽  
M R Gartenberg
Keyword(s):  
Coiled Coil ◽  
Axial Rotation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Interacting Protein ◽  
Segregation Behavior ◽  
Amino Acid Region ◽  
Dividing Cells ◽  
Nuclear Component ◽  
Acid Region

Circular plasmids containing telomeric TG1-3 arrays or the HMR E silencer segregate efficiently between dividing cells of the yeast Saccharomyces cerevisiae. Subtelomeric X repeats augment the TG1-3 partitioning activity by a process that requires the SIR2, SIR3, and SIR4 genes, which are also required for silencer-based partitioning. Here we show that targeting Sir4p to DNA directly via fusion to the bacterial repressor LexA confers efficient mitotic segregation to otherwise unstable plasmids. The Sir4p partitioning activity resides within a 300-amino-acid region (residues 950 to 1262) which precedes the coiled-coil dimerization motif at the extreme carboxy end of the protein. Using a topology-based assay, we demonstrate that the partitioning domain also retards the axial rotation of LexA operators in vivo. The anchoring and partitioning properties of LexA-Sir4p chimeras persist despite the loss of the endogenous SIR genes, indicating that these functions are intrinsic to Sir4p and not to a complex of Sir factors. In contrast, inactivation of the Sir4p-interacting protein Rap1p reduces partitioning by a LexA-Sir4p fusion. The data are consistent with a model in which the partitioning and anchoring domain of Sir4p (PAD4 domain) attaches to a nuclear component that divides symmetrically between cells at mitosis; DNA linked to Sir4p by LexA serves as a reporter of protein movement in these experiments. We infer that the segregation behavior of telomere- and silencer-based plasmids is, in part, a consequence of these Sir4p-mediated interactions. The assays presented herein illustrate two novel approaches to monitor the intracellular dynamics of nuclear proteins.

scholarly journals In vivo femoropopliteal arterial wall compliance in subjects with and without lower limb vascular disease

1999 ◽  
Vol 30 (5) ◽  
pp. 936-945 ◽  
Author(s):  
Nigel R.M. Tai ◽  
Alberto Giudiceandrea ◽  
Henryk J. Salacinski ◽  
Alexander M. Seifalian ◽  
George Hamilton
Keyword(s):  
Vascular Disease ◽  
Lower Limb ◽  
Arterial Wall ◽  
Wall Compliance

scholarly journals In Vivo Assessment of Lower Limb Muscle Stress State Based on Shear Wave Elastography

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 122185-122196
Author(s):  
Jing Liu ◽  
Kunyang Wang ◽  
Jianan Wu ◽  
Huaibin Miao ◽  
Zhihui Qian ◽  
...  
Keyword(s):  
Stress State ◽  
Shear Wave ◽  
Lower Limb ◽  
Shear Wave Elastography ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Muscle Stress ◽  
In Vivo Assessment

Noninvasive and in vivo assessment of upper and lower limb skeletal muscle oxidative metabolism activity and microvascular responses to glucose ingestion in humans

2019 ◽  
Vol 44 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Rogério Nogueira Soares ◽  
Alessandro L. Colosio ◽  
Juan Manuel Murias ◽  
Silvia Pogliaghi
Keyword(s):  
Oxidative Metabolism ◽  
Lower Limb ◽  
Near Infrared ◽  
Vascular Occlusion ◽  
Lower Limbs ◽  
Clinical Approach ◽  
Specific Detection ◽  
Glucose Ingestion ◽  
Glucose Challenge

This study investigated changes in muscle oxidative metabolism and microvascular responsiveness induced by glucose ingestion in the upper and lower limbs using near-infrared spectroscopy (NIRS). Fourteen individuals (aged 27 ± 1.4 years) underwent 5 vascular occlusion tests (VOT) (pre-intervention (Pre), 30 min, 60 min, 90 min, and 120 min after glucose challenge). NIRS-derived oxygen saturation (StO2) was measured on the forearm and leg muscle at each VOT. Muscle oxidative metabolism was determined by the StO2 downslope during cuff inflation (deoxygenation slope); microvascular responsiveness was estimated by the StO2 upslope (reperfusion slope) following cuff deflation. There was a significant increase in arm (p < 0.05; 1-β = 0.860) and leg (p < 0.05; 1-β = 1.000) oxidative metabolism activity as represented by the faster deoxygenation slope at 60, 90, and 120 min (0.08 ± 0.03, 0.08 ± 0.03, 0.08 ± 0.02%·s–1, respectively) (leg) and at 90 min (0.16 ± 0.08%·s−1) (arm) observed after glucose ingestion when compared with their respective Pre values (leg = 0.06 ± 0.02; arm = 0.11 ± 0.04%·s−1). There was a significant increase in arm (p < 0.05; 1-β = 0.880) and leg (p < 0.05; 1-β = 0.983) reperfusion slope at 60 min (arm = 3.63 ± 2.1%·s−1; leg = 1.56 ± 0.6%·s−1), 90 min (arm = 3.91 ± 2.1%·s−1; leg = 1.60 ± 0.6%·s−1), and 120 min (arm = 3.91 ± 1.6%·s−1; leg = 1.54 ± 0.6%·s−1) when compared with their Pre values (arm = 2.79 ± 1.7%·s−1; leg = 1.26 ± 0.5%·s−1). Our findings showed that NIRS–VOT technique is capable of detecting postprandial changes in muscle oxidative metabolism activity and microvascular reactivity in the upper and lower limb. Novelty NIRS-VOT is a promising noninvasive clinical approach that may help in the early, limb-specific detection of impairments in glucose oxidation and microvascular function.

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