C-axis lattice dynamics in Bi-based cuprate superconductors

We present results of a systematic study of the c axis lattice dynamics in single layer Bi2Sr2CuO6 (Bi2201), bilayer Bi2Sr2CaCu2O8 (Bi2212) and trilayer Bi2Sr2Ca2Cu3O10 (Bi2223) cuprate superconductors. Our study is based on both experimental data obtained by spectral ellipsometry on single crystals and theoretical calculations. The calculations are carried out within the framework of a classical shell model, which includes long-range Coulomb interactions and short-range interactions of the Buckingham form in a system of polarizable ions. Using the same set of the shell model parameters for Bi2201, Bi2212 and Bi2223, we calculate the frequencies of the Brillouin-zone center phonon modes of A2u symmetry and suggest the phonon mode eigenvector patterns. We achieve good agreement between the calculated A2u eigenfrequencies and the experimental values of the c axis TO phonon frequencies which allows us to make a reliable phonon mode assignment for all three Bi-based cuprate superconductors. We also present the results of our shell model calculations for the Gamma-point A1g symmetry modes in Bi2201, Bi2212 and Bi2223 and suggest an assignment that is based on the published experimental Raman spectra. The superconductivity-induced phonon anomalies recently observed in the c axis infrared and resonant Raman scattering spectra in trilayer Bi2223 are consistently explained with the suggested assignment.Comment: 29 pages, 13 figure

Effects of amino-terminus truncation in human cytochrome P450IID6 on its insertion into the endoplasmic reticulum membrane of Saccharomyces cerevisiae

AbstractA truncated form of cytochrome P450IID6 deprived of 22 NH2-terminal amino acids residues (P450IID6Δ1-22) was found in both the cytosol and the microsomal fraction of the yeast, Saccharomyces cerevisiae. A reduced CO difference spectrum of this form was characterized by the absence of absorption at 448 nm and weak absorption at 420 nm. Another peculiarity of P450IID6Δ1-22 expression was its reduced content in the yeast cells compared to that of P450IID6, with the intracellular levels of the corresponding mRNAs being the same. We suggest that the deleted form of P450IID6, i.e. lacking 22 NH2-terminal amino acid residues, is not inserted properly in the endoplasmic reticulum membrane: it does not take up the proper conformation to enable normal heme binding and is degraded in the yeast cells

Effects of recombinant IFN-α2b on the phenotype of neutrophil granulocyte subpopulations in patients with COVID-19

Investigation of molecular mechanisms associated with interferon (IFN) production and receptor function of neutrophil granulocytes (NGs) in COVID-19 is highly relevant because it can be promising in the search for new therapeutic strategies targeting NGs and their reactivity to restore and strengthen the innate immune response against SARS-CoV-2. Objective. To assess the effects of recombinant IFN-α2b on the phenotype of CD16+IFNα/βR1–CD119+, CD16+IFNα/βR1+CD119–, and CD16+IFNα/βR1+CD119+ NGs from peripheral blood of patients with COVID-19 in an in vitro experiment. Patients and methods. We analyzed blood samples from 31 patients with a mean age of 61 years (range: 57;71 years) with moderate COVID-19. We assessed the number of CD16+IFNα/βR1–CD119+, CD16+IFNα/βR1+CD119–, and CD16+IFNα/βR1+CD119+ NGs, receptor density (FC 500, ‘Beckman Coulter,’ USA), phagocytic activity of NGs before and after incubation with recombinant IFN-α2b. We also measured serum levels of several cytokines, including IFNα, IFNγ, IL-6, IL-8 (ELISA, ‘Vektor-Best’ LLC). The control group comprised 22 adult healthy individuals with a mean age of 58 years (range: 57; 70 years). Results. Patients with moderate COVID-19 demonstrated low serum levels of IFNα and IFNγ along with elevated levels of IL-6 and IL-8. We observed transformation of 3 phenotypes among NG subpopulations: CD16+IFNα/βR1–CD119+, CD16+IFNα/βR1+CD119-, and CD16+IFNα/βR1+CD119+. We observed positive remodulating effects of recombinant IFN-α2b on the number and phenotype of NG subpopulations and their phagocytic activity in our in vitro experiment. Conclusion. Recombinant IFN-α2b demonstrated positive effects in in vitro experiments; therefore, it can be considered in the future as a potential therapeutic tool for moderate COVID-19. Restoration of type I IFN might be an effective treatment option for COVID-19, because it can promote faster virus elimination, restore normal functioning of the IFN system, and have positive regulatory effects on the phenotype of NG subpopulations. © 2022, Dynasty Publishing House. All rights reserved

Transformations of tetrahydropyrido[4′,3′:4,5]thieno[2,3-d] pyrimidin-4(3H)-ones in the presence of alkynes bearing electron-withdrawing substituents

Tetrahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines in the presence of activated alkynes were transformed into mixtures of pyrimido[5′,4′:4,5]thieno[3,2-d]azocines and spiro[pyridine-4, 5′-thieno[2,3-d]pyrimidines]. © 2012 Springer Science+Business Media New York

Differentiated transformation of the phenotype of subpopulations of neutrophilic granulocytes in viral-viral and purulent bacterial infections in immunocomprometed children

Children with clinical signs of immunocompromise have impaired functioning of the immune system. At the same time, the state of subpopulations of multifunctional neutrophil granulocytes (NG), which provide antiviral and antibacterial protection, in such patients has been poorly studied. Objective of the study: To assess the features of the transformation of the phenotype of the three most significant subpopulations of NG, their association with impaired phagocytic and microbicidal activity in immunocompromised children with atypical viral-viral co-infections and bacterial infections, and to clarify their differential diagnostic significance. Materials and methods of research: The phenotypes of NG subpopulations expressing CD64, CD32, CD16, CD11b receptors, phagocytic and microbicidal activity of NG were studied in the peripheral blood of 43 immunocompromised children of both sexes aged of 5–9 years old suffering from recurrent ARVI, atypical chronic mono – or mixed herpes virus infections (HVI) and purulent bacterial infection. 3 study groups were formed: 1st – repeated ARVI/HVI mono, 2nd – repeated ARVI/HVI mixed, 3rd – minor purulent infection (MPI) and a comparison group (20 apparently healthy children). Results: Different differentiated transformation of the phenotype of functionally significant subpopulations of NG associated with impaired functional activity of NG as well as with the incidence of viral co-infections (repeated ARVI and recurrent HVI mixed) and the severity of clinical manifestations of MPI has been identified in the studied groups. Conclusion. Еvaluation of the features of transformation of phenotype of NG subpopulations, their effector functions in immunocompromised children with atypical viral-viral co-infections and purulent bacterial infections, will allow in the future to optimize the methods of target immunotherapy aimed at remodulating the negatively transformed phenotype of NG subpopulations, correcting their dysfunctions and, thereby, significantly increase the clinical effectiveness of therapeutic and preventive measures. © 2021, Pediatria Ltd.. All rights reserved

Synthesis of 2-(chloro(methoxy, morpholino)methyl)-hexahydropyrimidothieno[3,2-c]azocines and tetrahydrospiro[pyrido[4,5']thieno[2,3-d]pyrimidines]

2-(Chloromethyl)-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-ones reacted with acetylenedicarboxylate ester, methyl propiolate or acetylacetylene, forming mixtures of 2-(chloromethyl)-5,6,7,10-tetrahydropyrimido[5',4':4,5]thieno[3,2-d]azocin-4(3H)-ones and 2'-chloromethyl-6'-methylidene-2,3-dihydro-1H-spiro[pyrido[4,5']thieno[2,3-d]pyrimidin]-4'(3'H)-ones in various ratios. Analogous products were also obtained in the reaction of 2-(methoxymethyl) derivative with methyl propiolate, while using 2-[(morpholin-4-yl)-methyl] derivative in a similar reaction led to the formation of a more complex product mixture. © 2015 Springer Science+Business Media New York

Novel synthetic route toward benzofuran-pyridine-based spirans

A novel domino reaction of tetrahydrobenzofuro[3,2-c] or [2,3-c]pyridines with dimethylacetylene dicarboxylate (DMAD) or methyl propiolate (MP) resulted in the formation of spirobenzofuranpyridines in moderate yields. The spirobenzofuran derivatives reported may be considered analogs of the antifungal drug griseofulvin. © 2012 Copyright Taylor and Francis Group, LLC

In vitro phenotypic re-orientation of functionally important neutrophil subpopulations and their microbicidal activity in the children with purulent inflammatory diseases influenced by glucosaminil muramildipeptide

Numerous studies over last decade have shown that functional capacity of neutrophil granulocytes (NG) determines the course and outcome of many diseases. Identification of phenotypic variants of functionally significant NG subpopulations is a new approach allows us to assess the adequacy or deficiency of NG involvement into infectious inflammation processes at molecular level. An opportunity of reorienting a deficient NG subpopulational phenotype in purulent inflammatory diseases due to the rearrangement of the receptor set induced by various immunotropic substances may serve as a key to recovery of normal NG functioning. Our aim was to study the effect of glucosaminylmuramyldipeptide (GMDP) under in vitro conditions upon the phenotypic profile of four functionally significant subpopulations, i.e., CD62L+CD63-NG, CD62L+CD63+NG and CD64-CD32+CD16+CD11b+NG, CD64+CD32+CD16+CD11b+NG, along with assessment of expression density of appropriate membrane molecules and NG microbicidal activity in the children with purulent inflammatory diseases. 90 samples of peripheral blood (PC) were taken from children 2 to 4 years old, including 12 children with minor purulent infection (MPI), and 7 children were studied as conditionally healthy controls. Their peripheral blood was incubated for 60 minutes at 37 °C with GMP (10-6 g/l). Using flow cytometry technique, the relative numbers of some NG subpopulations, i.e., CD64-CD16+CD32+CD11b+NG, CD64+CD16+CD32+CD11b+NG, CD62L+CD63-NG, CD62L+CD63+NG were evaluated, and the phenotype features of each subpopulation were investigated according to the density of appropriate membrane molecule expression (MFI). In parallel, phagocytic and microbicidal activity of NG was tested in these study groups. The obtained data indicate for presence of for distinct NG subpopulations, both in healthy children and in children with MPI. We have revealed phenotypic transformation of the four studied NG subpopulations from MPI patients including disturbed phagocytic and microbicidal functions of the cells. Using of this in vitro system, we have shown that the transformed phenotype of the four functionally significant NG subpopulations of MPI patients was re-Arranged under GMDP treatment. At the same time, the number of CD62L+CD63+NG and CD64-CD32+CD16+CD11b+ NG subpopulations was increased, along with decreased amounts of CD64+CD32+CD16+CD11b+NG and CD62L+CD63-NG subpopulations, being accompanied by restoration of microbicidal activity of NGs. The obtained data allow us to accomplish current understanding of immunotropic effects of GMDP, and to extend the potential scope of its experimental and clinical application. The new data on GMDP effects revealed by in vitro system, i.e. phenotype rearrangement of functionally significant NG subpopulations CD64-CD16+CD32+CD11b+, CD64+CD16+CD32+CD11b+, CD62L+CD63-, CD62L+CD63+ in atypical purulent inflammatory diseases in children, may be used in the future in order to develop innovative strategies of immunotherapy aiming for correction of NG dysfunction in children with MPI. © 2021 Russian Association of Allergologists and Clinical Immunologists, St. Petersburg Regional Branch (SPb RAACI). All rights reserved

Novel synthetic route toward benzofuran-pyridine-based spirans

A novel domino reaction of tetrahydrobenzofuro[3,2-c] or [2,3-c]pyridines with dimethylacetylene dicarboxylate (DMAD) or methyl propiolate (MP) resulted in the formation of spirobenzofuranpyridines in moderate yields. The spirobenzofuran derivatives reported may be considered analogs of the antifungal drug griseofulvin. © 2012 Copyright Taylor and Francis Group, LLC