73 research outputs found

    Concept, Principles, and Objectives of Population Hematology

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    The article provides grounds for a new, expanded definition of a concept «population hematology». It is not only a hematological subsection of the traditional population and epidemiological medicine. It is focused on patients populations as its primary object; however, its uniqueness is in the fact that its primary object is the nested population hierarchy, such as blood cells, cell clones and human groups. The heterogeneity of the samples and changes in the heterogeneity with the course of time are most important. Taking into account the time factor, staging, and long-term observation are unique characteristics of the population hematology methodology. Mechanism of population formation, leaving, and changes in its composition significantly affect the analysis of clinical and population study findings. The peculiarity of this field of medical knowledge is interaction, overlapping of target populations. Donor-recipient, patient-doctor, blood cells-body, virus-carrier-host, blood component-sample, donor-recipient sample, etc. — these are only some of alive and lifeless study objects which may undergo a thorough study. Despite the complexity and various natures of hematological populations, they have common characteristics. Therefore, a common methodology and tools for study designing, collection of experimental data, modeling, and analysis can be developed

    The Comparison of De Novo Grade 3 Follicular Lymphoma and Transformed Grade 3 Follicular Lymphoma: Own Data

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    Background. Grade 3 follicular lymphoma (FL) is a heterogenetic group of tumors. The selections of patients with similar characteristics of the tumor process is important for classification 3 grade forms of FL and risk stratification, as well as for the development of new therapeutic approaches. Different morphological, immunohistochemical and cytogenetical characteristics of the tumor result in different clinical forms of the disease. Aim. To describe the clinical, morphological, immunohistochemical and cytogenetical characteristics of grade 3 FL and evaluate their prognostic value for R-CHOP-21 chemotherapy. Materials & Methods. We performed retrospective and prospective analysis of morphological, immunohistochemical and genetical characteristics of 93 primary patients with grade 3 FL (21–78 years, median 53 years, women to men — 1:1.4) admitted to National Medical Hematology Research Center from years 2001 to 2016. Morphological and immunohistochemical assessment of the affected lymph nodes and bone marrow biopsy material was performed. Data obtained from the standard cytogenetic and FISH assessment were compared to identify the BCL2 rearrangement. Results. We proposed an algorithm for differential diagnosis of the 2 types of grade 3 FL: de novo FL (n = 22) and transformed FL (n = 21). De novo grade 3 FL had the immunophenotype of CD10– in 19 (86 %) cases, MUM1++ (monomorphically) in 19 (90 %), and BCL-2 in 5 (22 %). It was characterized by the absence of the BCL2 rearrangement (n = 22, 100 %) and bone marrow involvement (n = 14, 67 %) and/or bone marrow involvement (n = 7, 100 %). Third grade FL transformed from grades 1 or 2 had was CD10+ (n = 19, 90 %), MUM1+ (heterogeneously, n = 16, 76 %) or MUM1– (n = 4, 19 %), BCL-2+ (n = 20, 95 %) and had BCL2 rearrangement (n = 19, 90 %). Small cell bone marrow involvement was observed in 71 % of cases, whereas large cell involvement was seen predominantly in de novo FL (p = 0.06). The analysis showed that 5-year relapse-free survival in patients with grade 3 de novo FL after R-CHOP-21 therapy was 87 % compared to 16 % with transformed FL (p = 0.06) for the median 41 months of follow up. Conclusion. We described the morphological, immunohistochemical and cytogenetical characteristics of grade 3 de novo FL and grade 3 FL, transformed from grades 1 or 2. The described variants show different sensitivity to immunochemotherapy

    MAGE-A cancer/testis antigens inhibit MDM2 ubiquitylation function and promote increased levels of MDM4

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    Melanoma antigen A (MAGE-A) proteins comprise a structurally and biochemically similar sub-family of Cancer/Testis antigens that are expressed in many cancer types and are thought to contribute actively to malignancy. MAGE-A proteins are established regulators of certain cancer-associated transcription factors, including p53, and are activators of several RING finger-dependent ubiquitin E3 ligases. Here, we show that MAGE-A2 associates with MDM2, a ubiquitin E3 ligase that mediates ubiquitylation of more than 20 substrates including mainly p53, MDM2 itself, and MDM4, a potent p53 inhibitor and MDM2 partner that is structurally related to MDM2. We find that MAGE-A2 interacts with MDM2 via the N-terminal p53-binding pocket and the RING finger domain of MDM2 that is required for homo/hetero-dimerization and for E2 ligase interaction. Consistent with these data, we show that MAGE-A2 is a potent inhibitor of the E3 ubiquitin ligase activity of MDM2, yet it does not have any significant effect on p53 turnover mediated by MDM2. Strikingly, however, increased MAGE-A2 expression leads to reduced ubiquitylation and increased levels of MDM4. Similarly, silencing of endogenous MAGE-A expression diminishes MDM4 levels in a manner that can be rescued by the proteasomal inhibitor, bortezomid, and permits increased MDM2/MDM4 association. These data suggest that MAGE-A proteins can: (i) uncouple the ubiquitin ligase and degradation functions of MDM2; (ii) act as potent inhibitors of E3 ligase function; and (iii) regulate the turnover of MDM4. We also find an association between the presence of MAGE-A and increased MDM4 levels in primary breast cancer, suggesting that MAGE-A-dependent control of MDM4 levels has relevance to cancer clinically

    Azimuthal anisotropy and correlations at large transverse momenta in p+pp+p and Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV

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    Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in p+pp+p at the same energy. Elliptic anisotropy, v2v_2, is found to reach its maximum at pt3p_t \sim 3 GeV/c, then decrease slowly and remain significant up to pt7p_t\approx 7 -- 10 GeV/c. Stronger suppression is found in the back-to-back high-ptp_t particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of v2v_2 at intermediate ptp_t is compared to simple models based on jet quenching.Comment: 4 figures. Published version as PRL 93, 252301 (2004

    Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

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    The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape

    Rapidity and Centrality Dependence of Proton and Anti-proton Production from Au+Au Collisions at sqrt(sNN) = 130GeV

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    We report on the rapidity and centrality dependence of proton and anti-proton transverse mass distributions from Au+Au collisions at sqrt(sNN) = 130GeV as measured by the STAR experiment at RHIC. Our results are from the rapidity and transverse momentum range of |y|<0.5 and 0.35 <p_t<1.00GeV/c. For both protons and anti-protons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y|<0.5. Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton(anti-proton) yields and transverse mass distributions the possibility of pre-hadronic collective expansion may have to be taken into account.Comment: 4 pages, 3 figures, 1 table, submitted to PR

    Direct Observation of Single Amyloid-β(1-40) Oligomers on Live Cells: Binding and Growth at Physiological Concentrations

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    Understanding how amyloid-β peptide interacts with living cells on a molecular level is critical to development of targeted treatments for Alzheimer's disease. Evidence that oligomeric Aβ interacts with neuronal cell membranes has been provided, but the mechanism by which membrane binding occurs and the exact stoichiometry of the neurotoxic aggregates remain elusive. Physiologically relevant experimentation is hindered by the high Aβ concentrations required for most biochemical analyses, the metastable nature of Aβ aggregates, and the complex variety of Aβ species present under physiological conditions. Here we use single molecule microscopy to overcome these challenges, presenting direct optical evidence that small Aβ(1-40) oligomers bind to living neuroblastoma cells at physiological Aβ concentrations. Single particle fluorescence intensity measurements indicate that cell-bound Aβ species range in size from monomers to hexamers and greater, with the majority of bound oligomers falling in the dimer-to-tetramer range. Furthermore, while low-molecular weight oligomeric species do form in solution, the membrane-bound oligomer size distribution is shifted towards larger aggregates, indicating either that bound Aβ oligomers can rapidly increase in size or that these oligomers cluster at specific sites on the membrane. Calcium indicator studies demonstrate that small oligomer binding at physiological concentrations induces only mild, sporadic calcium leakage. These findings support the hypothesis that small oligomers are the primary Aβ species that interact with neurons at physiological concentrations

    Transverse-momentum and collision-energy dependence of high-p(T) hadron suppression in Au+Au collisions at ultrarelativistic energies

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    We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at rootS(NN)=200 GeV. A large, approximately constant hadron suppression is observed in central Au+Au collisions for 5<p(T)<12 GeV/c. The collision energy dependence of the yields and the centrality and p(T) dependence of the suppression provide stringent constraints on theoretical models of suppression. Models incorporating initial-state gluon saturation or partonic energy loss in dense matter are largely consistent with observations. We observe no evidence of p(T)-dependent suppression, which may be expected from models incorporating jet attenuation in cold nuclear matter or scattering of fragmentation hadrons

    Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au plus Au collisions at RHIC

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    We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at roots(NN)=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions
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