Detection of early membrane and nuclear alterations of thymocytes upon in vitro ionizing irradiation.

Some membrane and nuclear parameters of rat thymocytes were studied after in vitro X- or gamma-irradiation with doses of 0.5, 1, 2 and 4 Gy followed by incubation for 0.5 to 4 hours at 21-22 degrees C. Early (within the first 2 hours) distinct functional changes of plasma membranes, i.e. increase in Con A binding, autologous rosette-forming capacity, Alcian Blue-induced agglutination, and a decrease in amount of surface negative charges were observed. Meanwhile, the doses applied did not influence the DNA content, and the proportion of pyknotic nuclei did not grossly differ from that of the time-matched controls. However, an increase in AT-rich DNA component was noted. The radiation-induced changes proved to be transient and dose-dependent. In the whole cell populations no irreversible, death-associated events could be detected under the given experimental conditions.

[The Central Scientific Research Roentgenoradiology Institute of the USSR Ministry of Public Health--70th anniversary (on the history of the Institute)]. / Tsentral'nomu nauchno-issledovatel'skomu rentgenoradiologicheskomu institutu Minzdrava SSSR--70 let (k istorii instituta)

The paper is devoted to the history of the organization of the Central Research Roentgenoradiology Institute, USSR Ministry of Health and its 70th anniversary. The great role of the Institute in the organization of Soviet and world roentgenoradiology is emphasized; the main stages of its investigations are described; qualified personnel has been trained over this period. The authors briefly describe the on-going investigations and prospects of their development.

[Functional changes in the bronchoalveolar macrophages during the development of long-term radiation-induced pulmonary complications]. / Funktsional'nye izmeneniia bronkhoal'veoliarnykh makrofagov pri razvitii pozdnykh luchevykh legochnykh oslozhnenii.

The right hemithorax of albino rats was subjected to irradiation of 14.3 Gy at a single dose of 2.2 Gy/min. Local macrophages (BM) were lavaged and studied at different time-points (1 day to 6 mos.) following irradiation. During the phase of radiation pneumonitis, BM activation was revealed, according to an increase in the spreading index, DNA relaxation, enhanced phagocytic capacity of isologous thymocytes. Six months after treatment (the phase of lung fibrosis), the yield of BM from affected lungs was increased along with a diminished percentage of cells capable of phagocytizing dead thymocytes. A phasic time-dependence of BM changes in the postirradiation period was discussed.

[Spontaneous adhesion of blood leukocytes in cancer patients and healthy subjects]. / Izuchenie spontannoi adgezii leikotsitov krovi u onkologicheskikh bol'nykh i zdorovykh lits.

The adherence of peripheral blood leukocyte to a hydrophilic substrate (cotton wool) was studied in healthy donors and patients with Hodgkin's disease and solid tumors. It was shown that neutrophils, eosinophils and lymphocytes contribute to the adhesive ability. Patients with primary solid neoplasms revealed an increased leukocyte adherence. Following a single therapeutic irradiation, this index appeared significantly enhanced in those with Hodgkin's disease. Possible causes of the disturbances are discussed.

[Proton therapy: clinico-methodological aspects, treatment results]. / Protonnaia terapiia: kliniko-metodicheskie aspekty, rezul'taty lecheniia.

In the period of 1975-1986, 457 patients (81 with breast and prostatic cancer, 24 with endocrine ophthalmopathy, 20 with diabetic angioretinopathy, 206 with pituitary adenomas, 115 with arteriovenous and 6 with arterial brain malformations, and 6 with epilepsy) were given proton beam therapy at the Central Research Roentgenoradiology Institute using the 1000 MeV synchrocyclotron of the Leningrad Institute for Nuclear Physics. A prolonged remission was noted in 75-90% of the patients with pituitary adenomas. Angiography showed complete exclusion of aneurysm from the blood flow 2 yrs. after irradiation almost in 50% of the patients with arteriovenous malformations. A high efficacy and safety of the method was shown.

[Proteinase inhibitors of the blood plasma in the early period of the development of acute radiation sickness in monkeys]. / Ingibitory proteinaz plazmy krovi v rannii period razvitiia ostroi luchevoi bolezni u obez'ian.

A study was made of the postirradiation kinetics of blood antiproteinase activity in monkeys (Macaca nemestrina). Whole-body uniform gamma-irradiation (LD100/45) was shown to induce a significant decrease in the activity of alpha 2-macroglobulin during the first 24 h following irradiation: the decreased activity level was retained throughout the entire latent period of radiation sickness. At the height of radiation sickness (the 7th-10th day) up to the animals' death, a sharp increase was registered in the activity of alpha 1-inhibitor of blood plasma proteinases. The authors discuss a pathogenetic role of the diminution of the inhibitory potential of blood in the course of radiation sickness.

Degree of chromatin fragmentation and frequency of nuclear pyknosis in Percoll-fractionated thymocytes of irradiated rats.

The relationship between nuclear chromatin degradation to polydeoxyribonucleotides (PDN) and other features of interphase death were studied using thymocytes of normal and X-irradiated rats. Fractionation of the thymic cells in Percoll gradients was performed in order to separate dead from intact cells. The degree of radiation-induced chromatin fragmentation, as assessed by electrophoresis, was similar for PDN from all Percoll bands. Following irradiation 87-98 per cent of 'heavy' thymocytes were pyknotic and almost devoid of receptors to autologous erythrocytes thus comprising a dead cell population. A direct relationship between PDN content and nuclear pyknosis was noted throughout the gradient. The loss of autologous rosette-forming ability was directly related to other indices of interphase death. The possibility of PDN originating from pyknosis-prone cells and the capacity of radiosensitive thymocytes to form autologous rosettes are discussed.

Effects in vitro of cadmium ions on some membrane and nuclear parameters of normal and irradiated thymic lymphoid cells.

Effects of cadmium chloride upon 3H-Con A binding, number of autologous rosette-forming cells (ARFC), cell viability and the degree of DNA supercoiling were studied in normal and irradiated thymic lymphoid cells, isolated from rats and incubated up to 6 h in vitro. Cd (10-100 microM) did not significantly alter the patterns of surface markers and viability of normal thymocytes, as measured by supravital staining or nuclear pyknotic criteria. The following effects of Cd were noted for irradiated thymic cells: 1) Cd ions (25 microM) caused elimination of radiation-induced increase of Con A binding; 2) the characteristic loss of ARFC receptors, like development of nuclear pyknosis, was prevented in the presence of CdCl2 (10-100 microM); 3) the postradiation relaxation of nuclear supercoiled DNA was distinctly less pronounced with Cd. Possible reasons for these effects of Cd are discussed. Irradiated lymphoid cells are proposed as a suitable experimental model for the studies of different toxic actions of Cd and other heavy metals.

[Inhibition of radiation-induced pyknosis of cell nuclei by cadmium ions]. / Podavlenie radiatsionnogo piknoza kletochnykh iader ionami kadmiia.

The effect of cadmium chloride (1 to 100 microM) on the frequency of radiation pyknosis, autologous rosette-formation and supercoiled DNA structure was studied in the thymic cells of rats upon gamma-radiation and incubation of cells for 5 h at 37 degrees C. A protective effect of cadmium ions was found at concentrations of 10 to 100 microM and 0.5--4.0 Gy of gamma-radiation, when using pyknotic criterion. Similar effects of Cd2+ were noted in surface receptor assay employing the nucleoid technique. A possible role of cadmium in the inhibition of the interphase death programme is discussed.

[Effect of total gaseous hypoxia on the frequency of occurrence and types of neoplasms in irradiated animals]. / Vliianie obshchei gazovoi gipoksii na chastotu vozniknoveniia i vid novoobrazovanii u obluchennykh zhivotnykh.

The study of neoplasm patterns and frequency in F1(CBAxC57BL) mice totally exposed to a single dose of gamma-radiation (2.5-5.5 Gy) under gaseous hypoxia conditions established a sharp drop in the incidence of mammary gland cancer as compared with a similar experiment conducted in air. Longer mean survival time following exposure in hypoxia was chiefly attributed to the beneficial effect of the latter in the course of postradiation sclerotic development in vital organs.

[Interaction of intact and irradiated macrophages with thymus lymphoid cells]. / Vzaimodeistvie intaktnykh i obluchennykh makrofagov s limfoidnymi k;etkami timusa.

The rat broncho-alveolar macrophages, subjected to gamma-irradiation, were incubated for 4 hours with irradiated (4 Gy) thymocytes. Following the total 24 hour incubation, some morphological features of macrophages were revealed in addition to their influence on survival, autologous rosetting and mitotic index of intact thymocytes. The increase in macrophage spreading was shown which was dose-dependent in the 1 to 4 Gy scale. Enhanced viability of thymocytes was revealed in the presence of macrophages irradiated at the dose of 1-2 Gy. Addition of 24 hour cultures of intact or irradiated macrophages elicited a significant decrease in rosette-forming capacity among thymocytes. Gamma-irradiation of 2 to 4 Gy inhibited the ability of macrophages to suppress the mitotic activity of thymic cells. A possibility of postradiational modification of some specific functions and properties of macrophages, including their thymotropic effects, is discussed.

[Effect of gamma- and gamma-neutron irradiation on the composition of the metabolic amino acid pool, blood antiprotease activity and the life-span of animals]. / Vliianie gamma- i gamma-neitronnogo oblucheniia na sostav metabolicheskogo fonda aminokislot, antiproteaznuiu aktivnost' krovi i prodolzhitel'nost' zhizni zhivotnykh.

A study was made of the effect of gamma- and gamma-neutron-radiation, with neutron energy of 0.9 MeV, on the free amino acid composition and antiprotease activity of blood as well as on the life span of albino mongrel rats. The data obtained indicate that changes in the metabolic pool of blood amino acids and inhibitory capacity of blood with respect to alpha 2-macroglobulin depend upon the type and dose of radiation. An attempt is made to find a correlation between early changes in the metabolic pool of amino acids and antiprotease activity and the degree of life span shortening after gamma- and gamma-neutron irradiation.

[Relative biological effectiveness of gamma-neutron irradiation with neutron energy of 0.9 MeV]. / Otnositel'naia biologicheskaia éffektivnost' gamma-neitronnogo izlucheniia s énergiei neitronov 0,9 MéV.

Relative biological effectiveness (RBE) of gamma-neutron radiation with neutron energy of 0.9 MeV was estimated with a reference to rat death. It was shown that RBE of gamma-neutron radiation (the share of neutrons was 67% as related to dose) at LD33/30 and LD100/30 was 2, and RBE of 0.9 MeV neutrons, in experiments with mixed radiation, was 3.1 and 2.86 at LD33/30 and LD100/30, respectively. The value of a maximum dose at which death was not registered during 30 days, was 1 Gy with gamma-neutron radiation and 4 Gy with X-radiation.

[Basis for allowable errors in determining doses to patients during roentgenologic examinations]. / Obosnovanie dopustimoi pogreshnosti opredeleniia dozovykh nagruzok na patsientov pri rentgenologicheskikh issledovaniiakh.

Basing on the utilization of the benefit-injury concept the authors put forward an approach to the substantiation of permissible errors in the values of the mean doses intended for the patient's critical organs in x-ray examination. It was shown that in the elaboration of methods to determine the mean tissue doses one should aim at reaching a mean quadratic error of +/- 30% in their values.

[Loss of specific membrane receptors during the interphase death of thymus cells]. / Utrata spetsificheskikh membrannykh retseptorov v protsesse interfaznoi gibeli kletok timusa.

Thymic cells of the white rats were incubated in medium 199 with isologous sera. A dose-dependent decrease in number of membrane receptors to autologous red blood cells, alongside with nuclear pyknosis and maesophage adhesion, were noted during the first 6 hours after gamma-irradiation at the doses up to 8 Gy. A decline of rosette-forming ability preceded the process of massive nuclear pyknosis. A conclusion is made on a possible interrelation between the membrane and nuclear pathology after radiation treatment.

Possible association of membrane and nuclear changes in gamma-irradiated rat thymocytes.

gamma-irradiated rat thymocytes were incubated in medium containing fresh rat serum. After 6 hours in culture, an equal dose dependency was noted for nuclear pyknosis and the loss of surface receptors to autologous erythrocytes. Decreased rosette formation preceded the expression of pyknosis. A possible relation between the membrane changes and pyknosis during interphase death of the thymocytes is discussed.