Synthesis of GnRH analogues and their application in targeted gene delivery systems

A set of GnRH analogues containing the nuclear localization signal (NLS) of the SV-40 virus was synthesized using solid phase peptide synthesis and chemical ligation techniques. Selective chemical ligation was achieved through hydrazone formation upon the interaction of NLS hydrazide and GnRH analogue modified with pyruvic acid. The efficiency of the synthesized compounds was demonstrated in experiments on transfection of various human cancer cell lines with reporter luciferase and β-galactosidase genes, as well as suicide thymidine kinase gene of HSV-1. Selectivity of the peptide-DNA complex effect on cancer cells is achieved as a result of its penetration through the cell membrane via GnRH receptor-mediated endocytosis pathway.     

Modeling of the composition of materials for soft X-ray sources used in research on inertial confinement fusion

A method for calculating and optimizing the composition of materials for soft X-ray sources used in research on inertial confinement fusion is described. For a target-converter, a material composition is determined with which the conversion of laser light into X radiation is highly efficient. A comparative analysis is carried out of the efficiencies of generation of soft X-ray emission in the plasmas of some composite materials of thin conductors (wires) used as loads in X-and Z-pinches. Numerical calculations of the optical plasma properties are reported whose results make it possible to judge the emissivity of plasmas of different materials. The results obtained are compared to the data from other studies.     

Computer System “Gene Discovery” to Search for Patterns in Eukaryotic Regulatory Nucleotide Sequences

A method is proposed to automatically search for patterns in the mutual location of context signals in regulatory DNA sequences. The procedure is based on the methods of Data Mining and Knowledge Discovery software, implemented in a computer system Gene Discovery. This system was used to study erythroid-specific promoters and promoters of the endocrine-system genes from TRRD. We detected some trends in occurrence and localization of specific oligonucleotide groups.     

Na/K Pump and Intracellular Monovalent Cations: Novel Mechanism of Excitation–Transcription Coupling Involved in Inhibition of Apoptosis

The Na/K pump plays a key role in the regulation of the intracellular concentrations of monovalent cations and related cell function leading to electrogenesis and excitation–contraction coupling. We focus this review on the analysis of recent data showing that (i) inhibition of the Na/K pump triggers a signaling cascade independently of modulation of the intracellular [Na⁺]_i/[K⁺]_i ratio; (ii) elevation of [Na⁺]_i under sustained inhibition of the Na/K pump leads to expression of a set of genes by [Ca²⁺]_i-dependent and independent pathways; (iii) [Na⁺]_i-sensitive genes are involved in the inhibition of programmed cell death (apoptosis) in vascular smooth muscle cells.     

On the Morphology of Arrowhead Flounders of the Genus Atheresthes in the Pacific Waters of the Northern Kuril Islands and Southeastern Kamchatka

This paper presents the results of studies on the morphology of arrowhead flounders, the Kamchatka flounder Atheresthes evermanni (35 specimens), and the American arrowtooth flounder A. stomias (37 specimens) collected in Pacific waters of the northern Kuril Islands and southeastern Kamchatka in 1998–1999. The morphology of the discussed species is compared with that of arrowtooth flounders from other areas. From this comparison, available information on the sharp increase in the density of the American arrowtooth flounder in the surveyed area (since 1997), and similarities in size compositions of the fish in Kuril and Aleutian waters, a conclusion has been made about the penetration of this species from Aleutian Pacific waters into the area of the northern Kuril Islands and southeastern Kamchatka. This is a result of expansion of the geographical range of this species due to general water warming in the northwestern Pacific during the second half of the 1990s.     

Comparative analysis of the theoretical models of a hot dense plasma and the density functional theory

A general set of self-consistent field equations that describes the state of the whole ensemble of atoms and ions in a hot dense plasma is derived using the density functional theory. The set of equations is used to obtain equations of the Thomas-Fermi model, the Hartree-Fock-Slater model, the detail configuration account method, and the ion model. This approach makes it possible to identify the physical approximations underlying the theoretical models and to analyze their applicability ranges. Some of the results obtained from the Hartree-Fock-Slater model, the detail configuration account method, and the ion model are compared with the experimental data.     

On measurements of the higher harmonics of transmembrane current

The higher harmonics of the current caused by an alternating voltage applied to bilayer lipid membranes made of diphytanoyl phosphatidylcholine (DPhPC) in decane and tetradecane were measured. A universal relation between the amplitudes of harmonics was proposed and experimentally verified. This allowed the coefficients of expansion of the capacitance in even powers of voltage to be calculated for the DPhPC membrane in tetradecane; it also permitted comparison of the inhomogeneity in the thickness of the DPhPC membranes in decane and tetradecane.     

The role of free calmodulin in the regulation of calcium-pump activity in erythrocytes

The activity of Ca-pump in inside-out oriented vesicles obtained from erythrocyte membranes after their 30 min treatment with EGTA at 20 degrees C (membranes A) and 37 degrees C (membranes B) was investigated. It was shown that in membranes A placed into an incubation medium containing 0.1 mM EGTA (pH 7.4) the overall effect of exogenous calmodulin is due to the increase in the maximal activity of the enzyme, its affinity for Ca2+ being unaffected thereby. In membranes B placed into the same medium (pH 6.75) the activation of the Ca-pump by calmodulin is due to the increased affinity for Ca2+ at a constant maximal activity of the enzyme. The dependencies of the value of the calmodulin-stimulated component of membranes A and the Ca2+-binding capacity of calmodulin measured by the intensity of N-phenyl-1-naphthylamine fluorescence on the concentration of free Ca2+ are coincident. In the case of membranes B, the stimulation of Ca-pump by calmodulin occurs at much lower Ca2+ concentrations than the Ca2+ binding-induced conformational shifts in calmodulin. The experimental results suggest that the affinity of the Ca-pump for Ca2+ may affect calmodulin existing in a Ca2+-independent state. The hydrophobic interactions between the Ca-calmodulin complex and the Ca-ATPase molecule are apparently essential for the regulation of the maximal enzyme activity.