Isoproterenol stimulation of the repair of single-stranded DNA breaks in Chinese hamster cells induced by gamma irradiation

The action of the increased intracellular content of adenosine monophosphate (cAMP) in CHO-K1 cells (clones 773 and ADr112eb), treated with isoproterenol, on gamma-induced DNA single-strand breaks repair has been investigated. The hormonal treatment stimulates gamma-induced (180 Gr) DNA single-strand repair during the post-irradiation incubation (45 min) by 75 +/- 16%. The results show the involvement of the cAMP system in radiosensitivity of cultured mammalian cells and in regulation of cellular mechanisms of DNA repair.     

Release of beta-alanine from the frog skeletal muscle determined by thin-layer chromatography

The release of beta-alanine from the resting and contracting frog sartorius muscles was demonstrated by the two-dimensional thin-layer chromatography. The release of beta-alanine from indirectly stimulated muscles of frogs in winter was about 230% higher than at rest. When synaptic transmission was blocked by d-tubocurarine the release of beta-alanine from directly stimulated muscles did not exceed the release at rest. Thus, activation of neuromuscular synapse leads to increased beta-alanine release from contracting muscle.     

Noninvasive Prenatal Testing Using Next Generation Sequencing: Pilot Experience of the D.O. Ott Research Institute of Obstetrics,Gynecology and Reproductology

Russian Journal of Genetics - In recent years, noninvasive prenatal testing (NIPT) for fetal chromosomal abnormalities has come into wide use. NIPT allows detection of fetal chromosomal...     

Compensation mechanisms in hemopoietic stem cell pool (CFUs) under the conditions of experimental chronic gamma-irradiation

The kinetics, proliferation and differentiation potentials of hemopoietic stem cells (CFUs) of bone marrow and spleen were investigated in CBA-line mice in the early period (1-30 days) of chronic gamma-irradiation at a dose rate of 0.16 Gy/day to attain a cumulative dose of 4.8 Gy. The results of the experimental study showed the prevalent maintenance of productivity of granulocytic and erythrocytic hemopoietic cell series within the range of reference values, persistent inhibition of the megakaryocytic series (in terms of all hemopoiesis parameters of interest), more marked suppression of the population of polypotential CFUs in the bone marrow as compared with that in the spleen. The obtained results indicated that the mechanisms of hemopoiesis compensation at stem cell pool level were as follows: the increase in proliferation potency of erythrocytic and in polypotential precursors, the rise in the proportion of granulocytic precursors in the real differentiation potential of CFUs, and the processes of repopulation manifested with different intensity in all stem cell populations under study. For maintenance of the necessary productivity of CFUs in each of hemopoietic cell series, consecutively or simultaneously, several compensatory-adaptive mechanisms are started, which allows the avoidance of a sharp competition between hemopoietic cell series under the conditions of stem cell pool depopulation, and preservation of the hemopoiesis as a whole.     

The Interaction of Dipole Modifiers with Polyene-Sterol Complexes

Recently, we showed that the effect of dipole modifiers (flavonoids and styrylpyridinium dyes) on the conductance of single amphotericin B (AmB) channels in sterol-containing lipid bilayers primarily resulted from changes in the membrane dipole potential. The present study examines the effect of dipole modifiers on the AmB multi-channel activity. The addition of phloretin to cholesterol-containing membranes leads to a significant increase in the steady-state AmB-induced transmembrane current. Quercetin significantly decreases and RH 421 increases the current through ergosterol-containing bilayers. Other tested flavonoids and styrylpyridinium dyes do not affect the channel-forming activity of AmB independently on the sterol composition of the bilayers. The effects obtained in these trials may instead be attributed to the direct interaction of dipole modifiers with AmB/sterol complexes and not to the effect of dipole potential changes. The presence of double bonds in the Δ7 and Δ22 positions of sterol molecules, the number of conjugated double bonds and amino sugar residues in polyene molecules, and the conformation and adsorption plane of dipole modifiers are important factors impacting this interaction.     

Strain-specific antibodies as an indicator of the circulation of wild poliomyelitis viruses and their role in the formation of collective immunity in the population

Essential differences in the intensity of collective immunity to poliomyelitis in the donors of Moscow and Kaluga were established. To find out the nature of high characteristics of collective immunity to poliovirus, types 1 and 2, in the donors of Kaluga, strain-specific antibodies to wild and vaccine polioviruses were studied. In a considerable number of donors strain-specific antibodies to poliovirus, types 1 and 2, were detected. This made it possible to presume a sufficiently wide circulation of these viruses among the population of the city in the middle of the 20th century and, as a consequence, high level of collective immunity appeared. Strain-specific antibodies to poliovirus of type 3 were rarely detected. This made it possible to suggest that the circulation of viruses of this type among the population was limited. Immunity to viruses of this type was due only to immunization. For this reason the characteristics of collective immunity in the donors of Moscow and Kaluga coincided. The detection of strain-specific antibodies to poliomyelitis virus allowed to retrospectively form the opinion of the spread and time of the circulation of wild poliomyelitis viruses in the population.     

Level of natural autoantibodies to interferon-alpha and characteristics of interferon status during chronic hepatitis and liver cirrhosis

Level of autoantibodies to interferon-alpha and characteristics of interferon status were studied in 118 patients with chronic diffuse liver diseases (CDLD). During formation of liver cirrhosis in patients with CDLD level of natural autoantibodies to endogenous interferon-alpha increased. During progression of CDLD, decrease of interferon-alpha level and its functional activity were observed as well as change in the ratio between active fraction of interferon-alpha and its inactivated forms towards increase of the latter. One cause of observed decrease in biological functional activity of interferon-alpha in patients with chronic hepatitis and liver cirrhosis was increased titer of interferon-alpha neutralizing autoantibodies in blood. Level of natural autoantibodies to interferon-alpha, its antiviral activity and concentration during chronic hepatitis and liver cirrhosis can be used as markers of disease severity and predictors of its outcome.     

Synthesis of arginine-containing peptides and their conjugates with protohemin IX and tetraphenylporphyrin

Arg-containing peptides and their conjugates with protohemin IX were synthesized by the solid phase method using Merrifield resin. The conjugates of Arg-containing peptides with tetraphenylporphyrin were obtained by using phosphorus trichloride as an activating agent.     

Immunodetection of RNA-dependent RNA polymerase from turnip yellow luteovirus using monoclonal antibodies

Monoclonal antibodies (MAs) to the RNA-dependent RNA polymerase from turnip yellow luteovirus (TYV) were prepared using a recombinant protein as immunogen and were shown to be directed to C-terminal part of the viral replicase. These MAs were found to interact with a 70-kDa protein found in extracts from TYV-infected plants. Our result is the first successful attempt at detecting the RNA-dependent RNA polymerase of a luteovirus in infected plant extracts. We also found that the protein is not processed further and its accumulation and content in the infected plant obey a definite dynamics during the infection. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 1; see also http://www.maik.ru.