20 research outputs found

    Plasmodium Protease ROM1 Is Important for Proper Formation of the Parasitophorous Vacuole

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    Apicomplexans are obligate intracellular parasites that invade host cells by an active process leading to the formation of a non-fusogenic parasitophorous vacuole (PV) where the parasite replicates within the host cell. The rhomboid family of proteases cleaves substrates within their transmembrane domains and has been implicated in the invasion process. Although its exact function is unknown, Plasmodium ROM1 is hypothesized to play a role during invasion based on its microneme localization and its ability to cleave essential invasion adhesins. Using the rodent malaria model, Plasmodium yoelii, we carried out detailed quantitative analysis of pyrom1 deficient parasites during the Plasmodium lifecycle. Pyrom1(-) parasites are attenuated during erythrocytic and hepatic stages but progress normally through the mosquito vector with normal counts of oocyst and salivary gland sporozoites. Pyrom1 steady state mRNA levels are upregulated 20-fold in salivary gland sporozoites compared to blood stages. We show that pyrom1(-) sporozoites are capable of gliding motility and traversing host cells normally. Wildtype and pyrom1(-) sporozoites do not differ in the rate of entry into Hepa1–6 hepatocytes. Within the first twelve hours of hepatic development, however, only 50% pyrom1(-) parasites have developed into exoerythrocytic forms. Immunofluorescence microscopy using the PVM marker UIS4 and transmission electron microscopy reveal that the PV of a significant fraction of pyrom1(-) parasites are morphologically aberrant shortly after invasion. We propose a novel function for PyROM1 as a protease that promotes proper PV modification to allow parasite development and replication in a suitable environment within the mammalian host

    Complex Assessment of the Blood Oxidative Metabolism in Qualified Athletes

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    The purpose of this research was to study the structure of the shifts in the blood oxidative metabolism in professional athletes. Materials and Methods: The study included 262 highly qualified athletes (Group 1) aged between 19 and 29 years. The control group (Group 2) consisted of healthy untrained volunteers of similar age. In blood plasma, we estimated the levels of 8-isoprostane, ox-LDL, alpha- and beta-carotene, alpha- and gamma-tocopherols, and tissue-specific antioxidants (lycopine, luteine and zeaxantine) and the activity of superoxide dismutase and glutathione peroxidase. Results: Thus, in qualified athletes, characteristic changes in the state of oxidative metabolism, concerning the components of the pro- and antioxidant systems, were determined; however, the inhomogeneity of these metabolic transformations attracts attention. The revealed regularity allows confirming the previously stated hypothesis about the heterogeneity of shifts in oxidative metabolism in professional athletes, which suggests different approaches to their correction

    The effect of the synthesis conditions on the crystal structure of palladium(II) oxide nanofilms

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    Nanocrystalline films of palladium(II) oxide obtained by oxidation of the initial metallic Pd layers with a thickness of 35 nm on Si (100) substrates in atmospheric air were studied using XRD analysis, TEM, and RHEED. PdO/SiO2/Si (100) heterostructures were synthesised in two stages. First, we obtained finely dispersed layers of metallic Pd on SiO2/Si (100) substrates with an ~ 300 nm SiO2 buffer layer using thermal sublimation in a high vacuum. The Pd layers were then oxidised in the temperature range Tox = 620 – 1100 K in atmospheric air (with the partial pressure of oxygen of about 21 kPa). The study determined that the deformation of the tetragonal crystal structure of homogeneous nanocrystalline PdO films is explained by an increase in the values of lattice parameters with the oxidation temperature. The deformation reaches its maximum values at Tox ~ 970 K. Comparison of the obtained results with the earlier data regarding PdO/SiO2/Si (100) heterostructures synthesised in a dry oxygen atmosphere (with the partial pressure of oxygen of about 101.3 kPa) demonstrated that PdO films synthesized in an oxygen atmosphere are characterized by a higher degree of deformation of the crystal structure. The effect of the oxidation temperature and O2 partial pressure on the increase in the tetragonal lattice parameters of the PdO films can be explained by the formation of interstitial oxygen atoms in the octahedral void in the centre of the palladium(II) oxide unit cell

    Evaluation of Changes in Some Functional Properties of Human Mesenchymal Stromal Cells Induced by Low Doses of Ionizing Radiation

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    Each person is inevitably exposed to low doses of ionizing radiation (LDIR) throughout their life. The research results of LDIR effects are ambiguous and an accurate assessment of the risks associated with the influence of LDIR is an important task. Mesenchymal stromal cells (MSCs) are the regenerative reserve of an adult organism; because of this, they are a promising model for studying the effects of LDIR. The qualitative and quantitative changes in their characteristics can also be considered promising criteria for assessing the risks of LDIR exposure. The MSCs from human connective gingiva tissue (hG-MSCs) were irradiated at doses of 50, 100, 250, and 1000 mGy by the X-ray unit RUST-M1 (Russia). The cells were cultured continuously for 64 days after irradiation. During the study, we evaluated the secretory profile of hG-MSCs (IL-10, IDO, IL-6, IL-8, VEGF-A) using an ELISA test, the immunophenotype (CD45, CD34, CD90, CD105, CD73, HLA-DR, CD44) using flow cytometry, and the proliferative activity using the xCelligence RTCA cell analyzer at the chosen time points. The results of study have indicated the development of stimulating effects in the early stages of cultivation after irradiation using low doses of X-ray radiation. On the contrary, the effects of the low doses were comparable with the effects of medium doses of X-ray radiation in the long-term periods of cultivation after irradiation and have indicated the inhibition of the functional activity of MSCs

    Conductivity of YBCO ceramics in a wide range of temperatures and hafnium impurities concentrations

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    Conductivity of Hf doped YBa₂Cu₃O₇-δ ceramics was studied in the work. It was shown that introduction of Hf additive leads to increase of amount of scattering effective centers of the normal carriers. Excessive conductivity of the samples studied in a wide temperature range obeys the exponential temperature dependence, and near Tc satisfactorily described by the theoretical model of Aslamazov-Larkin. At the same time the Hf additive leads to significant increase of the temperature range of existence of the pseudogap anomaly in ab-plane

    Draft genomes of Enterococcus faecium strains isolated from human feces before and after eradication therapy against Helicobacter pylori

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    The abundance of Enterococci in the human intestinal microbiota environment is usually < 0.1% of the total bacterial fraction. The multiple resistance to antibiotics of the opportunistic Enterococcus spp. is alarming for the world medical community because of their high prevalence among clinically significant strains of microorganisms. Enterococci are able to collect different mobile genetic elements and transmit resistance to antibiotics to wide range of Gram-positive and Gram-negative species of microorganisms, including the transmission of vancomycin resistance to methicillin-resistant strains of Staphylococcus aureus. The number of infections caused by antibiotics resistant strains of Enterococcus spp. is increasing. Here we present a draft genomes of Enterococcus faecium strains. These strains were isolated from human feces before and after (1 month) Helicobacter pylori eradication therapy. The samples were subject to whole-genome sequencing using Illumina HiSeq. 2500 platform. The data is available at NCBI https://www.ncbi.nlm.nih.gov/bioproject/PRJNA412824

    Data on gut metagenomes of the patients with Helicobacter pylori infection before and after the antibiotic therapy

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    Antibiotic therapy can lead to the disruption of gut microbiota community with possible negative outcomes for human health. One of the diseases for which the treatment scheme commonly included antibiotic intake is Helicobacter pylori infection. The changes in taxonomic and functional composition of microbiota in patients can be assessed using “shotgun” metagenomic sequencing. Ten stool samples were collected from 4 patients with Helicobacter pylori infection before and directly after the H. pylori eradication course. Additionally, for two of the subjects, the samples were collected 1 month after the end of the treatment. The samples were subject to “shotgun” (whole-genome) metagenomic sequencing using Illumina HiSeq platform. The reads are deposited in the ENA (project ID: PRJEB18265)

    Data on gut metagenomes of the patients with Helicobacter pylori infection before and after the antibiotic therapy

    No full text
    Antibiotic therapy can lead to the disruption of gut microbiota community with possible negative outcomes for human health. One of the diseases for which the treatment scheme commonly included antibiotic intake is Helicobacter pylori infection. The changes in taxonomic and functional composition of microbiota in patients can be assessed using “shotgun” metagenomic sequencing. Ten stool samples were collected from 4 patients with Helicobacter pylori infection before and directly after the H. pylori eradication course. Additionally, for two of the subjects, the samples were collected 1 month after the end of the treatment. The samples were subject to “shotgun” (whole-genome) metagenomic sequencing using Illumina HiSeq platform. The reads are deposited in the ENA (project ID: PRJEB18265)

    Integrated Jingmenvirus Polymerase Gene in <i>Ixodes ricinus</i> Genome

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    Members of the jingmenviruses group have been found in arthropods and mammals on all continents except Australia and Antarctica. Two viruses of this group were isolated from patients with fever after a tick bite. Using a nested RT-PCR assay targeting a jingmenvirus polymerase gene fragment, we screened ticks collected in seven regions of Russia and found that the abundant jingmenvirus-positive were of Ixodes ricinus species, with the prevalence ranging from 19.8% to 34.3%. In all cases, DNase/RNase treatment suggested that the detected molecule was DNA and subsequent next generation sequencing (NGS) proved that the viral polymerase gene was integrated in the I. ricinus genome. The copy number of the integrated polymerase gene was quantified by qPCR relative to the ITS2 gene and estimated as 1.32 copies per cell. At least three different genetic variants of the integrated polymerase gene were found in the territory of Russia. Phylogenetic analysis of the integrated jingmenvirus polymerase gene showed the highest similarity with the sequence of the correspondent gene obtained in Serbia from I. ricinus
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