Biomedical subjects
Publications and source records attributed to A B Luchkov.
In experiments on rats it has been shown that under the influence of alantone (50 mg/kg of the body weight daily during 30 days) a number and level of maturity of peritoneal and mesenteric mast cells increased, and blood clotting decreased. It might be important for the well-known ability of alantone to increase both the peripheral blood circulation and microcirculation.
The most promising devices of those for radionuclide diagnosis that can be used for control of nuclides incorporated in the human body during a radiation incident are hybrid scanners. The authors made the calibration of devices of this type to register a mixture of 137Cs and 134Cs. The minimum detected activity was 40 nCi. A methodological error of measurements was +/- 3%. A mathematical criterion for optimization of the geometry of measurements was drawn for devices, including the methodological and statistical components of a total error. This criterion was used for finding optimum sizes of a slot collimator of the device.
The authors represent summarized data on the time course of incorporated Cs in the population of the Krasnogorsk District of Bryansk Province over the period of June 1986-July 1989. A RIKh-5M device used as a counter of human radiations, its technical data and calibration methods were described. A retrospective analysis has shown that the main accumulation of radionuclides occurred before May 15 1986. The highest rates of Cs clearance from the body were noted in the period of August 1986 till February 1987, the average resultant periods of semiclearance for different populated areas and groups of population were 55-85 days. The ratio of accumulated Cs in children and adults was 0.3, in men and women--1.4. The effectiveness of measures aimed at reducing collective doses of internal irradiation was analyzed.
The problem of dosimetry of internal irradiation necessitates the use of human radiation counters (HRC). A state system of radiation safety should be based on a HRC stock in case of large-scale radiation accidents. Radiodiagnostic units can run in the HRC mode therefore they must be considered as an active reserve widely spread throughout the country. Radiodiagnostic devices can be used for control of the thyroid level of 131I and the whole-body content of a mixture of 134Cs and 137Cs.
The paper is concerned with methods of monitoring of integral inhomogeneity (II) used in standards of international organizations and in recommendations of the IAAE. Quantitative analysis of errors at different stages of measurement and processing was performed. Statistical effects were investigated on a mathematical model of an absolutely homogeneous detector. The precision of theoretical calculations was confirmed by experimental testing. Nomograms and their description by simplified formulas with account of such errors in II determination were presented by the authors. They proposed methods for calculation of a 95% confidence interval for an II value of a response of a gamma-camera detector, and issued recommendations for testing computerized gamma-cameras without corresponding special programs of processing.
Radionuclide functional dynamic investigation of the thyroid with 99mTc-pertechnetate was performed in 62 patients with diffuse euthyroid and toxic goiter, thyroiditides and in 17 controls. An analysis of the results of investigations and their comparison with clinical findings, an echo- and scintigraphic picture of the thyroid as well as with the levels of total thyroxine, triidothyronine and thyrotropin of the hypophysis showed that the results of a dynamic test of pertechnetate trapping corresponded, to a large extent, to the clinical status of patients with diffuse thyroid changes, correlated with an echographic picture and made it possible to define significant radiodiagnostic signs of thyroiditides. The proposed methods made it possible to increase the volume and improve the quality of diagnostic information in functional investigations of the thyroid status raising the efficacy of diagnosis of thyroid diseases and reducing radiation exposures and the time of investigations.
Altogether 120 studies with a dynamic kidney phantom (DKP) were conducted permitting one to imitate the normal functioning of the kidneys or different pathological states of the organ. The studies were conducted with the help of a gamma-chamber of MV-9100 type using a computer system SEGAMS (Hungary) and a chronoscope RIKh-5M-01. On completion of the experiment the activity-time curves were plotted characterizing the time course of the passage of a radioactive tracer through phantom cylinders that imitate the kidneys. The results obtained have demonstrated DKP potentialities for the imitation of various renal functional states. Studies with a DKP make it possible to select an optimum regimen for research and to assess the quality of performance of nuclear medical diagnostic equipment.