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The paper presents the results of statistical processing of experimental data on the volumetric activity of radon within the premises of various buildings. The results were used to estimate internal radiation doses of inhaled radon and its short-lived degradation products in the population of Tomsk. The average annual population-weighed value of the effective dose was 1.24 mSv, which is 1.5-times higher than the estimated value for the Russian Federation.

The paper presents the results of the studies of the levels of radon in the premises of 30 kindergartens and 36 schools of Tomsk and its region, which were conducted in 1989 to 2000. The volume activity of radon in the air of the premises was measured by using passive track detectors of gamma-radiation upon a long-term exposure of 1-3 months. In parallel with these measurements, statistical data required for a more accurate assessment of effective doses were collected. Analysis of the statistical processing of the data on the levels of radon has indicated that the arithmetic mean, geometric mean, and standard deviation are 60, 51, and 33 Bq/m3, respectively, for kindergartens and 50, 38, and 56 Bq/m3 for schools. The mean annual radiation doses obtained on inhalation exposure to radon-222 and its degradation products are 1.06 and 1.08 mZv for preschool and school children, respectively.

Polymorphonuclear leukocytes from 115 patients with opisthrochiasis at its different (acute and chronic) stages were studied before and 1-3 days, 1-3 months, and 1-2 years after antihelminthic therapy with bilthricide. The functional activity of the cells in question was evaluated following an hour load with different drugs: bilthricide, ascorbic acid, decaris, cyclophosphane, doxycycline in a final concentration of 2.5 x 10(-5) mole/l. Physiological solution and autologous plasma were test controls. The changes in the activity of extracellular (secreted), intracellular (reserve), and summary myeloperoxidase on incubation with each test agent were found to depend on the stage of the disease and the interval after antihelminthic therapy. In early Opisthorchis invasion, the maximum increase in the induced activity of secreted myeloperoxidase is followed by a fall in the level of reserve myeloperoxidase in response to these drugs. With this, there is the most pronounced decrease in reserve myeloperoxidase of polymorphonuclear leukocytes in chronic opisthorchiasis, which may be due to the disrupted controlling processes of its production at late stages of the disease. The distinctive features of the action of agents on the overall activity of granular leukocytic myeloperoxidase in acute and chronic opisthorchiasis suggests that autologous plasma, ascorbic acid, and doxycycline should be used as a test control at the clinical stage of Opisthorchis invasion.

Cytochemistry was used to study the level of lysosomal cationic proteins of polymorphonuclear peripheral leukocytes in 25 and 20 patients with acute and chronic opisthorchiasis, respectively, before treatment. Comparison groups included patients with chronic viral hepatitis C, bronchial asthma, as well as apparently healthy individuals free of Opisthorchis invasion. That the ratios of an increase in the intracellular content of lysosomal cationic proteins to that in the control individuals were found to be 13.86 and 4.50 for acute and chronic opisthorchiasis, respectively. At the same time, the contribution of an allergic component (bronchial asthma) to the changes in the index studied is greater than that of somatic lesions of the hepatic parenchyma (viral hepatitis C). The authors suggest that it is expedient to use lysosomal cationic proteins in combination with other indices for making a diagnosis and determining the stage of the disease in Opisthorchis invasion.

The higher absorptivity of neutrophils during their alpha-tocopherol stimulation has been found to promote lower adaptability in the metacercariae of Opisthorchis felineus, a reverse picture was observed when cyclophosphanum was used. The antihelminthic effect of biltricide is probably to be unassociated with the changed functional activity of polymorphonuclear leukocytes, but to be determined by its direct action on helminths. This phenomenon was studied on golden hamsters inoculated with Opisthorchis felineus. On day 2 after inoculation, the following drugs were given for a fortnight: biltricide in a single dose of 60 mg/kg weight; biltricide used in a daily fractionated dose of 60 mg/kg; cyclophosphanum (6 mg/kg, every second day); alpha-tocopherol in a daily dose of 30 mg every day.

Upon long-term exposure, the radioactive gas radon-222 and its decay products in increased doses adversely affect human health. Since the human being spends about 65% of his time in the buildings, it is necessary to evaluate air radiation purity in the rooms, which can be obtained by making a sanitary radiological survey of residential buildings. The scope of the rooms in many-storeyed buildings to be examined can be considerably reduced if the regularities in radon distribution are known. This paper deals with searches for regularities in the distribution of radon levels by the floors of many-storeyed buildings in Tomsk. The room air concentrations of radon were measured for 18 residential buildings with tract detectors upon 1-3--month exposure. The findings showed a different pattern in the distribution of radon levels by the floors in relation to the structural features of a building and to the type of a building material. The wooden and slag-concrete buildings show a 2-3--fold increase in radon levels on the lower floors as compared to the upper ones. A statistical analysis of measurements in the bearing-wall and brick buildings revealed no association of the concentration of radon with the level of a floor, the distribution is near-uniform with 15-30% standard deviation, which is within the limits of measurement error.

A total of 152 patients with Opisthorchis infection at the acute and chronic stage of the diseases, as well as 1-3 days and 1-2 months after therapy with biltricide in a dose of 60 mg/kg body weight. Intracellular myeloperoxidase was spectrophotometrically determined. Its activity was demonstrated to be significantly varying at the different opisthorchiasis stage. At the acute stage there was a 6-fold increase in the activity of the enzyme as compared with that at the chronic stage. The therapy resulted in the drop of myeloperoxidase levels, at the same time the authors interpret the heterodirectional changes in the activity of myeloperoxidase in the early post-therapeutic period as a fact of individual anthelmintic intolerance the normalization of the parameter studied 1 month after the therapy only in 42.1% of the cases as a fact residual Opisthorchis antigen persistence.

Lungs of 20 rats flown aboard Cosmos-936 for 18.5 days and sacrificed within 5-13 hours (8 weightless and 4 centrifuged rats) and 25 days (4 weightless and 4 centrifuged rats) after recovery were studied histologically. An identical number of lung specimens were withdrawn from rats of synchronous and vivarium controls. Lungs of the flight rats did not show any pathological changes or morphological signs of prolonged congestion, thus indicating the lack of hypertension in pulmonary circulation. Lungs of the flight rats exhibited an increased leukocyte count, which was more marked in the weightless rats killed 8-13 hours postflight. The elevation in the count of neutrophilic leukocytes in the flight rats was due to peripheral neutrophilia which is a manifestation of an acute stress-reaction. An exposure of rats to artificial gravity was responsible for a lesser increase in the count of neutrophilic leukocytes.

This paper presents data on pulmonary circulation of rats during prolonged hypokinesia (30 to 165 days). It was found that the hypokinetic exposure of 30 to 60 days produced venous and, in particular, capillary plethora associated with blood redistribution and pooling in the lungs. As the exposure continued, the plethora level decreased due to the development of compensatory-adaptive reactions in the lung vessels. For instance, on hypokinetic day 90 small arteries of the muscle type developed a spasm which accelerated circulation stabilization. By hypokinetic days 120-165 pulmonary circulation returned to normal due to the further development of compensatory-adaptive mechanisms in lung vessels (tendency for hypertrophy of the media of small arteries and increase of its cross-sectional area).

Histological and histochemical investigation was carried out with rat liver specimens taken 9-11 h (from 6 rats), 24 (from 7 rats), 48 h (from 8 rats), and 25 (from 5 rats) and 27 days (from 7 rats) after the completion of 19.5- and 22.5-day of space bioflights in "Cosmos-605" and "Cosmos-782". The same number of specimens was investigated from corresponding models of the experiments carried out in the laboratory and from the control rats. The investigations demonstrated that in the rats sacrificed during the first two days, and in 25 and 27 days after the completion of the flight, no morphological changes developed in comparison with the control and with the animals from the laboratory experiments. Only some fluctuations in lipid content could be noticed in connection with the time of samples taking after the completion of the experiments. The greatest amount of lipids in the liver was observed in the rats sacrified 9-11 h after the completion of the flight, in 24 h the lipid level was still rather high, and in 48 h there was a tendency to their decrease. In 25 and 27 days the livers of the animals from the experimental group did not differ in their lipid content from those of the control animals. The changes in the lipid content observed in the liver during 8-48 h after the flight completion and during the period of afteraction indicate the reversibility of the adipose infiltration process, connected with lipid mobilization, dependent on stress-reaction.

Liver samples of 12 rats flown aboard the biosatellite Cosmos-690 and irradiated with a dose of 800 rad and of 12 rats from the synchronous experiment were examined histologically and histochemically. On the 2nd and 27th postexperimental days the following morphological changes were detected; nuclear polymorphism of hepatocytes, a significant increase in the number of binuclear cells, and lipid accumulation in central lobes. The changes were more expressed on the 2nd day. These changes were induced by prolonged irradiation in space flight and synchronous experiment: they were not detected in the untreated animals.

A morphological examination of 27 rats flown onboard the biosatellite and sacrificed on the 1st-2nd and 26-27th postflight days demonstrated no significant changes in the structural organization of the vital organs and systems of the animal body. It was, however, found that the space exposure induced morphologically detectable changes in the musculo-skeletal system, hemo- and lymphopoiesis, hypothalamic-pituitary-adrenal system and the juxtaglomerular apparatus of the kidneys. The changes were reversible and nonspecific, and could be seen in animals exposed to ground-based hypokinetic and other stress experiments. Postflight the animals developed some reactions that were similar to those in humans. This helps to identify the morphological substrate of certain changes in the human body and to investigate their pathogenesis.

Dogs were exposed to six-year gamma-irradiation with doses of 21-1140 rad/year; pathomorphological changes were studied in testicles thyroid gland, adrenals, liver and kidneys. The level of morphological changes in the organs during the six-year exposure was dissimilar and depended on the radiosensitivity of a specific organ, dose rate and acute irradiations that were applied during the experiment. In testicles morphological changes (reduction of layers of the spermatogenous epithelium, decrease of the number of spermatozoids in testicular canals) appeared during the first year of irradiation at a dose rate of 0.34 rad/day. Later, these changes progressed and by the end of the six-year exposure were followed by a distinct sclerosis of the interstitial tissue and hyperplasia of Leydig's cells. In the thyroid gland signs of the hypofunctional state were seen by the end of the second year of irradiation at a dose rate of 0.34 rad/day and persisted afterwards. In adrenals hypertrophy of the bundle and glomerular zones were observed during the second-fourth years of irradiation at a dose rate of 0.34 rad/day. As irradiation proceeded hyperplastic processes developed in the thyroid gland and adrenals (adenomatous nodes in the thyroid gland, adenomatous hyperplasia in the adrenal cortex). Vacuolar and fat dystrophy of hepatocytes and disturbed permeability of glomerular capillaries in the kidneys were detected only at the end of the third year of irradiation. During the fifth and, particularly, the sixth year of the exposure sclerotic changes in the liver vessels, hyalinosis of small arteries and nephrosclerotic foci in the kidneys were found.

In order to estimate end effects of chronic prolonged gammairradiation of dogs, an exposure of 80 animals to irradiation was terminated and they were followed up closely. Out of 80 animals 30 dogs (1st series) were irradiated for 3 years and 50 dogs (II series) for 6 years. The dogs were exposed to irradiation at doses of 21 to 190 rad per year. Out of the total number of animals 22 dogs died. Post-mortem examinations showed neoformations in 13 animals (7 malignant and 12 benign neoformations). The highest number of tumors developed in dogs of the II series (10 out of 11) one-two years after irradiation (6 malignant tumors--malignant pheochromocytoma of adrenals; malignant adenoma of the hypophysis: polymorphocellular sarcoma of the liver; leucomyosarcoma of the uterus; bladder cancer; breast cancer; and 10 benign tumors--pancreatic adenoma; liver angioma; 2 papillary adenomas of the prostate; 3 renal adenomas; lipoma; polyps of the gall-bladder). Animals of the 1st series displayed 3 neoformations (1 malignant tumor--bladder tumor and 2 benign tumorsliver hepatoma and spleen angioma) 4--5 years after irradiation.