|
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