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V M Lakhtin

Publications and source records attributed to V M Lakhtin.

At least 19 recordsLinked to original sources
PubMed2006

[Lectins, adhesins, and lectin-like substances of lactobacilli and bifidobacteria].

Cell-surface adhesion factors of lactobacilli and bifidobacteria, such as lectin/adhesin proteins of S-layers, secreted lectin-like bacteriocins, and lectin-like complexes, are considered and classified in the article. Certain general and specific properties of these factors are noted, such as in vitro and in vivo adhesion, cell co(aggregation), participation in the forming of microbial biofilms and colonization of mammalian alimentary tract, as well as complexation with biopolymers and bioeffectors, specificity to glycanes and natural glycoconjugates, domain and spatial organization of adhesion factors, co-functioning with other cytokines (pro- and anti-inflammatory ones), regulation of target cell properties, and other biological and physiological activities. The authors also note possibilities of application of lectins and lectin-like proteins of probiotic strains of lactobacilli and bifidobacteria in medicine and biotechnology.

Adhesins, Bacterial↗
PubMed2006

[Biological characterization and prospects of application of a new bifidobacterial strain as an ingradient of probiotics].

The study was dedicated to investigation of a bifidobacterial strain, isolated from a healthy chick, its biological properties and lectins produced by the strain; a restrictive analysis of the chromosomal DNA was conducted as well. Presumably B. gallinarum was identified. The strain displayed adhesive, lectinic and antagonistic activities; it was resistant to the leading chemotherapeutic pharmaceuticals and antibiotics, and, when given to chicks, it had probiotic effect. The study identified a set of lectins binding phosphorylated mannan, with isoelectric points in the pH interval of 4 to 8; the set differed from the sets of lectins of other bifidobacteria.

Animals↗
PubMed2005

[Formation of probioticotherapy in Russia].

Probioticotherapy and probioticoprophylaxis have been applied widely in Russia and the world of late. The article presents the main medical, strain-related, and biotechnological stages of their development in this country, in comparison with the results of the world practice. The authors substantiate appropriateness of creation of probiotics and which would contain either only growth medium components, able to activate normoflora (to increase colonization ability and stimulate production of biologically active substances) upon entering the organism, or only probiotic strain components and/or biologically active substances produced by biologically active strains in mono- or associative cultivation, or combination of the listed components.

Food Industry↗
PubMed2005

[The effects of the microbial components of the probiotic Acilact on the cell-mediated immunity factors under experimental conditions].

The authors analyzed the effects of the microbial components of the probiotic Acilact on the cell-mediated factors of the immune homeostasis. According to the results, L. acidophilis stimulates the functional activity of immunocompetent cells, especially T-cell mediated immunity with strain- and dose-depending differences in intensity. The study demonstrated the ability of L. acidophilis to activate expression of the genes of pro-inflammatory cytokines (IFNgamma, IL-6, 12, and TNFalpha), to induce production of IFNalpha and IFNgamma, and increase interferon production, with additional stimulation of lymphoid organ cells with specific inductors in vitro. The study established that L. acidophilis stimulates production of macrophage migration inhibition factor by immunocompetent cells of Peyer's plaques and the splen, and induces its quantitative increase in the serum of CBA mice. The study detected immunocorrecting effect of L. acidophilis by the example of experimental shigellous infection, demonstrated intensification of the prolipherative activity of immunocompetent T-cells, induction of the expression of the genes of pro-inflammatory cytokines (IFNgamma, IL-1beta, 6, 12, and TNFalpha), but not IL4 and 10, increase of synthesis of IFNalpha and IFNgamma by the cells of Peyer's plaques, the splen and thymus. The obtained results prove the immunological effect of the probiotic preparation Acilact, based on the strains L. acidophilis NK1 and L. acidophilis K3(111)24.

Animals↗
PubMed2000

[Isotyping of human C4 complement using differences in the functional activity of C4A and C4B isotypes].

The difference in the functional activity of the isotypes A and B of component C4 of human complement was used to determine their ratio and to detect the inherited deficiency of the isotypes. ELISA methods were developed for the quantitative assay of component C4 (conventional sandwich method) and its functional activity. When determining the functional activity, the classic pathway of the complement and therefore of component C4 was activated by activators sorbed on ELISA microplates (immunoglobulin IgG3 or liposaccharide of the Shigella sonnei cell walls, which activates the complement by binding component C1). The nascent fragment C4b is covalently bound to the target activator; C4Ab binds better to the target protein (immunoglobulin), and C4Bb to the target carbohydrate (liposaccharide). Therefore, when immunoglobulin is a target activator, isotype C4A is bound and determined; and when the complement is activated by liposaccharide, isotype C4B is determined. The ratio of the activities determined by the two methods indicates a deficiency in the individual isotypes of component C4 or its absence. The rabbit polyclonal monospecific antibodies against the human component C4 and the conjugates of these antibodies with horseradish peroxidase were used in the methods described.

Animals↗
PubMed2000

[Inhibition of binding of activated compliment component C4b with its target].

The inhibition of covalent binding of the nascent C4b fragment of the human complement component to its natural target, immunoglobulin G, was studied. To this end, an immunoenzyme system was developed. In this ELISA method, the complement was activated on the sorbed IgG molecules and the resulting nascent C4b fragment acylated IgG or interacted with a competitive inhibitor added to the system. The inhibition constants for binding of the nascent C4b to its target were determined for immunoglobulins G1, G2, G3, G4, M, and A1, as well as for ferritin, yeast mannan, capsid polysaccharides of the Neisseria meningitidis A, B, and C serotypes, diphtheria anatoxin, epinephrine, and salicylic acid. On the basis of the experimental data, the immunoglobulin role at the activation stage of the complement regulation cascade, the relationship between the antigen immunogenicity and its ability to interact with C4b, and the direct effect of a number of therapeutic agents on the complement system were discussed. Lectins of various specificities were shown to inhibit the enzymic activation of C4 by the first complement component and the subsequent C4b sorption to its target, which allowed us to suggest that some oligosaccharide fragments of the C1s and C4 molecules are spatially close to the C1s active site and to the thioester bond of C4.

Complement Activation↗
PubMed1993

[Relative hydrophobicity and other properties of lectins in aqueous binary phase polymeric systems].

The relative hydrophobicity of ten purified lectins preparations (SBA, LCA, PNA, PSA, STA, WGA, Con A, PHA-P, RCA-I and HPA) was determined using the aqueous two-phase polymeric system Ficoll 400-dextran 70 (13.53% - 11.59%, w/w in H2O, respectively). The linear correlation was found between the relative hydrophobicity of the lectin preparations and their hemagglutinating activity towards native rabbit erythrocytes (r2 = 0.925). Con A specific carbohydrate ligands added to the system decreased the relative hydrophobicity of lectin. Using cross partition, isoelectric points for the lectins were determined.

Animals↗
PubMed1990

Structure and properties of a Cephalosporium acremonium alpha-galactosidase.

The amino acid and sugar composition of the enzyme protein, the effect of urea, sodium dodecyl sulphate and Concanavalin A on the purified alpha-galactosidase (EC 3.2.1.22) from the mold Cephalosporium acremonium has been studied. The results obtained by gas liquid chromatography indicated the presence of N-acetylglucosamine, mannose, galactose and N-acetylneuramic acid in the molar proportions 2:7:3:11. The presence of two types of Asn-linked oligosaccharide structures in the enzyme molecule is assumed. The alpha-galactosidase liberates alpha(1-3), alpha(1-4) and alpha(1-6)-linked D-galactose units from various synthetic and natural substrates which have been tested. The effects of pH, substrate concentration and temperature on the catalytic activity of the enzyme are described. The purified alpha-galactosidase also exhibited a lectin activity with an affinity towards glucose, and to some extent mannose.

Acremonium↗
PubMed1985

[Differential affinity of pathogenic species of microorganisms for a set of lectins detectable by the sandwich method using fluorescein isothiocyanate (FITC)].

The qualitative differences in the affinity of concanavalin A (Con A), wheat-germ agglutinin (WGA) and Phaseolus vulgaris lectin to the surface of 10 microbial strains inducing various diseases in humans and agricultural animals have been demonstrated by means of the indirect immunofluorescence tests. Enterobacteria, Coxiella burnetii and Bacillus anthracis have been found to possess pronounced affinity to Con A and WGA, while Rickettsia prowazekii, Francisella tularensis and Brucella abortus, as well as Treponema pallidum, have proved to be resistant to lectins. WGA has been found to bind specifically to Brucella abortus and Treponema pallidum. Con A and WGA are seemingly suitable for use in the preliminary test for the total capacity of lectin receptors to come in contact with biological macromolecules.

Animals↗
PubMed1979

[Determination of structural differences in DNA by pyrimidine isopliths ratios].

Using a modified Burton procedure, twelve pyrimidine nucleotide isopliths of DNA from five mammalian species (human, rabbit, guinea pig, rat and cattle) were determined. A method is proposed for mathematical estimation of DNA block analysis data, revealing a correlation between the specific DNA primary structure, the systemic status of the organism under investigation and the organism's radiosensitivity. In some cases DNA structural differences as determined by pyrimidine isoplith ratios help to distinguish between families of the same mammalian order. Quantitative isoplith ratios demonstrate that ionizing radiation treatment brings about certain changes in DNA primary structure. Their direction is quite the opposite to the main trend in the changes of DNA structure in the course of biological evolution.

Animals↗
PubMed1976

[Determination of pyrimidine nucleotide sequences of DNA].

A modification of the Burton method for determination of pyrimidine nucleotide blocks (isopliths) of DNA, providing a higher yield of large-sized nucleotide isopliths, is described. The amount of side products (interisopliths) does not exceed their amount upon DNA hydrolysis according to the Burton method. Another advantage of the technique recommended is a considerable shortening of hudrolysis time (20 min instead of 18 hours). The modification described has been successfully used to determine the pyrimidine nucleotide blocks of some warm-blooded animals DNAs. It has been found that the DNA of animals with higher sensitivity to ionised irradiation contains more oligothymidylic sequences as compared to the DNA of animals, less sensitive to irradiation.

Animals↗
PubMedDate not supplied

[Inborn deficiency of complement C4A and C4B isotypes in persons infected with Chlamydia].

The difference in the functional activity of the isotypes A and B of component C4 of human complement was used to determine their ratio to detect the inherited deficiency of the isotypes. The frequency of deficiency in healthy persons blood donors was equal for C4A and C4B (0.14 for each isotype), i.e. 14% of total number (22) donors, or 28% totally. These results agree with the literary data, on which the frequency of deficiency of C4A is 0.14, and of C4B is 0.11-0.16. The inherent deficiencies of C4A and C4B for persons infected by Chlamydia were studied. For this purpose the patients (35 persons) with in blood antibodies (IgG or IgM) to Chlamydia (C. trachomatis, C. psittaci and C. pneumoniae) were investigated. The frequencies of deficiency of C4A and C4B were 0.29 and 0.46 respectively. Thus, the number of the undeficiency patients was only 25%, while among healthy persons 70-75% of individuals not having deficiencies of isotypes C4 were observed. The deficiencies of isotypes of C4 at this pathology is detected for the first time. The obtained data suggest the existence of the predisposition to the development of diseases stipulated by Chlamydia in persons with inherent deficiency of C4 component of complement.

Adult↗
PubMedDate not supplied

[Isolation and some properties of a lectin from the venom of the Vietnamese scorpion Buthus occitanus sp].

A lectin was isolated from the venom of scorpion Buthus occitanus sp. by means of Sephadex G-50 gel filtration and CM-cellulose ion exchange chromatography. The homogeneous lectin preparation consisted of homodimeric molecules with a subunit Mr of 9.3 kDa. Glycine, alanine, and serine dominated in the lectin amino acid composition. The lectin was a glycoprotein containing 20% carbohydrates (predominantly mannose and glucose). Trypsin-treated murine erythrocytes agglutinated at the lectin concentration of 32 micrograms/ml. Hemagglutination was inhibited by carbohydrates (L-fucose > D-glucose > L-rhamnose > D-xylose). The lectin revealed no phospholipase or hyaluronidase, nor toxic activity.

Animals↗