Fall-winter sea surface temperature anomalies affect subsequent spring-summer phytoplankton succession and bioluminescence patterns in the Black Sea coastal waters near Crimea.

Seasonal and interannual dynamics of bioluminescence intensity and succession of the major phytoplankton taxonomic groups were analyzed using the six-year monitoring of Crimean coastal waters (the northern Black Sea) in 2009-2014. Monitoring program included regular CTD and bioluminescence intensity casts in the upper 60 m layer by means of "Salpa-M" sonde accompanied with phytoplankton sampling from subsurface (∼0.2 m) and from the layer of maximal bioluminescence intensity.

New PMMA-Based Hydroxyapatite/ZnFeO/ZnO Composite with Antibacterial Performance and Low Toxicity.

Polymethylmethacrylate (PMMA) is the most commonly used bone void filler in orthopedic surgery. However, the biocompatibility and radiopacity of PMMA are insufficient for such applications. In addition to insufficient biocompatibility, the microbial infection of medical implants is one of the frequent causes of failure in bone reconstruction.

Bioluminescence of the tropical Indian Ocean: a multiple-scale variation.

Large-scale surveys represented by 5800 bathymetric casts in the western Indian Ocean (0-22 N, 54-58 E), elucidated the 10-fold variation of the bioluminescent potential (BP) in the upper mixed layer, during the winter (north-east) monsoon season. The mesoscale survey in February 2017 consisted of 26 drift stations (4 N-3 S, 65-68 E) on which 5-10 bathymetric casts were deployed down to 60 m. The maximal BP was associated with the periphery of a cyclonic eddy.

The theory of interceptor-protector action of DNA binding drugs.

The review discusses the theory of interceptor-protector action (the IPA theory) as the new self-consistent biophysical theory establishing a quantitative interrelation between parameters measured in independent physico-chemical experiment and in vitro biological experiment for the class of DNA binding drugs. The elements of the theory provide complete algorithm of analysis, which may potentially be applied to any system of DNA targeting aromatic drugs. Such analytical schemes, apart from extension of current scientific knowledge, are important in the context of rational drug design for managing drug's response by changing the physico-chemical parameters of molecular complexation.

Hetero-association models of non-covalent molecular complexation.

The present review discusses the current state-of-the-art in building models enabling the description of non-covalent equilibrium complexation of different types of molecules in solution, which results in the formation of supramolecular structures different in length and composition (hetero-association or supramolecular multicomponent co-polymerisation). The description is focused on standard physical and chemical quantities such as experimental observables and equilibrium parameters of interaction (equilibrium constants and concentrations). The major partial cases of the hetero-association models, such as finite and indefinite isodesmic and cooperative complexations, and Benesi-Hildebrand and Langmuir adsorption models are considered.

The Effects of Repetitive Transcranial Magnetic Stimulation on Picrotoxin-Induced Convulsions in Mice.

Background: Clinical and experimental results show that repetitive transcranial magnetic stimulation (rTMS) is effective and safe in the treatment of epilepsy. The characteristics of the impulse magnetic field (IMF) are empirical in these studies, making impossible to compare their effectiveness.

Objectives: The article presents the results of a study of the anticonvulsive effects of different modes of IMF on the picrotoxin seizure model, which is important for studying GABAergic brain mechanisms activated by rTMS.

Theoretical description of metabolism using queueing theory.

A theoretical description of the process of metabolism has been developed on the basis of the Pachinko model (see Nicholson and Wilson in Nat Rev Drug Discov 2:668-676, 2003) and the queueing theory. The suggested approach relies on the probabilistic nature of the metabolic events and the Poisson distribution of the incoming flow of substrate molecules. The main focus of the work is an output flow of metabolites or the effectiveness of metabolism process.

The effect of structural white matter abnormalities on the clinical course of epilepsy.

Objectives: The aim of this study was to assess the impact of the extent of brain white matter lesions on the development of cognitive and psychoemotional disorders, and to investigate correlations between the degree of integration of brain pathway structures and the clinical features of epilepsy.

Material And Methods: Forty-six epileptic patients (36 with pharmacoresistant epilepsy and 10 who had been in remission for over a year) and 10 normal volunteers (the control group) were examined. To evaluate diffusion tensor MRI findings, the index of fractional anisotropy (FA) and index of apparent diffusion coefficient (ADC) were used.

On the reliability of quantitation of biological effect in drug-interceptor-DNA systems.

Relative insensitivity of theoretical estimation of biological effect in drug-interceptor-DNA systems is found with respect to variation of parameters of quasiphysiological conditions. The "inertness" of the biological response, in part, justifies the use of parameters of intermolecular interaction, derived from independent physicochemical experiments, in estimation of relative biological effect in the theory of interceptor/protector action.

Random versus sequential pathway of molecular self-assembly.

Two important assumptions are often made in the analysis of molecular self-assembly at equilibrium, viz., that sequential is preferred to random aggregation and that the equilibrium constants at each stage of aggregation are equal, though both assumptions have not been justified strictly. In the present work we show that molecular self-assembly leading to formation of linear polymers and proceeding in a random manner appears to be less entropically favored than sequential aggregation, which provides a physical background for assuming sequential aggregation when studying molecular self-assembly in solution.

Quantification of the interceptor action of caffeine on the in vitro biological effect of the anti-tumour agent topotecan.

Using published in vitro data on the dependence of the percentage of apoptosis induced by the anti-cancer drug topotecan in a leukaemia cell line on the concentration of added caffeine, and a general model of competitive binding in a system containing two aromatic drugs and DNA, it has been shown to be possible to quantify the relative change in the biological effect just using a set of component concentrations and equilibrium constants of the complexation of the drugs. It is also proposed that a general model of competitive binding and parameterization of that model may potentially be applied to any system of DNA-targeting aromatic drugs under in vitro conditions. The main reasons underpinning the proposal are the general feature of the complexation of aromatic drugs with DNA and their interaction in physiological media via hetero-association.

Complete solution of the problem of one-dimensional non-covalent non-cooperative self-assembly in two-component systems.

Equations for the mass conservation law and the molecular parameters observed in spectroscopic experiments have been derived for non-covalent, non-cooperative, one-dimensional self-assembly in systems containing two types of interacting molecules (hetero-association), taking into account "reflected" complexes and "edge effects."

Quantitation of the molecular mechanisms of biological synergism in a mixture of DNA-acting aromatic drugs.

It is suggested that the widely reported biological synergism of a mixture of DNA-targeting aromatic drug molecules both in vivo and in vitro can be explained, in part, at the molecular level by competition between two basic mechanisms: the 'interceptor' (hetero-association between Drug1 and Drug2) and 'protector' mechanisms (complexation of Drug1 and Drug2 on DNA-binding sites). In the present work a complete analytical methodology has been developed to quantify these processes, providing an estimate of the relative importance of the interceptor/protector mechanisms using just a set of equilibrium association constants. The general methodology may be applied to other molecules with receptors for aromatic drugs.

A method for analysis of multicomponent systems of interacting aromatic molecules in solution.

A method has been developed for analyzing multicomponent mixtures containing N different types of noncovalently interacting aromatic molecules using spectroscopic data [nuclear magnetic resonance (NMR), UV-vis, fluorescence, circular dichroism]. The method is based on an algorithmical approach to modeling of the N-component dynamic equilibrium (N-STOCH algorithm), dealing with numbers in N-based numerical systems as analogs of molecular complexes being formed in solution. A basic property of the algorithm is the ability to incorporate any known specificity of molecular interactions without constructing complex mathematical formulas.

Attachment of LcrV from Yersinia pestis at dual binding sites to human TLR-2 and human IFN-gamma receptor.

The virulence antigen (V-antigen, LcrV) of Yersinia pestis, the causative agent of bubonic plague, is an established protective antigen known to regulate, target, and mediate type III translocation of cytotoxic yersiniae outer proteins termed Yops; LcrV also prompts TLR2-dependent upregulation of anti-inflammatory IL-10. In this study, we determined the parameters of specific interaction of LcrV with TLR2 expressed on human transfected HEK293 cells (TLR2+/CD14-), VTEC2.HS cells (TLR2+/CD14-), primary monocytes (TLR2+/CD14+), and THP-1 cells (TLR2+/CD14+).

[Interaction between aromatic antibiotics and vitamins: 1H NMR analysis of the heteroassociation of nicotinamide and anthracycline antitumor antibiotics].

The interaction between anthracycline antitumor antibiotics daunomycin and novatrone and the vitamin nicotinamide has been investigated by one- and two-dimensional 1H NMR spectroscopy (500 MHz). Due to significant differences in structures of the chromophores of interacting molecules, a two-site heteroassociation model has been developed, allowing the arrangement of one and two nicotinamide molecules on the chromophore of the antibiotic. The equilibrium association constant, thermodynamical parameters (deltaH, deltaS) of the heteroassociation of nicotinamide with daunomycin and novatrone and the induced proton chemical shifts in the heterocomplexes have been determined from the concentration and temperature dependences of proton chemical shifts of interacting molecules.

Effect of a mixture of caffeine and nicotinamide on the solubility of vitamin (B2) in aqueous solution.

The effect of caffeine (CAF) and nicotinamide (NMD) on the solubility of a vitamin B2 derivative (FMN) has been evaluated for mixtures containing either a single hydrotrope (CAF or NMD) or the two hydrotropes simultaneously. A model for analysis of ternary systems, which takes into account all possible complexes between the molecules, has been developed and tested with experimental NMR data on the three-component mixture FMN-CAF-NMD. The results indicate that special attention should be given to the concentration of a hydrotropic agent used to enhance the solubility of a particular drug.

[Evaluation of the effectiveness of antibacterial substances in treating an experimental form of bubonic plague in monkeys].

The modelling of glandular plague and selection of the conditions for estimating the efficacy of new antibacterials for the treatment of the infection were performed on hamadryads (baboons). The experiments showed that the average LD50 of the culture of a highly virulent strain of Yersinia pestis on its subcutaneous administration to the animals was 2089 viable microbes. In 18 per cent of the episodes the experimental glandular plague in the animals was complicated by secondary plague pneumonia.

[Extrachromosomal genetic elements of Clostridium botulinum. II. Isolation and analysis of DNA from bacteriophages of Clostridium botulinum types C and A].

The DNAs of bacteriophage c-st, known to realize the lysogenic conversion of toxinogenicity among C. botulinum types C and D strains, and the nucleic acid of a virulent mutant of bacteriophage CB propagated in type A C. botulinum cells were purified and examined.

[Combined (associated) vaccination against quarantinable infections].

The presence of several active foci of infection of different etiology is an indication for complex (combined) immunization against these diseases. The scheme of complex (combined) immunization against plague, cholera and yellow fever has been experimentally substantiated and successfully tested on volunteers.

[The safety of the jet (needle-free) injection].

The analysis of literature doesn't give strong confirmation that jet injection could provoke the transmission of the infection. Nevertheless such infection is possible because of retrograde flow of vaccine preparation which just has mixed with tissue liquid of a previous patient or taking into account a continuous contact of an injector head with patient's skin during injection. The design of the injector head has a certain significance on this matter.

[Extrachromosomal genetic elements of Clostridium botulinum. I. Plasmids of toxigenic and atoxigenic strains of Clostridium botulinum type A].

Plasmid profiles in fifteen toxigenic and six nontoxigenic strains of Clostridium botulinum type A were investigated. The electrophoretic patterns of nucleic acids from the bacterial lysates were shown to vary in relation to the mode of bacterial cells lysis and the stage of microbial population growth. Two toxigenic strains harbour a unique 3.

[The adaptation of the human immune system during an ecological disaster].

This article studies the adaptative mechanisms of the immune system of servicemen in the Aral Sea region in response to the influence of unfavourable xenobiotic factors of the environment. The greatest homeostatic shifts were disclosed in servicemen of the 2nd and the 4th periods of service (6 months and 2 years of active duty correspondingly). Precisely these periods of selective service have the highest infectivity index.