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Biomedical subjects

S P Osinskiĭ

Publications and source records attributed to S P Osinskiĭ.

15 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

[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

[Hydrogen ion concentration in tumor issue and artificial hyperglycemia].

A series of articles concerned with determination of pH in the tumour and with studies of pH changes under induced hyperglycemia are reviewed. Based on the available data the following conclusions are drawn: pH in the tumour tissue is lower than in the initial normal or surrounding tissues by 0.5 units on the average; the optimal pH value is more acidic; alkalosis in the tumour-bearing organism is a hypercompensatory reaction of the host as a result of advanced tumour in which pH is dropped; the induced hyperglycemia promotes a pronounced decrease of pH in the tumour, pH of the normal tissues being unchanged; the possibility to decrease pH in the tumour should be taken into account when developing new methods of the antitumour therapy.

Animals↗
PubMed1985

[Local blood flow into tumors during artificial hyperglycemia].

The blood flow in the rat Guerin carcinoma was measured by the hydrogen clearance method. It was shown that the blood flow in the tumour tissue decreased almost 3.5 times to the 3 hours of the intravenous glucose infusion at a dose of 80 mg X kg-1 X min-1. In some tumours the microcirculation ceased completely. The results obtained help developing the new schemes of local hyperthermia and induced hyperglycemia in the complex antitumour therapy.

Animals↗
PubMed1984

[Metabolic factors determining the selective enhancement of the effect of ionizing radiation on tumors].

Two alternative approaches to enhance the damaging effect of X-rays on radioresistant tumours are discussed. One of them, hypoxyradiotherapy, suggests a preferential protection of normal host tissue, the other, short-term hyperglycemia, is directed to a selective intensification of tumour destruction. Both approaches take into account peculiarities of tumour metabolism. Theoretical considerations are put forward and experimental data are described elucidating the mechanisms of the selective action of hyperglycemia on the tumour and specifying the conditions which significantly enhance the antitumour radiation effect. In particular, a way to enhance the postradiation effect on tumour cells results in their interphase death. A combined use of gas hypoxia, hyperglycemia and hyperthermia is substantiated.

Animals↗
PubMed1984

[Determination of the pH of solid tumors].

The design and production technique of pH-electrode for measuring pH in solid tissues are described. Main characteristics of the pH electrode are determined: external diameter 0.25-0.4 mm, length of the pH-sensitive part--4-10 mm, sensitivity at 37 degrees C--55-60 mV/pH, and drift--less than or equal to 0.005 pH/h.

Animals↗
PubMed1977

[Acid-base and water-electrolyte status in animals with experimental tumors].

It is noted that rats with Heren carcinoma show alkalization of blood, decreased pH levels of the urine, hypokalemia, hypocalcemia, hypomagnesiemia, sodium and water retention, increased kalium level in the liver. Analogous changes are observed in rabbits with Brown-Pearce carcinoma. The organism of tumor-bearing rats responds to stress effects otherwise than the organism of normal animals.

Acid-Base Equilibrium↗