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Introduction: Varicella-Zoster virus (VZV) is a highly contagious alpha-herpes virus. The diagnosis of chickenpox remains a difficult task especially in cases of breakthrough chickenpox, so the development of reliable laboratory tests is necessary. The simplest and most sensitive serological test for detecting antibodies in human and animal sera is the passive hemagglutination reaction (PHAR)., The Aim: To develop of a simple, highly sensitive and specific serological tests for the detection of antibodies to VZV in human and animal blood sera., Materials and Methods: Human and animal cell cultures; various strains of VZV; human and animal immune sera; monoclonal antibody to VZV glycoprotein (GP) E. Formalin-treated erythrocytes of sheep, chickens and goats, sensibilised with GP of VZV from a virus-containing supernatant were used for PHAR., Results: Cell cultures with the maximum cytopathic effect at VZV infection were selected. A simple original method for obtaining virus-specific VZV GPs using lectins has been developed. Purified GPs were obtained by their elution from sheep erythrocytes after adsorption. The activity of VZV GP was confirmed in PHAR by an antibody diagnostic assay using formalin-treated sheep erythrocytes sensibilised using monoclonal antibodies to GP E of the "vOka" VZV strain (USA). Using GPs from different VZV strains, PHAR test and GP-based enzyme-linked immunosorbent assay (gpELISA) have been developed to detect antibodies in human and animal immune sera. These tests have high sensitivity, specificity and lack of cross-reactivity., Conclusion: A highly specific, sensitive and reproducible tests for the detection of antibodies to VZV have been developed.

We studied toxicity of recombinant Streptococcus pneumoniae pneumolysin protein in experiments on mice and its cytopathogenic effect on cultures of Vero green monkey kidney cells and human lung carcinoma A549 cells in vitro. In vivo and in vitro experiments proved the absence of compromised toxicity and direct cytopathogenic action of the recombinant protein., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Influenza is one of the most pressing global health problems. Despite the wide range of available anti-influenza drugs, the viral drug resistance is an increasing concern and requires the search for new approaches to overcome it. A promising solution is the development of drugs with action that is based on the inhibition of the activity of cellular genes through RNA interference., Aim: Evaluation in vivo of the preventive potential of miRNAs directed to the cellular genes FLT4, Nup98 and Nup205 against influenza infection., Materials and Methods: The A/California/7/09 strain of influenza virus (H1N1) and BALB/c mice were used in the study. The administration of siRNA and experimental infection of animals were performed intranasally. The results of the experiment were analyzed using molecular genetic and virological methods., Results: The use of siRNA complexes Nup98.1 and Nup205.1 led to a significant decrease in viral reproduction and concentration of viral RNA on the 3rd day after infection. When two siRNA complexes (Nup98.1 and Nup205.1) were administered simultaneously, a significant decrease in viral titer and concentration of viral RNA was also noted compared with the control groups., Conclusions: The use of siRNAs in vivo can lead to an antiviral effect when the activity of single or several cellular genes is suppressed. The results indicate that the use of siRNAs targeting the cellular genes whose expression products are involved in viral reproduction is one of the promising methods for the prevention and treatment of not only influenza, but also other respiratory infections.

A recombinant form of pneumolysin from Streptococcus pneumoniae was obtained. By using Vector NTI Advance 11.0 bioinformatic analysis software, specific primers were designed in order to amplify the genome fragment of strain No. 3358 S. pneumoniae serotype 19F containing the nucleotide sequence encoding the full-length pneumolysin protein. A PCR product with a molecular weight corresponding to the nucleotide sequence of the S. pneumoniae genome fragment encoding the full-length pneumolysin was obtained. An expression system for recombinant pneumolysin in E. coli was constructed. Sequencing confirmed the identity of the inserted nucleotide sequence encoding the full-length recombinant pneumolysin synthesized in E. coli M15 strain. Purification of the recombinant protein was performed by affinity chromatography using Ni-Sepharose in 8 M urea buffer solution. Confirmation of the recombinant protein was performed by immunoblotting with monoclonal antibodies to pneumolysin., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature.)

The genus Rhodococcus includes polymorphic non-spore-forming gram-positive bacteria belonging to the class Actinobacteria. Together with Mycobacterium and Corynebacterium, Rhodococcus belongs to the Mycolata group. Due to their relatively high growth rate and ability to form biof ilms, Rhodococcus are a convenient model for studying the effect of biologically active compounds on pathogenic Mycolata. Colchicine was previously found to reduce biof ilm formation by P. carotovorum VKM B-1247 and R. qingshengii VKM Ac-2784D. To understand the mechanism of action of this alkaloid on the bacterial cell, we have studied the change in the fatty acid composition and microviscosity of the R. qingshengii VKM Ac-2784D membrane. Nystatin, which is known to reduce membrane microviscosity, is used as a positive control. It has been found that colchicine at concentrations of 0.01 and 0.03 g/l and nystatin (0.03 g/l) have no signif icant effect on the survival of R. qingshengii VKM Ac-2784D cultivated in a buffered saline solution with 0.5 % glucose (GBSS). However, colchicine (0.03 g/l) signif icantly inhibits biof ilm formation. Rhodococcus cells cultivated for 24 hours in GBSS with colchicine acquire a rounded shape. Colchicine at 0.01 g/l concentration increases C16:1(n-7), C17:0, C20:1(n-9) and C21:0 fatty acids. The microviscosity of the membrane of individual cells was distributed from the lowest to the highest values of the generalized laurdan f luorescence polarization index (GP), which indicates a variety of adaptive responses to this alkaloid. At a higher concentration of colchicine (0.03 g/l) in the membranes of R. qingshengii VKM Ac-2784D cells, the content of saturated fatty acids increases and the content of branched fatty acids decreases. This contributes to an increase in membrane microviscosity, which is conf irmed by the data on the GP f luorescence of laurdan. All of the above indicates that colchicine induces a rearrangement of the Rhodococcus cell membrane, probably in the direction of increasing its microviscosity. This may be one of the reasons for the negative effect of colchicine on the formation of R. qingshengii VKM Ac-2784D biof ilms., (Copyright © AUTHORS.)

The gasdynamic electron cyclotron resonance (ECR) ion source is a type of the device in which the ionization efficiency is achieved primarily due to a high plasma density. Because of a high particle collision rate, the confinement is determined by a gasdynamic plasma outflow from a magnetic trap. Due to high efficiency of resonant heating, electrons gain energy significantly higher than that in inductively or capacitively coupled plasmas. As a consequence of such a parameter combination, the gasdynamic ECR plasma can be a unique source of low to medium charged ions, providing a high current and an ultimate quality of an ion beam. One of the most demanded directions of its application today is a development of high-current proton injectors for modern accelerators and neutron sources of different intensities. Special plasma parameters allow for the use of diagnostic techniques, traditional for multiply charged ECR plasmas as well as for other types of discharges with a high plasma density. Among the additional techniques, one can mention the methods of numerical simulation and reconstruction of the plasma density and temperature from the parameters of the extracted ion beams. Another point is that the high plasma density makes it possible to measure it from the Stark broadening of hydrogen lines by spectroscopy of plasma emission in the visible range, which is a fairly convenient non-invasive diagnostic method. The present paper discusses the main physical aspects of the gasdynamic ECR plasma, suitable diagnostic techniques, and possibilities and future prospects for its various applications.

The physical and functional organisation of the OXPHOS system in mitochondria in vivo remains elusive. At present, different models of OXPHOS arrangement, representing either highly ordered respiratory strings or, vice versa, a set of randomly dispersed supercomplexes and respiratory complexes, have been suggested. In the present study, we examined a supramolecular arrangement of the OXPHOS system in pea shoot mitochondria using digitonin solubilisation of its constituents, which were further analysed by classical BN-related techniques and a multidimensional gel electrophoresis system when required. As a result, in addition to supercomplexes I 1 III 2 , I 1 III 2 IV n and III 2 IV 1 - 2 , dimer V 2 , and individual complexes I-V previously detected in plant mitochondria, new OXPHOS structures were also revealed. Of them, (1) a megacomplex (II x III y IV z )n including complex II, (2) respirasomes I 2 III 4 IV n with two copies of complex I and dimeric complex III 2 , (3) a minor new supercomplex IV 1 Va 2 comigrating with I 1 III 2 , and (4) a second minor form of ATP synthase, Va, were found. The activity of singular complexes I, IV, and V was higher than the activity of the associated forms. The detection of new supercomplex IV 1 Va 2 , along with assemblies I 1 III 2 and I 1 - 2 III 2 - 4 IV n , prompted us to suggest the occurrence of in vivo oxphosomes comprising complexes I, III 2 , IV, and V. The putative oxphosome's stoichiometry, historical background, assumed functional significance, and subcompartmental location are discussed herein., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Immunogenic and protective activity of recombinant pneumolysin was studied in experiments on male BALB/c mice. The mice were immunized intraperitoneally with recombinant pneumolysin sorbed on Al(OH) 3 (200 μg per mouse). In 2 weeks after immunization, the isotypes of antibodies to recombinant pneumolysin in the serum of immunized mice were determined by ELISA. The animals were infected with Streptococcus pneumoniae serotype 3. Immunization with recombinant pneumolysin induced the production of anti-pneumolysin antibodies, mainly of IgG1 subisotype. On day 21 after intraperitoneal infection with S. pneumoniae serotype 3 in a dose of 10 6 microbial cells, the survival rate of animals immunized with recombinant pneumolysin in a dose of 25 μg/mouse was 67% vs. 0% in the control (p<0.001). Recombinant pneumolysin could be considered as a promising protective antigen for inclusion in the serotype-independent vaccine against S. pneumoniae.

The paper presents recent results of a "pointlike" neutron source development based on a D-D fusion in a D-loaded target caused by its bombardment with a sharply focused deuterium ion beam. These developments are undergoing at the Institute of Applied Physics of Russian Academy of Sciences in order to study a possibility to create an effective and compact device for fast-neutron radiography. The last experiments with a beam produced by a gasdynamic high-current ECR ion source and its focusing with a magnetic lens demonstrated that 60 mA of deuterium ions may be constricted to a transversal size of ∼1 mm at the focal plane. With a purpose to improve this result in terms of the beam current and its size, a combined electrostatic and magnetic focusing system is proposed and analyzed. It is shown that the combined system may enhance the total beam current and reduce its footprint down to 0.13 mm. All numerical analysis was performed using the IBSimu code.

Results of experimental investigation of the ECR discharge in a single coil magnetic field as an alternative to rf and helicon discharges for wide-aperture dense plasma fluxes production are presented. A possibility of obtaining wide-aperture high density hydrogen plasma fluxes with homogeneous transverse distribution was demonstrated in such a system. The prospects of using this system for obtaining high current ion beams are discussed.

The oncolytic potential of the attenuated mumps virus (MV) vaccine strain Leningrad-3 (L-3) was evaluated in a panel of four human metastatic melanoma cell lines. The lines were shown to be susceptible and permissive to MV infection. Efficient MV replication led to death of melanoma cells, but the effect differed among the cell lines. Possible mechanisms mediating the selectivity of MV L-3 towards the cell lines were explored. Replicative and oncolytic activity of MV was found to depend on the expression pattern of type I interferon genes. None of the melanoma cell lines showed induction of expression of the total spectrum of genes required to inhibit virus replication. Based on the results, MV L-3 was assumed to be a promising oncolytic agent for human melanoma cells.

Mesoporous silver nanoparticles were easily synthesized through the bulk reduction of crystalline silver(I) oxide and used for the preparation of highly porous surface-enhanced Raman scattering (SERS)-active substrates. An analogous procedure was successfully performed for the production of mesoporous silver films by chemical reduction of oxidized silver films. The sponge-like silver blocks with high surface area and the in-situ-prepared mesoporous silver films are efficient as both analyte adsorbents and Raman signal enhancement mediators. The efficiency of silver reduction was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The developed substrates were applied for SERS detection of rhodamine 6G (enhancement factor of about 1-5 × 10 5 ) and an anti-ischemic mildronate drug (meldonium; enhancement factor of ≈10 2 ) that is known for its ability to increase the endurance performance of athletes.

A novel concept of advanced SERS (surface enhanced Raman spectroscopy) planar sensors is suggested for fast analysis of sulfur-containing hazardous oil components and persistent pollutants. The main advantage of the proposed sensors is the utilization of an additional preconcentrating layer of optically transparent chitosan gel, which is chemically modified with appropriate π-acceptor compounds to selectively form charge-transfer complexes (CTCs) at the interface with nanostructured silver coatings. The CTCs shift absorption bands of polycyclic aromatic sulfur heterocycles (PASHs) and other important analytes in a controllable way and thus provide a surplus enhancement of vibration modes due to resonant Raman scattering. This novel indicator system provides multiplex determination of PASHs in different forms in a small volume of oil without any tedious sample pretreatment steps. This approach opens new possibilities of increasing either spectral and concentration sensitivity or specificity of SERS-based sensors, allowing for new developments in the fields of ecology, advanced fuel analysis, and other prospective applications.

Plasma of electron cyclotron resonance (ECR) discharge sustained by millimeter wave radiation is widely used for production of ion beams of different kind. The main trend in ECR ion sources development nowadays is an increase of frequency and power of microwave heating. The most advanced systems use gyrotrons in 24-60 GHz frequency range. In previous studies at IAP RAS it was demonstrated that ECR source SMIS 37 (Simple Mirror Ion Source) with 37.5 GHz heating operating in quasigasdynamic regime of plasma confinement is able to produce proton and deuteron beams with ion current density about 700 mA/cm 2 . As the next step of these investigations plasma properties of the discharge sustained by 75 GHz radiation have been studied. Plasma density and electron temperature were determined using spectroscopic and Langmuir probe techniques. It was demonstrated that plasma density could reach values close to 10 14 cm -3 and that is of great interest for further development of high current ion sources for various applications.

The natriuretic peptides regulate pressure and water metabolism in human organism. The concentration of N-thermal cerebral natriuretic propeptide (NT-proBNP) in tear and blood serum was analyzed. The sampling included 49 patients divided on three groups. The group I (main) included 14 patients with primary open-angle sub-compensated glaucoma degree I-III. The group II (comparative group) included 15 patients with age-related immature cataract. The group III (control) included volunteers without any visual organ diseases. The concentration of NT-proBNP in tear and blood serum was detected by solid-phase enzyme-linked immunosorbent assay technique using test system NT-proBNP - IFA - BEST» («Vektor-Best», Russia). The median of content of NT-proBNP in tear turned out to be less than in blood serum in all groups (р1 = 0,00763; р2 = 0,00452; р3 = 0,00029) and made up to in patients with glaucoma 41,3 pg/ml, with cataract - 37.5 pg/ml, in healthy people 0 25.0 pg/ml (inter-quartile range made up to 20-60 pg/ml, 20-65 pg/ml, 10-49,5 pg/ml correspondingly). No differences in concentration of NT-proBNP were established in all groups both for blood serum (p = 0,494) and tear (p = 0,388). The concentration of NT-proBNP in tear correlated with its concentration in blood serum (r = 0,694). However, no dependencies were established from value of intra-ocular pressure (r = 0,168). Therefore, the concentration of NTproBNP in tear is not a perspective laboratory arker for diagnostic of increased intra-ocular pressure and stratification of development of glaucoma., Competing Interests: The authors declare no conflict of interest.

Aim: Demonstrate the possibility of using nested PCR method for determination of Varicella Zoster virus (VZV) in clinical samples of peripheral blood of patients., Materials and Methods: Material from 35 patients with clinical manifestations of herpes zoster and control group of 20 healthy donors was used in the study. Monocyte fraction of venous blood cells, pretreated with heparin, was isolated by centrifugation in ficoll-verografin density gradient, total DNA was then isolated from cells by phenol-chloroform extraction with subsequent precipitation with alcohol. Polymerase chain reaction was carried out in thermocyclers Tercyc and TProfessional Gradient (Biometra), amplified DNA was analyzed by electrophoresis on 1.6% agarose gel in the presence of ethidium bromide., Results: Data on detection of viral DNA in blood monocytes in 17 (49%) of ill patients, as well as in 1 (out of 20 in control group) practically healthy donor were obtained. A possibility of a subclinical reactivation of the virus is discussed in the latter case., Conclusion: A possibility of viral DNA determination in monocytes of patient blood without using expensive equipment is shown, that could find application in clinical practice, especially for diagnostics of patients with non-characteristic clinical manifestations, as well as patients with subclinical forms of the disease.

Plasma LDL content increased in rats with mild chronic heart failure, but decreased in animals with severe pathology. The lipid profile of β-adrenoceptor antagonists depended on their selectivity. The most selective antagonists of β-adrenoceptors had little effect on the lipid composition. Nonselective β-adrenoceptor antagonists increased the index of plasma atherogenicity, which did not depend on the severity of a pathological process. In mild chronic heart failure, these changes were associated with a decrease in HDL concentration, while in severe chronic heart failure; they were related to a tendency towards a decrease in HDL content and an increase in LDL concentration. The increase in survival rate was associated with true antagonism of the agent to β-adrenoceptors (the absence of intrinsic sympathomimetic activity) and, to a lesser extent, with nonselective blockade of β-adrenoceptors.

The character of lipid spectrum changes in rats with experimental heart failure of non-ischemic genesis depended on its severity. In mild heart failure there was found an increase in the low density lipoprotein levels, whereas in the severe one--a decrease of total cholesterol levels at the expense of the low density lipoproteins. The ACE inhibitors produced no significant changes in the lipid spectrum. The effect of beta-adrenoblockers was determined by their selectivity for beta1-adrenoreceptors. The most selective drugs were distinguished by the metabolically neutral activity. On the contrary, nonselective beta-adrenoblockers increased the degree of plasma atherogeneity.

In rats with relatively mild chronic heart failure (CHF) there was an increase in plasma LDL levels. In turn, in severe CHF it was revealed a significant decrease in total cholesterol concentration due to LDL levels decline. ACE inhibitors (captopril, enalapril and lisinopril) and the most selective beta1-adrenoblockers (metoprolol, nebivolol) had not any significant influence on plasma lipids. Less selective and especially nonselective beta-adrenoblockers pindolol and propranolol brought up the atherogenic potential of plasma because of HDL levels reduction in mild CHF whereas in case of severe model--due to the trends toward decrease in HDL concentration and toward increase in LDL levels. Lipophilic ACE-inhibitors and beta-adrenoblockers without intrinsic sympathomimetic activity improved survival in rats with mild CHF to the equal extent. On the contrary in severe CHF beta-adrenoblockers, especially non-selective, had an advantage over ACE inhibitors on the survival effect.

By using model of chronic heart failure (CHF) occurring with induced decompensations, it was shown that inhibitors of angiotensin-converting enzyme (ACE) and beta-adrenoblockers promoted to different degree the correction of hypercatecholaminemia and an increase of survival of rats. The most pronounced effect was characteristic of beta-adrenoblockers atenolol, propranolol, and carvedilol. The lower activity was demonstrated by other adrenoblockers that had no intrinsic sympathomimetic activity, as well as captopril. However, positive effect of these drugs on rat survival occurred regardless of their action on the sympathoadrenal system. The ACE inhibitors, particularly hydrophilic lysinopril, to the lesser degree than beta-adrenoblockers, prevented death of animals at the period of the CHF decompensation. The combined use of ACE inhibitors with beta-adrenoblockers, especially with carvedilol, promoted the maximally expressed decrease of the sympathoadrenal activity and an increase of the rat survival, including that at the CHF decompensation.

The review considers key problems connected with historical development of the nervous system, including intercellular contacts and brain neurotransmitter systems. A particular attention is paid to structural-functional organization of the central nervous system of the fresh-water pulmonary mollusc Lymnaea stagnalis.

The pair of giant reciprocally coupled neurons VD1 and RPaD2 within the CNS of the freshwater pond snail Lymnaea stagnalis was used to analyse the effect of hydrogen peroxide on gap-junction connection. Electrical activity of VD1/RPaD2 was recorded with intracellular microelectrodes in order to analyse gap-junction signalling. Hydrogen peroxide application (1 × 10⁻⁴ M) results in a rapid, 1.3-fold, increase in VD1/RPaD2 spiking frequency within 30 s after application. This was accompanied by a slight reduction in action potential amplitude. In addition, H₂O₂ induced a significant reduction in the steady-state bidirectional coupling ratio between the neurons. The maximal reduction in the coupling ratio, 1.8-1.9 fold, was measured 3 min after H₂O₂ application. However, the network input resistance did not undergo a detectable change. The voltage-gated Ca²⁺ channel blocker, nifedipine (1 × 10⁻⁴ M), abolished the effect of H₂O₂ on the coupling ratio and firing frequency. All the effects of H₂O₂ were reversible, that is, washing the preparation with standard physiological saline restored the properties of the neuronal coupling to the pre-treatment value. These data are consistent with a dynamic modulation of the gap-junction properties by H₂O₂ between these two neurons.

Pulmonary respiration of molluscs (spontaneous and mediated by intracavital injection of monoamines) was studied at different environmental temperatures (5, 15, and 25 degrees C). It was established that monoamines (dopamine, serotonin, adrenalin) did not enlarge the temperature diapason, in which the respiratory behavior was realized. Microelectrode studies of spontaneous electrical activity of neurons from the respiratory network of Lymnaea stagnalis (RPeD1, VD4, cells of the Vi cluster) have shown that the respiratory program, both spontaneous and the monoamine-induced, is terminated in hypothermia. The indicated effects are suggested to be due to temperature dependence of the chemical, predominantly peptidergical, transmission of signal between neurons of the central pattern generator of respiratory pattern in Lymnaea.

We studied the effects of three various angiotensin converting enzyme inhibitors (enalapril, lisinopril and quinapril) on heart rhythm variability in anesthetized and immobilized rats. In all cases (except for quinapril in experiments on anesthetized animals), the preparations reduced the total rhythm variability and, according to spectrum analysis, increased activity of the parasympathetic autonomic nervous system to different degrees and decreased sympathetic tone. Quinapril and lisinopril produced the most pronounced influence on heart rhythm in anesthetized rats; enalapril was less potent in this respect. In immobilized animals, quinapril and enalapril showed the greatest activity and lisinopril the lowest. The more pronounced effect of quinapril both under anesthesia and during immobilization appears to be linked to the highest affinity of quinaprilat to circulatory and tissue compartments of the renin-angiotensin-aldosterone system.

Influence of shear flows of the dense plasma created under conditions of the electron cyclotron resonance (ECR) gas breakdown on the plasma confinement in the axisymmetric mirror trap ("vortex" confinement) was studied experimentally and theoretically. A limiter with bias potential was set inside the mirror trap for plasma rotation. The limiter construction and the optimal value of the potential were chosen according to the results of the preliminary theoretical analysis. This method of "vortex" confinement realization in an axisymmetric mirror trap for non-equilibrium heavy-ion plasmas seems to be promising for creation of ECR multicharged ion sources with high magnetic fields, more than 1 T.

The initial stages of nonischemic chronic heart failure in rats (model of oleothorax) were accompanied by the development of dyslipidemia. This state was characterized by an increase in total cholesterol concentration (due to the fraction of low-density lipoproteins) and atherogenicity index. The concentrations of plasma total cholesterol and low-density lipoproteins were shown to decrease in animals with severe course of nonischemic chronic heart failure. These changes were accompanied by a decrease in the atherogenicity index. Intragastric administration of cholesterol had little effect on the lipid composition of blood plasma in rats, irrespective of the severity of heart failure.

The present study confirms involvement of the sympathicoadrenal system in adaptation of heart to overload. Besides, at formation of chronic heart failure (CHF) there have been revealed a rise of the histamine and serotonin levels in blood plasma and myocardium as well as glucocorticoid hyperactivation.

Neuronal correlates of temperature dependence of alimentary behavior were studied in experiments on molluscs. It was found that a decrease of temperature led to suppression of food-procuring activity of the animals: to a decrease of the consumed food amount and of the number of food holes on the substrate. These behavioral changes are associated with a fall of impulsation frequency of the motoneuron alimentary network and with decrease of efficiency of synaptic transmission within the limits of central generator of the Lymnaea stagnalis alimentary rhythm. It is suggested that change of character of intercellular interactions within the CNS limits underlies the temperature dependence of the mollusc food-procuring activity.

In experiments on molluscs Lymnnaea stagnalis the state of antioxidative protection is studied in central nervous ganglia during a long-term activation (inhibition) of synthesis of nitric monoxide (NO) in the body. Effect of the blocker of NO-synthase N(G)-nitro-L-arginine (L-NNA) at the background of enhancement of pulmonary respiration has been established to be associated with a rise of levels of reduced glutathione and TBK-active products in the nervous tissue at preservation of a relatively high superoxide dismutase activity and a low glutathione peroxidase activity as compared with control group and the animals treated with the metabolic precursor of NO synthesis L-arginine. In spite of the revealed disturbances of balance of the body pro- and antioxidative system, DNA electrophoresis detected no products of its degradation, which can indicate the absence of massive programmed death of the nervous tissue cells in Lymnaea stagnalis during modulation of activity of the NO-ergic system.

A careful study of pulsed mode operation of the PHOENIX electron cyclotron resonance (ECR) ion source has clearly demonstrated the reality of an unexpected transient current peak, occurring at the very beginning of the plasma breakdown. This regime was named the preglow, as an explicit reference to the afterglow occurring at the microwave pulse end. After the transient preglow peak, the plasma regime relaxes to the classical steady state one. Argon preglow experiments performed at LPSC are presented. A theoretical model of ECR gas breakdown in a magnetic trap, developed at IAP, showing satisfactory agreement with the experimental results is suggested.

In narcotized rats, beta-adrenoceptor blockers changed all parameters of heart rate variability indicating up-regulation of parasympathetic activity and down-regulation of the sympathetic one. In immobilized awake rats, the temporal and geometrical parameters varied similarly, while spectral analysis indicated possible activation of other neurohumoral mechanisms against the background of beta-blocker treatment.

Lipophilic inhibitors of angiotensin-converting enzyme increased 6-month survival and/or lifetime of rats with experimental chronic heart failure. These drugs had no effect on the mortality rate of animals with acute decompensation of the disease. beta-Adrenoceptor blockers without intrinsic sympathomimetic activity not only prolonged 6-month survival and lifetime, but also decreased the mortality rate of rats with decompensation of chronic heart failure.

A dynamic model ofbiventricular chronic heart failure (CHF) induced by fractional introduction of silicon oil into the pleural cavity in rats is proposed. Silicon oil led to enlargement of the heart, myocardial hypertrophy of both ventricles, considerable pulmonary and hepatic congestion due to circulatory failure, decreased stroke volume and cardiac output, increased peripheral vascular resistance, changes in the activity of sympathoadrenal system of the heart and blood. The severity of the induced CHF varied with the dose and number of silicon oil administrations.

Two modified 2'-deoxynucleoside 5'-triphosphates have been used for the in vitro selection of a modified deoxyribozyme (DNAzyme) capable of the sequence-specific cleavage of a 12 nt RNA target in the absence of divalent metal ions. The modified nucleotides, a C5-imidazolyl-modified dUTP and 3-(aminopropynyl)-7-deaza-dATP were used in place of TTP and dATP during the selection and incorporate two extra protein-like functionalities, namely, imidazolyl (histidine analogue) and primary amino (lysine analogue) into the DNAzyme. The functional groups are analogous to the catalytic Lys and His residues employed during the metal-independent cleavage of RNA by the protein enzyme RNaseA. The DNAzyme requires no divalent metal ions or other cofactors for catalysis, remains active at physiological pH and ionic strength and can recognize and cleave a 12 nt RNA substrate with sequence specificity. This is the first example of a functionalized, metal-independent DNAzyme that recognizes and cleaves an all-RNA target in a sequence-specific manner. The selected DNAzyme is two orders of magnitude more efficient in its cleavage of RNA than an unmodified DNAzyme in the absence of metal ions and represents a rate enhancement of 10(5) compared with the uncatalysed hydrolysis of RNA.

Temperature dependence of lung respiration, defensive behavior and locomotion of Lymnaea stagnalis snail was studied. At the temperature in the range of 4-6 degrees C the rates of locomotion and respiration were reduced (as compared to control temperature of 14-16 degrees C), whereas defensive reactions were much more intense. Vice versa, the temperature rise to 24-26 degrees C activates respiration and locomotion but inhibits defensive behavior. It is suggested that the observed changes in Lymnaea behavior result from temperature-dependent reactions of neurons underlying these activities.

The mollusc, Lymnaea stagnalis, has been used as a model to study the mechanisms of temperature-dependent processes in the central nervous system. Effects of temperature changes on transmission in monosynaptic connections, made by the FMRFamide-containing neurone VD4 and the giant dopaminergic neurone RPeD1 with follower neurones, were recorded with intracellular microelectrodes. In the temperature range of 4-6 degrees C, inhibitory postsynaptic potentials (IPSP) in response to VD4 stimulation were not observed in postsynaptic cells while the IPSPs persisted in the RPeD1 followers. A temperature rise resulted in a sharp increase in the IPSP amplitude in followers of both VD4 and RPeD1. In isolated nervous systems taken from molluscs which have been kept at 4-6 degrees C for 2 weeks and more, no coupling between VD4, RPeD1 and synaptically connected cells was seen in the full experimental temperature range. The synaptic coupling recovered only after maintaining the molluscs at a water temperature of 14-16 degrees C for at least 2 days. The changes observed in synaptic responses to temperature alterations correspond to the behaviour of the molluscs., (Copyright 2002 Elsevier Science Ireland Ltd.)

At a stimulation rate of 1 Hz, activation of alpha-adrenoreceptors prolonged the AP duration at 10%, 50%, and 90% repolarisation at 10(-7), 10(-6) M in the rat isolated right atria, but shortened it at a higher concentration of 10(-5) M. The frequency-induced depression of the AP duration became more evident in cardiomyocytes stimulated by 10(-7), 10(-6) M and less obvious at 10(-5) M of alpha-adrenoagonist. Activation of alpha-adrenoreceptors by isoprenalin shortened the AP duration and enhanced the stimulation-rate-dependent changes in the atrial AP configuration.

The isolated CNS of the freshwater mollusc Lymnaea stagnalis was used as a model to study the role of cAMP in NO-mediated mechanisms. The NO donor, DEA/NO (10(-5)-10(-3) M) increased cAMP concentrations in the cerebral, pedal, pleural, parietal and visceral ganglia. In contrast, in the buccal ganglia the same doses of DEA/NO decreased the level of cAMP production. The NOS inhibitor, L-NNA (10(-4) M) increased cAMP concentrations in all areas of the CNS. L-arginine (1 mM), a metabolic precursor of NO, mimicked the action of the NO-donor. The coefficient of electrical coupling between two viscero-parietal peptidergic neurons (VD1/RPaD2) was enhanced by both DEA/NO (10(-4) M) and 8-Br-cAMP (10(-4) M) whereas 8-Br-cGMP (2x10(-4) M) reduced the coupling. We suggest that cAMP-dependent mechanisms are involved in neuronal NO signaling in this simpler nervous system.

Receptor CD4, expressed on the surface of immunocompetent cells, plays the key role in the pathogenesis of HIV infection, facilitating the penetration of the virus into the susceptible tissues of the host body. In this work the nucleotide sequence of the site on the gene of receptor CD4, responsible for the regulation of its transcription, has been determined.

The nucleotide sequence of the long terminal repeat (LTR) of human endogenous retrovirus element (HERV), localized in the first introne of the CD4 gene in the antisense direction, is determined. This new retrotransposon is highly homologous with different LTR HERV and belongs to HERV-K family. A peculiar feature of this element is an insertion of the Alu repeated sequence inside LTR. This Alu repeat has the same orientation as LTR HERV and contains two short open frames with a high level of homology with DAF (decay accelerating factor) proteins and the fifth complement component. In addition, this Alu repeat of LTR HERV contains regulatory elements: enhancer, TATAA box, poly A site, etc. Preservation of putative regulatory elements in the LTR suggests that they can render distinct regulatory properties to CD4 receptor gene.

The causes of differences in the stability of CD4 receptor and diphtherial toxin based recombinant receptorotoxins synthesized in E.coli and differing by their primary structure were under study. Insertion of a CD4 receptor fragment, responsible for HIV binding, on the N terminus of hybrid protein was found to lead to a drastic reduction of the stability of the hybrid polypeptide in E.coli and to impossibility of obtaining full-size protein product. In vitro experiments on a model of human T lymphocyte culture demonstrated that recombinant receptorotoxin stably expressed in E.coli inhibited the cytopathic effect of type 1 HIV and the effect of syncytium formation induced by the virus.