Low frequency therapeutic ultrasound causes vasodilation and enhanced tissue perfusion

2011 ◽  
Vol 130 (4) ◽  
pp. 2501-2501
Author(s):  
Robert J. Siegel
Keyword(s):  
Therapeutic Ultrasound ◽  
Low Frequency ◽  
Tissue Perfusion

scholarly journals Effect of Low-Frequency Therapeutic Ultrasound on Induction of Nitric Oxide in CKD: Potential to Prevent Acute Kidney Injury

2020 ◽  
Vol 6 (6) ◽  
pp. 453-460
Author(s):  
Michael W. Dae ◽  
Kathleen D. Liu ◽  
Richard J. Solomon ◽  
Dong W. Gao ◽  
Carol A. Stillson
Keyword(s):  
Nitric Oxide ◽  
Acute Kidney Injury ◽  
Animal Model ◽  
Blood Flow ◽  
Radionuclide Imaging ◽  
Therapeutic Ultrasound ◽  
Low Frequency ◽  
Kidney Injury ◽  
Large Animal Model ◽  
Large Animal

<b><i>Introduction:</i></b> Post-contrast acute kidney injury (PC-AKI) develops in a significant proportion of patients with CKD after invasive cardiology procedures and is strongly associated with adverse outcomes. <b><i>Objective:</i></b> We sought to determine whether increased intrarenal nitric oxide (NO) would prevent PC-AKI. <b><i>Methods:</i></b> To create a large animal model of CKD, we infused 250 micron particles into the renal arteries in 56 ± 8 kg pigs. We used a low-frequency therapeutic ultrasound device (LOTUS – 29 kHz, 0.4 W/cm<sup>2</sup>) to induce NO release. NO and laser Doppler probes were used to assess changes in NO content and blood flow. Glomerular filtration rate (GFR) was measured by technetium-diethylene-triamine-pentaacetic acid (Tc-99m-DTPA) radionuclide imaging. PC-AKI was induced by intravenous infusion of 7 cm<sup>3</sup>/kg diatrizoate. In patients with CKD, we measured GFR at baseline and during LOTUS using Tc-99m--DTPA radionuclide imaging. <b><i>Results:</i></b> In the pig model, CKD developed over 4 weeks (serum creatinine [Cr], mg/dL, 1.0 ± 0.2–2.6 ± 0.9, <i>p</i> &#x3c; 0.01, <i>n</i> = 12). NO and renal blood flow (RBF) increased in cortex and medulla during LOTUS. GFR increased 75 ± 24% (<i>p</i> = 0.016, <i>n</i> = 3). PC-AKI developed following diatrizoate i.v. infusion (Cr 2.6 ± 0.7 baseline to 3.4 ± 0.6 at 24 h, <i>p</i> &#x3c; 0.01, <i>n</i> = 3). LOTUS (starting 15 min prior to contrast and lasting for 90 min) prevented PC-AKI in the same animals 1 week later (Cr 2.5 ± 0.4 baseline to 2.6 ± 0.7 at 24 h, <i>p</i> = ns, <i>n</i> = 3). In patients with CKD (<i>n</i> = 10), there was an overall 25% increase in GFR in response to LOTUS (<i>p</i> &#x3c; 0.01). <b><i>Conclusions:</i></b> LOTUS increased intrarenal NO, RBF, and GFR and prevented PC-AKI in a large animal model of CKD, and significantly increased GFR in patients with CKD. This novel approach may provide a noninvasive nonpharmacological means to prevent PC-AKI in high-risk patients.

scholarly journals Ultrasound stimulates formation and release of vasoactive compounds in brain endothelial cells

2015 ◽  
Vol 309 (4) ◽  
pp. H583-H591 ◽  
Author(s):  
Catherine M. Davis ◽  
Azzdine Y. Ammi ◽  
Nabil J. Alkayed ◽  
Sanjiv Kaul
Keyword(s):  
Endothelial Cells ◽  
Therapeutic Ultrasound ◽  
Tissue Perfusion ◽  
Therapeutic Benefit ◽  
Brain Endothelial Cells ◽  
Ultrasound Exposure ◽  
Vasoactive Substances ◽  
Enos Phosphorylation ◽  
Endothelial Nitric Oxide

Stroke outcome is improved by therapeutic ultrasound. This benefit is presumed to be principally from ultrasound-mediated thrombolysis. We hypothesized that the therapeutic benefit of ultrasound in stroke may, in part, be mediated by the release of beneficial vasoactive substances. Accordingly, we investigated the effect of ultrasound on levels of cytochrome P-450, lipoxygenase, and cyclooxygenase metabolites of arachidonic acid as well as adenosine release and endothelial nitric oxide synthase (eNOS) phosphorylation in primary brain endothelial cells in vitro. Brain endothelial cells were exposed to 1.05-MHz ultrasound at peak rarefactional acoustic pressure amplitudes of 0.35, 0.55, 0.90, and 1.30 MPa. Epoxyeicosatrienoic acids (EETs), hydroxyeicosatetraenoic acids (HETEs), PGE2, adenosine, nitrate/nitrite, and eNOS phosphorylation were measured after ultrasound exposure. Levels of 8,9-EET, 11,12-EET, and 14,15-EET increased by 230 ± 28%, 240 ± 30%, and 246 ± 31% ( P < 0.05), respectively, whereas 5-HETE and 15-HETE levels were reduced to 24 ± 14% and 10 ± 3% ( P < 0.05), respectively, compared with cells not exposed to ultrasound. PGE2 levels were reduced to 56 ± 14% of control. Adenosine increased more than sixfold after ultrasound exposure compared with unstimulated cells (1.36 ± 0.22 vs. 0.37 ± 0.10 ng/ml, P < 0.05), nitrate/nitrite was below levels of quantification, and eNOS phosphorylation was not altered significantly. Our results suggest that ultrasound may enhance tissue perfusion during stroke by augmenting the generation of vasodilator compounds and inhibiting that of vasoconstrictors. Such regulation supports a beneficial role for therapeutic ultrasound in stroke independent of its effect on the occlusive thrombus.

Low-Frequency Therapeutic Ultrasound with Varied Duty Cycle: Effects on the Ischemic Brain and the Inner Ear

2010 ◽  
Vol 36 (7) ◽  
pp. 1188-1195 ◽  
Author(s):  
Peter Reuter ◽  
Julia Masomi ◽  
Holger Kuntze ◽  
Ilka Fischer ◽  
Kai Helling ◽  
...  
Keyword(s):  
Inner Ear ◽  
Duty Cycle ◽  
Therapeutic Ultrasound ◽  
Low Frequency ◽  
Ischemic Brain

scholarly journals Low frequency oscillations assessed by diffuse speckle contrast analysis for foot angiosome concept

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chaebeom Yeo ◽  
Hanbeen Jung ◽  
Kijoon Lee ◽  
Cheol Song
Keyword(s):  
Reactive Hyperemia ◽  
Low Frequency ◽  
Tissue Perfusion ◽  
Arterial Blood Flow ◽  
Speckle Contrast ◽  
Arterial Blood ◽  
Low Frequency Oscillations ◽  
Power Spectral ◽  
Contrast Analysis ◽  
Monitoring Modality

Abstract An angiosome refers to a 3D tissue volume that is vascularized by a single artery and is a relatively new concept that is useful in vascular surgery; however, the direct relationship between arterial blood flow and micro-perfusion is still controversial. Here, we propose a diffuse speckle contrast analysis (DSCA), which is an emerging tissue perfusion monitoring modality, to investigate the correlations among low frequency oscillations (LFOs) measured from different areas on the feet of healthy subjects. We obtained reproducible results from the correlation analyses of LFOs, and their physiological implications were discussed. In order to confirm the changes in the frequency oscillations, we analyzed and compared the power spectral density changes due to heart rate variability in the electrocardiographic signal during reactive hyperemia and head-up tilt protocols.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

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