[Dynamics of changes in the rat skin lipids during stress: effects of exogenous melatonin].
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Animals↗
Biomedical subjects
V A Bykov
Publications and source records attributed to V A Bykov.
[Effect of dikvertin on the cyclic nucleotide level in thrombocytes].
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Blood Platelets↗
Scanning tunnelling microscopic investigation of fullerene monolayers.
C(60) fullerene monolayers have been investigated by scanning tunnelling microscopy/spectroscopy. Single C(60) molecules have been resolved and a regular surface lattice structure of fullerene - in - surfactant is observed. Tunnel electron spectroscopic measurements results in typical I(V) curves which are interpreted in terms of the two-junction Coulomb blockade effect.
Journal Article↗
[Lipid parameters of the skin, cerebellum, and medulla oblongata during immersion stress in rats].
The influence of short-form water immersion stress of rats on lipids in the skin, the cerebellum and the medulla oblongata was studied. The level of total lipids and absolute and relative contents of the main lipid fractions (phospholipids, nonesterified cholesterol, free fatty acids, triglycerides, and cholesterol esters) were measured. Stress induced delayed changes of the lipid component of the skin. The first significant changes of lipid fractions were only observed 20 h later after the stress procedure. These changes were retained (being at nearly constant levels) till the end of the second day. The decrease in contents of total lipids and esterified cholesterol was revealed in the cerebellum of stressed rats (in comparison to these levels in control rats). These results suggest the involvement of cholesterol metabolic system in the stress reaction. The content of total lipids decreased also in the medulla oblongata. However, levels of the main lipid fractions changed differently. The content of diglycerides increased and the content of cholesterol decreased. The data obtained suggest that degradation of triglycerides is the principle pathway of metabolic conversions of lipids. Free fatty acids formed during these processes are probably involved in the synthesis of phospholipids and cholesterol esters. The data indicate absolutely different mechanisms of interrelations between individual lipid fractions in the brain regions studied. Various roles of the brain structures in the stress response of the body may account for the differences revealed.
Animals↗
[Effect of melatonin on wound healing and various biochemical characteristics of granulation-fibrous tissue in rats].
The influence of melatonin application on wounds healing and biochemical composition of rat regenerating granulation tissue was studied. Melatonin decreased healing rate of wounds. The differences in electrophoretic pattern of proteins extracted by neutral saline solutions were detected. Melatonin increased quantity of neutral soluble collagen fraction and gene expression of minor types of collagen in normal skin. Spectrum of glycosaminoglycans' was changed, and earlier increase of chondroitinsulfats induced by administration of melatonin was observed.
Animals↗
[Water-exchange processes in hyaline cartilage and its basic components in a normal state and in osteoarthritis].
The content of different forms of tissue water was studied in the normal articular cartilage and osteoarthrosis cartilage and its structural components: collagen, potassium hyaluronate, sodium chondroitinsulphate and its complexes. In the components of cartilage matrix a few of fractions of bound water different in the strength of binding are present. At the maximal humidity, all water in collagen binds with the active groups of biopolymers and in the glycosaminoglycans, in addition to bound water, are present, two crystal forms of freezing water (free water) at least. The quantity of free water in the collagen-chondroitin sulphat membrane, is increased with the increase of chondroitin sulphate. In the collagen-hyaluronate complex, fraction of free water is found only at the low concentration of hyaluronate kalium. It was shown that in the hyalin cartilage, in different from the other connective tissue (skin, achilles tendon), the most part of water is free water and its quantity is increased in the osteoarthrosis. It is supposed that the rearrangement of binding and free-water fractions in the osteoarthrosis is the result of deficiency of hyaluronic acid and therefore this may be regarded in the improvement of methods of treatment. This scientific and methodical approach allow to receive information on the forms and binding energy of water in the biological tissues, which is absorbed from fluids and steam phase and determine characters of the pathological changes.
Adult↗
[Effect of parenteral administration of melatonin on the biochemical composition of the rat granulation tissue].
The influence of long term parenteral melatonin administration on the biochemical composition of granulation tissue of surgical wounds in rats during healing was investigated. Physiological solution and solutions containing various concentrations of melatonin were subcutaneously injected to the animals within 3 weeks. Control and injected animals were wounded. Samples of gramilation tissue were investigated on the 5-th and the 8-th day of healing. The contents of oxyprolin, uronic acids, hexosamines, total lipids and their fractions, fractional composition of glycosaminoglicans and proteins composition of salt extracts were determined in the se samples. Repeated injections during three weeks caused the changes in biochemical composition of researched samples which were characteristic for stressful reaction of connective tissue. The specific changes are most expressed at long term introduction of a physiological solution to animals. The introduction of melatonin during similar period cansed protective effect, partially defending biochemical composition of granulation tissue from changes, which were induced by stressful situation.
Animals↗
[Changes in biochemical characteristics of collagen and the cartilage water in osteoarthritis].
The stability of collagen molecules and moisture capacity of human normal and osteoarthrotic (OA) cartilage were studied before and after extraction of glycosaminoglycans (GAG) by 4M guanidinum chloride. The content and nature of water were determined by Fisher titration, DSC and analysis of sorbtion-desorbtion processes of water vapour in cartilage. The stability of collagen molecules was determined by the degree of enzymatic hydrolysis: collagenase, pronase and pepsin. It was found that weakening of bonds between main compounds of the cartilage matrix and decrease of GAG quantities in the OA cartilage were accompanied by structural disorganization of the collagen network, which is manifested by breakdowns of intramolecular bonds in telopeptides and intermolecular bonds in the spiral part of collagen molecules, these changes may contribute to increase of total water in OA cartilage. The correlation of free and bound water fractions in cartilage was increased from 5 to 44 in OA cartilage. These results can be used as a criterion of pathological condition of human articular cartilage.
Adult↗
[Evaluation of preservation and the collagen structure state in the mummy tissues].
The content and state of collagen in skin, muscle and bone of 2500-year-old Altai mummies were studied. Collagen is the predominant protein in studied tissues of the mummies. High degree of the resistance of collagen to the effect of various proteases (collagenase, pronase, pepsin) and to alkline and acidic hydrolysis suggests on the considerable chemical modification of tissue collagen structures of the mummy. The possibility of increased collagen cross-linkages in tissues of the mummies during long-term storage and of nonenzymatic glycosylation of collagen leading to the formation an Amadori products and other modified structures are discussed.
Bone and Bones↗
[Structural features of proteins by intermittent-contact atomic force microscopy].
Optimal conditions of protein scanning by atomic force microscopy were developed. Proteins of different molecular masses (950-11.5 kDa) and different three-dimensional organization were used to investigate the structural features of proteins. The most distinct images of proteins were obtained using a tip with the free amplitude in the range of 5-15 nm and with the set-point amplitude in the regime of repulsion from the sample. The method allowed one to clearly recognize the structural details of large molecules such as immunoglobulins IgM and IgG1 and Ricinus agglutinin. The revealing of the structural properties of proteins with molecular masses of 60 kDa and less was limited by the sharpness of probe tips used in the present study. It was shown that, by a quantitative analysis of the geometric parameters of molecules, it is possible to distinguish IgG1, Ricinus agglutinin, and ricin.
Immunoglobulin G↗
[Detection of immune complexes using atomic force microscopy].
Complex formation between immunoglobulins and ligands immobilized on mica was studied by atomic force microscopy in two different systems. In the first system, 60-kDa ligands possessing only one site for antibody recognition were used. In the other system, a more complex interaction of human immunoglobulin with immobilized polyclonal antibodies was studied. In both systems, specific complexes with proper ligand appeared, and unspecific interaction was not detected. The method of revealing immunocomplexes by image atomic force microscopy can be used in the development of modern diagnostic systems.
Aluminum Silicates↗
[A quantitative analysis of complex formation between IgM and immobilized ligand using atomic force microscopy].
Specific interaction between human IgM and polyclonal antibodies immobilized on support was studied by atomic force microscopy. Human IgMs are responsible for a number of side effects arising during the xenotransplantation of mammalian organs to man. On the basis of atomic force microscopy, a quantitative analysis of complexes with IgM was performed. The data of the analysis agree well with the results of enzyme immunoassay. It was shown that the method of detection of immune complexes based on atomic force microscopy is able to detect specific antibodies/antigens in serum.
Aluminum Silicates↗
[Various forms of water in the rat myocardium and liver during blood loss and the early postresuscitation period].
Different forms of water content were studied in myocardium and liver of male rats at 2-h hypotension and during the early postreanimation period. The phenomenon of redistribution of free and bound water was found. Comparison of water balance during the postreanimation period in the myocardium and liver revealed that normalization of different forms of water occured in myocardium. In hepatocytes oedema remained over the whole period studied.
Animals↗
[Investigation of ribosomes of E. coli and T. maritima by atomic force microscopy].
Subunits 70S, 50S, and 30S of ribosomes of E. coli and T. maritima have been studied by atomic force microscopy. A considerable heterogeneity of structures was visualized when 70S and 30S subunits were sorbed on mica. The linear size and the height of molecules were estimated. It was found that the heights of ribosomes of E. coli and T. maritima substantially differ. The average height of 70S ribosomes of E. coli was 9.4 + 0.01 nm and that of T. maritima was 10.35 +/- 0.02 nm. The differences in the dimensions were probably determined by special organization of the mobile ribosomal element the L7/L12-stalk.
Escherichia coli↗