[The distribution of chromosome aberrations in cells under the action of radiation of different qualities]. / Raspredelenie aberratsii khromosom po kletkam pri deistvii izluchenii razlichnogo kachestva.

The distribution of chromosome aberrations in the cultured human peripheral blood lymphocytes exposed to 6 MeV neutrons was compared with that of lymphocytes exposed to gamma-rays. The regularities of both distributions were similar.

[The cytogenetic effects of 137Cs gamma quanta]. / Tsitogeneticheskie éffekty gamma-kvantov 137Cs.

The data on the human chromosomal level have been first obtained showing that the values of relative biological effectiveness of the 137Cs radionuclide exceed 1. These findings were allowed for during intracavitary radiotherapy in more than 50 patients with uterine body cancer.

[The cytogenetic effects of 22-MeV neutrons]. / Tsitogeneticheskie éffekty 22 MéV neitronov.

22-MeV neutrons affecting the culture of human peripheral blood lymphocytes have been studied for their cytogenetic peculiarities. Linear character of the dependence of chromosome aberrations yield within the dose range of 0.2-4.0 Gy is noted. Relative biological efficiency of 22-MeV neutrons reaches the highest values at low doses (18.8-2.4). Pair fragments and dicentrics prevail in spectrum of aberrations.

[The modifying action of caffeine on the effect of fast neutrons in human cells]. / Modifitsiruiushchee deistvie kofeina na éffekt bystrykh neitronov v kletkakh cheloveka.

The cytogenetic data obtained indicate a real possibility to intensify damage of the human cells as affected by rapid neurons. It can be achieved by combination of reparation inhibitors (caffeine) and rare-ionizing radiation (gamma rays) and is expressed in 5.5-fold increase of yield of chromosome damages in caffeine case and in increase of yield of exchange aberrations in the case of combination with gamma radiation.

[The state of the molecular electron carriers of the cell energy system at early periods following irradiation]. / Sostoianie molekuliarnykh perenoschikov élektronov énergeticheskoi sistemy kletki na rannykh étapakh posle radiatsionnogo vozdeistviia.

The content of non-heme iron-sulfur proteins and free radicals in the liver, cardiac muscle, and brain was studied during the period from 10 min to 7 days following X-irradiation with doses of 11.0, 7.5, and 4.5 Gy. Ionizing radiation caused substantial changes in the function of electron-transport chains of mitochondria. The change rating was a function of dose while their character depended, in addition, upon the structural and functional characteristics of the organ.

[Damage susceptibility of human lymphocyte chromosomes at different stages of the mitotic cycle in combined exposure to fast neutrons and postradiation hyperthermia]. / Porazhaemost' khromosom limfotsitov cheloveka v razlichnykh stadiiakh mitoticheskogo tsikla pri sochetannom deistvii bystrykh neitronov i postluchevoi gipertermii.

The combined action of gamma rays (1-4 Gy) and postradiation hyperthermia on the human lymphocyte culture induces intensification of the damaging effect at the stage of DNA synthesis, i.e. at the most radioresistant stage of the mitotic cycle, the thermal intensification factor (TIF) being 1.7-2.0. After the neutron action (0.5-1.5 Gy) the hyperthermia has no effect on the chromosome aberration spectrum, the TIF being 1.8-2.5 at G1 phase and 1.8-2.4 at S phase, which testifies to the possible modification of neutron irradiation.

[Effect of sodium humate on animals irradiated with lethal doses]. / Vliianie gumata natriia na zhivotnykh, obluchennykh v letal'nykh dozakh.

A therapeutic effect of natrium humate given to experimental mongrel rats exposed to 60Co-gamma-radiation of lethal doses has been studied. A single administration of natrium humate, 5-10 min following irradiation with a dose of 193.5 mC/kg (LD100/30) leads to a 43.3 per cent survival of animals after 60 days; with a dose of 232.2 mC/kg (LD100/8) there is a trend toward the increase in the life span of exposed rats.

[The problem of peroxidation in radiobiology]. / Problema perekisnogo okisleniia v radiobiologii.

A hypothesis is validated concerning the products of free radical oxidation of lipids and the phenol compounds as a mediator unit of the stress-syndrome. The data are reviewed on activation of peroxidation under the effect of radiation, cytochemical agents, etc., secondarily stimulating the neurohumoral system function of homeostasis regulation. With the emotional-algesic and cold-stresses, the regulatory system stimulation is of primary, reflex, nature, but it secondarily promotes the peroxidation activation. The radiotoxins (of the quinoid and lipid nature) appearing in tissues under the effect of ionizing radiation, are similar in structure and mechanism of action to peroxidation activation products formed under the effect of other stress-agents.

[Neutral cytoplasmatic deoxyribonuclease of the rat liver and spleen in carcinogenesis]. / Neitral'naia tsitoplazmaticheskaia dezoksiribonukleaza pecheni i selezenki krys pri kantserogeneze.

The activity of cytoplasmic neutral DNA in the liver and spleen of albino rats is studied when the tumour process develops after fast neutrons irradiation, when tumour is induced by 3,4-benzpyrene and after sarcoma 45 transplantation. It is shown that an increase in the enzymic activity with a further decrease during the process development is observed for all studied types of carcinogenesis in the pretumour period. Changes in the activity of natural inhibitor and the enzyme form bound with the inhibitor were not found (except for one or another index in the spleen of animals with sarcoma 45). The enzyme activation in the pretumour period is considered as a tumour defence response of the organism aimed at elimination of damages in DNA which arise as a result of direct or indirect action of carcinogen.

[Cyclic nucleotides and lipids in the realization of the radioprotective effect of ceruloplasmin]. / Tsiklicheskie nukleotidy i lipidy v realizatsii radiozashchitnogo deistviia tseruloplazmina.

Ceruloplasmin administered 60 min before irradiation diminished cAMP and cGMP levels, which were increased by irradiation at LD50 and LD100, and normalized cAMP/cGMP ratio in the rat liver during the first 24 h following irradiation with a dose of 6.24 Gy. The content of phospholipids increased and that of cholesterol decreased under the effect of ceruloplasmin leading to normalization of the molar cholesterol/phospholipid ratio in the rat liver on the 7th day of radiation sickness (LD50, 6.24 Gy).

[Susceptibility to damage of human lymphocyte chromosomes in different stages of the mitotic cycle when exposed to fast neutrons with an average energy of 6 MeV]. / Porazhaemost' khromosom limfotsitov cheloveka v razlichnykh stadiiakh mitoticheskogo tsikla pri deistvii bystrykh neitronov so srednei énergiei 6 MéV.

Cytogenetic susceptibility of human lymphocytes in the culture to lesion is studied under the effect of neutrons with 6 MeV energy at different stages of the mitotic cycle. Radiosensitivity of human lymphocytes under the influence of gamma-quanta and neutrons is found to vary identically during the whole cycle. These variations are less expressed in the case of neutron irradiation. The data allow concluding that the repair system functions most actively at the S stage in case of both types of radiation.

[Circadian and seasonal rhythms in the radiosensitivity of mongrel white rats]. / Sutochnye i sezonnye ritmy radiochuvstvitel'nosti belykh besporodnykh krys.

From experiments in albino mongrel rats it is shown that the radiosensitivity of gamma-irradiated (60Co) animals follows a daily rhythm. A synchronization of the daily rhythms in radiosensitivity was noted in winter and during the first spring month which was impaired in April. Established were the rhythms of radiosensitivity for three seasons, i. e. winter, spring and summer, with the extremes in the dependence upon mean annual values varying significantly.

[Effect of fast neutrons on the process of muscle cell differentiation]. / Vliianie bystrykh neitronov na protsess differentsirovki myshechnykh kletok.

A study was made of the effect of fast neutron on differentiation of myoblasts in vitro. The results obtained indicate that irradiation inhibits the differentiation of myoblasts in culture. Irradiation with fast neutrons (1.5 and 2.0 Gy) inhibits the uninucleate myoblast fusion thus preventing the formation of multinuclear tissue structures with myofibrils, myosymplasts.

[Participation of cyclic nucleotides in realizing the effect of ceruloplasmin during irradiation]. / Uchastie tsiklicheskikh nukleotidov v realizatsii deistviia tseruloplazmina pri obluchenii.

It was shown that a single intraperitoneal administration of human ceruloplasmin 60 min before irradiation (4.22, 5.28 and 7.20 Gy) increases the content of cyclic AMP and cyclic GMP in the thymus and spleen of rats 3 and 6 h following X-irradiation. Ceruloplasmin increases the cyclic AMP/cyclic GMP ratio in the above-mentioned rat organs in normal conditions and on radiation pathology.

[Role of ceruloplasmin in the resistance of the organism to x-irradiation]. / Rol' tseruloplazmina v rezistentnosti organizma k rentgenovskomu oblucheniiu.

It was shown that a single administration of homogeneous and heterogeneous ceruloplasmin in different doses 1 h before or after irradiation ( LD40 and LD100) increased the survival rate of rats. Ceruloplasmin improved some indices of peripheral blood and bone marrow at early stages of radiation affection. A higher ceruloplasmin activity was observed in blood serum of irradiated animals.

[Neutral DNAse activity in rat tissues in radiation carcinogenesis]. / Aktivnost' neitral'noi DNKazy v tkaniakh krys pri luchevom kantserogeneze.

The activity of neutral DNAse and its natural protein inhibitor was determined in the liver, brain and spleen of albino rats with malignant tumours of mammary gland and other organs. The tumours appeared 14-20 months after the irradiation of rats with fast neutrons (0.5-1.0 Gy). It is shown that the activity of DNAse I and its protein inhibitor increases in the liver and brain of tumour-bearing rats, while the enzyme and inhibitor capacity to form the nuclease-inhibitor complex decreases, especially in the liver. It is suggested that the increase in the DNAse activity in the tumour-bearing rats liver is important in the antitumour activity of the organism.

[Dosimetric and radiobiological characteristics of the radiation field from the reaction d(50 MeV)--Be]. / Nekotorye dozimetricheskie i radiobiologicheskie kharakteristiki radiatsionnogo polia iz reaktsii d(50 MéV)--Be.

The rate of the total absorbed dose within a radiation field produced by the reaction of accelerated (up to 50 MeV) deuterons with a thick beryllium target has been determined and the uniformity of the dose field studied. LD50/30 for C57Bl mice has been evaluated in a mixed gamma/neutron field.