Diagnostic ultrasound: effects on the DNA and growth patterns of animal cells.

The effects of diagnostic levels of ultrasound on DNA of HeLa cells included: increased immunoreactivity to antinucleoside antibodies in G1 cells, strongly suggestive of unwinding of the helix or single-strand break induction, and low levels of non-semiconservative synthesis in logarithmically growing cells treated with hydroxyurea, indicating repair synthesis. In the C3H mouse cell line 10T-1/2, Cl 8, loss of contact inhibition with a criss-crossed growth pattern was seen. In one experiment, tumors developed in syngeneic mice at the site of injection of ultrasonically treated cells. Ultrasound in the diagnostic range appears to cause detectable effects on DNA and growth patterns of animal cells.