Tsutomu Yonezawa

Thermotolerance in regional hyperthermia in vivo : an experimental study using the MH134 tumor

In the clinical application of hyperthermia, determining the thermotolerance that influences the anti-tumor effect is an important problem. The purpose of this study was to investigate the methods of induction and disappearance of thermotolerancein vivo. After transplanting MH134 cancer cells into the paws of C3H mice, local hyperthermia with warm water was administered, and the movement of thermotolerancein vivo studied in terms of the heating intervals and tumor growth times. When the first heating was applied on the 8th day after transplantation, thermotolerance appeared within 1 hour, increasing gradually to reach a maximum at 18 hours, after which it decreased gradually and disappeared after 48 hours. When the first heating was applied on the 13th day after transplantation, which fell during the rapid tumor proliferation period, the movement of thermotolerance presented a similar pattern of appearance and disappearance. The results of this study made it clear that there was no difference in the movement of thermotolerance between the two periods even though each had a different rate of tumor proliferation.In the clinical application of hyperthermia, determining the thermotolerance that influences the anti-tumor effect is an important problem. The purpose of this study was to investigate the methods of induction and disappearance of thermotolerance in vivo. After transplanting MH134 cancer cells into the paws of C3H mice, local hyperthermia with warm water was administered, and the movement of thermotolerance in vivo studied in terms of the heating intervals and tumor growth times. When the first heating was applied on the 8th day after transplantation, thermotolerance appeared within 1 hour, increasing gradually to reach a maximum at 18 hours, after which it decreased gradually and disappeared after 48 hours. When the first heating was applied on the 13th day after transplantation, which fell during the rapid tumor proliferation period, the movement of thermotolerance presented a similar pattern of appearance and disappearance. The results of this study made it clear that there was no difference in the movement of thermotolerance between the two periods even though each had a different rate of tumor proliferation.

Tricuspid regurgitation due to chest trauma: An unusual laceration around the annulus of the anterior leaflet

SummaryA 70-year-old male with tricuspid regurgitation due to a blunt chest trauma inflicted 16 years previously underwent prosthetic valve replacement. At surgery, a tear, which produced tricuspid regurgitation, was found around the annulus of the anterior leaflet of the tricuspid valve. Since this area has not been reported as a location for heart trauma-producing tricuspid regurgitation, a possible mechanism of tricuspid regurgitation is discussed in this patient.