TY  - JOUR
A1  - Güder, Gülmisal
A1  - Brenner, Susanne
A1  - Angermann, Christiane E.
A1  - Ertl, Georg
A1  - Held, Matthias
A1  - Sachs, Alfred P.
A1  - Lammers, Jan Willem
A1  - Zanen, Peter
A1  - Hoes, Arno W.
A1  - Störk, Stefan
A1  - Rutten, Frans H.
T1  - "GOLD or lower limit of normal definition? a comparison with expert-based diagnosis of chronic obstructive pulmonary disease in a prospective cohort-study"
N2  - Background: The Global initiative for chronic Obstructive Lung Disease (GOLD) defines COPD as a fixed postbronchodilator ratio of forced expiratory volume in 1 second and forced vital capacity (FEV1/FVC) below 0.7. Agedependent cut-off values below the lower fifth percentile (LLN) of this ratio derived from the general population have been proposed as an alternative. We wanted to assess the diagnostic accuracy and prognostic capability of the GOLD and LLN definition when compared to an expert-based diagnosis. Methods: In a prospective cohort study, 405 patients aged ≥ 65 years with a general practitioner’s diagnosis of COPD were recruited and followed up for 4.5 (median; quartiles 3.9; 5.1) years. Prevalence rates of COPD according to GOLD and three LLN definitions and diagnostic performance measurements were calculated. The reference standard was the diagnosis of COPD of an expert panel that used all available diagnostic information, including spirometry and bodyplethysmography. Results: Compared to the expert panel diagnosis, ‘GOLD-COPD’ misclassified 69 (28%) patients, and the three LLNs misclassified 114 (46%), 96 (39%), and 98 (40%) patients, respectively. The GOLD classification led to more false positives, the LLNs to more false negative diagnoses. The main predictors beyond the FEV1/FVC ratio for an expert diagnosis of COPD were the FEV1 % predicted, and the residual volume/total lung capacity ratio (RV/TLC). Adding FEV1 and RV/TLC to GOLD or LLN improved the diagnostic accuracy, resulting in a significant reduction of up to 50% of the number of misdiagnoses. The expert diagnosis of COPD better predicts exacerbations, hospitalizations and mortality than GOLD or LLN. Conclusions: GOLD criteria over-diagnose COPD, while LLN definitions under-diagnose COPD in elderly patients as compared to an expert panel diagnosis. Incorporating FEV1 and RV/TLC into the GOLD-COPD or LLN-based definition brings both definitions closer to expert panel diagnosis of COPD, and to daily clinical practice.
KW  - Medizin
KW  - COPD diagnosis
KW  - lower limit of normal
KW  - GOLD
KW  - validation
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75193
ER  - 
TY  - JOUR
A1  - Klotz, Barbara
A1  - Mentrup, Birgit
A1  - Regensburger, Martina
A1  - Zeck, Sabine
A1  - Schneidereit, Jutta
A1  - Schupp, Nicole
A1  - Linden, Christian
A1  - Merz, Cornelia
A1  - Ebert, Regina
A1  - Jakob, Franz
T1  - 1,25-Dihydroxyvitamin D3 Treatment Delays Cellular Aging in Human Mesenchymal Stem Cells while Maintaining Their Multipotent Capacity
JF  - PLoS ONE
N2  - 1,25-dihydroxyvitamin D3 (1,25D3) was reported to induce premature organismal aging in fibroblast growth factor-23 (Fgf23) and klotho deficient mice, which is of main interest as 1,25D3 supplementation of its precursor cholecalciferol is used in basic osteoporosis treatment. We wanted to know if 1,25D3 is able to modulate aging processes on a cellular level in human mesenchymal stem cells (hMSC). Effects of 100 nM 1,25D3 on hMSC were analyzed by cell proliferation and apoptosis assay, beta-galactosidase staining, VDR and surface marker immunocytochemistry, RT-PCR of 1,25D3-responsive, quiescence-and replicative senescence-associated genes. 1,25D3 treatment significantly inhibited hMSC proliferation and apoptosis after 72 h and delayed the development of replicative senescence in long-term cultures according to beta-galactosidase staining and P16 expression. Cell morphology changed from a fibroblast like appearance to broad and rounded shapes. Long term treatment did not induce lineage commitment in terms of osteogenic pathways but maintained their clonogenic capacity, their surface marker characteristics (expression of CD73, CD90, CD105) and their multipotency to develop towards the chondrogenic, adipogenic and osteogenic pathways. In conclusion, 1,25D3 delays replicative senescence in primary hMSC while the pro-aging effects seen in mouse models might mainly be due to elevated systemic phosphate levels, which propagate organismal aging.
KW  - perspectives
KW  - bone marrow
KW  - mutant mice
KW  - oxidative stress
KW  - transcription factors
KW  - vitamin-D-receptor
KW  - differentiation
KW  - tissue
KW  - 2',7'-dichlorofluorescin
KW  - homeostasis
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133392
VL  - 7
IS  - 1
ER  - 
TY  - JOUR
A1  - Finze, Maik
A1  - Reiss, Guido J.
A1  - Frohn, Hermann-Josef
T1  - 2,3,5,6-Tetrafluoro-1,4-bis(trimethylsilyl)benzene
N2  - no abstract available
KW  - Chemie
KW  - single-crystal X-ray study
KW  - T = 199 K
KW  - R factor = 0.027
KW  - wR factor = 0.068
KW  - data-to-parameter ratio = 14.0.
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75401
ER  - 
TY  - JOUR
A1  - Li, Xiang
A1  - Samnick, Samuel
A1  - Lapa, Constantin
A1  - Israel, Ina
A1  - Buck, Andreas K.
A1  - Kreissl, Michael C.
A1  - Bauer, Wolfgang
T1  - 68Ga-DOTATATE PET/CT for the detection of inflammation of large arteries: correlation with18F-FDG, calcium burden and risk factors
N2  - Background: Ga-[1,4,7,10-tetraazacyclododecane-N,N0,N00,N000-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) positron emission tomography (PET) is commonly used for the visualization of somatostatin receptor (SSTR)-positive neuroendocrine tumors. SSTR is also known to be expressed on macrophages, which play a major role in inflammatory processes in the walls of coronary arteries and large vessels. Therefore, imaging SSTR expression has the potential to visualize vulnerable plaques. We assessed 68Ga-DOTATATE accumulation in large vessels in comparison to 18F-2-fluorodeoxyglucose (FDG) uptake, calcified plaques (CPs), and cardiovascular risk factors. Methods: Sixteen consecutive patients with neuroendocrine tumors or thyroid cancer underwent both 68Ga-DOTATATE and 18F-FDG PET/CT for staging or restaging purposes. Detailed clinical data, including common cardiovascular risk factors, were recorded. For a separate assessment, they were divided into a high-risk and a low-risk group. In each patient, we calculated the maximum target-to-background ratio (TBR) of eight arterial segments. The correlation of the TBRmean of both tracers with risk factors including plaque burden was assessed. Results: The mean TBR of 68Ga-DOTATATE in all large arteries correlated significantly with the presence of CPs (r = 0.52; p < 0.05), hypertension (r = 0.60; p < 0.05), age (r = 0.56; p < 0.05), and uptake of 18F-FDG (r = 0.64; p < 0.01). There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05). Out of the 37 sites with the highest focal 68Ga-DOTATATE uptake, 16 (43.2%) also had focal 18F-FDG uptake. Of 39 sites with the highest 18F-FDG uptake, only 11 (28.2%) had a colocalized 68Ga-DOTATATE accumulation. Conclusions: In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries. Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.
KW  - Medizin
KW  - Atherosclerotic plaque
KW  - 68Ga-DOTATATE
KW  - Somatostatin receptor
KW  - Cardiovascular risk factors
KW  - Macrophage
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76231
ER  - 
TY  - JOUR
A1  - Homola, György A.
A1  - Jbabdi, Saad
A1  - Beckmann, Christian F.
A1  - Bartsch, Andreas J.
T1  - A Brain Network Processing the Age of Faces
N2  - Age is one of the most salient aspects in faces and of fundamental cognitive and social relevance. Although face processing has been studied extensively, brain regions responsive to age have yet to be localized. Using evocative face morphs and fMRI, we segregate two areas extending beyond the previously established face-sensitive core network, centered on the inferior temporal sulci and angular gyri bilaterally, both of which process changes of facial age. By means of probabilistic tractography, we compare their patterns of functional activation and structural connectivity. The ventral portion of Wernicke’s understudied perpendicular association fasciculus is shown to interconnect the two areas, and activation within these clusters is related to the probability of fiber connectivity between them. In addition, post-hoc age-rating competence is found to be associated with high response magnitudes in the left angular gyrus. Our results provide the first evidence that facial age has a distinct representation pattern in the posterior human brain. We propose that particular face-sensitive nodes interact with additional object-unselective quantification modules to obtain individual estimates of facial age. This brain network processing the age of faces differs from the cortical areas that have previously been linked to less developmental but instantly changeable face aspects. Our probabilistic method of associating activations with connectivity patterns reveals an exemplary link that can be used to further study, assess and quantify structure-function relationships.
KW  - Medizin
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75513
ER  - 
TY  - THES
A1  - Platt, Christian
T1  - A Common Thread in Unconventional Superconductivity: The Functional Renormalization Group in Multi-Band Systems
T1  - Unkonventionelle Supraleitung in Multi-Band Systemen
N2  - Die supraleitenden Eigenschaften von komplexen Materialsystemen, wie den erst kürzlich entdeckten Eisen-Pniktiden oder den Strontium-Ruthenaten, sind oftmals durch das Zusammenspiel vieler elektronischer Orbitale bestimmt. Um die Supraleitung in derartigen Systemen besser zu verstehen, entwickeln wir in dieser Arbeit eine Multi-Orbital-Implementierung der funktionalen Renormierungsgruppe und untersuchen die Elektronenpaarung in verschiedenen charakteristischen Materialverbindungen. In den Eisen-Pniktiden finden wir hierbei mehrere Spinfluktuationskanäle, die eine Elektronenpaarung hervorrufen, sofern die Paarwellenfunktion einen Vorzeichenwechsel zwischen den verschiedenen genesteten Bereichen der Fermifläche aufweist. Abhängig von den spezifischen Materialeigenschaften, wie der Dotierung oder der Position des Pniktogenatoms, führen diese Spinfluktuationen dann zu $s_{\pm}$-wellenartiger Paarung mit durchgängiger Energielücke oder mit Knoten auf der Fermifläche. In manchen Fällen wird zudem auch $d$-wellenartige Paarung induziert, die in der Nähe des Übergangs zur $s_{\pm}$-Symmetrie einen gemischten $(s+id)$-Zustand mit gebrochener Zeitinversionssymmetrie aufweist. Diese neuartige Phase zeigt faszinierende Eigenschaften, wie zum Beispiel das spontane Entstehen von Supraströmen am Probenrand und um nichtmagnetische Störstellen. Auf Grund der durchgängigen Energielücke ist dieser $(s+id)$-Zustand energetisch begünstigt. Im Folgenden untersuchen wir zudem auch die elektronischen Instabilitäten eines weiteren außergewöhnlichen Materials -- dotiertes Graphen. Diese rein zweidimensionale Kohlenstoffverbindung ist schon seit mehreren Jahren im Fokus der Festkörperforschung und wurde mittlerweile auch durch neuartige experimentelle Verfahren dotiert, ohne die zugrundeliegende hexagonale Gittersturktur merklich zu stören. Eine theoretische Beschreibung dieses Systems erfordert die Berücksichtigung zweier nicht-equivalenter Gitterplätze, was wiederum effektiv als Zwei-Orbital-System aufgefasst werden kann. Durch die besondere Symmetrie der hexagonalen Gitterstruktur sind beide $d$-wellenartigen Paarungskanäle entartet und ahnlich der $(s+id)$-Paarung in den Pniktiden finden wir hier eine chirale $(d+id)$-Paarung in einem weiten Dotierungsbereich um van-Hove Füllung. Des Weiteren identifizieren wir Spin-Triplet-Paarung und eine exotische Form der Spindichtewelle, welche beide durch leichte Veränderung der langreichweitigen Hüpfamplituden und Wechselwirkungensparameter realisiert werden können. Als drittes Beispiel betrachten wir die Supraleitung in dem Strontium-Ruthenat Sr$_2$RuO$_4$. Die Besonderheit dieser Materialverbindung liegt in der möglichen Realisierung einer chiralen Spin-Triplet Paarung, die wiederum faszinierende Eigenschaften wie die Existenz von halbganzzahligen Flussvortizes mit nicht-Abelscher Vertauschungsstatistik aufweisen würde. Mittels eines mikroskopischen Drei-Orbital-Modells und der Berücksichtigung von Spin-Bahn-Kopplung finden wir hierbei, dass moderate ferromagnetische Spinfluktuationen immer noch ausreichen, um diesen speziellen Paarungszustand anzutreiben. Die berechnete Energielücke zeigt im Weiteren sehr starke Anisotropien auf dem $d_{xy}$-Orbital-dominierten Bereich der Fermifläche und verschwindet nahezu vollständig auf den anderen beiden Fermiflächen.
N2  - The superconducting properties of complex materials like the recently discovered iron-pnictides or strontium-ruthenate are often governed by multi-orbital effects. In order to unravel the superconductivity of those materials, we develop a multi-orbital implementation of the functional renormalization group and study the pairing states of several characteristic material systems. Starting with the iron-pnictides, we find competing spin-fluctuation channels that become attractive if the superconducting gap changes sign between the nested portions of the Fermi surface. Depending on material details like doping or pnictogen height, these spin fluctuations then give rise to $s_{\pm}$-wave pairing with or without gap nodes and, in some cases, also change the symmetry to $d$-wave. Near the transition from nodal $s_{\pm}$-wave to $d$-wave pairing, we predict the occurrence of a time-reversal symmetry-broken $(s+id)$-pairing state which avoids gap nodes and is therefore energetically favored. We further study the electronic instabilities of doped graphene, another fascinating material which has recently become accessible and which can effectively be regarded as multi-orbital system. Here, the hexagonal lattice structure assures the degeneracy of two $d$-wave pairing channels, and the system then realizes a chiral $(d+id)$-pairing state in a wide doping range around van-Hove filling. In addition, we also find spin-triplet pairing as well as an exotic spin-density wave phase which both become leading if the long-ranged hopping or interaction parameters are slightly modified, for example, by choosing different substrate materials. Finally, we consider the superconducting state of strontium-ruthenate, a possible candidate for chiral spin-triplet pairing with fascinating properties like the existence of half-quantum vortices obeying non-Abelian statistics. Using a microscopic three orbital description including spin-orbit coupling, we demonstrate that ferromagnetic fluctuations are still sufficient to induce this $\bs{\hat{z}}(p_x\pm ip_y)$-pairing state. The resulting superconducting gap reveals strong anisotropies on the $d_{xy}$-dominated Fermi-surface pocket and nearly vanishes on the other remaining two pockets.
KW  - Supraleitung
KW  - Renormierungsgruppe
KW  - Eisen-basierte Supraleiter
KW  - iron-pnictides
KW  - ruthenates
KW  - graphene
KW  - multi-band superconductivity
KW  - functional renormalization group
KW  - Hochtemperatursupraleitung
KW  - Ruthenate
KW  - Pnictide
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78824
ER  - 
TY  - JOUR
A1  - Hagemann, Carsten
A1  - Anacker, Jelena
A1  - Ernestus, Ralf-Ingo
A1  - Vince, Giles H.
T1  - A complete compilation of matrix metalloproteinase expression in human malignant gliomas
JF  - World Journal of Clinical Oncology
N2  - Glioblastomas are characterized by an aggressive local growth pattern, a marked degree of invasiveness and poor prognosis. Tumor invasiveness is facilitated by the increased activity of proteolytic enzymes which are involved in destruction of the extracellular matrix of the surrounding healthy brain tissue. Elevated levels of matrix metalloproteinases (MMPs) were found in glioblastoma (GBM) cell-lines, as well as in GBM biopsies as compared with low-grade astrocytoma (LGA) and normal brain samples, indicating a role in malignant progression. A careful review of the available literature revealed that both the expression and role of several of the 23 human MMP proteins is controversely discussed and for some there are no data available at all. We therefore screened a panel of 15 LGA and 15 GBM biopsy samples for those MMPs for which there is either no, very limited or even contradictory data available. Hence, this is the first complete compilation of the expression pattern of all 23 human MMPs in astrocytic tumors. This study will support a better understanding of the specific expression patterns and interaction of proteolytic enzymes in malignant human glioma and may provide additional starting points for targeted patient therapy.
KW  - glioblastoma cell-lines
KW  - matrix metalloproteinase
KW  - glioblastoma multiforme
KW  - astrocytic tumor
KW  - expression pattern
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123982
VL  - 3
IS  - 5
ER  - 
TY  - JOUR
A1  - Fröhlich, Kathrin S.
A1  - Papenfort, Kai
A1  - Berger, Allison A.
A1  - Vogel, Jörg
T1  - A conserved RpoS-dependent small RNA controls the synthesis of major porin OmpD
JF  - Nucleic Acids Research
N2  - A remarkable feature of many small non-coding RNAs (sRNAs) of Escherichia coli and Salmonella is their accumulation in the stationary phase of bacterial growth. Several stress response regulators and sigma factors have been reported to direct the transcription of stationary phase-specific sRNAs, but a widely conserved sRNA gene that is controlled by the major stationary phase and stress sigma factor, Sigma(S) (RpoS), has remained elusive. We have studied in Salmonella the conserved SdsR sRNA, previously known as RyeB, one of the most abundant stationary phase-specific sRNAs in E. coli. Alignments of the sdsR promoter region and genetic analysis strongly suggest that this sRNA gene is selectively transcribed by Sigma(S). We show that SdsR down-regulates the synthesis of the major Salmonella porin OmpD by Hfq-dependent base pairing; SdsR thus represents the fourth sRNA to regulate this major outer membrane porin. Similar to the InvR, MicC and RybB sRNAs, SdsR recognizes the ompD mRNA in the coding sequence, suggesting that this mRNA may be primarily targeted downstream of the start codon. The SdsR-binding site in ompD was localized by 3'-RACE, an experimental approach that promises to be of use in predicting other sRNA-target interactions in bacteria.
KW  - shock sigma factor
KW  - general stress response
KW  - down regulation
KW  - stationary phase
KW  - salmonella enterica
KW  - messenger RNA
KW  - escherichia coli
KW  - enterica serovar typhimurium
KW  - outer-membrane proteins
KW  - small noncoding RNAs
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134230
VL  - 40
IS  - 8
ER  - 
TY  - JOUR
A1  - Jain, M.
A1  - Vélez, J. I.
A1  - Acosta, M. T.
A1  - Palacio, L. G.
A1  - Balog, J.
A1  - Roessler, E.
A1  - Pineda, D.
A1  - Londoño, A. C.
A1  - Palacio, J. D.
A1  - Arbelaez, A.
A1  - Lopera, F.
A1  - Elia, J.
A1  - Hakonarson, H.
A1  - Seitz, C.
A1  - Freitag, C. M.
A1  - Palmason, H.
A1  - Meyer, J.
A1  - Romanos, M.
A1  - Walitza, S.
A1  - Hemminger, U.
A1  - Warnke, A.
A1  - Romanos, J.
A1  - Renner, T.
A1  - Jacob, C.
A1  - Lesch, K.-P.
A1  - Swanson, J.
A1  - Castellanos, F. X.
A1  - Bailey-Wilson, J. E.
A1  - Arcos-Burgos, M.
A1  - Muenke, M.
T1  - A cooperative interaction between LPHN3 and 11q doubles the risk for ADHD
JF  - Molecular Psychiatry
N2  - In previous studies of a genetic isolate, we identified significant linkage of attention deficit hyperactivity disorder (ADHD) to 4q, 5q, 8q, 11q and 17p. The existence of unique large size families linked to multiple regions, and the fact that these families came from an isolated population, we hypothesized that two-locus interaction contributions to ADHD were plausible. Several analytical models converged to show significant interaction between 4q and 11q (P<1 × 10−8) and 11q and 17p (P<1 × 10−6). As we have identified that common variants of the LPHN3 gene were responsible for the 4q linkage signal, we focused on 4q–11q interaction to determine that single-nucleotide polymorphisms (SNPs) harbored in the LPHN3 gene interact with SNPs spanning the 11q region that contains DRD2 and NCAM1 genes, to double the risk of developing ADHD. This interaction not only explains genetic effects much better than taking each of these loci effects by separated but also differences in brain metabolism as depicted by proton magnetic resonance spectroscopy data and pharmacogenetic response to stimulant medication. These findings not only add information about how high order genetic interactions might be implicated in conferring susceptibility to develop ADHD but also show that future studies of the effects of genetic interactions on ADHD clinical information will help to shape predictive models of individual outcome.
KW  - ADHD
KW  - genetic interaction
KW  - LPHN3
KW  - NCAM1
KW  - DRD2
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125128
VL  - 17
ER  - 
TY  - JOUR
A1  - Staiger, Christine
A1  - Cadot, Sidney
A1  - Kooter, Raul
A1  - Dittrich, Marcus
A1  - Müller, Tobias
A1  - Klau, Gunnar W.
A1  - Wessels, Lodewyk F. A.
T1  - A Critical Evaluation of Network and Pathway-Based Classifiers for Outcome Prediction in Breast Cancer
JF  - PLoS One
N2  - Recently, several classifiers that combine primary tumor data, like gene expression data, and secondary data sources, such as protein-protein interaction networks, have been proposed for predicting outcome in breast cancer. In these approaches, new composite features are typically constructed by aggregating the expression levels of several genes. The secondary data sources are employed to guide this aggregation. Although many studies claim that these approaches improve classification performance over single genes classifiers, the gain in performance is difficult to assess. This stems mainly from the fact that different breast cancer data sets and validation procedures are employed to assess the performance. Here we address these issues by employing a large cohort of six breast cancer data sets as benchmark set and by performing an unbiased evaluation of the classification accuracies of the different approaches. Contrary to previous claims, we find that composite feature classifiers do not outperform simple single genes classifiers. We investigate the effect of (1) the number of selected features; (2) the specific gene set from which features are selected; (3) the size of the training set and (4) the heterogeneity of the data set on the performance of composite feature and single genes classifiers. Strikingly, we find that randomization of secondary data sources, which destroys all biological information in these sources, does not result in a deterioration in performance of composite feature classifiers. Finally, we show that when a proper correction for gene set size is performed, the stability of single genes sets is similar to the stability of composite feature sets. Based on these results there is currently no reason to prefer prognostic classifiers based on composite features over single genes classifiers for predicting outcome in breast cancer.
KW  - modules
KW  - protein-interaction networks
KW  - expression signature
KW  - classification
KW  - set
KW  - metastasis
KW  - stability
KW  - survival
KW  - database
KW  - markers
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131323
VL  - 7
IS  - 4
ER  -