Effect of low doses of radiation on vitamin A and E levels in rat liver

It has been established that under intake of small doses of 137Cs by rat for 9 months the radioactivity of whole rat body was increased in irregular manner. Under this condition the level of fat-soluble vitamins A and E is decreased and the decrease is well correlated with a level of radionuclide accumulation by rat's body. The possible causes of decrease of the vitamins A and E level under intake of small doses of radionuclide are discussed.     

Intensification of the excretory flow of plutonium-239 from the body in the late stage of its metabolism

The paper deals with the effect of iron preparations on the excretion of plutonium 239 from a body at a later stage of the radionuclide metabolism. The experimental results show that oral administration of the iron preparation at a later stage of 239Pu metabolism enhances the radionuclide excretion both in urine and in faeces. On the basis of the results obtained the coefficients are calculated for 239Pu excretion in urine and faeces and for its content in the organs of deposition. This may be used for increasing the sensitivity of indirect dosimetry of plutonium-239 within the body.     

The frequency of chromosome aberrations in rat bone marrow cells in the late period after a single uptake of tritium

A prolonged self-maintenance of haemopoietic tissue cells with stable chromosome rearrangements following a single intake of tritium oxide in the amount of 24 MBq/g of body weight (absorbed dose of 11 Gy) is shown. Mutant cells revealed long after the radionuclide exposure are descendants of stem-cell precursors, bearing stable chromosome aberrations during the period of formation of radiation injury after the radionuclide administration.     

Practical assessment of radiation doses using labelled antibodies for therapy

For safe therapy with radiolabelled antibodies it is essential to maximise the uptake of radionuclide in the tumor compared with normal tissue. This paper outlines the methods and limitations of establishing the dosimetry before administering the therapeutic dose. Whole body distributions and kinetics are established using quantitative radionuclide scanning techniques, single photon tomography and blood counts in conjunction with images from other modalities such as x-ray CT. Our experience with about 40 therapeutic cases, involving mostly intracavity administration, will be outlined.     

The applicability of the concept of morpho-physiologic metabolic factors to the modification of the distribution of 239Pu deposited in the respiratory organs

At the stage of intensive resorption of plutonium from lungs to blood the competitive per os administration of an iron preparation increased plutonium excretion from blood. As a result, soft tissues were enriched with plutonium at an early stage of metabolism. However, at the end of the experiment (30 days) the radionuclide content of soft tissues dropped to control values. Simultaneously, the share of plutonium deposited in bone tissue decreased considerably and that of the radionuclide eliminated from the body increased throughout the entire period of observation.     

An assessment of the permissible level of a mixture of radionuclides from the Chernobyl fallout in human lungs]

The permissible level of a radionuclide mixture, resulted from the Chernobyl burst, in the human being lungs was determined for two kinds of compounds: absolutely insoluble compounds and soluble compounds in the state of equilibrium. For this purpose the data were used concerning the radionuclide composition and aerosol disperse in lower atmosphere which were obtained by the Department for Dosimetric Control (NPO "Pripiat'"). The results of measurements of 137Cs content taken by the use of human radiation spectrometer (HRS) needed an adequate estimation: low level of 137Cs in the human lungs and body within the Chernobyl NPP, zone does not guarantee radiation security. The notion "permissible content" and the possibility of using thereof in the individual dosimetric control are discussed.     

Absorbed doses and hematological shifts in dogs inhaling submicron 239Pu dioxide

In dogs breathing submicron 239Pu dioxide, the absorbed doses were determined in 12 organs and tissues where the radionuclide was deposited; the integral doses to a whole body were also determined by the sum of the exposed organs. The relationship of the hematologic changes not only with the doses for "critical" tissues but also with the integral dose was studied.     

Possibility of a change in the parameters of plutonium-238 metabolism in the body

The influence of macro amounts of iron on 238Pu metabolism in the animal body has been studied. The data obtained indicate that 238Pu metabolism parameters change under the effect of iron. The efficiency of the agent used is demonstrated by a diminished deposition of the radionuclide in bone tissues and an increased (by 2.65 times as compared with the control) excretion of plutonium 238 in faeces.     

Cytogenetic effects of alpha-irradiation due to incorporated 239Pu

Intravenous injection of plutonium dioxide with 1-2 microns particle sizes in amount of 92.5, 46.3 and 23.2 kBq/kg of body mass increased the yield of chromosome aberrations in bone marrow cells of rats by 3.7, 2.3 and 1.7 times, correspondingly, in comparison with the spontaneous level. The model of chromosome aberration dependence on dose of radionuclide was developed based on the experimental results.     

Behavior of plutonium in the body of rats following its intragastric administration in a complex with tributyl phosphate

A study was made of the distribution of plutonium-239 within the rat body after single intragastric administration thereof (1.85 MBq) in a mixture with tributyl phosphate (TBP) and as Pu(IV) nitrate at a time interval from 4 min to 512 days. It was shown that the distribution of the radionuclide was virtually the same but its absorption from the gastrointestinal tract with Pu-TBP was higher by one order of magnitude and exceeded the value recommended by ICRP for soluble plutonium compounds.     

Reconstruction of radionuclide intakes for the residents of East Urals Radioactive Trace (1957–2011)

The East Urals Radioactive Trace (EURT) was formed after a chemical explosion in the radioactive waste-storage facility of the Mayak Production Association in 1957 (Southern Urals, Russia) and resulted in an activity dispersion of 7.4?×?10¹⁶ Bq into the atmosphere. Internal exposure due to ingestion of radionuclides with local foodstuffs was the main factor of public exposure at the EURT. The EURT cohort, combining residents of most contaminated settlements, was formed for epidemiological study at the Urals Research Center for Radiation Medicine, Russia (URCRM). For the purpose of improvement of radionuclide intake estimates for cohort members, the following data sets collected in URCRM were used: (1) Total β-activity and radiochemical measurements of ⁹⁰Sr in local foodstuffs over all of the period of interest (1958–2011; n?=?2200), which were used for relative ⁹⁰Sr intake estimations. (2) ⁹⁰Sr measurements in human bones and whole body (n?=?338); these data were used for average ⁹⁰Sr intake derivations using an age- and gender-dependent Sr-biokinetic model. Non-strontium radionuclide intakes were evaluated on the basis of ⁹⁰Sr intake data and the radionuclide composition of contaminated foodstuffs. Validation of radionuclide intakes during the first years after the accident was first carried out using measurements of the feces β-activity of EURT residents (n?=?148). The comparison of experimental and reconstructed values of feces β-activity shows good agreement. ⁹⁰Sr intakes for residents of settlements evacuated 7–14 days after the accident were also obtained from ⁹⁰Sr measurements in human bone and whole body. The results of radionuclide intake reconstruction will be used to estimate the internal doses for the members of the EURT cohort.     

Efficacy of polymeric 239Pu removal by liposome-encapsulated pentacin

Liposome-incapsulated pentacine (DTPA) removes intracellular polimeric 239Pu and colloidal hydroxide of polymeric 239Pu from a rat body in the amounts 2- and 4 times, respectively, exceeding those eliminated by free DTPA. However the amount of 239Pu removed decreases sharply with increasing 239Pu hydrolysation and polymerization. It is concluded that the effectiveness of 239Pu removal depends on the physico-chemical status of the radionuclide and its interaction with the biosubstrate rather than on the amount of DTPA entering the cells.     

Polonium-210 in fishes from the Black Sea

The specific activity of naturally occurring radionuclide 210Po in main species of the Black Sea fishes and some their organs were used for the calculation of absorbed and equivalent dose rates. The values of the dose in investigated fish depend on their ecological belonging. Maximum values of equivalent dose rates for viscera and, first of all, liver exceed such for the whole body of fishes. But they are significantly lower than the dose rate limit recommended by IAEA for the protection of aquatic organisms from ionizing radiation.     

90Sr, 137Cs, 238Pu, 239+240Pu,and 241Am radionuclides in macrophytes within the Krasnensky flood plain: species specificity of concentration and distribution in phytocenosis components

The analysis of the content of radionuclides 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am in water vegetation of flood plain reservoirs has allowed studing features of radionuclide accumulation by various species of macrophytes and revealing bioindicators of radionuclide contamination. Thus species-specificity of radionuclide accumulation can essentially change the contribution of different species to a percentage ratio of the radionuclide content in phytomass of reservoirs in comparison with fund of higher aquatic plants.     

Reducing the radiation dose from inhaled americium-241 using continuously administered DTPA therapy

Accelerating the removal of a radionuclide from the body of a contaminated individual is the only available approach to decreasing the radiation dose from such exposures. In this study, continuous infusion of a chelating agent, DTPA, was given to dogs that had inhaled a moderately soluble aerosol, 241 AmO2, not only to accelerate clearance of the radionuclide from the lung but also to prevent its deposition in liver and bone. Treatment was begun with an intravenous injection of CaDTPA 1 h after exposure, and was continued for 64 days after exposure by implanting subcutaneously osmotic pumps containing ZnDTPA at 1 day after exposure. The results showed that the infusion therapy was effective in blocking the translocation of 99.5 per cent of the 241Am that would have been deposited in liver, and 98.3 per cent of the 241Am that would have been deposited in bone. This result was significantly better than the result achieved using repeated intravenous injections of DTPA, the method of treatment in current use for actinide contamination cases.     

Effect of low doses of internal irradiation resulting from the administration of 75Se- and 35S-labeled compounds on the cellular immune response

The administration to rats of radioactive preparations. 75Se- selenomethionine, 35S-methionine or sodium 75Se-selenite in the amounts creating the absorbed dose in the body of 0.5 Gy suppressed the delayed hypersensitivity reaction as was registered 1-12 months after the injection. The delayed hypersensitivity was tested in vitro by the method of inhibimacrophage spreding inhibition. The degree of suppression of the cellular immune response depended upon the type of the compound administered, of which the radionuclide was a component, and upon characteristics of radiation spectrum of the radionuclide.     

Modelling of long-term radionuclide migration in a non-running fresh-water reservoir

A mathematical model is presented for radionuclide migration in a non-running fresh-water reservoir that takes into account removal of microimpurities from water as a result of both molecular and ion exchange sorption at the bottom sediments water interface and detritus formation. The model was tested for sensitivity to precisely estimate experimental parameters. The test showed that the model is universal. Prediction was made of reduction in water of 137Cs and 90Sr contents and distribution of these radionuclides in the water body affected by the accident at the "Mayak" chemical plant.     

Determination of the plutonium-239 content of the body

In order to increase the informativeness of the indirect dosimetric estimates of plutonium-239 body levels complex makers are widely used to enhance natural excretion of the radionuclide in urine, the ratio between 239Pu levels in urine and skeleton being measured. However, as the onset of chelate application is postponed its efficacy, with respect to the skeleton, sharply decreases making it impossible to obtain reliable information concerning plutonium 239 levels in bone tissues at later times.     

The diagnostic value of digital subtraction arthrography and radionuclide arthrography in revision total hip arthroplasty.

An analysis of plain radiographs, digital subtraction arthrography, and radionuclide arthrography was performed in 25 revision hip arthroplasties to evaluate the efficacy and usefulness of these methods in the diagnosis of loosening. The findings by each method were compared with intraoperative assessment of the status of components and expressed in terms of sensitivity, specificity, and predictive accuracy. Overall accuracy for the acetabular component by plain radiographs was 80%; by digital subtraction arthrography, 88%; by radionuclide arthrography, 68%. Overall accuracy for the femoral component by plain radiographs was 92%; by digital subtraction arthrography, 84%; radionuclide arthrography, 76%. We consider subtraction arthrography and radionuclide arthrography to be adjuvant diagnostic tools which may be indicated in individual cases of suspected implant loosening of total hip arthroplasty. The routine use of these two methods is not warranted when compared to plain radiographs.     

Spinal CSF absorption in healthy individuals

The present study examines the extent of spinal cerebrospinal fluid (CSF) absorption in healthy individuals in relation to physical activity, CSF production, intracranial pressure (ICP), and spinal CSF movement. Thirty-four healthy individuals aged 21-35 yr were examined by lumbar puncture and radionuclide cisternography with repeated imaging. ICP was registered before and after CSF drainage, and CSF production was calculated. Spinal CSF absorption was calculated as reduction in spinal radionuclide activity. The radionuclide activity in the spinal subarachnoidal space was gradually decreased by 20 +/- 13% (mean +/- SD) during 1 h. The reduction was higher in active than in resting individuals (27 +/- 12% vs. 13 +/- 9%). The mean ICP in 19 of the individuals was 13.6 +/- 3.1 cm H(2)O. B-waves were found in 79% of the individuals, with a mean frequency of 0.6 +/- 0.3 min(-1). The mean CSF production rate was 0.34 +/- 0.13 ml/min. There were no correlations between radionuclide reduction, spinal movement of the radionuclide, and CSF production rate. The spinal radionuclide reduction found in this study indicates a spinal CSF absorption of 0.11-0.23 ml/min, more pronounced in active than in resting individuals.