Bioacoustics Research Lab
University of Illinois at Urbana-Champaign | Department of Electrical and Computer Engineering | Department of Bioengineering
Department of Statistics | Coordinated Science Laboratory | Beckman Institute | Food Science and Human Nutrition | Division of Nutritional Sciences | College of Engineering
 Friday, March 29th, 2024
BRL Home
About BRL
Publications
Projects
People
History
Facilities
Abstracts Database
Seminars
Downloads
Archives
Bioengineering Research Partnership
William D. O'Brien, Jr. publications:

Michael L. Oelze publications:

Aiguo Han publications:

BRL Abstracts Database

Search - a quick way to search the entire Abstracts Database.
 
Advanced Search - search specific fields within the Abstracts Database.
Title
Author
Journal
Volume
Year
Abstract Text
Sort by:     Title     Author     Journal     Year
Number of records to return:     10     20     30     50

Your search for ultrasound produced 3296 results.

Page 320 out of 330

Title Ultrasound-enhanced tissue plasminogen activator thrombolysis in an in vitro porcine clot model.
Author Holland CK, Vaidya SS, Datta S, Coussios CC, Shaw GJ.
Journal Throm Res
Volume
Year 2008
Abstract Introduction Thrombolytics such as recombinant tissue plasminogen activator (rt-PA) have advanced the treatment of ischemic stroke, myocardial infarction, deep vein thrombosis and pulmonary embolism. Objective To improve the efficacy of this thrombolytic therapy, the synergistic effect of rt-PA and 120 kHz or 1.0 MHz ultrasound was assessed in vitro using a porcine clot model. Materials and methods Fully retracted whole blood clots prepared from fresh porcine blood were employed to compare rt-PA thrombolytic treatment with and without exposure to 120-kHz or 1-MHz ultrasound. For sham studies (without ultrasound), clot mass loss was measured as a function of rt-PA concentration from 0.003 to 0.107 mg/ml. For combined ultrasound and rt-PA treatments, peak-to-peak pressure amplitudes of 0.35, 0.70 or 1.0 MPa were employed. The range of duty cycles varied from 10% to 100% (continuous wave) and the pulse repetition frequency was fixed at 1.7 KHz. Results For rt-PA alone, the mass loss increased monotonically as a function of rt-PA concentration up to approximately 0.050 mg/ml. With ultrasound and rt-PA exposure, clot mass loss increased by as much as 104% over rt-PA alone. Ultrasound without the presence of rt-PA did not significantly enhance thrombolysis compared to control treatment. The ultrasound-mediated clot mass loss enhancement increased with the square root of the overall treatment duration. Conclusions Both 120-kHz and 1-MHz pulsed and CW ultrasound enhanced rt-PA thrombolysis in a porcine whole blood clot model in vitro. No clear dependence of the observed thrombolytic enhancement on ultrasound duty cycle was evident. The lack of duty cycle dependence suggests a more complex mechanism that could not be sustained by merely increasing the pulse duration.


Title Ultrasound-enhanced tissue plasminogen activator thrombolysis in an in vitro porcine clot model.
Author Holland CK, Vaidya SS, Datta S, Coussios CC, Shaw GJ.
Journal Throm Res
Volume
Year 2007
Abstract Introduction Thrombolytics such as recombinant tissue plasminogen activator (rt-PA) have advanced the treatment of ischemic stroke, myocardial infarction, deep vein thrombosis and pulmonary embolism. Objective To improve the efficacy of this thrombolytic therapy, the synergistic effect of rt-PA and 120 kHz or 1.0 MHz ultrasound was assessed in vitro using a porcine clot model. Materials and methods Fully retracted whole blood clots prepared from fresh porcine blood were employed to compare rt-PA thrombolytic treatment with and without exposure to 120-kHz or 1-MHz ultrasound. For sham studies (without ultrasound), clot mass loss was measured as a function of rt-PA concentration from 0.003 to 0.107 mg/ml. For combined ultrasound and rt-PA treatments, peak-to-peak pressure amplitudes of 0.35, 0.70 or 1.0 MPa were employed. The range of duty cycles varied from 10% to 100% (continuous wave) and the pulse repetition frequency was fixed at 1.7 KHz. Results For rt-PA alone, the mass loss increased monotonically as a function of rt-PA concentration up to approximately 0.050 mg/ml. With ultrasound and rt-PA exposure, clot mass loss increased by as much as 104% over rt-PA alone. Ultrasound without the presence of rt-PA did not significantly enhance thrombolysis compared to control treatment. The ultrasound-mediated clot mass loss enhancement increased with the square root of the overall treatment duration. Conclusions Both 120-kHz and 1-MHz pulsed and CW ultrasound enhanced rt-PA thrombolysis in a porcine whole blood clot model in vitro. No clear dependence of the observed thrombolytic enhancement on ultrasound duty cycle was evident. The lack of duty cycle dependence suggests a more complex mechanism that could not be sustained by merely increasing the pulse duration.


Title Ultrasound-enhanced transgene expression in vascular cells is not dependent upon cavitation-induced free radicals.
Author Lawrie A,Brisken AF,francis SE,Wyllie D,Kiss-Toth E,Qwarnstrom EE,Dower SK,Crossman DC,Newman CM.
Journal Ultrasound Med Biol
Volume
Year 2003
Abstract Although acoustic cavitation is clearly important in ultrasound (US)-enhanced gene delivery (UEGD), the relative importance of mechanical and sonochemical (free radical) bioeffects remains unclear, as does the mechanism of gene delivery at the cellular level. Porcine vascular smooth muscle cells (VSMC) were transfected with luciferase or green fluorescent protein (GFP) plasmid +/- pulsed 956 kHz US (2.0 mechanical index (MI), 128 W cm-2 spatial peak pulse average intensity, ISPPA) for 60 s, in the presence or absence of 20 mM cysteamine or N-acetyl-L-cysteine. Both compounds effectively scavenged free radical production following US, leaving unaffected the 50- to 100-fold enhancements in luciferase expression seen in US-treated VSMC. US exposure enhanced plasmid uptake (25 +/- 4.6 vs. 3 +/- 1.9 cells/field, n=4, p<0.05), most likely directly into the cytoplasm, and increased both the total number (>sevenfold) and average fluorescence intensity (>sixfold) of GFP-transfected cells. UEGD is not dependent upon cavitation-induced free radical generation and has potential for use with a wide range of therapeutic transgenes.


Title Ultrasound-facilitated thrombolysis using tissue-plasminogen activator-loaded echogenic liposomes.
Author Tiukinhoy-Laing SD, Huang S, Klegerman M, Holland CK, McPherson DD.
Journal Throm Res
Volume
Year 2006
Abstract Targeted delivery of thrombolytics to the site of occlusion is an attractive concept, with implications for the treatment of many thrombo-occlusive diseases. Ultrasound enhances thrombolysis, which can be augmented by the addition of a contrast agent. We have previously reported development of echogenic liposomes (ELIP) for targeted highlighting of structures with potential for drug and gene delivery. This study evaluated the potential of ELIP for thrombolytic loading, and the effect of ultrasound exposure of thrombolytic-loaded ELIP on thrombolytic efficacy. MATERIALS AND METHODS: Tissue-plasminogen activator (tPA) was loaded into ELIP. Echogenicity was assessed and reported as mean grayscale values. Whole porcine clots were treated with plasma, free tPA, tPA+Optison (echocontrast agent), or tPA-loaded ELIP, with and without ultrasound (1 MHz, continuous wave, 2 W/cm(2), for 2 min). Clots were weighed before and after a 30-min treatment period, and results reported as percent clot mass loss. RESULTS: tPA entrapment into ELIP was feasible with 50% entrapment, and retention of echogenicity. Treatment with tPA-loaded ELIP resulted in effective clot lysis with an effect similar to treatment with free tPA. Ultrasound exposure of tPA-loaded ELIP resulted in enhanced thrombolysis (49.5% relative improvement vs. no ultrasound). Much of the ultrasound effect appeared to be related to drug release from the tPA-ELIP complex. CONCLUSIONS: We have demonstrated entrapment of tPA into ELIP with effective clot lysis and drug release using ultrasound. Our tPA-loaded ELIP has potential for specific highlighting of clots to confirm agent delivery and help focus ultrasound therapy for targeted ultrasound-facilitated thrombolysis.


Title Ultrasound-guided localized detection of cavitation during lithotripsy in pig kidney in vivo.
Author Sapozhnikov OA Bailey MR Crum LA Miller NA Cleveland RO Pishchalnikov YA Pishchalnikov IV McAteer JA Connors BA Blomgren PM Evan AP.
Journal J Ultrason Symp
Volume
Year 2001
Abstract It is supposed that inertial cavitation plays a significant role in tissue damage during extracorporeal shock wave lithotripsy (ESWL). In this work we attempted to detect cavitation in tissue. In vivo experiments with pigs were conducted in a Dornier HM3 electrohydraulic lithotripter. Kidney alignment was made using fluoroscopy and B-mode ultrasound. Cavitation was detected by a dual passive cavitation detection (DPCD) system consisting of two confocal spherical bowl PZT transducers (1.15 MHz, focal length 10 cm, radius 10 cm). An ultrasound scanhead was placed between the transducers, an hyperechoic spots in the image indicated pockets of bubbles during ESWL. A coincidence-detection algorithm and the confocal transducers made it possible to localize cavitation to within a 4 mm diameter region. The signals from both the collecting system and kidney tissue were recorded. The targeting of the DPCD focus was confirmed by using the DPCD transducers as high intensity focused ultrasound (HIFU) sources at HIFU durations below the lesion formation threshold. In this HIFU regime, a bright spot appears in the B-mode image indicating the position of the DPCD focus. In this way we could confirm that refraction and scattering in tissue did not cause a misalignment. The tissue region interrogated was also marked with a lesion produced by HIFU. Clear cavitation signals were detected from the collecting system and from pools of blood that formed near the kidney capsule and weak signals were recorded from tissue during the ESWL treatment.


Title Ultrasound-induced angiogenic response in endothelial cells.
Author Mizrahi N, Seliktar D, Kimmel E.
Journal Ultrasound Med Biol
Volume
Year 2007
Abstract Mechanical forces are known to affect endothelial cell (EC) function and can promote the formation of mature, muscular arterioles and arteries (arteriogenesis). The present study explores the possible angiogenic role of ultrasonic irradiation on EC phenotype using an in-vitro approach. Therapeutic ultrasound (TUS) stimulation at 1-MHz frequency was applied to bovine aortic endothelial cells (BAECs) in 2-D monolayer cultures and 3-D spheroid cultures. An angiogenic EC phenotype was characterized by the proliferation rate, migration, sprouting and Flk-1 expression in response to ultrasound stimulation. Irradiation lasting as long as 30 min caused a down-regulation and redistribution of Flk-1, increased EC proliferation rates and enhanced migration and sprouting in the 3-D spheroid cultures. The ultrasound-mediated EC stimulation in monolayers may be attributed to stable cavitation and micro-streaming, which are induced by pulsating microbubbles near the EC surface. Three-dimensional EC spheroid cultures surrounded by a highly viscous gel phase also exhibited ultrasound-induced angiogenic characteristics, although microbubbles may not participate in this response because of the impeding medium. The described in-vitro influence of low-intensity ultrasound on angiogenic EC phenotype has implications for TUS as a safe and controlled noninvasive stimulus for vascular regeneration.


Title Ultrasound-induced cell lysis and sonoporation enhanced by contrast agents.
Author Ward M, Wu J, Chiu JF.
Journal J Acoust Soc Am
Volume
Year 1999
Abstract The enhancement of ultrasound-induced cell destruction, lysis, and sonoporation in low cell concentration suspensions (2 x 10(5)/mL) by the presence of contrast agents (gas bubble to cell ratio = 230) was demonstrated using cervical cancer cells (HeLa S3) suspensions containing micron-size denatured albumin microspheres filled with air (Albunex) or octafluoropropane (Optison). The suspensions were insonificated by 2-MHz continuous or tone burst ultrasound in near field. The spatial peak-pressure amplitude was 0.2 MPa. The enhancement of cell destruction due to Optison was shown to be much higher than that due to Albunex for similar bubble concentration and ultrasound conditions. For tone burst exposures, significant lysis and sonoporation only occurred in the presence of a contrast agent. The majority of the bioeffects observed occurred in the first 5 min of exposure. The relationship between the enhancement of bioeffects and duty cycle of tone burst ultrasound appears to indicate that both stable gas spheres of contrast agents and cavitation nuclei created by the disruption of the gas spheres play a significant role in causing the bioeffects.


Title Ultrasound-induced cell membrane porosity.
Author Deng CX, Sieling F, Pan H, Cui J.
Journal Ultrasound Med Biol
Volume
Year 2004
Abstract Recent studies of ultrasound (US) methods for targeted drug delivery and nonviral gene transfection revealed new, advantageous possibilities. These studies utilized US contrast agents, commonly stabilized microbubbles, to facilitate delivery and suggested that US delivery resulted from cell sonoporation, the formation of temporary pores in the cell membrane induced by US. Using voltage clamp techniques, we obtained real-time measurements of sonoporation of single Xenopus oocyte in the presence of Optison?, an agent consisting of albumin-shelled C3F8 gas bubbles (mean diameter 3.2 ?m). Ultrasound increased the transmembrane current as a direct result of decreased membrane resistance due to pore formation. We observed a distinct delay of sonoporation following US activation and characteristic stepwise increases of transmembrane current throughout US duration. We discovered that the resealing of cell membrane following US exposure required Ca2+ entering the cell through US-induced pores.


Title Ultrasound-induced changes in rates of influx and efflux of.potassium ions in rat thymocytes in vitro.
Author Chapman IV, MacNally NA, Tucker S.
Journal Ultrasound Med Biol
Volume
Year 1980
Abstract It is demonstrated that the potassium content of rat thymocytes in vitro is decreased following exposure to 2W/cm2, 3 MHz ultrasound for 40 min at 37 C, without inducing cell lysis or gross membrane damage. The abnormal values for potassium are maintained after completion of insonation. .The changes are shown to arise from ultrasound-induced decreases in ion influx together with increases in potassium efflux. Recorded temperature changes in the media are shown to be insufficient to account for the observed decreases in cell potassium..The magnitude of cell potassium decrease at 3 MHz is shown to be similar in aerated and degassed water. Acoustic microstreaming either at the cell membrane or within the cell is suggested as the damage mechanism leading to ion flux changes.


Title Ultrasound-induced cytolysis of cancer cells is enhanced in the presence of micron-sized alumina particles.
Author Miyoshi N, Tuziuti T, Yasui K, Iida Y, Shimizu N, Riesz P, Sostaric JZ.
Journal Ultrason Sonochem
Volume
Year 2008
Abstract Micron-sized alumina particles have been shown to enhance sonochemical free radical formation in aqueous solutions and simultaneously increase the solution temperature and acoustic (white) noise, effects attributable to enhanced inertial cavitation [T. Tuziuti, J. Phys. Chem. A 109 (2005) 4869-4872]. In the current study, the same ultrasound exposure system was applied to in vitro cancer cells as a model system to determine the effect of alumina particles on the long-term survival of cells and on the major pathways of cell death, i.e., either apoptosis or necrosis. Following 6 h of incubation after ultrasound treatment, it was found that the cells died mainly through necrosis, irrespective of whether the exposure was conducted in the presence of alumina particles or not. Alumina particles were nontoxic to cells alone, but were found to decrease the long-term survivability of cells that survived the initial exposure. This effect depended on the size and concentration of particles. These results correlated well with the effect of alumina particles on the sonochemical oxidation of KI under the same exposure conditions. Spin-trapping with 5,5-dimethyl-pyroline N-oxide (DMPO) and electron spin resonance spectroscopy indicated that the sonochemical formation of -OH radicals increased in the presence of alumina particles. The current study is consistent with the well known observation that micron-sized particles enhance the acoustic cavitation process.


Page 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160 | 161 | 162 | 163 | 164 | 165 | 166 | 167 | 168 | 169 | 170 | 171 | 172 | 173 | 174 | 175 | 176 | 177 | 178 | 179 | 180 | 181 | 182 | 183 | 184 | 185 | 186 | 187 | 188 | 189 | 190 | 191 | 192 | 193 | 194 | 195 | 196 | 197 | 198 | 199 | 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 208 | 209 | 210 | 211 | 212 | 213 | 214 | 215 | 216 | 217 | 218 | 219 | 220 | 221 | 222 | 223 | 224 | 225 | 226 | 227 | 228 | 229 | 230 | 231 | 232 | 233 | 234 | 235 | 236 | 237 | 238 | 239 | 240 | 241 | 242 | 243 | 244 | 245 | 246 | 247 | 248 | 249 | 250 | 251 | 252 | 253 | 254 | 255 | 256 | 257 | 258 | 259 | 260 | 261 | 262 | 263 | 264 | 265 | 266 | 267 | 268 | 269 | 270 | 271 | 272 | 273 | 274 | 275 | 276 | 277 | 278 | 279 | 280 | 281 | 282 | 283 | 284 | 285 | 286 | 287 | 288 | 289 | 290 | 291 | 292 | 293 | 294 | 295 | 296 | 297 | 298 | 299 | 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308 | 309 | 310 | 311 | 312 | 313 | 314 | 315 | 316 | 317 | 318 | 319 | 320 | 321 | 322 | 323 | 324 | 325 | 326 | 327 | 328 | 329 | 330