86 research outputs found

    Hydrological changes in the White Sea during the historical period inferred from analysis of dinocysts

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    According to available historical evidence, colonization of the White Sea region began in the 9th–8th centuries B.C. [2]. This unique region with ancient residence sites experiences progressively increasing anthropogenic load against the background of natural climatic changes. The intense economic development of the region requires complex ecological and paleogeographic studies aimed at detailed reconstruction of past sedimentation settings. The analysis of dinocysts, which makes it possible to reconstruct various parameters of water masses washing the Arctic shelf, has become a promising method in paleohydrological studies, widely used in recent years [10, 11]. Dinoflagellates, which represent one of the main phytoplankton groups in the Arctic Seas, the White Sea included, form cysts with biopolymer envelopes, which are preserved in sediments. Thus, information on glacial–hydrological conditions is recorded in marine sediments. In the White Sea, this method was first used for the study of bottom sediments only in 2003 [3, 15]. In this communication, we present the first results obtained during the thorough study of dinocysts in bottom sediment cores from the White Sea, which cover the last 250 years. The study of this microfossil group made it possible to reconstruct in detail changes in glacial–hydrological settings in the sea and reveal their relations with known climatic–hydrological events that occurred in neighboring regions during the historical period

    Dinoflagellate cysts in the surface sediments of the White Sea

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    Dinoflagellate cysts were studied in 42 samples from the surface sediments of the White Sea. The total concentration of dinocysts varies from single cysts to 25 000 cyst/g of dry sediments, which reflects the biological productivity in the White Sea waters and the regional particular features of the sedimentation processes. The highest concentrations are observed in silts; they are related to the regions of propagation of the highly productive Barents Sea waters in the White Sea. Generally, the spatial distribution of dinocysts species in the surface sediments corresponds to the distribution of the major types of water masses in the White Sea. The cysts of the relatively warm-water species (Operculodinium centrocarpum, Spiniferites sp.) of North Atlantic origin that dominate in the sediments indicate an intensive intrusion of the Barents Sea water masses to the White Sea along with hydrological dwelling conditions in the White Sea favorable for the development of these species during their vegetation period. The cold-water dinocyst assemblage (Islandinium minutum, Polykrikos sp.) is rather strictly confined to the inner parts of shallow-water bays, firstly, those adjacent to the Onega and Severnaya Dvina river mouths

    RegPredict: an integrated system for regulon inference in prokaryotes by comparative genomics approach

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    RegPredict web server is designed to provide comparative genomics tools for reconstruction and analysis of microbial regulons using comparative genomics approach. The server allows the user to rapidly generate reference sets of regulons and regulatory motif profiles in a group of prokaryotic genomes. The new concept of a cluster of co-regulated orthologous operons allows the user to distribute the analysis of large regulons and to perform the comparative analysis of multiple clusters independently. Two major workflows currently implemented in RegPredict are: (i) regulon reconstruction for a known regulatory motif and (ii) ab initio inference of a novel regulon using several scenarios for the generation of starting gene sets. RegPredict provides a comprehensive collection of manually curated positional weight matrices of regulatory motifs. It is based on genomic sequences, ortholog and operon predictions from the MicrobesOnline. An interactive web interface of RegPredict integrates and presents diverse genomic and functional information about the candidate regulon members from several web resources. RegPredict is freely accessible at http://regpredict.lbl.gov

    Identification and Intraspecific Typing of Plague Microbe Strains with Their Potential Virulence Determination Using PCR

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    Developed is the method of identification and intraspecific typing of plague microbe strains along with their potential virulence determination. Intraspecific differentiation and focal attribution of the examined plague microbe strains can be determined by monolocus VNTR-PCR, and main virulence determinants (chromosomal pigmentation region and calcium-dependence plasmid genes) - by multiplex PCR

    Hematopoietic stem cell transplantation with alpha/beta T-lymphocyte depletion and short course of eculizumab in adolescents and young adults with paroxysmal nocturnal hemoglobinuria

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    The main goal is to optimize hematopoietic stem cell transplantation (HSCT) approach among adolescents and young adults with paroxysmal nocturnal hemoglobinuria (PNH) by means of Graft-versus-host disease (GVHD) and post-transplant complications risk lowering. Materials and methods. We report our experience of HSCT from HLA-matched unrelated donors using TCR alfa/beta and CD19 depletion in 5 pts (1M/4F) with PNH, developed after successful immunosuppressive therapy (IST) of acquired aplastic anemia (AA). Median age of pts at the moment of transplantation was 17,8 years (range 14,5-22,7), median interval from IST to PNH was 4 years (5mo - 6,5 y). In all patients non-severe pancytopenia was present: granulocytes 0,8х109/l (0,8-1,8 х109/l) platelets 106 х109/l (27-143 х109/l) and Hb -78 g/l, median PNH clone size in granulocytes was 94 (range 75-99)%. One pts previously developed sinus thrombosis. Conditioning consisted of thoraco-abdominal irradiation 4-6 Gy, cyclophosphamide 100 mg/kg, fludarabine 150 mg/m2 and anti-thymocyte globulin (ATG) or alemtuzumab. Eculizumab was given from day (-7) till day (+14) (every 7 days, only 4 times). GVHD prophylaxis was tacrolimus ± methotrexate. Results. Infusedgraft characteristics were: CD34+ - 8,1х106/kg, CD3TCRab·150х103/kg, CD3gd+ - 7,3х106/kg, СD19+ - 221х103/kg, NK -6,4х108/kg. Engraftment was achieved in all 5 pts with a median of 15(12-18) и 13(10-18) days for granulocytes and platelets, respectively. Skin acute GVHD grade I developed in only 1 pt, and subsided with short course of glucocorticoids. CMV reactivation occurred in 1 pt; there were no episodes of Epstein-Barr Virus (EBV) o rAdenovirus (AdV) reactivation. Full donor myeloid chimerism was established in all pts by day +30. Immune reconstitution was delayed until 6 months after transplant but no severe infections occurred. All pts are alive 1,7-5,5 years (med 4 years) after HSCT with normal hematopoiesis and immune function, full donor chimerism and no late sequelae. Conclusions. Transplantation of TCRalfa/beta and CD19 depleted hematopoietic cells from matched unrelated donor after immunoablative conditioning and supported with short course of eculizumab is perfectly safe and efficient technology leading to cure in young patients with PNH

    BTK, NuTM2A, and PRPF19 are Novel KMT2A Partner Genes in Childhood Acute Leukemia

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    Chromosomal rearrangements of the human KMT2A/MLL gene are associated with acute leukemias, especially in infants. KMT2A is rearranged with a big variety of partner genes and in multiple breakpoint locations. Detection of all types of KMT2A rearrangements is an essential part of acute leukemia initial diagnostics and follow-up, as it has a strong impact on the patients’ outcome. Due to their high heterogeneity, KMT2A rearrangements are most effectively uncovered by next-generation sequencing (NGS), which, however, requires a thorough prescreening by cytogenetics. Here, we aimed to characterize uncommon KMT2A rearrangements in childhood acute leukemia by conventional karyotyping, FISH, and targeted NGS on both DNA and RNA level with subse-quent validation. As a result of this comprehensive approach, three novel KMT2A rearrangements were discovered: ins(X;11)(q26;q13q25)/KMT2A-BTK, t(10;11)(q22;q23.3)/KMT2A-NUTM2A, and inv(11)(q12.2q23.3)/KMT2A-PRPF19. These novel KMT2A-chimeric genes expand our knowledge of the mechanisms of KMT2A-associated leukemogenesis and allow tracing the dynamics of minimal residual disease in the given patients. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: KMT2A rearrangement assessment was supported by the Russian Science Foundation (grant no. 19-75-10056). Quantitative RT-PCR for MRD monitoring was supported by Russian Presidential (grant no. MK-1645.2020.7)

    Exploratory Study of the Long-Term Persistence of <i>Yersinia pestis</i> in the Cells of Soil-Inhabiting Ameba - <i>Acanthamoeba Sp.</i>

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    Objective of the study is to explore the feasibility of the long-term persistence of Yersinia pestis strains in association with ameba - Acanthamoeba sp. Materials and methods. Investigated has been interaction of ameba - Acanthamoeba sp., isolated from rodent burrows in the Pre-Caspian sandy, Volga-Ural steppe, and Pre-Caspian North-Western steppe natural foci, with 4 strains of Y. pestis of the main subspecies, 1 strain of caucasica and 1 strain of altai subspecies. Results and discussion. It is established that the strains of the main subspecies survive in the cells of ameba at 26 °C and 20 % humidity (modeling of the drought conditions in the natural plague foci) within 2-4 months of experiment, and 10-20 times longer that in pure culture. Two strains of the non-main ssp. have not demonstrated an increase in persistency in association with Acanthamoeba sp., which may occur due to degraded resistance to phagocytosis in the ameba of this specie. Using fluorescent and transmission electronic microscopy, it is determined that the cells of plague agent persist in ameba cells in individual vacuoles, enclosed in endoplasmic reticulum. The data obtained may testify to the possible involvement of ameba Acanthamoeba sp. . into sustainment of Y. pestis in soil biocoenoses of natural plague foci

    Temperature and spatial connectivity drive patterns in freshwater macroinvertebrate diversity across the Arctic

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    Warming in the Arctic is predicted to change freshwater biodiversity through loss of unique taxa and northward range expansion of lower latitude taxa. Detecting such changes requires establishing circumpolar baselines for diversity, and understanding the primary drivers of diversity. We examined benthic macroinvertebrate diversity using a circumpolar dataset of &gt;1,500 Arctic lake and river sites. Rarefied α diversity within catchments was assessed along latitude and temperature gradients. Community composition was assessed through region-scale analysis of β diversity and its components (nestedness and turnover), and analysis of biotic–abiotic relationships. Rarefied α diversity of lakes and rivers declined with increasing latitude, although more strongly across mainland regions than islands. Diversity was strongly related to air temperature, with the lowest diversity in the coldest catchments. Regional dissimilarity was highest when mainland regions were compared with islands, suggesting that connectivity limitations led to the strongest dissimilarity. High contributions of nestedness indicated that island regions contained a subset of the taxa found in mainland regions. High Arctic rivers and lakes were predominately occupied by Chironomidae and Oligochaeta, whereas Ephemeroptera, Plecoptera, and Trichoptera taxa were more abundant at lower latitudes. Community composition was strongly associated with temperature, although geology and precipitation were also important correlates. The strong association with temperature supports the prediction that warming will increase Arctic macroinvertebrate diversity, although low diversity on islands suggests that this increase will be limited by biogeographical constraints. Long-term harmonised monitoring across the circumpolar region is necessary to detect such changes to diversity and inform science-based management.</p

    The role of nelarabine in the treatment of T-cell acute lymphoblastic leukemia: literature review and own experience

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    Aim. The analysis of experience of nelarabine use in refractory/relapsed T-cell acute lymphoblastic leukemia (T-ALL) depending on the immunophenotype and the line of therapy. Materials and methods. All the patients with relapsed or refractory T-ALL aged from 0 to 18 years who received treatment with nelarabine as a part of the therapeutic element R6 were included in the study. For all patients a detailed immunological analysis of leukemia cells with discrimination of immunological variants TI, TII, TIII or TIV was performed. Patients administered with nelarabine as a first therapeutic element were referred to the first-line therapy group, other patients were referred to the second-line therapy group. Nelarabine was administered as intravenous infusion at a dose of 650 mg/m2, on days 1-5. Allogeneic hematopoietic stem cells transplantation (allo-HSCT) was considered for all patients. Results. From 2009 to 2017, 54 patients with refractory/relapsed T-ALL were treated with nelarabine. Five-year event-free survival (EFS) and overall survival (OS) was 28% for all patients, cumulative risk of relapse (CIR) was 27%. EFS was significantly higher in nelarabine first-line therapy group in comparison with second-line therapy group (34±8% vs 8±8%, p=0,05). In patients after allo-HSCT EFS, OS and CIR were 51±10%, 50±10% and 39,1±9,5% accordingly. The best results were achieved in patients with TI immunophenotype. No toxicity-related mortality as well as severe neurologic complications or discontinuation of therapy associated with use of nelarabine were reported. Conclusion. The use of nelarabine is an effective strategy for the treatment of relapsed and refractory T-ALL. The best treatment outcomes were obtained in patients with TI immunophenotype and in the first-line therapy group. Optimal dosage regimens can be established during controlled clinical trials

    Особенности использования мультимедийных презентаций и электронных учебников при обучении иностранных граждан в российских вузах

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    The article raises the problem of training cadets of the CIS countries who receive higher education in military universities of our country. Russian language proficiency is the main problem, as the training is exclusively in Russian, and as part of a Russian group. Language acquisition occurs gradually during interpersonal communication, and most of all, at classes. One of the first subjects that cadets start studying is mathematics. The main feature of mathematics is the universality of formulas for communication in its language both in the CIS countries and in the world. It greatly simplifies the process of transmitting information to students, allows the teacher to minimize the number of Russian words at the first stages of training (first year of training) gradually raising the volume of definitions and theorems. The great majority of students from the CIS countries freely perceive the lecture and fully assimilate the information even in such a section of «Higher mathematics»as probability theory by the end of the second year. The article shows the transition from the overwhelming number of formulas in the lectures to the prevalence of definitions and theorems. The number of Russian words also increases at practical classes. Their introduction is based on drawings (topic «Analytical geometry»), graphs («Introduction to mathematical analysis», «Definite integral »). The laboratory works are of the greatest interest, of course, where students must draw conclusions about the suitability of the formula obtained as the experiment result. The article details the methodological features of organizing various types of classes using multimedia tools and electronic textbooks in groups with cadets from the CIS countries.В данной статье поднимается проблема обучения курсантов стран СНГ, которые получают высшее образование в военных вузах нашей страны. Следует отметить, что проблема связана, в первую очередь, с владением русским языком, так как обучение осуществляется исключительно на русском языке и в составе русской группы. Овладение языком происходит постепенно в ходе межличностного общения, а больше всего, во время занятий. Одним из первых предметов, которые начинают изучать курсанты, является математика. Основной особенностью математики можно считать универсальность формул для общения на ее языке не только в странах СНГ, но и во всем мире, что значительно упрощает процесс передачи информации обучающимся, позволяет преподавателю минимизировать количество русских слов на первых этапах обучения (первый год обучения), постепенно увеличивая объем определений и теорем. К концу второго курса курсанты из стран СНГ, в подавляющем большинстве, свободно воспринимают лекцию и полностью усваивают информацию даже по такому разделу дисциплины «Высшая математика», как теория вероятностей. В статье на примерах показан переход от подавляющего количества формул на лекции к превалированию определений и теорем. На практических занятиях также происходит увеличение количества русских слов. Их введение опирается на чертежи (тема «Аналитическая геометрия»), графики («Введение в математический анализ», «Определенный интеграл»). Но, безусловно, наибольший интерес вызывают лабораторные работы, в ходе выполнения которых обучаемые должны сделать выводы о пригодности полученной в результате эксперимента формулы. В статье подробно описаны методические особенности организации различных видов занятий в группах, где присутствуют курсанты стран СНГ, с использованием мультимедийных средств и электронных учебников
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