Publications

228 Publications visible to you, out of a total of 228

Abstract (Expand)

Sex hormones have been implicated in neurite outgrowth, synaptogenesis, dendritic branching, myelination and other important mechanisms of neural plasticity. Here we review the evidence from animal experiments and human studies reporting interactions between sex hormones and the dominant neurotransmitters, such as serotonin, dopamine, GABA and glutamate. We provide an overview of accumulating data during physiological and pathological conditions and discuss currently conceptualized theories on how sex hormones potentially trigger neuroplasticity changes through these four neurochemical systems. Many brain regions have been demonstrated to express high densities for estrogen- and progesterone receptors, such as the amygdala, the hypothalamus, and the hippocampus. As the hippocampus is of particular relevance in the context of mediating structural plasticity in the adult brain, we put particular emphasis on what evidence could be gathered thus far that links differences in behavior, neurochemical patterns and hippocampal structure to a changing hormonal environment. Finally, we discuss how physiologically occurring hormonal transition periods in humans can be used to model how changes in sex hormones influence functional connectivity, neurotransmission and brain structure in vivo.

Authors: C. Barth, A. Villringer, J. Sacher

Date Published: 10th Mar 2015

Publication Type: Not specified

Abstract (Expand)

The pathogenesis of diffuse large B-cell lymphomas (DLBCL) is only partly understood. We analyzed 148 DLBCL by single nucleotide polymorphism (SNP)-chips to characterize genomic imbalances. Seventy-nine cases were of the germinal center B-cell like (GCB) type of DLBCL, 49 of the activated B-cell like (ABC) subtype and 20 were unclassified DLBCL. Twenty-four regions of recurrent genomic gains and 38 regions of recurrent genomic losses were identified over the whole cohort, with a median of 25 imbalances per case for ABC-DLBCL and 19 per case for GCB-DLBCL. Several recurrent copy number changes showed differential frequencies in the GCB- and ABC-DLBCL subgroups, including gains of HDAC7A predominantly in GCB-DLBCL (38% of cases) and losses of BACH2 and CASP8AP2 predominantly in ABC-DLBCL (35%), hinting at disparate pathogenetic mechanisms in these entities. Correlating gene expression and copy number revealed a strong gene dosage effect in all tumors, with 34% of probesets showing a concordant expression change in affected regions. Two new potential tumor suppressor genes emerging from the analysis, CASP3 and IL5RA, were sequenced in ten and 16 candidate cases, respectively. However, no mutations were found, pointing to a potential haploinsufficiency effect of these genes, considering their reduced expression in cases with deletions. Our study thus describes differences and similarities in the landscape of genomic aberrations in the DLBCL subgroups in a large collection of cases, confirming already known targets, but also discovering novel copy number changes with possible pathogenetic relevance.

Authors: R. Scholtysik, M. Kreuz, M. Hummel, M. Rosolowski, M. Szczepanowski, W. Klapper, M. Loeffler, L. Trumper, R. Siebert, R. Kuppers

Date Published: 1st Mar 2015

Publication Type: Not specified

Human Diseases: diffuse large B-cell lymphoma

Abstract (Expand)

BACKGROUND: Reference intervals for leukocyte subsets from peripheral blood are helpful for the understanding of disease states and therapy effects. METHODS: We performed in-depth immunophenotyping for 608 healthy German adults from the Leipzig region from 40 to 79 years by 10-color flow cytometry (FCM) to gain reference information for various leukocyte subsets including subsets of granulocytes, monocytes and lymphocytes. RESULTS: First, we derived gender- and age-specific reference intervals for males and females from 40 to 59 and from 60 to 79 years, respectively. Second, we further investigated the influence of gender and age on leukocyte counts. We found significantly higher cell counts for monocytes (P < 0.001) and NK cells (P < 0.001) in men, whereas women had higher counts for B cells (P < 0.001), Th cells (P < 0.001) and regulatory T cells (P = 0.008). Furthermore, with increasing age, a decrease in Tc cells (about 8% within 5 years) and an increase in NK cells (<4% within 5 years) were observed. CONCLUSION: In future research, it should be investigated whether these are real ageing effects that can be confirmed in longitudinal studies. Furthermore, it is important to understand if the Tc cell count drop is functionally compensated by the increase of NK cells.

Authors: S. Melzer, S. Zachariae, J. Bocsi, C. Engel, M. Loffler, A. Tarnok

Date Published: 24th Feb 2015

Publication Type: Not specified

Abstract (Expand)

Metadata Repositories sind Datenbanken für Datenelemente, die sowohl in der Forschung, z.B. in klinischen Studien oder epidemiologischen Kohorten, wie auch in der Versorgung, z.B. in Informationssystemen des Krankenhauses genutzt werden (können). Bei diesen Datenelementen handelt es sich nicht um die eigentlichen Patientendaten (Fakten), sondern um eine vollständige Definition der verwendeten Variablen bzw. Merkmale inklusive der Kodierung, der Maßeinheit, des Datentyps und anderer Aspekte. In einem BMBF-geförderten und TMF-koordinierten Projekt wurde neben konzeptionellen Grundlagen ein Softwareprototyp für den Aufbau eines Nationalen Metadata Repositories für die klinische und epidemiologische Forschung in Deutschland (MDR) erarbeitet. Der Prototyp implementiert ein Datenmodell nach der aktualisierten Version 3 der ISO/IEC-Norm 11179/3 und steht unter einer Open-Source-Lizenz zur Verfügung . Basis für die realisierten Funktionalitäten des MDRs waren die in einem TMF-Vorprojekt analysierten funktionalen Anforderungen (TMF V063-01 Arbeitspaket 2), welche aber aufgrund der begrenzten Projektmittel nicht vollumfänglich umgesetzt werden konnten. Wesentliche Funktionen wie das Erstellen/Modifizieren/Importieren/Klassifizieren von Datenelementen und Formularen sowie einige der avisierten Community-Funktionen stehen jedoch zur Verfügung. Ziel des hier beschriebenen Projekts MDR-Evaluation war eine Evaluation der möglichen Anwendungsszenarien für Metadata Repositories durch eine größere Gruppe von Fachexperten. Dabei stand nicht eine konkrete Software im Vordergrund, sondern die prinzipielle Erwartung der Community an eine webbasierte Datenbank von Datenelementen. Zur Erreichung des Ziels wurde ein Fragebogen entworfen, der sowohl Fragen zu generellen Aspekten des Aufbaus einer zentralen Bibliothek für Datenelemente der biomedizinischen Forschung wie auch konkretere Punkte im Hinblick auf notwendige Funktionalitäten, gewünschte Inhalte, Werkzeuge zur Communityarbeit und zur Güte von Datenelementen enthielt. Der Fragebogen wurde im Rahmen einer Web-Umfrage einer breiten Community präsentiert. Aus den Antworten lassen sich strategische Erfolgskriterien für die Implementierung eines communityorientierten Metadata Repositories gewinnen.

Author: Matthias Löbe

Date Published: 1st Feb 2015

Publication Type: Not specified

Abstract (Expand)

OBJECTIVE: Research consistently shows a negative view of individuals with obesity in the general public and in various other settings. Stigma and discrimination can be considered chronic stressors, as these factors have a profound impact on the psychological well-being of the affected individuals. This article proposes a framework that entails a mediation of the adverse effects of discrimination and stigmatization on mental well-being through elevated psychological risk factors that are not unique to weight but that could affect overweight and normal-weight individuals alike. METHODS: A systematic review was conducted to assess the prevalence of psychological risk factors, such as self-esteem and coping, in individuals with obesity. RESULTS: Forty-six articles were assessed and included for detailed analysis. The number of studies on these topics is limited to certain dimensions of psychological processes. The best evaluated association of obesity and psychosocial aspects is seen for self-esteem. Most studies establish a negative association of weight and self-esteem in children and adults. All studies with mediation analysis find a positive mediation through psychological risk factors on mental health outcomes. CONCLUSIONS: This review shows that elevated psychological risk factors are existent in individuals with obesity and that they may be a mediator between weight discrimination and pathopsychological outcomes.

Authors: C. Sikorski, M. Luppa, T. Luck, S. G. Riedel-Heller

Date Published: 29th Jan 2015

Publication Type: Not specified

Abstract (Expand)

Glioma is a clinically and biologically diverse disease. It challenges diagnosis and prognosis due to its molecular heterogeneity and diverse regimes of biological dysfunctions which are driven by genetic and epigenetic mechanisms. We discover the functional impact of sets of DNA methylation marker genes in the context of brain cancer subtypes as an exemplary approach how bioinformatics and particularly machine learning using self organizing maps (SOM) complements modern high-throughput genomic technologies. DNA methylation changes in gliomas comprise both, hyper- and hypomethylation in a subtype specific fashion. We compared pediatric (2 subtypes) and adult (4) glioblastoma and non-neoplastic brain. The functional impact of differential methylation marker sets is discovered in terms of gene set analysis which comprises a large collection of markers related to biological processes, literature data on gliomas and also chromatin states of the healthy brain. DNA methylation signature genes from alternative studies well agree with our signatures. SOM mapping of gene sets robustly identifies similarities between different marker sets even under conditions of noisy compositions. Mapping of previous sets of glioma markers reveals high redundancy and mixtures of subtypes in the reference cohorts. Consideration of the regulatory level of DNA methylation is inevitable for understanding cancer genesis and progression. It provides suited markers for diagnosis of glioma subtypes and disentangles tumor heterogeneity.

Authors: E. Willscher, H. Loffler-Wirth, H. Binder, Lydia Hopp

Date Published: 2015

Publication Type: Not specified

Human Diseases: brain glioma

Abstract (Expand)

LIFE is an epidemiological study determining thousands of Leipzig inhabitants with a wide spectrum of interviews, questionnaires, and medical investigations. The heterogeneous data are centrally integrated into a research database and are analyzed by specific analysis projects. To semantically describe the large set of data, we have developed an ontological framework. Applicants of analysis projects and other interested people can use the LIFE Investigation Ontology (LIO) as central part of the framework to get insights, which kind of data is collected in LIFE. Moreover, we use the framework to generate queries over the collected scientific data in order to retrieve data as requested by each analysis project. A query generator transforms the ontological specifications using LIO to database queries which are implemented as project-specific database views. Since the requested data is typically complex, a manual query specification would be very timeconsuming, error-prone, and is, therefore, unsuitable in this large project. We present the approach, overview LIO and show query formulation and transformation. Our approach runs in production mode for two years in LIFE.

Authors: Toralf Kirsten, A. Uciteli

Date Published: 2015

Publication Type: Not specified

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