Thermal Medicine(Japanese Journal of Hyperthermic Oncology)
Online ISSN : 1881-9516
Print ISSN : 0911-2529
ISSN-L : 0911-2529
Volume 19, Issue 1
Displaying 1-4 of 4 articles from this issue
  • HIDEOMI WATANABE, TETSUYA SHINOZAKI, TAKASHI YANAGAWA, TSUTOMU KOBAYAS ...
    2003 Volume 19 Issue 1 Pages 1-10
    Published: March 01, 2003
    Released on J-STAGE: October 21, 2009
    JOURNAL FREE ACCESS
    For skeletal reconstruction after resection of malignant bone tumors, hyperthermia-treated bone has been used with more favorable results by the method of pasteurization (60-65°C for 30min) over autoclaving or boiling. Experimental studies demonstrated clearly that pasteurization destroys malignant cells while preserving the bone-inducing properties. Clinical investigations reveal few recurrences related to pasteurized tumor tissues. Complications include non-union, fracture, absorption, and infection. The operation protocol, while not ideal, is superior to that of other reconstruction procedures because many fundamental complications, such as the low long-term survival of massive prosthesis, the lethal risk of transfections, such as HIV, and immunological responses of the allograft, can be avoided.
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  • YOUJI KOTSUKA, HIROSHI OKADA
    2003 Volume 19 Issue 1 Pages 11-22
    Published: March 01, 2003
    Released on J-STAGE: January 29, 2010
    JOURNAL FREE ACCESS
    Designing a small millimeter-sized implant is very difficult because common implant materials such as small ferrite materials, iron materials, ni-chrome wire etc., cannot be heated well by inductive heating when these implant sizes are less than 10 millimeters. This fact is based on the inherent nature of eddy currents which distributes over only the surface of heating material when applying RF magnetic fields to it.
    To break through the problems of an inductive deep local heating, a small high efficiency implant has been newly proposed not from conventional material compositions but from electrical circuit theory viewpoint. This new implant is simply composed of a small coil and a microchip condenser. It is heated efficiently based on the resonant circuit theory when RF magnetic field is applied.
    In this paper, after the fundamental investigations on an optimum condition for the present implant, rise-time heating characteristics, how to obtain a smaller implant, and how to design an omni-directional implant are described.
    A small implant of coil diameter and a coil length being 6.5mm and 1.6 mm, respectively shows a temperature rise more than 20°C within one minute heating in the depth of 10cm at the frequency of 4MHz when using ferrite core applicator with output power of 500 W. Through this development of a small high efficient implant, the essential technology that we are aiming at constituting the wireless thermometer with the function of local heating implant could be paved.
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  • SATOSHI KOKURA, SHUJI NAKAGAWA, YOSHIO BOKU, TAKU HARA, YUJI NIATO, NO ...
    2003 Volume 19 Issue 1 Pages 23-30
    Published: March 01, 2003
    Released on J-STAGE: October 21, 2009
    JOURNAL FREE ACCESS
    We have demonstrated that free radical reactions play an important role in the mechanism of the antitumor effect of hyperthermia (HT). In an attempt to enhance its antitumor effect, we studied the influence of the depletion of glutathione (GSH), a typical radical scavenger in AH 109A carcinoma, a rat liver cancer. Oral administration of buthionine sulphoximine (BSO), a GSH synthesis inhibitor, caused a decrease in the tumor GSH content and enhanced the effect of HT. However, oral administration has the potential to cause adverse effects because it also decreases GSH in other tissues. To avoid this problem, we injected BSO into the feeding artery for the tumor, and examined the changes of the GSH content in the tumor, liver, and kidneys. It was found that the GSH content of the liver and kidneys decreased soon after the injection of BSO and recovered completely after 24 h, while the decrease of GSH in the tumor persisted. When HT was done at this time, it showed an enhanced antitumor effect.
    The above results suggest that the intraarterial injection of BSO can specifically decrease the tumor GSH content, and can enhance the antitumor effect of HT without having an adverse effect on normal organs.
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  • HIROYUKI SAKURAI, TAKASHI NOGUCHI, IORI ITO, MAYUKO SAKAIDA
    2003 Volume 19 Issue 1 Pages 31-42
    Published: March 01, 2003
    Released on J-STAGE: October 21, 2009
    JOURNAL FREE ACCESS
    Although HSP 70 has been reported to play a major role in establishing the ischemic tolerance, the precise mechanism of this phenomenon has not been quitely understood. The purposes of the present study are to evaluate the cytoprotective effect of ischemic preconditioning, and administration of geranylgeranylacetone (GGA), which is expected to induce HSP 70, and to elucidate the cytoprotective mechanism of HSP 70 from the standpoint of the functional relationship between HSP 70 and transcription factor NF-κB.
    Materials and methods. Male Wistar rats were subjected to 45 minutes of hepatic ischemia followed reperfusion. The animals were divided into 3 groups. Group I were subjected to 45-minute liver ischemia/reperfusion (I/R). Group P were subjected to 30-minute I/R as a preconditioning prior to 45-minute I/R. Group G were given to oral geranylgeranylacetone (GGA) at a dose of 200 mg/kg body weight for 7 days prior to 45-minute I/R. Examined were survival rate, liver function (ALT and hyaluronic acid), hepatic tissue blood flow (laser Doppler), histological findings (TEM, SEM), expression of HSP 70 and NF-κB (Western blot analysis), NF-κB DNA binding activity (electrophoretic mobility shift assay), and NO-2 +NO-3 concentration in isolated hepatocyte culture (Griess method). Results. Hepatic blood flow, serum ALT levels, serum HA levels, and histological findings showed a significant improvement in groups P and G, whereas ischemia/reperfusion injury was very severe in group I. HSP 70 induction was significantly increased in groups P and G. And the expression and activation of NF-κB were inhibited in groups P and G. The NO production was suppressed in groups P and G. Conclusion. Ischemic preconditioning and the oral administration of GGA induced the ischemic tolerance by inducing HSP 70. The mechanism was not only 1) that Hsp 70 suppressed NF-κB and regulated the overproduction of NO attributable to iNOS but 2) that it was involved in the maintaining the function of eNOS within 6 hours after reflow as well.
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