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In this paper, some final results of 25-year investigations carried out in Scientific Centre for Radiation Medicine and Burns MH RA (SCRMB) on the Armenian cohort of the Chernobyl accident consequences liquidators are shown. These results show that health conditions of the liquidators became worse during the whole observation period. A considerable development of both pathological states atypical of radiation damages and diseases, which may be considered as radiation-induced ones, was determined. Rise of the sickness rate of almost all organism systems, first of all, nervous, cardiovascular, respiratory and digestive ones, was observed. In 70% of liquidators the main disease was primarily detected after working on CNPP. In the intervening years, the average number of diagnoses per 1 liquidator increased from 1.5 in 1987 to 7-8 in the recent time. In addition to the detected diseases, particular functional shifts in neuropsychological and vegetative status of the liquidators were observed. The overwhelming majority of them have increased tonicity of the sympathetic vegetative nervous system, asthenic and depressive syndromes occurring in the form of weakness, somnolence, mood instability, mental capacity decrease, and memory defects. In the paper, the results of investigations aimed at clarification of changes in biological aging processes of the liquidators and assessment of their "life quality" features in terms of physical, psychical and social welfare are considered. Biological aged-related passportization in a definite part of liquidators elucidated an accelerated aging rate. The studies were performed with the help of SF-36 inquirer and indicated that health status aggravation of the liquidators also affected their life satisfaction. The "life quality" indices of the liquidators significantly concede the overall average standards by both physical health and psychical and social welfare scales.

Health effects as a result of the accident at the Chernobyl nuclear power plant occurred in 1986 are considered in the paper. Wrong prognosis of the health effects with respect to mortality and morbidity among the population exposed to low radiation doses is shown. Proven increase in thyroid cancer cases among people who were children aged from 0 to 18 at the time of the accident is shown. Linear relationship between thyroid cancer cases and dose to thyroid ranged from 0.2 to 4.0 Gy is considered. An additional absolute risk of thyroid cancer in children varies in the range 1.9-2.6 cases per 10(4) person-year Gy. During the fifteen years following the accident no cases of acute and chronic radiation sickness have been revealed because the population living in contaminated areas received low radiation doses. Also, exposures to low radiation doses did not result in excess of malignant tumors among population. In some cases the outcomes of acute radiation sickness were as follows: radiation damages to the skin, cancer cataracts, development of oncopathology.

The paper presents the results of 14-year (1987-2000) random cytogenetic monitoring of the Ukraine's population exposed to radiation due to the Chernobyl Atomic Power Plant accident. Conventional, G-banding, and molecular (FISH-WCP) cytogenetic methods were used to examine groups of victims exposed to radiation of varying intensity (reconvalescents diagnosed as having acute radiation disease, liquidators, Chernobyl power plant staff, and persons who had lived in the radionuclide-polluted areas, etc.). The examinees from all groups were found to have a considerable increase in the incidence of chromosomal aberrations in the peripheral lymphocytes as compared to their spontaneous levels. There was an interindividual variability in the chromosomal aberrations under identical radiation conditions. It was ascertained that even small human doses of long-term ionizing radiation could induce specific chromosomal aberrations. The findings show that conventional cytogenetic monitoring, and particularly by applying FISH and WCP methods, is an good procedure for assessing the human cell genetic apparatuses after radiation.

The paper presents the results of implementation of the first stage of WHO programme concerning consequences of the Chernobyl accident in terms of influence of radiation on mental health of children whose mothers were exposed to radiation. 4210 children born in the period from April 26, 1986 to February 1, 1987 in Byelorussia, Ukraine, Russia in contaminated and non-polluted (control) regions. In radiation-contaminated regions there was higher frequency of mental retardation and other mental disorders as well as deterioration of both mental and physic health of their parents. A preliminary character of the data obtained is emphasized as well as the necessity of more detailed follow-up of these groups.

The paper discusses the approaches and scientific and organizational principles used in the development of some International research projects in the study of consequences of the Chernobyl accident, which are under way by Russia's Ministry of Science and Engineering Policy. Special attention is given to sociomedical aspects and the possibilities of defining an individual medical policy while working with the liquidators and the members of their families.

The paper reports on the preliminary experience of treatment of those patients having been the victims to the reactor accident at the Chernobyl NPP as well as of those with acute and chronic leukoses, having received courses of modern cytostatic therapy. The patients were exposed to therapeutic plasmapheresis and enterosorption as part of a complex conventional treatment programme. The conclusion the authors have come to is as follows: enterosorption strikingly reduces manifestations of "cytostatic disease"; the use of plasmapheresis in those persons having been previously exposed to small dose chronic radiation, makes for improvement of clinical and laboratory values but further studies are warranted to determine indications for therapeutic plasmapheresis.

The paper presents the results of psychopathological and clinical examinations of the subjects exposed to low-dose radiation consequent to the Chernobyl accident. Relevant psychic disorders are specified. A close correlation was found between some psychopathological syndromes and somatovegetative disturbances.

The paper is concerned with the results of therapy of 115 patients with acute radiation syndrome after the Chernobyl accident. The chief methods of the effective therapy of bone marrow syndrome are antimicrobial drugs and fresh donor platelet mass transfusions. Hemopoietic stem cell transplantation (allogenic bone marrow or embryonic hepatocytes) is indicated and effective in a very limited number of patients in accident irradiation. Severe beta-burns of the skin remain an unsolved problem as a result of their spreading. Organizational principles of therapy of a great number of patients with acute radiation syndrome in a specialized hospital were described.

The paper is concerned with the results of measurements of characteristics of the air media in the zone of the damaged reactor as with the assessment of doses from internal irradiation on the basis of calculations of air media parameters and the results of actual measurements of the uptake and content of radionuclides in the personnel of the Chernobyl Nuclear Power Station and persons sent on mission there in 1986-1987, the results being obtained by indirect and direct biophysical methods of control of internal irradiation. The calculated data are well in accord with the results of actual measurements of the contents of radionuclides in the body. Internal irradiation of all tissues and organs, determined by the inhalation of a mixture of radionuclides, worked almost completely within the first year following the accident, the thyroid being the critical organ. In the next years internal irradiation for the personnel of the Chernobyl Nuclear Power Station was determined entirely by transuranic elements and was about 0.1 M.P.D annually for bone tissue. The value of a mean effective equivalent dose from internal irradiation in 50 years is 85 mSv for professionals, and a contribution of internal irradiation to the whole-body one over the first well as is 13%.

The paper is concerned with the results of determining the total number of lymphocytes, T-lymphocytes and their immunoregulatory subpopulations, B-lymphocyte of peripheral blood, serum IgA, IgG and IgM in 44 patients with ARS, II-IV degree at days 37-109 after the Chernobyl accident. Bone marrow transplantation was performed in all the patients not later than on the 14th day. Among lymphocytes, T-lymphocytes were shown to restore to normal first, the T-helpers/T-suppressors ratio being decreased. In 2 survivors this ratio remained decreased 2 mos. after the normalization of peripheral blood indices. Possibilities of correction of the revealed disorders with immunomodulators were discussed.

The paper is concerned with analysis of the data on a picture of the blood of 115 patients with acute radiation syndrome. Basing on the literature data, the authors discuss a possibility of developing leukemia in these patients and in persons, irradiated at lower doses, as a result of radiation affection of hemopoiesis.

The paper is devoted to the main stages of development of radiation clinical neurology, paying attention to the contribution of Soviet clinicians in the problem. Neurological disorders in ARS of various degrees of severity at different periods of disease as well as during irradiation at doses, not causing ARS development were described. The importance of clinicophysiological investigations for assessment of CNS function during the development of disease and its aftereffects was shown. The role of psychological investigations and studies on mental abilities of persons, exposed to acute ionizing radiation, was emphasized.

The paper is concerned with analysis of correlation of the time of appearance of vomit in a person and a mean dose rate of prolonged gamma-radiation in the persons affected at the Chernobyl accident. The data were approximated by power function. For irradiation with a constant dose rate (P) such correlation looks like Tp = 2.48p-0.5, where Tp is the time of the beginning of vomit, hours after the beginning of irradiation. A semiempirical model combining different conditions of irradiation was formed. Prognosis of a severity of lesion with relation to the time of vomit was given for different conditions of irradiation.

The paper deals with the problems in the case follow-up of the population exposed to radiation caused by the accident at the Chernobyl Atomic Power Station on the basis of the automated systems for collecting and processing medical information. A number of organizational, medical, technological, computational problems in setting up teh National Distribution Registry should be solved for a complete and long-term follow-up. A differential approach was proposed to the information provision of health care services and to the determination of a population size and principles of selecting the populations to be followed up in the Registry.

The paper is concerned with analysis of strategy of the regulation of radiation exposure of the population and the practical use of the levels of intervention in different phases after the Chernobyl accident. The author represents data on the levels of whole-body irradiation of the population in the areas under strict control, and dose exposure of the thyroid in children and adults. Mean individual and collective doses of whole-body irradiation over the period of 1986-1989 and predictable dose exposures were assessed. Some data on probable pathology of radiation genesis in the population in affect on 1990 were considered.

The paper is concerned with the results of analysis of a clinico-laboratory study of persons (residents of Armenia) who took part in the elimination of the effects of the Chernobyl accident. Investigation of general morbidity revealed no correlation with exposure to ionizing radiation. The symptom complex of pathological changes included CNS functional disorders, a transition from the hypokinetic type of a heart response to exercise to the normokinetic one, lowered immune status and tissue peripheral blood flow, unmarked hematological and biochemical shifts, suggesting suppression of the body antioxidant system.