Localized versus regional hyperthermia: comparison of xenotransplants treated with a small animal ultrasound system and waterbath limb immersion.

The response of xenotransplants were compared with waterbath immersion vs focal ultrasound (US) hyperthermia using tumour growth delay, immunhistochemistry and histopathology assays. Waterbath hyperthermia was performed by limb immersion. Precautions were taken to minimize total body heating by surrounding the mouse with plastic insulators. Thermometry was performed with clinical-grade, 20-gauge needle thermocouples and monitored with a Labthermics unit. Significant differences in cytotoxicity between ultrasound and waterbath treatment of tumors at 43 degrees C were observed as determined by TUNNEL assay. Conversely, contralateral (non-treated) tumours in animals treated with similar temperature demonstrated no significant differences between modalities. Western blot analysis revealed increased hsp70 induction at 43 degrees C in waterbath vs focal ultrasound hyperthermia. Comparison of tumour growth delay between tumours heated with waterbath vs ultrasound at 43 degrees C but not at 41 degrees C revealed significant differences. This is the first study comparing localized vs regional hyperthermia using the small animal ultrasound system (SAHUS) delivery system. Consistent ultrasound hyperthermia can be achieved throughout a xenotransplant. At equivalent temperature of 43 degrees C for 60?min, waterbath hyperthermia demonstrated greater local response vs ultrasound hyperthermia.

Hypoplastic left heart syndrome: factors influencing therapeutic choice.

Parent's choices among therapeutic options for their infants born with hypoplastic left heart syndrome are difficult and controversial. Currently, management options include surgical reconstruction, cardiac transplantation, and comfort measures only. We retrospectively reviewed medical records of 47 patients (1989-1999) to create a database of clinical features of infants who received either an operation or comfort care only. Eleven families were interviewed by means of a structured questionnaire pertaining to their experience and reasons for their choice. Of the 47, 20 were prenatally diagnosed and nine of these (45%) aborted. The remaining 38 of the 47 were liveborns. Of the 38, 20/38 (53%) chose comfort care only. The other 18 chose operation. Although 17 were able to survive until first stage repair, only 8/17 (47%) survived beyond five months. At the time of last contact (ages one to 4.5 years), 5/17 (29%) remained alive. Over the nine years an increasing proportion of parents chose operative reconstruction; 8/11 (73%) for 1996-99 vs 10/27 (37%) for 1989-1995. Interviewed families who chose comfort care were more likely to believe the rate of survival following operation was poor, quality of life was diminished, and seemed concerned that their infant would suffer. Influence by optimistic physicians at surgical centers seemed important for an operative choice. Most suggested that provision of written materials, professional family counseling, and support groups of hypoplastic left heart syndrome families are or would be helpful.