Identification of structural DNA variations in human cell cultures after long-term passage

Random amplified polymorphic DNA (RAPD) analysis was adapted for genomic identification of cell cultures and evaluation of DNA stability in cells of different origin at different culture passages. DNA stability was observed in cultures after no more than 5 passages. Adipose-derived stromal cells demonstrated increased DNA instability. RAPD fragments from different cell lines after different number of passages were cloned and sequenced. The chromosomal localization of these fragments was identified and single-nucleotide variations in RAPD fragments isolated from cell lines after 8–12 passages were revealed. Some of them had permanent localization, while most variations demonstrated random distribution and can be considered as de novo mutations.     

Comparative genetic analysis of diploid naked wheat <Emphasis Type="Italic">Triticum sinskajae</Emphasis> and the progenitor <Emphasis Type="Italic">T. monococcum</Emphasis> accession

The inheritance of several morphological and biochemical traits was studied in diploid (2n = 2x = 14) naked wheat Triticum sinskajae. The electrophoretic pattern of storage proteins (gliadins) of T. sinskajae differed only in two components from the pattern of T. monococcum accession K-20970, in a population of which T. sinskajae had been discovered. Analysis of biochemical polymorphisms revealed a difference between T. monococcum K-20970 and T. sinskajae in a slow 6-phosphogluconate dehydrogenase zone but not in the other eight enzyme systems examined. Nucleotide sequence analysis of the nuclear Acc-1 (acetyl-CoA carboxylase) gene revealed a 46-bp deletion from intron 11 in T. monococcum K-20970 but not in T. sinskajae. This difference was not regarded as species-specific in view of the intraspecific polymorphism of the Acc-1 locus in T. monococcum. A monogenic control was demonstrated for the spring growth habit of T. sinskajae, and the monogenic control of the specific T. sinskajae ear shape was verified. The T. sinskajae ear shape is controlled by a recessive gene, while the T. monococcum ear shape is controlled by a dominant gene. The T. sinskajae ear shape, nakedness, soft glume, aristate glume, and the oblique brachium of the outer glume proved to be linked. The set of T. sinskajae diagnostic characters is determined by a single (possibly, regulatory) gene or a set of closely linked genes. The two other genes specific to T. sinskajae—awnS, determining the awnlessness, and fig, determining the nonfissile inner (flower) glume—are, respectively, 1.35 ± 0.98 and 3.34 ± 1.54% of crossing over away from the mon gene, which determines the T. sinskajae ear shape.     

Analysis of probabilistic characteristics of brain biopotentials in healthy humans using electronic computer technology]

Results are given of determination by means of a Minsk-22 electronic computer of the probabilistic characteristics and correlation coefficients for some parameters of the background EEG (frontal-occipital records) in a group of healthy subjects. The parameters studied (the number and amplitude of alpha- and other waves) are subject to the normal law of distribution of random values. A probabilistic model of background EEG has been plotted. Correlations between the factors of the statistic model of background EEG have been studied. The results presented in the paper may prove useful in studying the EEG characteristics and the functional state of the brain.     

EEG alpha indices depending on the menstrual cycle phase and salivary progesterone level

The effects of neurohumoral status on the EEG α activity were studied in 78 women (18–27 years old) during one or two menstrual cycles using a within-subjects design. The psychometric and electroencephalographic (EEG) indices of α waves, basal body temperature, and salivary progesterone level were monitored every two or three days. The menstrual and follicular recording sessions occurred before the basal temperature rise caused by ovulation, the luteal recording session occurred after the increase in progesterone level by more than 20% compared to the day before, and the premenstrual recording sessions occurred after the decrease in progesterone level by more than 20% compared to the day before. The EEG, electromyographic (EMG) and electrocardiographic (ECG) characteristics of cognitive efficiency and psycho-emotional tension were recorded at rest and during task performance. The experiments were started in the menstrual phase in half the subjects and in the luteal phase in the other half. Psychometric characteristics, EEG α activity, EMG and ECG indices were compared for all the five phases at rest and in response to cognitive task performance. The results have shown that all psychometric and α EEG indices are menstrual-cycle-dependent. The maximum cognitive fluency, α peak frequency, α band width, and power in the α₂ frequency band are observed in the luteal phase, while the maximum power in the low-frequency α₁ band, as well as visual and cognitive activation calculated from α power reduction, are observed in the follicular phase of the menstrual cycle. The hypothesis that EEG α activity depends on the neurohumoral status is supported by the positive correlation of salivary progesterone level with the α peak frequency and the power in the α₂ band and its negative correlation with the power in the α₁ band. It is concluded that psycho-physiological recording sessions in women must be carried out with due consideration of the menstrual cycle phase.     

Synthesis and biological activity of new glycyrrhizic acid conjugates with amino acids and dipeptides

New glycyrrhizic acid (GA) conjugates were synthesized with the use of tert-butyl esters of amino acids or benzyl esters of dipeptides; they contained two residues of L-amino acids (Met, Phe, Pro, and Ile or dipeptides Gly-Leu and Gly-Phe). Activation of GA carboxy groups was carried out with the help of N-hydroxysuccinimide, N,N′-dicyclohexylcarbodiimide, or N-hydroxybenzotriazole with dicyclohexylcarbodiimide. A proline-containing GA derivative is a low-toxic substance; it raises the level of agglutinins by 3.7 times in the blood of mice and 3 times that of hemolysins compared with the control. Dipeptide GA derivatives possess an expressed anti-HIV-1 activity in cultures of MT-4 cells and are 90-70 times less cytotoxic than azidothymidine. The selectivity index of the compounds exceeds those of GA by 110 and 34 times, respectively.     

Synthesis and immunomodulating activity of new glycopeptides of glycyrrhizic acid containing residues of L-glutamic acid

New glycopeptides of glycyrrhizic acid (GA) containing Glu residues and their α-methyl esters, γ-methyl esters, and α,γ-dimethyl esters were synthesized using N,N′-dicyclohexylcarbodiimide in the presence of N-hydroxybenzotriazole or N-hydroxysuccinimide. Formation of amide bonds was observed on all the three COOH groups of GA, or selectively on the COOH groups of the GA carbohydrate part in dependence on the ratio of reagents and the reaction conditions. The GA glycopeptide with three residues of Glu(OH)-OMe at a dose of 2 mg/kg stimulated the production of antibody-forming cells in mouse spleen in comparison with the control. The GA glycopeptide containing Glu residues only in the GA carbohydrate part turned out to be an immunosuppressor. The glycopeptide of the 30-methyl ester of GA with residues of free Glu in its carbohydrate part increased the hemagglutinine titer at oral doses of 2 and 10 mg/kg. All the studied compounds had practically no effect on the delayed-type hypersensitivity in mice.     

Nonlinear theory of the excitation of azimuthal surface waves during dissipative instability

A theoretical study is made of the surface electromagnetic eigenmodes that are excited by an annular charged-particle beam due to dissipative instability and propagate across the external axial magnetic field in a cylindrical metal waveguide partially filled with plasma. A self-consistent set of differential equations for a cold low-density charged-particle beam moving above the plasma surface is constructed in the single-mode approximation and is solved numerically. It is shown that the larger the dissipation, the slower the instability growth rate and the larger the wave amplitude in the saturation stage of the instability. An increase in the transverse dimensions of a charged-particle beam results in a slower growth of the dissipative instability, in which case, however, the beam transfers a larger fraction of its kinetic energy to the wave.     

Orienting behavior of female white rats in estrus cycle and its dependence on handling

Characteristics of orienting behavior of intact and handled female white rats were studied in the "open field" test. Experimental group of animals were formed according to stages of estrous cycle: (1) diestrus, (2) proestrus, (3) estrus, and (4) metestrus. The stage of the cycle was determined by vaginal smears. Over the period of 10 days rats were handled daily for 5 minutes. No behavioral changes over the course of estrous cycle were found in intact rats. Handling revealed some behavioral features related to the levels of steroid hormones in reproductive cycle. Most prominent changes in orienting behavior were observed at transition from estrous to metestrous. At the stage of estrous motor activity was maximal and grooming was minimal. The maximal contrast in the structure of orienting behavior was observed between estrous and diestrous stages.     

Effect of testosterone on nucleic acid synthesis in spermatogenic epithelial cells of irradiated animals

A study was made of changes in nucleic acid synthesis in proliferating germ cell populations of animals irradiated with doses of 2 and 4 Gy. The administration of exogenous testosterone was shown to stimulate DNA synthesis, inhibited by the effect of radiation, in spermatogonium populations of A1-4, intermediate, and B types, and in preleptotene primary spermatocytes; RNA synthesis was increased in the same populations of spermatogonia and pachytene primary spermatocytes. The obtained results indicate that exogenous testosterone exerts a beneficial effect on spermatogenesis damaged by ionizing radiation.