The immunobiological properties of the antigenic preparations obtained from a vaccinal strain of Klebsiella pneumoniae 204 grown in media of differing compositions

In the technology of the cultivation of K. pneumoniae vaccine strain 204 with a view to obtaining biomass for the production of antigenic preparations the traditionally used culture medium with full nutritional value has been replaced by the alternative variant of synthetic medium. The specific physiological and morphological features of this strain grown in synthetic culture medium have been studied and described. Irrespective of the composition of the culture media used for cultivation, the antigenic preparations have been shown to have no difference in their chemical composition, immunogenic and toxic properties.     

Phagocytosis-stimulating effect of polysaccharides isolated from ginseng tissue culture

Materials characterizing immunostimulating activity of a polysaccharide fraction isolated from two lines of the ginseng tissue culture are presented. It was shown that under the drug action, the effector functions of polymorphonuclear leukocytes and macrophages activated.     

Analysis of matrix metalloproteinase activity during differentiation of mesenchymal stem cells isolated from different tissues of one donor

Mesenchymal stem cells established from bone marrow (FetMSC) and limb bud (M-FetMSC) of early human embryo, as well as spheroids derived these cells, were induced to undergo osteogenic and adipogenic differentiation. Differentiated cells exhibited the activity of metalloproteinase (MMP)-9, -2, and -1. Its activity was different in osteogenic and adipogenic cells, as well as in monolayer cultures (2D) and cell spheroids (3D). The direct correlation between the level of adipogenic differentiation and gelatinases MMP-9 and MMP-2 activities in both cell lines in 2D and 3D culture was shown. M-FetMSC cells in 2D culture 12 days in culture during showed low potential for adipogenesis and reduced activity of MMP-2 and MMP-9. The low level of adipogenic differentiation in 2D M-FetMSC culture was accompanied with increased MMP-1 activity and enhanced differentiation (3D culture) resulted in a significant increase of both MMP activities. MMP-1 activity varied oppositely. MMP-1 activity declined in 3D cultures with a higher level of adipogenic differentiation. The level of osteogenic differentiation was similar in both cell lines during 2D and 3D cultivation. MMP-1 and -9 activities in both cell lines were not associated with osteogenic differentiation. MMP-2 and MMP-2 activity in these cells remained unchanged. The results suggest MMP implication in FetMSC and М-FetMSC differentiation. The difference in MMP activities during the cell differentiation may be caused by variations in the microenvironment or ECM properties in 2D and 3D cultures.     

Involvement of microbial alkyl hydroxybenzenes in the regulation of autolytic degradation of yeast cells

A comparative study was performed of the processes of autolytic degradation of the cells of Saccharomyces cerevisiae and Schizosaccharomyces pombe under conditions simulating the phase of cell death in microbial cultures: (1) during autolysis induced by oleic acid, which is the chemical analogue of factors d2 (autolysis autoinducer), (2) under the effect of extracellular microbial proteinases (enzymatic lysis), and (3) under concomitant effect of the enzymes of the endogenous autolytic complex and exogenous proteinases (heterolysis). Regulatory mechanisms controlling the rate and profundity of autolysis were elucidated, relying on the stabilization of hydrolytic enzymes and enhancement of their activity in their complexes with a chemical analogue of microbial autoregulatory factors d1, which belong to alkylhydroxybenzenes and fulfil functions of chemical chaperons. The changes in the activity of proteinases and enzymes of the autolytic complex were shown to be dependent on the concentration of the analogue at the moment of complex formation.     

Cloning in Escherichia coli of the mutant gene coding the diphtheria toxin

Bacteriophage beta 45 of Corynebacterium diphtheriae was harvested. The extracted DNA of the bacteriophage was digested by the restriction endonuclease BamHI and inserted into the BamHI cleavage site of pUC19 vector plasmid. Plasmid pNVY5 containing a mutant gene crm45 of diphtheriae toxin in a 3.9 bpn fragment was isolated from the hybrid plasmids obtained. Cell free extracts of E. coli strain TG1 (pVNY5) contain the nontoxic protein crm45 possessing the specific enzymatic activity of diphtheriae toxin (ADP ribosylation on wheat elongation factor two). According to orientation of BamHI fragment in pNVY5 plasmid it is concluded that the crm45 gene is expressed using its own promoter.     

Effect of ethylene oxide and propylene oxide block copolymers on the permeability of bilayer lipid membranes to small solutes including doxorubicin

The effects of ethylene oxide and propylene oxide block copolymers (pluronics) on the permeability of several weak acids and bases through bilayer lipid membranes have been studied by the methods of monitoring (1) pH shifts near planar bilayers, (2) doxorubicin fluorescence quenching inside liposomes, and (3) current transients in the presence of hydrophobic anions. It has been shown that pluronics facilitate the permeation of comparatively large molecules (such as 2-n-undecylmalonic acid and doxorubicin) across lipid bilayers, while the permeation of small solutes (such as ammonium and acetic acid) remains unaffected. Pluronics also accelerate the translocation of large hydrophobic anions (tetraphenylborate). The effect of pluronics correlates with the content of propylene oxide units: it is enhanced when the portion of polypropylene oxide block in the copolymer is increased. The action of the pluronic on lipid membrane permeability differs from the effect of the conventional detergent Triton X-100, which does not affect doxorubicin transport if added at concentrations similar to those used for pluronics. It has been proposed that pluronics accelerate the processes of solute diffusion within lipid bilayers (in a structure-dependent manner) rather than influencing the rate of solute adsorption/desorption on the membrane surface. We suppose that the effect of pluronics on doxorubicin permeation across lipid bilayers along with the known effect on the multidrug resistance protein determines its influence on the therapeutic activity of anthracycline drugs.     

Proliferation of cultured glioma cells mediated by coenzyme Q<Subscript>10</Subscript> under conditions of serum deprivation

The effect of coenzyme Q₁₀ on glioma-cell proliferation under serum-deprived conditions has been studied. Our results have shown that the addition of coenzyme Q₁₀ into a serum-free culture medium enhances cell viability, stimulates cell growth, restores mitochondrial potential, and increases the quantity of energized mitochondria. It is found that coenzyme Q₁₀-induced glioma-cell proliferation in conditions of serum deficiency is a result of an intracellular reduced glutathione concentration with subsequent activation of protein kinase C, ERK1/2, and phosphoinositol-3-kinase.     

Previously unclassified mutation of mtDNA m.3472T&gt;C: Evidence of pathogenicity in Leber’s hereditary optic neuropathy

Leber’s hereditary optic neuropathy (LHON) refers to a group of mitochondrial diseases and is characterized by defects of the mitochondrial electron transport chain and decreased level of oxidative phosphorylation. The list of LHON primary mtDNA mutations is regularly updated. In this study, we describe the homoplasmic nucleotide substitution m.3472T>C in the MT-ND1 (NADH-ubiquinone oxidoreductase chain 1) gene and specific changes in cell metabolism in a patient with LHON and his asymptomatic sister. To confirm the presence of mutation-related mitochondrial dysfunction, respiration of skin fibroblasts and platelets from the patient and his sister was studied, as well as the mitochondrial potential and production of reactive oxygen species in the skin fibroblasts. In addition, based on characteristics of the toxic effect of paraquat, a new approach was developed for detecting the functional activity of complex I of the mitochondrial respiratory chain.