Experience with a small animal hyperthermia ultrasound system (SAHUS): report on 83 tumours.

An external local ultrasound (US) system was developed to induce controlled hyperthermia of subcutaneously implanted tumours in small animals (e.g., mice and rats). It was designed to be compatible with a small animal positron emission tomography scanner (microPET) to facilitate studies of hyperthermia-induced tumour re-oxygenation using a PET radiopharmaceutical, but it is applicable for any small animal study requiring controlled heating. The system consists of an acrylic applicator bed with up to four independent 5 MHz planar disc US transducers of 1 cm in diameter, a four-channel radiofrequency (RF) generator, a multiple thermocouple thermometry unit, and a personal computer with custom monitoring and controlling software. Although the system presented here was developed to target tumours of up to 1 cm in diameter, the applicator design allows for different piezoelectric transducers to be exchanged and operated within the 3.5-6.5 MHz band to target different tumour sizes. Temperature feedback control software was developed on the basis of a proportional-integral-derivative (PID) approach when the measured temperatures were within a selectable temperature band about the target temperature. Outside this band, an on/off control action was applied. Perfused tissue-mimicking phantom experiments were performed to determine optimum controller gain constants, which were later employed successfully in animal experiments. The performance of the SAHUS (small animal hyperthermia ultrasound system) was tested using several tumour types grown in thighs of female nude (nu/nu) mice. To date, the system has successfully treated 83 tumours to target temperatures in the range of 41-43 degrees C for periods of 65 min on average.

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.

MicroPET-compatible, small animal hyperthermia ultrasound system (SAHUS) for sustainable, collimated and controlled hyperthermia of subcutaneously implanted tumours.

An external ultrasound system was developed for the heating of subcutaneously implanted tumours in small animals. This small animal hyperthermia ultrasound system (SAHUS) was designed to be compatible with a microPET (small animal positron emission tomography) scanner to facilitate studies of hyperthermia effects on tumour hypoxia. Collimation and localization of energy deposition, a specific goal for the new device to avoid regional and/or systemic heating of small animals, was demonstrated using thermoradiography following high-power short-time heating of a layered gel phantom. The in vivo heating capabilities of the SAHUS were tested using PC3 cell line tumours (2000-2700 mm(3)) grown in the lateral proximal thighs of Nu-/Nu- nuBR nude mice. Intratumour temperatures were recorded during heating trials with deep and superficial interstitial thermocouples. The experimental data showed that the SAHUS could produce hyperthermia in 8 +/- 2 mm diameter tumours in small animals to a target temperature of 41.5 degrees C and maintain it within a narrow temperature range (+/- 0.3 degrees C) for up to 4 h without raising the core temperature of the animals. PET imaging studies, data to be published separately, were conducted before and during SAHUS-induced hyperthermia. Both devices performed as expected and there was no significant decrease in image quality. In this paper, the new SAHUS is described and data from phantom and in vivo experiments presented.

[Psychotherapeutic care and public health]. / Psychotherapeutische Versorgung und Public Health.

In 1992 the German Medical Association had passed a resolution in order to adapt the specialized training of physicians to future demands. This implied the introduction of the new special field of "psychotherapeutic medicine" and a redefinition of the special field of "psychiatry and psychotherapy". The expectable impacts of these innovations will be discussed regarding future perspectives of aims and structures of psychotherapeutic care as well as of interdisciplinary research and cooperation with other health-professionals, patients, and self-help-organisations. In particular, an argumentation is presented, how psychotherapy can be enabled to specific contributions to the promotion of the new public health-paradigm in Germany.

Observations on respiratory and cardiovascular rhythmicities during yogic high-frequency respiration.

Yogic high-frequency respiration--kapalabhati (KB)--was studied in 24 subjects from a point of rhythmicity. Respiratory movements, blood pressure and R-R intervals of ECG were recorded in parallel and evaluated by spectral analysis of time series. Respiratory signals during KB were modulated by 0.1 Hz rhythm in 82% of experiments. This component was also present in R-R intervals and blood pressure during KB. Frequency (0.2-0.3 Hz) was observed in 67% of respiratory records. The presence of the component 0.2-0.3 Hz in respiration was dependent on resting respiratory frequency. This frequency component was reduced in R-R intervals but increased in blood pressure during kapalabhati as compared to that at rest. The occurrence of both frequency components in respiration during KB supports the hypothesis about the integrative role of cardiovascular and respiratory rhythms in physiological states characterized by altered respiratory frequency.

The Buddha and the computer: Meditation in an age of information.

Information overload is one of the factors behind current alarming statistics on stress. Meditation helps the body-mind resist the deleterious effects of the information onslaught. Though meditation is well known as a relaxation technique, its noetic value is often overlooked. Its benefits extend well beyond superficial soothing: it trains attention; it increases pattern recognition; and it reconnects us to the whole of our intelligence, enhancing coordination between its complementary poles. Meditation is a potent high-touch resource in a high-tech world.

[The effects of glucocorticoid treatment during pregnancy on lecithin synthesis in the fetal rat lung (author's transl)]. / Die Wirkung der während de Gravidität durchgeführten glucokortikoidbehandlung auf die Lezithinsynthese in der fetalen Rattenlunge.

In the course of investigations in pregnant rats the authors established that the effect of prednisolone-sodium succinate on the maturation of the fetal lung depends on the dose administered and/or on the time at which it was given. The prednisolone only increased the surface-active lecithin concentration - thus accelerating the functional maturation of the lung - if it was given on the 17th or 18th day of gestation, in a dose of 1.0 mg/kg or 2.0 mg/kg. A dose of 0.5 mg/kg had no effect, while a high dose not only inhibited lecithin synthesis but also caused significant side-effects. The authors point out that the glucocorticoids only have a favorable effect on lung maturation if administered during a certain period in their development, and link this to the maturation process of the specific cortisol receptors in the lung. They also point out the potential danger of glucocorticoids administered to prevent dyspnea and emphasize the importance of determining the lowest effective dose of the various synthetic preparations and/or the optimum time for giving them. They raise the question of whether there is also an ideal time for glucocorticoid treatment in human pregnancies.

Effect of antenatal glucocorticoid administered in a single dose on the incidence of respiratory distress syndrome in premature infants.

Authors administered glucocorticoid in the cases of 116 pregnant women admitted with premature delivery beginning between 28--36 weeks of gestation to prevent respiratory distress syndrome (RDS). Prednisolone-sodium succinate (Di-Adreson F. Organon) was given intramuscularly in a single dose of 100 mg. 314 infants born before introduction of the corticosteroid prevention on the 28--36 weeks of gestation whose mothers had not been given corticosteroid served as a control group. The frequency of RDS on the treated group was 8,62% while 101 of 314 infants on the control group showed RDS (32,16%). Number of infants of hyaline membrane disease was 3 and 40, respectively. A close correlation could be observed between the interval lasting from therapy to delivery and RDS incidence. In infants born within 24 hours after administration of Di-Adreson F. aquosum injection RDS developed in 58,33% while in those born within 24--48 hours RDS was diagnosed only on 3 cases (8,57%). No RDS was found in babies born after 2 days following the therapy. There were no significant differences between treated and control groups in Apgar scores and the mean weights of infants. These findings seem to suggest that 100 mg of prednisolonesodium succinate administered in a single dose significantly reduces the incidence of RDS in premature infants.