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958 Publications visible to you, out of a total of 958
Analysis of microRNA expression using machine learning.
LHA - Leipzig Health Atlas

Abstract (Expand)

The systematic analysis of miRNA expression and its potential mRNA targets constitutes a basal objective in miRNA research in addition to miRNA gene detection and miRNA target prediction. In this chapter … we address methodical issues of miRNA expression analysis using self-organizing maps (SOM), a neural network machine learning algorithm with strong visualization and second-level analysis capabilities widely used to categorize large-scale, high-dimensional data. We shortly review selected experimental and theoretical aspects of miRNA expression analysis. Then, the protocol of our SOM method is outlined with special emphasis on miRNA/mRNA coexpression. The method allows extracting differentially expressed RNA transcripts, their functional context, and also characterization of global properties of expression states and profiles. In addition to the separate study of miRNA and mRNA expression landscapes, we propose the combined analysis of both entities using a covariance SOM.

Authors: H. Wirth, M. V. Cakir, L. Hopp, H. Binder

Date Published: 26th Nov 2013

Publication Type: Not specified

Systematic review of the effect of the psychosocial working environment on cognition and dementia.
LIFE Adult

Abstract (Expand)

The high incidence of cognitive impairment in the ageing population, together with the challenges it imposes to health systems, raises the question of what affect working life has on cognitive abilities. … The study, therefore, reviews recent work on the longitudinal impact of psychosocial work conditions on cognitive functioning and on dementia. Relevant articles were identified by a systematic literature search in PubMed and PsycINFO using a standardised search string and specific inclusion and exclusion criteria. We included articles reporting longitudinal effects that were investigated in cohort studies, case-control studies or randomised controlled trials in the working population. Two independent reviewers evaluated the studies in three subsequent phases: (i) title-abstract screening, (ii) full-text screening and (iii) checklist-based quality assessment.Methodical evaluation of the identified articles resulted in 17 studies of adequate quality. We found evidence for a protective effect of high job control and high work complexity with people and data on the risk of cognitive decline and dementia. Moreover, cognitively demanding work conditions seem to be associated with a decreased risk of cognitive deterioration in old age.Psychosocial work conditions can have an impact on cognitive functioning and even on the risk of dementia. As the world of work is undergoing fundamental changes, such as accelerated technological advances and an ageing working population, optimising work conditions is essential in order to promote and maintain cognitive abilities into old age.

Authors: F. S. Then, T. Luck, M. Luppa, M. Thinschmidt, S. Deckert, K. Nieuwenhuijsen, A. Seidler, S. G. Riedel-Heller

Date Published: 22nd Nov 2013

Publication Type: Not specified

Human Diseases: dementia

Massive transcriptional perturbation in subgroups of diffuse large B-cell lymphomas.
MMML - Molecular mechanisms in malignant lymphoma

Abstract (Expand)

Based on the assumption that molecular mechanisms involved in cancerogenesis are characterized by groups of coordinately expressed genes, we developed and validated a novel method for analyzing … transcriptional data called Correlated Gene Set Analysis (CGSA). Using 50 extracted gene sets we identified three different profiles of tumors in a cohort of 364 Diffuse large B-cell (DLBCL) and related mature aggressive B-cell lymphomas other than Burkitt lymphoma. The first profile had high level of expression of genes related to proliferation whereas the second profile exhibited a stromal and immune response phenotype. These two profiles were characterized by a large scale gene activation affecting genes which were recently shown to be epigenetically regulated, and which were enriched in oxidative phosphorylation, energy metabolism and nucleoside biosynthesis. The third and novel profile showed only low global gene activation similar to that found in normal B cells but not cell lines. Our study indicates novel levels of complexity of DLBCL with low or high large scale gene activation related to metabolism and biosynthesis and, within the group of highly activated DLBCLs, differential behavior leading to either a proliferative or a stromal and immune response phenotype.

Authors: M. Rosolowski, J. Lauter, D. Abramov, H. G. Drexler, M. Hummel, W. Klapper, R. A. Macleod, S. Pellissery, F. Horn, R. Siebert, M. Loeffler

Date Published: 14th Nov 2013

Publication Type: Not specified

Human Diseases: diffuse large B-cell lymphoma

Impact of rituximab and radiotherapy on outcome of patients with aggressive B-cell lymphoma and skeletal involvement.
GLA - German Lymphoma Alliance

Abstract (Expand)

PURPOSE: To study clinical presentation, outcome, and the role of radiotherapy in patients with aggressive B-cell lymphoma and skeletal involvement treated with and without rituximab. PATIENTS AND … METHODS: Outcome of patients with skeletal involvement was analyzed in a retrospective study of nine consecutive prospective trials of the German High-Grade Non-Hodgkin lymphoma Study Group. RESULTS: Of 3,840 patients, 292 (7.6%) had skeletal involvement. In the MabThera International Trial (MInT) for young good-prognosis patients and the Rituximab With CHOP Over 60 Years (RICOVER-60) study for elderly patients, the randomized addition of rituximab improved event-free survival (EFS; hazard ratio for MInT [HRMInT] = 0.4, P > 001; hazard ratio for RICOVER-60 [HRRICOVER-60] = 0.6, P > .001) and overall survival (OS; HRMInT = 0.4, P < .001; HRRICOVER-60 = 0.7, P = .002) in patients without skeletal involvement, but failed to improve the outcome of patients with skeletal involvement (EFS: HRMInT = 1.4, P = .444; HRRICOVER-60 = 0.8, P = .449; OS: HRMInT = 0.6, P = .449; HRRICOVER-60 = 1.0, P = .935). Skeletal involvement was associated with a worse outcome after cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus rituximab (HREFS = 1.5, P = .048; HROS = 1.1; P = .828), but not after CHOP without rituximab (HREFS = 0.8, P = .181; HROS = 0.7, P = .083). In contrast to rituximab, additive radiotherapy to sites of skeletal involvement was associated with a decreased risk (HREFS = 0.3, P = .001; HROS = 0.5; P = .111). CONCLUSION: Rituximab failed to improve the outcome of patients with diffuse large B-cell lymphoma with skeletal involvement, although our data suggest a beneficial effect of radiotherapy to sites of skeletal involvement. Whether radiotherapy to sites of skeletal involvement can be spared in cases with a negative positron emission tomography after immunochemotherapy should be addressed in appropriately designed prospective trials.

Authors: G. Held, S. Zeynalova, N. Murawski, M. Ziepert, B. Kempf, A. Viardot, M. Dreyling, M. Hallek, M. Witzens-Harig, J. Fleckenstein, C. Rube, C. Zwick, B. Glass, N. Schmitz, M. Pfreundschuh

Date Published: 10th Nov 2013

Publication Type: Not specified

Human Diseases: B-cell lymphoma

Biological characterization of adult MYC-translocation-positive mature B-cell lymphomas other than molecular Burkitt lymphoma.
MMML - Molecular mechanisms in malignant lymphoma

Abstract (Expand)

Chromosomal translocations affecting the MYC oncogene are the biological hallmark of Burkitt lymphomas but also occur in a subset of other mature B-cell lymphomas. If accompanied by a chromosomal break … targeting the BCL2 and/or BCL6 oncogene these MYC translocation-positive (MYC(+)) lymphomas are called double-hit lymphomas, otherwise the term single-hit lymphomas is applied. In order to characterize the biological features of these MYC(+) lymphomas other than Burkitt lymphoma we explored, after exclusion of molecular Burkitt lymphoma as defined by gene expression profiling, the molecular, pathological and clinical aspects of 80 MYC-translocation-positive lymphomas (31 single-hit, 46 double-hit and 3 MYC(+)-lymphomas with unknown BCL6 status). Comparison of single-hit and double-hit lymphomas revealed no difference in MYC partner (IG/non-IG), genomic complexity, MYC expression or gene expression profile. Double-hit lymphomas more frequently showed a germinal center B-cell-like gene expression profile and had higher IGH and MYC mutation frequencies. Gene expression profiling revealed 130 differentially expressed genes between BCL6(+)/MYC(+) and BCL2(+)/MYC(+) double-hit lymphomas. BCL2(+)/MYC(+) double-hit lymphomas more frequently showed a germinal center B-like gene expression profile. Analysis of all lymphomas according to MYC partner (IG/non-IG) revealed no substantial differences. In this series of lymphomas, in which immunochemotherapy was administered in only a minority of cases, single-hit and double-hit lymphomas had a similar poor outcome in contrast to the outcome of molecular Burkitt lymphoma and lymphomas without the MYC break. Our data suggest that, after excluding molecular Burkitt lymphoma and pediatric cases, MYC(+) lymphomas are biologically quite homogeneous with single-hit and double-hit lymphomas as well as IG-MYC and non-IG-MYC(+) lymphomas sharing various molecular characteristics.

Authors: S. M. Aukema, M. Kreuz, C. W. Kohler, M. Rosolowski, D. Hasenclever, M. Hummel, R. Kuppers, D. Lenze, G. Ott, C. Pott, J. Richter, A. Rosenwald, M. Szczepanowski, C. Schwaenen, H. Stein, H. Trautmann, S. Wessendorf, L. Trumper, M. Loeffler, R. Spang, P. M. Kluin, W. Klapper, R. Siebert

Date Published: 2nd Nov 2013

Publication Type: Not specified

Human Diseases: non-Hodgkin lymphoma, diffuse large B-cell lymphoma

Analysis of a rare functional truncating mutation rs61757459 in vaspin (SERPINA12) on circulating vaspin levels
Genetical Statistics and Systems Biology

Abstract (Expand)

UNLABELLED\backslashr\backslashnA recent genome-wide association study suggests that genetic variation within the vaspin gene might contribute to the variability in circulating serum visceral adipose … tissue-derived serine protease inhibitor (vaspin) concentrations. Here, we analyzed the functional consequences of the rare variant rs61757459 predicting a premature stop codon and its impact on circulating serum vaspin concentrations. In order to identify genetic variation, we sequenced the vaspin gene in 48 nonrelated Caucasian subjects. Rs61757459 was subsequently genotyped in three metabolically well-characterized German cohorts (N = 4,019). We addressed the impact of rs61757459 on the crystal structure of vaspin and investigated its effects on vaspin expression in vivo as well as in vitro using various cell lines (Escherichia coli, HEK293). Along with previously reported common genetic variants, sequencing of vaspin revealed a rare variant (rs61757459; minor allele frequency: 1 %) which predicts a premature stop codon p.R211X. Heterozygous carriers of this mutation had lower circulating vaspin levels when compared with noncarriers. In silico structure analysis of the truncated vaspin, which was estimated to be 24.5 kDa, suggested misfolding and potential instability due to the absence of core structural domains. Indeed, the truncated protein was detected after recombinant expression in E. coli and in lysate, but not in supernatant of HEK293 cells. We conclude that rs61757459 is a functional mutation that results in a truncated protein whose instability likely results in reduced serum vaspin levels.\backslashr\backslashnKEY MESSAGE\backslashr\backslashnA rare variant (rs61757459) in vaspin coding for the stop codon p.R211X is related to lower circulating vaspin concentrations. Structure analysis suggests misfolding and instability due to the absence of core structural domains. The truncated protein is detectable after recombinant expression in E. coli and in lysate, but not in supernatant of HEK293 cells.

Authors: Jana Breitfeld, John T. Heiker, Yvonne Böttcher, Dorit Schleinitz, Anke Tönjes, Kerstin Weidle, Kerstin Krause, E. Bartholomeus Kuettner, Markus Scholz, Wieland Kiess, Norbert Sträter, Annette G. Beck-Sickinger, Michael Stumvoll, Antje Körner, Matthias Blüher, Peter Kovacs

Date Published: 1st Nov 2013

Publication Type: Journal article

Secretory phospholipase A(2)-IIA and cardiovascular disease: a mendelian randomization study
Genetical Statistics and Systems Biology

Abstract (Expand)

OBJECTIVES\backslashr\backslashnThis study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease.\backslashr\backslashnBACKGROUND\backslashr\backslashnHigher … circulating levels of sPLA2-IIA mass or sPLA2 enzyme activity have been associated with increased risk of cardiovascular events. However, it is not clear if this association is causal. A recent phase III clinical trial of an sPLA2 inhibitor (varespladib) was stopped prematurely for lack of efficacy.\backslashr\backslashnMETHODS\backslashr\backslashnWe conducted a Mendelian randomization meta-analysis of 19 general population studies (8,021 incident, 7,513 prevalent major vascular events [MVE] in 74,683 individuals) and 10 acute coronary syndrome (ACS) cohorts (2,520 recurrent MVE in 18,355 individuals) using rs11573156, a variant in PLA2G2A encoding the sPLA2-IIA isoenzyme, as an instrumental variable.\backslashr\backslashnRESULTS\backslashr\backslashnPLA2G2A rs11573156 C allele associated with lower circulating sPLA2-IIA mass (38% to 44%) and sPLA2 enzyme activity (3% to 23%) per C allele. The odds ratio (OR) for MVE per rs11573156 C allele was 1.02 (95% confidence interval [CI]: 0.98 to 1.06) in general populations and 0.96 (95% CI: 0.90 to 1.03) in ACS cohorts. In the general population studies, the OR derived from the genetic instrumental variable analysis for MVE for a 1-log unit lower sPLA2-IIA mass was 1.04 (95% CI: 0.96 to 1.13), and differed from the non-genetic observational estimate (OR: 0.69; 95% CI: 0.61 to 0.79). In the ACS cohorts, both the genetic instrumental variable and observational ORs showed a null association with MVE. Instrumental variable analysis failed to show associations between sPLA2 enzyme activity and MVE.\backslashr\backslashnCONCLUSIONS\backslashr\backslashnReducing sPLA2-IIA mass is unlikely to be a useful therapeutic goal for preventing cardiovascular events.

Authors: Michael V. Holmes, Tabassome Simon, Holly J. Exeter, Lasse Folkersen, Folkert W. Asselbergs, Montse Guardiola, Jackie A. Cooper, Jutta Palmen, Jaroslav A. Hubacek, Kathryn F. Carruthers, Benjamin D. Horne, Kimberly D. Brunisholz, Jessica L. Mega, Erik P A van Iperen, Mingyao Li, Maarten Leusink, Stella Trompet, Jeffrey J W Verschuren, G. Kees Hovingh, Abbas Dehghan, Christopher P. Nelson, Salma Kotti, Nicolas Danchin, Markus Scholz, Christiane L. Haase, Dietrich Rothenbacher, Daniel I. Swerdlow, Karoline B. Kuchenbaecker, Eleonora Staines-Urias, Anuj Goel, Ferdinand van ’t Hooft, Karl Gertow, Ulf de Faire, Andrie G. Panayiotou, Elena Tremoli, Damiano Baldassarre, Fabrizio Veglia, Lesca Miriam Holdt, Frank Beutner, Ron T. Gansevoort, Gerjan J. Navis, Irene Mateo Leach, Lutz P. Breitling, Hermann Brenner, Joachim Thiery, Dhayana Dallmeier, Anders Franco-Cereceda, Jolanda M A Boer, Jeffrey W. Stephens, Marten H. Hofker, Alain Tedgui, Albert Hofman, André G. Uitterlinden, Vera Adamkova, Jan Pitha, N. Charlotte Onland-Moret, Maarten J. Cramer, Hendrik M. Nathoe, Wilko Spiering, Olaf H. Klungel, Meena Kumari, Peter H. Whincup, David A. Morrow, Peter S. Braund, Alistair S. Hall, Anders G. Olsson, Pieter A. Doevendans, Mieke D. Trip, Martin D. Tobin, Anders Hamsten, Hugh Watkins, Wolfgang Koenig, Andrew N. Nicolaides, Daniel Teupser, Ian N M Day, John F. Carlquist, Tom R. Gaunt, Ian Ford, Naveed Sattar, Sotirios Tsimikas, Gregory G. Schwartz, Debbie A. Lawlor, Richard W. Morris, Manjinder S. Sandhu, Rudolf Poledne, Anke H Maitland-van der Zee, Kay-Tee Khaw, Brendan J. Keating, Pim van der Harst, Jackie F. Price, Shamir R. Mehta, Salim Yusuf, Jaqueline C M Witteman, Oscar H. Franco, J. Wouter Jukema, Peter de Knijff, Anne Tybjaerg-Hansen, Daniel J. Rader, Martin Farrall, Nilesh J. Samani, Mika Kivimaki, Keith A A Fox, Steve E. Humphries, Jeffrey L. Anderson, S. Matthijs Boekholdt, Tom M. Palmer, Per Eriksson, Guillaume Paré, Aroon D. Hingorani, Marc S. Sabatine, Ziad Mallat, Juan P. Casas, Philippa J. Talmud

Date Published: 1st Nov 2013

Publication Type: Journal article

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