Publications

265 Publications visible to you, out of a total of 265

Abstract (Expand)

The composition of atherosclerotic (AS) plaques is crucial concerning rupture, thrombosis and clinical events. Two plaque types are distinguished: stable and vulnerable plaques. Vulnerable plaques are rich in inflammatory cells, mostly only M1 macrophages, and are highly susceptible to rupture. These plaques represent a high risk particularly with the standard invasive diagnosis by coronary angiography. So far there are no non-invasive low-risk clinical approaches available to detect and distinguish AS plaque types in vivo. The perspective review introduces a whole work-flow for a novel approach for non-invasive detection and classification of AS plaques using the diffusion reflection method with gold nanoparticle loaded macrophages in combination with flow and image cytometric analysis for quality assurance. Classical biophotonic methods for AS diagnosis are summarized. Phenotyping of monocytes and macrophages are discussed for specific subset labelling by nanomaterials, as well as existing studies and first experimental proofs of concept for the novel approach are shown. In vitro and in vivo detection of NP loaded macrophages (MPhi). Different ways of MPhi labelling include (1) in vitro labelling in suspension (whole blood or buffy coat) or (2) labelling of short-term MPhi cultures with re-injection of MPhi-NP into the animal to detect migration of the cells in the plaques and (3) in vivo injection of NP into the organism.

Authors: S. Melzer, R. Ankri, D. Fixler, A. Tarnok

Date Published: 26th Jun 2015

Publication Type: Not specified

Human Diseases: atherosclerosis

Abstract (Expand)

In humans, mutations in ATGL lead to TG accumulation in LDs of most tissues and cells, including peripheral blood leukocytes. This pathologic condition is called Jordans' anomaly, in which functional consequences have not been investigated. In the present study, we tested the hypothesis that ATGL plays a role in leukocyte LD metabolism and immune cell function. Similar to humans with loss-of-function mutations in ATGL, we found that global and myeloid-specific Atgl(-/-) mice exhibit Jordans' anomaly with increased abundance of intracellular TG-rich LDs in neutrophil granulocytes. In a model of inflammatory peritonitis, lipid accumulation was also observed in monocytes and macrophages but not in eosinophils or lymphocytes. Neutrophils from Atgl(-/-) mice showed enhanced immune responses in vitro, which were more prominent in cells from global compared with myeloid-specific Atgl(-/-) mice. Mechanistically, ATGL(-/-) as well as pharmacological inhibition of ATGL led to an impaired release of lipid mediators from neutrophils. These findings demonstrate that the release of lipid mediators is dependent on the liberation of precursor molecules from the TG-rich pool of LDs by ATGL. Our data provide mechanistic insights into Jordans' anomaly in neutrophils and suggest that ATGL is a potent regulator of immune cell function and inflammatory diseases.

Authors: S. Schlager, M. Goeritzer, K. Jandl, R. Frei, N. Vujic, D. Kolb, H. Strohmaier, J. Dorow, T. O. Eichmann, A. Rosenberger, A. Wolfler, A. Lass, E. E. Kershaw, U. Ceglarek, A. Dichlberger, A. Heinemann, D. Kratky

Date Published: 26th Jun 2015

Publication Type: Not specified

Abstract (Expand)

Phonological awareness is the best-validated predictor of reading and spelling skill and therefore highly relevant for developmental dyslexia. Prior imaging genetics studies link several dyslexia risk genes to either brain-functional or brain-structural factors of phonological deficits. However, coherent evidence for genetic associations with both functional and structural neural phenotypes underlying variation in phonological awareness has not yet been provided. Here we demonstrate that rs11100040, a reported modifier of SLC2A3, is related to the functional connectivity of left fronto-temporal phonological processing areas at resting state in a sample of 9- to 12-year-old children. Furthermore, we provide evidence that rs11100040 is related to the fractional anisotropy of the arcuate fasciculus, which forms the structural connection between these areas. This structural connectivity phenotype is associated with phonological awareness, which is in turn associated with the individual retrospective risk scores in an early dyslexia screening as well as to spelling. These results suggest a link between a dyslexia risk genotype and a functional as well as a structural neural phenotype, which is associated with a phonological awareness phenotype. The present study goes beyond previous work by integrating genetic, brain-functional and brain-structural aspects of phonological awareness within a single approach. These combined findings might be another step towards a multimodal biomarker for developmental dyslexia.

Authors: M. A. Skeide, H. Kirsten, I. Kraft, G. Schaadt, B. Muller, N. Neef, J. Brauer, A. Wilcke, F. Emmrich, J. Boltze, A. D. Friederici

Date Published: 17th Jun 2015

Publication Type: Not specified

Human Diseases: dyslexia

Abstract (Expand)

OBJECTIVE: Dementia is known to increase mortality, but the relative loss of life years and contributing factors are not well established. Thus, we aimed to investigate mortality in incident dementia from disease onset. METHOD: Data were derived from the prospective longitudinal German AgeCoDe study. We used proportional hazards models to assess the impact of sociodemographic and health characteristics on mortality after dementia onset, Kaplan-Meier method for median survival times. RESULTS: Of 3214 subjects at risk, 523 (16.3%) developed incident dementia during a 9-year follow-up period. Median survival time after onset was 3.2 years (95% CI = 2.8-3.7) at a mean age of 85.0 (SD = 4.0) years (>/=2.6 life years lost compared with the general German population). Survival was shorter in older age, males other dementias than Alzheimer's, and in the absence of subjective memory complaints (SMC). CONCLUSION: Our findings emphasize that dementia substantially shortens life expectancy. Future studies should further investigate the potential impact of SMC on mortality in dementia.

Authors: S. Roehr, T. Luck, H. Bickel, C. Brettschneider, A. Ernst, A. Fuchs, K. Heser, H. H. Konig, F. Jessen, C. Lange, E. Mosch, M. Pentzek, S. Steinmann, S. Weyerer, J. Werle, B. Wiese, M. Scherer, W. Maier, S. G. Riedel-Heller

Date Published: 9th Jun 2015

Publication Type: Not specified

Human Diseases: cognitive disorder, dementia

Abstract (Expand)

Cryptococcus neoformans is an opportunistic fungal pathogen that causes lung inflammation and meningoencephalitis in immunocompromised patients but is also able to asymptomatically infect immunocompetent individuals. C. neoformans is found ubiquitously especially in urban areas where it is spread by pigeons, and fungal exposure may predispose for asthma development already at an early age, as soon as confronted with pigeon droppings. In the study presented here, we investigated the presence of specific immunoglobulin G (IgG) against C. neoformans in sera from patients suffering from asthma in comparison to a healthy control cohort, accrued from the Leipzig Research Centre for Civilization Diseases (LIFE). For serological analysis we developed a flow cytometry (FACS) based assay specific for an acapsular strain of C. neoformans to comprehensively analyze different cryptococcal serotypes. Compared with the non-asthmatic cohort, asthmatics exhibited, as expected, an elevated level of total serum immunoglobulin E (IgE), whereas the IgG seroreactivity against C. neoformans was not significantly different among the two groups (P = .118). Nevertheless, there was a trend toward increased Cryptococcus-specific IgG antibodies in the serum of asthmatics. Additionally, in male asthmatics an increased IgG-mediated seroreactivity compared to female asthmatics was found. This points to a higher prevalence of subclinical C. neoformans infection in male asthmatics and may support the hypothesis of C. neoformans as a risk factor for the development of asthma in urban areas.

Authors: A. Grahnert, U. Muller, H. von Buttlar, R. Treudler, G. Alber

Date Published: 31st May 2015

Publication Type: Not specified

Human Diseases: asthma, allergic hypersensitivity disease

Abstract (Expand)

OBJECTIVES: The aim of the present study was to investigate how different mentally demanding work conditions during the professional life-i.e., enriched environments at work-might influence the rate of cognitive decline in old age. METHODS: Individuals (n = 1,054) of the Leipzig Longitudinal Study of the Aged, a representative population-based cohort study of individuals aged 75 years and older, underwent cognitive testing via the Mini-Mental State Examination (MMSE) in up to 6 measurement waves. Type and level of mentally demanding work conditions in the participants' former professional life were classified based on the O*NET job descriptor database. RESULTS: In multivariate mixed-model analyses (controlling for sociodemographic and health-related factors), a high level of mentally demanding work tasks stimulating verbal intelligence was significantly associated with a better cognitive functioning at baseline (on average 5 MMSE points higher) as well as a lower rate of cognitive decline (on average 2 MMSE points less) over the 8-year follow-up period compared with a low level. The rate of cognitive decline in old age was also significantly lower (on average 3 MMSE points less) in individuals who had a high level of mentally demanding work tasks stimulating executive functions than those who had a low level. CONCLUSIONS: The results suggest that a professional life enriched with work tasks stimulating verbal intelligence and executive functions may help to sustain a good cognitive functioning in old age (75+ years). The findings thus emphasize that today's challenging work conditions may also promote positive health effects.

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

Date Published: 26th May 2015

Publication Type: Not specified

Human Diseases: dementia

Abstract (Expand)

OBJECTIVE: Microsatellite instability (MSI) is detected in approximately 15% of all colorectal cancers (CRC) and virtually in all cases with Lynch syndrome. The MSI phenotype is caused by dysfunctional mismatch repair (MMR) and leads to accumulation of DNA replication errors. Sporadic MSI CRC often harbours BRAF(V600E); however, no consistent data exist regarding targeted treatment approaches in BRAF(wt) MSI CRC. DESIGN: Mutations and quantitative MSI were analysed by deep sequencing in 196 formalin fixed paraffin embedded (FFPE) specimens comprising Lynch and Lynch-like CRCs from the German Hereditary Nonpolyposis Colorectal Cancer registry. Functional relevance of recurrent ERBB2/HER2 mutations was investigated in CRC cell lines using reversible and irreversible HER-targeting inhibitors, EGFR-directed antibody cetuximab, HER2-directed antibody trastuzumab and siRNA-mediated ERBB2/HER2 knockdown. RESULTS: Quantification of nucleotide loss in non-coding mononucleotide repeats distinguished microsatellite status with very high accuracy (area under curve=0.9998) and demonstrated progressive losses with deeper invasion of MMR-deficient colorectal neoplasms (p=0.008). Characterisation of BRAF(wt) MSI CRC revealed hot-spot mutations in well-known oncogenic drivers, including KRAS (38.7%), PIK3CA (36.5%), and ERBB2 (15.0%). L755S and V842I substitutions in ERBB2 were highly recurrent. Functional analyses in ERBB2-mutated MSI CRC cell lines revealed a differential response to HER-targeting compounds and superiority of irreversible pan-HER inhibitors. CONCLUSIONS: We developed a high-throughput deep sequencing approach for concomitant MSI and mutational analyses in FFPE specimens. We provided novel insights into clinically relevant alterations in MSI CRC and a rationale for targeting ERBB2/HER2 mutations in Lynch and Lynch-like CRC.

Authors: M. Kloth, V. Ruesseler, C. Engel, K. Koenig, M. Peifer, E. Mariotti, H. Kuenstlinger, A. Florin, U. Rommerscheidt-Fuss, U. Koitzsch, C. Wodtke, F. Ueckeroth, S. Holzapfel, S. Aretz, P. Propping, M. Loeffler, S. Merkelbach-Bruse, M. Odenthal, N. Friedrichs, L. C. Heukamp, T. Zander, R. Buettner

Date Published: 24th May 2015

Publication Type: Not specified

Human Diseases: colorectal cancer

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