Bulletin of Experimental Biology and Medicine

We studied the involvement of protein kinase Mζ (PKMζ) in the mechanisms of amnesia development within 10 days after disruption of conditioned food aversion memory with ZIP (a PKMζ inhibitor). Repeated training performed in 3 days after amnesia induction with ZIP, led to the formation of conditioned food aversion memory, but the number of combined presentations of food and reinforcer stimuli was lower than during the initial training. Repeated training performed in 10 days after amnesia induction also led to memory formation, but the number of combined presentations of the stimuli was similar to that during the initial training. It was hypothesized that at the early stages of ZIP-induced amnesia, residual memory trace can be restored and amplified during repeated training, which led to memory expression at the behavioral level. At the late stages of amnesia, this memory trace was completely erased and repeated training led to the formation of a new memory. Thus, PKMζ inhibition results in the relatively fast impairment of memory retrieval and induces long-term process of memory erasing.

The effects of neuropeptide Y (10^—9-10^—6 M) on electrical activity of right atrial cardiomyocytes of rats aging 7, 21, and 100 days were examined in vitro. Neuropeptide Y affected the amplitude-temporal parameters of the action potential in these cells. It decreased the duration of repolarization phase in 7-day-old rats in concentrations of 10^—8 and 10^—7 M, in 21-day-old rats at 10^—8 and 10^—6 M, and in 100-day-old at 10^—6 M. The data indicate elevation of total membrane potassium current under the action of neuropeptide Y.

The study was aimed at assessing the role of chemokines in inflammatory changes in tissue following abdominoplasty. The levels of neutrophil-coupled chemokines and their receptors in the serum and blood cells, as well as in cells isolated from the subcutaneous adipose tissue sampled during abdominoplasty were compared in patients with obesity and normal body weight. The levels of chemokines CCL3, CCL3, and CCL5 in blood serum and expression of chemokine receptor CXCR2 and CXCR6 on blood neutrophils were significantly higher (p<0.05) in obese patients in comparison with patients with normal body weight. Elevated expression of chemokines CCL2, CCL3, CCL4, CCL5, CCL18, and CCL20 (p<0.05) was detected in subcutaneous adipose tissue cells isolated obese patients in comparisons with persons with normal body weight. These findings attest to favorable conditions for enhanced neutrophil migration to the adipose tissue in patients with obesity, which can promote leukocyte infiltration of the suture site after abdominoplasty and serves as additional risk factor for the development of postoperative complications associated with activity of neutrophil-derived proteolytic enzymes.

We studied membranotropic properties of NO donor 2-nitroxysuccinate 3-hydroxy-6-methyl-2-ethylpyridine and its structural analog succinate 3-hydroxy-6-methyl-2-ethylpyridine (Mexidol). It was shown that the compounds under study are incorporated into modeled membranes and form long-living complexes with pyrene in the region of fatty acid tails of phospholipids. Luminol-amplified chemiluminescence analysis showed that both compounds exhibited antiradical activity and in a concentration of 0.1 mM reduced chemiluminescence intensity by more than 70%. 2-Nitroxysuccinate 3-hydroxy-6-methyl-2-ethylpyridine inhibited catalytic activity of monoamine oxidase A more efficiently than its structural analogue Mexidol.

Gut microbiome of adolescents with obesity and different duration of breastfeeding was analyzed by metagenomic analysis of V3-V4 variable domains of the 16S rRNA gene. In subgroup with breastfeeding duration <3 months, intrapopulation structure of gut microbiome by alpha diversity indices was similar in adolescents with obesity and normal body weight. The decrease in phylotype abundance in the structure of communities was associated only with obesity, while dysbiotic state persisted in both lean and overweight adolescents, which confirmed the effect of breastfeeding duration on stability of gut microbiome.

Five cytological types of hepatocellular carcinoma-29 (G-29) grown in the muscle tissue of the thigh of experimental animals were identified by transmission electron microscopy; 89% of these were poorly differentiated type I-III cells. Lithium in a concentration of 20 mM produced a damaging effect on poorly differentiated G-29 cells: the number of cells with zones of intracellular component destruction and volume density of these zones increased, while volume density of cisterns of endoplasmic reticulum decreased. These results suggest that lithium carbonate can cause destructive changes in the heterogeneous population of G-29 cells during in vivo tumor development.

Histotopography of lymphocytes expressing bitter taste receptors of T2R family and α-gustducin (receptor-associated subunit of the G-protein complex) in mouse spleen in the norm and in 48 h after intraperitoneal administration of LPS was studied by the immunohistochemical method. Two populations of immunopositive lymphocytes expressing the above proteins were detected in the spleen; they were located in the marginal zones of lymphoid follicles and periarteriolar lymphoid sheaths. In most α-gustducin-positive lymphocytes, co-expression of α-gustducin and CD19 (B-cell marker) was found. Intraperitoneal administration of LPS significantly increased the number of gustducinergic lymphocytes in periarteriolar lymphoid sheaths. We hypothesize that spleen lymphocytes with gustducin signaling are involved in T-dependent immune response to the blood bacterial polysaccharides.

Prostatotropic activity of (3,5-dimethyl-4-hydroxy)benzyl thiododecane (T-DD) was evaluated on a model of benign prostatic hyperplasia induced in Wistar rats by chronic (2 months) intraperitoneal administration of sulpiride (40 mg/kg). Morphometric analysis of the dorsolateral lobe of the prostate showed that after the 2-month course of intragastric T-DD (100 mg/kg) administered in parallel with sulpiride, the volume density of glandular epithelium decreased by 1.7 times, while the volume density of prostate stroma increased by 2 times. After administration of the reference drug Permixon at a dose of 50 mg/kg, the volume densities of epithelium decreased by 1.3 times and stromal volume density increased by 1.5 times. The observed effects are presumably related to suppression of 5α-reductase activity and modulation of estrogen receptors in the prostate.

The potentialities of postmortem MRI for differential diagnosis of stillbirth and death of a live newborn are studied. The results of MRI and pathomorphological studies of autopsy material from 20 stillborns dead at weeks 22-40 of gestation (group 1) and 19 newborns dead at the age of 2 h to 36 days (group 2) are analyzed. Control group has been formed from 7 live newborns aged 1-7 days. Postmortem MRI provides an objective quantitative evaluation of the intensity of MR signal in various tissues and regions. Calculation of the proportions of MR signal intensities in the lung tissue and environmental air and/or pleural fluid and the respiration values promotes an objective differential diagnosis of stillbirth and death of a live newborn. These data are expected to facilitate clearing out the circumstances and the direct cause of death. However, postmortem MRI cannot completely replace autopsy with complex macroscopic and microscopic studies of organs and tissues.

We studied the involvement of cAMP/PKA signaling in the realization of the growth potential of neural progenitors and secretion of neurotrophic growth factors by glial elements under conditions of ethanol-induced neurodegeneration in vitro and in vivo. The stimulating role of cAMP and PKA in cell cycle progression of the neural progenitor cells and in production of neurotrophins by the cells in nervous tissue under the optimal conditions to vital activity was demonstrated. Ethanol inverted the role of cAMP/PKA signaling pathways in determination of the proliferation-differentiation status of neural stem cells. Selective blockade of adenylate cyclase or PKA in neural stem cells increased the rate of their division against the background of relative decrease in differentiation rate. In addition, cAMP/PKA signaling does not longer participate in neurotrophin production by glial cells in neurodegeneration. These findings suggest that inhibitors of activity/expression of adenylate cyclase and PKA can be considered as possible drugs with regenerative activity for the treatment of nervous system pathologies provoked by alcohol.

Generation of ROS (including free radicals) in rat platelets during physical exercises of different intensities was evaluated by the chemiluminescent method. The acute or chronic submaximal exercises increased the platelet chemiluminescence by 2.5-3.0 times. In the control, platelet activation with physiological aggregant ADP enhanced their chemiluminescence by 7.5 times. Addition of ADP to platelets isolated from animals subjected to exercise of any intensity increased chemiluminescence by 4-5 times. In a trained organism, functional reserve of the platelets is preserved during long-term physical exercise of any intensity, but is exhausted after acute physical exercise. Thus, intensive physical exercises enhanced the hemostatic potential of the blood, which is associated with the risk of thrombohemorrhagic complications, especially in acute or submaximal long-term exercises.

Comparison of the cognition-stimulating effects of Dimebon in a wide dose range revealed a non-monotonic and nontrivial wave-like dose-dependence of its activity. Positive results were obtained at low (0.02-0.05 mg/kg) or high (5-10 mg/kg) doses of Dimebon, while intermediate doses were ineffective. This type of the dose dependence of the pharmacological effect can indicate that the substance has several targets. This fact should be taken into consideration when selecting the doses and concentrations of the substance and its analogues for further studies, and for planning treatment schemes and administration doses in clinical studies.

We studied the effect of Leu-Ile-Lys tripeptide on the course of experimental oxalate nephrolithiasis modeled in rats by administration of 1% ethylene glycol solution instead of drinking water for 6 weeks. The Leu-Ile-Lys tripeptide obtained by chemical synthesis (purity ≥98%) was administered through a gastric tube (11.5 mg/kg in 1 ml saline). Administration of Leu-Ile-Lys tripeptide against the background of experimental oxalate nephrolithiasis significantly alleviated the course of experimental pathology, which was confirmed by typical biochemical and morphological changes: decrease in urinary activity of γ-glutamyltransferase (by 2.1 times in comparison with the initial level) and intensity of oxidative stress (the content of TBA-reactive products decreased by 1.3 times in comparison with that in untreated animals) and increase in glutathione peroxidase activity by 1.8 times; no histological signs of nephrolithiasis were found in animals treated with the tripeptide.

We studied ntimicrobial activity of L. plantarum strain against different pathogens: Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus aureus. It was shown that supernatant of 48-h L. plantarum culture in liquid nutrient medium exhibits inhibitory activity against gram-positive and gram-negative pathogenic microorganisms. Supernatant of 24-h culture exhibited lower activity, while supernatant of 72-h culture produced no inhibitory effect. Boiling and proteinase K treatment did not affect activity of the preparation, i.e. antimicrobial activity of the supernatant was not associated with protein or peptide component. These data were confirmed by the results observed after ultrafiltration of the preparation: the growth of E. coli, P. aeruginosa, and S. aureus was inhibited by the low-molecular-weight fraction, but not high-molecular-weight fraction of the supernatant. On the other hand, the high-molecular-weight fraction suppressed the growth of streptococcus by 3 times. We hypothesized that L. plantarum supernatant obtained in our experiments contained at least two antimicrobial components with different molecular weights.

The correlation of gene polymorphisms rs4025935 (large deletion), rs1695 (313A>G), rs71748309 (large deletion), and rs1800566 (609C>T) of GSTM1, GSTT1, and NQO1 genes encoding glutathione-S-transferases (GST) M1, P1, and T1 and NADPH-quinone oxidoreductase with the risk of development of classical Ph-negative myeloproliferative neoplasms (polycythemia vera, essential thrombocythemia, and primary myelofibrosis) was studied in the Caucasian ethnicity population of Vyatka region of the Russian Federation. It was found that NQO1*609T allele, NQO1*609T genotypes, and homozygous carriage of a deletion (null) allele of GSTT1 gene are associated with the risk of development of myeloproliferative neoplasms (OR=1.29, 95%CI=1.02-1.64, p=0.04; OR=1.39, 95%CI=1.04-1.85, p=0.03; and OR=1.48, 95%CI=1.03-2.12, p=0.03, respectively). However, no influence of GSTM1 and GSTP1 gene polymorphisms on the risk of development of myeloproliferative disorders was registered.

Copy number variation of some gene loci in lung tumor cells extracted by laser capture microdissection and in cell-free DNA in the plasma of patients with lung cancer was analyzed for identification of potential molecular markers. Tissue specimens fixed in formalin and embedded in paraffin blocks (FFPE-blocks) from 90 patients and extracellular DNA from plasma samples of 70 patients and 30 donors were used. Copy number variation was assayed for 30 genes (BAX, BCL2, C-FLAR, P53, MDM2, CASP9, CASP3, CASP8, SOX2, OCT4, PIK3, MKI67, HV2, HIF1A1, XRCC1, MMP1, TERT, CTNNB1, KRAS, EGFR, GRB2, SOS1, MAPK1, STAT1, BRAF, FTO, and mir3678) and reference loci (ACTB, B2M, and GAPDH) by the real-time quantitative PCR. Changed copy numbers were detected for genes responsible for apoptosis regulation (BAX, P53, and CASP3), proliferation (SOX2), DNA reparation (XRCC1), oxidative phosphorylation (HV2), EGFR signaling pathway (GRB2, SOS1, MAPK1, STAT1, and BRAF), and for mir3678 gene in lung tumor cells and extracellular DNA.

Antibacterial activity of powdered preparations based on copper and silver nanoparticles was compared with activity of the reference preparation Baneocin on the model of local staphylococcal infection in white rats. The developed preparations exhibited pronounced antibacterial activity against methicillin-resistant S. epidermidis strains in vivo significantly (p<0.001) exceeding that of Baneocin, reduced microbial contamination of the wound on day 5 of study by 2 lg and more in comparison with bacterial load before treatment, and provided effective decontamination of the wound within 7-10 days.

The study examined the relationships between SERCA2a expression in the myocardium and structural and functional indices in patients with atrial fibrillation. In uniform cohort of patients, this expression differed significantly but positively correlated with the size of the left atrium, end-systolic volume, and end-diastolic volume. In contrast, SERCA2a expression negatively correlated with early (peak E) and late (peak A) diastolic filling rates in left ventricle. SERCA2a expression was also associated with echocardiographic parameters reflecting structural and functional status of the heart in patients with persistent atrial fibrillation.

We performed an electron microscopic study of samples of urethral polyps obtained from 90 women (mean age 52.5±4.9 years). According to PCR and culture studies, the most common infectious agent in patients with urethral polyps is U. urealyticum (100% cases). In 70% cases, this infectious agent was present as monoinfection, of these, clinically significant concentration (>10⁶ CFU/ml) were found in 53.3% cases. In 30% cases, associations with C. trachomatis, T. vaginalis, and M. genitalium were found. We observed significant ultrastructural heterogeneity of the epithelial cells in urethral polyps, which manifested in a combination of hyperplastic and metaplastic changes and signs of cytodestruction. Detection of mycoplasma-like bodies in connective tissue mononuclear cells and viral particles in epithelial cells during ultrastructural study, including cases with negative PCR results, indicates the pathogenetic role of latent infection in the formation of urethral polyps.

We developed a technological accessory bacteriophage-based preparation and a method for phage-mediated bioprocessing for elimination of pathogenic microorganisms from the surface of fresh fish and for prolongation of the shelf-life of chilled hydrobionts. Specimens of rainbow trout (Salmo irideus) served as the objects of the study carried out at a fish-processing plant in the Republic of Karelia. The specimens were decontaminated by a bacteriophage cocktail containing six original virulent phage strains characterized by their pheno- and genotypical properties. A new method of biodecontamination (plunging the rainbow trout for 30 sec into a solution of bacteriophage cocktail (bacteriophage titers ≥10⁸ PFU/ml) delayed bacterial degradation of hydrobionts by 3 days. The use of the new method for decontamination of food half-products — phage-mediated bioprocessing — promoted preservation of the initial ecological purity, nutritive value, and taste of the products and prolonged their shelf-life in comparison with the actual standards.