Compound Delivery and Local Blood Flows

2003 ◽  
pp. 171-198
Author(s):  
James B. Bassingthwaighte
Keyword(s):  
Blood Flows

COMPARISON OF ANTIHYPERTENSIVE EFFECT OF MOXONIDINE VERSUS CLONIDINE IN RENAL FAILURE PATIENTS.

2018 ◽  
Vol 6 (9) ◽  
Author(s):  
DR.MATHEW GEORGE ◽  
DR.LINCY JOSEPH ◽  
MRS.DEEPTHI MATHEW ◽  
ALISHA MARIA SHAJI ◽  
BIJI JOSEPH ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Failure ◽  
Blood Flow ◽  
Blood Vessel ◽  
Blood Vessels ◽  
High Blood Pressure ◽  
Antihypertensive Effect ◽  
The Body ◽  
Ability To Work ◽  
Blood Flows

Blood pressure is the force of blood pushing against blood vessel walls as the heart pumps out blood, and high blood pressure, also called hypertension, is an increase in the amount of force that blood places on blood vessels as it moves through the body. Factors that can increase this force include higher blood volume due to extra fluid in the blood and blood vessels that are narrow, stiff, or clogged(1). High blood pressure can damage blood vessels in the kidneys, reducing their ability to work properly. When the force of blood flow is high, blood vessels stretch so blood flows more easily. Eventually, this stretching scars and weakens blood vessels throughout the body, including those in the kidneys.

Effect of cardiac rhythm on vena caval blood flows

1966 ◽  
Vol 210 (3) ◽  
pp. 505-508 ◽  
Author(s):  
AL Pinkerson ◽  
MH Luria ◽  
ED Freis
Keyword(s):  
Cardiac Rhythm ◽  
Blood Flows

Myocardial blood flow determined with krypton 85 in unanesthetized dogs

1962 ◽  
Vol 203 (1) ◽  
pp. 122-124 ◽  
Author(s):  
J. A. Herd ◽  
M. Hollenberg ◽  
G. D. Thorburn ◽  
H. H. Kopald ◽  
A. C. Barger
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Myocardial Blood Flow ◽  
Exponential Function ◽  
Scintillation Detector ◽  
Left Ventricular ◽  
Blood Flows ◽  
Single Exponential Function ◽  
Single Exponential ◽  
Rapid Measurements

Serial, rapid measurements of left ventricular myocardial blood flow in trained, unanesthetized dogs have been made by injecting krypton 85 through chronically implanted coronary artery catheters and counting with an external scintillation detector. Precordial radioactivity declined as a single exponential function during the first 2 min after injection, suggesting a single rate of myocardial blood flow. Simultaneous estimations with Kr85 and blood flowmeters in acute experiments established the accuracy and reproducibility of the technique. Myocardial blood flows between 40 and 55 ml/100 g/min were observed repeatedly in three well-trained, unanesthetized dogs in the basal state.

scholarly journals Randomized Trial of Oxygen Saturation Targets during and after Resuscitation and Reversal of Ductal Flow in an Ovine Model of Meconium Aspiration and Pulmonary Hypertension

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 594
Author(s):  
Amy L. Lesneski ◽  
Payam Vali ◽  
Morgan E. Hardie ◽  
Satyan Lakshminrusimha ◽  
Deepika Sankaran
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Oxygen Saturation ◽  
Ductus Arteriosus ◽  
Neonatal Resuscitation ◽  
Meconium Aspiration Syndrome ◽  
Ovine Model ◽  
Neurodevelopmental Outcomes ◽  
Meconium Aspiration ◽  
Blood Flows

Neonatal resuscitation (NRP) guidelines suggest targeting 85–95% preductal SpO2 by 10 min after birth. Optimal oxygen saturation (SpO2) targets during resuscitation and in the post-resuscitation management of neonatal meconium aspiration syndrome (MAS) with persistent pulmonary hypertension (PPHN) remains uncertain. Our objective was to compare the time to reversal of ductal flow from fetal pattern (right-to-left), to left-to-right, and to evaluate pulmonary (QPA), carotid (QCA)and ductal (QDA) blood flows between standard (85–94%) and high (95–99%) SpO2 targets during and after resuscitation. Twelve lambs asphyxiated by endotracheal meconium instillation and cord occlusion to induce MAS and PPHN were resuscitated per NRP guidelines and were randomized to either standard (85–94%) or high (95–99%) SpO2 targets. Out of twelve lambs with MAS and PPHN, six each were randomized to standard and high SpO2 targets. Median [interquartile range] time to change in direction of blood flow across the ductus arteriosus from right-to-left, to left-to-right was significantly shorter with high SpO2 target (7.4 (4.4–10.8) min) compared to standard SpO2 target (31.5 (21–66.2) min, p = 0.03). QPA was significantly higher during the first 10 min after birth with higher SpO2 target. At 60 min after birth, the QPA, QCA and QDA were not different between the groups. To conclude, targeting SpO2 of 95–99% during and after resuscitation may hasten reversal of ductal flow in lambs with MAS and PPHN and transiently increase QPA but no differences were observed at 60 min. Clinical studies comparing low and high SpO2 targets assessing hemodynamics and neurodevelopmental outcomes are warranted.

scholarly journals 3D ultrasound coronarography: first proof of concept study on isolated beating rat hearts

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
O Demeulenaere ◽  
P Mateo ◽  
P Sandoval ◽  
O Villemain ◽  
M Tanter ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Flow Velocity ◽  
Coronary Flow ◽  
3D Ultrasound ◽  
Frame Rate ◽  
Doppler Imaging ◽  
Coronary Perfusion ◽  
Blood Flows ◽  
Flow Reserve ◽  
Rat Hearts

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Bettencourt Foundation Background/Introduction We demonstrated recently that Ultrafast ultrasound Doppler imaging can image the intramyocardial coronary circulation in beating hearts of large animals and patients [1]. Yet, ultrasound spatial resolution remains limited by wave physics and coronaries smaller than ∼100 µm could not be imaged. Ultrasound Localization Microscopy (ULM) [2] was recently introduced to tackle this issue and exploit the micrometric localization of microbubble contrast agents at ultrafast frame rate in order to image blood flows in micrometer vessels. Purpose The objective of this work was to demonstrate that 3D ultrafast ultrasound with contrast agents can provide the full 3D mapping of the coronary microcirculation with quantitative flow velocity on a beating rat heart. Methods Acquisitions were performed on ex vivo rat hearts (n = 5) with retrograde perfusion (Langendorff model). A flow of a Krebs–Henseleit solution mixed with a diluted microbubbles solution (0.22%) was perfused at controlled pressure into the coronary arteries (between 5 and 15 mL/min). We used a 32 × 32 elements, 8-MHz matrix-array ultrasound transducer connected to a 1024-channel programmable ultrasound scanner. An ultrafast Doppler imaging sequence consisting of 9 plane waves was transmitted at a PRF of 20 kHz during 270 ms and repeated 40 times. After beamforming and SVD clutter filtering, the microbubbles were localized and tracked in 3D. Flow velocity were mapped at baseline and after infusion of Adenosine (10e-5 µMol) at constant coronary perfusion pressure (120 mm Hg). Eventually, the hearts were fixed using formaldehyde perfusion and imaged by µCT after injection of radio opaque agent. Results We successfully imaged the coronary blood flows of entire rat hearts. It revealed the entire vasculature from large main coronaries arteries (cross section up to 1 mm) to small arterioles (smaller than 40 µm). Coronary flow velocities ranged from [1 – 50] cm/s depending on the arteries diameter. Velocity estimates were validated in vitro in tubes of Ø0.58mm and were in good agreement with theoretical values of a Poiseuille’s flow (relative ratio of 10% for maximum velocities). After Adenosine infusion, perfusion flow rates increased 102% ± 50% (p < 0.05) on average. Eventually, anatomy revealed by 3D ultrasound coronarography was in accordance with the anatomy revealed by the µCT. Conclusion(s) We demonstrated the feasibility of 3D ultrasound coronarography on isolated beating rat hearts. This technique has the potential to become a novel imaging tool to investigate the coronary micro-circulation and quantify non-invasively the Coronary Flow Reserve (CFR). Abstract Figure. Ultrasound coronarography

scholarly journals 152 Impact of chorionic somatomammotropin RNA interference on uterine blood flow and placental glucose uptake in the absence of intrauterine growth restriction

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 121-121
Author(s):  
Amelia R Tanner ◽  
Asghar Ali ◽  
Quinton A Winger ◽  
Paul J Rozance ◽  
Russell V Anthony
Keyword(s):  
Rna Interference ◽  
Glucose Uptake ◽  
Intrauterine Growth Restriction ◽  
Growth Restriction ◽  
Intrauterine Growth ◽  
Blood Flows ◽  
Umbilical Blood ◽  
Exact Function ◽  
Chorionic Somatomammotropin ◽  
The Impact

Abstract Chorionic somatomammotropin (CSH) is one of the most abundant hormones produced by the sheep placenta, yet the exact function of CSH has been elusive. Previously we reported the use of in vivo RNA interference (RNAi) to assess the impact of CSH deficiency on placental and fetal growth in sheep. Near-term (135 dGA), there are two distinct CSH RNAi phenotypes: 1) pregnancies with intrauterine growth restriction (IUGR), and 2) pregnancies with normal fetal and placental weights. This study describes physiological changes in the latter phenotype. To generate the CSH RNAi pregnancies, the trophectoderm of hatched blastocysts (9 dGA) were infected with lentiviral-constructs expressing either a scrambled control (NTS) or CSH-specific shRNA (CSH RNAi), prior to transfer into synchronized recipient ewes. At 120 dGA, 6 NTS and 6 CSH RNAi pregnancies were fitted with maternal and fetal catheters. Uterine and umbilical blood flows were measured utilizing the 3H2O transplacental diffusion technique at 132 dGA, and nutrient uptakes were calculated by the Fick principle. Resulting data were analyzed by Student’s t-test and significance was set at P ≤ 0.05. CSH RNAi tended (P ≤ 0.10) to reduce placentome weight with no effect on fetal weight. Absolute (ml/min) and relative (ml/min/kg fetus) uterine blood flows were reduced (P ≤ 0.05) in CSH RNAi pregnancies, but umbilical flows were not impacted. The uterine artery-to-vein glucose gradient (mmol/l) was significantly (P ≤ 0.05) increased, whereas the gradients for taurine and glycine were reduced (P ≤ 0.05). Uteroplacental glucose uptake (mmol/min/kg placenta) was increased 27% (P ≤ 0.05), whereas umbilical glucose uptake (mmol/min/kg fetus) was reduced 13%. This cohort demonstrates that even in the absence of IUGR, CSH deficiency has significant physiological ramifications, and the investigation of CSH RNAi pregnancies exhibiting both IUGR and non-IUGR phenotypes may help determine the direct effects of CSH and its potential impact on fetal programming. Supported by NIH R01 HD093701.

scholarly journals The superficial venous pump

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Konstantin Mazayshvili
Keyword(s):  
Saphenous Vein ◽  
Great Saphenous Vein ◽  
Lower Limbs ◽  
Superficial Fascia ◽  
Step Cycle ◽  
Cross Sectional ◽  
Blood Flows ◽  
Active Function ◽  
Vein Segment ◽  
The Relationship

The present study has revealed the relationship between the cross sectional area of the great saphenous vein and the degree of tension in the superficial fascia of the thigh. We conducted an ultrasound examination with 27 patients (54 lower limbs) in both standing and walking positions. With an increase and decrease in the degree of tension of the superficial fascia, the blood is pushed to the sapheno-femoral junction. Nearly 200 mm3 of blood flows in, and is pushed out of, a 100-mm great saphenous vein segment in the thigh, towards the sapheno-femoral junction during a step cycle. As a result, the active function of the fascial compartment of the great saphenous vein has been found. We have called this mechanism the superficial venous pump.

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