Formation of the diffusion layer in gas boring

© Published under licence by IOP Publishing Ltd. Boriding in powder media is successfully used to increase the life of parts. To increase the depth of the diffusion layer and improve its properties, a method for activating the surface of a saturable part by means of electromechanical processing is proposed. The results on the structure of the resulting layer and its dimensions are presented

Significance of polymorphism in 2’,5’-oligoadenylate synthetase genes in HIV infection

© 2016, Nizhny Novgorod State Medical Academy. All rights reserved.The aim of the investigation was to assess the prognostic value of polymorphism of genes encoding 2’,5’-oligoadenylate synthetase (OAS) synthesis in HIV infection. Materials and Methods. The DNA of 94 HIV infected patients have been sequenced using multiplex polymerase chain reaction. For molecular genetic testing we used DNA samples isolated from the scraping of oral epithelial cells. We studied interferon-induced genes, namely: OAS enzyme. It was a case–control study. Depending on the decrease rate of CD4-lymphocytes, the patients were divided into two groups: with typical disease progression and those with slow progression. We determined the frequencies of mutant alleles and genotypes in patients with different progression rates, and assessed genotype associations with different outcomes. Results. There have been found oligonucleotide polymorphisms of OAS genes of different enzyme forms: OAS2 rs2072137 (chr12:113440921) and OAS3 rs1859330 (chr12:113376388). The frequency of mutant allele C of OAS2 rs2072137 polymorphism appeared to be significantly higher in a group with a typical disease progression (p=0.03). The frequency of mutant allele A of OAS3 rs1859330 polymorphism had no difference in the groups. In a group with mutant genotypes TC and CC of OAS2 rs2072137 polymorphism, the frequency of typical disease progression was significantly higher than that in the group with the main (“wild”) genotype TT (p=0.0125). Logistic regression revealed typical HIV infection progression in patients to be significantly associated with OAS2 rs2072137 polymorphism and age. Conclusion. OAS2 rs2072137 polymorphism is associated with typical progressive HIV infection, and, probably, presents a new genetic prognostic marker of the disease

Effect of a new coronavirus infection Covid-19 on the immunological status of pregnant women

The aim of the investigation was to review the foreign and domestic literature data on the immune system status of novel coronavirus infection COVID-19 during pregnancy, its effect on perinatal outcomes.Цель исследования – изучить данные зарубежных и отечественных источников литературы о состоянии иммунной системы при новой коронавирусной инфекции COVID-19 во время беременности, влияние ее на перинатальные исходы

Ex Vivo VEGF Delivery by Neural Stem Cells Enhances Proliferation of Glial Progenitors, Angiogenesis, and Tissue Sparing after Spinal Cord Injury

The present study was undertaken to examine multifaceted therapeutic effects of vascular endothelial growth factor (VEGF) in a rat spinal cord injury (SCI) model, focusing on its capability to stimulate proliferation of endogenous glial progenitor cells. Neural stem cells (NSCs) can be genetically modified to efficiently transfer therapeutic genes to diseased CNS. We adopted an ex vivo approach using immortalized human NSC line (F3 cells) to achieve stable and robust expression of VEGF in the injured spinal cord. Transplantation of NSCs retrovirally transduced to overexpress VEGF (F3.VEGF cells) at 7 days after contusive SCI markedly elevated the amount of VEGF in the injured spinal cord tissue compared to injection of PBS or F3 cells without VEGF. Concomitantly, phosphorylation of VEGF receptor flk-1 increased in F3.VEGF group. Stereological counting of BrdU+ cells revealed that transplantation of F3.VEGF significantly enhanced cellular proliferation at 2 weeks after SCI. The number of proliferating NG2+ glial progenitor cells (NG2+/BrdU+) was also increased by F3.VEGF. Furthermore, transplantation of F3.VEGF increased the number of early proliferating cells that differentiated into mature oligodendrocytes, but not astrocytes, at 6 weeks after SCI. F3.VEGF treatment also increased the density of blood vessels in the injured spinal cord and enhanced tissue sparing. These anatomical results were accompanied by improved BBB locomotor scores. The multifaceted effects of VEGF on endogenous gliogenesis, angiogenesis, and tissue sparing could be utilized to improve functional outcomes following SCI

Caveolin-1 Plays a Crucial Role in Inhibiting Neuronal Differentiation of Neural Stem/Progenitor Cells via VEGF Signaling-Dependent Pathway

In the present study, we aim to elucidate the roles of caveolin-1(Cav-1), a 22 kDa protein in plasma membrane invaginations, in modulating neuronal differentiation of neural progenitor cells (NPCs). In the hippocampal dentate gyrus, we found that Cav-1 knockout mice revealed remarkably higher levels of vascular endothelial growth factor (VEGF) and the more abundant formation of newborn neurons than wild type mice. We then studied the potential mechanisms of Cav-1 in modulating VEGF signaling and neuronal differentiation in isolated cultured NPCs under normoxic and hypoxic conditions. Hypoxic embryonic rat NPCs were exposed to 1% O2 for 24 h and then switched to 21% O2 for 1, 3, 7 and 14 days whereas normoxic NPCs were continuously cultured with 21% O2. Compared with normoxic NPCs, hypoxic NPCs had down-regulated expression of Cav-1 and up-regulated VEGF expression and p44/42MAPK phosphorylation, and enhanced neuronal differentiation. We further studied the roles of Cav-1 in inhibiting neuronal differentiation by using Cav-1 scaffolding domain peptide and Cav-1-specific small interfering RNA. In both normoxic and hypoxic NPCs, Cav-1 peptide markedly down-regulated the expressions of VEGF and flk1, decreased the phosphorylations of p44/42MAPK, Akt and Stat3, and inhibited neuronal differentiation, whereas the knockdown of Cav-1 promoted the expression of VEGF, phosphorylations of p44/42MAPK, Akt and Stat3, and stimulated neuronal differentiation. Moreover, the enhanced phosphorylations of p44/42MAPK, Akt and Stat3, and neuronal differentiation were abolished by co-treatment of VEGF inhibitor V1. These results provide strong evidence to prove that Cav-1 can inhibit neuronal differentiation via down-regulations of VEGF, p44/42MAPK, Akt and Stat3 signaling pathways, and that VEGF signaling is a crucial target of Cav-1. The hypoxia-induced down-regulation of Cav-1 contributes to enhanced neuronal differentiation in NPCs