[Experience of contemporary treatment of radiation burns in individuals subjected to ionizing radiation].

The article presents new approach to treatment of radiation disorders presenting as indolent ulcers. The approach is based on autologous multipotent mesenchimal stromal cells applied locally and injected around the injuried zone. The ulcers heal due to the fact that the transplanted cells stimulate local regeneration processes, angiogenesis, ceased inflammation and apoptosis. The method is a new medical technology based on vast preclinical studies and could be put into medical practice.

[Hematopoiesis during remote period after acute radiation syndrome].

Based on the long (19.7 +/- 1.8 year) hemopoiesis follow-up study in 152 patients after acute radiation syndrome (ARS) as a result of exposure to gamma-, gamma-beta and gamma-eta radiation in a wide dose range (1.2-9.8 Gy) it was detected that cytopenia appears in the late consequences period: thrombocytopenia was found in 26.9% cases, leukocytopenia, neutropenia and lymphocytopenia--in 13.1% patients. A higher ARS degree causes the increase of various disorders (cytopenia and cytosis) in the late period. It reflects a tight interrelation between blood cell contents and radiation dose. Frequency of cytopenias increases if such somatic disorders: persistent hepatitis, hepatic cirrhosis and late radiation ulcers as appear.

[The results of 25 year-cytogenetic investigation of survivors exposed to different doses of irradiation in the Chernobyl accident].

Changes of registered levels of chromosome aberrations were studied in the peripheral blood lymphocyte cultures of 74 patients irradiated as a result of the Chernobyl accident by the instrumentality of the routine method during 25 year. The initial dose estimations by average dicentrics frequency varied from 0.2 to 9.8 Gy On the whole, the model of a double exponential type was the most adequate for the quantitative description of elimination of cytogenetical indices associated with different types of unstable chromosome aberrations. High individual variability of the elimination rate of chromosome aberrations and its dependency from the value of originally evaluated dose were discovered in the first period. The computer method of retrospective dose estimation was developed on the basis of this material. The method is based on the analysis of cell distributions in accordance with the number of dicentrics and as a whole, unstable chromosome aberrations, contained in them. In addition the dynamics of translocation frequencies in the peripheral blood lymphocyte cultures of a number of patients from this contingent was investigated starting from 10 years after irradiation by the instrumentality of FISH-method of chromosome staining.

[Mesenchymal stem cells transplantation in the treatment of radiation skin lesions].

Transplantation of mesenchymal stem cells, both at early and later stage after local exposure of rats source beta radiation dose, 90Sr/90Y 140 GR, stimulates recovery of damaged skin. Diminution area local radiation injuries and accelerate healing radiation ulcers. Clinically shows the high efficiency of the transplantations autologous mesenchymal stem cells in treatment of deep beam ulcers, intractable standard conservative treatment. Found promising application of mesenchymal stem cells for treatment of severe local radiation injuries and the need to develop the best possible conditions for their use.

[The comparison of molecular-biochemical and cytogenetic analyses of blood cells of patients long after the acute radiation sickness].

Molecular-biochemical and cytogenetic analyses were made on blood cells of 17 radiation accident victims who, from 1.7 to 43.8 years previously, had suffered acute radiation sickness (ARS) ranging from severity grades I to IV. Molecular-biochemical data were obtained with patients' leukocytes and with mononuclear cells on their oxidative status by a) the level of an anion-radical O2*- in the 3-(4,5-dimethyl-2-thiazol-2-yl)-2,5-diphenyl-2-tetrazolium bromide (MTT) test and b) the sum of reactive oxygen species in the 2,7-dichlorodihydrofluorescein diacetate (DCFDA) test together with a test for DNA strand unwinding in alkaline conditions by measurements of fluorescence intensity of ethidium bromide. Each parameter was measured in freshly sampled cells and during a 5-hour incubation as absolute means on 5 measurements and in % change from the initial values. Cytogenetic data were obtained from the standard metaphase preparations scored for routine unstable chromosomal aberrations (us-CA)--dicentrics; and stable aberrations (sCA)--translocations. The latter ones were assayed by the FISH method using whole chromosome 2, 4 and 12 fluorescent probes and scaled up to genome equivalence. For all patients reduced oxidative status of about 25-30% was obtained by the MTT-test (p < 0.005), and the DCFDA-test (p < 0.027). The yield of usCA depended on the time after irradiation with higher yields associated with the shorter postirradiation times and reducing almost to expected background frequencies. The yield of sCA was high for all patients, correlating with the severity of ARS whilst the molecular-biochemical parameters showed no relationship with ARS. A correlation was observed between parameters of oxidative status and % of cells with usCA: by the MTT-test r = from 0.50 up to 0.61 (p = from 0.06 up to 0.003), but by the DCFDA-test the strength of correlation was smaller: r = from 0.38 up to 0.48. An inverse correlation was found between initial oxidative state of mononuclear cells and the frequency of CA in lymphocytes. Similarly a marked inverse correlation between degree of DNA unwinding by the ethidium bromide assay on leukocytes and sCA in lymphocytes was also noted. The feasibility of radiation-induced delayed genomic instability in vivo for humans long time after irradiation is discussed.

[Infection syndrome in acute radiation sickness patients subjected to Chernobyl accident].

In spite of intensive antimicrobial prophylaxis and therapy, most patients with acute radiation sickness I-IV severity grade (dose of 0.1-13.7 Gy) developed infections caused by bacteria, fungi and viruses. Frequency and intensity of those infections were proportional to the radiation dose and severity grade of radiation sickness.

Late T cell deficiency in victims of the Chernobyl radiation accident: possible mechanisms of induction.

T cell number, serum concentrations of thymic hormones and anti-epithelial autoantibodies were studied in people affected at Chernobyl NPP. Group 1 took part in the clearing-up operation and had no clinical manifestations of acute radiation sickness. Group 2 worked at the NPP during the accident; they survived acute radiation sickness (degree I-II, subgroup 2a; degree III-IV, subgroup 2b). The total doses of external radiation were 0.1-0.5 Gy in group 1, up to 4 Gy in subgroup 2a and up to 9 Gy in subgroup 2b. Total T cell number, serum thymic activity and alpha 1-thymosin concentration were decreased in all groups of affected persons. CD8+ cell number decreased only in group 1; CD4+ cell number in subgroup 2b. A decrease in thymic hormone level was most prominent in subgroup 2b. The titres of anti-epithelial antibodies were increased in all groups of affected persons independently of radiation dose. The titres were higher in patients with subnormal levels of alpha 1-thymosin. It has been proposed that radiation alters the function of thymic epithelial cells by direct action and/or through indirect mechanisms including participation of autoantibodies. The observed complex of alterations is similar to that in the normal process of immunological ageing.

Determination of somatic mutant frequencies at glycophorin A and T-cell receptor loci for biodosimetry of prolonged irradiation.

PURPOSE: To determine the variant frequencies (VF) at glycophorin A (GPA) and T-cell receptor (TCR) loci in persons exposed to prolonged ionizing radiation at different doses and to assess the significance of the GPA and TCR assays for biodosimetry of prolonged irradiation. MATERIALS AND METHODS: The VF values were determined by means of flow cytometry in 120 persons exposed between 1968-1996. Most exposures were in Chernobyl clean-up workers in 1986-1987. RESULTS: A significant correlation was shown between the NO GPA variant cell frequency and dose (r = 0.61, p < 0.0001). The slope of the linear regression was 6.3 x 10(-6) NO mutant cells/Gy. Dose-dependent increase in the TCR VF was found in the group with recent exposures (slope 2.1 x 10(-4) variant cells/Gy, r = 0.75, p = 0.0002). In the Chernobyl clean up workers who received doses less than 0.25 Gy the TCR VF unlike the GPA VF was significantly higher than in the control non-irradiated individuals (p < 0.01 and p > 0.05 respectively). CONCLUSIONS: The GPA assay has limited potential to be used as a biodosimeter of prolonged irradiation, at least in dose interval up to 2.0 Gy. The TCR assay is likely to have greater potential in estimation of recent radiation exposure than the GPA assay.

Determination of somatic mutant frequencies at glycophorin A and T-cell receptor loci for biodosimetry of acute and prolonged irradiation.

Somatic mutant frequencies at glycophorin A (GPA) and T-cell receptor (TCR) loci were assessed. The dependence of the GPA mutant frequency on doses of acute and prolonged irradiation was shown. In the case of acute irradiation the GPA mutant frequency displayed a three-fold greater dose-related increase as compared to prolonged irradiation. A dose-dependent increase in the TCR variant frequency was found only in a group of subjects with recent exposures. In Chernobyl clean-up workers the TCR mutant frequency was significantly higher than in control non-irradiated individuals.

[Determination of mutation frequency at loci of glycophorin A and T-cell receptors: informativeness for biological dosimetry of acute and prolonged irradiation]. / Opredelenie chastoty mutatsii po lokusam glikoforina A i T-kletochnogo retseptora: informativnost' dlia biologicheskoi dozimetrii ostrogo i prolongirovannogo oblucheniia.

The frequencies of somatic mutations at loci of glycophorin A (GPA) and T-cell receptor (TCR) were determined in persons exposed professionally to ionizing radiation or a result of accidents at nuclear power plants and in control donors. Dependence of glycophorin A mutant (NO) cell frequency on doses of acute (up to 3.5 Gy) and prolonged (up to 15.0 Gy) irradiation was shown. The slope of linear regression corresponded to increase of NO-mutant frequency by 31.1 x 10(-6)/Gy (r = 0.87, p < 0.0001) for acute irradiation and by 6.3 x 10(-6)/Gy (r = 0.61, p < 0.0001) for prolonged one. The 5-fold decrease of the linear regression slope in the case of prolonged irradiation makes significantly worse permissive ability of the GPA test. Therefore its use for biological dosimetry of prolonged irradiation is not expedient in dose interval up to 1 Gy. The frequency of mutations in genes of T-cell receptor significantly correlated with dose of irradiation only in group of donors with recent radiation exposure (r = 0.75, p = 0.0002). Meanwhile, the TCR method is more sensitive and informative for biological dosimetry of recent radiation, than the GPA test.

[Health status of persons with acute radiation sickness caused by Chernobyl AES accident]. / Sostoianie zdorov'ia lits, perenesshikh ostruiu luchevuiu bolezn' v rezul'tate avarii na ChAES.

After Chernobyl accident 75 survivors with acute radiation syndrome (ARS) have been under observation in the Clinic of the Institute of Biophysics. Years after accident serious problems occurred in the individuals, who suffered from late effects from radiation injuries (late radiation ulcers and radiation cataracts). One patient suffered on hypernephroma, one-kidney cyst. Observed somatic diseases are gastrointestinal diseases, different neurological diseases and syndromes and upper pulmonary tract diseases. Hemopoiesis system condition was characterised by the development of transient moderate cytopenia (light and moderate degree of ARS patients) as well as the periodical increase of blood cell counts above standard indices (severe degree of ARS patients).

[Prevention of infectious complications in patients with acute bone marrow depression]. / Profilaktika infektsionnykh oslozhnenii u bolnykh s ostrymi mielodepressiiami.

Clinical efficacy of intravenous gentamicin in combination with oral use of gentamicin, ristomycin and nystatin was studied in 1977. In 1980-1984 two antiinfectious regimens were tested: intravenous administration of gentamicin in combination with total decontamination (oral use of gentamicin and nystatin) and selective decontamination (biseptol with nystatin of amphoglucamine). It was shown that the incidence of severe infections in the patients under the observation dropped against the controls. The incidence and spectrum of infectious complications in cases with acute myelodepressions were proved to depend on the intestinal autoflora inhibition.

[Acute local radiation lesions and their consequences (contingency in flaw inspection)]. / Ostrye mestnye luchevye porazheniia i ikh posledstviia (neshtatnaia situatsiia pri defektoskopicheskikh rabotakh).

Illustrated with case history (patient F), the authors represented diagnosis, prognosis, treatment, long-term consequences of local radiation lesions.

[Experience in organizing medical care for the victims of the accident at the Chernobyl Atomic Electric Power Station at a specialized hospital]. / Opyt organizatsii meditsinskoi pomoshchi postradavshim pri avarii na Chernobyl'skoi AES v usloviiakh spetsializirovannogo statsionara.

Organization of health care for victims of radiation accidents requires well-adjusted organizational activities, including an inpatient clinic with well-equipped reception, dosimetric, karyological and bacteriological laboratories, an intensive care department, a surgical (burn) department, a blood transfusion laboratory and equipment for plasmapheresis and hemosorption. Therapy of such patients should be developed along the following lines: 1) prevention and therapy of infectious complications: 2) blood cell substitution therapy; 3) bone marrow transplantation; 4) detoxicating therapy; 5) correction of water-electrolyte metabolism; 6) therapy of local radiation injuries.

[Clinico-electrocardiographic evaluation of the state of the cardiovascular system inpersonnel engaged in liquidating the consequences of the accident at the Chernobyl Atomic Power Station]. / Kliniko-élektrokardiograficheskaia otsenka sostoianiia serdechno-sosudistoi sistemy u likvidatorov posledstvii avarii na Chernobyl'skoi AES.

The paper is concerned with analysis of the results of clinico-electrocardiographic investigation of 107 rescuers, engaged in the elimination of the effects of the Chernobyl accident. A high percent (27.2%) of the detectability of borderline arterial hypertension was noted among the rescuers (aged to 39) that was determined by a strong psychoemotional tension resulting from work and radiation phobia.

[Several indices of the peripheral immune system in clean up team workers and patients who survived acute radiation disease 5 years after effects of the radiation accident factors]. / Nekotorye pokazateli perifericheskogo zvena immunnoi sistemy u likvidatorov i bol'nykh, perenesshikh ostruiu luchevuiu bolezn', cherez 5 let posle vozdeistviia faktorov radiatsionnoi avarii.

A group of liquidators and patients survived acute radiation sickness (ARS) was studied five years after the effect of radiation factors resulted from the Chernobyl A.P.S. disaster. Studied were the number of T-lymphocytes (SD2+, SD3+, SD5+), subpopulations SD16+ and SD25+, the content of SD16+ and SD25+ lymphocytes and B-cells, as well as the levels of serum IgM, A, G; determined was the concentration of serum alpha 1-thymosin. A decrease was noted in the number of T-cells of the examined patients, with respect to all markers studied: the number of SD4+ cells was found decreased in patients with ARS sequelae and normal in liquidators. The decrease in serum alpha 1-thymosin was a function of dose. Dynamics of changes in the T-cells of the examinees may reflect the new trends in the radiation response of T-lymphocytes which were not directly related to initial damages to the latter. The injury to the stroma of the thymus and especially to its epithelial cells may be the basis for later postirradiation damages to the immune system. The decrease in the concentration of alpha 1-thymosin in the blood serum of the examinee is the manifestation of the thymus hypofunction. In liquidators and patients with the ARS sequelae the number of SD25+ cells increased markedly indicating the existence of the source of endogenous cell activation. The content of B-lymphocytes in all studied groups of patients was reduced which may serve as a criterion of chronic stress.