The interaction of ultrasonic heating and cavitation in vascular bioeffects on mouse intestine
The interaction of ultrasonic heating and cavitation in vascular bioeffects on mouse intestine
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DOI：
10.1016/s0301-5629(97)00209-3
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发表时间：
1998-01-01
影响因子：
2.9
通讯作者：
Gies, RA
中科院分区：
文献类型：
--
作者：
Miller, DL;Gies, RA
麻醉无毛小鼠暴露于400 kHz聚焦超声，连续或脉冲与100 μ s的脉冲，在温度控制的水浴中。暴露后，评价肠道的瘀点（推测由加热引起）和水肿（推测由空化引起）。在37 ℃下连续暴露1000 s，在0.28 MPa（2.6 W cm（-2））以上出现瘀点（高达约100个），1000 s脉冲暴露（0.001占空因数）阈值增加至6.5 MPa（1.4 W cm（-2）时间平均值）。对于连续暴露（10 s、100 s或1000 s），在0.65 MPa以上观察到出血（高达约10），对于1000 s脉冲暴露（0.001占空因数），阈值仅增加至1.6 MPa。将短暂的连续暴露分成低占空因数脉冲暴露，可大大减少瘀点，但实际上增加了出血，例如，在3.2MPa下，1 s的连续暴露（340 W cm（-2））平均每只小鼠0.33次曝光，1 s的脉冲曝光时间（1000 s持续时间，0.001占空因数）在3.2 MPa（0.34 W cm（-2）时间平均值）下，平均每只小鼠4.3次电击。相对于32 ℃或37 ℃，在42 ℃浴温下诱导更多的瘀点，并且升高的温度在一定程度上增强了出血效应。一般来说，加热和空化似乎有很大程度上独立的作用，血管生物效应对小鼠肠道。(C)1998年世界医学和生物学超声联合会。
Anesthetized hairless mice were exposed at the midsection to 400-kHz focused ultrasound that was continuous or pulsed with 100-mu s pulses, in a temperature-controlled water bath. After exposure, the intestines were evaluated for petechiae, presumably induced by heating, and hemorrhages, presumably induced by cavitation. Petechiae (up to about 100) occurred above 0.28 MPa (2.6 W cm(-2)) for 1000 s continuous exposure at 37 degrees C, and the threshold increased to 6.5 MPa (1.4 W cm(-2) temporal average) for 1000 s pulsed exposure (0.001 duty factor). Hemorrhages (up to about 10) were seen above 0.65 MPa for continuous exposure (10 s, 100 s or 1000 s), and the threshold increased only to 1.6 MPa for 1000 s pulsed exposure (0.001 duty factor). Fractionating a brief continuous exposure into a low duty-factor pulsed exposure greatly decreased the petechiae, but actually increased the hemorrhages, For example, 1 s continuous exposure at 3.2 MPa (340 W cm(-2)) averaged 0.33 hemorrhages per mouse, and 1 s on-time pulsed exposure (1000 s duration, 0.001 duty factor) at 3.2 MPa (0.34 W cm(-2) temporal average) averaged 4.3 hemorrhages per mouse. More petechiae were induced at 42 degrees C bath temperature relative to 32 degrees C or 37 degrees C, and the hemorrhage effect was somewhat enhanced by elevated temperature. Generally, heating and cavitation appeared to have largely independent roles in vascular bioeffects on mouse intestine. (C) 1998 World Federation for Ultrasound in Medicine & Biology.