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960 Publications visible to you, out of a total of 960
Progesterone mediates brain functional connectivity changes during the menstrual cycle-a pilot resting state MRI study.
LIFE Adult

Abstract (Expand)

The growing interest in intrinsic brain organization has sparked various innovative approaches to generating comprehensive connectivity-based maps of the human brain. Prior reports point to a sexual … dimorphism of the structural and functional human connectome. However, it is uncertain whether subtle changes in sex hormones, as occur during the monthly menstrual cycle, substantially impact the functional architecture of the female brain. Here, we performed eigenvector centrality (EC) mapping in 32 longitudinal resting state fMRI scans of a single healthy subject without oral contraceptive use, across four menstrual cycles, and assessed estrogen and progesterone levels. To investigate associations between cycle-dependent hormones and brain connectivity, we performed correlation analyses between the EC maps and the respective hormone levels. On the whole brain level, we found a significant positive correlation between progesterone and EC in the bilateral dorsolateral prefrontal cortex (DLPFC) and bilateral sensorimotor cortex. In a secondary region-of-interest analysis, we detected a progesterone-modulated increase in functional connectivity of both bilateral DLPFC and bilateral sensorimotor cortex with the hippocampus. Our results suggest that the menstrual cycle substantially impacts intrinsic functional connectivity, particularly in brain areas associated with contextual memory-regulation, such as the hippocampus. These findings are the first to link the subtle hormonal fluctuations that occur during the menstrual cycle, to significant changes in regional functional connectivity in the hippocampus in a longitudinal design, given the limitation of data acquisition in a single subject. Our study demonstrates the feasibility of such a longitudinal Resting-state functional Magnetic Resonance Imaging (rs-fMRI) design and illustrates a means of creating a personalized map of the human brain by integrating potential mediators of brain states, such as menstrual cycle phase.

Authors: K. Arelin, K. Mueller, C. Barth, P. V. Rekkas, J. Kratzsch, I. Burmann, A. Villringer, J. Sacher

Date Published: 11th Mar 2015

Publication Type: Not specified

Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods.
LIFE Adult

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

Characterization of genomic imbalances in diffuse large B-cell lymphoma by detailed SNP-chip analysis.
MMML - Molecular mechanisms in malignant lymphoma

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

Complexin2 modulates working memory-related neural activity in patients with schizophrenia
Genetical Statistics and Systems Biology

Abstract (Expand)

The specific contribution of risk or candidate gene variants to the complex phenotype of schizophrenia is largely unknown. Studying the effects of such variants on brain function can provide insight … into disease-associated mechanisms on a neural systems level. Previous studies found common variants in the complexin2 (CPLX2) gene to be highly associated with cognitive dysfunction in schizophrenia patients. Similarly, cognitive functioning was found to be impaired in Cplx2 gene-deficient mice if they were subjected to maternal deprivation or mild brain trauma during puberty. Here, we aimed to study seven common CPLX2 single-nucleotide polymorphisms (SNPs) and their neurogenetic risk mechanisms by investigating their relationship to a schizophrenia-related functional neuroimaging intermediate phenotype. We examined functional MRI and genotype data collected from 104 patients with DSM-IV-diagnosed schizophrenia and 122 healthy controls who participated in the Mind Clinical Imaging Consortium study of schizophrenia. Seven SNPs distributed over the whole CPLX2 gene were tested for association with working memory-elicited neural activity in a frontoparietal neural network. Three CPLX2 SNPs were significantly associated with increased neural activity in the dorsolateral prefrontal cortex and intraparietal sulcus in the schizophrenia sample, but showed no association in healthy controls. Since increased working memory-related neural activity in individuals with or at risk for schizophrenia has been interpreted as ’neural inefficiency,’ these findings suggest that certain variants of CPLX2 may contribute to impaired brain function in schizophrenia, possibly combined with other deleterious genetic variants, adverse environmental events, or developmental insults.   The specific contribution of risk or candidate gene variants to the complex phenotype of schizophrenia is largely unknown. Studying the effects of such variants on brain function can provide insight into disease-associated mechanisms on a neural systems level. Previous studies found common variants in the complexin2 (CPLX2) gene to be highly associated with cognitive dysfunction in schizophrenia patients. Similarly, cognitive functioning was found to be impaired in Cplx2 gene-deficient mice if they were subjected to maternal deprivation or mild brain trauma during puberty. Here, we aimed to study seven common CPLX2 single-nucleotide polymorphisms (SNPs) and their neurogenetic risk mechanisms by investigating their relationship to a schizophrenia-related functional neuroimaging intermediate phenotype. We examined functional MRI and genotype data collected from 104 patients with DSM-IV-diagnosed schizophrenia and 122 healthy controls who participated in the Mind Clinical Imaging Consortium study of schizophrenia. Seven SNPs distributed over the whole CPLX2 gene were tested for association with working memory-elicited neural activity in a frontoparietal neural network. Three CPLX2 SNPs were significantly associated with increased neural activity in the dorsolateral prefrontal cortex and intraparietal sulcus in the schizophrenia sample, but showed no association in healthy controls. Since increased working memory-related neural activity in individuals with or at risk for schizophrenia has been interpreted as ’neural inefficiency,’ these findings suggest that certain variants of CPLX2 may contribute to impaired brain function in schizophrenia, possibly combined with other deleterious genetic variants, adverse environmental events, or developmental insults.   The specific contribution of risk or candidate gene variants to the complex phenotype of schizophrenia is largely unknown. Studying the effects of such variants on brain function can provide insight into disease-associated mechanisms on a neural systems level. Previous studies found common variants in the complexin2 (CPLX2) gene to be highly associated with cognitive dysfunction in schizophrenia patients. Similarly, cognitive functioning was found to be impaired in Cplx2 gene-deficient mice if they were subjected to maternal deprivation or mild brain trauma during puberty. Here, we aimed to study seven common CPLX2 single-nucleotide polymorphisms (SNPs) and their neurogenetic risk mechanisms by investigating their relationship to a schizophrenia-related functional neuroimaging intermediate phenotype. We examined functional MRI and genotype data collected from 104 patients with DSM-IV-diagnosed schizophrenia and 122 healthy controls who participated in the Mind Clinical Imaging Consortium study of schizophrenia. Seven SNPs distributed over the whole CPLX2 gene were tested for association with working memory-elicited neural activity in a frontoparietal neural network. Three CPLX2 SNPs were significantly associated with increased neural activity in the dorsolateral prefrontal cortex and intraparietal sulcus in the schizophrenia sample, but showed no association in healthy controls. Since increased working memory-related neural activity in individuals with or at risk for schizophrenia has been interpreted as ’neural inefficiency,’ these findings suggest that certain variants of CPLX2 may contribute to impaired brain function in schizophrenia, possibly combined with other deleterious genetic variants, adverse environmental events, or developmental insults. //  The specific contribution of risk or candidate gene variants to the complex phenotype of schizophrenia is largely unknown. Studying the effects of such variants on brain function can provide insight into disease-associated mechanisms on a neural systems level. Previous studies found common variants in the complexin2 (CPLX2) gene to be highly associated with cognitive dysfunction in schizophrenia patients. Similarly, cognitive functioning was found to be impaired in Cplx2 gene-deficient mice if they were subjected to maternal deprivation or mild brain trauma during puberty. Here, we aimed to study seven common CPLX2 single-nucleotide polymorphisms (SNPs) and their neurogenetic risk mechanisms by investigating their relationship to a schizophrenia-related functional neuroimaging intermediate phenotype. We examined functional MRI and genotype data collected from 104 patients with DSM-IV-diagnosed schizophrenia and 122 healthy controls who participated in the Mind Clinical Imaging Consortium study of schizophrenia. Seven SNPs distributed over the whole CPLX2 gene were tested for association with working memory-elicited neural activity in a frontoparietal neural network. Three CPLX2 SNPs were significantly associated with increased neural activity in the dorsolateral prefrontal cortex and intraparietal sulcus in the schizophrenia sample, but showed no association in healthy controls. Since increased working memory-related neural activity in individuals with or at risk for schizophrenia has been interpreted as ’neural inefficiency,’ these findings suggest that certain variants of CPLX2 may contribute to impaired brain function in schizophrenia, possibly combined with other deleterious genetic variants, adverse environmental events, or developmental insults.

Authors: Johanna Hass, Esther Walton, Holger Kirsten, Jessica Turner, Rick Wolthusen, Veit Roessner, Scott R. Sponheim, Daphne Holt, Randy Gollub, Vince D. Calhoun, Stefan Ehrlich

Date Published: 1st Mar 2015

Publication Type: Journal article

Reference intervals for leukocyte subsets in adults: Results from a population-based study using 10-color flow cytometry.
LIFE Adult

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

Different biological risk factors in young poor-prognosis and elderly patients with diffuse large B-cell lymphoma.
GLA - German Lymphoma Alliance

Abstract (Expand)

Prognostically relevant risk factors in patients with diffuse large B-cell lymphoma (DLBCL) have predominantly been evaluated in elderly populations. We tested whether previously described risk factors … are also valid in younger, poor-prognosis DLBCL patients. Paraffin-embedded samples from 112 patients with de novo DLBCL, enrolled in the R-MegaCHOEP trial of the German High Grade Non-Hodgkin Lymphoma Study Group (DSHNHL) were investigated using immunohistochemistry (MYC, FOXP1, LMO2, GCET1, CD5, CD10, BCL2, BCL6, IRF4/MUM1) and fluorescence in situ hybridization (MYC, BCL2, BCL6). MYC, BCL2 and BCL6 breaks occurred in 14, 21 and 31%, respectively. In the majority of cases, MYC was simultaneously rearranged with BCL2 and/or BCL6. The adverse impact of MYC rearrangements was confirmed, but the sole presence of BCL2 breaks emerged as a novel prognostic marker associated with inferior overall survival (OS) (P=0.002). Combined overexpression of MYC and BCL2 showed only limited association with inferior OS. All immunohistochemical cell of origin classifiers applied failed to predict survival time. DLBCL tumors with significant proportion of immunoblastic and/or immunoblastic-plasmacytoid cells had inferior OS, independently from from BCL2 break. Younger, poor-prognosis DLBCL patients, therefore, display different biological risk factors compared with an elderly population, with BCL2 translocations emerging as a powerful negative prognostic marker.

Authors: H. Horn, M. Ziepert, M. Wartenberg, A. M. Staiger, T. F. Barth, H. W. Bernd, A. C. Feller, W. Klapper, C. Stuhlmann-Laeisz, M. Hummel, H. Stein, D. Lenze, S. Hartmann, M. L. Hansmann, P. Moller, S. Cogliatti, M. Pfreundschuh, L. Trumper, M. Loeffler, B. Glass, N. Schmitz, G. Ott, A. Rosenwald

Date Published: 18th Feb 2015

Publication Type: Not specified

Human Diseases: diffuse large B-cell lymphoma

[Final Report Evaluation Metadata Repository (MDR-Eval)]
Evaluation Metadata Repository

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

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