Enhancement of Hyperthermic Cell Killing by Non-thermal Effect of Ultrasound

Kondo, Takashi; Kano, Eiichi

doi:10.1080/09553008714550591

Cited by 36 publications

(9 citation statements)

References 23 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These N2 0 effects were also observed in the previous studies of 1 . 0 MHz ultrasound at hyperthermic temperature (Kondo and Kano 1987) . In addition, our ESR experiments showed that N 2 0 suppresses OH radical formation (Kondo et al .…”

Section: Discussionmentioning

confidence: 99%

Effect of Free Radicals Induced by Ultrasonic Cavitation on Cell Killing

Kondo

Kano

1988

International Journal of Radiation Biology

Self Cite

View full text Add to dashboard Cite

The present study was undertaken to elucidate the mechanism of in vitro cell killing induced by 1.0 MHz continuous wave ultrasound at an intensity of 5.8 W/cm2. The chemical effects and mechanical effects arising from acoustic cavitation were determined by the amount of liberated iodine and the number of DNA double-strand breaks, respectively. The survival of mouse L cells immediately after irradiation was estimated by counting the number of cells which are not stained by trypan blue and the clonogenicity of surviving cells remaining immediately after irradiation was monitored by colony-forming ability. The effectiveness of the dissolved gases in liberating iodine was in the order O2 greater than Ar greater than N2 greater than N2O approximately 0. However, the effect of dissolved gases on the yield of double-strand breaks of DNA and on the two kinds of end points of cell killing was in the order O2 = Ar = N2 greater than N2O approximately 0. These results suggest that the different amounts of free radicals induced by ultrasound are not directly related to the ultrasonically induced cell killing. The presence of cysteamine (2 mmol dm-3) during sonication completely inhibited a decrease in clonogenicity of surviving cells, but did not inhibit that of cell survival immediately after sonication. These results suggest that the decrease of survival immediately after sonication is due to mechanical shear stress arising from cavitation, while the decrease of clonogenicity of the remaining surviving cells is due to free radicals induced by cavitation. The contribution of free radicals to total cell killing was estimated as about 1 per cent at the level of 95 per cent cell killing immediately after sonication.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of Free Radicals Induced by Ultrasonic Cavitation on Cell Killing

Kondo

Kano

1988

International Journal of Radiation Biology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Hyperthermia induced by ultrasound was investigated and found to be more advantageous because of its manageability in terms of focusing, control and sufficient tissue attenuation coefficient for deep tumor targets 83 . Moreover, hyperthermia combined with non-thermal ultrasound also showed synergistic effects on cell killing 84 . Kondo and Kano 84 treated mouse L-cells with a low-intensity ultrasound (1 MHz, 3.7 W/cm 2 ) and/or 44 °C hyperthermia.…”

Section: Combination Of Sdt With Other Cancer Treatment Methodsmentioning

confidence: 97%

“…Moreover, hyperthermia combined with non-thermal ultrasound also showed synergistic effects on cell killing 84 . Kondo and Kano 84 treated mouse L-cells with a low-intensity ultrasound (1 MHz, 3.7 W/cm 2 ) and/or 44 °C hyperthermia. More significant synergistic effects on cell killing were observed in combination treatment of ultrasound and hyperthermia.…”

Section: Combination Of Sdt With Other Cancer Treatment Methodsmentioning

confidence: 97%

Recent advances of sonodynamic therapy in cancer treatment

Wan

Liu²,

Chen

et al. 2016

Cancer Biology &Amp; Medicine

229

157

View full text Add to dashboard Cite

Sonodynamic therapy (SDT) is an emerging approach that involves a combination of low-intensity ultrasound and specialized chemical agents known as sonosensitizers. Ultrasound can penetrate deeply into tissues and can be focused into a small region of a tumor to activate a sonosensitizer which offers the possibility of non-invasively eradicating solid tumors in a site-directed manner. In this article, we critically reviewed the currently accepted mechanisms of sonodynamic action and summarized the classification of sonosensitizers. At the same time, the breath of evidence from SDT-based studies suggests that SDT is promising for cancer treatment.

show abstract

“…The peak rarefactional pressure amplitudes were 0.08, 0.12 and 0.17 MPa, respectively. The beam pattern of the US and the attenuation of the sound were determined previously using an active hydrophone MKII (Medisonics Ltd, Watford, UK) by Kondo and Kano (1987). Attenuation by the inverted T-tube was estimated to be about 12%.…”

Section: Ultrasound Apparatus and Intensity Measurementmentioning

confidence: 99%