PubMed Health⌕ Search

Biomedical subjects

V A Bykov

Publications and source records attributed to V A Bykov.

At least 19 recordsLinked to original sources
PubMed2004

Expression and characterization of hepatitis B surface antigen in transgenic potato plants.

Transgenic potato plants expressing the gene of hepatitis B surface antigen (HBsAg) under the control of the double promoter of 35S RNA of cauliflower mosaic virus (CaMV 35SS) and the promoter of patatin gene of potato tubers have been obtained. Biochemical analysis of the plants was performed. The amount of HBsAg in leaves, microtubers, and tubers of transgenic potatoes growing in vitro and in vivo was 0.005-0.035% of the total soluble protein. HBsAg content reached 1 microg/g in potato tubers and was maximal in plants expressing the HBsAg gene under the control of CaMV 35SS promoter. In transgenic plants expressing HBsAg gene under the control of tuber-specific patatin promoter, HBsAg was found only in microtubers and tubers and was absent in leaves. Western blot analysis of HBsAg eluted from immunoaffinity protein A-Sepharose matrix has been performed. The molecular weight of HBsAg peptide was approximately 24 kD, which is in agreement with the size of the major protein of the envelope of hepatitis B virus. Using gel filtration, it was determined that the product of HBsAg gene expression in potato plants is converted into high-molecular-weight multimeric particles. Therefore, as well as in recombinant HBsAg-yeast cells, assembling of HBsAg monomers into immunogenic aggregates takes place in HBsAg-transgenic potato, which can be used as a source of recombinant vaccine against hepatitis B virus.

Chromatography, Gel↗
PubMed2003

Phospholipid composition of granulation and fibrous tissues in rats after local application of melatonin.

We studied the effect of melatonin applied locally in doses of 1.5 and 15 mg/ml on the phospholipid composition of granulation and fibrous tissues in rats at various stages of regeneration. Melatonin (especially in a dose of 1.5 mg/ml) increased the total phospholipid content on day 8 of regeneration, which was primarily related to accumulation of ethanolamine- and serine-containing fractions. Melatonin in a dose of 15 mg/ml increased the concentration of choline-containing fractions on day 5 of regeneration.

Administration, Topical↗
PubMed2003

Comparison of cytotoxicity of aminoglycoside antibiotics using a panel cellular biotest system.

The cytotoxicity of four aminoglycoside antibiotics was studied by estimation of the dose-effect relationship using a panel cellular biotest system including cell cultures for test objects. The cultures represented 4 differentiation types: normal human fibroblasts and myoblasts, human or Syrian hamster hepatoma cells, and mouse/mouse hybridoma cells. It was found that three widely used antibiotics gentamicin, kanamycin, and neomycin exhibit similar, but not identical cytotoxicity parameters and differ distinctly from geneticin. Hence, the proposed panel biotest system helps to quantitatively evaluate and differentiate the effects of bioactive substances with similar chemical structure.

Aminoglycosides↗
PubMed2003

Characteristics of collagenolytic enzymes secreted by deuteromycete fungi Aspergillus flavus.

Collagen induced the synthesis of collagenolytic enzymes in the culture of Aspergillus flavus. Enzyme activity of the culture increased during storage and passage on a medium with this inductor. We developed a method for isolation and purification of collagenolytic enzymes and obtained two electrophoretically homogenous enzyme preparations belonging to neutral thermolabile collagenolytic metalloproteinases.

Amino Acids↗
PubMed2003

[Analysis of transgenic tobacco plants carrying the gene for the surface antigen of the hepatitis B virus].

The plasmids carrying the gene encoding the hepatitis B surface antigen (HBsAg) under the control of 35S RNA single or dual promoters of the cauliflower mosaic virus CaMV 35S were constructed. These constructions were used for obtaining transgenic tobacco plants that synthesize the HBS antigen. The presence of HBsAg in tobacco plant extracts was confirmed by the enzyme-linked immunoassay using antibodies against the native HBs antigen. The antigen amount in plants carrying the HbsAg gene under a single 35 S promoter was 0.0001-0.001 of the total soluble protein whereas the use of a dual 35S promoter increased the antigen synthesis to 0.002-0.05% of the protein. The antigen-synthesizing ability was inherited by the offspring. In the F1 plants, the antigen expression varied in different lines comprising 0.001 to 0.03% of the total soluble protein, which corresponded to the antigen amount in the F0 plants.

Genes, Plant↗
PubMed2003

[Phagocytosis of polymer microspheres immobilized with bioligands by peripheral blood leukocytes in patients with acute pancreatitis].

Phagocytosis of polymer microspheres both modified and unmodified by bioligands (gelatin, fibronectin and A protein) by leukocytic blood cells of patients with acute pancreatitis. The presence of bioligands in the surface of polymer microspheres and their activity were monitored by the reaction of latex agglutination with an appropriate ligand being involved. The study resulted in designing a method of phagocytosis implementation that can be used to evaluate the content of certain receptors in cellular membranes and, subsequently, to define the changed receptor cell apparatus caused by a disease. The nature of polymer microspheric bioligands immobilized to the surface was shown to influence significantly the activity of leukocytic blood cells.

Acute Disease↗
PubMed2002

Structural modification of collagen during nonenzymatic glycosylation in vitro.

We studied changes in collagen resistance to proteases and formation of new fluorescent compounds during in vitro nonenzymatic glycosylation. The inhibitory effects of guanidine chloride and catalase were different: guanidine chloride inhibited cross-linking in collagen molecules, while catalase inhibited the formation of chromophore-containing compounds.

Catalase↗
PubMed2002

Comparative study of Saccharomyces cerevisiae LPS.

LPS of yeast strains producing human epidermal growth factor were studied. Experiments demonstrated the absence of essential differences in the characteristics of these LPS and LPS of nonrecombinant Saccharomyces cerevisiae strains, which allowed us to develop a universal complex technology of simultaneous preparation of heterologous proteins and highly active immunomodulating LPS.

Animals↗
PubMed2002

Biochemical characteristics and water exchange in the surface layer of human joint cartilage.

We compared the contents of collagen, glycosaminoglycans, and various forms of water in the surface layer and whole tissue of joint cartilages of different localization. It was found that the surface layer is characterized by reduced content of glycosaminoglycans compared to the whole tissue and higher water-holding capacity due high content of bound water.

Cartilage, Articular↗
PubMed2000

Use of cultured human fibroblasts for rapid evaluation of cytotoxic effects of bioactive substances.

A test system for detecting cytotoxic effects of bioactive substances based on human fibroblast culture is proposed. The effects of acrylamide, streptomycin, cycloheximide, sodium dodecyl sulfate, sanguiritrine, and ethanol were evaluated by organic stain binding. Typical dose-effect relationships were detected for all substances except cycloheximide. The proposed test system can be used for screening of bioactive substances in preclinical trials.

Cell Culture Techniques↗
PubMed2000

Double-stranded nucleic acids in liquid-crystalline dispersions as building blocks for cross-linked supramolecular structures.

Double-stranded DNA fixed in a cholesteric liquid-crystalline dispersion was used for generating an ordered supramolecular structure in the presence of anthracycline and copper (II) ions. The structure is stable in a water-salt solution and does not require poly(ethyleneglycol).The ordered network can be immobilized on the surface of a polymeric film, and may collapse in the presence of biologically and pharmacologically relevant compounds. Accordingly, the DNA-based liquid-crystalline network represents the basis to obtain novel highly sensitive biosensing units.

Animals↗