Unified Methodology for the Primary Preclinical In Vivo Screening of New Anticoagulant Pharmaceutical Agents from Hematophagous Organisms.

The development of novel anticoagulants requires a comprehensive investigational approach that is capable of characterizing different aspects of antithrombotic activity. The necessary experiments include both in vitro assays and studies on animal models. The required in vivo approaches include the assessment of pharmacokinetic and pharmacodynamic profiles and studies of hemorrhagic and antithrombotic effects. Comparison of anticoagulants with different mechanisms of action and administration types requires unification of the experiment scheme and its adaptation to existing laboratory conditions. The rodent thrombosis models in combination with the assessment of hemostasis parameters and hematological analysis are the classic methods for conducting preclinical studies. We report an approach for the comparative study of the activity of different anticoagulants in vivo, including the investigation of pharmacodynamics and the assessment of hemorrhagic effects (tail-cut bleeding model) and pathological thrombus formation (inferior vena cava stenosis model of venous thrombosis). The reproducibility and uniformity of our set of experiments were illustrated on unfractionated heparin and dabigatran etexilate (the most common pharmaceuticals in antithrombic therapy) as comparator drugs and an experimental drug variegin from the tick Amblyomma variegatum. Variegin is notorious since it is a potential analogue of bivalirudin (Angiomax, Novartis AG, Basel, Switzerland), which is now being actively introduced into antithrombotic therapy.

Analysis of rhizosphere fungal community of agricultural crops cultivated in laboratory experiments on Chernevaya taiga soil.

Chernevaya taiga of Western Siberia, Russia, is a unique ecosystem characterized by fertile soil, exceptionally large herbaceous plant sizes, and extraordinarily rapid rates of plant residue degradation. We expected that growing crops on soil collected from Chernevaya taiga, which has never been used for agricultural purposes before, would result in a distinct rhizospheric fungal community. This community could potentially yield novel, potent biostimulators and biocontrol fungi for modern agriculture. To check this idea, we used high-throughput ITS sequencing to examine the microbial communities in the rhizosphere of spring wheat and radish grown in greenhouse experiments on Chernevaya and control soils. Additionally, representative fungal strains were isolated and assessed for their ability to promote growth in wheat seedlings. The study revealed that the most abundant phyla in the rhizospheric fungal community were Mortierellomycota, primarily consisting of Mortierella species, and Ascomycota. Mucor and Umbelopsis comprised the majority of Mucoromycota in the control soils. Fusarium and Oidiodendron, two potentially plant-pathogenic fungi, were only found in the rhizosphere of crops grown in the control soil. Conversely, Chernevaya soil contained a diverse range of potential biocontrol fungi for plants. Tested novel fungal isolates showed a stimulating effect on the development of wheat seedlings and positively affected their rate of biomass accumulation. The results of the study demonstrate that the soil of Chernevaya taiga do indeed contain fungi with prominent potential to stimulate agricultural plants growth.

Post-Vaccination and Post-Infection Immunity to the Hepatitis B Virus and Circulation of Immune-Escape Variants in the Russian Federation 20 Years after the Start of Mass Vaccination.

A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 years ago, with catch-up immunization for adolescents and adults under the age of 60 years launched in 2006. Here, we have assessed the humoral immunity to HBV in different regions of Russia, as well as the infection frequency following 20 years of a nationwide vaccination campaign. We have also evaluated the role of immune-escape variants in continuing HBV circulation. A total of 36,149 healthy volunteers from nine regions spanning the Russian Federation from west to east were tested for HBV surface antigen (HBsAg), antibodies to HBV capsid protein (anti-HBc), and antibodies to HBsAg (anti-HBs). HBV sequences from 481 chronic Hepatitis B patients collected from 2018-2022 were analyzed for HBsAg immune-escape variants, compared with 205 sequences obtained prior to 2010. Overall, the HBsAg detection rate was 0.8%, with this level significantly exceeded only in one study region, the Republic of Dagestan (2.4%, p < 0.0001). Among the generation vaccinated at birth, the average HBsAg detection rate was below 0.3%, ranging from 0% to 0.7% depending on the region. The anti-HBc detection rate in subjects under 20 years was 7.4%, indicating ongoing HBV circulation. The overall proportion of participants under 20 years with vaccine-induced HBV immunity (anti-HBs positive, anti-HBc negative) was 41.7% but below 10% in the Tuva Republic and below 25% in the Sverdlovsk and Kaliningrad regions. The overall prevalence of immune-escape HBsAg variants was 25.2% in sequences obtained from 2018-2022, similar to the prevalence of 25.8% in sequences collected prior to 2010 (p > 0.05). The population dynamics of immune-escape variants predicted by Bayesian analysis have remained stable over the last 20 years, indicating the absence of vaccine-driven positive selection. In contrast, the wild-type HBV population size experienced a rapid decrease starting in the mid-1990s, following the introduction of mass immunization, but it subsequently began to recover, reaching pre-vaccination levels by 2020. Taken together, these data indicate that it is gaps in vaccination, and not virus evolution, that may be responsible for the continued virus circulation despite 20 years of mass vaccination.

Agricultural Crops Grown in Laboratory Conditions on Chernevaya Taiga Soil Demonstrate Unique Composition of the Rhizosphere Microbiota.

Chernevaya taiga in West Siberia is a unique environment, with gigantism of grasses and shrubs. Exceptionally high productivity of plants is determined by the synergistic interaction of various factors, with a special role belonging to microorganisms colonizing the plant roots. This research explored whether agricultural plants can recruit specific microorganisms from within virgin Chernevaya Umbrisol and thus increase their productivity. Radish and wheat plants were grown on the Umbrisol (T1) and control Retisol of Scotch pine forest stand (T3) soils in the phytotron, and then a bacterial community analysis of the rhizosphere was performed using high-throughput sequencing of the 16S rRNA genes. In laboratory experiments, the plant physiological parameters were significantly higher when growing on the Umbrisol as compared to the Retisol. Bacterial diversity in T1 soil was considerably higher than in the control sample, and the principal coordinate analysis demonstrated apparent differences in the bacterial communities associated with the plants. Agricultural plants growing in the T1 soil form specific prokaryotic communities, with dominant genera Chthoniobacter, Pseudomonas, Burkholderia, and Massilia. These communities also include less abundant but essential for plant growth nitrifiers Cand. Nitrosocosmius and Nitrospira, and representatives of Proteobacteria, Bacilli, and Actinobacteria, known to be gibberellin-producers.

Efficacy of Ficus tikoua Bur. extract in ethylene glycol-induced urolithiasis model in SD rats.

The development of new herbal preparations for the treatment of urolithiasis is an urgent task of medical science. Ficus have attracted the attention of pharmacologists due to a wide range of biological properties, including antioxidant, anti-inflammatory, antibacterial and antifungal activity. We studied the effectiveness of Ficus tikoua Bur. in SD rats in which urolithiasis was induced by 6 weeks of oral administration of ethylene glycol 0.5% ad libitum instead of drinking water. Administration of the extract of Ficus tikoua Bur., as well as comparative drug Cystone® after modeling of urolithiasis lead to the restoration of diuresis and the concentration of inorganic phosphates starting from the 6th week of the experiment. The use of the Ficus tikoua Bur. extract for 6 weeks, both during the modeling of urolithiasis and during the recovery period, led to the restoration of the percentage of lymphocytes in the blood, content of sodium, chlorine and inorganic phosphates in the blood to the control level. Thus, the extract of Ficus tikoua Bur. seems to be a promising drug for effective treatment of the initial stages of the development of urolithiasis.

Methylocystis silviterrae sp.nov., a high-affinity methanotrophic bacterium isolated from the boreal forest soil.

A novel species is proposed for a high-affinity methanotrophic representative of the genus Methylocystis. Strain FST was isolated from a weakly acidic (pH 5.3) mixed forest soil of the southern Moscow area. Cells of FST are aerobic, Gram-negative, non-motile, curved coccoids or short rods that contain an intracytoplasmic membrane system typical of type-II methanotrophs. Only methane and methanol are used as carbon sources. FST grew at a temperature range of 4-37 °C (optimum 25-30 °C) and a pH range of 4.5 to 7.5 (optimum pH 6.0-6.5). The major fatty acids were C18  :  1ω8c, C18  :  1ω7c and C18  :  0; the major quinone as Q-8. FST displays 16S rRNA gene sequences similarity to other taxonomically recognized members of the genus Methylocystis, with Methylocystis hirsuta CSC1T (99.6 % similarity) and Methylocystis rosea SV97T (99.3 % similarity) as its closest relatives. The genome comprises 3.85 Mbp and has a DNA G+C content of 62.6 mol%. Genomic analyses and DNA-DNA relatedness with genome-sequenced members of the genus Methylocystis demonstrated that FST could be separated from its closest relatives. FST possesses two particulate methane monooxygenases (pMMO): low-affinity pMMO1 and high-affinity pMMO2. In laboratory experiments, it was demonstrated that FST might oxidize methane at atmospheric concentration. The genome contained various genes for nitrogen fixation, polyhydroxybutyrate synthesis, antibiotic resistance and detoxification of arsenic, cyanide and mercury. On the basis of genotypic, phenotypic and chemotaxonomic characteristics, it is proposed that the isolate represents a novel species, Methylocystis silviterrae sp. nov. The type strain is FST (=KCTC 82935T=VKM B-3535T).

Xanthobacter oligotrophicus sp.nov., isolated from paper mill sewage.

A novel, aerobic nitrogen-fixing methylotrophic bacterium, strain 29kT, was enriched and isolated from sludge generated during wastewater treatment at a paper mill in Baikal, Russian Federation. Cells were Gram-stain-variable. The cell wall was of the negative Gram-type. Cells were curved oval rod-shaped, 0.5-0.7×1.7-3.4 µm and formed yellow-coloured colonies. Cells tended to be pleomorphic if grown on media containing succinate or coccoid if grown in the presence of methyl alcohol as the sole carbon source. Cells were non-motile, non-spore-forming and contained retractile (polyphosphate) and lipid (poly-ß-hydroxybutyrate) bodies. The major respiratory quinone was ubiquinone Q-10 and the predominant cellular fatty acids were C18:1 ω7, C19:0 cyclo and C16:0. The genomic DNA G+C content was 67.95 mol%. Strain 29kT was able to grow at 4-37 °C (optimum, 30 °C), at pH 6.0-8.5 (optimum, pH 6.5-7.0) and at salinities of 0-0.5% (w/v) NaCl (optimum, 0% NaCl). Catalase and oxidase were positive. Strain 29kT could grow chemolithoautotrophically in mineral media under an atmosphere of H2, O2 and CO2 as well as chemoorganoheterotrophically on methanol, ethanol, n-propanol, n-butanol and various organic acids. The carbohydrate utilization spectrum is limited by glucose and raffinose. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the newly isolated strain was a member of the genus Xanthobacter with Xanthobacter autotrophicus 7cT (99.9% similarity) and Xanthobacter viscosus 7dT (99.4 % similarity) as closest relatives among species with validly published names. The average nucleotide identity and digital DNA-DNA hybridization values of 92.7 and 44.9%, respectively, of the 29kT to the genome of the most closely related species, X. autotrophicus 7cT, were below the species cutoffs. Based on genotypic, phenotypic and chemotaxonomic characteristics, it is proposed that the isolate represents a novel species, Xanthobacter oligotrophicus sp. nov. The type strain is 29kT (=KCTC 72777T=VKM B-3453T).

Temperature sensitivity of SOM decomposition is linked with a K-selected microbial community.

Temperature sensitivity (Q10 ) of soil organic matter (SOM) decomposition is a crucial parameter to predict the fate of soil carbon (C) under global warming. Nonetheless, the response pattern of Q10 to continuous warming and the underlying mechanisms are still under debate, especially considering the complex interactions between Q10 , SOM quality, and soil microorganisms. We examined the Q10 of SOM decomposition across a mean annual temperature (MAT) gradient from -1.9 to 5.1°C in temperate mixed forest ecosystems in parallel with SOM quality and bioavailability, microbial taxonomic composition, and functional genes responsible for organic carbon decomposition. Within this temperature gradient of 7.0°C, the Q10 values increased with MAT, but decreased with SOM bioavailability. The Q10 values increased with the prevalence of K-strategy of soil microbial community, which was characterized by: (i) high ratios of oligotrophic to copiotrophic taxa, (ii) ectomycorrhizal to saprotrophic fungi, (iii) functional genes responsible for degradation of recalcitrant to that of labile C, and (iv) low average 16S rRNA operon copy number. Because the recalcitrant organic matter was mainly utilized by the K-strategists, these findings independently support the carbon quality-temperature theory from the perspective of microbial taxonomic composition and functions. A year-long incubation experiment was performed to determine the response of labile and recalcitrant C pools to warming based on the two-pool model. The decomposition of recalcitrant SOM was more sensitive to increased temperature in southern warm regions, which might attribute to the dominance of K-selected microbial communities. It implies that climate warming would mobilize the larger recalcitrant pools in warm regions, exacerbating the positive feedback between increased MAT and CO2 efflux. This is the first attempt to link temperature sensitivity of SOM decomposition with microbial eco-strategies by incorporating the genetic information and disentangling the complex relationship between Q10 and soil microorganisms.

Screening of the Promising Direct Thrombin Inhibitors from Haematophagous Organisms. Part I: Recombinant Analogues and Their Antithrombotic Activity In Vitro.

The success in treatment of venous thromboembolism and acute coronary syndromes using direct thrombin inhibitors has stimulated research aimed at finding a new anticoagulant from haematophagous organisms. This study deals with the comparison between hirudin-1 from Hirudomedicinalis(desirudin), being the first-known and most well-studied natural anticoagulant, along with recombinant analogs of haemadin from the leech Haemadipsa sylvestris, variegin from the tick Amblyomma variegatum, and anophelin from Anopheles albimanus. These polypeptides were chosen due to their high specificity and affinity for thrombin, as well as their distinctive inhibitory mechanisms. We have developed a universal scheme for the biotechnological production of these recombinant peptides as pharmaceutical substances. The anticoagulant activities of these peptides were compared using the thrombin amidolytic activity assay and prolongation of coagulation time (thrombin time, prothrombin time, and activated partial thromboplastin time) in mouse and human plasma. The preliminary results obtained suggest haemadin as the closest analog of recombinant hirudin-1, the active substance of the medicinal product Iprivask (Aventis Pharmaceuticals, USA) for the prevention of deep venous thrombosis in patients undergoing elective hip or knee replacement surgery. In contrast, variegin can be regarded as a natural analog of bivalirudin (Angiomax, The Medicines Company), a synthetic hirudin-1 derivative certified for the treatment of patients undergoing percutaneous coronary intervention and of patients with unstable angina pectoris after percutaneous transluminal coronary angioplasty.

Cyclodextrin nanosponge as a temoporfin nanocarrier: Balancing between accumulation and penetration in 3D tumor spheroids.

As the intertissue delivery of hydrophobic temoporfin (mTHPC) remains inefficient, we propose the use of cyclodextrin-based nanosponges as a smart, advanced system for improved mTHPC delivery. Recently, we demonstrated that cyclodextrins (CDs) allow mTHPC to penetrate into tumor spheroids via a nanoshuttle mechanism. However, the CD complexes were very sensitive to the dilution, thus limiting their translation invivo. Hypercrosslinked CD monomers in a three-dimensional network (namely, CD nanosponges), however, may form both inclusion and non-inclusion complexes with drug molecules, providing controlled release and prolonged exposure to the drug. In the present work, we demonstrate that epichlorohydrin-crosslinked CD nanosponges based on ß-CD (ßCDp) and carboxymethyl-ß-CD (CMßCDp) monomers efficiently encapsulated mTHPC. We calculated the apparent binding constants between mTHPC and CD polymers (K=(6.3-8.8) × 106M-1 and K=(1.2-1.7) × 106M-1 for ßCDp and CMßCDp, respectively) using fluorescence titration curve fitting. The encapsulation of mTHPC in a CD polymer matrix had slower photosensitizer (PS) release compared to monomer CD units, providing deep penetration of mTHPC in 3D tumor spheroids in a concentration-dependent manner. However, the improvement of mTHPC penetration in 3D human pharynx squamous cell carcinoma (FaDu) spheroids using CD polymers was strongly accompanied by the inhibition of PS cellular uptake, demonstrating the delicate balance between the accumulation and the penetration of PS in FaDu spheroids. In summary, mTHPC-loaded CD nanosponges are a strong candidate for further invivo study in preclinical models, which could be considered as an advanced smart system for mTHPC delivery.

Effect of amino acids on IGF1 gene expression in human myotubes and skeletal muscle.

OBJECTIVE: Insulin-like growth factor I (IGF1) is an important regulator of collagen and extracellular matrix protein expression. We aimed to evaluate the effect of amino acids (AAs) on expression of IGF1 and IGF1-dependent genes in human myotubes and skeletal muscle and supposed that AAs administration increases IGF1 levels in blood and expression of IGF1 and IGF1-dependent genes in trained skeletal muscle, thereby reducing training-induced muscle damage. DESIGN: Human myotubes were incubated with Arg and Leu for 24 h. Then, the effects of long-term branched chain AAs administration (10 weeks, 0.1 g/kg body mass/day) to volunteers (six subjects per AAs and placebo groups) performing large training volumes regularly (cross country skiers, training twice a day) were examined. RESULTS: Incubating the myotubes with AAs increases expression of IGF1 mRNA isoforms and IGF1 secretion by 2-3 times. In athletes, long-term AAs administration increased basal blood levels of IGF1 (~50%) and expression of IGF1Ea mRNA slightly in skeletal muscle. There is no marked increase in expression of COL1A1, COL3A1, COL5A1, and LOX genes in skeletal muscle after AAs administration. However, expression of these genes in the combined group (placebo + AAs; n = 12) significantly correlated with the expression of IGF1Ea mRNA in muscle and did not correlate with IGF1 levels in the blood. CONCLUSIONS: AAs administration increases IGF1 expression in vitro and in vivo. To obtain more pronounced changes in expression of IGF1 and IGF1-dependent genes in skeletal muscle, it may be necessary to increase the dose and/or duration of AAs administration.

Glycated albumin stimulates expression of inflammatory cytokines in muscle cells.

The effects of glycated albumin on the expression of inflammatory cytokines in differentiated myotubes were investigated. Glycated albumin stimulates the expression of TNF α, IL-1ß, IL-6 and CCL-2 both at the mRNA and protein levels via the receptor of AGEs. Various cytokines demonstrated different kinetics of stimulation by glycated albumin. At a high glucose concentration, the stimulation effect was more pronounced than at a low one. At physiological concentrations of albumin and fructosamine, the stimulation effect of glycated albumin on inflammatory cytokine expression in myotubes was also observed. The induction of expression of all studied cytokines was sensitive to the inhibitors of JNK, p38 MAPK, MEK1/2, Src family protein kinases and NF-κB. At the same time, the induction of TNFα and IL-1ß was diminished by the Ca2+/calmodulin-dependent protein kinase inhibitor, whereas the induction of IL-6 and CCL-2 was reduced by the inhibitor of phosphoinositide 3-kinase. Possible implications of observed stimulation of cytokine expression by glycated albumin in the development of diabetes mellitus symptoms are discussed.

Innovative anthelmintic based on mechanochemical technology and their efficacy against parasitic infection of sheeps.

OBJECTIVE: Solubility and bioavailability are crucial for maximizing the activity of an antiparasitic drug. This study aimed to develop a combined preparation for antiparasitic medicines using ivermectin (Iver), fenbendazole (FBZ), and triclabendazole (TBZ), considering their solubility, bioavailability, and activity. MATERIALS AND METHODS: Innovative preparations in solid dispersions (SD) were obtained using the joint mechanical processing of drug substances with polyvinylpyrrolidone (PVP) in an LE-101 roller mill. The preparations' efficacy was studied in 140 sheep spontaneously infected with gastrointestinal Strongylata, Dicrococelium dendriticum, Moniezia expansa, and Melophagus ovinus. The preparations were given individually to the sheep in the form of an aqueous suspension orally. Their effectiveness was evaluated using intravital and postmortem parasitological examinations. RESULTS: The results confirmed the increase in solubility of substances by 13-29 times. The experiments have shown the high efficacy of SD composition of FBZ/Iver/PVP (1/1/9) containing FBZ (at 3.0 mg/kg b/w) and Iver (at 0.2 mg/kg b/w) when used against gastrointestinal Strongylates and M. expansa (95.8% and 100%, respectively), to a lesser extent against M. ovinus (38.5%). The SD composition of TBZ/Iver/PVP (1/1/9) of TBZ (at 3.0 mg/kg b/w) and Iver (at 0.2 mg/kg b/w) showed a high efficacy against gastrointestinal Strongylata and D. dendriticum (96.8% and 100%, respectively) and less activity against M. ovinus (61.6%). CONCLUSION: The high parasiticidal activity of SD based on FBZ, TBZ, and Iver in comparison with initial substances is explained by the formation of inclusion complexes of these substances with PVP when SD is dissolved in water and the synergistic effect of the active substances of the preparations. The resulting complexes have increased solubility in water and bioavailability. The use of such an SD suggests a significant reduction in the dosages of FBZ and TBZ without losing parasiticidal activity.

Genome Sequences of Novel Azospirillum sp. Strains B21 and Sh1, Isolated from Raised Sphagnum Bogs, and Type Strains Azospirillum lipoferum 59b and Azospirillum oryzae COC8.

Here, we report the genomic sequences of the novel Azospirillum sp. strains B21 and Sh1, isolated from raised bogs, along with the genome sequences of Azospirillum lipoferum 59bT, the type species of the genus, and Azospirillum oryzae COC8T, which were analyzed to get more knowledge about the genus Azospirillum.

Azospirillum palustre sp. nov., a methylotrophic nitrogen-fixing species isolated from raised bog.

Nitrogen-fixing bacterial strain, designated B2T, was isolated from methane-oxidation enrichment originating from a Sphagnum-dominated raised peatland in Tver region, Russia, and its phenotypic, chemotaxonomic and genomic characteristics were investigated. Cells of isolate were Gram-negative, aerobic, rod or spiral-shaped, with motility provided by a single polar flagellum in liquid media and peritrichous flagella on solid media. Strain was able to grow at 15-40 °C, pH 5.5-8.5 and tolerated NaCl to 2.0 % (w/v). Strain B2T gave positive amplification for dinitrogen reductase (nifH gene) and acetylene reduction activity was recorded up to 1250 nmol ethylene h-1 (mg protein)-1. Analysis of 16S rRNA showed that B2T represents a member of the genus Azospirillum and had the highest sequence similarity with A. humicireducens SgZ-5T (97.92 %). The predominant quinone system was ubiquinone Q-10 and the major fatty acids were C18 : 1ω7, C16 : 1ω7 and C16 : 0. The strain was facultative methylotrophic and used methanol and formate for the growth. Genome sequencing revealed a genome size of 8.0 Mbp and a G+C content of 67.8 mol%. The mxaFI genes encoding methanol dehydrogenase were absent, but a homologous xoxF gene was detected. The genes encoding enzymes involved in the biosynthesis of tetrahydromethanopterin (H4MPT) (formaldehyde oxidation) and NAD-linked formate dehydrogenase (fdsABG) were identified. Pairwise determined whole genome average nucleotide identity (gANI) values confirmed that strain B2T represents a novel species, for which we propose the name Azospirillum palustre sp. nov. with the type strain B2T (VKM B-3233T, КСТС 62613Т).

Potassium chloride released from contracting skeletal muscle may stimulate development of its hypertrophy.

The effects of potassium chloride on the expression of IGF-1 splice forms and myoblast proliferation were investigated. KCl at the concentrations of 7-12 mM stimulated the synthesis of IGF-1 and mechano growth factor (MGF) in murine myoblasts as well as in myotubes both at the mRNA and protein levels. Pan-calcium channel blocker CdCl2 completely abolished stimulation of growth factor expression, whereas blocker of HCN and Nav1.4 channels ZD7288 drastically reduced it. In addition, potassium chloride stimulated myoblast proliferation, while IGF-1 autocrine signaling inhibition partially suppressed these mitogenic effects.

Genome Sequence of Methylotrophic Azospirillum sp. Strain B2, Isolated from a Raised Sphagnum Bog.

Azospirillum sp. strain B2 is a soil bacterium which was originally isolated from the Sosvyatskoe raised Sphagnum bog in Russia. Here, we present the approximately 8-Mb draft genome sequence of Azospirillum sp. B2, with the aim of providing insight into the genomic basis of its ecological success in peatland settings.

Azemiopsin, a Selective Peptide Antagonist of Muscle Nicotinic Acetylcholine Receptor: Preclinical Evaluation as a Local Muscle Relaxant.

Azemiopsin (Az), a linear peptide from the Azemiops feae viper venom, contains no disulfide bonds, is a high-affinity and selective inhibitor of nicotinic acetylcholine receptor (nAChR) of muscle type and may be considered as potentially applicable nondepolarizing muscle relaxant. In this study, we investigated its preclinical profile in regard to in vitro and in vivo efficacy, acute and chronic toxicity, pharmacokinetics, allergenic capacity, immunotoxicity and mutagenic potency. The peptide effectively inhibited (IC50 ~ 19 nM) calcium response of muscle nAChR evoked by 30 µM (EC100) acetylcholine but was less potent (IC50 ~ 3 µM) at α7 nAChR activated by 10 µM (EC50) acetylcholine and had a low affinity to α4ß2 and α3-containing nAChR, as well as to GABAA or 5HT3 receptors. Its muscle relaxant effect was demonstrated at intramuscular injection to mice at doses of 30-300 µg/kg, 30 µg/kg being the initial effective dose and 90 µg/kg-the average effective dose. The maximal muscle relaxant effect of Az was achieved in 10 min after the administration and elimination half-life of Az in mice was calculated as 20-40 min. The longest period of Az action observed at a dose of 300 µg/kg was 55 min. The highest acute toxicity (LD50 510 µg/kg) was observed at intravenous injection of Az, at intramuscular or intraperitoneal administration it was less toxic. The peptide showed practically no immunotoxic, allergenic or mutagenic capacity. Overall, the results demonstrate that Az has good drug-like properties for the application as local muscle relaxant and in its parameters, is not inferior to the relaxants currently used. However, some Az modification might be effective to extend its narrow therapeutic window, a typical characteristic and a weak point of all nondepolarizing myorelaxants.

Specific titin and myomesin domains stimulate myoblast proliferation.

Myofibrillar proteins titin and myomesin stimulated myoblast proliferation as determined by MTT-test and labelled thymidine incorporation in the DNA. Specific Fn type III and Ig-like domains of these proteins were able to exert mitogenic effects as well. Proliferative effect of Fn type III domains was highly sensitive to inhibition of Ca2+/calmodulin dependent protein kinase, whereas the effect of Ig-like domains showed greater sensitivity to the inhibition of adenylyl cyclase - cAMP - PKA pathway. IGF-1 autocrine signalling inhibition partially suppressed mitogenic effects revealed by both domain types.

Analysis of Serum Cytokines and Single-Nucleotide Polymorphisms of SOD1, SOD2, and CAT in Erysipelas Patients.

Increased free radical production had been documented in group A (ß-hemolytic) streptococcus infection cases. Comparing 71 erysipelas patients to 55 age-matched healthy individuals, we sought for CAT, SOD1, and SOD2 single polymorphism mutation (SNPs) interactions with erysipelas' predisposition and serum cytokine levels in the acute and recovery phases of erysipelas infection. Whereas female patients had a higher predisposition to erysipelas, male patients were prone to having a facial localization of the infection. The presence of SOD1 G7958, SOD2 T2734, and CAT C262 alleles was linked to erysipelas' predisposition. T and C alleles of SOD2 T2734C individually were linked to patients with bullous and erythematous erysipelas, respectively. G and A alleles of SOD1 G7958A individually were associated with lower limbs and higher body part localizations of the infection, respectively. Serum levels of IL-1ß, CCL11, IL-2Rα, CXCL9, TRAIL, PDGF-BB, and CCL4 were associated with symptoms accompanying the infection, while IL-6, IL-9, IL-10, IL-13, IL-15, IL-17, G-CSF, and VEGF were associated with predisposition and recurrence of erysipelas. While variations of IL-1ß, IL-7, IL-8, IL-17, CCL5, and HGF were associated with the SOD2 T2734C SNP, variations of PDFG-BB and CCL2 were associated with the CAT C262T SNP.