scholarly journals Pulsed Focused Ultrasound-Induced Displacements in Confined In Vitro Blood Clots

2012 ◽  
Vol 59 (3) ◽  
pp. 842-851 ◽  
Author(s):  
C. C. Wright ◽  
K. Hynynen ◽  
D. E. Goertz
Keyword(s):  
Focused Ultrasound ◽  
Blood Clots ◽  
Pulsed Focused Ultrasound

scholarly journals Transcranial MR-guided focused ultrasound sonothrombolysis in the treatment of intracerebral hemorrhage

2013 ◽  
Vol 34 (5) ◽  
pp. E14 ◽  
Author(s):  
Stephen J. Monteith ◽  
Neal F. Kassell ◽  
Oded Goren ◽  
Sagi Harnof
Keyword(s):  
Minimally Invasive ◽  
Intracerebral Hemorrhage ◽  
Focused Ultrasound ◽  
Focal Point ◽  
Disruptive Technology ◽  
Invasive Approach ◽  
Blood Clots ◽  
Volume Blood

Intracerebral hemorrhage remains a significant cause of morbidity and mortality. Current surgical therapies aim to use a minimally invasive approach to remove as much of the clot as possible without causing undue disruption to surrounding neural structures. Transcranial MR-guided focused ultrasound (MRgFUS) surgery is an emerging technology that permits a highly concentrated focal point of ultrasound energy to be deposited to a target deep within the brain without an incision or craniotomy. With appropriate ultrasound parameters it has been shown that MRgFUS can effectively liquefy large-volume blood clots through the human calvaria. In this review the authors discuss the rationale for using MRgFUS to noninvasively liquefy intracerebral hemorrhage (ICH), thereby permitting minimally invasive aspiration of the liquefied clot via a small drainage tube. The mechanism of action of MRgFUS sonothrombolysis; current investigational work with in vitro, in vivo, and cadaveric models of ICH; and the potential clinical application of this disruptive technology for the treatment of ICH are discussed.

scholarly journals HSP70-Mediated NLRP3 Inflammasome Suppression Underlies Reversal of Acute Kidney Injury Following Extracellular Vesicle and Focused Ultrasound Combination Therapy

2020 ◽  
Vol 21 (11) ◽  
pp. 4085
Author(s):  
Mujib Ullah ◽  
Daniel D. Liu ◽  
Sravanthi Rai ◽  
Waldo Concepcion ◽  
Avnesh S. Thakor
Keyword(s):  
Acute Kidney Injury ◽  
Combination Therapy ◽  
Nlrp3 Inflammasome ◽  
Mesenchymal Stromal Cell ◽  
Focused Ultrasound ◽  
Kidney Injury ◽  
Extracellular Vesicle ◽  
Pulsed Focused Ultrasound ◽  
Pro Inflammatory Cytokines

Acute kidney injury (AKI) is the abrupt loss of renal function, for which only supportive therapies exist. Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have been shown to be therapeutically effective in treating AKI by spurring endogenous cell proliferation and survival while suppressing inflammation. Pre-treating kidneys with pulsed focused ultrasound (pFUS) has also been shown to enhance MSC therapy for AKI, but its role in MSC-derived EV therapy remains unexplored. Using a mouse model of cisplatin-induced AKI, we show that combination therapy with pFUS and EVs restores physiological and molecular markers of kidney function, more so than either alone. Both pFUS and EVs downregulate heat shock protein 70 (HSP70), the NLRP3 inflammasome, and its downstream pro-inflammatory cytokines IL-1β and IL-18, all of which are highly upregulated in AKI. In vitro knockdown studies suggest that HSP70 is a positive regulator of the NLRP3 inflammasome. Our study therefore demonstrates the ability of pFUS to enhance EV therapy for AKI and provides further mechanistic understanding of their anti-inflammatory and regenerative effects.

scholarly journals In VitroDemonstration of Focused Ultrasound Thrombolysis Using Bifrequency Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Izella Saletes ◽  
Bruno Gilles ◽  
Vincent Auboiroux ◽  
Nadia Bendridi ◽  
Rares Salomir ◽  
...  
Keyword(s):  
Thermal Effects ◽  
Focused Ultrasound ◽  
Power Level ◽  
Pharmacological Agent ◽  
Inertial Cavitation ◽  
Blood Clots ◽  
Before And After ◽  
Passive Acoustic ◽  
Cavitation Activity

Focused ultrasound involving inertial cavitation has been shown to be an efficient method to induce thrombolysis without any pharmacological agent. However, further investigation of the mechanisms involved and further optimization of the process are still required. The present work aims at studying the relevance of a bifrequency excitation compared to a classical monofrequency excitation to achieve thrombolysis without any pharmacological agent.In vitrohuman blood clots were placed at the focus of a piezoelectric transducer. Efficiency of the thrombolysis was assessed by weighing each clot before and after sonication. The efficiencies of mono- (550 kHz) and bifrequency (535 and 565 kHz) excitations were compared for peak power ranging from 70 W to 220 W. The thrombolysis efficiency appears to be correlated to the inertial cavitation activity quantified by passive acoustic listening. In the conditions of the experiment, the power needed to achieve 80% of thrombolysis with a monofrequency excitation is reduced by the half with a bifrequency excitation. The thermal effects of bifrequency and monofrequency excitations, studied using MR thermometry measurements in turkey muscle samples where no cavitation occurred, did not show any difference between both types of excitations when using the same power level.

Refining Histotripsy: Defining the Parameter Space for the Creation of Nonthermal Lesions With High Intensity, Pulsed Focused Ultrasound of the In Vitro Kidney

2007 ◽  
Vol 178 (2) ◽  
pp. 672-676 ◽  
Author(s):  
Kathleen Kieran ◽  
Timothy L. Hall ◽  
Jessica E. Parsons ◽  
J. Stuart Wolf ◽  
J. Brian Fowlkes ◽  
...  
Keyword(s):  
Parameter Space ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Pulsed Focused Ultrasound ◽  
The Creation

scholarly journals Facilitating islet transplantation using a three-step approach with mesenchymal stem cells, encapsulation, and pulsed focused ultrasound

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehdi Razavi ◽  
Tanchen Ren ◽  
Fengyang Zheng ◽  
Arsenii Telichko ◽  
Jing Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Focused Ultrasound ◽  
Islet Function ◽  
Cytoprotective Effect ◽  
Post Transplantation ◽  
Close Proximity ◽  
Pulsed Focused Ultrasound ◽  
And Function

Abstract Background The aim of this study was to examine the effect of a three-step approach that utilizes the application of adipose tissue-derived mesenchymal stem cells (AD-MSCs), encapsulation, and pulsed focused ultrasound (pFUS) to help the engraftment and function of transplanted islets. Methods In step 1, islets were co-cultured with AD-MSCs to form a coating of AD-MSCs on islets: here, AD-MSCs had a cytoprotective effect on islets; in step 2, islets coated with AD-MSCs were conformally encapsulated in a thin layer of alginate using a co-axial air-flow method: here, the capsule enabled AD-MSCs to be in close proximity to islets; in step 3, encapsulated islets coated with AD-MSCs were treated with pFUS: here, pFUS enhanced the secretion of insulin from islets as well as stimulated the cytoprotective effect of AD-MSCs. Results Our approach was shown to prevent islet death and preserve islet functionality in vitro. When 175 syngeneic encapsulated islets coated with AD-MSCs were transplanted beneath the kidney capsule of diabetic mice, and then followed every 3 days with pFUS treatment until day 12 post-transplantation, we saw a significant improvement in islet function with diabetic animals re-establishing glycemic control over the course of our study (i.e., 30 days). In addition, our approach was able to enhance islet engraftment by facilitating their revascularization and reducing inflammation. Conclusions This study demonstrates that our clinically translatable three-step approach is able to improve the function and viability of transplanted islets.

scholarly journals Noninvasive Ureterocele Puncture Using Pulsed Focused Ultrasound: An In Vitro Study

2014 ◽  
Vol 28 (3) ◽  
pp. 342-346 ◽  
Author(s):  
Adam D. Maxwell ◽  
Ryan S. Hsi ◽  
Michael R. Bailey ◽  
Pasquale Casale ◽  
Thomas S. Lendvay
Keyword(s):  
Focused Ultrasound ◽  
In Vitro Study ◽  
Vitro Study ◽  
Pulsed Focused Ultrasound

scholarly journals Improving the Function and Engraftment of Transplanted Pancreatic Islets Using Pulsed Focused Ultrasound Therapy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mehdi Razavi ◽  
Fengyang Zheng ◽  
Arsenii Telichko ◽  
Jing Wang ◽  
Gang Ren ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Islet Transplantation ◽  
Focused Ultrasound ◽  
Fold Increase ◽  
Resting Membrane Potential ◽  
Diabetic Patients ◽  
Islet Function ◽  
Non Invasive ◽  
Pulsed Focused Ultrasound

Abstract This study demonstrates that pulsed focused ultrasound (pFUS) therapy can non-invasively enhance the function and engraftment of pancreatic islets following transplantation. In vitro, we show that islets treated with pFUS at low (peak negative pressure (PNP): 106kPa, spatial peak temporal peak intensity (Isptp): 0.71 W/cm2), medium (PNP: 150kPa, Isptp: 1.43 W/cm2) or high (PNP: 212kPa, Isptp: 2.86 W/cm2) acoustic intensities were stimulated resulting in an increase in their function (i.e. insulin secretion at low-intensity: 1.15 ± 0.17, medium-intensity: 2.02 ± 0.25, and high-intensity: 2.54 ± 0.38 fold increase when compared to control untreated islets; P < 0.05). Furthermore, we have shown that this improvement in islet function is a result of pFUS increasing the intracellular concentration of calcium (Ca2+) within islets which was also linked to pFUS increasing the resting membrane potential (Vm) of islets. Following syngeneic renal sub-capsule islet transplantation in C57/B6 mice, pFUS (PNP: 2.9 MPa, Isptp: 895 W/cm2) improved the function of transplanted islets with diabetic animals rapidly re-establishing glycemic control. In addition, pFUS was able to enhance the engraftment by facilitating islet revascularization and reducing inflammation. Given a significant number of islets are lost immediately following transplantation, pFUS has the potential to be used in humans as a novel non-invasive therapy to facilitate islet function and engraftment, thereby improving the outcome of diabetic patients undergoing islet transplantation.

Noninvasive Imaging of Thermal Fields Induced in Soft Tissues In Vitro by Pulsed Focused Ultrasound Using Analysis of Echoes Displacement

2015 ◽  
Vol 39 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Piotr Karwat ◽  
Jerzy Litniewski ◽  
Tamara Kujawska ◽  
Wojciech Secomski ◽  
Kazimierz Krawczyk
Keyword(s):  
Focused Ultrasound ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Point Of View ◽  
Temperature Fields ◽  
Local Temperature ◽  
Ultrasound Technique ◽  
Displacement Estimation ◽  
Pulsed Focused Ultrasound

Abstract Therapeutic and surgical applications of focused ultrasound require monitoring of local temperature rises induced inside tissues. From an economic and practical point of view ultrasonic imaging techniques seem to be the most suitable for the temperature control. This paper presents an implementation of the ultrasonic echoes displacement estimation technique for monitoring of local temperature rise in tissue during its heating by focused ultrasound The results of the estimation were compared to the temperature measured with thermocouple. The obtained results enable to evaluate the temperature fields induced in tissues by pulsed focused ultrasonic beams using non-invasive imaging ultrasound technique

Studies on Thrombolysis with Streptokinase

1971 ◽  
Vol 25 (02) ◽  
pp. 354-378 ◽  
Author(s):  
R Gottlob ◽  
L Stockinger ◽  
U Pötting ◽  
G Schattenmann
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Whole Blood ◽  
Jugular Vein ◽  
Thin Sections ◽  
The Third ◽  
Morphological Findings ◽  
Blood Clots ◽  
Arteries And Veins

SummaryIn vitro whole blood clots of various ages, experimental thrombi produced in the jugular vein of rabbits and human thrombi from arteries and veins were examined in semi-thin sections and by means of electron microscopy.In all types of clots examined a typical course of retraction was found. Retraction starts with a dense excentrical focus which grows into a densification ring. After 24 hours the entire clot becomes almost homogeneously dense; later a secondary swelling sets in.Shortly after coagulation the erythrocytes on the rim of the clot are bi-concave discs. They then assume the shape of crenate spheres, turn into smooth spheres and finally become indented ghosts which have lost the largest part of their contents. In the inner zone, which makes up the bulk of the clot, we observed bi-concave discs prior to retraction. After retraction we see no crenations but irregularly shaped erythrocytes. Once the secondary swelling sets in, the cross-section becomes polygonal and later spherical. After extensive hemolysis we observe the “retiform thrombus” made up of ghosts.Experimental and clinical thrombi present the same morphology but are differentiated from in vitro clots by: earlier hemolysis, immigration of leukocytes, formation of a rim layer consisting of fibrin and thrombocytes, and the symptoms of organization. Such symptoms of organization which definitely will prevent lysis with streptokinase were found relatively late in experimental and clinical thrombi. Capillary buds and capillary loops were never found in clinical thrombi prior to the third month.The morphological findings agree with earlier physical and enzymatic investigations. The observation that phenomena of reorganization occur relatively late and frequently only in the rim areas of large thrombi explains why lytic therapy is possible in some of the chronic obliterations.

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