A new structural analog of human insulin--glycine-B30-insulin

Enzymatic-chemical preparation of glycine-B30-insulin, a new structural analog of human insulin has been performed. The new analog differs from the natural hormone by a substituted ThrB30 residue in the glycine residue. The biological activity of the glycine-B30-insulin as measured by the mouse convulsion assay is 100%.     

Crimean-Congo Hemorrhagic Fever Virus Entry into Host Cells Occurs through the Multivesicular Body and Requires ESCRT Regulators

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne bunyavirus causing outbreaks of severe disease in humans, with a fatality rate approaching 30%. There are no widely accepted therapeutics available to prevent or treat the disease. CCHFV enters host cells through clathrin-mediated endocytosis and is subsequently transported to an acidified compartment where the fusion of virus envelope with cellular membranes takes place. To better understand the uptake pathway, we sought to identify host factors controlling CCHFV transport through the cell. We demonstrate that after passing through early endosomes in a Rab5-dependent manner, CCHFV is delivered to multivesicular bodies (MVBs). Virus particles localized to MVBs approximately 1 hour after infection and affected the distribution of the organelle within cells. Interestingly, blocking Rab7 activity had no effect on association of the virus with MVBs. Productive virus infection depended on phosphatidylinositol 3-kinase (PI3K) activity, which meditates the formation of functional MVBs. Silencing Tsg101, Vps24, Vps4B, or Alix/Aip1, components of the endosomal sorting complex required for transport (ESCRT) pathway controlling MVB biogenesis, inhibited infection of wild-type virus as well as a novel pseudotyped vesicular stomatitis virus (VSV) bearing CCHFV glycoprotein, supporting a role for the MVB pathway in CCHFV entry. We further demonstrate that blocking transport out of MVBs still allowed virus entry while preventing vesicular acidification, required for membrane fusion, trapped virions in the MVBs. These findings suggest that MVBs are necessary for infection and are the sites of virus-endosome membrane fusion.     

Combination of Hypomorphic Mutations of the Drosophila Homologues of Aryl Hydrocarbon Receptor and Nucleosome Assembly Protein Family Genes Disrupts Morphogenesis,Memory and Detoxification

Aryl hydrocarbon receptor is essential for biological responses to endogenous and exogenous toxins in mammals. Its Drosophila homolog spineless plays an important role in fly morphogenesis. We have previously shown that during morphogenesis spineless genetically interacts with CG5017 gene, which encodes a nucleosome assembly factor and may affect cognitive function of the fly. We now demonstrate synergistic interactions of spineless and CG5017 in pathways controlling oxidative stress response and long-term memory formation in Drosophila melanogaster. Oxidative stress was induced by low doses of X-ray irradiation of flies carrying hypomorphic mutation of spineless, mutation of CG5017, and their combination. To determine the sensitivity of these mutants to pharmacological modifiers of the irradiation effect, we irradiated flies growing on standard medium supplemented by radiosensitizer furazidin and radioprotector serotonin. The effects of irradiation were investigated by analyzing leg and antenna morphological structures and by using real-time PCR to measure mRNA expression levels for spineless, Cyp6g1 and Gst-theta genes. We also examined long-term memory in these mutants using conditioned courtship suppression paradigm. Our results show that the interaction of spineless and CG5017 is important for regulation of morphogenesis, long-term memory formation, and detoxification during oxidative stress. Since spineless and CG5017 are evolutionary conserved, these results must be considered when evaluating the risk of combining similar mutations in other organisms, including humans.     

A new method for morphometric analysis of tissue distribution of mobile cells in relation to immobile tissue structures

The distribution of cells in stained tissue sections provides information that may be analyzed by means of morphometric computation. We developed an algorithm for automated analysis for the purpose of answering questions pertaining to the relative densities of wandering cells in the vicinity of comparatively immobile tissue structures such as vessels or tumors. As an example, we present the analysis of distribution of CD56-positive cells and of CXCR3-positive cells (relative densities of peri-vascular versus non-vascular cell populations) in relation to the endothelium of capillaries and venules of human parietal decidua tissue of first trimester pregnancy. In addition, the distribution of CD56-positive cells (mostly uterine NK cells) in relation to spiral arteries is analyzed. The image analysis is based on microphotographs of two-color immunohistological stainings. Discrete distances (10-50 μm) from the fixed structures were chosen for the purpose of defining the extent of neighborhood areas. For the sake of better comparison of cell distributions at different overall cell densities a model of random distribution of "cells" in relation to neighborhood areas and rest decidua of a specific sample was built. In the chosen instances, we found increased perivascular density of CD56-positive cells and of CXCR3-positive cells. In contrast, no accumulation of CD56-positive cells was found in the neighborhood of spiral arteries.     

Secretion of enteric α-defensin 5 into bloodstream by colon tumors

The screening for enteric α-defensin was performed in the blood serum of oncology patients and healthy donors. Enteric α-defensin was not detected in all serum samples from five healthy donors, while serum samples from two of the five oncology patients had the processed form of this protein. The acquired results allow us to suggest the possibility of the serological diagnostics of large intestinal tumors in high-risk groups.     

Metal‐Ion Coupled Electron Transfer Kinetics in Intercalation‐Based Transition Metal Oxides

Electrochemical metal‐ion intercalation systems are acknowledged to be a critical energy storage technology. The kinetics of the intercalation processes in transition‐metal based oxides determine the practical characteristics of metal‐ion batteries, such as the energy density, power, and cyclability. With the emergence of post lithium‐ion batteries, such as sodium‐ion and potassium‐ion batteries, which function predominately in nonaqueous electrolytes of special formulation and exhibit quite varied material stability with regard to their surface chemistries and reactivity with electrolytes, the practical routes for the optimization of metal‐ion battery performance become essential. Electrochemical methods offer a variety of means to quantitatively study the diffusional, charge transfer, and phase transformation rates in complex systems, which are, however, rather rarely fully adopted by the metal‐ion battery community, which slows down the progress in rationalizing the rate‐controlling factors in complex intercalation systems. Herein, several practical approaches for diagnosing the origin of the rate limitations in intercalation materials based on phenomenological models are summarized, focusing on the specifics of charge transfer, diffusion, and nucleation phenomena in redox‐active solid electrodes. It is demonstrated that information regarding rate‐determining factors can be deduced from relatively simple analysis of experimental methods including cyclic voltammetry, chronoamperometry, and impedance spectroscopy.     

Dynamics of glucocorticoids in the ontogenesis of freshwater crawfish Astacus leptodactylus Esch

Dynamics of changes in glucocorticoid (hydrocortisone and corticosterone) levels was studied in the ontogenesis of freshwater crawfish Astacus Leptodactylus Esch. It was shown that steroid concentrations increase during the embryogenesis period. Decrease in the glucocorticoid levels during postembryonic development is most probably related to the stabilization of young fish growth and the attainment of hormone levels typical for adult individuals. The correlation ofglucocorticoid levels with physiological-biochemical changes at different stages of ontogenesis indicates that these steroids play an essential role in the regulation of freshwater crawfish vital functions.     

Compounds of the 1,5-di(4-R-phenyl)- 3-selenopentanediones-1,5 series interaction with the basidiomycete Lentinula edodes lectins: computations and experiment

The role of spatial and electron structure, hydrophobic properties and concentration of organoselenium compounds on their interaction with fungal metabolites--extracellular lectins of Lentinula edodes (shiitake mushroom) has been considered. By the hybrid method of density functional theory at the B3LYP/6-31G(d,p) theory level, spatial and electronic structure of the 1,5-diphenyl-3-selenopentanedione-1,5 (preparation DAPS-25), 1,5-di(4-methoxyphenyl)-3-selenopentanedione-1,5 and 1,5-di(4-ethoxyphenyl)-3-selenopentanedione-1,5 molecules has been studied. The above molecules have been stated to be substantially similar to each other by their electronic and spatial characteristics. By means of the QSAR properties evaluation by the atomic-additive schemes, it has been shown that the molecules of the preparation DAPS-25, its dimethoxy- and diethoxy-substituted are close to each other by the hydrophilic-lipophilic balance, whereas di-n-octoxy derivative DAPS-25 is explicitly hydrophobic. The hemagglutinating activity of lectins in the presence of the preparation DAPS-25 and its alkyloxy-substituted increases, therewith the most effective addition is 1,5-di(4-ethoxyphenyl)-3-selenopentanedione-1,5. Apparently, the greater effectiveness of the said substance compared to DAPS -25 is caused by the formation of hydrogen bonds with a participation of unshared electron pairs of oxygen atoms from the ethoxy groups and mobile hydrogen atoms from the OH groups of glycoconjugates on erythrocytes surface. The positive effect of 1,5-di(4-n-octoxyphenyl)-3-selenopentanedione-1,5 is not so prominent, since the enlarged alkyl chain shields the aromatic fragments of organoselenium molecule participating in the binding with lectin.     

Isolation and characterization of lectin from the surface of <Emphasis Type="Italic">Grifola frondosa</Emphasis> (Fr.) S.F.Gray mycelium

From the surface of the dikaryotic mycelium of the xylotrophic basidiomycete Grifola frondosa 0917 a lectin has been isolated with a molecular mass of 68 ± 1 kDa, consisting of two subunits of 33–34 kDa each. The lectin is a hydrophilic glycoprotein with the protein: glycan ratio of 3: 1. It exhibits high affinity to native rabbit erythrocytes and to human erythrocytes of the 0 blood group, but not to trypsin-treated ones. The hemagglutination (HA) caused by lectin was not blocked by any of the 25 tested mono-, di-, and amino sugars; it was also not blocked by some of glyco derivatives. Only 13.9 μg/ml of the homogeneous preparation of a polysaccharide, a linear D-rhamnan with the structure of the repeated component →2)-β-D-Rhap-(1→3)-α-D-Rhap-(1→3)-α-D-Rhap-(1→2)-α-D-Rhap-(1→2)-α-sD-Rhap-1(→ blocked hemagglutination completely. The analysis of the amino acid composition of the lectin showed the greatest percentage of amino acids with positively charged R groups, arginine, lysine, and histidine, as well as the complete absence of sulfurcontaining amino acids, cysteine, and methionine. D-glucose and D-glucosamine were detected in the carbohydrate part. Original Russian Text ? L.V. Stepanova, V.E. Nikitina, A.S. Boiko, 2007, published in Mikrobiologiya, 2007, Vol. 76, No. 4, pp. 488–493.