Real-Time Fluorescence Visualization and Quantitation of Cell Growth and Death in Response to Treatment in 3D Collagen-Based Tumor Model.

The use of 3D in vitro tumor models has become a common trend in cancer biology studies as well as drug screening and preclinical testing of drug candidates. The transition from 2D to 3D matrix-based cell cultures requires modification of methods for assessing tumor growth. We propose the method for assessing the growth of tumor cells in a collagen hydrogel using macro-scale registration and quantification of the gel epi-fluorescence.

Hybrid Proteins with Short Conformational Epitopes of the Receptor-Binding Domain of SARS-CoV-2 Spike Protein Promote Production of Virus-Neutralizing Antibodies When Used for Immunization.

Based on the previously developed approach, hybrid recombinant proteins containing short conformational epitopes (a.a. 144-153, 337-346, 414-425, 496-507) of the receptor-binding domain (RBD) of SARS-CoV-2 Spike protein (S protein) were synthesized in Escherichia coli cells as potential components of epitope vaccines.

Comparative Analysis of Cell-Cell Contact Abundance in Ovarian Carcinoma Cells Cultured in Two- and Three-Dimensional In Vitro Models.

Tumor resistance to therapy is associated with the 3D organization and peculiarities of the tumor microenvironment, of which intercellular adhesion is a key participant. In this work, the abundance of contact proteins was compared in SKOV-3 and SKOV-3.ip human ovarian adenocarcinoma cell lines, cultivated in monolayers, tumor spheroids and collagen hydrogels.

Use of paracrine factors from stem cells to treat local radiation burns in rats.

Background: Mesenchymal stem cells based paracrine bioactive factors that deploy their task as an essential mechanism, but their efficiency for skin regeneration still requires clarification.

Methods: The mesenchymal stem cell-based paracrine factors were administered by subcutaneous injection of 0.5 mL peptides (general protein 8 mg/mL).

A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones suppresses Salmonella infection in vivo.

Therapeutic strategies that target bacterial virulence have received considerable attention. The type III secretion system (T3SS) is important for bacterial virulence and represents an attractive therapeutic target. A novel compound with a predicted T3SS inhibitory activity named CL-55 (N-(2,4-difluorophenyl)-4-(3-ethoxy-4-hydroxybenzyl)-5-oxo-5,6-dihydro-4H-[1,3,4]-thiadiazine-2-carboxamide) was previously characterized by low toxicity, high levels of solubility, stability and specific efficiency toward Chlamydia trachomatis in vitro and in vivo.

[Role of phage LØ7 lysogeny in genetic variability of Escherichia coli].

Aim: Determine the possibility of Iysogenization of Escherichia coli single strain DNA (ssDNA) by 1ø7 bacteriophage from the Microviridae family and determine the role of phage lø7 lysogeny in genetic variability of these bacteria.

Materials And Methods: A method of E. coli K12 lysogenization by phage lø7 was developed.

[Experimental model of severe local radiation injuries of the skin after X-rays].

The experimental model of severe local radiation injuries skin under the influence of a relatively soft X-rays on a modified device RAP 100-10 produced by "Diagnostica-M" (Russia) was proposed. The model can be used as pre-clinical studies in small experimental animals in order to improve the treatment of local radiation injuries, especially in the conditions of application of cellular therapy.

[Sensor systems for medical application based on hemoproteins and nanocomposite materials].

Recent advances in nanotechnologies stimulate the development of sensor systems based on nanocomposite materials. This review discusses the prospects and challenges of sensors coupled with functionally important for medicine hemoproteins and nanoscale materials. Authors summarized their own experimental results and literature data on hemoprotein-based sensor systems.

[Precise excision of TN5 in Escherichia coli K12 mutants with alterations in common component of phosphotransferase system and in subunits of DNA-gyrase].

The effect of ptsH and gyrA mutations on precise excision (PE) of transposon Tn5 was studied in Escherichia coli K12. The conjugative plasmid with Tn5 integrated in the tet gene of Tn10 was used as a model in experiments. It was shown that mutational damage of HPr, a common component of the bacterial PEP-dependent phosphotransferase system (PTS), increased the frequency of PE.

[The influence of Bordetella pertussis bvgAS operon on formation and resolution of plasmid-chromosome cointegrates in Escherichia coli K12 mutants with damages in common components of the phosphoenolpyruvate:sugar phosphotransferase system].

The plasmids containing the genetically marked variants of Bordetela pertussi transposon TnBP were synthesized on the base of the plasmid with thermosensitive replication. The integration frequency of these plasmids into the E.coli K12 chromosome at non-permissive temperature (42 degrees C) was determined.

[An experimental model of studynig radiation oppression of antitumor resistance].

In experiences on mice (CBA x C57Bl) F1 the experimental model for studying action of radiation on antineoplastic resistance is developed. Adequate ways of statistical processing of the received data testifying to amplification of tumoral growth in the irradiated organism are offered. The use of model of the solid form of the tumor developing after introduction in a shin of a hinder leg of the mouse of 1000 cells ascetic carcinoma of Ehrlich in a combination to radiating depression of antineoplastic resistance at animals after an irradiation on installation IGUR (137Cs) in a doze 6 Gy is proved.

[Nitrogen assimilation enzymes in Bacillus subtilis mutants with hyperproduction of riboflavin].

Three groups of the nitrogen assimilation cycle enzymes (glutamate synthases (GTS), glutamine synthases (GS), and glutamate dehydrogenases (GD)) were studied in Bacillus subtilis strains with hyperproduction of riboflavin (vitamin B2). It was found that in all strains tested activity of GS was virtually the same, activity of GD was absent, and activity of GTS was reduced. In strains 41 and 24, riboflavin producers, activity of GTS was 30-60% the enzyme activity in the original strain (wild-type RosR).

[Quantitative regularities and peculiarities of the development of the cerebral form of radiation sickness at fractionated irradiation].

Several peculiarities in manifestations of cerebral form of radiation sickness have been revealed at a fractionated double irradiation with equal and unequal doses per fraction and different intervals between the fractions. A reliable increase in average lifespan of rats irradiated with (100 + 100 Gy) equal doses at 10 and 60 min intervals between two fractions compared to the single radiation exposure to 200 Gy has been obtained. Lifespan of rats irradiated with a total dose greater than 200 Gy in most cases of double exposures with 10 min interval was reliably less than that for animals after a single exposure.

[Identification of the open reading frame coding transposase of Bordetella pertussis RS-element].

A computer-aided analysis of the repeating sequence of Bordetella pertussis chromosome (RSBP3) revealed 3 open reading frames, one of whose (ORF1) can code a protein whose structure and properties are similar to those of transposasas, i.e. enzymes in charges for the traveling of migrating genetic elements of pro- and eukaryote.

[Properties of mutants of bacteria belonging to the genus Erwinia devoid of common components of the phosphoenolpyruvate-dependent phosphotransferase system].

Biochemical consequences of mutational damage to common components of the Erwinia phosphoenolpyruvate-dependent phosphotransferase system (the HPr protein and enzyme I) were studied. The transport of glucose, mannose, fructose, and mannitol in Erwinia was shown to require a preliminary induction of proteins of the phosphotransferase system. A drastic decrease in the rate of the transport of these carbohydrates was observed in ptsI and ptsH mutants.

[The multifunctional fructose-specific component of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli K12--fruA gene product].

Mutational damage of the ptsH gene leads to pleiotropic disturbance of sugar utilization in Escherichia coli K12. A fruS mutation suppresses the defect because of a constitutional expression of the fruB and fruA genes. FruB protein possessing a pseudo-HPr activity replaces the HPr.

[Isolation and properties of mutants devoid of pseudo-HPr activity of the fructose transfer system in Escherichia coli K12].

Mutants without pseudo-HPr activity intrinsic to the H domain of the FruB protein were obtained in Escherichia coli K12 through insertional mutagenesis by means of the MudIlac phage and TnPhoA transposon. For isolating these mutants, double mutants of enteric bacterium (ptsH fruR of ptsH fruS) were used as original strains. These double mutants were inactive with respect to the total HPr protein of the phosphoenolpyruvate-carbohydrate phosphotransferase system and could not provide constitutive synthesis of fructose-specific proteins of this system.

[Determination of the direction of transcription of Escherichia coli K-12 structural genes of the fructose regulon in vivo].

The direction of transcription of specific components of the fructose phosphotransferase system, the fruA, fruK, and fruB genes, was determined in vivo by plasmid F'ts1141ac. Transcription from each of these genes was shown to run in the same direction, counterclockwise with respect to the E. coli chromosomal map.

[Reparation of hepatocyte mitochondrial membranes using phosphatidylcholine liposomes].

The influence of multibilayer phosphatidylcholine liposomes on the properties of rat hepatocyte mitochondria membranes damages caused by hepatotropic toxin--CCl4 was investigated. Alterations of the membrane structure were estimated by the decrease in phospholipid/protein ratio /by 33%/ and via changes of quantitative and qualitative composition of phospholipid components. The possibility of reparation of the hepatocytes mitochondria damaged membrane by egg yolk phosphatidylcholine liposomes is shown.

[Reparation of the hepatocyte plasma membrane using phosphatidylcholine liposomes].

Rat hepatocyte plasmatic membrane damages caused by the administration of tetrachloromethane of heliotrine was investigated. Phospholipid content in plasmatic membranes decreased. Heliotrine caused complete and CCL4 twofold inhibition of Na, K-ATPase.

[Mutation fruB in the fructose regulon affecting beta-galactosidase synthesis and adenylate cyclase activity of E. coli K12].

Escherichia coli mutant devoid of fructosespecific factor III (factor IIIfru) of phosphoenolpyruvate (PEP) carbohydrate phosphotransferase system was isolated. The mutation fruB was localized on 46 min of chromosomal map of Escherichia coli in the fru-operon region. The mutant bacteria are unable to accumulate fructose.

[Use of phospholipids to repair rat liver membranes during carbon tetrachloride poisoning].

The effect of phospholipid multilayer liposomes on the properties of endoplasmic reticular membranes has been studied in hepatic cells damaged with CCl4. It has been shown that the repair effect of phosphatidylcholine liposomes was manifested in vivo by normalization of phospholipid membrane composition, reduction in the degree of cytochrome P-450 inactivation, partial normalization of its hydroxylase activity and recovery of glucose-6-phosphatase activity. The degree of phosphatidylcholine unsaturation, and the introduction of antioxidants--SH-compounds, sphingomyelin, phosphatidyl inositol--into liposomes did not influence the efficacy of liposomes.

[Phosphatidylcholine-induced repair of damaged hepatocyte membranes in heliotrine poisoning].

Hepatocyte membranes destruction in experimental toxic hepatitis caused by heliotrine administration was accompanied by a 10-fold increase in blood serum activity of aldolase fructose-I-monophosphate, a decrease in cytochrome P-450 content, an increase in the rate of cytochrome P-450 inactivation, as well as a decrease in microsomal glucose-6-phosphatase activity. Administration of phosphatidylcholine liposomes decreased the activity of aldolase twofold, which indirectly shows partial reconstitution of liver cell membranes. Phosphatidylcholine protective action is also manifested in an increase in the activity of glucose-6-phosphatase, a microsomal marker enzyme, up to its control level and in a 20% reduced rate of cytochrome P-450 inactivation.