[Use of a neodymium lasers for fluorescent diagnosis and photodynamic destruction of tumors]. / Primenenie neodimovogo lazera dlia fluorestsentnoi diagnostiki i fotodinamicheskogo razrusheniia opukholi.

Fluorescence and photodynamic destruction of tumor tissues containing hematoporphyrin derivative was studied during excitation by II and III harmonics of AY:Nd(3+)-laser. This laser system can be effectively used for diagnosis of malignant tumours and photodynamic therapy.

[The distribution of hematoporphyrin derivatives in the animal body]. / Raspredelenie proizvodnykh gematoporfirina v organizme zhivotnykh.

The pharmacokinetic distribution of haematoporphyrin derivative (HPD) and synthetic oligomeric haematoporphyrin (OG) which showed various lipophilicity was studied in animal tumor and normal tissues. The accumulation of dyes in tissue and their tumor-seeking capacity depended on the degree of polymerization, lipophilicity, and ratio of dye components. The difference in the absolute concentrations of HPD and OG (6.9 and 16.1 micrograms per g tissue, respectively) in tumor after dye injection in an adequate concentration (10 mg/kg b. w.) indicates that synthetic OG is beneficial for tumor diagnosis and photodynamic therapy.

[The effect of enterosorption on lipid peroxidation and antioxidant activity of liver and blood lipids during combined thermal injury]. / Vliianie énterosorbtsii na perekisnoe okislenie i antioksidantnuiu aktivnost' lipidov pecheni i krovi pri kombinirovannoi termicheskoi travme.

Enterosorbents IHANT, VUGS and PMS decreased considerably the lipid peroxidation products content in liver tissue within 3 days after combined thermic trauma. The effect observed appears to occur due to adsorption of endotoxins including lipid toxins in gastrointestinal tract. Content of lipid peroxidation products in liver tissue under pathologic conditions may serve as a criterion in evaluation of enterosorbents efficiency in gastrointestinal detoxication.

Oxidative stress, disturbance of energy balance, and death of ascites tumour cells under menadione (vitamin K3) action.

Resting ascites tumour cells (Ehrlich and EL-4 thymoma) treated with menadione (50 microM) died (up to 80% cell death over 2 h) without dividing (i.e. interphase). Glucose (25 mM) added to the cell suspensions partially protected these cells from menadione action. During incubation of the cells with menadione, the rates of free oxidation and lipid peroxidation were elevated, cellular ATP and nonprotein SH-group levels were much decreased, and [Ca2+]i was moderately increased. From a comparison of these effects and cell survival rates with those seen with rotenone, KCN (both inhibitors of oxidative phosphorylation), and H2O2 (an inducer of oxidative stress), it is concluded that ATP depletion is the main factor leading to the death of cells treated with menadione. The level of cellular ATP dropped to less than 10% of its initial value after 1 h incubation with menadione and may have resulted in irreversible damage to cytoskeletal structures, bleb formation, and changes in plasma membrane permeability that are incompatible with cell viability.

[The effect of fast electrons and menadione on the structural-functional status of Ehrlich ascites carcinoma cells in the early periods following irradiation]. / Deistvie bystrykh élektronov i menadiona na strukturno-funktsional'noe sostoianie kletok astsitnoi kartsinomy Erlikha v rannie sroki posle oblucheniia.

Irradiation of Ehrlich ascites tumor cells stimulates oxygen consumption, and menadione suppresses cell respiration. The combined effect of the two factors produces an additional, in comparison with the effect of menadione alone, inhibition of the rate of oxygen consumption by cells. There is an additive effect of radiation and menadione with regard to the level of cell thiols and interphase cell death.

[Change in the replicative synthesis of DNA and in respiration during gamma-irradiation of cultured human lymphocytes]. / Izmenenie replikativnogo sinteza DNK i dykhaniia pri gamma-obluchenii limfotsitov cheloveka v kul'ture.

The onset of 3H-thymidine incorporation in DNA precedes a short-term activation of cell respiration. gamma-Irradiation (5 Gy, 0.1 Gy/s) significantly inhibits oxygen consumption by human peripheral blood lymphocytes. It should be noted that time dependence maxima of oxygen consumption are shifted towards later times of cultivation.

[Effect of radiomodifiers on lipid peroxidation and the structural-functional state of irradiated mitochondria]. / Vliianie radiomodifikatorov na perekisnoe okislenie lipidov i strukturno-funktsional'noe sostoianie obluchennykh mitokhondrii.

SH-Containing radioprotective agents, for instance, cysteine, cystamine, dithiothreitol, exert an antioxidant effect on gamma-radiation-induced lipid peroxidation in mitochondrial membranes and, concurrently, uncouple oxidation from phosphorylation. A radiosensitizer, N-ethylmaleimide, on the contrary, being a pro-oxidant of lipid peroxidation couples oxidation and phosphorylation. At the same time, changes in the lipid peroxidation system and in the energy production processes, observed after irradiation of a mitochondrion suspension containing modifiers, are accompanied by the increased destruction of mitochondrial membranes as compared to irradiated controls.

[Changes in the SH-group level and respiration during gamma- and Fe2+-induced lipid peroxidation in Ehrlich ascites carcinoma cells]. / Izmenenie soderzhaniia SH-grupp i dykhaniia v protsesse gamma- i Fe2+-indutsirovannogo perekisnogo okisleniia lipidov v kletkakh astsitnoi kartsinomy Erlikha.

In experiments on Ehrlich ascites tumor cells it was shown that lipid peroxidation induced by gamma-rays and Fe2+ ions was accompanied by a decrease in the endogenous SH-group content at early times after exposure (during 3-hour incubation). It was also established that no significant changes occurred in the oxygen uptake by Ehrlich ascites tumor cells depending on radiation dose of Fe2+ ion concentration. If cells were pre-kept under hypotonic conditions an additional decrease in cell respiration and SH-group content and activation of lipid peroxidation was noted.

[Effect of Fe2+- and gamma-induced lipid peroxidation on respiration and oxidative phosphorylation in the mitochondria]. / Vliianie Fe2 - i gamma-indutsirovannogo perekisnogo okisleniia lipidov na dykhanie i okislitel'noe fosforilirovanie v mitokhondriiakh.

Lipid peroxidation activated by low concentrations of Fe2+ ions in a medium (1-5 microM) and gamma-quanta (10-50 Gy) stimulates the oxygen consumption and oxidative phosphorylation during the initial period of incubation (10-20 min). With relatively high concentrations of Fe2+ ions and higher radiation doses (50-100 Gy) inhibition of the activity of mitochondria is registered with respect to both indices.

[Formation of malondialdehyde during liposome interaction with cells]. / Obrazovanie malonovogo dial'degida pri vzaimodeistvii liposom s kletkami.

When AKE cells and leukocytes interact with egg lecithin liposomes malone dialdehyde (MDA) is formed and accumulated in the incubation medium. When synthetic dipalmitoyl--lecithin is used and at heat or hypotonic cell damage the rate of MDA accumulation abruptly decreases. The maximal rate of MDA accumulation in case of natural lecithin is (1.25 +/- 0.05) . 10(-15) mole of MDA per cell/hour. It is suggested that the sources of MDA are higher unsaturated fat acids of natural liposomal lipids, whose oxidation is performed by intact cells, possibly with the participation of active forms of oxygen.

[Relationship between lipid peroxide oxidation and cell respiration]. / Sviaz' perekisnogo okisleniia lipidov i kletochnogo dykhaniia.

A relationship between lipid peroxide oxidation (LPO) in biomembranes and kinetics of oxygen uptake by intact cells and cells under hypotonic shock in the course of their incubation has been studied. Different effect of bivalent ferrum ions--activators of LPO was found; it depended on cell integrity. In the cells under normal physiological conditions the rate of oxygen uptake was independent of the amount of LPO products, while in the cells placed into hypotonic medium it decreased on the background of LPO intensification as compared to the normal one. Peculiar effects of the LPO products on intact cells seem to be related to spatial disconnection of respiratory centres and to localization of peroxide oxidation reactions.