Abstract

 

Nonthermal Impact of High Intensity Ultrasound on a Malignant Tumor

V.A.Burov, O.V.Rudenko (Department of Acoustics, Faculty of Physics, Moscow State University, Moscow, Russia); N.P.Dmitrieva (Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia)

e-mail: burov@phys.msu.su

The progress of resent researchers of "universal" immune response of organism to malignant cells as a reaction induced by a telomerase [1] encouraged us to review the old results, obtained many years ago [2]. A high-malignancy strain of Brown-Pears was used as a model of tumor transplanted to experimental animals (rabbits). The most experiments were performed at a frequency of 1.5 MHz with (unfocused) beam intensity 100-200W/cm^2. In 40-80% of cases, the tumor resolved completely. However, the most important effect was the clear immune response of organism - resorption of metastases, which were not exposed directly, and immune reaction on repeated inoculations. The exposure was rather shot (1 sec) and the ultrasound thermal effect was not essential. Electron microscopy of the sonicated tissue revealed changes in mitochondria and nuclei of tumor cells [3]. Later this new method of treatment was offered on a few patients with the terminal stage of melanoma. Complete resorption of melanoma was observed in some cases. The role of telomerase in the development of the immune response was reviewed in [1]. There is evidence that telomerase contained in malignant cells can be released as a result of the power ultrasonic exposure. The estimation of the acceleration magnitude in the used ultrasound waves gives the order of 10^9g. These high values are obtained because of progressive nonlinear distortion of the waveform. This and other types of hydrodynamics process are capable to cause damage of membranes and nuclei structures. References. 1. Nair S. K., Heiser A., Boczkowski D. et al // Nature Medicine. 2000. V.6. N8. P.1011-1017.  2. Burov A.K., Andreevskaya G.D. Doklady Akademiya Nauk SSSR. 1956. V.106. N3. P.445-448.  3. Dmitrieva N.P. Doklady Akademiya Nauk SSSR. 1960. V.132. N1. P.210-212.

 

Section : 5