Filters








26 Hits in 0.43 sec

Literatur-Rundschau

Johanna Haberer, Petra Hemmelmann, Annika Franzetti, Alexander Godulla, Wolfgang Langenbucher, Claudia Paganini
2012 Communicatio Socialis  
Petra Hemmelmann, Eichstätt ).  ...  Claudia Paganini, Innsbruck  ... 
doi:10.5771/0010-3497-2012-3-315 fatcat:zkcghv4gfzf5tbnp6qxngjbkze

Literatur-Rundschau

Christina Enders, Michael Schmolke, Walter Hömberg, Claudia Paganini, Alexander Godulla, Petra Hemmelmann
2013 Communicatio Socialis  
Claudia Paganini, Innsbruck Klaus Meier / Christoph Neuberger (Hg.): Journalismusforschung. Stand und Perspektiven. Baden-Baden: Nomos Verlagsgesellschaft 2013 (= Aktuell.  ...  Petra Hemmelmann, Eichstätt literatur-rundschau  ... 
doi:10.5771/0010-3497-2013-2-258 fatcat:vh6f3wozafe3pdhvdag5qutgiy

Statistical analysis of rare sequence variants: an overview of collapsing methods

Carmen Dering, Claudia Hemmelmann, Elizabeth Pugh, Andreas Ziegler
2011 Genetic Epidemiology  
With the advent of novel sequencing technologies, interest in the identification of rare variants that influence common traits has increased rapidly. Standard statistical methods, such as the Cochrane-Armitage trend test or logistic regression, fail in this setting for the analysis of unrelated subjects because of the rareness of the variants. Recently, various alternative approaches have been proposed that circumvent the rareness problem by collapsing rare variants in a defined genetic region
more » ... r sets of regions. We provide an overview of these collapsing methods for association analysis and discuss the use of permutation approaches for significance testing of the data-adaptive methods. Genet. Epidemiol. 35:S12-S17, 2011. r 2011 Wiley Periodicals, Inc.
doi:10.1002/gepi.20643 pmid:22128052 pmcid:PMC3277891 fatcat:qocdbbfhj5adlp2ekhinwbhsma

Comparison of collapsing methods for the statistical analysis of rare variants

Carmen Dering, Andreas Ziegler, Inke R König, Claudia Hemmelmann
2011 BMC Proceedings  
* Correspondence: hemmelmann@imbs.uni-luebeck.de Institut für Medizinische Biometrie und Statistik, Universität zu Lübeck, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Maria-Goeppert-Str.  ... 
doi:10.1186/1753-6561-5-s9-s115 pmid:22373249 pmcid:PMC3287839 fatcat:55xndsadbbcaxn35k6etd7atpu

Decreased EEG coherence between prefrontal electrodes: a correlate of high language proficiency?

Susanne Reiterer, Michael L. Berger, Claudia Hemmelmann, Peter Rappelsberger
2005 Experimental Brain Research  
To investigate the influence of proficiency level on the cortical organization of foreign language processing, two groups of German speaking students, differing only in their proficiency in English as a second language, were subjected to EEG coherence analysis during foreign and native language processing (news reports, alpha1 frequency band). In the group with minor experience with English, coherence increase was observed with all electrode combinations, with left hemisphere (LH) predominance.
more » ... In the high proficiency group, coherence increase was limited to temporal electrodes over LH. In the latter group only, coherence between prefrontal electrodes was significantly lower during the language tasks than during the baseline task (silence, noisy screen). Both results were obtained with foreign as well as native language processing. We suggest that reduced EEG coherence in highly proficient foreign language speakers reflects a more efficient operating strategy not only for their second, but also for their native language.
doi:10.1007/s00221-005-2215-z pmid:15821933 fatcat:tao7ezo5hfb6bmp6lsvw5rio7y

Quality control issues and the identification of rare functional variants with next-generation sequencing data

Claudia Hemmelmann, E. Warwick Daw, Alexander F. Wilson
2011 Genetic Epidemiology  
Next-generation sequencing of large numbers of individuals presents challenges in data preparation, quality control, and statistical analysis because of the rarity of the variants. The Genetic Analysis Workshop 17 (GAW17) data provide an opportunity to survey existing methods and compare these methods with novel ones. Specifically, the GAW17 Group 2 contributors investigate existing and newly proposed methods and study design strategies to identify rare variants, predict functional variants,
more » ... /or examine quality control. We introduce the eight Group 2 papers, summarize their approaches, and discuss their strengths and weaknesses. For these investigations, some groups used only the genotype data, whereas others also used the simulated phenotype data. Although the eight Group 2 contributions covered a wide variety of topics under the general idea of identifying rare variants, they can be grouped into three broad categories according to their common research interests: functionality of variants and quality control issues, family-based analyses, and association analyses of unrelated individuals. The aims of the first subgroup were quite different. These were population structure analyses that used rare variants to predict functionality and examine the accuracy of genotype calls. The aims of the family-based analyses were to select which families should be sequenced and to identify high-risk pedigrees; the aim of the association analyses was to identify variants or genes with regression-based methods. However, power to detect associations was low in all three association studies. Thus this work shows opportunities for incorporating rare variants into the genetic and statistical analyses of common diseases.
doi:10.1002/gepi.20645 pmid:22128054 pmcid:PMC3268158 fatcat:l4um6tlbofcadic2lyizdhvmya

Multivariate tests for the evaluation of high-dimensional EEG data

Claudia Hemmelmann, Manfred Horn, Susanne Reiterer, Bärbel Schack, Thomas Süsse, Sabine Weiss
2004 Journal of Neuroscience Methods  
In this paper several multivariate tests are presented, in particular permutation tests, which can be used in multiple endpoint problems as for example in comparisons of high-dimensional vectors of EEG data. We have investigated the power of these tests using artificial data in simulations and real EEG data. It is obvious that no one multivariate test is uniformly most powerful. The power of the different methods depends in different ways on the correlation between the endpoints, on the number
more » ... f endpoints for which differences exist and on other factors. Based on our findings, we have derived rules of thumb regarding under which configurations a particular test should be used. In order to demonstrate the properties of different multivariate tests we applied them to EEG coherence data. As an example for the paired samples case, we compared the 171-dimensional coherence vectors observed for the alpha1-band while processing either concrete or abstract nouns and obtained significant global differences for some sections of time. As an example for the unpaired samples case, we compared the coherence vectors observed for language students and non-language students who processed an English text and found a significant global difference.
doi:10.1016/j.jneumeth.2004.04.013 pmid:15351527 fatcat:x3kiponn5vbfbivc5s6kmrkp5u

Triple-Target Treatment Versus Low-Frequency Electrostimulation for Anal Incontinence

Thilo Schwandner, Claudia Hemmelmann, Tankred Heimerl, Walter Kierer, Gerd Kolbert, Reinhard Vonthein, Rolf Weinel, Markus Hirschburger, Andreas Ziegler, Winfried Padberg
2011 Deutsches Ärzteblatt International  
A Randomized , Randomized Controlled Trial Thilo Schwandner*, Claudia Hemmelmann*, Tankred Heimerl, Walter Kierer, Gerd Kolbert, Reinhard Vonthein, Rolf Weinel, Markus Hirschburger, Andreas Ziegler, and  ...  Hemmelmann*, Tankred Heimerl, Walter Kierer, Gerd Kolbert, Reinhard Vonthein, Rolf Weinel, Markus Hirschburger, Andreas Ziegler, and Winfried Padberg Univ.  ... 
doi:10.3238/arztebl.2011.0653 pmid:22013492 pmcid:PMC3196995 fatcat:5ypz7hhrn5eglevcnbtnpkropq

Mutant Parkin Impairs Mitochondrial Function and Morphology in Human Fibroblasts

Anne Grünewald, Lisa Voges, Aleksandar Rakovic, Meike Kasten, Himesha Vandebona, Claudia Hemmelmann, Katja Lohmann, Slobodanka Orolicki, Alfredo Ramirez, Anthony H. V. Schapira, Peter P. Pramstaller, Carolyn M. Sue (+2 others)
2010 PLoS ONE  
Mutations in Parkin are the most common cause of autosomal recessive Parkinson disease (PD). The mitochondrially localized E3 ubiquitin-protein ligase Parkin has been reported to be involved in respiratory chain function and mitochondrial dynamics. More recent publications also described a link between Parkin and mitophagy. Methodology/Principal Findings: In this study, we investigated the impact of Parkin mutations on mitochondrial function and morphology in a human cellular model. Fibroblasts
more » ... were obtained from three members of an Italian PD family with two mutations in Parkin (homozygous c.1072delT, homozygous delEx7, compound-heterozygous c.1072delT/delEx7), as well as from two relatives without mutations. Furthermore, three unrelated compound-heterozygous patients (delEx3-4/duplEx7-12, delEx4/c.924C.T and delEx1/c.924C.T) and three unrelated age-matched controls were included. Fibroblasts were cultured under basal or paraquat-induced oxidative stress conditions. ATP synthesis rates and cellular levels were detected luminometrically. Activities of complexes I-IV and citrate synthase were measured spectrophotometrically in mitochondrial preparations or cell lysates. The mitochondrial membrane potential was measured with 5,59,6,69-tetrachloro-1,19,3,39tetraethylbenzimidazolylcarbocyanine iodide. Oxidative stress levels were investigated with the OxyBlot technique. The mitochondrial network was investigated immunocytochemically and the degree of branching was determined with image processing methods. We observed a decrease in the production and overall concentration of ATP coinciding with increased mitochondrial mass in Parkin-mutant fibroblasts. After an oxidative insult, the membrane potential decreased in patient cells but not in controls. We further determined higher levels of oxidized proteins in the mutants both under basal and stress conditions. The degree of mitochondrial network branching was comparable in mutants and controls under basal conditions and decreased to a similar extent under paraquat-induced stress. Conclusions: Our results indicate that Parkin mutations cause abnormal mitochondrial function and morphology in nonneuronal human cells.
doi:10.1371/journal.pone.0012962 pmid:20885945 pmcid:PMC2946349 fatcat:k742bynho5c7hp3amphdpjqi3m

Metachronous metastasis- and survival-analysis show prognostic importance of lymphadenectomy for colon carcinomas

Tilman Laubert, Jens K Habermann, Claudia Hemmelmann, Markus Kleemann, Elisabeth Oevermann, Ralf Bouchard, Philipp Hildebrand, Thomas Jungbluth, Conny Bürk, Hamed Esnaashari, Erik Schlöricke, Martin Hoffmann (+3 others)
2012 BMC Gastroenterology  
Acknowledgements We gratefully thank Claudia Killaitis for IT support.  ... 
doi:10.1186/1471-230x-12-24 pmid:22443372 pmcid:PMC3349572 fatcat:oygjqn24yrc7rn254kg77y3qie

Observation and execution of upper-limb movements as a tool for rehabilitation of motor deficits in paretic stroke patients: protocol of a randomized clinical trial

Denis Ertelt, Claudia Hemmelmann, Christian Dettmers, Andreas Ziegler, Ferdinand Binkofski
2012 BMC Neurology  
Evidence exist that motor observation activates the same cortical motor areas that are involved in the performance of the observed actions. The so called "mirror neuron system" has been proposed to be responsible for this phenomenon. We employ this neural system and its capability to re-enact stored motor representations as a tool for rehabilitating motor control. In our new neurorehabilitative schema (videotherapy) we combine observation of daily actions with concomitant physical training of
more » ... e observed actions focusing on the upper limbs. Following a pilot study in chronic patients in an ambulatory setting, we currently designed a new multicenter clinical study dedicated to patients in the sub-acute state after stroke using a home-based self-induced training. Within our protocol we assess 1) the capability of action observation to elicit rehabilitational effects in the motor system, and 2) the capacity of this schema to be performed by patients without assistance from a physiotherapist. The results of this study would be of high health and economical relevance. Methods/design: A controlled, randomized, multicenter, paralleled, 6 month follow-up study will be conducted on three groups of patients: one group will be given the experimental treatment whereas the other two will participate in control treatments. All patients will undergo their usual rehabilitative treatment beside participation in the study. The experimental condition consists in the observation and immediate imitation of common daily hand and arm actions. The two parallel control groups are a placebo group and a group receiving usual rehabilitation without any trial-related treatment. Trial randomization is provided via external data management. The primary efficacy endpoint is the improvement of the experimental group in a standardized motor function test (Wolf Motor Function Test) relative to control groups. Further assessments refer to subjective and qualitative rehabilitational scores. This study has been reviewed and approved by the ethics committee of Aachen University. Discussion: This therapy provides an extension of therapeutic procedures for recovery after stroke and emphasizes the importance of action perception in neurorehabilitation The results of the study could become implemented into the wide physiotherapeutic practice, for example as an ad on and individualized therapy.
doi:10.1186/1471-2377-12-42 pmid:22708612 pmcid:PMC3495666 fatcat:wfizklmzsvfkbp6hn3agz4zmze

Incidence of therapy-related acute leukaemia in mitoxantrone-treated multiple sclerosis patients in Germany

Anke Stroet, Claudia Hemmelmann, Michaela Starck, Uwe Zettl, Jan Dörr, Friedemann Paul, Peter Flachenecker, Vinzenz Fleischer, Frauke Zipp, Holger Nückel, Bernd C Kieseier, Andreas Ziegler (+2 others)
2012 Therapeutic Advances in Neurological Disorders  
The incidence of therapy-related acute leukaemia (TRAL) in mitoxantrone treatment in multiple sclerosis (MS) is controversially discussed. Methods and results: In a retrospective meta-analysis from six centres, we observed six cases of acute myeloid leukaemia (AML) (incidence 0.41% for patients with mean follow up after end of treatment of 3.6 years, n = 1.156; incidence 0.25% for all patients, n = 2.261). Potential influencing factors such as myelotoxic or glucocorticosteroid pretreatment/
more » ... eatment were present in all but one case of TRAL. Between 1990 and 2010, 11 cases of TRAL were reported to the Drug Commission of the German Medical Association (estimated risk of 0.09-0.13%). Conclusions: Regional differences in reported TRAL incidence may point to confounding cofactors such as administration protocols and cotreatments.
doi:10.1177/1756285611433318 pmid:22435072 pmcid:PMC3302202 fatcat:j64l47bhvbbllpdvccequyv3my

Characteristic functional networks in high- versus low-proficiency second language speakers detected also during native language processing: An explorative EEG coherence study in 6 frequency bands

Susanne Reiterer, Claudia Hemmelmann, Peter Rappelsberger, Michael L. Berger
2005 Cognitive Brain Research  
An EEG coherence study was performed with a twofold objective: first, to scrutinize the theoretical concept of "cortical efficiency" in connection with second language (L2) acquisition and, second, to detect cooperations between cortical areas in specific frequency bands indicative for highly proficient L2 processing. Two groups differing only in their level of L2 proficiency were contrasted during presentation of natural language videos in English (L2) and German (native language, L1), with
more » ... lorative coherence analysis in 6 frequency bands (0.5 -31.5 Hz). The coherence brain maps revealed more pronounced and widespread increases in coherences in the a1band (8 -10 Hz) in low-proficiency than in the high-proficiency L2 speakers. Surprisingly, this difference was obtained also during L1 processing and corroborated for both languages by multivariate permutation tests. These tests revealed additional differences between the low-and the high-proficiency group also for coherences within the h1-(13 -18 Hz) and the h2-band (18.5 -31.5 Hz), again during L2 and L1 processing. Since the same group differences were observed during L1 and L2 processing, our high-proficiency group might have profited from a more generic advantage in language or text processing strategy. This strategic advantage was most evident at a1 frequencies, possibly related to a specific way of processing internal mental states (top-down processing).
doi:10.1016/j.cogbrainres.2005.08.010 pmid:16185851 fatcat:m66cyfdoj5g3jdoebqm36c35jy

Epidemic Microclusters of Blood-Culture Proven Sepsis in Very-Low-Birth Weight Infants: Experience of the German Neonatal Network

Christoph Härtel, Kirstin Faust, Stefan Avenarius, Bettina Bohnhorst, Michael Emeis, Corinna Gebauer, Peter Groneck, Friedhelm Heitmann, Thomas Hoehn, Mechthild Hubert, Angela Kribs, Helmut Küster (+17 others)
2012 PLoS ONE  
We evaluated blood culture-proven sepsis episodes occurring in microclusters in very-low-birth-weight infants born in the German Neonatal Network (GNN) during 2009-2010. Methods: Thirty-seven centers participated in GNN; 23 centers enrolled $50 VLBW infants in the study period. Data quality was approved by on-site monitoring. Microclusters of sepsis were defined as occurrence of at least two blood-culture proven sepsis events in different patients of one center within 3 months with the same
more » ... erial species. For microcluster analysis, we selected sepsis episodes with typically cross-transmitted bacteria of high clinical significance including gramnegative rods and Enterococcus spp.
doi:10.1371/journal.pone.0038304 pmid:22768043 pmcid:PMC3387163 fatcat:uapbdhkmhzdb7oqvxpnex3qbju

Polymorphisms in FTO and MAF Genes and Birth Weight, BMI, Ponderal Index, Weight Gain in a Large Cohort of Infants with a Birth Weight below 1500 Grams

Sebastian Haller, Juliane Spiegler, Claudia Hemmelmann, Helmut Küster, Matthias Vochem, Jens Möller, Dirk Müller, Angela Kribs, Thomas Hoehn, Christoph Härtel, Egbert Herting, Wolfgang Göpel (+1 others)
2013 PLoS ONE  
The FTO gene, located on chromosome 16q12.2, and the MAF gene, located on chromosome 16q22-23, were identified as genes harboring common variants with an impact on obesity predisposition. We studied the association of common variants with birth weight, gain of body weight, body mass index (BMI), Ponderal index and relevant neonatal outcomes in a large German cohort of infants with a birth weight below 1500 grams. Methods: The single nucleotide polymorphisms rs9939609 (FTO gene) and rs1424233
more » ... F gene) were genotyped using allelic discrimination assays in a prospective multicenter cohort study conducted in 15 neonatal intensive care units in Germany from September 2003 until January 2008. DNA samples were extracted from buccal swabs according to standard protocols. Results: 1946 infants were successfully genotyped at FTO and 2149 infants at MAF. Allele frequencies were not significantly different from other European cohorts. The polymorphisms were in Hardy-Weinberg equilibrium. The polymorphisms did not show associations with birth weight, BMI and Ponderal Index at discharge, and weight gain, neither testing for a dominant, additive nor for a recessive model. Discussion: Since an association of the polymorphisms with weight gain has been demonstrated in multiple populations, the lack of association in a population of preterm infants with regular tube feeding after birth and highly controlled feeding volumes provides evidence for the hypothesis that these polymorphisms affect food intake behavior and hunger rather than metabolism and energy consumption.
doi:10.1371/journal.pone.0066331 pmid:23840443 pmcid:PMC3694095 fatcat:lsnrepqyzjhjfo72c6v574z6qi
« Previous Showing results 1 — 15 out of 26 results