PubMed Health⌕ Search

Biomedical subjects

N V Kuznetsov

Publications and source records attributed to N V Kuznetsov.

15 recordsLinked to original sources
PubMed2006

[Antioxidants in complex treatment of Parkinson's disease].

Experimental and clinical study of mexidol efficacy in the complex therapy of Parkinson's disease has been carried out. It is shown that in a Parkinsonian animal model using oxotremorine, mexidol reduces Parkinsonian symptoms and decreases expression of neurophysiological changes caused by oxotremorine. Neurohistological study of substantia nigra neurons in a Parkinsonian model using MPTP revealed a neuroprotective effect of mexidol. An assignment of mexidol (4,0 ml intravenous in drops during 10 days) to patients with Parkinson's disease, receiving the basic therapy with antiparkinsonic drugs, reduced tremor, rigidity and bradykinesia. The most marked effect was observed in patients with prevalence of trembling symptoms at early stages of the disease. The results of clinical study have been confirmed by electromyographic and electroneuromyographic data.

Animals↗
PubMed2002

The dependence of solar energetic particle fluxes in the Earth-Mars-Earth route on solar activity period.

This report presents the results of analyzing the relative importance of particle fluxes of different origin in the Earth-Mars-Earth route during different solar activity periods. The analysis has been made in terms of the galactic cosmic ray and solar energetic particle flux models developed at Moscow State University. The results demonstrate the extreme importance of the high-energy solar particle fluxes in interplanetary space even during the years of "quiet" Sun.

Cosmic Radiation↗
PubMed2001

Amino acid substitutions of coiled-coil protein Tpr abrogate anchorage to the nuclear pore complex but not parallel, in-register homodimerization.

Tpr is a protein component of nuclear pore complex (NPC)-attached intranuclear filaments. Secondary structure predictions suggest a bipartite structure, with a large N-terminal domain dominated by heptad repeats (HRs) typical for coiled-coil--forming proteins. Proposed functions for Tpr have included roles as a homo- or heteropolymeric architectural element of the nuclear interior. To gain insight into Tpr's ultrastructural properties, we have studied recombinant Tpr segments by circular dichroism spectroscopy, chemical cross-linking, and rotary shadowing electron microscopy. We show that polypeptides of the N-terminal domain homodimerize in vitro and represent alpha-helical molecules of extended rod-like shape. With the use of a yeast two-hybrid approach, arrangement of the coiled-coil is found to be in parallel and in register. To clarify whether Tpr can self-assemble further into homopolymeric filaments, the full-length protein and deletion mutants were overexpressed in human cells and then analyzed by confocal immunofluorescence microscopy, cell fractionation, and immuno-electron microscopy. Surplus Tpr, which does not bind to the NPC, remains in a soluble state of approximately 7.5 S and occasionally forms aggregates of entangled molecules but neither self-assembles into extended linear filaments nor stably binds to other intranuclear structures. Binding to the NPC is shown to depend on the integrity of individual HRs; amino acid substitutions within these HRs abrogate NPC binding and render the protein soluble but do not abolish Tpr's general ability to homodimerize. Possible contributions of Tpr to the structural organization of the nuclear periphery in somatic cells are discussed.

Animals↗
PubMed2000

[Effects of heavy charged particles on strains of microorganisms-producers of biologically active substances].

Effects of heavy charged particles on strains of Bacillus thuringiensis ssp. Kurstaki Z-52 and Arthrobacter OC-1 have been studied. Evidence was obtained that heavy charged particles impact the morphologocultural and physiological properties of culture. As noted, the conditions of orbital flight may be considered a source of mutagenic effects on cultures of microorganisms.

Alpha Particles↗
PubMed1999

An analysis of the SEU rate of microcircuits exposed by the various components of space radiation.

In the present paper the experimental and calculated data of SEU rate in microcircuits operating onboard spacecraft are compared. The main features of models and the calculation methods, which are incorporated in the SEREIS software package, are considered. The main features of models, and the calculation methods are considered. The contribution of the different space radiation components (ERB Protons; GCR particles and SEPs) to the SEU rate is discussed with an allowance for the shielding thickness.

Cosmic Radiation↗
PubMed1996

Single event upsets of spacecraft microelectronics exposed to solar cosmic rays.

The technique for evaluating the SEU rate induced by solar particle incidence on spacecraft microelectronics is described, including the contributions from the primary (heavy ion-induced) and secondary proton-induced) SEU mechanisms. The technique is based on original computational models for solar particle energy spectra and for SEU occurrence in electronics. The technique was used to analyze the data of the TDRS-1 Fairchild 93L422 IC exposed to protons and ions during the solar cosmic ray event of September-October 1989. The analysis included the distribution of the microcircuit shielding. A strong dependence of solar proton-to-ion ratio on the shielding thickness was indicated by the calculations.

Cosmic Radiation↗
PubMed1994

[ANSA analysis. II. Aminonaphthalenesulfonamides--detecting groups for polysubstrate analysis of proteases].

The properties and synthetic methods of aminonaphthalenesulfonamides (ANSA) used as detectable groups of protease substrates are described. A list of chemical and physical properties of seventeen 5.1-ANSA with simple substituents is presented. A comparison of condition for the introduction and removal of acyl protecting groups (acetyl, trifluoroacetyl, phthaloyl, carbobenzoxy) used in ANSA synthesis is given. Examples of applicability of nitronaphthalenesulfonamides as intermediate compounds are given. The possibility of ANSA alkylation at both N(C) and N(S) is demonstrated. Substituted ANSA--sulfonylaziridenes--are used for the production of water-soluble derivatives containing the alcoxy group in the sulfonamide fragment. Criteria for the selection of detectable groups for polysubstrate analysis are discussed. Eighteen typical procedures for ANSA synthesis according to the schemes discussed are presented.

Alkylation↗
PubMed1994

[ANSA analysis. III. Synthesis of aminonaphthalinesulfonamide chromogenic substrates for protease analysis].

A review of synthetic methods of peptide substrates containing aminonaphthalenesulphonamide (ANSA) as the detected leaving group is presented. Variations of aminoacylic and peptide ANSA derivatives using ANSA as the C-protect group at all stages of the peptide synthesis, condensations of the ANSA with the N-protected peptide fragment obtained preliminary, the application of aminoacyl-ANSA as syntones are discussed. The synthesis scheme used while determining optimal ANSA substrates that involves reactions of aminoacyl derivatives of aminonaphthalenesulfonylchlorides with amines is shown. The application of di-tert-butylpyrocarbonate, DCC, chlorodimethylformiminium chloride, alkylchloroformate as condensing agents is described. The protection of amino groups was carried out by using Boc- and Cbz- groups.

Anilino Naphthalenesulfonates↗