Vol 166, No 6 (2019)

An original concept of a two-stage mechanism of positive reinforcement is proposed. The first stage, “virtual” reinforcement, is formed in parallel with the action result acceptor when the result is still not achieved. At this stage, the importance of the planned result and the probability of its achievement are assessed. The greater are these indices, the stronger is “virtual” reinforcement. Hypothetically, the “virtual” reinforcement is mediated by dopamine release from nerve terminals in the mesencephalon. The “real” reinforcement (the second stage) occurs after achievement of the result. Probably, an important role in the mechanisms of the “real” reinforcement is given to endogenous opioids, cannabinoids, and GABA. Based on the advanced hypothesis on interaction between the central and peripheral subdivisions of the corresponding neurochemical systems, the review focuses on possibility of pharmacological intervention into the mechanisms of positive reinforcement by modifying activity of the peripheral opioid and dopamine receptors with the ligands that cannot cross blood—brain barrier.

Specific features of neurological deficit and changes in the cellular composition of tracheal lymphoid structures during the immediate stage (day 1) of hemorrhagic stroke were studied in rats with various behavioral parameters. Modeling of hemorrhage in the left caudate nucleus of the brain was followed by the development of motor disturbances in the forelimb use asymmetry test and corner rotation paradigm. These animals preferred to use the left forelimb (ipsilateral to the side of hemorrhage) to lean on the cylinder wall. The frequency of using the right forelimb or both forelimbs was reduced under these conditions. The number of left-sided rotations increased, while the percentage of right-sided rotations decreased. The observed changes were accompanied by immune dysfunction. It was manifested in the depletion of lymphoid aggregates of the tracheal wall in lymphocytes and plasma cells. The severity of abnormal neurological symptoms and disturbances in immune homeostasis during the immediate stage of hemorrhagic stroke was greater in behaviorally passive rats than in active specimens.

Pulmonary edema is the major factor of tissue hypoxia in acute lung injury. Disruption of cell—cell contacts and lung interstitium increases permeability of the vascular endothelium and alveolar epithelium, which leads to the development of pulmonary edema. Meprin metalloproteases cleave extracellular matrix proteins, thus aggravating pulmonary edema. Meprin inhibitor actinonin was administered to rats with LPS-induced acute lung injury. Damaged lungs looked spotted and had multiple hemorrhage focuses, protein concentration in lavage fluid was increased, and lung weight coefficient was high. Administration of meprin inhibitor actinonin considerably reduced protein content in the bronchoalvelolar lavage and lung coefficient; only solitary lung hemorrhages were seen after this treatment. Thus, inhibition of meprins potentially alleviates LPS-induced disorders in the lung tissue permeability and reduces pulmonary edema.

Autonomic regulation of the heart was examined in 5 groups of rats: intact, sham-operated, experimental chronic obstructive pulmonary disease, acute cerebral ischemia, and acute cerebral ischemia modeled against the background of chronic obstructive pulmonary disease. The latter was provoked by combination of inhaled papain and intraperitoneal bacterial LPS, whereas acute cerebral ischemia was modeled by single-stage bilateral occlusion of the common carotid arteries. Chronic obstructive pulmonary disease was verified by X-ray computed microtomography. The disturbances in autonomic control of the heart during comorbid pathologies were most prominent; they were manifested by overstrain and decompensation of the mechanisms implicated in the heart control and systolic-diastolic arterial hypotension. The correlations were established between blood oxygenation, respiration rate, and some parameters of autonomic cardiac regulation. The data attest to relevance and usefulness of the developed model of respiratory and cerebrovascular comorbidity in assessment of pathophysiological mechanisms underlying dysregulation of the heart and the development of personalized approaches for its pharmacological correction.

Activities of noncompetitive NMDA receptor antagonists (aminoadamantane derivatives) were assessed in random-bred rats with modeled morphine withdrawal syndrome. A single intraperitoneal injection of hemantane (10 or 20 mg/kg) significantly and dose-dependently moderated some behavioral symptoms (teeth-chattering, ptosis, and vocalization) and reduced total score of morphine withdrawal syndrome. In morphine-abstinent rats, hemantane partially prevented the decrease in the thresholds of tactile sensitivity, but had no effect on locomotor activity and body weight loss. Under conditions of morphine withdrawal, intraperitoneal injection of amantadine (10 or 20 mg/kg) decreased motor activity and promoted body weight loss in parallel with the development of mechanical allodynia, but had no effect on the total withdrawal score. Comparison of aminoadamantane derivatives by behavioral and physiological parameters demonstrated the advantage of hemantane during morphine abstinence indicating the need of its study as a promising anti-addiction remedy.

Antithrombotic activity of a novel tricyclic derivative of diazepino[1,2-α]benzimidazole (DAB-15) was examined on the model of arterial thrombosis developed in rats without concomitant pathology and in rats with experimental myocardial infarction. DAB-15 demonstrated high antithrombotic efficacy in modeled thrombosis of carotid artery in rats without the concomitant pathology surpassing that of the reference drugs acetylsalicylic acid and clopidogrel by 5.1 and 4.8 times, respectively. In rats with experimental noncoronary myocardial infarction, DAB-15 increased the thrombus formation time by 86.2% in comparison with experimental control level in non-treated rats with similar myocardial infarction.

Campylobacter genus bacteria causing campylobacteriasis are difficult to culture. This fact necessitates creation of special approaches to studies of the behavior of these pathogens during the manufacture and storage of foodstuffs. The regularities of Campylobacter jejuni transition into an uncultivable state are studied under conditions simulating the process of immersion cooling of fresh poultry products. The proportion of viable colony-forming (CFU) cells to the total count of planktonic and uncultivable cells in the population was calculated by the level of genomic DNA in the samples evaluated by quantitative real-time PCR with intercalating dyes. PCR was carried out with primers detecting the cytolethal toxin subunit B gene cdtB and invasion gene ciaB in C. jejuni strains. The count of detected cells was 5-10-fold higher than the count of CFU; the cultural method failed to detect the agent in 40% analyzed samples of superficially infected products, while the level of uncultivable cells detected by PCR was significantly higher. The relationship between culturing conditions and formation of C. jejuni biofilms was studied. The most intensive formation of film exomatrix was observed under unfavorable conditions for this microorganism at 25oC. In microaerophilic gaseous medium, weak formation of films and intensive growth of C. jejuni populations were observed. Culturing at higher temperatures (37-42oC) was in fact inessential for the film formation process.

The cytotoxicity and antioxidant effects of chitosan-(poly)nitoxides of different molecular weights containing a nitroxide radical of the piperidine structure were studied on tumor (HeLa, A172, and HepG2) and normal (Vero) cell lines. The chitosan-(poly)nitroxides exhibited low cytotoxicity. Under conditions of oxidative stress induced with tert-butyl hydroperoxide, the most pronounced decrease in ROS levels in the presence of chitosan-(poly)nitroxides was observed in normal cells. In cell homogenates, the decrease in malondialdehyde levels was observed only in the presence of low-molecular-weight chitosan-(poly)nitroxide irrespective of the cell line. Our data demonstrate that the cell-specific antioxidant properties of chitosan-(poly)nitroxides are related to their penetration into cells and interaction with intracellular membranes.

We studied the intensity of age-specific changes in the dermis (number and proliferative activity of fibroblasts) in mice with normal and experimentally changed level of thyroid hormones. Receptors of thyroid hormones, TR-α and TR-β, in mouse dermal fibroblasts were identified by immunohistochemical methods. The relative expression of Thra, Thrb, and Dio2 genes was assessed by real-time PCR analysis. From the second to fifth month of life, the number of fibroblasts in the connective tissue layer of mouse skin decreased by 42.3%. The number of fibroblasts in the dermis of 5-month-old mice treated with Thyrozol significantly decreases by 25.9% (p<0.05), and vice versa, in mice receiving thyroxin this parameter increased by 4.7% in comparison with the control (p>0.05). TR-α and TR-β were identified in dermal fibroblasts in all groups of mice. No differences in the content TR-α and Thra gene expression in 2- and 5-month-old mice of the control and experimental were revealed. TR-β content in dermal fibroblasts of 2-month-old animals was maximum and exceeded this value in 5-month-old control mice by 25%. The number of these receptors decreased by 33.3% in mice treated with Thyrozol and increased by 25% in animals receiving thyroxin injection in comparison with the control. Relative expression of Thrb gene significantly increased only in mice treated with thyroxin. Comparative analysis of the relative expression of Dio2 gene revealed no differences between the experimental and control groups. Changes in the level of thyroid hormones, content of TR-β, and relative Thrb gene expression contribute to agerelated shifts in the number and proliferative activity of mouse dermal fibroblasts.

We studied the effects of in vivo modulation of activity of mitochondrial ATP-dependent potassium channel (mitoK_ATP) by uridine on the morphofunctional state of mitochondria in rat cardiomyocytes under conditions of acute hypoxia. Preinjection of uridine to animals reduced the number of structurally modified mitochondria, but had practically no effect on their morphogenesis after hypoxia. Uridine in vivo stimulated the formation of micromitochondria and their release into the cytoplasm. The number of “maternal” mitochondria containing three and more new micromitochondria, increased as well. The use of mitoK_ATP blocker 5-hydroxydecanoate in parallel with uridine abolished its protective effect, as it significantly inhibited the formation of micromitochondria in rat cardiomyocytes after acute hypoxic exposure.

Antiviral drug Kagocel in concentrations of 0.0008, 0.004, 0.02, 0.1, 0.5, and 2.5 mg/ml with or without metabolic activation does not induce gene mutations in S. typhimurium strains ТА98, ТА100, ТА1535, and ТА1537 and in a combination of E. coli strains pKM101 and uvrA. A single intragastric administration of Kagocel in a daily therapeutic dose and a 10-fold daily therapeutic dose to male mice or multiple administrations in daily therapeutic dose to male and female mice did not led to a significant increase in the percentage of chromosomal aberrations in the bone marrow cells. DNA comet assay revealed no significant increase in the incidence of DNA breaks in cells of mouse testes after single or multiple administration of Kagocel at daily therapeutic and 10-fold daily therapeutic doses. Our results indicate that Kagocel exhibits no genotoxic activity in the studied dose range.

In vivo experiments showed that antibodies to OmpC and OmpF porins of Yersinia pseudotuberculosis increased thyroxine (T4) level in the blood of experimental animals. The mice were immunized with different antigens: recombinant OmpF porin in a soluble monomeric form, trimers of OmpC and OmpF porins isolated from the outer membrane, or antibodies to them. The level of thyroxine in the blood of mice immunized with OmpF and OmpC porins increased by 5.47 and 22.3 times, respectively; after immunization with antibodies to these proteins, blood thyroxine increased by 9.28 and 14.29 times. Immunization with recombinant OmpF porin induced no reliable increase in thyroxine level. Hence, the serum to recombinant OmpF porin contains no antibodies specific to conformational antigenic determinants that are present in the protein trimer and, according to our previous findings from molecular docking studies, determine cross-reactions between OmpF porin of Y. pseudotuberculosis and thyroidstimulating hormone receptor.

Plant lipid transfer proteins and homologues of the main birch pollen allergen Bet v 1 are involved in the development of allergic reactions of varying severity to plant foods and pollen. In this study, the sera from patients with tree and weed pollen allergies in the Moscow region were examined. The levels of IL-4, IL-5, IL-9, IL-10, IL-13, IL-17A, IFNγ, TNFα, and TNFβ cytokines were determined in the sera of patients with specific IgE antibodies to Bet v 1 and Pru p 3 allergens. It was confirmed that patients with pollen allergy are often characterized by Th2 response of the immune system, though other mechanisms of allergy development occurred in some cases. The data obtained demonstrate the necessity of detailed analysis of the individual mechanism of allergic reactions and patient-centered approach to the personalized allergy treatment.

We performed immunohistochemical analysis of the expression of TGFβ, galectin-1, vimentin, and thrombospondin in the mucosa in gastric cancer of diffuse and intestinal type associated with systemic undifferentiated connective tissue dysplasia. In diffuse gastric cancer, both with and without association with connective tissue dysplasia, a higher level of expression of TGFβ, galectin-1, vimentin, and thrombospondin in the tumor was detected in comparison with the perifocal and tumor zones in intestinal gastric cancer, which may reflect the pathogenetic peculiarities of the two histotypes of gastric cancer. Intestinal type of gastric cancer associated with connective tissue dysplasia is characterized by a high level of expression of galectin-1 and vimentin in the perifocal zone and TGFβ in the tumor zone. The pattern of expression of the studied markers can reflect both the pathogenetic peculiarities of the two histotypes of gastric cancer and peculiar expression of some growth factors, cytoskeleton proteins, and matrix-cell proteins associated with undifferentiated connective tissue dysplasia which may contribute to epithelial—mesenchymal transition.

The effect of low concentrations of miRNA on the ability of GeneChip miRNA 4.0 hybridization chips to evaluate their representation in the sample was studied. It is shown that the evaluation of the expression of 61 miRNAs is statistically significantly associated with the multiplicity of plasma dilution. Only 12 miRNAs showed very high Pearson correlation coefficient (>0.95) and they all decreased in response to dilution. High abundance of has-miR-4532 miRNA in plasma was demonstrated. This miRNA was never detected during sequencing of similar samples. It was concluded that in case of miRNA expression <1.12±0.33 units in log2 scale, dilution was not followed by further decrease in the signal intensity in GeneChip miRNA 4.0 chips.

One of the most common models of sporadic form of Alzheimer’s disease is injection of streptozotocin into the lateral ventricles of rat brain. In 3 months after this injection, an increase in the expression of astroglia in the corpus callosum and a decrease in the thickness of the corpus callosum and intensity of its staining with luxol fast blue were observed. This can reflect a decrease in the content of myelinated fibers. In layer V of the sensorimotor cortex, intensive degeneration of neurons was revealed. The lateral ventricles were significantly enlarged and the expression of PSA-NCAM protein, a marker of immature neurons, was reduced in subventricular zone, which can be associated with disturbed neurogenesi

Intraocular neurografts of the septal region of rats were used as the model of deafferentiated brain area where the lack of adequate innervation is compensated for own interneuronal connections. Septum anlage from the brain of a 17-day fetus served as the donor material. The grafts developing in the anterior eye chamber over 3 months represented well-differentiated samples of the nervous tissue. A comparative morphometric study of the tripartite organization of synapses in the grafts and in the septum in situ was conducted. In the grafts, the mean volume and perimeter of synaptic terminals were below the normal. At the same time, postsynaptic densities did not differ from the control. A significant difference was found in the degree of surrounding of presynaptic terminals by astrocytic processes: in the grafts this parameter was higher by 1.8 times. Our results attest to an important role of perisynaptic glia in the formation of functionally active synaptic contacts with unusual neuronal targets.