|
|
|
BRL Abstracts Database |
|
Your search for ultrasound produced 3296 results. Page 110 out of 330
| Title |
Electrokinetic properties of isolated cells exposed to low levels of ultrasound. |
| Author |
Hrazdira I, Adler J. |
| Journal |
Proc Int Symp Ultrasound Interact Biol Med |
| Volume |
|
| Year |
1980 |
| Abstract |
No abstract available. |
| Title |
Electrophoretic mobility of Ehrlich cell suspensions exposed to ultrasound of varying parameters. |
| Author |
Taylor KJW, Newman DL. |
| Journal |
Phys Med Biol |
| Volume |
|
| Year |
1972 |
| Abstract |
The effects of ultrasound on the electrophoretic mobility of Ehrlich ascites-tumour cells are reported using micro-electrophoresis. Frequency, pulse length and exposure time were individually varied using a constant peak intensity of 10 W/cm(^-2), with delivery pulse 1:9. Reduction in mobility occurred at all frequencies and increased with the square root of the frequency. No further change was found after 5 min of total irradiation time. The reduction was found to be independent of the pulse length between 20 ?s and 10 ms and was not affected by increasing the ambient pressure to 1?7 atmospheres, sufficient to prevent cavitation at this intensity and at a frequency of 1 MHz. The biological implications are discussed in terms of alteration of the carbohydrate-rich coats and the physical mechanism proposed is that of shear forces acting on the boundary layers.. |
| Title |
Embryotoxic and teratogenic effect of high intensity, low frequency ultrasonic vibration on chicken embryos. |
| Author |
Shpuntoff H, Wuchinich D. |
| Journal |
Ultrasound Med Biol |
| Volume |
|
| Year |
1984 |
| Abstract |
Controlled exposure of chicken embryos to continuous 30 W/cm2, 29 kHz ultrasonic vibration in a water medium produced, in proportion to exposure, progressively retarded growth or death. Analysis supports, and observation confirms, the.presence of cavitation in the water medium. The effects reported here differ substantially from published observations of megaHertz insonation of chicken embryos at similar intensities. The experiments closely resemble in method of application, frequency and intensity the operation of several ultrasonic surgical and dental instruments. |
| Title |
Emhancement of ultrasonically induced cell transfection with atrificial cavitation nuclei. |
| Author |
Greenleaf WJ, Bolander ME, |
| Journal |
Proc Ultrason Symp IEEE |
| Volume |
|
| Year |
1997 |
| Abstract |
Ultrasound mediated gene transfection in cultured immortalized human chondrocytes
was enhanced three-fold using artificial cavitation nuclei in the form of AlbunexB. 1.0 MHz ultrasound transmitted through the bottoms of six-well
culture plates containing media with green fluorescent protein reporter gene plasmids at a concentration of 40pg/ml and AlbunexB at 5Ox1O6 bubbles/ml, exhibited a peak transfection efficiency of about 50% of the living cells when
exposed to 4x10’ Pascals spatial average peak pressure (SAPP) for 20 minutes. Using these parameters, transfection efficiency increased linearly
with ultrasound exposure pressure with a transfection threshold observed at a SAPP of lo5 Pascals. Adding fresh AlbunexB at 5Ox1O6 bubbledml prior to sequential one second 3.2 or 4 . 0 ~ 1 0P~as cal exposures increased transfection
efficiency by 15% for each of three consecutive exposures. Efficient in vim and perhaps in vivo transfection appears possible with ultrasound. |
| Title |
Endoluminal gynecologic ultrasound: Preliminary results. |
| Author |
Goldberg BB, Liu JB, Kuhlman K, Merton DA, Kurtz AB. |
| Journal |
J Ultrasound Med |
| Volume |
|
| Year |
1991 |
| Abstract |
Specially developed high-resolution real-time ultrasound transducers (12.5 and 20 MHz) on the tip of endoluminal catheters were inserted into the endometrial canal to evaluate the usefulness of this approach. Uterine abnormalities, most confirmed by biopsy, surgery, or both, were detected in 12 patients, including submucosal myomas, nabothian cysts, endometrial polyps, synechiae, and endometrial and cervical carcinoma. In one case the catheter was directed under hysteroscopic guidance into a fallopian tube, demonstrating its potential usefulness in this region. In 4 of the 12 cases in which a hysterectomy was performed, an in vitro ultrasound examination of the organ was performed, which confirmed the initial in vivo ultrasound impressions. Anatomic cross-sectional slices of the uterus resulted in excellent correlation with the ultrasound findings. These preliminary results suggest that this new sonographic procedure will become an important diagnostic tool, supplementing abdominal and endovaginal ultrasound approaches. |
| Title |
Endoluminal sonography of the urinary tract: preliminary observations. |
| Author |
Goldberg BB, Bagley D, Liu JB, Merton DA, Alexander A, Kurtz AB..Department of Radiology, Jefferson Medical College, Philadelphia, PA. |
| Journal |
AJR Am J Roentgenol |
| Volume |
|
| Year |
1991 |
| Abstract |
Endoluminal sonography of the urinary tract was performed by using endoluminal ultrasound transducers contained within 2-mm-diameter catheters. The catheters.were inserted into the urinary bladder via the urethra and advanced into the ureters and renal pelvis under cystoscopic control; then, cross-sectional images of the.bladder, ureters, and renal pelvis were obtained. Two dogs and seven human patients were studied. In one dog, a 4.5-mm pseudopolyp, which was surgically.created in the bladder wall, was successfully imaged; in the other, stones 2 mm or larger inserted into the bladder were identified. Of the seven patients, sonography.showed stones embedded in the renal parenchyma (one patient) and the mucosa of the distal ureter (one patient). These were ultimately confirmed by their eventual.removal. In a third, sonography showed a tumor of the distal ureter and identified the depth of the tumor. This was confirmed by biopsy. In a fourth, sonography.clearly showed a crossing vessel as the cause for narrowing of the proximal ureter. In a fifth, sonography showed that the cause of a ureteral stricture was idiopathic..In the last two cases, sonography did not reveal a cause for hematuria. In these last three cases, negative sonographic results were confirmed by direct ureteroscopic.examinations and follow-up studies. Our observations based on this limited study suggest that endoluminal sonography is a useful procedure for diagnosing diseases.of the urinary tract. Further study is warranted. |
| Title |
Endoluminal US: Experiments with nonvascular uses in animals. |
| Author |
Goldberg BB, Liu JB, Merton DA, Kurtz AB. |
| Journal |
Radiology |
| Volume |
|
| Year |
1990 |
| Abstract |
Catheters containing miniature ultrasound (US) transducers, originally developed for intravascular evaluation of plaque, were used in a series of in vivo and in vitro animal experiments to image a variety of nonvascular lumina. Measurements of the wall thickness and echotexture of the urethra, urinary bladder, ureter, renal pelvis, bile ducts, small bowel, fallopian tubes, and uterus were carried out. Close correlation between the US images and actual anatomic specimens was obtained. Structures outside of the lumen were identified and confirmed with both direct visualization and radiographic localization. Two small stones artifically inserted into the renal pelvis and a polyp-like projection artificially created within the fallopian tube were clearly identified by using the US probe. These initial US studies demonstrate the potential feasibility of these miniature transducers contained within catheters for intraluminal analysis in humans. |
| Title |
Endothelial cell injury in venule and capillary induced by contrast ultrasonography. |
| Author |
Kobayashi N, Yasu T, Yamada S, Kudo N, Kuroki M, Kawakami M, Miyatake K, Saito M. |
| Journal |
Ultrasound Med Biol |
| Volume |
|
| Year |
2002 |
| Abstract |
The aim of the present study was to test the hypothesis that microvascular endothelial cells (EC) are subject to the bioeffects induced by contrast ultrasound (US) because of their proximity to the circulating microbubbles. We examined EC injury in each microvessel section (arteriole, capillary or venule) in rat mesenteries among the following five groups: three controls (sham operation, microbubble injection alone, US exposure with saline injection), and two contrast-US groups (US exposure at a 1-Hz or 30-Hz frame rate with microbubble injection). Propidium iodide (PI), a fluorescent indicator of cell injury, was employed to visualize impaired EC. PI-positive nuclei were equally few among the three controls. Contrast-US increased PI-positive cells in capillaries (1-Hz frame rate, 2.4 +/- 2.2 cells per 0.1-mm vessel length, p = 0.09; 30-Hz frame rate, 4.3 +/- 1.8 cells, p < 0.01) and in venules (1-Hz frame rate, 4.1 +/- 2.5 cells, p < 0.05; 30-Hz frame rate, 13.8 +/- 3.6 cells, p < 0.01) compared with sham operation (0.10 +/- 0.22 cells). The finding indicates that diagnostic contrast US potentially causes EC injury, particularly in venules and capillaries. |
| Title |
Enhanced color flow imaging of breast cancer vasculature: Continuous wave Doppler and three-dimensional display. |
| Author |
Carson PL, Adler DD, Fowlkes JB, Harnist K, Rubin J. |
| Journal |
J Ultrasound Med |
| Volume |
|
| Year |
1992 |
| Abstract |
Two methods of potentially improving the detection and assessment of breast cancer vasculature by color flow Doppler ultrasonography were studied. Use of continuous wave (CW) Doppler imaging was one method evaluated by a comparison of system sensitivity to small vessel flow by continuous wave and pulsed Doppler methods. The second technique demonstrated color flow image acquisition and three-dimensional (3D) display. Six breast cancer patients were examined with both a color flow pulsed system and a CW Doppler system employing a hand-held transmitter-receiver pair with crossed-beam patterns. The CW unit consistently revealed more regions of tumor flow and multidirectional flow. Good 3D displays were achieved on larger pulsatile vessels, from images obtained during systole and selected for minimal noise. |
| Title |
Enhanced ultrasound transmission through the human skull using shear mode conversion. |
| Author |
Clement GT, Hynynen K, White PJ. |
| Journal |
J Acoust Soc Am |
| Volume |
|
| Year |
2004 |
| Abstract |
A new transskull propagation technique, which deliberately induces a shear mode in the skull bone, is investigated. Incident waves beyond Snell's critical angle experience a mode conversion from an incident longitudinal wave into a shear wave in the bone layers and then back to a longitudinal wave in the brain. The skull's shear speed provides a better impedance match, less refraction, and less phase alteration than its longitudinal counterpart. Therefore, the idea of utilizing a shear wave for focusing ultrasound in the brain is examined. Demonstrations of the phenomena, and numerical predictions are first studied with plastic phantoms and then using an ex vivo human skull. It is shown that at a frequency of 0.74 MHz the transskull shear method produces an amplitude on the order of—and sometimes higher than—longitudinal propagation. Furthermore, since the shear wave experiences a reduced overall phase shift, this indicates that it is plausible for an existing noninvasive transskull focusing method [Clement, Phys. Med. Biol. 47(8), 1219–1236 (2002)] to be simplified and extended to a larger region in the brain. |
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
|
|
|
|
