Publications

959 Publications visible to you, out of a total of 959

Abstract (Expand)

We present a working approach for a clinical research database as part of an archival information system. The CDISC ODM standard is target for clinical study and research relevant routine data, thus decoupling the data ingest process from the access layer. The presented research database is comprehensive as it covers annotating, mapping and curation of poorly annotated source data. Besides a conventional relational database the medical data warehouse i2b2 serves as main frontend for end-users. The system we developed is suitable to support patient recruitment, cohort identification and quality assurance in daily routine.

Authors: Frank Meineke, Sebastian Stäubert, Matthias Löbe, Alfred Winter

Date Published: 2014

Publication Type: Journal article

Abstract

Not specified

Authors: Franziska Jahn, M. Schaaf, Barbara Paech, Alfred Winter

Date Published: 2014

Publication Type: InCollection

Abstract (Expand)

As revealed by optical coherence tomography (OCT), the shape of the fovea may vary greatly among individuals. However, none of the hitherto available mathematical descriptions comprehensively reproduces all individual characteristics such as foveal depth, slope, naso-temporal asymmetry, and others. Here, a novel mathematical approach is presented to obtain a very accurate model of the complete 3D foveal surface of an individual, by utilizing recent developments in OCT. For this purpose, a new formula was developed serving as a simple but very flexible way to represent a given fovea. An extensive description of the used model parameters, as well as, of the complete method of reconstructing a foveal surface from OCT data, is presented. Noteworthy, the formula analytically provides characteristic foveal parameters and thus allows for extensive quantification. The present approach was verified on 432 OCT scans and has proved to be able to capture the whole range of asymmetric foveal shapes with high accuracy (i.e. a mean fit error of 1.40 mum).

Authors: P. Scheibe, A. Lazareva, U. D. Braumann, A. Reichenbach, P. Wiedemann, M. Francke, F. G. Rauscher

Date Published: 3rd Dec 2013

Publication Type: Not specified

Human Diseases: eye disease

Abstract (Expand)

We present an analytic framework based on Self-Organizing Map (SOM) machine learning to study large scale patient data sets. The potency of the approach is demonstrated in a case study using gene expression data of more than 200 mature aggressive B-cell lymphoma patients. The method portrays each sample with individual resolution, characterizes the subtypes, disentangles the expression patterns into distinct modules, extracts their functional context using enrichment techniques and enables investigation of the similarity relations between the samples. The method also allows to detect and to correct outliers caused by contaminations. Based on our analysis, we propose a refined classification of B-cell Lymphoma into four molecular subtypes which are characterized by differential functional and clinical characteristics.

Authors: L. Hopp, K. Lembcke, H. Binder, H. Wirth

Date Published: 2nd Dec 2013

Publication Type: Not specified

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

Abstract (Expand)

The 10q26 locus in the second intron of FGFR2 is the locus most strongly associated with estrogen-receptor-positive breast cancer in genome-wide association studies. We conducted fine-scale mapping in case-control studies genotyped with a custom chip (iCOGS), comprising 41 studies (n = 89,050) of European ancestry, 9 Asian ancestry studies (n = 13,983), and 2 African ancestry studies (n = 2,028) from the Breast Cancer Association Consortium. We identified three statistically independent risk signals within the locus. Within risk signals 1 and 3, genetic analysis identified five and two variants, respectively, highly correlated with the most strongly associated SNPs. By using a combination of genetic fine mapping, data on DNase hypersensitivity, and electrophoretic mobility shift assays to study protein-DNA binding, we identified rs35054928, rs2981578, and rs45631563 as putative functional SNPs. Chromatin immunoprecipitation showed that FOXA1 preferentially bound to the risk-associated allele (C) of rs2981578 and was able to recruit ER\textgreeka to this site in an allele-specific manner, whereas E2F1 preferentially bound the risk variant of rs35054928. The risk alleles were preferentially found in open chromatin and bound by Ser5 phosphorylated RNA polymerase II, suggesting that the risk alleles are associated with changes in transcription. Chromatin conformation capture demonstrated that the risk region was able to interact with the promoter of FGFR2, the likely target gene of this risk region. A role for FOXA1 in mediating breast cancer susceptibility at this locus is consistent with the finding that the FGFR2 risk locus primarily predisposes to estrogen-receptor-positive disease.

Authors: Kerstin B. Meyer, Martin O’Reilly, Kyriaki Michailidou, Saskia Carlebur, Stacey L. Edwards, Juliet D. French, Radhika Prathalingham, Joe Dennis, Manjeet K. Bolla, Qin Wang, Ines de Santiago, John L. Hopper, Helen Tsimiklis, Carmel Apicella, Melissa C. Southey, Marjanka K. Schmidt, Annegien Broeks, Laura J. van ’t Veer, Frans B. Hogervorst, Kenneth Muir, Artitaya Lophatananon, Sarah Stewart-Brown, Pornthep Siriwanarangsan, Peter A. Fasching, Michael P. Lux, Arif B. Ekici, Matthias W. Beckmann, Julian Peto, Isabel Dos Santos Silva, Olivia Fletcher, Nichola Johnson, Elinor J. Sawyer, Ian Tomlinson, Michael J. Kerin, Nicola Miller, Federick Marme, Andreas Schneeweiss, Christof Sohn, Barbara Burwinkel, Pascal Guénel, Thérèse Truong, Pierre Laurent-Puig, Florence Menegaux, Stig E. Bojesen, Børge G. Nordestgaard, Sune F. Nielsen, Henrik Flyger, Roger L. Milne, M. Pilar Zamora, Jose I. Arias, Javier Benitez, Susan Neuhausen, Hoda Anton-Culver, Argyrios Ziogas, Christina C. Dur, Hermann Brenner, Heiko Müller, Volker Arndt, Christa Stegmaier, Alfons Meindl, Rita K. Schmutzler, Christoph Engel, Nina Ditsch, Hiltrud Brauch, Thomas Brüning, Yon-Dschun Ko, Heli Nevanlinna, Taru A. Muranen, Kristiina Aittomäki, Carl Blomqvist, Keitaro Matsuo, Hidemi Ito, Hiroji Iwata, Yasushi Yatabe, Thilo Dörk, Sonja Helbig, Natalia V. Bogdanova, Annika Lindblom, Sara Margolin, Arto Mannermaa, Vesa Kataja, Veli-Matti Kosma, Jaana M. Hartikainen, Georgia Chenevix-Trench, Anna H. Wu, Chiu-Chen Tseng, David van den Berg, Daniel O. Stram, Diether Lambrechts, Bernard Thienpont, Marie-Rose Christiaens, Ann Smeets, Jenny Chang-Claude, Anja Rudolph, Petra Seibold, Dieter Flesch-Janys, Paolo Radice, Paolo Peterlongo, Bernardo Bonanni, Loris Bernard, Fergus J. Couch, Janet E. Olson, Xianshu Wang, Kristen Purrington, Graham G. Giles, Gianluca Severi, Laura Baglietto, Catriona McLean, Christopher A. Haiman, Brian E. Henderson, Fredrick Schumacher, Loic Le Marchand, Jacques Simard, Mark S. Goldberg, France Labrèche, Martine Dumont, Soo-Hwang Teo, Cheng-Har Yip, Sze-Yee Phuah, Vessela Kristensen, Grethe Grenaker Alnæs, Anne-Lise Børresen-Dale, Wei Zheng, Sandra Deming-Halverson, Martha Shrubsole, Jirong Long, Robert Winqvist, Katri Pylkäs, Arja Jukkola-Vuorinen, Saila Kauppila, Irene L. Andrulis, Julia A. Knight, Gord Glendon, Sandrine Tchatchou, Peter Devilee, Robert A. E. M. Tollenaar, Caroline M. Seynaeve, Montserrat García-Closas, Jonine Figueroa, Stephen J. Chanock, Jolanta Lissowska, Kamila Czene, Hartef Darabi, Kimael Eriksson, Maartje J. Hooning, John W. M. Martens, Ans M. W. van den Ouweland, Carolien H. M. van Deurzen, Per Hall, Jingmei Li, Jianjun Liu, Keith Humphreys, Xiao-Ou Shu, Wei Lu, Yu-Tang Gao, Hui Cai, Angela Cox, Malcolm W. R. Reed, William Blot, Lisa B. Signorello, Qiuyin Cai, Paul D. P. Pharoah, Maya Ghoussaini, Patricia Harrington, Jonathan Tyrer, Daehee Kang, Ji-Yeob Choi, Sue K. Park, Dong-Young Noh, Mikael Hartman, Miao Hui, Wei-Yen Lim, Shaik A. Buhari, Ute Hamann, Asta Försti, Thomas Rüdiger, Hans-Ulrich Ulmer, Anna Jakubowska, Jan Lubinski, Katarzyna Jaworska, Katarzyna Durda, Suleeporn Sangrajrang, Valerie Gaborieau, Paul Brennan, James McKay, Celine Vachon, Susan Slager, Florentia Fostira, Robert Pilarski, Chen-Yang Shen, Chia-Ni Hsiung, Pei-Ei Wu, Ming-Feng Hou, Anthony Swerdlow, Alan Ashworth, Nick Orr, Minouk J. Schoemaker, Bruce A. J. Ponder, Alison M. Dunning, Douglas F. Easton

Date Published: 1st Dec 2013

Publication Type: Journal article

Human Diseases: hereditary breast ovarian cancer syndrome

Abstract (Expand)

BACKGROUND\backslashr\backslashnAnkle-brachial-Index (ABI) measured by manual Dopplersonography is an easily assessable marker of global cardiovascular risk. The aim of this study was to establish novel photo-plethysmography (PPG)-based ABI assessments in an epidemiologic context and to compare its results with those of Doppler.\backslashr\backslashnMETHODS\backslashr\backslashnTwo devices for PPG-based ABI assessments (Vicorder, Vascular Explorer) were tested and compared against Doppler in 56 putatively healthy subjects. We determined acceptance, time requirements, agreement of repeat measurements, agreement with Doppler and intra- and inter-observer concordances for both devices and compared the results. Differences between cuff inflation- and deflation-based methods were also studied for Vascular Explorer.\backslashr\backslashnRESULTS\backslashr\backslashnAcceptance was similar for both devices but Vascular Explorer was more time consuming. Agreement of multiple measurements was moderate for both methods highlighting the importance of measurement replicates. Both automated devices showed significantly higher ABI compared to Doppler which can be traced back to higher brachial pressures (Vicorder) or higher ankle pressures (Vascular Explorer). This effect is more pronounced for Vascular Explorer but can be ameliorated using the deflation method of measurement. Intra-observer concordances were similar. Inter-observer concordance was non-significantly better for Vicorder.\backslashr\backslashnCONCLUSIONS\backslashr\backslashnBoth devices proved to be feasible in epidemiologic studies, but compared to Doppler, do not constitute an advantage regarding time requirement and accuracy of ABI assessment. Since PPG-based ABI values are inflated compared to Doppler, it will be necessary to adjust Doppler-based cut-offs for risk stratification. BACKGROUND Ankle-brachial-Index (ABI) measured by manual Dopplersonography is an easily assessable marker of global cardiovascular risk. The aim of this study was to establish novel photo-plethysmography (PPG)-based ABI assessments in an epidemiologic context and to compare its results with those of Doppler. METHODS Two devices for PPG-based ABI assessments (Vicorder, Vascular Explorer) were tested and compared against Doppler in 56 putatively healthy subjects. We determined acceptance, time requirements, agreement of repeat measurements, agreement with Doppler and intra- and inter-observer concordances for both devices and compared the results. Differences between cuff inflation- and deflation-based methods were also studied for Vascular Explorer. RESULTS Acceptance was similar for both devices but Vascular Explorer was more time consuming. Agreement of multiple measurements was moderate for both methods highlighting the importance of measurement replicates. Both automated devices showed significantly higher ABI compared to Doppler which can be traced back to higher brachial pressures (Vicorder) or higher ankle pressures (Vascular Explorer). This effect is more pronounced for Vascular Explorer but can be ameliorated using the deflation method of measurement. Intra-observer concordances were similar. Inter-observer concordance was non-significantly better for Vicorder. CONCLUSIONS Both devices proved to be feasible in epidemiologic studies, but compared to Doppler, do not constitute an advantage regarding time requirement and accuracy of ABI assessment. Since PPG-based ABI values are inflated compared to Doppler, it will be necessary to adjust Doppler-based cut-offs for risk stratification.

Authors: Andrej Teren, Frank Beutner, Kerstin Wirkner, Markus Loeffler, Markus Scholz

Date Published: 1st Dec 2013

Publication Type: Journal article

Abstract

Not specified

Authors: Peter Loos, Tobias Mettler, Robert Winter, Matthias Goeken, Ulrich Frank, Alfred Winter

Date Published: 1st Dec 2013

Publication Type: Journal article

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