Acoustic cavitation nuclei survive the apparent ultrasonic destruction of Albunex(R) microspheres

The hypothesis tested was that gas bodies capable of nucleating violent cavitation activity in vitro would survive the rapid disruption of Albunex(R) microspheres by 1-MHz ultrasound. Human erythrocyte hemolysis was used as a proxy measure of cavitation. Fluid (5% human serum albumin [HSA]) with or without Albunex(R) (ALX) was exposed or sham-exposed to 1-MHz ultrasound (P+ = 1.25 +/- 0.01 MPa, P- = 0.81 +/- 0.01 MPa; I-SPTP similar to 35 W/cm(2)) for 60 s using 10-mu s pulses and a duty factor of 0.5. An equal volume of whole human blood was then added to the fluid, followed by a second 60-s treatment. Insonation of cell suspensions prepared in previously sham-exposed HSA + ALX fluid produced about 4% hemolysis, a level significantly greater than in the controls. Insonation of cell suspensions prepared in previously insonated HSA + ALS fluid produced about 0.4% hemolysis; this also differed significantly from the controls. The data thus support the hypothesis, (C) 1997 World Federation for Ultrasound in Medicine and Biology.