Publications

100 Publications visible to you, out of a total of 100

Abstract (Expand)

Obesity is known to affect the brain's gray matter (GM) and white matter (WM) structure but the interrelationship of such changes remains unclear. Here we used T1-weighted magnetic resonance imaging (MRI) in combination with voxel-based morphometry (VBM) and diffusion-tensor imaging (DTI) with tract-based spatial statistics (TBSS) to assess the relationship between obesity-associated alterations of gray matter density (GMD) and anisotropic water diffusion in WM, respectively. In a small cohort of lean to obese women, we confirmed previous reports of obesity-associated alterations of GMD in brain regions involved in executive control (i.e., dorsolateral prefrontal cortex, DLPFC) and habit learning (i.e., dorsal striatum). Gray matter density alterations of the DLPFC were negatively correlated with radial diffusivity in the entire corpus callosum. Within the genu of the corpus callosum we found a positive correlation with axial diffusivity. In posterior region and inferior areas of the body of the corpus callosum, axial diffusivity correlated negatively with altered GMD in the dorsal striatum. These findings suggest that, in women, obesity-related alterations of GMD in brain regions involved in executive control and habit learning might relate to alterations of associated WM fiber bundles within the corpus callosum.

Authors: K. Mueller, A. Horstmann, H. E. Moller, A. Anwander, J. Lepsien, M. L. Schroeter, A. Villringer, B. Pleger

Date Published: 11th Dec 2014

Publication Type: Not specified

Human Diseases: obesity

Abstract (Expand)

Herpes simplex encephalitis (HSE) is a severe neurological disease that often leads to persistent cognitive deficits in survivors. Memory and naming impairments have been reported most, although direct association between memory and naming performance and disease-related atrophy has not yet been demonstrated in vivo for a larger sample of patients. In the present work, a voxel-based morphometry (VBM) analysis was conducted on 3T magnetic resonance imaging (MRI) of 13 HSE survivors. The gray matter density values were correlated with scores indicating verbal memory decline, as well as errors/omissions in picture naming; both were obtained through neuropsychological assessment. Analysis of individual lesion patterns revealed a considerable inter-individual variability, mainly with atrophy in the basal forebrain, adjacent frontal cortex, medial and lateral temporal cortex, insula and thalamus. The neuropsychological data analysis revealed correlation between verbal memory decline and atrophy especially in the left hippocampal region, whereas naming problems were associated with gray matter loss especially in the lateral temporal lobe, the thalamus and the left insula. These results confirm, for the first time, the assumptions of earlier studies about the considerable variability of individual lesion patterns in HSE in a whole-brain approach in vivo, and thus the anatomical validity of VBM.

Authors: S. Frisch, F. Thiel, A. Marschhauser, A. Villringer, A. Horstmann, M. L. Schroeter

Date Published: 10th Dec 2014

Publication Type: Not specified

Human Diseases: viral encephalitis

Abstract (Expand)

OBJECTIVES: This study investigates the impact of occupation-based motivational processes and social network variables on the incidence of dementia over 8 years. METHOD: Data were derived from the Leipzig Longitudinal Study of the Aged (LEILA75+), a population-based longitudinal study of individuals aged 75 years and older (n=1692 at baseline). Motivational processes were estimated based on the main occupation using the Occupational Information Network database. RESULTS: In a Cox proportional hazard model, motivational processes were not associated with the risk of dementia (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.74-1.16). Individuals with a higher frequency of social contact at baseline had a significantly lower risk of dementia (HR: 0.96, 95% CI: 0.91-0.99), while proximity of social contacts was not linked to the risk of dementia (HR: 1.03, 95% CI: 0.98-1.08). In individuals with low indices of motivational processes, the frequency of social contacts was associated with a lower risk of dementia (HR: 0.94, 95% CI: 0.88-1.00). On the other hand, proximity of social contacts was linked to a higher risk of dementia in individuals with high indices of motivational processes (HR: 1.09, 95% CI: 1.01-1.19). DISCUSSION: Results indicate that the frequency and proximity of social contacts have a differential impact on the risk of dementia according to lower or higher indices of motivational processes, while the impact of motivational processes on risk of dementia could not be confirmed. Future studies should carefully disentangle different aspects of social interactions and their association with motivational processes.

Authors: S. Fankhauser, S. Forstmeier, A. Maercker, M. Luppa, T. Luck, S. G. Riedel-Heller

Date Published: 29th Nov 2014

Publication Type: Not specified

Human Diseases: dementia

Abstract (Expand)

OBJECTIVE: To test for a possible effect of the apolipoprotein E epsilon 4 (APOE epsilon4) allele on memory performance and executive functioning (EF) in cognitively intact elderly. METHOD: The authors studied 202 randomly selected and cognitively intact older adults (65+ years) of the Leipzig Research Center for Civilization Diseases Health Care Study. Intact global cognitive functioning was defined using a Mini-Mental Status Examination (MMSE) score >/= 28. Performance in memory was assessed with the CERAD Word List and Constructional Praxis Recall, performance in EF with the Trail Making Test Part B (TMT-B). Multivariable linear regressions were used to evaluate the association between cognitive performance and APOE status, controlled for covariates. RESULTS: Among the cognitively intact older adults, 21.3% (n = 43) were carriers of the APOE epsilon4 allele. Carriers did not differ significantly from noncarriers in terms of age, gender, intelligence level, or performance in memory but showed a significantly lower TMT-B performance as a measure of EF (TMT-B M time/SD = 105.6/36.2 vs. 91.9/32.7 s; Mann-Whitney U = 4,313.000; p = .009). The association between lower TMT-B performance and APOE epsilon4 genotype remained significant in multivariable linear regression analysis. Similar findings were found for the subsample of those 78 elderly, who reached a perfect MMSE-score of 30. CONCLUSIONS: A lower EF performance in cognitively intact older APOE epsilon4 allele carriers might be related to an early Alzheimer's dementia (AD) prodrome. In this case, a stronger focus on first subtle changes in EF may help to improve early AD detection in those being at genetic risk.

Authors: T. Luck, F. S. Then, M. Luppa, M. L. Schroeter, K. Arelin, R. Burkhardt, J. Thiery, M. Loffler, A. Villringer, S. G. Riedel-Heller

Date Published: 4th Nov 2014

Publication Type: Not specified

Abstract

Not specified

Authors: M. L. Schroeter, D. Bzdok, S. B. Eickhoff, J. Neumann

Date Published: 25th Sep 2014

Publication Type: Not specified

Human Diseases: frontotemporal dementia

Abstract (Expand)

OBJECTIVE: In this study, we aimed to analyze the association between new-incident-subjective memory complaints (SMC) and risk of subsequent dementia in a general population sample aged 75+ years. METHOD: Data were derived from follow-up (FUP) waves I-V of the population-based Leipzig Longitudinal Study of the Aged (LEILA75+). We used the Kaplan-Meier survival method to estimate dementia-free survival times of individuals with and without incident SMC and multivariable Cox proportional hazards regression to assess the association between incident SMC and risk of subsequent dementia, controlled for covariates. RESULTS: Of 443 non-demented individuals, 58 (13.1%) developed dementia during a subsequent 5.4-year follow-up period. Participants with incident SMC showed a significantly higher progression to dementia (18.5% vs. 10.0%; P=0.010) and a significantly shorter mean dementia-free survival time than those without (6.2 vs. 6.8 years; P=0.008). The association between incident SMC and risk of subsequent dementia remained significant in the multivariable Cox analysis (adjusted hazard ratio=1.8; P=0.028). CONCLUSION: Our findings suggest higher progression to dementia and shorter dementia-free survival in older individuals with incident SMC. These findings support the notion that such subjective complaints should be taken seriously in clinical practice as possible early indicators of incipient dementia.

Authors: T. Luck, M. Luppa, H. Matschinger, F. Jessen, M. C. Angermeyer, S. G. Riedel-Heller

Date Published: 10th Sep 2014

Publication Type: Not specified

Human Diseases: dementia

Abstract (Expand)

Follicular lymphoma (FL) with a t(14;18) is a B-cell neoplasm clinically characterized by multiple recurrencies. In order to investigate the clonal evolution of this lymphoma, we studied paired primary and relapse tumor samples from 33 patients with recurrent non-transformed t(14;18)-positive FL. We reconstructed phylogenetic trees of the evolution by taking advantage of the activation-induced cytidine deaminase (AID)-mediated somatic hypermutation (SHM) active in the germinal center reaction using sequences of the clonal VHDHJH rearrangements of the immunoglobulin heavy chain (IGH) locus. Mutational analysis of the IGH locus showed evidence for ongoing somatic mutation and for counter-selection of mutations affecting the BCR conformation during tumor evolution. We further followed evolutionary divergence by targeted sequencing of gene loci affected by aberrant SHM as well as of known driver genes of lymphomagenesis, and by array-based genome-wide chromosomal imbalance and DNA methylation analysis. We observed a wide spectrum of evolutionary patterns ranging from almost no evolution to divergent evolution within recurrent non-transformed t(14;18) FL. Remarkably, we observed a correlation of the magnitude of evolutionary divergence across all genetic and epigenetic levels suggesting co-evolution. The distribution of coding mutations in driver genes and the correlation with SHM suggest CREBBP and AID to be potential modifiers of genetic and epigenetic co-evolution in FL.

Authors: M. Loeffler, M. Kreuz, A. Haake, D. Hasenclever, H. Trautmann, C. Arnold, K. Winter, K. Koch, W. Klapper, R. Scholtysik, M. Rosolowski, S. Hoffmann, O. Ammerpohl, M. Szczepanowski, D. Herrmann, R. Kuppers, C. Pott, R. Siebert

Date Published: 17th Jul 2014

Publication Type: Not specified

Human Diseases: follicular lymphoma

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