Erythropoietin: function and therapeutic potential

Erythropoietin (EPO) exerts its effect on erythroid lineage cells through interaction with the EPO receptor (EPOR), the so-called canonical pathway, and through a complex consisting of EPOR and a common cytokine receptor beta subunit (CD131) – a non-canonical pathway for non-hematopoietic cells of the human and animal body. EPO realizes its effects through the launch of a signaling cascade, which begins with the phosphorylation of Janus kinase 2 (JAK2) and then with the involvement of phosphatidylinositol-3 kinase B (PI3K) or Ras-mitogen-activated protein kinase (MAPK) or signal transducers and transcription activators (STAT). EPO exhibits a direct cytoprotective effect through increased CD131 expression and subsequent development of anti-apoptotic and anti-inflammatory effects in target cells. In addition to its use in the treatment of anemia, EPO is increasingly being used in correction of inflammatory and degenerative processes, both in experimental and clinical studies. EPO promotes the engraftment of stem cells, differentiation of mesenchymal stem cells in the connective tissue direction, suppresses the inflammatory response and apoptosis of cells in the lesion. The article includes literature data concerning EPO and its clinical use in inflammatory and degenerative processes, based on data from eLibrary and the National Center for Biotechnological Information (NCBI) for the period 1998–2022

Mesenchymal stem cells: properties and clinical application

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into various cell types, including adipocytes, osteocytes, chondrocytes, etc. MSCs can be isolated from various human and animal tissues. MSCs are characterized by high proliferative capacity, differentiation in the connective-tissue direction, paracrine and trophic activity (they produce a wide range of biologically active molecules), are capable of migrating to the zone of organ and tissue damage, and exhibit immunosuppression. There are similarities and differences between human and mammalian MSCs in phenotype and functional activity. The therapeutic potential of MSCs has been shown on experimental models and in clinical trials, which allows us to consider the MSC-oriented cell technologies as an alternative to traditional methods of treatment. The article presents a review and analysis of the literature devoted to the study of MSCs properties, signaling pathways involved in the regulation of cell activity, the prospects for the use of MSCs in the treatment of inflammatory and degenerative diseases. During preparation of the review full-text, free access articles for the period from 2006 to 2022 were taken from eLibrary and National Center for Biotechnology Information (NCBI) databases

Estimations of electron-positron pair production at high-intensity laser interaction with high-Z targets

Electron-positron pairs' generation occuring in the interaction of $10^{18}$-$10^{20}$~W/cm$^2$ laser radiation with high-Z targets are examined. Computational results are presented for the pair production and the positron yield from the target with allowance for the contribution of pair production processes due to electrons and bremsstrahlung photons. Monte-Carlo simulations using the PRIZMA code confirm the estimates obtained. The possible positron yield from high-Z targets irradiated by picosecond lasers of power $10^2$-$10^3$~TW is estimated to be $10^9$-$10^{11}$

Heat Capacity of PbS: Isotope Effects

In recent years, the availability of highly pure stable isotopes has made possible the investigation of the dependence of the physical properties of crystals, in particular semiconductors, on their isotopic composition. Following the investigation of the specific heat ($C_p$, $C_v$) of monatomic crystals such as diamond, silicon, and germanium, similar investigations have been undertaken for the tetrahedral diatomic systems ZnO and GaN (wurtzite structure), for which the effect of the mass of the cation differs from that of the anion. In this article we present measurements for a semiconductor with rock salt structure, namely lead sulfide. Because of the large difference in the atomic mass of both constituents ($M_{\rm Pb}$= 207.21 and ($M_{\rm S}$=32.06 a.m.u., for the natural isotopic abundance) the effects of varying the cation and that of the anion mass are very different for this canonical semiconductor. We compare the measured temperature dependence of $C_p \approx C_v$, and the corresponding derivatives with respect to ($M_{\rm Pb}$ and $M_{\rm S}$), with \textit{\textit{ab initio}} calculations based on the lattice dynamics obtained from the local density approximation (LDA) electronic band structure. Quantitative deviations between theory and experiment are attributed to the absence of spin-orbit interaction in the ABINIT program used for the electronic band structure calculations.Comment: 17 pages including 10 Fig

Effect of extracts from microalgae on cytokine levels in female C57Bl6 mice

Microalgae from the freshwater basins and seas are a valuable source of broad-spectrum biologically active substances that can affect the cells of immune system and their functional state. Cytokines are involved in all vital processes proceeding in the living cells (proliferation, maturation, differentiation, apoptosis/ necrosis). A study was performed in order to assess the effects of standard food formula for experimental animals supplemented with oil extract of microalgae from various systematic groups upon the levels of cytokines in blood serum, culture media conditioned by immunocytes, as well as kidney and liver tissues. The standard food was impregnated in oil extracts of microalgae (C. vulgaris, Coelastrella sp., A. platensis, C. closterium, and P. purpureum). In control series, the food was impregnated with pure vegetable oil. The animals were fed these foods for 12 days. Blood, spleen and thymus were taken to isolate immunocytes, kidneys and liver, and dimethyl sulfoxide extracts of the cells were produced. The conditioned media of splenocytes and thymocytes were obtained by adding concanavalin A (0 and 10 μg/ml) to the cultured cells. The levels of NO, IL-1β, IL-10, TNFα, and NO were determined in serum, conditioned media, and tissue extracts. In serum, the influence of microalgae on the levels of IL-1β and TNFα was revealed. Activation of immunocytes in experimental groups was followed by changes in IL-1β, TNFα and IL-10 production. Changes of cytokine and NO levels were revealed in liver and kidney extracts in experimental groups. Thus, microalgae extracts of various systematic groups affect the levels of cytokines in blood serum, cultural media conditioned by splenocytes and thymocytes, kidney and liver tissues

Cloning and sequence analysis of cDNA for a human homolog of eubacterial ATP-dependent Lon proteases

AbstractOverlapping cDNA clones containing mRNA for a putative Lon protease (LonHS) were isolated from cDNA libraries prepared from human brain poly(A)+ RNA. The determined nucleotide sequence contains a 2814-bp open reading frame with two potential initiation codons (positions 62–64 and 338–340). The 5'-terminal 337-nucleotide fragment of LonHS mRNA is highly enriched with G and C nucleotides and could direct synthesis of the LonHS N-terminal domain. More likely this region promotes initiation of protein synthesis from the second AUG codon in a cap-independent manner. The amino acid sequence initiated at the second AUG codon includes 845 residues, over 30% of which are identical to those of eubacterial Lon proteases. Residues of the ‘A’ and ‘B’ motifs of NTP-binding pattern and a plausible catalytic serine residue are conserved in LonHS. Northern blot analysis revealed LonHS mRNA in lung, duodenum, liver and heart, but not in thymus cells

Recording and light scattering on dynamic holographic gratings in Sr0.61Ba0.39Nb2O6: 0.002 wt.% CeO2 crystal

This work was supported by VolkswagenStiftung, Grant No. Az. 90.261 and Presidium RAS Program No. 5: “Photonic technologies in probing inhomogeneous media and biological objects”

Dynamical Phases of Driven Vortices Interacting with Periodic Pinning

The finite temperature dynamical phases of vortices in films driven by a uniform force and interacting with the periodic pinning potential of a square lattice of columnar defects are investigated by Langevin dynamics simulations of a London model. Vortices driven along the [0,1] direction and at densities for which there are more vortices than columnar defects ($B>B_{\phi}$) are considered. At low temperatures, two new dynamical phases, elastic flow and plastic flow, and a sharp transition between them are identified and characterized according to the behavior of the vortex spatial order, velocity distribution and frequency-dependent velocity correlationComment: 4 pages with 4 figures. To be published in Phys. Rev. B Rapid Communication