Publications

1004 Publications visible to you, out of a total of 1004

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INTRODUCTION Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNAA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. METHODS We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. RESULTS We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. CONCLUSIONS This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.

Authors: Sophie Blein, Claire Bardel, Vincent Danjean, Lesley McGuffog, Sue Healey, Daniel Barrowdale, Andrew Lee, Joe Dennis, Karoline B. Kuchenbaecker, Penny Soucy, Mary Beth Terry, Wendy K. Chung, David E. Goldgar, Saundra S. Buys, Ramunas Janavicius, Laima Tihomirova, Nadine Tung, Cecilia M. Dorfling, Elizabeth J. van Rensburg, Susan L. Neuhausen, Yuan Chun Ding, Anne-Marie Gerdes, Bent Ejlertsen, Finn C. Nielsen, Thomas vO Hansen, Ana Osorio, Javier Benitez, Raquel Andrés Conejero, Ena Segota, Jeffrey N. Weitzel, Margo Thelander, Paolo Peterlongo, Paolo Radice, Valeria Pensotti, Riccardo Dolcetti, Bernardo Bonanni, Bernard Peissel, Daniela Zaffaroni, Giulietta Scuvera, Siranoush Manoukian, Liliana Varesco, Gabriele L. Capone, Laura Papi, Laura Ottini, Drakoulis Yannoukakos, Irene Konstantopoulou, Judy Garber, Ute Hamann, Alan Donaldson, Angela Brady, Carole Brewer, Claire Foo, D. Gareth Evans, Debra Frost, Diana Eccles, Fiona Douglas, Jackie Cook, Julian Adlard, Julian Barwell, Lisa Walker, Louise Izatt, Lucy E. Side, M. John Kennedy, Marc Tischkowitz, Mark T. Rogers, Mary E. Porteous, Patrick J. Morrison, Radka Platte, Ros Eeles, Rosemarie Davidson, Shirley Hodgson, Trevor Cole, Andrew K. Godwin, Claudine Isaacs, Kathleen Claes, Kim de Leeneer, Alfons Meindl, Andrea Gehrig, Barbara Wappenschmidt, Christian Sutter, Christoph Engel, Dieter Niederacher, Doris Steinemann, Hansjoerg Plendl, Karin Kast, Kerstin Rhiem, Nina Ditsch, Norbert Arnold, Raymonda Varon-Mateeva, Rita K. Schmutzler, Sabine Preisler-Adams, Nadja Bogdanova Markov, Shan Wang-Gohrke, Antoine de Pauw, Cédrick Lefol, Christine Lasset, Dominique Leroux, Etienne Rouleau, Francesca Damiola, Hélène Dreyfus, Laure Barjhoux, Lisa Golmard, Nancy Uhrhammer, Valérie Bonadona, Valérie Sornin, Yves-Jean Bignon, Jonathan Carter, Linda van Le, Marion Piedmonte, Paul A. DiSilvestro, Miguel de La Hoya, Trinidad Caldes, Heli Nevanlinna, Kristiina Aittomäki, Agnes Jager, Ans Mw van den Ouweland, Carolien M. Kets, Cora M. Aalfs, Flora E. van Leeuwen, Frans Bl Hogervorst, Hanne Ej Meijers-Heijboer, Jan C. Oosterwijk, Kees Ep van Roozendaal, Matti A. Rookus, Peter Devilee, Rob B. van der Luijt, Edith Olah, Orland Diez, Alex Teulé, Conxi Lazaro, Ignacio Blanco, Jesús Del Valle, Anna Jakubowska, Grzegorz Sukiennicki, Jacek Gronwald, Jan Lubinski, Katarzyna Durda, Katarzyna Jaworska-Bieniek, Bjarni A. Agnarsson, Christine Maugard, Alberto Amadori, Marco Montagna, Manuel R. Teixeira, Amanda B. Spurdle, William Foulkes, Curtis Olswold, Noralane M. Lindor, Vernon S. Pankratz, Csilla I. Szabo, Anne Lincoln, Lauren Jacobs, Marina Corines, Mark Robson, Joseph Vijai, Andreas Berger, Anneliese Fink-Retter, Christian F. Singer, Christine Rappaport, Daphne Geschwantler Kaulich, Georg Pfeiler, Muy-Kheng Tea, Mark H. Greene, Phuong L. Mai, Gad Rennert, Evgeny N. Imyanitov, Anna Marie Mulligan, Gord Glendon, Irene L. Andrulis, Sandrine Tchatchou, Amanda Ewart Toland, Inge Sokilde Pedersen, Mads Thomassen, Torben A. Kruse, Uffe Birk Jensen, Maria A. Caligo, Eitan Friedman, Jamal Zidan, Yael Laitman, Annika Lindblom, Beatrice Melin, Brita Arver, Niklas Loman, Richard Rosenquist, Olufunmilayo I. Olopade, Robert L. Nussbaum, Susan J. Ramus, Katherine L. Nathanson, Susan M. Domchek, Timothy R. Rebbeck, Banu K. Arun, Gillian Mitchell, Beth Y. Karlan, Jenny Lester, Sandra Orsulic, Dominique Stoppa-Lyonnet, Gilles Thomas, Jacques Simard, Fergus J. Couch, Kenneth Offit, Douglas F. Easton, Georgia Chenevix-Trench, Antonis C. Antoniou, Sylvie Mazoyer, Catherine M. Phelan, Olga M. Sinilnikova, David G. Cox

Date Published: 1st Dec 2015

Publication Type: Journal article

Human Diseases: hereditary breast ovarian cancer syndrome

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OBJECTISVES The purpose of this study was to identify the independent risk factors for fast-track failure (FTF) in cardiac surgery patients. DESIGN A retrospective analysis. SETTING A university-affiliatediated heart center. PARTICIPANTS In a 2-year period, 1,704 consecutive preselected patients undergoing elective cardiac surgery were treated according to the local fast-track protocol in the postanesthetic care unit (PACU), bypassing the intensive care unit (ICU). MEASUREMENTS AND RESULTS Independent risk factors for FTF in the univariate regression analysis were tested in a multivariate regression analysis. FTF was defined as any transfer of the preselected patient to the ICU. FTF was primary when the patient was transferred directly from the postanesthetic care unit to the ICU and secondary when the patient was transferred from the intermediate care unit or ward to the ICU. FTF rate was 11.6% for primary and 5.6% for secondary FTF. In the multivariate regression analysis, age\textgreater70 years, female sex, prolonged surgery, and prolonged cross-clamp time could be defined as independent risk factors for FTF. CONCLUSIONS In a preselected patient population, fast-track treatment could be done with a low FTF rate. Independent risk factors for FTF are age, female sex, prolonged surgery, and prolonged cross-clamp time.

Authors: Zakhary Waseem, Jacob Lindner, Sophia Sgouropoulou, Sarah Eibel, Stefan Probst, Markus Scholz, Joerg Ender

Date Published: 1st Dec 2015

Publication Type: Journal article

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Higher levels of fibrinogen or cholesterol were associated with improved hearing recovery in SSHL patients after treatment with HELP-apheresis (Heparin-induced extracorporeal LDL precipitation apheresis). The present trial was performed to demonstrate HELP-related effects on relevant metabolic and inflammatory parameters in the context of SSHL treatment. In the framework of a single arm non-controlled trial, we investigated the variation of metabolic and inflammatory parameters using HELP-apheresis for a defined group of 100 patients with SSHL. Based on cut off inclusion criteria (Serum LDL-cholesterol >1.6 g/l and/or fibrinogen >2.0 g/l, SSHL in minimum three frequencies more than 30 dB, time after event not longer than 6 days), the protocol followed a strict time line with one single shot HELP-apheresis and follow-up monitoring including laboratory parameters at six defined time points. If HELP-apheresis could not effect improvement of hearing on day 5, additional corticosteroid treatment was applied. Concentration of anti-inflammatory IL-10 increased while other proinflammatory parameters declined. Serum levels of all measured sterols and apolipoproteins decreased significantly. None of the investigated parameters were suitable to predict hearing improvement of the patients. Levels of fibrinogen and LDL-cholesterol were not prognostic for outcome after HELP-apheresis. A significant (p < 0.001) increase of anti-inflammatory IL-10 after apheresis was notable, while most of the proinflammatory parameters declined. Despite the limited validity of a single arm non-controlled trial, these alterations on immune modulating factors indicate possible secondary pleiotropic effects caused by HELP-apheresis.

Authors: T. Berger, T. Kaiser, M. Scholz, A. Bachmann, U. Ceglarek, G. Hesse, B. Hagemeyer, M. Stumvoll, J. Thiery, A. Dietz

Date Published: 1st Dec 2015

Publication Type: Journal article

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BACKGROUND: Smartphones and related applications are increasingly gaining relevance in the healthcare domain. We previously assessed the demands and preferences of medical students towards an application accompanying them during a course on general practice. The current study aims to elucidate the factors associated with adoption of such a technology. Therefore we provided students with a prototype of an application specifically related to their studies in general practice. METHODS: A total estimation among students participating in a general practice examination at the Leipzig Medical School was conducted in May 2014. Students were asked to answer a structured self-designed questionnaire. Univariable comparisons were made to identify significant differences between those students who reported to have used the application frequently and those who did not. Multivariable binary logistic regression was used to reveal independent predictors of frequent application usage. RESULTS: The response rate was 99.3 % (n = 305/307). The majority (59 %, n = 180/305) were female students. The mean age was 24.5 years and 79.9 % (n = 243/304) owned a smartphone or tablet computer. Regarding the usage of the provided application, 2.3 % (n = 7/303) did not use the app while 68.0 % (n = 206/303) replied to have used it more than five times. Frequent users significantly differed from non-frequent users with regard to being female rather than male, higher mobile device ownership, more frequent exchange about obtaining the course certificate, higher personal interest in new technologies, larger enjoyment of the technology, lower intention to not use smartphone applications in the future, better opinion towards smartphone applications for the profession of a doctor, higher perceived importance of medical applications on the job, higher compatibility of smartphone applications with personal work style, higher perceived relevance of university support and personal benefit of use. Multivariable analysis revealed a set of four variables independently predicting frequent usage: being female, a higher perceived benefit of the supplied application, a higher personal interest in new technologies, and a higher perceived impact of previous experiences on smartphone adoption (Pseudo-R(2) Nagelkerke = 0.245). CONCLUSIONS: Understanding medical students’ adoption of smartphone applications used for educational purposes may provide useful information to guide the implementation process as well as the design of respective applications.

Authors: M. Sandholzer, T. Deutsch, T. Frese, Alfred Winter

Date Published: 1st Dec 2015

Publication Type: Journal article

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Neural correlates of consciousness (NCC) have been a topic of study for nearly two decades. In functional imaging studies, several regions have been proposed to constitute possible candidates for NCC, but as of yet, no quantitative summary of the literature on NCC has been done. The question whether single (striate or extrastriate) regions or a network consisting of extrastriate areas that project directly to fronto-parietal regions are necessary and sufficient neural correlates for visual consciousness is still highly debated [e.g., Rees et al., 2002, Nat Rev. Neurosci 3, 261-270; Tong, 2003, Nat Rev. Neurosci 4, 219-229]. The aim of this work was to elucidate this issue and give a synopsis of the present state of the art by conducting systematic and quantitative meta-analyses across functional magnetic resonance imaging (fMRI) studies using several standard paradigms for conscious visual perception. In these paradigms, consciousness is operationalized via perceptual changes, while the visual stimulus remains invariant. An activation likelihood estimation (ALE) meta-analysis was performed, representing the best approach for voxel-wise meta-analyses to date. In addition to computing a meta-analysis across all paradigms, separate meta-analyses on bistable perception and masking paradigms were conducted to assess whether these paradigms show common or different NCC. For the overall meta-analysis, we found significant clusters of activation in inferior and middle occipital gyrus; fusiform gyrus; inferior temporal gyrus; caudate nucleus; insula; inferior, middle, and superior frontal gyri; precuneus; as well as in inferior and superior parietal lobules. These results suggest a subcortical-extrastriate-fronto-parietal network rather than a single region that constitutes the necessary NCC. The results of our exploratory paradigm-specific meta-analyses suggest that this subcortical-extrastriate-fronto-parietal network might be differentially activated as a function of the paradigms used to probe for NCC.

Authors: S. Bisenius, S. Trapp, J. Neumann, M. L. Schroeter

Date Published: 15th Nov 2015

Publication Type: Not specified

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In humans, action errors and perceptual novelty elicit activity in a shared frontostriatal brain network, allowing them to adapt their ongoing behavior to such unexpected action outcomes. Healthy and pathologic aging reduces the integrity of white matter pathways that connect individual hubs of such networks and can impair the associated cognitive functions. Here, we investigated whether structural disconnection within this network because of small-vessel disease impairs the neural processes that subserve motor slowing after errors and novelty (post-error slowing, PES; post-novel slowing, PNS). Participants with intact frontostriatal circuitry showed increased right-lateralized beta-band (12-24 Hz) synchrony between frontocentral and frontolateral electrode sites in the electroencephalogram after errors and novelty, indexing increased neural communication. Importantly, this synchrony correlated with PES and PNS across participants. Furthermore, such synchrony was reduced in participants with frontostriatal white matter damage, in line with reduced PES and PNS. The results demonstrate that behavioral change after errors and novelty result from coordinated neural activity across a frontostriatal brain network and that such cognitive control is impaired by reduced white matter integrity.

Authors: J. R. Wessel, M. Ullsperger, H. Obrig, A. Villringer, E. Quinque, M. L. Schroeter, K. J. Bretschneider, K. Arelin, E. Roggenhofer, S. Frisch, T. A. Klein

Date Published: 14th Nov 2015

Publication Type: Not specified

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During implantation of deep-brain stimulation (DBS) electrodes in the target structure, neurosurgeons and neurologists commonly observe a "microlesion effect" (MLE), which occurs well before initiating subthalamic DBS. This phenomenon typically leads to a transitory improvement of motor symptoms of patients suffering from Parkinson's disease (PD). Mechanisms behind MLE remain poorly understood. In this work, we exploited the notion of ranking to assess spontaneous brain activity in PD patients examined by resting-state functional magnetic resonance imaging in response to penetration of DBS electrodes in the subthalamic nucleus. In particular, we employed a hypothesis-free method, eigenvector centrality (EC), to reveal motor-communication-hubs of the highest rank and their reorganization following the surgery; providing a unique opportunity to evaluate the direct impact of disrupting the PD motor circuitry in vivo without prior assumptions. Penetration of electrodes was associated with increased EC of functional connectivity in the brainstem. Changes in connectivity were quantitatively related to motor improvement, which further emphasizes the clinical importance of the functional integrity of the brainstem. Surprisingly, MLE and DBS were associated with anatomically different EC maps despite their similar clinical benefit on motor functions. The DBS solely caused an increase in connectivity of the left premotor region suggesting separate pathophysiological mechanisms of both interventions. While the DBS acts at the cortical level suggesting compensatory activation of less affected motor regions, the MLE affects more fundamental circuitry as the dysfunctional brainstem predominates in the beginning of PD. These findings invigorate the overlooked brainstem perspective in the understanding of PD and support the current trend towards its early diagnosis.

Authors: S. Holiga, K. Mueller, H. E. Moller, D. Urgosik, E. Ruzicka, M. L. Schroeter, R. Jech

Date Published: 29th Oct 2015

Publication Type: Not specified

Human Diseases: Parkinson's disease

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