Approbation of a New Model of Secondary Damage after Traumatic Brain Injury Based on Reprogrammed Rat Embryo Fibroblasts.

The paper presents a new model of secondary injuries after traumatic brain injury. The model is based on the cultivation of rat embryonic fibroblasts reprogrammed to a neuronal phenotype in the presence of cerebrospinal fluid from injured rats. The presented model was used to test the therapeutic effect of inducers of the synthesis of chaperones from the classes of pyrrolylazines and indolylazines, which have neuroprotective properties.

Development of Drugs with Direct Antiviral Action Based on Azaheterocyclic Systems.

This article discusses the results of studies carried out in recent years by a team of scientists from the Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, in cooperation with the First President of Russia Boris Yeltsin Ural Federal University, Ural State Medical University, Volgograd State Medical University, and other scientific and production organizations of the country to create triazavirin (riamilovir) and other direct etiotropic antiviral drugs based on azaheterocyclic derivatives.

Effects of Succinate-Containing Preparation on Characteristics of Rat Erythrocytes in Exhaustive Swimming with a Load.

We studied the dynamics of the red blood cell composition of Wistar male rats at rest and when swimming with a load (4% body weight) before and after administration of a succinatecontaining preparation (meso-2,3-dimercaptosuccinic acid). In rats receiving the succinatecontaining preparation, a decrease in the number of red blood cells and an increase in their volume and absolute and relative number of reticulocytes were observed at rest in comparison with vivarium control. In rats exposed to exhaustive swimming after preliminary administration of the test preparation (12 h before the test), we observed a decrease in hematocrit and erythrocyte diameter in comparison with the corresponding parameters in rats not treated with the preparation; the level of hemoglobin did not change. The pattern of changes in the cellular composition of red blood in rats at rest and during swimming against the background of treatment with the succinate-containing preparation in comparison with vivarium control is considered as a result of its effect on physical exercise under conditions of stabilization of hemoglobin and hematocrit levels, activation of proliferative activity of red bone marrow, and an increase in time of swimming to exhaustion by 2.8 times.

Indolyl- and Pyrrolylazine Derivatives Cause the Accumulation of Heat Shock Protein Hsp70 in Sh-Sy5Y Human Neuroblastoma Cells.

The heat shock protein Hsp70 is involved in cell defense from various types of stress, including the proteotoxic stress, which occurs during the development of many neurodegenerative diseases. This work presents data on the detection of small molecules, derivatives of indolyl- and pyrrolylazines, which can activate the synthesis of Hsp70 and cause its accumulation in the cell. The toxicity level of the new Hsp70 synthesis inducers was evaluated, and the safety of these compounds was demonstrated in experiments on SH-SY5Y neuroblastoma cell line. Derivatives of indolyl- and pyrrolylazines presented in this work can be potential therapeutic agents in models of neurodegenerative diseases that should be studied in more detail.

Silicon-hydroxyapatite‒glycerohydrogel as a promising biomaterial for dental applications.

Nanocomposite silicon-hydroxyapatite‒glycerohydrogel (Si-HA‒glycerohydrogel) with different hydroxyapatite (HA) contents of 0.75 and 1.75 wt.% and the same Si content (2.04 wt.%) was obtained by the sol‒gel method. Silicon tetraglycerolate in the form of glycerol solution was used as a biocompatible precursor and HА in the form of aqueous colloidal suspension - as a template and property modifier. Transmission electron microscopy was applied to demonstrate that there are nanoscale HA particles that are in the crystalline state. For the first time, using the atomic force microscopy method, the remineralizing properties of Si-HA‒glycerohydrogel were studied on human teeth extracted for orthodontic reasons. It was found that Si-HA‒glycerohydrogel containing 1.75 wt.% HA has a pronounced remineralizing effect. Immersion of tooth enamel samples in the gel for one month significantly reduces roughness and makes the enamel surface more uniform. Silicon contained in glycerolates in a biologically active and accessible form exerts an additional positive effect on the process of remineralization of tooth enamel. By the energy dispersive X-ray analysis, it was demonstrated that the tooth enamel had an increased silicon content; and the Vickers microhardness test showed greater microhardness values. The obtained data analysis allows the remineralizing Si-HA‒glycerohydrogel to be considered as a promising biomaterial for dental applications.

Effects of a compound from the group of substituted thiadiazines with hypothermia inducing properties on brain metabolism in rats, a study in vivo and in vitro.

The aim of the present study was to examine how administration of a compound of 1,3,4- thiadiazine class 2-morpholino-5-phenyl-6H-1,3,4-thiadiazine, hydrobromide (L-17) with hypothermia inducing properties affects the brain metabolism. The mechanism by which L-17 induces hypothermia is unknown; it may involve hypothalamic central thermoregulation as well as act via inhibition of energy metabolism. We tested the hypothesis that L-17 may induce hypothermia by directly inhibiting energy metabolism. The study in vivo was carried out on Sprague-Dawley adult rats. Two doses of L-17 were administered (190 mg/kg and 760 mg/kg). Brain metabolites were analyzed in control and treated groups using magnetic resonance spectroscopy, along with blood flow rate measurements in carotid arteries and body temperature measurements. Further in vitro studies on primary cultures from rat hippocampus were carried out to perform a mitochondria function test of L-17 pre-incubation (100 µM, 30 min). Analysis of brain metabolites showed no significant changes in 190 mg/kg treated group along with a significant reduction in body temperature by 1.5°C. However, administration of L-17 in higher dose 760 mg/kg provoked changes in brain metabolites indicative of neurotoxicity as well as reduction in carotid arteries flow rate. In addition, a balance change of excitatory and inhibitory neurotransmitters was observed. The L-17 pre-incubation with cell primary cultures from rat brain showed no significant changes in mitochondrial function. The results obtained in the study indicate that acute administration of L-17 190 mg/kg in rats induces mild hypothermia with no adverse effects onto brain metabolism.

2-Morpholino-5-Phenyl-6H-1,3,4-Thiadiazine Corrects Metabolic Disorders during the Development of Alloxan Diabetes Mellitus in Rats.

Metabolic disorders were evaluated in rats with alloxan diabetes mellitus after administration of 2-morpholino-5-phenyl-6H-1,3,4-thiadiazine (compound L-17). Administration of L-17 reduced the severity of metabolic disorders associated with diabetes mellitus. At the end of the experiment, the concentration of glucose, glycated hemoglobin, malonic dialdehyde, and catalase activity were significantly higher and peroxidase activity was significantly lower in the group of animals receiving L-17. The decrease of glycemia, glucose concentration, and glycated hemoglobin content was reached by the 3rd-4th week of the experiment. These data suggest that correction of biochemical parameters in rats with alloxan diabetes was reached after administration of L-17 for at least 3 weeks.

[Experimental comparative pharmacokinetics of levofloxacin, triazavirin, and related conjugate].

A comparative study of the pharmacokinetics of levofloxacin and triazavirine as well as 2-methylthio-6-nitro-1,2,4-triazolo[5,1-ñ]-1,2,4-triazine-7(4Í)-ide (3S)-(-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-d,e]-1,4-benzoxazine-6-carboxylic acid (conjugate 2) obtained by conjugation of triazavirine and levofloxacin, representing a new class of pharmacological agents, was carried out in experiments on rats. It is established that conjugate 2 in comparison to individual levofloxacin and triazavirine has a higher relative bioavailability and lower rate of elimination, which can lead to improved effectiveness of therapy at reduced dose and frequency of drug administration.

The impact of immunomodulator compound from the group of substituted thiadiazines on the course of stress reaction.

A significant role of the stress response to many different diseases prompted a search for new specialized and non-specialized anti-stress agents. This study examines the effect of the compound L17 from the group of 5-phenyl substituted-6H-1,3,4-thiadiazine-2-amines, on the manifestations of the stress response. The authors used a standard model of immobilization stress, in which an animal was immobilized on its back for 6h a day. Parameters of the morphological and functional states of the organs studied were measured and biochemical and enzyme-immunoassays were carried out on the first and second days. This study reveals that the main mechanism by which the L17 compound mediates of its anti-stress was by activation of macrophages on the second day of the experiments and the inhibition of apoptosis in the thymus. The results enable us to suggest that the compound L17 does not improve resistance to stress; however, it does lower the reaction to stress.

Features of silicon- and titanium-polyethylene glycol precursors in sol-gel synthesis of new hydrogels.

The formation of organic/inorganic hydrogels based on silicon and titanium polyethylene glycolates, new biocompatible water-soluble precursors in sol-gel processing, was investigated. The influence of different factors on the gelation process, such as excess of PEG, water molar content, pH of medium, electrolyte additives, was investigated in comparison with silicon- and titanium-glycerol precursors. The specific features of gelation for each type of precursor were revealed. It has been determined that titanium polyethylene glycolates synthesized and used in the excess of PEG formed transparent polymeric hydrogels resistant to syneresis under certain conditions. The titanium polyethylene glycolates synthesized without excess of PEG formed turbid heterogeneous colloidal gels. In the case of silicon polyethylene glycolates the hydrogels obtained were polymeric. Dynamic light scattering was used to confirm the polymeric or colloidal type of gelation. The solid and liquid phases of polymeric silicon- and titanium-polyethylene glycol hydrogels were separated by exhaustive extraction. The solid phase was characterized by combined thermal analysis with simultaneous quadruple mass spectrometry, XRD, IR spectroscopy, and liquid phase-atomic emission spectroscopy. The structural features of polymeric gels were investigated by SEM and TEM methods. The cross-linking density of polymeric hydrogels was evaluated using Flory-Rehner theory based on the mechanical properties of swollen networks of flexible polymeric chains.

Alkyl 2-arylhydrazinylidene-3-oxo-3-polyfluoroalkylpropionates as new effective and selective inhibitors of carboxylesterase.

A series of alkyl 2-Arylhydrazinylidene-3-oxo-3-polyfluoroalkylpropionates was synthesized and their inhibitory activity with respect to porcine liver carboxylesterase (CaE, EC 3.1.1.1), human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7), and horse serum butyrylcholinesterase (BChE, EC 3.1.1.8) was studied. The molecular docking method was used to study the binding mode of the compounds in the active site of CaE. It was found that compounds containing the trifluoromethyl group in the third position of carbonyl chain are highly effective and selective inhibitors of CaE with nanomolar IC50 values, which agrees well with the results of molecular docking.

[Investigation of Therapeutic Efficacy of Triazavirin Against Experimental Forest-Spring Encephalitis on Albino Mice].

The comparative study of the therapeutic efficacy of Triazavirin against experimental Forest-Spring encephalitis on albino mice vs. the active drug Ribavirin® showed that in high doses (200-400 mg/kg) Triazavirin moderately protected the infected animals. A significant increase of the animal lifespan in the test groups (from 4.1 to 4.8 days) and a statistically (p ≤ 0.05) valid decrease of the virus accumulation in the target organ (the brain) were observed.

[Investigation of Triazavirin antiviral activity against tick-borne encephalitis pathogen in cell culture].

The efficacy of Triazavirin against the tick-borne encephalitis virus was estimated in the sensitive cell culture vs. the active drug Ribavirin. In a concentration of 128 mcg/ml Triazavirin was shown active in inhibition of the tick-borne encephalitis virus reproduction (strain Sofiin) by accumulation in the SKEV cell culture.

Modulation of inflammatory response improves myocardial infarct healing in rats.

It is reputed that the ideal therapeutic approaches to treatment of patients with acute coronary syndrome (ACS) and myocardium infarction (MI) should be aimed at the inflammation reaction triggers. This study investigated the effectiveness of the impact of L- 17 compound of the group of 5- phenyl substituted-6H-1,3,4-thiadiazine-2-amines upon the course of experimental MI as compared to the impact of a preparation, officially registered in Russia as an immunomodulator, Tamerit, belonging to phthalhydrazid derivative substance. Acute MI in rats was induced by left coronary artery coagulation. Histological study of the myocardium sections and biochemical analysis has been carried out at the 1st and 7th days of the experimental MI. The conducted investigations have shown that under the action of immunocorrectors the inflammation reaction character changes, exudative/destructive inflammation is replaced by a proliferative-cellular one. Animals' blood biochemical analysis at the background of L-17 and Tamerit introduction has shown a decrease of aminotransferases and lactatedehydrogenases activity in blood as compared to the reference group of animals' indicators, which is evidently caused by epicardial injury of myocardium and lesser amount of the alternative cardiomyocytes. At the same time, no noticeable difference in biochemical characteristics in groups, having been treated to immunomodulators of different chemical composition was identified, which is the sign of the essential similarity of their impact. Thus, immunocorrectors of different chemical groups (Tamerit and compound L17) diminish the volume of initial myocardial infarction and accelerate the granulation processes in course of MI, and represent a new category of treatment agents.

[The antiaggregant action of 2-morpholino-5-(thienyl-2)-6-H-1,3,4-thiadiazine in in vitro and ex vivo experiments].

The influence of 2-morpholino-5-(thienyl-2)-6-H-1,3,4-thiadiazine (H-29) on the platelet aggregation has been studied in experiments on donor plasma in vitro. It is established that H-29 causes a decrease in the platelet interaction induced by ADP and arachidonic acid. The influence of H-29 on platelet aggregation was also studied in ex vivo experiments with intravenous and oral administration, and some parameters of plasmatic hemostasis were evaluated.

[A new antiviral drug Triazavirin: results of phase II clinical trial].

The results of the clinical trial testing the efficacy of a new anti-influenza drug Triazavirin are presented in this work. The data of the trial were gathered during the 2010 influenza season. The treatment with oral Triazavirin significantly reduced the duration of the main clinical symptoms of influenza (intoxication, fever, respiratory symptoms), decreased the incidence of the influenza-related complications and the use of symptomatic drugs. The re-isolation rate of the influenza A and B viruses was significantly lower in the patients who were using Triazavirin. The analysis of the clinical data showed that the optimal prescribed dosage was 250 mg 3 times a day.

[Toxicity of triazavirin, a novel Russian antiinfluenza chemotherapeutic].

The study of the toxicity of triazavirin, a new antiinfluenza agent, showed that the maximum concentration of the drug, inducing no microscopically visible changes in the structure of the monolayer and the cells of the MDCK and SKEV cell cultures, was 128 and 100 mcg/ml respectively. The maximum drug dose for single intraperitoneal administration inducing no signs of acute intoxication in albino mice weighing 10-12 g was 1000 mg/kg. In investigation of the chronic toxicity it was shown that oral administration of the drug (by 0.05 ml) to the albino mice in a dose of 200 mg/kg (maximum possible concentration by the solubility) daily for 10 days was well tolerated by the laboratory animals. The maximum tolerable dose of triazavirin for the albino mice was > or = 200 mg/kg.

[Therapeutic efficacy of Triazavirin, a novel Russian chemotherapeutic, against influenza virus A (H5N1)].

Therapeutic activity of Triazavirin against experimental influenza A was studied on albino mice intranazally infected with influenza virus A/Chicken/Kurgan/Russia/02/05 (H5N1) vs. reference drugs (Oseltamivir, Remantadin and Arbidol). The study showed that in a therapeutic dose of 1 mg/kg Triazavirin was efficient in protection of the animals from death. Its protective therapeutic efficacy (36.7+/-1.7%) was close to that of Oseltamivir (50.0+/-0.0%), comparable with that of Remantadin (38.3+/-1.7%) and higher than that of Arbidol (11.7+/-1.7%). During the whole observation period (up to the terminal phase) Triazavirin inhibited the influenza virus A accumulation in the lungs of the infected albino mice by more than 3 lg.

1,2,4-Triazoloazine derivatives as a new type of herpes simplex virus inhibitors.

A new class of inhibitors of herpes simplex virus replication was found. The compounds under study are derived from condensed 1,2,4-triazolo[5,1-c][1,2,4]triazines and 1,2,4-triazolo[1,5-a]pyrimidines, structural analogues of natural nucleic bases. Antiherpetic activity and cytotoxicity of the compounds were studied. The corresponding triphosphates of several active compounds were prepared and tested as inhibitors of DNA synthesis catalyzed by herpes simplex virus polymerase. The potential mechanism of their action is blocking of DNA dependent DNA polymerase, a key enzyme of viral replication.