Rapid diagnostics of urinary iodine using a portable EDXRF spectrometer.

A method for urinary iodine diagnostics using a portable energy-dispersion X-ray fluorescent (EDXRF) spectrometer is proposed. The principle of the method consists in excitation of the sample atoms fluorescence by the energy spectrum intentionally formed from the spectrum of an X-ray tube using an optimized X-ray scheme. The optimization by the criterion of the minimum detection limit for L-series iodine fluorescence lines included the calculation of optimal atomic numbers for materials of a re-radiator and a filter, and their thicknesses, the collimation system parameters, and an X-ray tube voltage. Experimentally achieved detection limits were 45 and 75 µg/L by I-Lα and I-Lß lines, respectively, at the theoretically extreme value 30 µg/L. This sensitivity is found to be sufficient for urinary iodine diagnostics in the range from 50 to 200 µg/L. The results obtained from different patients have shown the satisfactory convergence for the iodine concentration determination by Lα and I-Lß fluorescence lines. The simple sample preparation procedure and comparably small sizes of the apparatus allows rapid researches directly in clinical settings.

[Role of children physical development in radiation hygienic monitoring system].

The article deals with longstanding work on studies of physical development parameters among preschoolers aged 4-7 and dwelling on territories near to objects with potential radiation danger, also on radiation-connected anxiety in parents of the examined children. The stated objects when exploited in normal mode were proved to cause no influence on the children's development. Social and economical factors appeared to play leading role in developmental parameters formation. Increased level of radiation-connected anxiety in parents of the children examined appeared to be out of proportion to real favorable radiation background of the territories examined.

Effects of physicochemical forms of phenazepam and Panavir on their action at ultra-low doses.

A concept of physicochemical forms of biologically active substances introduced in investigation of the action mechanism of ultra-low doses allows qualitative explanation of the main effects of ultra-low doses, chemical diversity of biologically active substances, and physical boundaries for these effects. Phenazepam was shown to possess activity in ultra-low doses only in disperse state, in the form of nanoparticles with a diameter <100-300 nm; these nanoparticles appear as micelles of surface active substances and solvated. Panavir possesses pharmacological activity in ultra-low doses and appears as nanoparticles with a diameter of 200-300 nm, which have uncompensated negative surface charge and polymer nature.

Metric similarity of dynamic commutation processes in situ and in vitro.

The dynamics of string growth was studied in model homochiral solutions of biomimetics, trifluoroacetylated amino alcohols (TFAAA) in heptane, water, and inverted heptane-water emulsion. In heptane and water, a thick (~1 µ in diameter) string had a crown of thin strings on its growing terminal and these thin strings effectively adsorbed dissolved TFAAA. In emulsion, the strings grew inside the water droplets, in which this TFAAA cannot be solved, presumably due to transport of TFAAA molecules from heptane into water in the surface layer surrounding the string. Applications of these phenomena to in vivo cell commutation were discussed.

[Mental and physical development of children living in the area of monitoring pollution from a plant for processing and long-term storage of radioactive waste].

Environmental conditions in the area hosting a plant for processing and long storage of low- to moderately-active radioactive waste are described as reasonably safe. Residence in the area does not exert negative influence on the physical and mental development of children. Several indicators of physical development give better estimates than at the control territory. The difference can be accounted for by a better social situation in the study area (housing conditions, financial standing, food patterns, general lifestyle).

[Children's physical and mental development in the Moscow North-Western Administrative District].

The paper gives development quotients in 5-6-year-old children from the North-Western Administrative District of Moscow, which were obtained from the survey made in 2005. Only 41.9% of the boys and 30.7% of the girls were ascertained to have no physical developmental deviations. The major problem of childhood development is the underdevelopment of the functional parameters of the locomotor apparatus and respiratory system. The physical development is significantly worse in the girls than that in the boys in the majority of integral indices.

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum.

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3 ). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

Incorporation of hydrophilic protein modified with hydrophobic agent into liposome membrane.

The hydrophilic protein-enzyme, alpha-chymotrypsin, can be bound to the liposomal membrane after the preliminary increase in hydrophobicity induced by acylation of protein amino groups with palmitic chloroanhydride. The efficacy of binding depends on the degree of modification. The bound enzyme almost completely preserves its catalytic properties and the ability to interact with a high molecular weight inhibitor. Binding can be performed during both the process of liposome formation and the incubation of a modified enzyme with preformed liposomes. According to ESR and fluorescence spectroscopy, the hydrophobic tail of the modified enzyme is incorporated into the membrane and the protein globule is located on the surface of the membrane. Protein incorportation causes an increase in the amorphous nature of the membrane, and the bound protein is not as mobile as the free protein. The approach discussed can be useful in binding soluble hydrophilic proteins to artificial membranes.

[Parameters of physical and mental development of children and adolescents residing near enterprise for radioactive waste processing and stationary storage].

Operation of enterprise for radioactive waste processing and disposal does not influence negatively physical and mental development of children and adolescents residing in the area under observation. In some parameters, physical and mental development of children and adolescents residing in the area under observation surpasses that in reference area--that could be due to social and economic peculiarities.

[Whole-body diffusion-weighted magnetic resonance imaging by estimating the measurable diffusion coefficient in Hodgkin Iymphoma].

OBJECTIVE: To determine whether the measurable diffusion coefficient (MIC) may be used to differentiate normal and lymphomatosis-altered lymph nodes (LNs) in patients with Hodgkin lymphoma (HL). MATERIAL AND METHODS: Whole-body magnetic resonance (MR) imaging was used to compare the MICs of LNs in 27 apparently healthy individuals and 41 patients with a verified diagnosis of HL. RESULTS: Construction of 95% confidence intervals showed that the MICs of normal LNs were in the range of 1.00 to 1.73 x x10(-3) mm2/sec and significantly higher (p < 0.05) than those of lymphomatosis-affected LNs (MIC, 0.59 to 0.94 x 10(-3) mm2/sec). The cut-off point (for discretization) of normal and lymphomatosis-altered LNs was in the range of 0.94 to 1.00 x 10(-3) mm2/sec. Consequently, the LN with a MIC of less than 0.94 x 10(-3) mm2/sec may be thought of as affected by the lymphomatous process. CONCLUSION: MIC calculation permits differentiation of normal and affected LNs having equal signal characteristics (including those on diffusion-weighted MR images).

[Free-radical label--new approach to the study of dynamics of lipid systems]. / Svobodnorakikal'nais metka--novyi podkhod k issledovaniiu dinamiki lipidnykh sistem.

A new method of EPR-spectroscopy--the recombination of free radicals appearing as a result of indirect radiolysis of biological molecules after a low temperature irradiation--is applied to the study of molecular dynamics of phosphatidylcholine dimyristoyl in mass and in the structure of liposomes above and below the transition temperature. It was shown, that the mobility of lipid molecules in crystalline liposomes is higher than in the structure of liquid-crystalline liposomes. The addition of cholesterol in liposome membranes decreases the lateral molecular motion of lipids in crystalline and liquid-crystalline state, in the latter case the effect of cholesterol addition is more pronounced. The activation energy for the displacement of the fragments of lipid molecules and the lipid molecule as a whole was estimated, and it was shown, that lipid matrix possesses a high degree of heterogeneity.

[ESR study of the superslow diffusion of lysozyme macroradicals in an aqueous matrix]. / Issledovanie sverkhmedlennoi diffuzii makroradikalov lizotsima v vodnoi matritse metodom EPR.

Using kinetic data on recombination macroradicals in freezed water solutions of lyzozyme, superslow molecular motions of biopolymer have been studied. Recombination of macroradicals is observed at 160--240 K and it has a stepwise character. The kinetic data are described quantitatively by the model, in which the set of processes with different rate constants is considered (the so-called model of polychromatic kinetics). It has been shown that polychromatic character of the process is conditioned by energy activation distribution, which is changed from Emin = 8+/-1 kcal/mol to Emax = 13 +/- 1 kcal/mol with "rectangular" distribution function f(E) approximately equal to: formula: (see text). Preexponential factor K0 = 2 . 10 (-9)cm3.s-1. The recombination-kinetic method used permits to estimate frequencies (inverse correlation time) translation mobility macroradicals of protein up to the frequency order 10(-2)s-1 (or velocities of motions approximately 1 A/s).

[Electrical activity of the limbic structures of the dog brain during simultaneous stimulation of the cingulate gyrus and hypothalamus]. / Elektricheskaia aktivnost' limbicheskikh struktur mozga sobaki pri odnovremennom razdrazhenii poiasnoi izviliny i gipotalamusa

Simultaneous electrical stimulation of the anterior part of the cingulate gyrus and the anterior-lateral part of the hypothalamus in the dog brought about EEG synchronization in the limbic system structures and increased correlation coefficients between them. The animal's behaviour exhibited positive emotionally reactions (licking, sniffing, wagging the tail), attended with slowing of the heart rate. The indicated changes directly depend on the degree of emotional stress (the changes are more pronounced in hungry than in sated animals). Simultaneous stimulation of the anterior part of the cingulate gyrus and the anterior-lateral part of the hypothalamus apparently activates a system which reduces the level of emotional stress.

[Subcellular changes in the cortex of the motor analyzer and hippocampus of dogs with locally manifested neuroses]. / Subkletochnye izmeneniia v kore dvigatel'nogo analizatora i gippokampa sobak pri nevroze s lokal'nym proiavleniem.

In experiments on dogs with local neurosis-continuous flexion of the foreleg-changes were revealed in the beta-rhythm amplitude and the frequency of mean unit activity in the motor cortex, and the appearance and increased amplitude of the theta-rhythm in the hippocampus. Specific activity of Na+-K+-activated, and Mg2+-dependent ATPase decreases in subcortical fractions of the experimental animals' cerebral cortex by 55.0% in the synaptic membranes and 2 to 2.5 times in light and heavy synaptosomes, respectively. In similar fractions of the dorsal hippocampus, the activity of the enzyme decreases by 30.0% in the synaptic membranes and increases by 16.6% in the light synaptosomes and by 6.6% in the heavy ones.

[Electroencephalographic correlates of a pathologic inert motor reaction in dogs]. / Elektroéntsefalograficheskie korreliaty patologicheskoi zastoinoi dvigatel'noi reaktsii u sobak

Changes in EEG were examined during setting in of a pathological inert motor reaction in dogs with parts of the tongue brought out and electrodes implanted in the motor cortical area and limbic structures. The reaction was formed when combining stimulation by a salt solution of the part of the tongue with electrical stimulation of the paw. The inert motor reaction is characterized by enhanced synchronization (theta-rhythm) in the hippocampus and increased amplitude of the beta-rhythm in the motor cortical areas. A frequency-amplitude analysis of the summary EEG has shown that the highest correlation was established at the beginning of elaboration of the inert motor reaction only between a small number of limbic structures (the hippocampus, the hypothalamus and the cingulate gyrus), then between all the examined structures of the brain; when the inert reaction became elaborated the number of structures with a high correlation coefficient diminished again and was reduced to the hippocampus, the hypothalamus and the cortical motor area.

[Participation of the hippocampus in regulating a pathologic inactive motor reaction in dogs]. / Uchastie gippokampa v reguliatsii patologicheskoi zastoinoi dvigatel'noi reaktsii u sobak

A local pathological inert motor reaction, involving a forced flexion of the forepaw, was formed after simultaneous stimulation with NaCl solution of a part of the tongue brought out to the cheek and electrical stimulation of the forepaw. The reaction decreased (by 70 to 80%) after electrical stimulation of the dorsal hippocampus (beyond CA3). At the same time the animal's emotional stress diminished, as evidenced by the reduced heart rate and a reduced theta-rhythm in the hippocampus.

[Use of fiber-optic elements in ophthalmological instruments and light sources]. / Primenenie volokonno-opticheskikh élementov v oftal'mologicheskikh instrumentakh i osvetitel'nykh ustroistvakh.

Application of flexible light guides in ophthalmological devices and light sources permits to develop the tools for illumination of surgical field, transilluminators for eyes, combinations of instruments with tools for intraocular manipulations. An eye transilluminator has been produced and tested with a set of attachments comprising fiver-optic light-guiding elements. This instrument allows to reveal foreign particles in the eye's vitreous body and in the surrounding tissues, and to diagnose some pathological changes.

[Ocular microforceps with fiber lightguides]. / Glaznye mikropintsety s volokonnymi svetovodami.

Application of fiber-optic elements for intraocular illumination facilitates the search, capture and holding of foreign particles at their removal from the human eye's vitrecus body.

[Magnetic resonance imaging in the staging of malignant lymphomas].

Computed tomography, 18FDG-PET and the hybrid FDG-PET/CT are the most commonly used diagnostic tools for the initial staging and treatment response assessment of malignant lymphomas. MRI techniques such as whole-body MRI and diffusion-weighted imaging may become good radiation-free alternatives to FDG-PET/CT. Diffusion-weighted imaging is characterized by high sensitivity for the detection of lesions and allows quantitative assessment of diffusion that may aid in the evaluation of malignant lymphomas. This article will review the value of these emerging MRI techniques for the staging and response assessment of malignant lymphoma.