58 research outputs found

    Pauling Entropy, Metastability, and Equilibrium in Dy_{2}Ti_{2}O_{7} Spin Ice

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    Determining the fate of the Pauling entropy in the classical spin ice material Dy_{2}Ti_{2}O_{7} with respect to the third law of thermodynamics has become an important test case for understanding the existence and stability of ice-rule states in general. The standard model of spin ice-the dipolar spin ice model-predicts an ordering transition at T≈0.15  K, but recent experiments by Pomaranski et al. suggest an entropy recovery over long timescales at temperatures as high as 0.5 K, much too high to be compatible with the theory. Using neutron scattering and specific heat measurements at low temperatures and with long timescales (0.35  K/10^{6}  s and 0.5  K/10^{5}  s, respectively) on several isotopically enriched samples, we find no evidence of a reduction of ice-rule correlations or spin entropy. High-resolution simulations of the neutron structure factor show that the spin correlations remain well described by the dipolar spin ice model at all temperatures. Furthermore, by careful consideration of hyperfine contributions, we conclude that the original entropy measurements of Ramirez et al. are, after all, essentially correct: The short-time relaxation method used in that study gives a reasonably accurate estimate of the equilibrium spin ice entropy due to a cancellation of contributions

    IgCaller for reconstructing immunoglobulin gene rearrangements and oncogenic translocations from whole-genome sequencing in lymphoid neoplasms

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    Immunoglobulin (Ig) gene rearrangements and oncogenic translocations are routinely assessed during the characterization of B cell neoplasms and stratification of patients with distinct clinical and biological features, with the assessment done using Sanger sequencing, targeted next-generation sequencing, or fluorescence in situ hybridization (FISH). Currently, a complete Ig characterization cannot be extracted from whole-genome sequencing (WGS) data due to the inherent complexity of the Ig loci. Here, we introduce IgCaller, an algorithm designed to fully characterize Ig gene rearrangements and oncogenic translocations from short-read WGS data. Using a cohort of 404 patients comprising different subtypes of B cell neoplasms, we demonstrate that IgCaller identifies both heavy and light chain rearrangements to provide additional information on their functionality, somatic mutational status, class switch recombination, and oncogenic Ig translocations. Our data thus support IgCaller to be a reliable alternative to Sanger sequencing and FISH for studying the genetic properties of the Ig loci.We are indebted to the Genomics Core Facility of the Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) for the technical support, to R. Siebert and D. Huebschmann for sharing the CSR regions, and to K. Stamatopoulos, E. Vlachonikola and F. Psomopoulos for their helpful comments on the manuscript. We thank R. Eils, P. Lichter, C. von Kalle, S. Fröhling, H. Glimm, M. Zapatka, S. Wolf, K. Beck, and J. Kirchhof for infrastructure and pipeline development within DKFZ-HIPO and NCT POP. This study was supported by the Instituto de Salud Carlos III and the European Regional Development Fund “Una manera de hacer Europa” (PMP15/00007 to E.C.), the “la Caixa” Foundation (CLLEvolution-LCF/PR/HR17/52150017, Health Research 2017 Program HR17-00221 to E.C.), the National Institute of Health “Molecular Diagnosis, Prognosis, and Therapeutic Targets in Mantle Cell Lymphoma” (P01CA229100 to E.C.), and CERCA Programme/Generalitat de Catalunya. F.N. is supported by a pre-doctoral fellowship of the Ministerio de Economía y Competitividad (BES-2016-076372). F.M. is supported by the Memorial Sloan Kettering Cancer Center NCI Core Grant (P30 CA 008748). E.C. is an Academia Researcher of the “Institució Catalana de Recerca i Estudis Avançats” (ICREA) of the Generalitat de Catalunya. This work was partially developed at the Centre Esther Koplowitz (CEK, Barcelona, Spain).Peer ReviewedPostprint (published version

    Pauling Entropy, Metastability, and Equilibrium in Dy_{2}Ti_{2}O_{7} Spin Ice

    Get PDF
    Determining the fate of the Pauling entropy in the classical spin ice material Dy_{2}Ti_{2}O_{7} with respect to the third law of thermodynamics has become an important test case for understanding the existence and stability of ice-rule states in general. The standard model of spin ice-the dipolar spin ice model-predicts an ordering transition at T≈0.15  K, but recent experiments by Pomaranski et al. suggest an entropy recovery over long timescales at temperatures as high as 0.5 K, much too high to be compatible with the theory. Using neutron scattering and specific heat measurements at low temperatures and with long timescales (0.35  K/10^{6}  s and 0.5  K/10^{5}  s, respectively) on several isotopically enriched samples, we find no evidence of a reduction of ice-rule correlations or spin entropy. High-resolution simulations of the neutron structure factor show that the spin correlations remain well described by the dipolar spin ice model at all temperatures. Furthermore, by careful consideration of hyperfine contributions, we conclude that the original entropy measurements of Ramirez et al. are, after all, essentially correct: The short-time relaxation method used in that study gives a reasonably accurate estimate of the equilibrium spin ice entropy due to a cancellation of contributions

    Subcutaneous Rituximab-MiniCHOP compared with subcutaneous Rituximab-MiniCHOP plus Lenalidomide in diffuse large B-Cell lymphoma for patients age 80 years or older.

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    peer reviewedPURPOSE The prognosis of elderly patients with diffuse large B-cell lymphoma (DLBCL) is worse than that of young patients. An attenuated dose of chemotherapy—cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab (R-miniCHOP)—is a good compromise between efficacy and safety in very elderly patients. In combination with R-CHOP (R2-CHOP), lenalidomide has an acceptable level of toxicity and may mitigate the negative prognosis of the non–germinal center B-cell–like phenotype. The Lymphoma Study association conducted a multicentric, phase III, open-label, randomized trial to compare R-miniCHOP and R2- miniCHOP. PATIENTS AND METHODS Patients of age 80 years or older with untreated DLBCL were randomly assigned into the R-miniCHOP21 group or the R2-miniCHOP21 group for six cycles and stratified according to CD10 expression and age. The first cycle of rituximab was delivered by IV on D1 after a prephase and then delivered subcutaneously on D1 of cycles 2-6. Lenalidomide was delivered at a dose of 10 mg once daily on D1-D14 of each cycle. The primary end point was overall survival (OS). RESULTS A total of 249 patients with new DLBCL were randomly assigned (127 R-miniCHOP and 122 R2- miniCHOP). The median age was 83 years (range, 80-96), and 55% of the patients were classified as non-GCB. The delivered dose for each R-miniCHOP compound was similar in both arms. Over a median follow-up of 25.1 months, the intention-to-treat analysis revealed that R2-miniCHOP did not improve OS (2-year OS 66% in R-miniCHOP and 65.7% in R2-miniCHOP arm, P5 .98) in the overall population or in the non-GCB population. Grade 3-4 adverse events occurred in 53% of patients with R-miniCHOP and in 81% of patients with R2- miniCHOP. CONCLUSION The addition of lenalidomide to R-miniCHOP does not improve OS. Rituximab delivered subcutaneously was safe in this population

    Defining signatures of peripheral T-cell lymphoma with a targeted 20-marker gene expression profiling assay.

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    Peripheral T-cell lymphoma comprises a heterogeneous group of mature non-Hodgkin lymphomas. Their diagnosis is challenging, with up to 30% of cases remaining unclassifiable and referred to as "not otherwise specified". We developed a reverse transcriptase-multiplex ligation-dependent probe amplification gene expression profiling assay to differentiate the main T-cell lymphoma entities and to study the heterogeneity of the "not specified" category. The test evaluates the expression of 20 genes, including 17 markers relevant to T-cell immunology and lymphoma biopathology, one Epstein-Barr virus-related transcript, and variants of RHOA (G17V) and IDH2 (R172K/T). By unsupervised hierarchical clustering, our assay accurately identified 21 of 21 ALK-positive anaplastic large cell lymphomas, 16 of 16 extranodal natural killer (NK)/T-cell lymphomas, 6 of 6 hepatosplenic T-cell lymphomas, and 13 of 13 adult T-cell leukemia/lymphomas. ALK-negative anaplastic lymphomas (n=34) segregated into one cytotoxic cluster (n=10) and one non-cytotoxic cluster expressing Th2 markers (n=24) and enriched in DUSP22-rearranged cases. The 63 T <sub>FH</sub> -derived lymphomas divided into two subgroups according to a predominant T <sub>FH</sub> (n=50) or an enrichment in Th2 (n=13) signatures. We next developed a support vector machine predictor which attributed a molecular class to 27 of 77 not specified T-cell lymphomas: 17 T <sub>FH</sub> , five cytotoxic ALK-negative anaplastic and five NK/T-cell lymphomas. Among the remaining cases, we identified two cell-of-origin subgroups corresponding to cytotoxic/Th1 (n=19) and Th2 (n=24) signatures. A reproducibility test on 40 cases yielded a 90% concordance between three independent laboratories. This study demonstrates the applicability of a simple gene expression assay for the classification of peripheral T-cell lymphomas. Its applicability to routinely-fixed samples makes it an attractive adjunct in diagnostic practice

    Fetuin-A Induces Cytokine Expression and Suppresses Adiponectin Production

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    BACKGROUND: The secreted liver protein fetuin-A (AHSG) is up-regulated in hepatic steatosis and the metabolic syndrome. These states are strongly associated with low-grade inflammation and hypoadiponectinemia. We, therefore, hypothesized that fetuin-A may play a role in the regulation of cytokine expression, the modulation of adipose tissue expression and plasma concentration of the insulin-sensitizing and atheroprotective adipokine adiponectin. METHODOLOGY AND PRINCIPAL FINDINGS: Human monocytic THP1 cells and human in vitro differenttiated adipocytes as well as C57BL/6 mice were treated with fetuin-A. mRNA expression of the genes encoding inflammatory cytokines and the adipokine adiponectin (ADIPOQ) was assessed by real-time RT-PCR. In 122 subjects, plasma levels of fetuin-A, adiponectin and, in a subgroup, the multimeric forms of adiponectin were determined. Fetuin-A treatment induced TNF and IL1B mRNA expression in THP1 cells (p<0.05). Treatment of mice with fetuin-A, analogously, resulted in a marked increase in adipose tissue Tnf mRNA as well as Il6 expression (27- and 174-fold, respectively). These effects were accompanied by a decrease in adipose tissue Adipoq mRNA expression and lower circulating adiponectin levels (p<0.05, both). Furthermore, fetuin-A repressed ADIPOQ mRNA expression of human in vitro differentiated adipocytes (p<0.02) and induced inflammatory cytokine expression. In humans in plasma, fetuin-A correlated positively with high-sensitivity C-reactive protein, a marker of subclinical inflammation (r = 0.26, p = 0.01), and negatively with total- (r = -0.28, p = 0.02) and, particularly, high molecular weight adiponectin (r = -0.36, p = 0.01). CONCLUSIONS AND SIGNIFICANCE: We provide novel evidence that the secreted liver protein fetuin-A induces low-grade inflammation and represses adiponectin production in animals and in humans. These data suggest an important role of fatty liver in the pathophysiology of insulin resistance and atherosclerosis

    Obinutuzumab versus Rituximab in young patients with advanced DLBCL, a PET-guided and randomized phase 3 study by LYSA.

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    Rituximab plus polychemotherapy is standard of care in diffuse large B-cell lymphoma (DLBCL). GAINED trial compares obinutuzumab to rituximab. GAINED (NCT01659099) is an open-label, randomized phase 3 trial. Transplant-eligible patients (18-60yrs) with untreated aged-adjusted international prognostic index (aaIPI) ≥1 DLBCL were randomized (1:1) between obinutuzumab or rituximab. Patients were stratified by aaIPI (1; 2-3) and chemotherapy regimen (ACVBP; CHOP). Consolidation treatment was determined according to response assessed by centrally reviewed interim semi-quantitative PET. Responders after cycle 2 and 4 (PET2-/PET4-) received planned immuno-chemotherapy consolidation. Responders only after cycle 4 (PET2+/4-) received highdose methotrexate plus transplantation. The primary objective was an 8% improvement (HR=0.73; 80% power; alpha risk 2.5%; one-sided) in 2-year event-free survival (EFS) in the obinutuzumab arm. Events included death, progression, PET 2 or 4 positivity, modification of planned treatment. From September 20, 2012, 670 patients were enrolled (obinutuzumab n=336; rituximab n=334). 383 (57.2%) were aaIPI 2-3, 339 (50.6%) received CHOP and 324 (48.4%) received ACVBP. Median follow-up was 38.7 months. The 2-year EFS were similar in obinutuzumab and rituximab groups (59.8% vs 56.6%; p=0.123; HR=0.88). The 2-year PFS in the whole cohort was 83.1% (95%CI 80–85.8). PET2-/4- and PET2+/4- had similar 2-year PFS and OS (89.9% vs 83.9%) and 94.8% vs 92.8%). The 2-year PFS and OS for PET4+ patients were 62% and 83.1%. Grade 3-5 infections were more frequent in the obinutuzumab arm (21% vs 12%). Obinutuzumab is not superior to rituximab in untreated aaIPI≥1 DLBCL transplant-eligible patients

    Multiple Coulomb phase in the fluoride pyrochlore CsNiCrF6

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    The Coulomb phase is an idealized state of matter whose properties are determined by factors beyond conventional considerations of symmetry, including global topology, conservation laws and emergent order. Theoretically, Coulomb phases occur in ice-type systems such as water ice and spin ice; in dimer models; and in certain spin liquids. However, apart from ice-type systems, more general experimental examples are very scarce. Here we study the partly disordered material CsNiCrF6 and show that this material is a multiple Coulomb phase with signature correlations in three degrees of freedom: charge configurations, atom displacements and spin configurations. We use neutron and X-ray scattering to separate these correlations and to determine the magnetic excitation spectrum. Our results show how the structural and magnetic properties of apparently disordered materials may inherit, and be dictated by, a hidden symmetry—the local gauge symmetry of an underlying Coulomb phase

    Fetuin-B, a second member of the fetuin family in mammals.

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    A set of orthologous plasma proteins found in human, sheep, pig, cow and rodents, now collectively designated fetuin-A, constitutes the fetuin family. Fetuin-A has been identified as a major protein during fetal life and is also involved in important functions such as inhibition of the insulin receptor tyrosine kinase activity, protease inhibitory activities and development-associated regulation of calcium metabolism and osteogenesis. Furthermore, fetuin-A is a key partner in the recovery phase of an acute inflammatory response. We now describe a second protein of the fetuin family, called fetuin-B, which is found at least in human and rodents. On grounds of domain homology, overall conservation of cysteine residues and chromosomal assignments of the corresponding genes in these species, fetuin-B is unambiguously a paralogue of fetuin-A. Yet, fetuin-A and fetuin-B exhibit significant differences at the amino acid sequence level, notably including variations with respect to the archetypal fetuin-specific signature. Differences and similarities in terms of gene regulation were also observed. Indeed, studies performed during development in rat and mouse showed for the first time high expression of a member of the fetuin family in adulthood, as shown with the fetuin-B mRNA in rat. However, like its fetuin-A counterpart, the fetuin-B mRNA level is down-regulated during the acute phase of experimentally induced inflammation in rat
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