PubMed Health⌕ Search

Biomedical subjects

A N Gusev

Publications and source records attributed to A N Gusev.

9 recordsLinked to original sources
PubMed1988

[Methods for creating hyperthermia in tumors by using electromagnetic fields].

Evidence on the methods for creation of hyperthermia in treatment of human tumours using superhigh-frequency external, intracavitary, and implanted irradiators are generalized. Inductive, capacitive and interstitial methods of heating are described. Advantages and shortcomings, depths of heating and heat-production structures are presented for each method. The known devices for regional hyperthermia are considered.

Brachytherapy↗
PubMed1987

[Interstitial hyperthermia method in spontaneous tumors].

To induce hyperthermia of spontaneous tumors in dogs an interstitial method of heating was used: electrodes in the form of injection needles were implanted around tumors. Necessary temperature levels could not be attained in a dog with circumanal angiosarcoma because the tumor was well vascularized and had a considerable volume. No thermal damage of the animals' skin was observed during all sessions of hyperthermia. A conclusion was made that the interstitial method of heating could be used in multimodality therapy of malignant tumors of a complex shape.

Animals↗
PubMed1987

[The microenvironment of tumor cells and the antitumor effect of hyperthermia].

Intravenous infusion of 20% solution of glucose (80 mg/kg of body mass per 1 min) resulted in considerable changes in microenvironment of tumor cells: by the 90th-120th min of infusion there was a decrease in pH, pO2, blood flow inhibition, an increase in the relative number of cells in the S-phase of the mitotic cycle in a tumor. There was no increase in tumor ATP and glucose up to the values at which these substance could enhance thermoresistance, a situation being rather favorable for realizing a damaging effect of hyperthermia. The use of hyperglycemia in the above regimen prior to MWF-hyperthermia enhanced 2-3 times its antitumor effect on the model of subcutaneously transplanted Guéren carcinoma and Pliss lymphosarcoma. Glucose at the concentration of 5-0 mmol enhanced the thermosensitivity of L-1210 cells. The results indicated the efficacy of hyperglycemia combined with hyperthermia.

Animals↗
PubMed1986

[Multifield local hyperthermia as a method for heating deeply located neck tissues].

Distribution of the thermal field in neck tissues in local SHF-hyperthermia is studied. The two-field method of irradiation permits a uniform heating of more deeply located layers of the tissue due to summation of the radiant energy. So, the contact method of irradiation using "Luch-2" and "Luch-3" sets permits elevating the temperature inside the larynx up to 41-41.5 degrees C and maintaining it under given conditions for 25-30 min, but the heat loading on the skin and subcutaneous fat remains high. When using noncontact irradiators and "Parus" set the deeply located neck tissues are heated to 42-43 degrees C, the temperature of surface layers not exceeding 41-42 degrees C. This temperature rate is possible to be maintained for 25 min; its prolongation induces a sharp rise in the temperature of surface layers. Long-term SHF-hyperthermia of deeply located neck tumours necessitates cooling of the integument surface.

Animals↗
PubMed1986

[Enhancement of the antineoplastic effect of local hyperthermia by induced hyperglycemia].

It is shown that the antitumour effect of local hyperthermia (2450 MHz, 43 degrees C, 60 min) is enhanced essentially if it follows immediately after i. v. infusion of 20% glucose solution at a rate of 80 mg X kg-1 X min-1 for 90 min in experiments on rats bearing the Guerin carcinoma. Under such a combined treatment the rate of tumour growth decreases by a factor of 2. An assumption is advanced that such an enhancement of the hyperthermia effect is caused mainly by low pH values of the tumour which are observed under hyperglycemia.

Animals↗
PubMed1986

[Model study of the structure of heat release when using interstitial hyperthermia on tumors].

Heat distribution structures are given with application of the interstitial method of heating with the 1.7 MHz frequency, 8 implanted needles arranged in 2 rows were used as electrodes. Heat distribution structures are obtained on the basis of the mathematical model which was constructed in the electrostatic approximation and with the investigation of the spatial distribution of temperatures in the tissue-equivalent phantom. The results obtained in the both cases coincide.

Hot Temperature↗
PubMed1985

[Thermal field created by an irradiator with a slot capacitance studied on tissue-equivalent phantoms].

Experiments were carried out on phantoms imitating muscular and fatty tissues which were exposed to a single action of microwave hyperthermia in microwave set "Volna-2" (460 MHz installation with a modified antenna. The temperature in the phantoms was measured by copper-constant thermocouples in periods of automatic switching off the microwave power. Temperature distribution in the phantoms was found to depend on the depth, exposure time and power.

Adipose Tissue↗