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Biomedical subjects

F Cavagnetto

Publications and source records attributed to F Cavagnetto.

3 recordsLinked to original sources

Radio-hyperthermia in post-surgical recurrence of melanoma.

AIMS AND BACKGROUND: Malignant melanoma is one of the most radioresistant tumors. It can be treated with combinated hyperthermia and radiation therapy. METHODS: From January 1991 through June 1992, 7 patients, 1 male and 6 female, aged 40-88 years (mean 75), with skin and nodal post-surgical recurrences of melanoma, were treated with a combination of radiation therapy and hyperthermia. Two patients presented systemic disease when they reached our observation, but all of them were without symptoms. None of them underwent surgical excision of the recurrence before or during thermoradiotherapy. None received chemotherapy for these recurrences or had received radiotherapy in the past. They were irradiated with electron beams, with electron energies selected according to the depth of the lesions. The total dose was 40 Gy in 10 fractions in 5 weeks. Hyperthermia was administered for 10 minutes to 1 hour after irradiation. An inductive method of radiofrequency heating at 434 of 915 MHz was used depending on the depth of the lesions. In all of these treatments a ionized water bolus was used. The prescribed hyperthermic dose was 42 degrees C for half a hour. The treatments were carried out twice a week for 5 weeks. A fiberoptic multichannel thermometer was used for thermometry. RESULTS: Four patients (57%) achieved a complete response, 2 patients (29%) a partial response, and 1 patient (14%) stabilization. We found no correlation between tumor volume and response rate. Site effects and complications of the treatment were minimal (moderate erythema). CONCLUSIONS: Our results are in the wide range of values reported in the literature.

Adult

A personal dosimeter prototype for static magnetic fields.

A personal dosimeter prototype, for static magnetic fields with three Hall probes, has been designed and built to provide a reliable instrument for long-term analysis. The probe output signals, proportional to the magnetic flux density components of the vector B, are filtered, sampled, and stored in a buffer memory sufficient to cover a whole worker shift. The data sampling rate is high enough to record the operator movements within the fringes of the magnetic field. The content of the buffer memory is then transferred on a personal computer and registered on individual dosimetric cards. The data can be used for personal exposure monitoring.

Electromagnetic Fields

Molecular packing parameters of bipolar lipids.

The bipolar lipid fractions extracted from the thermophilic archaeobacterium Sulfolobus solfataricus have different chemical structures and geometrical shapes. The conditions which lead to the formation of vesicles were investigated in order to study the self-assembly of these molecules. Such conditions are fulfilled when an appropriate mixture of two different molecular species (both bipolar or bipolar and monopolar) is used. According to the theory introduced by Israelachvili and co-workers, lipid self-assembly results from the balance of interaction free energy, entropy and molecular geometry. We have shown that this theory can be extended to bipolar lipids, in spite of their more complex nature, and the experimental results obtained combining 1H-NMR, light scattering and entrapped volume techniques closely match theoretical expectations. To carry out calculations, it was necessary to introduce hypotheses about the disposition of bipolar molecules in the vesicle membrane. These hypotheses have been tested indirectly by measuring the transport properties mediated by carriers or channels, whose transport mechanism can be considered to be a probe of the membrane structure.

Hot Temperature