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Biomedical subjects

V V Novikov

Publications and source records attributed to V V Novikov.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Hydrolysis of various peptides and proteins in weak permanent and low frequency fluctuating magnetic fields].

It was shown that weak combined magnetic fields (constant field 25-130 microT; variable field 0.01-0.2 microT; the range of effective frequencies of the alternating component 1-10 Hz) substantially increase the rate of hydrolysis of some proteins and peptides (eight various sequences). The concentration dependence of the dynamics of the process and the dependence of the magnitude of the effect on the parameters of the magnetic field. It was found that: (1) the effect is transmitted through a solvent preliminarily treated by magnetic fields and (2) the effect occurs in the presence of inhibitors of proteases and enzymes inactivating peroxides (catalase and horse radish peroxidase with substrate).

Chromatography, High Pressure Liquid↗
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[Hydrolysis of the bovine insulin B-chain in bidistilled modified water].

It was shown that bidistilled modified water substantially enhances the hydrolysis of the peptide the bovine insulin B-chain. The exposure of the peptide to bidistilled modified water for 20 hours at room temperature leads to an almost complete hydrolysis of its molecule into fragments that differ from the initial molecule in elution time from a column in high-performance liquid chromatography.

Animals↗
PubMedDate not supplied

[Effect of weak and superweak magnetic fields on intensity and asexual reproduction of the planarian Dugesia tigrina].

It was shown that the exposure to combined weak and extraweak magnetic fields (permanent component 42 microT; variable component of an amplitude of 100 nT, frequency 1-60 Hz) increases the intensity of asexual propagation of planarians Dugesia tigrina. The effect of combined magnetic fields is most pronounced at frequencies of 1, 3.7, and 32 Hz. The presence of concomitant technogeneous fields (50 Hz, 30 nT) does not markedly influence the effects of weak magnetic fields with a small variable component. Upon realization of effects of weak magnetic fields, their both components are of great importance; the absence of one (permanent) component changes the sing of the effect to the opposite. The transfer of the effect to planarians through water pretreated with magnetic fields probably indicates that aqueous medium is involved in the realization of biological effects of weak magnetic fields.

Animals↗
PubMedDate not supplied

[Effect of an aqueous salt solution exposed to weak magnetic fields on the sensitivity of bacterial plasma membrane to reactive oxygen species].

It was shown by electroorientation spectroscopy that hydroxyl radicals OH* generated in a Cu(2+)-ascorbate system disturb the barrier properties of the plasma membrane in Escherichia coli K12 cells. It was also found that in water containing small additions of H+, Na+, and Cl-, preliminarily exposed to weak combined permanent (42 microT) and polyfrequency alternating (amplitude 0.06 microT and frequencies 1, 3.7, and 32.2 Hz) magnetic fields, the sensitivity of the plasma membrane to the radical attack considerably decreased, whereas dimethylsulfoxide did not protect active oxygen species in this system. It was assumed that treating the aqueous solution with magnetic fields affects the oxidation of ascorbate. Spectrophotometric measurements did reveal a decrease in the rate of oxidation of ascorbate by Cu2+ ions in a solution preliminarily treated with magnetic fields.

Antioxidants↗
PubMedDate not supplied

[Coupling of microbial processes of methane and ammonium oxidation in soils].

The effect of ammonium ions on the activity of methane oxidation in soils was studied. The degree of inhibition of the methanotrophic activity in the presence of ammonium in the soil solution was quantitatively assessed as dependent on ammonium concentration and the properties of different types of soils of the European part of Russia.

Ammonium Chloride↗
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[Water structure formation by weak magnetic fields and xenon. Electron microscopic analysis].

Exposure of deionized water of high purity grade to weak magnetic fields (collinear fields: the constant component 42 +/- 0.1 microT; the alternating component: amplitude 60 +/- 2 nT, frequency 3.7 Hz) for 12 h affects the structure formation in a water-xenon system. This is evidenced by the formation of xenon clathrate crystals a few submicrons and microns in size whereas in initial water solution these crystals were absent. The changes in water properties persist for at least two days after the treatment with magnetic fields. The addition into water of calcium ions at a concentration close to physiological completely eliminates the effect of the formation of submicron and micron crystals of xenon gas hydrates.

Electromagnetic Fields↗
PubMedDate not supplied

[Dependence of effects of weak combined low-frequency variable and constant magnetic fields on the intensity of asexual reproduction of planarians Dugesia tigrina on the magnitude of the variable field].

It was shown that the stimulating effect of weak combined magnetic fields (constant component 42 microT, frequency of the variable component 3.7 Hz) on the division of planarians depends on the amplitude of the variable component of the field. The effect is particularly pronounced at 40 (the main maximum), 120, 160, and 640 nT. Narrow ranges of effective amplitudes alternate in some cases with equally narrow ranges in which the system does not respond to he treatment. In the range of super weak amplitudes of the variable field (0.1 and 1 nT), the stimulating effect is poorly pronounced. The data obtained indicate the presence of narrow amplitude windows in the response of the biological systems to weak and super weak magnetic fields. In a special series of experiments, it was shown that the effect of fields on planarians is partially mediated via aqueous medium preliminarily treated with weak magnetic fields. It is noteworthy that in experiments with water treated with weak magnetic fields, there were no pronounced maxima and minima in the magnitude of the effect in the range of amplitude of the variable magnetic field from 40 to 320 nT.

Animals↗
PubMedDate not supplied

[Biological activity in the modern and buried soils of the St.Petersburg's historical center].

Biological activity in the urban modern and medieval soils of St. Petersburg was determined using soil samples taken from sections located at the historical center of this city nearby the Kazan Cathedral, the Twelve Colleges building (now the main building of St. Petersburg State University), and on the site where the Swedish fortress Nienshants formerly existed. The studied parameters of biological activity included the microbial transformation rate of organic matter under aerobic and anaerobic conditions, the intensity of denitrification and nitrogen fixation, and the amount of microbial biomass. This investigation is the first attempt to comparatively study modern urban anthropogenically impacted soils and buried soils that had formed the soil cover of this region before St. Petersburg was founded. The major microbiological and physicochemical parameters of the soils were subjected to correlation analysis.

Biomass↗
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[Destruction of amyloid beta-protein by exposure to weak magnetic fields].

It was found that weak magnetic fields (constant 42 microT; variable 0.05 microT; summation of frequencies in the range of 3.58-4.88 Hz) substantially (approximately fourfold) accelerate the hydrolysis of the amyloid beta-protein in aqueous solution. A region of the amyloid beta-protein most sensitive to the action of weak magnetic fields was determined. It is localized between Asp and Ser amino acid residues in positions 7 and 8 of the peptide sequence. It is in this region that the hydrolysis of the molecule of the amyloid beta-protein by the action of magnetic fields predominantly takes place.

Amyloid beta-Peptides↗
PubMedDate not supplied

[Soluble HLA class I and HLA class II antigens in the blood of HIV infected patients].

The levels of HLA, class I, antigen and HLA-DR antigen in the blood sera of HIV-infected persons were determined by the enzyme immunoassay. The levels of soluble antigens HLR-DR and of HLA, class I, in serum samples containing only antibodies to HIV were elevated, respectively, 1.8- and 1.3-fold in comparison with the norm. The level of soluble HLA-DR antigen in samples containing the markers of other infections (HBsAg, antibodies to hepatitis C virus, anti-IgM antibodies to cytomegalovirus) was significantly higher in comparison with samples containing only antibodies to HIV and serum samples from healthy donors (p < 0.05). The concentration of soluble HLA antigen, class I, in the samples containing antibodies to HIV and markers of other infections was also elevated, but the statistically authentic increase in comparison with the normal level was observed only in the presence of the markers of HIV infection, hepatitis C and cytomegalovirus infection.

Cytomegalovirus Infections↗
PubMedDate not supplied

[Effect of tumor necrosis factor DNA on immune response to DNA immunization against herpes simplex virus].

A study was made of the adjuvant effect of the mouse tumor necrosis factor alpha (mTNF alpha) on DNA immunization against the herpes simplex virus type 1 (HSV1). The HSV1 gD gene (pDNAgD) served as an immunogen; mTNF alpha or its gene cloned in an eukaryotic expression vector (pDNAmTNF) were used to modulate the immune response. Double immunization with pDNAgD led to a sixfold increase in the in vitro T-cell response, a high (1:2000) titer of anti-HSV1 antibodies (including virus-neutralizing antibodies), an increase in IgG2a/IgG1 (suggesting a shift of the immune response to the Th1 type), and no change in CD4/CD8 T-cell ratio. A single injection of mTNF alpha along with inactivated HSV1 allowed a twice higher antibody titer and a fourfold higher T-cell response as compared with immunization with HSV1 alone. Double immunization with both pDNAgD and pDNAmTNF increased the titer of anti-HSV1 antibodies and the T-cell response by factors of 8 and 1.5, respectively, as compared with immunization with pDNAgD alone. However, the protective effect was significantly lower with the two plasmids than with pDNAgD (73 vs. 100%). Thus, DNA immunization with pDNAgD induced both B- and T-cell responses and completely protected mice from a lethal doze of HSV1. The adjuvant properties of mTNF alpha and pDNAmTNF need further investigation.

Antibodies, Viral↗
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[Comparison of adjuvant activities of glucosaminyl-muramyl dipeptide and of the gene coding for granulocyte-macrophage colony-stimulating factor in DNA immunization against herpes simplex virus].

Adjuvant activities of granulocyte-macrophage colony-stimulating factor (GM-CSF) and synthetic glucosaminyl-muramyl dipeptide (GMDP) were studied in immunization against type 1 herpes simplex virus (HSV1). Gene encoding the gD HSV1 protein (pDNAgD) was used as an immunogen. Gene encoding GM-CSF in pDNAGM-CSF plasmid, which was developed for eukaryotic expression, and GM-DP were used as immune response modulators. GMDP and plasmid DNA with inserted GM-CSF gene enhanced T-cell immune response to HSV1 after a single injection (pDNAGM-CSF) or 24 h before (GMDP) immunization with the gD HSV1 gene. Both adjuvants increased protective effect of DNA-immunization by a virus gene with 63 up to 100% after injection of two genes and up to 96% after the viral gene was inoculated 24 h after GMDP. These high effects indicate that further investigation of anti-HSV1 DNA-based vaccines used with genetic and peptide adjuvant is prospective.

Acetylmuramyl-Alanyl-Isoglutamine↗
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[The superoxide-scavenging activity of some amino acids in water solutions].

The superoxide-scavenging activity of a number of amino acids was revealed. The activity is comparable in effectiveness with known antioxidants. An original method for the estimation of antioxidant properties of amino acids was proposed. Quantum mechanical calculation of the interaction of lysine with superoxide anion was made. It was assumed that the mechanisms of the biological action of some physical factors, such as weak magnetic fields adjusted to the cyclotron frequency of ions of some amino acids, are associated with the modulation of the antioxidant activity of these molecules.

Free Radical Scavengers↗
PubMedDate not supplied

[A comparative structural analysis of Fab-fragments of monoclonal rheumatoid and non-rheumatoid immunoglobulins M].

The spin-labeling method was used to study the Fab- and Fab-RF-fragments of IgM and IgM-RF, respectively. The spin-label 2,2,6,6-tetramethyl-4-dichloro-sym-triazinyl-aminopiperidine-1-oxyl was introduced into the peptide moiety of the proteins. The rotational correlation time t of the spin-label carrier was determined based on the temperature-viscosity dependence of the EPR spectra parameters of the spin-labeled proteins. The tau values for Fab- and Fab-RF-fragments were 21 +/- 2 and 12 +/- 1 ns, respectively. The data strongly suggest that the significantly lower tau value for the Fab-RF-fragment may be due to the local structural flexibility of the fragment, which in turn may explain the peculiarities of IgM-RF as an autoantibody.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

[Serum level of soluble forms of membranous antigens of immune system cells in carriers of virus hepatitis G markers].

The levels of soluble CD38 (sCD38), CD50 (sCD50), and CD95 (sCD95) antigens and HLA class I (sHLA-I) were determined in the serum samples from persons infected with hepatitis G virus (HGV). HGV monoinfection was accompanied by a rise in the serum content of sCD38, sCD50, and sCD95 antigens. The serum presence of HGV RNA and anti-E2 HGV antibodies was characterized by the normal content of sCD38 and sCD95 while the level of sCD50 was elevated and the serum content of sHLA-I was decreased. If the serum contained only anti-E2 HGV antibodies, the level of sCD50 remained increased 4-fold. It is suggested that the higher adhesion-inhibiting level of sCD50 is a reason of a weak immune response to HGV and hence of a long HGV persistence in the body.

Antigens, CD↗
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[Immunomodulating properties of khlotazol].

A nonsteroidal anti-inflammatory agent khlotazol administered to rats in doses of 40-80 mg/kg for 5 days stimulated synthesis of IgM- and IgG-antibodies to ram erythrocytes and increased the number of antibody-forming cells (AFC) and rosette-forming cells (RFC) in the spleen. When the doses were increased to 160-320 mg/kg, the stimulating effect of the drug on the production of hemagglutinins retained but dose-dependent inhibition of the number of AFC and RFC was found. When administered in a dose of 80 mg/kg khlotazol markedly activated the reaction of hypersensitivity of delayed type induced by ram erythrocytes.

Adjuvants, Immunologic↗