In-vitro validation of a novel model-based approach to the measurement of arterial blood flow waveforms from dynamic digital x-ray images

2002 ◽  
Author(s):  
Kawal Rhode ◽  
Tryphon Lambrou ◽  
Alexander M. Seifalian ◽  
David J. Hawkes
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
X Ray ◽  
Model Based ◽  
Arterial Blood ◽  
Flow Waveforms ◽  
Novel Model

A novel laboratory approach for the demonstration of hemodynamic principles: the arterial blood flow reflection

2013 ◽  
Vol 37 (4) ◽  
pp. 321-326 ◽  
Author(s):  
Marina Djelić ◽  
Sanja Mazić ◽  
Dejan Žikić
Keyword(s):  
Blood Flow ◽  
Age Groups ◽  
Exercise Program ◽  
Arterial Blood Flow ◽  
New Approach ◽  
Arterial Blood ◽  
Before And After ◽  
Physical Laws ◽  
Laboratory Training ◽  
Flow Waveforms

In the frame of a laboratory training course for medicine students, a new approach for laboratory exercises has been applied to teach the phenomena of circulation. The exercise program included measurements of radial artery blood flow waveform for different age groups using a noninvasive optical sensor. Arterial wave reflection was identified by measurements of blood flow waveforms before and after arterial branching. Students were able to distinguish between different waveforms of blood flow within different age groups. Furthermore, students were given the opportunity to explore the effect of aging on the elasticity of blood vessels. This exercise is an introduction to the fundamental physical laws of hemodynamics that can facilitate the learning and understanding of cardiovascular physiology to students of medicine.

scholarly journals Endothelial miR-17∼92 cluster negatively regulates arteriogenesis via miRNA-19 repression of WNT signaling

2015 ◽  
Vol 112 (41) ◽  
pp. 12812-12817 ◽  
Author(s):  
Shira Landskroner-Eiger ◽  
Cong Qiu ◽  
Paola Perrotta ◽  
Mauro Siragusa ◽  
Monica Y. Lee ◽  
...  
Keyword(s):  
Blood Flow ◽  
Wnt Signaling ◽  
Critical Role ◽  
Arterial Blood Flow ◽  
In Vivo Model ◽  
Mirna Regulation ◽  
Arterial Blood ◽  
Specific Deletion

The contribution of endothelial-derived miR-17∼92 to ischemia-induced arteriogenesis has not been investigated in an in vivo model. In the present study, we demonstrate a critical role for the endothelial-derived miR-17∼92 cluster in shaping physiological and ischemia-triggered arteriogenesis. Endothelial-specific deletion of miR-17∼92 results in an increase in collateral density limbs and hearts and in ischemic limbs compared with control mice, and consequently improves blood flow recovery. Individual cluster components positively or negatively regulate endothelial cell (EC) functions in vitro, and, remarkably, ECs lacking the cluster spontaneously form cords in a manner rescued by miR-17a, -18a, and -19a. Using both in vitro and in vivo analyses, we identified FZD4 and LRP6 as targets of miR-19a/b. Both of these targets were up-regulated in 17∼92 KO ECs compared with control ECs, and both were shown to be targeted by miR-19 using luciferase assays. We demonstrate that miR-19a negatively regulates FZD4, its coreceptor LRP6, and WNT signaling, and that antagonism of miR-19a/b in aged mice improves blood flow recovery after ischemia and reduces repression of these targets. Collectively, these data provide insights into miRNA regulation of arterialization and highlight the importance of vascular WNT signaling in maintaining arterial blood flow.

Relationship between vascular reactivity in vitro and blood flows in rats with cirrhosis

1999 ◽  
Vol 97 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Dominique PATERON ◽  
Frédéric OBERTI ◽  
Pascale LEFILLIATRE ◽  
Nary VEAL ◽  
Khalid A. TAZI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Reactivity ◽  
Regional Blood Flow ◽  
Arterial Blood Flow ◽  
Blood Flows ◽  
Arterial Blood ◽  
Vascular Responsiveness ◽  
Microsphere Method ◽  
Radioactive Microsphere Method

In cirrhosis there is a hyperdynamic circulation, which occurs mainly in the systemic and splanchnic regions. Using isolated-vessel models, previous studies have shown reduced aortic reactivity to vasoconstrictors in rats with cirrhosis. The aim of the present study was to evaluate and compare the vascular responsiveness to phenylephrine in arterial rings and the blood flows from different regions in rats with cirrhosis and controls. Reactivity was studied in isolated thoracic aortic, superior mesenteric arterial and carotid arterial rings from sham-operated and bile-duct-ligated rats by measuring the cumulative concentration-dependent tension induced by phenylephrine (10-9–10-4 M). Blood flows were measured by the radioactive microsphere method. In rats with cirrhosis, a significant hyporeactivity to phenylephrine was observed in both the aorta and the superior mesenteric artery compared with the corresponding arteries of normal rats. This hyporesponsiveness was corrected by Nω-nitro-l-arginine (0.1 mM). In contrast, carotid artery reactivity and the responses to Nω-nitro-l-arginine were similar in the cirrhotic and control groups. In each case, cardiac output and mesenteric arterial blood flow were significantly higher in cirrhotic than in normal rats. Cerebral blood flows were not significantly different between the two groups. In cirrhotic rats, arterial hyporeactivity may be a consequence of increased regional blood flow and increased production of nitric oxide.

Abstract P214: Mechanotransduction And Uterine Blood Flow In Preeclampsia- The Role Of Piezo 1 Ion Channels.

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Olufunke O Arishe ◽  
Vanessa Dela Justina ◽  
Fernanda B Priviero ◽  
Clinton R Webb
Keyword(s):  
Blood Flow ◽  
Vascular Remodeling ◽  
Vascular Reactivity ◽  
Small Diameter ◽  
Subsequent Development ◽  
Normal Pregnancy ◽  
Arterial Blood Flow ◽  
Pregnant Rats ◽  
Arterial Blood

Background: There is a large increase in uterine arterial blood flow during normal pregnancy. Structural and cellular adjustments occur in the uterine vasculature during pregnancy to accommodate this increased blood flow through a process is known as ‘vascular remodeling’. The etiology of preeclampsia involves aberrant placentation and vascular remodeling leading to reduced uteroplacental perfusion. However, the underlying source of the deficient vascular remodeling and the subsequent development of preeclampsia remains to be fully understood. Piezo 1 channels have been shown to be highly expressed in vascular smooth muscle cells of small-diameter arteries and play a role in the structural remodeling of the arteries. Studies have also shown that Piezo 1 is present in uterine arteries and it’s not exclusive to the endothelial cells. Hypothesis: This study tests the hypothesis that reduced Piezo 1 activity contributes to decreased uterine vascular relaxation in hypertensive pregnant rats. Methods: Hypertension was induced by treating the pregnant rats with synthetic CpG ODN (ODN 2395) via three intraperitoneal injections (100μg/rats) while the normotensive controls were treated with saline (vehicle) on the 14 th , 17th and 18 th days of pregnancy. Mean arterial pressure (MAP) was measured. In vitro vascular reactivity of uterine arterial (UA) ring segments were evaluated using isometric wire myograph system. Rings were pre-contracted with 3μM phenylephrine (PE), concentration responses of to Yoda1; a pharmacological agonist of Piezo 1 channel were compared. Statistical analysis was performed using nonlinear regression and Students’ t-test. Results: Our results show that MAP was greater in rats treated with ODN2395 vs untreated rats (112 ± 1 vs 90 ± 1 p =0.0004). Concentration-dependent relaxation responses to Yoda1 were greater in UAs of untreated rats compared to those treated with ODN2395 (EC50 0.06571 ± 0.09781 vs. 0.5774 ± 0.1187 p =0.0018). Conclusion: These results suggest that the reduced vasodilation in pregnancy-associated hypertension may be due to a reduced Piezo 1 channel activity.

Novel approaches to the measurement of arterial blood flow from dynamic digital X-ray images

2005 ◽  
Vol 24 (4) ◽  
pp. 500-513 ◽  
Author(s):  
K.S. Rhode ◽  
T. Lambrou ◽  
D.J. Hawkes ◽  
A.M. Seifalian
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
X Ray ◽  
Arterial Blood ◽  
Novel Approaches
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