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Search Results: 1 - 10 of 159636 matches for " Andreas Hüttmann "
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Searches for New Physics Using H1 and ZEUS Data
Antje Hüttmann
Physics , 2010,
Abstract: Recent searches for new physics in ep collisions performed by the H1 and ZEUS collaborations are presented. Limits on different contact interaction models, large extra dimensions, R-parity violating SUSY, excited fermions and anomalous flavour-changing top couplings are shown. In addition, searches for new physics in exclusive final states such as events with isolated leptons and large missing transverse momentum or multi-lepton final states are presented.
Epigenetic Silencing of the Circadian Clock Gene CRY1 is Associated with an Indolent Clinical Course in Chronic Lymphocytic Leukemia
Maher Hanoun, Lewin Eisele, Masako Suzuki, John M. Greally, Andreas Hüttmann, Semra Aydin, René Scholtysik, Ludger Klein-Hitpass, Ulrich Dührsen, Jan Dürig
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034347
Abstract: Disruption of circadian rhythm is believed to play a critical role in cancer development. Cryptochrome 1 (CRY1) is a core component of the mammalian circadian clock and we have previously shown its deregulated expression in a subgroup of patients with chronic lymphocytic leukemia (CLL). Using real-time RT-PCR in a cohort of 76 CLL patients and 35 normal blood donors we now demonstrate that differential CRY1 mRNA expression in high-risk (HR) CD38+/immunoglobulin variable heavy chain gene (IgVH) unmutated patients as compared to low-risk (LR) CD38?/IgVH mutated patients can be attributed to down-modulation of CRY1 in LR CLL cases. Analysis of the DNA methylation profile of the CRY1 promoter in a subgroup of 57 patients revealed that CRY1 expression in LR CLL cells is silenced by aberrant promoter CpG island hypermethylation. The methylation pattern of the CRY1 promoter proved to have high prognostic impact in CLL where aberrant promoter methylation predicted a favourable outcome. CRY1 mRNA transcript levels did not change over time in the majority of patients where sequential samples were available for analysis. We also compared the CRY1 expression in CLL with other lymphoid malignancies and observed epigenetic silencing of CRY1 in a patient with B cell acute lymphoblastic leukemia (B-ALL).
Development, Alteration and Real Time Dynamics of Conjunctiva-Associated Lymphoid Tissue
Sebastian Siebelmann, Uta Gehlsen, Gereon Hüttmann, Norbert Koop, Torsten B?lke, Andreas Gebert, Michael E. Stern, Jerry Y. Niederkorn, Philipp Steven
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082355
Abstract: Purpose Conjunctiva-associated lymphoid tissue (CALT) is thought to play a key role in initiating ocular surface related immune responses. This study was planned to get first profound insights into the function of CALT related to development, cellular dynamics and morphological alteration using a novel mouse model. Methods Expression and morphology of CALT were investigated using BALB/c mice kept under different housing conditions, after topical antigen-stimulation and following lymphadenectomy and splenectomy. Particles and bacteria were applied topically to study antigen-transport. Intravital visualization was performed using two-photon microscopy. Results Postnatal development and ultrastructure of CALT in the mouse is similar to humans. Topical antigen-challenge significantly alters CALT expression. Bacterial translocation is demonstrated via lymphoepithelium whereas cellular velocities within follicles were approximately 8 μm/min. Conclusions CALT in the mouse is an immunological interface of the ocular surface, featuring dynamic processes such as morphological plasticity, particle/bacteria transport and cellular migration.
Versatile and Simple Approach to Determine Astrocyte Territories in Mouse Neocortex and Hippocampus
Antje Grosche, Jens Grosche, Mark Tackenberg, Dorit Scheller, Gwendolyn Gerstner, Annett Gumprecht, Thomas Pannicke, Petra G. Hirrlinger, Ulrika Wilhelmsson, Kerstin Hüttmann, Wolfgang H?rtig, Christian Steinh?user, Milos Pekny, Andreas Reichenbach
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069143
Abstract: Background Besides their neuronal support functions, astrocytes are active partners in neuronal information processing. The typical territorial structure of astrocytes (the volume of neuropil occupied by a single astrocyte) is pivotal for many aspects of glia–neuron interactions. Methods Individual astrocyte territorial volumes are measured by Golgi impregnation, and astrocyte densities are determined by S100β immunolabeling. These data are compared with results from conventionally applied methods such as dye filling and determination of the density of astrocyte networks by biocytin loading. Finally, we implemented our new approach to investigate age-related changes in astrocyte territories in the cortex and hippocampus of 5- and 21-month-old mice. Results The data obtained by our simplified approach based on Golgi impregnation were compared to previously published dye filling experiments, and yielded remarkably comparable results regarding astrocyte territorial volumes. Moreover, we found that almost all coupled astrocytes (as indicated by biocytin loading) were immunopositive for S100β. A first application of this new experimental approach gives insight in age-dependent changes in astrocyte territorial volumes. They increased with age, while cell densities remained stable. In 5-month-old mice, the overlap factor was close to 1, revealing little or no interdigitation of astrocyte territories. However, in 21-month-old mice, the overlap factor was more than 2, suggesting that processes of adjacent astrocytes interdigitate. Conclusion Here we verified the usability of a simple, versatile method for assessing astrocyte territories and the overlap factor between adjacent territories. Second, we found that there is an age-related increase in territorial volumes of astrocytes that leads to loss of the strict organization in non-overlapping territories. Future studies should elucidate the physiological relevance of this adaptive reaction of astrocytes in the aging brain and the methods presented in this study might be a powerful tool to do so.
Comparison of Two Devices and Two Breathing Patterns for Exhaled Breath Condensate Sampling
Eva-Maria Hüttmann, Timm Greulich, Akira Hattesohl, Severin Schmid, Sarah Noeske, Christian Herr, Gerrit John, Rudolf A. J?rres, Bernd Müller, Claus Vogelmeier, Andreas Rembert Koczulla
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0027467
Abstract: Introduction Analysis of exhaled breath condensate (EBC) is a noninvasive method to access the epithelial lining fluid of the lungs. Due to standardization problems the method has not entered clinical practice. The aim of the study was to assess the comparability for two commercially available devices in healthy controls. In addition, we assessed different breathing patterns in healthy controls with protein markers to analyze the source of the EBC. Methods EBC was collected from ten subjects using the RTube and ECoScreen Turbo in a randomized crossover design, twice with every device - once in tidal breathing and once in hyperventilation. EBC conductivity, pH, surfactant protein A, Clara cell secretory protein and total protein were assessed. Bland-Altman plots were constructed to display the influence of different devices or breathing patterns and the intra-class correlation coefficient (ICC) was calculated. The volatile organic compound profile was measured using the electronic nose Cyranose 320. For the analysis of these data, the linear discriminant analysis, the Mahalanobis distances and the cross-validation values (CVV) were calculated. Results Neither the device nor the breathing pattern significantly altered EBC pH or conductivity. ICCs ranged from 0.61 to 0.92 demonstrating moderate to very good agreement. Protein measurements were greatly influenced by breathing pattern, the device used, and the way in which the results were reported. The electronic nose could distinguish between different breathing patterns and devices, resulting in Mahalanobis distances greater than 2 and CVVs ranging from 64% to 87%. Conclusion EBC pH and (to a lesser extent) EBC conductivity are stable parameters that are not influenced by either the device or the breathing patterns. Protein measurements remain uncertain due to problems of standardization. We conclude that the influence of the breathing maneuver translates into the necessity to keep the volume of ventilated air constant in further studies.
Progranulin Is a Novel Independent Predictor of Disease Progression and Overall Survival in Chronic Lymphocytic Leukemia
Maria G?bel, Lewin Eisele, Michael M?llmann, Andreas Hüttmann, Patricia Johansson, René Scholtysik, Manuela Bergmann, Raymonde Busch, Hartmut D?hner, Michael Hallek, Till Seiler, Stephan Stilgenbauer, Ludger Klein-Hitpass, Ulrich Dührsen, Jan Dürig
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0072107
Abstract: Progranulin (Pgrn) is a 88 kDa secreted protein with pleiotropic functions including regulation of cell cycle progression, cell motility, wound repair and tumorigenesis. Using microarray based gene expression profiling we have recently demonstrated that the gene for Pgrn, granulin (GRN), is significantly higher expressed in aggressive CD38+ZAP-70+ as compared to indolent CD38?ZAP-70? chronic lymphocytic leukemia (CLL) cases. Here, we measured Pgrn plasma concentrations by enzyme-linked immunosorbent assay (ELISA) in the Essen CLL cohort of 131 patients and examined Pgrn for association with established prognostic markers and clinical outcome. We found that high Pgrn plasma levels were strongly associated with adverse risk factors including unmutated IGHV status, expression of CD38 and ZAP-70, poor risk cytogenetics (11q-, 17p-) as detected by flourescence in situ hybridization (FISH) and high Binet stage. Pgrn as well as the aforementioned risk factors were prognostic for time to first treatment and overall survival in this series. Importantly, these results could be confirmed in the independent multicentric CLL1 cohort of untreated Binet stage A patients (n = 163). Here, multivariate analysis of time to first treatment revealed that high risk Pgrn (HR = 2.06, 95%-CI = 1.13–3.76, p = 0.018), unmutated IGHV status (HR = 5.63, 95%-CI = 3.05–10.38, p<0.001), high risk as defined by the study protocol (HR = 2.06, 95%-CI = 1.09–3.89, p = 0.026) but not poor risk cytogenetics were independent prognostic markers. In summary our results suggest that Pgrn is a novel, robust and independent prognostic marker in CLL that can be easily measured by ELISA.
Identification of a Caldariomyces fumago Mutant Secreting an Inactive Form of Chloroperoxidase Lacking the Heme Group and N-Glycans
Sonja Hüttmann, Markus Buchhaupt, Jens Schrader
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0067857
Abstract: By mutant colony screening of Caldariomyces fumago a mutant was isolated which was slightly greenish on fructose minimal medium and grew slower in comparison to the wild type. The supernatant samples lacked the Soret band typical for the heme group of the CPO and nearly no CPO activity was detected. SDS-PAGE analysis of mutant culture supernatant samples showed production of a 38–40 kDa protein while wild type samples contain the 42 kDa CPO protein. Protein identification using nanoLC-ESI-MS/MS was performed and based on three peptides the protein in the mutant culture was identified as CPO. No differences in the CPO gene sequences of wild type and mutant were found indicating a post-translational defect in protein maturation. Deglycosylation experiments using CPO from wild type and mutant were carried out. After removing N-linked oligosaccharides from wild type CPO a protein band at 38–40 kDa was detected. Our results reveal that the mutant protein lacks the heme group as well as the N-glycans.
Intravital Two-Photon Microscopy of Immune Cell Dynamics in Corneal Lymphatic Vessels
Philipp Steven, Felix Bock, Gereon Hüttmann, Claus Cursiefen
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0026253
Abstract: Background The role of lymphatic vessels in tissue and organ transplantation as well as in tumor growth and metastasis has drawn great attention in recent years. Methodology/Principal Findings We now developed a novel method using non-invasive two-photon microscopy to simultaneously visualize and track specifically stained lymphatic vessels and autofluorescent adjacent tissues such as collagen fibrils, blood vessels and immune cells in the mouse model of corneal neovascularization in vivo. The mouse cornea serves as an ideal tissue for this technique due to its easy accessibility and its inducible and modifiable state of pathological hem- and lymphvascularization. Neovascularization was induced by suture placement in corneas of Balb/C mice. Two weeks after treatment, lymphatic vessels were stained intravital by intrastromal injection of a fluorescently labeled LYVE-1 antibody and the corneas were evaluated in vivo by two-photon microscopy (TPM). Intravital TPM was performed at 710 nm and 826 nm excitation wavelengths to detect immunofluorescence and tissue autofluorescence using a custom made animal holder. Corneas were then harvested, fixed and analyzed by histology. Time lapse imaging demonstrated the first in vivo evidence of immune cell migration into lymphatic vessels and luminal transport of individual cells. Cells immigrated within 1–5.5 min into the vessel lumen. Mean velocities of intrastromal corneal immune cells were around 9 μm/min and therefore comparable to those of T-cells and macrophages in other mucosal surfaces. Conclusions To our knowledge we here demonstrate for the first time the intravital real-time transmigration of immune cells into lymphatic vessels. Overall this study demonstrates the valuable use of intravital autofluorescence two-photon microscopy in the model of suture-induced corneal vascularizations to study interactions of immune and subsequently tumor cells with lymphatic vessels under close as possible physiological conditions.
Alteration of Protein Levels during Influenza Virus H1N1 Infection in Host Cells: A Proteomic Survey of Host and Virus Reveals Differential Dynamics
Susann Kummer, Max Fl?ttmann, Bj?rn Schwanh?usser, Christian Sieben, Michael Veit, Matthias Selbach, Edda Klipp, Andreas Herrmann
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0094257
Abstract: We studied the dynamics of the proteome of influenza virus A/PR/8/34 (H1N1) infected Madin-Darby canine kidney cells up to 12 hours post infection by mass spectrometry based quantitative proteomics using the approach of stable isotope labeling by amino acids in cell culture (SILAC). We identified 1311 cell proteins and, apart from the proton channel M2, all major virus proteins. Based on their abundance two groups of virus proteins could be distinguished being in line with the function of the proteins in genesis and formation of new virions. Further, the data indicate a correlation between the amount of proteins synthesized and their previously determined copy number inside the viral particle. We employed bioinformatic approaches such as functional clustering, gene ontology, and pathway (KEGG) enrichment tests to uncover co-regulated cellular protein sets, assigned the individual subsets to their biological function, and determined their interrelation within the progression of viral infection. For the first time we are able to describe dynamic changes of the cellular and, of note, the viral proteome in a time dependent manner simultaneously. Through cluster analysis, time dependent patterns of protein abundances revealed highly dynamic up- and/or down-regulation processes. Taken together our study provides strong evidence that virus infection has a major impact on the cell status at the protein level.
Introduction to dissipation and decoherence in quantum systems
Florian Marquardt,Annett Püttmann
Physics , 2008,
Abstract: These lecture notes address an audience of physicists or mathematicians who have been exposed to a first course in quantum mechanics. We start with a brief discussion of the general "system-bath" paradigm of quantum dissipative systems, analyze in some detail the simplest example of "pure dephasing" of a two-level system, and review the basic concept of the density matrix. We then treat the general dissipative time-evolution, introducing completely positive maps, their relation to entanglement theory, and their Kraus decomposition. Restricting ourselves to Markovian evolution, we discuss the Lindblad form of master equations. The notes conclude with an overview of topics of current interest that go beyond Lindblad Markov master equations. (These notes were prepared for lectures delivered by F. Marquardt in October 2007 at the Langeoog workshop of the SFB/TR 12, "Symmetries and Universality in Mesoscopic Systems")
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