[Prospects for Application of Gases and Gas Hydrates to Cryopreservation]

In the present review, we tried to evaluate the known properties of gas hydrates and gases participating in the formation of gas hydrates from the point of view of the mechanisms of cryoinjury and cryoprotection, to consider the papers on freezing biological materials in the presence of inert gases, and to analyze the perspectives for the development of this direction. For the purpose, we searched for the information on the physical properties of gases and gas hydrates, compared processes occured during the formation of gas hydrates and water ice, analyzed the influence of the formation and growth of gas hydrates on the structure of biological objects. We prepared a short review on the biological effects of xenon, krypton, argon, carbon dioxide, hydrogen sulfide, and carbon monoxide especially on hypothermal conditions and probable application of these properties in cryopreservation technologies. The description of the existing experiments on cryopreservation of biological objects with the use of gases was analyzed. On the basis of the information we found, the most perspective directions of work in the field of cryopreservation of biological objects with the use of gases were outlined. An attempt was made to forecast the potential problems in this field.

[On the Effect of α-Tocopherol on Protein Kinase C Activity in vitro]

The effect of the antioxidant α-tocopherol on rat brain protein kinase C activity as a model to study bimodal dose-dependent effect has been investigated. Enzyme activity has been monitored photometrically with a luciferase reporter assay that measures ADP produced by posphorylation. The inhibition of protein kinase C activity by α-tocopherol was found at the concentration range from 10(-3) to 10(-6) M with no effect of ultra low doses of the antioxidant (below. 10(-12) M). The absence of bimodal dose-dependent effect may be associated with the enzyme source.

[Action of Combined Magnetic Fields with a Very Weak Low-frequency Alternating Component on Luminol-dependent Chemiluminescence in Mammalian Blood]

It is shown that the exposure of heparinized venous human blood diluted in phosphate buffer saline to extremely weak alternating magnetic fields of the ultralow-frequency (1 Hz, 600 nT; 4.4 Hz, 100 nT; 16.5 Hz, 160 nT) in combination with a collinear static magnetic field of 42 microT at physiological temperatures, causes a sharp 3-4 fold increase in its chemiluminescence after addition of luminol.

Modulation of inflammatory response in mice with severe autoimmune disease by thymic peptide thymulin and an inhibitor of NF-kappaB signalling

To investigate some cellular and molecular aspects of the autoimmune response and anti-inflammatory efficiency of potential therapeutic agents in a severe form of experimental autoimmune encephalomyelitis (sEAE), an inhibitor of NF-kappaB signalling, IKK Inhibitor XII, and/or thymic peptide thymulin, were injected intraperitoneally at 1.8 and 0.15mg/kg e.o.d, respectively, to C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein and several adjuvants. The immunization induced high lethality in three weeks. The biphasic cytokine response observed in earlier and delayed phases was attributed to the activity of Th1 and Th17 cells, respectively. Phosphorylation of RelA protein from the NF-kappaB family increased during the earlier phase and decreased in the delayed phase. SAPK/JNK signalling protein and heat shock protein Hsp72 significantly increased in lymphocytes. Both the IKK Inhibitor XII and thymulin reduced disease severity, attenuated immune imbalance, and increased mouse life-span. Co-administration of the agents produced no additive effect. Both the inhibitor and thymulin reduced the Th1 response but not the Th17 response. Therefore, RelA-associated Th1 activation and RelA-independent Th17 activation occurred in sEAE. Thymulin and the inhibitor demonstrate similar patterns of activity, potentially through the RelA pathway inhibition, resulting in a partial therapeutic effect on the animals' health status.

[Modulating effect of weak combined magnetic fields on duration of mealworm beetle Tenebrio molitor metamorphosis stage]

It is shown that an exposure of pupae of the mealworm beetle Tenebrio molitor to the combined static (42 μT) and very weak alternating (250 nT) magnetic fields exerts different influence, depending on the frequency of the alternating magnetic field, on duration of metamorphosis processes in these insects. For instance, an exposure of pupae to weak combined magnetic fields, adjusted to the frequency of ion cyclotron resonance for glutaminic acid (4,4 Hz), stimulates metamorphosis process--a transitional stage from pupae to imago lasts shorter. An inhibiting effect was observed when adjusted to the frequency of ion cyclotron resonance for Ca2 (32,2 Hz). At some frequencies this effect is not seen. For instance, an exposure at a frequency of ion cyclotron resonance for K+ (16,5 Hz) exerts no noticeable effect on the duration of the pupal metamorphosis stage.

[The process of heme synthesis in bone marrow mesenchymal stem cells cultured under fibroblast growth factor bFGF and hypoxic conditions]

It was demonstrated that fibroblast growth factor bFGF influences the process of heme synthesis, the proliferation activity and viability of bone marrow mesenchymal stem cells in culture under hypoxic conditions. The addition of fibroblast growth factor bFGF (7 ng/ml) to the medium under above conditions led to the accumulation of aminolevulinic acid--an early porphyrin and heme precursor, an increase in CD 71 expression--a transferrin receptor, and also a decrease in porphyrin pigments and heme contents--a late precursor and end products of heme synthesis, respectively. It was found that cultivation of the cells under hypoxic conditions and bFGF is an optimum to maintain high viability and proliferation capacity of the mesenchymal stem cells.

Changes in immune cell signalling, apoptosis and stress response functions in mice returned from the BION-M1 mission in space

To explore the effect of the spaceflight environment on immunity in animals, C57/BL6 mice flown on a 30-day space high-orbit satellite mission (BION-M1) were analyzed. Cytokine response in mice was measured in tandem with the following parameters: the synthesis of inducible forms of the heat shock proteins HSP72 and HSP90α; activity of the NF-κB, IFR3, and SAPK/JNK signalling pathways; and TLR4 expression. In addition, apoptosis in the thymus was measured by caspase-3 and ph-p53/p53 ratio testing. In response to flight environment exposure, mice had a reduction in spleen and thymus masses and decreased splenic and thymic lymphocyte counts. Plasma concentration of IL-6 and IFN-γ but not TNF-α was decreased in C57BL6 mice. The NF-κB activity in splenic lymphocytes through the canonical pathway involving IκB degradation was significantly increased at 12h after landing. One week after landing, however, the activity of NF-κB was markedly decreased below even the control values. Non-canonical NF-κB activity increased during the whole observation period. The activities of SAPK/JNK and IRF-3 were invariable at 12h but significantly increased 7 days after landing. The expression of Hsp72 and Hsp90α was somewhat increased 12h (Hsp72) and 7 days (Hsp90α). TLR4 expression in splenic cells was significantly increased only at 12h, returning to normal 7 days after landing. To assess the apoptosis in thymus lymphocytes, caspase-3 and levels of p53 protein along with its phosphorylated form were measured in thymic lymphocytes. The results indicated that the high-orbit spaceflight environment caused an increase in the level of p53 but more notably in the activated, phosphorylated form of the p53 protein. The calculated ratio of the active to inactive forms of the protein (ph-53/p53) 12h after landing increased by more than twofold, indicating the apparent induction of apoptosis in thymus cells. Interestingly, 7 days after the landing, this ratio was not restored, but rather increased: the specified ratio was four times higher compared to the ground-based control. Measurements of caspase-3 in thymic cells indicated more expressive increase in apoptosis. Taken together, the results of the present study indicate that spaceflight induces an imbalance in the immunity of mice, showing variation in signalling, apoptosis and stress response that are not restored by 7 days after landing. These changes are distinguished from classic stress-related alterations usually caused by conventional stressors.

[Calculation of the amount of free water molecules in aqueous solutions by means of spectral parameters from the terahertz frequency domain taking into account processes of screening]

In this paper we derive a formula to calculate the amount of free water molecules in solution. Physical values in this formula may be obtained by analyzing the spectra of aqueous solutions in the terahertz frequency range. Formula is derived on the basis of considering water polarization process in electric field. It is shown that without processes of shielding the electric field in the water calculations lead to very high estimation of a share of free water molecule.

[The influence of fibroblast growth factor (FGF2) on cardiomyocytes differentiation of mesenchymal stem cells of bone marrow ex vivo]

The influence of FGF2 on the efficiency of cardiomyocytes differentiation of mesenchymal stem cells (MSC) of bone marrow induced by 5-azacetidine (5-aza) was studied. The effect of FGF2 developing by the 14th day after the combined action of a differentiating agent and growth factor was manifested in an increase in Mef2A, Mef2D and gene transcription and a rise of ionized Ca2+ concentration in cytoplasm keeping cell viability and proliferation activity. In the presence of FGF2 this approach provided cardiomyogenesis and the increase in the formation of early precursors of cardiomyocytes.

[On peculiarities of temperature dependences of water spectra in the terahertz frequency domain]

We analyzed spectra of light and heavy water at temperatures from 4 up to 50 degrees C in a frequency range of 0.15 to 6.5 THz. It was shown that the amplitude of high-frequency relaxation absorption band with its maximum at 0.5 THz extends with increasing, temperature and this temperature dependence for light water has a marked feature at 35-40 degrees C as a sharp growth. This fact is noteworthy because this range corresponds to physiological values of a body temperature of the warm-blooded organisms. At the same time, the analogous temperature dependence for heavy water in the considered temperature range lacks this particular feature. Thus, the water with its properties differs significantly not only from other fluids, but also from its own isotopologues.

[A role of trophoblastic cells in regulation of mouse blastocyst survival in vitro after microinjection and osmotic stress]

We have evaluated the morphology of the mouse preimplantation embryos at developmental stages from morula to late-blastocyst after two different impacts: microinjection of modified Witten's medium and osmotic stress in physiological osmolarity (310 mOsM), in 5% glucose (560 mOsM) at high concentration of NaCl (614 mOsM). Results of our research showed that these stresses caused similar changes in embryo morphology: volume was reduced followed by its recovery in culture medium (osmolality was less than a physiological value, 260 MOsM). The ability of embryos to recover the volume and morphology up to the initial level depends on a stage of embryo development and consequently competence of TB cells. In this study it was revealed that a key role in regulation of volume homeostasis after microinjection and after short-time (30-60 min) osmotic stress belongs to TB cells. Both physical effects induce the further embryo development in vitro up to the formation of primary colonies of embryonic and trophoblastic cells. These data could be used to develop the morphological criteria for a prediction of blastocyst-stage embryonic implantation potential.

[On singularities of molecular relaxation in water solutions]

In this paper, we analyzed spectra of liquid water and water solutions in a frequency domain, characteristic of the collective dynamics of water molecules (from 0 to 200 cm(-1)). Particular attention is paid to the relaxation processes, one of which is observed in the terahertz region of the spectrum (approximately 5-50 cm(-1)). The physical essence of this process at the molecular level is still unclear. Based on data obtained this process is strongly suggested to interpret as a monomolecular relaxation of unbound water molecules.

[Calculation of the portion of free water molecules in water solutions by means of spectral analysis]

In this paper we present the results of spectral studies of water solutions and water at different temperatures. The calculation method for estimation of the portion of free water molecules is offered. The method is based on the analysis of transmissions spectra features in the terahertz region. The calculation using the proposed method shows that the portion of free water molecules at room temperature ranges from 10 to 16% for a variety of water solutions. In case of pure water, the temperature increase from 20 to 50 degrees C results in the increase of the free molecule fraction from 12% to 19%. Moreover, the increase in the number of free water molecules within a specified temperature range exhibits significant nonuniformity: the most intense growth was observed in the range of 30-40 degrees C. This is particularly interesting because this temperature range includes the optimum temperatures for the existence of warm-blooded animals.

Structural and dynamic properties of thymopoietin mimetics

We propose a hypothesis that the T-cell receptor is a possible target of thymic hormones. We modelled the conformational dynamics of thymopentin and its structural variants in solution, as well as the interactions of these short peptides with the proposed molecular target. Thymopentin is a five-amino-acid fragment of the thymic hormone thymopoietin (residues 32 to 36) that reproduces the immunomodulatory activity of the complete hormone. Using molecular dynamics and flexible docking methods, we demonstrated high-affinity binding of thymopentin and its prospective mimetics with the T-cell receptor. The calculated biological activity spectra of thymopentin and its two promising modifications can be used in immunomodulatory activity screenings with live systems.

[Effects of several inhibitors of intracellular signaling on production of cytokines and signal proteins in RAW 264.7 cells cultivated with low dose ammonium]

Effects of four inhibitors of NF-kappaB, SAPK/JNK and TLR4 signaling, namely, inhibitor XII, SP600125, CLI-095 and Oxpapc on a macrophage response to low dose ammonium were studied in RAW 264.7 cells. Low dose ammonium induced pro-inflammatory response in cells as judged from enhanced production of TNF-alpha, IF-gamma, and IL-6, and by activation of signal cascades. The increase in production of cytokines, namely TNF, IFN, and IL-6, demonstrated that low-dose ammonium induced a pro-inflammatory cellular response. In addition, an activation of NF-kappaB and SAPK/JNK cascades, as well as enhancement of TLR4 expression was shown. Each of used inhibitors reduced to a variable degree the pro-inflammatory response of RAW 264.7 cells on chemical toxin by decreasing cytokine production. The inhibitor of NF-kappaB cascade, IKK Inhibitor XII, was more effective, and not only prevented the development of pro-inflammatory response induced by ammonium, but also decreased cytokine production below control values. The inhibitor of extra cellular domains of TLR2 and TLR4 (OxPAPC) had almost the same anti-inflammatory effect, and an addition of the inhibitor of JNK cascade (SP600125) to cell culture practically neutralized effect of ammonium ions by decreasing cytokine production to control level. Inhibitory analysis showed that activation of RAW 264.7 cells induced by chemical toxin coincide incompletely with intracellular signaling pathways that were early determined regarding macrophage's response to toxin from gram-negative bacteria. Nevertheless, application of the inhibitors defended RAW 264.7 from toxic effect of the low dose ammonium.

[Frequency dependence of heating of human skin exposed to millimeter waves]

In this paper we studied experimentally the frequency dependence of heating of human skin exposed to millimeter waves. Theoretical modeling of obtained data was performed using the hybrid bio-heat equation. It was found that the skin heating and SAR increased with increasing the exposure frequency. The frequency dependence of heating was entirely resulted from that of reflection from the skin. Unlike temperature, the frequency dependence of the SAR was due to the increased absorption of millimeter wave energy within the thin surface layer of the skin.

Thymus peptides regulate activity of RAW 264.7 macrophage cells: inhibitory analysis and a role of signal cascades

OBJECTIVES

The aim of this study was to reveal T-lymphocyte-independent mechanisms of thymic peptide-mediated immunomodulation.

METHODS

The effects of two thymic peptides- thymulin and thymopentin were studied in cultured RAW 264.7 macrophages (lipopolysaccharide-stimulated or unstimulated) by measuring cytokine production and signal protein levels.

RESULTS

Both peptides increased proinflammatory cytokine secretion by unstimulated RAW 264.7 macrophages and these effects were blocked by the NF-κB cascade inhibitor, stress-activated protein kinase (SAPK)/JNK cascade inhibitor and, to a lesser extent, Toll-like 4 receptor activity inhibitor. In macrophages stimulated by bacterial lipopolysaccharide, peptides alone did not affect cytokine secretion, but significantly enhanced effects of each of the inhibitors. Thymopentin increased activation of both NF-κB and SAPK/JNK cascades in unstimulated macrophages, while thymulin significantly decreased activation of the SAPK/JNK but not NF-κB cascade in LPS-stimulated macrophages. Thymulin and thymopentin increased production of the heat shock protein HSP72 both in LPS-stimulated and unstimulated cells.

CONCLUSIONS

Thymulin and thymopentin are effective anti-inflammatory modulators with direct actions on innate immune cells; the effects involve multiple signal cascades, including NF-κB and SAPK/JNK pathways. Since signaling cascades are now considered to be targets for new therapies, thymic peptides may be prospective modulators of signaling cascades, acting alone or in combination with other agents.

[Two peroxiredoxins 6 of Xenopus laevis]

Two different genes of peroxiredoxin 6 are encoded in the genome of Xenopus laevis: xen1 (Acc.no. EMBL Data Bank - BCO54278) and xen2 (Acc.no. EMBL Data Bank - BC540309). Both genes were cloned and expressed in Escherichi coil. Proteins were purified and analyzed. The amino acid sequences of the enzymes Xen1 and Xen2 are 95% identical with the same peroxidase activity, pH and temperature optimums, as well as thermostability, being approximately equal. The expression of peroxiredoxin 6 genes significantly differ during ontogenesis of X. laevis. The expression of xen1 starts on a later stage of development 47-48, while the gene xen2 is expressed on all stages of development with the same increase starting from stage 0-5. The level of xen2 expression in embryos increased after incubation in presence of hydrogen peroxide. The comparison of amino acid sequences of proteins Xen1 and Xen2 shows that only the enzyme Xen2 may have phospholipase activity, since it has residues of phospholipase A2 active center: Ser31, His25, Asp139.

[Modified peroxiredoxins as prototypes of drugs a powerful antioxidant]

The possibility of using modified peroxyredoxins as powerful antioxidant agents has been considered. Peroxyredoxins immobilized on perfluorocarbon emulsions and PTD-modified peroxyredoxins have been studied. It has been shown that peroxyredoxins efficiently bind to particles of perfluorocarbon emulsions, while maintaining their antioxidant properties. A panel of PTD-modified peroxyredoxins has been created and peroxyredoxins most effective both in antioxidant properties and the ability to penetrate cells have been selected. The modified peroxyredoxins obtained may serve as the basis for the design of drug with powerful antioxidant action.

[Problems of using a thermocouple for measurements of skin temperature rise during the exposure to millimeter waves]

The possibility of using thermocouples for the artifact-free measurements of skin temperature during millimeter wave exposure was studied. The distributions of the specific absorption rate (SAR) in the human skin were calculated for different orientations of the thermocouple relative to the E-field of exposure. It was shown that, at the parallel orientation of a thermocouple relative to the E-field, SAR significantly increased at the tip of the thermocouple. This can result in an overheating of the thermocouple. At the perpendicular orientation of a thermocouple, the distortions of the SAR were insignificant. The data obtained confirm that the skin temperature can be measured with a thermocouple during exposure under the condition that the thermocouple is located perpendicular to the E-vector of the electromagnetic field. For the accurate determination of SAR from the rate of the initial temperature rise, it is necessary to fit the temperature kinetics measured with the thermocouple to the solution of the bio-heat transfer equation.