[Advances and prospects of a combined therapy of acute radiation injury in experiments]. / Dostizheniia i perspektivy kompleksnoi terapii ostroi luchevoi bolezni v éksperimente.

We present the results of a long-standing experimental development of ways and means for acute radiation sickness treatment that have been authorized for application in medicine and are mostly aimed at large-scale accidental injuries. The paper describes means for early treatment (prodigiosan, desoxynate, typhoid vaccine, proteus vaccine), a myeolopoiesis stimulant (estradiol dipropionate), a detoxication procedure (hemosorption), substitution therapy with bone marrow cells and peripheral blood mononuclears, anti-infectious schemes comprising antibiotics and polyvitamins.

[Treatment of infectious complications of experimental acute radiation injury with combined antibiotic sulacillin]. / Lechenie infektsionnykh oslozhnenii éksperimental'noi ostroi luchevoi bolezni kombinirovannym antibiotikom sulatsillinom.

An anti-infectious effect of sulacillin (ampicillin/sulbactam) is higher than that of ampicillin in treatment of irradiated mice infected with a beta-lactamaseproducing strain of Kl. pneumoniae. Involving of sulacillin as a principal antibiotic into the therapeutic scheme for acute radiation sickness results in 67% dogs survival at LD90/45.

[Efficiency of polysaccharide translam for early treatment of acute radiation illness]. / Effektivnost' polisakharida translama kak sredstva rannego lecheniia ostroi luchevoi bolezni.

Antiradiation therapeutic efficiency of translam (1-->3; 1-->6-beta-D-glucan) produced by enzymatic synthesis out of laminarin, polysaccharide of Laminaria cychorioides, has been studied in four animal species (mice, guinea-pigs, dogs, monkeys). A stable curative effect has been observed following its administration within first 24 h after radiation exposure at doses that cause acute radiation sickness (about LD90). The preparation is nontoxic and has a broad therapeutic range which permits its practical application.

Space radiobiology program in Russia.

The space radiobiology program in Russia is aimed at obtaining fundamental data for developing radiation safety criteria. These criteria are necessary for long-term space missions. This program includes : -substantiation of radiation hazard estimation principles based on the radiation risk conception, -investigation of the radiation affection regularities under the combined influence of the spaceflight factors, -experimental investigation of the HZE-particle delayed effects and acute somatic effects induced by protons and electrons, -individual radiosensitivity investigation, -mathematic modeling of radiobiological effects , -radiobiological basis of control and forecast of radiation influence in space, -development of methods and means of an organism's radioresistance increase.

[Experimental study of long-term effects of irradiation on various indices of homeostasis]. / Eksperimental'noe issledovanie nekotorykh pokazatelei gomeostaza v otdalennye sroki posle oblucheniia.

Following radiation damage from LD50-LD97, changes in blood, immune and endocrine parameters were revealed and followed up in dogs at the time of late effects development, 3-18 months after exposure. The changes result from post-radiation immunodeficiency and resemble those observed in residents of radioactive contaminated areas or in men participated in Chernobyl accident amelioration.

[Radiation-protective effectiveness of N-methylascorbigen, a synthetic derivative of natural ascorbigen]. / Radiozashchitnaia éffektivnost' N-metilaskorbigena--sinteticheskogo proizvodnogo prirodnogo askorbigena.

In experiments with mice radioprotective effect of N-methylascorbigen was revealed. DRF calculated from survival data was 1.16 when N-methylascorbigen (100 mg/kg) was administered i/p 24 h before irradiation.

[An experimental approach to determining the protective properties of drugs against ionizing radiation in low and sublethal doses]. / Eksperimental'nye podkhody k vyiavleniiu zashchitnykh svoistv preparatov pri vozdeistvii ioniziruiushchego izlucheniia v malykh i subletal'nykh dozakh.

In experiments with mice, the efficiency of radioprotective agents against acute gamma-irradiation with nonlethal and low doses (0.5-4 Gy) was estimated by nine parameters. The treatment with cystamine, cysteamine and riboxine prior to irradiation (< 2 Gy) did not influence the postirradiation values of the parameters under study. With a dose of up to 4 Gy, the effect of riboxine was noted. The determinations of the number of aberrant mitoses, cellularity and mitotic activity of the bone marrow have proved to be most informative. The data obtained are discussed with due regard for the specific effect of low-level radiation and mechanisms of the protective action of the agents under study.

[Characteristics of the dynamics of hematopoietic precursor cells cloned in diffusion chambers and recorded in experiments on mice and dogs irradiated in median lethal doses]. / Osobennosti dinamiki krovetvornykh kletok-predshestvennikov, kloniruemykh v diffuzionnykh kamerakh, otmechennye v opytakh na myshakh i sobakakh, obluchennykh v sredneletal'noi doze.

In experiments with mice and dogs irradiated with LD50, it was shown the postirradiation depopulation of haemopoietic polypotent (CFUs) cell-precursors in mouse bone marrow was more pronounced than that of granulocytic and macrophagal cells (CFUdc). The rate of repopulation of CFUs during the first week was higher than that of CFUdc (T1/2 was 2.5 and 8.8 days respectively). In dogs, one could notice a partial change in the colony formation, a prolonged plateau period in the postirradiation CFUdc dynamics, and a coincidence in time with cellularity restoration in the bone marrow and peripheral blood leukocytes. It is suggested that in conditions of heterogeneous incubation in diffuse chambers, the haemopoietic cell-precursors are more mature than in the syngeneic system. The method of CFUdc determination has proved to be ineffective in estimating the onset and intensity of the postirradiation haemopoiesis recovery in dogs. The study of the bone marrow CFUdc population may, however, be used in intact animals to predict the probability of their death after irradiation within the median lethal dose range.

Protection of monkeys against prolonged gamma-irradiation.

The radioprotective effect of the Bulgarian drug Adeturone was tested on prolonged irradiated monkeys. The animals were gamma-irradiated (137Cs) in a dose of 8.3 Gy (exposure rate 3.95 X 10(-3) mA.kg-1; (0.92 R.min-1]. Adeturone, given by i.v. injection at a dose of 100 mg.kg-1 body weight according to a pre- and postradiation scheme will afford protection to monkeys by ensuring 50% survival and mitigating the severity of some symptoms of radiation disease. A similar effect was obtained with ATP-administration by two i.m. injections of 37 mg.kg-1 body weight. The survival in control group was only 5% (LD95/45).

[Study of the antiradiation properties of contrykal in experiments on mice]. / Izuchenie protivoluchevykh svoistv kontrikala v opytakh na myshakh.

From experiments in mice exposed to gamma-rays (LD95 and LD91) it is shown that single intraperitoneal administration of contrykal (30-50 units per animal) elicits a slight (20-30%) radioprotective and therapeutic effect. An insignificant therapeutic effect is also registered after repeated injections of the drug at the height of radiation sickness (on the 5th-20th days).

[Radiation-protective effectiveness of ATP and adenosine against high-energy protons]. / Radiozashchitnaia effektivnost' ATF i adenozina pri vozdeistvi protonov vysokikh energii.

The radioprotective effect of ATP and adenosine was investigated on CBA and C57Bl mice hybrids F1 irradiated with 9 GeV protons. The prophylactic treatment of the animals with ATP at a dose of 350-700 mg/kg increased their survival to 63-80% for LD78-83/30 (7.5-8.0 Gy) and to 40% for LD96/30 (8.5 Gy). The administration of adenosine at a dose of 340 mg/kg, equimolar to 700 mg/kg ATP, increased their survival to 93-100% and 73%, respectively. It was found that ATP produced a favorable effect on the hemopoiesis of irradiated mice.

[Changes in hemostatic system indices during hemosorption in healthy dogs]. / Izmenenie nekotorykh pokazatelei sistemy gemostaza pri gemosorbtsii u zdorovykh sobak.

Experiments on normal dogs were made to study the effect of hemosorption on some of the characteristics marking down the hemostatic system: the content of platelets and fibrinogen, the times of plasma recalcification and euglobulin lysis, the prothrombin time, the ethanol and protamine sulfate tests, and fibrinase activity. Hemosorption produces no abrupt shifts on the part of the blood coagulation system. Additional administration of heparin does not prevent "caking" of the sorbent. The reduction in the number of circulating platelets induced by hemosorption is then replaced by pronounced thrombocytosis.