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Biomedical subjects

F Bistolfi

Publications and source records attributed to F Bistolfi.

At least 37 records · Page 2Linked to original sources
PubMed1981

[Heat in oncologic therapy].

Three types of "fire" are used today against cancer: diathermocoagulation, hyperthermia and radiotherapy. Their selective (HT, RT) and non selective (DTC) cytotoxic action are briefly discussed. Hyperthermia, of which the Author summarizes the biological basis, the means of production and the clinical results, is particularly to be considered as an optimal integration of radiotherapy.

Cell Cycle↗
PubMed1981

[Outlines for the combination of hyperthermia therapy and radiotherapy in clinical oncology with special reference to the reciprocal action moment].

The reciprocal moment of action between ionising rays and heat was defined by Vallebona in the Thirties, and is of primary importance in associations between hyperthermia and radiotherapy as a means of obtaining the maximum effect on the neoplasia without serious damage to healthy tissues. The literature data on the use of such combinations in clinical oncology are assessed, together with three other variables; the interval between radiation and heat, the hyperthermic dose, and the interval between two combined treatments. The conclusion is drawn that the thermoradiobiological bases for the rational execution of controlled clinical studies of the hyperthermoradiotherapy of human tumours now exist.

Biophysical Phenomena↗
PubMedDate not supplied

[Equivalent dose and efficient dose in risk assessment of stochastic effects in diagnostic radiology].

INTRODUCTION: Purpose. The equivalent dose absorbed during a radiological examination and the resulting effective dose correlate with the probability of late stochastic effects, of which the ICRP 60 has determined the nominal coefficients normalized to 1 Sv. We have normalized the risk coefficients to 1 mSv for better simulation of working conditions. We propose a simple method for estimating the radiological stochastic risk by correctly using both the equivalent dose and the effective dose concepts. MATERIAL AND METHODS: The effective dose depends on the irradiated body volume; thus, we calculated the stochastic risk in three hypothetical radiological examinations. The equivalent dose in the volume irradiated by the main beam was assumed to be 10 mSv and homogeneous; the equivalent dose in adjacent volumes was assumed to decrease by two different dose gradients. In our models, the sum of the equivalent dose absorbed by various tissues multiplied by the different weight-tissue values gives three effective dose values. Finally, the stochastic risk is estimated by multiplying the effective dose values by the nominal risk coefficient determined by ICRP 60. RESULTS: The effective dose is highest when the volume irradiated by the main beam is largest and the dose gradient in adjacent volumes is slowest. With a slow gradient, the effective dose is 10 mSv for total body examinations, 6.25 mSv for abdominopelvic examinations and 1.4 mSv for head and neck examinations. With a fast gradient, the effective dose is 10 mSv, 5.99 mSv and 1.10 mSv, respectively. The lethal tumor probability over the entire life-span is 65/10(6) for head and neck examinations, 300/10(6) for abdominopelvic examinations and 500/10(6) for total body examinations. CONCLUSIONS: The risk of stochastic effects in diagnostic radiology is low, inasmuch as it is projected over the entire life-span of the subject. Nevertheless, it must not be overlooked. Our calculation method aims to explain the correct use of equivalent dose and effective dose concepts, particularly relative to that great majority of radiological examinations which involve limited body volumes. In these cases it is important to estimate correctly the dose gradient from the examined volume towards the adjacent volumes. Close collaboration between physicist and radiologist is therefore essential, as their respective specialist tasks must necessarily be integrated.

Radiation Dosage↗
PubMedDate not supplied

The bioelectronic connectional system (BCS): a therapeutic target for non ionizing radiation.

Among cells and extracellular matrix have been demonstrated reciprocal interactions of oriented morphogenesis. As collagen fibers of the matrix, keratin filaments of desmosomes and the cytoskeleton elements are all piezoelectric substances, with particular biophysical characters, it is possible that these three classes of biostructures are the morphological expressions of a large and unitary cooperative system for coherent communication among cells, by means of piezoelectric interactions and photon/phonon transduction of electromagnetic signals, both endogenous and exogenous. The Author has proposed in 1989 to classify this morphofunctional complex as a bioelectronic connectional system (BCS), in which connective tissue is largely included, but the functions of which go well beyond its classical mechanical ones. The hypothesis is consistent both with the model of Welch and Berry (protonic energy continuum) and with the concept of bioplasma (Inyushin, Sedlak et al.). Physiology and pathology of BCS could also work as a starting point for experimental research aiming at inducing order in biostructures by means of non ionizing radiation.

Cell Communication↗
PubMedDate not supplied

A hydrogen-harps model for intracellular communication and its implications for the second genetic code.

Hydrogen bonds (HB) in proteins and nucleic acids oscillate with frequencies of 10(11)-10(12) Hz, so giving rise to mm waves and far infrared emission. As HB undergo stretching and compression, their oscillation frequency will correspondingly change. The author (1989) 1b has devised a "musical" model, in which HB are compared to the strings of a string instrument: the harp. On the length, number and cooperation of "strings" (small and large hydrogen-harps) will depend the frequency, intensity and quality of "sound" (i.e. electromagnetic emission). Of course, this elementary hydrogen-harps model needs a physico-mathematical development. Nevertheless it can already be utilized to explain some essential moments of proteins and DNA function, on the base of its logical connection with Fröhlich's theory of coherent excitations. It might also help the understanding of the second genetic code mechanisms.

Cell Communication↗
PubMedDate not supplied

[Ferrofluids].

Ferrofluids are colloidal suspensions of extremely small ferromagnetic particles, the physical properties of which belong to a very complex chapter of modern magnetohydro-dynamics. Because of that, ferrofluids will possibly open new perspectives of medical applications, both in diagnostic radiology and therapeutic oncology.

Colloids↗